Point-of-care testing for sexually transmitted infections: recent advances and implications for disease control

PubMed Central

Tucker, Joseph D.; Bien, Cedric H.; Peeling, Rosanna W.

2013-01-01

Purpose of review Sexually transmitted infections (STIs) remain a major global public health issue, with more than 448 million incident bacterial infections each year. We review recent advances in STI point-of-care (POC) testing and implications for STI prevention and control. Recent findings Accurate immunochromatographic assays to detect HIV, hepatitis C virus (HCV) and syphilis antibodies have made home or supervised self-testing possible. Several studies have demonstrated feasibility and excellent test characteristics for HIV, HCV and syphilis POC tests. Rapid oral HIV tests are now available for purchase at retail sites across the United States. Combined HIV and syphilis tests using a single finger prick blood sample are under evaluation. Summary Oral POC STI tests with comparable performance to blood-based POC tests are available for self-testing. POC tests can expand screening, improve syndromic management and reduce loss to follow up. POC STI tests have the potential to facilitate prompt treatment and partner services. POC STI tests create opportunities for new social and financial models of community-based testing services. Increasing equity and access to testing will create challenges in linkage to care, quality assurance, partner services and surveillance. These important developments warrant research to understand appropriate contexts for implementation. PMID:23242343

BRIEF REPORT: The Role of Point of Care Testing for Patients with Acute Pharyngitis

PubMed Central

Atlas, Steven J; McDermott, Steven M; Mannone, Carol; Barry, Michael J

2005-01-01

Background There is no consensus favoring a particular strategy for evaluating patients with pharyngitis. Objective To compare a clinical decision aid and a rapid office-based point of care (POC) test with routine culture for group A β-hemolytic streptococcus (GAS). Design Prospective observational study. Participants Among 179 patients enrolled, 150 were eligible and 148 had POC testing and cultures initially performed. Measurements An encounter form included eligibility criteria, clinical information based upon the Centor rule, and treatment provided. Sensitivity and specificity of POC test compared to routine culture for GAS. Results Thirty-eight patients (25.7%) had a positive GAS culture. The POC test was 92.1% sensitive (95% confidence interval [CI] 80% to 98%) and 100% specific (95% CI 97% to 100%). Although the Centor rule did not adequately discriminate among symptomatic patients with or without GAS (receiver operating curve area 0.63), the 3 patients with a false-negative POC test had a Centor score of less than 2. Among patients with a negative POC test, 26% initially received antibiotics. Conclusions For patients with a Centor score of ≥2, a POC test was highly sensitive for GAS. Future studies should confirm these results and assess whether implementation of POC testing as part of a local practice guideline can decrease variability in testing and treatment. PMID:16050888

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

In this quarterly technical progress report, UTSI reports on progress on a multitask contract to develop the necessary technology for the steam bottoming plant of the MHD Steam Combined Cycle power plant. A Proof-Of-Concept (POC) test was conducted during the quarter and the results are reported. This POC test was terminated after 88 hours of operation due to the failure of the coal pulverizer main shaft. Preparations for the test and post-test activities are summarized. Modifications made to the dry electrostatic precipitator (ESP) are described and measurements of its performance are reported. The baghouse performance is summarized, together with actionsmore » being taken to improve bag cleaning using reverse air. Data on the wet ESP performance is included at two operating conditions, including verification that it met State of Tennessee permit conditions for opacity with all the flow through it. The results of experiments to determine the effect of potassium seed on NO{sub x} emissions and secondary combustion are reported. The status of efforts to quantify the detailed mass balance for all POC testing is summarized. The work to develop a predictive ash deposition model is discussed and results compared with deposition actually encountered during the test. Plans to measure the kinetics of potassium and sulfur on flames like the secondary combustor, are included. Advanced diagnostic work by both UTSI and MSU is reported. Efforts to develop the technology for a high temperature air heater using ceramic tubes are summarized.« less

Perceptions of point-of-care infectious disease testing among European medical personnel, point-of-care test kit manufacturers, and the general public.

PubMed

Kaman, Wendy E; Andrinopoulou, Eleni-Rosalina; Hays, John P

2013-01-01

The proper development and implementation of point-of-care (POC) diagnostics requires knowledge of the perceived requirements and barriers to their implementation. To determine the current requirements and perceived barriers to the introduction of POC diagnostics in the field of medical microbiology (MM)-POC a prospective online survey (TEMPOtest-QC) was established. The TEMPOtest-QC survey was online between February 2011 and July 2012 and targeted the medical community, POC test diagnostic manufacturers, general practitioners, and the general public. In total, 293 individuals responded to the survey, including 91 (31%) medical microbiologists, 39 (13%) nonmedical microbiologists, 25 (9%) employees of POC test manufacturers, and 138 (47%) members of the general public. Responses were received from 18 different European countries, with the largest percentage of these living in The Netherlands (52%). The majority (>50%) of medical specialists regarded the development of MM-POC for blood culture and hospital acquired infections as "absolutely necessary", but were much less favorable towards their use in the home environment. Significant differences in perceptions between medical specialists and the general public included the: (1) Effect on quality of patient care; (2) Ability to better monitor patients; (3) Home testing and the doctor-patient relationship; and (4) MM-POC interpretation. Only 34.7% of the general public is willing to pay more than a€10 ($13) for a single MM-POC test, with 85.5% preferring to purchase their MM-POC test from a pharmacy. The requirements for the proper implementation of MM-POC were found to be generally similar between medical specialists and POC test kit manufacturers. The general public was much more favorable with respect to a perceived improvement in the quality of healthcare that these tests would bring to the hospital and home environment.

Use of Rapid, Point-of-Care Assays by Private Practitioners in Chennai, India: Priorities for Tuberculosis Diagnostic Testing.

PubMed

Bronner Murrison, Liza; Ananthakrishnan, Ramya; Sukumar, Sumanya; Augustine, Sheela; Krishnan, Nalini; Pai, Madhukar; Dowdy, David W

2016-01-01

Private practitioners are frequently the first point of healthcare contact for patients with tuberculosis (TB) in India. As new molecular tests are developed for point-of-care (POC) diagnosis of TB, it is imperative to understand these individuals' practices and preferences for POC testing. To evaluate rapid testing practices and identify priorities for novel POC TB tests among private practitioners in Chennai. We conducted a cross-sectional survey of 228 practitioners practicing in the private sector from January 2014 to February 2015 who saw at least one TB patient in the previous year. Practitioners were randomly selected from both the general community and a list of practitioners who referred patients to a public-private mix program for TB treatment. We used standardized questionnaires to collect data on current practices related to point-of-care diagnosis and interest in hypothetical POC tests. We used multivariable Poisson regression with robust estimates of standard error to calculate measures of association. Among 228 private practitioners, about half (48%) utilized any rapid testing in their current practice, most commonly for glucose (43%), pregnancy (21%), and malaria (5%). Providers using POC tests were more likely to work in hospitals (56% vs. 43%, P = 0.05) and less likely to be chest specialists (21% vs. 54%, P<0.001). Only half (51%) of providers would use a hypothetical POC test for TB that was accurate, equipment-free, and took 20 minutes to complete. Chest specialists were half as likely to express interest in performing the hypothetical POC TB test in-house as other practitioners (aPR 0.5, 95%CI: 0.2-0.9). Key challenges to performing POC testing for TB in this study included time constraints, easy access to local private labs and lack of an attached lab facility. As novel POC tests for TB are developed and scaled up, attention must be paid to integrating these diagnostics into healthcare providers' routine practice and addressing barriers for POC testing.

Dynamic temperature and humidity environmental profiles: impact for future emergency and disaster preparedness and response.

PubMed

Ferguson, William J; Louie, Richard F; Tang, Chloe S; Paw U, Kyaw Tha; Kost, Gerald J

2014-02-01

During disasters and complex emergencies, environmental conditions can adversely affect the performance of point-of-care (POC) testing. Knowledge of these conditions can help device developers and operators understand the significance of temperature and humidity limits necessary for use of POC devices. First responders will benefit from improved performance for on-site decision making. To create dynamic temperature and humidity profiles that can be used to assess the environmental robustness of POC devices, reagents, and other resources (eg, drugs), and thereby, to improve preparedness. Surface temperature and humidity data from the National Climatic Data Center (Asheville, North Carolina USA) was obtained, median hourly temperature and humidity were calculated, and then mathematically stretched profiles were created to include extreme highs and lows. Profiles were created for: (1) Banda Aceh, Indonesia at the time of the 2004 Tsunami; (2) New Orleans, Louisiana USA just before and after Hurricane Katrina made landfall in 2005; (3) Springfield, Massachusetts USA for an ambulance call during the month of January 2009; (4) Port-au-Prince, Haiti following the 2010 earthquake; (5) Sendai, Japan for the March 2011 earthquake and tsunami with comparison to the colder month of January 2011; (6) New York, New York USA after Hurricane Sandy made landfall in 2012; and (7) a 24-hour rescue from Hawaii USA to the Marshall Islands. Profiles were validated by randomly selecting 10 days and determining if (1) temperature and humidity points fell inside and (2) daily variations were encompassed. Mean kinetic temperatures (MKT) were also assessed for each profile. Profiles accurately modeled conditions during emergency and disaster events and enclosed 100% of maximum and minimum temperature and humidity points. Daily variations also were represented well with 88.6% (62/70) of temperature readings and 71.1% (54/70) of relative humidity readings falling within diurnal patterns. Days not represented well primarily had continuously high humidity. Mean kinetic temperature was useful for severity ranking. Simulating temperature and humidity conditions clearly reveals operational challenges encountered during disasters and emergencies. Understanding of environmental stresses and MKT leads to insights regarding operational robustness necessary for safe and accurate use of POC devices and reagents. Rescue personnel should understand these principles before performing POC testing in adverse environments.

Evidence-based point-of-care tests and device designs for disaster preparedness.

PubMed

Brock, T Keith; Mecozzi, Daniel M; Sumner, Stephanie; Kost, Gerald J

2010-01-01

To define pathogen tests and device specifications needed for emerging point-of-care (POC) technologies used in disasters. Surveys included multiple-choice and ranking questions. Multiple-choice questions were analyzed with the chi2 test for goodness-of-fit and the binomial distribution test. Rankings were scored and compared using analysis of variance and Tukey's multiple comparison test. Disaster care experts on the editorial boards of the American Journal of Disaster Medicine and the Disaster Medicine and Public Health Preparedness, and the readers of the POC Journal. Vibrio cholera and Staphylococcus aureus were top-ranked pathogens for testing in disaster settings. Respondents felt that disaster response teams should be equipped with pandemic infectious disease tests for novel 2009 H1N1 and avian H5N1 influenza (disaster care, p < 0.05; POC, p < 0.01). In disaster settings, respondents preferred self-contained test cassettes (disaster care, p < 0.05; POC, p < 0.001) for direct blood sampling (POC, p < 0.01) and disposal of biological waste (disaster care, p < 0.05; POC, p < 0.001). Multiplex testing performed at the POC was preferred in urgent care and emergency room settings. Evidence-based needs assessment identifies pathogen detection priorities in disaster care scenarios, in which Vibrio cholera, methicillin-sensitive and methicillin-resistant Staphylococcus aureus, and Escherichia coli ranked the highest. POC testing should incorporate setting-specific design criteria such as safe disposable cassettes and direct blood sampling at the site of care.

Cost-Effectiveness of POC Coagulation Testing Using Multiple Electrode Aggregometry.

PubMed

Straub, Niels; Bauer, Ekaterina; Agarwal, Seema; Meybohm, Patrick; Zacharowski, Kai; Hanke, Alexander A; Weber, Christian F

2016-01-01

The economic effects of Point-of-Care (POC) coagulation testing including Multiple Electrode Aggregometry (MEA) with the Multiplate device have not been examined. A health economic model with associated clinical endpoints was developed to calculate the effectiveness and estimated costs of coagulation analyses based on standard laboratory testing (SLT) or POC testing offering the possibility to assess platelet dysfunction using aggregometric measures. Cost estimates included pre- and perioperative costs of hemotherapy, intra- and post-operative coagulation testing costs, and hospitalization costs, including the costs of transfusion-related complications. Our model calculation using a simulated true-to-life cohort of 10,000 cardiac surgery patients assigned to each testing alternative demonstrated that there were 950 fewer patients in the POC branch who required any transfusion of red blood cells. The subsequent numbers of massive transfusions and patients with transfusion-related complications were reduced with the POC testing by 284 and 126, respectively. The average expected total cost in the POC branch was 288 Euro lower for every treated patient than that in the SLT branch. Incorporating aggregometric analyses using MEA into hemotherapy algorithms improved medical outcomes in cardiac surgery patients in the presented health economic model. There was an overall better economic outcome associated with POC testing compared with SLT testing despite the higher costs of testing.

Laboratory Evaluation of the Alere q Point-of-Care System for Early Infant HIV Diagnosis.

PubMed

Hsiao, Nei-yuan; Dunning, Lorna; Kroon, Max; Myer, Landon

2016-01-01

Early infant diagnosis (EID) and prompt linkage to care are critical to minimise the high morbidity and mortality associated with infant HIV infection. Attrition in the "EID cascade" is common; however, point-of-care (POC) EID assays with same-day result could facilitate prompt linkage of HIV-infected infant to treatment. Despite a number of POC EID assays in development, few have been independently evaluated and data on new technologies are urgently needed to inform policy. We compared Alere q 1/2 Detect POC system laboratory test characteristics with the local standard of care (SOC), Roche CAP/CTM HIV-1 qualitative PCR in an independent laboratory-based evaluation in Cape Town, South Africa. Routinely EID samples collected between November 2013 and September 2014 were each tested by both SOC and POC systems. Repeat testing was done to troubleshoot any discrepancy between POC and SOC results. Overall, 1098 children with a median age of 47 days (IQR, 42-117) were included. Birth PCR (age <7 days) comprised of 8% (n = 92) tests while 56% (n = 620) of children tested as part of routine EID (ages 6-14 weeks). In the overall direct comparison, Alere q Detect achieved sensitivity of 95.5% (95% CI, 91.7-97.9%) and a specificity of 99.8% (95% CI, 99.1-100%). Following repeat testing of discordant samples and exclusion of any inconclusive results, the POC assay sensitivity and specificity were 96.9% (95% CI 93.4-98.9%) and 100% (lower 95% CI 98%) respectively. Among birth PCR tests the POC assay had slightly lower sensitivity (93.3% vs 96.5% in routine EID) and higher assay error rate (10% vs 5% in samples of older children, p = 0.04). Our results indicate this POC assay performs well for EID in the laboratory. The high specificity and thus high positive predictive value would suggest a positive POC result may be adequate for immediate infant ART initiation. While POC testing for EID may have particular utility for birth testing at delivery facilities, the lower sensitivity and error rate requires further attention, as does field implementation of POC EID technologies in other clinical care settings.

Improving the Accessibility and Efficiency of Point-of-Care Diagnostics Services in Low- and Middle-Income Countries: Lean and Agile Supply Chain Management.

PubMed

Kuupiel, Desmond; Bawontuo, Vitalis; Mashamba-Thompson, Tivani P

2017-11-29

Access to point-of-care (POC) diagnostics services is essential for ensuring rapid disease diagnosis, management, control, and surveillance. POC testing services can improve access to healthcare especially where healthcare infrastructure is weak and access to quality and timely medical care is a challenge. Improving the accessibility and efficiency of POC diagnostics services, particularly in resource-limited settings, may be a promising route to improving healthcare outcomes. In this review, the accessibility of POC testing is defined as the distance/proximity to the nearest healthcare facility for POC diagnostics service. This review provides an overview of the impact of POC diagnostics on healthcare outcomes in low- and middle-income countries (LMICs) and factors contributing to the accessibility of POC testing services in LMICs, focusing on characteristics of the supply chain management and quality systems management, characteristics of the geographical location, health infrastructure, and an enabling policy framework for POC diagnostics services. Barriers and challenges related to the accessibility of POC diagnostics in LMICs were also discussed. Bearing in mind the reported barriers and challenges as well as the disease epidemiology in LMICs, we propose a lean and agile supply chain management framework for improving the accessibility and efficiency of POC diagnostics services in these settings.

Improving the Accessibility and Efficiency of Point-of-Care Diagnostics Services in Low- and Middle-Income Countries: Lean and Agile Supply Chain Management

PubMed Central

Kuupiel, Desmond; Bawontuo, Vitalis

2017-01-01

Access to point-of-care (POC) diagnostics services is essential for ensuring rapid disease diagnosis, management, control, and surveillance. POC testing services can improve access to healthcare especially where healthcare infrastructure is weak and access to quality and timely medical care is a challenge. Improving the accessibility and efficiency of POC diagnostics services, particularly in resource-limited settings, may be a promising route to improving healthcare outcomes. In this review, the accessibility of POC testing is defined as the distance/proximity to the nearest healthcare facility for POC diagnostics service. This review provides an overview of the impact of POC diagnostics on healthcare outcomes in low- and middle-income countries (LMICs) and factors contributing to the accessibility of POC testing services in LMICs, focusing on characteristics of the supply chain management and quality systems management, characteristics of the geographical location, health infrastructure, and an enabling policy framework for POC diagnostics services. Barriers and challenges related to the accessibility of POC diagnostics in LMICs were also discussed. Bearing in mind the reported barriers and challenges as well as the disease epidemiology in LMICs, we propose a lean and agile supply chain management framework for improving the accessibility and efficiency of POC diagnostics services in these settings. PMID:29186013

A STUDY OF RECOVERING A REED ECOSYSTEM USING POROUS CONCRETE IN THE LAKE BIWA SHORE

NASA Astrophysics Data System (ADS)

Takeda, Naho; Kato, Hayato; Okamoto, Takahisa; Kojima, Takayuki

In this study, reed planting tests were carried out at the Biyo-center, an experiment station on the Lake Biwa shore, in order to evaluate the feasibility of a planting method with porous concrete (PoC method). Reed planting tests with coconut-fiber mats (mat method), which were generally used around Lake Biwa, were simultaneously carried out to compare with the PoC method. The reeds planted by the PoC method grew better than the ones planted by the mat method, and the number of reeds which were washed away by waves was smaller than that planted by the mat method. The result of the observation of reeds planted in the PoC showed plant maturation, and reeds could ta ke root into the PoC without interference with the voids of the PoC. As a result, it was shown that the reed planting tests with the PoC method was simple and effective, so it would become in harmony with the environment around Lake Biwa.

Mapping patient pathways and estimating resource use for point of care versus standard testing and treatment of chlamydia and gonorrhoea in genitourinary medicine clinics in the UK.

PubMed

Adams, Elisabeth J; Ehrlich, Alice; Turner, Katherine M E; Shah, Kunj; Macleod, John; Goldenberg, Simon; Meray, Robin K; Pearce, Vikki; Horner, Patrick

2014-07-23

We aimed to explore patient pathways using a chlamydia/gonorrhoea point-of-care (POC) nucleic acid amplification test (NAAT), and estimate and compare the costs of the proposed POC pathways with the current pathways using standard laboratory-based NAAT testing. Workshops were conducted with healthcare professionals at four sexual health clinics representing diverse models of care in the UK. They mapped out current pathways that used chlamydia/gonorrhoea tests, and constructed new pathways using a POC NAAT. Healthcare professionals' time was assessed in each pathway. The proposed POC pathways were then priced using a model built in Microsoft Excel, and compared to previously published costs for pathways using standard NAAT-based testing in an off-site laboratory. Pathways using a POC NAAT for asymptomatic and symptomatic patients and chlamydia/gonorrhoea-only tests were shorter and less expensive than most of the current pathways. Notably, we estimate that POC testing as part of a sexual health screen for symptomatic patients, or as stand-alone chlamydia/gonorrhoea testing, could reduce costs per patient by as much as £16 or £6, respectively. In both cases, healthcare professionals' time would be reduced by approximately 10 min per patient. POC testing for chlamydia/gonorrhoea in a clinical setting may reduce costs and clinician time, and may lead to more appropriate and quicker care for patients. Further study is warranted on how to best implement POC testing in clinics, and on the broader clinical and cost implications of this technology. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

A simple and inexpensive point-of-care test for hepatitis B surface antigen detection: serological and molecular evaluation.

PubMed

Gish, R G; Gutierrez, J A; Navarro-Cazarez, N; Giang, K; Adler, D; Tran, B; Locarnini, S; Hammond, R; Bowden, S

2014-12-01

Early identification of chronic hepatitis B is important for optimal disease management and prevention of transmission. Cost and lack of access to commercial hepatitis B surface antigen (HBsAg) immunoassays can compromise the effectiveness of HBV screening in resource-limited settings and among marginalized populations. High-quality point-of-care (POC) testing may improve HBV diagnosis in these situations. Currently available POC HBsAg assays are often limited in sensitivity. We evaluated the NanoSign(®) HBs POC chromatographic immunoassay for its ability to detect HBsAg of different genotypes and with substitutions in the 'a' determinant. Thirty-seven serum samples from patients with HBV infection, covering HBV genotypes A-G, were assessed for HBsAg titre with the Roche Elecsys HBsAg II quantification assay and with the POC assay. The POC assay reliably detected HBsAg at a concentration of at least 50 IU/mL for all genotypes, and at lower concentrations for some genotypes. Eight samples with substitutions in the HBV 'a' determinant were reliably detected after a 1/100 dilution. The POC strips were used to screen serum samples from 297 individuals at risk for HBV in local clinical settings (health fairs and outreach events) in parallel with commercial laboratory HBsAg testing (Quest Diagnostics EIA). POC testing was 73.7% sensitive and 97.8% specific for detection of HBsAg. Although the POC test demonstrated high sensitivity over a range of genotypes, false negatives were frequent in a clinical setting. Nevertheless, the POC assay offers advantages for testing in both developed and resource-limited countries due to its low cost (0.50$) and immediately available results. © 2014 John Wiley & Sons Ltd.

Economic evaluations of point of care testing strategies for active tuberculosis.

PubMed

Zwerling, Alice; Dowdy, David

2013-06-01

Point of care (POC) diagnostics are often hailed as having the potential to transform tuberculosis (TB) control efforts. However, POC testing is better conceptualized as a system of diagnosis and treatment, not simply a test that can provide rapid, deployable results. Economic evaluations may help decision makers allocate scarce resources for TB control, but evaluations of POC testing face unique challenges that include evaluating the full diagnostic system, incorporating implementation costs, translating diagnostic results into health and accounting for downstream treatment costs. For economic evaluations to reach their full potential as decision-making tools for POC testing in TB, these challenges must be understood and addressed.

Are point-of-care (POC) virological tests what is needed?

PubMed

Madeley, C R

2007-07-01

Point-of-care (POC) tests are becoming more available, although the way in which they should be used is currently undecided. Any 'laboratory'-based diagnosis of respiratory infections has three components: the specimen taken, the test used, and the interpretation of the results. Each of these components needs to be carefully addressed when using POC tests for the diagnosis of respiratory tract infections. Given the enthusiasm with which POC tests are being developed, it is likely that they will be used more and more widely. If so, the advantages and limitations of their use should be fully discussed and the implications recognised.

Cost-effectiveness of point-of-care testing for dehydration in the pediatric ED.

PubMed

Whitney, Rachel E; Santucci, Karen; Hsiao, Allen; Chen, Lei

2016-08-01

Acute gastroenteritis (AGE) and subsequent dehydration account for a large proportion of pediatric emergency department (PED) visits. Point-of-care (POC) testing has been used in conjunction with clinical assessment to determine the degree of dehydration. Despite the wide acceptance of POC testing, little formal cost-effective analysis of POC testing in the PED exists. We aim to examine the cost-effectiveness of using POC electrolyte testing vs traditional serum chemistry testing in the PED for children with AGE. This was a cost-effective analysis using data from a randomized control trial of children with AGE. A decision analysis model was constructed to calculate cost-savings from the point of view of the payer and the provider. We used parameters obtained from the trial, including cost of testing, admission rates, cost of admission, and length of stay. Sensitivity analyses were performed to evaluate the stability of our model. Using the data set of 225 subjects, POC testing results in a cost savings of $303.30 per patient compared with traditional serum testing from the point of the view of the payer. From the point-of-view of the provider, POC testing results in consistent mean savings of $36.32 ($8.29-$64.35) per patient. Sensitivity analyses demonstrated the stability of the model and consistent savings. This decision analysis provides evidence that POC testing in children with gastroenteritis-related moderate dehydration results in significant cost savings from the points of view of payers and providers compared to traditional serum chemistry testing. Copyright © 2016 Elsevier Inc. All rights reserved.

Rapid point-of-care CD4 testing at mobile HIV testing sites to increase linkage to care: an evaluation of a pilot program in South Africa.

PubMed

Larson, Bruce A; Schnippel, Kathryn; Ndibongo, Buyiswa; Xulu, Thembisile; Brennan, Alana; Long, Lawrence; Fox, Matthew P; Rosen, Sydney

2012-10-01

A mobile HIV counseling and testing (HCT) program around Johannesburg piloted the integration of point-of-care (POC) CD4 testing, using the Pima analyzer, to improve linkages to HIV care. We report results from this pilot program for patients testing positive (n = 508) from May to October 2010. We analyzed 3 primary outcomes: assignment to testing group (offered POC CD4 or not), successful follow-up (by telephone), and completed the referral visit for HIV care within 8 weeks after HIV testing if successfully followed up. Proportions for each outcome were calculated, and relative risks were estimated using a modified Poisson approach. Three hundred eleven patients were offered the POC CD4 test, and 197 patients were not offered the test. No differences in patient characteristics were observed between the 2 groups. Approximately 62.7% of patients were successfully followed up 8 weeks after HIV testing, with no differences observed between testing groups. Among those followed up, 54.4% reported completing their referral visit. Patients offered the POC CD4 test were more likely to complete the referral visit for further HIV care (relative risk 1.25, 95% confidence interval: 1.00 to 1.57). In this mobile HCT setting, patients offered POC CD4 testing as part of the HCT services were more likely to visit a referral clinic after testing, suggesting that rapid CD4 testing technology may improve linkage to HIV care. Future research can evaluate options for adjusting HCT services if POC CD4 testing was included permanently and the cost-effectiveness of the POC CD4 testing compared with other approaches for improving linkage of care.

MHD program plan, FY 1991

NASA Astrophysics Data System (ADS)

1990-10-01

The current magnetohydrodynamic MHD program being implemented is a result of a consensus established in public meetings held by the Department of Energy in 1984. The public meetings were followed by the formulation of a June 1984 Coal-Fired MHD Preliminary Transition and Program Plan. This plan focused on demonstrating the proof-of-concept (POC) of coal-fired MHD electric power plants by the early 1990s. MHD test data indicate that while there are no fundamental technical barriers impeding the development of MHD power plants, technical risk remains. To reduce the technical risk three key subsystems (topping cycle, bottoming cycle, and seed regeneration) are being assembled and tested separately. The program does not require fabrication of a complete superconducting magnet, but rather the development and testing of superconductor cables. The topping cycle system test objectives can be achieved using a conventional iron core magnet system already in place at a DOE facility. Systems engineering-derived requirements and analytical modeling to support scale-up and component design guide the program. In response to environmental, economic, engineering, and utility acceptance requirements, design choices and operating modes are tested and refined to provide technical specifications for meeting commercial criteria. These engineering activities are supported by comprehensive and continuing systems analyses to establish realistic technical requirements and cost data. Essential elements of the current program are to: develop technical and environmental data for the integrated MHD topping cycle and bottoming cycle systems through POC testing (1000 and 4000 hours, respectively); design, construct, and operate a POC seed regeneration system capable of processing spent seed materials from the MHD bottoming cycle; prepare conceptual designs for a site specific MHD retrofit plant; and continue supporting research necessary for system testing.

Point-of-care testing in the diagnosis of gastrointestinal cancers: Current technology and future directions

PubMed Central

Huddy, Jeremy R; Ni, Melody Z; Markar, Sheraz R; Hanna, George B

2015-01-01

Point-of-care (POC) tests enable rapid results and are well established in medical practice. Recent advances in analytical techniques have led to a new generation of POC devices that will alter gastrointestinal diagnostic pathways. This review aims to identify current and new technologies for the POC diagnosis of gastrointestinal cancer. A structured search of the Embase and Medline databases was performed. Papers reporting diagnostic tests for gastrointestinal cancer available as a POC device or containing a description of feasibility for POC application were included. Studies recovered were heterogeneous and therefore results are presented as a narrative review. Six diagnostic methods were identified (fecal occult blood, fecal proteins, volatile organic compounds, pyruvate kinase isoenzyme type M2, tumour markers and DNA analysis). Fecal occult blood testing has a reported sensitivity of 66%-85% and specificity greater than 95%. The others are at a range of development and clinical application. POC devices have a proven role in the diagnosis of gastrointestinal cancer. Barriers to their implementation exist and the transition from experimental to clinical medicine is currently slow. New technologies demonstrate potential to provide accurate POC tests and an ability to diagnose gastrointestinal cancer at an early stage with improved clinical outcome and survival. PMID:25892860

Point-of-care testing in the diagnosis of gastrointestinal cancers: current technology and future directions.

PubMed

Huddy, Jeremy R; Ni, Melody Z; Markar, Sheraz R; Hanna, George B

2015-04-14

Point-of-care (POC) tests enable rapid results and are well established in medical practice. Recent advances in analytical techniques have led to a new generation of POC devices that will alter gastrointestinal diagnostic pathways. This review aims to identify current and new technologies for the POC diagnosis of gastrointestinal cancer. A structured search of the Embase and Medline databases was performed. Papers reporting diagnostic tests for gastrointestinal cancer available as a POC device or containing a description of feasibility for POC application were included. Studies recovered were heterogeneous and therefore results are presented as a narrative review. Six diagnostic methods were identified (fecal occult blood, fecal proteins, volatile organic compounds, pyruvate kinase isoenzyme type M2, tumour markers and DNA analysis). Fecal occult blood testing has a reported sensitivity of 66%-85% and specificity greater than 95%. The others are at a range of development and clinical application. POC devices have a proven role in the diagnosis of gastrointestinal cancer. Barriers to their implementation exist and the transition from experimental to clinical medicine is currently slow. New technologies demonstrate potential to provide accurate POC tests and an ability to diagnose gastrointestinal cancer at an early stage with improved clinical outcome and survival.

The Point-of-Care Laboratory in Clinical Microbiology

PubMed Central

Michel-Lepage, Audrey; Boyer, Sylvie; Raoult, Didier

2016-01-01

SUMMARY Point-of-care (POC) laboratories that deliver rapid diagnoses of infectious diseases were invented to balance the centralization of core laboratories. POC laboratories operate 24 h a day and 7 days a week to provide diagnoses within 2 h, largely based on immunochromatography and real-time PCR tests. In our experience, these tests are conveniently combined into syndrome-based kits that facilitate sampling, including self-sampling and test operations, as POC laboratories can be operated by trained operators who are not necessarily biologists. POC laboratories are a way of easily providing clinical microbiology testing for populations distant from laboratories in developing and developed countries and on ships. Modern Internet connections enable support from core laboratories. The cost-effectiveness of POC laboratories has been established for the rapid diagnosis of tuberculosis and sexually transmitted infections in both developed and developing countries. PMID:27029593

Point of care testing: The impact of nanotechnology.

PubMed

Syedmoradi, Leila; Daneshpour, Maryam; Alvandipour, Mehrdad; Gomez, Frank A; Hajghassem, Hassan; Omidfar, Kobra

2017-01-15

Point-of-care (POC) diagnostic devices are integral in the health care system and particularly for the diagnosis and monitoring of diseases. POC testing has a variety of advantages including the ability to provide rapid and accurate results, ease of use, low cost, and little need for specialized equipment. One of the goals of POC testing is the development of a chip-based, miniaturized, portable, and self-containing system that allows for the assay of different analytes in complex samples. To achieve these goals, many researchers have focused on paper-based and printed electrode technologies as the material for fabricating POC diagnostic systems. These technologies are affordable, sensitive, user-friendly, rapid, and scalable for manufacturing. Moreover, the combination such devices with nanomaterials provide a path for the development of highly sensitive and selective biosensors for future generation POC tools. This review article discusses present technologies in on-site or at home POC diagnostic assays implemented in paper-based microfluidic and screen printing devices over the past decade as well as in the near future. In addition, recent advances in the application of nanomaterials such as gold nanoparticles, carbon nanotubes (CNTs), magnetic nanoparticles, and graphene in POC devices will be reviewed. The factors that limit POC testing to become real world products and future directions are also identified. Copyright © 2016 Elsevier B.V. All rights reserved.

Fabricating poly(1,8-octanediol citrate) elastomer based fibrous mats via electrospinning for soft tissue engineering scaffold.

PubMed

Zhu, Lei; Zhang, Yuanzheng; Ji, Yali

2017-06-01

Poly(1,8-octanediol citrate) (POC) is a recently developed biodegradable crosslinked elastomer that possesses good cytocompatibility and matchable mechanical properties to soft tissues. However, the thermosetting characteristic reveals a big challenge to manufacture its porous scaffold. Herein, POC elastomer was electrospun into fiber mat using poly(L-lactic acid) (PLLA) as a spinnable carrier. The obtained POC/PLLA fiber mats were characterized by scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), uniaxial tensile test, static-water-contact-angle, thermal analysis, in vitro degradation and biocompatibility test. It was found that the fibrous structure could be formed so long as the POC pre-polymer's content was no more than 50 wt%. The presence of elastic POC component not only strengthened the fiber mats but also toughened the fiber mats. The hydrophilicity of 50/50 fiber mat significantly improved. In vitro degradation rate of POC based fiber mats was much faster than that of pure PLLA. Cyto- and histo-compatibility tests confirmed that the POC/PLLA fiber mats had good biocompatibility for potential applications in soft tissue engineering.

Allergy Diagnosis in Children and Adults: Performance of a New Point-of-Care Device, ImmunoCAP Rapid.

PubMed

Hedlin, Gunilla; Moreno, Carmen; Petersson, Carl Johan; Lilja, Gunnar; Toledano, Félix Lorente; García, Antonio Nieto; Nordvall, Lennart; Palmqvist, Mona; Rak, Sabina; Ahlstedt, Staffan; Borres, Magnus P

2009-07-01

: Allergy is a serious problem affecting approximately 1 of 4 individuals. The symptoms with and without allergy etiology are often difficult to distinguish from each other without using an IgE antibody test. The aim of this study was to investigate the performance of a new point-of-care (POC) test for IgE antibodies to relevant allergens in Europe. : IgE antibodies from children and adults with allergies recruited from allergy clinics in Sweden and Spain were analyzed for 10 allergens, suitable for the age groups, using the new POC test and ImmunoCAP laboratory test. The IgE antibody level best discriminating between positive and negative results (the cutoff point) for the different allergens of the POC test and the efficacy of the POC and the ImmunoCAP laboratory tests for diagnosing allergy compared with that of clinical diagnosis were investigated. : The estimated cutoffs for the different allergens in the POC test ranged from 0.70 to 2.56 kUA/L. Taking into account all positive allergen results in a given patient, the POC test could identify 95% of the patients with allergies. Seventy-eight percent of the allergen-specific physicians' diagnoses were identified and 97% of the negative ones. Most allergens exhibited good performance, identifying about 80% of clinically relevant cases. However, dog, mugwort, and wall pellitory would benefit from improvement. : The POC test will be a valuable adjunct in the identification or exclusion of patients with allergies and their most likely offending allergens, both in specialist and general care settings.

Allergy Diagnosis in Children and Adults: Performance of a New Point-of-Care Device, ImmunoCAP Rapid

PubMed Central

2009-01-01

Background Allergy is a serious problem affecting approximately 1 of 4 individuals. The symptoms with and without allergy etiology are often difficult to distinguish from each other without using an IgE antibody test. The aim of this study was to investigate the performance of a new point-of-care (POC) test for IgE antibodies to relevant allergens in Europe. Methods IgE antibodies from children and adults with allergies recruited from allergy clinics in Sweden and Spain were analyzed for 10 allergens, suitable for the age groups, using the new POC test and ImmunoCAP laboratory test. The IgE antibody level best discriminating between positive and negative results (the cutoff point) for the different allergens of the POC test and the efficacy of the POC and the ImmunoCAP laboratory tests for diagnosing allergy compared with that of clinical diagnosis were investigated. Results The estimated cutoffs for the different allergens in the POC test ranged from 0.70 to 2.56 kUA/L. Taking into account all positive allergen results in a given patient, the POC test could identify 95% of the patients with allergies. Seventy-eight percent of the allergen-specific physicians' diagnoses were identified and 97% of the negative ones. Most allergens exhibited good performance, identifying about 80% of clinically relevant cases. However, dog, mugwort, and wall pellitory would benefit from improvement. Conclusions The POC test will be a valuable adjunct in the identification or exclusion of patients with allergies and their most likely offending allergens, both in specialist and general care settings. PMID:23283063

Prevalence of gestational diabetes mellitus based on various screening strategies in western Kenya: a prospective comparison of point of care diagnostic methods.

PubMed

Pastakia, Sonak D; Njuguna, Benson; Onyango, Beryl Ajwang'; Washington, Sierra; Christoffersen-Deb, Astrid; Kosgei, Wycliffe K; Saravanan, Ponnusamy

2017-07-14

Early diagnosis of gestational diabetes mellitus (GDM) is crucial to prevent short term delivery risks and long term effects such as cardiovascular and metabolic diseases in the mother and infant. Diagnosing GDM in Sub-Saharan Africa (SSA) however, remains sub-optimal due to associated logistical and cost barriers for resource-constrained populations. A cost-effective strategy to screen for GDM in such settings are therefore urgently required. We conducted this study to determine the prevalence of gestational diabetes mellitus (GDM) and assess utility of various GDM point of care (POC) screening strategies in a resource-constrained setting. Eligible women aged ≥18 years, and between 24 and 32 weeks of a singleton pregnancy, prospectively underwent testing over two days. On day 1, a POC 1-h 50 g glucose challenge test (GCT) and a POC glycated hemoglobin (HbA1c) was assessed. On day 2, fasting blood glucose, 1-h and 2-h 75 g oral glucose tolerance test (OGTT) were determined using both venous and POC tests, along with a venous HbA1c. The International Association of Diabetes in Pregnancy Study Group (IADPSG) criteria was used to diagnose GDM. GDM prevalence was reported with 95% confidence interval (CI). Specificity, sensitivity, positive predictive value, and negative predictive value of the various POC testing strategies were determined using IADPSG testing as the standard reference. Six hundred-sixteen eligible women completed testing procedures. GDM was diagnosed in 18 women, a prevalence of 2.9% (95% CI, 1.57% - 4.23%). Compared to IADPSG testing, POC IADPSG had a sensitivity and specificity of 55.6% and 90.6% respectively while that of POC 1-h 50 g GCT (using a diagnostic cut-off of ≥7.2 mmol/L [129.6 mg/dL]) was 55.6% and 63.9%. All other POC tests assessed showed poor sensitivity. POC screening strategies though feasible, showed poor sensitivity for GDM detection in our resource-constrained population of low GDM prevalence. Studies to identify sensitive and specific POC GDM screening strategies using adverse pregnancy outcomes as end points are required. Clinical trials.gov : NCT02978807 , Registered 29 November 2016.

Gas Hydrate Storage of Natural Gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rudy Rogers; John Etheridge

2006-03-31

Environmental and economic benefits could accrue from a safe, above-ground, natural-gas storage process allowing electric power plants to utilize natural gas for peak load demands; numerous other applications of a gas storage process exist. A laboratory study conducted in 1999 to determine the feasibility of a gas-hydrates storage process looked promising. The subsequent scale-up of the process was designed to preserve important features of the laboratory apparatus: (1) symmetry of hydrate accumulation, (2) favorable surface area to volume ratio, (3) heat exchanger surfaces serving as hydrate adsorption surfaces, (4) refrigeration system to remove heat liberated from bulk hydrate formation, (5)more » rapid hydrate formation in a non-stirred system, (6) hydrate self-packing, and (7) heat-exchanger/adsorption plates serving dual purposes to add or extract energy for hydrate formation or decomposition. The hydrate formation/storage/decomposition Proof-of-Concept (POC) pressure vessel and supporting equipment were designed, constructed, and tested. This final report details the design of the scaled POC gas-hydrate storage process, some comments on its fabrication and installation, checkout of the equipment, procedures for conducting the experimental tests, and the test results. The design, construction, and installation of the equipment were on budget target, as was the tests that were subsequently conducted. The budget proposed was met. The primary goal of storing 5000-scf of natural gas in the gas hydrates was exceeded in the final test, as 5289-scf of gas storage was achieved in 54.33 hours. After this 54.33-hour period, as pressure in the formation vessel declined, additional gas went into the hydrates until equilibrium pressure/temperature was reached, so that ultimately more than the 5289-scf storage was achieved. The time required to store the 5000-scf (48.1 hours of operating time) was longer than designed. The lower gas hydrate formation rate is attributed to a lower heat transfer rate in the internal heat exchanger than was designed. It is believed that the fins on the heat-exchanger tubes did not make proper contact with the tubes transporting the chilled glycol, and pairs of fins were too close for interior areas of fins to serve as hydrate collection sites. A correction of the fabrication fault in the heat exchanger fin attachments could be easily made to provide faster formation rates. The storage success with the POC process provides valuable information for making the process an economically viable process for safe, aboveground natural-gas storage.« less

Enhancing crisis standards of care using innovative point-of-care testing.

PubMed

Kost, Gerald J; Sakaguchi, Ann; Curtis, Corbin; Tran, Nam K; Katip, Pratheep; Louie, Richard F

2011-01-01

To identify strategies with tactics that enable point-of-care (POC) testing (medical testing at or near the site of care) to effectively improve outcomes in emergencies, disasters, and public health crises, especially where community infrastructure is compromised. Logic model-critical path-feedback identified needs for improving practices. Reverse stress analysis showed POC should be integrated, responders should be properly trained, and devices should be staged in small-world networks (SWNs). First responder POC resources were summarized, test clusters were strategized, assay environmental vulnerabilities were assessed, and tactics useful for SWNs, alternate care facilities, shelters, point-of-distribution centers, and community hospitals were designed. PARTICIPANTS AND ENVIRONMENT: Emergency-disaster needs assessment survey respondents and Center experience. Important tactics are as follows: a) develop training/education courses and '"just-in-time" on-line web resources to ensure the competency of POC coordinators and high-quality testing performance; b) protect equipment from environmental extremes by sealing reagents, by controlling temperature and humidity to which they are exposed, and by establishing near-patient testing in defined environments that operate within current Food and Drug Administration licensing claims (illustrated with human immunodeficiency virus-1/2 tests); c) position testing in defined sites within SWNs and other environments; d) harden POC devices and reagents to withstand wider ranges of environmental extremes in field applications; e) promote new POC technologies for pathogen detection and other assays, per needs assessment results; and f) select tests according to mission objectives and value propositions. Careful implementation of POC testing will facilitate evidence-based triage, diagnosis, treatment, and monitoring of victims and patients, while advancing standards of care in emergencies and disasters, as well as public health crises.

ENHANCING CRISIS STANDARDS OF CARE USING INNOVATIVE POINT-OF-CARE TESTING

PubMed Central

Kost, Gerald J.; Sakaguchi, Ann; Curtis, Corbin; Tran, Nam K.; Katip, Pratheep; Louie, Richard F.

2011-01-01

Objective To identify strategies with tactics that enable point-of-care (POC) testing (medical testing at or near the site of care) to improve outcomes effectively in emergencies, disasters, and public health crises, especially where community infrastructure is compromised. Design Logic model-critical path-feedback identified needs for improving practices. Reverse stress analysis showed POC should be integrated, responders properly trained, and devices staged in small-world networks (SWNs). We summarize first responder POC resources, strategize test clusters, address assay environmental vulnerabilities, and design tactics useful for SWNs, alternate care facilities, shelters, point-of-distribution centers, and community hospitals. Participants and Environment Emergency-disaster needs assessment survey respondents and Center experience. Outcomes Important tactics are: a) develop training/education courses and “just-in-time” on-line web resources to assure the competency of POC coordinators and high quality testing performance; b) protect equipment from environmental extremes by sealing reagents, controlling temperature and humidity to which they are exposed, and establishing near-patient testing in defined environments that operate within current FDA licensing claims (illustrated with HIV-1/2 tests); c) position testing in defined sites within SWNs and other environments; d) harden POC devices and reagents to withstand wider ranges of environmental extremes in field applications; e) promote new POC technologies for pathogen detection and other assays, per needs assessment results; and f) select tests according to mission objectives and value propositions. Conclusions Careful implementation of POC testing will facilitate evidence-based triage, diagnosis, treatment, and monitoring of victims and patients, while advancing standards of care in emergencies and disasters, as well as public health crises. PMID:22338316

The clinical and economic impact of point-of-care CD4 testing in mozambique and other resource-limited settings: a cost-effectiveness analysis.

PubMed

Hyle, Emily P; Jani, Ilesh V; Lehe, Jonathan; Su, Amanda E; Wood, Robin; Quevedo, Jorge; Losina, Elena; Bassett, Ingrid V; Pei, Pamela P; Paltiel, A David; Resch, Stephen; Freedberg, Kenneth A; Peter, Trevor; Walensky, Rochelle P

2014-09-01

Point-of-care CD4 tests at HIV diagnosis could improve linkage to care in resource-limited settings. Our objective is to evaluate the clinical and economic impact of point-of-care CD4 tests compared to laboratory-based tests in Mozambique. We use a validated model of HIV testing, linkage, and treatment (CEPAC-International) to examine two strategies of immunological staging in Mozambique: (1) laboratory-based CD4 testing (LAB-CD4) and (2) point-of-care CD4 testing (POC-CD4). Model outcomes include 5-y survival, life expectancy, lifetime costs, and incremental cost-effectiveness ratios (ICERs). Input parameters include linkage to care (LAB-CD4, 34%; POC-CD4, 61%), probability of correctly detecting antiretroviral therapy (ART) eligibility (sensitivity: LAB-CD4, 100%; POC-CD4, 90%) or ART ineligibility (specificity: LAB-CD4, 100%; POC-CD4, 85%), and test cost (LAB-CD4, US$10; POC-CD4, US$24). In sensitivity analyses, we vary POC-CD4-specific parameters, as well as cohort and setting parameters to reflect a range of scenarios in sub-Saharan Africa. We consider ICERs less than three times the per capita gross domestic product in Mozambique (US$570) to be cost-effective, and ICERs less than one times the per capita gross domestic product in Mozambique to be very cost-effective. Projected 5-y survival in HIV-infected persons with LAB-CD4 is 60.9% (95% CI, 60.9%-61.0%), increasing to 65.0% (95% CI, 64.9%-65.1%) with POC-CD4. Discounted life expectancy and per person lifetime costs with LAB-CD4 are 9.6 y (95% CI, 9.6-9.6 y) and US$2,440 (95% CI, US$2,440-US$2,450) and increase with POC-CD4 to 10.3 y (95% CI, 10.3-10.3 y) and US$2,800 (95% CI, US$2,790-US$2,800); the ICER of POC-CD4 compared to LAB-CD4 is US$500/year of life saved (YLS) (95% CI, US$480-US$520/YLS). POC-CD4 improves clinical outcomes and remains near the very cost-effective threshold in sensitivity analyses, even if point-of-care CD4 tests have lower sensitivity/specificity and higher cost than published values. In other resource-limited settings with fewer opportunities to access care, POC-CD4 has a greater impact on clinical outcomes and remains cost-effective compared to LAB-CD4. Limitations of the analysis include the uncertainty around input parameters, which is examined in sensitivity analyses. The potential added benefits due to decreased transmission are excluded; their inclusion would likely further increase the value of POC-CD4 compared to LAB-CD4. POC-CD4 at the time of HIV diagnosis could improve survival and be cost-effective compared to LAB-CD4 in Mozambique, if it improves linkage to care. POC-CD4 could have the greatest impact on mortality in settings where resources for HIV testing and linkage are most limited. Please see later in the article for the Editors' Summary.

Compounding diagnostic delays: a qualitative study of point-of-care testing in South Africa.

PubMed

Engel, Nora; Davids, Malika; Blankvoort, Nadine; Pai, Nitika Pant; Dheda, Keertan; Pai, Madhukar

2015-04-01

Successful point-of-care (POC) testing (completion of test-and-treat cycle in one patient encounter) has immense potential to reduce diagnostic and treatment delays, and improve patient and public health outcomes. We explored what tests are done and how in public/private, rural/urban hospitals and clinics in South Africa and whether they can ensure successful POC testing. This qualitative research study examined POC testing across major diseases in Cape Town, Durban and Eastern Cape. We conducted 101 semi-structured interviews and seven focus group discussions with doctors, nurses, community health workers, patients, laboratory technicians, policymakers, hospital managers and diagnostic manufacturers. In South Africa, diagnostics are characterised by a centralised system. Most tests conducted on the spot can be made to work successfully as POC tests. The majority of public/private clinics and smaller hospitals send samples via couriers to centralised laboratories and retrieve results the same way, via internet, fax or phone. The main challenge to POC testing lies in transporting samples and results, while delays risk patient loss from diagnostic/treatment pathways. Strategies to deal with associated delays create new problems, such as artificially prolonged turnaround times, strains on human resources and quality of testing, compounding additional diagnostic and treatment delays. For POC testing to succeed, particular characteristics of diagnostic ecosystems and adaptations of professional practices to overcome associated challenges must be taken into account. © 2014 John Wiley & Sons Ltd.

An early evaluation of clinical and economic costs and benefits of implementing point of care NAAT tests for Chlamydia trachomatis and Neisseria gonorrhoea in genitourinary medicine clinics in England.

PubMed

Turner, Katherine M E; Round, Jeff; Horner, Patrick; Macleod, John; Goldenberg, Simon; Deol, Arminder; Adams, Elisabeth J

2014-03-01

To estimate the costs and benefits of clinical pathways incorporating a point of care (POC) nucleic acid amplification test (NAAT) for chlamydia and gonorrhoea in genitourinary medicine (GUM) clinics compared with standard off-site laboratory testing. We simulated 1.2 million GUM clinic attendees in England. A simulation in Microsoft Excel was developed to compare existing standard pathways of management for chlamydia and gonorrhoea with a POC NAAT. We conducted scenario analyses to evaluate the robustness of the model findings. The primary outcome was the incremental cost-effectiveness ratio. Secondary outcomes included the number of inappropriate treatments, complications and transmissions averted. The baseline cost of using the point of POC NAAT was £103.9 million compared with £115.6 million for standard care. The POC NAAT was also associated with a small increase of 46 quality adjusted life years, making the new test both more effective and cheaper. Over 95 000 inappropriate treatments might be avoided by using a POC NAAT. Patients receive diagnosis and treatment on the same day as testing, which may also prevent 189 cases of pelvic inflammatory disease and 17 561 onward transmissions annually. Replacing standard laboratory tests for chlamydia and gonorrhoea with a POC test could be cost saving and patients would benefit from more accurate diagnosis and less unnecessary treatment. Overtreatment currently accounts for about a tenth of the reported treatments for chlamydia and gonorrhoea and POC NAATs would effectively eliminate the need for presumptive treatment.

A fully disposable and integrated paper-based device for nucleic acid extraction, amplification and detection.

PubMed

Tang, Ruihua; Yang, Hui; Gong, Yan; You, MinLi; Liu, Zhi; Choi, Jane Ru; Wen, Ting; Qu, Zhiguo; Mei, Qibing; Xu, Feng

2017-03-29

Nucleic acid testing (NAT) has been widely used for disease diagnosis, food safety control and environmental monitoring. At present, NAT mainly involves nucleic acid extraction, amplification and detection steps that heavily rely on large equipment and skilled workers, making the test expensive, time-consuming, and thus less suitable for point-of-care (POC) applications. With advances in paper-based microfluidic technologies, various integrated paper-based devices have recently been developed for NAT, which however require off-chip reagent storage, complex operation steps and equipment-dependent nucleic acid amplification, restricting their use for POC testing. To overcome these challenges, we demonstrate a fully disposable and integrated paper-based sample-in-answer-out device for NAT by integrating nucleic acid extraction, helicase-dependent isothermal amplification and lateral flow assay detection into one paper device. This simple device allows on-chip dried reagent storage and equipment-free nucleic acid amplification with simple operation steps, which could be performed by untrained users in remote settings. The proposed device consists of a sponge-based reservoir and a paper-based valve for nucleic acid extraction, an integrated battery, a PTC ultrathin heater, temperature control switch and on-chip dried enzyme mix storage for isothermal amplification, and a lateral flow test strip for naked-eye detection. It can sensitively detect Salmonella typhimurium, as a model target, with a detection limit of as low as 10 2 CFU ml -1 in wastewater and egg, and 10 3 CFU ml -1 in milk and juice in about an hour. This fully disposable and integrated paper-based device has great potential for future POC applications in resource-limited settings.

Evaluation of a new point-of-care test for influenza A and B virus in travellers with influenza-like symptoms.

PubMed

Weitzel, T; Schnabel, E; Dieckmann, S; Börner, U; Schweiger, B

2007-07-01

Point-of-care (POC) tests for influenza facilitate clinical case management, and might also be helpful in the care of travellers who are at special risk for influenza infection. To evaluate influenza POC testing in travellers, a new assay, the ImmunoCard STAT! Flu A and B, was used to investigate travellers presenting with influenza-like symptoms. Influenza virus infection was diagnosed in 27 (13%) of 203 patients by influenza virus-specific PCR and viral culture. The POC test had sensitivity and specificity values of 64% and 99% for influenza A, and 67% and 100% for influenza B, respectively. Combined sensitivity and specificity were 67% and 99%, respectively, yielding positive and negative predictive values of 95%, and positive and negative likelihood ratios of 117 and 0.34, respectively. The convenient application, excellent specificity and high positive likelihood ratio of the POC test allowed rapid identification of influenza cases. However, negative test results might require confirmation by other methods because of limitations in sensitivity. Overall, influenza POC testing appeared to be a useful tool for the management of travellers with influenza-like symptoms.

Marine boundary layer cloud regimes and POC formation in an LES coupled to a bulk aerosol scheme

NASA Astrophysics Data System (ADS)

Berner, A. H.; Bretherton, C. S.; Wood, R.; Muhlbauer, A.

2013-07-01

A large-eddy simulation (LES) coupled to a new bulk aerosol scheme is used to study long-lived regimes of aerosol-boundary layer cloud-precipitation interaction and the development of pockets of open cells (POCs) in subtropical stratocumulus cloud layers. The aerosol scheme prognoses mass and number concentration of a single log-normal accumulation mode with surface and entrainment sources, evolving subject to processing of activated aerosol and scavenging of dry aerosol by cloud and rain. The LES with the aerosol scheme is applied to a range of steadily-forced simulations idealized from a well-observed POC case. The long-term system evolution is explored with extended two-dimensional simulations of up to 20 days, mostly with diurnally-averaged insolation. One three-dimensional two-day simulation confirms the initial development of the corresponding two-dimensional case. With weak mean subsidence, an initially aerosol-rich mixed layer deepens, the capping stratocumulus cloud slowly thickens and increasingly depletes aerosol via precipitation accretion, then the boundary layer transitions within a few hours into an open-cell regime with scattered precipitating cumuli, in which entrainment is much weaker. The inversion slowly collapses for several days until the cumulus clouds are too shallow to efficiently precipitate. Inversion cloud then reforms and radiatively drives renewed entrainment, allowing the boundary layer to deepen and become more aerosol-rich, until the stratocumulus layer thickens enough to undergo another cycle of open-cell formation. If mean subsidence is stronger, the stratocumulus never thickens enough to initiate drizzle and settles into a steady state. With lower initial aerosol concentrations, this system quickly transitions into open cells, collapses, and redevelops into a different steady state with a shallow, optically thin cloud layer. In these steady states, interstitial scavenging by cloud droplets is the main sink of aerosol number. The system is described in a reduced two-dimensional phase plane with inversion height and boundary-layer average aerosol concentrations as the state variables. Simulations with a full diurnal cycle show similar evolutions, except that open-cell formation is phase-locked into the early morning hours. The same steadily-forced modeling framework is applied to the development and evolution of a POC and the surrounding overcast boundary layer. An initial aerosol perturbation applied to a portion of the model domain leads that portion to transition into open-cell convection, forming a POC. Reduced entrainment in the POC induces a negative feedback between areal fraction covered by the POC and boundary layer depth changes. This stabilizes the system by controlling liquid water path and precipitation sinks of aerosol number in the overcast region, while also preventing boundary-layer collapse within the POC, allowing the POC and overcast to coexist indefinitely in a quasi-steady equilibrium.

Impact of Rapid Susceptibility Testing and Antibiotic Selection Strategy on the Emergence and Spread of Antibiotic Resistance in Gonorrhea

PubMed Central

Tuite, Ashleigh R; Gift, Thomas L; Chesson, Harrell W; Hsu, Katherine; Salomon, Joshua A; Grad, Yonatan H

2017-01-01

Abstract Background Increasing antibiotic resistance limits treatment options for gonorrhea. We examined the impact of a hypothetical point-of-care (POC) test reporting antibiotic susceptibility profiles on slowing resistance spread. Methods A mathematical model describing gonorrhea transmission incorporated resistance emergence probabilities and fitness costs associated with resistance based on characteristics of ciprofloxacin (A), azithromycin (B), and ceftriaxone (C). We evaluated time to 1% and 5% prevalence of resistant strains among all isolates with the following: (1) empiric treatment (B and C), and treatment guided by POC tests determining susceptibility to (2) A only and (3) all 3 antibiotics. Results Continued empiric treatment without POC testing was projected to result in >5% of isolates being resistant to both B and C within 15 years. Use of either POC test in 10% of identified cases delayed this by 5 years. The 3 antibiotic POC test delayed the time to reach 1% prevalence of triply-resistant strains by 6 years, whereas the A-only test resulted in no delay. Results were less sensitive to assumptions about fitness costs and test characteristics with increasing test uptake. Conclusions Rapid diagnostics reporting antibiotic susceptibility may extend the usefulness of existing antibiotics for gonorrhea treatment, but ongoing monitoring of resistance patterns will be critical. PMID:28968710

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The NOXSO Process uses a regenerable sorbent that removes SO{sub 2} and NO{sub x} simultaneously from flue gas. The sorbent is a stabilized {gamma}-alumina bed impregnated with sodium carbonate. The process was successfully tested at three different scales, equivalent to 0.017, 0.06 and 0.75 MW of flue gas generated from a coal-fired power plant. The Proof-of-Concept (POC) Test is the last test prior to a full-scale demonstration. A slip stream of flue gas equivalent to a 5 MW coal-fired power plant was used for the POC test. This paper summarizes the NOXSO POC plant and its test results.

Impact of point-of-care implementation of Xpert® MTB/RIF: product vs. process innovation.

PubMed

Schumacher, S G; Thangakunam, B; Denkinger, C M; Oliver, A A; Shakti, K B; Qin, Z Z; Michael, J S; Luo, R; Pai, M; Christopher, D J

2015-09-01

Both product innovation (e.g., more sensitive tests) and process innovation (e.g., a point-of-care [POC] testing programme) could improve patient outcomes. To study the respective contributions of product and process innovation in improving patient outcomes. We implemented a POC programme using Xpert(®) MTB/RIF in an out-patient clinic of a tertiary care hospital in India. We measured the impact of process innovation by comparing time to diagnosis with routine testing vs. POC testing. We measured the impact of product innovation by comparing accuracy and time to diagnosis using smear microscopy vs. POC Xpert. We enrolled 1012 patients over a 15-month period. Xpert had high accuracy, but the incremental value of one Xpert over two smears was only 6% (95%CI 3-12). Implementing Xpert as a routine laboratory test did not reduce the time to diagnosis compared to smear-based diagnosis. In contrast, the POC programme reduced the time to diagnosis by 5.5 days (95%CI 4.3-6.7), but required dedicated staff and substantial adaptation of clinic workflow. Process innovation by way of a POC Xpert programme had a greater impact on time to diagnosis than the product per se, and can yield important improvements in patient care that are complementary to those achieved by introducing innovative technologies.

Point-of-care diagnostics: an advancing sector with nontechnical issues.

PubMed

Huckle, David

2008-11-01

The particular reasons for the relative lack in development of point-of-care (PoC) diagnostics in a business context were discussed in our sister journal, Expert Review of Medical Devices, over 2 years ago. At that time, it could be seen that the concept of PoC testing was being revisited for at least the fifth time in the last 20 years. There had been important advances in technology but, with changes in global healthcare structures and funding, the overall in vitro diagnostics sector has had sluggish growth. Only molecular diagnostics and PoC testing are growing strongly. PoC testing is now a quarter of the total global in vitro diagnostics market, but largely due to use in diabetes monitoring. An increased focus on areas other than glucose self-testing has created a disturbance in the market. An implementation issue from this disturbance is that of control between central laboratories and the proposed sites for PoC testing. Evidence is presented to show that the first step is likely to be increased use in clinics and outpatient facilities closely linked with the laboratory. The aim will be to control the quality of the test, maintenance of equipment and provide support for the clinician in interpretation. The major problem for effective PoC implementation will be the significant changes to patient pathways that are required. The changes will benefit the patient and clinical outcomes but will require healthcare professionals to change their work patterns. This will be an uphill task!

Pipe Overpack Container Fire Testing: Phase I II & III.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Figueroa, Victor G.; Ammerman, Douglas J.; Lopez, Carlos

The Pipe Overpack Container (POC) was developed at Rocky Flats to transport plutonium residues with higher levels of plutonium than standard transuranic (TRU) waste to the Waste Isolation Pilot Plant (WIPP) for disposal. In 1996 Sandia National Laboratories (SNL) conducted a series of tests to determine the degree of protection POCs provided during storage accident events. One of these tests exposed four of the POCs to a 30-minute engulfing pool fire, resulting in one of the 7A drum overpacks generating sufficient internal pressure to pop off its lid and expose the top of the pipe container (PC) to the firemore » environment. The initial contents of the POCs were inert materials, which would not generate large internal pressure within the PC if heated. POCs are now being used to store combustible TRU waste at Department of Energy (DOE) sites. At the request of DOE’s Office of Environmental Management (EM) and National Nuclear Security Administration (NNSA), starting in 2015 SNL conducted a series of fire tests to examine whether PCs with combustibles would reach a temperature that would result in (1) decomposition of inner contents and (2) subsequent generation of sufficient gas to cause the PC to over-pressurize and release its inner content. Tests conducted during 2015 and 2016 were done in three phases. The goal of the first phase was to see if the PC would reach high enough temperatures to decompose typical combustible materials inside the PC. The goal of the second test phase was to determine under what heating loads (i.e., incident heat fluxes) the 7A drum lid pops off from the POC drum. The goal of the third phase was to see if surrogate aerosol gets released from the PC when the drum lid is off. This report will describe the various tests conducted in phase I, II, and III, present preliminary results from these tests, and discuss implications for the POCs.« less

Pipe Overpack Container Fire Testing: Phase I & II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Figueroa, Victor G.; Ammerman, Douglas J.; Lopez, Carlos

The Pipe Overpack Container (POC) was developed at Rocky Flats to transport plutonium residues with higher levels of plutonium than standard transuranic (TRU) waste to the Waste Isolation Pilot Plant (WIPP) for disposal. In 1996 Sandia National Laboratories (SNL) conducted a series of tests to determine the degree of protection POCs provided during storage accident events. One of these tests exposed four of the POCs to a 30-minute engulfing pool fire, resulting in one of the 7A drum overpacks generating sufficient internal pressure to pop off its lid and expose the top of the pipe container (PC) to the firemore » environment. The initial contents of the POCs were inert materials, which would not generate large internal pressure within the PC if heated. However, POCs are now being used to store combustible TRU waste at Department of Energy (DOE) sites. At the request of DOE’s Office of Environmental Management (EM) and National Nuclear Security Administration (NNSA), starting in 2015 SNL conducted a new series of fire tests to examine whether PCs with combustibles would reach a temperature that would result in (1) decomposition of inner contents and (2) subsequent generation of sufficient gas to cause the PC to over-pressurize and release its inner content. Tests conducted during 2015 and 2016, and described herein, were done in two phases. The goal of the first phase was to see if the PC would reach high enough temperatures to decompose typical combustible materials inside the PC. The goal of the second test phase was to determine under what heating loads (i.e., incident heat fluxes) the 7A drum lid pops off from the POC drum. This report will describe the various tests conducted in phase I and II, present preliminary results from these tests, and discuss implications for the POCs.« less

Proof of concept testing report.

DOT National Transportation Integrated Search

2008-09-17

This report documents the methodology and results of the U.S. Department of : Transportation (USDOT) Next Generation 9-1-1 Initiative (NG9-1-1) Proof of Concept : (POC) testing. It describes in detail the NG9-1-1 POC test results and provides a basel...

Clinical accuracy of point-of-care urine culture in general practice.

PubMed

Holm, Anne; Cordoba, Gloria; Sørensen, Tina Møller; Jessen, Lisbeth Rem; Frimodt-Møller, Niels; Siersma, Volkert; Bjerrum, Lars

2017-06-01

To assess the clinical accuracy (sensitivity (SEN), specificity (SPE), positive predictive value and negative predictive value) of two point-of-care (POC) urine culture tests for the identification of urinary tract infection (UTI) in general practice. Prospective diagnostic accuracy study comparing two index tests (Flexicult™ SSI-Urinary Kit or ID Flexicult™) with a reference standard (urine culture performed in the microbiological department). General practice in the Copenhagen area patients. Adult female patients consulting their general practitioner with suspected uncomplicated, symptomatic UTI. (1) Overall accuracy of POC urine culture in general practice. (2) Individual accuracy of each of the two POC tests in this study. (3) Accuracy of POC urine culture in general practice with enterococci excluded, since enterococci are known to multiply in boric acid used for transportation for the reference standard. (4) Accuracy based on expert reading of photographs of POC urine cultures performed in general practice. Standard culture performed in the microbiological department was used as reference standard for all four measures. Twenty general practices recruited 341 patients with suspected uncomplicated UTI. The overall agreement between index test and reference was 0.76 (CI: 0.71-0.80), SEN 0.88 (CI: 0.83-0.92) and SPE 0.55 (CI: 0.46-0.64). The two POC tests produced similar results individually. Overall agreement with enterococci excluded was 0.82 (0.77-0.86) and agreement between expert readings of photographs and reference results was 0.81 (CI: 0.76-0.85). POC culture used in general practice has high SEN but low SPE. Low SPE could be due to both misinterpretation in general practice and an imperfect reference standard. Registration number: ClinicalTrials.gov NCT02323087.

Influence of point-of-care C-reactive protein testing on antibiotic prescription habits in primary care in the Netherlands.

PubMed

Schuijt, Tim J; Boss, David S; Musson, Ruben E A; Demir, Ayse Y

2018-03-27

Bacterial resistance to antibiotics represents a serious global challenge that is associated with high morbidity and mortality. One of the most important causes of this threat is antibiotic overuse. The Dutch College of General Practitioners (DCGP) recommends the use of point-of-care (POC) testing for C-reactive protein (CRP) in two guidelines ('Acute Cough' and 'Diverticulitis') to achieve a more sensible prescription pattern of antibiotics. To evaluate the use of POC-CRP testing in light of the DCGP guidelines and the effect of CRP measurements on antibiotic prescription policy in primary care. In a prospective observational study, which included 1756 patients, general practitioners (GPs) were asked to complete a questionnaire after every POC-CRP testing, stating the indication for performing the test, the CRP result and their decision whether or not to prescribe antibiotics. Indications were verified against the DCGP guidelines and categorized. Antibiotic prescription was evaluated in relation to CRP concentrations. Indications to perform POC-CRP test and the prescription pattern of antibiotics based on CRP value varied considerably between GPs. Differences in antibiotic prescription rate were most obvious in patients who presented with CRP values between 20 and 100 mg/l, and could in part be explained by the indication for performing POC-CRP test and patient age. Most GPs followed the DCGP guidelines and used low CRP values to underpin their decision to refrain from antibiotic prescription. Peer-based reflection on differences in POC-CRP usage and antibiotic prescription rate amongst GPs may further nourish a more critical approach to prescription of antibiotics.

Principles of Point of Care Culture, the Spatial Care Path™, and Enabling Community and Global Resilience: Enabling Community and Global Resilience.

PubMed

Gerald, J Kost; William, J Ferguson; Laurie, E Kost

2014-09-01

This article a) defines point of care (POC) culture; b) presents seven underlying fundamental principles; c) describes the importance of needs assessment; d) introduces a new innovation, the spatial care path™; and e) illustrates how POC testing that properly fulfills needs and spatial care paths™ enable community and global resilience. Often, POC testing supplants the conventional clinical laboratory, which may be too distant, prohibitively expensive, or simply not available in limited-resource settings. New POC technologies "fit" future medical problem solving. Screening and testing directly in the home or primary care facilitate rapid diagnosis, monitoring, and treatment. In contrast to the past where attention has been placed on emergency departments, hospitals, and referral centers, the spatial care path™ starts with the patient and guides him or her through an efficient strategy of care in small-world networks (SWNs) defined by local geography and topology, long-standing customs, public health jurisdictions, and geographic information systems (GIS). POC testing needs in limited-resource settings are striking. Fulfillment is best guided by thorough understanding of POC culture. Quick feedback and fast decision-making by patients and physicians alike yield significant value that motivates changes in patient lifestyles and physician interactions. Culturally sensitive technology assimilation addresses leadership challenges in nations adapting to increasing populations of young and old, despite scarcity of resources. The spatial care path™ facilitates an essential balance of prevention and intervention in public health and shifts future focus to the patient, empowerment, and primary care within the context of POC culture.

Household point of care CD4 testing and isoniazid preventive therapy initiation in a household TB contact tracing programme in two districts of South Africa.

PubMed

Page-Shipp, Liesl; Lewis, James J; Velen, Kavindhran; Senoge, Sedikanelo; Zishiri, Elizabeth; Popane, Flora; Chihota, Violet N; Clark, Dave; Churchyard, Gavin J; Charalambous, Salome

2018-01-01

In South Africa, TB household contact tracing provides an opportunity for increased TB and HIV case finding. We aimed to determine the effect of two new potential interventions for TB contact tracing programmes: Point of Care CD4 (PoC CD4) on HIV linkage to care and household Isoniazid Preventive Therapy (IPT) provision on uptake and retention of IPT. A pragmatic, three-arm, cluster-randomized trial was undertaken. TB Household contacts were randomised to 3 arms: 1) Standard of Care TB and HIV testing (SOC); 2) SOC with POC CD4 for those testing HIV positive; 3) SOC with POC CD4 and IPT for eligible household members. Linkage to care within 90 days was assessed either through patient visits (at 10 weeks and 6 months) or via telephonic contact. 2,243 index TB patients and 3,012 contacts (64,3% female, median age 30 years) were enrolled. On self-report, 26(1.2%) were currently receiving TB treatment and 1816 (60.3%) reported a prior HIV test. HIV testing uptake was 34.7% in the SoC arm, 40.2% in the PoC CD4 arm (RR1.16, CI 0.99-1.36, p-value = 0.060) and 39.9% in the PoC CD4 + HH-IPT arm (RR = 1.15, CI 0.99-1.35, p-value = 0.075). Linkage to care within 3 months was 30.8% in the SoC arm and 42.1% in the POC CD4 arms (RR 1.37; CI: 0.68-2.76, p-value = 0.382). 20/21 contacts (95.2%) initiated IPT in the PoC CD4 + HH-IPT arm, compared to 3/20 (15.0%) in the PoC CD4 arm (p = 0.004; p-value from Fisher's exact test < 0.001). Among 3,008 contacts screened for tuberculosis, 15 (3.4%) had bacteriologically confirmed TB with an overall yield of TB of 0.5% (95% CI: 0.3%, 0.8%). Household PoC CD4 testing and IPT initiation is feasible. There was only weak evidence that PoCCD4 led to a small increase in HCT uptake and no evidence for an increase in linkage-to-care. IPT initiation and completion was increased by the household intervention. Although feasible, these interventions had low impact due to the low uptake of HIV testing in households.

32 CFR 651.37 - Public availability.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., use of public libraries and a list of POCs for supportive documents is encouraged. A depository should be chosen which is open beyond normal business hours. To the extent possible, the WWW should also be...

32 CFR 651.37 - Public availability.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., use of public libraries and a list of POCs for supportive documents is encouraged. A depository should be chosen which is open beyond normal business hours. To the extent possible, the WWW should also be...

Task-shifting point-of-care CD4+ testing to lay health workers in HIV care and treatment services in Namibia.

PubMed

Kaindjee-Tjituka, Francina; Sawadogo, Souleymane; Mutandi, Graham; Maher, Andrew D; Salomo, Natanael; Mbapaha, Claudia; Neo, Marytha; Beukes, Anita; Gweshe, Justice; Muadinohamba, Alexinah; Lowrance, David W

2017-01-01

Access to CD4+ testing remains a common barrier to early initiation of antiretroviral therapy among persons living with HIV/AIDS in low- and middle-income countries. The feasibility of task-shifting of point-of-care (POC) CD4+ testing to lay health workers in Namibia has not been evaluated. From July to August 2011, Pima CD4+ analysers were used to improve access to CD4+ testing at 10 selected public health facilities in Namibia. POC Pima CD4+ testing was performed by nurses or lay health workers. Venous blood samples were collected from 10% of patients and sent to centralised laboratories for CD4+ testing with standard methods. Outcomes for POC Pima CD4+ testing and patient receipt of results were compared between nurses and lay health workers and between the POC method and standard laboratory CD4+ testing methods. Overall, 1429 patients received a Pima CD4+ test; 500 (35.0%) tests were performed by nurses and 929 (65.0%) were performed by lay health workers. When Pima CD4+ testing was performed by a nurse or a lay health worker, 93.2% and 95.2% of results were valid ( p = 0.1); 95.6% and 98.1% of results were received by the patient ( p = 0.007); 96.2% and 94.0% of results were received by the patient on the same day ( p = 0.08). Overall, 97.2% of Pima CD4+ results were received by patients, compared to 55.4% of standard laboratory CD4+ results ( p < 0.001). POC CD4+ testing was feasible and effective when task-shifted to lay health workers. Rollout of POC CD4+ testing via task-shifting can improve access to CD4+ testing and retention in care between HIV diagnosis and antiretroviral therapy initiation in low- and middle-income countries.

Evaluation of a Urine Pooling Strategy for the Rapid and Cost-Efficient Prevalence Classification of Schistosomiasis.

PubMed

Lo, Nathan C; Coulibaly, Jean T; Bendavid, Eran; N'Goran, Eliézer K; Utzinger, Jürg; Keiser, Jennifer; Bogoch, Isaac I; Andrews, Jason R

2016-08-01

A key epidemiologic feature of schistosomiasis is its focal distribution, which has important implications for the spatial targeting of preventive chemotherapy programs. We evaluated the diagnostic accuracy of a urine pooling strategy using a point-of-care circulating cathodic antigen (POC-CCA) cassette test for detection of Schistosoma mansoni, and employed simulation modeling to test the classification accuracy and efficiency of this strategy in determining where preventive chemotherapy is needed in low-endemicity settings. We performed a cross-sectional study involving 114 children aged 6-15 years in six neighborhoods in Azaguié Ahoua, south Côte d'Ivoire to characterize the sensitivity and specificity of the POC-CCA cassette test with urine samples that were tested individually and in pools of 4, 8, and 12. We used a Bayesian latent class model to estimate test characteristics for individual POC-CCA and quadruplicate Kato-Katz thick smears on stool samples. We then developed a microsimulation model and used lot quality assurance sampling to test the performance, number of tests, and total cost per school for each pooled testing strategy to predict the binary need for school-based preventive chemotherapy using a 10% prevalence threshold for treatment. The sensitivity of the urine pooling strategy for S. mansoni diagnosis using pool sizes of 4, 8, and 12 was 85.9%, 79.5%, and 65.4%, respectively, when POC-CCA trace results were considered positive, and 61.5%, 47.4%, and 30.8% when POC-CCA trace results were considered negative. The modeled specificity ranged from 94.0-97.7% for the urine pooling strategies (when POC-CCA trace results were considered negative). The urine pooling strategy, regardless of the pool size, gave comparable and often superior classification performance to stool microscopy for the same number of tests. The urine pooling strategy with a pool size of 4 reduced the number of tests and total cost compared to classical stool microscopy. This study introduces a method for rapid and efficient S. mansoni prevalence estimation through examining pooled urine samples with POC-CCA as an alternative to widely used stool microscopy.

Evaluation of a Urine Pooling Strategy for the Rapid and Cost-Efficient Prevalence Classification of Schistosomiasis

PubMed Central

Coulibaly, Jean T.; Bendavid, Eran; N’Goran, Eliézer K.; Utzinger, Jürg; Keiser, Jennifer; Bogoch, Isaac I.; Andrews, Jason R.

2016-01-01

Background A key epidemiologic feature of schistosomiasis is its focal distribution, which has important implications for the spatial targeting of preventive chemotherapy programs. We evaluated the diagnostic accuracy of a urine pooling strategy using a point-of-care circulating cathodic antigen (POC-CCA) cassette test for detection of Schistosoma mansoni, and employed simulation modeling to test the classification accuracy and efficiency of this strategy in determining where preventive chemotherapy is needed in low-endemicity settings. Methodology We performed a cross-sectional study involving 114 children aged 6–15 years in six neighborhoods in Azaguié Ahoua, south Côte d’Ivoire to characterize the sensitivity and specificity of the POC-CCA cassette test with urine samples that were tested individually and in pools of 4, 8, and 12. We used a Bayesian latent class model to estimate test characteristics for individual POC-CCA and quadruplicate Kato-Katz thick smears on stool samples. We then developed a microsimulation model and used lot quality assurance sampling to test the performance, number of tests, and total cost per school for each pooled testing strategy to predict the binary need for school-based preventive chemotherapy using a 10% prevalence threshold for treatment. Principal Findings The sensitivity of the urine pooling strategy for S. mansoni diagnosis using pool sizes of 4, 8, and 12 was 85.9%, 79.5%, and 65.4%, respectively, when POC-CCA trace results were considered positive, and 61.5%, 47.4%, and 30.8% when POC-CCA trace results were considered negative. The modeled specificity ranged from 94.0–97.7% for the urine pooling strategies (when POC-CCA trace results were considered negative). The urine pooling strategy, regardless of the pool size, gave comparable and often superior classification performance to stool microscopy for the same number of tests. The urine pooling strategy with a pool size of 4 reduced the number of tests and total cost compared to classical stool microscopy. Conclusions/Significance This study introduces a method for rapid and efficient S. mansoni prevalence estimation through examining pooled urine samples with POC-CCA as an alternative to widely used stool microscopy. PMID:27504954

"Hook-like effect" causes false-negative point-of-care urine pregnancy testing in emergency patients.

PubMed

Griffey, Richard T; Trent, Caleb J; Bavolek, Rebecca A; Keeperman, Jacob B; Sampson, Christopher; Poirier, Robert F

2013-01-01

Failure to detect pregnancy in the emergency department (ED) can have important consequences. Urine human chorionic gonadotropin (uhCG) point-of-care (POC) assays are valued for rapidly detecting early pregnancy with high sensitivity. However, under certain conditions, POC uhCG tests can fail to detect pregnancy. In investigating a series of late first-trimester false-negative pregnancy tests in our ED, a novel and distinct causative phenomenon was recently elucidated in our institution. We discuss uhCG POC tests, review our false-negative rate, and describe mechanisms for false negatives and potential remedies. The false-negative POC uhCG rate is very low, but in the setting of a large volume of tests, the numbers are worth consideration. In positive uhCG POC tests, free and fixed antibodies bind hCG to form a "sandwich"; hCG is present in several variant forms that change in their concentrations at different stages of pregnancy. When in excess, intact hCG can saturate the antibodies, preventing sandwich formation (hook effect phenomenon). Some assays may include an antibody that does not recognize certain variants present in later stages of pregnancy. When this variant is in excess, it can bind one antibody avidly and the other not at all, resulting in a false-negative test (hook-like phenomenon). In both situations, dilution is key to an accurate test. Manufacturers should consider that uhCG tests are routinely used at many stages of pregnancy. Characterizing uhCG variants recognized by their tests and eliminating lot-to-lot variability may help improve uhCG test performance. Clinicians need to be aware of and familiarize themselves with the limitations of the specific type of uhCG POC tests used in their practice, recognizing that under certain circumstances, false-negative tests can occur. Copyright © 2013 Elsevier Inc. All rights reserved.

Value of interactive scanning for improving the outcome of new-learners in transcontinental tele-echocardiography (VISION-in-Tele-Echo) study.

PubMed

Bansal, Manish; Singh, Shaanemeet; Maheshwari, Puneet; Adams, David; McCulloch, Marti L; Dada, Tanuj; Sengupta, Shantanu P; Kasliwal, Ravi R; Pellikka, Patricia A; Sengupta, Partho P

2015-01-01

Point-of-care (POC) echocardiography may be helpful for mass triage, but such a strategy requires adequately trained sonographers at the remote site. The aim of this study was to test the feasibility of using a novel POC echocardiography training program for improving physicians' imaging skills during preanesthetic cardiac evaluations performed in a community camp organized for treating cataract blindness. Seventeen physicians were provided 6 hours of training in the use of POC echocardiography; nine were taught on site and eight were taught online through a transcontinental tele-echocardiography system. The trained physicians subsequently scanned elderly patients undergoing cataract surgery. The quality of images was graded, and agreement between local physicians' interpretations and Web-based interpretations by worldwide experts was compared. A total of 968 studies were performed, with 660 used for validating physicians' competence. Major cardiac abnormalities were seen in 136 patients (14.2%), with 32 (3.3%) deemed prohibitive to surgery in unmonitored settings. Although good-quality images were obtained more frequently by physicians trained on site rather than online (P = .03), there were no differences between the two groups in agreement with expert interpretations. The majority of physicians (70.6%) expressed satisfaction with the training (average Likert-type scale score, 4.24 of 5), with no difference seen between the two groups. The training resulted in significant improvements in self-perceived competence in all components of POC echocardiography (P < .001 for all). This study establishes the feasibility of using short-duration, one-on-one, personalized transcontinental tele-echocardiography education for wider dissemination of echocardiographic skills to local physicians in remote communities, essential for optimizing global cardiovascular health. Copyright © 2015 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Instrument Development of Real Time Holographic Water Drop Size Measurement System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Springston, Stephen

2007-02-09

BNL participated with multiple correspondences with Physical Optics Corporation (POC) on the design considerations of an airbome instrument. A pod for extemal deployment ofthe POC unit on the DOE Research Aircraft Facility (RAF), an instrumented, Grumman G-1 aircraft was loaned to POC. BNL proposed evaluation flight tests between the POC unit and the BNL Cloud Aerosol Probe Spectrometer (CAPS) as a reference method. BNL's involvement is described in the semi-annual report ofPOC to DOE. Because of unanticipated technical and engineering difficulties, POC was unable to fit their instrument into an aircraft pod. As a result they are now focusing onmore » a ground-based version first. A prototype laboratory version of the Real-Time Holographic Water Drop Size Measurement (WDSM) System has been constructed.« less

Advances Afoot in Microbiology

PubMed Central

Karon, Brad S.

2017-01-01

ABSTRACT In 2016, the American Academy of Microbiology convened a colloquium to examine point-of-care (POC) microbiology testing and to evaluate its effects on clinical microbiology. Colloquium participants included representatives from clinical microbiology laboratories, industry, and the government, who together made recommendations regarding the implementation, oversight, and evaluation of POC microbiology testing. The colloquium report is timely and well written (V. Dolen et al., Changing Diagnostic Paradigms for Microbiology, 2017, https://www.asm.org/index.php/colloquium-reports/item/6421-changing-diagnostic-paradigms-for-microbiology?utm_source=Commentary&utm_medium=referral&utm_campaign=diagnostics). Emerging POC microbiology tests, especially nucleic acid amplification tests, have the potential to advance medical care. PMID:28539341

[Point-of-care Coagulation Testing in Neurosurgery].

PubMed

Adam, Elisabeth Hannah; Füllenbach, Christoph; Lindau, Simone; Konczalla, Jürgen

2018-06-01

Disorders of the coagulation system can seriously impact the clinical course and outcome of neurosurgical patients. Due to the anatomical location of the central nervous system within the closed skull, bleeding complications can lead to devastating consequences such as an increase in intracranial pressure or enlargement of intracranial hematoma. Point-of-care (POC) devices for the testing of haemostatic parameters have been implemented in various fields of medicine. Major advantages of these devices are that results are available quickly and that analysis can be performed at the bedside, directly affecting patient management. POC devices allow identification of increased bleeding tendencies and therefore may enable an assessment of hemorrhagic risks in neurosurgical patients. Although data regarding the use of POC testing in neurosurgical patients are limited, they suggest that coagulation testing and hemostatic therapy using POC devices might have beneficial effects in this patient population. This article provides an overview of the application of point-of-care coagulation testing in clinical practice in neurosurgical patients. Georg Thieme Verlag KG Stuttgart · New York.

Point-of-Care Diagnostics for Improving Maternal Health in South Africa

PubMed Central

Mashamba-Thompson, Tivani P.; Sartorius, Benn; Drain, Paul K.

2016-01-01

Improving maternal health is a global priority, particularly in high HIV-endemic, resource-limited settings. Failure to use health care facilities due to poor access is one of the main causes of maternal deaths in South Africa. “Point-of-care” (POC) diagnostics are an innovative healthcare approach to improve healthcare access and health outcomes in remote and resource-limited settings. In this review, POC testing is defined as a diagnostic test that is carried out near patients and leads to rapid clinical decisions. We review the current and emerging POC diagnostics for maternal health, with a specific focus on the World Health Organization (WHO) quality-ASSURED (Affordability, Sensitivity, Specificity, User friendly, Rapid and robust, Equipment free and Delivered) criteria for an ideal point-of-care test in resource-limited settings. The performance of POC diagnostics, barriers and challenges related to implementing POC diagnostics for maternal health in rural and resource-limited settings are reviewed. Innovative strategies for overcoming these barriers are recommended to achieve substantial progress on improving maternal health outcomes in these settings. PMID:27589808

Routine use of point-of-care tests: usefulness and application in clinical microbiology.

PubMed

Clerc, O; Greub, G

2010-08-01

Point-of-care (POC) tests offer potentially substantial benefits for the management of infectious diseases, mainly by shortening the time to result and by making the test available at the bedside or at remote care centres. Commercial POC tests are already widely available for the diagnosis of bacterial and viral infections and for parasitic diseases, including malaria. Infectious diseases specialists and clinical microbiologists should be aware of the indications and limitations of each rapid test, so that they can use them appropriately and correctly interpret their results. The clinical applications and performance of the most relevant and commonly used POC tests are reviewed. Some of these tests exhibit insufficient sensitivity, and should therefore be coupled to confirmatory tests when the results are negative (e.g. Streptococcus pyogenes rapid antigen detection test), whereas the results of others need to be confirmed when positive (e.g. malaria). New molecular-based tests exhibit better sensitivity and specificity than former immunochromatographic assays (e.g. Streptococcus agalactiae detection). In the coming years, further evolution of POC tests may lead to new diagnostic approaches, such as panel testing, targeting not just a single pathogen, but all possible agents suspected in a specific clinical setting. To reach this goal, the development of serology-based and/or molecular-based microarrays/multiplexed tests will be needed. The availability of modern technology and new microfluidic devices will provide clinical microbiologists with the opportunity to be back at the bedside, proposing a large variety of POC tests that will allow quicker diagnosis and improved patient care.

Evidence-Based Point-of-Care Diagnostics: Current Status and Emerging Technologies

NASA Astrophysics Data System (ADS)

Chan, Cangel Pui Yee; Mak, Wing Cheung; Cheung, Kwan Yee; Sin, King Keung; Yu, Cheuk Man; Rainer, Timothy H.; Renneberg, Reinhard

2013-06-01

Point-of-care (POC) diagnostics brings tests nearer to the site of patient care. The turnaround time is short, and minimal manual interference enables quick clinical management decisions. Growth in POC diagnostics is being continuously fueled by the global burden of cardiovascular and infectious diseases. Early diagnosis and rapid initiation of treatment are crucial in the management of such patients. This review provides the rationale for the use of POC tests in acute coronary syndrome, heart failure, human immunodeficiency virus, and tuberculosis. We also consider emerging technologies that are based on advanced nanomaterials and microfluidics, improved assay sensitivity, miniaturization in device design, reduced costs, and high-throughput multiplex detection, all of which may shape the future development of POC diagnostics.

The introduction of syphilis point of care tests in resource limited settings.

PubMed

Marks, Michael; Mabey, David Cw

2017-04-01

Syphilis remains an important and preventable cause of stillbirth and neonatal mortality. About 1 million women with active syphilis become pregnant each year. Without treatment, 25% of them will deliver a stillborn baby and 33% a low birth weight baby with an increased chance of dying in the first month of life. Adverse pregnancy outcomes due to syphilis can be prevented by screening pregnant women, and treating those who test positive with a single dose of penicillin before 28 weeks' gestation. Areas covered: This manuscript covers the impact of syphilis on pregnancy outcome, the diagnosis of syphilis, with a special focus on point of care (POC) tests, and challenges to the introduction of POC tests, and their potential impact on the control and prevention of syphilis in resource limited settings. Expert commentary: POC tests for syphilis are available which meet the ASSURED criteria, and could make syphilis screening accessible to all women anywhere in the world who attend an antenatal clinic. High quality dual POC tests for HIV and syphilis could ensure that well-funded programmes for the prevention of mother to child transmission of HIV can contribute towards increased coverage of antenatal syphilis screening, and prevent more than 300,000 adverse pregnancy outcomes due to syphilis annually. Alongside investment to increase availability of syphilis POC tests, operational research is needed to understand how best to improve screening of pregnant women and to translate test availability into improved pregnancy outcomes.

Evaluating Laboratory Performance on Point-of-Care Glucose Testing with Six Sigma Metric for 151 Institutions in China.

PubMed

Fei, Yang; Wang, Wei; He, Falin; Zhong, Kun; Wang, Zhiguo

2015-10-01

The aim of this study was to use Six Sigma(SM) (Motorola Trademark Holdings, Libertyville, IL) techniques to analyze the quality of point-of-care (POC) glucose testing measurements quantitatively and to provide suggestions for improvement. In total, 151 laboratories in China were included in this investigation in 2014. Bias and coefficient of variation were collected from an external quality assessment and an internal quality control program, respectively, for POC glucose testing organized by the National Center for Clinical Laboratories. The σ values and the Quality Goal Index were used to evaluate the performance of POC glucose meters. There were 27, 30, 57, and 37 participants in the groups using Optium Xceed™ (Abbott Diabetes Care, Alameda, CA), Accu-Chek(®) Performa (Roche, Basel, Switzerland), One Touch Ultra(®) (Abbott), and "other" meters, respectively. The median of the absolute value of percentage difference varied among different lots and different groups. Among all the groups, the Abbott One Touch Ultra group had the smallest median of absolute value of percentage difference except for lot 201411, whereas the "other" group had the largest median in all five lots. More than 85% of participate laboratories satisfied the total allowable error (TEa) requirement in International Organization for Standardization standard 15197:2013, and 85.43% (129/151) of laboratories obtained intralaboratory coefficient of variations less than 1/3TEa. However, Six Sigma techniques suggested that 41.72% (63/151) to 65.56% (99/151) of the laboratories needed to improve their POC glucose testing performance, in either precision, trueness, or both. Laboratories should pay more attention on the practice of POC glucose testing and take actions to improve their performance. Only in this way can POC glucose testing really function well in clinical practice.

Evaluating a point-of-care circulating cathodic antigen test (POC-CCA) to detect Schistosoma mansoni infections in a low endemic area in north-eastern Brazil.

PubMed

Bezerra, Fernando Schemelzer Moraes; Leal, Joames Kauffimann Freitas; Sousa, Mariana Silva; Pinheiro, Marta Cristhiany Cunha; Ramos, Alberto Novaes; Silva-Moraes, Vanessa; Katz, Naftale

2018-06-01

Schistosomiasis is still a public health problem in Brazil. The Kato-Katz test is the most frequently used diagnostic method for Schistosoma mansoni infection. However, it lacks sensitivity in areas of low prevalence. We have assessed the positivity rate of S. mansoni infection in Bananeiras, a village on Capistrano, Ceara, Brazil by performing a point-of-care test in urine to determine the circulating cathodic antigens (POC-CCA), and we compared the findings with those of the Kato-Katz technique for egg detection in stool and an enzyme-linked immunosorbent assay for specific antibodies against adult worms (SWAP-ELISA) in serum before treatment (baseline). Additionally, the POC-CCA and Kato-Katz test results were compared at one and two years post-treatment, and only POC-CCA strips were utilised for follow-up testing on urine samples at 3-6 weeks. Only one sample of stool and urine was collected per event. Overall, 258 individuals were investigated at the baseline. The POC-CCA test detected 10 (3.9%) positive cases; however, this amount increased to 30 (11.6%) when considering trace readings as positive (t + ), whereas the Kato-Katz method found only 4 (1.6%) positive cases and the SWAP-ELISA detected 105 (40.7%) positive cases. The consistency observed between a single POC-CCA (t + ) or (t-) and the Kato-Katz (three slides) was poor (Kappa indexes <0.20). The highest positivity rate as determined by CCA and Kato-Katz was found in adults. At the baseline, a praziquantel treatment was administered to all individuals regardless of their infection status. According to the POC-CCA test, 93% of the previous positive cases became negative by the third week after the treatment; this rate reached 100% at the sixth week assessment. The follow-up showed that of the 175 individuals evaluated at one year post-treatment, only one (0.6%) showed 'trace' results, and all the individuals were negative for eggs in the stool. At two years, all 185 examined individuals were negative by the Kato-Katz method, and 11 (5.9%) presented traces by POC-CCA. Our results indicate that a single POC-CCA test reveals a significantly higher number of positive cases than the Kato-Katz technique for diagnosing S. mansoni in a low endemic setting, when trace results are considered as positive cases. Nevertheless, the true significance of the trace is not clear. These findings reinforce the need to associate different tools for improved schistosomiasis diagnosis in individuals with low parasite burdens. Copyright © 2018. Published by Elsevier B.V.

Data acquisition and analysis plan.

