Science.gov

Sample records for general screening method

  1. Offering fragile X syndrome carrier screening: a prospective mixed-methods observational study comparing carrier screening of pregnant and non-pregnant women in the general population

    PubMed Central

    Martyn, M; Anderson, V; Archibald, A; Carter, R; Cohen, J; Delatycki, M; Donath, S; Emery, J; Halliday, J; Hill, M; Sheffield, L; Slater, H; Tassone, F; Younie, S; Metcalfe, S

    2013-01-01

    Introduction Fragile X syndrome (FXS) is the leading cause of inherited intellectual and developmental disability. Policy development relating to carrier screening programmes for FXS requires input from large studies examining not only test uptake but also psychosocial aspects. This study will compare carrier screening in pregnant and non-pregnant populations, examining informed decision-making, psychosocial issues and health economics. Methods and Analysis Pregnant and non-pregnant women are being recruited from general practices and obstetric services. Women receive study information either in person or through clinic mail outs. Women are provided pretest counselling by a genetic counsellor and make a decision about testing in their own time. Data are being collected from two questionnaires: one completed at the time of making the decision about testing and the second 1 month later. Additional data are gathered through qualitative interviews conducted at several time points with a subset of participating women, including all women with a positive test result, and with staff from recruiting clinics. A minimum sample size of 500 women/group has been calculated to give us 88% power to detect a 10% difference in test uptake and 87% power to detect a 10% difference in informed choice between the pregnant and non-pregnant groups. Questionnaire data will be analysed using descriptive statistics and multivariate logistic regression models. Interview data will be thematically analysed. Willingness-to-pay and cost effectiveness analyses will also be performed. Recruitment started in July 2009 and data collection will be completed by December 2013. Ethics and Dissemination Ethics approval has been granted by the Universities of Melbourne and Western Australia and by recruiting clinics, where required. Results will be reported in peer-reviewed publications, conference presentations and through a website http://www.fragilexscreening.net.au. The results of this study will

  2. Allergic sensitization: screening methods.

    PubMed

    Ladics, Gregory S; Fry, Jeremy; Goodman, Richard; Herouet-Guicheney, Corinne; Hoffmann-Sommergruber, Karin; Madsen, Charlotte B; Penninks, André; Pomés, Anna; Roggen, Erwin L; Smit, Joost; Wal, Jean-Michel

    2014-01-01

    Experimental in silico, in vitro, and rodent models for screening and predicting protein sensitizing potential are discussed, including whether there is evidence of new sensitizations and allergies since the introduction of genetically modified crops in 1996, the importance of linear versus conformational epitopes, and protein families that become allergens. Some common challenges for predicting protein sensitization are addressed: (a) exposure routes; (b) frequency and dose of exposure; (c) dose-response relationships; (d) role of digestion, food processing, and the food matrix; (e) role of infection; (f) role of the gut microbiota; (g) influence of the structure and physicochemical properties of the protein; and (h) the genetic background and physiology of consumers. The consensus view is that sensitization screening models are not yet validated to definitively predict the de novo sensitizing potential of a novel protein. However, they would be extremely useful in the discovery and research phases of understanding the mechanisms of food allergy development, and may prove fruitful to provide information regarding potential allergenicity risk assessment of future products on a case by case basis. These data and findings were presented at a 2012 international symposium in Prague organized by the Protein Allergenicity Technical Committee of the International Life Sciences Institute's Health and Environmental Sciences Institute. PMID:24739743

  3. Allergic sensitization: screening methods

    PubMed Central

    2014-01-01

    Experimental in silico, in vitro, and rodent models for screening and predicting protein sensitizing potential are discussed, including whether there is evidence of new sensitizations and allergies since the introduction of genetically modified crops in 1996, the importance of linear versus conformational epitopes, and protein families that become allergens. Some common challenges for predicting protein sensitization are addressed: (a) exposure routes; (b) frequency and dose of exposure; (c) dose-response relationships; (d) role of digestion, food processing, and the food matrix; (e) role of infection; (f) role of the gut microbiota; (g) influence of the structure and physicochemical properties of the protein; and (h) the genetic background and physiology of consumers. The consensus view is that sensitization screening models are not yet validated to definitively predict the de novo sensitizing potential of a novel protein. However, they would be extremely useful in the discovery and research phases of understanding the mechanisms of food allergy development, and may prove fruitful to provide information regarding potential allergenicity risk assessment of future products on a case by case basis. These data and findings were presented at a 2012 international symposium in Prague organized by the Protein Allergenicity Technical Committee of the International Life Sciences Institute’s Health and Environmental Sciences Institute. PMID:24739743