DOT National Transportation Integrated Search

2008-03-01

The U.S. Department of Transportation (USDOT) Next Generation 9-1-1 (NG9-1-1) : Proof-of-Concept (POC) demonstration will test key features and functionalities of the : envisioned NG9-1-1 system. The POC will also serve as a test-bed to validate tech...

Advances Afoot in Microbiology.

PubMed

Patel, Robin; Karon, Brad S

2017-07-01

In 2016, the American Academy of Microbiology convened a colloquium to examine point-of-care (POC) microbiology testing and to evaluate its effects on clinical microbiology. Colloquium participants included representatives from clinical microbiology laboratories, industry, and the government, who together made recommendations regarding the implementation, oversight, and evaluation of POC microbiology testing. The colloquium report is timely and well written (V. Dolen et al., Changing Diagnostic Paradigms for Microbiology , 2017, https://www.asm.org/index.php/colloquium-reports/item/6421-changing-diagnostic-paradigms-for-microbiology?utm_source=Commentary&utm_medium=referral&utm_campaign=diagnostics). Emerging POC microbiology tests, especially nucleic acid amplification tests, have the potential to advance medical care. Copyright © 2017 American Society for Microbiology.

Laboratory-based performance evaluation of PIMA CD4+ T-lymphocyte count point-of-care by lay-counselors in Kenya.

PubMed

Zeh, Clement; Rose, Charles E; Inzaule, Seth; Desai, Mitesh A; Otieno, Fredrick; Humwa, Felix; Akoth, Benta; Omolo, Paul; Chen, Robert T; Kebede, Yenew; Samandari, Taraz

2017-09-01

CD4+ T-lymphocyte count testing at the point-of-care (POC) may improve linkage to care of persons diagnosed with HIV-1 infection, but the accuracy of POC devices when operated by lay-counselors in the era of task-shifting is unknown. We examined the accuracy of Alere's Pima™ POC device on both capillary and venous blood when performed by lay-counselors and laboratory technicians. In Phase I, we compared the perfomance of POC against FACSCalibur™ for 280 venous specimens by laboratory technicians. In Phase II we compared POC performance by lay-counselors versus laboratory technicians using 147 paired capillary and venous specimens, and compared these to FACSCalibur™. Statistical analyses included Bland-Altman analyses, concordance correlation coefficient, sensitivity, and specificity at treatment eligibility thresholds of 200, 350, and 500cells/μl. Phase I: POC sensitivity and specificity were 93.0% and 84.1% at 500cells/μl, respectively. Phase II: Good agreement was observed for venous POC results from both lay-counselors (concordance correlation coefficient (CCC)=0.873, bias -86.4cells/μl) and laboratory technicians (CCC=0.920, bias -65.7cells/μl). Capillary POC had good correlation: lay-counselors (CCC=0.902, bias -71.2cells/μl), laboratory technicians (CCC=0.918, bias -63.0cells/μl). Misclassification at the 500 cells/μl threshold for venous blood was 13.6% and 10.2% for lay-counselors and laboratory technicians and 12.2% for capillary blood in both groups. POC tended to under-classify the CD4 values with increasingly negative bias at higher CD4 values. Pima™ results were comparable to FACSCalibur™ for both venous and capillary specimens when operated by lay-counselors. POC CD4 testing has the potential to improve linkage to HIV care without burdening laboratory technicians in resource-limited settings. Published by Elsevier B.V.

Considerations for point-of-care diagnostics: evaluation of acridine orange staining and postprocessing methods for a three-part leukocyte differential test

NASA Astrophysics Data System (ADS)

Powless, Amy J.; Conley, Roxanna J.; Freeman, Karan A.; Muldoon, Timothy J.

2017-03-01

There exists a broad range of techniques that can be used to classify and count white blood cells in a point-of-care (POC) three-part leukocyte differential test. Improvements in lenses, light sources, and cameras for image-based POC systems have renewed interest in acridine orange (AO) as a contrast agent, whereby subpopulations of leukocytes can be differentiated by colorimetric analysis of AO fluorescence emission. We evaluated the effect on test accuracy using different AO staining and postprocessing methods in the context of an image-based POC colorimetric cell classification scheme. Thirty blood specimens were measured for percent cell counts using our POC system and a conventional hematology analyzer for comparison. Controlling the AO concentration used during whole-blood staining, the incubation time with AO, and the colorimetric ratios among the three population of leukocytes yielded a percent deviation of 0.706%, -1.534%, and -0.645% for the lymphocytes, monocytes, and granulocytes, respectively. Overall, we demonstrated that a redshift in AO fluorescence was observed at elevated AO concentrations, which lead to reproducible inaccuracy of cell counts. This study demonstrates there is a need for a strict control of the AO staining and postprocessing methods to improve test accuracy in these POC systems.

The impact of a point-of-care testing device on CVD risk assessment completion in New Zealand primary-care practice: A cluster randomised controlled trial and qualitative investigation.

PubMed

Wells, Sue; Rafter, Natasha; Kenealy, Timothy; Herd, Geoff; Eggleton, Kyle; Lightfoot, Rose; Arcus, Kim; Wadham, Angela; Jiang, Yannan; Bullen, Chris

2017-01-01

To assess the effect of a point of care (POC) device for testing lipids and HbA1c in addition to testing by community laboratory facilities (usual practice) on the completion of cardiovascular disease (CVD) risk assessments in general practice. We conducted a pragmatic, cluster randomised controlled trial in 20 New Zealand general practices stratified by size and rurality and randomised to POC device plus usual practice or usual practice alone (controls). Patients aged 35-79 years were eligible if they met national guideline criteria for CVD risk assessment. Data on CVD risk assessments were aggregated using a web-based decision support programme common to each practice. Data entered into the on-line CVD risk assessment form could be saved pending blood test results. The primary outcome was the proportion of completed CVD risk assessments. Qualitative data on practice processes for CVD risk assessment and feasibility of POC testing were collected at the end of the study by interviews and questionnaire. The POC testing was supported by a comprehensive quality assurance programme. A CVD risk assessment entry was recorded for 7421 patients in 10 POC practices and 6217 patients in 10 control practices; 99.5% of CVD risk assessments had complete data in both groups (adjusted odds ratio 1.02 [95%CI 0.61-1.69]). There were major external influences that affected the trial: including a national performance target for CVD risk assessment and changes to CVD guidelines. All practices had invested in systems and dedicated staff time to identify and follow up patients to completion. However, the POC device was viewed by most as an additional tool rather than as an opportunity to review practice work flow and leverage the immediate test results for patient education and CVD risk management discussions. Shortly after commencement, the trial was halted due to a change in the HbA1c test assay performance. The trial restarted after the manufacturing issue was rectified but this affected the end use of the device. Performance incentives and external influences were more powerful modifiers of practice behaviours than the POC device in relation to CVD risk assessment completion. The promise of combining risk assessment, communication and management within one consultation was not realised. With shifts in policy focus, the utility of POC devices for patient engagement in CVD preventive care may be demonstrated if fully integrated into the clinical setting. Australian New Zealand Clinical Trials Registry ACTRN12613000607774.

Integration of an optical CMOS sensor with a microfluidic channel allows a sensitive readout for biological assays in point-of-care tests.

PubMed

Van Dorst, Bieke; Brivio, Monica; Van Der Sar, Elfried; Blom, Marko; Reuvekamp, Simon; Tanzi, Simone; Groenhuis, Roelf; Adojutelegan, Adewole; Lous, Erik-Jan; Frederix, Filip; Stuyver, Lieven J

2016-04-15

In this manuscript, a microfluidic detection module, which allows a sensitive readout of biological assays in point-of-care (POC) tests, is presented. The proposed detection module consists of a microfluidic flow cell with an integrated Complementary Metal-Oxide-Semiconductor (CMOS)-based single photon counting optical sensor. Due to the integrated sensor-based readout, the detection module could be implemented as the core technology in stand-alone POC tests, for use in mobile or rural settings. The performance of the detection module was demonstrated in three assays: a peptide, a protein and an antibody detection assay. The antibody detection assay with readout in the detection module proved to be 7-fold more sensitive that the traditional colorimetric plate-based ELISA. The protein and peptide assay showed a lower limit of detection (LLOD) of 200 fM and 460 fM respectively. Results demonstrate that the sensitivity of the immunoassays is comparable with lab-based immunoassays and at least equal or better than current mainstream POC devices. This sensitive readout holds the potential to develop POC tests, which are able to detect low concentrations of biomarkers. This will broaden the diagnostic capabilities at the clinician's office and at patient's home, where currently only the less sensitive lateral flow and dipstick POC tests are implemented. Copyright © 2015 Elsevier B.V. All rights reserved.

Point-of-care diagnostics: market trends and growth drivers.

PubMed

Rajan, Aruna; Glorikian, Harry

2009-01-01

There is a significant demand for in vitro diagnostic (IVD) testing to move closer to the patient point-of-care diagnostics [POC]), whether in the hospital, physician's office, rapid clinic or the home, effectively cutting time to results and helping patients make better informed decisions about their health. To analyze the point-of-care market and its trends and growth drivers. In 2007, POC made up 30% of the IVD market and is expected to grow at 9% a year. Although the overall POC market is expected to grow steadily, infectious POC is now the most attractive segment. Availability of rapid random access molecular diagnostic system for critical care infectious diseases such as MRSA and sepsis in the near future is likely to be a significant driver of infectious POC post 2012. Owing to the extraordinary increase in the cost of care, healthcare delivery is moving to increasingly decentralized settings such as rapid clinics and the home, driven by point-of-care diagnostics that provide accurate and directional results. We are evolving from the analog testing world to the digital testing world, where diagnosis is exact and therapy can be administered and be predictably effective.

Loop-mediated isothermal DNA amplification for asymptomatic malaria detection in challenging field settings: Technical performance and pilot implementation in the Peruvian Amazon

PubMed Central

Serra-Casas, Elisa; Manrique, Paulo; Ding, Xavier C.; Carrasco-Escobar, Gabriel; Alava, Freddy; Gave, Anthony; Rodriguez, Hugo; Contreras-Mancilla, Juan; Rosas-Aguirre, Angel; Speybroeck, Niko; González, Iveth J.

2017-01-01

Background Loop-mediated isothermal DNA amplification (LAMP) methodology offers an opportunity for point-of-care (POC) molecular detection of asymptomatic malaria infections. However, there is still little evidence on the feasibility of implementing this technique for population screenings in isolated field settings. Methods Overall, we recruited 1167 individuals from terrestrial (‘road’) and hydric (‘riverine’) communities of the Peruvian Amazon for a cross-sectional survey to detect asymptomatic malaria infections. The technical performance of LAMP was evaluated in a subgroup of 503 samples, using real-time Polymerase Chain Reaction (qPCR) as reference standard. The operational feasibility of introducing LAMP testing in the mobile screening campaigns was assessed based on field-suitability parameters, along with a pilot POC-LAMP assay in a riverine community without laboratory infrastructure. Results LAMP had a sensitivity of 91.8% (87.7–94.9) and specificity of 91.9% (87.8–95.0), and the overall accuracy was significantly better among samples collected during road screenings than riverine communities (p≤0.004). LAMP-based diagnostic strategy was successfully implemented within the field-team logistics and the POC-LAMP pilot in the riverine community allowed for a reduction in the turnaround time for case management, from 12–24 hours to less than 5 hours. Specimens with haemolytic appearance were regularly observed in riverine screenings and could help explaining the hindered performance/interpretation of the LAMP reaction in these communities. Conclusions LAMP-based molecular malaria diagnosis can be deployed outside of reference laboratories, providing similar performance as qPCR. However, scale-up in remote field settings such as riverine communities needs to consider a number of logistical challenges (e.g. environmental conditions, labour-intensiveness in large population screenings) that can influence its optimal implementation. PMID:28982155

Community pharmacy-based point-of-care testing: A case study of pharmacist-physician collaborative working relationships.

PubMed

Bacci, Jennifer L; Klepser, Donald; Tilley, Heather; Smith, Jaclyn K; Klepser, Michael E

2018-01-01

Building collaborative working relationships (CWRs) with physicians or other prescribers is an important step for community pharmacists in establishing a collaborative practice agreement (CPA). This case study describes the individual, context, and exchange factors that drive pharmacist-physician CWR development for community pharmacy-based point-of-care (POC) testing. Two physicians who had entered in a CPA with community pharmacists to provide POC testing were surveyed and interviewed. High scores on the pharmacist-physician collaborative index indicated a high level of collaboration between the physicians and the pharmacist who initiated the relationship. Trust was established through the physicians' personal relationships with the pharmacist or due to the community pharmacy organization's strong reputation. The physicians' individual perceptions of community pharmacy-based POC testing affected their CWRs and willingness to establish a CPA. These findings suggest that exchange characteristics remain significant factors in CWR development. Individual factors may also contribute to physicians' willingness to advance their CWR to include a CPA for POC testing. Copyright © 2017 Elsevier Inc. All rights reserved.

How to estimate the cost of point-of-care CD4 testing in program settings: an example using the Alere Pima Analyzer in South Africa.

PubMed

Larson, Bruce; Schnippel, Kathryn; Ndibongo, Buyiswa; Long, Lawrence; Fox, Matthew P; Rosen, Sydney

2012-01-01

Integrating POC CD4 testing technologies into HIV counseling and testing (HCT) programs may improve post-HIV testing linkage to care and treatment. As evaluations of these technologies in program settings continue, estimates of the costs of POC CD4 tests to the service provider will be needed and estimates have begun to be reported. Without a consistent and transparent methodology, estimates of the cost per CD4 test using POC technologies are likely to be difficult to compare and may lead to erroneous conclusions about costs and cost-effectiveness. This paper provides a step-by-step approach for estimating the cost per CD4 test from a provider's perspective. As an example, the approach is applied to one specific POC technology, the Pima Analyzer. The costing approach is illustrated with data from a mobile HCT program in Gauteng Province of South Africa. For this program, the cost per test in 2010 was estimated at $23.76 (material costs  = $8.70; labor cost per test  = $7.33; and equipment, insurance, and daily quality control  = $7.72). Labor and equipment costs can vary widely depending on how the program operates and the number of CD4 tests completed over time. Additional costs not included in the above analysis, for on-going training, supervision, and quality control, are likely to increase further the cost per test. The main contribution of this paper is to outline a methodology for estimating the costs of incorporating POC CD4 testing technologies into an HCT program. The details of the program setting matter significantly for the cost estimate, so that such details should be clearly documented to improve the consistency, transparency, and comparability of cost estimates.

Sensitivity and specificity of the circulating cathodic antigen rapid urine test in the diagnosis of Schistosomiasis mansoni infection and evaluation of morbidity in a low- endemic area in Brazil.

PubMed

Ferreira, Fernanda Teixeira; Fidelis, Thiago André; Pereira, Thiago Almeida; Otoni, Alba; Queiroz, Leonardo Campos; Amâncio, Frederico Figueiredo; Antunes, Carlos Maurício; Lambertucci, José Roberto

2017-01-01

The Kato-Katz technique is the standard diagnostic test for Schistosoma mansoni infection in rural areas. However, the utility of this method is severely limited by the day-to-day variability in host egg excretion in the stool. In high-transmission areas, the point-of-care circulating cathodic antigen (POC-CCA) urine assay has proven to be a reliable test. However, investigations of the reliability of the POC-CCA assay in low-transmission regions are under way. This study aimed to evaluate the sensitivity and specificity of the POC-CCA assay and the morbidity of schistosomiasis in a low-endemic area in Brazil. Pains City is a low-transmission zone for schistosomiasis. A total of 300 subjects aged 7-76 years were randomly selected for the POC-CCA cassette test. For S. mansoni diagnosis, three stool samples on six slides were compared with one urine sample for each subject. The sensitivity and specificity in the absence of a gold standard were calculated using latent class analysis. Clinical examinations and abdominal ultrasounds were performed in 181 volunteers to evaluate morbidity associated with schistosomiasis. The sensitivity and specificity of the Kato-Katz technique were 25.6% and 94.6%, respectively. By contrast, the sensitivity and specificity of the POC-CCA assay were 68.1% and 72.8%, respectively. Hepatosplenic schistosomiasis was diagnosed in two patients (1.1%). Overall, the POC-CCA urine assay proved to be a useful test for diagnosing S. mansoni in a low-endemic area in Brazil. Severe clinical forms of schistosomiasis can be present even in such low-endemic areas.

Simple and inexpensive point-of-care tests improve diagnosis of vaginal infections in resource constrained settings.

PubMed

Madhivanan, Purnima; Krupp, Karl; Hardin, Jill; Karat, Chitra; Klausner, Jeffrey D; Reingold, Arthur L

2009-06-01

Bacterial vaginosis (BV) and Trichomonas vaginalis infection (TV) have been associated with adverse birth outcomes and increased risk for HIV. We compare the performance of simple inexpensive point-of-care (POC) tests to laboratory diagnosis and syndromic management of BV and TV in poor settings. Between November 2005 and March 2006, 898 sexually active women attending two reproductive health clinics in Mysore, India were recruited into a cohort study investigating the relationship between vaginal flora and HSV-2 infection. Participants were interviewed and screened for reproductive tract infections. Laboratory tests included serology for HSV-2; cultures for TV, Candida sp., and Neisseria gonorrhoeae; Gram stains; and two POC tests: vaginal pH; and Whiff test. Of the 898 participants, 411 [45.7%, 95% confidence interval (95% CI): 42.4-49.0%] had any laboratory diagnosed vaginal infection. BV was detected in 165 women (19.1%, 95%CI: 16.5-21.9%) using Nugent score. TV was detected in 76 women (8.5%, 95%CI: 6.7-10.4%) using culture. Among the entire study population, POC correctly detected 82% of laboratory diagnosed BV cases, and 83% of laboratory diagnosed TV infections. Among women with complaints of vulval itching, burning, abnormal vaginal discharge, and/or sores (445/898), POC correctly detected 83% (60 of 72 cases) of laboratory diagnosed BV cases vs. 40% (29 of 72 cases) correctly managed using the syndromic approach (P < 0.001). Similarly, POC would have detected 82% (37 of 45 cases) of TV cases vs. 51% (23 of 45 cases) correctly managed using the syndromic approach (P = 0.001). In the absence of laboratory diagnostics, POC is not only inexpensive and practical, but also significantly more sensitive than the syndromic management approach, resulting in less overtreatment. .

NEXIS Reservoir Cathode 2000 Hour Life Test

NASA Technical Reports Server (NTRS)

Vaughn, Jason; Schneider, Todd; Polk, Jay; Goebel, Dan; Ohlinger, Wayne; Hill, D. Norm

2004-01-01

The current design of the Nuclear Electric Xenon Ion System (NEXIS) employs a reservoir cathode as both the discharge and neutralizer cathode to meet the 10 yr thruster design life. The main difference between a reservoir cathode and a conventional discharge cathode is the source material (barium-containing compound) is contained within a reservoir instead of in an impregnated insert in the hollow tube. However, reservoir cathodes do not have much life test history associated with them. In order to demonstrate the feasibility of using a reservoir cathode as an integral part of the NEXIS ion thruster, a 2000 hr life test was performed. Several proof-of-concept (POC) reservoir cathodes were built early in the NEXIS program to conduct performance testing as well as life tests. One of the POC cathodes was sent to Marshall Space Flight Center (MSFC) where it was tested for 2000 hrs in a vacuum chamber. The cathode was operated at the NEXIS design point of 25 A discharge current and a xenon flow rate of 5.5 sccm during the 2000 hr test. The cathode performance parameters, including discharge current, discharge voltage, keeper current; keeper voltage, and flow rate were monitored throughout test. Also, the temperature upstream of cathode heater, the temperature downstream of the cathode heater, and the temperature of the orifice plate were monitored throughout the life of the test. The results of the 2000 hr test will be described in this paper. Included in the results will be time history of discharge current, discharge voltage, and flow rate. Also, a time history of the cathode temperature will be provided.

Observation of a Pharmacist-Conducted Group A Streptococcal Pharyngitis Point-of-Care Test: A Time and Motion Study.

PubMed

Corn, Carolyn E; Klepser, Donald G; Dering-Anderson, Allison M; Brown, Terrence G; Klepser, Michael E; Smith, Jaclyn K

2018-06-01

Acute pharyngitis is among the most common infectious diseases encountered in the United States, resulting in 13 million patient visits annually, with group A streptococcus (GAS) being a common causative pathogen. It is estimated that annual expenditures for the treatment of adult pharyngitis will exceed US$1.2 billion annually. This substantial projection reinforces the need to evaluate diagnosis and treatment of adult pharyngitis in nontraditional settings. The objective of this research is to quantify the amount of pharmacist time required to complete a point-of-care (POC) test for a patient presenting with pharyngitis symptoms. A standardized patient with pharyngitis symptoms visited 11 pharmacies for POC testing services for a total of 33 patient encounters. An observer was present at each encounter and recorded the total encounter time, divided into 9 categories. Pharmacists conducted POC testing in 1 of 2 ways: sequence 1-pharmacists performed all service-related tasks; sequence 2-both pharmacists and pharmacist interns performed service-related tasks. The average time for completion of a POC test for GAS pharyngitis was 25.3 ± 4.8 minutes. The average pharmacist participation time per encounter was 12.7 ± 3.0 minutes (sequence 1), which decreased to 2.6 ± 1.1 minutes when pharmacist interns were involved in the testing (sequence 2). Although additional studies are required to further assess service feasibility, this study indicates that a GAS POC testing service could be implemented in a community pharmacy with limited disruption or change to workflow and staff.

Simultaneous point-of-care detection of anemia and sickle cell disease in Tanzania: the RAPID study.

PubMed

Smart, Luke R; Ambrose, Emmanuela E; Raphael, Kevin C; Hokororo, Adolfine; Kamugisha, Erasmus; Tyburski, Erika A; Lam, Wilbur A; Ware, Russell E; McGann, Patrick T

2018-02-01

Both anemia and sickle cell disease (SCD) are highly prevalent across sub-Saharan Africa, and limited resources exist to diagnose these conditions quickly and accurately. The development of simple, inexpensive, and accurate point-of-care (POC) assays represents an important advance for global hematology, one that could facilitate timely and life-saving medical interventions. In this prospective study, Robust Assays for Point-of-care Identification of Disease (RAPID), we simultaneously evaluated a POC immunoassay (Sickle SCAN™) to diagnose SCD and a first-generation POC color-based assay to detect anemia. Performed at Bugando Medical Center in Mwanza, Tanzania, RAPID tested 752 participants (age 1 day to 20 years) in four busy clinical locations. With minimally trained medical staff, the SCD POC assay diagnosed SCD with 98.1% sensitivity and 91.1% specificity. The hemoglobin POC assay had 83.2% sensitivity and 74.5% specificity for detection of severe anemia (Hb ≤ 7 g/dL). Interobserver agreement was excellent for both POC assays (r = 0.95-0.96). Results for the hemoglobin POC assay have informed the second-generation assay design to be more suitable for low-resource settings. RAPID provides practical feasibility data regarding two novel POC assays for the diagnosis of anemia and SCD in real-world field evaluations and documents the utility and potential impact of these POC assays for sub-Saharan Africa.

Cost-effectiveness of point-of-care viral load monitoring of antiretroviral therapy in resource-limited settings: mathematical modelling study.

PubMed

Estill, Janne; Egger, Matthias; Blaser, Nello; Vizcaya, Luisa Salazar; Garone, Daniela; Wood, Robin; Campbell, Jennifer; Hallett, Timothy B; Keiser, Olivia

2013-06-01

Monitoring of HIV viral load in patients on combination antiretroviral therapy (ART) is not generally available in resource-limited settings. We examined the cost-effectiveness of qualitative point-of-care viral load tests (POC-VL) in sub-Saharan Africa. Mathematical model based on longitudinal data from the Gugulethu and Khayelitsha township ART programmes in Cape Town, South Africa. Cohorts of patients on ART monitored by POC-VL, CD4 cell count or clinically were simulated. Scenario A considered the more accurate detection of treatment failure with POC-VL only, and scenario B also considered the effect on HIV transmission. Scenario C further assumed that the risk of virologic failure is halved with POC-VL due to improved adherence. We estimated the change in costs per quality-adjusted life-year gained (incremental cost-effectiveness ratios, ICERs) of POC-VL compared with CD4 and clinical monitoring. POC-VL tests with detection limits less than 1000 copies/ml increased costs due to unnecessary switches to second-line ART, without improving survival. Assuming POC-VL unit costs between US$5 and US$20 and detection limits between 1000 and 10,000 copies/ml, the ICER of POC-VL was US$4010-US$9230 compared with clinical and US$5960-US$25540 compared with CD4 cell count monitoring. In Scenario B, the corresponding ICERs were US$2450-US$5830 and US$2230-US$10380. In Scenario C, the ICER ranged between US$960 and US$2500 compared with clinical monitoring and between cost-saving and US$2460 compared with CD4 monitoring. The cost-effectiveness of POC-VL for monitoring ART is improved by a higher detection limit, by taking the reduction in new HIV infections into account and assuming that failure of first-line ART is reduced due to targeted adherence counselling.

Bacterial growth and the decomposition of particulate organic carbon collected in sediment traps

NASA Astrophysics Data System (ADS)

Ducklow, Hugh W.; Hill, Suzanne M.; Gardner, Wilford D.

We have studied bacterial abundance and production in samples from sediment traps deployed for 1 and 100 days in several areas of the shelf and slope regions of the Middle Atlantic Bight, U.S.A. By making a series of assumptions about bacterial growth at the expense of POC in traps, we have estimated that the turnover time of organic particles collected in traps during long deployments is slow (mean 1500 ± 300 days), if only bacterial activity is considered. However the abundance and biomass of bacteria in traps is very high, ranging from 3 to 30 × 10 11 cells gC -1, i.e., 0.3 to 3% of the POC is bacterial carbon. Fifteen to 88% of the particles in traps were colonized by bacteria, but usually about half the particles had only 0 to 1 cell attached. Growth of bacteria was observed at all scales relevant to these trap deployments; over periods ranging from hours to weeks, at rates of 0.01 to 0.3 d -1. In spite of slow growth, bacteria appeared to be physiologically active in that [ 3H]adenine and [ 3H]thymidine were incorporated more rapidly into RNA and protein than into DNA. Total incorporation rates were high. We conclude that even relatively old (ca. 1 y) POC in sediment traps supports high levels of active bacterial biomass, but that POC decomposition is slow, so that bacteria may not be the principal agents of POC turnover following collection.

Point-of-care CD4 testing to inform selection of antiretroviral medications in south african antenatal clinics: a cost-effectiveness analysis.

PubMed

Ciaranello, Andrea L; Myer, Landon; Kelly, Kathleen; Christensen, Sarah; Daskilewicz, Kristen; Doherty, Katie; Bekker, Linda-Gail; Hou, Taige; Wood, Robin; Francke, Jordan A; Wools-Kaloustian, Kara; Freedberg, Kenneth A; Walensky, Rochelle P

2015-01-01

Many prevention of mother-to-child HIV transmission (PMTCT) programs currently prioritize antiretroviral therapy (ART) for women with advanced HIV. Point-of-care (POC) CD4 assays may expedite the selection of three-drug ART instead of zidovudine, but are costlier than traditional laboratory assays. We used validated models of HIV infection to simulate pregnant, HIV-infected women (mean age 26 years, gestational age 26 weeks) in a general antenatal clinic in South Africa, and their infants. We examined two strategies for CD4 testing after HIV diagnosis: laboratory (test rate: 96%, result-return rate: 87%, cost: $14) and POC (test rate: 99%, result-return rate: 95%, cost: $26). We modeled South African PMTCT guidelines during the study period (WHO "Option A"): antenatal zidovudine (CD4 ≤350/μL) or ART (CD4>350/μL). Outcomes included MTCT risk at weaning (age 6 months), maternal and pediatric life expectancy (LE), maternal and pediatric lifetime healthcare costs (2013 USD), and cost-effectiveness ($/life-year saved). In the base case, laboratory led to projected MTCT risks of 5.7%, undiscounted pediatric LE of 53.2 years, and undiscounted PMTCT plus pediatric lifetime costs of $1,070/infant. POC led to lower modeled MTCT risk (5.3%), greater pediatric LE (53.4 years) and lower PMTCT plus pediatric lifetime costs ($1,040/infant). Maternal outcomes following laboratory were similar to POC (LE: 21.2 years; lifetime costs: $23,860/person). Compared to laboratory, POC improved clinical outcomes and reduced healthcare costs. In antenatal clinics implementing Option A, the higher initial cost of a one-time POC CD4 assay will be offset by cost-savings from prevention of pediatric HIV infection.

Analytical validation of a new point-of-care assay for serum amyloid A in horses.

PubMed

Schwartz, D; Pusterla, N; Jacobsen, S; Christopher, M M

2018-01-17

Serum amyloid A (SAA) is a major acute phase protein in horses. A new point-of-care (POC) test for SAA (Stablelab) is available, but studies evaluating its analytical accuracy are lacking. To evaluate the analytical performance of the SAA POC test by 1) determining linearity and precision, 2) comparing results in whole blood with those in serum or plasma, and 3) comparing POC results with those obtained using a previously validated turbidimetric immunoassay (TIA). Assay validation. Analytical validation of the POC test was done in accordance with American Society of Veterinary Clinical Pathology guidelines using residual equine serum/plasma and whole blood samples from the Clinical Pathology Laboratory at the University of California-Davis. A TIA was used as the reference method. We also evaluated the effect of haematocrit (HCT). The POC test was linear for SAA concentrations of up to at least 1000 μg/mL (r = 0.991). Intra-assay CVs were 13, 18 and 15% at high (782 μg/mL), intermediate (116 μg/mL) and low (64 μg/mL) concentrations. Inter-assay (inter-batch) CVs were 45, 14 and 15% at high (1372 μg/mL), intermediate (140 μg/mL) and low (56 μg/mL) concentrations. SAA results in whole blood were significantly lower than those in serum/plasma (P = 0.0002), but were positively correlated (r = 0.908) and not affected by HCT (P = 0.261); proportional negative bias was observed in samples with SAA>500 μg/mL. The difference between methods exceeded the 95% confidence interval of the combined imprecision of both methods (15%). Analytical validation could not be performed in whole blood, the sample most likely to be used stall side. The POC test has acceptable accuracy and precision in equine serum/plasma with SAA concentrations of up to at least 1000 μg/mL. Low inter-batch precision at high concentrations may affect serial measurements, and the use of the same test batch and sample type (serum/plasma or whole blood) is recommended. Comparison of results between the POC test and the TIA is not recommended. © 2018 EVJ Ltd.

Antibiotic prescribing and C-reactive protein testing for pulmonary infections in patients with intellectual disabilities

PubMed Central

Peters, Catharina M; Schouwenaars, Francesca M; Haagsma, Ellen; Evenhuis, Heleen M; Echteld, Michael A

2013-01-01

Background Excessive prescribing of antibiotics in patients with lower respiratory tract infections (LRTIs) is common in the general population. Due to communication difficulties, it is hypothesised that prescriptions are even more commonplace in the primary care of individuals with intellectual disabilities. Point-of-care C-reactive protein (POC-CRP) testing might lead to more efficient prescribing of antibiotics. Aim To evaluate the effect of POC-CRP testing on antibiotic prescriptions for LRTIs by physicians specialising in the care of individuals with intellectual disabilities. Design and setting A prospective case-control study in four care centres for individuals with intellectual disabilities in The Netherlands. Method Between 27 October 2010 and 27 October 2011, a prospective efficiency study was performed with a base population of 1472 individuals. This population consisted of 882 individuals in whom POC-CRP tests were used and a control group (n = 590) in whom no POC-CRP test was performed. Results Of the 48 patients in the control group who were diagnosed as having an LRTI, 43 (90%) received antibiotics, compared with 59 out of the 144 patients (41%) in the case group (OR = 12.0; 95% CI = 4.1–35.3). No significant differences in outcome were found between both groups during a follow-up period of 1 month. Conclusion This study shows that the use of POC-CRP testing in patients with intellectual disabilities and LRTIs can lead to a significant reduction in antibiotic prescriptions, with no significant differences in outcome during follow-up. PMID:23643230

What Can We Learn From Point-of-Care Blood Glucose Values Deleted and Repeated by Nurses?

PubMed

Corl, Dawn; Yin, Tom; Ulibarri, May; Lien, Heather; Tylee, Tracy; Chao, Jing; Wisse, Brent E

2018-03-01

Hospitals rely on point-of-care (POC) blood glucose (BG) values to guide important decisions related to insulin administration and glycemic control. Evaluation of POC BG in hospitalized patients is associated with measurement and operator errors. Based on a previous quality improvement (QI) project we introduced an option for operators to delete and repeat POC BG values suspected as erroneous. The current project evaluated our experience with deleted POC BG values over a 2-year period. A retrospective QI project included all patients hospitalized at two regional academic medical centers in the Pacific Northwest during 2014 and 2015. Laboratory Medicine POC BG data were reviewed to evaluate all inpatient episodes of deleted and repeated POC BG. Inpatient operators choose to delete and repeat only 0.8% of all POC BG tests. Hypoglycemic and extreme hyperglycemic BG values are more likely to be deleted and repeated. Of initial values <40 mg/dL, 58% of deleted values (18% of all values) are errors. Of values >400 mg/dL, 40% of deleted values (5% of all values) are errors. Not all repeated POC BG values are first deleted. Optimal use of the option to delete and repeat POC BG values <40 mg/dL could decrease reported rates of severe hypoglycemia by as much as 40%. This project demonstrates that operators are frequently able to identify POC BG values that are measurement/operator errors. Eliminating these errors significantly reduces documented rates of severe hypoglycemia and hyperglycemia, and has the potential to improve patient safety.

Long-term combined chemical and manure fertilizations increase soil organic carbon and total nitrogen in aggregate fractions at three typical cropland soils in China.

PubMed

He, Y T; Zhang, W J; Xu, M G; Tong, X G; Sun, F X; Wang, J Z; Huang, S M; Zhu, P; He, X H

2015-11-01

Soil organic carbon (SOC), total nitrogen (TN), microbial biomass carbon (MBC) and nitrogen (MBN) are important factors of soil fertility. However, effects of the combined chemical fertilizer and organic manure or straw on these factors and their relationships are less addressed under long-term fertilizations. This study addressed changes in SOC, TN, MBC and MBN at 0-20 cm soil depth under three 17 years (September 1990-September 2007) long-term fertilization croplands along a heat and water gradient in China. Four soil physical fractions (coarse free and fine free particulate organic C, cfPOC and ffPOC; intra-microaggregate POC, iPOC; and mineral associated organic C, MOC) were examined under five fertilizations: unfertilized control, chemical nitrogen (N), phosphorus (P) and potassium (K) (NPK), NPK plus straw (NPKS, hereafter straw return), and NPK plus manure (NPKM and 1.5NPKM, hereafter manure). Compared with Control, manure significantly increased all tested parameters. SOC and TN in fractions distributed as MOC > iPOC > cfPOC > ffPOC with the highest increase in cfPOC (329.3%) and cfPTN (431.1%), and the lowest in MOC (40.8%) and MTN (45.4%) under manure. SOC significantly positively correlated with MBC, cfPOC, ffPOC, iPOC and MOC (R(2) = 0.51-0.84, P < 0.01), while TN with cfPTN, ffPTN, iPTN and MTN (R(2) = 0.45-0.79, P < 0.01), but not with MBN, respectively. Principal component analyses explained 86.9-91.2% variance of SOC, TN, MBC, MBN, SOC and TN in each fraction. Our results demonstrated that cfPOC was a sensitive SOC indicator and manure addition was the best fertilization for improving soil fertility while straw return should take into account climate factors in Chinese croplands. Copyright © 2015 Elsevier B.V. All rights reserved.

Point-of-care testing for Toxoplasma gondii IgG/IgM using Toxoplasma ICT IgG-IgM test with sera from the United States and implications for developing countries.

PubMed

Begeman, Ian J; Lykins, Joseph; Zhou, Ying; Lai, Bo Shiun; Levigne, Pauline; El Bissati, Kamal; Boyer, Kenneth; Withers, Shawn; Clouser, Fatima; Noble, A Gwendolyn; Rabiah, Peter; Swisher, Charles N; Heydemann, Peter T; Contopoulos-Ioannidis, Despina G; Montoya, Jose G; Maldonado, Yvonne; Ramirez, Raymund; Press, Cindy; Stillwaggon, Eileen; Peyron, François; McLeod, Rima

2017-06-01

Congenital toxoplasmosis is a serious but preventable and treatable disease. Gestational screening facilitates early detection and treatment of primary acquisition. Thus, fetal infection can be promptly diagnosed and treated and outcomes can be improved. We tested 180 sera with the Toxoplasma ICT IgG-IgM point-of-care (POC) test. Sera were from 116 chronically infected persons (48 serotype II; 14 serotype I-III; 25 serotype I-IIIa; 28 serotype Atypical, haplogroup 12; 1 not typed). These represent strains of parasites infecting mothers of congenitally infected children in the U.S. 51 seronegative samples and 13 samples from recently infected persons known to be IgG/IgM positive within the prior 2.7 months also were tested. Interpretation was confirmed by two blinded observers. A comparison of costs for POC vs. commercial laboratory testing methods was performed. We found that this new Toxoplasma ICT IgG-IgM POC test was highly sensitive (100%) and specific (100%) for distinguishing IgG/IgM-positive from negative sera. Use of such reliable POC tests can be cost-saving and benefit patients. Our work demonstrates that the Toxoplasma ICT IgG-IgM test can function reliably as a point-of-care test to diagnose Toxoplasma gondii infection in the U.S. This provides an opportunity to improve maternal-fetal care by using approaches, diagnostic tools, and medicines already available. This infection has serious, lifelong consequences for infected persons and their families. From the present study, it appears a simple, low-cost POC test is now available to help prevent morbidity/disability, decrease cost, and make gestational screening feasible. It also offers new options for improved prenatal care in low- and middle-income countries.

Point-of-care testing for Toxoplasma gondii IgG/IgM using Toxoplasma ICT IgG-IgM test with sera from the United States and implications for developing countries

PubMed Central

Zhou, Ying; Lai, Bo Shiun; Levigne, Pauline; El Bissati, Kamal; Boyer, Kenneth; Withers, Shawn; Clouser, Fatima; Noble, A. Gwendolyn; Rabiah, Peter; Swisher, Charles N.; Heydemann, Peter T.; Contopoulos-Ioannidis, Despina G.; Montoya, Jose G.; Maldonado, Yvonne; Ramirez, Raymund; Press, Cindy; Stillwaggon, Eileen; Peyron, François

2017-01-01

Background Congenital toxoplasmosis is a serious but preventable and treatable disease. Gestational screening facilitates early detection and treatment of primary acquisition. Thus, fetal infection can be promptly diagnosed and treated and outcomes can be improved. Methods We tested 180 sera with the Toxoplasma ICT IgG-IgM point-of-care (POC) test. Sera were from 116 chronically infected persons (48 serotype II; 14 serotype I-III; 25 serotype I-IIIa; 28 serotype Atypical, haplogroup 12; 1 not typed). These represent strains of parasites infecting mothers of congenitally infected children in the U.S. 51 seronegative samples and 13 samples from recently infected persons known to be IgG/IgM positive within the prior 2.7 months also were tested. Interpretation was confirmed by two blinded observers. A comparison of costs for POC vs. commercial laboratory testing methods was performed. Results We found that this new Toxoplasma ICT IgG-IgM POC test was highly sensitive (100%) and specific (100%) for distinguishing IgG/IgM-positive from negative sera. Use of such reliable POC tests can be cost-saving and benefit patients. Conclusions Our work demonstrates that the Toxoplasma ICT IgG-IgM test can function reliably as a point-of-care test to diagnose Toxoplasma gondii infection in the U.S. This provides an opportunity to improve maternal-fetal care by using approaches, diagnostic tools, and medicines already available. This infection has serious, lifelong consequences for infected persons and their families. From the present study, it appears a simple, low-cost POC test is now available to help prevent morbidity/disability, decrease cost, and make gestational screening feasible. It also offers new options for improved prenatal care in low- and middle-income countries. PMID:28650970

Proof of concept deployment plan.

DOT National Transportation Integrated Search

2008-02-01

The U.S. Department of Transportation (USDOT) Next Generation 9-1-1 (NG9-1-1) : Proof-of-Concept (POC) demonstration is envisioned to test key features and : functionalities of the NG9-1-1 system. The Interim POC System Design Document : defines the ...

Experiential or behavioral processes: which one is prominent in physical activity? Examining the processes of change 1 year after an intervention of therapeutic education among adults with obesity.

PubMed

Romain, A J; Attalin, V; Sultan, A; Boegner, C; Gernigon, C; Avignon, A

2014-11-01

Although physical activity (PA) is essential, most obese people will not engage in its practice. The transtheoretical model (TTM) and its processes of change (POC) contribute to the understanding of behavior change regarding PA. The present study aimed to test how POC are associated with a progression through the stages of change (SOC) and whether they predict BMI change. Interventional study. A total of 134 subjects participated in an education program, were called at 1 year and 62 of them provided follow-up data. Participants completed the SOC and POC questionnaires at baseline, at 1 year and were classified according to their SOC progression. Participants who progressed through SOC lost more weight (p<0.001). Significant interactions were found for three out of five POC (p<0.05). Progression through SOC was associated with an increased use of POC. Weight loss was predicted by two behavioral POC. Results support the previous cross-sectional studies showing that physically active people use more frequently POC. The present findings support the development of TTM-grounded behavioral interventions targeted to obese patients. Identifying methods to promote POC use to improve adherence to weight guidelines may lead to improved clinical outcomes and quality of life. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Construction and Validation of the Perceived Opportunity to Craft Scale.

PubMed

van Wingerden, Jessica; Niks, Irene M W

2017-01-01

We developed and validated a scale to measure employees' perceived opportunity to craft (POC) in two separate studies conducted in the Netherlands (total N = 2329). POC is defined as employees' perception of their opportunity to craft their job. In Study 1, the perceived opportunity to craft scale (POCS) was developed and tested for its factor structure and reliability in an explorative way. Study 2 consisted of confirmatory analyses of the factor structure and reliability of the scale as well as examination of the discriminant and criterion-related validity of the POCS. The results indicated that the scale consists of one dimension and could be reliably measured with five items. Evidence was found for the discriminant validity of the POCS. The scale also showed criterion-related validity when correlated with job crafting (+), job resources (autonomy +; opportunities for professional development +), work engagement (+), and the inactive construct cynicism (-). We discuss the implications of these findings for theory and practice.

Diagnostics in a digital age: an opportunity to strengthen health systems and improve health outcomes.

PubMed

Peeling, Rosanna W

2015-11-01

Diagnostics play a critical role in clinical decision making, and in disease control and prevention. Rapid point-of-care (POC) tests for infectious diseases can improve access to diagnosis and patient management, but the quality of these tests vary, quality of testing is often not assured and there are few mechanisms to capture test results for surveillance when the testing is so decentralised. A new generation of POC molecular tests that are highly sensitive and specific, robust and easy to use are now available for deployment in low resource settings. Decentralisation of testing outside of the laboratory can put tremendous stress on the healthcare system and presents challenges for training and quality assurance. A feature of many of these POC molecular devices is that they are equipped with data transmission capacities. In a digital age, it is possible to link data from diagnostic laboratories and POC test readers and devices to provide data on testing coverage, disease trends and timely information for early warning of infectious disease outbreaks to inform design or optimisation of disease control and elimination programmes. Data connectivity also allows control programmes to monitor the quality of tests and testing, and optimise supply chain management; thus, increasing the efficiency of healthcare systems and improving patient outcomes. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Assessing the Risk of Contrast-Induced Nephropathy Using a Finger Stick Analysis in Recalls from Breast Screening: The CINFIBS Explorative Study.

PubMed

Houben, I P L; van Berlo, C J L Y; Bekers, O; Nijssen, E C; Lobbes, M B I; Wildberger, J E

2017-01-01

To evaluate whether a handheld point-of-care (POC) device is able to predict and discriminate patients at potential risk of contrast-induced nephropathy (CIN) prior to iodine-based contrast media delivery. Between December 2014 and June 2016, women undergoing contrast-enhanced spectral mammography (CESM) with an iodine-based contrast agent were asked to have their risk of CIN assessed by a dedicated POC device (StatSensor CREAT) and a risk factor questionnaire based on national guidelines. Prior to contrast injection, a venous blood sample was drawn to compare the results of POC with regular laboratory testing. A total of 351 patients were included; 344 were finally categorized as low risk patients by blood creatinine evaluation. Seven patients had a eGFR below 60 ml/min/1.73 m 2 , necessitating additional preparation prior to contrast delivery. The POC device failed to categorize six out of seven patients (86%), leading to (at that stage) unwanted contrast administration. Two patients subsequently developed CIN after 2-5 days, which was self-limiting after 30 days. The POC device tested was not able to reliably assess impairment of renal function in our patient cohort undergoing CESM. Consequently, we still consider classic clinical laboratory testing preferable in patients at potential risk for developing CIN.

Public health implications of molecular point-of-care testing for chlamydia and gonorrhoea in remote primary care services in Australia: a qualitative study.

PubMed

Natoli, L; Guy, R J; Shephard, M; Whiley, D; Tabrizi, S N; Ward, J; Regan, D G; Badman, S G; Anderson, D A; Kaldor, J; Maher, L

2015-04-28

With accurate molecular tests now available for diagnosis of chlamydia and gonorrhoea (Chlamydia trachomatis (CT)/Neisseria gonorrhoeae (NG)) at the point-of-care (POC), we aimed to explore the public health implications (benefits and barriers) of their integration into remote primary care in Australia. Qualitative interviews were conducted with a purposively selected group of 18 key informants reflecting sexual health, primary care, remote Aboriginal health and laboratory expertise. Participants believed that POC testing may decrease community prevalence of sexually transmitted infections (STIs), and associated morbidity by reducing the time to treatment and infectious period and expediting partner notification. Also, POC testing could improve acceptability of STI testing, increase testing coverage and result in more targeted prescribing, thereby minimising the risk of antibiotic resistance. Conversely, some felt the immediacy of diagnosis could deter certain young people from being tested. Participants also noted that POC testing may reduce the completeness of communicable disease surveillance data given the current dependence on reporting from pathology laboratories. Others expressed concern about the need to maintain and improve the flow of NG antibiotic sensitivity data, already compromised by the shift to nucleic acid-based testing. This is particularly relevant to remote areas where culture viability is problematic. Results indicate a high level of support from clinicians and public health practitioners for wider access to CT/NG POC tests citing potential benefits, including earlier, more accurate treatment decisions and reductions in ongoing transmission. However, the data also highlight the need for new systems to avoid adverse impact on disease surveillance. Australian and New Zealand Clinical Trials Registry: ACTRN12613000808741. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Portable devices and mobile instruments for infectious diseases point-of-care testing.

PubMed

Bissonnette, Luc; Bergeron, Michel G

2017-05-01

Rapidity, simplicity, and portability are highly desirable characteristics of tests and devices designed for performing diagnostics at the point of care (POC), either near patients managed in healthcare facilities or to offer bioanalytical alternatives in external settings. By reducing the turnaround time of the diagnostic cycle, POC diagnostics can reduce the dissemination, morbidity, and mortality of infectious diseases and provide tools to control the global threat of antimicrobial resistance. Areas covered: A literature search of PubMed and Google Scholar, and extensive mining of specialized publications, Internet resources, and manufacturers' websites have been used to organize and write this overview of the challenges and requirements associated with the development of portable sample-to-answer diagnostics, and showcase relevant examples of handheld devices, portable instruments, and less mobile systems which may or could be operated at POC. Expert commentary: Rapid (<1 h) diagnostics can contribute to control infectious diseases and antimicrobial resistant pathogens. Portable devices or instruments enabling sample-to-answer bioanalysis can provide rapid, robust, and reproducible testing at the POC or close from it. Beyond testing, to realize some promises of personalized/precision medicine, it will be critical to connect instruments to healthcare data management systems, to efficiently link decentralized testing results to the electronic medical record of patients.

Comparing the performance of circulating cathodic antigen and Kato-Katz techniques in evaluating Schistosoma mansoni infection in areas with low prevalence in selected counties of Kenya: a cross-sectional study.

PubMed

Okoyo, Collins; Simiyu, Elses; Njenga, Sammy M; Mwandawiro, Charles

2018-04-11

Kato-Katz technique has been the mainstay test in Schistosoma mansoni diagnosis in endemic areas. However, recent studies have documented its poor sensitivity in evaluating Schistosoma mansoni infection especially in areas with lower rates of transmission. It's the primary diagnostic tool in monitoring impact of the Kenya national school based deworming program on infection transmission, but there is need to consider a more sensitive technique as the prevalence reduces. Therefore, this study explored the relationship between results of the stool-based Kato-Katz technique with urine-based point-of-care circulating cathodic antigen (POC-CCA) test in view to inform decision-making by the program in changing from Kato-Katz to POC-CCA test. We used two cross-sectional surveys conducted pre- and post- mass drug administration (MDA) using praziquantel in a representative random sample of children from 18 schools across 11 counties. A total of 1944 children were randomly sampled for the study. Stool and urine samples were tested for S. mansoni infection using Kato-Katz and POC-CCA methods, respectively. S. mansoni prevalence using each technique was calculated and 95% confidence intervals obtained using binomial regression model. Specificity (Sp) and sensitivity (Sn) were determined using 2 × 2 contingency tables and compared using the McNemar's chi-square test. A total of 1899 and 1878 children were surveyed at pre- and post-treatment respectively. S. mansoni infection prevalence was 26.5 and 21.4% during pre- and post-treatment respectively using POC-CCA test, and 4.9 and 1.5% for pre- and post-treatment respectively using Kato-Katz technique. Taking POC-CCA as the gold standard, Kato-Katz was found to have significantly lower sensitivity both at pre- and post-treatment, Sn = 12.5% and Sn = 5.2% respectively, McNemar test χ 2 m  = 782.0, p < 0.001. In overall, the results showed a slight/poor agreement between the two methods, kappa index (k) = 0.11, p < 0.001, inter-rater agreement = 77.1%. Results showed POC-CCA technique as an effective, sensitive and accurate screening tool for Schistosoma mansoni infection in areas of low prevalence. It was up to 14-fold accurate than Kato-Katz which had extremely inadequate sensitivity. We recommend usage of POC-CCA alongside Kato-Katz examinations by Schistosomiasis control programs in low prevalence areas.

Screening method to evaluate point-of-care human chorionic gonadotropin (hCG) devices for susceptibility to the hook effect by hCG β core fragment: evaluation of 11 devices.

PubMed

Nerenz, Robert D; Song, Haowei; Gronowski, Ann M

2014-04-01

The predominant hCG variant in urine, hCG β core fragment (hCGβcf), has been demonstrated to cause false-negative results in qualitative point-of-care (POC) hCG devices. This is a major concern for healthcare professionals using POC pregnancy tests. We developed a screening method to evaluate qualitative POC hCG devices for their susceptibility to inhibition by hCGβcf. Using this method, we evaluated the performance of 11 commonly used devices. A wide range of purified hCG and hCGβcf concentrations were mixed and tested on 2 POC devices. By use of those results, a screening method was defined and 9 additional POC devices were evaluated. Two solutions containing (a) 500 pmol/L (171 IU/L) intact hCG with 0 pmol/L hCGβcf and (b) 500 pmol/L intact hCG with 500 000 pmol/L hCGβcf were used to screen all POC devices. The OSOM and Cen-Med Elite devices were found to be most susceptible to false-negative results due to hCGβcf. The BC Icon 20 and the Alere were the least susceptible. The remaining 7 were moderately affected. Devices that gave the strongest signal with hCGβcf alone were those that were least likely to show a hook effect. The screening method put forth here can be used by device users and manufacturers to evaluate POC devices for inhibition by hCGβcf. Of 11 devices evaluated, only 2 have been identified that exhibit minimal to no susceptibility to hCGβcf.

Effect of Point-of-Care Diagnostics on Maternal Outcomes in Human Immunodeficiency Virus–Infected Women: Systematic Review and Meta-analysis

PubMed Central

Mashamba-Thompson, Tivani P; Morgan, Rebecca L; Sartorius, Benn; Dennis, Brittany; Drain, Paul K; Thabane, Lehana

2017-01-01

Introduction The World Health Organization advocates for increased accessibility of HIV-related point-of-care (POC) diagnostics in settings that lack laboratory infrastructure. The aim of this study is to assess the impact of POC diagnostics on maternal health outcomes in HIV-infected women. Methods A systematic literature review used multiple data sources as follows: Cochrane Infectious Disease Group Specialized Register; Cochrane Central Register of Control Trials, published in The Cochrane Library; PubMed; EBSCOhost and LILACS from January 2000 to October 2015. References of included studies were hand searched. Randomized controlled trials (RCTs) and observational studies examining health outcomes of HIV-infected women were eligible for inclusion in this review. The Cochrane Risk of Bias tool was used for bias assessment of the included studies. PRISMA guidelines were used for reporting. Results Of the 695 studies identified, six retrievable studies (five cross-sectional studies and one case control study) met the inclusion criteria and were included in this study. These studies examined a total of 167 HIV-infected women in different study settings. No studies reported evidence of CD4 count, viral load and TB, and the syphilis POC test impact on HIV-infected women was not found by this study. Included studies reported the impact of various HIV rapid tests across the following five maternal outcomes: timely receipt of results with pooled effect size (ES) = 1.00 (95% confidence interval [CI]: (0.98; 1.02); enabling partner testing, ES = 0.95 (0.85; 1.04); prevention of mother-to-child transmission of HIV, ES = 0.86 (0.79; 0.93); linkage to antiretroviral treatment (ART), ES = 0.76 (0.69; 0.84); and linkage to HIV care, ES = 0.50 (0.18; 0.82). No studies reported evidence of the impact of POC testing on maternal mortality or maternal and child morbidity of HIV-infected women. Conclusions The review provides an international overview of the impact of HIV POC diagnostics on maternal outcomes in HIV-infected women, showing the evidence that the HIV POC test is significantly associated with decreased mother-to-child transmission of HIV and increased linkage to ART and HIV care for HIV-infected women. It also revealed a gap in the literature aimed at assessing the impact of POC diagnostics on maternal morbidity and mortality in HIV-infected women. PMID:29242711

Quality assurance for HIV point-of-care testing and treatment monitoring assays

PubMed Central

Sandstrom, Paul; Denny, Thomas N.; Hurlston, Mackenzie; Ball, Terry B.; Peeling, Rosanna W.; Boeras, Debrah I.

2016-01-01

In 2015, UNAIDS launched the 90-90-90 targets aimed at increasing the number of people infected with HIV to become aware of their status, access antiretroviral therapies and ultimately be virally suppressed. To achieve these goals, countries may need to scale up point-of-care (POC) testing in addition to strengthening central laboratory services. While decentralising testing increases patient access to diagnostics, it presents many challenges with regard to training and assuring the quality of tests and testing. To ensure synergies, the London School of Hygiene & Tropical Medicine held a series of consultations with countries with an interest in quality assurance and their implementing partners, and agreed on an external quality assessment (EQA) programme to ensure reliable results so that the results lead to the best possible care for HIV patients. As a result of the consultations, EQA International was established, bringing together EQA providers and implementers to develop a strategic plan for countries to establish national POC EQA programmes and to estimate the cost of setting up and maintaining the programme. With the dramatic increase in the number of proficiency testing panels required for thousands of POC testing sites across Africa, it is important to facilitate technology transfer from global EQA providers to a network of regional EQA centres in Africa for regional proficiency testing panel production. EQA International will continue to identify robust and cost-effective EQA technologies for quality POC testing, integrating novel technologies to support sustainable country-owned EQA programmes in Africa. PMID:28879133

Beyond syndromic management: Opportunities for diagnosis-based treatment of sexually transmitted infections in low- and middle-income countries.

PubMed

Garrett, Nigel J; Osman, Farzana; Maharaj, Bhavna; Naicker, Nivashnee; Gibbs, Andrew; Norman, Emily; Samsunder, Natasha; Ngobese, Hope; Mitchev, Nireshni; Singh, Ravesh; Abdool Karim, Salim S; Kharsany, Ayesha B M; Mlisana, Koleka; Rompalo, Anne; Mindel, Adrian

2018-01-01

In light of the limited impact the syndromic management approach has had on the global sexually transmitted infection (STI) epidemic, we assessed a care model comprising point-of-care (POC) STI testing, immediate treatment, and expedited partner therapy (EPT) among a cohort of young women at high HIV risk in South Africa. HIV negative women presenting for STI care underwent POC testing for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV), and swabs were sent for NG culture and susceptibility testing. Results were available within 2 hours and women with STIs were immediately treated and offered EPT packs, including medication, condoms, and information for sexual partners. An EPT questionnaire was administered after one week, and women retested for STIs after 6 and 12 weeks. 267 women, median age 23 (IQR 21-26), were recruited and 88.4% (236/267) reported genital symptoms. STI prevalence was CT 18.4% (95%CI 13.7-23.0), NG 5.2% (95%CI 2.6-7.9) and TV 3.0% (95%CI 1.0-5.0). After 12 weeks, all but one NG and two CT infections were cleared. No cephalosporin-resistant NG was detected. Of 63/267 women (23.6%) diagnosed with STIs, 98.4% (62/63) were offered and 87.1% (54/62) accepted EPT. At one week 88.9% (48/54) stated that their partner had taken the medication. No allergic reactions or social harms were reported. Of 51 women completing 6-week follow up, detection rates were lower amongst women receiving EPT (2.2%, 1/46) compared to those who did not (40.0%, 2/5), p = 0.023. During focus group discussions women supported the care model, because they received a rapid, specific diagnosis, and could facilitate their partners' treatment. POC STI testing and EPT were acceptable to young South African women and their partners, and could play an important role in reducing STI reinfection rates and HIV risk. Larger studies should evaluate the feasibility and cost-effectiveness of implementing this strategy at population level.

Beyond syndromic management: Opportunities for diagnosis-based treatment of sexually transmitted infections in low- and middle-income countries

PubMed Central

Osman, Farzana; Naicker, Nivashnee; Norman, Emily; Samsunder, Natasha; Ngobese, Hope; Mitchev, Nireshni; Singh, Ravesh; Kharsany, Ayesha B. M.

2018-01-01

Introduction In light of the limited impact the syndromic management approach has had on the global sexually transmitted infection (STI) epidemic, we assessed a care model comprising point-of-care (POC) STI testing, immediate treatment, and expedited partner therapy (EPT) among a cohort of young women at high HIV risk in South Africa. Methods and findings HIV negative women presenting for STI care underwent POC testing for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV), and swabs were sent for NG culture and susceptibility testing. Results were available within 2 hours and women with STIs were immediately treated and offered EPT packs, including medication, condoms, and information for sexual partners. An EPT questionnaire was administered after one week, and women retested for STIs after 6 and 12 weeks. 267 women, median age 23 (IQR 21–26), were recruited and 88.4% (236/267) reported genital symptoms. STI prevalence was CT 18.4% (95%CI 13.7–23.0), NG 5.2% (95%CI 2.6–7.9) and TV 3.0% (95%CI 1.0–5.0). After 12 weeks, all but one NG and two CT infections were cleared. No cephalosporin-resistant NG was detected. Of 63/267 women (23.6%) diagnosed with STIs, 98.4% (62/63) were offered and 87.1% (54/62) accepted EPT. At one week 88.9% (48/54) stated that their partner had taken the medication. No allergic reactions or social harms were reported. Of 51 women completing 6-week follow up, detection rates were lower amongst women receiving EPT (2.2%, 1/46) compared to those who did not (40.0%, 2/5), p = 0.023. During focus group discussions women supported the care model, because they received a rapid, specific diagnosis, and could facilitate their partners’ treatment. Conclusions POC STI testing and EPT were acceptable to young South African women and their partners, and could play an important role in reducing STI reinfection rates and HIV risk. Larger studies should evaluate the feasibility and cost-effectiveness of implementing this strategy at population level. PMID:29689080

Validation of a point-of-care (POC) lactate testing device for fetal scalp blood sampling during labor: clinical considerations, practicalities and realities.

PubMed

Reif, Philipp; Lakovschek, Ioanna; Tappauf, Carmen; Haas, Josef; Lang, Uwe; Schöll, Wolfgang

2014-06-01

Although fetal blood sampling for pH is well established the use of lactate has not been widely adopted. This study validated the performance and utility of a handheld point-of-care (POC) lactate device in comparison with the lactate and pH values obtained by the ABL 800 blood gas analyzer. The clinical performance and influences on accuracy and decision-making criteria were assessed with freshly taken fetal blood scalp samples (n=57) and umbilical cord samples (n=310). Bland-Altman plot was used for data plotting and analyzing the agreement between the two measurement devices and correlation coefficients (R²) were determined using Passing-Bablok regression analysis. Sample processing errors were much lower in the testing device (22.8% vs. 0.5%). Following a preclinical assessment and calibration offset alignment (0.5 mmol/L) the test POC device showed good correlation with the reference method for lactate FBS (R²=0.977, p<0.0001, 95% CI 0.9 59-0.988), arterial cord blood (R²=0.976, p<0.0001, 95% CI 0.967-0.983) and venous cord blood (R²=0.977, p<0.0001, 95% CI 0.968-0.984). A POC device which allows for a calibration adjustment to be made following preclinical testing can provide results that will correlate closely to an incumbent lactate method such as a blood gas analyzer. The use of a POC lactate device can address the impracticality and reality of pH sample collection and testing failures experienced in day to day clinical practice. For the StatStrip Lactate meter we suggest using a lactate cut-off of 5.1 mmol/L for predicting fetal acidosis (pH<7.20).

Vehicle infrastructure integration proof-of-concept results and findings--infrastructure : final report, volume 3B.

DOT National Transportation Integrated Search

2009-05-01

In 2005, the US Department of Transportation (DOT) initiated a program to develop and test a 5.9GHzbased : Vehicle Infrastructure Integration (VII) proof of concept (POC). The POC was implemented in the northwest : suburbs of Detroit, Michigan. Th...

Driver Performance and IVHS Collision Avoidance Systems: A Search for Design-Relevant Measurement Protocols

DOT National Transportation Integrated Search

1993-04-14

In 2005, the US Department of Transportation (DOT) initiated a program to develop and test a 5.9GHzbased Vehicle Infrastructure Integration (VII) proof of concept (POC). The POC was implemented in the northwest suburbs of Detroit, Michigan. This r...

Importance of Oceanian small mountainous rivers (SMRs) in global land-to-ocean output of lignin and modern biospheric carbon

PubMed Central

Bao, Hongyan; Lee, Tsung-Yu; Huang, Jr-Chuan; Feng, Xiaojuan; Dai, Minhan; Kao, Shuh-Ji

2015-01-01

The land-to-ocean export of particulate organic carbon (POC) connects carbon flow from the atmosphere through land to the ocean, of which the contemporary fraction that reaches the deep sea for burial may effectively affect atmospheric CO2. In this regard, small mountainous rivers (SMRs) in Oceania, a global erosion hotspot driven by torrential typhoon rain and active earthquakes are potentially important. Here we measured typhoon lignin discharges for Taiwan SMRs. We found that the particulate lignin export in 96 hours by a single SMR amounting to ~20% of the annual export by Mississippi River. The yearly particulate lignin discharge from Taiwan Island (35,980 km2) is governed by the frequency and magnitude of typhoon; thus, the historical lignin export ranged widely from 1.5 to 99.7 Gg yr−1, which resulted in a 10–100 times higher areal yield relative to non-Oceanian rivers. The lignin-derived modern POC output from Oceania region is 37 ± 21 Tg C yr−1, account for approximately 20% of the annual modern POC export from global rivers. Coupled with the hyperpycnal pathway, the forested watersheds of SMRs in Oceania may serve as a giant factory to rapidly produce and efficiently convey modern POC into deep sea for sequestration. PMID:26584586

Implementation and Operational Research: Cost and Efficiency of a Hybrid Mobile Multidisease Testing Approach With High HIV Testing Coverage in East Africa.

PubMed

Chang, Wei; Chamie, Gabriel; Mwai, Daniel; Clark, Tamara D; Thirumurthy, Harsha; Charlebois, Edwin D; Petersen, Maya; Kabami, Jane; Ssemmondo, Emmanuel; Kadede, Kevin; Kwarisiima, Dalsone; Sang, Norton; Bukusi, Elizabeth A; Cohen, Craig R; Kamya, Moses; Havlir, Diane V; Kahn, James G

2016-11-01

In 2013-2014, we achieved 89% adult HIV testing coverage using a hybrid testing approach in 32 communities in Uganda and Kenya (SEARCH: NCT01864603). To inform scalability, we sought to determine: (1) overall cost and efficiency of this approach; and (2) costs associated with point-of-care (POC) CD4 testing, multidisease services, and community mobilization. We applied microcosting methods to estimate costs of population-wide HIV testing in 12 SEARCH trial communities. Main intervention components of the hybrid approach are census, multidisease community health campaigns (CHC), and home-based testing for CHC nonattendees. POC CD4 tests were provided for all HIV-infected participants. Data were extracted from expenditure records, activity registers, staff interviews, and time and motion logs. The mean cost per adult tested for HIV was $20.5 (range: $17.1-$32.1) (2014 US$), including a POC CD4 test at $16 per HIV+ person identified. Cost per adult tested for HIV was $13.8 at CHC vs. $31.7 by home-based testing. The cost per HIV+ adult identified was $231 ($87-$1245), with variability due mainly to HIV prevalence among persons tested (ie, HIV positivity rate). The marginal costs of multidisease testing at CHCs were $1.16/person for hypertension and diabetes, and $0.90 for malaria. Community mobilization constituted 15.3% of total costs. The hybrid testing approach achieved very high HIV testing coverage, with POC CD4, at costs similar to previously reported mobile, home-based, or venue-based HIV testing approaches in sub-Saharan Africa. By leveraging HIV infrastructure, multidisease services were offered at low marginal costs.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, L; Han, Y; Jin, M

Purpose: To develop an iterative reconstruction method for X-ray CT, in which the reconstruction can quickly converge to the desired solution with much reduced projection views. Methods: The reconstruction is formulated as a convex feasibility problem, i.e. the solution is an intersection of three convex sets: 1) data fidelity (DF) set – the L2 norm of the difference of observed projections and those from the reconstructed image is no greater than an error bound; 2) non-negativity of image voxels (NN) set; and 3) piecewise constant (PC) set - the total variation (TV) of the reconstructed image is no greater thanmore » an upper bound. The solution can be found by applying projection onto convex sets (POCS) sequentially for these three convex sets. Specifically, the algebraic reconstruction technique and setting negative voxels as zero are used for projection onto the DF and NN sets, respectively, while the projection onto the PC set is achieved by solving a standard Rudin, Osher, and Fatemi (ROF) model. The proposed method is named as full sequential POCS (FS-POCS), which is tested using the Shepp-Logan phantom and the Catphan600 phantom and compared with two similar algorithms, TV-POCS and CP-TV. Results: Using the Shepp-Logan phantom, the root mean square error (RMSE) of reconstructed images changing along with the number of iterations is used as the convergence measurement. In general, FS- POCS converges faster than TV-POCS and CP-TV, especially with fewer projection views. FS-POCS can also achieve accurate reconstruction of cone-beam CT of the Catphan600 phantom using only 54 views, comparable to that of FDK using 364 views. Conclusion: We developed an efficient iterative reconstruction for sparse-view CT using full sequential POCS. The simulation and physical phantom data demonstrated the computational efficiency and effectiveness of FS-POCS.« less

Cost and efficiency of a hybrid mobile multi-disease testing approach with high HIV testing coverage in East Africa

PubMed Central

Chang, Wei; Chamie, Gabriel; Mwai, Daniel; Clark, Tamara D.; Thirumurthy, Harsha; Charlebois, Edwin D.; Petersen, Maya; Kabami, Jane; Ssemmondo, Emmanuel; Kadede, Kevin; Kwarisiima, Dalsone; Sang, Norton; Bukusi, Elizabeth A.; Cohen, Craig R.; Kamya, Moses; Havlir, Diane V.; Kahn, James G.

2016-01-01

Background In 2013-14, we achieved 89% adult HIV testing coverage using a hybrid testing approach in 32 communities in Uganda and Kenya (SEARCH: NCT01864603). To inform scalability, we sought to determine: 1) overall cost and efficiency of this approach; and 2) costs associated with point-of-care (POC) CD4 testing, multi-disease services, and community mobilization. Methods We applied micro-costing methods to estimate costs of population-wide HIV testing in 12 SEARCH Trial communities. Main intervention components of the hybrid approach are census, multi-disease community health campaigns (CHC), and home-based testing (HBT) for CHC non-attendees. POC CD4 tests were provided for all HIV-infected participants. Data were extracted from expenditure records, activity registers, staff interviews, and time and motion logs. Results The mean cost per adult tested for HIV was $20.5 (range: $17.1 - $32.1) [2014 US$], including a POC CD4 test at $16 per HIV+ person identified. Cost per adult tested for HIV was $13.8 at CHC vs. $31.7 via HBT. The cost per HIV+ adult identified was $231 ($87 - $1,245), with variability due mainly to HIV prevalence among persons tested (i.e., HIV positivity rate). The marginal costs of multi-disease testing at CHCs were $1.16/person for hypertension and diabetes, and $0.90 for malaria. Community mobilization constituted 15.3% of total costs. Conclusions The hybrid testing approach achieved very high HIV testing coverage, with POC CD4, at costs similar to previously reported mobile, home-based, or venue-based HIV testing approaches in sub-Saharan Africa. By leveraging HIV infrastructure, multi-disease services were offered at low marginal costs. PMID:27741031

Point-of-Care Coagulation Monitoring in Trauma Patients.

PubMed

Stein, Philipp; Kaserer, Alexander; Spahn, Gabriela H; Spahn, Donat R

2017-06-01

Trauma remains one of the major causes of death and disability all over the world. Uncontrolled blood loss and trauma-induced coagulopathy represent preventable causes of trauma-related morbidity and mortality. Treatment may consist of allogeneic blood product transfusion at a fixed ratio or in an individualized goal-directed way based on point-of-care (POC) and routine laboratory measurements. Viscoelastic POC measurement of the developing clot in whole blood and POC platelet function testing allow rapid and tailored coagulation and transfusion treatment based on goal-directed, factor concentrate-based algorithms. The first studies have been published showing that this concept reduces the need for allogeneic blood transfusion and improves outcome. This review highlights the concept of goal-directed POC coagulation management in trauma patients, introduces a selection of POC devices, and presents algorithms which allow a reduction in allogeneic blood product transfusion and an improvement of trauma patient outcome. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

The economic costs of routine INR monitoring in infants and children--examining point-of-care devices used within the home setting compared to traditional anticoagulation clinic monitoring.

PubMed

Gaw, James R; Crowley, Steven; Monagle, Paul; Jones, Sophie; Newall, Fiona

2013-07-01

The use of point-of-care (POC) devices within the home for routine INR monitoring has demonstrated reliability, safety and effectiveness in the management of infants and children requiring long-term warfarin therapy. However, a comprehensive cost-analysis of using this method of management, compared to attending anticoagulation clinics has not been reported. The aim of this study was to compare the estimated societal costs of attending anticoagulation clinics for routine INR monitoring to using a POC test in the home. This study used a comparative before-and-after design that included 60 infants and children managed via the Haematology department at a tertiary paediatric centre. Each participant was exposed to both modes of management at various times for a period of ≥3 months. A questionnaire, consisting of 25 questions was sent to families to complete and return. Data collected included: the frequency of monitoring, mode of travel to and from clinics, total time consumed, and primary carer's income level. The home monitoring cohort saved a total of 1 hour 19 minutes per INR test compared to attending anticoagulation clinics and had a cost saving to society of $66.83 (AUD) per INR test compared to traditional care; incorporating health sector costs, travel expenses and lost time. The traditional model of care requires a considerable investment of time per test from both child and carer. Home INR monitoring in infants and children provides greater societal economic benefits compared to traditional models. Copyright © 2013 Elsevier Ltd. All rights reserved.

Development and fate of the postovulatory follicle complex, postovulatory follicle, and observations on folliculogenesis and oocyte atresia in ovulated common snook, Centropomus undecimalis (Bloch, 1792).

PubMed

Grier, Harry J; Neidig, Carole L; Quagio-Grassiotto, Irani

2017-04-01

The common snook, Centropomus undecimalis, was induced to ovulate using a time-release, GnRH analogue. Ovulation occurred the afternoon or evening the day after hormone administration. The time of ovulation was established within half an hour. At ovulation, three fish per time-group were divided into 0, 6, 12, 18 hr and one thru five days post-ovulation to study changes in the postovulatory follicle complex (POC). Histology of the ovaries revealed changes in the POC, postovulatory follicle (POF) and oocyte atresia through five days post-ovulation. Within 24 hr, nuclei of the POF cells lost their initial spherical or oval configuration, and by four days the basement membrane within the POC had fragmented. There was a temporal separation between ovulation and post-ovulation folliculogenesis; that is, in that the formation of new follicles commenced within the germinal epithelium between 12-48 hrs after ovulation. Morphology of the POC was best revealed with the reticulin stain; it is composed of the POF and postovulatory theca (POT). These are separated by a basement membrane, reflecting the origin of a follicle from a germinal epithelium while the theca is derived from stroma. The POF is composed of the former follicle cells that surrounded and contacted the oocyte during its development; the follicle is composed of the oocyte and its surrounding follicle cells. The POC is composed of a prominent basement membrane separating the POT from the POF. The reticulin stain clearly defines compartmentation in the ovary and supports redefinition of the POF as the follicle cells that formerly surrounded the oocyte prior to ovulation. J. Morphol. 278:547-562, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Cost-effectiveness analysis of early point-of-care lactate testing in the emergency department.

PubMed

Ward, Michael J; Self, Wesley H; Singer, Adam; Lazar, Danielle; Pines, Jesse M

2016-12-01

To determine the cost-effectiveness of implementing a point-of-care (POC) Lactate Program in the emergency department (ED) for patients with suspected sepsis to identify patients who can benefit from early resuscitation. We constructed a cost-effectiveness model to examine an ED with 30 000 patients annually. We evaluated a POC lactate program screening patients with suspected sepsis for an elevated lactate ≥4 mmol/L. Those with elevated lactate levels are resuscitated and their lactate clearance is evaluated by serial POC lactate measurements. The POC Lactate Program was compared with a Usual Care Strategy in which all patients with sepsis and an elevated lactate are admitted to the intensive care unit. Costs were estimated from the 2014 Medicare Inpatient and National Physician Fee schedules, and hospital and industry estimates. In the base-case, the POC Lactate Program cost $39.53/patient whereas the Usual Care Strategy cost $33.20/patient. The screened patients in the POC arm resulted in 1.07 quality-adjusted life years for an incremental cost-effectiveness ratio of $31 590 per quality-adjusted life year gained, well below accepted willingness-to-pay-thresholds. Implementing a POC Lactate Program for screening ED patients with suspected sepsis is a cost-effective intervention to identify patients responsive to early resuscitation. Copyright © 2016 Elsevier Inc. All rights reserved.

Integrated network modelling for identifying microbial mechanisms of particulate organic carbon accumulation in coastal marine systems

NASA Astrophysics Data System (ADS)

McDonald, Karlie; Turk, Valentina; Mozetič, Patricija; Tinta, Tinkara; Malfatti, Francesca; Hannah, David; Krause, Stefan

2016-04-01

Accumulation of particulate organic carbon (POC) has the potential to change the structure and function of marine ecosystems. High abidance of POC can develop into aggregates, known as marine snow or mucus aggregates that can impair essential marine ecosystem functioning and services. Currently marine POC formation, accumulation and sedimentation processes are being explored as potential pathways to remove CO2 from the atmosphere by CO2 sequestration via fixation into biomass by phytoplankton. However, the current ability of scientists, environmental managers and regulators to analyse and predict high POC concentrations is restricted by the limited understanding of the dynamic nature of the microbial mechanisms regulating POC accumulation events in marine environments. We present a proof of concept study that applies a novel Bayesian Networks (BN) approach to integrate relevant biological and physical-chemical variables across spatial and temporal scales in order to identify the interactions of the main contributing microbial mechanisms regulating POC accumulation in the northern Adriatic Sea. Where previous models have characterised only the POC formed, the BN approach provides a probabilistic framework for predicting the occurrence of POC accumulation by linking biotic factors with prevailing environmental conditions. In this paper the BN was used to test three scenarios (diatom, nanoflagellate, and dinoflagellate blooms). The scenarios predicted diatom blooms to produce high chlorophyll a at the water surface while nanoflagellate blooms were predicted to occur at lower depths (> 6m) in the water column and produce lower chlorophyll a concentrations. A sensitivity analysis identified the variables with the greatest influence on POC accumulation being the enzymes protease and alkaline phosphatase, which highlights the importance of microbial community interactions. The developed proof of concept BN model allows for the first time to quantify the impacts of biological, chemical and physical parameters influencing microbial community interactions mechanisms that regulate POC accumulation in marine environments. The dynamic modular nature of the developed BN will allow successive updating and improvement of the model structure as new data are emerging, thus, providing a powerful interactive framework for the investigation, prediction and mitigation of future POC accumulation events.

Cross-sectional comparison of point-of-care with laboratory HbA1c in detecting diabetes in real-world remote Aboriginal settings

PubMed Central

Marley, Julia V; Oh, May S; Hadgraft, Nyssa; Singleton, Sally; Isaacs, Kim; Atkinson, David

2015-01-01

Objectives To determine if point-of-care (POC) glycated haemoglobin (HbA1c) is sufficiently accurate in real-world remote settings to predict or exclude the diagnosis of diabetes based on laboratory HbA1c measurements. Design Cross-sectional study comparing POC capillary HbA1c results with corresponding venous HbA1c levels measured in a reference laboratory. Participants Aboriginal patients ≥15 years old who were due for diabetes screening at the participating clinics were invited to participate. Two hundred and fifty-five Aboriginal participants were enrolled and 241 were included in the analysis. Setting 6 primary healthcare sites in the remote Kimberley region of Western Australia from September 2011 to November 2013. Main outcome measures Concordance and mean differences between POC capillary blood HbA1c measurement and laboratory measurement of venous blood HbA1c level; POC capillary blood HbA1c equivalence value for screening for diabetes or a high risk of developing diabetes; sensitivity, specificity and positive-predictive value for diagnosing and screening for diabetes; barriers to conducting POC testing. Results Concordance between POC and laboratory results was good (ρ=0.88, p<0.001). The mean difference was −0.15% (95% limits of agreement, −0.67% to 0.36%). POC HbA1c measurements ≥6.5%, 48 mmol/mol had a specificity of 98.2% and sensitivity of 73.7% for laboratory measurements ≥6.5%. The POC equivalence value for screening for diabetes or a high risk of developing diabetes was ≥5.7%, 39 mmol/mol (sensitivity, 91%; specificity, 76.7% for laboratory measurements ≥6.0%, 42 mmol/mol). Staff trained by other clinic staff ‘on the job’ performed as well as people with formal accredited training. Staff reported difficulty in maintaining formal accreditation. Conclusions POC HbA1c testing is sufficiently accurate to be a useful component in screening for, and diagnosing, diabetes in remote communities. Limited local training is adequate to produce results comparable to laboratory results and accreditation processes need to reflect this. PMID:25765020

Does provision of point-of-care CD4 technology and early knowledge of CD4 levels affect early initiation and retention on antiretroviral treatment in HIV-positive pregnant women in the context of Option B+ for PMTCT?

PubMed

Mangwiro, Alexio-Zambezi; Makomva, Kudzai; Bhattacharya, Antoinette; Bhattacharya, Gaurav; Gotora, Tendai; Owen, Mila; Mushavi, Angela; Mangwanya, Douglas; Zinyowera, Sekesai; Rusakaniko, Simbarashe; Mugurungi, Owen; Zizhou, Simukai; Busumani, William; Masuka, Nyasha

2014-11-01

Evidence for Elimination (E4E) is a collaborative project established in 2012 as part of the INSPIRE (INtegrating and Scaling up PMTCT through Implementation REsearch) initiative. E4E is a cluster-randomized trial with 2 arms; Standard of care and "POC Plus" [in which point-of-care (POC) CD4 devices and related counseling support are provided]; aimed at improving retention-in-care of HIV-infected pregnant women and mothers. In November 2013, Zimbabwe adopted Option B+ for HIV-positive pregnant women under which antiretroviral treatment eligibility is no longer based on CD4 count. However, Ministry of Health and Child Care guidelines still require baseline and 6-monthly CD4 testing for treatment monitoring, until viral load testing becomes widely available. Considering the current limited capacity for viral-load testing, the significant investments in CD4 testing already made and the historical reliance on CD4 by health care workers for determining eligibility for antiretroviral treatment, E4E seeks to compare the impact of the provision of POC CD4 technology and early knowledge of CD4 levels on retention-in-care at 12 months, with the current standard of routine, laboratory-based CD4 testing. The study also compares rates of initiation and time-to-initiation between the 2 arms and according to level of maternal CD4 count, the cost of retaining HIV-positive pregnant women in care and the acceptability and feasibility of POC CD4 in the context of Option B+. Outcome measures are derived from routine health systems data. E4E will provide data on POC CD4 testing and retention-in-care associated with Option B+ and serve as an early learning platform to inform implementation of Option B+ in Zimbabwe.

Perception of competence in middle school physical education: instrument development and validation.

PubMed

Scrabis-Fletcher, Kristin; Silverman, Stephen

2010-03-01

Perception of Competence (POC) has been studied extensively in physical activity (PA) research with similar instruments adapted for physical education (PE) research. Such instruments do not account for the unique PE learning environment. Therefore, an instrument was developed and the scores validated to measure POC in middle school PE. A multiphase design was used consisting of an intensive theoretical review, elicitation study, prepilot study, pilot study, content validation study, and final validation study (N=1281). Data analysis included a multistep iterative process to identify the best model fit. A three-factor model for POC was tested and resulted in root mean square error of approximation = .09, root mean square residual = .07, goodness offit index = .90, and adjusted goodness offit index = .86 values in the acceptable range (Hu & Bentler, 1999). A two-factor model was also tested and resulted in a good fit (two-factor fit indexes values = .05, .03, .98, .97, respectively). The results of this study suggest that an instrument using a three- or two-factor model provides reliable and valid scores ofPOC measurement in middle school PE.

Long-Term Performance of Point-of-Care Hemoglobin A1c Assays

PubMed Central

Paknikar, Sujaytha; Sarmah, Rohan; Sivaganeshan, Losika; Welke, Adam; Rizzo, Al; Larson, Kirk; Rendell, Marc

2016-01-01

Background: Point-of-care (POC) testing of HbA1c is used as a time-efficient tool to improve treatment and management planning for diabetes in the clinic setting. HbA1c values are the basis for monitoring ongoing response to treatment and to make adjustments to diabetes therapy. Yet, there is ongoing controversy as to the accuracy of POC assays. Diabetes is a lifelong disease, so comparability of results over a long period of time is needed to follow the response to treatment. Methods: We compared the Afinion™ automated boronate affinity assay and the DCA Vantage immunoassay-based POC techniques to the Tosoh G8 and Bio-Rad Variant II ion-exchange high-performance liquid chromatography (HPLC) central laboratory methods in a study lasting 3 years. College of American Pathology Survey results and American Proficiency testing were utilized to assess the external validity of the POC techniques. Results: Despite high correlations among the 4 techniques, there were significant and variable differences obtained over time. The Biorad values varied from 0.1 to 0.4% higher than the Afinion values. The DCA results were usually higher than the Afinion values, but fell below the Afinion results in the last 6 months of our study. Both POC techniques gave systematically lower values than the Tosoh measurements, and both the POC and the central laboratory measurements showed variable differences from the National Glycohemoglobin Standardization Program values over the duration of this study. Conclusions: All who rely on POC methods as well as on central laboratory measurement of HbA1c must understand the potential limitations of these assays. The assessment of diabetes blood sugar control should proceed from the evaluation of HbA1c combined with review of plasma glucose and of self-monitored blood glucose values. PMID:27113451

Optical systems for point-of-care diagnostic instrumentation: analysis of imaging performance and cost.

PubMed

Pierce, Mark C; Weigum, Shannon E; Jaslove, Jacob M; Richards-Kortum, Rebecca; Tkaczyk, Tomasz S

2014-01-01

One of the key elements in point-of-care (POC) diagnostic test instrumentation is the optical system required for signal detection and/or imaging. Many tests which use fluorescence, absorbance, or colorimetric optical signals are under development for management of infectious diseases in resource limited settings, where the overall size and cost of the device is of critical importance. At present, high-performance lenses are expensive to fabricate and difficult to obtain commercially, presenting barriers for developers of in vitro POC tests or microscopic image-based diagnostics. We recently described a compact "hybrid" objective lens incorporating both glass and plastic optical elements, with a numerical aperture of 1.0 and field-of-view of 250 μm. This design concept may potentially enable mass-production of high-performance, low-cost optical systems which can be easily incorporated in the readout path of existing and emerging POC diagnostic assays. In this paper, we evaluate the biological imaging performance of these lens systems in three broad POC diagnostic application areas; (1) bright field microscopy of histopathology slides, (2) cytologic examination of blood smears, and (3) immunofluorescence imaging. We also break down the fabrication costs and draw comparisons with other miniature optical systems. The hybrid lenses provided images with quality comparable to conventional microscopy, enabling examination of neoplastic pathology and infectious parasites including malaria and cryptosporidium. We describe how these components can be produced at below $10 per unit in full-scale production quantities, making these systems well suited for use within POC diagnostic instrumentation.

Measuring the Processes of Change From the Transtheoretical Model for Physical Activity and Exercise in Overweight and Obese Adults.

PubMed

Romain, Ahmed Jerôme; Bernard, Paquito; Hokayem, Marie; Gernigon, Christophe; Avignon, Antoine

2016-03-01

This study aimed to test three factorial structures conceptualizing the processes of change (POC) from the transtheoretical model and to examine the relationships between the POC and stages of change (SOC) among overweight and obese adults. Cross-sectional study. This study was conducted at the University Hospital of Montpellier, France. A sample of 289 overweight or obese participants (199 women) was enrolled in the study. Participants completed the POC and SOC questionnaires during a 5-day hospitalization for weight management. Structural equation modeling was used to compare the different factorial structures. The unweighted least-squares method was used to identify the best-fit indices for the five fully correlated model (goodness-of-fit statistic = .96; adjusted goodness-of-fit statistic = .95; standardized root mean residual = .062; normed-fit index = .95; parsimonious normed-fit index = .83; parsimonious goodness-of-fit statistic = .78). The multivariate analysis of variance was significant (p < .001). A post hoc test showed that individuals in advanced SOC used more of both experiential and behavioral POC than those in preaction stages, with effect sizes ranging from .06 to .29. This study supports the validity of the factorial structure of POC concerning physical activity and confirms the assumption that, in this context, people with excess weight use both experiential and behavioral processes. These preliminary results should be confirmed in a longitudinal study. © The Author(s) 2016.

Clinical validation of a point-of-care multiplexed in vitro immunoassay using monoclonal antibodies (the MSD influenza test) in four hospitals in Vietnam.

PubMed

van Doorn, H Rogier; Kinh, Nguyen van; Tuan, Ha Manh; Tuan, Tran Anh; Minh, Ngo Ngoc Quang; Bryant, Juliet E; Hang, Vu thi Ty; Uyen, Le thi Tham; Thinh, Le Quoc; Anh, Tran thi Ngoc; Lan, Nguyen Phu Huong; Trung, Nguyen Vu; Taylor, Walter; Merson, Laura; Wertheim, Heiman F L; Farrar, Jeremy; Wolbers, Marcel; Chau, Nguyen van Vinh; de Jong, Menno D

2012-05-01

Point-of-care (POC) diagnostic tests for influenza can considerably shorten the time to clinical decision making. An investigational POC test based on a multiplexed immunoassay was developed by Meso Scale Diagnostics, LLC (MSD), with the objective to make a more sensitive rapid test that can also subtype influenza A viruses (1977 H1, H3, and H5). Between February and November 2010, we conducted a prospective multicenter study at four hospitals in Vietnam and compared the performance of this test to that of the WHO/CDC real-time reverse transcriptase PCR (RT-PCR) on nasal and throat swab specimens from patients presenting with influenza-like illness. Five hundred sixty-three adults and children with a median age of 25 months were enrolled. Sensitivity and specificity of the test with combined results from nasal and throat swab samples were 74.0% (131/177) and 99.7% (351/352), respectively, compared to RT-PCR. The POC test was as sensitive for influenza virus B as for influenza virus A (74.4% [64/86] versus 73.6% [67/91]). The positivity rate was associated with lower cycle threshold values (a marker for higher viral loads), sample type (73.6% for nasal swab versus 52.4% for throat swab), and younger age. A total of 210 (18.7%) out of 1,126 MSD tests failed, and for 34 (6%) of patients, both test samples failed (these were excluded from the performance analysis). Subtyping could be assessed only for influenza virus A/H3N2, as 1977 H1N1 was not circulating at the time and no H5N1-infected patients were enrolled, and was successful only in 9/54 patients infected with H3 influenza virus who had a positive POC test result for influenza virus A. This novel POC test provided highly sensitive detection of influenza viruses A and B compared to the reported sensitivities of other rapid tests. However, 18.7% of tests failed for technical reasons and subtyping for H3 was poor. Drawbacks to the technology include the requirement for a dedicated reader instrument and the need for continual updating of subtyping antibodies within the test array.

Analytical sensitivity of four commonly used hCG point of care devices.

PubMed

Kamer, Sandy M; Foley, Kevin F; Schmidt, Robert L; Greene, Dina N

2015-04-01

Point of care (POC) hCG assays are often used to rule-out pregnancy and therefore diagnostic sensitivity, especially at low concentrations of hCG, is important. There are very few studies in the literature that seek to verify the claimed analytical sensitivity of hCG POC devices. The analytical sensitivity of four commonly used hCG POC devices (Alere hCG Combo Cassette, ICON 20 hCG, OSOM hCG Combo Test, and Sure-Vue Serum/Urine hCG-STAT) was challenged using urine samples (n=50) selected based on quantitative hCG concentrations. The majority of these specimens (n=40) had an hCG concentration between 20 and 200 U/L. Each specimen/device combination was reviewed by three individuals. Statistical calculations were performed using Stata 12. The analytical sensitivity of the OSOM was significantly lower inferior than that of the other POC devices. There was no significant difference in the sensitivity of the Alere, ICON 20 and Sure-Vue devices. There was no significant difference in the individual interpretation of the hCG POC results. All hCG POC devices evaluated in this study were susceptible to false negative results at low concentrations of urine hCG. Laboratorians and clinicians should be aware that there are limitations when using urine hCG POC devices to rule out early pregnancy. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Investigation of an N-Terminal Prohormone of Brain Natriuretic Peptide Point-of-Care ELISA in Clinically Normal Cats and Cats With Cardiac Disease.

PubMed

Harris, A N; Beatty, S S; Estrada, A H; Winter, B; Bohannon, M; Sosa, I; Hanscom, J; Mainville, C A; Gallagher, A E

2017-07-01

N-terminal prohormone of brain natriuretic peptide (NT-proBNP) concentrations may be increased in cats with various cardiac disorders. The point-of-care (POC) ELISA assay uses the same biologic reagents as the quantitative NT-proBNP ELISA. Previous studies have evaluated the sensitivity and specificity of the POC ELISA in cats with cardiac disease. To prospectively evaluate the diagnostic utility of the POC ELISA in a select population of cats. Thirty-eight client-owned cats presented to the University of Florida Cardiology Service for cardiac evaluation. Fifteen apparently healthy cats recruited as part of another study. Physical examination and echocardiography were performed in all cats. The POC ELISA was assessed visually as either positive or negative by a reader blinded to the echocardiographic findings, and results were analyzed relative to quantitative assay results. Twenty-six cats were diagnosed with underlying cardiac disease, and 27 cats were considered free of cardiac disease. Cats with cardiac disease included: 21 with hypertrophic cardiomyopathy, 2 with unclassified cardiomyopathy, 2 with restrictive cardiomyopathy, and 1 with 3rd degree atrioventricular (AV) block. The POC ELISA differentiated cats with cardiac disease with a sensitivity of 65.4% and specificity of 100%. The POC NT-proBNP ELISA performed moderately well in a selected population of cats. A negative test result cannot exclude the presence of underlying cardiac disease, and a positive test result indicates that cardiac disease likely is present, but further diagnostic investigation would be indicated for a definitive diagnosis. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Analytical performance of three whole blood point-of-care lactate devices compared to plasma lactate comparison methods and a flow-injection mass spectrometry method.

PubMed

Tolan, Nicole V; Wockenfus, Amy M; Koch, Christopher D; Crews, Bridgit O; Dietzen, Dennis J; Karon, Brad S

2017-03-01

Point of care (POC) whole blood lactate testing may facilitate rapid detection of sepsis. We evaluated three POC methods against both plasma lactate comparison methods and a flow-injection mass spectrometric (MS) method. Nova StatStrip, Abbott i-STAT CG4+ and Radiometer ABL90 POC lactate methods were evaluated against the mean of Cobas Integra 400 and Vitros 350 plasma lactate. POC methods were also compared to a flow-injection mass spectrometric assay measuring lactate in ZnSO 4 -precipitated whole blood extracts. Intra- and inter-assay precision was determined using quality control material. Method comparison included specimens from normal donors at rest, after exertion, and after spiking with lactic acid. Intra- and inter-assay coefficient of variation was <5% for i-STAT and ABL90; but ranged from 3.1-8.2% on two StatStrip meters. Mean (±SD) bias between POC and plasma lactate ranged from -0.2±0.9 (i-STAT and ABL90) to -0.4±1.2 (StatStrip) mmol/L. At concentrations >6mmol/L, all POC methods showed proportional negative bias compared to plasma methods; but this bias was not observed when compared to the MS method. Despite proportional negative bias, all POC methods demonstrated acceptable concordance (94-100%) with plasma lactate within the reference interval (<2.3mmol/L) and >4mmol/L, commonly used clinical cut-offs for detection of sepsis. POC lactate methods demonstrate acceptable concordance with plasma lactate across commonly used clinical cut-offs for detection of sepsis. Due to systematic negative bias at higher lactate concentrations, POC and plasma lactate should not be used interchangeably to monitor patients with elevated lactate concentrations. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Portable oxygen concentrators versus oxygen cylinder during walking in interstitial lung disease: A randomized crossover trial.

PubMed

Khor, Yet H; McDonald, Christine F; Hazard, Anita; Symons, Karen; Westall, Glen; Glaspole, Ian; Goh, Nicole S L; Holland, Anne E

2017-11-01

Ambulatory oxygen therapy is often provided to patients with interstitial lung disease (ILD). Lightweight portable oxygen concentrators (POCs) provide an alternative to traditional portable systems such as compressed oxygen cylinders; however, their efficacy in patients with ILD has not been assessed. This study aimed to evaluate the clinical performance of three ambulatory oxygen systems (two different POCs and a compressed oxygen cylinder) during 6-min walk tests (6MWTs) in patients with ILD and exertional desaturation. A total of 20 participants with ILD of varying aetiologies who demonstrated exertional desaturation to <90% on room air during 6MWT were recruited. Each participant performed two 6MWTs while breathing room air. On a subsequent day, two further 6MWTs were performed, in random order: one breathing oxygen via a POC (either the Inogen One G2 POC or the EverGo POC at the setting of 6) and one with a compressed oxygen cylinder (at 5 L/min). There were no significant differences in nadir oxygen saturation (SpO 2 ) during 6MWTs using different portable oxygen devices (Trial 1: mean SpO 2 for Inogen One G2 POC: 82.3 ± 3.5% vs oxygen cylinder: 80.3 ± 2.2%, P = 0.14; Trial 2: mean SpO 2 for EverGo POC: 85.7 ± 7.7% vs oxygen cylinder: 86.1 ± 6.1%, P = 0.79). The mean 6-min walk distances were not significantly different among the three devices. The performance of the Inogen One G2 POC and the EverGo POC had comparable performance with that of the compressed oxygen cylinder during walking in patients with ILD and exertional desaturation. © 2017 Asian Pacific Society of Respirology.

Validation of a new point-of-care assay for determination of β-carotene concentration in bovine whole blood and plasma.

PubMed

Raila, Jens; Enjalbert, Francis; Mothes, Ralf; Hurtienne, Andrea; Schweigert, Florian J

2012-03-01

β-Carotene is an important precursor of vitamin A, and is associated with bovine fertility. β-Carotene concentrations in plasma are used to optimize β-carotene supplementation in cattle, but measurement requires specialized equipment to separate plasma and extract and measure β-carotene, either using spectrophotometry or high performance liquid chromatography (HPLC). The objective of this study was to validate a new 2-step point-of-care (POC) assay for measuring β-carotene in whole blood and plasma. β-carotene concentrations in plasma from 166 cows were measured using HPLC and compared with results obtained using a POC assay, the iCheck-iEx-Carotene test kit. Whole blood samples from 23 of these cattle were also evaluated using the POC assay and compared with HPLC-plasma results from the same 23 animals. The POC assay includes an extraction vial (iEx Carotene) and hand-held photometer (iCheck Carotene). Concentrations of β-carotene in plasma measured using the POC assay ranged from 0.40 to 15.84 mg/L (n = 166). No differences were observed between methods for assay of plasma (mean ± SD; n = 166): HPLC-plasma 4.23 ± 2.35 mg/L; POC-plasma 4.49 ± 2.36 mg/L. Similar good agreement was found when plasma analyzed using HPLC was compared with whole blood analyzed using the POC system (n = 23): HPLC-plasma 3.46 ± 2.12 mg/L; POC-whole blood 3.67 ± 2.29 mg/L. Concentrations of β-carotene can be measured in blood and plasma from cattle easily and rapidly using a POC assay, and results are comparable to those obtained by the highly sophisticated HPLC method. Immediate feedback regarding β-carotene deficiency facilitates rapid and appropriate optimization of β-carotene supplementation in feed. © 2012 American Society for Veterinary Clinical Pathology.

Utility of point of care test devices for infectious disease testing of blood and oral fluid and application to rapid testing in the field

NASA Astrophysics Data System (ADS)

Lee, Stephen R.; Kardos, Keith W.; Yearwood, Graham D.; Guillon, Geraldine B.; Kurtz, Lisa A.; Mokkapati, Vijaya K.

2008-04-01

Rapid, point of care (POC) testing has been increasingly deployed as an aid in the diagnosis of infectious disease, due to its ability to deliver rapid, actionable results. In the case of HIV, a number of rapid test devices have been FDA approved and CLIA-waived in order to enable diagnosis of HIV infection outside of traditional laboratory settings. These settings include STD clinics, community outreach centers and mobile testing units, as well as identifying HIV infection among pregnant women and managing occupational exposure to infection. The OraQuick ® rapid test platform has been widely used to identify HIV in POC settings, due to its simplicity, ease of use and the ability to utilize oral fluid as an alternative specimen to blood. More recently, a rapid test for antibodies to hepatitis C virus (HCV) has been developed on the same test platform which uses serum, plasma, finger-stick blood, venous blood and oral fluid. Clinical testing using this POC test device has shown that performance is equivalent to state of the art, laboratory based tests. These devices may be suitable for rapid field testing of blood and other body fluids for the presence of infectious agents.

Cost analysis of a novel HIV testing strategy in community pharmacies and retail clinics.

PubMed

Lecher, Shirley Lee; Shrestha, Ram K; Botts, Linda W; Alvarez, Jorge; Moore, James H; Thomas, Vasavi; Weidle, Paul J

2015-01-01

To document the cost of implementing point-of-care (POC) human immunodeficiency virus (HIV) rapid testing in busy community pharmacies and retail clinics. Providing HIV testing services in community pharmacies and retail clinics is an innovative way to expand HIV testing. The cost of implementing POC HIV rapid testing in a busy retail environment needs to be documented to provide program and policy leaders with adequate information for planning and budgeting. Cost analysis from a pilot project that provided confidential POC HIV rapid testing services in community pharmacies and retail clinics. The pharmacy sites were operated under several different ownership structures (for-profit, nonprofit, sole proprietorship, corporation, public, and private) in urban and rural areas. We included data from the initial six sites that participated in the project. We collected the time spent by pharmacy and retail clinic staff for pretest and posttest counseling in an activity log for time-in-motion for each interaction. Pharmacists and retail clinic staff. HIV rapid testing. The total cost was calculated to include costs of test kits, control kits, shipping, test supplies, training, reporting, program administration, and advertising. The six sites trained 22 staff to implement HIV testing. A total of 939 HIV rapid tests were conducted over a median time of 12 months, of which 17 were reactive. Median pretest counseling time was 2 minutes. Median posttest counseling time was 2 minutes for clients with a nonreactive test and 10 minutes for clients with a reactive test. The average cost per person tested was an estimated $47.21. When we considered only recurrent costs, the average cost per person tested was $32.17. Providing POC HIV rapid testing services required a modest amount of staff time and costs that are comparable to other services offered in these settings. HIV testing in pharmacies and retail clinics can provide an additional alternative venue for increasing the availability and accessibility of HIV testing services in the United States.

Costs and health consequences of chlamydia management strategies among pregnant women in sub-Saharan Africa.

PubMed

Romoren, M; Hussein, F; Steen, T W; Velauthapillai, M; Sundby, J; Hjortdahl, P; Kristiansen, I S

2007-12-01

Chlamydia is the most common bacterial sexually transmitted infection worldwide and a major cause of morbidity-particularly among women and neonates. We compared costs and health consequences of using point-of-care (POC) tests with current syndromic management among antenatal care attendees in sub-Saharan Africa. We also compared erythromycin with azithromycin treatment and universal with age-based chlamydia management. A decision analytical model was developed to compare diagnostic and treatment strategies, using Botswana as a case. Model input was based upon (1) a study of pregnant women in Botswana, (2) literature reviews and (3) expert opinion. We expressed the study outcome in terms of costs (US$), cases cured, magnitude of overtreatment and successful partner treatment. Azithromycin was less costly and more effective than erythromycin. Compared with syndromic management, testing all attendees on their first visit with a 75% sensitive POC test increased the number of cases cured from 1500 to 3500 in a population of 100,000 women, at a cost of US$38 per additional case cured. This cost was lower in high-prevalence populations or if testing was restricted to teenagers. The specific POC tests provided the advantage of substantial reductions in overtreatment with antibiotics and improved partner management. Using POC tests to diagnose chlamydia during antenatal care in sub-Saharan Africa entails greater health benefits than syndromic management does-and at acceptable costs-especially when restricted to younger women. Changes in diagnostic strategy and treatment regimens may improve people's health and even reduce healthcare budgets.

[THE COMPARATIVE ANALYSIS OF EFFECTIVENESS OF QUICK TESTS IN DIAGNOSTIC OF INFLUENZA AND RESPIRATORY SYNCYTIAL VIRAL INFECTION IN CHILDREN].

PubMed

Petrova, E R; Sukhovetskaia, V P; Pisareva, M M; Maiorova, V G; Sverlova, M V; Danilenko, D M; Petrova, P A; Krivitskaia, V Z; Sominina, A A

2015-11-01

The analysis was implemented concerning diagnostic parameters of commercial quick tests (immune chromatographic tests BinaxNOW Influenza A&B and BinaxNow RSV Alere, Scarborough Inc., USA) under detection of antigens of influenza virus A and respiratory syncytial virus in clinical materials. The polymerase chain reaction in real-time and isolation ofviruses in cell cultures. The analysis of naso-pharyngeal smears from 116 children demonstrated that sensitivity and specifcity of detection of influenza virus A using device mariPOC in comparison with polymerase chain reaction made up to 93.8% and 99.0% correspondingly at total concordance of results of both techniques as 98.3%. At diagnosing of respiratory syncytial virus using device mariPOC parameters made up to 77.3%, 98.9% and 862% as compared with polymerase chain reaction. The sensitivity, specificity and total concordance of results of immune chromatographic tests BinaxNOW in comparison ofpolymerase chain reaction made up to 86.7%, 100% and 96.2% correspondingly at detection of influenza virus A and 80.9%, 97.4% and 91.6% correspondingly at detection of respiratory syncytial virus. In comparison with isolation technique in cell cultures sensitivity of system mariPOC and immune chromatographic tests proved to be in 1.3-1.4 times higher at detection of influenza virus A and in 1.7-2 times higher in case of isolation of respiratory syncytial virus. There is no statistically significant differences between diagnostic parameters received for mariPOC and immune chromatographic tests at diagnosing influenza virus A and respiratory syncytial viral infection.

Improved assay to detect Plasmodium falciparum using an uninterrupted, semi-nested PCR and quantitative lateral flow analysis

PubMed Central

2013-01-01

Background A rapid, non-invasive, and inexpensive point-of-care (POC) diagnostic for malaria followed by therapeutic intervention would improve the ability to control infection in endemic areas. Methods A semi-nested PCR amplification protocol is described for quantitative detection of Plasmodium falciparum and is compared to a traditional nested PCR. The approach uses primers that target the P. falciparum dihydrofolate reductase gene. Results This study demonstrates that it is possible to perform an uninterrupted, asymmetric, semi-nested PCR assay with reduced assay time to detect P. falciparum without compromising the sensitivity and specificity of the assay using saliva as a testing matrix. Conclusions The development of this PCR allows nucleic acid amplification without the need to transfer amplicon from the first PCR step to a second reaction tube with nested primers, thus reducing both the chance of contamination and the time for analysis to < two hours. Analysis of the PCR amplicon yield was adapted to lateral flow detection using the quantitative up-converting phosphor (UCP) reporter technology. This approach provides a basis for migration of the assay to a POC microfluidic format. In addition the assay was successfully evaluated with oral samples. Oral fluid collection provides a simple non-invasive method to collect clinical samples. PMID:23433252

Point-of-Care Hemoglobin/Hematocrit Testing: Comparison of Methodology and Technology.

PubMed

Maslow, Andrew; Bert, Arthur; Singh, Arun; Sweeney, Joseph

2016-04-01

Point-of-care (POC) testing allows rapid assessment of hemoglobin (Hgb) and hematocrit (Hct) values. This study compared 3 POC testing devices--the Radical-7 pulse oximeter (Radical-7, Neuchȃtel, Switzerland), the i-STAT (Abbott Point of Care, Princeton, NJ), and the GEM 4000 (Instrumentation Laboratory, Bedford, MA)--to the hospital reference device, the UniCel DxH 800 (Beckman Coulter, Brea, CA) in cardiac surgery patients. Prospective study. Tertiary care cardiovascular center. Twenty-four consecutive elective adult cardiac surgery patients. Hgb and Hct values were measured using 3 POC devices (the Radical-7, i-STAT, and GEM 4000) and a reference laboratory device (UniCel DxH 800). Data were collected simultaneously before surgery, after heparin administration, after heparin reversal with protamine, and after sternal closure. Data were analyzed using bias analyses. POC testing data were compared with that of the reference laboratory device. Hgb levels ranged from 6.8 to 15.1 g/dL, and Hct levels ranged from 20.1% to 43.8%. The overall mean bias was lowest with the i-STAT (Hct, 0.22%; Hgb 0.05 g/dL) compared with the GEM 4000 (Hct, 2.15%; Hgb, 0.63 g/dL) and the Radical-7 (Hgb 1.16 g/dL). The range of data for the i-STAT and Radical-7 was larger than that with the GEM 4000, and the pattern or slopes changed significantly with the i-STAT and Radical-7, whereas that of the GEM 4000 remained relatively stable. The GEM 4000 demonstrated a consistent overestimation of laboratory data, which tended to improve after bypass and at lower Hct/Hgb levels. The i-STAT bias changed from overestimation to underestimation, the latter in the post-cardiopulmonary bypass period and at lower Hct/Hgb levels. By contrast, the Radical-7 biases increased during the surgical procedure and in the lower ranges of Hgb. Important clinical differences and limitations were found among the 3 POC testing devices that should caution clinicians from relying on these data as sole determinants of when or when not to perform transfusion in patients. Even though a low bias might support the use of POC data, further analysis of the bias plots demonstrates pattern changes during the surgical procedure and across the range of Hct/Hgb data. Copyright © 2016 Elsevier Inc. All rights reserved.

Microfluidic point-of-care diagnostics for resource-poor environments

NASA Astrophysics Data System (ADS)

Laksanasopin, Tassaneewan; Chin, Curtis D.; Moore, Hannah; Wang, Jennifer; Cheung, Yuk Kee; Sia, Samuel K.

2009-05-01

Point-of-care (POC) diagnostics have tremendous potential to improve human health in remote and resource-poor settings. However, the design criteria for diagnostic tests appropriate in settings with limited infrastructure are unique and challenging. Here we present a custom optical reader which quantifies silver absorbance from heterogeneous immunoassays. The reader is simple and low-cost and suited for POC diagnostics.

Point-of-care diagnostics: extending the laboratory network to reach the last mile.

PubMed

Drain, Paul K; Rousseau, Christine

2017-03-01

More point-of-care (POC) diagnostic tests are becoming available for HIV diagnosis and treatment in resource-limited settings. These novel technologies have the potential to foster decentralized HIV care and treatment for the benefit of clinical laboratories, HIV clinics, and HIV-infected patients. There continue to be many business, technological, and operational challenges that limit product development and regulatory approval, which limits products available for the required operational and cost-effectiveness studies and delays policy adoption and implementation. Although the rapid HIV diagnostic test has been widely successful, the pathways for POC CD4 cell count and HIV viral load assay analyzers have been more challenging. We describe significant hurdles for product development, approval, and implementation, which include the business case, technical development, clinical impact, and integrating laboratory and clinical networks. The objective of this review is to highlight the obstacles for developing and implementing appropriate strategies for POC HIV testing assays to improve the clinical services for HIV-infected patients in resource-limited settings.

Maximizing return on socioeconomic investment in phase II proof-of-concept trials.

PubMed

Chen, Cong; Beckman, Robert A

2014-04-01

Phase II proof-of-concept (POC) trials play a key role in oncology drug development, determining which therapeutic hypotheses will undergo definitive phase III testing according to predefined Go-No Go (GNG) criteria. The number of possible POC hypotheses likely far exceeds available public or private resources. We propose a design strategy for maximizing return on socioeconomic investment in phase II trials that obtains the greatest knowledge with the minimum patient exposure. We compare efficiency using the benefit-cost ratio, defined to be the risk-adjusted number of truly active drugs correctly identified for phase III development divided by the risk-adjusted total sample size in phase II and III development, for different POC trial sizes, powering schemes, and associated GNG criteria. It is most cost-effective to conduct small POC trials and set the corresponding GNG bars high, so that more POC trials can be conducted under socioeconomic constraints. If δ is the minimum treatment effect size of clinical interest in phase II, the study design with the highest benefit-cost ratio has approximately 5% type I error rate and approximately 20% type II error rate (80% power) for detecting an effect size of approximately 1.5δ. A Go decision to phase III is made when the observed effect size is close to δ. With the phenomenal expansion of our knowledge in molecular biology leading to an unprecedented number of new oncology drug targets, conducting more small POC trials and setting high GNG bars maximize the return on socioeconomic investment in phase II POC trials. ©2014 AACR.

Vulnerability of point-of-care test reagents and instruments to environmental stresses: implications for health professionals and developers.

PubMed

Louie, Richard F; Ferguson, William J; Curtis, Corbin M; Vy, John H; Kost, Gerald J

2014-03-01

Strategic integration of point-of-care (POC) diagnostic tools during crisis response can accelerate triage and improve management of victims. Timely differential diagnosis is essential wherever care is provided to rule out or rule in disease, expedite life-saving treatment, and improve utilization of limited resources. POC testing needs to be accurate in any environment in which it is used. Devices are exposed to potentially adverse storage and operating conditions, such as high/low temperature and humidity during emergencies and field rescues. Therefore, characterizing environmental conditions allows technology developers, operators, and responders to understand the broad operational requirements of test reagents, instruments, and equipment in order to improve the quality and delivery of care in complex emergencies, disasters, and austere environmental settings. This review aims to describe the effects of environmental stress on POC testing performance and its impact on decision-making, to describe how to study the effects, and to summarize ways to mitigate the effects of environmental stresses through good laboratory practice, development of robust reagents, and novel thermal packaging solutions.

Large-scale performance evaluation of Accu-Chek inform II point-of-care glucose meters.

PubMed

Jeong, Tae-Dong; Cho, Eun-Jung; Ko, Dae-Hyun; Lee, Woochang; Chun, Sail; Hong, Ki-Sook; Min, Won-Ki

2016-12-01

The aim of this study was to report the experience of large-scale performance evaluation of 238 Accu-Chek Inform II point-of-care (POC) glucose meters in a single medical setting. The repeatability of 238 POC devices, the within-site imprecision of 12 devices, and the linearity of 49 devices were evaluated using glucose control solutions. The glucose results of 24 POC devices and central laboratory were compared using patient samples. Mean concentration of control solutions was 2.39 mmol/L for Level 1 and 16.52 mmol/L for Level 2. The pooled repeatability coefficient of variation (CV) of the 238 devices was 2.0% for Level 1 and 1.6% for Level 2. The pooled within-site imprecision CV and reproducibility CV of the 12 devices were 2.7% and 2.7% for Level 1, and 1.9%, and 1.9% for Level 2, respectively. The test results of all 49 devices were linear within analytical measurement range from 1.55-31.02 mmol/L. The correlation coefficient for individual POC devices ranged from 0.9967-0.9985. The total correlation coefficient for the 24 devices was 0.998. The Accu-Chek Inform II POC blood glucose meters performed well in terms of precision, linearity, and correlation evaluations. Consensus guidelines for the large-scale performance evaluations of POC devices are required.

A critical insight into the development pipeline of microfluidic immunoassay devices for the sensitive quantitation of protein biomarkers at the point of care.

PubMed

Barbosa, Ana I; Reis, Nuno M

2017-03-13

The latest clinical procedures for the timely and cost-effective diagnosis of chronic and acute clinical conditions, such as cardiovascular diseases, cancer, chronic respiratory diseases, diabetes or sepsis (i.e. the biggest causes of death worldwide), involve the quantitation of specific protein biomarkers released into the blood stream or other physiological fluids (e.g. urine or saliva). The clinical thresholds are usually in the femtomolar to picolomar range, and consequently the measurement of these protein biomarkers heavily relies on highly sophisticated, bulky and automated equipment in centralised pathology laboratories. The first microfluidic devices capable of measuring protein biomarkers in miniaturised immunoassays were presented nearly two decades ago and promised to revolutionise point-of-care (POC) testing by offering unmatched sensitivity and automation in a compact POC format; however, the development and adoption of microfluidic protein biomarker tests has fallen behind expectations. This review presents a detailed critical overview into the pipeline of microfluidic devices developed in the period 2005-2016 capable of measuring protein biomarkers from the pM to fM range in formats compatible with POC testing, with a particular focus on the use of affordable microfluidic materials and compact low-cost signal interrogation. The integration of these two important features (essential unique selling points for the successful microfluidic diagnostic products) has been missed in previous review articles and explain the poor adoption of microfluidic technologies in this field. Most current miniaturised devices compromise either on the affordability, compactness and/or performance of the test, making current tests unsuitable for the POC measurement of protein biomarkers. Seven core technical areas, including (i) the selected strategy for antibody immobilisation, (ii) the surface area and surface-area-to-volume ratio, (iii) surface passivation, (iv) the biological matrix interference, (v) fluid control, (vi) the signal detection modes and (vii) the affordability of the manufacturing process and detection system, were identified as the key to the effective development of a sensitive and affordable microfluidic protein biomarker POC test.

Point-of-Care Versus Central Laboratory Measurements of Hemoglobin, Hematocrit, Glucose, Bicarbonate and Electrolytes: A Prospective Observational Study in Critically Ill Patients.

PubMed

Allardet-Servent, Jérôme; Lebsir, Melissa; Dubroca, Christian; Fabrigoule, Martine; Jordana, Sylvie; Signouret, Thomas; Castanier, Matthias; Thomas, Guillemette; Soundaravelou, Rettinavelou; Lepidi, Anne; Delapierre, Laurence; Penaranda, Guillaume; Halfon, Philippe; Seghboyan, Jean-Marie

2017-01-01

Rapid detection of abnormal biological values using point-of-care (POC) testing allows clinicians to promptly initiate therapy; however, there are concerns regarding the reliability of POC measurements. We investigated the agreement between the latest generation blood gas analyzer and central laboratory measurements of electrolytes, bicarbonate, hemoglobin, hematocrit, and glucose. 314 paired samples were collected prospectively from 51 critically ill patients. All samples were drawn simultaneously in the morning from an arterial line. BD Vacutainer tubes were analyzed in the central laboratory using Beckman Coulter analyzers (AU 5800 and DxH 800). BD Preset 3 ml heparinized-syringes were analyzed immediately in the ICU using the POC Siemens RAPIDPoint 500 blood gas system. We used CLIA proficiency testing criteria to define acceptable analytical performance and interchangeability. Biases, limits of agreement (±1.96 SD) and coefficients of correlation were respectively: 1.3 (-2.2 to 4.8 mmol/L, r = 0.936) for sodium; 0.2 (-0.2 to 0.6 mmol/L, r = 0.944) for potassium; -0.9 (-3.7 to 2 mmol/L, r = 0.967) for chloride; 0.8 (-1.9 to 3.4 mmol/L, r = 0.968) for bicarbonate; -11 (-30 to 9 mg/dL, r = 0.972) for glucose; -0.8 (-1.4 to -0.2 g/dL, r = 0.985) for hemoglobin; and -1.1 (-2.9 to 0.7%, r = 0.981) for hematocrit. All differences were below CLIA cut-off values, except for hemoglobin. Compared to central Laboratory analyzers, the POC Siemens RAPIDPoint 500 blood gas system satisfied the CLIA criteria of interchangeability for all tested parameters, except for hemoglobin. These results are warranted for our own procedures and devices. Bearing these restrictions, we recommend clinicians to initiate an appropriate therapy based on POC testing without awaiting a control measurement.

Point-of-Care Versus Central Laboratory Measurements of Hemoglobin, Hematocrit, Glucose, Bicarbonate and Electrolytes: A Prospective Observational Study in Critically Ill Patients

PubMed Central

Lebsir, Melissa; Dubroca, Christian; Fabrigoule, Martine; Jordana, Sylvie; Signouret, Thomas; Castanier, Matthias; Thomas, Guillemette; Soundaravelou, Rettinavelou; Lepidi, Anne; Delapierre, Laurence; Penaranda, Guillaume; Halfon, Philippe; Seghboyan, Jean-Marie

2017-01-01

Introduction Rapid detection of abnormal biological values using point-of-care (POC) testing allows clinicians to promptly initiate therapy; however, there are concerns regarding the reliability of POC measurements. We investigated the agreement between the latest generation blood gas analyzer and central laboratory measurements of electrolytes, bicarbonate, hemoglobin, hematocrit, and glucose. Methods 314 paired samples were collected prospectively from 51 critically ill patients. All samples were drawn simultaneously in the morning from an arterial line. BD Vacutainer tubes were analyzed in the central laboratory using Beckman Coulter analyzers (AU 5800 and DxH 800). BD Preset 3 ml heparinized-syringes were analyzed immediately in the ICU using the POC Siemens RAPIDPoint 500 blood gas system. We used CLIA proficiency testing criteria to define acceptable analytical performance and interchangeability. Results Biases, limits of agreement (±1.96 SD) and coefficients of correlation were respectively: 1.3 (-2.2 to 4.8 mmol/L, r = 0.936) for sodium; 0.2 (-0.2 to 0.6 mmol/L, r = 0.944) for potassium; -0.9 (-3.7 to 2 mmol/L, r = 0.967) for chloride; 0.8 (-1.9 to 3.4 mmol/L, r = 0.968) for bicarbonate; -11 (-30 to 9 mg/dL, r = 0.972) for glucose; -0.8 (-1.4 to -0.2 g/dL, r = 0.985) for hemoglobin; and -1.1 (-2.9 to 0.7%, r = 0.981) for hematocrit. All differences were below CLIA cut-off values, except for hemoglobin. Conclusions Compared to central Laboratory analyzers, the POC Siemens RAPIDPoint 500 blood gas system satisfied the CLIA criteria of interchangeability for all tested parameters, except for hemoglobin. These results are warranted for our own procedures and devices. Bearing these restrictions, we recommend clinicians to initiate an appropriate therapy based on POC testing without awaiting a control measurement. PMID:28072822

The performance of non-NAAT point-of-care (POC) tests and rapid NAAT tests for chlamydia and gonorrhoea infections. An assessment of currently available assays.

PubMed

Brook, Gary

2015-12-01

To identify point-of-care (POC) and rapid nucleic acid amplification techniques (NAATs) for the diagnosis of chlamydia and gonorrhoea and assess their utility. Literature search for available POC and rapid NAATs. The performance from the best-performing assays were applied hypothetically to patients in the clinic in which 100 consecutive patients with chlamydia and 100 with gonorrhoea were diagnosed in 1737 and 4575 patients respectively, with 44/100 and 54/100 treated at first attendance, respectively. 11 POC and 1 rapid NAAT were identified. Published performances for the best POC for chlamydia (CRT) were: sensitivity 41%-87%, specificity 89%-99.6%. Our data suggest that if this assay was used instead of our current NAAT, for every 100 patients diagnosed currently, 23-46 extra patients would be treated at first attendance; 10-35 would go undiagnosed with 7-191 false-positives. Best chlamydia rapid NAAT (GeneXpert): sensitivity 97.5%-98.7%, specificity 99.4%-99.9%. Anticipated performance for every 100 patients diagnosed currently: 0 extra patients treated at first attendance, 1-3 undiagnosed, 0-2 false-positives. Best POC for gonorrhoea (GC Check): sensitivity 54%-70%, specificity 97%-98%. Anticipated performance for every 100 patients diagnosed currently: 14-18 extra patients treated at first attendance, 28-32 undiagnosed, 92-137 false-positives. Best rapid NAAT for gonorrhoea (GeneXpert): sensitivity 96%-100%, specificity 99.9%-100%. Anticipated performance for every 100 patients diagnosed currently: 0 extra patients treated at first attendance, 0-4 undiagnosed, 0-5 false-positives. Rapid NAAT would reduce time to treatment by 4 days for initially untreated patients. POC assays would need to be used in conjunction with a NAAT, increasing early treatment rates expense and false-positive results. The rapid NAAT could be used alone, with a reduction in average time-to-treat and a small reduction in sensitivity and specificity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Point of care testing provides an accurate measurement of creatinine, anion gap, and osmolal gap in ex-vivo whole blood samples with nitromethane.

PubMed

Cao, D; Maynard, S; Mitchell, A M; Kerns, W P; Beuhler, M

2014-07-01

Nitromethane interferes with Jaffé measurements of creatinine, potentially mimicking acute kidney injury. We determined the proportional contribution of nitromethane in blood samples to creatinine measured by the Jaffé colorimetric and the point-of-care (POC) reactions and determined whether the difference can reliably estimate the concentration of nitromethane. Additionally, we determined whether the presence of nitromethane interferes with anion/osmolal gaps and ascertained the stability of nitromethane in serum after 7 days. Nitromethane was added to whole blood from four healthy volunteers to achieve concentrations of 0, 0.25, 0.5, 1, and 2 mmol/L. The following tests were performed: creatinine (Jaffé and POC), electrolytes (associated with Jaffé and POC), osmolality and nitromethane concentration (gas chromatography [GC]). Remaining samples were refrigerated and reanalyzed using GC at 7 days. Anion and osmolal gaps were calculated. Proportional recovery and degradation of nitromethane were measured using GC. Data were analyzed for agreement with single-factor ANOVA (p = 0.05). Mean creatinine for POC and Jaff methods were 0.93 vs. 0.76 mg/dL, respectively. Jaff creatinine concentrations increased linearly with increasing nitromethane concentrations (R(2) = 1, p = 0.01): measured creatinine (mg/dL) = 7.1*nitromethane (mmol/L) = 0.79. POC creatinine remained unchanged across the range of nitromethane concentrations (p = 0.99). Anion and osmolal gaps also remained unchanged. Nitromethane was reliably identified in all sample concentrations using GC on Day 0. Detection of 0.25 mmol/L nitromethane was not consistently recovered on Day 7. Nitromethane degradation was most pronounced at 2 mmol/L concentrations (81% recovery). Nitromethane alters apparent concentration of creatinine using the Jaffé reaction in a linear fashion but not when using the POC reaction. Measured difference between Jaffé and POC creatinine may identify the presence and estimate concentration of nitromethane. Presence of nitromethane did not alter the anion or osmolal gap; thus it would not potentially interfere with the diagnosis of co-exposure to a toxic alcohol.

Combined use of radiocarbon and stable carbon isotope to constrain the sources and cycling of particulate organic carbon in a large freshwater lake, China.

PubMed

Chen, Jingan; Yang, Haiquan; Zeng, Yan; Guo, Jianyang; Song, Yilong; Ding, Wei

2018-06-01

The concentrations and isotopic compositions of dissolved inorganic carbon (DIC) and particulate organic carbon (POC) were measured in order to better constrain the sources and cycling of POC in Lake Fuxian, the largest deep freshwater lake in China. Model results based on the combined δ 13 C and Δ 14 C, showed that the average lake-wide contributions of autochthonous POC, terrestrial POC, and resuspended sediment POC to the bulk POC in Lake Fuxian were 61%, 22%, and 17%, respectively. This indicated autochthonous POC might play a dominant role in sustaining large oligotrophic lake ecosystem. A mean 17% contribution of resuspended sediment POC to the bulk POC implied that sediment might have more significant influence on aquatic environment and ecosystem than previously recognized in large deep lakes. The contributions of different sources POC to the water-column POC were a function of the initial composition of the source materials, photosynthesis, physical regime of the lake, sediment resuspension, respiration and degradation of organic matter, and were affected indirectly by environmental factors such as light, temperature, DO, wind speed, turbidity, and nutrient concentration. This study is not only the first systematic investigation on the radiocarbon and stable isotope compositions of POC in large deep freshwater lake in China, but also one of the most extensive radiocarbon studies on the ecosystem of any great lakes in the world. The unique data constrain relative influences of autochthonous POC, terrestrial POC, and resuspended sediment POC, and deepen the understanding of the POC cycling in large freshwater lakes. This study is far from comprehensive, but it serves to highlight the potential of combined radiocarbon and stable carbon isotope for constraining the sources and cycling of POC in large lake system. More radiocarbon investigations on the water-column POC and the aquatic food webs are necessary to illuminate further the fate of autochthonous POC, terrestrial POC, and resuspended sediment POC, and their eco-environmental effects. Copyright © 2017 Elsevier B.V. All rights reserved.

Detection of schistosomiasis in an area directly affected by the São Francisco River large-scale water transposition project in the Northeast of Brazil.

PubMed

Silva, José Damião da; Pinheiro, Marta Cristhiany Cunha; Sousa, Mariana Silva; Gomes, Vivian da Silva; Castro, Issis Maria Nogueira de; Ramos, Alberto Novaes; Bezerra, Fernando Schemelzer de Moraes

2017-01-01

The development of the São Francisco River Integration Project [Projeto de Integração do Rio São Francisco (PISF)] in the State of Ceará, Brazil, has resulted in environmental and socioeconomic changes with potential risks to public health. We aimed to determine the presence of Schistosoma mansoni infections in schoolchildren (aged 7-14 years) and workers from the construction site in an area under the direct influence of the PISF in the municipality of Brejo Santo-CE, to aid in the prevention and control of schistosomiasis. We conducted a cross-sectional study using two S. mansoni-detection methods: detection of S. mansoni eggs by the Kato-Katz parasitological method in stool samples (assessed in triplicate for each sample) and S. mansoni circulating cathodic antigen by the point-of-care immunochromatographic rapid test (POC-CCA) in urine. In general, the positivity rates for S. mansoni detection were 1.9% (2/106) among schoolchildren and 2.9% (4/138) among workers. No child had evidence of S. mansoni eggs in their stools; 1.9% tested positive by the POC-CCA method. Among workers, two (1.4%) tested positive by the Kato-Katz test and three (2.2%) by the POC-CCA test. If the POC-CCA test results that were scored as traces were considered negative, then the positivity rates dropped to 0.9% and 0.7% for schoolchildren and workers, respectively. The active transmission of schistosomiasis in a region covered by the PISF was recognized, reinforcing the necessity to consolidate surveillance and control actions, as well as structural sanitation measures to reverse the social determinants of the disease.

Effects of environmental conditions on point-of-care cardiac biomarker test performance during a simulated rescue: implications for emergency and disaster response.

PubMed

Louie, Richard F; Ferguson, William J; Curtis, Corbin M; Vy, John H; Tang, Chloe S; Kost, Gerald J

2013-01-01

To characterize the effects of environmental stress on point-of-care (POC) cardiac biomarker testing during a simulated rescue. Multiplex test cassettes for cardiac troponin I (cTnI), brain natriuretic peptide (BNP), CK-MB, myoglobin, and D-dimer were exposed to environmental stresses simulating a 24-hour rescue from Hawaii to the Marshall Islands and back. We used Tenney environmental chambers (T2RC and BTRC) to simulate flight conditions (20°C, 10 percent relative humidity) and ground conditions (22.3-33.9°C, 73-77 percent). We obtained paired measurements using stressed versus control (room temperature) cassettes at seven time points (T1-7 with T1,2,6,7 during flight and T3-5 on ground). We analyzed paired differences (stressed minus control) with Wilcoxon signed rank test. We assessed the impact on decision-making at clinical thresholds. cTnI results from stressed test cassettes (n = 10) at T4 (p < 0.05), T5 (p < 0.01), and T7 (p < 0.05) differed significantly from control, when testing samples with median cTnI concentration of 90 ng/L. During the ground rescue, 36.7 percent (11/30) of cTnI measurements from stressed cassettes generated significantly lowered results. At T5, 20 percent (2/10) of cTnI results were highly discrepant-stressed cassettes reported normal results, when control results were >100 ng/L. With sample median concentration of 108 pg/mL, BNP results from stressed test cassettes differed significantly from controls (p < 0.05). Despite modest, short-term temperature elevation, environmental stresses led to erroneous results. False negative cTnI and BNP results potentially could miss acute myocardial infarction and congestive heart failure, confounded treatment, and increased mortality and morbidity. Therefore, rescuers should protect POC reagents from temperature extremes.

45,X product of conception after preimplantation genetic diagnosis and euploid embryo transfer: evidence of a spontaneous conception confirmed by DNA fingerprinting.

PubMed

Bettio, Daniela; Capalbo, Antonio; Albani, Elena; Rienzi, Laura; Achille, Valentina; Venci, Anna; Ubaldi, Filippo Maria; Levi Setti, Paolo Emanuele

2016-09-06

Preimplantation genetic screening (PGS) provides an opportunity to eliminate a potential implantation failure due to aneuploidy in infertile couples. Some studies clearly show that twins following single embryo transfer (SET) can be the result of a concurrent natural conception and an incidence as high as 1 in 5 twins has been reported. In our case PGS was performed on trophectoderm (TE) biopsies by quantitative polymerase chain reaction (qPCR). The product of conception (POC) was cytogenetically investigated after selection of the placental villi by means of the direct method. Molecular cytogenetic characterization of the POC was performed by fluorescence in situ hybridization (FISH) and array-comparative genomic hybridization (a-CGH) analyses. To investigate the possibility of a spontaneous conception, a panel of 40 single nucleotide polymorphisms (SNPs) was used to compare genetic similarity between the DNA of the POC and the DNA leftover of the TE biopsy. We describe a 36-year old infertile woman undergoing PGS who had a spontaneous abortion after a single euploid embryo transfer on a spontaneous cycle. The POC showed a 45,X karyotype confirmed by FISH and a-CGH. DNA fingerprinting demonstrated a genetic similarity of 75 % between the DNA of the POC and TE biopsy, consistent with a sibling status. All supernumerary euploid embryos were also tested showing a non-self relationship with the POC, excluding a mix-up event at the time of fetal embryo transfer. DNA fingerprinting of the transferred blastocyst and POC, confirmed the occurrence of a spontaneous conception. This case challenges the assumption that a pregnancy after assisted reproductive technology (ART) is always a result of ART, and strengthens the importance to avoid intercourses during PGS and natural transfer cycles. Moreover, cytogenetic analysis of the POCs is strongly recommended along with fingerprinting children born after PGS to see what the concordance is between the embryo transferred and the resultant child.

Fast degradable citrate-based bone scaffold promotes spinal fusion.

PubMed

Tang, Jiajun; Guo, Jinshan; Li, Zhen; Yang, Cheng; Xie, Denghui; Chen, Jian; Li, Shengfa; Li, Shaolin; Kim, Gloria B; Bai, Xiaochun; Zhang, Zhongmin; Yang, Jian

2015-07-21

It is well known that high rates of fusion failure and pseudoarthrosis development (5~35%) are concomitant in spinal fusion surgery, which was ascribed to the shortage of suitable materials for bone regeneration. Citrate was recently recognized to play an indispensable role in enhancing osteconductivity and osteoinductivity, and promoting bone formation. To address the material challenges in spinal fusion surgery, we have synthesized mechanically robust and fast degrading citrate-based polymers by incorporating N-methyldiethanolamine (MDEA) into clickable poly(1, 8-octanediol citrates) (POC-click), referred to as POC-M-click. The obtained POC-M-click were fabricated into POC-M-click-HA matchstick scaffolds by compositing with hydroxyapatite (HA) for interbody spinal fusion in a rabbit model. Spinal fusion was analyzed by radiography, manual palpation, biomechanical testing, and histological evaluation. At 4 and 8 weeks post surgery, POC-M-click-HA scaffolds presented optimal degradation rates that facilitated faster new bone formation and higher spinal fusion rates (11.2±3.7, 80±4.5 at week 4 and 8, respectively) than the poly(L-lactic acid)-HA (PLLA-HA) control group (9.3±2.4 and 71.1±4.4) (p<0.05). The POC-M-click-HA scaffold-fused vertebrates possessed a maximum load and stiffness of 880.8±14.5 N and 843.2±22.4 N/mm, respectively, which were also much higher than those of the PLLA-HA group (maximum: 712.0±37.5 N, stiffness: 622.5±28.4 N/mm, p<0.05). Overall, the results suggest that POC-M-click-HA scaffolds could potentially serve as promising bone grafts for spinal fusion applications.

Fast degradable citrate-based bone scaffold promotes spinal fusion

PubMed Central

Tang, Jiajun; Guo, Jinshan; Li, Zhen; Yang, Cheng; Xie, Denghui; Chen, Jian; Li, Shengfa; Li, Shaolin; Kim, Gloria B.; Bai, Xiaochun; Zhang, Zhongmin; Yang, Jian

2015-01-01

It is well known that high rates of fusion failure and pseudoarthrosis development (5~35%) are concomitant in spinal fusion surgery, which was ascribed to the shortage of suitable materials for bone regeneration. Citrate was recently recognized to play an indispensable role in enhancing osteconductivity and osteoinductivity, and promoting bone formation. To address the material challenges in spinal fusion surgery, we have synthesized mechanically robust and fast degrading citrate-based polymers by incorporating N-methyldiethanolamine (MDEA) into clickable poly(1, 8-octanediol citrates) (POC-click), referred to as POC-M-click. The obtained POC-M-click were fabricated into POC-M-click-HA matchstick scaffolds by compositing with hydroxyapatite (HA) for interbody spinal fusion in a rabbit model. Spinal fusion was analyzed by radiography, manual palpation, biomechanical testing, and histological evaluation. At 4 and 8 weeks post surgery, POC-M-click-HA scaffolds presented optimal degradation rates that facilitated faster new bone formation and higher spinal fusion rates (11.2±3.7, 80±4.5 at week 4 and 8, respectively) than the poly(L-lactic acid)-HA (PLLA-HA) control group (9.3±2.4 and 71.1±4.4) (p<0.05). The POC-M-click-HA scaffold-fused vertebrates possessed a maximum load and stiffness of 880.8±14.5 N and 843.2±22.4 N/mm, respectively, which were also much higher than those of the PLLA-HA group (maximum: 712.0±37.5 N, stiffness: 622.5±28.4 N/mm, p<0.05). Overall, the results suggest that POC-M-click-HA scaffolds could potentially serve as promising bone grafts for spinal fusion applications. PMID:26213625

Impact of HbA1c Testing at Point of Care on Diabetes Management

PubMed Central

Schnell, Oliver; Crocker, J. Benjamin; Weng, Jianping

2016-01-01

Diabetes is a highly prevalent disease also implicated in the development of several other serious complications like cardiovascular or renal disease. HbA1c testing is a vital step for effective diabetes management, however, given the low compliance to testing frequency and, commonly, a subsequent delay in the corresponding treatment modification, HbA1c at the point of care (POC) offers an opportunity for improvement of diabetes care. In this review, based on data from 1999 to 2016, we summarize the evidence supporting a further implementation of HbA1c testing at POC, discuss its limitations and propose recommendations for further development. PMID:27898388

Surgical approach to cervical spondylotic myelopathy on the basis of radiological patterns of compression: prospective analysis of 129 cases

PubMed Central

Chaudhary, Kshitij; Sharma, Amit; Laheri, Vinod

2008-01-01

This is a prospective analysis of 129 patients operated for cervical spondylotic myelopathy (CSM). Paucity of prospective data on surgical management of CSM, especially multilevel CSM (MCM), makes surgical decision making difficult. The objectives of the study were (1) to identify radiological patterns of cord compression (POC), and (2) to propose a surgical protocol based on POC and determine its efficacy. Average follow-up period was 2.8 years. Following POCs were identified: POC I: one or two levels of anterior cord compression. POC II: one or two levels of anterior and posterior compression. POC III: three levels of anterior compression. POC III variant: similar to POC III, associated with significant medical morbidity. POC IV: three or more levels of anterior compression in a developmentally narrow canal or with multiple posterior compressions. POC IV variant: similar to POC IV with one or two levels, being more significant than the others. POC V: three or more levels of compression in a kyphotic spine. Anterior decompression and reconstruction was chosen for POC I, II and III. Posterior decompression was chosen in POC III variant because they had more incidences of preoperative morbidity, in spite of being radiologically similar to POC III. Posterior surgery was also performed for POC IV and IV variant. For POC IV variant a targeted anterior decompression was considered after posterior decompression. The difference in the mJOA score before and after surgery for patients in each POC group was statistically significant. Anterior surgery in MCM had better result (mJOA = 15.9) versus posterior surgery (mJOA = 14.96), the difference being statistically significant. No major graft-related complications occurred in multilevel groups. The better surgical outcome of anterior surgery in MCM may make a significant difference in surgical outcome in younger and fitter patients like those of POC III whose expectations out of surgery are more. Judicious choice of anterior or posterior approach should be made after individualizing each case. PMID:18946692

Smartphones for cell and biomolecular detection.

PubMed

Liu, Xiyuan; Lin, Tung-Yi; Lillehoj, Peter B

2014-11-01

Recent advances in biomedical science and technology have played a significant role in the development of new sensors and assays for cell and biomolecular detection. Generally, these efforts are aimed at reducing the complexity and costs associated with diagnostic testing so that it can be performed outside of a laboratory or hospital setting, requiring minimal equipment and user involvement. In particular, point-of-care (POC) testing offers immense potential for many important applications including medical diagnosis, environmental monitoring, food safety, and biosecurity. When coupled with smartphones, POC systems can offer portability, ease of use and enhanced functionality while maintaining performance. This review article focuses on recent advancements and developments in smartphone-based POC systems within the last 6 years with an emphasis on cell and biomolecular detection. These devices typically comprise multiple components, such as detectors, sample processors, disposable chips, batteries, and software, which are integrated with a commercial smartphone. One of the most important aspects of developing these systems is the integration of these components onto a compact and lightweight platform that requires minimal power. Researchers have demonstrated several promising approaches employing various detection schemes and device configurations, and it is expected that further developments in biosensors, battery technology and miniaturized electronics will enable smartphone-based POC technologies to become more mainstream tools in the scientific and biomedical communities.

Significance of pregnancy test false negative results due to elevated levels of β-core fragment hCG.

PubMed

Johnson, Sarah; Eapen, Saji; Smith, Peter; Warren, Graham; Zinaman, Michael

2017-01-01

Very high levels of β-core fragment human chorionic gonadotrophin (βcf-hCG) are reported to potentially cause false negative results in point-of-care (POC)/over-the-counter (OTC) pregnancy tests. To investigate this further, women's daily early morning urine samples, collected prior to conception and during pregnancy, were analysed for intact, free β-, and βcf-hCG. The proportion of βcf-hCG was found to be related to that of hCG produced and in circulation. Therefore, best practice for accuracy testing of POC/OTC pregnancy tests would be to test devices against clinical samples containing high levels of βcf-hCG as well as standards spiked with biologically relevant ratios.

Impact on ART initiation of point-of-care CD4 testing at HIV diagnosis among HIV-positive youth in Khayelitsha, South Africa.

PubMed

Patten, Gabriela E M; Wilkinson, Lynne; Conradie, Karien; Isaakidis, Petros; Harries, Anthony D; Edginton, Mary E; De Azevedo, Virginia; van Cutsem, Gilles

2013-07-04

Despite the rapid expansion of antiretroviral therapy (ART) programmes in developing countries, pre-treatment losses from care remain a challenge to improving access to treatment. Youth and adolescents have been identified as a particularly vulnerable group, at greater risk of loss from both pre-ART and ART care. Point-of-care (POC) CD4 testing has shown promising results in improving linkage to ART care. In Khayelitsha township, South Africa, POC CD4 testing was implemented at a clinic designated for youth aged 12-25 years. We assessed whether there was an associated reduction in attrition between HIV testing, assessment for eligibility and ART initiation. A before-and-after observational study was conducted using routinely collected data. These were collected on patients from May 2010 to April 2011 (Group A) when baseline CD4 count testing was performed in a laboratory and results were returned to the clinic within two weeks. Same-day POC CD4 testing was implemented in June 2011, and data were collected on patients from August 2011 to July 2012 (Group B). A total of 272 and 304 youth tested HIV-positive in Group A and Group B, respectively. Group B patients were twice as likely to have their ART eligibility assessed compared to Group A patients: 275 (90%) vs. 183 (67%) [relative risk (RR)=2.4, 95% CI: 1.8-3.4, p<0.0001]. More patients in World Health Organization (WHO) Stage 1 disease (85% vs. 69%), with CD4 counts≥350 cells/µL (58% vs. 35%) and more males (13% vs. 7%) were detected in Group B. The proportion of eligible patients who initiated ART was 50% and 44% (p=0.6) in Groups B and A, respectively; and 50% and 43% (p=0.5) when restricted to patients with baseline CD4 count≤250 cells/µL. Time between HIV-testing and ART initiation was reduced from 36 to 28 days (p=0.6). POC CD4 testing significantly improved assessment for ART eligibility. The improvement in the proportion initiating ART and the reduction in time to initiation was not significant due to sample size limitations. POC CD4 testing reduced attrition between HIV-testing and assessment of ART eligibility. Strategies to improve uptake of ART are needed, possibly by improving patient support for HIV-positive youth immediately after diagnosis.

Surface enhanced Raman spectroscopy (SERS) for in vitro diagnostic testing at the point of care

NASA Astrophysics Data System (ADS)

Marks, Haley; Schechinger, Monika; Garza, Javier; Locke, Andrea; Coté, Gerard

2017-06-01

Point-of-care (POC) device development is a growing field that aims to develop low-cost, rapid, sensitive in-vitro diagnostic testing platforms that are portable, self-contained, and can be used anywhere - from modern clinics to remote and low resource areas. In this review, surface enhanced Raman spectroscopy (SERS) is discussed as a solution to facilitating the translation of bioanalytical sensing to the POC. The potential for SERS to meet the widely accepted "ASSURED" (Affordable, Sensitive, Specific, User-friendly, Rapid, Equipment-free, and Deliverable) criterion provided by the World Health Organization is discussed based on recent advances in SERS in vitro assay development. As SERS provides attractive characteristics for multiplexed sensing at low concentration limits with a high degree of specificity, it holds great promise for enhancing current efforts in rapid diagnostic testing. In outlining the progression of SERS techniques over the past years combined with recent developments in smart nanomaterials, high-throughput microfluidics, and low-cost paper diagnostics, an extensive number of new possibilities show potential for translating SERS biosensors to the POC.

Satellite observation of particulate organic carbon dynamics in ...

EPA Pesticide Factsheets

Particulate organic carbon (POC) plays an important role in coastal carbon cycling and the formation of hypoxia. Yet, coastal POC dynamics are often poorly understood due to a lack of long-term POC observations and the complexity of coastal hydrodynamic and biogeochemical processes that influence POC sources and sinks. Using field observations and satellite ocean color products, we developed a nw multiple regression algorithm to estimate POC on the Louisiana Continental Shelf (LCS) from satellite observations. The algorithm had reliable performance with mean relative error (MRE) of ?40% and root mean square error (RMSE) of ?50% for MODIS and SeaWiFS images for POC ranging between ?80 and ?1200 mg m23, and showed similar performance for a large estuary (Mobile Bay). Substantial spatiotemporal variability in the satellite-derived POC was observed on the LCS, with high POC found on the inner shelf (<10 m depth) and lower POC on the middle (10–50 m depth) and outer shelf (50–200 m depth), and with high POC found in winter (January–March) and lower POC in summer to fall (August–October). Correlation analysis between long-term POC time series and several potential influencing factors indicated that river discharge played a dominant role in POC dynamics on the LCS, while wind and surface currents also affected POC spatial patterns on short time scales. This study adds another example where satellite data with carefully developed algorithms can greatly increase

Cholesterol Point-of-Care Testing for Community Pharmacies: A Review of the Current Literature.

PubMed

Haggerty, Lauren; Tran, Deanna

2017-08-01

To summarize the literature on cholesterol point-of-care tests (POCTs). This article would serve as a resource to assist community pharmacists in developing cholesterol point-of-care (POC) pharmacy services. A literature search was performed in MEDLINE Ovid, PubMed, EMBASE, and Cochrane database using the following medical subject headings (MeSH) terms: point-of-care test, cholesterol, blood chemical analysis, rapid testing, collaborative practice, community pharmacy, and ambulatory care. Additional resources including device manufacturer web sites were summarized to supplement the current literature. All human research articles, review articles, meta-analyses, and abstracts published in English through September 1, 2014, were considered. A total of 36 articles were applicable for review. Information was divided into the following categories to be summarized: devices, pharmacists' impact, and operational cost for the pharmacy. The current literature suggests that POCTs in community pharmacies assist with patient outcomes by providing screenings and referring patients with dyslipidemia for further evaluation. The majority of studies on cholesterol POC devices focused on accuracy, revealing the need for further studies to develop best practices and practice models with successful reimbursement. Accuracy, device specifications, required supplies, and patient preference should be considered when selecting a POC device for purchase.

Towards Detection and Diagnosis of Ebola Virus Disease at Point-of-Care

PubMed Central

Kaushik, Ajeet; Tiwari, Sneham; Jayant, Rahul Dev; Marty, Aileen; Nair, Madhavan

2015-01-01

Ebola outbreak-2014 (mainly Zaire strain related Ebola virus) has been declared most widely spread deadly persistent epidemic due to unavailability of rapid diagnostic, detection, and therapeutics. Ebola virus disease (EVD), a severe viral hemorrhagic fever syndrome caused by Ebola virus (EBOV) is transmitted by direct contact with the body fluids of infected person and objects contaminated with virus or infected animals. World Health Organization (WHO) has declared EVD epidemic as public health emergency of international concern with severe global economic burden. At fatal EBOV infection stage, patients usually die before the antibody response. Currently, rapid blood tests to diagnose EBOV infection include the antigen or antibodies capture using ELISA and RNA detection using RT/Q-PCR within 3–10 days after the onset of symptoms. Moreover, few nanotechnology-based colorimetric and paper-based immunoassay methods have been recently reported to detect Ebola virus. Unfortunately, these methods are limited to laboratory only. As state-of-the art (SoA) diagnostics time to confirm Ebola infection, varies from 6 hours to about 3 days, it causes delay in therapeutic approaches. Thus developing a cost-effective, rapid, sensitive, and selective sensor to detect EVD at point-of-care (POC) is certainly worth exploring to establish rapid diagnostics to decide therapeutics. This review highlights SoA of Ebola diagnostics and also a call to develop rapid, selective and sensitive POC detection of EBOV for global health care. We propose that adopting miniaturized electrochemical EBOV immunosensing can detect virus level at pM concentration within ~40 minute compared to 3 days of ELISA test at nM levels. PMID:26319169

Variation pattern of particulate organic carbon and nitrogen in oceans and inland waters

NASA Astrophysics Data System (ADS)

Huang, Changchun; Jiang, Quanliang; Yao, Ling; Yang, Hao; Lin, Chen; Huang, Tao; Zhu, A.-Xing; Zhang, Yimin

2018-03-01

We examined the relationship between, and variations in, particulate organic carbon (POC) and particulate organic nitrogen (PON) based on previously acquired ocean and inland water data. The latitudinal dependency of POC / PON is significant between 20 and 90° N but weak in low-latitude areas and in the Southern Hemisphere. The mean values of POC / PON in the Southern Hemisphere and Northern Hemisphere were 7.40 ± 3.83 and 7.80 ± 3.92, respectively. High values of POC / PON appeared between 80-90 (12.2 ± 7.5) and 70-80° N (9.4 ± 6.4), while relatively low POC / PON was found from 20 (6.6 ± 2.8) to 40° N (6.7 ± 2.7). The latitudinal variation of POC / PON in the Northern Hemisphere is much stronger than in the Southern Hemisphere due to the influence of more terrestrial organic matter. Higher POC and PON could be expected in coastal waters. POC / PON growth ranged from 6.89 ± 2.38 to 7.59 ± 4.22 in the Northern Hemisphere, with an increasing rate of 0.0024 km from the coastal to open ocean. Variations of POC / PON in lake water also showed a similar latitude-variation tendency of POC / PON with ocean water but were significantly regulated by the lakes' morphology, trophic state and climate. Small lakes and high-latitude lakes prefer relatively high POC / PON, and large lakes and low-latitude lakes tend to prefer low POC / PON. The coupling relationship between POC and PON in oceans is much stronger than in inland waters. Variations in POC, PON and POC / PON in inland waters should receive more attention due to the implications of these values for the global carbon and nitrogen cycles and the indeterminacy of the relationship between POC and PON.

Comparison between available serologic tests for detecting antibodies against Anaplasma phagocytophilum and Borrelia burgdorferi in horses in Canada.

PubMed

Schvartz, Gili; Epp, Tasha; Burgess, Hilary J; Chilton, Neil B; Lohmann, Katharina L

2015-07-01

To investigate the agreement between available serologic tests for the detection of antibodies against Anaplasma phagocytophilum and Borrelia burgdorferi, 50 serum samples from horses of unknown clinical status and at low risk for infection were tested. In addition to a point-of-care enzyme-linked immunosorbent assay (pocELISA), the evaluated tests included 2 indirect fluorescent antibody tests (IFATs) for antibodies against A. phagocytophilum and an IFAT, an ELISA confirmed with Western blot, and the Lyme multiplex assay for antibodies against B. burgdorferi. For each pair-wise comparison between serologic tests, the difference in the proportion of seropositive results as well as kappa and the prevalence-adjusted, bias-adjusted kappa were calculated. The proportion of seropositive results differed significantly in each pairwise comparison of tests for detection of antibodies against A. phagocytophilum, and between the pocELISA and IFAT as well as between the pocELISA and Lyme multiplex assay for detection of antibodies against B. burgdorferi. Agreement based on kappa varied from poor to fair while agreement was improved when evaluating prevalence-adjusted, bias-adjusted kappa. Lack of agreement may be explained by differences in methodology between the evaluated tests, cross-reactivity or false-positive and false-negative tests. In addition to the limitations of serologic test interpretation in the absence of clinical disease, this data suggest that screening of horses for exposure to tick-borne diseases in nonendemic areas may not be warranted. © 2015 The Author(s).

The Ebola Spatial Care Path™: Accelerating point-of-care diagnosis, decision making, and community resilience in outbreaks.

PubMed

Kost, Gerald J; Ferguson, William J; Hoe, Jackie; Truong, Anh-Thu; Banpavichit, Arirat; Kongpila, Surin

2015-01-01

To present a vision where point-of-care testing (POCT) accelerates an Ebola Spatial Care Path™ (SCP) and future molecular diagnostics enable facilitated-access self-testing (FAST POC); to design an alternate care facility (ACF) for the SCP; to innovate an Ebola diagnostic center (DC); and to propel rapid POCT to the frontline to create resilience that stops future outbreaks. PubMed, literature, and web searches. Centers for Disease Control and Prevention (CDC), Food and Drug Administration (FDA), Medicine Without Frontiers, and World Health Organization (WHO) document analyses. Investigations in China, the Philippines, Thailand, and the United States. Review of SE Asia, US, and West Africa isolation-treatment centers. Innovation of a SCP, ACF, and DC suitable for American and other communities. The authors designed an ACF and DC to integrate SCP principles for urgent Ebola care. FDA emergency use authorizations for Ebola molecular diagnostics were discovered, but no portable, handheld, or self-contained molecular POC instruments are yet available, although feasible. The WHO initiated design criteria and an acceptance protocol for testing. Financial investment in POCT will downsize Ebola outbreaks. POCT is facilitating global health. Now, global health problems are elevating POCT to new levels of importance for accelerating diagnosis and evidence-based decision making during disease outbreaks. Authorities concur that rapid diagnosis has potential to stop disease spread. With embedded POCT, strategic SCPs planned by communities fulfill CDC recommendations. POC devices should consolidate multiplex test clusters supporting patients with Ebola in isolation. The ultimate future solution is FAST POC. New technologies offer minimally significant risks. Diagnostic centers in ACFs and transportable formats also will optimize Ebola SCPs.

Reliable and accurate CD4+ T cell count and percent by the portable flow cytometer CyFlow MiniPOC and "CD4 Easy Count Kit-Dry", as revealed by the comparison with the gold standard dual platform technology.

PubMed

Nasi, Milena; De Biasi, Sara; Bianchini, Elena; Gibellini, Lara; Pinti, Marcello; Scacchetti, Tiziana; Trenti, Tommaso; Borghi, Vanni; Mussini, Cristina; Cossarizza, Andrea

2015-01-01

An accurate and affordable CD4+ T cells count is an essential tool in the fight against HIV/AIDS. Flow cytometry (FCM) is the "gold standard" for counting such cells, but this technique is expensive and requires sophisticated equipment, temperature-sensitive monoclonal antibodies (mAbs) and trained personnel. The lack of access to technical support and quality assurance programs thus limits the use of FCM in resource-constrained countries. We have tested the accuracy, the precision and the carry-over contamination of Partec CyFlow MiniPOC, a portable and economically affordable flow cytometer designed for CD4+ count and percentage, used along with the "CD4% Count Kit-Dry". Venous blood from 59 adult HIV+ patients (age: 25-58 years; 43 males and 16 females) was collected and stained with the "MiniPOC CD4% Count Kit-Dry". CD4+ count and percentage were then determined in triplicate by the CyFlow MiniPOC. In parallel, CD4 count was performed using mAbs and a CyFlow Counter, or by a dual platform system (from Beckman Coulter) based upon Cytomic FC500 ("Cytostat tetrachrome kit" for mAbs) and Coulter HmX Hematology Analyzer (for absolute cell count). The accuracy of CyFlow MiniPOC against Cytomic FC500 showed a correlation coefficient (CC) of 0.98 and 0.97 for CD4+ count and percentage, respectively. The accuracy of CyFlow MiniPOC against CyFlow Counter showed a CC of 0.99 and 0.99 for CD4 T cell count and percentage, respectively. CyFlow MiniPOC showed an excellent repeatability: CD4+ cell count and percentage were analyzed on two instruments, with an intra-assay precision below ± 5% deviation. Finally, there was no carry-over contamination for samples at all CD4 values, regardless of their position in the sequence of analysis. The cost-effective CyFlow MiniPOC produces rapid, reliable and accurate results that are fully comparable with those from highly expensive dual platform systems.

The universe of ANA testing: a case for point-of-care ANA testing.

PubMed

Konstantinov, Konstantin N; Rubin, Robert L

2017-12-01

Testing for total antinuclear antibodies (ANA) is a critical tool for diagnosis and management of autoimmune diseases at both the primary care and subspecialty settings. Repurposing of ANA from a test for lupus to a test for any autoimmune condition has driven the increase in ANA requests. Changes in ANA referral patterns include early or subclinical autoimmune disease detection in patients with low pre-test probability and use of negative ANA results to rule out underlying autoimmune disease. A positive result can lead to further diagnostic considerations. Currently, ANA tests are performed in centralized laboratories; an alternative would be ANA testing at the clinical point-of-care (POC). By virtue of its near real-time data collection capability, low cost, and ease of use, we believe the POC ANA has the potential to enable a new paradigm shift in autoimmune serology testing.

Development and clinical validation of the Genedrive point-of-care test for qualitative detection of hepatitis C virus.

PubMed

Llibre, Alba; Shimakawa, Yusuke; Mottez, Estelle; Ainsworth, Shaun; Buivan, Tan-Phuc; Firth, Rick; Harrison, Elliott; Rosenberg, Arielle R; Meritet, Jean-François; Fontanet, Arnaud; Castan, Pablo; Madejón, Antonio; Laverick, Mark; Glass, Allison; Viana, Raquel; Pol, Stanislas; McClure, C Patrick; Irving, William Lucien; Miele, Gino; Albert, Matthew L; Duffy, Darragh

2018-04-03

Recently approved direct acting antivirals provide transformative therapies for chronic hepatitis C virus (HCV) infection. The major clinical challenge remains to identify the undiagnosed patients worldwide, many of whom live in low-income and middle-income countries, where access to nucleic acid testing remains limited. The aim of this study was to develop and validate a point-of-care (PoC) assay for the qualitative detection of HCV RNA. We developed a PoC assay for the qualitative detection of HCV RNA on the PCR Genedrive instrument. We validated the Genedrive HCV assay through a case-control study comparing results with those obtained with the Abbott RealTi m e HCV test. The PoC assay identified all major HCV genotypes, with a limit of detection of 2362 IU/mL (95% CI 1966 to 2788). Using 422 patients chronically infected with HCV and 503 controls negative for anti-HCV and HCV RNA, the Genedrive HCV assay showed 98.6% sensitivity (95% CI 96.9% to 99.5%) and 100% specificity (95% CI 99.3% to 100%) to detect HCV. In addition, melting peak ratiometric analysis demonstrated proof-of-principle for semiquantification of HCV. The test was further validated in a real clinical setting in a resource-limited country. We report a rapid, simple, portable and accurate PoC molecular test for HCV, with sensitivity and specificity that fulfils the recent FIND/WHO Target Product Profile for HCV decentralised testing in low-income and middle-income countries. This Genedrive HCV assay may positively impact the continuum of HCV care from screening to cure by supporting real-time treatment decisions. NCT02992184. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Novel POC1A mutation in primordial dwarfism reveals new insights for centriole biogenesis.

PubMed

Koparir, Asuman; Karatas, Omer F; Yuceturk, Betul; Yuksel, Bayram; Bayrak, Ali O; Gerdan, Omer F; Sagiroglu, Mahmut S; Gezdirici, Alper; Kirimtay, Koray; Selcuk, Ece; Karabay, Arzu; Creighton, Chad J; Yuksel, Adnan; Ozen, Mustafa

2015-10-01

POC1A encodes a WD repeat protein localizing to centrioles and spindle poles and is associated with short stature, onychodysplasia, facial dysmorphism and hypotrichosis (SOFT) syndrome. These main features are related to the defect in cell proliferation of chondrocytes in growth plate. In the current study, we aimed at identifying the molecular basis of two patients with primordial dwarfism (PD) in a single family through utilization of whole-exome sequencing. A novel homozygous p.T120A missense mutation was detected in POC1A in both patients, a known causative gene of SOFT syndrome, and confirmed using Sanger sequencing. To test the pathogenicity of the detected mutation, primary fibroblast cultures obtained from the patients and a control individual were used. For evaluating the global gene expression profile of cells carrying p.T120A mutation in POC1A, we performed the gene expression array and compared their expression profiles to those of control fibroblast cells. The gene expression array analysis showed that 4800 transcript probes were significantly deregulated in cells with p.T120A mutation in comparison to the control. GO term association results showed that deregulated genes are mostly involved in the extracellular matrix and cytoskeleton. Furthermore, the p.T120A missense mutation in POC1A caused the formation of abnormal mitotic spindle structure, including supernumerary centrosomes, and changes in POC1A were accompanied by alterations in another centrosome-associated WD repeat protein p80-katanin. As a result, we identified a novel mutation in POC1A of patients with PD and showed that this mutation causes the formation of multiple numbers of centrioles and multipolar spindles with abnormal chromosome arrangement. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Point-of-Care Ultrasound: A Trend in Health Care.

PubMed

Buerger, Anita M; Clark, Kevin R

2017-11-01

To discuss the current and growing use of point-of-care (POC) ultrasound in the management and care of patients. Several electronic research databases were searched to find articles that emphasized the use of POC ultrasound by health care providers who manage and treat critically ill or injured patients. Thirty-five relevant peer-reviewed journal articles were selected for this literature review. Common themes identified in the literature included the use of POC ultrasound in emergency medicine, military medicine, and remote care; comparison of POC ultrasound to other medical imaging modalities; investigation of the education and training required for nonimaging health care professionals who perform POC ultrasound in their practices; and discussion of the financial implications and limitations of POC ultrasound. POC ultrasound provides clinicians with real-time information to better manage and treat critically ill or injured patients in emergency medicine, military medicine, and remote care. In addition to providing immediate bedside diagnostic information, use of POC ultrasound has increased because of concerns regarding radiation protection. Finally, the expansion of POC ultrasound to other specialty areas requires nonimaging health care professionals to perform bedside ultrasound examinations and interpret the resulting images. Because POC ultrasound is user-dependent, adequate training is essential for all who perform and interpret the examinations. Research involving POC ultrasound will continue as innovations and confidence in ultrasound applications advance. Future research should continue to examine the broad use of POC ultrasound in patient care and management. ©2017 American Society of Radiologic Technologists.

Experimental study of ASCs combined with POC-PLA patch for the reconstruction of full-thickness chest wall defects.

PubMed

Zhang, Yuanzheng; Fang, Shuo; Dai, Jiezhi; Zhu, Lei; Fan, Hao; Tang, Weiya; Fan, Yongjie; Dai, Haiying; Zhang, Peipei; Wang, Ying; Xing, Xin; Yang, Chao

2017-01-01

To explore the repairing effect of combination of adipose stem cells (ASCs) and composite scaffolds on CWR, the electrospun Poly 1, 8-octanediol-co-citric acid (POC)-poly-L-lactide acid (PLA) composite scaffolds were prepared, followed by in vitro and in vivo biocompatibility evaluation of the scaffolds. Afterwards, ASCs were seeded on POC-PLA to construct the POC-PLA-ASCs scaffolds, and the POC-PLA, POC-PLA-ASCs, and traditional materials expanded polytetrafluoroethylene (ePTFE) were adopt for CWR in New Zealand white (NZW) rabbit models. As results, the POC-PLA-ASCs patches possessed good biocompatibility as the high proliferation ability of cells surrounding the patches. Rabbits in POC-PLA-ASCs groups showed better pulmonary function, less pleural adhesion, higher degradation rate and more neovascularization when compared with that in other two groups. The results of western blot indicated that POC-PLA-ASCs patches accelerated the expression of VEGF and Collagen I in rabbit models. From the above, our present study demonstrated that POC-PLA material was applied for CWR successfully, and ASCs seeded on the sheets could improve the pleural adhesions and promote the reparation of chest wall defects.

Semiquantitative Nucleic Acid Test with Simultaneous Isotachophoretic Extraction and Amplification.

PubMed

Bender, Andrew T; Borysiak, Mark D; Levenson, Amanda M; Lillis, Lorraine; Boyle, David S; Posner, Jonathan D

2018-06-19

Nucleic acid amplification tests (NAATs) provide high diagnostic accuracy for infectious diseases and quantitative results for monitoring viral infections. The majority of NAATs require complex equipment, cold chain dependent reagents, and skilled technicians to perform the tests. This largely confines NAATs to centralized laboratories and can significantly delay appropriate patient care. Low-cost, point-of-care (POC) NAATs are especially needed in low-resource settings to provide patients with diagnosis and treatment planning in a single visit to improve patient care. In this work, we present a rapid POC NAAT with integrated sample preparation and amplification using electrokinetics and paper substrates. We use simultaneous isotachophoresis (ITP) and recombinase polymerase amplification (RPA) to rapidly extract, amplify, and detect target nucleic acids from serum and whole blood in a paper-based format. We demonstrate simultaneous ITP and RPA can consistently detect 5 copies per reaction in buffer and 10 000 copies per milliliter of human serum with no intermediate user steps. We also show preliminary extraction and amplification of DNA from whole blood samples. Our test is rapid (results in less than 20 min) and made from low-cost materials, indicating its potential for detecting infectious diseases and monitoring viral infections at the POC in low resource settings.

An Integrated Tiered Service Delivery Model (ITSDM) Based on Local CD4 Testing Demands Can Improve Turn-Around Times and Save Costs whilst Ensuring Accessible and Scalable CD4 Services across a National Programme

PubMed Central

Glencross, Deborah K.; Coetzee, Lindi M.; Cassim, Naseem

2014-01-01

Background The South African National Health Laboratory Service (NHLS) responded to HIV treatment initiatives with two-tiered CD4 laboratory services in 2004. Increasing programmatic burden, as more patients access anti-retroviral therapy (ART), has demanded extending CD4 services to meet increasing clinical needs. The aim of this study was to review existing services and develop a service-model that integrated laboratory-based and point-of-care testing (POCT), to extend national coverage, improve local turn-around/(TAT) and contain programmatic costs. Methods NHLS Corporate Data Warehouse CD4 data, from 60–70 laboratories and 4756 referring health facilities was reviewed for referral laboratory workload, respective referring facility volumes and related TAT, from 2009–2012. Results An integrated tiered service delivery model (ITSDM) is proposed. Tier-1/POCT delivers CD4 testing at single health-clinics providing ART in hard-to-reach areas (<5 samples/day). Laboratory-based testing is extended with Tier-2/POC-Hubs (processing ≤30–40 CD4 samples/day), consolidating POCT across 8–10 health-clinics with other HIV-related testing and Tier-3/‘community’ laboratories, serving ≤40 health-clinics, processing ≤150 samples/day. Existing Tier-4/‘regional’ laboratories serve ≤100 facilities and process <350 samples/day; Tier-5 are high-volume ‘metro’/centralized laboratories (>350–1500 tests/day, serving ≥200 health-clinics). Tier-6 provides national support for standardisation, harmonization and quality across the organization. Conclusion The ITSDM offers improved local TAT by extending CD4 services into rural/remote areas with new Tier-3 or Tier-2/POC-Hub services installed in existing community laboratories, most with developed infrastructure. The advantage of lower laboratory CD4 costs and use of existing infrastructure enables subsidization of delivery of more expensive POC services, into hard-to-reach districts without reasonable access to a local CD4 laboratory. Full ITSDM implementation across 5 service tiers (as opposed to widespread implementation of POC testing to extend service) can facilitate sustainable ‘full service coverage’ across South Africa, and save>than R125 million in HIV/AIDS programmatic costs. ITSDM hierarchical parental-support also assures laboratory/POC management, equipment maintenance, quality control and on-going training between tiers. PMID:25490718

Earthquake-driven erosion of organic carbon at the eastern margin of the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Li, G.; West, A. J.; Hara, E. K.; Hammond, D. E.; Hilton, R. G.

2016-12-01

Large earthquakes can trigger massive landsliding that erodes particulate organic carbon (POC) from vegetation, soil and bedrocks, potentially linking seismotectonics to the global carbon cycle. Recent work (Wang et al., 2016, Geology) has highlighted a dramatic increase in riverine export of biospheric POC following the 2008 Mw7.9 Wenchuan earthquake, in the steep Longmen Shan mountain range at the eastern margin of the Tibetan Plateau. However, a complete, source-to-sink picture of POC erosion after the earthquake is still missing. Here we track POC transfer across the Longmen Shan range from high mountains to the downstream Zipingpu reservoir where riverine-exported POC has been trapped. Building on the work of Wang et al. (2016), who measured the compositions and fluxes of riverine POC, this study is focused on constraining the source and fate of the eroded POC after the earthquake. We have sampled landslide deposits and river sediment, and we have cored the Zipingpu reservoir, following a source-to-sink sampling strategy. We measured POC compositions and grain size of the sediment samples, mapped landslide-mobilized POC using maps of landslide inventory and biomass, and tracked POC loading from landslides to the reservoir sediment to constrain the fate of eroded OC. Constraints on carbon sources, fluxes and fate provide the foundation for constructing a post-earthquake POC budget. This work highlights the role of earthquakes in the mobilization and burial of POC, providing new insight into mechanisms linking tectonics and the carbon cycle and building understanding needed to interpret past seismicity from sedimentary archives.

Global evaluation of particulate organic carbon flux parameterizations and implications for atmospheric pCO2

NASA Astrophysics Data System (ADS)

Gloege, Lucas; McKinley, Galen A.; Mouw, Colleen B.; Ciochetto, Audrey B.

2017-07-01

The shunt of photosynthetically derived particulate organic carbon (POC) from the euphotic zone and deep remineralization comprises the basic mechanism of the "biological carbon pump." POC raining through the "twilight zone" (euphotic depth to 1 km) and "midnight zone" (1 km to 4 km) is remineralized back to inorganic form through respiration. Accurately modeling POC flux is critical for understanding the "biological pump" and its impacts on air-sea CO2 exchange and, ultimately, long-term ocean carbon sequestration. Yet commonly used parameterizations have not been tested quantitatively against global data sets using identical modeling frameworks. Here we use a single one-dimensional physical-biogeochemical modeling framework to assess three common POC flux parameterizations in capturing POC flux observations from moored sediment traps and thorium-234 depletion. The exponential decay, Martin curve, and ballast model are compared to data from 11 biogeochemical provinces distributed across the globe. In each province, the model captures satellite-based estimates of surface primary production within uncertainties. Goodness of fit is measured by how well the simulation captures the observations, quantified by bias and the root-mean-square error and displayed using "target diagrams." Comparisons are presented separately for the twilight zone and midnight zone. We find that the ballast hypothesis shows no improvement over a globally or regionally parameterized Martin curve. For all provinces taken together, Martin's b that best fits the data is [0.70, 0.98]; this finding reduces by at least a factor of 3 previous estimates of potential impacts on atmospheric pCO2 of uncertainty in POC export to a more modest range [-16 ppm, +12 ppm].

Source, transport and fluxes of Amazon River particulate organic carbon: Insights from river sediment depth-profiles

NASA Astrophysics Data System (ADS)

Bouchez, Julien; Galy, Valier; Hilton, Robert G.; Gaillardet, Jérôme; Moreira-Turcq, Patricia; Pérez, Marcela Andrea; France-Lanord, Christian; Maurice, Laurence

2014-05-01

In order to reveal particulate organic carbon (POC) source and mode of transport in the largest river basin on Earth, we sampled the main sediment-laden tributaries of the Amazon system (Solimões, Madeira and Amazon) during two sampling campaigns, following vertical depth-profiles. This sampling technique takes advantage of hydrodynamic sorting to access the full range of solid erosion products transported by the river. Using the Al/Si ratio of the river sediments as a proxy for grain size, we find a general increase in POC content with Al/Si, as sediments become finer. However, the sample set shows marked variability in the POC content for a given Al/Si ratio, with the Madeira River having lower POC content across the measured range in Al/Si. The POC content is not strongly related to the specific surface area (SSA) of the suspended load, and bed sediments have a much lower POC/SSA ratio. These data suggest that SSA exerts a significant, yet partial, control on POC transport in Amazon River suspended sediment. We suggest that the role of clay mineralogy, discrete POC particles and rock-derived POC warrant further attention in order to fully understand POC transport in large rivers.

Fabrication and characterization of toughness-enhanced scaffolds comprising β-TCP/POC using the freeform fabrication system with micro-droplet jetting.

PubMed

Gao, Li; Li, Cuidi; Chen, Fangping; Liu, Changsheng

2015-06-24

A novel elastomeric material, poly(1,8-octanediol-co-citrate) (POC), has demonstrated tremendous versatility because of its advantageous toughness, tunable degradation properties, and efficient drug release capability. In this study, POC was used to improve the mechanical performance of β-tricalcium phosphate (β-Ca3(PO4)2, β-TCP). (3D) β-TCP/POC composite scaffolds were fabricated by a 3D printing technique based on the freeform fabrication system with micro-droplet jetting (FFS-MDJ). The physiochemical properties, compressive modulus, drug release behavior, and cell response of β-TCP/POC composite scaffolds were systematically investigated. The results showed that β-TCP/POC scaffolds had uniform macropores of 300-400 μm, porosity of approximately 45%, biodegradability in phosphate-buffered saline, and high compressive modulus of 50-75 MPa. With the incorporation of POC into β-TCP, the toughness of the composite scaffolds was improved significantly. Moreover, β-TCP/POC scaffolds exhibited sustained drug (ibuprofen (IBU)) release capability. Additionally, β-TCP/POC scaffolds facilitated C2C12 cell attachment and proliferation. It was indicated that the 3D-printed porous β-TCP/POC scaffolds with high compressive modulus and good drug delivery performance might be a promising candidate for bone defect repair.

Technical note: Evaluation of the diagnostic accuracy of 2 point-of-care β-hydroxybutyrate devices in stored bovine plasma at room temperature and at 37°C.

PubMed

Leal Yepes, F A; Nydam, D V; Heuwieser, W; Mann, S

2018-04-25

The use of point-of-care (POC) devices to measure blood metabolites, such as β-hydroxybutyrate (BHB), on farm have become an important diagnostic and screening tool in the modern dairy industry. The POC devices allow for immediate decision making and are often more economical than the use of laboratory-based methods; however, precision and accuracy may be lower when measurements are performed in an uncontrolled environment. Ideally, the advantages of the POC devices and the standardized laboratory environment could be combined when measuring samples that do not require an immediate result-for example, in research applications or when immediate intervention is not the goal. The objective of this study was to compare the capability of 2 POC devices (TaiDoc, Pharmadoc, Lübeck, Germany; Precision Xtra, Abbott Diabetes Care, Abingdon, UK) to measure BHB concentrations either at room temperature (RT; 20-22°C) or at 37°C compared with the gold standard test in stored plasma samples. Whole blood from multiparous Holstein dairy cows (n = 113) was sampled from the coccygeal vessels between 28 d before expected calving and 42 DIM. Whole-blood BHB concentrations were determined cow-side using the TaiDoc POC device. Plasma was separated within 1 h of collection and stored until analysis. A subset of stored plasma samples (n = 100) consisting of 1 sample per animal was chosen retrospectively based on the BHB concentrations in whole blood within the range of 0.2 to 4.0 mmol/L. The samples were analyzed for BHB plasma concentration using an automated chemistry analyzer (Hitachi 917, Hitachi, Tokyo, Japan), which was considered the gold standard. On the same day, the samples were also measured with the 2 POC devices, with samples either at RT or heated up to 37°C. Our study showed high Spearman correlation coefficients (>0.99) using either device and with samples at both temperatures compared with the gold standard. Passing-Bablok regression revealed a very strong correlation (>0.99), indicating good agreement between both POC devices and the gold standard method. For hyperketonemia detection, defined as BHB concentration ≥1.2 mmol/L, the sensitivity for both POC devices at RT and 37°C was equally high at 100%. Specificity was lowest (67.4%) for the TaiDoc used with plasma at RT and was highest (86.5%) when plasma was measured at 37°C with the Precision Xtra meter. Bland-Altman plots revealed a mean bias of 0.25 and 0.4 mmol/L for the Precision Xtra meter and TaiDoc, respectively, when tested on plasma at 37°C. Our data showed that both POC devices are suitable for measuring BHB concentration in stored bovine plasma, and accuracy was highest when samples were heated to 37°C compared with RT. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Global carbon export from the terrestrial biosphere controlled by erosion.

PubMed

Galy, Valier; Peucker-Ehrenbrink, Bernhard; Eglinton, Timothy

2015-05-14

Riverine export of particulate organic carbon (POC) to the ocean affects the atmospheric carbon inventory over a broad range of timescales. On geological timescales, the balance between sequestration of POC from the terrestrial biosphere and oxidation of rock-derived (petrogenic) organic carbon sets the magnitude of the atmospheric carbon and oxygen reservoirs. Over shorter timescales, variations in the rate of exchange between carbon reservoirs, such as soils and marine sediments, also modulate atmospheric carbon dioxide levels. The respective fluxes of biospheric and petrogenic organic carbon are poorly constrained, however, and mechanisms controlling POC export have remained elusive, limiting our ability to predict POC fluxes quantitatively as a result of climatic or tectonic changes. Here we estimate biospheric and petrogenic POC fluxes for a suite of river systems representative of the natural variability in catchment properties. We show that export yields of both biospheric and petrogenic POC are positively related to the yield of suspended sediment, revealing that POC export is mostly controlled by physical erosion. Using a global compilation of gauged suspended sediment flux, we derive separate estimates of global biospheric and petrogenic POC fluxes of 157(+74)(-50) and 43(+61)(-25) megatonnes of carbon per year, respectively. We find that biospheric POC export is primarily controlled by the capacity of rivers to mobilize and transport POC, and is largely insensitive to the magnitude of terrestrial primary production. Globally, physical erosion rates affect the rate of biospheric POC burial in marine sediments more strongly than carbon sequestration through silicate weathering. We conclude that burial of biospheric POC in marine sediments becomes the dominant long-term atmospheric carbon dioxide sink under enhanced physical erosion.

The direct liquefaction proof of concept program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Comolli, A.G.; Lee, L.K.; Pradhan, V.R.

1995-12-31

The goal of the Proof of Concept (POC) Program is to develop Direct Coal Liquefaction and associated transitional technologies towards commercial readiness for economically producing premium liquid fuels from coal in an environmentally acceptable manner. The program focuses on developing the two-stage liquefaction (TSL) process by utilizing geographically strategic feedstocks, commercially feasible catalysts, new prototype equipment, and testing co-processing or alternate feedstocks and improved process configurations. Other high priority objectives include dispersed catalyst studies, demonstrating low rank coal liquefaction without solids deposition, improving distillate yields on a unit reactor volume basis, demonstrating ebullated bed operations while obtaining scale-up data, demonstratingmore » optimum catalyst consumption using new concepts (e.g. regeneration, cascading), producing premium products through on-line hydrotreating, demonstrating improved hydrogen utilization for low rank coals using novel heteroatom removal methods, defining and demonstrating two-stage product properties for upgrading; demonstrating efficient and economic solid separation methods, examining the merits of integrated coal cleaning, demonstrating co-processing, studying interactions between the preheater and first and second-stage reactors, improving process operability by testing and incorporating advanced equipment and instrumentation, and demonstrating operation with alternate coal feedstocks. During the past two years major PDU Proof of Concept runs were completed. POC-1 with Illinois No. 6 coal and POC-2 with Black Thunder sub-bituminous coal. Results from these operations are continuing under review and the products are being further refined and upgraded. This paper will update the results from these operations and discuss future plans for the POC program.« less

Comparative performance assessment of point-of-care testing devices for measuring glucose and ketones at the patient bedside.

PubMed

Ceriotti, Ferruccio; Kaczmarek, Ewa; Guerra, Elena; Mastrantonio, Fabrizio; Lucarelli, Fausto; Valgimigli, Francesco; Mosca, Andrea

2015-03-01

Point-of-care (POC) testing devices for monitoring glucose and ketones can play a key role in the management of dysglycemia in hospitalized diabetes patients. The accuracy of glucose devices can be influenced by biochemical changes that commonly occur in critically ill hospital patients and by the medication prescribed. Little is known about the influence of these factors on ketone POC measurements. The aim of this study was to assess the analytical performance of POC hospital whole-blood glucose and ketone meters and the extent of glucose interference factors on the design and accuracy of ketone results. StatStrip glucose/ketone, Optium FreeStyle glucose/ketone, and Accu-Chek Performa glucose were also assessed and results compared to a central laboratory reference method. The analytical evaluation was performed according to Clinical and Laboratory Standards Institute (CLSI) protocols for precision, linearity, method comparison, and interference. The interferences assessed included acetoacetate, acetaminophen, ascorbic acid, galactose, maltose, uric acid, and sodium. The accuracies of both Optium ketone and glucose measurements were significantly influenced by varying levels of hematocrit and ascorbic acid. StatStrip ketone and glucose measurements were unaffected by the interferences tested with exception of ascorbic acid, which reduced the higher level ketone value. The accuracy of Accu-Chek glucose measurements was affected by hematocrit, by ascorbic acid, and significantly by galactose. The method correlation assessment indicated differences between the meters in compliance to ISO 15197 and CLSI 12-A3 performance criteria. Combined POC glucose/ketone methods are now available. The use of these devices in a hospital setting requires careful consideration with regard to the selection of instruments not sensitive to hematocrit variation and presence of interfering substances. © 2014 Diabetes Technology Society.

Coverage of HIV prevention components among people with long-standing diagnosed HIV infection in El Salvador.

PubMed

Jacobson, Jerry O; Creswell, Jacob; Guardado, Maria Elena; Lee, Janet C; Isabel Nieto, Ana; Paz-Bailey, Gabriela

2012-09-01

There is scarce information on prevention coverage and management of sexually transmitted infections (STIs) in people with HIV in resource-limited settings. Six hundred eighty nine sexually active people diagnosed with HIV ≥12 months before the study, including 110 men who have sex with men, 237 heterosexual men, and 342 women, were recruited from HIV support groups and hospitals in El Salvador and completed self-administered computer-assisted questionnaires and STI testing. Logistic models identified correlates of exposure to posttest counseling (POC) and subsequent prevention interventions (PIs). Past-year transmission risk factors included unprotected sex with noncommercial partners (28.7%), having multiple sex partners (76.4%), a casual sex partner (31.4%), selling (3.5%) and purchasing sex (6.4%), herpes simplex virus type 2 (86.3%), and treatable STIs (18.6%). Men who have sex with men reported more recent casual partners, sex work, and alcohol and drug use than other subgroups. POC (22.8%), PIs (31.3%), and access to advice and information regarding HIV at the point of HIV care (24.1%) were limited. Of subjects with past-year STI symptoms (N = 267), 44.1% had sought medical attention. In multivariate analysis, POC was negatively associated with multiple partners. PI was associated with self-initiated testing, treatable STIs, and female sex. Both outcomes were associated with HIV-related discrimination outside of the health services context. Coverage of POC, PIs, and treatment-seeking for STI symptoms was low among individuals with diagnosed HIV infection, although most were in regular contact with care and treatment. Prevention programs at testing and treatment sites should be intensified and should incorporate risk behavior screening to improve targeting.

Reliable and Accurate CD4+ T Cell Count and Percent by the Portable Flow Cytometer CyFlow MiniPOC and “CD4 Easy Count Kit-Dry”, as Revealed by the Comparison with the Gold Standard Dual Platform Technology

PubMed Central

Nasi, Milena; De Biasi, Sara; Bianchini, Elena; Gibellini, Lara; Pinti, Marcello; Scacchetti, Tiziana; Trenti, Tommaso; Borghi, Vanni; Mussini, Cristina; Cossarizza, Andrea

2015-01-01

Background An accurate and affordable CD4+ T cells count is an essential tool in the fight against HIV/AIDS. Flow cytometry (FCM) is the “gold standard” for counting such cells, but this technique is expensive and requires sophisticated equipment, temperature-sensitive monoclonal antibodies (mAbs) and trained personnel. The lack of access to technical support and quality assurance programs thus limits the use of FCM in resource-constrained countries. We have tested the accuracy, the precision and the carry-over contamination of Partec CyFlow MiniPOC, a portable and economically affordable flow cytometer designed for CD4+ count and percentage, used along with the “CD4% Count Kit-Dry”. Materials and Methods Venous blood from 59 adult HIV+ patients (age: 25–58 years; 43 males and 16 females) was collected and stained with the “MiniPOC CD4% Count Kit-Dry”. CD4+ count and percentage were then determined in triplicate by the CyFlow MiniPOC. In parallel, CD4 count was performed using mAbs and a CyFlow Counter, or by a dual platform system (from Beckman Coulter) based upon Cytomic FC500 (“Cytostat tetrachrome kit” for mAbs) and Coulter HmX Hematology Analyzer (for absolute cell count). Results The accuracy of CyFlow MiniPOC against Cytomic FC500 showed a correlation coefficient (CC) of 0.98 and 0.97 for CD4+ count and percentage, respectively. The accuracy of CyFlow MiniPOC against CyFlow Counter showed a CC of 0.99 and 0.99 for CD4 T cell count and percentage, respectively. CyFlow MiniPOC showed an excellent repeatability: CD4+ cell count and percentage were analyzed on two instruments, with an intra-assay precision below ±5% deviation. Finally, there was no carry-over contamination for samples at all CD4 values, regardless of their position in the sequence of analysis. Conclusion The cost-effective CyFlow MiniPOC produces rapid, reliable and accurate results that are fully comparable with those from highly expensive dual platform systems. PMID:25622041

Differing Daphnia magna assimilation efficiencies for terrestrial, bacterial, and algal carbon and fatty acids.

PubMed

Taipale, Sami J; Brett, Michael T; Hahn, Martin W; Martin-Creuzburg, Dominik; Yeung, Sean; Hiltunen, Minna; Strandberg, Ursula; Kankaala, Paula

2014-02-01

There is considerable interest in the pathways by which carbon and growth-limiting elemental and biochemical nutrients are supplied to upper trophic levels. Fatty acids and sterols are among the most important molecules transferred across the plant-animal interface of food webs. In lake ecosystems, in addition to phytoplankton, bacteria and terrestrial organic matter are potential trophic resources for zooplankton, especially in those receiving high terrestrial organic matter inputs. We therefore tested carbon, nitrogen, and fatty acid assimilation by the crustacean Daphnia magna when consuming these resources. We fed Daphnia with monospecific diets of high-quality (Cryptomonas marssonii) and intermediate-quality (Chlamydomonas sp. and Scenedesmus gracilis) phytoplankton species, two heterotrophic bacterial strains, and particles from the globally dispersed riparian grass, Phragmites australis, representing terrestrial particulate organic carbon (t-POC). We also fed Daphnia with various mixed diets, and compared Daphnia fatty acid, carbon, and nitrogen assimilation across treatments. Our results suggest that bacteria were nutritionally inadequate diets because they lacked sterols and polyunsaturated omega-3 and omega-6 (omega-3 and omega-6) fatty acids (PUFAs). However, Daphnia were able to effectively use carbon and nitrogen from Actinobacteria, if their basal needs for essential fatty acids and sterols were met by phytoplankton. In contrast to bacteria, t-POC contained sterols and omega-6 and omega-3 fatty acids, but only at 22%, 1.4%, and 0.2% of phytoplankton levels, respectively, which indicated that t-POC food quality was especially restricted with regard to omega-3 PUFAs. Our results also showed higher assimilation of carbon than fatty acids from t-POC and bacteria into Daphnia, based on stable-isotope and fatty acids analysis, respectively. A relatively high (>20%) assimilation of carbon and fatty acids from t-POC was observed only when the proportion of t-POC was >60%, but due to low PUFA to carbon ratio, these conditions yielded poor Daphnia growth. Because of lower assimilation for carbon, nitrogen, and fatty acids from t-POC relative to diets of bacteria mixed with phytoplankton, we conclude that the microbial food web, supported by phytoplankton, and not direct t-POC consumption, may support zooplankton production. Our results suggest that terrestrial particulate organic carbon poorly supports upper trophic levels of the lakes.

Temporal and spatial variations of surface particulate organic carbon in the Bohai and Yellow Sea of China

NASA Astrophysics Data System (ADS)

Hang, F.; Wang, X.; Yu, Z.

2017-12-01

The Yellow-Bohai Sea is a semi-closed marginal sea in the east of China, affected much by human activities, especially the Bohai Sea. The present study evaluates spatial and seasonal variations of surface particulate organic carbon (POC) that was derived from MODIS month-average data for the period of July 2002-December 2016. Our analyses show that POC concentrations are significantly higher in the Bohai Sea (314.7-587.9 mg m-3) than in the Yellow Sea (181.3-492.2 mg m-3). In general, POC concentrations were higher in the nearshore waters than in the offshore. There are strong seasonal to interannual variations in POC. Mean POC was highest in spring in both Bohai Sea and Yellow Sea; the lowest POC was found in summer in the Yellow Sea, but in winter in the Bohai Sea. The elevated POC from summer to fall indicates that there was allochthonous source of POC. Overall, there was a decreasing trend in POC prior to year 2012, followed by a strong upward trend until the end of 2015. The interannual variability in POC was significantly correlated with NPGO, PDO and ENSO in the Yellow Sea, but only with NPGO in the Bohai Sea. Our analyses point out that both climate variability and human activity may impacts the carbon cycle in the Yellow-Bohai Sea.