  4. Screening Outcomes Following Implementation of Digital Breast Tomosynthesis in a General-Population Screening Program

    PubMed Central

    McCarthy, Anne Marie; Kontos, Despina; Synnestvedt, Marie; Tan, Kay See; Heitjan, Daniel F.; Schnall, Mitchell

    2014-01-01

    Background Early data on breast cancer screening utilizing digital breast tomosynthesis (DBT) combined with digital mammography (DM) have shown improvements in false-positive and false-negative screening rates compared with DM alone. However, these trials were performed at sites where conventional mammographic screening was concurrently performed, possibly leading to selection biases or with complex, multireader algorithms not reflecting general clinical practice. Our study reports the impact on screening outcomes for DBT screening implemented in an entire clinic population. Methods Recall rates, cancer detection, and positive predictive values of screening were compared for 15571 women screened with DBT and 10728 screened with DM alone prior to DBT implementation at a single breast imaging center. Generalized linear mixed-effects models were used to estimate the odds ratio (OR) for recall rate adjusted for age, race, presence of prior mammograms, breast density and reader. All statistical tests were two-sided. Results DBT screening showed a statistically significant reduction in recalls compared to DM alone. For the entire population, there were 16 fewer recalls (8.8% vs 10.4%, P <.001, adjusted OR = 0.80, 95% confidence interval [CI] = 0.74 to 0.88, P < .001) and 0.9 additional cancers detected per 1000 screened with DBT compared to DM alone. There was a statistically significant increase in PPV1 (6.2% vs 4.4%, P = .047). In women younger than age 50 years screened with DBT, there were 17 fewer recalls (12.3% vs 14.0%, P = .02) and 3.6 additional cancer detected per 1000 screened (5.7 vs 2.2 per 1000, P = .02). Conclusions Our data support the clinical implementation of DBT in breast cancer screening; however, larger prospective trials are needed to validate our findings in specific patient subgroups. PMID:25313245

  5. Display screen and method of manufacture therefor

    NASA Technical Reports Server (NTRS)

    Dubin, Matthew B. (Inventor); Larson, Brent D. (Inventor)

    2002-01-01

    A screen assembly that combines an angle re-distributing prescreen with a conventional diffusion screen. The prescreen minimizes or eliminates the sensitivity of the screen assembly to projector location. The diffusion screen provides other desirable screen characteristics. Compatible screen structures, along with methods for fabricating high resolution prescreens and methods and devices for maintaining the desired relationship between the prescreen and the diffusion screen are contemplated.

  6. Fast 3-D seismic modeling and prestack depth migration using generalized screen methods. Final report for period January 1, 1998 - December 31, 2000

    SciTech Connect

    Toksoz, M. Nafi

    2001-03-31

    Completed a theoretical analysis of phase screen propagators to answer several critical questions: the existence of a singularity in the Green's function for the case of a zero vertical wavenumber, the stability and accuracy of such propagators, and the effects of backscattering for large contrast heterogeneous media. The theory is based on separating the wavefield into forescattering and backscattering parts. The approach is robust and appropriate for earth structures with high velocity contrast. This theory also resolves the apparent singularity problem that has persisted in generalized screen propagator formulations. With this formulation we studied the effects of the commonly used approximations as a function of the degree of velocity contrast in the media.

  7. Screening for Generalized Anxiety Disorder (GAD)

    MedlinePlus

    ... Screening for Posttraumatic Stress Disorder (PTSD) Screening for Social Anxiety Disorder Screening for Specific Phobias Screening for an Anxiety Disorder: Children Screening for an Anxiety Disorder: Family Member Self-Help Strategies: Webinars to Calm Anxious Minds "Triumph" E-News ...

  8. Prestack elastic generalized-screen migration for multicomponent data

    NASA Astrophysics Data System (ADS)

    Kim, Byoung Yeop; Seol, Soon Jee; Lee, Ho-Young; Byun, Joongmoo

    2016-03-01

    An efficient prestack depth migration method based on the elastic one-way wave equation was developed using an improved elastic generalized-screen propagator, which effectively describes the behavior of elastic waves with mode conversion at the interfaces and efficiently computes wave propagation in media with lateral velocity variations. The elastic propagator presented in this study was improved from the elastic generalized-screen propagator. Several terms of the vertical slowness right symbol with orders are corrected from the original formulation, and the vertical slowness operator in the propagator was expanded up to the 2nd order which yields a more accurate approximation. In each screen propagation step, the multicomponent wavefields are automatically separated into the P and S wavefields by the P-S decomposition operator included in the elastic generalized-screen propagator. This process facilitates the imaging of the P and S waves separately without any additional P and S separation process after the wavefield extrapolation. Impulse response tests of the improved elastic generalized-screen propagator in a uniform-property medium proved that propagation accuracy increases with order, even when large medium perturbations are assigned. Migration tests using the developed algorithm on a simple layered model and two complex models (the SEG/EAGE salt and elastic Marmousi-2 model) demonstrated the functional advantages and capabilities of the algorithm compared with elastic migration using the scalar wave equation.