An adaptive two-stage dose-response design method for establishing proof of concept.

PubMed

Franchetti, Yoko; Anderson, Stewart J; Sampson, Allan R

2013-01-01

We propose an adaptive two-stage dose-response design where a prespecified adaptation rule is used to add and/or drop treatment arms between the stages. We extend the multiple comparison procedures-modeling (MCP-Mod) approach into a two-stage design. In each stage, we use the same set of candidate dose-response models and test for a dose-response relationship or proof of concept (PoC) via model-associated statistics. The stage-wise test results are then combined to establish "global" PoC using a conditional error function. Our simulation studies showed good and more robust power in our design method compared to conventional and fixed designs.

Development of Face Gear Technology for Industrial and Aerospace Power Transmission

NASA Technical Reports Server (NTRS)

Heath, Gregory F.; Filler, Robert R.; Tan, Jie

2002-01-01

Tests of a 250 horsepower proof-of-concept (POC) split torque face gear transmission were completed by The Boeing Company in Mesa, Arizona, while working under a Defense Advanced Research Projects Agency (DARPA) Technology Reinvestment Program (TRP) This report provides a summary of these cooperative tests, which were jointly funded by Boeing and DARPA Design, manufacture and testing of the scaled-power TRP split torque gearbox followed preliminary evaluations of the concept performed early in the program The testing demonstrated the theory of operation for the concentric, tapered face gear assembly The results showed that the use of floating pinions in a concentric face gear arrangement produces a nearly even torque split The POC split torque tests determined that, with some improvements, face gears can be applied effectively in a split torque configuration which yields significant weight, cost and reliability improvements over conventional designs.

Significance of non-sinking particulate organic carbon and dark CO2 fixation to heterotrophic carbon demand in the mesopelagic northeast Atlantic

NASA Astrophysics Data System (ADS)

Baltar, Federico; Arístegui, Javier; Sintes, Eva; Gasol, Josep M.; Reinthaler, Thomas; Herndl, Gerhard J.

2010-05-01

It is generally assumed that sinking particulate organic carbon (POC) constitutes the main source of organic carbon supply to the deep ocean's food webs. However, a major discrepancy between the rates of sinking POC supply (collected with sediment traps) and the prokaryotic organic carbon demand (the total amount of carbon required to sustain the heterotrophic metabolism of the prokaryotes; i.e., production plus respiration, PCD) of deep-water communities has been consistently reported for the dark realm of the global ocean. While the amount of sinking POC flux declines exponentially with depth, the concentration of suspended, buoyant non-sinking POC (nsPOC; obtained with oceanographic bottles) exhibits only small variations with depth in the (sub)tropical Northeast Atlantic. Based on available data for the North Atlantic we show here that the sinking POC flux would contribute only 4-12% of the PCD in the mesopelagic realm (depending on the primary production rate in surface waters). The amount of nsPOC potentially available to heterotrophic prokaryotes in the mesopelagic realm can be partly replenished by dark dissolved inorganic carbon fixation contributing between 12% to 72% to the PCD daily. Taken together, there is evidence that the mesopelagic microheterotrophic biota is more dependent on the nsPOC pool than on the sinking POC supply. Hence, the enigmatic major mismatch between the organic carbon demand of the deep-water heterotrophic microbiota and the POC supply rates might be substantially smaller by including the potentially available nsPOC and its autochthonous production in oceanic carbon cycling models.

Precisão e confiabilidade de um teste imuno-cromatográfico rápido NS1 para diagnóstico DENV-1 no ponto de atendimento e no laboratório.

PubMed

Mata, Verónica Elizabeth; Passos, Sonia Regina Lambert; Hökerberg, Yara Hahr Marques; Berardinelli, Guilherme Miguéis; Dos Santos, Maria Angelica Borges; Fukuoka, Levy Vilas Boas; Maciel, Anna Carolina Fontoura Seixas Rangel; Dos Santos Rodrigues, Cintia Damasceno; da Silva Santos, Aline; de Vasconcellos Carvalhaes de Oliveira, Raquel

2017-08-29

Rapid immunochromatographic tests (ICT) for dengue non-structural protein 1 (NS1) have shown good performance for diagnosing acute-phase dengue in serum in laboratory settings, but rarely have been assessed in whole blood and at point of care (POC). This study compare the accuracy and inter- and intra-observer reliability of the NS1 Bioeasy™ ICT in whole blood at POC versus serum in the laboratory, during a DENV-1 epidemic. Cross-sectional study involving 144 adults spontaneously demanding care in an emergency department within 4 days of onset of acute febrile illness. Accuracy of NS1 Bioeasy™ ICT was compared in whole blood and serum, both at 15 and 30 min, blinded to the reference RT-PCR or NS1 ELISA. Non-dengue patients were also tested for Zika virus with RT-PCR. Reliability of whole blood and serum readings by the same or different observers was measured by simple kappa (95% CI). At 15 min, sensitivity (Sn) of NS1 Bioeasy™ ICT in whole blood/POC was 76.7% (95% CI: 68.0-84.1) and specificity (Sp) was 87.0% (95% CI: 66.4-97.2). Sn in serum/laboratory was 82% (95% CI: 74.1-88.6) and Sp 100% (95% CI: 85.8-100). Positive likelihood ratio was 5.9 (95% CI: 2.0-17.0) for whole blood/POC and 19.8 (95% CI: 2.9-135.1) for serum/laboratory. Reliability of matched readings of whole blood/POC and serum/laboratory by the same observer (k = 0.83, 95% CI: 0.74-0.93) or different observers (k = 0.81, 95% CI: 0.72-0.92) was almost perfect, with higher discordant levels in the absence of dengue. Results did not differ statistically at 5%. NS1 Bioeasy™ ICT in DENV-1 epidemics is a potentially confirmatory test. Invalid results at 15 min should be reread at 30 min. To optimize impact of implementing ICT in the management of false-negatives it should be incorporated into an algorithm according to setting and available specimen. UTN U1111-1145-9451 .

Proof of concept and dose estimation with binary responses under model uncertainty.

PubMed

Klingenberg, B

2009-01-30

This article suggests a unified framework for testing Proof of Concept (PoC) and estimating a target dose for the benefit of a more comprehensive, robust and powerful analysis in phase II or similar clinical trials. From a pre-specified set of candidate models, we choose the ones that best describe the observed dose-response. To decide which models, if any, significantly pick up a dose effect, we construct the permutation distribution of the minimum P-value over the candidate set. This allows us to find critical values and multiplicity adjusted P-values that control the familywise error rate of declaring any spurious effect in the candidate set as significant. Model averaging is then used to estimate a target dose. Popular single or multiple contrast tests for PoC, such as the Cochran-Armitage, Dunnett or Williams tests, are only optimal for specific dose-response shapes and do not provide target dose estimates with confidence limits. A thorough evaluation and comparison of our approach to these tests reveal that its power is as good or better in detecting a dose-response under various shapes with many more additional benefits: It incorporates model uncertainty in PoC decisions and target dose estimation, yields confidence intervals for target dose estimates and extends to more complicated data structures. We illustrate our method with the analysis of a Phase II clinical trial. Copyright (c) 2008 John Wiley & Sons, Ltd.

Basal body stability and ciliogenesis requires the conserved component Poc1

PubMed Central

Osborn, Daniel P.S.; Giddings, Thomas H.; Beales, Philip L.; Winey, Mark

2009-01-01

Centrioles are the foundation for centrosome and cilia formation. The biogenesis of centrioles is initiated by an assembly mechanism that first synthesizes the ninefold symmetrical cartwheel and subsequently leads to a stable cylindrical microtubule scaffold that is capable of withstanding microtubule-based forces generated by centrosomes and cilia. We report that the conserved WD40 repeat domain–containing cartwheel protein Poc1 is required for the structural maintenance of centrioles in Tetrahymena thermophila. Furthermore, human Poc1B is required for primary ciliogenesis, and in zebrafish, DrPoc1B knockdown causes ciliary defects and morphological phenotypes consistent with human ciliopathies. T. thermophila Poc1 exhibits a protein incorporation profile commonly associated with structural centriole components in which the majority of Poc1 is stably incorporated during new centriole assembly. A second dynamic population assembles throughout the cell cycle. Our experiments identify novel roles for Poc1 in centriole stability and ciliogenesis. PMID:20008567

hPOC5 is a centrin-binding protein required for assembly of full-length centrioles.

PubMed

Azimzadeh, Juliette; Hergert, Polla; Delouvée, Annie; Euteneuer, Ursula; Formstecher, Etienne; Khodjakov, Alexey; Bornens, Michel

2009-04-06

Centrin has been shown to be involved in centrosome biogenesis in a variety of eukaryotes. In this study, we characterize hPOC5, a conserved centrin-binding protein that contains Sfi1p-like repeats. hPOC5 is localized, like centrin, in the distal portion of human centrioles. hPOC5 recruitment to procentrioles occurs during G2/M, a process that continues up to the full maturation of the centriole during the next cell cycle and is correlated with hyperphosphorylation of the protein. In the absence of hPOC5, RPE1 cells arrest in G1 phase, whereas HeLa cells show an extended S phase followed by cell death. We show that hPOC5 is not required for the initiation of procentriole assembly but is essential for building the distal half of centrioles. Interestingly, the hPOC5 family reveals an evolutionary divergence between vertebrates and organisms like Drosophila melanogaster or Caenorhabditis elegans, in which the loss of hPOC5 may correlate with the conspicuous differences in centriolar structure.

Implementation of Point-of-Care Diagnostics in Rural Primary Healthcare Clinics in South Africa: Perspectives of Key Stakeholders.

PubMed

Mashamba-Thompson, Tivani P; Jama, Ngcwalisa A; Sartorius, Benn; Drain, Paul K; Thompson, Rowan M

2017-01-08

Key stakeholders' involvement is crucial to the sustainability of quality point-of-care (POC) diagnostics services in low-and-middle income countries. The aim of this study was to explore key stakeholder perceptions on the implementation of POC diagnostics in rural primary healthcare (PHC) clinics in South Africa. We conducted a qualitative study encompassing in-depth interviews with multiple key stakeholders of POC diagnostic services for rural and resource-limited PHC clinics. Interviews were digitally recorded and transcribed verbatim prior to thematic content analysis. Thematic content analysis was conducted using themes guided by the World Health Organisation (WHO) quality-ASSURED (Affordable, Sensitive, Specific, User friendly, Rapid and to enable treatment at first visit and Robust, Equipment free and Delivered to those who need it) criteria for POC diagnostic services in resource-limited settings. 11 key stakeholders participated in the study. All stakeholders perceived the main advantage of POC diagnostics as enabling access to healthcare for rural patients. Stakeholders perceived the current POC diagnostic services to have an ability to meet patients' needs, but recommended further improvement of the following areas: research on cost-effectiveness; improved quality management systems; development of affordable POC diagnostic and clinic-based monitoring and evaluation. Key stakeholders of POC diagnostics in rural PHC clinics in South Africa highlighted the need to assess affordability and ensure quality assurance of current services before adopting new POC diagnostics and scaling up current POC diagnostics.

Implementation of Point-of-Care Diagnostics in Rural Primary Healthcare Clinics in South Africa: Perspectives of Key Stakeholders

PubMed Central

Mashamba-Thompson, Tivani P.; Jama, Ngcwalisa A.; Sartorius, Benn; Drain, Paul K.; Thompson, Rowan M.

2017-01-01

Introduction: Key stakeholders’ involvement is crucial to the sustainability of quality point-of-care (POC) diagnostics services in low-and-middle income countries. The aim of this study was to explore key stakeholder perceptions on the implementation of POC diagnostics in rural primary healthcare (PHC) clinics in South Africa. Method: We conducted a qualitative study encompassing in-depth interviews with multiple key stakeholders of POC diagnostic services for rural and resource-limited PHC clinics. Interviews were digitally recorded and transcribed verbatim prior to thematic content analysis. Thematic content analysis was conducted using themes guided by the World Health Organisation (WHO) quality-ASSURED (Affordable, Sensitive, Specific, User friendly, Rapid and to enable treatment at first visit and Robust, Equipment free and Delivered to those who need it) criteria for POC diagnostic services in resource-limited settings. Results: 11 key stakeholders participated in the study. All stakeholders perceived the main advantage of POC diagnostics as enabling access to healthcare for rural patients. Stakeholders perceived the current POC diagnostic services to have an ability to meet patients’ needs, but recommended further improvement of the following areas: research on cost-effectiveness; improved quality management systems; development of affordable POC diagnostic and clinic-based monitoring and evaluation. Conclusions: Key stakeholders of POC diagnostics in rural PHC clinics in South Africa highlighted the need to assess affordability and ensure quality assurance of current services before adopting new POC diagnostics and scaling up current POC diagnostics. PMID:28075337

Developing a semi-analytical algorithm to estimate particulate organic carbon (POC) levels in inland eutrophic turbid water based on MERIS images: A case study of Lake Taihu

NASA Astrophysics Data System (ADS)

Lyu, Heng; Wang, Yannan; Jin, Qi; Shi, Lei; Li, Yunmei; Wang, Qiao

2017-10-01

Particulate organic carbon (POC) plays an important role in the carbon cycle in water due to its biological pump process. In the open ocean, algorithms can accurately estimate the surface POC concentration. However, no suitable POC-estimation algorithm based on MERIS bands is available for inland turbid eutrophic water. A total of 228 field samples were collected from Lake Taihu in different seasons between 2013 and 2015. At each site, the optical parameters and water quality were analyzed. Using in situ data, it was found that POC-estimation algorithms developed for the open ocean and coastal waters using remote sensing reflectance were not suitable for inland turbid eutrophic water. The organic suspended matter (OSM) concentration was found to be the best indicator of the POC concentration, and POC has an exponential relationship with the OSM concentration. Through an analysis of the POC concentration and optical parameters, it was found that the absorption peak of total suspended matter (TSM) at 665 nm was the optimum parameter to estimate POC. As a result, MERIS band 7, MERIS band 10 and MERIS band 12 were used to derive the absorption coefficient of TSM at 665 nm, and then, a semi-analytical algorithm was used to estimate the POC concentration for inland turbid eutrophic water. An accuracy assessment showed that the developed semi-analytical algorithm could be successfully applied with a MAPE of 31.82% and RMSE of 2.68 mg/L. The developed algorithm was successfully applied to a MERIS image, and two full-resolution MERIS images, acquired on August 13, 2010, and December 7, 2010, were used to map the POC spatial distribution in Lake Taihu in summer and winter.

Spatial patterns and environmental controls of particulate organic carbon in surface waters in the conterminous United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Qichun; Zhang, Xuesong; Xu, Xingya

2016-06-01

Carbon stocks and fluxes in inland waters have been identified as important, but poorly constrained components of the global carbon cycle. In this study, we compile and analyze particulate organic carbon (POC) concentration data from 1145 U.S. Geological Survey (USGS) hydrologic stations to investigate the spatial variability and environmental controls of POC concentration. We observe substantial spatial variability in POC concentration (1.43 ± 2.56 mg C/ L, Mean ± Standard Deviation), with the Upper Mississippi River basin and the Piedmont region in the eastern U.S. having the highest POC concentration. Further, we employ generalized linear regression models to analyze themore » impacts of sediment transport and algae growth as well as twenty-one other environmental factors on the POC variability. Suspended sediment and chlorophyll-a explain 26% and 17% of the variability in POC concentration, respectively. At the national level, the twenty-one selected environmental factors combined can explain ca. 40% of the spatial variance in POC concentration. Overall, urban area and soil clay content show significant negative correlation with POC concentration, while soil water content and soil bulk density correlate positively with POC. In addition, total phosphorus concentration and dam density covariate positively with POC concentration. Furthermore, regional scale analyses reveal substantial variation in environmental controls determining POC concentration across the 18 major water resource regions in the U.S. The POC concentration and associated environmental controls also vary non-monotonically with river order. These findings indicate complex interactions among multiple factors in regulating POC production over different spatial scales and across various sections of the river networks. This complexity together with the large unexplained uncertainty highlight the need for consideration of non-linear processes that control them and developing appropriate methodologies to track the transformation and transport of carbon in these terrestrial-aquatic systems. Such scientific advancements will also benefit greatly the Earth system models that are currently deficient in representing properly this component of global carbon cycle.« less

[Distribution and source of particulate organic carbon and particulate nitrogen in the Yangtze River Estuary in summer 2012].

PubMed

Xing, Jian-Wei; Xian, Wei-Wei; Sheng, Xiu-Zhen

2014-07-01

Based on the data from the cruise carried out in August 2012 in the Yangtze River Estuary and its adjacent waters, spatial distributions of particulate organic carbon (POC), particulate nitrogen (PN) and their relationships with environmental factors were studied, and the source of POC and the contribution of phytoplankton to POC were analyzed combined with n (C)/n (N) ratio and chlorophyll a (Chl a) in the Yangtze River Estuary in summer 2012. The results showed that the concentrations of POC in the Yangtze River Estuary ranged from 0.68 mg x L(-1) to 34.80 mg x L(-1) in summer and the average content was 3.74 mg x L(-1), and PN contents varied between 0.03 mg x L(-1) and 9.13 mg x L(-1) with an average value of 0.57 mg x L(-1). Both of them presented that the concentrations in bottom layers were higher than those in the surface. POC and PN as well as total suspended matter (TSM) showed a extremel similar horizontal distribution trend that the highest values appeared in the near of the mouth and southwest of the survey waters, and decreased rapidly as toward the open seas, both of them showed higher contents in coastal zones and lower in outer sea. There was a fairly good positive linear relationship between POC and PN, which indicated that they had the same source. POC and PN expressed significantly positive correlations with TSM and chemical oxygen demand (COD), but showed relatively weak correlations with salinit and chlorophyll a, which demonstrated that terrestrial inputs had a strong influence on the distribution of POC and PN, and phytoplankton production was not the major source of organic matters in the Yangtze River Estuary. Both the n (C)/n (N) ratio and POC/Chl a analysis showed that the main source of POC was terrestrial inputs, and organic debris was the main existence form of POC. Quantitative analysis showed the biomass of phytoplankton only made an average of 2.54% contribution to POC in the Yangtze Rive Estuary in summer and non-living POC occupied the overwhelming advantage.

Erosion of particulate organic material from an Andean river and its delivery to the Amazon Basin

NASA Astrophysics Data System (ADS)

Clark, Kathryn; Hilton, Robert; West, A. Joshua; Robles Caceres, Arturo; Grocke, Darren; Marthews, Toby; Asner, Greg; New, Mark; Mahli, Yadvinder

2016-04-01

Organic carbon and nutrients discharged by mountainous rivers can play an important role in biogeochemical cycles from regional to global scales. The eastern Andes host productive forests on steep, rapidly eroding slopes, a combination that is primed to deliver sediment, carbon and nutrients to the lowland Amazon River. We quantify clastic sediment and particulate organic carbon (POC) discharge for the Kosñipata River, Peru, an Andean tributary of the Madre de Dios River, using suspended sediment samples and discharge measurements over one year at two gauging stations. Calculations of sediment yield on the basis of this data suggest that the Madre de Dios basin may have erosion rates ˜10 times greater than the Amazon Basin average. The total POC yield over the sampling period was up to five times higher than the yield in the lowland Amazon Basin, with most POC (70-80%) exported between December and March in the wet season. We use radiocarbon, stable C isotopes and C/N ratios to distinguish between the erosion and discharge of POC from sedimentary rocks (petrogenic POC) and POC eroded from the modern terrestrial biosphere, from vegetation and soil (biospheric POC). We find that biospheric POC discharge was significantly enhanced during flood events, over that of clastic sediment and petrogenic POC. The ultimate fate of the eroded POC may play a central role in the net carbon budget of Andean forest. In these forests, net productivity minus heterotrophic respiration is close to zero at the scale of forest plots, and the erosion of biospheric POC by this Andean river is sufficiently rapid that its fate downstream (sedimentary burial/preservation versus oxidation/degradation) may determine whether the mountain forest is a carbon sink or source to the atmosphere. In addition, the measured discharge of petrogenic POC suggests that fluxes from the Andes may be considerably higher than measured downstream in the Madeira River. If this petrogenic POC is oxidised rather than stored in the Amazon River floodplains, it could contribute an important release of CO2 which is not considered in forest-plot scale measurements. Overall, our results suggest that the erosion of biospheric and petrogenic POC from the Andes and its discharge by rivers comprise an important part of the organic carbon budget of the Amazon River Basin, one that depends on the fate of material delivered to the lowlands.

Epidemiology of alcohol and other drug use among motor vehicle crash victims admitted to a trauma center.

PubMed

Walsh, J Michael; Flegel, Ron; Cangianelli, Leo A; Atkins, Randolph; Soderstrom, Carl A; Kerns, Timothy J

2004-09-01

The objectives of this research were to (1) determine the incidence and prevalence of alcohol and other drug use among motor vehicle crash (MVC) victims admitted to a regional Level-I trauma center, and (2) to examine the utility of using a rapid point-of-collection (POC) drug-testing device to identify MVC patients with drug involvement. Blood and urine specimens were routinely collected per clinical protocol for each MVC victim at the time of admission. Blood alcohol concentration (BAC) levels were determined per standard clinical protocol. Clinical urine specimens were routinely split so that a POC drug-testing device for the detection of commonly abused drugs (Marijuana, Cocaine, Amphetamines, Methamphetamines, and Opiates) could be compared to that of the standard hospital laboratory analysis of each urine specimen (which also included Barbiturates and Benzodiazepines). In the six-month period of this study, nearly two-thirds of trauma center admissions were victims of motor vehicle crashes. During this time, blood and urine was collected from 322 MVC victims. Toxicology results indicated that 59.3% of MVC victims tested positive for either commonly abused drugs or alcohol. More patients tested positive for drug use than tested positive for alcohol, with 33.5% testing positive for drug use only, 15.8% testing positive for alcohol use only, and 9.9% testing positive for both drugs and alcohol. Less than half (45.2%) of the substance-abusing patients in this study would have been identified by an alcohol test alone. After alcohol, marijuana and benzodiazepines were the most frequently detected drugs. Point of collection (POC) test results correlated well with laboratory results and provide important information to initiate rapid intervention/treatment for substance use problems among injured patients.

Development of a POC Test for TB Based on Multiple Immunodominant Epitopes of M. tuberculosis Specific Cell-Wall Proteins

PubMed Central

Gonzalez, Jesus M.; Francis, Bryan; Burda, Sherri; Hess, Kaitlyn; Behera, Digamber; Gupta, Dheeraj; Agarwal, Ashutosh Nath; Verma, Indu; Verma, Ajoy; Myneedu, Vithal Prasad; Niedbala, Sam; Laal, Suman

2014-01-01

The need for an accurate, rapid, simple and affordable point-of-care (POC) test for Tuberculosis (TB) that can be implemented in microscopy centers and other peripheral health-care settings in the TB-endemic countries remains unmet. This manuscript describes preliminary results of a new prototype rapid lateral flow TB test based on detection of antibodies to immunodominant epitopes (peptides) derived from carefully selected, highly immunogenic M. tuberculosis cell-wall proteins. Peptide selection was initially based on recognition by antibodies in sera from TB patients but not in PPD-/PPD+/BCG-vaccinated individuals from TB-endemic settings. The peptides were conjugated to BSA; the purified peptide-BSA conjugates striped onto nitrocellulose membrane and adsorbed onto colloidal gold particles to devise the prototype test, and evaluated for reactivity with sera from 3 PPD-, 29 PPD+, 15 PPD-unknown healthy subjects, 10 patients with non-TB lung disease and 124 smear-positive TB patients. The assay parameters were adjusted to determine positive/negative status within 15 minutes via visual or instrumented assessment. There was minimal or no reactivity of sera from non-TB subjects with the striped BSA-peptides demonstrating the lack of anti-peptide antibodies in subjects with latent TB and/or BCG vaccination. Sera from most TB patients demonstrated reactivity with one or more peptides. The sensitivity of antibody detection ranged from 28–85% with the 9 BSA-peptides. Three peptides were further evaluated with sera from 400 subjects, including additional PPD-/PPD+/PPD-unknown healthy contacts, close hospital contacts and household contacts of untreated TB patients, patients with non-TB lung disease, and HIV+TB- patients. Combination of the 3 peptides provided sensitivity and specificity>90%. While the final fully optimized lateral flow POC test for TB is under development, these preliminary results demonstrate that an antibody-detection based rapid POC lateral flow test based on select combinations of immunodominant M. tb-specific epitopes may potentially replace microscopy for TB diagnosis in TB-endemic settings. PMID:25247820

Proof of concept test plan.

DOT National Transportation Integrated Search

2008-06-05

This document is the Proof of Concept (POC) Test Plan and procedures that will be used : to verify that hardware and application functionality meet the requirements of the U.S. : Department of Transportation (USDOT) Next Generation 9-1-1 Initiative (...

Integrating Patient Reported Outcomes With Clinical Cancer Registry Data: A Feasibility Study of the Electronic Patient-Reported Outcomes From Cancer Survivors (ePOCS) System

PubMed Central

Jones, Helen; Thomas, James; Newsham, Alex; Downing, Amy; Morris, Eva; Brown, Julia; Velikova, Galina; Forman, David; Wright, Penny

2013-01-01

Background Routine measurement of Patient Reported Outcomes (PROs) linked with clinical data across the patient pathway is increasingly important for informing future care planning. The innovative electronic Patient-reported Outcomes from Cancer Survivors (ePOCS) system was developed to integrate PROs, collected online at specified post-diagnostic time-points, with clinical and treatment data in cancer registries. Objective This study tested the technical and clinical feasibility of ePOCS by running the system with a sample of potentially curable breast, colorectal, and prostate cancer patients in their first 15 months post diagnosis. Methods Patients completed questionnaires comprising multiple Patient Reported Outcome Measures (PROMs) via ePOCS within 6 months (T1), and at 9 (T2) and 15 (T3) months, post diagnosis. Feasibility outcomes included system informatics performance, patient recruitment, retention, representativeness and questionnaire completion (response rate), patient feedback, and administration burden involved in running the system. Results ePOCS ran efficiently with few technical problems. Patient participation was 55.21% (636/1152) overall, although varied by approach mode, and was considerably higher among patients approached face-to-face (61.4%, 490/798) than by telephone (48.8%, 21/43) or letter (41.0%, 125/305). Older and less affluent patients were less likely to join (both P<.001). Most non-consenters (71.1%, 234/329) cited information technology reasons (ie, difficulty using a computer). Questionnaires were fully or partially completed by 85.1% (541/636) of invited participants at T1 (80 questions total), 70.0% (442/631) at T2 (102-108 questions), and 66.3% (414/624) at T3 (148-154 questions), and fully completed at all three time-points by 57.6% (344/597) of participants. Reminders (mainly via email) effectively prompted responses. The PROs were successfully linked with cancer registry data for 100% of patients (N=636). Participant feedback was encouraging and positive, with most patients reporting that they found ePOCS easy to use and that, if asked, they would continue using the system long-term (86.2%, 361/419). ePOCS was not administratively burdensome to run day-to-day, and patient-initiated inquiries averaged just 11 inquiries per month. Conclusions The informatics underlying the ePOCS system demonstrated successful proof-of-concept – the system successfully linked PROs with registry data for 100% of the patients. The majority of patients were keen to engage. Participation rates are likely to improve as the Internet becomes more universally adopted. ePOCS can help overcome the challenges of routinely collecting PROs and linking with clinical data, which is integral for treatment and supportive care planning and for targeting service provision. PMID:24161667

Falsely elevated sodium levels during thiopental treatment in the ICU: technical interference on a laboratory device with important clinical relevance.

PubMed

Feyen, Bart F E; Coenen, Dries; Jorens, Philippe G; Wouters, Kristien; Maas, Andrew I R; Van Hoof, Viviane; Verbrugghe, Walter

2013-02-01

Thiopental is a cornerstone in the treatment of refractory status epilepticus and intractable intracranial hypertension. In our center we observed that thiopental might cause falsely elevated serum sodium levels. Triggered by a recent case experience of extremely elevated serum sodium levels during thiopental treatment, we retrospectively identified 53 patients treated with thiopental in our intensive care unit between 2007 and 2011 and evaluated electrolyte changes. We differentiated the analysis before and after introduction of a new device for sodium assays (Dimension Vista, Siemens) in the central laboratory in April 2010. Standardized in vitro laboratory tests were performed to study the effect of thiopental on sodium analysis. Before April 2010, serum sodium levels determined in the central laboratory showed a good agreement with the bedside point-of-care (POC) device during thiopental therapy with [sodium](laboratory) - [sodium](POC) of only 1.08 mmol/L (P = .0517). After April 2010, a strong discrepancy between laboratory values and POC values was observed with [sodium](laboratory) - [sodium](POC) = 11.57 mmol/L (P < .0001). Standardized in vitro testing confirmed that thiopental induced a dose-dependent false hypernatremia (P = .002). Thiopental treatment can result in falsely elevated serum sodium. This is a critical finding since high sodium levels preclude administrating mannitol or hypertonic saline for the treatment of elevated intracranial pressure. Moreover, a false high sodium level might lead to the inappropriate administration of hypotonic fluids potentially resulting in increased brain edema and even higher intracranial pressure. To our knowledge, this is the first paper describing this clinically relevant phenomenon.

Nanoporous Glass Integrated in Volumetric Bar-Chart Chip for Point-of-Care Diagnostics of Non-Small Cell Lung Cancer.

PubMed

Li, Ying; Xuan, Jie; Song, Yujun; Qi, Wenjin; He, Bangshun; Wang, Ping; Qin, Lidong

2016-01-26

Point-of-care (POC) testing has the potential to enable rapid, low-cost, and large-scale screening. POC detection of a multiplexed biomarker panel can facilitate the early diagnosis of non-small cell lung cancer (NSCLC) and, thus, may allow for more timely surgical intervention for life-saving treatment. Herein, we report the nanoporous glass (NPG) integrated volumetric bar-chart chip (V-Chip) for POC detection of the three NSCLC biomarkers CEA, CYFRA 21-1, and SCCA, by the naked eye. The 3D nanostructures in the NPG membrane efficiently increase the number of binding sites for antibodies and decrease the diffusion distance between antibody and antigen, enabling the low detection limit and rapid analysis time of the NPG-V-Chip. We utilized the NPG-V-Chip to test the NSCLC biomarker panel and found that the limit of detection can reach 50 pg/mL (10-fold improvement over the original V-Chip), and the total assay time can be decreased from 4 to 0.5 h. We then detected CEA in 21 serum samples from patients with common cancers, and the on-chip results showed good correlation with the clinical results. We further assayed 10 lung cancer samples using the device and confirmed the results obtained using conventional ELISA methods. In summary, the NPG-V-Chip platform has the ability of multiplex, low detection limit, low cost, lack of need for accessory equipment, and rapid analysis time, which may render the V-Chip a useful platform for quantitative POC detection in resource-limited settings and personalized diagnostics.

Carbon Composition of Particulate Organic Carbon in the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Rogers, K.; Montoya, J. P.; Weber, S.; Bosman, S.; Chanton, J.

2016-02-01

The Deepwater Horizon blowout released 5.0x1011 g C from gaseous hydrocarbons and up to 6.0x1011g C from oil into the water column. Another carbon source, adding daily to the water column, leaks from the natural hydrocarbon seeps that pepper the seafloor of the Gulf of Mexico. How much of this carbon from the DWH and natural seeps is assimilated into particulate organic carbon (POC) in the water column? We filtered seawater collected in 2010, 2012, and 2013 from seep and non-seep sites, collecting POC on 0.7µm glass microfiber filters and analyzing the POC for stable and radiocarbon isotopes. Mixing models based on carbon isotopic endmembers of methane, oil, and modern production were used to estimate the percentage of hydrocarbon incorporated into POC. Significant differences were seen between POC from shallow and deep waters and between POC collected from seep, non-seep, and blowout sites; however yearly differences were not as evident suggesting the GOM has a consistent supply of depleted carbon. Stable carbon isotopes signatures of POC in the Gulf averaged -23.7±2.5‰ for shallow samples and -26.65±2.9‰ for deep POC samples, while radiocarbon signatures averaged -100.4±146.1‰ for shallow and -394.6±197‰ for deep samples. POC in the northern Gulf are composed of 23-91% modern carbon, 2-21% methane, and 0-71% oil. Oil plays a major role in the POC composition of the GOM, especially at the natural seep GC600.

Molecular diagnosis of protozoan parasites by Recombinase Polymerase Amplification.

PubMed

Castellanos-Gonzalez, A; White, A C; Melby, P; Travi, B

2018-06-01

Infections caused by protozoan parasites affect millions of people around the world. Traditionally, diagnosis was made by microscopy, which is insensitive and in some cases not specific. Molecular methods are highly sensitive and specific, but equipment costs and personnel training limit its availability only to specialized centers, usually far from populations with the highest risk of infection. Inexpensive methods that can be applied at the point of care (POC), especially in places with limited health infrastructure, would be a major advantage. Isothermal amplification of nucleic acids does not require thermocyclers and is relatively inexpensive and easy to implement. Among isothermal methods, recombinase polymerase amplification (RPA) is sensitive and potentially applicable at POC. We and others have developed RPA diagnostic tests to detect protozoan parasites of medical importance. Overall, our results have shown high specificity with limits of detection similar to PCR. Currently, the optimization of RPA for use at the POC is under development, and in the near future the tests should become available to detect protozoan infections in the field. In this review we discuss the current status, challenges, and future of RPA in the field of molecular diagnosis of protozoan parasites. Copyright © 2018 Elsevier B.V. All rights reserved.

Augmenting epidemiological models with point-of-care diagnostics data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pullum, Laura L.; Ramanathan, Arvind; Nutaro, James J.

Although adoption of newer Point-of-Care (POC) diagnostics is increasing, there is a significant challenge using POC diagnostics data to improve epidemiological models. In this work, we propose a method to process zip-code level POC datasets and apply these processed data to calibrate an epidemiological model. We specifically develop a calibration algorithm using simulated annealing and calibrate a parsimonious equation-based model of modified Susceptible-Infected-Recovered (SIR) dynamics. The results show that parsimonious models are remarkably effective in predicting the dynamics observed in the number of infected patients and our calibration algorithm is sufficiently capable of predicting peak loads observed in POC diagnosticsmore » data while staying within reasonable and empirical parameter ranges reported in the literature. Additionally, we explore the future use of the calibrated values by testing the correlation between peak load and population density from Census data. Our results show that linearity assumptions for the relationships among various factors can be misleading, therefore further data sources and analysis are needed to identify relationships between additional parameters and existing calibrated ones. As a result, calibration approaches such as ours can determine the values of newly added parameters along with existing ones and enable policy-makers to make better multi-scale decisions.« less

Augmenting epidemiological models with point-of-care diagnostics data

DOE PAGES

Pullum, Laura L.; Ramanathan, Arvind; Nutaro, James J.; ...

2016-04-20

Although adoption of newer Point-of-Care (POC) diagnostics is increasing, there is a significant challenge using POC diagnostics data to improve epidemiological models. In this work, we propose a method to process zip-code level POC datasets and apply these processed data to calibrate an epidemiological model. We specifically develop a calibration algorithm using simulated annealing and calibrate a parsimonious equation-based model of modified Susceptible-Infected-Recovered (SIR) dynamics. The results show that parsimonious models are remarkably effective in predicting the dynamics observed in the number of infected patients and our calibration algorithm is sufficiently capable of predicting peak loads observed in POC diagnosticsmore » data while staying within reasonable and empirical parameter ranges reported in the literature. Additionally, we explore the future use of the calibrated values by testing the correlation between peak load and population density from Census data. Our results show that linearity assumptions for the relationships among various factors can be misleading, therefore further data sources and analysis are needed to identify relationships between additional parameters and existing calibrated ones. As a result, calibration approaches such as ours can determine the values of newly added parameters along with existing ones and enable policy-makers to make better multi-scale decisions.« less

Prediction of Physical Activity Level Using Processes of Change From the Transtheoretical Model: Experiential, Behavioral, or an Interaction Effect?

PubMed

Romain, Ahmed Jérôme; Horwath, Caroline; Bernard, Paquito

2018-01-01

The purpose of the present study was to compare prediction of physical activity (PA) by experiential or behavioral processes of change (POCs) or an interaction between both types of processes. A cross-sectional study. This study was conducted using an online questionnaire. A total of 394 participants (244 women, 150 men), with a mean age of 35.12 ± 12.04 years and a mean body mass index of 22.97 ± 4.25 kg/m 2 were included. Participants completed the Processes of Change, Stages of Change questionnaires, and the International Physical Activity Questionnaire to evaluate self-reported PA level (total, vigorous, and moderate PA). Hierarchical multiple regression models were used to test the prediction of PA level. For both total PA (β = .261; P < .001) and vigorous PA (β = .297; P < .001), only behavioral POCs were a significant predictor. Regarding moderate PA, only the interaction between experiential and behavioral POCs was a significant predictor (β = .123; P = .017). Our results provide confirmation that behavioral processes are most prominent in PA behavior. Nevertheless, it is of interest to note that the interaction between experiential and behavioral POCs was the only element predicting moderate PA level. Experiential processes were not associated with PA level.

Carbon Explorer Assessment of Carbon Biomass Variability and Carbon Flux Systematics in the Upper Ocean During SOFEX

NASA Astrophysics Data System (ADS)

Bishop, J. K.; Wood, T. J.; Sherman, J. T.

2002-12-01

Three autonomous Carbon Explorers built on SIO's Orbcomm/GPS enhanced Sounding Oceanographic Lagrangian Observer were launched near 55S 172W in the "North" SOFEX experiment area in early January 2002. All Explorers at 55S were programmed to perform profiles from 1000, 300, and 300 m with surfacings, GPS position, and telemetry of profile data initiating at local 0600, 1200, and 1800 hours. The floats were programmed to 'sleep' at 100 m depth between profiles to maximize tracking of the surface layer. Each Explorer carried SeaBird T and S sensors and was additionally fitted with a WETLabs transmissometer based "POC" sensor and a Seapoint scattering meter to assess particulate matter variability. A carbon flux "index" obtained during the 100 m sleep periods was also derived from the POC sensor readings. Explorer 1177 was deployed as a control outside of Fe treated waters on Jan 11 2002 (UTC) and drifted initially to the North East at 10 cm/sec. Explorer 2104, deployed on Jan 19 2002 after the 3rd Fe infusion, advected with the patch to the NE on a course that closely paralleled that of the "control". By Feb 8 2002, the two floats had drifted with the circumpolar current nearly 200 km; Explorer 2104 had recorded a 4-fold build-up of of particles in the upper 60 m whereas records from the nearby control Explorer 1177 showed little change. Ship survey data (Revelle) indicated that Explorer 2104 was near but "in" the trailing edge of the patch. Beginning Feb 14 (several days after the 4th infusion of Fe) and ending on Feb 24 2002, Explorer 2104 data showed isolines of POC concentration beginning to deepen in waters below 60 m and a coincident loss of POC from above; the POC flux index also began to show clearly different and enhanced 'spikes' compared to that recorded by the control. The spikes either reflected temporal variability of particle export from the patch or the intermingled sampling of the "in patch" settling plume of particles and "out-of-patch" background flux. Preliminary analysis of POC flux index integrated over time since the initial Fe amendment indicated a >2 fold enhancement of export from the iron treated waters. If the Explorer was indeed sampling the plume of sinking material intermittently, then the true export enhancement from the patch would be considerably greater. The last 'trace' of Fe treated waters was seen in early March 2002. Explorers 1177 and 2104 continue operations in the howling 50's of the Southern Ocean 8+ months after their deployment.

Antifungal Activity and Pharmacokinetics of Posaconazole (SCH 56592) in Treatment and Prevention of Experimental Invasive Pulmonary Aspergillosis: Correlation with Galactomannan Antigenemia

PubMed Central

Petraitiene, Ruta; Petraitis, Vidmantas; Groll, Andreas H.; Sein, Tin; Piscitelli, Stephen; Candelario, Myrna; Field-Ridley, Aida; Avila, Nilo; Bacher, John; Walsh, Thomas J.

2001-01-01

The antifungal efficacy, safety, and pharmacokinetics of posaconazole (SCH 56592) (POC) were investigated in treatment and prophylaxis of primary pulmonary aspergillosis due to Aspergillus fumigatus in persistently neutropenic rabbits. Antifungal therapy consisted of POC at 2, 6, and 20 mg/kg of body weight per os; itraconazole (ITC) at 2, 6, and 20 mg/kg per os; or amphotericin B (AMB) at 1 mg/kg intravenously. Rabbits treated with POC showed a significant improvement in survival and significant reductions in pulmonary infarct scores, total lung weights, numbers of pulmonary CFU per gram, numbers of computerized-tomography-monitored pulmonary lesions, and levels of galactomannan antigenemia. AMB and POC had comparable therapeutic efficacies by all parameters. By comparison, animals treated with ITC had no significant changes in outcome variables in comparison to those of untreated controls (UC). Rabbits receiving prophylactic POC at all dosages showed a significant reduction in infarct scores, total lung weights, and organism clearance from lung tissue in comparison to results for UC (P < 0.01). There was dosage-dependent microbiological clearance of A. fumigatus from lung tissue in response to POC. Serum creatinine levels were greater (P < 0.01) in AMB-treated animals than in UC and POC- or ITC-treated rabbits. There was no elevation of serum hepatic transaminase levels in POC- or ITC-treated rabbits. The pharmacokinetics of POC and ITC in plasma demonstrated dose dependency after multiple dosing. The 2-, 6-, and 20-mg/kg dosages of POC maintained plasma drug levels above the MICs for the entire 24-h dosing interval. In summary, POC at ≥6 mg/kg/day per os generated sustained concentrations in plasma of ≥1 μg/ml that were as effective in the treatment and prevention of invasive pulmonary aspergillosis as AMB at 1 mg/kg/day and more effective than cyclodextrin ITC at ≥6 mg/kg/day per os in persistently neutropenic rabbits. PMID:11181372

Effects of particulate oxidation catalyst on unregulated pollutant emission and toxicity characteristics from heavy-duty diesel engine.

PubMed

Feng, Xiangyu; Ge, Yunshan; Ma, Chaochen; Tan, Jianwei

2015-01-01

To evaluate the effects of particulate oxidation catalyst (POC) on unregulated pollutant emission and toxicity characteristics, polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), soot, soluble organic fractions (SOF) and sulphate emissions emitted from a heavy-duty diesel engine retrofitted with a POC were investigated on a diesel bench. The particulate matter (PM) in the exhaust was collected by Teflon membrane, and the PAHs and VOCs were analysed by a gas chromatography/mass spectrometer (GC/MS). The results indicate that the POC exhibits good performance on the emission control of VOCs, PAHs and PM. The POC and the diesel particulate filters (DPF) both show a good performance on reducing the VOCs emission. Though the brake-specific emission (BSE) reductions of the total PAHs by the POC were lower than those by the DPF, the POC still removed almost more than 50% of the total PAHs emission. After the engine was retrofitted with the POC, the reductions of the PM mass, SOF and soot emissions were 45.2-89.0%, 7.8-97.7% and 41.7-93.3%, respectively. The sulphate emissions decreased at low and medium loads, whereas at high load, the results were contrary. The PAHs emissions were decreased by 32.4-69.1%, and the contributions of the PAH compounds were affected by the POC, as well as by load level. The benzo[a]pyrene equivalent (BaPeq) of PAHs emissions were reduced by 35.9-97.6% with the POC. The VOCs emissions were reduced by 21.8-94.1% with the POC, and the reduction was more evident under high load.

Evaluation of a point-of-care glucose and β-hydroxybutyrate meter operated in various environmental conditions in prepartum and postpartum sheep.

PubMed

Hornig, Katlin J; Byers, Stacey R; Callan, Robert J; Holt, Timothy; Field, Megan; Han, Hyungchul

2013-08-01

To compare β-hydroxybutyrate (BHB) and glucose concentrations measured with a dual-purpose point-of-care (POC) meter designed for use in humans and a laboratory biochemical analyzer (LBA) to determine whether the POC meter would be reliable for on-farm measurement of blood glucose and BHB concentrations in sheep in various environmental conditions and nutritional states. 36 pregnant mixed-breed ewes involved in a maternal feed restriction study. Blood samples were collected from each sheep at multiple points throughout gestation and lactation to allow for tracking of gradually increasing metabolic hardship. Whole blood glucose and BHB concentrations were measured with the POC meter and compared with serum results obtained with an LBA. 464 samples were collected. Whole blood BHB concentrations measured with the POC meter compared well with LBA results, and error grid analysis showed the POC values were acceptable. Whole blood glucose concentrations measured with the POC meter had more variation, compared with LBA values, over the glucose ranges evaluated. Results of error grid analysis of POC-measured glucose concentrations were not acceptable, indicating errors likely to result in needless treatment with glucose or other supplemental energy sources in normoglycemic sheep. The POC meter was user-friendly and performed well across a wide range of conditions. The meter was adequate for detection of pregnancy toxemia in sheep via whole blood BHB concentration. Results should be interpreted with caution when the POC meter is used to measure blood glucose concentrations.

Feasibility test of a UK-scalable electronic system for regular collection of patient-reported outcome measures and linkage with clinical cancer registry data: the electronic Patient-reported Outcomes from Cancer Survivors (ePOCS) system.

PubMed

Ashley, Laura; Jones, Helen; Forman, David; Newsham, Alex; Brown, Julia; Downing, Amy; Velikova, Galina; Wright, Penny

2011-10-26

Cancer survivors can face significant physical and psychosocial challenges; there is a need to identify and predict which survivors experience what sorts of difficulties. As highlighted in the UK National Cancer Survivorship Initiative, routine post-diagnostic collection of patient reported outcome measures (PROMs) is required; to be most informative, PROMs must be linked and analysed with patients' diagnostic and treatment information. We have designed and built a potentially cost-efficient UK-scalable electronic system for collecting PROMs via the internet, at regular post-diagnostic time-points, for linking these data with patients' clinical data in cancer registries, and for electronically managing the associated patient monitoring and communications; the electronic Patient-reported Outcomes from Cancer Survivors (ePOCS) system. This study aims to test the feasibility of the ePOCS system, by running it for 2 years in two Yorkshire NHS Trusts, and using the Northern and Yorkshire Cancer Registry and Information Service. Non-metastatic breast, colorectal and prostate cancer patients (largest survivor groups), within 6 months post-diagnosis, will be recruited from hospitals in the Yorkshire Cancer Network. Participants will be asked to complete PROMS, assessing a range of health-related quality-of-life outcomes, at three time-points up to 15 months post-diagnosis, and subsequently to provide opinion on the ePOCS system via a feedback questionnaire. Feasibility will be examined primarily in terms of patient recruitment and retention rates, the representativeness of participating patients, the quantity and quality of collected PROMs data, patients' feedback, the success and reliability of the underpinning informatics, and the system running costs. If sufficient data are generated during system testing, these will be analysed to assess the health-related quality-of-life outcomes reported by patients, and to explore if and how they relate to disease, treatment and/or individual differences characteristics. There is currently no system in the UK for collecting PROMs online and linking these with patients' clinical data in cancer registries. If feasible, ePOCS has potential to provide an affordable UK-scalable technical platform to facilitate and support longitudinal cohort research, and improve understanding of cancer survivors' experiences. Comprehensive understanding of survivorship difficulties is vital to inform the development and provision of supportive services and interventions.

A Dual Point-of-Care Test Shows Good Performance in Simultaneously Detecting Nontreponemal and Treponemal Antibodies in Patients With Syphilis: A Multisite Evaluation Study in China

PubMed Central

Yin, Yue-Ping; Chen, Xiang-Sheng; Wei, Wan-Hui; Gong, Kuang-Long; Cao, Wen-Ling; Yong, Gang; Feng, Liang; Huang, Shu-Jie; Wang, Dong-Mei; Han, Yan; Chen, Shao-Chun; Mabey, David; Peeling, Rosanna W.

2013-01-01

Background. Rapid point-of-care (POC) syphilis tests based on simultaneous detection of treponemal and nontreponemal antibodies (dual POC tests) offer the opportunity to increase coverage of syphilis screening and treatment. This study aimed to conduct a multisite performance evaluation of a dual POC syphilis test in China. Methods. Participants were recruited from patients at sexually transmitted infection clinics and high-risk groups in outreach settings in 6 sites in China. Three kinds of specimens (whole blood [WB], fingerprick blood [FB], and blood plasma [BP]) were used for evaluating sensitivity and specificity of the Dual Path Platform (DPP) Syphilis Screen and Confirm test using its treponemal and nontreponemal lines to compare Treponema pallidum particle agglutination (TPPA) assay and toluidine red unheated serum test (TRUST) as reference standards. Results. A total of 3134 specimens (WB 1323, FB 488, and BP 1323) from 1323 individuals were collected. The sensitivities as compared with TPPA were 96.7% for WB, 96.4% for FB, and 94.6% for BP, and the specificities were 99.3%, 99.1%, and 99.6%, respectively. The sensitivities as compared with TRUST were 87.2% for WB, 85.8% for FB, and 88.4% for BP, and the specificities were 94.4%, 96.1%, and 95.0%, respectively. For specimens with a TRUST titer of 1:4 or higher, the sensitivities were 100.0% for WB, 97.8% for FB, and 99.6% for BP. Conclusions. DPP test shows good sensitivity and specificity in detecting treponemal and nontreponemal antibodies in 3 kinds of specimens. It is hoped that this assay can be considered as an alternative in the diagnosis of syphilis, particularly in resource-limited areas. PMID:23132172

Feasibility Studies of Palm Oil Mill Waste Aggregates for the Construction Industry.

PubMed

Kanadasan, Jegathish; Fauzi, Auni Filzah Ahmad; Razak, Hashim Abdul; Selliah, Paramananthan; Subramaniam, Vijaya; Yusoff, Sumiani

2015-09-22

The agricultural industry in Malaysia has grown rapidly over the years. Palm oil clinker (POC) is a byproduct obtained from the palm oil industry. Its lightweight properties allows for its utilization as an aggregate, while in powder form as a filler material in concrete. POC specimens obtained throughout each state in Malaysia were investigated to evaluate the physical, chemical, and microstructure characteristics. Variations between each state were determined and their possible contributory factors were assessed. POC were incorporated as a replacement material for aggregates and their engineering characteristics were ascertained. Almost 7% of density was reduced with the introduction of POC as aggregates. A sustainability assessment was made through greenhouse gas emission (GHG) and cost factor analyses to determine the contribution of the addition of POC to the construction industry. Addition of POC helps to lower the GHG emission by 9.6% compared to control specimens. By channeling this waste into the construction industry, an efficient waste-management system can be promoted; thus, creating a cleaner environment. This study is also expected to offer some guides and directions for upcoming research works on the incorporation of POC.

Point-of-Care Virologic Testing to Improve Outcomes of HIV-Infected Children in Zambia: A Clinical Trial Protocol.

PubMed

Chibwesha, Carla J; Ford, Catherine E; Mollan, Katie R; Stringer, Jeffrey S A

2016-08-01

In the absence of early infant diagnosis (EID) and immediate antiretroviral therapy (ART), some 50% of untreated HIV-infected infants die before age 2. Conventional EID requires sophisticated instruments that are typically placed in centralized or reference laboratories. In low-resource settings, centralized systems often lead to result turnaround times of several months, long delays in diagnosis, and adverse outcomes for HIV-infected children. Our clinical trial tests the effectiveness of a new point-of-care (POC) diagnostic technology to identify HIV-infected infants and start providing them life-saving ART as soon as possible. The study uses a randomized, controlled design to test whether the Alere q platform for HIV DNA polymerase chain reaction (PCR) testing improves outcomes of HIV-infected children in Zambia. We aim to enroll 2867 HIV-exposed infants aged 4-12 weeks and to follow those who are HIV infected for 12 months as they receive HIV care at 6 public health facilities in Lusaka. The trial's primary endpoint is the proportion of HIV-infected infants in each study arm who start ART and remain alive, in care, and virally suppressed 12 months after their diagnostic blood draw. Our trial will provide evidence for the incremental benefit of implementing a POC EID strategy in low-resource settings where only off-site PCR services are currently available. The results will be useful in guiding future decisions regarding investments in POC virologic testing as part of overall pediatric AIDS mitigation strategies in sub-Saharan Africa. clinicaltrials.gov NCT02682810.

High performance data transfer

NASA Astrophysics Data System (ADS)

Cottrell, R.; Fang, C.; Hanushevsky, A.; Kreuger, W.; Yang, W.

2017-10-01

The exponentially increasing need for high speed data transfer is driven by big data, and cloud computing together with the needs of data intensive science, High Performance Computing (HPC), defense, the oil and gas industry etc. We report on the Zettar ZX software. This has been developed since 2013 to meet these growing needs by providing high performance data transfer and encryption in a scalable, balanced, easy to deploy and use way while minimizing power and space utilization. In collaboration with several commercial vendors, Proofs of Concept (PoC) consisting of clusters have been put together using off-the- shelf components to test the ZX scalability and ability to balance services using multiple cores, and links. The PoCs are based on SSD flash storage that is managed by a parallel file system. Each cluster occupies 4 rack units. Using the PoCs, between clusters we have achieved almost 200Gbps memory to memory over two 100Gbps links, and 70Gbps parallel file to parallel file with encryption over a 5000 mile 100Gbps link.

Atmospheric iron supply and enhanced vertical carbon flux in the NE subarctic Pacific: Is there a connection?

NASA Astrophysics Data System (ADS)

Boyd, P. W.; Wong, C. S.; Merrill, J.; Whitney, F.; Snow, J.; Harrison, P. J.; Gower, J.

1998-09-01

Recent studies have confirmed the relationship between iron supply and phytoplankton growth rates in all three high-nitrate low-chlorophyll (HNLC) oceanic provinces. However, there is little evidence, so far, of the role of iron in altering the efficiency of the biological pump via increased downward export of particulate organic carbon (POC). The NE subarctic Pacific is unique among HNLC regions in that long time series pelagic observations and deep-moored sediment trap records exist which may provide the best opportunity thus far to test aspects of the iron hypothesis. Episodic elevated levels of chlorophyll a (> 2.0 μg L-1) were observed 6 times between 1964 and 1976 at the former site of Ocean Station Papa (OSP). In addition, between 1984 and 1990 on at least three occasions, concurrent pulses of POC and biogenic silica were recorded in deep-moored traps at OSP. Possible explanations for these events, such as lateral advection of more productive waters, iron-mediated blooms, or grazing by salp swarms are discussed and tested using an existing downward POC flux model. Owing to the episodic nature of such events, no available data are sufficiently comprehensive to unequivocally rule out any of these explanations. Nevertheless, from the data available, the occurrence of pelagic or deep water pulses, approximately once every 3 years, are most consistent with iron-mediated diatom blooms, and of the sinking of POC and biogenic silica (from such a bloom) to depth, respectively. A comparison of the timing of these iron-mediated pulses with that of the transport probabilities of atmospheric dust supply from Asia and Alaska provides an opportunity to assess the likelihood of a coupling between the atmosphere and the ocean.

Particulate organic carbon mass distribution at the Bermuda Atlantic Time-series Study (BATS) site

NASA Astrophysics Data System (ADS)

Gundersen, Kjell; Orcutt, Karen M.; Purdie, Duncan A.; Michaels, Anthony F.; Knap, Anthony H.

Errors in total particulate organic carbon (total POC) measurements caused by particles settling in Niskin water samplers, loss of bacterial cells during filtration and undersampling of rare particles such as the diazotrophic cyanobacterium Trichodesmium spp. were investigated at the Bermuda Atlantic Time-series Study (BATS) site. Regular core samples of temperature, primary production, bacterial abundance, chlorophyll- a (Chl- a) and POC were collected at monthly intervals from 1991 to 1996. During this period of time, shorter investigations of particles settling in water samples (1991-1992), bacterial cells lost during filtration (1992-1993), and Trichodesmium abundance (1995-1996) were performed at the BATS site. The BATS site shows striking seasonal patterns in hydrography and phytoplankton primary productivity, with a strong maximum immediately following the deep winter mixing of the water column. Following the peak in primary production, bacterial abundance showed only slightly elevated levels in spring. Maxima of Chl- a and POC also were associated with the primary production peaks, but these particle concentrations became less pronounced through summer and fall. An average of 26% of total POC collected in Niskin water bottles settled below the spigot before it could be sampled. An average of 47% of all bacterial cells passed the nominal pore size of a Whatman GF/F filter, and total POC measurements generated from GF/F filtered seawater samples had to be corrected for this loss. The average integrated stocks of total POC in the upper 65 m of the water column was 32% pigmented phytoplankton, 15% microheterotrophs, 54% other detrital matter (32 : 15 : 54). Phytoplankton C equaled bacterial C in the 65-135 m depth range (16 : 19 : 65), but phytoplankton C was virtually non-existent deeper than 135 m (2 : 14 : 74). Bacterial C biomass was higher than phytoplankton in surface waters outside the spring bloom period, but carbon not accounted for by phytoplankton and bacteria (other C) showed an overall dominance throughout the year. Uncorrected, suspended POC collected on GF/F filters (POC SW) was nearly equal to the sum of phytoplankton C and bacterial C alone, and hence, the other C fraction of total POC was largely generated by the addition of settling particles (POC Dreg). Seasonal occurrences of rare particles such as Trichodesmium colonies in surface waters in late summer may account for as much as 17-56% of total POC. Settling particles and Trichodesmium colonies, seldom included in POC estimates from temperate and tropical regions, constituted more than half of total POC measured in surface waters at BATS.

Benchmarking glycemic control in u.s. Hospitals.

PubMed

Bersoux, Sophie; Cook, Curtiss B; Kongable, Gail L; Shu, Jianfen; Zito, Denise R

2014-09-01

Report data on glucose control from 635 U.S. hospitals. Point-of-care blood glucose (POC-BG) test data from January through December 2012 from 635 facilities were extracted. Glucose control was evaluated using patient-day-weighted mean POC-BG values. We calculated hypoglycemia and hyperglycemia rates, stratified by presence or absence of intensive care unit (ICU) admission, and we evaluated the relationship between glycemic control and hospital characteristics. In total, 51,375,764 POC-BG measurements (non-ICU, 39,197,762; ICU, 12,178,002) from 2,612,966 patients (non-ICU, 2,415,209; ICU, 575,084) were analyzed. The mean POC-BG was 167 mg/dL for non-ICU patients and 170 mg/dL for ICU patients. The prevalence of hyperglycemia (defined as glucose value >180 mg/dL) was 32.3 and 28.2% in non-ICU and ICU patients, respectively. The prevalence of hypoglycemia (defined as glucose value <70 mg/dL) was 6.1 and 5.6% in non-ICU and ICU patients, respectively. In non-ICU and ICU settings, the patient-day-weighted mean glucose was highest in the smallest hospitals, in rural hospitals, and in hospitals located in the Northeast (all P<.01). For non-ICU patients, we observed a significant difference in the percentage of patient days with hypoglycemia by geographic region only (P<.001). In ICU patients, the prevalence of hypoglycemia varied significantly by hospital type (P<.03) and geographic region (P<.01). In this largest POC-BG data set analysis conducted to date, glycemic control varied according to hospital characteristics. Our findings remain consistent with previous reports. Among other variables, national benchmarking of inpatient glucose data will need to consider differences in hospital characteristics.

Performance of solvent-borne intumescent fire protective coating with Palm oil clinker as novel bio-filler on steel

NASA Astrophysics Data System (ADS)

Mustapa, S. A. S.; Ramli Sulong, N. H.

2017-06-01

This research deals with contribution of hybrid fillers with palm oil clinker (POC) as a novel bio-filler in solvent-borne intumescent fire protective coating for steel. The hybrid fillers with POC were mixed in appropriate amount of additives and acrylic binder to produce the intumescent coatings. The intumescent coatings were characterized by using Bunsen burner test, surface spread of flame, thermogravimetric analysis, field emission scanning electron microscopy, static immersion and Instron micro tester equipment. Specimen with POC as a single filler has significantly enhanced the fire protection performances of the intumescent coating due to the high thermal stability of POC, where less than 10% of temperature different when compared to specimens with hybrid fillers. From the flame spread classification, class 1 is the best classification while Class 4 is the worst and considered high risk. All specimens was classified as class 1 since the final spread of flame was less than 165 mm. For hybrid fillers composition, specimen consist of POC/Al(OH)3/TiO2 has significantly improved the water resistance of the coating due to the low solubility of Al(OH)3 in water, while specimen contain of Mg(OH)2 had higher mechanical strength due to the strong bonding between the metal surface and acrylic binder/Mg(OH)2 filler. It was found that coating with the incorporation of all hybrid fillers gives excellent fire protection performance with good thermal stability, water resistance and mechanical properties. It can be concluded that, the selection of appropriate composition of fillers and binder in intumescent coating was highly influence the intumescent coating performance.

How well do TTM measures work among a sample of individuals with unhealthy alcohol use that is characterized by low readiness to change?

PubMed

Baumann, Sophie; Gaertner, Beate; Schnuerer, Inga; Bischof, Gallus; John, Ulrich; Freyer-Adam, Jennis

2013-09-01

Little is known about the applicability of the transtheoretical model of intentional behavior change (TTM) to individuals with unhealthy alcohol use that is primarily characterized by low readiness to change. This study examined the psychometric properties of short measures by assessing three core constructs of the TTM: the 20-item Processes of Change (POC-20) scale, and short versions of the Alcohol Decisional Balance Scale (ADBS) and the Alcohol Abstinence Self-Efficacy (AASE) scale. A sample of 427 individuals with unhealthy alcohol use (Mage = 30 years, 65% men), identified at job agencies in northeastern Germany, completed all three scales. Item difficulty (d), selectivity (rit), and Cronbach's alpha were calculated. Confirmatory factory analyses were used to test for construct validity and latent mean differences across the stages. The psychometric properties of the 8-item AASE were adequate (d range: 0.59-0.78; rit range: 0.59-0.68; α range: 0.74-0.81), except for one subscale. Most items of the POC-20 and the 10-item ADBS were difficult (dPOC range: 0.08-0.40; dADBS range: 0.21-0.58); selectivity (ritPOC range: 0.26-0.62; ritADBS range: 0.34-0.68) and internal consistency (αPOC range: 0.41-0.76; αADBS range: 0.64-0.78) were low to moderate. Construct validity was acceptable (Comparative Fit Index range: 0.95-0.99). The association between stages and TTM constructs partially followed expected patterns. Suggestions for modifications of TTM measures are discussed for better applicability among proactively recruited samples of individuals with unhealthy alcohol use and with primarily low readiness to change. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

Cleaning Products and Air Fresheners: Emissions and ResultingConcentrations of Glycol Ethers and Terpenoids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singer, Brett C.; Destaillat, Hugo; Hodgson, Alfred T.

2005-08-01

Experiments were conducted to quantify emissions and concentrations of glycol ethers and terpenoids from cleaning product and air freshener use in a 50-m{sup 3} room ventilated at {approx}0.5 h{sup -1}. Five cleaning products were applied full-strength (FS); three were additionally used in dilute solution. FS application of pine-oil cleaner (POC) yielded 1-h concentrations of 10-1300 {micro}g m{sup -3} for individual terpenoids, including {alpha}-terpinene (90-120), d-limonene (1000-1100), terpinolene (900-1300), and {alpha}-terpineol (260-700). One-hour concentrations of 2-butoxyethanol and/or dlimonene were 300-6000 {micro}g m{sup -3} after FS use of other products. During FS application including rinsing with sponge and wiping with towels, fractionalmore » emissions (mass volatilized/dispensed) of 2-butoxyethanol and d-limonene were 50-100% with towels retained, {approx}25-50% when towels were removed after cleaning. Lower fractions (2-11%) resulted from dilute use. Fractional emissions of terpenes from FS use of POC were {approx}35-70% with towels retained, 20-50% with towels removed. During floor cleaning with dilute solution of POC, 7-12% of dispensed terpenes were emitted. Terpene alcohols were emitted at lower fractions: 7-30% (FS, towels retained), 2-9% (FS, towels removed), and 2-5% (dilute). During air-freshener use, d-limonene, dihydromyrcenol, linalool, linalyl acetate, and {beta}-citronellol were emitted at 35-180 mg d{sup -1} over three days while air concentrations averaged 30-160 {micro}g m{sup -3}.« less

The dynamic ocean biological pump: Insights from a global compilation of particulate organic carbon, CaCO3, and opal concentration profiles from the mesopelagic

NASA Astrophysics Data System (ADS)

Lam, Phoebe J.; Doney, Scott C.; Bishop, James K. B.

2011-09-01

We have compiled a global data set of 62 open ocean profiles of particulate organic carbon (POC), CaCO3, and opal concentrations collected by large volume in situ filtration in the upper 1000 m over the last 30 years. We define concentration-based metrics for the strength (POC concentration at depth) and efficiency (attenuation of POC with depth in the mesopelagic) of the biological pump. We show that the strength and efficiency of the biological pump are dynamic and are characterized by a regime of constant and high transfer efficiency at low to moderate surface POC and a bloom regime where the height of the bloom is characterized by a weak deep biological pump and low transfer efficiency. The variability in POC attenuation length scale manifests in a clear decoupling between the strength of the shallow biological pump (e.g., POC at the export depth) and the strength of the deep biological pump (POC at 500 m). We suggest that the paradigm of diatom-driven export production is driven by a too restrictive perspective on upper mesopelagic dynamics. Indeed, our full mesopelagic analysis suggests that large, blooming diatoms have low transfer efficiency and thus may not export substantially to depth; rather, our analysis suggests that ecosystems characterized by smaller cells and moderately high %CaCO3 have a high mesopelagic transfer efficiency and can have higher POC concentrations in the deep mesopelagic even with relatively low surface or near-surface POC. This has negative implications for the carbon sequestration prospects of deliberate iron fertilization.

Quantification of the lithogenic carbon pump following a dust deposition event

NASA Astrophysics Data System (ADS)

Bressac, M.; Guieu, C.; Doxaran, D.; Bourrin, F.; Desboeufs, K.; Leblond, N.; Ridame, C.

2013-08-01

Lithogenic particles, such as desert dust, have been postulated to influence particulate organic carbon (POC) export to the deep ocean by acting as mineral ballasts. However, an accurate understanding and quantification of the POC-dust association that occurs within the upper ocean is required in order to affine the "ballast hypothesis". In the framework of the DUNE project, two artificial seedings were performed seven days apart within large mesocosms. A suite of optical and biogeochemical measurements were used to quantify surface POC export following simulated dust events within a low-nutrient low-chlorophyll ecosystem. The two successive seedings led to a 2.3-6.7 fold higher POC flux as compared to the POC flux observed in controlled mesocosms. A simple linear regression analysis revealed that the lithogenic fluxes explained more than 85% of the variance in POC fluxes. At the scale of a dust deposition event, we estimated that 42-50% of POC fluxes were strictly associated with lithogenic particles through an aggregation process. Lithogenic ballasting also likely impacted the remaining POC fraction which resulted from the fertilization effect. The observations support the "ballast hypothesis" and provide a quantitative estimation of the surface POC export abiotically triggered by dust deposition. In this work, we demonstrate that the strength of such a "lithogenic carbon pump" depends on the biogeochemical conditions of the water column at the time of deposition. Based on these observations, we suggest that this "lithogenic carbon pump" could represent a major component of the biological pump in oceanic areas subjected to intense atmospheric forcing.

Initiating NTD programs targeting schistosomiasis and soil-transmitted helminthiasis in two provinces of the Democratic Republic of the Congo: Establishment of baseline prevalence for mass drug administration.

PubMed

Kabore, Achille; Ibikounle, Moudachirou; Tougoue, Jean Jacques; Mupoyi, Sylvain; Ndombe, Martin; Shannon, Scott; Ottesen, Eric A; Mukunda, Faustin; Awaca, Naomi

2017-02-01

Schistosomiasis (SCH) and soil-transmitted helminthiasis (STH) are widely distributed in the Democratic Republic of the Congo (DRC) and constitute a serious public health problem. As recommended by the World Health Organization (WHO), before launching mass chemotherapy to control these diseases, parasitological surveys were conducted in sentinel sites in six health zones (HZs) in Bandundu and Maniema provinces. Baseline prevalence and intensity of infection for SCH and STH were determined to establish the appropriate treatment plan using Praziquantel (PZQ) and Albendazole (ALB). Parasitological surveys were conducted from April to May 2015 in twenty-six selected sampling units (schools) for baseline mapping in six HZs: Fifty school children (25 females and 25 males) aged 9-15 years were randomly selected per sampling unit. A total of 1300 samples (urine and stool) were examined using haematuria dipsticks, parasite-egg filtration and the point-of-care Circulating Cathodic Antigen (POC-CCA) assay for urine samples and the Kato-Katz technique for stool specimens. Three species of schistosomes (S. mansoni, S. haematobium and S. intercalatum) and three groups of STH (hookworm, Ascaris and Trichuris) were detected at variable prevalence and intensity among the schools, the HZs and the provinces. In Bandundu, no SCH was detected by either Kato-Katz or the POC-CCA technique, despite a high prevalence of STH with 68% and 80% at Kiri and Pendjua HZs, respectively. In Maniema, intestinal schistosomiasis was detected by both Kato-Katz and POC-CCA with an average prevalence by Kato-Katz of 32.8% and by POC-CCA of 42.1%. Comparative studies confirmed the greater sensitivity (and operational feasibility) of the POC-CCA test on urine compared to Kato-Katz examination of stool for diagnosing intestinal schistosomiasis even in areas of comparatively light infections. STH was widely distributed and present in all HZs with a mean prevalence (95% CI) of 59.62% (46.00-65.00%). The prevalence of hookworm, roundworm and whipworm were 51.62% (32.40%-71.50%), 15.77% (0.50%-39.60%) and 13.46 (0.50%-33.20%), respectively. This study provided the evidence base for implementing programs targeting SCH and STH in these Health Zones. Observations also reinforce the operational value and feasibility of the POC-CCA test to detect S. mansoni and, for the first time, S. intercalatum infections in a routine NTD program setting. Copyright © 2016 Elsevier B.V. All rights reserved.

On-Site Classification of Pansteatitis in Mozambique Tilapia (Oreochromis mossambicus) using a Portable Lipid-Based Analyzer

PubMed Central

Somerville, Stephen E.; Cantu, Theresa M.; Guillette, Matthew P.; Botha, Hannes; Boggs, Ashley S. P.; Luus-Powell, Wilmien; Guillette, Louis J.

2017-01-01

While no pansteatitis-related large-scale mortality events have occurred since 2008, the current status of pansteatitis (presence and pervasiveness) in the Olifants River system and other regions of South Africa remain largely unknown. In part, this is due to both a lack of known biological markers of pansteatitis and a lack of suitable non-invasive assays capable of rapidly classifying the disease. Here, we propose the application of a point-of-care (POC) device using lipid-based test strips (total cholesterol (TC) and total triglyceride (TG)), for classifying pansteatitis status in the whole blood of pre-spawning Mozambique tilapia (Oreochromis mossambicus). Using the TC strips, the POC device was able to non-lethally classify the tilapia as either healthy or pansteatitis-affected; the sexes were examined independently because sexual dimorphism was observed for TC (males p = 0.0364, females χ2 = 0.0007). No significant difference between diseased and pansteatitis-affected tilapia was observed using the TG strips. This is one of the first described applications of using POC devices for on-site environmental disease state testing. A discussion on the merits of using portable lipid-based analyzers as an in-field disease-state diagnostic tool is provided. PMID:28729886

Olfactory Deficit Detected by fMRI in Early Alzheimer’s Disease

PubMed Central

Wang, Jianli; Eslinger, Paul J.; Doty, Richard L.; Zimmerman, Erin K.; Grunfeld, Robert; Sun, Xiaoyu; Connor, James R.; Price, Joseph L.; Smith, Michael B.; Yang, Qing X.

2012-01-01

Alzheimer’s disease (AD) is accompanied by smell dysfunction, as measured by psychophysical tests. Currently it is unknown whether AD-related alterations in central olfactory system neural activity, as measured by functional magnetic resonance imaging (fMRI), are detectable beyond those observed in healthy elderly. Moreover, it is not known whether such changes are correlated with indices of odor perception and dementia. To investigate these issues, twelve early stage AD patients and thirteen non-demented controls underwent fMRI while being exposed to each of three concentrations of lavender oil odorant. All participants were administered the University of Pennsylvania Smell Identification Test (UPSIT), the Mini-Mental State Examination (MMSE), the Mattis Dementia Rating Scale-2 (DRS-2), and the Clinical Dementia Rating Scale (CDR). The Blood oxygen level-dependent (BOLD) signal at primary olfactory cortex (POC) was weaker in AD than in HC subjects. At the lowest odorant concentration, the BOLD signals within POC, hippocampus, and insula were significantly correlated with UPSIT, MMSE, DRS-2, and CDR scores. The BOLD signal intensity and activation volume within the POC increased significantly as a function of odorant concentration in the AD group, but not in the control group. These findings demonstrate that olfactory fMRI is sensitive to the AD-related olfactory and functional cognitive decline. PMID:20709038

GryphSens: A Smartphone-Based Portable Diagnostic Reader for the Rapid Detection of Progesterone in Milk

PubMed Central

Jang, Hyunwook; Ahmed, Syed Rahin; Neethirajan, Suresh

2017-01-01

Enzyme-linked immunosorbent assay (ELISA) is a popular assay technique for the detection and quantification of various biological substances due its high sensitivity and specificity. More often, it requires large and expensive laboratory instruments, which makes it difficult to conduct when the tests must be performed quickly at the point-of-care (POC). To increase portability and ease of use, we propose a portable diagnostic system based on a Raspberry Pi imaging sensor for the rapid detection of progesterone in milk samples. We designed, assembled, and tested a standalone portable diagnostic reader and validated it for progesterone detection against a standard ELISA assay using a commercial plate reader. The portable POC device yielded consistent results, regardless of differences in the cameras and flashlights between various smartphone devices. An Android application was built to provide front-end access to users, control the diagnostic reader, and display and store the progesterone measurement on the smartphone. The diagnostic reader takes images of the samples, reads the pixel values, processes the results, and presents the results on the handheld device. The proposed POC reader can perform to superior levels of performance as a plate reader, while adding the desirable qualities of portability and ease of use. PMID:28489036

GryphSens: A Smartphone-Based Portable Diagnostic Reader for the Rapid Detection of Progesterone in Milk.

PubMed

Jang, Hyunwook; Ahmed, Syed Rahin; Neethirajan, Suresh

2017-05-10

Enzyme-linked immunosorbent assay (ELISA) is a popular assay technique for the detection and quantification of various biological substances due its high sensitivity and specificity. More often, it requires large and expensive laboratory instruments, which makes it difficult to conduct when the tests must be performed quickly at the point-of-care (POC). To increase portability and ease of use, we propose a portable diagnostic system based on a Raspberry Pi imaging sensor for the rapid detection of progesterone in milk samples. We designed, assembled, and tested a standalone portable diagnostic reader and validated it for progesterone detection against a standard ELISA assay using a commercial plate reader. The portable POC device yielded consistent results, regardless of differences in the cameras and flashlights between various smartphone devices. An Android application was built to provide front-end access to users, control the diagnostic reader, and display and store the progesterone measurement on the smartphone. The diagnostic reader takes images of the samples, reads the pixel values, processes the results, and presents the results on the handheld device. The proposed POC reader can perform to superior levels of performance as a plate reader, while adding the desirable qualities of portability and ease of use.

Point-of-care washing of allogeneic red blood cells for the prevention of transfusion-related respiratory complications (WAR-PRC): a protocol for a multicenter randomised clinical trial in patients undergoing cardiac surgery

PubMed Central

Warner, Matthew A; Welsby, Ian J; Norris, Phillip J; Silliman, Christopher C; Armour, Sarah; Wittwer, Erica D; Santrach, Paula J; Meade, Laurie A; Liedl, Lavonne M; Nieuwenkamp, Chelsea M; Douthit, Brian; van Buskirk, Camille M; Schulte, Phillip J; Kor, Daryl J

2017-01-01

Introduction The transfusion-related respiratory complications, transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO), are leading causes of transfusion-related morbidity and mortality. At present, there are no effective preventive strategies with red blood cell (RBC) transfusion. Although mechanisms remain incompletely defined, soluble biological response modifiers (BRMs) within the RBC storage solution may play an important role. Point-of-care (POC) washing of allogeneic RBCs may remove these BRMs, thereby mitigating their impact on post-transfusion respiratory complications. Methods and analysis This is a multicenter randomised clinical trial of standard allogeneic versus washed allogeneic RBC transfusion for adult patients undergoing cardiac surgery testing the hypothesis that POC RBC washing is feasible, safe, and efficacious and will reduce recipient immune and physiologic responses associated with transfusion-related respiratory complications. Relevant clinical outcomes will also be assessed. This investigation will enrol 170 patients at two hospitals in the USA. Simon’s two-stage design will be used to assess the feasibility of POC RBC washing. The primary safety outcomes will be assessed using Wilcoxon Rank-Sum tests for continuous variables and Pearson chi-square test for categorical variables. Standard mixed modelling practices will be employed to test for changes in biomarkers of lung injury following transfusion. Linear regression will assess relationships between randomised group and post-transfusion physiologic measures. Ethics and dissemination Safety oversight will be conducted under the direction of an independent Data and Safety Monitoring Board (DSMB). Approval of the protocol was obtained by the DSMB as well as the institutional review boards at each institution prior to enrolling the first study participant. This study aims to provide important information regarding the feasibility of POC washing of allogeneic RBCs and its potential impact on ameliorating post-transfusion respiratory complications. Additionally, it will inform the feasibility and scientific merit of pursuing a more definitive phase II/III clinical trial. Registration ClinicalTrials.gov registration number is NCT02094118 (Pre-results). PMID:28821525

Comparing point-of-care A1C and random plasma glucose for screening diabetes in migrant farm workers.

PubMed

Wensil, Ashley M; Smith, Jennifer D; Pound, Melanie W; Herring, Charles

2013-01-01

To compare point-of-care (POC) glycosylated hemoglobin (A1C) and random plasma glucose (RPG) as a POC screening tool for prediabetes and diabetes in migrant farm workers of eastern North Carolina. Prospective, observational, single-center study. Federally qualified community health center in eastern North Carolina, from August to October 2011. Migrant farm workers 18 years or older who resided in a migrant camp in eastern North Carolina. Diabetes screening using POC A1C and RPG via fingerstick followed by venipuncture A1C and basic metabolic panel in individuals with a positive screening. Positive predictive value (PPV) of POC A1C and RPG, incidence of positive screening, incidence of confirmed diagnosis, concordance rate of the screening tools, and correlation between POC A1C and laboratory A1C. 206 workers participated in the screenings; screening identified 39 individuals with a POC A1C greater than 5.7% and 1 individual with both an RPG of 200 mg/dL or more and a POC A1C greater than 5.7%. Of the 39 individuals found to have a positive screening, 24 presented to Carolina Family Health Centers, Inc., for follow-up venipuncture; however, 1 participant did not have a venipuncture A1C, leaving 23 individuals with complete data. Two participants were diagnosed with diabetes and 17 with prediabetes. POC A1C had a PPV of 82.6%; however, the PPV of RPG could not be calculated due to the number of participants lost to follow-up. POC A1C correlated well with laboratory A1C regardless of time to follow-up. POC A1C should be considered for diabetes screening in high-risk populations. If the screening had been performed with RPG alone, 38 individuals would have gone undetected. Early identification of individuals with elevated blood glucose will likely decrease the risk of long-term complications.

Awareness, Interest, and Preferences of Primary Care Providers in Using Point-of-Care Cancer Screening Technology

PubMed Central

Kim, Chloe S.; Vanture, Sarah; Cho, Margaret; Klapperich, Catherine M.; Wang, Catharine; Huang, Franklin W.

2016-01-01

Well-developed point-of-care (POC) cancer screening tools have the potential to provide better cancer care to patients in both developed and developing countries. However, new medical technology will not be adopted by medical providers unless it addresses a population’s existing needs and end-users’ preferences. The goals of our study were to assess primary care providers’ level of awareness, interest, and preferences in using POC cancer screening technology in their practice and to provide guidelines to biomedical engineers for future POC technology development. A total of 350 primary care providers completed a one-time self-administered online survey, which took approximately 10 minutes to complete. A $50 Amazon gift card was given as an honorarium for the first 100 respondents to encourage participation. The description of POC cancer screening technology was provided in the beginning of the survey to ensure all participants had a basic understanding of what constitutes POC technology. More than half of the participants (57%) stated that they heard of the term “POC technology” for the first time when they took the survey. However, almost all of the participants (97%) stated they were either “very interested” (68%) or “somewhat interested” (29%) in using POC cancer screening technology in their practice. Demographic characteristics such as the length of being in the practice of medicine, the percentage of patients on Medicaid, and the average number of patients per day were not shown to be associated with the level of interest in using POC. These data show that there is a great interest in POC cancer screening technology utilization among this population of primary care providers and vast room for future investigations to further understand the interest and preferences in using POC cancer technology in practice. Ensuring that the benefits of new technology outweigh the costs will maximize the likelihood it will be used by medical providers and patients. PMID:26771309

Awareness, Interest, and Preferences of Primary Care Providers in Using Point-of-Care Cancer Screening Technology.

PubMed

Kim, Chloe S; Vanture, Sarah; Cho, Margaret; Klapperich, Catherine M; Wang, Catharine; Huang, Franklin W

2016-01-01

Well-developed point-of-care (POC) cancer screening tools have the potential to provide better cancer care to patients in both developed and developing countries. However, new medical technology will not be adopted by medical providers unless it addresses a population's existing needs and end-users' preferences. The goals of our study were to assess primary care providers' level of awareness, interest, and preferences in using POC cancer screening technology in their practice and to provide guidelines to biomedical engineers for future POC technology development. A total of 350 primary care providers completed a one-time self-administered online survey, which took approximately 10 minutes to complete. A $50 Amazon gift card was given as an honorarium for the first 100 respondents to encourage participation. The description of POC cancer screening technology was provided in the beginning of the survey to ensure all participants had a basic understanding of what constitutes POC technology. More than half of the participants (57%) stated that they heard of the term "POC technology" for the first time when they took the survey. However, almost all of the participants (97%) stated they were either "very interested" (68%) or "somewhat interested" (29%) in using POC cancer screening technology in their practice. Demographic characteristics such as the length of being in the practice of medicine, the percentage of patients on Medicaid, and the average number of patients per day were not shown to be associated with the level of interest in using POC. These data show that there is a great interest in POC cancer screening technology utilization among this population of primary care providers and vast room for future investigations to further understand the interest and preferences in using POC cancer technology in practice. Ensuring that the benefits of new technology outweigh the costs will maximize the likelihood it will be used by medical providers and patients.

3D printed auto-mixing chip enables rapid smartphone diagnosis of anemia

PubMed Central

Plevniak, Kimberly; Campbell, Matthew; Hodges, Abby; He, Mei

2016-01-01

Clinical diagnosis requiring central facilities and site visits can be burdensome for patients in resource-limited or rural areas. Therefore, development of a low-cost test that utilizes smartphone data collection and transmission would beneficially enable disease self-management and point-of-care (POC) diagnosis. In this paper, we introduce a low-cost iPOC3D diagnostic strategy which integrates 3D design and printing of microfluidic POC device with smartphone-based disease diagnosis in one process as a stand-alone system, offering strong adaptability for establishing diagnostic capacity in resource-limited areas and low-income countries. We employ smartphone output (AutoCAD 360 app) and readout (color-scale analytical app written in-house) functionalities for rapid 3D printing of microfluidic auto-mixers and colorimetric detection of blood hemoglobin levels. The auto-mixing of reagents with blood via capillary force has been demonstrated in 1 second without the requirement of external pumps. We employed this iPOC3D system for point-of-care diagnosis of anemia using a training set of patients (nanemia = 16 and nhealthy = 6), which showed consistent measurements of blood hemoglobin levels (a.u.c. = 0.97) and comparable diagnostic sensitivity and specificity, compared with standard clinical hematology analyzer. Capable of 3D fabrication flexibility and smartphone compatibility, this work presents a novel diagnostic strategy for advancing personalized medicine and mobile healthcare. PMID:27733894

Nano-Calorimetry based point of care biosensor for metabolic disease management.

PubMed

Kazura, Evan; Lubbers, Brad R; Dawson, Elliott; Phillips, John A; Baudenbacher, Franz

2017-09-01

Point of care (POC) diagnostics represents one of the fastest growing health care technology segments. Developments in microfabrication have led to the development of highly-sensitive nanocalorimeters ideal for directly measuring heat generated in POC biosensors. Here we present a novel nano-calorimeter-based biosensor design with differential sensing to eliminate common mode noise and capillary microfluidic channels for sample delivery to the thermoelectric sensor. The calorimeter has a resolution of 1.4 ± 0.2 nJ/(Hz) 1/2 utilizing a 27 junction bismuth/titanium thermopile, with a total Seebeck coefficient of 2160 μV/K. Sample is wicked to the calorimeter through a capillary channel making it suitable for monitoring blood obtained through a finger prick (<1 μL sample required). We demonstrate device performance in a model assay using catalase, achieving a threshold for hydrogen peroxide quantification of 50 μM. The potential for our device as a POC blood test for metabolic diseases is shown through the quantification of phenylalanine (Phe) in serum, an unmet necessary service in the management of Phenylketonuria (PKU). Pegylated phenylalanine ammonia-lyase (PEG-PAL) was utilized to react with Phe, but reliable detection was limited to <5 mM due to low enzymatic activity. The POC biosensor concept can be multiplexed and adapted to a large number of metabolic diseases utilizing different immobilized enzymes.

Feasibility Studies of Palm Oil Mill Waste Aggregates for the Construction Industry

PubMed Central

Kanadasan, Jegathish; Ahmad Fauzi, Auni Filzah; Abdul Razak, Hashim; Selliah, Paramananthan; Subramaniam, Vijaya; Yusoff, Sumiani

2015-01-01

The agricultural industry in Malaysia has grown rapidly over the years. Palm oil clinker (POC) is a byproduct obtained from the palm oil industry. Its lightweight properties allows for its utilization as an aggregate, while in powder form as a filler material in concrete. POC specimens obtained throughout each state in Malaysia were investigated to evaluate the physical, chemical, and microstructure characteristics. Variations between each state were determined and their possible contributory factors were assessed. POC were incorporated as a replacement material for aggregates and their engineering characteristics were ascertained. Almost 7% of density was reduced with the introduction of POC as aggregates. A sustainability assessment was made through greenhouse gas emission (GHG) and cost factor analyses to determine the contribution of the addition of POC to the construction industry. Addition of POC helps to lower the GHG emission by 9.6% compared to control specimens. By channeling this waste into the construction industry, an efficient waste-management system can be promoted; thus, creating a cleaner environment. This study is also expected to offer some guides and directions for upcoming research works on the incorporation of POC. PMID:28793579

Determination of piezo-optic coefficients of crystals by means of four-point bending.

PubMed

Krupych, Oleg; Savaryn, Viktoriya; Krupych, Andriy; Klymiv, Ivan; Vlokh, Rostyslav

2013-06-10

A technique developed recently for determining piezo-optic coefficients (POCs) of isotropic optical media, which represents a combination of digital imaging laser interferometry and a classical four-point bending method, is generalized and applied to a single-crystalline anisotropic material. The peculiarities of measuring procedures and data processing for the case of optically uniaxial crystals are described in detail. The capabilities of the technique are tested on the example of canonical nonlinear optical crystal LiNbO3. The high precision achieved in determination of the POCs for isotropic and anisotropic materials testifies that the technique should be both versatile and reliable.

Characteristics of process oils from HTI coal/plastics co-liquefaction runs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robbins, G.A.; Brandes, S.D.; Winschel, R.A.

1995-12-31

The objective of this project is to provide timely analytical support to DOE`s liquefaction development effort. Specific objectives of the work reported here are presented. During a few operating periods of Run POC-2, HTI co-liquefied mixed plastics with coal, and tire rubber with coal. Although steady-state operation was not achieved during these brief tests periods, the results indicated that a liquefaction plant could operate with these waste materials as feedstocks. CONSOL analyzed 65 process stream samples from coal-only and coal/waste portions of the run. Some results obtained from characterization of samples from Run POC-2 coal/plastics operation are presented.

Abundance, stable isotopic composition, and export fluxes of DOC, POC, and DIC from the Lower Mississippi River during 2006–2008

USGS Publications Warehouse

Cai, Yihua; Guo, Laodong; Wang, Xuri; Aiken, George R.

2015-01-01

Sources, abundance, isotopic compositions, and export fluxes of dissolved inorganic carbon (DIC), dissolved and colloidal organic carbon (DOC and COC), and particulate organic carbon (POC), and their response to hydrologic regimes were examined through monthly sampling from the Lower Mississippi River during 2006–2008. DIC was the most abundant carbon species, followed by POC and DOC. Concentration and δ13C of DIC decreased with increasing river discharge, while those of DOC remained fairly stable. COC comprised 61 ± 3% of the bulk DOC with similar δ13C abundances but higher percentages of hydrophobic organic acids than DOC, suggesting its aromatic and diagenetically younger status. POC showed peak concentrations during medium flooding events and at the rising limb of large flooding events. While δ13C-POC increased, δ15N of particulate nitrogen decreased with increasing discharge. Overall, the differences in δ13C between DOC or DIC and POC show an inverse correlation with river discharge. The higher input of soil organic matter and respired CO2 during wet seasons was likely the main driver for the convergence of δ13C between DIC and DOC or POC, whereas enhanced in situ primary production and respiration during dry seasons might be responsible for their isotopic divergence. Carbon export fluxes from the Mississippi River were estimated to be 13.6 Tg C yr−1 for DIC, 1.88 Tg C yr−1 for DOC, and 2.30 Tg C yr−1 for POC during 2006–2008. The discharge-normalized DIC yield decreased during wet seasons, while those of POC and DOC increased and remained constant, respectively, implying variable responses in carbon export to the increasing discharge.

The Usefulness and Limitations of Point-of-care Cardiac Troponin Measurement in the Emergency Department.

PubMed

Suzuki, Kenichiro; Komukai, Kimiaki; Nakata, Kotaro; Kan, Renshi; Oi, Yuhei; Muto, Eri; Kashiwagi, Yusuke; Tominaga, Mitsutoshi; Miyanaga, Satoru; Ishikawa, Tetsuya; Okuno, Kenji; Uzura, Masahiko; Yoshimura, Michihiro

2018-02-09

Objective This study was carried out to examine the usefulness of point-of-care (POC) cardiac troponin in diagnosing acute coronary syndrome (ACS) and to understand the limitations of a POC cardiac troponin I/T-based diagnoses. Methods Patients whose cardiac troponin levels were measured in the emergency department using a POC system (AQT System; Radiometer, Tokyo, Japan) between January and December 2016 were retrospectively examined (N=1449). Patients who were < 20 years of age or who were admitted with cardiopulmonary arrest were excluded. The sensitivity and specificity of the POC cardiac troponin levels for the diagnosis of ACS were determined. Result One hundred and twenty of 1449 total patients had ACS (acute myocardial infarction, n=88; unstable angina n=32). On comparing the receiver operating characteristic (ROC) curves, the area under the curve (AUC) values for POC cardiac troponin I and cardiac troponin T were 0.833 and 0.786, respectively. The sensitivity and specificity of POC cardiac troponin I when using the 99th percentile (0.023 ng/mL) as the diagnostic cut-off value were 69.0% and 88.1%, respectively. The sensitivity of POC cardiac troponin I (99th percentile) was higher in the patients sampled > 3 h after symptom onset (83.3%) than in those sampled ≤ 3 h after symptom onset (58.8%, p < 0.01). Conclusion When sampled > 3 h after the onset of symptoms, the POC cardiac troponin I level is considered to be suitable for use in diagnosing ACS. However, when sampled ≤ 3 h after the onset of symptoms, careful interpretation of POC cardiac troponins is therefore required to rule out ACS.

Quantification of the lithogenic carbon pump following a simulated dust-deposition event in large mesocosms

NASA Astrophysics Data System (ADS)

Bressac, M.; Guieu, C.; Doxaran, D.; Bourrin, F.; Desboeufs, K.; Leblond, N.; Ridame, C.

2014-02-01

Lithogenic particles, such as desert dust, have been postulated to influence particulate organic carbon (POC) export to the deep ocean by acting as mineral ballasts. However, an accurate understanding and quantification of the POC-dust association that occurs within the upper ocean is required in order to refine the "ballast hypothesis". In the framework of the DUNE (a DUst experiment in a low-Nutrient, low-chlorophyll Ecosystem) project, two artificial seedings were performed seven days apart within large mesocosms. A suite of optical and biogeochemical measurements were used to quantify surface POC export following simulated dust events within a low-nutrient, low-chlorophyll ecosystem. The two successive seedings led to a 2.3-6.7-fold higher POC flux than the POC flux observed in controlled mesocosms. A simple linear regression analysis revealed that the lithogenic fluxes explained more than 85% of the variance in POC fluxes. On the scale of a dust-deposition event, we estimated that 42-50% of POC fluxes were strictly associated with lithogenic particles (through aggregation and most probably sorption processes). Lithogenic ballasting also likely impacted the remaining POC fraction which resulted from the fertilization effect. The observations support the "ballast hypothesis" and provide a quantitative estimation of the surface POC export abiotically triggered by dust deposition. In this work, we demonstrate that the strength of such a "lithogenic carbon pump" depends on the biogeochemical conditions of the water column at the time of deposition. Based on these observations, we suggest that this lithogenic carbon pump could represent a major component of the biological pump in oceanic areas subjected to intense atmospheric forcing.

A riboswitch-regulated antisense RNA in Listeria monocytogenes.