  9. The organization of cervical screening in general practice

    PubMed Central

    Havelock, Christine; Edwards, Robert; Cuzick, Jack; Chamberlain, Jocelyn

    1988-01-01

    Well organized cervical screening in general practice can have considerable clinical and financial rewards. Yet in a randomized survey of general practitioners in the United Kingdom only 43% operated a system for cervical screening which allows previously untested women to be identified and invited for testing. A younger age of general practitioner, a more rural practice, a larger practice size, employment of a practice nurse, a belief in the effectiveness of cervical screening and a positive view of the time spent on screening were all strong predictors of an organized approach to cervical screening within a practice. Being female or having a female partner was not statistically associated with systematic screening. The results demonstrate a need for education within general practice which emphasizes the relevance and significance of cervical screening and the essential contribution that can be made by each individual general practitioner to the success of the whole cervical screening programme. PMID:3210183

  10. Screening fifth forces in generalized Proca theories

    NASA Astrophysics Data System (ADS)

    De Felice, Antonio; Heisenberg, Lavinia; Kase, Ryotaro; Tsujikawa, Shinji; Zhang, Ying-li; Zhao, Gong-Bo

    2016-05-01

    For a massive vector field with derivative self-interactions, the breaking of the gauge invariance allows the propagation of a longitudinal mode in addition to the two transverse modes. We consider generalized Proca theories with second-order equations of motion in a curved space-time and study how the longitudinal scalar mode of the vector field gravitates on a spherically symmetric background. We show explicitly that cubic-order self-interactions lead to the suppression of the longitudinal mode through the Vainshtein mechanism. Provided that the dimensionless coupling of the interaction is not negligible, this screening mechanism is sufficiently efficient to give rise to tiny corrections to gravitational potentials consistent with solar-system tests of gravity. We also study the quartic interactions with the presence of nonminimal derivative coupling with the Ricci scalar and find the existence of solutions where the longitudinal mode completely vanishes. Finally, we discuss the case in which the effect of the quartic interactions dominates over the cubic one and show that local gravity constraints can be satisfied under a mild bound on the parameters of the theory.

  11. Interlaboratory comparison of a general method to screen foods for pesticides using QuEChERs extraction with high performance liquid chromatography and high resolution mass spectrometry.

    PubMed

    Eitzer, Brian D; Hammack, Walter; Filigenzi, Michael

    2014-01-01

    An interlaboratory comparison of a multipesticide residue analytical method is reported. The goal of the comparison was to evaluate the potential for liquid chromatography/high resolution mass spectrometry along with a specific automated screening procedure to allow the determination of the presence or absence of a set of targeted compounds without additional manual review. The method utilized an off the shelf QuEChERs based extraction followed by analysis with an orbitrap mass spectrometer with the data evaluated by ToxID. The method was tested at three laboratories, with three produce matrices (spinach, carrots, and oranges), and three levels of spiked pesticides with all analyses in triplicate. A series of 247 compounds were tested, and it was found that the three laboratories produced consistent data; however, manual review was still necessary. The data was shown to have no false negatives for 211 compounds in the three produce matrixes at 200 ppb. Of these 211 compounds, 189 had no false negatives at 50 ppb, and 129 had no false negatives at 10 ppb. The HRMS method was shown to be robust with similar data being achieved by all three laboratories and detectable concentrations only slightly above the range shown for triple quadrupole MS/MS. PMID:24320559

  12. 43 CFR 11.23 - Preassessment screen-general.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... or OSC Report, unless doing so would unnecessarily delay the preassessment screen. (3) Where a... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Preassessment screen-general. 11.23... ASSESSMENTS Preassessment Phase § 11.23 Preassessment screen—general. (a) Requirement. Before beginning...