PubMed

Mellin, J R; Tiensuu, Teresa; Bécavin, Christophe; Gouin, Edith; Johansson, Jörgen; Cossart, Pascale

2013-08-06

Riboswitches are ligand-binding elements located in 5' untranslated regions of messenger RNAs, which regulate expression of downstream genes. In Listeria monocytogenes, a vitamin B12-binding (B12) riboswitch was identified, not upstream of a gene but downstream, and antisense to the adjacent gene, pocR, suggesting it might regulate pocR in a nonclassical manner. In Salmonella enterica, PocR is a transcription factor that is activated by 1,2-propanediol, and subsequently activates expression of the pdu genes. The pdu genes mediate propanediol catabolism and are implicated in pathogenesis. As enzymes involved in propanediol catabolism require B12 as a cofactor, we hypothesized that the Listeria B12 riboswitch might be involved in pocR regulation. Here we demonstrate that the B12 riboswitch is transcribed as part of a noncoding antisense RNA, herein named AspocR. In the presence of B12, the riboswitch induces transcriptional termination, causing aspocR to be transcribed as a short transcript. In contrast, in the absence of B12, aspocR is transcribed as a long antisense RNA, which inhibits pocR expression. Regulation by AspocR ensures that pocR, and consequently the pdu genes, are maximally expressed only when both propanediol and B12 are present. Strikingly, AspocR can inhibit pocR expression in trans, suggesting it acts through a direct interaction with pocR mRNA. Together, this study demonstrates how pocR and the pdu genes can be regulated by B12 in bacteria and extends the classical definition of riboswitches from elements governing solely the expression of mRNAs to a wider role in controlling transcription of noncoding RNAs.

The use of upconverting phosphors in point-of-care (POC) testing

NASA Astrophysics Data System (ADS)

Tanke, Hans J.; Zuiderwijk, Michel; Wiesmeijer, Karien C.; Breedveld, Robert N.; Abrams, William R.; de Dood, Claudia J.; Tjon Kon Fat, Elisa M.; Corstjens, Paul L. A. M.

2014-03-01

Point-of-care (POC) testing is increasingly applied as a cost effective alternative to many diagnostic tests. Key in POC testing is to create sufficient assay sensitivity with relatively low cost reagents and equipment. For this purpose we have employed a unique reporter, upconverting phosphor (UCP) particles, in combination with lateral flow (LF) assays. UCPs, submicron ceramic particles doped with rare earth ions (lanthanides), convert infrared to visible light and do not suffer from autofluorescence which limits conventional fluorescence based assays. Low cost handheld readers and microfluidics were evaluated in various applications. Designed assays are well suited for applications outside diagnostic laboratories, in resource poor settings, and can even be used by patients at home. Using two distinctly different UCP-LF assay formats, we focussed on assays for infectious diseases based on the detection of pathogen-specific antibodies and/or antigens including nucleic acids to demonstrate active infection with HIV. Only minor adaptation of the standard UCP-LF assay format is needed to render the format suitable for applications involving low affinity capture antibodies (e.g. in the detection of neurotoxin, botulism), capture of small molecules (e.g. detection of melatonin, a key hormone in chronopharmacology) or the use of dry UCP reagents (e.g. detection of protein based fruit-ripening markers, of economic interest in agriculture). Finally, we anticipate on developments in healthcare (personalized medicine) by discussing the potential of one of the UCP-LF assay formats to measure serum trough levels of immunodrugs (e.g. infliximab or adalimumab) in patients treated for inflammatory bowel disease and rheumatoid arthritis.

Advances in point-of-care technologies for molecular diagnostics.

PubMed

Zarei, Mohammad

2017-12-15

Advances in miniaturization, nanotechnology, and microfluidics, along with developments in cloud-connected point-of-care (POC) diagnostics technologies are pushing the frontiers of POC devices toward low-cost, user-friendly, and enhanced sensitivity molecular-level diagnostics. The combination of various bio-sensing platforms within smartphone-integrated electronic readers provides accurate on-site and on-time diagnostics based on various types of chemical and biological targets. Further, 3D printing technology shows a huge potential toward fabrication and improving the performance of POC devices. Integration of skin-like flexible sensors with wireless communication technology creates a unique opportunity for continuous, real-time monitoring of patients for both preventative healthcare and during disease outbreaks. Here, we review recent developments and advances in POC technologies and describe how these advances enhance the performance of POC platforms. Also, this review describes challenges, directions, and future trends on application of emerging technologies in POC diagnostics. Copyright © 2017 Elsevier B.V. All rights reserved.

We were all young once: an intragenomic perspective on parent-offspring conflict.

PubMed

Bossan, Benjamin; Hammerstein, Peter; Koehncke, Arnulf

2013-03-07

Parent-offspring conflict (POC) describes the evolutionary conflict between offspring and their parents over parental resource allocation. Offspring are expected to demand more resources than their parents are willing to supply because these offspring are more related to their own than to their siblings' offspring. Kin selection acts to limit these divergent interests. Our model departs from previous models by describing POC as an intragenomic conflict between genes determining life-history traits during infancy or parenthood. We explain why a direct fitness approach that measures the total fitness effect during exactly one generation is required to correctly assess POC in interbrood rivalry. We find that incorrect assumptions in previous models led to an overestimation of the scope of POC. Moreover, we show why the degree of monogamy is more important for POC than previously thought. Overall, we demonstrate that a life-history-centred intragenomic approach is necessary to correctly interpret POCs. We further discuss how our work relates to the current debate about the usefulness of inclusive fitness theory.

Methane Hydrate Formation from Enhanced Organic Carbon Burial During Glacial Lowstands: Examples from the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Malinverno, A.; Cook, A.; Daigle, H.; Oryan, B.

2017-12-01

Methane hydrates in fine-grained marine sediments are often found within veins and fractures occupying discrete depth intervals that are surrounded by hydrate-free sediments. As they are not connected with gas sources beneath the base of the methane hydrate stability zone (MHSZ), these isolated hydrate-bearing intervals have been interpreted as formed by in situ microbial methane. We investigate here the hypothesis that these hydrate deposits form in sediments that were deposited during glacial lowstands and contain higher amounts of labile particulate organic carbon (POC), leading to enhanced microbial methanogenesis. During Pleistocene lowstands, river loads are deposited near the steep top of the continental slope and turbidity currents transport organic-rich, fine-grained sediments to deep waters. Faster sedimentation rates during glacial periods result in better preservation of POC because of decreased exposure times to oxic conditions. The net result is that more labile POC enters the methanogenic zone and more methane is generated in these sediments. To test this hypothesis, we apply an advection-diffusion-reaction model with a time-dependent deposition of labile POC at the seafloor controlled by glacioeustatic sea level variations in the last 250 kyr. The model is run for parameters estimated at three sites drilled by the 2009 Gulf of Mexico Joint Industry Project: Walker Ridge in the Terrebonne Basin (WR313-G and WR313-H) and Green Canyon near the canyon embayment into the Sigsbee Escarpment (GC955-H). In the model, gas hydrate forms in sediments with higher labile POC content deposited during the glacial cycle between 230 and 130 kyr (marine isotope stages 6 and 7). The corresponding depth intervals in the three sites contain hydrates, as shown by high bulk electrical resistivities and resistive subvertical fracture fills. This match supports the hypothesis that enhanced POC burial during glacial lowstands can result in hydrate formation from in situ microbial methanogenesis. Our results have implications for carbon cycling during glacial/interglacial cycles and for hydrate accumulation in the MHSZ. In particular, once hydrate-bearing intervals formed during glacial periods are buried beneath the MHSZ and dissociate, gas bubbles can rise and recycle microbial methane into the MHSZ.

Distribution and transport of particle-bound polycyclic aromatic hydrocarbons in a river-influenced continental margin: the northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Adhikari, P. L.; Maiti, K.

2017-12-01

Polycyclic aromatic hydrocarbons (PAHs) are particle-reactive and get preferentially sorbed on particulate organic carbon (POC), thus, the transport and fate of POC in aquatic systems plays an important role in biogeochemical cycling of PAHs. In this study, we examine POC and PAHs in finer suspended particulate matter collected from the Louisiana coast, shelf and slope - progressively south-west transect along the direction of the Mississippi River plume, and also from a transect of Atchafalaya River. The concentrations of total particulate PAHs (ΣPAH43) varied between 0.92 to 7.04 ng/L, while POC varied between 4 to 131 µg/L. The concentrations of total particulate ΣPAH43 as well as individual PAH analytes were significantly positively correlated to the concentrations of POC which indicates that the concentrations and transport of POC plays an important role in distribution of PAHs in marine systems. The river influence, characterized by the change in salinity, had significant negative correlation with both the concentrations of particulate PAHs and POC. These results show that the Mississippi River derived particle influx can be an important vector in delivering particle-reactive hydrophobic organic pollutants such as PAHs into the river dominated continental ecosystems in the northern Gulf of Mexico. The underlying seafloor sediment PAHs' concentration and accumulation rates were not correlated to the water column particulate PAH and POC concentrations, which is attributed to re-mineralization during vertical transport, sediment resuspension/redistribution and different timescales of comparison.

Cost Analysis of the STONE Randomized Trial: Can Health Care Costs be Reduced One Test at a Time?

PubMed

Melnikow, Joy; Xing, Guibo; Cox, Ginger; Leigh, Paul; Mills, Lisa; Miglioretti, Diana L; Moghadassi, Michelle; Smith-Bindman, Rebecca

2016-04-01

Decreasing the use of high-cost tests may reduce health care costs. To compare costs of care for patients presenting to the emergency department (ED) with suspected kidney stones randomized to 1 of 3 initial imaging tests. Patients were randomized to point-of-care ultrasound (POC US, least costly), radiology ultrasound (RAD US), or computed tomography (CT, most costly). Subsequent testing and treatment were the choice of the treating physician. A total of 2759 patients at 15 EDs were randomized to POC US (n=908), RAD US, (n=893), or CT (n=958). Mean age was 40.4 years; 51.8% were male. All medical care documented in the trial database in the 7 days following enrollment was abstracted and coded to estimate costs using national average 2012 Medicare reimbursements. Costs for initial ED care and total 7-day costs were compared using nonparametric bootstrap to account for clustering of patients within medical centers. Initial ED visit costs were modestly lower for patients assigned to RAD US: $423 ($411, $434) compared with patients assigned to CT: $448 ($438, $459) (P<0.0001). Total costs were not significantly different between groups: $1014 ($912, $1129) for POC US, $970 ($878, $1078) for RAD US, and $959 ($870, $1044) for CT. Hospital admissions contributed over 50% of total costs, though only 11% of patients were admitted. Mean total costs (and admission rates) varied substantially by site from $749 to $1239. Assignment to a less costly test had no impact on overall health care costs for ED patients. System-level interventions addressing variation in admission rates from the ED might have greater impact on costs.

Satellite observation of particulate organic carbon dynamics on the Louisiana continental shelf

EPA Science Inventory

Particulate organic carbon (POC) plays an important role in coastal carbon cycling and the formation of hypoxia. Yet, coastal POC dynamics are often poorly understood due to a lack of long-term POC observations and the complexity of coastal hydrodynamic and biogeochemical process...

78 FR 2438 - Agency Information Collection Activities; Existing Collection, Comments Requested: The National...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-11

... Collection, Comments Requested: The National Instant Criminal Background Check System (NICS) Point-of-Contact... Background Check System (NICS) Point-of-Contact (POC) State Final Determination Electronic Submission. (3... required to respond, as well as a brief abstract: Primary: Full Point-of-Contact (POC) States; Partial POC...

Current Nucleic Acid Extraction Methods and Their Implications to Point-of-Care Diagnostics.

PubMed

Ali, Nasir; Rampazzo, Rita de Cássia Pontello; Costa, Alexandre Dias Tavares; Krieger, Marco Aurelio

2017-01-01

Nucleic acid extraction (NAE) plays a vital role in molecular biology as the primary step for many downstream applications. Many modifications have been introduced to the original 1869 method. Modern processes are categorized into chemical or mechanical, each with peculiarities that influence their use, especially in point-of-care diagnostics (POC-Dx). POC-Dx is a new approach aiming to replace sophisticated analytical machinery with microanalytical systems, able to be used near the patient, at the point of care or point of need . Although notable efforts have been made, a simple and effective extraction method is still a major challenge for widespread use of POC-Dx. In this review, we dissected the working principle of each of the most common NAE methods, overviewing their advantages and disadvantages, as well their potential for integration in POC-Dx systems. At present, it seems difficult, if not impossible, to establish a procedure which can be universally applied to POC-Dx. We also discuss the effects of the NAE chemicals upon the main plastic polymers used to mass produce POC-Dx systems. We end our review discussing the limitations and challenges that should guide the quest for an efficient extraction method that can be integrated in a POC-Dx system.

Spatial and temporal variations of particulate organic carbon in the Yellow-Bohai Sea over 2002-2016.

PubMed

Fan, Hang; Wang, Xiujun; Zhang, Haibo; Yu, Zhitong

2018-05-22

The Yellow-Bohai Sea (YBS) is a typical marginal sea in the Northwest Pacific Ocean; however, little is known about the dynamics of particulate organic carbon (POC) and underlying mechanisms. Here, we analyze the spatial and temporal variations of surface POC derived from MODIS-Aqua during 2002-2016. Overall, POC is higher in the Bohai Sea (315-588 mg m -3 ) than in the Yellow Sea (181-492 mg m -3 ), and higher in the nearshore than in the offshore. Surface POC is highest in spring in the YBS, and lowest in winter (summer) in the Bohai Sea (the Yellow Sea). The spatial and seasonal patterns of POC are due to combined influences of primary productivity, water exchange, sediment resuspension and terrestrial inputs. Surface POC shows an overall decreasing trend prior to 2012 followed by an upward trend until 2015 in the YBS, which is almost opposite to chlorophyll; the decrease (increase) may result from strengthened (weakened) water exchange with the East China Sea through the Yellow Sea Warm Current. Declined terrestrial runoff is also partly responsible for the decrease prior to 2012. Our study suggests that water exchange and sediment resuspension are dominant factors regulating the spatial and temporal variability of POC in the YBS.

Current Nucleic Acid Extraction Methods and Their Implications to Point-of-Care Diagnostics

PubMed Central

Ali, Nasir; Rampazzo, Rita de Cássia Pontello; Krieger, Marco Aurelio

2017-01-01

Nucleic acid extraction (NAE) plays a vital role in molecular biology as the primary step for many downstream applications. Many modifications have been introduced to the original 1869 method. Modern processes are categorized into chemical or mechanical, each with peculiarities that influence their use, especially in point-of-care diagnostics (POC-Dx). POC-Dx is a new approach aiming to replace sophisticated analytical machinery with microanalytical systems, able to be used near the patient, at the point of care or point of need. Although notable efforts have been made, a simple and effective extraction method is still a major challenge for widespread use of POC-Dx. In this review, we dissected the working principle of each of the most common NAE methods, overviewing their advantages and disadvantages, as well their potential for integration in POC-Dx systems. At present, it seems difficult, if not impossible, to establish a procedure which can be universally applied to POC-Dx. We also discuss the effects of the NAE chemicals upon the main plastic polymers used to mass produce POC-Dx systems. We end our review discussing the limitations and challenges that should guide the quest for an efficient extraction method that can be integrated in a POC-Dx system. PMID:28785592

Discharge modulates stream metabolism dependence on fine particulate organic carbon in a Mediterranean WWTP-influenced stream

NASA Astrophysics Data System (ADS)

Drummond, J. D.; Bernal, S.; Meredith, W.; Schumer, R.; Martí Roca, E.

2017-12-01

Waste water treatment plant (WWTP) effluents constitute point source inputs of fine sediment, nutrients, carbon, and microbes to stream ecosystems. A range of responses to these inputs may be observed in recipient streams, including increases in respiration rates, which augment CO2 emissions to the atmosphere. Yet, little is known about which fractions of organic carbon (OC) contribute the most to stream metabolism in WWTP-influenced streams. Fine particulate OC (POC) represents ca. 40% of the total mass of OC in river networks, and is generally more labile than dissolved OC. Therefore, POC inputs from WWTPs could contribute disproportionately to higher rates of heterotrophic metabolism by stream microbial communities. The aim of this study was to investigate the influence of POC inputs from a WWTP effluent on the metabolism of a Mediterranean stream over a wide range of hydrologic conditions. We hypothesized that POC inputs would have a positive effect on respiration rates, and that the response to POC availability would be larger during low flows when the dilution capacity of the recipient stream is negligible. We focused on the easily resuspended fine sediment near the sediment-water interface (top 3 cm), as this region is a known hot spot for biogeochemical processes. For one year, samples of resuspended sediment were collected bimonthly at 7 sites from 0 to 800 m downstream of the WWTP point source. We measured total POC, organic matter (OM) content (%), and the associated metabolic activity of the resuspended sediment using the resazurin-resorufin smart tracer system as a proxy for aerobic ecosystem respiration. Resuspended sediment showed no difference in total POC over the year, while the OM content increased with decreasing discharge. This result together with the decreasing trend of total POC observed downstream of the point source during autumn after a long dry period, suggests that the WWTP effluent was the main contributor to stream POC. Furthermore, there was a positive relationship between aerobic ecosystem respiration and OM content in resuspended sediments. Our results suggest that WWTP effluents can be important sources of POC to recipient streams, and that the increased availability of POC enhances aerobic ecosystem respiration, especially when the dilution capacity of the recipient streams is low.

[Distribution of organic carbon and carbon fixed strength of phytoplankton in Enteromorpha prolifera outbreak area of the Western South Yellow Sea, 2008].

PubMed

Xia, Bin; Ma, Shao-Sai; Chen, Ju-Fa; Zhao, Jun; Chen, Bi-Juan; Wang, Fang

2010-06-01

Based on the analysis of dissolved organic carbon (DOC), particulate organic carbon (POC) and particulate nitrogen (PN) of the samples collected from stations in Enteromorpha prolifera outbreak area of the Western South Yellow Sea during the period August 9-13 of 2008, combining with the data of environmental hydrology, the horizontal distribution, source and influential factors of organic carbon and carbon fixed strength of phytoplankton were discussed. The results showed that the concentrations of DOC and POC ranged from 1.55 mg/L to 3.22 mg/L, 0.11 mg/L to 0.68 mg/L, with average values of 2.44 mg/L and 0.27 mg/L. The horizontal distributions of DOC and POC were similar in study area. The concentrations of DOC and POC in coastal area were higher than that in the outer sea and the concentrations of DOC and POC at surface water layer were higher than those at the bottom water layer. There were a positive correlation between POC and TSS, indicating that the concentrations and source of TSS were main factors for the POC. According to the univariate linear regression model between POC and PN, the concentrations of particulate inorganic nitrogen (PIN) were evaluated. Removing the content of PIN in the samples, the average POC/PON values in most coastal waters were less than 8, combining with the values of POC/chlorophyll a, suggesting that the marine primary production were the important source of POC in most coastal waters, and the presence of degraded organic matter which derived from degraded Enteromorph prolifera was in the latter period of green tide outbreak. The results of evaluated carbon fixed strength based on primary productivity showed that carbon fixed strength of phytoplankton in Enteromorpha prolifera outbreak area of the Western South Yellow Sea ranged from 167 mg/(m2 x d) to 2017 mg/(m2 x d), with the average of 730 mg/(m2 x d). The daily carbon fixed quantities of the study area were up to 2.95 x 10(4) t. Then the daily carbon fixed quantities of the Yellow Sea were 28.03 x 10(4) t.

Sources and Reactivity of Terrestrial Organic Carbon to the Colville River Delta, Beaufort Sea, Alaska

NASA Astrophysics Data System (ADS)

Schreiner, K. M.; Bianchi, T. S.; Rosenheim, B. E.

2014-12-01

Terrestrial particulate organic carbon (tPOC) delivery to nearshore deltaic regions is an important mechanism of OC storage and burial, and continental margins worldwide account for approximately 90% of the carbon burial in the ocean. Increasing warming in the Arctic is leading to an acceleration of the hydrologic cycle, warming of permafrost, and broad shifts in vegetation. All of these changes are likely to affect the delivery, reactivity, and burial of tPOC in nearshore Arctic regions, making the Arctic an ideal place to study the effects of climate change on tPOC delivery. However, to date, most studies of tPOC delivery from North America to the Arctic Ocean have focused on large Arctic rivers like the Mackenzie and Yukon, and a significant portion of those watersheds lie in sub-Arctic latitudes, meaning that their tPOC delivery is likely not uniquely representative of the high Arctic tundra. Here, we focus on tPOC delivery by the Colville River, the largest North American river with a watershed that does not include sub-Arctic latitudes. Sediment samples from the river delta and nearby Simpson's Lagoon were taken in August of 2010 and subsequently fractionated by density, in order to study the delivery of both discrete and sediment-sorbed tPOC. Samples were analyzed for stable carbon isotopes, bulk radiocarbon, terrestrial biomarkers (including lignin-phenols, and other CuO reaction products), and aquatic biomarkers (algal pigments), and additionally a subset of the samples were analyzed by ramped pyrolysis-14C. Results show that tPOC delivery near the river mouth is sourced from coastal plain tundra, with additional delivery of tPOC from peat released into the lagoon from the seaward limit of the tundra by coastal erosion. Ramped pyrolysis-14C analysis also shows a clear differentiation between tPOC delivered by the river and tPOC delivered by coastal retreat in the lagoon. Additionally, a significant portion of the OC released by the Colville River is relatively thermochemically reactive and sourced from Pleistocene-aged yedoma-like deposits, and could contribute to increased OC mineralization in the Beaufort shelf. These results are the first to combine biomarker and ramped pyrolysis-14C analyses in an Arctic setting.

Seasonal patterns of water column particulate organic carbon and fluxes in the Ross Sea, Antarctica

NASA Astrophysics Data System (ADS)

Gardner, Wilford D.; Richardson, Mary Jo; Smith, Walker O.

The standing stock of particulate organic carbon (POC) was determined during five cruises in the Ross Sea in 1996 and 1997 and compared with primary production of carbon measured in short-term 14C-incubations and the flux of organic carbon collected in moored sediment traps. POC concentrations were estimated from transmissometer profiles that were calibrated with discrete POC bottle samples from each cruise. The mean standing stock of POC integrated to a depth of 100 m and averaged along a 330 km transect at 76.5°S in mid-October (early spring) was only 240 mmol C m -2, but more than doubled to 560 mmol C m -2 10 days later. By mid-January (summer) the standing stock had increased by an order of magnitude to ˜5300 mmol C m -2, but dropped to 3500 mmol C m -2 one week later. By late April (autumn), the standing stock was only 200 mmol C m -2. The following spring the standing stock increased from 700 mmol C m -2 in late November to 2200 mmol C m -2 in early December. Despite the high standing stock in the photic zone in summer, 1997, little POC was collected in the moored sediment traps until late summer (February-March) when the traps showed an increase in POC and silica flux. A three-fold increase in POC flux occurred in autumn (March-April) dominated by pteropods, but the standing stock of POC in the photic zone at that time was very low. Light-scattering sensor data suggest that, although present in all seasons, aggregates were most abundant in autumn and were distributed throughout the water column. These aggregates may have temporarily stored POC and provided food support for a pteropod population that died and settled into the traps in March-April. Still, the trap POC flux was only 5% of the peak standing stock. Resuspension and lateral advection of recently settled organic matter from a nearby topographic high may explain the larger flux measured in the deep sediment traps, a flux that continued into winter.

Portable Microfluidic Integrated Plasmonic Platform for Pathogen Detection

PubMed Central

Tokel, Onur; Yildiz, Umit Hakan; Inci, Fatih; Durmus, Naside Gozde; Ekiz, Okan Oner; Turker, Burak; Cetin, Can; Rao, Shruthi; Sridhar, Kaushik; Natarajan, Nalini; Shafiee, Hadi; Dana, Aykutlu; Demirci, Utkan

2015-01-01

Timely detection of infectious agents is critical in early diagnosis and treatment of infectious diseases. Conventional pathogen detection methods, such as enzyme linked immunosorbent assay (ELISA), culturing or polymerase chain reaction (PCR) require long assay times, and complex and expensive instruments, which are not adaptable to point-of-care (POC) needs at resource-constrained as well as primary care settings. Therefore, there is an unmet need to develop simple, rapid, and accurate methods for detection of pathogens at the POC. Here, we present a portable, multiplex, inexpensive microfluidic-integrated surface plasmon resonance (SPR) platform that detects and quantifies bacteria, i.e., Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) rapidly. The platform presented reliable capture and detection of E. coli at concentrations ranging from ~105 to 3.2 × 107 CFUs/mL in phosphate buffered saline (PBS) and peritoneal dialysis (PD) fluid. The multiplexing and specificity capability of the platform was also tested with S. aureus samples. The presented platform technology could potentially be applicable to capture and detect other pathogens at the POC and primary care settings. PMID:25801042

Observations on the use of ready-to-use and point-of-care activated parenteral products in automated dispensing cabinets in U.S. hospitals.

PubMed

Fanikos, John; Erickson, Abbie; Munz, Kristin E; Sanborn, Mike D; Ludwig, Brad C; Van Hassel, Tom

2007-10-01

The use of ready-to-use (RTU) and point-of-care (POC) activated parenteral products and their storage in automated dispensing cabinets (ADCs) in U.S. hospitals were evaluated. A survey on the use of RTU and POC activated parenteral products, including storage and dispensing of the products, was developed and sent electronically to hospital pharmacy administrators. Survey respondents were identified using the American Society of Health-System Pharmacists' member database. Of the 4070 surveys sent, 965 (23.7%) were completed and returned. Most pharmacy administrators (94.7%) reported that their institution used some form of RTU and POC activated parenteral product, with 74% using ADCs to dispense these products. Efficiency was the most common reason cited for storage of RTU and POC activated products in ADCs. Facilities varied on reasons for not implementing this technology, with 47 facilities citing implementation costs, limited number of RTU and POC activated products on the hospital's formulary, lack of available pediatric formulations, and safety concerns as the main reasons. More than half of respondents noted space limitations as the greatest challenge to adding RTU and POC activated products to ADCs. Nearly three fourths of survey respondents reported using RTU and POC products in conjunction with ADCs; however, the approach to including these products in ADCs varied based on the characteristics, policies, and preferences of the individual facility. Advantages of RTU and POC products identified by respondents included enhanced safety benefits, increased dispensing efficiency, cost avoidance due to reduced waste, and improved compliance with federal and state regulations.

Seasonal variation in the quality of dissolved and particulate organic matter exchanged between a salt marsh and its adjacent estuary

NASA Astrophysics Data System (ADS)

Osburn, Christopher L.; Mikan, Molly P.; Etheridge, J. Randall; Burchell, Michael R.; Birgand, François

2015-07-01

Fluorescence was used to examine the quality of dissolved and particulate organic matter (DOM and POM) exchanging between a tidal creek in a created salt marsh and its adjacent estuary in eastern North Carolina, USA. Samples from the creek were collected hourly over four tidal cycles in May, July, August, and October 2011. Absorbance and fluorescence of chromophoric DOM (CDOM) and of base-extracted POM (BEPOM) served as the tracers for organic matter quality while dissolved organic carbon (DOC) and base-extracted particulate organic carbon (BEPOC) were used to compute fluxes. Fluorescence was modeled using parallel factor analysis (PARAFAC) and principle components analysis (PCA) of the PARAFAC results. Of nine PARAFAC components (C) modeled, C3 represented recalcitrant DOM and C4 represented fresher soil-derived source DOM. Component 1 represented detrital POM, and C6 represented planktonic POM. Based on mass balance, recalcitrant DOC export was 86 g C m-2 yr-1 and labile DOC export was 49 g C m-2 yr-1; no planktonic DOC was exported. The marsh also exported 41 g C m-2 yr-1 of detrital terrestrial POC, which likely originated from lands adjacent to the North River estuary. Planktonic POC export from the marsh was 6 g C m-2 yr-1. Assuming the exported organic matter was oxidized to CO2 and scaled up to global salt marsh area, respiration of salt marsh DOC and POC transported to estuaries could amount to a global CO2 flux of 11 Tg C yr-1, roughly 4% of the recently estimated CO2 release for marshes and estuaries globally.

Robotic observations of high wintertime carbon export in California coastal waters

NASA Astrophysics Data System (ADS)

Bishop, James K. B.; Fong, Michael B.; Wood, Todd J.

2016-05-01

Biologically mediated particulate organic and inorganic carbon (POC and PIC) export from surface waters is the principal determinant of the vertical oceanic distribution of pH and dissolved inorganic carbon and thus sets the conditions for air-sea exchange of CO2; exported organic matter also provides the energy fueling communities in the mesopelagic zone. However, observations are temporally and spatially sparse. Here we report the first hourly-resolved optically quantified POC and PIC sedimentation rate time series from an autonomous Lagrangian Carbon Flux Explorer (CFE), which monitored particle flux using an imaging optical sedimentation recorder (OSR) at depths below 140 m in the Santa Cruz Basin, CA, in May 2012, and in January and March 2013. Highest POC vertical flux ( ˜ 100-240 mmol C m-2 d-1) occurred in January, when most settling material was millimeter- to centimeter-sized aggregates but when surface biomass was low; fluxes were ˜ 18 and ˜ 6 mmol C m-2 d-1, respectively, in March and May, under high surface biomass conditions. An unexpected discovery was that January 2013 fluxes measured by CFE were 20 times higher than that measured by simultaneously deployed surface-tethered OSR; multiple lines of evidence indicate strong undersampling of aggregates larger than 1 mm in the latter case. Furthermore, the January 2013 CFE fluxes were about 10 times higher than observed during multiyear sediment trap observations in the nearby Santa Barbara and San Pedro basins. The strength of carbon export in biologically dynamic California coastal waters is likely underestimated by at least a factor of 3 and at times by a factor of 20.

76 FR 59184 - Agency Information Collection Activities: Requests for Comments; Clearance of Renewed Approval of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-23

... Personal Oxygen Concentrator (POC) Devices on Board Aircraft AGENCY: Federal Aviation Administration (FAA... Certain Personal Oxygen Concentrator (POC) Devices on Board Aircraft. Form Numbers: There are no FAA forms... prescribes extensive use of oxygen, brings a POC on board the aircraft. Also, we require passengers who have...

--No Title--

Science.gov Websites

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Oxadiazole-carbazole polymer (POC)-Ir(ppy)3 tunable emitting composites

NASA Astrophysics Data System (ADS)

Bruno, Annalisa; Borriello, Carmela; Di Luccio, Tiziana; Sessa, Lucia; Concilio, Simona; Haque, Saif A.; Minarini, Carla

2017-04-01

POC polymer is an oxadiazole-carbazole copolymer we have previously synthetized and established as light emitting material in Organic Light Emitting Devices (OLEDs), although POC quantum yield emission efficiency and color purity still need to be enhanced. On the other hand, tris[2-phenylpyridinato-C2,N]iridium(III) (Ir(ppy)3) complexes, namely Ir(ppy)3 are among the brightest luminophores employed in green light emitting devices. Our aim, in this work, is to take advantage of Ir(ppy)3 bright emission by combining the Ir complex with blue emitting POC to obtain tunable light emitting composites over a wide range of the visible spectrum. Here we have investigated the optical proprieties POC based nanocomposites with different concentrations of Ir(ppy)3, ranging from 1 to 10 wt%. Both spectral and time resolved fluorescence measurements show an efficient energy transfer from the polymer to the dopants, resulting in white-emitting composites. The most intense and stable emission has been found when POC was doped with about 5 wt% concentration of Ir(ppy)3.

"Invisible During My Own Crisis": Responses of LGBT People of Color to the Orlando Shooting.

PubMed

Ramirez, Johanna L; Gonzalez, Kirsten A; Galupo, M Paz

2018-01-01

On June 12, 2016, the Pulse nightclub in Orlando, Florida was the target of one of the country's deadliest mass shootings. Pulse, a gay nightclub, was hosting a Latin Pride Night the evening of the tragedy, which resulted in the death of 49 victims and 53 casualties, over 90% of whom were lesbian, gay, bisexual, and transgender (LGBT) Latinx people, specifically. The present research investigates the narrative responses from LGBT people of color (LGBT-POC) following the tragedy. Results included an analysis of 94 participant narrative responses. Results were collected online from a sample of LGBT-POC with varying sexual, gender, and racial identities. Thematic analysis revealed four major themes: (1) Violence is Not New for LGBT-POC; (2) Personal Identification with Victims; (3) Lack of Intersectionality in Others' Responses to Orlando; and (4) Acknowledgment of Intersectionality across LGBT-POC. Discussion focuses on describing the ways in which LGBT-POC responded to the shooting regarding their multiple minority identities. Implications of this research reinforce the need for continued intersectional research with LGBT-POC.

Infrastructural considerations for supporting POC devices. Healthcare executives must focus on creating integration-friendly environments for the most effective use of mobile devices.

PubMed

Hashem, Ahmad; Ruggeri, Roberto

2003-01-01

Creating an integration-friendly infrastructure is the best way to prepare for current as well as next-generation POC devices. Fortunately, hassle-free system integration is needed throughout healthcare today for reasons beyond the domain of POC devices, so integration progress already made in other areas helps pave the way for POC devices. Healthcare IT professionals, as much or more than any other IT group, have had to deal with the challenges of integrating disparate systems. When considering deployment of POC devices, you will want to make sure they adhere to open industry standards. In this way, these important devices won't add to the problem of disparate systems, but will contribute to the solution. We see XML and Web services as being especially important to the future of healthcare delivery and administration. XML and Web services, along with powerful orchestrators, can provide an ever-richer collection of clinical data to be delivered to, and received from, the POC devices that will become an ever more important addition to the physician armamentarium.

Selecting an A1C Point-of-Care Instrument

PubMed Central

Yong, Ee Vonn; Rasinen, Casey

2015-01-01

A1C point-of-care (POC) instruments benefit patients with diabetes by facilitating clinician decision making that results in significant glycemic improvements. Three National Glycohemoglobin Standardization Program (NGSP)–certified POC products are available in the United States: the handheld A1CNow (formerly manufactured by Bayer Diabetes Care but now made by Chek Diagnostics) and two bench-top models called the Axis-Shield Afinion Analyzer and the Siemens DCA Vantage. This article compares the three available NGSP-certified POC products in terms of accuracy, precision, ease of use, cost, and additional features. Its goal is to aid health care facilities in conveniently identifying the A1C POC product that best meets their needs. It additionally reviews evidence that supports the continued use of A1C POC instruments in the clinical arena. PMID:26300614

3D printed auto-mixing chip enables rapid smartphone diagnosis of anemia.

PubMed

Plevniak, Kimberly; Campbell, Matthew; Myers, Timothy; Hodges, Abby; He, Mei

2016-09-01

Clinical diagnosis requiring central facilities and site visits can be burdensome for patients in resource-limited or rural areas. Therefore, development of a low-cost test that utilizes smartphone data collection and transmission would beneficially enable disease self-management and point-of-care (POC) diagnosis. In this paper, we introduce a low-cost i POC 3D diagnostic strategy which integrates 3D design and printing of microfluidic POC device with smartphone-based disease diagnosis in one process as a stand-alone system, offering strong adaptability for establishing diagnostic capacity in resource-limited areas and low-income countries. We employ smartphone output (AutoCAD 360 app) and readout (color-scale analytical app written in-house) functionalities for rapid 3D printing of microfluidic auto-mixers and colorimetric detection of blood hemoglobin levels. The auto-mixing of reagents with blood via capillary force has been demonstrated in 1 second without the requirement of external pumps. We employed this i POC 3D system for point-of-care diagnosis of anemia using a training set of patients (n anemia  = 16 and n healthy  = 6), which showed consistent measurements of blood hemoglobin levels (a.u.c. = 0.97) and comparable diagnostic sensitivity and specificity, compared with standard clinical hematology analyzer. Capable of 3D fabrication flexibility and smartphone compatibility, this work presents a novel diagnostic strategy for advancing personalized medicine and mobile healthcare.

Variability of particulate organic carbon concentration in the north polar Atlantic based on ocean color observations with Sea-viewing Wide Field-of-view Sensor (SeaWiFS)

NASA Technical Reports Server (NTRS)

Stramska, Malgorzata; Stramski, Dariusz

2005-01-01

We use satellite data from Sea-viewing Wide Field-of-view Sensor (SeaWiFS) to investigate distributions of particulate organic carbon (POC) concentration in surface waters of the north polar Atlantic Ocean during the spring summer season (April through August) over a 6-year period from 1998 through 2003. By use of field data collected at sea, we developed regional relationships for the purpose of estimating POC from remote-sensing observations of ocean color. Analysis of several approaches used in the POC algorithm development and match-up analysis of coincident in situ derived and satellite-derived estimates of POC resulted in selection of an algorithm that is based on the blue-to-green ratio of remote-sensing reflectance R(sub rs) (or normalized water-leaving radiance L(sub wn)). The application of the selected algorithm to a 6-year record of SeaWiFS monthly composite data of L(sub wn) revealed patterns of seasonal and interannual variability of POC in the study region. For example, the results show a clear increase of POC throughout the season. The lowest values, generally less than 200 mg per cubic meters, and at some locations often less than 50 mg per cubic meters, were observed in April. In May and June, POC can exceed 300 or even 400 mg per cubic meters in some parts of the study region. Patterns of interannual variability are intricate, as they depend on the geographic location within the study region and particular time of year (month) considered. By comparing the results averaged over the entire study region and the entire season (April through August) for each year separately, we found that the lowest POC occurred in 2001 and the highest POC occurred in 2002 and 1999.

Evaluating the accessibility and utility of HIV-related point-of-care diagnostics for maternal health in rural South Africa: a study protocol

PubMed Central

Mashamba-Thompson, T P; Drain, P K; Sartorius, B

2016-01-01

Introduction Poor healthcare access is a major barrier to receiving antenatal care and a cause of high maternal mortality in South Africa (SA). ‘Point-of-care’ (POC) diagnostics is a powerful emerging healthcare approach to improve healthcare access. This study focuses on evaluating the accessibility and utility of POC diagnostics for maternal health in rural SA primary healthcare (PHC) clinics in order to generate a model framework of implementation of POC diagnostics in rural South African clinics. Method and analyses We will use several research methods, including a systematic review, quasi-experiments, survey, key informant interviews and audits. We will conduct a systematic review and experimental study to determine the impact of POC diagnostics on maternal health. We will perform a cross-sectional case study of 100 randomly selected rural primary healthcare clinics in KwaZulu-Natal to measure the context and patterns of POC diagnostics access and usage by maternal health providers and patients. We will conduct interviews with relevant key stakeholders to determine the reasons for POC deficiencies regarding accessibility and utility of HIV-related POC diagnostics for maternal health. We will also conduct a vertical audit to investigate all the quality aspects of POC diagnostic services including diagnostic accuracy in a select number of clinics. On the basis of information gathered, we will propose a model framework for improved implementation of POC diagnostics in rural South African public healthcare clinics. Statistical (Stata-13) and thematic (NVIVO) data analysis will be used in this study. Ethics and dissemination The study protocol was approved by the Ethics Committee of the University of KwaZulu-Natal (BE 484/14) and the KwaZulu-Natal Department of Health based on the Helsinki Declaration (HRKM 40/15). Findings of this study will be disseminated electronically and in print. They will be presented to conferences related to HIV/AIDS, diagnostics, maternal health and strengthening of health systems. PMID:27354074

Integrating cancer survivors' experiences into UK cancer registries: design and development of the ePOCS system (electronic Patient-reported Outcomes from Cancer Survivors)

PubMed Central

Ashley, L; Jones, H; Thomas, J; Forman, D; Newsham, A; Morris, E; Johnson, O; Velikova, G; Wright, P

2011-01-01

Background: Understanding the psychosocial challenges of cancer survivorship, and identifying which patients experience ongoing difficulties, is a key priority. The ePOCS (electronic patient-reported outcomes from cancer survivors) project aims to develop and evaluate a cost-efficient, UK-scalable electronic system for collecting patient-reported outcome measures (PROMs), at regular post-diagnostic timepoints, and linking these with clinical data in cancer registries. Methods: A multidisciplinary team developed the system using agile methods. Design entailed process mapping the system's constituent parts, data flows and involved human activities, and undertaking usability testing. Informatics specialists built new technical components, including a web-based questionnaire tool and tracking database, and established component-connecting data flows. Development challenges were overcome, including patient usability and data linkage and security. Results: We have developed a system in which PROMs are completed online, using a secure questionnaire administration tool, accessed via a public-facing website, and the responses are linked and stored with clinical registry data. Patient monitoring and communications are semiautomated via a tracker database, and patient correspondence is primarily Email-based. The system is currently honed for clinician-led hospital-based patient recruitment. Conclusions: A feasibility test study is underway. Although there are possible challenges to sustaining and scaling up ePOCS, the system has potential to support UK epidemiological PROMs collection and clinical data linkage. PMID:22048035

Potential for Pharmacy-Public Health Collaborations Using Pharmacy-Based Point-of-Care Testing Services for Infectious Diseases.

PubMed

Gubbins, Paul O; Klepser, Michael E; Adams, Alex J; Jacobs, David M; Percival, Kelly M; Tallman, Gregory B

Health care professionals must continually identify collaborative ways to combat antibiotic resistance while improving community health and health care delivery. Clinical Laboratory Improvement Amendments of 1988 (CLIA)-waived point-of-care (POC) testing (POCT) services for infectious disease conducted in community pharmacies provide a means for pharmacists to collaborate with prescribers and/or public health officials combating antibiotic resistance while improving community health and health care delivery. To provide a comprehensive literature review that explores the potential for pharmacists to collaborate with public health professionals and prescribers using pharmacy-based CLIA-waived POCT services for infectious diseases. Comprehensive literature review. PubMed and Google Scholar were searched for manuscripts and meeting abstracts for the following key words: infectious disease, community pharmacy, rapid diagnostic tests, rapid assay, and POC tests. All relevant manuscripts and meeting abstracts utilizing POCT in community pharmacies for infectious disease were reviewed. Information regarding the most contemporary evidence regarding CLIA-waived POC infectious diseases tests for infectious diseases and their use in community pharmacies was synthesized to highlight and identify opportunities to develop future collaborations using community pharmacy-based models for such services. Evidence demonstrates that pharmacists in collaboration with other health care professionals can leverage their knowledge and accessibility to provide CLIA-waived POCT services for infectious diseases. Testing for influenza may augment health departments' surveillance efforts, help promote rationale antiviral use, and avoid unnecessary antimicrobial therapy. Services for human immunodeficiency virus infection raise infection status awareness, increase access to health care, and facilitate linkage to appropriate care. Testing for group A streptococcal pharyngitis may curb inappropriate outpatient antibiotic prescribing. However, variance in pharmacy practice statues and the application of CLIA across states stifle collaboration. CLIA-waived POCT services for infectious diseases are a means for pharmacists, public health professionals, and prescribers to collaboratively combat antibiotic resistance and improve community health.

Oxfordshire community stroke project clinical stroke syndrome and appearances of tissue and vascular lesions on pretreatment ct in hyperacute ischemic stroke among the first 510 patients in the Third International Stroke Trial (IST-3).

PubMed

Kobayashi, Adam; Wardlaw, Joanna M; Lindley, Richard I; Lewis, Steff C; Sandercock, Peter A G; Czlonkowska, Anna

2009-03-01

The Oxfordshire Community Stroke Project (OCSP) clinical stroke syndrome classification correlates well with the stroke lesion in established ischemic stroke, but there are few data in patients with hyperacute stroke. We wished to assess whether the OCSP correlated with the site and size of the ischemic lesion and location of cerebral vessel lesion on computed tomography (CT) in hyperacute stroke. Prospective study of ischemic stroke patients presenting within 6 hours of onset in the Third International Stroke Trial (IST-3), a randomized, controlled trial of rt-PA. OCSP syndrome was assigned by a computer-based algorithm. The CT assessment was made by a neuroradiologist blinded to clinical details. We assessed baseline data and CT findings for the first 510 patients; early tissue ischemic changes were present in 329/510 (65%) total anterior circulation syndrome (TACS) - 79%; partial anterior circulation syndrome (PACS) - 57%, lacunar syndrome (LACS) - 40%; posterior circulation syndrome (POCS) - 33%. The site and size of ischemic change on CT was compatible with the clinical syndrome in 79%, 37%, 2%, and 14%, respectively. Assuming that all patients with a normal CT scan will develop an incompatible lesion these numbers reflected the "worst possible scenario." For the "best possible scenario" we presumed that those with a normal CT will develop concordant ischemic change and the proportions were 100%, 80%, 62% and 81%, respectively. The hyperattenuated artery sign was seen in 206/510 (40%); (TACS 54%; PACS 35%, LACS 5%, and POCS 19%). Within 6 hours of stroke, in patients with a nonlacunar syndrome, the OCSP syndrome correlated well with the pattern of ischemic change on CT. For clinicians who wish to restrict the use of thrombolytic therapy to large-artery ischemic stroke, concordance of clinical and CT appearances may give greater confidence in making therapeutic decisions in hyperacute stroke. In centers where immediate access to MR is limited, use of the classification may help focus use of MR on patients with suspected LACS and POCS. The utility of the classification may further increase if IST-3 establishes that the OCSP syndrome significantly modifies response to thrombolytic therapy.

Badlands as a major source of petrogenic particulate Organic Carbon and sediments to the Gulf of Lion (NW Mediterranean Sea)

NASA Astrophysics Data System (ADS)

Copard, Y.; Eyrolle-Boyer, F.; Radakovitch, O.; Poirel, A.; Raimbault, P.; Gairoard, S.; Di-Giovanni, C.

2017-12-01

Rivers feed the marine environments both in term of sediments and nutrients and consequently, the characterization of their nature, sources and changes over a different spatial and time ranges is a critical for many scientific (e.g. biogeochemical cycles, contaminants transfer, geomorphology, ecology) and societal issues (e.g. food security, catastrophic floods). Specifically, continental sources showing some high erosion rates deserve to be studied since their fingerprint can be significant for the rivers fluxes. These included some sedimentary rocks (e.g. marls) forming badlands and containing a significant amount of petrogenic particulate organic carbon (pPOC) for which its contribution to the Rivers still remains evasive. Our study focuses on the Mediterranean area considered as very sensitive to the Global Change and particularly the Gulf of Lion mainly fed by the Rhône River, one of the major conveyors of sediments to this Sea. Based on radiocarbon data performed on a set of riverine samples and time series analyses from monitoring stations from French CZOs, we (i) update the POC flux of the Rhône River, (ii) determine the pPOC content and flux in suspended sediments and (iii) estimate the badlands contribution from the Durance catchment (a major tributary of the Rhône River) to the pPOC flux and to sediment discharge. Sediment discharge by the Rhône River to the Sea is 6.5 ± 4.3 Tg yr-1 (period 1990-2014) , its POC discharge reaches 0.145 ± 0.095 Tg yr-1 (period 2007-2014) while pPOC (0.44 wt. %) contributes to 30 % of this POC flux. Despite their insignificant surfaces (0.2 %) regarding the Rhône catchment area, badlands presently in erosion from the Durance catchment provide respectively, 16, 5 and 20 % of the pPOC, POC and sediment fluxes to the Rhône River. Consequently, badlands can be considered as a major source of sediments and pPOC for the NW Mediterranean Sea. We suggest that river-dominated ocean margins, such as the Rhône River, with badlands in erosion in their catchment could export a significant amount of sediments and pPOC to the oceans. According to the natural climate variability and more recently to the anthropogenic (LULUCF) disorders occurring in continental surfaces, such contributions had to and will strongly vary with times (from the geological times to the next decades scales).

Moving from "optimal resources" to "optimal care" at trauma centers.

PubMed

Shafi, Shahid; Rayan, Nadine; Barnes, Sunni; Fleming, Neil; Gentilello, Larry M; Ballard, David

2012-04-01

The Trauma Quality Improvement Program has shown that risk-adjusted mortality rates at some centers are nearly 50% higher than at others. This "quality gap" may be due to different clinical practices or processes of care. We have previously shown that adoption of processes called core measures by the Joint Commission and Centers for Medicare and Medicaid Services does not improve outcomes of trauma patients. We hypothesized that improved compliance with trauma-specific clinical processes of care (POC) is associated with reduced in-hospital mortality. Records of a random sample of 1,000 patients admitted to a Level I trauma center who met Trauma Quality Improvement Program criteria (age ≥ 16 years and Abbreviated Injury Scale score 3) were retrospectively reviewed for compliance with 25 trauma-specific POC (T-POC) that were evidence-based or expert consensus panel recommendations. Multivariate regression was used to determine the relationship between T-POC compliance and in-hospital mortality, adjusted for age, gender, injury type, and severity. Median age was 41 years, 65% were men, 88% sustained a blunt injury, and mortality was 12%. Of these, 77% were eligible for at least one T-POC and 58% were eligible for two or more. There was wide variation in T-POC compliance. Every 10% increase in compliance was associated with a 14% reduction in risk-adjusted in-hospital mortality. Unlike adoption of core measures, compliance with T-POC is associated with reduced mortality in trauma patients. Trauma centers with excess in-hospital mortality may improve patient outcomes by consistently applying T-POC. These processes should be explored for potential use as Core Trauma Center Performance Measures.

Comparison of portable oxygen concentrators in a simulated airplane environment.

PubMed

Fischer, Rainald; Wanka, Eva R; Einhaeupl, Franziska; Voll, Klaus; Schiffl, Helmut; Lang, Susanne M; Gruss, Martin; Ferrari, Uta

2013-01-01

Portable oxygen concentrators (POC) are highly desirable for patients with lung disease traveling by airplane, as these devices allow theoretically much higher travel times if additional batteries can be used. However, it is unclear whether POCs produce enough oxygen in airplanes at cruising altitude, even if complying with aviation regulations. We evaluated five frequently used POCs (XPO2 (Invacare, USA), Freestyle (AirSep C., USA), Evergo (Philipps Healthcare, Germany), Inogen One (Inogen, USA), Eclipse 3 (Sequal, USA)) at an altitude of 2650 m (as simulated airplane environment) in 11 patients with chronic obstructive lung disease (COPD) and compared theses POCs with the standard oxygen system (WS120, EMS Ltd., Germany) used by Lufthansa. Oxygen was delivered by each POC for 30 min to each patient at rest, blood gases were then drawn from the arterialized ear lobe. All POCs were able to deliver enough oxygen to increase the PaO(2) of our subjects by at least 1.40 kPa (10 mmHg). However, to achieve this increase, the two most lightweight POCs (Freestyle and Invacare XPO2) had to be run at their maximum level. This causes a significant reduction of battery life. The three other POCs (EverGo, Inogen One, Eclipse 3) and the WS120 were able to increase the PaO(2) by more than 2.55 kPa (20 mmHg), which provides extra safety for patients with more severe basal hypoxemia. When choosing the right oxygen system for air travel in patients in COPD, not only weight, but also battery life and maximum possible oxygen output must be considered carefully. Copyright © 2012 Elsevier Ltd. All rights reserved.

Fast alternating projection methods for constrained tomographic reconstruction

PubMed Central

Liu, Li; Han, Yongxin

2017-01-01

The alternating projection algorithms are easy to implement and effective for large-scale complex optimization problems, such as constrained reconstruction of X-ray computed tomography (CT). A typical method is to use projection onto convex sets (POCS) for data fidelity, nonnegative constraints combined with total variation (TV) minimization (so called TV-POCS) for sparse-view CT reconstruction. However, this type of method relies on empirically selected parameters for satisfactory reconstruction and is generally slow and lack of convergence analysis. In this work, we use a convex feasibility set approach to address the problems associated with TV-POCS and propose a framework using full sequential alternating projections or POCS (FS-POCS) to find the solution in the intersection of convex constraints of bounded TV function, bounded data fidelity error and non-negativity. The rationale behind FS-POCS is that the mathematically optimal solution of the constrained objective function may not be the physically optimal solution. The breakdown of constrained reconstruction into an intersection of several feasible sets can lead to faster convergence and better quantification of reconstruction parameters in a physical meaningful way than that in an empirical way of trial-and-error. In addition, for large-scale optimization problems, first order methods are usually used. Not only is the condition for convergence of gradient-based methods derived, but also a primal-dual hybrid gradient (PDHG) method is used for fast convergence of bounded TV. The newly proposed FS-POCS is evaluated and compared with TV-POCS and another convex feasibility projection method (CPTV) using both digital phantom and pseudo-real CT data to show its superior performance on reconstruction speed, image quality and quantification. PMID:28253298

Stable carbon isotope signals in particulate organic and inorganic carbon of coccolithophores - A numerical model study for Emiliania huxleyi.

PubMed

Holtz, Lena-Maria; Wolf-Gladrow, Dieter; Thoms, Silke

2017-05-07

A recent numerical cell model, which explains observed light and carbonate system effects on particulate organic and inorganic carbon (POC and PIC) production rates under the assumption of internal pH homeostasis, is extended for stable carbon isotopes ( 12 C, 13 C). Aim of the present study is to mechanistically understand the stable carbon isotopic fractionation signal (ε) in POC and PIC and furthermore the vital effect(s) included in measured ε PIC values. The virtual cell is divided into four compartments, for each of which the 12 C as well as the 13 C carbonate system kinetics are implemented. The compartments are connected to each other via trans-membrane fluxes. In contrast to existing carbon fractionation models, the presented model calculates the disequilibrium state for both carbonate systems and for each compartment. It furthermore calculates POC and PIC production rates as well as ε POC and ε PIC as a function of given light conditions and the compositions of the external carbonate system. Measured POC and PIC production rates as well as ε PIC values are reproduced well by the model (comparison with literature data). The observed light effect on ε POC (increase of ε POC with increasing light intensities), however, is not reproduced by the basic model set-up, which is solely based on RubisCO fractionation. When extending the latter set-up by assuming that biological fractionation includes further carbon fractionation steps besides the one of RubisCO, the observed light effect on ε POC is also reproduced. By means of the extended model version, four different vital effects that superimpose each other in a real cell can be detected. Finally, we discuss potential limitations of the ε PIC proxy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of three feline leukaemia virus (FeLV) point-of-care antigen test kits using blood and saliva.

PubMed

Westman, Mark E; Malik, Richard; Hall, Evelyn; Sheehy, Paul A; Norris, Jacqueline M

2017-02-01

Feline leukaemia virus (FeLV) can be a challenging infection to diagnose due to a complex feline host-pathogen relationship and occasionally unreliable test results. This study compared the accuracy of three point-of-care (PoC) FeLV p27 antigen test kits commonly used in Australia and available commercially worldwide (SNAP FIV/FeLV Combo, Witness FeLV/FIV and Anigen Rapid FIV/FeLV), using detection of FeLV provirus by an in-house real-time polymerase chain reaction (qPCR) assay as the diagnostic gold standard. Blood (n=563) and saliva (n=419) specimens were collected from a population of cats determined to include 491 FeLV-uninfected and 72 FeLV-infected individuals (45 progressive infections [p27 and qPCR positive], 27 regressive infections [p27 negative, qPCR positive]). Sensitivity and specificity using whole blood was 63% and 94% for SNAP Combo, 57% and 98% for Witness, and 57% and 98% for Anigen Rapid, respectively. SNAP Combo had a significantly lower specificity using blood compared to the other two kits (P=0.004 compared to Witness, P=0.007 compared to Anigen Rapid). False-positive test results occurred with all three kits using blood, and although using any two kits in parallel increased specificity, no combination of kits completely eliminated the occurrence of false-positive results. We therefore recommend FeLV proviral PCR testing for any cat that tests positive with a PoC FeLV antigen kit, as well as for any cat that has been potentially exposed to FeLV but tests negative with a FeLV antigen kit, before final assignment of FeLV status can be made with confidence. For saliva testing, sensitivity and specificity was 54% and 100%, respectively, for all three test kits. The reduced sensitivity of saliva testing compared to blood testing, although not statistically significant, suggests saliva testing with the current generation of PoC FeLV antigen kits is unsuitable for screening large populations of cats, such as in shelters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhanced POC export in the oligotrophic northwest Pacific Ocean after extreme weather events

NASA Astrophysics Data System (ADS)

Chen, Kuo-Shu; Hung, Chin-Chang; Gong, Gwo-Ching; Chou, Wen-Chen; Chung, Chih-Ching; Shih, Yung-Yen; Wang, Chau-Chang

2013-11-01

study effects of extreme weather events (EWEs, e.g., dust storm and typhoon) on the export of particulate organic carbon (POC) measured by a floating sediment trap in the oligotrophic ocean, eight sea-going expeditions were conducted in the oligotrophic northwest Pacific (NWP) in 2007 and 2008, covering all four seasons and the passage of several EWEs. Results of year-round field observations demonstrate that the POC export fluxes in the oligotrophic NWP did not exhibit apparent seasonal variations yielding an average flux of 36.9 ± 5.8 mg-C m-2 d-1 without EWE effects. With EWE effects, however, the POC export flux (51.7 ± 13.2 mg-C m-2 d-1) showed an approximately 40% increase compared to the average flux measured without EWE effects. These results suggest that EWEs can trigger elevated POC export from the euphotic zone in the oligotrophic ocean.

Remote Sensing of Particulate Organic Carbon Pools in the High-Latitude Oceans

NASA Technical Reports Server (NTRS)

Stramski, Dariusz; Stramska, Malgorzata

2005-01-01

The general goal of this project was to characterize spatial distributions at basin scales and variability on monthly to interannual timescales of particulate organic carbon (POC) in the high-latitude oceans. The primary objectives were: (1) To collect in situ data in the north polar waters of the Atlantic and in the Southern Ocean, necessary for the derivation of POC ocean color algorithms for these regions. (2) To derive regional POC algorithms and refine existing regional chlorophyll (Chl) algorithms, to develop understanding of processes that control bio-optical relationships underlying ocean color algorithms for POC and Chl, and to explain bio-optical differentiation between the examined polar regions and within the regions. (3) To determine basin-scale spatial patterns and temporal variability on monthly to interannual scales in satellite-derived estimates of POC and Chl pools in the investigated regions for the period of time covered by SeaWiFS and MODIS missions.

Automated assembly of microfluidic "lab-on-a-disc"

NASA Astrophysics Data System (ADS)

Berger, M.; Müller, T.; Voebel, T.; Baum, C.; Glennon, T.; Mishra, R.; Kinahan, D.; King, D.; Ducrée, J.; Brecher, C.

2018-02-01

Point-of-care (POC) testing attracts more and more attention in the medical health sector because of their specific property to perform the diagnostic close to the patient. The fast diagnosis right at the hospital or the doctor's office improves the medical reaction time and the chances for a successful healing process. One of this POC test systems is a "Lab-on-a-Disc" (LoaD) which looks like a compact disc crisscrossed with microfluidic tubes and cavities. The fluid to be analysed is placed in the LoaD and an external device then rotates the LoaD. The cavities inside the LoaD and the centrifugal force ensure a clearly defined sequence of the analysis. Furthermore, we aim for an inexpensive manufacture of the medical product without neglecting its quality and functionality. Therefore, the Fraunhofer IPT works on an assembly cell to implement dissoluble films concisely into the disc. This dissoluble film demonstrates its successful usage as a gate for the fluid, which opens after a predefined moment in the cycle. Furthermore, we investigate to integrate a laser welding process into our gantry system and demonstrate its efficiency with the welding of polymer discs. This procedure is clinically safe because no further laser absorption material is needed in the sealing process, which might pollute the LoaD. Moreover, this process allows the alignment of several discs before the welding and therefore leads to precisely manufactured LoaDs in large quantities. All these methods together enable a fast, costefficient and reliable mass production to bring POC testing among the people.

Feasibility of using microbiology diagnostic tests of moderate or high complexity at the point - of - care in a delivery suite.

PubMed

Gray, J W; Milner, P J; Edwards, E H; Daniels, J P; Khan, K S

2012-07-01

Point-of-care testing (POCT) is one of the fastest growing sectors of laboratory diagnostics. Most tests in routine use are haematology or biochemistry tests that are of low complexity. Microbiology POCT has been constrained by a lack of tests that are both accurate and of low complexity. We describe our experience of the practical issues around using more complex POCT for detection of Group B streptococci (GBS) in swabs from labouring women. We evaluated two tests for their feasibility in POCT: an optical immune assay (Biostar OIA Strep B, Inverness Medical, Princetown, NJ) and a PCR (IDI-Strep B, Cepheid, Sunnyvale, CA), which have been categorised as being of moderate and high complexity, respectively. A total of 12 unqualified midwifery assistants (MA) were trained to undertake testing on the delivery suite. A systematic approach to the introduction and management of POC testing was used. Modelling showed that the probability of test results being available within a clinically useful timescale was high. However, in the clinical setting, we found it impossible to maintain reliable availability of trained testers. Implementation of more complex POC testing is technically feasible, but it is expensive, and may be difficult to achieve in a busy delivery suite.

Point-of-care washing of allogeneic red blood cells for the prevention of transfusion-related respiratory complications (WAR-PRC): a protocol for a multicenter randomised clinical trial in patients undergoing cardiac surgery.

PubMed

Warner, Matthew A; Welsby, Ian J; Norris, Phillip J; Silliman, Christopher C; Armour, Sarah; Wittwer, Erica D; Santrach, Paula J; Meade, Laurie A; Liedl, Lavonne M; Nieuwenkamp, Chelsea M; Douthit, Brian; van Buskirk, Camille M; Schulte, Phillip J; Carter, Rickey E; Kor, Daryl J

2017-08-18

The transfusion-related respiratory complications, transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO), are leading causes of transfusion-related morbidity and mortality. At present, there are no effective preventive strategies with red blood cell (RBC) transfusion. Although mechanisms remain incompletely defined, soluble biological response modifiers (BRMs) within the RBC storage solution may play an important role. Point-of-care (POC) washing of allogeneic RBCs may remove these BRMs, thereby mitigating their impact on post-transfusion respiratory complications. This is a multicenter randomised clinical trial of standard allogeneic versus washed allogeneic RBC transfusion for adult patients undergoing cardiac surgery testing the hypothesis that POC RBC washing is feasible, safe, and efficacious and will reduce recipient immune and physiologic responses associated with transfusion-related respiratory complications. Relevant clinical outcomes will also be assessed. This investigation will enrol 170 patients at two hospitals in the USA. Simon's two-stage design will be used to assess the feasibility of POC RBC washing. The primary safety outcomes will be assessed using Wilcoxon Rank-Sum tests for continuous variables and Pearson chi-square test for categorical variables. Standard mixed modelling practices will be employed to test for changes in biomarkers of lung injury following transfusion. Linear regression will assess relationships between randomised group and post-transfusion physiologic measures. Safety oversight will be conducted under the direction of an independent Data and Safety Monitoring Board (DSMB). Approval of the protocol was obtained by the DSMB as well as the institutional review boards at each institution prior to enrolling the first study participant. This study aims to provide important information regarding the feasibility of POC washing of allogeneic RBCs and its potential impact on ameliorating post-transfusion respiratory complications. Additionally, it will inform the feasibility and scientific merit of pursuing a more definitive phase II/III clinical trial. ClinicalTrials.gov registration number is NCT02094118 (Pre-results). © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Flexible substrate-based devices for point-of-care diagnostics

PubMed Central

Wang, ShuQi; Chinnasamy, Thiruppathiraja; Lifson, Mark; Inci, Fatih; Demirci, Utkan

2016-01-01

Point-of-care (POC) diagnostics play an important role in delivering healthcare, particularly for clinical management and disease surveillance in both developed and developing countries. Currently, the majority of POC diagnostics utilize paper substrates owing to their affordability, disposability, and mass production capability. Recently, flexible polymer substrates have been investigated due to their enhanced physicochemical properties, potential to be integrated into wearable devices with wireless communications for personalized health monitoring, and ability to be customized for POC diagnostics. Here, we focus on the latest advances in developing flexible substrate-based diagnostic devices, including paper and polymers, and their clinical applications at the POC. PMID:27344425

[Effect of microorganisms and seasonal factors on the isotope composition of organic carbon from Black Sea suspensions].

PubMed

Ivanov, M V; Lein, A Iu; Miller, Iu M; Iusunov, S K; Pimenov, N V; Wehrli, B; Rusanov, I I; Zehnder, A

2000-01-01

The isotopic composition of particulate organic carbon (POC) from the Black Sea deep-water zone was studied during a Russian-Swiss expedition in May 1998. POC from the upper part of the hydrogen sulfide zone (the C-layer) was found to be considerably enriched with the 12C isotope, as compared to the POC of the oxycline and anaerobic zone. In the C-layer waters, the concurrent presence of dissolved oxygen and hydrogen sulfide and an increased rate of dark CO2 fixation were recorded, suggesting that the change in the POC isotopic composition occurs at the expense of newly formed isotopically light organic matter of the biomass of autotrophic bacteria involved in the sulfur cycle. In the anaerobic waters below the C-layer, the organic matter of the biomass of autotrophs is consumed by the community of heterotrophic microorganisms; this results in weighting of the POC isotopic composition. Analysis of the data obtained and data available in the literature allows an inference to be made about the considerable seasonable variability of the POC delta 13C value, which depends on the ratio of terrigenic and planktonogenic components in the particulate organic matter.

Validation of the TTM processes of change measure for physical activity in an adult French sample.

PubMed

Bernard, Paquito; Romain, Ahmed-Jérôme; Trouillet, Raphael; Gernigon, Christophe; Nigg, Claudio; Ninot, Gregory

2014-04-01

Processes of change (POC) are constructs from the transtheoretical model that propose to examine how people engage in a behavior. However, there is no consensus about a leading model explaining POC and there is no validated French POC scale in physical activity This study aimed to compare the different existing models to validate a French POC scale. Three studies, with 748 subjects included, were carried out to translate the items and evaluate their clarity (study 1, n = 77), to assess the factorial validity (n = 200) and invariance/equivalence (study 2, n = 471), and to analyze the concurrent validity by stage × process analyses (study 3, n = 671). Two models displayed adequate fit to the data; however, based on the Akaike information criterion, the fully correlated five-factor model appeared as the most appropriate to measure POC in physical activity. The invariance/equivalence was also confirmed across genders and student status. Four of the five existing factors discriminated pre-action and post-action stages. These data support the validation of the POC questionnaire in physical activity among a French sample. More research is needed to explore the longitudinal properties of this scale.

Trends In Particulate Organic Carbon Composition In Oregon And California Coast Range Rivers

NASA Astrophysics Data System (ADS)

Hatten, J. A.; Goni, M. A.; Wheatcroft, R. A.; Borgeld, J.; Williamson, A.; Padgett, J.; Pasternack, G. B.; Gray, A.; Watson, E.

2009-12-01

The discharge of particulate organic carbon (POC) from small mountainous rivers may contribute nearly half of the world’s POC to the ocean. However, these smaller rivers have highly variable discharges throughout the year, which in turn affect the content and composition of POC being delivered to coastal margins. Further, POC composition has been shown to vary by season and throughout specific events. Understanding the composition of POC being discharged under these various conditions yields clues about the material’s stability in the coastal environment, its source within the watershed, and the process of delivery. During the 2008 and 2009 water years, suspended sediment samples were collected from the Alsea, Umpqua, Eel, and Salinas Rivers draining the Coast Ranges of Oregon and California. Events and discharges of various magnitudes were captured in this sample set. Fine (<63 μm) and coarse (>63 μm) particulate material was analyzed for OC, N, δ13C, δ15N, Δ14C, and cupric oxide oxidation products (e.g. lignin, cutin). This poster will present results from these coastal rivers and explore trends in POC in the context of watershed characteristics, discharge, season, and event-scale processes.

Point of care investigations in pediatric care to improve health care in rural areas.

PubMed

Walia, Kamini

2013-07-01

The good quality laboratory services in developing countries are often limited to major urban centers. As a result, many commercially available high-quality diagnostic tests for infectious diseases are neither accessible nor affordable to patients in the rural areas. Health facilities in rural areas are compromised and this limits the usability and performance of the best medical diagnostic technologies in rural areas as they are designed for air-conditioned laboratories, refrigerated storage of chemicals, a constant supply of calibrators and reagents, stable electrical power, highly trained personnel and rapid transportation of samples. The advent of new technologies have allowed miniaturization and integration of complex functions, which has made it possible for sophisticated diagnostic tools to move out of the developed-world laboratory in the form of a "point of care"(POC) tests. Many diagnostic tests are being developed using these platforms. However, the challenge is to develop diagnostics which are inexpensive, rugged and well suited to the medical and social contexts of the developing world and do not compromise on accuracy and reliability. The already available POC tests which are reliable and affordable, like for HIV infection, malaria, syphilis, and some neglected tropical diseases, and POC tests being developed for other diseases if correctly used and effectively regulated after rigorous evaluation, have the potential to make a difference in clinical management and improve surveillance. In order to use these tests effectively they would need to be supported by technically competent manpower, availability of good-quality reagents, and healthcare providers who value and are able to interpret laboratory results to guide treatment; and a system for timely communication between the laboratory and the healthcare provider. Strengthening the laboratories at the rural level can enable utilization of these diagnostics for improving the diagnosis and management of infectious diseases among children which require prompt treatment and thus, considerably reduce morbidity and mortality among the pediatric age group.

Methane Hydrate Formation from Enhanced Organic Carbon Burial During Glacial Lowstands: Examples from the Gulf of Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malinverno, Alberto; Cook, Ann; Daigle, Hugh

Methane hydrates in fine-grained marine sediments are often found within veins and fractures occupying discrete depth intervals that are surrounded by hydrate-free sediments. As they are not connected with gas sources beneath the base of the methane hydrate stability zone (MHSZ), these isolated hydrate-bearing intervals have been interpreted as formed by in situ microbial methane. We investigate here the hypothesis that these hydrate deposits form in sediments that were deposited during glacial lowstands and contain higher amounts of labile particulate organic carbon (POC), leading to enhanced microbial methanogenesis. During Pleistocene lowstands, river loads are deposited near the steep top ofmore » the continental slope and turbidity currents transport organic-rich, fine-grained sediments to deep waters. Faster sedimentation rates during glacial periods result in better preservation of POC because of decreased exposure times to oxic conditions. The net result is that more labile POC enters the methanogenic zone and more methane is generated in these sediments. To test this hypothesis, we apply an advection-diffusion-reaction model with a time-dependent deposition of labile POC at the seafloor controlled by glacioeustatic sea level variations in the last 250 kyr. The model is run for parameters estimated at three sites drilled by the 2009 Gulf of Mexico Joint Industry Project: Walker Ridge in the Terrebonne Basin (WR313-G and WR313-H) and Green Canyon near the canyon embayment into the Sigsbee Escarpment (GC955-H). In the model, gas hydrate forms in sediments with higher labile POC content deposited during the glacial cycle between 230 and 130 kyr (marine isotope stages 6 and 7). The corresponding depth intervals in the three sites contain hydrates, as shown by high bulk electrical resistivities and resistive subvertical fracture fills. This match supports the hypothesis that enhanced POC burial during glacial lowstands can result in hydrate formation from in situ microbial methanogenesis. Our results have implications for carbon cycling during glacial/interglacial cycles and for hydrate accumulation in the MHSZ. In particular, once hydrate-bearing intervals formed during glacial periods are buried beneath the MHSZ and dissociate, gas bubbles can rise and recycle microbial methane into the MHSZ.« less

Improving the management of warfarin in aged-care facilities utilising innovative technology: a proof-of-concept study.

PubMed

Bereznicki, Luke R E; Jackson, Shane L; Kromdijk, Wiete; Gee, Peter; Fitzmaurice, Kimbra; Bereznicki, Bonnie J; Peterson, Gregory M

2014-02-01

In aged-care facilities (ACFs) monitoring of warfarin can be logistically challenging and International Normalised Ratio (INR control) is often suboptimal. We aimed to determine whether an integrated information and communications technology system and the use of point-of-care (POC) monitors by nursing staff could improve the INR control of aged-care facility residents who take warfarin. Nursing staff identified residents who were prescribed warfarin in participating ACFs. A computer program (MedePOC) was developed to store and transmit INR results from the ACFs to general practitioners (GPs) for dosage adjustment. Nursing staff received training in the use of the CoaguChek XS point-of-care INR monitor and the MedePOC software. Following a run-in phase, eligible patients were monitored weekly for up to 12 weeks. The primary outcome was the change in the time in therapeutic range (TTR) in the intervention phase compared to the TTR in the 12 months preceding the study. All GPs, nursing staff and patients were surveyed for their experiences and opinions of the project. Twenty-four patients and 19 GPs completed the trial across six ACFs. The mean TTR for all patients improved non-significantly from 58.9 to 60.6% (P=0.79) and the proportion of INR tests in range improved non-significantly from 57.1 to 64.1% (P=0.21). The mean TTR improved in 14 patients (58%) and in these patients the mean absolute improvement in TTR was 23.1%. A post hoc analysis of the INR data using modified therapeutic INR ranges to reflect the dosage adjustment practices of GPs suggested that the intervention did lead to improved INR control. The MedePOC program and POC monitoring was well received by nursing staff. Weekly POC INR monitoring conducted in ACFs and electronic communication of the results and warfarin doses resulted in non-significant improvements in INR control in a small cohort of elderly residents. Further research involving modification to the communication strategy and a longer follow-up period is warranted to investigate whether this strategy can improve INR control and clinical outcomes in this vulnerable population. © 2013 The Authors. IJPP © 2013 Royal Pharmaceutical Society.

Consideration of black carbon and primary organic carbon emissions in life-cycle analysis of Greenhouse gas emissions of vehicle systems and fuels.

PubMed

Cai, Hao; Wang, Michael Q

2014-10-21

The climate impact assessment of vehicle/fuel systems may be incomplete without considering short-lived climate forcers of black carbon (BC) and primary organic carbon (POC). We quantified life-cycle BC and POC emissions of a large variety of vehicle/fuel systems with an expanded Greenhouse gases, Regulated Emissions, and Energy use in Transportation model developed at Argonne National Laboratory. Life-cycle BC and POC emissions have small impacts on life-cycle greenhouse gas (GHG) emissions of gasoline, diesel, and other fuel vehicles, but would add 34, 16, and 16 g CO2 equivalent (CO2e)/mile, or 125, 56, and 56 g CO2e/mile with the 100 or 20 year Global Warming Potentials of BC and POC emissions, respectively, for vehicles fueled with corn stover-, willow tree-, and Brazilian sugarcane-derived ethanol, mostly due to BC- and POC-intensive biomass-fired boilers in cellulosic and sugarcane ethanol plants for steam and electricity production, biomass open burning in sugarcane fields, and diesel-powered agricultural equipment for biomass feedstock production/harvest. As a result, life-cycle GHG emission reduction potentials of these ethanol types, though still significant, are reduced from those without considering BC and POC emissions. These findings, together with a newly expanded GREET version, help quantify the previously unknown impacts of BC and POC emissions on life-cycle GHG emissions of U.S. vehicle/fuel systems.

An accurate and inexpensive color-based assay for detecting severe anemia in a limited-resource setting

PubMed Central

McGann, Patrick T.; Tyburski, Erika A.; de Oliveira, Vysolela; Santos, Brigida; Ware, Russell E.; Lam, Wilbur A.

2016-01-01

Severe anemia is an important cause of morbidity and mortality among children in resource-poor settings, but laboratory diagnostics are often limited in these locations. To address this need, we developed a simple, inexpensive, and color-based point-of-care (POC) assay to detect severe anemia. The purpose of this study was to evaluate the accuracy of this novel POC assay to detect moderate and severe anemia in a limited-resource setting. The study was a cross-sectional study conducted on children with sickle cell anemia in Luanda, Angola. The hemoglobin concentrations obtained by the POC assay were compared to reference values measured by a calibrated automated hematology analyzer. A total of 86 samples were analyzed (mean hemoglobin concentration 6.6 g/dL). There was a strong correlation between the hemoglobin concentrations obtained by the POC assay and reference values obtained from an automated hematology analyzer (r=0.88, P<0.0001). The POC assay demonstrated excellent reproducibility (r=0.93, P<0.0001) and the reagents appeared to be durable in a tropical setting (r=0.93, P<0.0001). For the detection of severe anemia that may require blood transfusion (hemoglobin <5 g/dL), the POC assay had sensitivity of 88.9% and specificity of 98.7%. These data demonstrate that an inexpensive (<$0.25 USD) POC assay accurately estimates low hemoglobin concentrations and has the potential to become a transformational diagnostic tool for severe anemia in limited-resource settings. PMID:26317494

Diurnal variability in carbon and nitrogen pools within Chesapeake Bay and northern Gulf of Mexico: implications for future ocean color satellite sensors

NASA Astrophysics Data System (ADS)

Mannino, A.; Novak, M. G.; Tzortziou, M.; Salisbury, J.

2016-02-01

Relative to their areal extent, estuaries and coastal ocean ecosystems contribute disproportionately more to global biogeochemical cycling of carbon, nitrogen and other elements compared to the open ocean. Applying ocean color satellite data to study biological and biogeochemical processes within coastal ecosystems is challenging due to the complex mixtures of aquatic constituents derived from terrestrial, anthropogenic, and marine sources, human-impacted atmospheric properties, presence of clouds during satellite overpass, fine-scale spatial gradients, and time-varying processes on diurnal scales that cannot be resolved with current sensors. On diurnal scales, biological, photochemical, and biogeochemical processes are regulated by the variation in solar radiation. Other physical factors, such as tides, river discharge, estuarine and coastal ocean circulation, wind-driven mixing, etc., impart further variability on biological and biogeochemical processes on diurnal to multi-day time scales. Efforts to determine the temporal frequency required from a NASA GEO-CAPE ocean color satellite sensor to discern diurnal variability C and N stocks, fluxes and productivity culminated in field campaigns in the Chesapeake Bay and northern Gulf of Mexico. Near-surface drogues were released and tracked in quasi-lagrangian space to monitor hourly changes in community production, C and N stocks, and optical properties. While only small diurnal changes were observed in dissolved organic carbon (DOC) and colored dissolved organic matter (CDOM) absorption in Chesapeake Bay, substantial variation in particulate organic carbon (POC) and nitrogen (PN), chlorophyll-a, and inorganic nitrogen (DIN) were measured. Similar or greater diurnal changes in POC, PN, chlorophyll-a and DIN were found in Gulf of Mexico nearshore and offshore sites. These results suggest that satellite observations at hourly frequency are desirable to capture diurnal variability in carbon and nitrogen stocks, fluxes and productivity within coastal ecosystems.

Mobilization and degradation of particulate organic carbon from retrogressive thaw slumps in the western Canadian Arctic

NASA Astrophysics Data System (ADS)

Shakil, S.; Tank, S. E.; Kokelj, S.

2016-12-01

Rapid arctic climate warming has contributed to a significant intensification in the rate and occurrence of thermokarst features which can cause large quantities of frozen organic carbon to suddenly become an active part of the contemporary carbon cycle. Mobilized organic carbon becomes susceptible to bacterial decomposition to CO2, which can then act as a significant positive feedback to climate change. Increasingly, studies are showing dissolved organic carbon (DOC) released from thawing permafrost is highly biodegradable, however, we know little about the biodegradability of permafrost-derived particulate organic carbon (POC). On the Peel Plateau, NWT, Canada, where a warming and wetting climate has intensified the activity of massive retrogressive thaw slumps (RTS), and where some of the Arctic's largest RTS features occur, POC can be more than an order of magnitude greater in streams impacted by an RTS feature when compared to upstream, un-impacted locations, and this mobilization causes POC concentrations to be more than 200 times greater than DOC downstream of slumps. Furthermore, POC released from RTS features can be 6,000 to 13,000 years older than POC in un-impacted streams, indicating a significant mobilization of permafrost carbon in the particulate form. To determine the biodegradability of RTS-released POC in this region, incubations using water samples collected upstream, at, and downstream of RTS sites were conducted during the summer of 2015. Dissolved oxygen measurements were taken 1-2 times per day, and samples for POC and DOC concentration, SUVA254, and bacterial abundance were collected at 0 days, 7 days, and 11 days. Treatments containing a spike of RTS-runoff in filtered water declined in oxygen at a rate as much as 10 times greater than treatments containing filtered DOC controls and unfiltered upstream water indicating that the released of RTS-derived POC substantially increases carbon mineralization in impacted streams. This pool of organic carbon could therefore substantially contribute to the transfer of organic carbon from permafrost soils to the atmospheric carbon pool. Ongoing work is examining the balance between POC decomposition during downstream transport and re-sequestration into streambed sediments.

Temporal variability in terrestrially-derived sources of particulate organic carbon in the lower Mississippi River and its upper tributaries

NASA Astrophysics Data System (ADS)

Bianchi, Thomas S.; Wysocki, Laura A.; Stewart, Mike; Filley, Timothy R.; McKee, Brent A.

2007-09-01

In this study, we examined the temporal changes of terrestrially-derived particulate organic carbon (POC) in the lower Mississippi River (MR) and in a very limited account, the upper tributaries (Upper MR, Ohio River, and Missouri River). We used for the first time a combination of lignin-phenols, bulk stable carbon isotopes, and compound-specific isotope analyses (CSIA) to examine POC in the lower MR and upper tributaries. A lack of correlation between POC and lignin phenol abundances ( Λ8) was likely due to dilution effects from autochthonous production in the river, which has been shown to be considerably higher than previously expected. The range of δ 13C values for p-hydroxycinnamic and ferulic acids in POC in the lower river do support that POM in the lower river does have a significant component of C 4 in addition to C 3 source materials. A strong correlation between δ 13C values of p-hydroxycinnamic, ferulic, and vanillyl phenols suggests a consistent input of C 3 and C 4 carbon to POC lignin while a lack of correlation between these same phenols and POC bulk δ 13C further indicates the considerable role of autochthonous carbon in the lower MR POC budget. Our estimates indicate an annual flux of POC of 9.3 × 10 8 kg y -1 to the Gulf of Mexico. Total lignin fluxes, based on Λ8 values of POC, were estimated to be 1.2 × 10 5 kg y -1. If we include the total dissolved organic carbon (DOC) flux (3.1 × 10 9 kg y -1) reported by [Bianchi T. S., Filley T., Dria K. and Hatcher, P. (2004) Temporal variability in sources of dissolved organic carbon in the lower Mississippi River. Geochim. Cosmochim. Acta68, 959-967.], we get a total organic carbon flux of 4.0 × 10 9 kg y -1. This represents 0.82% of the annual total organic carbon supplied to the oceans by rivers (4.9 × 10 11 kg).

Transport of suspended sediment and organic carbon during storm events in a large agricultural catchment, southwest France.

NASA Astrophysics Data System (ADS)

Chantha, Oeurng; Sabine, Sauvage; David, Baqué; Alexandra, Coynel; Eric, Maneux; Henri, Etcheber; José-Miguel, Sánchez-Pérez

2010-05-01

Intensive agriculture has led to environmental degradation through soil erosion and carbon loss transferred from agricultural land to the stream networks. Suspended sediment transport from the agricultural catchment to the watercourses is responsible for aquatic habitat degradation, reservoir sedimentation, and for transporting sediment associated pollutants (pesticides, nutrient, heavy metals and other toxic substances). Consequently, the temporal transport of suspended sediment (SS), dissolved and particulate organic carbon (DOC and POC) was investigated during 18 months from January 2008 to June 2009 within a large agricultural catchment in southwest France. This study is based on an extensive dataset with high temporal resolution using manual and automatic sampling, especially during 15 flood events. Two main objectives aim at: (i) studying temporal transport in suspended sediment (SS), DOC and POC with factors explaining their dynamics and (ii) analysing the relationships between discharge, SSC, DOC and POC during flood events. The study demonstrates there is a strong variability of SS, POC and DOC during flood events. The SS transport during different seasonal floods varied by event from 513 to 41 750 t; POC transport varied from 12 to 748 t and DOC transport varied from 9 to 218 t. The specific yield of the catchment represents 76 t km-2 y-1 of sediment, 1.8 t km-2 y-1 of POC and 0.7 t km-2 y-1 of DOC, respectively. The POC associated with sediment transport from the catchment accounted for ~2.5% of the total sediment load. Flood duration and flood magnitude are key factors in determining the sediment and organic carbon transport. Statistical analyses revealed strong correlations between total precipitation, flood discharge, total water yield with suspended sediment and organic transport. The relationships of SSC, POC and DOC versus discharge over temporal flood events resulted in different hysteresis patterns which were used to suggest those dissolved and particulate origins. POC for both clockwise and anticlockwise also mostly followed the same patterns of discharge and suspended sediment hysteresis. DOC and discharge relationship were mainly dominated by mixing pattern of clockwise and anticlockwise due to dilution effects of water originating from different sources in the whole catchment.

Electrochemical magnetic microbeads-based biosensor for point-of-care serodiagnosis of infectious diseases.

PubMed

Cortina, María E; Melli, Luciano J; Roberti, Mariano; Mass, Mijal; Longinotti, Gloria; Tropea, Salvador; Lloret, Paulina; Serantes, Diego A Rey; Salomón, Francisco; Lloret, Matías; Caillava, Ana J; Restuccia, Sabrina; Altcheh, Jaime; Buscaglia, Carlos A; Malatto, Laura; Ugalde, Juan E; Fraigi, Liliana; Moina, Carlos; Ybarra, Gabriel; Ciocchini, Andrés E; Comerci, Diego J

2016-06-15

Access to appropriate diagnostic tools is an essential component in the evaluation and improvement of global health. Additionally, timely detection of infectious agents is critical in early diagnosis and treatment of infectious diseases. Conventional pathogen detection methods such as culturing, enzyme linked immunosorbent assay (ELISA) or polymerase chain reaction (PCR) require long assay times, and complex and expensive instruments making them not adaptable to point-of-care (PoC) needs at resource-constrained places and primary care settings. Therefore, there is an unmet need to develop portable, simple, rapid, and accurate methods for PoC detection of infections. Here, we present the development and validation of a portable, robust and inexpensive electrochemical magnetic microbeads-based biosensor (EMBIA) platform for PoC serodiagnosis of infectious diseases caused by different types of microorganisms (parasitic protozoa, bacteria and viruses). We demonstrate the potential use of the EMBIA platform for in situ diagnosis of human (Chagas disease and human brucellosis) and animal (bovine brucellosis and foot-and-mouth disease) infections clearly differentiating infected from non-infected individuals or animals. For Chagas disease, a more extensive validation of the test was performed showing that the EMBIA platform displayed an excellent diagnostic performance almost indistinguishable, in terms of specificity and sensitivity, from a fluorescent immunomagnetic assay and the conventional ELISA using the same combination of antigens. This platform technology could potentially be applicable to diagnose other infectious and non-infectious diseases as well as detection and/or quantification of biomarkers at the POC and primary care settings. Copyright © 2016 Elsevier B.V. All rights reserved.

Remote sensing of bacterial response to degrading phytoplankton in the Arabian Sea.

PubMed

Priyaja, P; Dwivedi, R; Sini, S; Hatha, M; Saravanane, N; Sudhakar, M

2016-12-01

A remote sensing technique has been developed to detect physiological condition of phytoplankton using in situ and moderate imaging spectroradiometer (MODIS)-Aqua data. The recurring massive mixed algal bloom of diatom and Noctiluca scintillans in the Northern Arabian Sea during winter-spring was used as test bed to study formation, growth and degradation of phytoplankton. The ratio of chlorophyll (chl) to particulate organic carbon (POC) was considered as an indicator of phytoplankton physiological condition and used for the approach development. Algal blooms represent the areas of new production, and therefore, knowledge of their degradation is important to the study microbial loop and export carbon flux. Relation of chl/POC ratio with bacterial abundance revealed Gaussian distribution. Bacteria were strongly correlated with POC, and hence, the latter which is available from satellite data could be used as a proxy for remote assessment of bacteria. Thresholds for active and degrading phytoplankton were determined using the ratio computed from the satellite data. The criteria were implemented on MODIS data to generate an image representing distribution of degrading algal bloom. Bacteria abundance data from two validation cruises during dinoflagellate and cyanobacteria bloom confirmed well match up of phytoplankton degradation information from the satellite. Comparison of environmental parameters during decay phase of dinoflagellate (N. scintillans bloom (winter) and Trichodesmium bloom (summer) revealed that degradation after active Trichodesmium bloom was more severe as compared to the N. scintillans. The present study also highlights the prediction capability of phytoplankton degradation using a time series of satellite retrieved chlorophyll/POC images.

Tetrahymena Poc1 ensures proper intertriplet microtubule linkages to maintain basal body integrity

PubMed Central

Meehl, Janet B.; Bayless, Brian A.; Giddings, Thomas H.; Pearson, Chad G.; Winey, Mark

2016-01-01

Basal bodies comprise nine symmetric triplet microtubules that anchor forces produced by the asymmetric beat pattern of motile cilia. The ciliopathy protein Poc1 stabilizes basal bodies through an unknown mechanism. In poc1∆ cells, electron tomography reveals subtle defects in the organization of intertriplet linkers (A-C linkers) that connect adjacent triplet microtubules. Complete triplet microtubules are lost preferentially near the posterior face of the basal body. Basal bodies that are missing triplets likely remain competent to assemble new basal bodies with nine triplet microtubules, suggesting that the mother basal body microtubule structure does not template the daughter. Our data indicate that Poc1 stabilizes basal body triplet microtubules through linkers between neighboring triplets. Without this stabilization, specific triplet microtubules within the basal body are more susceptible to loss, probably due to force distribution within the basal body during ciliary beating. This work provides insights into how the ciliopathy protein Poc1 maintains basal body integrity. PMID:27251062

Odd-Even Alternation in Tautomeric Porous Organic Cages with Exceptional Chemical Stability.

PubMed

Bera, Saibal; Basu, Arghya; Tothadi, Srinu; Garai, Bikash; Banerjee, Subhrashis; Vanka, Kumar; Banerjee, Rahul

2017-02-13

Amine-linked (C-NH) porous organic cages (POCs) are preferred over the imine-linked (C=N) POCs owing to their enhanced chemical stability. In general, amine-linked cages, obtained by the reduction of corresponding imines, are not shape-persistent in the crystalline form. Moreover, they require multistep synthesis. Herein, a one-pot synthesis of four new amine-linked organic cages by the reaction of 1,3,5-triformylphloroglucinol (Tp) with different analogues of alkanediamine is reported. The POCs resulting from the odd diamine (having an odd number of -CH 2 groups) is conformationally eclipsed, while the POCs constructed from even diamines adopt a gauche conformation. This odd-even alternation in the conformation of POCs has been supported by computational calculations. The synthetic strategy hinges on the concept of Schiff base condensation reaction followed by keto-enol tautomerization. This mechanism is the key for the exceptional chemical stability of cages and facilitates their resistance towards acids and bases. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preoperative oral carbohydrate therapy.

PubMed

Nygren, Jonas; Thorell, Anders; Ljungqvist, Olle

2015-06-01

Management of the postoperative response to surgical stress is an important issue in major surgery. Avoiding preoperative fasting using preoperative oral carbohydrates (POC) has been suggested as a measure to prevent and reduce the extent to which such derangements occur. This review summarizes the current evidence and rationale for this treatment. A recent review from the Cochrane Collaboration reports enhanced gastrointestinal recovery and shorter hospital stay with the use of POC with no effect on postoperative complication rates. Multiple randomized controlled trials demonstrate improved postoperative metabolic response after POC administration, including reduced insulin resistance, protein sparing, improved muscle function and preserved immune response. Cohort studies in patients undergoing major abdominal surgery have shown that the use of POC as part of an enhanced recovery after surgery protocol is a significant predictor for improved clinical outcomes. Avoiding preoperative fasting with POC is associated with attenuated postoperative insulin resistance, improved metabolic response, enhanced perioperative well-being, and better clinical outcomes. The impact is greatest for patients undergoing major surgeries.

A pilot evaluation of whole blood finger-prick sampling for point-of-care HIV viral load measurement: the UNICORN study.

PubMed

Fidler, Sarah; Lewis, Heather; Meyerowitz, Jodi; Kuldanek, Kristin; Thornhill, John; Muir, David; Bonnissent, Alice; Timson, Georgina; Frater, John

2017-10-20

There is a global need for HIV viral load point-of-care (PoC) assays to monitor patients receiving antiretroviral therapy. UNICORN was the first study of an off-label protocol using whole blood finger-prick samples tested with and without a simple three minute spin using a clinic-room microcentrifuge. Two PoC assays were evaluated in 40 HIV-positive participants, 20 with detectable and 20 with undetectable plasma viral load (pVL) (<20 copies/ml). Using 100 µl finger-prick blood samples, the Cepheid Xpert HIV-1 Viral Load and HIV-1 Qual cartridges were compared with laboratory pVL assessment (TaqMan, Roche). For participants with undetectable viraemia by TaqMan, there was poor concordance without centrifugation with the TaqMan platform with only 40% 'undetectable' using Xpert VL and 25% 'not detected' using the Qual assay. After a 3 minute spin, 100% of samples were undetectable using either assay, showing full concordance with the TaqMan assay. Defining a lower limit of detection of 1000 copies/ml when including a spin, there was 100% concordance with the TaqMan platform with strong correlation (rho 0.95 and 0.94; p < 0.0001 for both assays). When including a simple microcentrifugation step, finger-prick PoC testing was a quick and accurate approach for assessing HIV viraemia, with excellent concordance with validated laboratory approaches.

Skin Cancer Concerns in People of Color: Risk Factors and Prevention

PubMed Central

Gupta, Alpana K; Bharadwaj, Mausumi; Mehrotra, Ravi

2016-01-01

Background: Though people of color (POC) are less likely to become afflicted with skin cancer, they are much more likely to die from it due to delay in detection or presentation. Very often, skin cancer is diagnosed at a more advanced stage in POC, making treatment difficult. The purpose of this research was to improve awareness regarding skin cancers in people of color by providing recommendations to clinicians and the general public for early detection and photo protection preventive measures. Methods: Data on different types of skin cancers were presented to POC. Due to limited research, there are few resources providing insights for evaluating darkly pigmented lesions in POC. Diagnostic features for different types of skin cancers were recorded and various possible risk factors were considered. Results: This study provided directions for the prevention and early detection of skin cancer in POC based on a comprehensive review of available data. Conclusions: The increased morbidity and mortality rate associated with skin cancer in POC is due to lack of awareness, diagnosis at a more advanced stage and socioeconomic barriers hindering access to care. Raising public health concerns for skin cancer prevention strategies for all people, regardless of ethnic background and socioeconomic status, is the key to timely diagnosis and treatment. PMID:28125871

The role of effective discharge in the ocean delivery of particulate organic carbon by small, mountainous river systems

USGS Publications Warehouse

Wheatcroft, R.A.; Goni, M.A.; Hatten, J.A.; Pasternack, G.B.; Warrick, J.A.