  13. 43 CFR 11.23 - Preassessment screen-general.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... or OSC Report, unless doing so would unnecessarily delay the preassessment screen. (3) Where a... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Preassessment screen-general. 11.23... ASSESSMENTS Preassessment Phase § 11.23 Preassessment screen—general. (a) Requirement. Before beginning...

  14. Take the sex out of STI screening! Views of young women on implementing chlamydia screening in General Practice

    PubMed Central

    Pavlin, Natasha L; Parker, Rhian; Fairley, Christopher K; Gunn, Jane M; Hocking, Jane

    2008-01-01

    Background Australia is developing a chlamydia screening program. This study aimed to determine the attitudes of young women to the introduction of chlamydia screening in Australian General Practice. Methods In-depth face-to-face interviews with 24 young women from across Victoria, Australia, attending a randomly selected sample of general practices. Results Young women reported that they would accept age-based screening for chlamydia in general practice, during both sexual-health and non-sexual-health related consultations. Trust in their general practitioner (GP) was reported to be a major factor in the acceptability of chlamydia screening. The women felt chlamydia screening should be offered to all young women rather than targeted at "high risk" women based on sexual history and they particularly emphasised the importance of normalising chlamydia screening. The women reported that they did not want to be asked to provide a sexual history as part of being asked to have a chlamydia test. Some reported that they would lie if asked how many partners they had had Conclusion Women do not want a sexual history taken when being asked to have a chlamydia test while attending a general practitioner. They prefer the offer of chlamydia screening to be based on age rather than assessment of sexual risk. Chlamydia screening needs to be normalised and destigmatised. PMID:18471280

  15. Neonatal thyroid screening: methods-efficiency-failures.

    PubMed

    Yordam, N; Ozon, A

    2003-12-01

    Newborn screening for congenital hypothyroidism (CH) is one of the major achievements of preventive medicine, as the condition occurs frequently (1/4000 newborns) and results in brain damage if not detected and treated in the first few days of life. Measurement of T4 and/or TSH in dried blood spots collected on the second through fifth days of life are the most widely used methods in screening programs for CH currently. Some children with the disease may be missd in any screening program, however, owing to factors related to the disease itself and the methods employed in its detection, as well as factors ascribed to the element of human error, ie screening errors. The methods employed in newborn screening programs for CH, their efficiency in disease detecetion, and biological factors as well as screening errors leading to missed cases are discussed. PMID:16444156

  16. Generalized Multicoincidence Analysis Methods

    SciTech Connect

    Warren, Glen A.; Smith, Leon E.; Aalseth, Craig E.; Ellis, J. E.; Valsan, Andrei B.; Mengesha, Wondwosen

    2005-10-01

    The ability to conduct automated trace radionuclide analysis at or near the sample collection point would provide a valuable tool for emergency response, nuclear forensics and environmental monitoring. Pacific Northwest National Laboratory is developing systems for this purpose based on dual gamma-ray spectrometers, e.g. NaI(TI) or HPGe, combined with thin organic scintillator sensors to detect light charged particles. Translating the coincident signatures recorded by these systems, which include , and , into the concentration of detectable radionuclides in the sample requires generalized multicoincidence analysis tools. The development and validation of the Coincidence Lookup Library, which currently contains the probabilities of single and coincidence signatures from more than 420 isotopes, is described. Also discussed is a method to calculate the probability of observing a coincidence signature which incorporates true coincidence summing effects. These effects are particularly important for high-geometric-efficiency detection systems. Finally, a process for validating the integrated analysis software package is demonstrated using GEANT 4 simulations of the prototype detector systems.

  17. Generalized Multicoincidence Analysis Methods

    SciTech Connect

    Warren, Glen A.; Smith, Leon E.; Aalseth, Craig E.; Ellis, J. E.; Valsan, Andrei B.; Mengesha, Wondwosen

    2006-02-01

    The ability to conduct automated trace radionuclide analysis at or near the sample collection point would provide a valuable tool for emergency response, environmental monitoring, and verification of treaties and agreements. Pacific Northwest National Laboratory is developing systems for this purpose based on dual gamma-ray spectrometers, e.g. NaI(TI) or HPGe, combined with thin organic scintillator sensors to detect light charged particles. Translating the coincident signatures recorded by these systems, which include beta-gamma, gamma-gamma and beta-gamma-gamma, into the concentration of detectable radionuclides in the sample requires generalized multicoincidence analysis tools. The development and validation of the Coincidence Lookup Library, which currently contains the probabilities of single and coincidence signatures from more than 420 isotopes, is described. Also discussed is a method to calculate the probability of observing a coincidence signature which incorporates true coincidence summing effects. These effects are particularly important for high-geometric-efficiency detection systems. Finally, a process for verifying the integrated analysis software package is demonstrated using GEANT 4 simulations of the prototype detector systems.

  18. LANL seismic screening method for existing buildings

    SciTech Connect

    Dickson, S.L.; Feller, K.C.; Fritz de la Orta, G.O.

    1997-01-01

    The purpose of the Los Alamos National Laboratory (LANL) Seismic Screening Method is to provide a comprehensive, rational, and inexpensive method for evaluating the relative seismic integrity of a large building inventory using substantial life-safety as the minimum goal. The substantial life-safety goal is deemed to be satisfied if the extent of structural damage or nonstructural component damage does not pose a significant risk to human life. The screening is limited to Performance Category (PC) -0, -1, and -2 buildings and structures. Because of their higher performance objectives, PC-3 and PC-4 buildings automatically fail the LANL Seismic Screening Method and will be subject to a more detailed seismic analysis. The Laboratory has also designated that PC-0, PC-1, and PC-2 unreinforced masonry bearing wall and masonry infill shear wall buildings fail the LANL Seismic Screening Method because of their historically poor seismic performance or complex behavior. These building types are also recommended for a more detailed seismic analysis. The results of the LANL Seismic Screening Method are expressed in terms of separate scores for potential configuration or physical hazards (Phase One) and calculated capacity/demand ratios (Phase Two). This two-phase method allows the user to quickly identify buildings that have adequate seismic characteristics and structural capacity and screen them out from further evaluation. The resulting scores also provide a ranking of those buildings found to be inadequate. Thus, buildings not passing the screening can be rationally prioritized for further evaluation. For the purpose of complying with Executive Order 12941, the buildings failing the LANL Seismic Screening Method are deemed to have seismic deficiencies, and cost estimates for mitigation must be prepared. Mitigation techniques and cost-estimate guidelines are not included in the LANL Seismic Screening Method.

  19. Generalized subspace correction methods

    SciTech Connect

    Kolm, P.; Arbenz, P.; Gander, W.

    1996-12-31

    A fundamental problem in scientific computing is the solution of large sparse systems of linear equations. Often these systems arise from the discretization of differential equations by finite difference, finite volume or finite element methods. Iterative methods exploiting these sparse structures have proven to be very effective on conventional computers for a wide area of applications. Due to the rapid development and increasing demand for the large computing powers of parallel computers, it has become important to design iterative methods specialized for these new architectures.

  20. Colorectal cancer screening of the general population in East Asia.

    PubMed

    Sano, Yasushi; Byeon, Jeong-Sik; Li, Xiao-Bo; Wong, Martin C S; Chiu, Han-Mo; Rerknimitr, Rungsun; Utsumi, Takahiro; Hattori, Santa; Sano, Wataru; Iwatate, Mineo; Chiu, Philip; Sung, Joseph

    2016-04-01

    In recent years, the incidence of colorectal cancer (CRC) has been increasing, and CRC has been becoming the major cause of cancer deaths in Asian countries. Therefore, an organized screening program to reduce CRC incidence and mortality is currently implemented in each country. In the present review, we summarize the current status and future perspectives of CRC screening of the general population in East Asian and South-East Asian countries. The fecal occult blood test is widely used for CRC screening in these countries, and its effectiveness in reducing CRC incidence and mortality has been demonstrated; however, the low participation rate in CRC screening programs is a problem to be solved in every country. Improvement in the public awareness of CRC and promotion of CRC screening by physicians will help to raise the participation rate and reduce the number of deaths caused by CRC. Regarding screening colonoscopy, several studies have recently demonstrated its effectiveness in reducing CRC incidence and mortality. However, at present, CRC screening colonoscopy is not adopted as a primary population-based screening tool because of staffing constraints in relation to large population sizes, increased medical costs, and potential adverse events (e.g. perforation and drug-induced anaphylaxis). Further study is required to consider colonoscopy as CRC screening that is established in Western countries. PMID:26595883