2010-01-01

Recent research has shown that small, mountainous river systems (SMRS) account for a significant fraction of the global flux of sediment and particulate organic carbon (POC) to the ocean. The enormous number of SMRS precludes intensive studies of the sort conducted on large systems, necessitating development of a conceptual framework that permits cross-system comparison and scaling up. Herein, we introduce the geomorphic concept of effective discharge to the problem of source-to-sink POC transport. This idea recognizes that transport effectiveness is the product of discharge frequency and magnitude, wherein the latter is quantified as a power-law relationship between discharge and load (the 'rating curve'). An analytical solution for effective discharge (Qe) identifies two key variables: the standard deviation of the natural logarithm of discharge (??q), and the rating exponent of constituent i (bi Data from selected SMRS are used to show that for a given river Qe-POC < Qesediment, Qe for different POC constituents (e.g., POCfossil vs. POC(modern) differs in predictable ways, and Qe for a particular constituent can vary seasonally. When coupled with the idea that discharge peaks of small rivers may be coincident with specific oceanic conditions (e.g., large waves, wind from a certain direction) that determine dispersal and burial, these findings have potentially important implications for POC fate on continental margins. Future studies of POC transport in SMRS should exploit the conceptual framework provided herein and seek to identify how constituent-specific effective discharges vary between rivers and respond to perturbations. ?? 2010, by the American Society of Limnology and Oceanography, Inc.

Variable reactivity of particulate organic matter in a global ocean biogeochemical model

NASA Astrophysics Data System (ADS)

Aumont, Olivier; van Hulten, Marco; Roy-Barman, Matthieu; Dutay, Jean-Claude; Éthé, Christian; Gehlen, Marion

2017-05-01

The marine biological carbon pump is dominated by the vertical transfer of particulate organic carbon (POC) from the surface ocean to its interior. The efficiency of this transfer plays an important role in controlling the amount of atmospheric carbon that is sequestered in the ocean. Furthermore, the abundance and composition of POC is critical for the removal of numerous trace elements by scavenging, a number of which, such as iron, are essential for the growth of marine organisms, including phytoplankton. Observations and laboratory experiments have shown that POC is composed of numerous organic compounds that can have very different reactivities. However, this variable reactivity of POC has never been extensively considered, especially in modelling studies. Here, we introduced in the global ocean biogeochemical model NEMO-PISCES a description of the variable composition of POC based on the theoretical reactivity continuum model proposed by Boudreau and Ruddick (1991). Our model experiments show that accounting for a variable lability of POC increases POC concentrations in the ocean's interior by 1 to 2 orders of magnitude. This increase is mainly the consequence of a better preservation of small particles that sink slowly from the surface. Comparison with observations is significantly improved both in abundance and in size distribution. Furthermore, the amount of carbon that reaches the sediments is increased by more than a factor of 2, which is in better agreement with global estimates of the sediment oxygen demand. The impact on the major macronutrients (nitrate and phosphate) remains modest. However, iron (Fe) distribution is strongly altered, especially in the upper mesopelagic zone as a result of more intense scavenging: vertical gradients in Fe are milder in the upper ocean, which appears to be closer to observations. Thus, our study shows that the variable lability of POC can play a critical role in the marine biogeochemical cycles which advocates for more dedicated in situ and laboratory experiments.

Harmonization activities of Noklus - a quality improvement organization for point-of-care laboratory examinations.

PubMed

Stavelin, Anne; Sandberg, Sverre

2018-05-16

Noklus is a non-profit quality improvement organization that focuses to improve all elements in the total testing process. The aim is to ensure that all medical laboratory examinations are ordered, performed and interpreted correctly and in accordance with the patients' needs for investigation, treatment and follow-up. For 25 years, Noklus has focused on point-of-care (POC) testing in primary healthcare laboratories and has more than 3100 voluntary participants. The Noklus quality system uses different tools to obtain harmonization and improvement: (1) external quality assessment for the pre-examination, examination and postexamination phase to monitor the harmonization process and to identify areas that need improvement and harmonization, (2) manufacturer-independent evaluations of the analytical quality and user-friendliness of POC instruments and (3) close interactions and follow-up of the participants through site visits, courses, training and guidance. Noklus also recommends which tests that should be performed in the different facilities like general practitioner offices, nursing homes, home care, etc. About 400 courses with more than 6000 delegates are organized annually. In 2017, more than 21,000 e-learning programs were completed.

Single DNA imaging and length quantification through a mobile phone microscope

NASA Astrophysics Data System (ADS)

Wei, Qingshan; Luo, Wei; Chiang, Samuel; Kappel, Tara; Mejia, Crystal; Tseng, Derek; Chan, Raymond Yan L.; Yan, Eddie; Qi, Hangfei; Shabbir, Faizan; Ozkan, Haydar; Feng, Steve; Ozcan, Aydogan

2016-03-01

The development of sensitive optical microscopy methods for the detection of single DNA molecules has become an active research area which cultivates various promising applications including point-of-care (POC) genetic testing and diagnostics. Direct visualization of individual DNA molecules usually relies on sophisticated optical microscopes that are mostly available in well-equipped laboratories. For POC DNA testing/detection, there is an increasing need for the development of new single DNA imaging and sensing methods that are field-portable, cost-effective, and accessible for diagnostic applications in resource-limited or field-settings. For this aim, we developed a mobile-phone integrated fluorescence microscopy platform that allows imaging and sizing of single DNA molecules that are stretched on a chip. This handheld device contains an opto-mechanical attachment integrated onto a smartphone camera module, which creates a high signal-to-noise ratio dark-field imaging condition by using an oblique illumination/excitation configuration. Using this device, we demonstrated imaging of individual linearly stretched λ DNA molecules (48 kilobase-pair, kbp) over 2 mm2 field-of-view. We further developed a robust computational algorithm and a smartphone app that allowed the users to quickly quantify the length of each DNA fragment imaged using this mobile interface. The cellphone based device was tested by five different DNA samples (5, 10, 20, 40, and 48 kbp), and a sizing accuracy of <1 kbp was demonstrated for DNA strands longer than 10 kbp. This mobile DNA imaging and sizing platform can be very useful for various diagnostic applications including the detection of disease-specific genes and quantification of copy-number-variations at POC settings.

Point of Care Tuberculosis Sero-Diagnosis Kit for Wild Animals: Combination of Proteins for Improving the Diagnostic Sensitivity and Specificity.

PubMed

Veerasami, Maroudam; Venkataraman, K; Karuppannan, Chitra; Shanmugam, Arun Attur; Prudhvi, Mallepaddi Chand; Holder, Thomas; Rathnagiri, Polavarapu; Arunmozhivarman, K; Raj, Gopal Dhinakar; Vordermeier, Martin; Mohana Subramanian, B

2018-03-01

Tuberculosis is a significant problem globally for domestic animals as well as captive and free ranging wild life. Rapid point of care (POC) serology kits are well suited for the diagnosis of TB in wild animals. However, wild animals are invariably exposed to environmental non-pathogenic mycobacterium species with the development of cross reacting antibodies. In the present study, POC TB diagnosis kit was developed using a combination of pathogenic Mycobacteria specific recombinant antigens and purified protein derivatives of pathogenic and non-pathogenic Mycobacteria . To benchmark the TB antibody detection kit, particularly in respect to specificity which could not be determined in wildlife due to the lack of samples from confirmed uninfected animals, we first tested well-characterized sera from 100 M. bovis infected and 100 uninfected cattle. Then we investigated the kit's performance using sera samples from wildlife, namely Sloth Bears (n = 74), Elephants (n = 9), Cervidae (n = 14), Felidae (n = 21), Cape buffalo (n = 2), Wild bear (n = 1) and Wild dog (n = 1).In cattle, a sensitivity of 81% and a specificity of 90% were obtained. The diagnostic sensitivity of the kit was 94% when the kit was tested using known TB positive sloth bear sera samples. 47.4% of the in-contact sloth bears turned seropositive using the rapid POC TB diagnostic kit. Seropositivity in other wild animals was 25% when the sera samples were tested using the kit. A point of care TB sero-diagnostic kit with the combination of proteins was developed and the kit was validated using the sera samples of wild animals.

Point-of-care screening for syphilis and HIV in the borderlands: challenges in implementation in the Brazilian Amazon.

PubMed

Ruffinen, Carole Zen; Sabidó, Meritxell; Díaz-Bermúdez, Ximena Pamela; Lacerda, Marcus; Mabey, David; Peeling, Rosanna W; Benzaken, Adele Schwartz

2015-11-05

Point-of-care (POC) screening for HIV and syphilis using rapid testing was implemented in indigenous communities in the triple-border area of the Brazilian Amazon. We describe the context of the early introduction of POC screening, explore hindering and enabling factors for POC implementation, and recommend strategies for feasible, viable, and sustainable syphilis and HIV screening interventions. This was a qualitative study based on grounded theory methodology. Data were collected using in-depth interviews, semi-structured questionnaires, and field observations and were analysed using the framework approach. Qualitative information was complemented by quantitative data for descriptive purposes. An overall high score for vulnerability to acquiring HIV and syphilis was observed among the indigenous communities. Health professionals reported satisfactory rapid testing acceptance, although concerns were raised about the pain of the fingerprick. Counselling-related challenges included ensuring the accuracy of translations, collaborating with translators and communicating positive test results. Over 3 months, 86.7% of the syphilis-positive individuals began treatment, and all of them notified their partners. Accessibility, measured as travel time via the local transportation network, was a barrier to health care access. A lack of gasoline for boats and other transportation was also a hindering factor at all levels of implementation. The recommendations address the preparation phase at the coordination level as well as at the training level. Tools such as strengths, weaknesses, opportunities, and threats (SWOT) analyses; checklists; context-adapted protocols; and fact sheets are very simple methods to facilitate implementation. The findings of this study are important because they may inform the implementation of new health technologies in low-resource national disease control programmes in remote communities.

A Novel Field-Deployable Point-of-Care Diagnostic Test for Cutaneous Leishmaniasis

DTIC Science & Technology

2017-10-01

AWARD NUMBER: W81XWH-14-2-0195 TITLE: A Novel Field-Deployable Point-of-Care Diagnostic Test for Cutaneous Leishmaniasis PRINCIPAL INVESTIGATOR...Field-Deployable Point-of-Care Diagnostic Test for Cutaneous Leishmaniasis 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...Month % completion Aim 1: To use simulated field conditions to optimize and produce the established RPA lateral flow diagnostic test for POC

An integrated paper-based sample-to-answer biosensor for nucleic acid testing at the point of care.

PubMed

Choi, Jane Ru; Hu, Jie; Tang, Ruihua; Gong, Yan; Feng, Shangsheng; Ren, Hui; Wen, Ting; Li, XiuJun; Wan Abas, Wan Abu Bakar; Pingguan-Murphy, Belinda; Xu, Feng

2016-02-07

With advances in point-of-care testing (POCT), lateral flow assays (LFAs) have been explored for nucleic acid detection. However, biological samples generally contain complex compositions and low amounts of target nucleic acids, and currently require laborious off-chip nucleic acid extraction and amplification processes (e.g., tube-based extraction and polymerase chain reaction (PCR)) prior to detection. To the best of our knowledge, even though the integration of DNA extraction and amplification into a paper-based biosensor has been reported, a combination of LFA with the aforementioned steps for simple colorimetric readout has not yet been demonstrated. Here, we demonstrate for the first time an integrated paper-based biosensor incorporating nucleic acid extraction, amplification and visual detection or quantification using a smartphone. A handheld battery-powered heating device was specially developed for nucleic acid amplification in POC settings, which is coupled with this simple assay for rapid target detection. The biosensor can successfully detect Escherichia coli (as a model analyte) in spiked drinking water, milk, blood, and spinach with a detection limit of as low as 10-1000 CFU mL(-1), and Streptococcus pneumonia in clinical blood samples, highlighting its potential use in medical diagnostics, food safety analysis and environmental monitoring. As compared to the lengthy conventional assay, which requires more than 5 hours for the entire sample-to-answer process, it takes about 1 hour for our integrated biosensor. The integrated biosensor holds great potential for detection of various target analytes for wide applications in the near future.

Sample size calculation for a proof of concept study.

PubMed

Yin, Yin

2002-05-01

Sample size calculation is vital for a confirmatory clinical trial since the regulatory agencies require the probability of making Type I error to be significantly small, usually less than 0.05 or 0.025. However, the importance of the sample size calculation for studies conducted by a pharmaceutical company for internal decision making, e.g., a proof of concept (PoC) study, has not received enough attention. This article introduces a Bayesian method that identifies the information required for planning a PoC and the process of sample size calculation. The results will be presented in terms of the relationships between the regulatory requirements, the probability of reaching the regulatory requirements, the goalpost for PoC, and the sample size used for PoC.

Human anti-HIV IgM detection by the OraQuick ADVANCE® Rapid HIV 1/2 Antibody Test.

PubMed

Guillon, Geraldine; Yearwood, Graham; Snipes, Casey; Boschi, Daniel; Reed, Michael R

2018-01-01

The Centers for Disease Control and Prevention (CDC) and many public health jurisdictions continue to advocate for the most sensitive rapid HIV test that is available. Currently, the recommendation is to utilize tests that can detect HIV infection biomarkers within 30 days of infection, when initial immune responses are mounted. The infected patient's IgM response is often used to detect acute infection within a 20-25 days window after infection. This requirement applies to lab-based testing with automated analyzers and rapid, point of care (POC) testing used for screening in a non-clinical setting. A recent study has demonstrated that POC tests using a Protein A-based detection system can detect samples with predominantly HIV-1 IgM reactivity (Moshgabadi et al., 2015). The OraQuick ADVANCE ® Rapid HIV-1/2 Antibody Test (OraQuick ADVANCE ®) also uses Protein A as the detection protein in the antibody-binding colloidal gold conjugate, so it is expected that the OraQuick ADVANCE ® Test will also detect samples with predominantly IgM reactivity. This report definitively demonstrates that the OraQuick ADVANCE ® Test can detect IgM antibodies during an acute infection window period of approximately 20-25 days after infection, and is therefore suitable for use in testing environments requiring adherence to current CDC recommendations.

Clinical presentation and blood gas analysis of multiple trauma patients for prediction of standard coagulation parameters at emergency department arrival.

PubMed

Hilbert-Carius, P; Hofmann, G O; Lefering, R; Stuttmann, R; Struck, M F

2016-04-01

Trauma-induced coagulopathy (TIC) in multiple trauma patients is a potentially lethal complication. Whether quickly available laboratory parameters using point-of-care (POC) blood gas analysis (BGA) may serve as surrogate parameters for standard coagulation parameters is unknown. The present study evaluated TraumaRegister DGU® of the German Trauma Society for correlations between POC BGA parameters and standard coagulation parameters. In the setting of 197 trauma centres (172 in Germany), 86,442 patients were analysed between 2005 and 2012. Of these, 40,129 (72% men) with a mean age 46 ± 21 years underwent further analysis presenting with direct admission from the scene of the accident to a trauma centre, injury severity score (ISS) ≥ 9, complete data available for the calculation of revised injury severity classification prognosis, and blood samples with valid haemoglobin (Hb) measurements taken immediately after emergency department (ED) admission. Correlations between standard coagulation parameters and POC BGA parameters (Hb, base excess [BE], lactate) were tested using Pearson's test with a two-tailed significance level of p < 0.05. A subgroup analysis including patients with ISS > 16, ISS > 25, ISS > 16 and shock at ED admission, and patients with massive transfusion was likewise carried out. Correlations were found between Hb and prothrombin time (r = 0.497; p < 0.01), Hb and activated partial thromboplastin time (aPTT; r = -0.414; p < 0.01), and Hb and platelet count (PLT; r = 0.301; p < 0.01). Patients presenting with ISS ≥ 16 and shock (systolic blood pressure < 90 mmHg) at ED admission (n = 4,329) revealed the strongest correlations between Hb and prothrombin time (r = 0.570; p < 0.01), Hb and aPTT (r = -0.457; p < 0.01), and Hb and PLT (r = 0.412; p < 0.01). Significant correlations were also found between BE and prothrombin time (r = -0.365; p < 0.01), and BE and aPTT (r = 0.327, p < 0.01). No correlations were found between Hb, BE and lactate lactate. POC BGA parameters Hb and BE of multiple trauma patients correlated with standard coagulation parameters in a large database analysis. These correlations were particularly strong in multiple trauma patients presenting with ISS > 16 and shock at ED admission. This may be relevant for hospitals with delayed availability of coagulation studies and those without viscoelastic POC devices. Future studies may determine whether clinical presentation/BGA-oriented coagulation therapy is an appropriate tool for improving outcomes after major trauma.

The Parasol Protocol: An Implementation Science Study of HIV Continuum of Care Interventions for Gay Men and Transgender Women in Burma/Myanmar

PubMed Central

Naing, Soe; Clouse, Emily; Thu, Kaung Htet; Mon, Sandra Hsu Hnin; Tun, Zin Min; Baral, Stefan; Paing, Aung Zayar; Beyrer, Chris

2017-01-01

Background Efforts to improve HIV diagnosis and antiretroviral therapy (ART) initiation among people living with HIV and reduce onward transmission of HIV rely on innovative interventions along multiple steps of the HIV care continuum. These innovative methods are particularly important for key populations, including men who have sex with men (MSM) and transgender women (TW). The HIV epidemic in Myanmar is concentrated among key populations, and national efforts now focus on reducing stigma and improving engagement of MSM and TW in HIV prevention and care. Objective This study aims to test the use of several innovations to address losses in the HIV care continuum: (1) use of respondent-driven sampling (RDS) to reach and engage MSM and TW in HIV testing, (2) HIV self-testing (HIVST) to increase HIV testing uptake and aid early diagnosis of infection, (3) community-based CD4 point-of-care (POC) technology to rapidly stage HIV disease for those who are HIV infected, and (4) peer navigation support to increase successful health system navigation for HIV-infected MSM and TW in need of ART or HIV engagement in care. Methods To assess the effect of HIVST, we will implement a randomized trial in which MSM and TW adults in the greater Yangon metropolitan area who are HIV uninfected will be recruited via RDS (N=366). Participants will complete a baseline socio-behavioral survey and will be randomized to standard, voluntary counseling and testing (VCT) or to HIVST. Biologic specimens will be collected during this baseline visit for confirmatory testing using dried blood spots. Participants will be asked to return to the study office to complete a second study visit in which they will report their HIV test result and answer questions on the acceptability of the assigned testing method. Aim 1 participants with confirmed HIV infection and who are not engaged in care (N=49) will be offered direct enrollment into Aims 2 and 3, which include immediate CD4 POC and the option for peer navigation, respectively. Aims 2 and 3 participants will be prospectively followed for 12 months with data collection including interviewer-administered sociobehavioral survey, CD4 POC, and viral load testing occurring biannually. Participants who accept peer navigation will be compared to those who decline peer navigation. Analyses will estimate the impact of CD4 POC on engagement in care and the impact of peer navigation on ART adherence and viral load. Results Formative qualitative research was conducted in June and September 2015 and led to further refinement of recruitment methods, HIVST instructions and counseling, and peer navigation methods. Aim 1 recruitment began in November 2015 with subsequent enrollment into Aims 2 and 3 and is currently ongoing. Conclusions These innovative interventions may resolve gaps in the HIV care continuum among MSM and TW and future implementation may aid in curbing the HIV epidemic among MSM and TW in Myanmar. PMID:28526661

Late summer particulate organic carbon export and twilight zone remineralisation in the Atlantic sector of the Southern Ocean

NASA Astrophysics Data System (ADS)

Planchon, F.; Cavagna, A.-J.; Cardinal, D.; André, L.; Dehairs, F.

2013-02-01

As part of the GEOTRACES Bonus-GoodHope (BGH) expedition (January-March 2008) in the Atlantic sector of the Southern Ocean, particulate organic carbon (POC) export was examined from the surface to the mesopelagic twilight zone using water column distributions of total 234Th and biogenic particulate Ba (Baxs). Surface POC export production was estimated from steady state and non steady state modelling of 234Th fluxes, which were converted into POC fluxes, using the POC/234Th ratio of large, potentially sinking particles (> 53 μm) collected via in situ pumps. Deficits in 234Th activities were observed at all stations from the surface to the bottom of the mixed layer, yielding 234Th export fluxes from the upper 100 m of 496 ± 214 dpm m-2 d-1 to 1195 ± 158 dpm m-2 d-1 for the steady state model and of 149 ±517 dpm m-2 d-1 to 1217 ± 231 dpm m-2 d-1 for the non steady state model. Using the POC/234Thp ratio of sinking particles (ratios varied from 1.7 ± 0.2 μmol dpm-1 to 4.8 ± 1.9 μmol dpm-1) POC export production at 100 m was calculated to range between 0.9 ± 0.4 and 5.1 ± 2.1 mmol C m-2 d-1,assuming steady state and between 0.3 ± 0.9 m-2 d-1 and 4.9 ± 3.3 mmol C m-2 d-1, assuming non steady state. From the comparison of both approaches, it appears that during late summer export decreased by 56 to 16% for the area between the sub-Antarctic zone and the southern Antarctic Circumpolar Current Front (SACCF), whereas it remained rather constant over time in the HNLC area south of the SACCF. POC export represented only 6 to 54% of new production, indicating that export efficiency was, in general, low, except in the vicinity of the SACCF, where export represented 56% of new production. Attenuation of the POC sinking flux in the upper mesopelagic waters (100-600 m depth interval) was evidenced both, from excess 234Th activities and from particulate biogenic Ba (Baxs) accumulation. Excess 234Th activities, reflected by 234Th/238U ratios as large as 1.21 ± 0.05, are attributed to remineralisation/disaggregation of 234Th-bearing particles. The accumulation of excess 234Th in the 100-600 m depth interval ranged from 458 ± 633 dpm m-2 d-1 to 3068 ± 897 dpm m-2 d-1, assuming steady state. Using the POC/234Thp ratio of sinking particles (> 53 μm), this 234Th accumulation flux was converted into a POC remineralisation flux which ranged between 0.9 ± 1.2 mmol C m-2 d-1 and 9.2 ± 2.9 mmol C m-2 d-1. Mesopelagic particulate biogenic Ba has been reported to reflect bacterial degradation of organic matter and to be related to oxygen consumption and bacterial carbon respiration. We observed that the highest Baxs contents (reaching up to > 1000 pM), in general, occurred between 200 and 400 m. Depth-weighted average mesopelagic Baxs (meso-Baxs) values were converted into respired C fluxes, which ranged between 0.23 and 6.4 mmol C m-2 d-1, in good agreement with 234Th-based remineralisation fluxes. A major outcome from this study is the observed significant positive correlation between POC remineralisation as estimated from meso-Baxs contents and from 234Th excess (R2 = 0.73; excluding 2 outliers). Remineralisation of POC in the twilight zone was particularly efficient relative to POC export resulting in negligible bathypelagic (> 600 m) POC export fluxes in the sub-Antarctic zone, the Polar Front zone and the northern Weddell Gyre, while the subtropical zone as well as the vicinity of the SACCF had significant deep POC fluxes.

Evaluation of Cortez OneStep Chlamydia Rapicard™ Insta Test for the Detection of Chlamydia trachomatis in Pregnant Women at Mbare Polyclinic in Harare, Zimbabwe.

PubMed

Stephen, Stephen; Muchaneta-Kubara, Chiwoneso Gwyneth Elizabeth; Munjoma, Marshall Wesley; Mandozana, Gibson

2017-01-01

Cervical chlamydia infection poses high risk of pregnancy complications and neonatal infection. Reference methods for the detection of chlamydia infection are not available for routine use in developing countries. Point-of-care (POC) tests can bridge this gap. This study evaluated Cortez Onestep Chlamydia Rapicard™ insta test for the detection of Chlamydia trachomatis in pregnant women at Mbare Polyclinic and determined the prevalence of C. trachomatis . This was a cross sectional study in 242 pregnant women aged ≥18 years attending their first ANC visit at Mbare polyclinic in Harare, Zimbabwe. Data collection form was used to obtain demographic and predisposing factors to Chlamydia infection and two endocervical swabs were collected from each patient. One specimen was examined by the POC test at the clinic and the other by SDA method in the laboratory. The sensitivity, specificity, positive and negative predictive values of the rapid kit were 71.4%, 99.6%, 90.9% and 98.3% respectively. Prevalence of C. trachomitis was 5.8% by SDA method. The kit's sensitivity (71.4%) and specificity (99.6%) implies that the rapid test is an important test which needs further evaluations. The prevalence of C. trichomitis of 5.8% is comparable to studies done elsewhere in Africa.

The Reusable Handheld Electrolyte and Lab Technology for Humans (rHEALTH) Sensor

NASA Technical Reports Server (NTRS)

Chan, Eugene

2015-01-01

The DNA Medicine Institute has produced a reusable microfluidic device that performs rapid, low-cost cell counts and measurements of electrolytes, proteins, and other biomarkers. The rHEALTH sensor is compact and portable, and it employs cutting-edge fluorescence detection optics, innovative microfluidics, and nanostrip reagents to perform a suite of hematology, chemistry, and biomarker assays from a single drop of blood. A handful of current portable POC devices provide generalized blood analysis, but they perform only a few tests at a time. These devices also rely on disposable components and depend on diverse detection technologies to complete routine tests-all ill-suited for space travelers on extended missions. In contrast, the rHEALTH sensor integrates sample introduction, processing, and detection with a compact, resource-conscious, and efficient design. Developed to monitor astronaut health on the International Space Station and during long-term space flight, this microscale lab analysis tool also has terrestrial applications that include POC diagnostics conducted at a patient's bedside, in a doctor's office, and in a hospital.

Seamless Phase IIa/IIb and enhanced dose-finding adaptive design.

PubMed

Yuan, Jiacheng; Pang, Herbert; Tong, Tiejun; Xi, Dong; Guo, Wenzhao; Mesenbrink, Peter

2016-01-01

In drug development, when the drug class has a relatively well-defined path to regulatory approval and the enrollment is slow with certain patient populations, one may want to consider combining studies of different phases. This article considers combining a proof of concept (POC) study and a dose-finding (DF) study with a control treatment. Conventional DF study designs sometimes are not efficient, or do not have a high probability to find the optimal dose(s) for Phase III trials. This article seeks more efficient DF strategies that allow the economical testing of more doses. Hypothetical examples are simulated to compare the proposed adaptive design vs. the conventional design based on different models of the overall quantitative representation of efficacy, safety, and tolerability. The results show that the proposed adaptive design tests more active doses with higher power and comparable or smaller sample size in a shorter overall study duration for POC and DF, compared with a conventional design.

Miniaturized technology for protein and nucleic acid point-of-care testing.

PubMed

Olasagasti, Felix; Ruiz de Gordoa, Juan Carlos

2012-11-01

The field of point-of-care (POC) testing technology is developing quickly and producing instruments that are increasingly reliable, while their size is being gradually reduced. Proteins are a common target for POC analyses and the detection of protein markers typically involves immunoassays aimed at detecting different groups of proteins such as tumor markers, inflammation proteins, and cardiac markers; but other techniques can also be used to analyze plasma proteins. In the case of nucleic acids, hybridization and amplification strategies can be used to record electromagnetic or electric signals. These techniques allow for the identification of specific viral or bacterial infections as well as specific cancers. In this review, we consider some of the latest advances in the analysis of specific nucleic acid and protein biomarkers, taking into account their trend toward miniaturization and paying special attention to the technology that can be implemented in future applications, such as lab-on-a-chip instruments. Copyright © 2012 Mosby, Inc. All rights reserved.

Practical interior tomography with radial Hilbert filtering and a priori knowledge in a small round area.

PubMed

Tang, Shaojie; Yang, Yi; Tang, Xiangyang

2012-01-01

Interior tomography problem can be solved using the so-called differentiated backprojection-projection onto convex sets (DBP-POCS) method, which requires a priori knowledge within a small area interior to the region of interest (ROI) to be imaged. In theory, the small area wherein the a priori knowledge is required can be in any shape, but most of the existing implementations carry out the Hilbert filtering either horizontally or vertically, leading to a vertical or horizontal strip that may be across a large area in the object. In this work, we implement a practical DBP-POCS method with radial Hilbert filtering and thus the small area with the a priori knowledge can be roughly round (e.g., a sinus or ventricles among other anatomic cavities in human or animal body). We also conduct an experimental evaluation to verify the performance of this practical implementation. We specifically re-derive the reconstruction formula in the DBP-POCS fashion with radial Hilbert filtering to assure that only a small round area with the a priori knowledge be needed (namely radial DBP-POCS method henceforth). The performance of the practical DBP-POCS method with radial Hilbert filtering and a priori knowledge in a small round area is evaluated with projection data of the standard and modified Shepp-Logan phantoms simulated by computer, followed by a verification using real projection data acquired by a computed tomography (CT) scanner. The preliminary performance study shows that, if a priori knowledge in a small round area is available, the radial DBP-POCS method can solve the interior tomography problem in a more practical way at high accuracy. In comparison to the implementations of DBP-POCS method demanding the a priori knowledge in horizontal or vertical strip, the radial DBP-POCS method requires the a priori knowledge within a small round area only. Such a relaxed requirement on the availability of a priori knowledge can be readily met in practice, because a variety of small round areas (e.g., air-filled sinuses or fluid-filled ventricles among other anatomic cavities) exist in human or animal body. Therefore, the radial DBP-POCS method with a priori knowledge in a small round area is more feasible in clinical and preclinical practice.

Radiocarbon constraints on the coupled growth of sediment and organic carbon reservoirs in fluvial systems

NASA Astrophysics Data System (ADS)

Torres, M. A.; Kemeny, P. C.; Fischer, W. W.; Lamb, M. P.

2017-12-01

Vast amounts of sediments are stored transiently in fluvial deposits as they move in rivers from source to sink. The timescale(s) of transient storage have the potential to set the cadence for biogeochemical reactions to occur in river sediments. However, the extent to which storage modulates the chemical composition of river sediments remains unclear. In case of the organic carbon (OC) cycle, transient sediment storage may leave an imprint in the radiocarbon (14C) content of riverine particulate OC (POC), offering a potential tool to trace the coupling of sediment storage and biogeochemical cycling in river systems. We investigated the modern and ancient budgets of sediments and POC in the Efi Haukadalsá River catchment in West Iceland to provide new empirical constraints on the role of sediment storage in the terrestrial OC cycle. This field site is attractive because the basaltic bedrock is free of rock-derived (i.e. "petrogenic") POC such that bulk 14C measurements can be interpreted more directly as constraints on catchment OC storage timescales. Additionally, Lake Haukadalsvatn at the outlet of the river catchment has captured sediment for nearly 13 ka, which offers a complementary record of the evolution of climate-sediment-OC linkages since deglaciation. New 14C measurements show that bulk POC in fine grained fluvial deposits within the Haukadalsá catchment is remarkably old (model ages between 1 and 10 ka). This evidence for "aged" POC in floodplain storage is consistent with previous measurements from Lake Haukadalsvatn, which show that POC is aged in the river system by thousands of years prior to deposition in the lake. Additionally, our estimate of the mean transit time of sediments through the river system matches the millennial-scale reservoir age of riverine POC derived from 14C, which implies a tight coupling between sediment storage and the OC cycle. We interpret the long-term increase in the 14C reservoir age of riverine POC over the last 10 ka preserved in the lake sediments to reflect the growth of a terrestrial sediment reservoir and concomitant POC storage in response to deglaciation. Our results illustrate how sediment storage by fluvial systems strongly influences the terrestrial OC cycle and its response to changes in environmental conditions.

Duration of antibody response following vaccination against feline immunodeficiency virus.

PubMed

Westman, Mark E; Malik, Richard; Hall, Evelyn; Harris, Matthew; Hosie, Margaret J; Norris, Jacqueline M

2017-10-01

Objectives Recently, two point-of-care (PoC) feline immunodeficiency virus (FIV) antibody test kits (Witness and Anigen Rapid) were reported as being able to differentiate FIV-vaccinated from FIV-infected cats at a single time point, irrespective of the gap between testing and last vaccination (0-7 years). The aim of the current study was to investigate systematically anti-FIV antibody production over time in response to the recommended primary FIV vaccination series. Methods First, residual plasma from the original study was tested using a laboratory-based ELISA to determine whether negative results with PoC testing were due to reduced as opposed to absent antibodies to gp40. Second, a prospective study was performed using immunologically naive client-owned kittens and cats given a primary FIV vaccination series using a commercially available inactivated whole cell/inactivated whole virus vaccine (Fel-O-Vax FIV, three subcutaneous injections at 4 week intervals) and tested systematically (up to 11 times) over 6 months, using four commercially available PoC FIV antibody kits (SNAP FIV/FeLV Combo [detects antibodies to p15/p24], Witness FeLV/FIV [gp40], Anigen Rapid FIV/FeLV [p24/gp40] and VetScan FeLV/FIV Rapid [p24]). Results The laboratory-based ELISA showed cats from the original study vaccinated within the previous 0-15 months had detectable levels of antibodies to gp40, despite testing negative with two kits that use gp40 as a capture antigen (Witness and Anigen Rapid kits). The prospective study showed that antibody testing with SNAP Combo and VetScan Rapid was positive in all cats 2 weeks after the second primary FIV vaccination, and remained positive for the duration of the study (12/12 and 10/12 cats positive, respectively). Antibody testing with Witness and Anigen Rapid was also positive in a high proportion of cats 2 weeks after the second primary FIV vaccination (8/12 and 7/12, respectively), but antibody levels declined below the level of detection in most cats (10/12) by 1 month after the third (final) primary FIV vaccination. All cats tested negative using Witness and Anigen Rapid 6 months after the third primary FIV vaccination. Conclusions and relevance This study has shown that a primary course of FIV vaccination does not interfere with FIV antibody testing in cats using Witness and Anigen Rapid, provided primary vaccination has not occurred within the previous 6 months. Consequently, Witness and Anigen Rapid antibody test kits can be used reliably to determine FIV infection status at the time of annual booster FIV vaccination to help detect 'vaccine breakthroughs' and in cats that have not received a primary course of FIV vaccination within the preceding 6 months. The duration of antibody response following annual booster FIV vaccination and the resulting effect on antibody testing using PoC kits needs to be determined by further research. The mechanism(s) for the variation in FIV antibody test kit performance remains unclear.

The Effect of Hurricane Lili on the Distribution of Organic Matter in the Inner Louisiana Shelf (Gulf of Mexico, USA)

NASA Astrophysics Data System (ADS)

Clinton, R.; Goni, M. A.; Gisewhite, R.; Monacci, N.; Gordon, E.; Allison, M.; Kineke, G.

2004-12-01

Suspended particles and surface sediments were collected from the inner shelf of the Louisiana central coast following the passage of Hurricane Lili. The elemental and stable isotopic data of these samples were compared to those determined prior to the hurricane. A week after the storm passage, turbidity levels and total suspended sediment concentrations were not that different from pre-storm values, suggesting most of the suspended sediments must have settled soon after the storm passage. Particulate organic carbon (POC) concentrations ranged from 0.1 mg/L to over 2.0 mg/L, with the highest concentrations measured near the seabed and in the inshore portions of the study area. In these locations, suspended particles displayed high POC/Chlorophyll ratios (POC/Chl of 400 to 4,000) and relatively elevated POC/particulate nitrogen ratios (POC/PN of 10 to 14) that indicated their source was locally resuspended seabed sediments. Relatively low POC/Chl (~200) and POC:PN (~7) ratios consistent with significant contributions from phytoplankton were measured only in the surface waters of the most offshore locations. Post hurricane sediment deposition resulted in a storm layer that ranged from 0.5 to 19 cm in thickness. The storm layer was generally composed of silty clays with a coarser, somewhat sandy 1-2 cm basal layer. These storm deposits were characterized by relatively high SA and OC contents. Similarities in the characteristics of the organic matter before and after reinforce the hypothesis that the source of the storm deposits was the finer fraction of locally resuspended seabed sediments, with little evidence for allochthonous land-derived inputs.

Assessing soil carbon vulnerability in the Western USA by geospatial modeling of pyrogenic and particulate carbon stocks

NASA Astrophysics Data System (ADS)

Ahmed, Zia U.; Woodbury, Peter B.; Sanderman, Jonathan; Hawke, Bruce; Jauss, Verena; Solomon, Dawit; Lehmann, Johannes

2017-02-01

To predict how land management practices and climate change will affect soil carbon cycling, improved understanding of factors controlling soil organic carbon fractions at large spatial scales is needed. We analyzed total soil organic (SOC) as well as pyrogenic (PyC), particulate (POC), and other soil organic carbon (OOC) fractions in surface layers from 650 stratified-sampling locations throughout Colorado, Kansas, New Mexico, and Wyoming. PyC varied from 0.29 to 18.0 mg C g-1 soil with a mean of 4.05 mg C g-1 soil. The mean PyC was 34.6% of the SOC and ranged from 11.8 to 96.6%. Both POC and PyC were highest in forests and canyon bottoms. In the best random forest regression model, normalized vegetation index (NDVI), mean annual precipitation (MAP), mean annual temperature (MAT), and elevation were ranked as the top four important variables determining PyC and POC variability. Random forests regression kriging (RFK) with environmental covariables improved predictions over ordinary kriging by 20 and 7% for PyC and POC, respectively. Based on RFK, 8% of the study area was dominated (≥50% of SOC) by PyC and less than 1% was dominated by POC. Furthermore, based on spatial analysis of the ratio of POC to PyC, we estimated that about 16% of the study area is medium to highly vulnerable to SOC mineralization in surface soil. These are the first results to characterize PyC and POC stocks geospatially using stratified sampling scheme at the scale of 1,000,000 km2, and the methods are scalable to other regions.

Erosion of organic carbon in the Arctic as a geological carbon dioxide sink.

PubMed

Hilton, Robert G; Galy, Valier; Gaillardet, Jérôme; Dellinger, Mathieu; Bryant, Charlotte; O'Regan, Matt; Gröcke, Darren R; Coxall, Helen; Bouchez, Julien; Calmels, Damien

2015-08-06

Soils of the northern high latitudes store carbon over millennial timescales (thousands of years) and contain approximately double the carbon stock of the atmosphere. Warming and associated permafrost thaw can expose soil organic carbon and result in mineralization and carbon dioxide (CO2) release. However, some of this soil organic carbon may be eroded and transferred to rivers. If it escapes degradation during river transport and is buried in marine sediments, then it can contribute to a longer-term (more than ten thousand years), geological CO2 sink. Despite this recognition, the erosional flux and fate of particulate organic carbon (POC) in large rivers at high latitudes remains poorly constrained. Here, we quantify the source of POC in the Mackenzie River, the main sediment supplier to the Arctic Ocean, and assess its flux and fate. We combine measurements of radiocarbon, stable carbon isotopes and element ratios to correct for rock-derived POC. Our samples reveal that the eroded biospheric POC has resided in the basin for millennia, with a mean radiocarbon age of 5,800 ± 800 years, much older than the POC in large tropical rivers. From the measured biospheric POC content and variability in annual sediment yield, we calculate a biospheric POC flux of 2.2(+1.3)(-0.9) teragrams of carbon per year from the Mackenzie River, which is three times the CO2 drawdown by silicate weathering in this basin. Offshore, we find evidence for efficient terrestrial organic carbon burial over the Holocene period, suggesting that erosion of organic carbon-rich, high-latitude soils may result in an important geological CO2 sink.

Diagnostic accuracy of point-of-care ultrasound for evaluation of early blood-induced joint changes: Comparison with MRI.

PubMed

Foppen, W; van der Schaaf, I C; Beek, F J A; Mali, W P T M; Fischer, K

2018-05-23

Recurrent joint bleeding is the hallmark of haemophilia. Synovial hypertrophy observed with Magnetic Resonance Imaging (MRI) is associated with an increased risk of future joint bleeding. The aim of this study was to investigate whether point-of-care ultrasound (POC-US) is an accurate alternative for MRI for the detection of early joint changes. In this single centre diagnostic accuracy study, bilateral knees and ankles of haemophilia patients with no or minimal arthropathy on X-rays were scanned using POC-US and 3 Tesla MRI. POC-US was performed by 1 medical doctor, blinded for MRI, according to the "Haemophilia Early Arthropathy Detection with Ultrasound" (HEAD-US) protocol. MRIs were independently scored by 2 radiologists, blinded for clinical data and ultrasound results. Diagnostic accuracy parameters were calculated with 95% confidence intervals (CI). Knees and ankles of 24 haemophilia patients (96 joints), aged 18-34, were studied. Synovial hypertrophy on MRI was observed in 20% of joints. POC-US for synovial tissue was correct (overall accuracy) in 97% (CI: 91-99) with a positive predictive value of 94% (CI: 73-100) and a negative predictive value of 97% (CI: 91-100). The overall accuracy of POC-US for cartilage abnormalities was 91% (CI: 83-96) and for bone surface irregularities 97% (CI: 91-99). POC-US could accurately assess synovial hypertrophy, bone surface irregularities and cartilage abnormalities in haemophilia patients with limited joint disease. As POC-US is an accurate and available alternative for MRI, it can be used for routine evaluation of early joint changes. © 2018 The Authors. Haemophilia published by John Wiley & Sons Ltd.

Rapid bedside coagulometry prior to urgent neurosurgical procedures in anticoagulated patients.

PubMed

Beynon, Christopher; Jakobs, Martin; Rizos, Timolaos; Unterberg, Andreas W; Sakowitz, Oliver W

2014-01-01

With the increased use of oral anticoagulation with vitamin K antagonists, emergency physicians encounter a growing number of patients requiring a rapid reversal of anticoagulant effects in order to perform urgent surgical procedures. Initiation of these procedures can be delayed because the coagulation status has to be assessed through examination of blood samples in central laboratories (CL). This delay may lead to negative effects, especially in potentially life-threatening conditions such as intracranial haemorrhage. Point-of-care (POC) devices for assessment of international normalized ratio (POC INR) have improved the management of anticoagulation therapy in the outpatient setting. The use of these devices may also have beneficial effects in the treatment of anticoagulated patients requiring urgent neurosurgical procedures. The primary aim of this study was to analyse the potential of POC-guided assessment of INR to reduce time to potentially life-saving neurosurgery in this setting. Feasibility and accuracy as well as the gain of time through the use of this device were analysed. The POC coagulometer CoaguChek XS(®) was used in 17 patients with a history of anticoagulant use and a condition requiring urgent anticoagulant reversal prior to neurosurgical procedures (burr-hole trepanation: n = 8, craniotomy: n = 7, laminectomy: n = 2). No technical difficulties occurred and rapid assessment of INR was achieved in all cases within 2 min. POC INR values correlated well with CL INR assessment with a mean INR deviation of 0.036 ± 0.12. The mean gain of time through the use of the POC INR device compared with CL assessment of INR was 47 ± 6 min (range: 37-61 min). Our initial experiences with a POC INR device in anticoagulated patients undergoing urgent neurosurgical procedures demonstrate that its use may contribute to an improved management of these patients.

Bioavailable dissolved and particulate organic carbon flux from coastal temperate rainforest watersheds

NASA Astrophysics Data System (ADS)

Fellman, J.; Hood, E. W.; D'Amore, D. V.; Moll, A.

2017-12-01

Coastal temperate rainforest (CTR) watersheds of southeast Alaska have dense soil carbon stocks ( 300 Mg C ha-1) and high specific discharge (1.5-7 m yr-1) driven by frontal storms from the Gulf of Alaska. As a result, dissolved organic carbon (DOC) fluxes from Alaskan CTR watersheds are estimated to exceed 2 Tg yr-1; however, little is known about the export of particulate organic carbon (POC). The magnitude and bioavailability of this land-to-ocean flux of terrigenous organic matter ultimately determines how much metabolic energy is translocated to downstream and coastal marine ecosystems in this region. We sampled streamwater weekly from May through October from four watersheds of varying landcover (gradient of wetland to glacial coverage) to investigate changes in the concentration and flux of DOC and POC exported to the coastal ocean. We also used headspace analysis of CO2 following 14 day laboratory incubations to determine the flux of bioavailable DOC and POC exported from CTR watersheds. Across all sites, bioavailable DOC concentrations ranged from 0.2 to 1.9 mg L-1 but were on average 0.6 mg L-1. For POC, bioavailable concentrations ranged from below detection to 0.3 mg L-1 but were on average 0.1 mg L-1. The concentration, flux and bioavailability of DOC was higher than for POC highlighting the potential importance of DOC as a metabolic subsidy to downstream and coastal environments. Ratios of DOC to POC decreased during high flow events because the increase in POC concentrations with discharge exceeds that for DOC. Overall, our findings suggest that projected increases in precipitation and storm intensity will drive changes in the speciation, magnitude and bioavailability of the organic carbon flux from CTR watersheds.

A new look at the multi-G model for organic carbon degradation in surface marine sediments for coupled benthic-pelagic simulations of the global ocean

NASA Astrophysics Data System (ADS)

Stolpovsky, Konstantin; Dale, Andrew W.; Wallmann, Klaus

2018-06-01

The kinetics of particulate organic carbon (POC) mineralization in marine surface sediments is not well constrained. This creates considerable uncertainties when benthic processes are considered in global biogeochemical or Earth system circulation models to simulate climate-ocean interactions and biogeochemical tracer distributions in the ocean. In an attempt to improve our understanding of the rate and depth distribution of organic carbon mineralization in bioturbated (0-20 cm) sediments at the global scale, we parameterized a 1-D diagenetic model that simulates the mineralization of three discrete POC pools (a multi-G model). The rate constants of the three reactive classes (highly reactive, reactive, refractory) are fixed and determined to be 70, 0.5 and ˜ 0.001 yr-1, respectively, based on the Martin curve model for pelagic POC degradation. In contrast to previous approaches, however, the reactivity of the organic material degraded in the seafloor is continuous with, and set by, the apparent reactivity of material sinking through the water column. Despite the simplifications of describing POC remineralization using G-type approaches, the model is able to simulate a global database (185 stations) of benthic oxygen and nitrate fluxes across the sediment-water interface in addition to porewater oxygen and nitrate distributions and organic carbon burial efficiencies. It is further consistent with degradation experiments using fresh phytoplankton reported in a previous study. We propose that an important yet mostly overlooked consideration in upscaling approaches is the proportion of the reactive POC classes reaching the seafloor in addition to their reactivity. The approach presented is applicable to both steady-state and non-steady state scenarios, and links POC degradation kinetics in sedimentary environments to water depth and the POC rain rate to the seafloor.

Adapting a large database of point of care summarized guidelines: a process description.

PubMed

Delvaux, Nicolas; Van de Velde, Stijn; Aertgeerts, Bert; Goossens, Martine; Fauquert, Benjamin; Kunnamo, Ilka; Van Royen, Paul

2017-02-01

Questions posed at the point of care (POC) can be answered using POC summarized guidelines. To implement a national POC information resource, we subscribed to a large database of POC summarized guidelines to complement locally available guidelines. Our challenge was in developing a sustainable strategy for adapting almost 1000 summarized guidelines. The aim of this paper was to describe our process for adapting a database of POC summarized guidelines. An adaptation process based on the ADAPTE framework was tailored to be used by a heterogeneous group of participants. Guidelines were assessed on content and on applicability to the Belgian context. To improve efficiency, we chose to first aim our efforts towards those guidelines most important to primary care doctors. Over a period of 3 years, we screened about 80% of 1000 international summarized guidelines. For those guidelines identified as most important for primary care doctors, we noted that in about half of the cases, remarks were made concerning content. On the other hand, at least two-thirds of all screened guidelines required no changes when evaluating their local usability. Adapting a large body of POC summarized guidelines using a formal adaptation process is possible, even when faced with limited resources. This can be done by creating an efficient and collaborative effort and ensuring user-friendly procedures. Our experiences show that even though in most cases guidelines can be adopted without adaptations, careful review of guidelines developed in a different context remains necessary. Streamlining international efforts in adapting international POC information resources and adopting similar adaptation processes may lessen duplication efforts and prove more cost-effective. © 2015 The Authors. Journal of Evaluation in Clinical Practice published by John Wiley & Sons, Ltd.

Point-of-Care Diagnostics in Low-Resource Settings and Their Impact on Care in the Age of the Noncommunicable and Chronic Disease Epidemic.

PubMed

Weigl, Bernhard H; Neogi, Tina; McGuire, Helen

2014-06-01

The emergence of point-of-care (POC) diagnostics specifically designed for low-resource settings coupled with the rapid increase in need for routine care of patients with chronic diseases should prompt reconsideration of how health care can be delivered most beneficially and cost-effectively in developing countries. Bolstering support for primary care to provide rapid and appropriate integrated acute and chronic care treatment may be a possible solution. POC diagnostics can empower local and primary care providers and enable them to make better clinical decisions. This article explores the opportunity for POC diagnostics to strengthen primary care and chronic disease diagnosis and management in a low-resource setting (LRS) to deliver appropriate, consistent, and integrated care. We analyze the requirements of resource-appropriate chronic disease care, the characteristics of POC diagnostics in LRS versus the developed world, the many roles of diagnostics in the care continuum in LRS, and the process and economics of developing LRS-compatible POC diagnostics. © 2013 Society for Laboratory Automation and Screening.

A Public Health Grid (PHGrid): Architecture and value proposition for 21st century public health.

PubMed

Savel, T; Hall, K; Lee, B; McMullin, V; Miles, M; Stinn, J; White, P; Washington, D; Boyd, T; Lenert, L

2010-07-01

This manuscript describes the value of and proposal for a high-level architectural framework for a Public Health Grid (PHGrid), which the authors feel has the capability to afford the public health community a robust technology infrastructure for secure and timely data, information, and knowledge exchange, not only within the public health domain, but between public health and the overall health care system. The CDC facilitated multiple Proof-of-Concept (PoC) projects, leveraging an open-source-based software development methodology, to test four hypotheses with regard to this high-level framework. The outcomes of the four PoCs in combination with the use of the Federal Enterprise Architecture Framework (FEAF) and the newly emerging Federal Segment Architecture Methodology (FSAM) was used to develop and refine a high-level architectural framework for a Public Health Grid infrastructure. The authors were successful in documenting a robust high-level architectural framework for a PHGrid. The documentation generated provided a level of granularity needed to validate the proposal, and included examples of both information standards and services to be implemented. Both the results of the PoCs as well as feedback from selected public health partners were used to develop the granular documentation. A robust high-level cohesive architectural framework for a Public Health Grid (PHGrid) has been successfully articulated, with its feasibility demonstrated via multiple PoCs. In order to successfully implement this framework for a Public Health Grid, the authors recommend moving forward with a three-pronged approach focusing on interoperability and standards, streamlining the PHGrid infrastructure, and developing robust and high-impact public health services. Published by Elsevier Ireland Ltd.

High biomass, low export regimes in the Southern Ocean

NASA Astrophysics Data System (ADS)

Lam, Phoebe J.; Bishop, James K. B.

2007-03-01

This paper investigates ballasting and remineralization controls of carbon sedimentation in the Twilight Zone (100-1000 m) of the Southern Ocean. Size-fractionated (<1 μm, 1-51 μm, >51 μm) suspended particulate matter was collected by large-volume in-situ filtration from the upper 1000 m in the Subantarctic (55°S, 172°W) and Antarctic (66°S, 172°W) zones of the Southern Ocean during the Southern Ocean Iron Experiment (SOFeX) in January-February 2002. Particles were analyzed for major chemical constituents (POC, P, biogenic Si, CaCO 3), and digital and SEM image analyses of particles were used to aid in the interpretation of the chemical profiles. Twilight Zone waters at 66°S in the Antarctic had a steeper decrease in POC with depth than at 55°S in the Subantarctic, with lower POC concentrations in all size fractions at 66°S than at 55°S, despite up to an-order-of magnitude higher POC in surface waters at 66°S. The decay length scale of >51-μm POC was significantly shorter in the upper Twilight Zone at 66°S ( δe=26 m) compared to 55°S ( δe=81 m). Particles in the carbonate-producing 55°S did not have higher excess densities than particles from the diatom-dominated 66°S, indicating that there was no direct ballast effect that accounted for deeper POC penetration at 55°S. An indirect ballast effect due to differences in particle packaging and porosities cannot be ruled out, however, as aggregate porosities were high (˜97%) and variable. Image analyses point to the importance of particle loss rates from zooplankton grazing and remineralization as determining factors for the difference in Twilight Zone POC concentrations at 55°S and 66°S, with stronger and more focused shallow remineralization at 66°S. At 66°S, an abundance of large (several mm long) fecal pellets from the surface to 150 m, and almost total removal of large aggregates by 200 m, reflected the actions of a single or few zooplankton species capable of grazing diatoms in the euphotic zone, coupled with a more diverse particle-feeding zooplankton community immediately below. Surface waters with high biomass levels and high proportion of biomass in the large-size fraction were associated with low particle loading at depth, with all indications implying conditions of low export. The 66°S region exhibits this "high biomass, low export" (HBLE) condition, with very high >51-μm POC concentrations at the surface (˜2.1 μM POC), but low concentrations below 200 m (<0.07 μM POC). The 66°S region remained HBLE after iron fertilization. Iron addition at 55°S caused a 10 fold increase in >51-μm biomass concentrations in the euphotic zone, bringing surface POC concentrations to levels found at 66°S (˜3.8 μM), and a concurrent decrease in POC concentrations below 200 m. The 55°S region, which began with moderate levels of biomass and stronger particle export, transitioned to being HBLE after iron fertilization. We propose that iron addition to already HBLE waters will not cause mass sedimentation events. The stability of an iron-induced HBLE condition is unknown. Better understanding of biological pump processes in non-HBLE Subantarctic waters is needed.

Contrasting composition of terrigenous organic matter in the dissolved, particulate and sedimentary organic carbon pools on the outer East Siberian Arctic Shelf

NASA Astrophysics Data System (ADS)

Salvadó, Joan A.; Tesi, Tommaso; Sundbom, Marcus; Karlsson, Emma; Kruså, Martin; Semiletov, Igor P.; Panova, Elena; Gustafsson, Örjan

2016-11-01

Fluvial discharge and coastal erosion of the permafrost-dominated East Siberian Arctic delivers large quantities of terrigenous organic carbon (Terr-OC) to marine waters. The composition and fate of the remobilized Terr-OC needs to be better constrained as it impacts the potential for a climate-carbon feedback. In the present study, the bulk isotope (δ13C and Δ14C) and macromolecular (lignin-derived phenols) composition of the cross-shelf exported organic carbon (OC) in different marine pools is evaluated. For this purpose, as part of the SWERUS-C3 expedition (July-September 2014), sediment organic carbon (SOC) as well as water column (from surface and near-bottom seawater) dissolved organic carbon (DOC) and particulate organic carbon (POC) samples were collected along the outer shelves of the Kara Sea, Laptev Sea and East Siberian Sea. The results show that the Lena River and the DOC may have a preferential role in the transport of Terr-OC to the outer shelf. DOC concentrations (740-3600 µg L-1) were 1 order of magnitude higher than POC (20-360 µg L-1), with higher concentrations towards the Lena River plume. The δ13C signatures in the three carbon pools varied from -23.9 ± 1.9 ‰ in the SOC, -26.1 ± 1.2 ‰ in the DOC and -27.1 ± 1.9 ‰ in the POC. The Δ14C values ranged between -395 ± 83 (SOC), -226 ± 92 (DOC) and -113 ± 122 ‰ (POC). These stable and radiocarbon isotopes were also different between the Laptev Sea and the East Siberian Sea. Both DOC and POC showed a depleted and younger trend off the Lena River plume. Further, the Pacific inflow and the sea-ice coverage, which works as a barrier preventing the input of "young" DOC and POC, seem to have a strong influence in these carbon pools, presenting older and more enriched δ13C signatures under the sea-ice extent. Lignin phenols exhibited higher OC-normalized concentrations in the SOC (0.10-2.34 mg g-1 OC) and DOC (0.08-2.40 mg g-1 OC) than in the POC (0.03-1.14 mg g-1 OC). The good relationship between lignin and Δ14C signatures in the DOC suggests that a significant fraction of the outer-shelf DOC comes from "young" Terr-OC. By contrast, the slightly negative correlation between lignin phenols and Δ14C signatures in POC, with higher lignin concentrations in older POC from near-bottom waters, may reflect the off-shelf transport of OC from remobilized permafrost in the nepheloid layer. Syringyl / vanillyl and cinnamyl / vannillyl phenol ratios presented distinct clustering between DOC, POC and SOC, implying that those pools may be carrying different Terr-OC of partially different origin. Moreover, 3,5-dihydroxybenzoic acid to vanillyl phenol ratios and p-coumaric acid to ferulic acid ratios, used as a diagenetic indicators, enhanced in POC and SOC, suggesting more degradation within these pools. Overall, the key contrast between enhanced lignin yields both in the youngest DOC and the oldest POC samples reflects a significant decoupling of terrestrial OC sources and pathways.

Modeling and Simulation of Fleet Air Defense Systems Using EADSIM

DTIC Science & Technology

1993-06-01

LT DAVID VAN VELDHUIZEN PHILLIPS LABORATORY/WST 3550ABERDEEN AVE SE KIRTLAND AFB NM 87117-5776 85 PLESSEY POC: Paul Markwardt Addr: PLESSEY ELECTRONICS...LAIL, JR. Addr: PEO, GPALS ATTN SFAE-GPL-TMD-SI-B (LAIL) PO BOX 1500 HUNTSVILLE AL 35807-301 84 PHILLIPS LABORATORY POC: L. David Van Velclhuizen Addr...SHURE PO BOX 92957 EL SEGUNDO CA 90009-2957 107 TRW-HUNTSVILLE POC: Don Owens Addr: TRW 213 WYNN DRIVE ATTN DON OWENS HUNTSVILLE AL 35805 108 TRW

The cost-effectiveness of monitoring strategies for antiretroviral therapy of HIV infected patients in resource-limited settings: software tool.

PubMed

Estill, Janne; Salazar-Vizcaya, Luisa; Blaser, Nello; Egger, Matthias; Keiser, Olivia

2015-01-01

The cost-effectiveness of routine viral load (VL) monitoring of HIV-infected patients on antiretroviral therapy (ART) depends on various factors that differ between settings and across time. Low-cost point-of-care (POC) tests for VL are in development and may make routine VL monitoring affordable in resource-limited settings. We developed a software tool to study the cost-effectiveness of switching to second-line ART with different monitoring strategies, and focused on POC-VL monitoring. We used a mathematical model to simulate cohorts of patients from start of ART until death. We modeled 13 strategies (no 2nd-line, clinical, CD4 (with or without targeted VL), POC-VL, and laboratory-based VL monitoring, with different frequencies). We included a scenario with identical failure rates across strategies, and one in which routine VL monitoring reduces the risk of failure. We compared lifetime costs and averted disability-adjusted life-years (DALYs). We calculated incremental cost-effectiveness ratios (ICER). We developed an Excel tool to update the results of the model for varying unit costs and cohort characteristics, and conducted several sensitivity analyses varying the input costs. Introducing 2nd-line ART had an ICER of US$1651-1766/DALY averted. Compared with clinical monitoring, the ICER of CD4 monitoring was US$1896-US$5488/DALY averted and VL monitoring US$951-US$5813/DALY averted. We found no difference between POC- and laboratory-based VL monitoring, except for the highest measurement frequency (every 6 months), where laboratory-based testing was more effective. Targeted VL monitoring was on the cost-effectiveness frontier only if the difference between 1st- and 2nd-line costs remained large, and if we assumed that routine VL monitoring does not prevent failure. Compared with the less expensive strategies, the cost-effectiveness of routine VL monitoring essentially depends on the cost of 2nd-line ART. Our Excel tool is useful for determining optimal monitoring strategies for specific settings, with specific sex-and age-distributions and unit costs.

The Cost-Effectiveness of Monitoring Strategies for Antiretroviral Therapy of HIV Infected Patients in Resource-Limited Settings: Software Tool

PubMed Central

Estill, Janne; Salazar-Vizcaya, Luisa; Blaser, Nello; Egger, Matthias; Keiser, Olivia

2015-01-01

Background The cost-effectiveness of routine viral load (VL) monitoring of HIV-infected patients on antiretroviral therapy (ART) depends on various factors that differ between settings and across time. Low-cost point-of-care (POC) tests for VL are in development and may make routine VL monitoring affordable in resource-limited settings. We developed a software tool to study the cost-effectiveness of switching to second-line ART with different monitoring strategies, and focused on POC-VL monitoring. Methods We used a mathematical model to simulate cohorts of patients from start of ART until death. We modeled 13 strategies (no 2nd-line, clinical, CD4 (with or without targeted VL), POC-VL, and laboratory-based VL monitoring, with different frequencies). We included a scenario with identical failure rates across strategies, and one in which routine VL monitoring reduces the risk of failure. We compared lifetime costs and averted disability-adjusted life-years (DALYs). We calculated incremental cost-effectiveness ratios (ICER). We developed an Excel tool to update the results of the model for varying unit costs and cohort characteristics, and conducted several sensitivity analyses varying the input costs. Results Introducing 2nd-line ART had an ICER of US$1651-1766/DALY averted. Compared with clinical monitoring, the ICER of CD4 monitoring was US$1896-US$5488/DALY averted and VL monitoring US$951-US$5813/DALY averted. We found no difference between POC- and laboratory-based VL monitoring, except for the highest measurement frequency (every 6 months), where laboratory-based testing was more effective. Targeted VL monitoring was on the cost-effectiveness frontier only if the difference between 1st- and 2nd-line costs remained large, and if we assumed that routine VL monitoring does not prevent failure. Conclusion Compared with the less expensive strategies, the cost-effectiveness of routine VL monitoring essentially depends on the cost of 2nd-line ART. Our Excel tool is useful for determining optimal monitoring strategies for specific settings, with specific sex-and age-distributions and unit costs. PMID:25793531

Seasonal Variation in the Quality of Dissolved and Particulate Organic Matter Exchanged Between a Salt Marsh and Its Adjacent Estuary

NASA Astrophysics Data System (ADS)

Osburn, C. L.; Mikan, M.; Etheridge, J. R.; Burchell, M. R.; Birgand, F.

2015-12-01

Salt marshes are transitional ecosystems between terrestrial and marine environments. Along with mangroves and other vegetated coastal habitats, salt marshes rank among the most productive ecosystems on Earth, with critical global importance for the planet's carbon cycle. Fluorescence was used to examine the quality of dissolved and particulate organic matter (DOM and POM) exchanging between a tidal creek in a created salt marsh and its adjacent estuary in eastern North Carolina, USA. Samples from the creek were collected hourly over four tidal cycles in May, July, August, and October of 2011. Absorbance and fluorescence of chromophoric DOM (CDOM) and of base-extracted POM (BEPOM) served as the tracers for organic matter quality while dissolved organic carbon (DOC) and base-extracted particulate organic carbon (BEPOC) were used to compute fluxes. Fluorescence was modeled using parallel factor analysis (PARAFAC) and principle components analysis (PCA) of the PARAFAC results. Of nine PARAFAC components modeled, we used multiple linear regression to identify tracers for recalcitrant DOM; labile soil-derived source DOM; detrital POM; and planktonic POM. Based on mass balance, recalcitrant DOC export was 86 g C m-2 yr-1 and labile DOC export was 49 g C m-2 yr-1. The marsh also exported 41 g C m-2 yr-1 of detrital terrestrial POC, which likely originated from lands adjacent to the North River estuary. Planktonic POC export from the marsh was 6 g C m-2 yr-1. Using the DOM and POM quality results obtained via fluorescence measurements and scaling up to global salt marsh area, we estimated that the potential release of CO2 from the respiration of salt marsh DOC and POC transported to estuaries could be 11 Tg C yr-1, roughly 4% of the recently estimated CO2 release for marshes and estuaries globally.

Nano-biosensors to detect beta-amyloid for Alzheimer's disease management.

PubMed

Kaushik, Ajeet; Jayant, Rahul Dev; Tiwari, Sneham; Vashist, Arti; Nair, Madhavan

2016-06-15

Beta-amyloid (β-A) peptides are potential biomarkers to monitor Alzheimer's diseases (AD) for diagnostic purposes. Increased β-A level is neurotoxic and induces oxidative stress in brain resulting in neurodegeneration and causes dementia. As of now, no sensitive and inexpensive method is available for β-A detection under physiological and pathological conditions. Although, available methods such as neuroimaging, enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR) detect β-A, but they are not yet extended at point-of-care (POC) due to sophisticated equipments, need of high expertize, complicated operations, and challenge of low detection limit. Recently, β-A antibody based electrochemical immuno-sensing approach has been explored to detect β-A at pM levels within 30-40 min compared to 6-8h of ELISA test. The introduction of nano-enabling electrochemical sensing technology could enable rapid detection of β-A at POC and may facilitate fast personalized health care delivery. This review explores recent advancements in nano-enabling electrochemical β-A sensing technologies towards POC application to AD management. These analytical tools can serve as an analytical tool for AD management program to obtain bio-informatics needed to optimize therapeutics for neurodegenerative diseases diagnosis management. Copyright © 2016 Elsevier B.V. All rights reserved.

Army Enlisted Personnel Competency Assessment Program: Phase III Pilot Tests

DTIC Science & Technology

2007-03-01

Officer’s Representatives and Subject Matter POCs: Tonia Heffner and Peter Greenston Contract for Manpower, Personnel, Leader Development, and Training ...3926 March 2007 Army Project Number Personnel Performance 622785A790 and Training Technology Approved for public release; distribution is unlimited. 111...8217 ARMY ENLISTED PERSONNEL COMPETENCY ASSESSMENT PROGRAM: PHASE III PILOT TESTS EXECUTIVE SUMMARY Research Requirement: The Army Training and Leader

Point-of-care Cognitive Support Technology in Emergency Departments: A Scoping Review of Technology Acceptance by Clinicians.

PubMed

Jun, Shelly; Plint, Amy C; Campbell, Sandy M; Curtis, Sarah; Sabir, Kyrellos; Newton, Amanda S

2018-05-01

Cognitive support technologies that support clinical decisions and practices in the emergency department (ED) have the potential to optimize patient care. However, limited uptake by clinicians can prevent successful implementation. A better understanding of acceptance of these technologies from the clinician perspective is needed. We conducted a scoping review to synthesize diverse, emerging evidence on clinicians' acceptance of point-of-care (POC) cognitive support technology in the ED. We systematically searched 10 electronic databases and gray literature published from January 2006 to December 2016. Studies of any design assessing an ED-based POC cognitive support technology were considered eligible for inclusion. Studies were required to report outcome data for technology acceptance. Two reviewers independently screened studies for relevance and quality. Study quality was assessed using the Mixed-Methods Appraisal Tool. A descriptive analysis of the features of POC cognitive support technology for each study is presented, illustrating trends in technology development and evaluation. A thematic analysis of clinician, technical, patient, and organizational factors associated with technology acceptance is also presented. Of the 1,563 references screened for eligibility, 24 met the inclusion criteria and were included in the review. Most studies were published from 2011 onward (88%), scored high for methodologic quality (79%), and examined POC technologies that were novel and newly introduced into the study setting (63%). Physician use of POC technology was the most commonly studied (67%). Technology acceptance was frequently conceptualized and measured by factors related to clinician attitudes and beliefs. Experience with the technology, intention to use, and actual use were also more common outcome measures of technology acceptance. Across studies, perceived usefulness was the most noteworthy factor impacting technology acceptance, and clinicians generally had positive perceptions of the use of POC cognitive support technology in the ED. However, the actual use of POC cognitive support technology reported by clinicians was low-use, by proportion of patient cases, ranged from 30% to 59%. Of the 24 studies, only two studies investigated acceptance of POC cognitive support technology currently implemented in the ED, offering "real-world" clinical practice data. All other studies focused on acceptance of novel technologies. Technical aspects such as an unfriendly user interface, presentation of redundant or ambiguous information, and required user effort had a negative impact on acceptance. Patient expectations were also found to have a negative impact, while patient safety implications had a positive impact. Institutional support was also reported to impact technology acceptance. Findings from this scoping review suggest that while ED clinicians acknowledge the utility and value of using POC cognitive support technology, actual use of such technology can be low. Further, few studies have evaluated the acceptance and use of POC technologies in routine care. Prospective studies that evaluate how ED clinicians appraise and consider POC technology use in clinical practice are now needed with diverse clinician samples. While this review identified multiple factors contributing to technology acceptance, determining how clinician, technical, patient, and organizational factors mediate or moderate acceptance should also be a priority. © 2017 by the Society for Academic Emergency Medicine.

[Effects of grazing disturbance on soil active organic carbon in mountain forest-arid valley ecotone in the upper reaches of Minjiang River].

PubMed

Liu, Shan-Shan; Zhang, Xing-Hua; Gong, Yuan-Bo; Li, Yuan; Wang, Yan; Yin, Yan-Jie; Ma, Jin-Song; Guo, Ting

2014-02-01

Effects of grazing disturbance on the soil carbon contents and active components in the four vegetations, i.e., artificial Robinia pseudoacacia plantation, artificial poplar plantation, Berberis aggregate shrubland and grassland, were studied in the mountain forest-arid valley ecotone in the upper Minjiang River. Soil organic carbon and active component contents in 0-10 cm soil layer were greater than in 10-20 cm soil layer at each level of grazing disturbance. With increasing the grazing intensity, the total organic carbon (TOC), light fraction organic carbon (LFOC), particulate organic carbon (POC) and easily oxidized carbon (LOC) contents in 0-10 cm soil layer decreased gradually in the artificial R. pseudoacacia plantation. The LFOC content decreased, the POC content increased, and the TOC and LOC contents decreased initially and then increased with increasing the grazing intensity in the artificial poplar plantation. The POC content decreased, and the TOC, LFOC and LOC contents decreased initially and then increased with increasing the grazing intensity in the B. aggregate shrubland. The POC and TOC contents decreased, and the LFOC and LOC contents decreased initially and then increased with increasing the grazing intensity in the grassland. The decreasing ranges of LOC, LFOC and POC contents were 0.1-7.9 times more than that of TOC content. There were significant positive relationships between TOC and LOC, LFOC and POC, suggesting that the active organic carbon components could reflect the change of soil total carbon content.

The spatial distribution of particulate organic carbon and microorganisms on seamounts of the South West Indian Ridge

NASA Astrophysics Data System (ADS)

Djurhuus, A.; Read, J. F.; Rogers, A. D.

2017-02-01

We used elemental analysis, to measure particulate organic carbon (POC), and flow cytometry, to estimate abundance of microorganisms from above four seamounts (Coral, Melville, Middle of What and Atlantis) along the Southwest Indian Ridge (SWIR) from latitude 32.6°S to 41.3°S, longitude 57.1°E to 42.7°E. Samples were collected from the surface to the bottom using a CTD fitted with optical sensors. POC was predicted from models created from in-situ transmission (optical) data (cp). The high resolution predicted POC in the euphotic zone showed a heterogeneous distribution both above individual and between seamounts. The shallow penetration of two of the seamounts displayed an effect on the POC concentration in the euphotic zone depleting the layer around the summit. The transmission data showed higher concentrations of particles towards the surface, caused by primary production, and near to the seabed, probably resulting from re-suspension of sediments. The POC concentrations and microbial abundance were positively correlated to cp and fluctuated with particle abundance, with microorganisms accounting for 50% of the observed POC. Based on non-metric multidimensional scaling it is clear that the microbial clusters strongly indicate three separate biological regimes associated with northeastern, central and southwestern zones of the section of the SWIR that was sampled. This biological zonation is associated with physical oceanographic boundaries represented by the Subtropical and Subantarctic Fronts, forming three distinct "biogeographical" regions.

Truncation of POC1A associated with short stature and extreme insulin resistance.

PubMed

Chen, Jian-Hua; Segni, Maria; Payne, Felicity; Huang-Doran, Isabel; Sleigh, Alison; Adams, Claire; Savage, David B; O'Rahilly, Stephen; Semple, Robert K; Barroso, Inês

2015-10-01

We describe a female proband with primordial dwarfism, skeletal dysplasia, facial dysmorphism, extreme dyslipidaemic insulin resistance and fatty liver associated with a novel homozygous frameshift mutation in POC1A, predicted to affect two of the three protein products of the gene. POC1A encodes a protein associated with centrioles throughout the cell cycle and implicated in both mitotic spindle and primary ciliary function. Three homozygous mutations affecting all isoforms of POC1A have recently been implicated in a similar syndrome of primordial dwarfism, although no detailed metabolic phenotypes were described. Primary cells from the proband we describe exhibited increased centrosome amplification and multipolar spindle formation during mitosis, but showed normal DNA content, arguing against mitotic skipping, cleavage failure or cell fusion. Despite evidence of increased DNA damage in cells with supernumerary centrosomes, no aneuploidy was detected. Extensive centrosome clustering both at mitotic spindles and in primary cilia mitigated the consequences of centrosome amplification, and primary ciliary formation was normal. Although further metabolic studies of patients with POC1A mutations are warranted, we suggest that POC1A may be added to ALMS1 and PCNT as examples of centrosomal or pericentriolar proteins whose dysfunction leads to extreme dyslipidaemic insulin resistance. Further investigation of links between these molecular defects and adipose tissue dysfunction is likely to yield insights into mechanisms of adipose tissue maintenance and regeneration that are critical to metabolic health. © 2015 Society for Endocrinology.

Future export of particulate and dissolved organic carbon from land to coastal zones of the Baltic Sea

NASA Astrophysics Data System (ADS)

Strååt, Kim Dahlgren; Mörth, Carl-Magnus; Undeman, Emma

2018-01-01

The Baltic Sea is a semi-enclosed brackish sea in Northern Europe with a drainage basin four times larger than the sea itself. Riverine organic carbon (Particulate Organic Carbon, POC and Dissolved Organic Carbon, DOC) dominates carbon input to the Baltic Sea and influences both land-to-sea transport of nutrients and contaminants, and hence the functioning of the coastal ecosystem. The potential impact of future climate change on loads of POC and DOC in the Baltic Sea drainage basin (BSDB) was assessed using a hydrological-biogeochemical model (CSIM). The changes in annual and seasonal concentrations and loads of both POC and DOC by the end of this century were predicted using three climate change scenarios and compared to the current state. In all scenarios, overall increasing DOC loads, but unchanged POC loads, were projected in the north. In the southern part of the BSDB, predicted DOC loads were not significantly changing over time, although POC loads decreased in all scenarios. The magnitude and significance of the trends varied with scenario but the sign (+ or -) of the projected trends for the entire simulation period never conflicted. Results were discussed in detail for the "middle" CO2 emission scenario (business as usual, a1b). On an annual and entire drainage basin scale, the total POC load was projected to decrease by ca 7% under this scenario, mainly due to reduced riverine primary production in the southern parts of the BSDB. The average total DOC load was not predicted to change significantly between years 2010 and 2100 due to counteracting decreasing and increasing trends of DOC loads to the six major sub-basins in the Baltic Sea. However, predicted seasonal total loads of POC and DOC increased significantly by ca 46% and 30% in winter and decreased by 8% and 21% in summer over time, respectively. For POC the change in winter loads was a consequence of increasing soil erosion and a shift in duration of snowfall and onset of the spring flood impacting the input of terrestrial litter, while reduced primary production mainly explained the differences predicted in summer. The simulations also showed that future changes in POC and DOC export can vary significantly across the different sub-basins of the Baltic Sea. These changes in organic carbon input may impact future coastal food web structures e.g. by influencing bacterial and phytoplankton production in coastal zones, which in turn may have consequences at higher trophic levels.

Spatial distribution and mobility of organic carbon (POC and DOC) in a coastal Mediterranean environment (Saronikos Gulf, Greece) during 2007-2009 period.

PubMed

Evangeliou, Nikolaos; Florou, Heleny

2013-08-01

Particulate (POC) and dissolved organic carbon (DOC) is an important parameter for the pollution assessment of coastal marine systems, especially those affected by anthropogenic, domestic, and industrial activities. In the present paper, a similar marine system (Saronikos Gulf) located in the west-central Aegean Sea (eastern Mediterranean Sea) was examined, in terms of the temporal and spatial distribution of organic carbon (POC and DOC), with respect to marine sources and pathways. POC was maximum in winter in the Saronikos Gulf, due to the bloom of phytoplankton, whereas in the Elefsis Bay (located in the north side of the Saronikos Gulf) in summer, since phytoplankton grazes in the Bay in the end of summer (except for winter). Approximately 60 % of the bulk DOC of the water column was estimated as non-refractory (labile and semi-labile), due to the major anthropogenic, domestic, and industrial effects of the region and the shallow depths. The spatial distribution of POC and DOC mainly affects the northeastern section of the Gulf, since that region has been accepted major organic discharges for a long time period, in connection to the relatively long renewal times of its waters.

Late summer particulate organic carbon export and twilight zone remineralisation in the Atlantic sector of the Southern Ocean

NASA Astrophysics Data System (ADS)

Planchon, F.; Cavagna, A.-J.; Cardinal, D.; André, L.; Dehairs, F.

2012-03-01

During the Bonus-GoodHope (BGH) expedition (Jan-Mar 2008) we studied the water column distribution of total 234Th and biogenic particulate Ba (Baxs) in the Atlantic sector of the Southern Ocean. The objective was to assess the export flux of particulate organic carbon (POC) from the surface to the mesopelagic twilight zone along a section between the Cape Basin and Weddell Gyre. Export production of POC was estimated from steady state and non steady state export fluxes of 234Th which were converted into POC fluxes, using the POC/234Th ratio of large (>53 μm) suspended particles, collected via in-situ pumps. Deficits in 234Th activities were observed at all stations from the surface to the bottom of the mixed-layer. 234Th export fluxes from the upper 100 m ranged from 496 ± 57 dpm m-2 d-1 to 1195 ± 120 dpm m-2 d-1 for the steady state model and from 149 ± 18 dpm m-2 d-1 to 1217 ± 146 dpm m-2 d-1 for the non steady state model calculated for a time window of 15 to 22 days preceding the timing of the present cruise. The POC/234Thp ratio of large, potentially sinking particles (>53 μm), was observed to increase with latitude, from 1.9 ± 0.2 μmol dpm-1 and 1.7 ± 0.3 μmol dpm-1 in the Subtropical Zone (STZ) and Subantarctic Zone (SAZ), respectively, to 3.0 ± 0.2 μmol dpm-1 in the Polar Front Zone (PFZ), 4.8 ± 1.9 μmol dpm-1 at the Southern Antarctic Circumpolar Current Front (SACCF) to 4.1 ± 1.7 μmol dpm-1 in the northern Weddell Gyre, in line with an increasing contribution of larger cell diatoms. Steady state and non steady state POC export from the upper 100 m ranged from 0.9 ± 0.2 mmolC m-2 d-1 to 5.1 ± 2.1 mmolC m-2 d-1 and from 0.3 ± 0.0 mmolC m-2 d-1 to 4.9 ± 3.2 mmolC m-2 d-1, respectively. From the SAZ to the SACCF, non steady state POC export production represented only 15 to 54 % of the steady state POC flux, suggesting that the intensity of export had decreased over time partly due to the fact that regenerated-production based communities of small-sized phytoplankton became predominant. In contrast, for the HNLC area south of the SACCF, we found an excellent agreement between the two modeling approaches indicating that surface POC export remained rather constant there. Estimated POC export represented between 6 to 54 % of the potential export as represented by new production, indicating that export efficiency was particularly low throughout the studied area, except close to the SACCF. Below the export layer, in the mesopelagic zone, 234Th activities generally reached equilibrium with 238U, but sometimes were in large excess relative to 238U (234Th/238U ratio>1.1), reflecting intense remineralisation/disaggregation of 234Th-bearing particles. The accumulation of excess 234Th in the 100-600 m depth interval ranged from 458 ± 55 dpm m-2 d-1 to 3068 ± 368 dpm m-2 d-1. Using POC to 234Th ratio of sinking particles, we converted this 234Th flux into a POC remineralisation flux, which ranged between 0.9 to 9.2 mmolC m-2 d-1. Mesopelagic remineralisation was also evidenced by Baxs inventories which are related to bacterial degradation of sinking material and offer a means to quantify the flux of respired C. Highest biogenic particulate Ba (Baxs) contents were generally observed in the 200-400 m depth interval with values reaching up to >1000 pM in the northern PFZ. Depth weighted average mesopelagic Baxs (meso-Baxs) was high in the PFZ and low in the northernmost (STZ-SAZ) and the southernmost (SACCF-AZ-WG) parts of the BGH section; conversion into respired C flux yielded a range of -0.23 to 6.4 mmolC m-2 d-1. Excluding two outliers, we found a significant positive correlation for mesopelagic waters between POC remineralisation estimated from meso-Baxs and from 234Th excess (R2 = 0.73). Our results indicate that POC export production in this area of the Southern Ocean was strongly attenuated in the mesopelagic waters due to remineralisation, a process which thus appears to strongly impact on longer term bathypelagic zone sequestration of POC.

The Role of Nanoparticle Design in Determining Analytical Performance of Lateral Flow Immunoassays.

PubMed

Zhan, Li; Guo, Shuang-Zhuang; Song, Fayi; Gong, Yan; Xu, Feng; Boulware, David R; McAlpine, Michael C; Chan, Warren C W; Bischof, John C

2017-12-13

Rapid, simple, and cost-effective diagnostics are needed to improve healthcare at the point of care (POC). However, the most widely used POC diagnostic, the lateral flow immunoassay (LFA), is ∼1000-times less sensitive and has a smaller analytical range than laboratory tests, requiring a confirmatory test to establish truly negative results. Here, a rational and systematic strategy is used to design the LFA contrast label (i.e., gold nanoparticles) to improve the analytical sensitivity, analytical detection range, and antigen quantification of LFAs. Specifically, we discovered that the size (30, 60, or 100 nm) of the gold nanoparticles is a main contributor to the LFA analytical performance through both the degree of receptor interaction and the ultimate visual or thermal contrast signals. Using the optimal LFA design, we demonstrated the ability to improve the analytical sensitivity by 256-fold and expand the analytical detection range from 3 log 10 to 6 log 10 for diagnosing patients with inflammatory conditions by measuring C-reactive protein. This work demonstrates that, with appropriate design of the contrast label, a simple and commonly used diagnostic technology can compete with more expensive state-of-the-art laboratory tests.

Method comparison and validation of a prototype device for measurement of ionized calcium concentrations cow-side against a point-of-care instrument and a benchtop blood-gas analyzer reference method.

PubMed

Neves, R C; Stokol, T; Bach, K D; McArt, J A A

2018-02-01

The objective of this study was to assess an optimized ion-selective electrode Ca-module prototype as a potential cow-side device for ionized Ca (iCa) measurements in bovine blood. A linearity experiment showed no deviation from linearity over a range of iCa concentrations compared with a commercial point-of-care (POC) device commonly used in the field (POC VS ; VetScan i-STAT, Abaxis North America, Union City, CA) and a laboratory gold standard benchtop blood-gas analyzer [reference analyzer (RA); ABL-800 FLEX, Radiometer Medical, Copenhagen, Denmark]. Coefficient of variation on 3 samples with high, within-range, and low iCa concentrations ranged from 1.0 to 3.9% for the prototype. A follow-up validation experiment was performed, in which our objectives were to (1) assess the performance of the prototype cow-side against the POC VS (farm gold-standard) using fresh non-anticoagulated whole-blood samples; (2) assess the performance of the prototype and the POC VS against the RA in a diagnostic laboratory using blood collected in a heparin-balanced syringe; and (3) assess the agreement of the prototype and POC VS on-farm (fresh non-anticoagulated whole blood) against the RA on heparin-balanced blood. Finally, sensitivity and specificity of the results obtained by the prototype and the POC VS cow-side compared with the results obtained by the laboratory RA using 3 different iCa cut points for classification of subclinical hypocalcemia were calculated. A total of 101 periparturient Holstein cows from 3 dairy farms in New York State were used for the second experiment. Ionized Ca results from the prototype cow-side were, on average, 0.06 mmol/L higher than the POC VS . With heparin-balanced samples under laboratory conditions, the prototype and POC VS measured an average 0.04 mmol/L higher and lower, respectively, compared with the RA. Results from the prototype and POC VS cow-side were 0.01 mmol/L higher and 0.05 mmol/L lower, respectively, compared with results from the laboratory RA on heparinized blood. Sensitivity and specificity for the prototype and the POC VS under farm conditions at 3 potential subclinical hypocalcemia cut points were 100 and ≥93.5%, respectively. This novel ion-selective electrode Ca-module could become a rapid low-cost tool for assessing iCa cow-side, while qualitatively allowing classification of subclinical hypocalcemia on-farm. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

Evaluation of Cortez OneStep Chlamydia Rapicard™ Insta Test for the Detection of Chlamydia trachomatis in Pregnant Women at Mbare Polyclinic in Harare, Zimbabwe

PubMed Central

Stephen, Stephen; Muchaneta-Kubara, Chiwoneso Gwyneth Elizabeth; Munjoma, Marshall Wesley; Mandozana, Gibson

2017-01-01

Background: Cervical chlamydia infection poses high risk of pregnancy complications and neonatal infection. Reference methods for the detection of chlamydia infection are not available for routine use in developing countries. Point-of-care (POC) tests can bridge this gap. This study evaluated Cortez Onestep Chlamydia Rapicard™ insta test for the detection of Chlamydia trachomatis in pregnant women at Mbare Polyclinic and determined the prevalence of C. trachomatis. Methods: This was a cross sectional study in 242 pregnant women aged ≥18 years attending their first ANC visit at Mbare polyclinic in Harare, Zimbabwe. Data collection form was used to obtain demographic and predisposing factors to Chlamydia infection and two endocervical swabs were collected from each patient. One specimen was examined by the POC test at the clinic and the other by SDA method in the laboratory. Results: The sensitivity, specificity, positive and negative predictive values of the rapid kit were 71.4%, 99.6%, 90.9% and 98.3% respectively. Prevalence of C. trachomitis was 5.8% by SDA method. Conclusion and Global Health Implications: The kit’s sensitivity (71.4%) and specificity (99.6%) implies that the rapid test is an important test which needs further evaluations. The prevalence of C. trichomitis of 5.8% is comparable to studies done elsewhere in Africa. PMID:28798890

How organic carbon derived from multiple sources contributes to carbon sequestration processes in a shallow coastal system?

PubMed Central

Watanabe, Kenta; Kuwae, Tomohiro

2015-01-01

Carbon captured by marine organisms helps sequester atmospheric CO2, especially in shallow coastal ecosystems, where rates of primary production and burial of organic carbon (OC) from multiple sources are high. However, linkages between the dynamics of OC derived from multiple sources and carbon sequestration are poorly understood. We investigated the origin (terrestrial, phytobenthos derived, and phytoplankton derived) of particulate OC (POC) and dissolved OC (DOC) in the water column and sedimentary OC using elemental, isotopic, and optical signatures in Furen Lagoon, Japan. Based on these data analysis, we explored how OC from multiple sources contributes to sequestration via storage in sediments, water column sequestration, and air–sea CO2 exchanges, and analyzed how the contributions vary with salinity in a shallow seagrass meadow as well. The relative contribution of terrestrial POC in the water column decreased with increasing salinity, whereas autochthonous POC increased in the salinity range 10–30. Phytoplankton-derived POC dominated the water column POC (65–95%) within this salinity range; however, it was minor in the sediments (3–29%). In contrast, terrestrial and phytobenthos-derived POC were relatively minor contributors in the water column but were major contributors in the sediments (49–78% and 19–36%, respectively), indicating that terrestrial and phytobenthos-derived POC were selectively stored in the sediments. Autochthonous DOC, part of which can contribute to long-term carbon sequestration in the water column, accounted for >25% of the total water column DOC pool in the salinity range 15–30. Autochthonous OC production decreased the concentration of dissolved inorganic carbon in the water column and thereby contributed to atmospheric CO2 uptake, except in the low-salinity zone. Our results indicate that shallow coastal ecosystems function not only as transition zones between land and ocean but also as carbon sequestration filters. They function at different timescales, depending on the salinity, and OC sources. PMID:25880367

The value of point-of-care CD4+ and laboratory viral load in tailoring antiretroviral therapy monitoring strategies to resource limitations.

PubMed

Hyle, Emily P; Jani, Ilesh V; Rosettie, Katherine L; Wood, Robin; Osher, Benjamin; Resch, Stephen; Pei, Pamela P; Maggiore, Paolo; Freedberg, Kenneth A; Peter, Trevor; Parker, Robert A; Walensky, Rochelle P

2017-09-24

To examine the clinical and economic value of point-of-care CD4 (POC-CD4) or viral load monitoring compared with current practices in Mozambique, a country representative of the diverse resource limitations encountered by HIV treatment programs in sub-Saharan Africa. We use the Cost-Effectiveness of Preventing AIDS Complications-International model to examine the clinical impact, cost (2014 US$), and incremental cost-effectiveness ratio [$/year of life saved (YLS)] of ART monitoring strategies in Mozambique. We compare: monitoring for clinical disease progression [clinical ART monitoring strategy (CLIN)] vs. annual POC-CD4 in rural settings without laboratory services and biannual laboratory CD4 (LAB-CD4), biannual POC-CD4, and annual viral load in urban settings with laboratory services. We examine the impact of a range of values in sensitivity analyses, using Mozambique's 2014 per capita gross domestic product ($620) as a benchmark cost-effectiveness threshold. In rural settings, annual POC-CD4 compared to CLIN improves life expectancy by 2.8 years, reduces time on failed ART by 0.6 years, and yields an incremental cost-effectiveness ratio of $480/YLS. In urban settings, biannual POC-CD4 is more expensive and less effective than viral load. Compared to biannual LAB-CD4, viral load improves life expectancy by 0.6 years, reduces time on failed ART by 1.0 year, and is cost-effective ($440/YLS). In rural settings, annual POC-CD4 improves clinical outcomes and is cost-effective compared to CLIN. In urban settings, viral load has the greatest clinical benefit and is cost-effective compared to biannual POC-CD4 or LAB-CD4. Tailoring ART monitoring strategies to specific settings with different available resources can improve clinical outcomes while remaining economically efficient.

The Parasol Protocol: An Implementation Science Study of HIV Continuum of Care Interventions for Gay Men and Transgender Women in Burma/Myanmar.

PubMed

Wirtz, Andrea L; Naing, Soe; Clouse, Emily; Thu, Kaung Htet; Mon, Sandra Hsu Hnin; Tun, Zin Min; Baral, Stefan; Paing, Aung Zayar; Beyrer, Chris

2017-05-17

Efforts to improve HIV diagnosis and antiretroviral therapy (ART) initiation among people living with HIV and reduce onward transmission of HIV rely on innovative interventions along multiple steps of the HIV care continuum. These innovative methods are particularly important for key populations, including men who have sex with men (MSM) and transgender women (TW). The HIV epidemic in Myanmar is concentrated among key populations, and national efforts now focus on reducing stigma and improving engagement of MSM and TW in HIV prevention and care. This study aims to test the use of several innovations to address losses in the HIV care continuum: (1) use of respondent-driven sampling (RDS) to reach and engage MSM and TW in HIV testing, (2) HIV self-testing (HIVST) to increase HIV testing uptake and aid early diagnosis of infection, (3) community-based CD4 point-of-care (POC) technology to rapidly stage HIV disease for those who are HIV infected, and (4) peer navigation support to increase successful health system navigation for HIV-infected MSM and TW in need of ART or HIV engagement in care. To assess the effect of HIVST, we will implement a randomized trial in which MSM and TW adults in the greater Yangon metropolitan area who are HIV uninfected will be recruited via RDS (N=366). Participants will complete a baseline socio-behavioral survey and will be randomized to standard, voluntary counseling and testing (VCT) or to HIVST. Biologic specimens will be collected during this baseline visit for confirmatory testing using dried blood spots. Participants will be asked to return to the study office to complete a second study visit in which they will report their HIV test result and answer questions on the acceptability of the assigned testing method. Aim 1 participants with confirmed HIV infection and who are not engaged in care (N=49) will be offered direct enrollment into Aims 2 and 3, which include immediate CD4 POC and the option for peer navigation, respectively. Aims 2 and 3 participants will be prospectively followed for 12 months with data collection including interviewer-administered sociobehavioral survey, CD4 POC, and viral load testing occurring biannually. Participants who accept peer navigation will be compared to those who decline peer navigation. Analyses will estimate the impact of CD4 POC on engagement in care and the impact of peer navigation on ART adherence and viral load. Formative qualitative research was conducted in June and September 2015 and led to further refinement of recruitment methods, HIVST instructions and counseling, and peer navigation methods. Aim 1 recruitment began in November 2015 with subsequent enrollment into Aims 2 and 3 and is currently ongoing. These innovative interventions may resolve gaps in the HIV care continuum among MSM and TW and future implementation may aid in curbing the HIV epidemic among MSM and TW in Myanmar. ©Andrea L Wirtz, Soe Naing, Emily Clouse, Kaung Htet Thu, Sandra Hsu Hnin Mon, Zin Min Tun, Stefan Baral, Aung Zayar Paing, Chris Beyrer. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 17.05.2017.

Considering Point-of-Care Electronic Medical Resources in Lieu of Traditional Textbooks for Medical Education.

PubMed

Hale, LaDonna S; Wallace, Michelle M; Adams, Courtney R; Kaufman, Michelle L; Snyder, Courtney L

2015-09-01

Selecting resources to support didactic courses is a critical decision, and the advantages and disadvantages must be carefully considered. During clinical rotations, students not only need to possess strong background knowledge but also are expected to be proficient with the same evidence-based POC resources used by clinicians. Students place high value on “real world” learning and therefore may place more value on POC resources that they know practicing clinicians use as compared with medical textbooks. The condensed nature of PA education requires students to develop background knowledge and information literacy skills over a short period. One way to build that knowledge and those skills simultaneously is to use POC resources in lieu of traditional medical textbooks during didactic training. Electronic POC resources offer several advantages over traditional textbooks and should be considered as viable options in PA education.

Seasonal variation and partitioning of endocrine disrupting chemicals in waters and sediments of the Pearl River system, South China.