  1. Screening for Chlamydia is acceptable and feasible during Cervical Screening in General Practice.

    PubMed

    Hassan, S J; Dunphy, E; Navin, E; Marron, L; Fitzsimmons, C; Loy, A; O'Shea, B

    2016-01-01

    The incidence of Chlamydia trachomatis (CT) & Neisseria gonorrhoeae (NG) are rising in Ireland. Both are often undiagnosed and may cause infertility amongst other complications. CT/NG screening is not routinely offered during cervical cancer screening. This study aimed to ascertain the feasibility and acceptability of screening for CT/NG at time of smear and to measure the diagnostic yield. Screening was offered to women aged 25-40 years attending four participating general practices as part of Cervical Check. A retrospective review of the three months preceding the study period, indicated that out of 138 smears, CT/NG testing was performed in 10 (7%) of cases. 236 (93%) patients consented to screening for CT/NG. The detection rate for Chlamydia was 6 (2.4%), with no positive results for NG. Feedback from patients was positive. Interestingly, 42 (18%) of participants who completed the questionnaire believed STI screening was already part of the routine smear. PMID:26904785

  2. Generalized charge-screening in relativistic Thomas-Fermi model

    NASA Astrophysics Data System (ADS)

    Akbari-Moghanjoughi, M.

    2014-10-01

    In this paper, we study the charge shielding within the relativistic Thomas-Fermi model for a wide range of electron number-densities and the atomic-number of screened ions. A generalized energy-density relation is obtained using the force-balance equation and taking into account the Chandrasekhar's relativistic electron degeneracy pressure. By numerically solving a second-order nonlinear differential equation, the Thomas-Fermi screening length is investigated, and the results are compared for three distinct regimes of the solid-density, warm-dense-matter, and white-dwarfs (WDs). It is revealed that our nonlinear screening theory is compatible with the exponentially decaying Thomas-Fermi-type shielding predicted by the linear response theory. Moreover, the variation of relative Thomas-Fermi screening length shows that extremely dense quantum electron fluids are relatively poor charge shielders. Calculation of the total number of screening electrons around a nucleus shows that there is a position of maximum number of screening localized electrons around the screened nucleus, which moves closer to the point-like nucleus by increase in the plasma number density but is unaffected due to increase in the atomic-number value. It is discovered that the total number of screening electrons, ( N s ∝ r T F 3 / r d 3 where rTF and rd are the Thomas-Fermi and interparticle distance, respectively) has a distinct limit for extremely dense plasmas such as WD-cores and neutron star crusts, which is unique for all given values of the atomic-number. This is equal to saying that in an ultrarelativistic degeneracy limit of electron-ion plasma, the screening length couples with the system dimensionality and the plasma becomes spherically self-similar. Current analysis can provide useful information on the effects of relativistic correction to the charge screening for a wide range of plasma density, such as the inertial-confined plasmas and compact stellar objects.

  3. A Screening Method for Early Identification of Learning Disabilities.

    ERIC Educational Resources Information Center

    Coury, Janine P.; Nessa, Donald B.

    This study was conducted in order to develop and evaluate a systematic screening method which could be used by counselors and school psychologists in the identification of first graders showing characteristics generally associated with learning disabilities. The study was conducted within three Title I schools in a large sourthern metropolitan…

  4. High-throughput screening methods for nitrilases.

    PubMed

    Xue, Ya-Ping; Yang, Yue-Kai; Lv, Sheng-Zhi; Liu, Zhi-Qiang; Zheng, Yu-Guo

    2016-04-01

    Nitrilases have been widely acknowledged as important alternatives to chemical catalysts, as they have been proved to transform an immense variety of nitriles under mild conditions and often in a stereoselective or regioselective manner. In the discovery of new nitrilases to establish viable industrial processes, screening plays an important role in identifying which subset of candidates contains a nitrilase of interest from a collection of organisms, clone banks, or enzyme libraries. However, the traditional methods for evaluating the nitrilases are a time-consuming, laborious, and costly process and have been regarded as a bottleneck in developing these nitrilases as industrial biocatalysts. In the past few years, a number of high-throughput screening methods have been developed for rapid evaluation and identification of nitrilases. Here, we review the various methodologies developed for high-throughput screening of nitrilases and focus on their advantages and limitations. PMID:26894402

  5. Diagnostic Methods for Platelet Bacteria Screening: Current Status and Developments

    PubMed Central

    Störmer, Melanie; Vollmer, Tanja

    2014-01-01

    Summary Bacterial contamination of blood components and the prevention of transfusion-associated bacterial infection still remains a major challenge in transfusion medicine. Over the past few decades, a significant reduction in the transmission of viral infections has been achieved due to the introduction of mandatory virus screening. Platelet concentrates (PCs) represent one of the highest risks for bacterial infection. This is due to the required storage conditions for PCs in gas-permeable containers at room temperature with constant agitation, which support bacterial proliferation from low contamination levels to high titers. In contrast to virus screening, since 1997 in Germany bacterial testing of PCs is only performed as a routine quality control or, since 2008, to prolong the shelf life to 5 days. In general, bacterial screening of PCs by cultivation methods is implemented by the various blood services. Although these culturing systems will remain the gold standard, the significance of rapid methods for screening for bacterial contamination has increased over the last few years. These new methods provide powerful tools for increasing the bacterial safety of blood components. This article summarizes the course of policies and provisions introduced to increase bacterial safety of blood components in Germany. Furthermore, we give an overview of the different diagnostic methods for bacterial screening of PCs and their current applicability in routine screening processes. PMID:24659944

  6. Generalized high order compact methods.

    SciTech Connect

    Spotz, William F.; Kominiarczuk, Jakub

    2010-09-01

    The fundamental ideas of the high order compact method are combined with the generalized finite difference method. The result is a finite difference method that works on unstructured, nonuniform grids, and is more accurate than one would classically expect from the number of grid points employed.

  7. Generalized charge-screening in relativistic Thomas–Fermi model

    SciTech Connect

    Akbari-Moghanjoughi, M.

    2014-10-15

    In this paper, we study the charge shielding within the relativistic Thomas-Fermi model for a wide range of electron number-densities and the atomic-number of screened ions. A generalized energy-density relation is obtained using the force-balance equation and taking into account the Chandrasekhar's relativistic electron degeneracy pressure. By numerically solving a second-order nonlinear differential equation, the Thomas-Fermi screening length is investigated, and the results are compared for three distinct regimes of the solid-density, warm-dense-matter, and white-dwarfs (WDs). It is revealed that our nonlinear screening theory is compatible with the exponentially decaying Thomas-Fermi-type shielding predicted by the linear response theory. Moreover, the variation of relative Thomas-Fermi screening length shows that extremely dense quantum electron fluids are relatively poor charge shielders. Calculation of the total number of screening electrons around a nucleus shows that there is a position of maximum number of screening localized electrons around the screened nucleus, which moves closer to the point-like nucleus by increase in the plasma number density but is unaffected due to increase in the atomic-number value. It is discovered that the total number of screening electrons, (N{sub s}∝r{sub TF}{sup 3}/r{sub d}{sup 3} where r{sub TF} and r{sub d} are the Thomas-Fermi and interparticle distance, respectively) has a distinct limit for extremely dense plasmas such as WD-cores and neutron star crusts, which is unique for all given values of the atomic-number. This is equal to saying that in an ultrarelativistic degeneracy limit of electron-ion plasma, the screening length couples with the system dimensionality and the plasma becomes spherically self-similar. Current analysis can provide useful information on the effects of relativistic correction to the charge screening for a wide range of plasma density, such as the inertial-confined plasmas and compact stellar

  8. A Screening Method for Assessing Cumulative Impacts

    PubMed Central

    Alexeeff, George V.; Faust, John B.; August, Laura Meehan; Milanes, Carmen; Randles, Karen; Zeise, Lauren; Denton, Joan

    2012-01-01

    The California Environmental Protection Agency (Cal/EPA) Environmental Justice Action Plan calls for guidelines for evaluating “cumulative impacts.” As a first step toward such guidelines, a screening methodology for assessing cumulative impacts in communities was developed. The method, presented here, is based on the working definition of cumulative impacts adopted by Cal/EPA [1]: “Cumulative impacts means exposures, public health or environmental effects from the combined emissions and discharges in a geographic area, including environmental pollution from all sources, whether single or multi-media, routinely, accidentally, or otherwise released. Impacts will take into account sensitive populations and socio-economic factors, where applicable and to the extent data are available.” The screening methodology is built on this definition as well as current scientific understanding of environmental pollution and its adverse impacts on health, including the influence of both intrinsic, biological factors and non-intrinsic socioeconomic factors in mediating the effects of pollutant exposures. It addresses disparities in the distribution of pollution and health outcomes. The methodology provides a science-based tool to screen places for relative cumulative impacts, incorporating both the pollution burden on a community- including exposures to pollutants, their public health and environmental effects- and community characteristics, specifically sensitivity and socioeconomic factors. The screening methodology provides relative rankings to distinguish more highly impacted communities from less impacted ones. It may also help identify which factors are the greatest contributors to a community’s cumulative impact. It is not designed to provide quantitative estimates of community-level health impacts. A pilot screening analysis is presented here to illustrate the application of this methodology. Once guidelines are adopted, the methodology can serve as a screening