PubMed

Gong, Jian; Duan, Dandan; Yang, Yu; Ran, Yong; Chen, Diyun

2016-12-01

Endocrine disrupting chemicals (EDCs) were seasonally investigated in surface water, suspended particulate matter, and sediments of the Pearl River Delta (PRD), South China. EDC concentrations in the surface water were generally higher in the summer than in winter. The surface water in the investigated rivers was heavily contaminated by the phenolic xenoestrogens. Moreover, the in-situ log K soc and log K poc values and their regression with log K ow in the field experiments suggest that binding mechanisms other than hydrophobic interaction are present for the sedimentary organic carbon and particulate organic carbon (SOC/POC). The logK soc -logK ow and logK poc -logK ow regression analyses imply that higher complexity of nonhydrophobic interactions with EDCs is present on the SOC samples comparing with the POC samples, which is related to their different sources. Copyright © 2016 Elsevier Ltd. All rights reserved.

Accuracy, user-friendliness and usefulness of the Cobas h232 point-of-care test for NT-proBNP in primary care.

PubMed

Hex, Chiel; Smeets, Miek; Penders, Joris; Van Hoof, Viviane; Verbakel, Jan; Buntinx, Frank; Vaes, Bert

2018-06-01

N-terminal pro-B-type natriuretic peptide (NT-proBNP) has been shown to be useful for ruling out heart failure in primary care. In this study, we examined the accuracy of the Cobas h232 point-of-care (POC) instrument in primary care compared with an in-hospital measurement. Furthermore, we investigated the user-friendliness and usefulness of the POC device. Five general practitioner (GP) groups were asked to evaluate adult patients who were suspected of having heart failure and to test NT-proBNP with the Cobas h232. The samples were subsequently delivered to and analysed at a central hospital laboratory by the Cobas e602 using conventional transport and storage. Difference between the paired measurements was analysed using a percentage difference plot, and correlation was assessed using Passing-Bablok linear regression analysis. User-friendliness and usefulness were assessed using semistructured questionnaires. Nineteen GPs studied 94 patients. Passing-Bablok analysis showed a slope of 1.05 (95% CI 1.00 to 1.11) (R 2 =0.97). The percentage difference plot showed a mean difference of 15.7% (95% CI -46.0% to -77.4%). User-friendliness and usefulness had median scores of 4 or 5 on a five-point Likert scale. Eighteen out of 19 GPs confirmed that the device influenced their clinical practice. During the study, GPs' confidence in using NT-proBNP increased significantly from a mean score of 4.4 (95% CI 3.2 to 5.6) to 7.6 out of 10 (95% CI 7.1 to 8.2). The Cobas h232 NT-proBNP POC test proved to be an accurate, user-friendly and useful test in primary care. Nearly all participating GPs were convinced that the test could benefit clinical decision making. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Protocol for a randomised controlled implementation trial of point-of-care viral load testing and task shifting: the Simplifying HIV TREAtment and Monitoring (STREAM) study

PubMed Central

Garrett, Nigel; Quame-Amaglo, Justice; Samsunder, Natasha; Ngobese, Hope; Ngomane, Noluthando; Moodley, Pravikrishnen; Mlisana, Koleka; Schaafsma, Torin; Donnell, Deborah; Barnabas, Ruanne; Naidoo, Kogieleum; Abdool Karim, Salim; Celum, Connie; Drain, Paul K

2017-01-01

Introduction Achieving the Joint United Nations Programme on HIV and AIDS 90-90-90 targets requires models of HIV care that expand antiretroviral therapy (ART) coverage without overburdening health systems. Point-of-care (POC) viral load (VL) testing has the potential to efficiently monitor ART treatment, while enrolled nurses may be able to provide safe and cost-effective chronic care for stable patients with HIV. This study aims to demonstrate whether POC VL testing combined with task shifting to enrolled nurses is non-inferior and cost-effective compared with laboratory-based VL monitoring and standard HIV care. Methods and analysis The STREAM (Simplifying HIV TREAtment and Monitoring) study is an open-label, non-inferiority, randomised controlled implementation trial. HIV-positive adults, clinically stable at 6 months after ART initiation, will be recruited in a large urban clinic in South Africa. Approximately 396 participants will be randomised 1:1 to receive POC HIV VL monitoring and potential task shifting to enrolled nurses, versus laboratory VL monitoring and standard South African HIV care. Initial clinic follow-up will be 2-monthly in both arms, with VL testing at enrolment, 6 months and 12 months. At 6 months (1 year after ART initiation), stable participants in both arms will qualify for a differentiated care model involving decentralised ART pickup at community-based pharmacies. The primary outcome is retention in care and virological suppression at 12 months from enrolment. Secondary outcomes include time to appropriate entry into the decentralised ART delivery programme, costs per virologically suppressed patient and cost-effectiveness of the intervention compared with standard care. Findings will inform the scale up of VL testing and differentiated care in HIV-endemic resource-limited settings. Ethics and dissemination Ethical approval has been granted by the University of KwaZulu-Natal Biomedical Research Ethics Committee (BFC296/16) and University of Washington Institutional Review Board (STUDY00001466). Results will be presented at international conferences and published in academic peer-reviewed journals. Trial registration NCT03066128; Pre-results. PMID:28963304

A paper/polymer hybrid microfluidic microplate for rapid quantitative detection of multiple disease biomarkers.

PubMed

Sanjay, Sharma T; Dou, Maowei; Sun, Jianjun; Li, XiuJun

2016-07-26

Enzyme linked immunosorbent assay (ELISA) is one of the most widely used laboratory disease diagnosis methods. However, performing ELISA in low-resource settings is limited by long incubation time, large volumes of precious reagents, and well-equipped laboratories. Herein, we developed a simple, miniaturized paper/PMMA (poly(methyl methacrylate)) hybrid microfluidic microplate for low-cost, high throughput, and point-of-care (POC) infectious disease diagnosis. The novel use of porous paper in flow-through microwells facilitates rapid antibody/antigen immobilization and efficient washing, avoiding complicated surface modifications. The top reagent delivery channels can simply transfer reagents to multiple microwells thus avoiding repeated manual pipetting and costly robots. Results of colorimetric ELISA can be observed within an hour by the naked eye. Quantitative analysis was achieved by calculating the brightness of images scanned by an office scanner. Immunoglobulin G (IgG) and Hepatitis B surface Antigen (HBsAg) were quantitatively analyzed with good reliability in human serum samples. Without using any specialized equipment, the limits of detection of 1.6 ng/mL for IgG and 1.3 ng/mL for HBsAg were achieved, which were comparable to commercial ELISA kits using specialized equipment. We envisage that this simple POC hybrid microplate can have broad applications in various bioassays, especially in resource-limited settings.

A paper/polymer hybrid microfluidic microplate for rapid quantitative detection of multiple disease biomarkers

PubMed Central

Sanjay, Sharma T.; Dou, Maowei; Sun, Jianjun; Li, XiuJun

2016-01-01

Enzyme linked immunosorbent assay (ELISA) is one of the most widely used laboratory disease diagnosis methods. However, performing ELISA in low-resource settings is limited by long incubation time, large volumes of precious reagents, and well-equipped laboratories. Herein, we developed a simple, miniaturized paper/PMMA (poly(methyl methacrylate)) hybrid microfluidic microplate for low-cost, high throughput, and point-of-care (POC) infectious disease diagnosis. The novel use of porous paper in flow-through microwells facilitates rapid antibody/antigen immobilization and efficient washing, avoiding complicated surface modifications. The top reagent delivery channels can simply transfer reagents to multiple microwells thus avoiding repeated manual pipetting and costly robots. Results of colorimetric ELISA can be observed within an hour by the naked eye. Quantitative analysis was achieved by calculating the brightness of images scanned by an office scanner. Immunoglobulin G (IgG) and Hepatitis B surface Antigen (HBsAg) were quantitatively analyzed with good reliability in human serum samples. Without using any specialized equipment, the limits of detection of 1.6 ng/mL for IgG and 1.3 ng/mL for HBsAg were achieved, which were comparable to commercial ELISA kits using specialized equipment. We envisage that this simple POC hybrid microplate can have broad applications in various bioassays, especially in resource-limited settings. PMID:27456979

A paper/polymer hybrid microfluidic microplate for rapid quantitative detection of multiple disease biomarkers

NASA Astrophysics Data System (ADS)

Sanjay, Sharma T.; Dou, Maowei; Sun, Jianjun; Li, Xiujun

2016-07-01

Enzyme linked immunosorbent assay (ELISA) is one of the most widely used laboratory disease diagnosis methods. However, performing ELISA in low-resource settings is limited by long incubation time, large volumes of precious reagents, and well-equipped laboratories. Herein, we developed a simple, miniaturized paper/PMMA (poly(methyl methacrylate)) hybrid microfluidic microplate for low-cost, high throughput, and point-of-care (POC) infectious disease diagnosis. The novel use of porous paper in flow-through microwells facilitates rapid antibody/antigen immobilization and efficient washing, avoiding complicated surface modifications. The top reagent delivery channels can simply transfer reagents to multiple microwells thus avoiding repeated manual pipetting and costly robots. Results of colorimetric ELISA can be observed within an hour by the naked eye. Quantitative analysis was achieved by calculating the brightness of images scanned by an office scanner. Immunoglobulin G (IgG) and Hepatitis B surface Antigen (HBsAg) were quantitatively analyzed with good reliability in human serum samples. Without using any specialized equipment, the limits of detection of 1.6 ng/mL for IgG and 1.3 ng/mL for HBsAg were achieved, which were comparable to commercial ELISA kits using specialized equipment. We envisage that this simple POC hybrid microplate can have broad applications in various bioassays, especially in resource-limited settings.

Recent Progress in the Development of Diagnostic Tests for Malaria.

PubMed

Krampa, Francis D; Aniweh, Yaw; Awandare, Gordon A; Kanyong, Prosper

2017-09-19

The impact of malaria on global health has continually prompted the need to develop effective diagnostic strategies. In malaria endemic regions, routine diagnosis is hampered by technical and infrastructural challenges to laboratories. These laboratories lack standard facilities, expertise or diagnostic supplies; thus, therapy is administered based on clinical or self-diagnosis. There is the need for accurate diagnosis of malaria due to the continuous increase in the cost of medication, and the emergence and spread of drug resistant strains. However, the widely utilized Giemsa-stained microscopy and immunochromatographic tests for malaria are liable to several drawbacks, including inadequate sensitivity and false-positive outcomes. Alternative methods that offer improvements in performance are either expensive, have longer turnaround time or require a level of expertise that makes them unsuitable for point-of-care (POC) applications. These gaps necessitate exploration of more efficient detection techniques with the potential of POC applications, especially in resource-limited settings. This minireview discusses some of the recent trends and new approaches that are seeking to improve the clinical diagnosis of malaria.

Selfish mothers? An empirical test of parent-offspring conflict over extended parental care.

PubMed

Paul, Manabi; Sen Majumder, Sreejani; Bhadra, Anindita

2014-03-01

Parent-offspring conflict (POC) theory is an interesting conceptual framework for understanding the dynamics of parental care. However, this theory is not easy to test empirically, as exact measures of parental investment in an experimental set-up are difficult to obtain. We have used free-ranging dogs Canis familiaris in India, to study POC in the context of extended parental care. We observed females and their pups in their natural habitat for the mother's tendency to share food given by humans with her pups in the weaning and post-weaning stages. Since these dogs are scavengers, and depend largely on human provided food for their sustenance, voluntary sharing of food by the mother with her pups is a good surrogate for extended parental care. Our behavioural observations convincingly demonstrate an increase of conflict and decrease of cooperation by the mother with her offspring over given food within a span of 4-6 weeks. We also demonstrate that the competition among the pups in a litter scales with litter size, an indicator of sib-sib competition. Copyright © 2013 Elsevier B.V. All rights reserved.

Electrochemistry-based Approaches to Low Cost, High Sensitivity, Automated, Multiplexed Protein Immunoassays for Cancer Diagnostics

PubMed Central

Dixit, Chandra K.; Kadimisetty, Karteek; Otieno, Brunah A.; Tang, Chi; Malla, Spundana; Krause, Colleen E.; Rusling, James F.

2015-01-01

Early detection and reliable diagnostics are keys to effectively design cancer therapies with better prognoses. Simultaneous detection of panels of biomarker proteins holds great promise as a general tool for reliable cancer diagnostics. A major challenge in designing such a panel is to decide upon a coherent group of biomarkers which have higher specificity for a given type of cancer. The second big challenge is to develop test devices to measure these biomarkers quantitatively with high sensitivity and specificity, such that there are no interferences from the complex serum or tissue matrices. Lastly, integrating all these tests into a technology that doesn’t require exclusive training to operate, and can be used at point-of-care (POC) is another potential bottleneck in futuristic cancer diagnostics. In this article, we review electrochemistry-based tools and technologies developed and/or used in our laboratories to construct low-cost microfluidic protein arrays for highly sensitive detection of the panel of cancer-specific biomarkers with high specificity and at the same time have the potential to be translated into a POC. PMID:26525998

Electrochemistry-based approaches to low cost, high sensitivity, automated, multiplexed protein immunoassays for cancer diagnostics.

PubMed

Dixit, Chandra K; Kadimisetty, Karteek; Otieno, Brunah A; Tang, Chi; Malla, Spundana; Krause, Colleen E; Rusling, James F

2016-01-21

Early detection and reliable diagnostics are keys to effectively design cancer therapies with better prognoses. The simultaneous detection of panels of biomarker proteins holds great promise as a general tool for reliable cancer diagnostics. A major challenge in designing such a panel is to decide upon a coherent group of biomarkers which have higher specificity for a given type of cancer. The second big challenge is to develop test devices to measure these biomarkers quantitatively with high sensitivity and specificity, such that there are no interferences from the complex serum or tissue matrices. Lastly, integrating all these tests into a technology that does not require exclusive training to operate, and can be used at point-of-care (POC) is another potential bottleneck in futuristic cancer diagnostics. In this article, we review electrochemistry-based tools and technologies developed and/or used in our laboratories to construct low-cost microfluidic protein arrays for the highly sensitive detection of a panel of cancer-specific biomarkers with high specificity which at the same time has the potential to be translated into POC applications.

78 FR 9108 - Proposed Information Collection (Conduct the Point-of-Care Research Questionnaire) Activity...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-07

... patient and provider attitudes and willingness to participate in Point-of-Care Research (POC-R). POC-R is... of a Point-of-care research innovation program by assessing the perceptions and attitudes of patients...

Novel nanoarchitectures for electrochemical biosensing

NASA Astrophysics Data System (ADS)

Archibald, Michelle M.

Sensitive, real-time detection of biomarkers is of critical importance for rapid and accurate diagnosis of disease for point-of-care (POC) technologies. Current methods, while sensitive, do not adequately allow for POC applications due to several limitations, including complex instrumentation, high reagent consumption, and cost. We have investigated two novel nanoarchitectures, the nanocoax and the nanodendrite, as electrochemical biosensors towards the POC detection of infectious disease biomarkers to overcome these limitations. The nanocoax architecture is composed of vertically-oriented, nanoscale coaxial electrodes, with coax cores and shields serving as integrated working and counter electrodes, respectively. The dendritic structure consists of metallic nanocrystals extending from the working electrode, increasing sensor surface area. Nanocoaxial- and nanodendritic-based electrochemical sensors were fabricated and developed for the detection of bacterial toxins using an electrochemical enzyme-linked immunosorbent assay (ELISA) and differential pulse voltammetry (DPV). Proof-of-concept was demonstrated for the detection of cholera toxin (CT). Both nanoarchitectures exhibited levels of sensitivity that are comparable to the standard optical ELISA used widely in clinical applications. In addition to matching the detection profile of the standard ELISA, these electrochemical nanosensors provide a simple electrochemical readout and a miniaturized platform with multiplexing capabilities toward POC implementation. Further development as suggested in this thesis may lead to increases in sensitivity, enhancing the attractiveness of the architectures for future POC devices.

Multigenerational Effects of Heavy Metals on Feeding, Growth, Initial Reproduction and Antioxidants in Caenorhabditis elegans

PubMed Central

Yu, ZhenYang; Zhang, Jing; Yin, DaQiang

2016-01-01

Earlier studies showed that toxicities of excessive metals lasted over generations. Yet, these studies mainly employed one-generation exposure, and the effects of multigenerational challenges need further studies. Presently, Caenorhabditis elegans were exposed to cadmium, copper, lead and zinc for four consecutive generations (G1 to G4) at environmental concentrations. The feeding, growth, initial reproduction, superoxide dismutase (SOD) and catalase (CAT) were determined. All data were represented in the percentage of that in control (POC), and POC in the control was normalized to 100%. In G1 and G2, the POC values in feeding, growth and initial reproduction were generally within 10% of the control (100%), indicating non-significant effects. The POC values in SOD and CAT were significantly higher than 100%, showing stimulatory effects. In G3 and G4, the POC values in feeding, growth and initial reproduction were significantly lower than 100%, showing inhibitory effects which were more severe in G4 than in G3. Meanwhile, SOD and CAT continuously showed stimulatory effects, and the stimulatory effects on SOD increased from G1 to G4. The effects with multigenerational challenges were different from those in one-generation exposure. The effects in later generations demonstrated the importance of multigenerational challenges in judging long-term influences of metals. PMID:27116222

Accelerating proof of concept for small molecule drugs using solid-state chemistry.

PubMed

Byrn, Stephen R; Zografi, George; Chen, Xiaoming Sean

2010-09-01

In this perspective we have shown that the process of "proof of concept" (POC) in the early part of drug development can be greatly accelerated by close attention to the underlying solid-state chemistry (SSC) of a new chemical entity. POC seeks data that provide confidence in the therapeutic activity and safety of a new chemical entity, which can rapidly lead to a key "GO/NO-GO" decision point for further development. Due to the high cost of the development of new chemical entities and the current low overall productivity of obtaining successful candidates, the pharmaceutical industry is being required to develop accelerated POC strategies. The success of accelerated approaches to POC depends on a full understanding of the SSC of drugs in relation to solubility and stability. Dissolution-limited absorption due to poor solubility of drug substances is particularly important because it can lead to low exposure in animals and undesired bioavailability in humans. Choosing a desirable solid form with sufficient solubility and acceptable stability is essential in developing formulations for POC with superior quality. In this perspective we present an approach that utilizes SSC as part of a novel 2-year development strategy for reaching the pivotal clinical trial stage of development.

Using a simulation model to assess risk of false negative point-of-care urinary human chorionic gonadotropin device results due to high-dose hook interference.

PubMed

Milhorn, Denise; Korpi-Steiner, Nichole

2015-02-01

It is unclear if the point-of-care (POC) Clinitest hCG device is subject to high-dose hook interference from physiological concentrations of intact human chorionic gonadotropin (hCG), β-core fragment of hCG (hCGβcf), and hCG free β-subunit (hCGβ) found in urine during pregnancy. We used a simulation model to address this question and related our findings to our institution's pregnant population in order to assess risk for potential false-negative hCG results. The expected distribution of days relative to ovulation during routine POC hCG testing was estimated from 182 patients. Clinitest-Clinitek Status hCG device susceptibility to high-dose hook interference from hCG variants and potential risk of false-negative results as it relates to this population were evaluated by testing increasing concentrations of hCG, hCGβcf, hCGβ as well as urine simulating physiological hCG, hCGβcf and hCGβ concentrations expected during early pregnancy (≤44 days post-ovulation). The Clinitest-Clinitek Status hCG device exhibited high-dose hook interference from hCGβcf alone, but not from hCG, hCGβ, or simulated physiological urinary concentrations of combined hCG, hCGβcf and hCGβ expected during early pregnancy. The majority of our patient population had urinary hCG testing conducted during early pregnancy. The Clinitest-Clinitek Status hCG device is unlikely to exhibit false-negative urinary hCG results due to high-dose hook interference for women in early healthy pregnancy, although additional studies are necessary to determine potential risk in other patient populations. Visual interpretation of POC urinary hCG device results is an important failure mode to consider in risk analyses for erroneous urinary hCG device results. Published by Elsevier Inc.

Recent Advances in Biosensor Development for Foodborne Virus Detection

PubMed Central

Neethirajan, Suresh; Ahmed, Syed Rahin; Chand, Rohit; Buozis, John; Nagy, Éva

2017-01-01

Outbreaks of foodborne diseases related to fresh produce have been increasing in North America and Europe. Viral foodborne pathogens are poorly understood, suffering from insufficient awareness and surveillance due to the limits on knowledge, availability, and costs of related technologies and devices. Current foodborne viruses are emphasized and newly emerging foodborne viruses are beginning to attract interest. To face current challenges regarding foodborne pathogens, a point-of-care (POC) concept has been introduced to food testing technology and device. POC device development involves technologies such as microfluidics, nanomaterials, biosensors and other advanced techniques. These advanced technologies, together with the challenges in developing foodborne virus detection assays and devices, are described and analysed in this critical review. Advanced technologies provide a path forward for foodborne virus detection, but more research and development will be needed to provide the level of manufacturing capacity required. PMID:29071193

Isolation and Characterization of an Endophytic Fungal Strain with Potent Antimicrobial and Termiticidal Activities From Port-Orford-Cedar.

PubMed

Sun, Liqing; Hse, Chung-Yun; Shupe, Todd; Sun, Mingjing; Wang, Xiaohua; Zhao, Kai

2015-06-01

Termites are responsible for an estimated US$1 billion annually in property damage, repairs, pest control, and prevention. There is an urgent need of finding a better alternative way to control and prevent termites. Port-Orford-Cedar (POC) has been known to have significant levels of natural durability and termiticidal activities due to its extractive contents. In this study, 25 endophytes including 22 fungal and 3 bacterial strains were isolated from the POC. Four strains, namely, HDZK-BYF21, HDZK-BYF1, HDZK-BYF2, and HDZK-BYB11, were chosen to test their termiticidal activities. The fermentation broth of strain HDZK-BYF21 displayed the potent antimicrobial and termiticidal activities. Morphological examination and 18 S rDNA sequence analysis demonstrated that strain HDZK-BYF21 belonged to the genus Aspergillus. This finding indicates the existence of an interesting chemical symbiosis between an endophytic fungus and its host. This is also the first report on endophytes isolated from the POC that may have potential termiticidal activities. Endophytes with termiticidal activities can be grown in bioreactor to provide an inexhaustible supply of bioactive compounds and thus can be exploited commercially. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

OM/OC Ratio and Specific Attenuation Coefficient in Ambient Particulate Matter at a Rural Site in Southern Ontario: Implications for Aerosol Aging and Emission Sources

NASA Astrophysics Data System (ADS)

Chan, T. W.; Huang, L.; Leaitch, R.; Sharma, S.; Brook, J.; Slowik, J.; Abbatt, J.

2008-05-01

Carbonaceous species (organic carbon (OC) and elemental carbon (EC)) contribute a large portion of atmospheric fine particle mass and influence air quality, human health, and climate forcing. However, their emission sources and atmospheric aging processes are not well understood. The OM/OC ratio, defined as the organic mass per unit OC mass, is useful to understand the degree of oxidation of aerosol particles in atmospheric processes. We define the modified BC/EC (mod BC/EC) ratio as the ratio of the non-scattering corrected absorption coefficient per unit mass of EC. The mod BC/EC ratio has a similar meaning as the site specific attenuation coefficient, which is an important parameter used to convert light absorption measurements to black carbon mass. The mod BC/EC ratio can vary due to light scattering effect on absorption measurements, in which the oxygenated organics may play a role. The pyrolysis organic carbon (POC) is defined as the carbon mass fraction obtained at T= 870°C under a pure helium environment using the thermal separation method [Huang et al., 2006]. Since POC mass is generally proportional to the amount of oxygenated OC, studying the relationships among OC, EC, POC, as well as OM/OC and mod BC/EC ratios may help us understand the mechanisms of aerosol aging from different emission sources. Two 1-month field studies were conducted at a rural site in southern Ontario (NW of Toronto) during fall 2005 and spring 2007. Quartz filter samples were collected and analyzed for OC, POC, and EC concentrations using a thermal/optical method [Huang et al., 2006]. Together with the total organic matter measured by an Aerodyne Aerosol Mass Spectrometer (AMS) and the absorption coefficient obtained from a Particle Soot Absorption Photometer (PSAP), the OM/OC and mod BC/EC ratios for ambient aerosols were obtained. Our results show that when air mass was mainly from south, OC, POC, and EC were relatively high, with average ratios of OC/EC, OM/OC, and POC/EC as 1.94, 1.41, and 0.52, respectively; this indicates significant anthropogenic impacts and relatively large portion of oxygenated OC, which might be due to either primary emissions or photo-chemical reactions occurred in a short period of time. When air mass was mainly from north, OC, POC, and EC were much lower, with average ratios of OC/EC, OM/OC, and POC/EC as 3.10, 1.20, and 0.79, respectively; this suggests less influence from anthropogenic emissions and relatively aged air mass from biogenic-source dominated clean air. Using POC, we estimate the specific attenuation at the site to be 5.8 m2 g-1 independent of the air mass origin. The relationships among OM/OC, mod BC/EC, and POC will be further discussed. References: Huang, L., Brook, J.R., Zhang, W., Li, S.M., Graham, L., Ernst, D., Chivulescu, A., and Lu, G. (2006) Stable isotope measurements of carbon fractions (OC/EC) in airborne particulate: a new dimension for source characterization and apportionment, Atmospheric Environment, 40, 2690-2705.

AFTOMS Technology Issues and Alternatives Report

DOT National Transportation Integrated Search

1989-12-01

This report was prepared to document the findings from the Proof of Concept (POC) work done in FY89 and the early part of FY90 on the US Air Force Technical Order Management System (AFTOMS) project. Objectives of the POC work were: Further developmen...

Greenland Ice Sheet exports labile organic carbon to the Arctic oceans

NASA Astrophysics Data System (ADS)

Lawson, E. C.; Wadham, J. L.; Tranter, M.; Stibal, M.; Lis, G. P.; Butler, C. E. H.; Laybourn-Parry, J.; Nienow, P.; Chandler, D.; Dewsbury, P.

2013-12-01

Runoff from small glacier systems contains dissolved organic carbon (DOC), rich in protein-like, low molecular weight (LMW) compounds, designating glaciers as an important source of bioavailable carbon for downstream heterotrophic activity. Fluxes of DOC and particulate organic carbon (POC) exported from large Greenland catchments, however, remain unquantified, despite the Greenland Ice Sheet (GrIS) being the largest source of global glacial runoff (ca. 400 km3 yr-1). We report high and episodic fluxes of POC and DOC from a large (1200 km2) GrIS catchment during contrasting melt seasons. POC dominates organic carbon (OC) export (70-89% on average), is sourced from the ice sheet bed and contains a significant bioreactive component (9% carbohydrates). A major source for the "bioavailable" (free carbohydrates) LMW-DOC fraction is microbial activity on the ice sheet surface, with some further addition of LMW-DOC to meltwaters by biogeochemical processes at the ice sheet bed. The bioavailability of the exported DOC (30-58%) to downstream marine microorganisms is similar to that reported from other glacial watersheds. Annual fluxes of DOC and free carbohydrates during two melt seasons were similar, despite the ~ 2 fold difference in runoff fluxes, suggesting production-limited DOC sources. POC fluxes were also insensitive to an increase in seasonal runoff volumes, indicating supply-limitation of suspended sediment in runoff. Scaled to the GrIS, the combined DOC and POC fluxes (0.13-0.17 Tg C yr-1 DOC, 0.36-1.52 Tg C yr-1 mean POC) are of a similar order of magnitude to a large Arctic river system, and hence represent an important OC source to the North Atlantic, Greenland and Labrador Seas.

Accuracy of point-of-care serum creatinine devices for detecting patients at risk of contrast-induced nephropathy: a critical overview.

PubMed

Martínez Lomakin, Felipe; Tobar, Catalina

2014-12-01

Contrast-induced nephropathy (CIN) is a common event in hospitals, with reported incidences ranging from 1 to 30%. Patients with underlying kidney disease have an increased risk of developing CIN. Point-of-care (POC) creatinine devices are handheld devices capable of providing quantitative data on a patient's kidney function that could be useful in stratifying preventive measures. This overview aims to synthesize the current evidence on diagnostic accuracy and clinical utility of POC creatinine devices in detecting patients at risk of CIN. Five databases were searched for diagnostic accuracy studies or clinical trials that evaluated the usefulness of POC devices in detecting patients at risk of CIN. Selected articles were critically appraised to assess their individual risk of bias by the use of standard criteria; 13 studies were found that addressed the diagnostic accuracy or clinical utility of POC creatinine devices. Most studies incurred a moderate to high risk of bias. Overall concordance between POC devices and reference standards (clinical laboratory procedures) was found to be moderate, with 95% limits of agreement often lying between -35.4 and +35.4 µmol/L (-0.4 and +0.4 mg/dL). Concordance was shown to decrease with worsening kidney function. Data on the clinical utility of these devices were limited, but a significant reduction in time to diagnosis was reported in two studies. Overall, POC creatinine devices showed a moderate concordance with standard clinical laboratory creatinine measurements. Several biases could have induced optimism in these estimations. Results obtained from these devices may be unreliable in cases of severe kidney failure. Randomized trials are needed to address the clinical utility of these devices.

Particulate organic matter quality influences nitrate retention and denitrification in stream sediments: evidence from a carbon burial experiment

USGS Publications Warehouse

Stelzer, Robert S.; Scott, J. Thad; Bartsch, Lynn; Parr, Thomas B.

2014-01-01

Organic carbon supply is linked to nitrogen transformation in ecosystems. However, the role of organic carbon quality in nitrogen processing is not as well understood. We determined how the quality of particulate organic carbon (POC) influenced nitrogen transformation in stream sediments by burying identical quantities of varying quality POC (northern red oak (Quercus rubra) leaves, red maple (Acer rubrum) leaves, red maple wood) in stream mesocosms and measuring the effects on nitrogen retention and denitrification compared to a control of combusted sand. We also determined how POC quality affected the quantity and quality of dissolved organic carbon (DOC) and dissolved oxygen concentration in groundwater. Nitrate and total dissolved nitrogen (TDN) retention were assessed by comparing solute concentrations and fluxes along groundwater flow paths in the mesocosms. Denitrification was measured by in situ changes in N2 concentrations (using MIMS) and by acetylene block incubations. POC quality was measured by C:N and lignin:N ratios and DOC quality was assessed by fluorescence excitation emission matrix spectroscopy. POC quality had strong effects on nitrogen processing. Leaf treatments had much higher nitrate retention, TDN retention and denitrification rates than the wood and control treatments and red maple leaf burial resulted in higher nitrate and TDN retention rates than burial of red oak leaves. Leaf, but not wood, burial drove pore water to severe hypoxia and leaf treatments had higher DOC production and different DOC chemical composition than the wood and control treatments. We think that POC quality affected nitrogen processing in the sediments by influencing the quantity and quality of DOC and redox conditions. Our results suggest that the type of organic carbon inputs can affect the rates of nitrogen transformation in stream ecosystems.

Dynamics of particulate organic matter composition in coastal systems: Forcing of spatio-temporal variability at multi-systems scale

NASA Astrophysics Data System (ADS)

Liénart, Camilla; Savoye, Nicolas; David, Valérie; Ramond, Pierre; Rodriguez Tress, Paco; Hanquiez, Vincent; Marieu, Vincent; Aubert, Fabien; Aubin, Sébastien; Bichon, Sabrina; Boinet, Christophe; Bourasseau, Line; Bozec, Yann; Bréret, Martine; Breton, Elsa; Caparros, Jocelyne; Cariou, Thierry; Claquin, Pascal; Conan, Pascal; Corre, Anne-Marie; Costes, Laurence; Crouvoisier, Muriel; Del Amo, Yolanda; Derriennic, Hervé; Dindinaud, François; Duran, Robert; Durozier, Maïa; Devesa, Jérémy; Ferreira, Sophie; Feunteun, Eric; Garcia, Nicole; Geslin, Sandrine; Grossteffan, Emilie; Gueux, Aurore; Guillaudeau, Julien; Guillou, Gaël; Jolly, Orianne; Lachaussée, Nicolas; Lafont, Michel; Lagadec, Véronique; Lamoureux, Jézabel; Lauga, Béatrice; Lebreton, Benoît; Lecuyer, Eric; Lehodey, Jean-Paul; Leroux, Cédric; L'Helguen, Stéphane; Macé, Eric; Maria, Eric; Mousseau, Laure; Nowaczyk, Antoine; Pineau, Philippe; Petit, Franck; Pujo-Pay, Mireille; Raimbault, Patrick; Rimmelin-Maury, Peggy; Rouaud, Vanessa; Sauriau, Pierre-Guy; Sultan, Emmanuelle; Susperregui, Nicolas

2018-03-01

In costal systems, particulate organic matter (POM) results from a multiplicity of sources having their respective dynamics in terms of production, decomposition, transport and burial. The POM pool experiences thus considerable spatial and temporal variability. In order to better understand this variability, the present study employs statistical multivariate analyses to investigate links between POM composition and environmental forcings for a panel of twelve coastal systems distributed along the three maritime regions of France and monitored weekly to monthly for 1 to 8 years. At multi-system scale, two main gradients of POC composition have been identified: a 'Continent-Ocean' gradient associated with hydrodynamics, sedimentary dynamics and depth of the water column, and a gradient of trophic status related to nutrient availability. At local scale, seasonality of POC composition appears to be station-specific but still related to part of the above-mentioned forcings. A typology of systems was established by coupling spatial and temporal variability of POC composition. Four groups were highlighted: (1) the estuarine stations where POC composition is dominated by terrestrial POM and driven by hydrodynamics and sedimentary processes, (2) the oligotrophic systems, characterized by the contribution of diazotrophs due to low nutrient availability, and the marine meso/eutroph systems whose POC composition is (3) either deeply dominated by phytoplankton or (4) dominated by phytoplankton but where the contribution of continental and benthic POC is not negligible and is driven by hydrodynamics, sedimentary processes and the height of the water column. Finally, the present study provides several insights into the different forcings to POM composition and dynamics in temperate coastal systems at local and multi-system scales. This work also presents a methodological approach that establishes statistical links between forcings and POM composition, helping to gain more objectively insight of forcings.

Permafrost Organic Carbon Mobilization From the Watershed to the Colville River Delta: Evidence From 14C Ramped Pyrolysis and Lignin Biomarkers

NASA Astrophysics Data System (ADS)

Zhang, Xiaowen; Bianchi, Thomas S.; Cui, Xingqian; Rosenheim, Brad E.; Ping, Chien-Lu; Hanna, Andrea J. M.; Kanevskiy, Mikhail; Schreiner, Kathryn M.; Allison, Mead A.

2017-11-01

The deposition of terrestrial-derived permafrost particulate organic carbon (POC) has been recorded in major Arctic river deltas. However, associated transport pathways of permafrost POC from the watershed to the coast have not been well constrained. Here we utilized a combination of ramped pyrolysis-oxidation radiocarbon analysis (RPO 14C) along with lignin biomarkers, to track the linkages between soils and river and delta sediments. Surface and deep soils showed distinct RPO thermographs which may be related to degradation and organo-mineral interaction. Soil material in the bed load of the river channel was mostly derived from deep old permafrost. Both surface and deep soils were transported and deposited to the coast. Hydrodynamic sorting and barrier island protection played important roles in terrestrial-derived permafrost POC deposition near the coast. On a large scale, ice processes (e.g., ice gauging and strudel scour) and ocean currents controlled the transport and distribution of permafrost POC on the Beaufort Shelf.

Two novel POC1A mutations in the primordial dwarfism, SOFT syndrome: Clinical homogeneity but also unreported malformations.

PubMed

Barraza-García, Jimena; Iván Rivera-Pedroza, Carlos; Salamanca, Luis; Belinchón, Alberta; López-González, Vanesa; Sentchordi-Montané, Lucía; del Pozo, Ángela; Santos-Simarro, Fernando; Campos-Barros, Ángel; Lapunzina, Pablo; Guillén-Navarro, Encarna; González-Casado, Isabel; García-Miñaur, Sixto; Heath, Karen E

2016-01-01

Primordial dwarfism encompasses rare conditions characterized by severe intrauterine growth retardation and growth deficiency throughout life. Recently, three POC1A mutations have been reported in six families with the primordial dwarfism, SOFT syndrome (Short stature, Onychodysplasia, Facial dysmorphism, and hypoTrichosis). Using a custom-designed Next-generation sequencing skeletal dysplasia panel, we have identified two novel homozygous POC1A mutations in two individuals with primordial dwarfism. The severe growth retardation and the facial profiles are strikingly similar between our patients and those described previously. However, one of our patients was diagnosed with severe foramen magnum stenosis and subglottic tracheal stenosis, malformations not previously associated with this syndrome. Our findings confirm that POC1A mutations cause SOFT syndrome and that mutations in this gene should be considered in patients with severe pre- and postnatal short stature, symmetric shortening of long bones, triangular facies, sparse hair and short, thickened distal phalanges. © 2015 Wiley Periodicals, Inc.

POC1A Truncation Mutation Causes a Ciliopathy in Humans Characterized by Primordial Dwarfism

PubMed Central

Shaheen, Ranad; Faqeih, Eissa; Shamseldin, Hanan E.; Noche, Ramil R.; Sunker, Asma; Alshammari, Muneera J.; Al-Sheddi, Tarfa; Adly, Nouran; Al-Dosari, Mohammed S.; Megason, Sean G.; Al-Husain, Muneera; Al-Mohanna, Futwan; Alkuraya, Fowzan S.

2012-01-01

Primordial dwarfism (PD) is a phenotype characterized by profound growth retardation that is prenatal in onset. Significant strides have been made in the last few years toward improved understanding of the molecular underpinning of the limited growth that characterizes the embryonic and postnatal development of PD individuals. These include impaired mitotic mechanics, abnormal IGF2 expression, perturbed DNA-damage response, defective spliceosomal machinery, and abnormal replication licensing. In three families affected by a distinct form of PD, we identified a founder truncating mutation in POC1A. This gene is one of two vertebrate paralogs of POC1, which encodes one of the most abundant proteins in the Chlamydomonas centriole proteome. Cells derived from the index individual have abnormal mitotic mechanics with multipolar spindles, in addition to clearly impaired ciliogenesis. siRNA knockdown of POC1A in fibroblast cells recapitulates this ciliogenesis defect. Our findings highlight a human ciliopathy syndrome caused by deficiency of a major centriolar protein. PMID:22840364

Flocculation of organic carbon from headwaters to estuary - the impact of soil erosion, water quality and land use on carbon transformation processes in eight streams draining Exmoor, UK

NASA Astrophysics Data System (ADS)

Snoalv, J.; Groeneveld, M.; Quine, T. A.; Tranvik, L.

2017-12-01

Flocculation of dissolved organic carbon (DOC) in streams and rivers is a process that contributes to the pool of particulate organic carbon (POC) in the aquatic system. In low-energy waters the increased sedimentation rates of this higher-density fraction of organic carbon (OC) makes POC important in allocating organic carbon into limnic storage, which subsequently influences emissions of greenhouse gases from the continental environment to the atmosphere. Allochthonous OC, derived from the terrestrial environment by soil erosion and litterfall, import both mineral aggregate-bound and free OC into freshwaters, which comprise carbon species of different quality and recalcitrance than autochthonous in-stream produced OC, such as from biofilms, aquatic plants and algae. Increased soil erosion due to land use change (e.g. agriculture, deforestation etc.) influences the input of allochthonous OC, which can lead to increased POC formation and sedimentation of terrestrial OC at flocculation boundaries in the landscape, i.e. where coagulation and flocculation processes are prone to occur in the water column. This study investigates the seasonal variation in POC content and flocculation capacity with respect to water quality (elemental composition) in eight river systems (four agricultural and four wooded streams) with headwaters in Exmoor, UK, that drain managed and non-managed land into Bristol Channel. Through flocculation experiments the samples were allowed to flocculate by treatments with added clay and salt standards that simulate the flocculation processes by 1) increased input of sediment into streams, and 2) saline mixing at the estuarine boundary, in order to quantify floc production and investigate POC quality by each process respectively. The results show how floc production, carbon quality and incorporation (e.g. complexation) of metals and rare earth elements (REE) in produced POC and remaining DOC in solution vary in water samples over the season and how these are related to different flocculation processes and affected by land use. This study improves our understanding on OC flocculation dynamics on a local catchment scale and how POC fate is affected by changed water quality in streams perturbed by land use change.

TH-E-17A-06: Anatomical-Adaptive Compressed Sensing (AACS) Reconstruction for Thoracic 4-Dimensional Cone-Beam CT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shieh, C; Kipritidis, J; OBrien, R

2014-06-15

Purpose: The Feldkamp-Davis-Kress (FDK) algorithm currently used for clinical thoracic 4-dimensional (4D) cone-beam CT (CBCT) reconstruction suffers from noise and streaking artifacts due to projection under-sampling. Compressed sensing theory enables reconstruction of under-sampled datasets via total-variation (TV) minimization, but TV-minimization algorithms such as adaptive-steepest-descent-projection-onto-convex-sets (ASD-POCS) often converge slowly and are prone to over-smoothing anatomical details. These disadvantages can be overcome by incorporating general anatomical knowledge via anatomy segmentation. Based on this concept, we have developed an anatomical-adaptive compressed sensing (AACS) algorithm for thoracic 4D-CBCT reconstruction. Methods: AACS is based on the ASD-POCS framework, where each iteration consists of a TV-minimizationmore » step and a data fidelity constraint step. Prior to every AACS iteration, four major thoracic anatomical structures - soft tissue, lungs, bony anatomy, and pulmonary details - were segmented from the updated solution image. Based on the segmentation, an anatomical-adaptive weighting was applied to the TV-minimization step, so that TV-minimization was enhanced at noisy/streaky regions and suppressed at anatomical structures of interest. The image quality and convergence speed of AACS was compared to conventional ASD-POCS using an XCAT digital phantom and a patient scan. Results: For the XCAT phantom, the AACS image represented the ground truth better than the ASD-POCS image, giving a higher structural similarity index (0.93 vs. 0.84) and lower absolute difference (1.1*10{sup 4} vs. 1.4*10{sup 4}). For the patient case, while both algorithms resulted in much less noise and streaking than FDK, the AACS image showed considerably better contrast and sharpness of the vessels, tumor, and fiducial marker than the ASD-POCS image. In addition, AACS converged over 50% faster than ASD-POCS in both cases. Conclusions: The proposed AACS algorithm was shown to reconstruct thoracic 4D-CBCT images more accurately and with faster convergence compared to ASD-POCS. The superior image quality and rapid convergence makes AACS promising for future clinical use.« less

Requirements for Successful Adoption of a Glucose Measurement System Into a Hospital POC Program.

PubMed

Füzéry, Anna K; Cembrowski, George S

2016-07-01

Widespread and successful implementation of any glucose measurement system in a hospital point-of-care (POC) program requires a number of features in addition to accurate and reliable analytical performance. Such features include, but are not limited to, a system's glucose-hematocrit dependence, durability, information technology capabilities, and battery capacity and battery life. While the study of Ottiger et al in this issue supports the analytical accuracy and reliability of Bayer's CONTOUR XT® blood glucose monitoring system, the suitability of other features of this system for a hospital POC program remains to be established. © 2016 Diabetes Technology Society.

Nature of POC transport in a mangrove ecosystem: A carbon stable isotopic study

NASA Astrophysics Data System (ADS)

Rezende, C. E.; Lacerda, L. D.; Ovall, A. R. C.; Silva, C. A. R.; Martinelli, L. A.

1990-06-01

The isotopic composition of particulate organic carbon (POC) was studied during five tidal cycles in a mangrove creek of Sepetiba Bay, Rio de Janeiro, Brazil. The results show that a mixture of organic carbon from mangrove and marine origins is always present in the creek. Mean mangrove contribution to the POC varied from 16% to 100% and was dependent on tidal amplitude. The results suggest that oceanic carbon can be an important component of carbon balance in mangrove ecosystems. Therefore, earlier carbon balance studies from mangroves which did not include measurements of carbon isotopic composition should be interpreted with care.

Flexible Substrate-Based Devices for Point-of-Care Diagnostics.

PubMed

Wang, ShuQi; Chinnasamy, Thiruppathiraja; Lifson, Mark A; Inci, Fatih; Demirci, Utkan

2016-11-01

Point-of-care (POC) diagnostics play an important role in delivering healthcare, particularly for clinical management and disease surveillance in both developed and developing countries. Currently, the majority of POC diagnostics utilize paper substrates owing to affordability, disposability, and mass production capability. Recently, flexible polymer substrates have been investigated due to their enhanced physicochemical properties, potential to be integrated into wearable devices with wireless communications for personalized health monitoring, and ability to be customized for POC diagnostics. Here, we focus on the latest advances in developing flexible substrate-based diagnostic devices, including paper and polymers, and their clinical applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Neurotoxicity of Legacy and Emerging Persistent Organic Chemicals: A Proteomic Approach to Understand Adverse Outcome Pathways

EPA Science Inventory

During the past century, a vast number of persistent organic chemicals (POCs) have been manufactured and used in industrial, agricultural, public health, consumer products and other applications. Widespread use of legacy POCs, including chlorinated, brominated and fluorinated com...

Exploring the clonal evolution of CD133/aldehyde-dehydrogenase-1 (ALDH1)-positive cancer stem-like cells from primary to recurrent high-grade serous ovarian cancer (HGSOC). A study of the Ovarian Cancer Therapy-Innovative Models Prolong Survival (OCTIPS) Consortium.

PubMed

Ruscito, Ilary; Cacsire Castillo-Tong, Dan; Vergote, Ignace; Ignat, Iulia; Stanske, Mandy; Vanderstichele, Adriaan; Ganapathi, Ram N; Glajzer, Jacek; Kulbe, Hagen; Trillsch, Fabian; Mustea, Alexander; Kreuzinger, Caroline; Benedetti Panici, Pierluigi; Gourley, Charlie; Gabra, Hani; Kessler, Mirjana; Sehouli, Jalid; Darb-Esfahani, Silvia; Braicu, Elena Ioana

2017-07-01

High-grade serous ovarian cancer (HGSOC) causes 80% of all ovarian cancer (OC) deaths. In this setting, the role of cancer stem-like cells (CSCs) is still unclear. In particular, the evolution of CSC biomarkers from primary (pOC) to recurrent (rOC) HGSOCs is unknown. Aim of this study was to investigate changes in CD133 and aldehyde dehydrogenase-1 (ALDH1) CSC biomarker expression in pOC and rOC HGSOCs. Two-hundred and twenty-four pOC and rOC intrapatient paired tissue samples derived from 112 HGSOC patients were evaluated for CD133 and ALDH1 expression using immunohistochemistry (IHC); pOCs and rOCs were compared for CD133 and/or ALDH1 levels. Expression profiles were also correlated with patients' clinicopathological and survival data. Some 49.1% of the patient population (55/112) and 37.5% (42/112) pOCs were CD133+ and ALDH1+ respectively. CD133+ and ALDH1+ samples were detected in 33.9% (38/112) and 36.6% (41/112) rOCs. CD133/ALDH1 coexpression was observed in 23.2% (26/112) and 15.2% (17/112) of pOCs and rOCs respectively. Pairwise analysis showed a significant shift of CD133 staining from higher (pOCs) to lower expression levels (rOCs) (p < 0.0001). Furthermore, all CD133 + pOC patients were International Federation of Gynaecology and Obstetrics (FIGO)-stage III/IV (p < 0.0001) and had significantly worse progression-free interval (PFI) (p = 0.04) and overall survival (OS) (p = 0.02). On multivariate analysis, CD133/ALDH1 coexpression in pOCs was identified as independent prognostic factor for PFI (HR: 1.64; 95% CI: 1.03-2.60; p = 0.036) and OS (HR: 1.71; 95% CI: 1.01-2.88; p = 0.045). Analysis on 52 pts patients with known somatic BRCA status revealed that BRCA mutations did not influence CSC biomarker expression. The study showed that CD133/ALDH1 expression impacts HGSOC patients' survival and first suggests that CSCs might undergo phenotypic change during the disease course similarly to non stem-like cancer cells, providing also a first evidence that there is no correlation between CSCs and BRCA status. Copyright © 2017 Elsevier Ltd. All rights reserved.

Spatial and temporal variability in coccolithophore abundance and production of PIC and POC in the NE subarctic Pacific during El Niño (1998), La Niña (1999) and 2000

NASA Astrophysics Data System (ADS)

Lipsen, M. S.; Crawford, D. W.; Gower, J.; Harrison, P. J.

2007-10-01

Seasonal variations in coccolithophore abundance, chlorophyll, nutrients and production of particulate organic and inorganic carbon (POC and PIC) were determined along a coastal to oceanic east-west transect (Line P) culminating at Ocean Station Papa in the northeastern subarctic Pacific between 1998 and 2000. Offshore stations generally exhibited low seasonality in chlorophyll concentrations, with moderate seasonality in POC production. Near shelf stations showed a similar pattern to offshore stations, but were also characterized by sporadic events of higher POC productivity. During the 1998 El Niño, June was characterized by low chlorophyll and POC productivity along the transect, presumably as a result of depleted surface nitrate. In contrast, during the 1999 La Niña, and in 2000, higher POC productivity and surface nitrate occurred along the transect in June. Chlorophyll and POC productivity were similar in late summer in all 3 years. The coccolithophore population was usually numerically dominated by Emiliania huxleyi, particularly in June. Along the transect, abundance of coccolithophores was much higher in June during the 1998 El Niño (mean of 221 cells ml -1) than in the 1999 La Niña (mean of 40 cells ml -1), with their abundance in late summers of both years being very low. Abundances were even higher along the transect in June and the late summer of 2000 with sporadic ‘blooms’ of >1000 cells ml -1 at some stations (cruise averages 395 and 552 cell ml -1, respectively). Production rates of PIC did not consistently correlate with areas of high coccolithophore abundance. PIC production was high (100-250 mg C m -2 d -1) along the transect during June 1998, and low (1-40 mg C m -2 d -1) during both winters, June 1999 and during late summers of 1998 and 1999. The year 2000 was more complicated, with high rates of PIC production accompanying high abundance of coccolithophores in late summer, but lower rates of PIC production accompanying high coccolithophore numbers in June. Our data suggest that the abundance of coccolithophores and the production rates of PIC in the subarctic are higher than previously thought. Occasional PIC:POC production ratios of 1 or greater in 1998 and 2000 suggest that coccolithophores in this region could have a significant impact on the efficiency of the biological carbon pump.

Step-by-step strategy in the management of residual hepatolithiasis using post-operative cholangioscopy

PubMed Central

Wen, Xu-dong; Wang, Tao; Huang, Zhu; Zhang, Hong-jian; Zhang, Bing-yin; Tang, Li-jun; Liu, Wei-hui

2017-01-01

Hepatolithiasis is the presence of calculi within the intrahepatic bile duct specifically located proximal to the confluence of the left and right hepatic ducts. The ultimate goal of hepatolithiasis treatment is the complete removal of the stone, the correction of the associated strictures and the prevention of recurrent cholangitis. Although hepatectomy could effectively achieve the above goals, it can be restricted by the risk of insufficient residual liver volume, and has a 15.6% rate of residual hepatolithiasis. With improvements in minimally invasive surgery, post-operative cholangioscopy (POC), provides an additional option for hepatolithiasis treatment with higher clearance rate and fewer severe complications. POC is very safe, and can be performed repeatedly until full patient benefit is achieved. During POC three main steps are accomplished: first, the analysis of the residual hepatolithiasis distribution indirectly by imaging methods or directly endoscopic observation; second, the establishment of the surgical pathway to relieve the strictures; and third, the removal of the stone by a combination of different techniques such as simple basket extraction, mechanical fragmentation, electrohydraulic lithotripsy or laser lithotripsy, among others. In summary, a step-by-step strategy of POC should be put forward to standardize the procedures, especially when dealing with complicated residual hepatolithiasis. This review briefly summarizes the classification, management and complications of hepatolithiasis during the POC process. PMID:29147136

Hemocompatibility evaluation of poly(1,8-octanediol citrate) blend polyethersulfone membranes.

PubMed

Zailani, Muhamad Zulhilmi; Ismail, Ahmad Fauzi; Sheikh Abdul Kadir, Siti Hamimah; Othman, Mohd Hafiz Dzarfan; Goh, Pei Sean; Hasbullah, Hasrinah; Abdullah, Mohd Sohaimi; Ng, Be Cheer; Kamal, Fatmawati

2017-05-01

In this study, poly (1,8-octanediol citrate) (POC) was used to modify polyethersulfone (PES)-based membrane to enhance its hemocompatibility. Different compositions of POC (0-3%) were added into the polyethersulfone (PES) dope solutions and polyvinylpyrrolidone (PVP) was used as pore forming agent. The hemocompatible POC modified PES membranes were fabricated through phase-inversion technique. The prepared membranes were characterized using attenuated total reflectance-Fourier transform infrared (ATR-FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Atomic-force microscopy (AFM), contact angle, Zeta-potential, membrane porosity and pore size and pure water flux (PWF) and BSA rejection. The hemocompatibility of the modified PES membranes was evaluated by human serum fibrinogen (FBG) protein adsorption, platelet adhesion, activated partial thromboplastin time (APTT) and prothrombin time (PT), and thrombin-antithrombin III (TAT), complement (C3a and C5a) activation and Ca 2+ absorption on membrane. Results showed that by increasing POC concentration, FBG adsorption was reduced, less platelets adhesion, prolonged APTT and PT, lower TAT, C5a and C3a activation and absorb more Ca 2+ ion. These results indicated that modification of PES with POC has rendered improved hemocompatibility properties for potential application in the field of blood purification, especially in hemodialysis. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1510-1520, 2017. © 2017 Wiley Periodicals, Inc.

Short-Term Effects of Tillage Practices on Soil Organic Carbon Turnover Assessed by δ 13C Abundance in Particle-Size Fractions of Black Soils from Northeast China

PubMed Central

Zhang, Xiaoping; Chen, Xuewen

2014-01-01

The combination of isotope trace technique and SOC fractionation allows a better understanding of SOC dynamics. A five-year tillage experiment consisting of no-tillage (NT) and mouldboard plough (MP) was used to study the changes in particle-size SOC fractions and corresponding δ 13C natural abundance to assess SOC turnover in the 0–20 cm layer of black soils under tillage practices. Compared to the initial level, total SOC tended to be stratified but showed a slight increase in the entire plough layer under short-term NT. MP had no significant impacts on SOC at any depth. Because of significant increases in coarse particulate organic carbon (POC) and decreases in fine POC, total POC did not remarkably decrease under NT and MP. A distinct increase in silt plus clay OC occurred in NT plots, but not in MP plots. However, the δ 13C abundances of both coarse and fine POC increased, while those of silt plus clay OC remained almost the same under NT. The C derived from C3 plants was mainly associated with fine particles and much less with coarse particles. These results suggested that short-term NT and MP preferentially enhanced the turnover of POC, which was considerably faster than that of silt plus clay OC. PMID:25162052

Evaluation of early efficacy endpoints for proof-of-concept trials.

PubMed

Chen, Cong; Sun, Linda; Li, Chih-Lin

2013-03-11

A Phase II proof-of-concept (POC) trial usually uses an early efficacy endpoint other than a clinical endpoint as the primary endpoint. Because of the advancement in bioscience and technology, which has yielded a number of new surrogate biomarkers, drug developers often have more candidate endpoints to choose from than they can handle. As a result, selection of endpoint and its effect size as well as choice of type I/II error rates are often at the center of heated debates in design of POC trials. While optimization of the trade-off between benefit and cost is the implicit objective in such a decision-making process, it is seldom explicitly accounted for in practice. In this research note, motivated by real examples from the oncology field, we provide practical measures for evaluation of early efficacy endpoints (E4) for POC trials. We further provide optimal design strategies for POC trials that include optimal Go-No Go decision criteria for initiation of Phase III and optimal resource allocation strategies for conducting multiple POC trials in a portfolio under fixed resources. Although oncology is used for illustration purpose, the same idea developed in this research note also applies to similar situations in other therapeutic areas or in early-stage drug development in that a Go-No Go decision has to rely on limited data from an early efficacy endpoint and cost-effectiveness is the main concern.

Smartphone-Based Dual-Modality Imaging System for Quantitative Detection of Color or Fluorescent Lateral Flow Immunochromatographic Strips

NASA Astrophysics Data System (ADS)

Hou, Yafei; Wang, Kan; Xiao, Kun; Qin, Weijian; Lu, Wenting; Tao, Wei; Cui, Daxiang

2017-04-01

Nowadays, lateral flow immunochromatographic assays are increasingly popular as a diagnostic tool for point-of-care (POC) test based on their simplicity, specificity, and sensitivity. Hence, quantitative detection and pluralistic popular application are urgently needed in medical examination. In this study, a smartphone-based dual-modality imaging system was developed for quantitative detection of color or fluorescent lateral flow test strips, which can be operated anywhere at any time. In this system, the white and ultra-violet (UV) light of optical device was designed, which was tunable with different strips, and the Sobel operator algorithm was used in the software, which could enhance the identification ability to recognize the test area from the background boundary information. Moreover, this technology based on extraction of the components from RGB format (red, green, and blue) of color strips or only red format of the fluorescent strips can obviously improve the high-signal intensity and sensitivity. Fifty samples were used to evaluate the accuracy of this system, and the ideal detection limit was calculated separately from detection of human chorionic gonadotropin (HCG) and carcinoembryonic antigen (CEA). The results indicated that smartphone-controlled dual-modality imaging system could provide various POC diagnoses, which becomes a potential technology for developing the next-generation of portable system in the near future.

Numerical modeling of benthic processes in the deep Arabian Sea

NASA Astrophysics Data System (ADS)

Luff, Roger; Wallmann, Klaus; Grandel, Sibylle; Schlüter, Michael

Aerobic and anaerobic degradation of particulate organic carbon (POC) and carbonate equilibria in deep-sea surface sediments were studied at five stations located in the western (WAST), northern (NAST), eastern (EAST), central (CAST), and southern (SAST) Arabian Sea. In situ oxygen fluxes, porewater profiles of dissolved oxygen, nitrate, and Mn, pH profiles and solid-phase profiles of particulate organic carbon, Mn, and Fe were measured at each station. An early diagenesis model was applied to simulate the degradation and dissolution processes and to determine the benthic fluxes of POC, oxygen, nitrate, phosphate, CO 2, HCO 3-, and CO 32-. The benthic data sets were evaluated to constrain the POC input and the kinetics of organic matter degradation used in the model. The modeling showed that the POC rain rate to the seafloor is high at the western and northern stations, and decreases towards the southeast. At stations located in the vicinity of continental margins (WAST, NAST, EAST), 5-7% of the primary production sinks to the deep-sea floor. This unusually high POC rain is either caused by dust particles that accelerate and amplify the particle export from the euphotic zone or by rapid lateral transport processes. At the more remote stations (CAST, SAST) that receive lower dust inputs, the rain efficiency decreases to 1-4%. In the model, organic matter was separated into three fractions (3-G-model) that differ considerably in reactivity. At stations WAST, NAST, EAST, and CAST the bulk of organic matter is composed of extremely labile organic matter with a first order degradation constant ( k) of 15-30 yr -1. The moderately labile fraction with a kinetic constant of 0.2-0.6 yr -1 dominates the POC input at the oligotrophic station in the southern Arabian Sea (SAST). The third fraction that has a very low reactivity ( k=2-5×10 -4 yr -1) is only a minor component of the POC rain at all investigated stations. More than 95% of the organic matter is consumed in aerobic degradation processes. Denitrification and metal oxide reduction only contribute 1-2% to the total POC degradation. At the western station (WAST) a non-negligible portion (2%) of organic matter is consumed via sulfate reduction. The modeling demonstrates that carbonate dissolution is a major process in the deep Arabian Sea; 52-83% of the carbonate rain to the seafloor is dissolved within the surface sediments. In the western Arabian Sea, the monsoon systems produce a strong seasonality in the primary production. Non-steady-state modeling indicates that the benthic oxygen, nutrient, and inorganic carbon fluxes closely follow the seasonal dynamics in primary and export production. This very close benthic-pelagic coupling is established by the extremely labile organic matter fraction that dominates the POC rain to the seafloor. The metabolically released CO 2 induces a seasonal change in carbonate dissolution and carbonate alkalinity fluxes.

Methods for screening Port-Orford-cedar for resistance to Phytophthora lateralis

Treesearch

Everett M. Hansen; Paul Reeser; Wendy Sutton; Richard A. Sniezko

2012-01-01

Port-Orford-cedar (Chamaecyparis lawsoniana (A. Murray) Parl.) (POC) is an economically and ecologically valuable tree in the forests of southwest Oregon and northern California and in the horticultural trade worldwide. Phytophthora lateralis, the aggressive, invasive cause of POC root disease, was introduced to the native...

Spatial and Temporal Trends of Persistent Organic Chemicals with Emphasis on Brominated Flame Retardants

EPA Science Inventory

Rapid growth in chemical and agrochemical industries during the past century have resulted in the release of large numbers of persistent organic chemicals (POCs) into the environment. Since POCs are prevalent in air, water, soil and tissue of organisms throughout the world and r...

76 FR 74840 - Agency Information Collection Activities: Requests for Comments; Clearance of Renewed Approval of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-01

... Personal Oxygen Concentrator (POC) Devices on Board Aircraft AGENCY: Federal Aviation Administration (FAA.... Title: Use of Certain Personal Oxygen Concentrator (POC) Devices on Board Aircraft. Form Numbers: There... physician statement describing the oxygen therapy needed, to determine whether an inflight diversion to an...

Cerulean Warbler Occurrence Atlas for Military Installations

DTIC Science & Technology

2010-04-01

Army Ammuniton Plant (Closed) IN NO 2009 Army IOWA ARMY AMMUNITION PLANT IA UNCERTAIN 2009 USACE J. Percy Priest Lake TN UNCERTAIN 2009 USACE J...Stonewall Jackson Lake WV UNCERTAIN 2009 USACE Summersville Lake WV no POC Army Sunflower Army Ammunition Plant KS no POC USACE Sutton Lake WV UNCERTAIN

Molecular blends of methylated-poly(ethylenimine) and amorphous porous organic cages for SO 2 adsorption

DOE PAGES

Zhu, Guanghui; Carrillo, Jan-Michael Y.; Sujan, Achintya; ...

2018-01-01

Porous organic cage (POCs) are explored as a support for hazardous gas sorbents. The molecular mixing between the POC and methylated poly(ethylene imine) was observed and resulted in the improvement of mass transfer and thermal stability of the composite material.

Estimation of seasonal diurnal variations in primary and secondary organic carbon concentrations in the urban atmosphere: EC tracer and multiple regression approaches

NASA Astrophysics Data System (ADS)

Kim, Woogyung; Lee, Hanlim; Kim, Jhoon; Jeong, Ukkyo; Kweon, Jung

2012-09-01

In order to investigate seasonal and diurnal variation of primary organic carbon (POC) and secondary organic carbon (SOC) concentrations in a megacity, hourly measurements of particulate and gaseous pollutants were carried out in Seoul from January to December 2010. The EC Tracer Method (ECTM) and the Multiple Regression Method (MRM) have been used to estimate seasonal and diurnal concentrations of POC and SOC concentrations. Annual mean SOC concentrations estimated by ECTM (SOCECTM) and MRM (SOCMRM) accounted for 14.61 and 17.21% of TOC concentrations, respectively. Seasonal patterns in SOCMRM were comparable to those of SOCECTM, but the annual average SOCMRM was about 15% greater than that of SOCECTM. In spring, however, a large discrepancy was observed between SOCECTM and SOCMRM, which is thought to be due to a high ozone concentration and primary TOC/EC ratio. Regarding the annual mean diurnal characteristics, POC concentration showed peaks around 10:00 and 00:00 local time that were also observed in diurnal variations of TOC and EC concentrations. Annual mean SOC concentration, however, showed peaks at around 15:00. In the morning over all seasons, we found discrepancies between SOCECTM and SOCMRM due to overestimated SOCECTM concentration. The diurnal variations in SOC concentrations were found to have seasonal characteristics. The diurnal pattern of SOC concentration in spring was similar to that in autumn, and SOC concentrations in all seasons with the exception of winter showed a peak at around 15:00. In summer, however, the SOC concentration peak at around 15:00 was greater by 70%, 81%, and 54% than the peaks seen in spring, autumn, and winter, respectively, which could be explained by the high ozone concentration and strong UV radiation in summer. From 10:00 to 15:00 in summer, the average increase rates in SOCECTM and SOCMRM were 0.39 and 0.24 μg m-3 h-1, respectively. In winter, negligible diurnal variations of estimated SOC concentrations demonstrate that SOC formation is less active than in other seasons. The high concentration level of mean SOC in winter could be attributed to a low mixing height or stagnant atmospheric condition.

Protocol for accuracy of point of care (POC) or in-office urine drug testing (immunoassay) in chronic pain patients: a prospective analysis of immunoassay and liquid chromatography tandem mass spectometry (LC/MS/MS).

PubMed

Manchikanti, Laxmaiah; Malla, Yogesh; Wargo, Bradley W; Cash, Kimberly A; Pampati, Vidyasagar; Damron, Kim S; McManus, Carla D; Brandon, Doris E

2010-01-01

Therapeutic use, overuse, abuse, and diversion of controlled substances in managing chronic non-cancer pain continues to be an issue for physicians and patients. It has been stated that physicians, along with the public and federal, state, and local government; professional associations; and pharmaceutical companies all share responsibility for preventing abuse of controlled prescription drugs. The challenge is to eliminate or significantly curtail abuse of controlled prescription drugs while still assuring the proper treatment of those patients. A number of techniques, instruments, and tools have been described to monitor controlled substance use and abuse. Thus, multiple techniques and tools available for adherence monitoring include urine drug testing in conjunction with prescription monitoring programs and other screening tests. However, urine drug testing is associated with multiple methodological flaws. Multiple authors have provided conflicting results in relation to diagnostic accuracy with differing opinions about how to monitor adherence in a non-systematic fashion. Thus far, there have not been any studies systematically assessing the diagnostic accuracy of immunoassay with laboratory testing. A diagnostic accuracy study of urine drug testing. An interventional pain management practice, a specialty referral center, a private practice setting in the United States. To compare the information obtained by point of care (POC) or in-office urine drug testing (index test) to the information found when all drugs and analytes are tested by liquid chromatography tandem mass spectroscopy (LC/MS/MS) reference test in the same urine sample. The study is designed to include 1,000 patients with chronic pain receiving controlled substances. The primary outcome measure is the diagnostic accuracy. Patients will be tested for various controlled substances, including opioids, benzodiazepines, and illicit drugs. The diagnostic accuracy study is performed utilizing the Standards for Reporting of Diagnostic Accuracy Studies (STARD) initiative which established reporting guidelines for diagnostic accuracy studies to improve the quality of reporting. The prototypical flow diagram of diagnostic accuracy study as described by STARD will be utilized. Results of diagnostic accuracy and correlation of clinical factors in relation to threshold levels, prevalence of abuse, false-positives, false-negatives, influence of other drugs, and demographic characteristics will be calculated. The limitations include lack of availability of POC testing with lower cutoff levels. This article presents a protocol for a diagnostic accuracy study of urine drug testing. The protocol also will permit correlation of various clinical factors in relation to threshold levels, prevalence of abuse, false-positives, false-negatives, influence of other drugs, and demographic characteristics. NCT 01052155.

Portable microfluidic and smartphone-based devices for monitoring of cardiovascular diseases at the point of care.

PubMed

Hu, Jie; Cui, Xingye; Gong, Yan; Xu, Xiayu; Gao, Bin; Wen, Ting; Lu, Tian Jian; Xu, Feng

2016-01-01

Cardiovascular diseases (CVDs) are the main causes of morbidity and mortality in the world where about 4 in every 5 CVD deaths happen in low- and middle-income countries (LMICs). Most CVDs are preventable and curable, which is largely dependent on timely and effective interventions, including diagnosis, prognosis and therapeutic monitoring. However, these interventions are high-cost in high income countries and are usually lacking in LMICs. Thanks to the rapid development of microfluidics and nanotechnology, lots of portable analytical devices are developed for detection of CVDs at the point-of-care (POC). In the meantime, smartphone, as a versatile and powerful handheld tool, has been employed not only as a reader for microfluidic assays, but also as an analyzer for physiological indexes. In this review, we present a comprehensive introduction of the current status and potential development direction on POC diagnostics for CVDs. First of all, we introduce some main facts about CVDs and their standard diagnostic procedures and methods. Second, we discuss about both commercially available POC devices and developed prototypes for detection of CVDs via immunoassays. Subsequently, we report the advances in smartphone-based readout for microfluidic assays. Finally, we present some examples using smartphone, individually or combined with other components or devices, for CVD monitoring. We envision an integrated smartphone-based system capable of functioning blood tests, disease examination, and imaging will come in the future. Copyright © 2016 Elsevier Inc. All rights reserved.

Automated real-time detection of drug-resistant Mycobacterium tuberculosis on a lab-on-a-disc by Recombinase Polymerase Amplification.

PubMed

Law, I L G; Loo, J F C; Kwok, H C; Yeung, H Y; Leung, C C H; Hui, M; Wu, S Y; Chan, H S; Kwan, Y W; Ho, H P; Kong, S K

2018-03-01

With the emergence of multi- and extensive-drug (MDR/XDR) resistant Mycobacterium tuberculosis (M. tb), tuberculosis (TB) persists as one of the world's leading causes of death. Recently, isothermal DNA amplification methods received much attention due to their ease of translation onto portable point-of-care (POC) devices for TB diagnosis. In this study, we aimed to devise a simple yet robust detection method for M. tb. Amongst the numerous up-and-coming isothermal techniques, Recombinase Polymerase Amplification (RPA) was chosen for a real-time detection of TB with or without MDR. In our platform, real-time RPA (RT-RPA) was integrated on a lab-on-a-disc (LOAD) with on-board power to maintain temperature for DNA amplification. Sputa collected from healthy volunteers were spiked with respective target M. tb samples for testing. A limit of detection of 10 2  colony-forming unit per millilitre in 15 min was achieved, making early detection and differentiation of M. tb strains highly feasible in extreme POC settings. Our RT-RPA LOAD platform has also been successfully applied in the differentiation of MDR-TB from H37Ra, an attenuated TB strain. In summary, a quantitative RT-RPA on LOAD assay with a high level of sensitivity was developed as a foundation for further developments in medical bedside and POC diagnostics. Copyright © 2018 Elsevier Inc. All rights reserved.

Fluorescent detection of C-reactive protein using polyamide beads

NASA Astrophysics Data System (ADS)

Jagadeesh, Shreesha; Chen, Lu; Aitchison, Stewart

2016-03-01

Bacterial infection causes Sepsis which is one of the leading cause of mortality in hospitals. This infection can be quantified from blood plasma using C - reactive protein (CRP). A quick diagnosis at the patient's location through Point-of- Care (POC) testing could give doctors the confidence to prescribe antibiotics. In this paper, the development and testing of a bead-based procedure for CRP quantification is described. The size of the beads enable them to be trapped in wells without the need for magnetic methods of immobilization. Large (1.5 mm diameter) Polyamide nylon beads were used as the substrate for capturing CRP from pure analyte samples. The beads captured CRP either directly through adsorption or indirectly by having specific capture antibodies on their surface. Both methods used fluorescent imaging techniques to quantify the protein. The amount of CRP needed to give a sufficient fluorescent signal through direct capture method was found suitable for identifying bacterial causes of infection. Similarly, viral infections could be quantified by the more sensitive indirect capture method. This bead-based assay can be potentially integrated as a disposable cartridge in a POC device due to its passive nature and the small quantities needed.

Surface-enhanced Raman spectroscopy competitive binding biosensor development utilizing surface modification of silver nanocubes and a citrulline aptamer

NASA Astrophysics Data System (ADS)

Walton, Brian M.; Jackson, George W.; Deutz, Nicolaas; Cote, Gerard

2017-07-01

A point-of-care (PoC) device with the ability to detect biomarkers at low concentrations in bodily fluids would have an enormous potential for medical diagnostics outside the central laboratory. One method to monitor analytes at low concentrations is by using surface-enhanced Raman spectroscopy (SERS). In this preliminary study toward using SERS for PoC biosensing, the surface of colloidal silver (Ag) nanocubes has been modified to test the feasibility of a competitive binding SERS assay utilizing aptamers against citrulline. Specifically, Ag nanocubes were functionalized with mercaptobenzoic acid, as well as a heterobifunctional polyethylene glycol linker that forms an amide bond with the amino acid citrulline. After the functionalization, the nanocubes were characterized by zeta-potential, transmission electron microscopy images, ultraviolet/visible spectroscopy, and by SERS. The citrulline aptamers were developed and tested using backscattering interferometry. The data show that our surface modification method does work and that the functionalized nanoparticles can be detected using SERS down to a 24.5 picomolar level. Last, we used microscale thermophoresis to show that the aptamers bind to citrulline with at least a 50 times stronger affinity than other amino acids.

Single-Use, Electricity-Free Amplification Device for Detection of HIV-1

PubMed Central

Curtis, Kelly A.; Rudolph, Donna L.; Morrison, Daphne; Guelig, Dylan; Diesburg, Steven; McAdams, David; Burton, Robert A.; LaBarre, Paul; Owen, Michele

2016-01-01

Early and accurate diagnosis of HIV is key for the reduction of transmission and initiation of patient care. The availability of a rapid nucleic acid test (NAT) for use at the point-of-care (POC) will fill a gap in HIV diagnostics, improving the diagnosis of acute infection and HIV in infants born to infected mothers. In this study, we evaluated the performance of non-instrumented nucleic acid amplification, single-use disposable (NINA-SUD) devices for the detection of HIV-1 in whole blood using reverse-transcription, loop-mediated isothermal amplification (RT-LAMP) with lyophilized reagents. The NINA-SUD heating device harnesses the heat from an exothermic chemical reaction initiated by the addition of saline to magnesium iron powder. Reproducibility was demonstrated between NINA-SUD units and comparable, if not superior, performance for detecting clinical specimens was observed as compared to the thermal cycler. The stability of the lyophilized HIV-1 RT-LAMP reagents was also demonstrated following storage at −20, 4, 25, and 30°C for up to one month. The single-use, disposable NAT minimizes hands-on time and has the potential to facilitate HIV-1 testing in resource-limited settings or at the POC. PMID:27616198

Reduced-gravity environment hardware demonstrations of a prototype miniaturized flow cytometer and companion microfluidic mixing technology.

PubMed

Phipps, William S; Yin, Zhizhong; Bae, Candice; Sharpe, Julia Z; Bishara, Andrew M; Nelson, Emily S; Weaver, Aaron S; Brown, Daniel; McKay, Terri L; Griffin, DeVon; Chan, Eugene Y

2014-11-13

Until recently, astronaut blood samples were collected in-flight, transported to earth on the Space Shuttle, and analyzed in terrestrial laboratories. If humans are to travel beyond low Earth orbit, a transition towards space-ready, point-of-care (POC) testing is required. Such testing needs to be comprehensive, easy to perform in a reduced-gravity environment, and unaffected by the stresses of launch and spaceflight. Countless POC devices have been developed to mimic laboratory scale counterparts, but most have narrow applications and few have demonstrable use in an in-flight, reduced-gravity environment. In fact, demonstrations of biomedical diagnostics in reduced gravity are limited altogether, making component choice and certain logistical challenges difficult to approach when seeking to test new technology. To help fill the void, we are presenting a modular method for the construction and operation of a prototype blood diagnostic device and its associated parabolic flight test rig that meet the standards for flight-testing onboard a parabolic flight, reduced-gravity aircraft. The method first focuses on rig assembly for in-flight, reduced-gravity testing of a flow cytometer and a companion microfluidic mixing chip. Components are adaptable to other designs and some custom components, such as a microvolume sample loader and the micromixer may be of particular interest. The method then shifts focus to flight preparation, by offering guidelines and suggestions to prepare for a successful flight test with regard to user training, development of a standard operating procedure (SOP), and other issues. Finally, in-flight experimental procedures specific to our demonstrations are described.

Cellphone-based hand-held microplate reader for point-of-care ELISA testing (Conference Presentation)

NASA Astrophysics Data System (ADS)

Berg, Brandon; Cortazar, Bingen; Tseng, Derek; Ozkan, Haydar; Feng, Steve; Wei, Qingshan; Chan, Raymond Y.; Burbano, Jordi; Farooqui, Qamar; Lewinski, Michael; Di Carlo, Dino; Garner, Omai B.; Ozcan, Aydogan

2016-03-01

Enzyme-linked immunosorbent assay (ELISA) in a microplate format has been a gold standard first-line clinical test for diagnosis of various diseases including infectious diseases. However, this technology requires a relatively large and expensive multi-well scanning spectrophotometer to read and quantify the signal from each well, hindering its implementation in resource-limited-settings. Here, we demonstrate a cost-effective and handheld smartphone-based colorimetric microplate reader for rapid digitization and quantification of immunoserology-related ELISA tests in a conventional 96-well plate format at the point of care (POC). This device consists of a bundle of 96 optical fibers to collect the transmitted light from each well of the microplate and direct all the transmission signals from the wells onto the camera of the mobile-phone. Captured images are then transmitted to a remote server through a custom-designed app, and both quantitative and qualitative diagnostic results are returned back to the user within ~1 minute per 96-well plate by using a machine learning algorithm. We tested this mobile-phone based micro-plate reader in a clinical microbiology lab using FDA-approved mumps IgG, measles IgG, and herpes simplex virus IgG (HSV-1 and HSV-2) ELISA tests on 1138 remnant patient samples (roughly 50% training and 50% testing), and achieved an overall accuracy of ~99% or higher for each ELISA test. This handheld and cost-effective platform could be immediately useful for large-scale vaccination monitoring in low-infrastructure settings, and also for other high-throughput disease screening applications at POC.

Reduced-gravity Environment Hardware Demonstrations of a Prototype Miniaturized Flow Cytometer and Companion Microfluidic Mixing Technology

PubMed Central

Bae, Candice; Sharpe, Julia Z.; Bishara, Andrew M.; Nelson, Emily S.; Weaver, Aaron S.; Brown, Daniel; McKay, Terri L.; Griffin, DeVon; Chan, Eugene Y.

2014-01-01

Until recently, astronaut blood samples were collected in-flight, transported to earth on the Space Shuttle, and analyzed in terrestrial laboratories. If humans are to travel beyond low Earth orbit, a transition towards space-ready, point-of-care (POC) testing is required. Such testing needs to be comprehensive, easy to perform in a reduced-gravity environment, and unaffected by the stresses of launch and spaceflight. Countless POC devices have been developed to mimic laboratory scale counterparts, but most have narrow applications and few have demonstrable use in an in-flight, reduced-gravity environment. In fact, demonstrations of biomedical diagnostics in reduced gravity are limited altogether, making component choice and certain logistical challenges difficult to approach when seeking to test new technology. To help fill the void, we are presenting a modular method for the construction and operation of a prototype blood diagnostic device and its associated parabolic flight test rig that meet the standards for flight-testing onboard a parabolic flight, reduced-gravity aircraft. The method first focuses on rig assembly for in-flight, reduced-gravity testing of a flow cytometer and a companion microfluidic mixing chip. Components are adaptable to other designs and some custom components, such as a microvolume sample loader and the micromixer may be of particular interest. The method then shifts focus to flight preparation, by offering guidelines and suggestions to prepare for a successful flight test with regard to user training, development of a standard operating procedure (SOP), and other issues. Finally, in-flight experimental procedures specific to our demonstrations are described. PMID:25490614

75 FR 28035 - Privacy Act of 1974; Department of Homeland Security/U.S. Citizenship and Immigration Services...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-19

..., Parent Company or Corporate Company, Name of Company Point of Contact (POC) for E-Verify Usage, POC Phone... information about user system usage. The information collected specifically on users includes: Name (last... improvement efforts and system enhancement planning, which may include conducting surveys, user interviews...

Perception of Competence in Middle School Physical Education: Instrument Development and Validation

ERIC Educational Resources Information Center

Scrabis-Fletcher, Kristin; Silverman, Stephen

2010-01-01

Perception of Competence (POC) has been studied extensively in physical activity (PA) research with similar instruments adapted for physical education (PE) research. Such instruments do not account for the unique PE learning environment. Therefore, an instrument was developed and the scores validated to measure POC in middle school PE. A…

POC1A truncation mutation causes a ciliopathy in humans characterized by primordial dwarfism.

PubMed

Shaheen, Ranad; Faqeih, Eissa; Shamseldin, Hanan E; Noche, Ramil R; Sunker, Asma; Alshammari, Muneera J; Al-Sheddi, Tarfa; Adly, Nouran; Al-Dosari, Mohammed S; Megason, Sean G; Al-Husain, Muneera; Al-Mohanna, Futwan; Alkuraya, Fowzan S

2012-08-10

Primordial dwarfism (PD) is a phenotype characterized by profound growth retardation that is prenatal in onset. Significant strides have been made in the last few years toward improved understanding of the molecular underpinning of the limited growth that characterizes the embryonic and postnatal development of PD individuals. These include impaired mitotic mechanics, abnormal IGF2 expression, perturbed DNA-damage response, defective spliceosomal machinery, and abnormal replication licensing. In three families affected by a distinct form of PD, we identified a founder truncating mutation in POC1A. This gene is one of two vertebrate paralogs of POC1, which encodes one of the most abundant proteins in the Chlamydomonas centriole proteome. Cells derived from the index individual have abnormal mitotic mechanics with multipolar spindles, in addition to clearly impaired ciliogenesis. siRNA knockdown of POC1A in fibroblast cells recapitulates this ciliogenesis defect. Our findings highlight a human ciliopathy syndrome caused by deficiency of a major centriolar protein. Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

A portfolio-based approach to optimize proof-of-concept clinical trials.

PubMed

Mallinckrodt, Craig; Molenberghs, Geert; Persinger, Charles; Ruberg, Stephen; Sashegyi, Andreas; Lindborg, Stacy

2012-01-01

Improving proof-of-concept (PoC) studies is a primary lever for improving drug development. Since drug development is often done by institutions that work on multiple drugs simultaneously, the present work focused on optimum choices for rates of false positive (α) and false negative (β) results across a portfolio of PoC studies. Simple examples and a newly derived equation provided conceptual understanding of basic principles regarding optimum choices of α and β in PoC trials. In examples that incorporated realistic development costs and constraints, the levels of α and β that maximized the number of approved drugs and portfolio value varied by scenario. Optimum choices were sensitive to the probability the drug was effective and to the proportion of total investment cost prior to establishing PoC. Results of the present investigation agree with previous research in that it is important to assess optimum levels of α and β. However, the present work also highlighted the need to consider cost structure using realistic input parameters relevant to the question of interest.

Using rare earth elements to constrain particulate organic carbon flux in the East China Sea.

PubMed

Hung, Chin-Chang; Chen, Ya-Feng; Hsu, Shih-Chieh; Wang, Kui; Chen, Jianfang; Burdige, David J

2016-09-27

Fluxes of particulate organic carbon (POC) in the East China Sea (ECS) have been reported to decrease from the inner continental shelf towards the outer continental shelf. Recent research has shown that POC fluxes in the ECS may be overestimated due to active sediment resuspension. To better characterize the effect of sediment resuspension on particle fluxes in the ECS, rare earth elements (REEs) and organic carbon (OC) were used in separate two-member mixing models to evaluate trap-collected POC fluxes. The ratio of resuspended particles from sediments to total trap-collected particles in the ECS ranged from 82-94% using the OC mixing model, and 30-80% using the REEs mixing model, respectively. These results suggest that REEs may be better proxies for sediment resuspension than OC in high turbidity marginal seas because REEs do not appear to undergo degradation during particle sinking as compared to organic carbon. Our results suggest that REEs can be used as tracers to provide quantitative estimates of POC fluxes in marginal seas.

Fourier transform infrared study on microemulsion system of potassium salt of bis(2-ethylhexyl) phosphinic acid (HA)

NASA Astrophysics Data System (ADS)

Zhou, Weijin; Shi, Nai; Wang, Yi; Chang, Zhiyuan; Wu, JinGuang

1994-01-01

To study microemulsion formation in a solvent extraction system is to probe into some basic principles of extraction chemistry in the light of combining extraction chemistry with surface chemistry. In our previous investigations, the microemulsions of the salts of HDEHP and PC88A have been studied systematically by FT-IR. In the experiment, we observed the change of peak positions and intensities of P equals O, P-O-C and P-O-H groups during saponification and hydration, and discovered that the peak of P-O-C splits apart into 1045 and 1075 cm-1. The vibration frequency of the P-O-C group in HDEHP and PC88A is quite close to the symmetric stretching frequency of the POO- group, and thus causes difficulties in the study of their peak position and absorbance variation. For this reason we synthesized bis(2-ethylhexyl) phosphinic acid without the P-O-C group. Infrared spectra in the range of 800 - 4000 cm-1 of this microemulsion system was studied.

Photonic crystals: emerging biosensors and their promise for point-of-care applications.

PubMed

Inan, Hakan; Poyraz, Muhammet; Inci, Fatih; Lifson, Mark A; Baday, Murat; Cunningham, Brian T; Demirci, Utkan

2017-01-23

Biosensors are extensively employed for diagnosing a broad array of diseases and disorders in clinical settings worldwide. The implementation of biosensors at the point-of-care (POC), such as at primary clinics or the bedside, faces impediments because they may require highly trained personnel, have long assay times, large sizes, and high instrumental cost. Thus, there exists a need to develop inexpensive, reliable, user-friendly, and compact biosensing systems at the POC. Biosensors incorporated with photonic crystal (PC) structures hold promise to address many of the aforementioned challenges facing the development of new POC diagnostics. Currently, PC-based biosensors have been employed for detecting a variety of biotargets, such as cells, pathogens, proteins, antibodies, and nucleic acids, with high efficiency and selectivity. In this review, we provide a broad overview of PCs by explaining their structures, fabrication techniques, and sensing principles. Furthermore, we discuss recent applications of PC-based biosensors incorporated with emerging technologies, including telemedicine, flexible and wearable sensing, smart materials and metamaterials. Finally, we discuss current challenges associated with existing biosensors, and provide an outlook for PC-based biosensors and their promise at the POC.

Using rare earth elements to constrain particulate organic carbon flux in the East China Sea

PubMed Central

Hung, Chin-Chang; Chen, Ya-Feng; Hsu, Shih-Chieh; Wang, Kui; Chen, Jian Feng; Burdige, David J.

2016-01-01

Fluxes of particulate organic carbon (POC) in the East China Sea (ECS) have been reported to decrease from the inner continental shelf towards the outer continental shelf. Recent research has shown that POC fluxes in the ECS may be overestimated due to active sediment resuspension. To better characterize the effect of sediment resuspension on particle fluxes in the ECS, rare earth elements (REEs) and organic carbon (OC) were used in separate two-member mixing models to evaluate trap-collected POC fluxes. The ratio of resuspended particles from sediments to total trap-collected particles in the ECS ranged from 82–94% using the OC mixing model, and 30–80% using the REEs mixing model, respectively. These results suggest that REEs may be better proxies for sediment resuspension than OC in high turbidity marginal seas because REEs do not appear to undergo degradation during particle sinking as compared to organic carbon. Our results suggest that REEs can be used as tracers to provide quantitative estimates of POC fluxes in marginal seas. PMID:27670426

Protocol for a randomised controlled implementation trial of point-of-care viral load testing and task shifting: the Simplifying HIV TREAtment and Monitoring (STREAM) study.

PubMed

Dorward, Jienchi; Garrett, Nigel; Quame-Amaglo, Justice; Samsunder, Natasha; Ngobese, Hope; Ngomane, Noluthando; Moodley, Pravikrishnen; Mlisana, Koleka; Schaafsma, Torin; Donnell, Deborah; Barnabas, Ruanne; Naidoo, Kogieleum; Abdool Karim, Salim; Celum, Connie; Drain, Paul K

2017-09-27

Achieving the Joint United Nations Programme on HIV and AIDS 90-90-90 targets requires models of HIV care that expand antiretroviral therapy (ART) coverage without overburdening health systems. Point-of-care (POC) viral load (VL) testing has the potential to efficiently monitor ART treatment, while enrolled nurses may be able to provide safe and cost-effective chronic care for stable patients with HIV. This study aims to demonstrate whether POC VL testing combined with task shifting to enrolled nurses is non-inferior and cost-effective compared with laboratory-based VL monitoring and standard HIV care. The STREAM (Simplifying HIV TREAtment and Monitoring) study is an open-label, non-inferiority, randomised controlled implementation trial. HIV-positive adults, clinically stable at 6 months after ART initiation, will be recruited in a large urban clinic in South Africa. Approximately 396 participants will be randomised 1:1 to receive POC HIV VL monitoring and potential task shifting to enrolled nurses, versus laboratory VL monitoring and standard South African HIV care. Initial clinic follow-up will be 2-monthly in both arms, with VL testing at enrolment, 6 months and 12 months. At 6 months (1 year after ART initiation), stable participants in both arms will qualify for a differentiated care model involving decentralised ART pickup at community-based pharmacies. The primary outcome is retention in care and virological suppression at 12 months from enrolment. Secondary outcomes include time to appropriate entry into the decentralised ART delivery programme, costs per virologically suppressed patient and cost-effectiveness of the intervention compared with standard care. Findings will inform the scale up of VL testing and differentiated care in HIV-endemic resource-limited settings. Ethical approval has been granted by the University of KwaZulu-Natal Biomedical Research Ethics Committee (BFC296/16) and University of Washington Institutional Review Board (STUDY00001466). Results will be presented at international conferences and published in academic peer-reviewed journals. NCT03066128; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Buried particulate organic carbon stimulates denitrification and nitrate retention in stream sediments at the groundwater-surface water interface

USGS Publications Warehouse

Stelzer, Robert S.; Scott, J. Thad; Bartsch, Lynn

2015-01-01

The interface between ground water and surface water in streams is a hotspot for N processing. However, the role of buried organic C in N transformation at this interface is not well understood, and inferences have been based largely on descriptive studies. Our main objective was to determine how buried particulate organic C (POC) affected denitrification and NO3− retention in the sediments of an upwelling reach in a sand-plains stream in Wisconsin. We manipulated POC in mesocosms inserted in the sediments. Treatments included low and high quantities of conditioned red maple leaves (buried beneath combusted sand), ambient sediment (sand containing background levels of POC), and a control (combusted sand). We measured denitrification rates in sediments by acetylene-block assays in the laboratory and by changes in N2 concentrations in the field using membrane inlet mass spectrometry. We measured NO3−, NH4+, and dissolved organic N (DON) retention as changes in concentrations and fluxes along groundwater flow paths in the mesocosms. POC addition drove oxic ground water to severe hypoxia, led to large increases in dissolved organic C (DOC), and strongly increased denitrification rates and N (NO3− and total dissolved N) retention relative to the control. In situ denitrification accounted for 30 to 60% of NO3− retention. Our results suggest that buried POC stimulated denitrification and NO3− retention by producing DOC and by creating favorable redox conditions for denitrification.

Organic carbon export from the Greenland Ice Sheet: sources, sinks and downstream fluxes

NASA Astrophysics Data System (ADS)

Wadham, J. L.; Lawson, E.; Tranter, M.; Stibal, M.; Telling, J.; Lis, G. P.; Nienow, P. W.; Anesio, A. M.; Butler, C. E.

2012-12-01

Runoff from small glacier systems has been shown to contain dissolved organic carbon (DOC) rich in low molecular weight (LMW), and hence more labile forms, designating glaciers as an important source of carbon for downstream heterotrophic activity. Here we assess glacier surfaces as potential sources of labile DOC to downstream ecosystems, presenting data from a wide range of glacier systems to determine sources and sinks of DOC in glacial and proglacial systems. We subsequently focus upon the Greenland Ice Sheet (GrIS) which is the largest source of glacial runoff at present (400 km3 yr-1), with predicted increases in future decades. We report high fluxes of particulate organic carbon (POC), DOC and LMW labile fractions from a large GrIS catchment during two contrasting melt seasons. POC dominates OC export, is sourced from the ice sheet bed and contains a significant bioreactive component (~10% carbohydrates). The LMW-DOC "labile" fraction derives almost entirely from microbial activity on the ice sheet surface, which is supported by data from glacier systems also presented here. Annual fluxes of DOC, POC and labile components were lower in 2010 than 2009, despite a ~2 fold increase in runoff fluxes in 2010, suggesting production-limited DOC/POC sources. Scaled to the entire ice sheet, combined DOC and POC fluxes are of a similar order of magnitude to other large Arctic river systems and may represent an important source of organic carbon to the North Atlantic, Greenland and Labrador Seas.

Institutional point-of-care glucometer identifies population trends in blood glucose associated with war.

PubMed

Boaz, Mona; Matas, Zipora; Chaimy, Tova; Landau, Zohar; Bar Dayan, Yosefa; Berlovitz, Yitzhak; Wainstein, Julio

2013-11-01

Acute physiological stress has been shown to impair glucose homeostasis. War is a period of acute psychological stress, and its effect on glucose control is unknown. In this study random point-of-care (POC) glucose levels were measured using an automated, institutional glucometer in hospitalized adult patients prior to versus during the Israeli Pillar of Defense campaign (November 7-10, 2012). Random POC glucose values measured with the institutional blood glucose monitoring system were obtained 1 week prior to the Pillar of Defense campaign (November 7-10, 2012) and compared with values to those obtained during the first 4 days of the war (November 14-17, 2012). In total, 3,573 POC glucose measures were included: 1,865 during the pre-war period and 1,708 during the campaign. POC glucose measures were significantly higher during the war compared with the week preceding the war: 9.7±4.7 versus 9.3±4.2 mmol/L (P=0.02). In a general linear model, period (pre-war vs. during war) persisted as a significant predictor of POC glucose even after controlling for age, sex, and department type (internal medicine vs. surgical). Acute stress, such as a wartime situation, is associated with a significant increase in random blood glucose values in a population of hospitalized adults. Long-term follow-up of the individuals hospitalized during these two periods can reveal differences in morbidity and mortality trends.

Adaptive-weighted Total Variation Minimization for Sparse Data toward Low-dose X-ray Computed Tomography Image Reconstruction

PubMed Central

Liu, Yan; Ma, Jianhua; Fan, Yi; Liang, Zhengrong

2012-01-01

Previous studies have shown that by minimizing the total variation (TV) of the to-be-estimated image with some data and other constraints, a piecewise-smooth X-ray computed tomography (CT) can be reconstructed from sparse-view projection data without introducing noticeable artifacts. However, due to the piecewise constant assumption for the image, a conventional TV minimization algorithm often suffers from over-smoothness on the edges of the resulting image. To mitigate this drawback, we present an adaptive-weighted TV (AwTV) minimization algorithm in this paper. The presented AwTV model is derived by considering the anisotropic edge property among neighboring image voxels, where the associated weights are expressed as an exponential function and can be adaptively adjusted by the local image-intensity gradient for the purpose of preserving the edge details. Inspired by the previously-reported TV-POCS (projection onto convex sets) implementation, a similar AwTV-POCS implementation was developed to minimize the AwTV subject to data and other constraints for the purpose of sparse-view low-dose CT image reconstruction. To evaluate the presented AwTV-POCS algorithm, both qualitative and quantitative studies were performed by computer simulations and phantom experiments. The results show that the presented AwTV-POCS algorithm can yield images with several noticeable gains, in terms of noise-resolution tradeoff plots and full width at half maximum values, as compared to the corresponding conventional TV-POCS algorithm. PMID:23154621

Adaptive-weighted total variation minimization for sparse data toward low-dose x-ray computed tomography image reconstruction.

PubMed

Liu, Yan; Ma, Jianhua; Fan, Yi; Liang, Zhengrong

2012-12-07

Previous studies have shown that by minimizing the total variation (TV) of the to-be-estimated image with some data and other constraints, piecewise-smooth x-ray computed tomography (CT) can be reconstructed from sparse-view projection data without introducing notable artifacts. However, due to the piecewise constant assumption for the image, a conventional TV minimization algorithm often suffers from over-smoothness on the edges of the resulting image. To mitigate this drawback, we present an adaptive-weighted TV (AwTV) minimization algorithm in this paper. The presented AwTV model is derived by considering the anisotropic edge property among neighboring image voxels, where the associated weights are expressed as an exponential function and can be adaptively adjusted by the local image-intensity gradient for the purpose of preserving the edge details. Inspired by the previously reported TV-POCS (projection onto convex sets) implementation, a similar AwTV-POCS implementation was developed to minimize the AwTV subject to data and other constraints for the purpose of sparse-view low-dose CT image reconstruction. To evaluate the presented AwTV-POCS algorithm, both qualitative and quantitative studies were performed by computer simulations and phantom experiments. The results show that the presented AwTV-POCS algorithm can yield images with several notable gains, in terms of noise-resolution tradeoff plots and full-width at half-maximum values, as compared to the corresponding conventional TV-POCS algorithm.

Sealing of Corneal Lacerations Using Photo-Activated Rose Bengal Dye and Amniotic Membrane

DTIC Science & Technology

2017-01-10

each retina. ONL thickness data 196 were tested by a two-tailed unpaired Student t test . 197 Each histologic evaluation was carried out in a masked... Research Division may pay for your basic journal publishing charges (to include costs for tables and black and white photos). We cannot pay for...reprints. If you are 59 MDW staff member, we can forward your request for funds to the designated wing POC. 4. Congratulations, and thank you for your

Simultaneous deblurring and iterative reconstruction of CBCT for image guided brain radiosurgery.

PubMed

Hashemi, SayedMasoud; Song, William Y; Sahgal, Arjun; Lee, Young; Huynh, Christopher; Grouza, Vladimir; Nordström, Håkan; Eriksson, Markus; Dorenlot, Antoine; Régis, Jean Marie; Mainprize, James G; Ruschin, Mark

2017-04-07

One of the limiting factors in cone-beam CT (CBCT) image quality is system blur, caused by detector response, x-ray source focal spot size, azimuthal blurring, and reconstruction algorithm. In this work, we develop a novel iterative reconstruction algorithm that improves spatial resolution by explicitly accounting for image unsharpness caused by different factors in the reconstruction formulation. While the model-based iterative reconstruction techniques use prior information about the detector response and x-ray source, our proposed technique uses a simple measurable blurring model. In our reconstruction algorithm, denoted as simultaneous deblurring and iterative reconstruction (SDIR), the blur kernel can be estimated using the modulation transfer function (MTF) slice of the CatPhan phantom or any other MTF phantom, such as wire phantoms. The proposed image reconstruction formulation includes two regularization terms: (1) total variation (TV) and (2) nonlocal regularization, solved with a split Bregman augmented Lagrangian iterative method. The SDIR formulation preserves edges, eases the parameter adjustments to achieve both high spatial resolution and low noise variances, and reduces the staircase effect caused by regular TV-penalized iterative algorithms. The proposed algorithm is optimized for a point-of-care head CBCT unit for image-guided radiosurgery and is tested with CatPhan phantom, an anthropomorphic head phantom, and 6 clinical brain stereotactic radiosurgery cases. Our experiments indicate that SDIR outperforms the conventional filtered back projection and TV penalized simultaneous algebraic reconstruction technique methods (represented by adaptive steepest-descent POCS algorithm, ASD-POCS) in terms of MTF and line pair resolution, and retains the favorable properties of the standard TV-based iterative reconstruction algorithms in improving the contrast and reducing the reconstruction artifacts. It improves the visibility of the high contrast details in bony areas and the brain soft-tissue. For example, the results show the ventricles and some brain folds become visible in SDIR reconstructed images and the contrast of the visible lesions is effectively improved. The line-pair resolution was improved from 12 line-pair/cm in FBP to 14 line-pair/cm in SDIR. Adjusting the parameters of the ASD-POCS to achieve 14 line-pair/cm caused the noise variance to be higher than the SDIR. Using these parameters for ASD-POCS, the MTF of FBP and ASD-POCS were very close and equal to 0.7 mm -1 which was increased to 1.2 mm -1 by SDIR, at half maximum.

Simultaneous deblurring and iterative reconstruction of CBCT for image guided brain radiosurgery

NASA Astrophysics Data System (ADS)

Hashemi, SayedMasoud; Song, William Y.; Sahgal, Arjun; Lee, Young; Huynh, Christopher; Grouza, Vladimir; Nordström, Håkan; Eriksson, Markus; Dorenlot, Antoine; Régis, Jean Marie; Mainprize, James G.; Ruschin, Mark

2017-04-01

One of the limiting factors in cone-beam CT (CBCT) image quality is system blur, caused by detector response, x-ray source focal spot size, azimuthal blurring, and reconstruction algorithm. In this work, we develop a novel iterative reconstruction algorithm that improves spatial resolution by explicitly accounting for image unsharpness caused by different factors in the reconstruction formulation. While the model-based iterative reconstruction techniques use prior information about the detector response and x-ray source, our proposed technique uses a simple measurable blurring model. In our reconstruction algorithm, denoted as simultaneous deblurring and iterative reconstruction (SDIR), the blur kernel can be estimated using the modulation transfer function (MTF) slice of the CatPhan phantom or any other MTF phantom, such as wire phantoms. The proposed image reconstruction formulation includes two regularization terms: (1) total variation (TV) and (2) nonlocal regularization, solved with a split Bregman augmented Lagrangian iterative method. The SDIR formulation preserves edges, eases the parameter adjustments to achieve both high spatial resolution and low noise variances, and reduces the staircase effect caused by regular TV-penalized iterative algorithms. The proposed algorithm is optimized for a point-of-care head CBCT unit for image-guided radiosurgery and is tested with CatPhan phantom, an anthropomorphic head phantom, and 6 clinical brain stereotactic radiosurgery cases. Our experiments indicate that SDIR outperforms the conventional filtered back projection and TV penalized simultaneous algebraic reconstruction technique methods (represented by adaptive steepest-descent POCS algorithm, ASD-POCS) in terms of MTF and line pair resolution, and retains the favorable properties of the standard TV-based iterative reconstruction algorithms in improving the contrast and reducing the reconstruction artifacts. It improves the visibility of the high contrast details in bony areas and the brain soft-tissue. For example, the results show the ventricles and some brain folds become visible in SDIR reconstructed images and the contrast of the visible lesions is effectively improved. The line-pair resolution was improved from 12 line-pair/cm in FBP to 14 line-pair/cm in SDIR. Adjusting the parameters of the ASD-POCS to achieve 14 line-pair/cm caused the noise variance to be higher than the SDIR. Using these parameters for ASD-POCS, the MTF of FBP and ASD-POCS were very close and equal to 0.7 mm-1 which was increased to 1.2 mm-1 by SDIR, at half maximum.

Sources and fate of organic (DOC, POC, CDOM) and inorganic (DIC) carbon in a mangrove dominated estuary (French Guiana)

NASA Astrophysics Data System (ADS)

Ray, R.; Michaud, E.; Vantrepotte, V.; Aller, R. C.; Morvan, S.; Thouzeau, G.

2016-12-01

We studied the mangrove dominated Sinnamary estuarine system in French Guiana during the dry and wet seasons in 2015 to examine the sources, transport and fate of surface water DOC, POC and DIC along the salinity gradient and the effect of tidal fluctuations on carbon dynamics. Elemental ratios, stable isotopes and optical properties (absorption) were applied as proxies to delineate the sources and molecular structure of the organic carbon. Results showed that during the wet season there were significant net inputs of POC and DOC along the salinity gradient from mangroves and enhanced surface runoff. Time series performed during the dry season at a station in channel water adjacent to mangroves revealed mangrove-derived export and exchanges of DOC and POC during the ebb and marine algae import during the flood. DOC was the dominant form of carbon in both seasons with DOC:POC ratios typically between 13 and 40. Both δ13DOC and CDOM descriptors (e.g., S275-295 and a*412) confirmed mangrove litter leaching to be the primary contributor of high molecular weight dissolved organic matter in the wet season which was replaced by marine phytoplanktonic OC during transport offshore in the dry season. CDOM aromaticity is lower in the dry season as mangrove inputs decrease. POC showed similar trends as DOC, with maximum contributions of terrestrial litter in the river and mixing zone, and in situ production dominant in the marine zone. The entire estuary is heterotrophic, exhibiting high pCO2 (837-5575µatm) and oxygen undersaturation (59-86%) in both seasons, and substantial CO2 emission fluxes (278-3671mmol m-2 d-1). Intense local remineralization and laterally transported CO2 originating from mangrove benthic respiration could account for the water column pCO2 enrichment during low tide and night time. Keywords: Organic carbon, stable isotopes, CDOM, pCO2, mangrove, French Guiana

Conformational Preference and Donor Atom Interaction Leading to Hexacoordination vs Pentacoordination in Bicyclic Tetraoxyphosphoranes(1).

PubMed

Sherlock, David J.; Chandrasekaran, A.; Prakasha, T. K.; Day, Roberta O.; Holmes, Robert R.

1998-01-12

New bicyclic tetraoxyphosphoranes all containing a six-membered oxaphosphorinane ring, C(6)H(8)(CH(2)O)(2)P(OC(12)H(8))(OXyl) (1), (C(6)H(4)O)(2)P(OC(12)H(8))(OXyl) (2), CH(2)[(t-Bu)(2)C(6)H(2)O](2)P(OC(12)H(8))(OXyl) (3), O(2)S[(t-Bu)MeC(6)H(2)O](2)P(OC(12)H(8))(OXyl) (4), and S[(t-Bu)MeC(6)H(2)O](2)P(OC(12)H(8))(OXyl) (5), were synthesized by the oxidative addition reaction of the cyclic phosphine P(OC(12)H(8))(OXyl) (6) with an appropriate diol in the presence of N-chlorodiisopropylamine. X-ray analysis revealed trigonal bipyramidal (TBP) geometries for 1-4 where the dioxa ring varied in size from six- to eight-membered. With a sulfur donor atom as part of an eight-membered ring in place of a potential oxygen donor atom of a sulfone group as in 4, the X-ray study of 5 showed the formation of a hexacoordinated structure via a P-S interaction. Ring constraints are evaluated to give an order of conformational flexibility associated with the (TBP) tetraoxyphosphoranes 4 > 3 approximately 1 > 2 which parallels the degree of shielding from (31)P NMR chemical shifts: 4 > 3 > 1 > 2. The six- and seven-membered dioxa rings in 1 and 2, respectively, are positioned at axial-equatorial sites, whereas the eight-membered dioxa ring in 3 and 4 occupies diequatorial sites of a TBP. V-T (1)H NMR data give barriers to xylyl group rotation about the C-OXyl bond. The geometry of 5 is located along a coordinate from square pyramidal toward octahedral to the extent of 60.7%. Achieving hexacoordination in bicyclic tetraoxyphosphoranes of reduced electrophilicity relative to bicyclic pentaoxyphosphoranes appears to be dependent on the presence of a sufficiently strong donor atom.

CSmetaPred: a consensus method for prediction of catalytic residues.

PubMed

Choudhary, Preeti; Kumar, Shailesh; Bachhawat, Anand Kumar; Pandit, Shashi Bhushan

2017-12-22

Knowledge of catalytic residues can play an essential role in elucidating mechanistic details of an enzyme. However, experimental identification of catalytic residues is a tedious and time-consuming task, which can be expedited by computational predictions. Despite significant development in active-site prediction methods, one of the remaining issues is ranked positions of putative catalytic residues among all ranked residues. In order to improve ranking of catalytic residues and their prediction accuracy, we have developed a meta-approach based method CSmetaPred. In this approach, residues are ranked based on the mean of normalized residue scores derived from four well-known catalytic residue predictors. The mean residue score of CSmetaPred is combined with predicted pocket information to improve prediction performance in meta-predictor, CSmetaPred_poc. Both meta-predictors are evaluated on two comprehensive benchmark datasets and three legacy datasets using Receiver Operating Characteristic (ROC) and Precision Recall (PR) curves. The visual and quantitative analysis of ROC and PR curves shows that meta-predictors outperform their constituent methods and CSmetaPred_poc is the best of evaluated methods. For instance, on CSAMAC dataset CSmetaPred_poc (CSmetaPred) achieves highest Mean Average Specificity (MAS), a scalar measure for ROC curve, of 0.97 (0.96). Importantly, median predicted rank of catalytic residues is the lowest (best) for CSmetaPred_poc. Considering residues ranked ≤20 classified as true positive in binary classification, CSmetaPred_poc achieves prediction accuracy of 0.94 on CSAMAC dataset. Moreover, on the same dataset CSmetaPred_poc predicts all catalytic residues within top 20 ranks for ~73% of enzymes. Furthermore, benchmarking of prediction on comparative modelled structures showed that models result in better prediction than only sequence based predictions. These analyses suggest that CSmetaPred_poc is able to rank putative catalytic residues at lower (better) ranked positions, which can facilitate and expedite their experimental characterization. The benchmarking studies showed that employing meta-approach in combining residue-level scores derived from well-known catalytic residue predictors can improve prediction accuracy as well as provide improved ranked positions of known catalytic residues. Hence, such predictions can assist experimentalist to prioritize residues for mutational studies in their efforts to characterize catalytic residues. Both meta-predictors are available as webserver at: http://14.139.227.206/csmetapred/ .

Amounts, isotopic character and ages of organic and inorganic carbon exported from rivers to ocean margins: Assessment of natural and anthropogenic controls

NASA Astrophysics Data System (ADS)

Bauer, J. E.; Hossler, K.

2012-12-01

Riverine exports of carbon (C) and organic matter (OM) are regulated by a variety of natural and anthropogenic factors. Understanding the relationships between these various factors and C and OM exports can help to constrain global C budgets, as well allow assessment of current and future anthropogenic impacts on both riverine and global C cycles. We quantified the effects of multiple natural and anthropogenic controls on riverine export fluxes and compositions of particulate organic C (POC), dissolved organic C (DOC), and dissolved inorganic C (DIC) for a regional group of eight rivers in the northeastern U.S. For allochthonous and aged C contributions to POC, DOC and DIC exports, we first estimated fractional contributions from six potential sources for POC and DOC (i.e., modern C3 plant material (C3-OC), modern C4 plant material (C4-OC), modern algal material (algal OC), slow-turnover soil OC (slow SOC; turnover time 25 yr), passive-turnover soil OC (passive SOC; turnover time 5,000 yr) and fossil OC and four potential sources for DIC (i.e., modern atmospheric CO2 exchange, carbonate dissolution, POC remineralization and DOC remineralization) using a novel time-varying isotope mixing model. Using these estimated source contributions, we then estimated the allochthonous proportions of (a) the POC and DOC pools to be the C3-OC, C4-OC, slow SOC, passive SOC, and fossil OC contributions; and (b) the DIC pools to be the dissolved carbonates, remineralized allochthonous POC, and remineralized allochthonous DOC contributions. We considered aged C to be anything older than ˜ 60 yr, which included passive SOC and fossil OC for POC and DOC and dissolved carbonates and aged fractions of remineralized POC and DOC for DIC. Potential controls related to hydrogeomorphology and regional climate, soil order, soil texture, bedrock lithology, land use, and additional anthropogenic factors were analyzed collectively, individually, and at scales of both local and regional influence. Factors related either to hydrogeomorphology and climate or to anthropogenic factors exhibited the strongest impacts on riverine C exports and compositions, particularly at broader regional scales. The effect of hydrogeomorphology and climate was primarily one of size, as larger watersheds with greater discharge exported more total C and terrestrial C. Principal anthropogenic factors included impacts of wastewater treatment plants (WWTPs) and river impoundments. The presence of WWTPs as well as anthropogenic use of carbonate-based materials (e.g., limestone) may have substantially increased riverine C exports, particularly fossil C exports, in the study region. The presence of nuclear power plants in the associated watersheds is also discussed because of the potential for anthropogenic 14C inputs and subsequent biasing of aquatic C studies utilizing natural abundance 14C.

Torque Splitting by a Concentric Face Gear Transmission

NASA Technical Reports Server (NTRS)

Filler, Robert R.; Heath, Gregory F.; Slaughter, Stephen C.; Lewicki, David G.

2002-01-01

Tests of a 167 Kilowatt (224 Horsepower) split torque face gearbox were performed by the Boeing Company in Mesa, Arizona, while working under a Defense Advanced Research Projects Agency (DARPA) Technology Reinvestment Program (TRP). This paper provides a summary of these cooperative tests, which were jointly funded by Boeing and DARPA. Design, manufacture and testing of the scaled-power TRP proof-of-concept (POC) split torque gearbox followed preliminary evaluations of the concept performed early in the program. The split torque tests were run using 200 N-m (1767 in-lbs) torque input to each side of the transmission. During tests, two input pinions were slow rolled while in mesh with the two face gears. Two idler gears were also used in the configuration to recombine torque near the output. Resistance was applied at the output face gear to create the required loading conditions in the gear teeth. A system of weights, pulleys and cables were used in the test rig to provide both the input and output loading. Strain gages applied in the tooth root fillets provided strain indication used to determine torque splitting conditions at the input pinions. The final two pinion-two idler tests indicated 52% to 48% average torque split capabilities for the two pinions. During the same tests, a 57% to 43% average distribution of the torque being recombined to the upper face gear from the lower face gear was measured between the two idlers. The POC split torque tests demonstrated that face gears can be applied effectively in split torque rotorcraft transmissions, yielding good potential for significant weight, cost and reliability improvements over existing equipment using spiral bevel gearing.

Designing a Micromixer for Rolling Circle Amplification in Cancer Biomarker Detection

NASA Astrophysics Data System (ADS)

Altural, Hayriye

2015-03-01

Rolling circle amplification (RCA) is an alternative method to the Polymerase Chain Reaction based amplification for point-of-care (POC) diagnosis. In future personalized cancer diagnostic for POC applications, smaller, faster and cheaper methods are needed instead of costly and time-consuming laboratory tests. Microfluidic chips can perform the detection of cancer biomarkers within less analysis time, and provide for improvement in the sensitivity and specificity required for biochemical analysis as well. Rapid mixing is essential in the chips used in cancer diagnostic. The goal of this study is to design a micromixer for rapid RCA-based analysis and develop the assay time in cancer biomarker detection. By combining assays with micromixers, multi-step bioreactions in microfluidic chips may be achieved with minimal external control. Here, simulation results related to the micromixer are obtained by COMSOL software. The Scientific and Technological Research Council of Turkey (TUBITAK) is acknowledged for granting of H. Altural postdoctoral study in the framework of TUBITAK-BIDEB 2219-International Postdoctoral Research Scholarship Program.

Advances in Developing HIV-1 Viral Load Assays for Resource-Limited Settings

PubMed Central

Wang, ShuQi; Xu, Feng; Demirci, Utkan

2010-01-01

Commercial HIV-1 RNA viral load assays have been routinely used in developed countries to monitor antiretroviral treatment (ART). However, these assays require expensive equipment and reagents, well-trained operators, and established laboratory infrastructure. These requirements restrict their use in resource-limited settings where people are most afflicted with the HIV-1 epidemic. Inexpensive alternatives such as the Ultrasensitive p24 assay, the Reverse Transcriptase (RT) assay and in-house reverse transcription quantitative polymerase chain reaction (RT-qPCR) have been developed. However, they are still time-consuming, technologically complex and inappropriate for decentralized laboratories as point-of-care (POC) tests. Recent advances in microfluidics and nanotechnology offer new strategies to develop low-cost, rapid, robust and simple HIV-1 viral load monitoring systems. We review state-of-the-art technologies used for HIV-1 viral load monitoring in both developed and developing settings. Emerging approaches based on microfluidics and nanotechnology, which have potential to be integrated into POC HIV-1 viral load assays, are also discussed. PMID:20600784

Point-of-Care Diagnostics in Low Resource Settings: Present Status and Future Role of Microfluidics

PubMed Central

Sharma, Shikha; Zapatero-Rodríguez, Julia; Estrela, Pedro; O’Kennedy, Richard

2015-01-01

The inability to diagnose numerous diseases rapidly is a significant cause of the disparity of deaths resulting from both communicable and non-communicable diseases in the developing world in comparison to the developed world. Existing diagnostic instrumentation usually requires sophisticated infrastructure, stable electrical power, expensive reagents, long assay times, and highly trained personnel which is not often available in limited resource settings. This review will critically survey and analyse the current lateral flow-based point-of-care (POC) technologies, which have made a major impact on diagnostic testing in developing countries over the last 50 years. The future of POC technologies including the applications of microfluidics, which allows miniaturisation and integration of complex functions that facilitate their usage in limited resource settings, is discussed The advantages offered by such systems, including low cost, ruggedness and the capacity to generate accurate and reliable results rapidly, are well suited to the clinical and social settings of the developing world. PMID:26287254

A perspective on 15 years of proof-of-concept aircraft development and flight research at Ames-Moffett by the Rotorcraft and Powered-Lift Flight Projects Division, 1970-1985

NASA Technical Reports Server (NTRS)

Few, David D.

1987-01-01

A proof-of-concept (POC) aircraft is defined and the concept of interest described for each of the six aircraft developed by the Ames-Moffet Rotorcraft and Powered-Lift Flight Projects Division from 1970 through 1985; namely, the OV-10, the C-8A Augmentor Wing, the Quiet Short-Haul Research Aircraft (QSRA), the XV-15 Tilt Rotor Research Aircraft (TRRA), the Rotor Systems Research Aircraft (RSRA)-compound, and the yet-to-fly RSRA/X-Wing Aircraft. The program/project chronology and most noteworthy features of the concepts are reviewed. The paper discusses the significance of each concept and the project demonstrating it; it briefly looks at what concepts are on the horizon as potential POC research aircraft and emphasizes that no significant advanced concept in aviation technology has ever been accepted by civilian or military users without first completing a demonstration through flight testing.

Rapid and Low-Cost CRP Measurement by Integrating a Paper-Based Microfluidic Immunoassay with Smartphone (CRP-Chip).

PubMed

Dong, Meili; Wu, Jiandong; Ma, Zimin; Peretz-Soroka, Hagit; Zhang, Michael; Komenda, Paul; Tangri, Navdeep; Liu, Yong; Rigatto, Claudio; Lin, Francis

2017-03-26

Traditional diagnostic tests for chronic diseases are expensive and require a specialized laboratory, therefore limiting their use for point-of-care (PoC) testing. To address this gap, we developed a method for rapid and low-cost C-reactive protein (CRP) detection from blood by integrating a paper-based microfluidic immunoassay with a smartphone (CRP-Chip). We chose CRP for this initial development because it is a strong biomarker of prognosis in chronic heart and kidney disease. The microfluidic immunoassay is realized by lateral flow and gold nanoparticle-based colorimetric detection of the target protein. The test image signal is acquired and analyzed using a commercial smartphone with an attached microlens and a 3D-printed chip-phone interface. The CRP-Chip was validated for detecting CRP in blood samples from chronic kidney disease patients and healthy subjects. The linear detection range of the CRP-Chip is up to 2 μg/mL and the detection limit is 54 ng/mL. The CRP-Chip test result yields high reproducibility and is consistent with the standard ELISA kit. A single CRP-Chip can perform the test in triplicate on a single chip within 15 min for less than 50 US cents of material cost. This CRP-Chip with attractive features of low-cost, fast test speed, and integrated easy operation with smartphones has the potential to enable future clinical PoC chronic disease diagnosis and risk stratification by parallel measurements of a panel of protein biomarkers.

Rapid and Low-Cost CRP Measurement by Integrating a Paper-Based Microfluidic Immunoassay with Smartphone (CRP-Chip)

PubMed Central

Dong, Meili; Wu, Jiandong; Ma, Zimin; Peretz-Soroka, Hagit; Zhang, Michael; Komenda, Paul; Tangri, Navdeep; Liu, Yong; Rigatto, Claudio; Lin, Francis

2017-01-01

Traditional diagnostic tests for chronic diseases are expensive and require a specialized laboratory, therefore limiting their use for point-of-care (PoC) testing. To address this gap, we developed a method for rapid and low-cost C-reactive protein (CRP) detection from blood by integrating a paper-based microfluidic immunoassay with a smartphone (CRP-Chip). We chose CRP for this initial development because it is a strong biomarker of prognosis in chronic heart and kidney disease. The microfluidic immunoassay is realized by lateral flow and gold nanoparticle-based colorimetric detection of the target protein. The test image signal is acquired and analyzed using a commercial smartphone with an attached microlens and a 3D-printed chip–phone interface. The CRP-Chip was validated for detecting CRP in blood samples from chronic kidney disease patients and healthy subjects. The linear detection range of the CRP-Chip is up to 2 μg/mL and the detection limit is 54 ng/mL. The CRP-Chip test result yields high reproducibility and is consistent with the standard ELISA kit. A single CRP-Chip can perform the test in triplicate on a single chip within 15 min for less than 50 US cents of material cost. This CRP-Chip with attractive features of low-cost, fast test speed, and integrated easy operation with smartphones has the potential to enable future clinical PoC chronic disease diagnosis and risk stratification by parallel measurements of a panel of protein biomarkers. PMID:28346363

[Point-of-Care Testing in Trauma Patients - Methods and Evidence].

PubMed

Dirkmann, Daniel; Britten, Martin W; Frey, Ulrich H

2018-06-01

In severely injured patients, trauma-induced coagulopathy (TIC) present at hospital admission is associated with increased transfusion requirements, morbidity and mortality. Early and effective treatment contributes to improved survival rates. Laboratory coagulation assays have long turn-around times and evidence for their usefulness, especially in the context of TIC, is weak. Due to the lack of appropriate guidance, transfusion of allogeneic blood products frequently follows a ratio-based concept (e.g., transfusion of erythrocytes and plasma in a 1 : 1 ratio). Point-of-care (PoC) tests enable the assessment of prothrombin time (PT) and activated partial thromboplastin time in few minutes. However, although normal PT in these tests allows to rule out relevant effects of several anticoagulants, they are not able to detect patients with TIC and/or requiring subsequent massive transfusion. Viscoelastic tests (VETs) make it possible to assess defects in thrombin generation, hypofibrinogenaemia, thrombocytopenia, and hyperfibrinolysis, and thus enable targeted therapy. Impairment of platelet function is the common blind spot not detectable using both standard laboratory-based tests and VETs. However, PoC platelet function tests enable to detect platelet defects and patients taking anti-platelet. Furthermore, impaired platelet function has been identified as a strong predictor for coagulopathy and massive transfusion in trauma patients. In other clinical settings, coagulation management based on VETs is associated with decreased transfusion requirements, incidence of acute kidney failure, and mortality, respectively. Data of the first small prospective randomised trial indicate superiority of VET guided coagulation management solely using coagulation factor concentrates, when compared to plasma transfusions in severe trauma. Georg Thieme Verlag KG Stuttgart · New York.

An Innovative Field-Applicable Molecular Test to Diagnose Cutaneous Leishmania Viannia spp. Infections

PubMed Central

Saldarriaga, Omar A.; Castellanos-Gonzalez, Alejandro; Porrozzi, Renato; Baldeviano, Gerald C.; Lescano, Andrés G.; de Los Santos, Maxy B.; Fernandez, Olga L.; Saravia, Nancy G.; Costa, Erika; Melby, Peter C.; Travi, Bruno L.

2016-01-01

Cutaneous and mucosal leishmaniasis is widely distributed in Central and South America. Leishmania of the Viannia subgenus are the most frequent species infecting humans. L. (V.) braziliensis, L. (V.) panamensis are also responsible for metastatic mucosal leishmaniasis. Conventional or real time PCR is a more sensitive diagnostic test than microscopy, but the cost and requirement for infrastructure and trained personnel makes it impractical in most endemic regions. Primary health systems need a sensitive and specific point of care (POC) diagnostic tool. We developed a novel POC molecular diagnostic test for cutaneous leishmaniasis caused by Leishmania (Viannia) spp. Parasite DNA was amplified using isothermal Recombinase Polymerase Amplification (RPA) with primers and probes that targeted the kinetoplast DNA. The amplification product was detected by naked eye with a lateral flow (LF) immunochromatographic strip. The RPA-LF had an analytical sensitivity equivalent to 0.1 parasites per reaction. The test amplified the principal L. Viannia species from multiple countries: L. (V.) braziliensis (n = 33), L. (V.) guyanensis (n = 17), L. (V.) panamensis (n = 9). The less common L. (V.) lainsoni, L. (V.) shawi, and L. (V.) naiffi were also amplified. No amplification was observed in parasites of the L. (Leishmania) subgenus. In a small number of clinical samples (n = 13) we found 100% agreement between PCR and RPA-LF. The high analytical sensitivity and clinical validation indicate the test could improve the efficiency of diagnosis, especially in chronic lesions with submicroscopic parasite burdens. Field implementation of the RPA-LF test could contribute to management and control of cutaneous and mucosal leishmaniasis. PMID:27115155

Root and aerial infections of Chamaecyparis lawsoniana by Phytophthora lateralis: a new threat for European countries

Treesearch

C. Robin; D. Piou; N. Feau; G. Douzon; N. Schenck; E. M. Hansen

2010-01-01

Phytophthora lateralis has been isolated from root and collar lesions in Port-Orford Cedar (POC) trees (Chamaecyparis lawsoniana) in north-western France (Brittany). These trees, planted in hedgerows, displayed symptoms similar to the typical symptoms of POC root disease. Until now, the disease has been found outside of the...

Root and aerial infections of Chamaecyparis lawsoniana by Phytophthora lateralis : a new threat for European countries

Treesearch

C. Robin; D. Piou; N. Feau; G. Douzon; N. Schenck; E.M. Hansen

2010-01-01

Phytophthora lateralis has been isolated from root and collar lesions in Port-Orford Cedar (POC) trees (Chamaecyparis lawsoniana) in north-western France (Brittany). These trees, planted in hedgerows, displayed symptoms similar to the typical symptoms of POC root disease. Until now, the disease has been found outside of the...

Climatology of sediment flux and composition in the subarctic Northeast Pacific Ocean with biogeochemical implications

NASA Astrophysics Data System (ADS)

Timothy, D. A.; Wong, C. S.; Barwell-Clarke, J. E.; Page, J. S.; White, L. A.; Macdonald, R. W.

2013-09-01

Sequentially sampling conical sediment traps were maintained at Ocean Station Papa (OSP; 50°N, 145°W) in the Alaska Gyre from September 1982 to June 2006. The time series began with a single trap at 3800 m and traps were added at 1000 m and 200 m in March 1983 and May 1989, respectively. A trap at 3500-3700 m also was moored 5° north of OSP from May 1990 to August 1992. Total mass, biogenic silica (BSi), calcium carbonate (CaCO3), particulate organic carbon (POC) and particulate nitrogen (PN) were routinely measured. In this paper, we develop climatologies of sediment flux and composition at OSP, describing the characteristic features for comparison to sedimentary conditions globally. We then expand our use of the climatologies to arrive at four main conclusions regarding ecology and geochemistry at OSP. Fluxes of BSi and CaCO3 at 200 m and 1000 m lag by one month the annual cycle of irradiance and arrive at 3800 m ∼16 d later, with maximum export occurring several months later for POC. Next, the annual cycle of BSi flux shows that diatom production in late winter and spring is higher than indicated by spring decline of surface nutrients. We then show that the annual cycle of POC flux implies a net community production of organic carbon (NCPOC) of 3.6-5.3 mol m-2 y-1, double estimates based on mixed layer tracers but similar to estimates unaffected by mixing. NCPOC, combined with a CaCO3:POC production ratio of 0.18 determined from trap fluxes, gives a net community production of CaCO3 (NCPIC) of 0.65-0.95 mol m-2 y-1, in agreement with CaCO3 dissolution in the water column plus abyssal CaCO3 flux. Lastly, the flux climatologies at 1000 m and 3800 m are used to infer particle transformations in the bathypelagic zone including disaggregation and remineralization. Fluxes at 3800 m are best described as the sum of a primary flux sinking rapidly and a slowly-sinking secondary flux. Disaggregation of the primary flux is the likely source of secondary fluxes, with a lithogenic component transported horizontally also reaching the 3800-m traps. A detailed description of the sampling also is provided so future experiments can benefit from the successes and failures encountered at OSP. Fluxes normalized to 2000 m are 2.7, 1.3 and 1.1 times higher than the global averages for BSi, CaCO3 and POC, respectively. The Alaska Gyre is thus a siliceous basin with unusually high calcareous fluxes. Lithogenic fluxes are minor at OSP, making this site ideal to detect dust-fall events. Fluxes of BSi and CaCO3 lag surface solar irradiance by about one month at 200 m and 1000 m, and by another ∼two weeks at 3800 m. POM is preferentially retained and recycled in the mixed layer, with maximum export occurring several months after maximum fluxes of BSi and CaCO3. Export fluxes are episodic at OSP despite perennially low chlorophyll concentrations showing little seasonality. As a result of episodically high fluxes, 40-50% of MARK7 traps with narrow sampling bottles became clogged during deployment at 3800 m. Given the common occurrence of this problem globally, traps with larger bottom orifices should become standard protocol. Sediment traps provide an excellent opportunity to test sedimentary tracers of past ocean conditions. In this regard, POC content at OSP is a poor indicator of mass or POC flux because POC is diluted by BSi and CaCO3 when mass flux is high. The annual cycle of BSi flux and a reanalysis of surface nutrient data show the spring delay in [Si(OH)4] decline, based on mixed-layer nutrient climatology, results from intense mixing in spring rather than delayed diatom growth as previously proposed. The annual cycle of POC flux, normalized to measures of net community production of organic carbon (NCPOC) in summer-fall (Emerson and Stump, 2010), implies an annual NCPOC of 3.6-5.3 mol m-2 y-1. This rate is similar to estimates of new production and of water-column OC remineralization plus deep POC flux, two equivalencies to NCPOC. It is also similar to estimates of export production at OSP made from global modeling, but it is double estimates of NCPOC based on mass balance of mixed-layer tracers. The estimate of NCPOC and a CaCO3:OC export ratio of 0.18 determined from trap data gives a net community production of CaCO3 (NCPIC) of 0.65-0.95 mol m-2 y-1 in agreement with water-column CaCO3 dissolution plus deep CaCO3 flux. The similarity between the CaCO3:POC flux ratio at 50 m and the CaCO3:POC production ratio from bottle incubations (Lipsen et al., 2007) requires that ∼70% of CaCO3 production must dissolve in the euphotic zone to match the rate of POC recycling at OSP. Flux climatologies at 1000 m and 3800 m imply sediments caught at 3800 m include a component sinking rapidly (the primary flux; ∼120-350 m d-1) and another component sinking slowly (the secondary flux; ∼10-20 m d-1). A mass-balance model finds that secondary fluxes contribute ∼40% to the annual mass flux at 3800 m. Based on compositional evidence and on the arrival times at 3800 m, the secondary flux likely derives from disaggregated primary fluxes with an additional lithogenic component transported horizontally to the bathypelagic zone at OSP. Remineralization of BSi, CaCO3, OC and N estimated from decreasing flux with depth in the bathypelagic zone agrees with estimates for the Pacific Ocean based on water-column tracers provided trapping efficiency at 1000 m is 0.6-0.8 and at 3800 m is 1. Alternatively, the estimates based on tracers may include a component of seafloor remineralization. In this case, remineralization in the water column at OSP is at least 30-45% of the remineralization determined by tracers, with the remainder occurring at the seafloor.

A Novel Field Deployable Point-of-Care Diagnostic Test for Cutaneous Leishmaniasis

DTIC Science & Technology

2015-10-01

include localized cutaneous leishmaniasis (LCL), and destructive nasal and oropharyngeal lesions of mucosal leishmaniasis (ML). LCL in the New World...the high costs, personnel training and need of sophisticated equipment. Therefore, novel methods to detect leishmaniasis at the POC are urgently needed...To date, there is no field-standardized molecular method based on DNA amplification coupled with Lateral Flow reading to detect leishmaniasis

Assessment of a bedside test for N-terminal pro B-type natriuretic peptide (NT-proBNP) to differentiate cardiac from non-cardiac causes of pleural effusion in cats.

PubMed

Wurtinger, Gabriel; Henrich, Estelle; Hildebrandt, Nicolai; Wiedemann, Nicola; Schneider, Matthias; Hassdenteufel, Esther

2017-12-20

Cats with pleural effusion represent common emergencies in small animal practice. The aim of this prospective study was to investigate the diagnostic ability of a point-of-care ELISA (POC-ELISA) for the measurement of N-terminal pro B-type natriuretic peptide (NT-proBNP) to differentiate cardiac from non-cardiac disease in cats with pleural effusion. The sample material for use of this rapid test was either plasma or diluted pleural effusion. Twenty cats with moderate to severe pleural effusion were prospectively recruited. The cats were grouped into two groups, with or without congestive heart failure (CHF; N-CHF), after complete work-up. Blood and effusion were collected in EDTA tubes. Plasma and pleural effusion supernatants were transferred into stabilizer tubes and frozen. POC-ELISA for NT-proBNP was performed with plasma and diluted effusion (1:1). Quantitative NT-proBNP measurement was performed in plasma and diluted and undiluted effusions. Six cats were assigned to the CHF group. Of the 14 cats in the N-CHF group, 6 had concurrent cardiac abnormalities that were not responsible for the effusion. For the detection of CHF, the test displayed respective sensitivities and specificities of 100% and 79% in plasma and 100% and 86% in diluted pleural fluid. Receiver operating characteristic (ROC) analysis for quantitative NT-proBNP measurement of plasma and diluted and undiluted pleural effusions displayed areas under the curve of 0.98, sensitivities of 100% and specificities of 86%. The optimum cut-off was calculated at 399 pmol/l in plasma and 229 pmol/l in the diluted effusion and 467 pmol/l in the undiluted effusion. POC-ELISA for NT-proBNP in both plasma and diluted pleural effusion was suitable to differentiate cardiac from non-cardiac causes of feline pleural effusion. According to our results, use of pleural effusion is feasible, but dilution of the effusion before measurement seems to improve specificity.

Methods for the field evaluation of quantitative G6PD diagnostics: a review.

PubMed

Ley, Benedikt; Bancone, Germana; von Seidlein, Lorenz; Thriemer, Kamala; Richards, Jack S; Domingo, Gonzalo J; Price, Ric N

2017-09-11

Individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency are at risk of severe haemolysis following the administration of 8-aminoquinoline compounds. Primaquine is the only widely available 8-aminoquinoline for the radical cure of Plasmodium vivax. Tafenoquine is under development with the potential to simplify treatment regimens, but point-of-care (PoC) tests will be needed to provide quantitative measurement of G6PD activity prior to its administration. There is currently a lack of appropriate G6PD PoC tests, but a number of new tests are in development and are likely to enter the market in the coming years. As these are implemented, they will need to be validated in field studies. This article outlines the technical details for the field evaluation of novel quantitative G6PD diagnostics such as sample handling, reference testing and statistical analysis. Field evaluation is based on the comparison of paired samples, including one sample tested by the new assay at point of care and one sample tested by the gold-standard reference method, UV spectrophotometry in an established laboratory. Samples can be collected as capillary or venous blood; the existing literature suggests that potential differences in capillary or venous blood are unlikely to affect results substantially. The collection and storage of samples is critical to ensure preservation of enzyme activity, it is recommended that samples are stored at 4 °C and testing occurs within 4 days of collection. Test results can be visually presented as scatter plot, Bland-Altman plot, and a histogram of the G6PD activity distribution of the study population. Calculating the adjusted male median allows categorizing results according to G6PD activity to calculate standard performance indicators and to perform receiver operating characteristic (ROC) analysis.

Dry Electrodes for ECG and Pulse Transit Time for Blood Pressure: A Wearable Sensor and Smartphone Communication Approach

NASA Astrophysics Data System (ADS)

Shyamkumar, Prashanth

Cardiovascular Diseases (CVDs) have been a major cause for deaths in both men and women in United States. Cerebrovascular Diseases like Strokes are known to have origins in CVDs as well. Moreover, nearly 18 Million Americans have a history of myocardial infarction and are currently undergoing cardiac rehabilitation. Consequently, CVDs are the highest costing disease groups and cost more than all types of cancer combined. However, significant cost reduction is possible through the effective use of the vast advances in embedded and pervasive electronic devices for healthcare. These devices can automate and move a significant portion of disease management to the patient's home through cyber connectivity, a concept known as point-of-care (POC) diagnostics and healthcare services. POC can minimize hospital visits and potentially avoid admission altogether with prognostic tools that give advanced notice of any abnormalities or chronic illnesses so that the treatment can be planned in advance. The POC concept requires continuous remote health monitoring. Therefore, the various sensors needed for comprehensive monitoring need to be worn daily and throughout the day. Moreover, true "roaming" capability is necessary so that it does not restrict the user's travel or his/her quotidian activities. Two biomedical signals namely, Electrocardiogram (ECG) and Blood Pressure are important diagnostic tests in assessing the cardiac health of a person. To that end, the research presented in this thesis: First , describes the development of a remote monitoring solution based on Bluetooth(TM), smartphones and cyber infrastructure for cardiac care called e-nanoflex. Second, Sensors for ECG that are compatible with everyday life style namely, (a) dry, gel-less vertically aligned gold nanowire electrodes, (b) dry textile-based conductive sensor electrodes to address the need for this technology to monitor cardiovascular diseases in women are tested with e-nanoflex and discussed. Third, non-invasive, cuff-less Blood pressure estimation based on Pulse Transit Time with multiple synchronized sensor nodes, is implemented with e-nanoflex and the results are discussed.

Toward unstained cytology and complete blood counts at the point of care (Conference Presentation)

NASA Astrophysics Data System (ADS)

Zuluaga, Andres F.; Pierce, Mark C.; MacAulay, Calum E.

2017-02-01

Cytology tests, whether performed on body fluids, aspirates, or scrapings are commonly used to detect, diagnose, and monitor a wide variety of health conditions. Complete blood counts (CBCs) quantify the number of red and white blood cells in a blood volume, as well as the different types of white blood cells. There is a critical unmet need for an instrument that can perform CBCs at the point of care (POC), and there is currently no product in the US that can perform this test at the bedside. We have developed a system that is capable of tomographic images with sub-cellular resolution with consumer-grade broadband (LED) sources and CMOS detectors suitable for POC implementation of CBC tests. The systems consists of cascaded static Michelson and Sagnac interferometers that map phase (encoding depth) and a transverse spatial dimension onto a two-dimensional output plane. Our approach requires a 5 microliter sample, can be performed in 5 minutes or less, and does not require staining or other processing as it relies on intrinsic contrast. We will show results directly imaging and differentiating unstained blood cells using supercontinuum fiber lasers and LEDs as sources and CMOS cameras as sensors. We will also lay out the follow up steps needed, including image segmentation, analysis and classification, to verify performance and advance toward CBCs that can be performed bedside and do not require CLIA-certified laboratories.

Towards biomarker-based tests that can facilitate decisions about prevention and management of preeclampsia in low-resource settings.

PubMed

Acestor, Nathalie; Goett, Jane; Lee, Arthur; Herrick, Tara M; Engelbrecht, Susheela M; Harner-Jay, Claudia M; Howell, Bonnie J; Weigl, Bernhard H

2016-01-01

In recent years, an increasing amount of literature is emerging on candidate urine and blood-based biomarkers associated with incidence and severity of preeclampsia (PE) in pregnant women. While enthusiasm on the usefulness of several of these markers in predicting PE is evolving, essentially all work so far has focused on the needs of high-resource settings and high-income countries, resulting primarily in multi-parameter laboratory assays based on proteomic and metabolomics analysis techniques. These highly complex methods, however, require laboratory capabilities that are rarely available or affordable in low-resource settings (LRS). The importance of quantifying maternal and perinatal risks and identifying which pregnancies can be safely prolonged is also much greater in LRS, where intensive care facilities that can rapidly respond to PE-related health threats for women and infants are limited. For these reasons, simple, low cost, sensitive, and specific point-of-care (POC) tests are needed that can be performed by antenatal health care providers in LRS and that can facilitate decisions about detection and management of PE. Our study aims to provide a comprehensive systematic review of current and emerging blood and urine biomarkers for PE, not only on the basis of their clinical performance, but also of their suitability to be used in LRS-compatible test formats, such as lateral flow and other variants of POC rapid assays.

A Paper-Based Device for Performing Loop-Mediated Isothermal Amplification with Real-Time Simultaneous Detection of Multiple DNA Targets.

PubMed

Seok, Youngung; Joung, Hyou-Arm; Byun, Ju-Young; Jeon, Hyo-Sung; Shin, Su Jeong; Kim, Sanghyo; Shin, Young-Beom; Han, Hyung Soo; Kim, Min-Gon

2017-01-01

Paper-based diagnostic devices have many advantages as a one of the multiple diagnostic test platforms for point-of-care (POC) testing because they have simplicity, portability, and cost-effectiveness. However, despite high sensitivity and specificity of nucleic acid testing (NAT), the development of NAT based on a paper platform has not progressed as much as the others because various specific conditions for nucleic acid amplification reactions such as pH, buffer components, and temperature, inhibitions from technical differences of paper-based device. Here, we propose a paper-based device for performing loop-mediated isothermal amplification (LAMP) with real-time simultaneous detection of multiple DNA targets. We determined the optimal chemical components to enable dry conditions for the LAMP reaction without lyophilization or other techniques. We also devised the simple paper device structure by sequentially stacking functional layers, and employed a newly discovered property of hydroxynaphthol blue fluorescence to analyze real-time LAMP signals in the paper device. This proposed platform allowed analysis of three different meningitis DNA samples in a single device with single-step operation. This LAMP-based multiple diagnostic device has potential for real-time analysis with quantitative detection of 10 2 -10 5 copies of genomic DNA. Furthermore, we propose the transformation of DNA amplification devices to a simple and affordable paper system approach with great potential for realizing a paper-based NAT system for POC testing.

A Paper-Based Device for Performing Loop-Mediated Isothermal Amplification with Real-Time Simultaneous Detection of Multiple DNA Targets

PubMed Central

Seok, Youngung; Joung, Hyou-Arm; Byun, Ju-Young; Jeon, Hyo-Sung; Shin, Su Jeong; Kim, Sanghyo; Shin, Young-Beom; Han, Hyung Soo; Kim, Min-Gon

2017-01-01

Paper-based diagnostic devices have many advantages as a one of the multiple diagnostic test platforms for point-of-care (POC) testing because they have simplicity, portability, and cost-effectiveness. However, despite high sensitivity and specificity of nucleic acid testing (NAT), the development of NAT based on a paper platform has not progressed as much as the others because various specific conditions for nucleic acid amplification reactions such as pH, buffer components, and temperature, inhibitions from technical differences of paper-based device. Here, we propose a paper-based device for performing loop-mediated isothermal amplification (LAMP) with real-time simultaneous detection of multiple DNA targets. We determined the optimal chemical components to enable dry conditions for the LAMP reaction without lyophilization or other techniques. We also devised the simple paper device structure by sequentially stacking functional layers, and employed a newly discovered property of hydroxynaphthol blue fluorescence to analyze real-time LAMP signals in the paper device. This proposed platform allowed analysis of three different meningitis DNA samples in a single device with single-step operation. This LAMP-based multiple diagnostic device has potential for real-time analysis with quantitative detection of 102-105 copies of genomic DNA. Furthermore, we propose the transformation of DNA amplification devices to a simple and affordable paper system approach with great potential for realizing a paper-based NAT system for POC testing. PMID:28740546

High particulate organic carbon export during the decline of a vast diatom bloom in the Atlantic sector of the Southern Ocean

NASA Astrophysics Data System (ADS)

Roca-Martí, Montserrat; Puigcorbé, Viena; Iversen, Morten H.; van der Loeff, Michiel Rutgers; Klaas, Christine; Cheah, Wee; Bracher, Astrid; Masqué, Pere

2017-04-01

Carbon fixation by phytoplankton plays a key role in the uptake of atmospheric CO2 in the Southern Ocean. Yet, it still remains unclear how efficiently the particulate organic carbon (POC) is exported and transferred from ocean surface waters to depth during phytoplankton blooms. In addition, little is known about the processes that control the flux attenuation within the upper twilight zone. Here, we present results of downward POC and particulate organic nitrogen fluxes during the decline of a vast diatom bloom in the Atlantic sector of the Southern Ocean in summer 2012. We used thorium-234 (234Th) as a particle tracer in combination with drifting sediment traps (ST). Their simultaneous use evidenced a sustained high export rate of 234Th at 100 m depth in the weeks prior to and during the sampling period. The entire study area, of approximately 8000 km2, showed similar vertical export fluxes in spite of the heterogeneity in phytoplankton standing stocks and productivity, indicating a decoupling between production and export. The POC fluxes at 100 m were high, averaging 26±15 mmol C m-2 d-1, although the strength of the biological pump was generally low. Only <20% of the daily primary production reached 100 m, presumably due to an active recycling of carbon and nutrients. Pigment analyses indicated that direct sinking of diatoms likely caused the high POC transfer efficiencies ( 60%) observed between 100 and 300 m, although faecal pellets and transport of POC linked to zooplankton vertical migration might have also contributed to downward fluxes.

Different sources and degradation state of dissolved, particulate, and sedimentary organic matter along the Eurasian Arctic coastal margin

NASA Astrophysics Data System (ADS)

Karlsson, Emma; Gelting, Johan; Tesi, Tommaso; van Dongen, Bart; Andersson, August; Semiletov, Igor; Charkin, Alexander; Dudarev, Oleg; Gustafsson, Örjan

2016-06-01

Thawing Arctic permafrost causes massive fluvial and erosional releases of dissolved and particulate organic carbon (DOC and POC) to coastal waters. Here we investigate how different sources and degradation of remobilized terrestrial carbon may affect large-scale carbon cycling, by comparing molecular and dual-isotope composition of waterborne high molecular weight DOC (>1 kD, aka colloidal OC), POC, and sedimentary OC (SOC) across the East Siberian Arctic Shelves. Lignin phenol fingerprints demonstrate a longitudinal trend in relative contribution of terrestrial sources to coastal OC. Wax lipids and cutins were not detected in colloidal organic carbon (COC), in contrast to POC and SOC, suggesting that different terrestrial carbon pools partition into different aquatic carrier phases. The Δ14C signal suggests overwhelmingly contemporary sources for COC, while POC and SOC are dominated by old C from Ice Complex Deposit (ICD) permafrost. Monte Carlo source apportionment (δ13C, Δ14C) constrained that COC was dominated by terrestrial OC from topsoil permafrost (65%) and marine plankton (25%) with smaller contribution ICD and other older permafrost stocks (9%). This distribution is likely a result of inherent compositional matrix differences, possibly driven by organomineral associations. Modern OC found suspended in the surface water may be more exposed to degradation, in contrast to older OC that preferentially settles to the seafloor where it may be degraded on a longer timescale. The different sources which partition into DOC, POC, and SOC appear to have vastly different fates along the Eurasian Arctic coastal margin and may possibly respond on different timescales to climate change.

Content and functional specifications for a standards-based multidisciplinary rounding tool to maintain continuity across acute and critical care.

PubMed

Collins, Sarah; Hurley, Ann C; Chang, Frank Y; Illa, Anisha R; Benoit, Angela; Laperle, Sarah; Dykes, Patricia C

2014-01-01

Maintaining continuity of care (CoC) in the inpatient setting is dependent on aligning goals and tasks with the plan of care (POC) during multidisciplinary rounds (MDRs). A number of locally developed rounding tools exist, yet there is a lack of standard content and functional specifications for electronic tools to support MDRs within and across settings. To identify content and functional requirements for an MDR tool to support CoC. We collected discrete clinical data elements (CDEs) discussed during rounds for 128 acute and critical care patients. To capture CDEs, we developed and validated an iPad-based observational tool based on informatics CoC standards. We observed 19 days of rounds and conducted eight group and individual interviews. Descriptive and bivariate statistics and network visualization were conducted to understand associations between CDEs discussed during rounds with a particular focus on the POC. Qualitative data were thematically analyzed. All analyses were triangulated. We identified the need for universal and configurable MDR tool views across settings and users and the provision of messaging capability. Eleven empirically derived universal CDEs were identified, including four POC CDEs: problems, plan, goals, and short-term concerns. Configurable POC CDEs were: rationale, tasks/'to dos', pending results and procedures, discharge planning, patient preferences, need for urgent review, prognosis, and advice/guidance. Some requirements differed between settings; yet, there was overlap between POC CDEs. We recommend an initial list of 11 universal CDEs for continuity in MDRs across settings and 27 CDEs that can be configured to meet setting-specific needs.

The relationship between land use and emerging and legacy contaminants in an Apex predator, the bottlenose dolphin (Tursiops truncatus), from two adjacent estuarine watersheds.

PubMed

Adams, Jeffrey; Speakman, Todd; Zolman, Eric; Mitchum, Greg; Wirth, Edward; Bossart, Gregory D; Fair, Patricia A

2014-11-01

Persistent organohalogen contaminant (POC) exposure is of concern in marine mammals due to the potential for adverse health effects. Studies have examined POCs in marine mammals on a regional scale; however, limited data exists on POC concentrations relative to land use and watersheds. Examine geographical variation of POC concentrations in bottlenose dolphins as it relates to land, and watershed, use. POC (PCBs, DDTs, and PBDEs) concentrations were measured in blubber of bottlenose dolphins (n= 40) sampled in estuarine waters near Charleston, SC. Photo-identification sighting histories were used to assess the dolphins' use of estuarine waters in two adjacent watersheds (Cooper Subbasin and Stono Subbasin) in the study area and to determine land use (developed, forested, agriculture, and wetland) associations. Dolphins with ≥ 75% of their sightings in the Cooper Subbasin, which is characterized by a higher degree of developed land use, exhibited higher levels of PCBs, PBDEs, and total pesticides than those with ≥ 75% of their sightings in the Stono Subbasin. Observed differences were significant for ΣPBDEs and ΣDDTs/ΣPCBs ratio. Significant positive correlations were observed between ΣPBDEs and developed land use and between ΣDDTs/ΣPCBs and wetland land use. A significant negative correlation was observed between ΣDDTs/ΣPCBs and developed land use. The spatial pattern of PBDEs and the ΣDDTs/ΣPCBs detected in dolphin blubber was shown to vary significantly with adjacent watersheds and land use associations. Copyright © 2014 Elsevier Inc. All rights reserved.

Evaluation of the performance of urine albumin, creatinine and albumin-creatinine ratio assay on two POCT analyzers relative to a central laboratory method.

PubMed

Omoruyi, Felix O; Mustafa, Gul M; Okorodudu, Anthony O; Petersen, John R

2012-03-22

The evaluation of microalbumin, creatinine and albumin-creatinine ratio is very important in patients with diabetes for the early detection of kidney disease and the identification of patients at risk for complications from diabetes or hypertension. A total of 88 spot urine samples previously analyzed using the Vitros 5,1 FS (creatinine) and Beckman Coulter Immage (microalbumin) located in the central laboratory and having microalbumin and creatinine values within the Afinion and DCA Vantage reportable ranges were run on 2 point of care (POC) instruments (Siemens DCA Vantage and Axis-Shield Afinion). The mean values for the DCA Vantage were: 42.6 mg/l for albumin, 10.3 mol/l for creatinine, and 5.4 mg/mol for ACR. For the Afinion AS100, the mean values were: 48.5mg/l for albumin, 9.5 mol/l for creatinine, and 6.7 mg/mol for ACR. The mean values obtained for CL were: 40.8 mg/l for albumin, 10.0 mol/l for creatinine, and 5.4 mg/mol for ACR. All POC analyzers showed good correlation to the central laboratory tests for microalbumin, creatinine and albumin creatinine ratio (ACR) for Afinion (R(2)=0.954, 0.974, and 0.964, respectively) and DCA Vantage (R(2)=0.989, 0.987, and 0.991, respectively). With the exception of the DCA Vantage ACR (p=0.53), the levels of microalbumin, creatinine and ACR obtained for the Afinion and DCA Vantage instruments as compared to the CL were statistically different (p<0.05). The inter and intraday imprecision for both POC instruments was <2.9% and total imprecision <8.7%. The 2 instruments evaluated in this study were in good agreement with the quantitative laboratory results and thus can be used for microalbumin, creatinine and ACR assays at the POC. However, facilities using Afinion will have to use different normal range for ACR. Copyright © 2011 Elsevier B.V. All rights reserved.

Mercury and Organic Carbon Relationships in Streams Draining Forested Upland/Peatland Watersheds

Treesearch

R. K. Kolka; D. F. Grigal; E. S. Verry; E. A. Nater

1999-01-01

We determined the fluxes of total mecury (HgT), total organic carbon (TOC), and dissolved organic carbon (DOC) from five upland/peatland watersheds at the watershed outlet. The difference between TOC and DOC was defined as particulate OC (POC). Concentrations of HgT showed moderate to strong relationships with POC (R2 = 0.77) when all watersheds...

Mercury and Organic Carbon Relationships in Streams Draining Forested Upland/Peatland Watersheds

Treesearch

Randall K. Kolka; D.F. Grigal; E.S. Verry; E.A. Nater

1999-01-01

We determined the fluxes of total mercury (HgT), total organic carbon (TOC), and dissolved organic carbon (DOC) from five upland/peatland watersheds at the watershed outlet. The difference between TOC and DOC was defined as particulate OC (POC). Concentrations of HgT showed moderate to strong relationships with POC (R2 = 0.77) when ah...

Incorporation of Chemical Contaminants into the Combined ICM/SEDZLJ Models

DTIC Science & Technology

2012-03-01

concentration of toxicant 1 in water column (g m-3) Δt = model integration time step (s) The deposition of toxicant 2 is: ERDC/EL TR-12-6 13 Δ Dpoc ...D Fpw TOX w t POC     1 2 (10) in which: Dpoc = deposition of labile and refractory particulate organic carbon (g m-2) POC = labile plus

Competing values: a case study of Pennsylvania's elk herd as a tourism attraction

Treesearch

Jeffrey A. Walsh; Leonard K. Long

2002-01-01

This paper qualitatively investigates the Pennsylvania Game Commission's (POC) "Elk Trap and Transfer Project" as a tourism development initiative. Beginning in 1998, a three-year trap and transfer project was initiated by the POC to relocate 33 elk from Elk County to Clinton County. The ecological goals of this project included re-establishing an elk...

LINE-1 Mediated Insertion into Poc1a (Protein of Centriole 1 A) Causes Growth Insufficiency and Male Infertility in Mice

PubMed Central

Geister, Krista A.; Brinkmeier, Michelle L.; Cheung, Leonard Y.; Wendt, Jennifer; Oatley, Melissa J.; Burgess, Daniel L.; Kozloff, Kenneth M.; Cavalcoli, James D.; Oatley, Jon M.; Camper, Sally A.

2015-01-01

Skeletal dysplasias are a common, genetically heterogeneous cause of short stature that can result from disruptions in many cellular processes. We report the identification of the lesion responsible for skeletal dysplasia and male infertility in the spontaneous, recessive mouse mutant chagun. We determined that Poc1a, encoding protein of the centriole 1a, is disrupted by the insertion of a processed Cenpw cDNA, which is flanked by target site duplications, suggestive of a LINE-1 retrotransposon-mediated event. Mutant fibroblasts have impaired cilia formation and multipolar spindles. Male infertility is caused by defective spermatogenesis early in meiosis and progressive germ cell loss. Spermatogonial stem cell transplantation studies revealed that Poc1a is essential for normal function of both Sertoli cells and germ cells. The proliferative zone of the growth plate is small and disorganized because chondrocytes fail to re-align after cell division and undergo increased apoptosis. Poc1a and several other genes associated with centrosome function can affect the skeleton and lead to skeletal dysplasias and primordial dwarfisms. This mouse mutant reveals how centrosome dysfunction contributes to defects in skeletal growth and male infertility. PMID:26496357

Optimization-based reconstruction for reduction of CBCT artifact in IGRT

NASA Astrophysics Data System (ADS)

Xia, Dan; Zhang, Zheng; Paysan, Pascal; Seghers, Dieter; Brehm, Marcus; Munro, Peter; Sidky, Emil Y.; Pelizzari, Charles; Pan, Xiaochuan

2016-04-01

Kilo-voltage cone-beam computed tomography (CBCT) plays an important role in image guided radiation therapy (IGRT) by providing 3D spatial information of tumor potentially useful for optimizing treatment planning. In current IGRT CBCT system, reconstructed images obtained with analytic algorithms, such as FDK algorithm and its variants, may contain artifacts. In an attempt to compensate for the artifacts, we investigate optimization-based reconstruction algorithms such as the ASD-POCS algorithm for potentially reducing arti- facts in IGRT CBCT images. In this study, using data acquired with a physical phantom and a patient subject, we demonstrate that the ASD-POCS reconstruction can significantly reduce artifacts observed in clinical re- constructions. Moreover, patient images reconstructed by use of the ASD-POCS algorithm indicate a contrast level of soft-tissue improved over that of the clinical reconstruction. We have also performed reconstructions from sparse-view data, and observe that, for current clinical imaging conditions, ASD-POCS reconstructions from data collected at one half of the current clinical projection views appear to show image quality, in terms of spatial and soft-tissue-contrast resolution, higher than that of the corresponding clinical reconstructions.

Carbon and nitrogen cycling in the Zhubi coral reef lagoon of the South China Sea as revealed by 210Po and 210Pb.

PubMed

Yang, W F; Huang, Y P; Chen, M; Qiu, Y S; Li, H B; Zhang, L

2011-05-01

The radionuclides (210)Po and (210)Pb were examined to trace the cycling of particulate organic carbon (POC) and particulate organic nitrogen (PON) in the Zhubi coral reef lagoon. The net export flux of POC to the open sea is 14 mg Cm(-2) d(-1). However, the net exchange of PON has not yet been observed. On average, the vertical export fluxes in the lagoon of POC and PON, as derived from (210)Po/(210)Pb disequilibria, are 43 mg Cm(-2) d(-1) and 13.8 mg Nm(-2) d(-1), respectively. The deficit of (210)Po relative to (210)Pb in particulate matter provides evidence for the degradation of particulate organic matter. According to the mass balance budgets, 310 mg Cm(-2) d(-1) and 121 mg Nm(-2) d(-1) were recycled into dissolved fractions. Based on a first-order kinetics model, the degradation rate constants of POC and PON are 0.28 and 0.30 m(-1), respectively. Thus, (210)Po and (210)Pb can quantify the cycling of carbon and nitrogen in this coral lagoon. Copyright © 2011 Elsevier Ltd. All rights reserved.

Satellite-Derived Distributions, Inventories and Fluxes of Dissolved and Particulate Organic Matter Along the Northeastern U.S. Continental Margin

NASA Technical Reports Server (NTRS)

Mannino, A.; Hooker, S. B.; Hyde, K.; Novak, M. G.; Pan, X.; Friedrichs, M.; Cahill, B.; Wilkin, J.

2011-01-01

Estuaries and the coastal ocean experience a high degree of variability in the composition and concentration of particulate and dissolved organic matter (DOM) as a consequence of riverine and estuarine fluxes of terrigenous DOM, sediments, detritus and nutrients into coastal waters and associated phytoplankton blooms. Our approach integrates biogeochemical measurements, optical properties and remote sensing to examine the distributions and inventories of organic carbon in the U.S. Middle Atlantic Bight and Gulf of Maine. Algorithms developed to retrieve colored DOM (CDOM), Dissolved (DOC) and Particulate Organic Carbon (POC) from NASA's MODIS-Aqua and SeaWiFS satellite sensors are applied to quantify the distributions and inventories of DOC and POC. Horizontal fluxes of DOC and POC from the continental margin to the open ocean are estimated from SeaWiFS and MODIS-Aqua distributions of DOC and POC and horizontal divergence fluxes obtained from the Northeastern North Atlantic ROMS model. SeaWiFS and MODIS imagery reveal the importance of estuarine outflow to the export of CDOM and DOC to the coastal ocean and a net community production of DOC on the shelf.

Molecular analysis of fungal populations in patients with oral candidiasis using next-generation sequencing.

PubMed

Imabayashi, Yumi; Moriyama, Masafumi; Takeshita, Toru; Ieda, Shinsuke; Hayashida, Jun-Nosuke; Tanaka, Akihiko; Maehara, Takashi; Furukawa, Sachiko; Ohta, Miho; Kubota, Keigo; Yamauchi, Masaki; Ishiguro, Noriko; Yamashita, Yoshihisa; Nakamura, Seiji

2016-06-16

Oral candidiasis is closely associated with changes in oral fungal biodiversity and is caused primarily by Candida albicans. However, the widespread use of empiric and prophylactic antifungal drugs has caused a shift in fungal biodiversity towards other Candida or yeast species. Recently, next-generation sequencing (NGS) has provided an improvement over conventional culture techniques, allowing rapid comprehensive analysis of oral fungal biodiversity. In this study, we used NGS to examine the oral fungal biodiversity of 27 patients with pseudomembranous oral candidiasis (POC) and 66 healthy controls. The total number of fungal species in patients with POC and healthy controls was 67 and 86, respectively. The copy number of total PCR products and the proportion of non-C. albicans, especially C. dubliniensis, in patients with POC, were higher than those in healthy controls. The detection patterns in patients with POC were similar to those in controls after antifungal treatment. Interestingly, the number of fungal species and the copy number of total PCR products in healthy controls increased with aging. These results suggest that high fungal biodiversity and aging might be involved in the pathogenesis of oral candidiasis. We therefore conclude that NGS is a useful technique for investigating oral candida infections.

Development of Biodegradable Poly(citrate)-Polyhedral Oligomeric Silsesquioxanes Hybrid Elastomers with High Mechanical Properties and Osteogenic Differentiation Activity.

PubMed

Du, Yuzhang; Yu, Meng; Chen, Xiaofeng; Ma, Peter X; Lei, Bo

2016-02-10

Biodegradable elastomeric biomaterials have attracted much attention in tissue engineering due to their biomimetic viscoelastic behavior and biocompatibility. However, the low mechanical stability at hydrated state, fast biodegradation in vivo, and poor osteogenic activity greatly limited bioelastomers applications in bone tissue regeneration. Herein, we develop a series of poly(octanediol citrate)-polyhedral oligomeric silsesquioxanes (POC-POSS) hybrids with highly tunable elastomeric behavior (hydrated state) and biodegradation and osteoblasts biocompatibility through a facile one-pot thermal polymerization strategy. POC-POSS hybrids show significantly improved stiffness and ductility in either dry or hydrated conditions, as well as good antibiodegradation ability (20-50% weight loss in 3 months). POC-POSS hybrids exhibit significantly enhanced osteogenic differentiation through upregulating alkaline phosphatase (ALP) activity, calcium deposition, and expression of osteogenic markers (ALPL, BGLAP, and Runx2). The high mechanical stability at hydrated state and enhanced osteogenic activity make POC-POSS hybrid elastomers promising as scaffolds and nanoscale vehicles for bone tissue regeneration and drug delivery. This study may also provide a new strategy (controlling the stiffness under hydrated condition) to design advanced hybrid biomaterials with high mechanical properties under physiological condition for tissue regeneration applications.

Low-dose X-ray computed tomography image reconstruction with a combined low-mAs and sparse-view protocol.

PubMed

Gao, Yang; Bian, Zhaoying; Huang, Jing; Zhang, Yunwan; Niu, Shanzhou; Feng, Qianjin; Chen, Wufan; Liang, Zhengrong; Ma, Jianhua

2014-06-16

To realize low-dose imaging in X-ray computed tomography (CT) examination, lowering milliampere-seconds (low-mAs) or reducing the required number of projection views (sparse-view) per rotation around the body has been widely studied as an easy and effective approach. In this study, we are focusing on low-dose CT image reconstruction from the sinograms acquired with a combined low-mAs and sparse-view protocol and propose a two-step image reconstruction strategy. Specifically, to suppress significant statistical noise in the noisy and insufficient sinograms, an adaptive sinogram restoration (ASR) method is first proposed with consideration of the statistical property of sinogram data, and then to further acquire a high-quality image, a total variation based projection onto convex sets (TV-POCS) method is adopted with a slight modification. For simplicity, the present reconstruction strategy was termed as "ASR-TV-POCS." To evaluate the present ASR-TV-POCS method, both qualitative and quantitative studies were performed on a physical phantom. Experimental results have demonstrated that the present ASR-TV-POCS method can achieve promising gains over other existing methods in terms of the noise reduction, contrast-to-noise ratio, and edge detail preservation.

LINE-1 Mediated Insertion into Poc1a (Protein of Centriole 1 A) Causes Growth Insufficiency and Male Infertility in Mice.

PubMed

Geister, Krista A; Brinkmeier, Michelle L; Cheung, Leonard Y; Wendt, Jennifer; Oatley, Melissa J; Burgess, Daniel L; Kozloff, Kenneth M; Cavalcoli, James D; Oatley, Jon M; Camper, Sally A

2015-10-01

Skeletal dysplasias are a common, genetically heterogeneous cause of short stature that can result from disruptions in many cellular processes. We report the identification of the lesion responsible for skeletal dysplasia and male infertility in the spontaneous, recessive mouse mutant chagun. We determined that Poc1a, encoding protein of the centriole 1a, is disrupted by the insertion of a processed Cenpw cDNA, which is flanked by target site duplications, suggestive of a LINE-1 retrotransposon-mediated event. Mutant fibroblasts have impaired cilia formation and multipolar spindles. Male infertility is caused by defective spermatogenesis early in meiosis and progressive germ cell loss. Spermatogonial stem cell transplantation studies revealed that Poc1a is essential for normal function of both Sertoli cells and germ cells. The proliferative zone of the growth plate is small and disorganized because chondrocytes fail to re-align after cell division and undergo increased apoptosis. Poc1a and several other genes associated with centrosome function can affect the skeleton and lead to skeletal dysplasias and primordial dwarfisms. This mouse mutant reveals how centrosome dysfunction contributes to defects in skeletal growth and male infertility.

A dynamic box model of bioactive elements in the southern Taiwan Strait

NASA Astrophysics Data System (ADS)

Hua-Sheng, Hong; Shao-Ling, Shang

1994-06-01

A dynamic box model was applied to study the characteristics of biogeochemical cycling of PO4-P, NO3-N, AOU, POC and PON in the southern Taiwan Strait region based on the field data of the “Minnan Taiwan Bank Fishing Ground Upwelling Ecosystem Study” during the period of Dec. 1987-Nov. 1988. According to the unique hydrological and topographical features of the region, six boxes and three layers were considered in the model. The variation rates and fluxes of elements induced by horizontal current, upwelling, by diffusion, sinking of particles and biogeochemical processes were estimated respectively. Results further confirmed that upwellings had important effects in this region. The nearshore upwelling areas had net input fluxes of nutrients brought by upwelling water, also had high depletion rates of nutrients and production rates of particulate organic matter and dissolved oxygen. The abnormal net production of nutrients in the middle layer, (10-30 m) indicated the important role of bacteria in this high production region. The phytoplankton POC contributed about 28% of the total POC. POC settling out from the euphotic zone was estimated to be 2×10-6 g/(m2·s) which was about 35% of the primary production.

Teaching and evaluating point of care learning with an Internet-based clinical-question portfolio.

PubMed

Green, Michael L; Reddy, Siddharta G; Holmboe, Eric

2009-01-01

Diplomates in the American Board of Internal Medicine (ABIM) Maintenance of Certification (MOC) program satisfy the self-evaluation of medical knowledge requirement by completing open-book multiple-choice exams. However, this method remains unlikely to affect practice change and often covers content areas not relevant to diplomates' practices. We developed and evaluated an Internet-based point of care (POC) learning portfolio to serve as an alternative. Participants enter information about their clinical questions, including characteristics, information pursuit, application, and practice change. After documenting 20 questions, they reflect upon a summary report and write commitment-to-change statements about their learning strategies. They can link to help screens and medical information resources. We report on the beta test evaluation of the module, completed by 23 internists and 4 internal medicine residents. Participants found the instructions clear and navigated the module without difficulty. The majority preferred the POC portfolio to multiple-choice examinations, citing greater relevance to their practice, guidance in expanding their palette of information resources, opportunity to reflect on their learning needs, and "credit" for self-directed learning related to their patients. Participants entered a total of 543 clinical questions, of which 250 (46%) resulted in a planned practice change. After completing the module, 14 of 27 (52%) participants committed to at least 1 change in their POC learning strategies. Internists found the portfolio valuable, preferred it to multiple-choice examinations, often changed their practice after pursuing clinical questions, and productively reflected on their learning strategies. The ABIM will offer this portfolio as an elective option in MOC.

Platinum Nanocatalyst Amplification: Redefining the Gold Standard for Lateral Flow Immunoassays with Ultrabroad Dynamic Range

PubMed Central

2017-01-01

Paper-based lateral flow immunoassays (LFIAs) are one of the most widely used point-of-care (PoC) devices; however, their application in early disease diagnostics is often limited due to insufficient sensitivity for the requisite sample sizes and the short time frames of PoC testing. To address this, we developed a serum-stable, nanoparticle catalyst-labeled LFIA with a sensitivity surpassing that of both current commercial and published sensitivities for paper-based detection of p24, one of the earliest and most conserved biomarkers of HIV. We report the synthesis and characterization of porous platinum core–shell nanocatalysts (PtNCs), which show high catalytic activity when exposed to complex human blood serum samples. We explored the application of antibody-functionalized PtNCs with strategically and orthogonally modified nanobodies with high affinity and specificity toward p24 and established the key larger nanoparticle size regimes needed for efficient amplification and performance in LFIA. Harnessing the catalytic amplification of PtNCs enabled naked-eye detection of p24 spiked into sera in the low femtomolar range (ca. 0.8 pg·mL–1) and the detection of acute-phase HIV in clinical human plasma samples in under 20 min. This provides a versatile absorbance-based and rapid LFIA with sensitivity capable of significantly reducing the HIV acute phase detection window. This diagnostic may be readily adapted for detection of other biomolecules as an ultrasensitive screening tool for infectious and noncommunicable diseases and can be capitalized upon in PoC settings for early disease detection. PMID:29215864

Gastrointestinal manifestations of hereditary angioedema diagnosed by ultrasound in the emergency department.

PubMed

Riguzzi, Christine; Losonczy, Lia; Teismann, Nathan; Herring, Andrew A; Nagdev, Arun

2014-11-01

Abdominal angioedema is a less recognized type of angioedema, which can occur in patients with hereditary angioedema (HAE). The clinical signs may range from subtle, diffuse abdominal pain and nausea, to overt peritonitis. We describe two cases of abdominal angioedema in patients with known HAE that were diagnosed in the emergency department by point-of-care (POC) ultrasound. In each case, the patient presented with isolated abdominal complaints and no signs of oropharyngeal edema. Findings on POC ultrasound included intraperitoneal free fluid and bowel wall edema. Both patients recovered uneventfully after receiving treatment. Because it can be performed rapidly, requires no ionizing radiation, and can rule out alternative diagnoses, POC ultrasound holds promise as a valuable tool in the evaluation and management of patients with HAE.

International Space Station (ISS)

NASA Image and Video Library

2001-02-01

The Payload Operations Center (POC) is the science command post for the International Space Station (ISS). Located at NASA's Marshall Space Flight Center in Huntsville, Alabama, it is the focal point for American and international science activities aboard the ISS. The POC's unique capabilities allow science experts and researchers around the world to perform cutting-edge science in the unique microgravity environment of space. The POC is staffed around the clock by shifts of payload flight controllers. At any given time, 8 to 10 flight controllers are on consoles operating, plarning for, and controlling various systems and payloads. This photograph shows the Operations Controllers (OC) at their work stations. The OC coordinates the configuration of resources to enable science operations, such as power, cooling, commanding, and the availability of items like tools and laboratory equipment.

Miniaturized Bio-and Chemical-Sensors for Point-of-Care Monitoring of Chronic Kidney Diseases

PubMed Central

Tricoli, Antonio

2018-01-01

This review reports the latest achievements in point-of-care (POC) sensor technologies for the monitoring of ammonia, creatinine and urea in patients suffering of chronic kidney diseases (CKDs). Abnormal levels of these nitrogen biomarkers are found in the physiological fluids, such as blood, urine and sweat, of CKD patients. Delocalized at-home monitoring of CKD biomarkers via integration of miniaturized, portable, and low cost chemical- and bio-sensors in POC devices, is an emerging approach to improve patients’ health monitoring and life quality. The successful monitoring of CKD biomarkers, performed on the different body fluids by means of sensors having strict requirements in term of size, cost, large-scale production capacity, response time and simple operation procedures for use in POC devices, is reported and discussed. PMID:29565315

Miniaturized Bio-and Chemical-Sensors for Point-of-Care Monitoring of Chronic Kidney Diseases.

PubMed

Tricoli, Antonio; Neri, Giovanni

2018-03-22

This review reports the latest achievements in point-of-care (POC) sensor technologies for the monitoring of ammonia, creatinine and urea in patients suffering of chronic kidney diseases (CKDs). Abnormal levels of these nitrogen biomarkers are found in the physiological fluids, such as blood, urine and sweat, of CKD patients. Delocalized at-home monitoring of CKD biomarkers via integration of miniaturized, portable, and low cost chemical- and bio-sensors in POC devices, is an emerging approach to improve patients' health monitoring and life quality. The successful monitoring of CKD biomarkers, performed on the different body fluids by means of sensors having strict requirements in term of size, cost, large-scale production capacity, response time and simple operation procedures for use in POC devices, is reported and discussed.

Export and losses of blue carbon-derived particulate and dissolved organic carbon (POC and DOC) in blackwater river-dominated and particle-dominated estuaries

NASA Astrophysics Data System (ADS)

Arellano, A. R.; Bianchi, T. S.; Osburn, C. L.; D'Sa, E. J.; Oviedo Vargas, D.; Ward, N. D.; Joshi, I.; Ko, D. S.

2016-12-01

Globally, coastal blue carbon environments (wetlands, seagrass beds and mangroves) sequester an estimated 67-215 Tg C yr-1. While most blue carbon research has focused on carbon burial/stocks and habitat fragmentation of these communities, few studies have examined the export and loss of blue carbon sources of particulate organic matter (POM) and dissolved organic matter (DOM) to adjacent coastal waters. These shifts in losses of DOM and POM are also partly due to large-scale changes in land-use and climate change. Due to the complexity of vascular plant inputs to estuarine systems (e.g. terrestrial vs. blue carbon), being able to separate blue carbon sources of POM and DOM are critical. Here, we investigate the temporal variability of the abundance, sources and breakdown of particulate and dissolved organic carbon (POC and DOC) in particle-dominated (Barataria Bay) and blackwater river-dominated (Apalachicola Bay) estuaries in the northern Gulf of Mexico, using bulk carbon, dissolved lignin phenols, δ13C and dissolved CO2. The range of DOC:POC ratios for Barataria and Apalachicola bays were 0.5-3.1 and 2.3-57.0, respectively. δ13C-POC values were more depleted in Apalachicola (x̅=-27.3‰) compared to those in Barataria (x̅=-24.8‰), and C:N ratios were higher in Apalachicola (x̅=10.8) than in Barataria (x̅=9.3). Although there was no significant temporal variability with δ13C-POC in both systems, Barataria Bay had the highest POC (0.08-0.23 mM) and C:N (7.0-13.4) values during spring, when enhanced southerly winds likely resulted in higher resuspension and marsh erosion rates. Additionally, in Apalachicola, the lowest C:N values (6.2-16.1) were observed during the dry season when fluvial DOM inputs were minimal. The highest dissolved lignin phenol and DOC (0.10-2.98 mM) concentrations in Apalachicola occurred during the wet season, reflecting the importance of riverine inputs to this system. In particular, the Carabelle River plume region had C:V and S:V values that indicated woody inputs (long-leaf pine communities), while the bay proper/East Bay were more indicative of blue carbon sources. Spatial and temporal variability of dissolved CO2 concentrations will be discussed as it relates to possible linkages with the export and losses of blue carbon-derived DOC and POC.

Geochemical composition of river loads in the Tropical Andes: first insights from the Ecuadorian Andes

NASA Astrophysics Data System (ADS)

Tenorio Poma, Gustavo; Govers, Gerard; Vanacker, Veerle; Bouillon, Steven; Álvarez, Lenín; Zhiminaicela, Santiago

2015-04-01

Processes governing the transport of total suspended material (TSM), total dissolved solids (TDS) and particulate organic carbon (POC) are currently not well known for Tropical Andean river systems. We analyzed the geochemical behavior and the budgets of the particulate and dissolved loads for several sub-catchments in the Paute River basin in the southern Ecuadorian Andes, and examined how anthropogenic activities influenced the dynamics of riverine suspended and dissolved loads. We gathered a large dataset by regularly sampling 8 rivers for their TSM, POC, and TDS. Furthermore, we determined the major elements in the dissolved load and stable isotope composition (δ13C) of both the POC, and the dissolved inorganic carbon (DIC). The rivers that were sampled flow through a wide range of land uses including: 3 nature conservation areas (100 - 300 Km²), an intensive grassland and arable zone (142 Km²); downstream of two cities (1611 and 443 Km²), and 2 degraded basins (286 and 2492 Km²). We described the geochemical characteristics of the river loads both qualitatively and quantitatively. Important differences in TSM, POC and TDS yields were found between rivers: the concentration of these loads increases according with human activities within the basins. For all rivers, TSM, TDS and POC concentrations were dependent on discharge. Overall, a clear relation between TSM and POC (r²=0.62) was observed in all tributaries. The C:N ratios and δ13CPOC suggest that the POC in most rivers is mainly derived from soil organic matter eroded from soils dominated by C3 vegetation (δ13CPOC < -22‰). Low Ca:Si ratios (<1)and high δ13CDIC (-9 to -4) in the Yanuncay, Tomebamba1 and Machángara, rivers suggest that weathering of silica rocks is dominant in these catchments, and that the DIC is mainly derived from the soil or atmospheric CO2. In contrast, the Ca:Si ratio was high for the Burgay and Jadán rivers (1-13), and the low δ13CDIC values (-9 to -15) suggest that carbonate rock weathering is dominant in these catchments. Our data suggest that anthropogenic effects are the dominant control on variations in sediment and carbon export between the river catchments we studied, while differences in topography are of lesser importance. However, the effects of anthropogenic disturbances may confound with differences in lithology, as the disturbed catchments are underlain by relatively soft, carbonate-rich sedimentary rocks while the less disturbed catchments are underlain by the silicate-rich rocks.

Pre-aged soil organic carbon as a major component of the Yellow River suspended load: Regional significance and global relevance

NASA Astrophysics Data System (ADS)

Tao, Shuqin; Eglinton, Timothy I.; Montluçon, Daniel B.; McIntyre, Cameron; Zhao, Meixun

2015-03-01

Large rivers connect the continents and the oceans, and corresponding material fluxes have a global impact on marine biogeochemistry. The Yellow River transports vast quantities of suspended sediments to the ocean, yet the nature of the particulate organic carbon (POC) carried by this system is not well known. The focus of this study is to characterize the sources, composition and age of suspended POC collected near the terminus of this river system, focusing on the abundance and carbon isotopic composition (13C and 14C) of specific biomarkers. The concentrations of vascular plant wax lipids (long-chain (≥C24) n-alkanes, n-fatty acids) and POC co-varied with total suspended solid (TSS) concentrations, indicating that both were controlled by the overall terrestrial sediment flux. POC exhibited relatively uniform δ13C values (-23.8 to -24.2‰), and old radiocarbon ages (4000-4640 yr). However, different biomarkers exhibited a wide range of 14C ages. Short-chain (C16, C18) fatty acid 14C ages were variable but generally the youngest organic components (from 502 yr to modern), suggesting they reflect recently biosynthesized material. Lignin phenol 14C ages were also variable and relatively young (1070 yr to modern), suggesting rapid export of carbon from terrestrial primary production. In contrast, long-chain plant wax lipids display relatively uniform and significantly older 14C ages (1500-1800 yr), likely reflecting inputs of pre-aged, mineral-associated soil OC from the Yellow River drainage basin. Even-carbon-numbered n-alkanes yielded the oldest 14C ages (up to 26 000 yr), revealing the presence of fossil (petrogenic) OC. Two isotopic mass balance approaches were explored to quantitively apportion different OC sources in Yellow River suspended sediments. Results indicate that the dominant component of POC (53-57%) is substantially pre-aged (1510-1770 yr), and likely sourced from the extensive loess-paleosol deposits outcropping within the drainage basin. Of the remaining POC, between 10 and 31% is fossil in origin (>26 000 yr), resulting from the physical erosion of ancient sedimentary rock and input of fossil fuel residues from anthropogenic activity, and 16-33% is modern carbon derived from terrestrial and aquatic productivity. These findings have implications both regarding the provenance and vintage of organic matter signatures emanating from the Yellow River basin and similar catchments containing extensive paleosol sequences, as well as for the reactivity and fate of this POC upon supply to adjacent marginal seas.

78 FR 73553 - Prospective Grant of Exclusive License: Development of Cripto-1 Point of Care (POC) Tests and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-06

...This is notice, in accordance with 35 U.S.C. 209 and 37 CFR Part 404, that the National Institutes of Health, Department of Health and Human Services, is contemplating the grant of an exclusive patent license to practice the inventions embodied in the following U.S. Patents and Patent Applications to Beacon Biomedical LLC (``Beacon'') located in Scottsdale, AZ, USA.

Dynamics of transparent exopolymer particle (TEP) production and aggregation during viral infection of the coccolithophore, Emiliania huxleyi.

PubMed

Nissimov, Jozef I; Vandzura, Rebecca; Johns, Christopher T; Natale, Frank; Haramaty, Liti; Bidle, Kay D

2018-06-19

Emiliania huxleyi produces calcium carbonate (CaCO 3 ) coccoliths and transparent exopolymer particles (TEP), sticky, acidic carbohydrates that facilitate aggregation. E. huxleyi's extensive oceanic blooms are often terminated by coccolithoviruses (EhVs) with the transport of cellular debris and associated particulate organic carbon (POC) to depth being facilitated by TEP-bound "marine snow" aggregates. The dynamics of TEP production and particle aggregation in response to EhV infection are poorly understood. Using flow cytometry, spectrophotometry, and FlowCam visualization of alcian blue (AB)-stained aggregates, we assessed TEP production and the size spectrum of aggregates for E. huxleyi possessing different degrees of calcification and cellular CaCO 3 :POC mass ratios, when challenged with two EhVs (EhV207 and EhV99B1). FlowCam imaging also qualitatively assessed the relative amount of AB-stainable TEP (i.e. blue:red ratio of each particle). We show significant increases in TEP during early phase EhV207-infection (∼24 hours) of calcifying strains and a shift towards large aggregates following EhV99B1-infection. We also observed the formation of large aggregates with low blue:red ratios, suggesting that other exopolymer substances contribute towards aggregation. Our findings show the potential for virus infection and the associated response of their hosts to impact carbon flux dynamics and provide incentive to explore these dynamics in natural populations. This article is protected by copyright. All rights reserved. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

U.S. Army Toxic Metal Reduction Program: Demonstrating Alternatives to Hexavalent Chromium and Cadmium in Surface Finishing

DTIC Science & Technology

2014-11-18

only) Medium Cal: M242 25mm Bushmaster, M230 30mm, GAU-12 25mm, 30mm Bushmaster II, EAPS 50mm POC: Vic Champagne , ARL, victor.k.champagne.civ...Shielding for Electronic Shelters) POC: Vic Champagne , ARL, victor.k.champagne.civ@mail.mil Cold Spray – Portable System and Internal Diameter

Improving predicted protein loop structure ranking using a Pareto-optimality consensus method.

PubMed

Li, Yaohang; Rata, Ionel; Chiu, See-wing; Jakobsson, Eric

2010-07-20

Accurate protein loop structure models are important to understand functions of many proteins. Identifying the native or near-native models by distinguishing them from the misfolded ones is a critical step in protein loop structure prediction. We have developed a Pareto Optimal Consensus (POC) method, which is a consensus model ranking approach to integrate multiple knowledge- or physics-based scoring functions. The procedure of identifying the models of best quality in a model set includes: 1) identifying the models at the Pareto optimal front with respect to a set of scoring functions, and 2) ranking them based on the fuzzy dominance relationship to the rest of the models. We apply the POC method to a large number of decoy sets for loops of 4- to 12-residue in length using a functional space composed of several carefully-selected scoring functions: Rosetta, DOPE, DDFIRE, OPLS-AA, and a triplet backbone dihedral potential developed in our lab. Our computational results show that the sets of Pareto-optimal decoys, which are typically composed of approximately 20% or less of the overall decoys in a set, have a good coverage of the best or near-best decoys in more than 99% of the loop targets. Compared to the individual scoring function yielding best selection accuracy in the decoy sets, the POC method yields 23%, 37%, and 64% less false positives in distinguishing the native conformation, indentifying a near-native model (RMSD < 0.5A from the native) as top-ranked, and selecting at least one near-native model in the top-5-ranked models, respectively. Similar effectiveness of the POC method is also found in the decoy sets from membrane protein loops. Furthermore, the POC method outperforms the other popularly-used consensus strategies in model ranking, such as rank-by-number, rank-by-rank, rank-by-vote, and regression-based methods. By integrating multiple knowledge- and physics-based scoring functions based on Pareto optimality and fuzzy dominance, the POC method is effective in distinguishing the best loop models from the other ones within a loop model set.

Nitrate removal from agricultural drainage ditch sediments with amendments of organic carbon: Potential for an innovative best management practice

USGS Publications Warehouse

Faust, Derek R.; Kröger, Robert; Miranda, Leandro E.; Rush, Scott A.

2016-01-01

Agricultural fertilizer applications have resulted in loading of nutrients to agricultural drainage ditches in the Lower Mississippi Alluvial Valley. The purpose of this study was to determine effects of dissolved organic carbon (DOC) and particulate organic carbon (POC) amendments on nitrate-nitrogen (NO3−-N) removal from overlying water, pore water, and sediment of an agricultural drainage ditch. Two experiments were conducted. In experiment 1, control (i.e., no amendment), DOC, and POC treatments were applied in laboratory microcosms for time intervals of 3, 7, 14, and 28 days. In experiment 2, control, DOC, and POC treatments were applied in microcosms at C/N ratios of 5:1, 10:1, 15:1, and 20:1. There were statistically significant effects of organic carbon amendments in experiment 1 (F2,71 = 27.1, P < 0.001) and experiment 2 (F2,53 = 39.1, P < 0.001), time (F1,71 = 14.5, P < 0.001) in experiment 1, and C/N ratio (F1,53 = 36.5, P < 0.001) in experiment 2. NO3−-N removal varied from 60 to 100 % in overlying water among all treatments. The lowest NO3−-N removals in experiment 1 were observed in the control at 14 and 28 days, which were significantly less than in DOC and POC 14- and 28-day treatments. In experiment 2, significantly less NO3−-N was removed in overlying water of the control compared to DOC and POC treatments at all C/N ratios. Amendments of DOC and POC made to drainage ditch sediment: (1) increased NO3−-N removal, especially over longer time intervals (14 to 28 days); (2) increased NO3−-N removal, regardless of C/N ratio; and (3) NO3−-N removal was best at a 5:1 C/N ratio. This study provides support for continued investigation on the use of organic carbon amendments as a best management practice for NO3−-N removal in agricultural drainage ditches.

Improving predicted protein loop structure ranking using a Pareto-optimality consensus method

PubMed Central

2010-01-01

Background Accurate protein loop structure models are important to understand functions of many proteins. Identifying the native or near-native models by distinguishing them from the misfolded ones is a critical step in protein loop structure prediction. Results We have developed a Pareto Optimal Consensus (POC) method, which is a consensus model ranking approach to integrate multiple knowledge- or physics-based scoring functions. The procedure of identifying the models of best quality in a model set includes: 1) identifying the models at the Pareto optimal front with respect to a set of scoring functions, and 2) ranking them based on the fuzzy dominance relationship to the rest of the models. We apply the POC method to a large number of decoy sets for loops of 4- to 12-residue in length using a functional space composed of several carefully-selected scoring functions: Rosetta, DOPE, DDFIRE, OPLS-AA, and a triplet backbone dihedral potential developed in our lab. Our computational results show that the sets of Pareto-optimal decoys, which are typically composed of ~20% or less of the overall decoys in a set, have a good coverage of the best or near-best decoys in more than 99% of the loop targets. Compared to the individual scoring function yielding best selection accuracy in the decoy sets, the POC method yields 23%, 37%, and 64% less false positives in distinguishing the native conformation, indentifying a near-native model (RMSD < 0.5A from the native) as top-ranked, and selecting at least one near-native model in the top-5-ranked models, respectively. Similar effectiveness of the POC method is also found in the decoy sets from membrane protein loops. Furthermore, the POC method outperforms the other popularly-used consensus strategies in model ranking, such as rank-by-number, rank-by-rank, rank-by-vote, and regression-based methods. Conclusions By integrating multiple knowledge- and physics-based scoring functions based on Pareto optimality and fuzzy dominance, the POC method is effective in distinguishing the best loop models from the other ones within a loop model set. PMID:20642859