  9. Alcohol screening for older adults in an acute general hospital: FAST v. MAST-G assessments.

    PubMed

    Knightly, Rachel; Tadros, George; Sharma, Juhi; Duffield, Peter; Carnall, Emma; Fisher, Jacqui; Salman, Shaza

    2016-04-01

    Aims and method Documented prevalence of alcohol misuse among older adult patients at Birmingham Heartlands Hospital is significantly lower than the national prevalence. We aimed to evaluate our alcohol misuse screening protocol for older adults to identify possible shortcomings. Hospital protocol is to screen all adults for alcohol misuse in the accident and emergency (A&E) department using the Fast Alcohol Screening Test (FAST). One hundred consecutive consenting in-patients aged 65-94 admitted via A&E subsequently undertook an additional alcohol screening test (Michigan Alcoholism Screening Test-Geriatric version; MAST-G). Results of the two tests were compared. Results FAST screening was completed for 71 patients and none were FAST-positive for alcohol misuse, yet using MAST-G, 18 patients scored positively for alcohol misuse. FAST screening failed to identify 8 patients with a documented history of alcohol misuse. Clinical implications Older adult alcohol misuse prevalence is significantly underreported using FAST. Screening older adults for alcohol problems requires a different approach to screening the general population. PMID:27087989

  10. Alcohol screening for older adults in an acute general hospital: FAST v. MAST-G assessments

    PubMed Central

    Knightly, Rachel; Tadros, George; Sharma, Juhi; Duffield, Peter; Carnall, Emma; Fisher, Jacqui; Salman, Shaza

    2016-01-01

    Aims and method Documented prevalence of alcohol misuse among older adult patients at Birmingham Heartlands Hospital is significantly lower than the national prevalence. We aimed to evaluate our alcohol misuse screening protocol for older adults to identify possible shortcomings. Hospital protocol is to screen all adults for alcohol misuse in the accident and emergency (A&E) department using the Fast Alcohol Screening Test (FAST). One hundred consecutive consenting in-patients aged 65-94 admitted via A&E subsequently undertook an additional alcohol screening test (Michigan Alcoholism Screening Test-Geriatric version; MAST-G). Results of the two tests were compared. Results FAST screening was completed for 71 patients and none were FAST-positive for alcohol misuse, yet using MAST-G, 18 patients scored positively for alcohol misuse. FAST screening failed to identify 8 patients with a documented history of alcohol misuse. Clinical implications Older adult alcohol misuse prevalence is significantly underreported using FAST. Screening older adults for alcohol problems requires a different approach to screening the general population. PMID:27087989

  11. 42 CFR 455.452 - Other State screening methods.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Other State screening methods. 455.452 Section 455....452 Other State screening methods. Nothing in this subpart must restrict the State Medicaid agency from establishing provider screening methods in addition to or more stringent than those required...

  12. 42 CFR 455.452 - Other State screening methods.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Other State screening methods. 455.452 Section 455....452 Other State screening methods. Nothing in this subpart must restrict the State Medicaid agency from establishing provider screening methods in addition to or more stringent than those required...

  13. Apparatus and method for radioactive waste screening

    DOEpatents

    Akers, Douglas W.; Roybal, Lyle G.; Salomon, Hopi; Williams, Charles Leroy

    2012-09-04

    An apparatus and method relating to screening radioactive waste are disclosed for ensuring that at least one calculated parameter for the measurement data of a sample falls within a range between an upper limit and a lower limit prior to the sample being packaged for disposal. The apparatus includes a radiation detector configured for detecting radioactivity and radionuclide content of the of the sample of radioactive waste and generating measurement data in response thereto, and a collimator including at least one aperture to direct a field of view of the radiation detector. The method includes measuring a radioactive content of a sample, and calculating one or more parameters from the radioactive content of the sample.

  14. The views of general practitioners on community carrier screening for cystic fibrosis.

    PubMed Central

    Boulton, M; Cummings, C; Williamson, R

    1996-01-01

    BACKGROUND: Recent developments in molecular genetics have made it possible to identify carriers of the cystic fibrosis (CF) mutation, regardless of family history, before they have an affected child. Using these techniques, population or 'community' carrier screening can offer informed reproductive choice to individuals and couples who would not otherwise know of their risk of having a CF child. AIM: This study set out to assess the views of general practitioners (GPs) on community carrier screening for CF and to consider the factors that influence their willingness to offer it themselves. METHOD: A self-administered questionnaires was sent to all 616 GPs in four areas of North Thames (West) Region. RESULTS: Two-thirds of respondents indicated that identifying carrier couples to offer genetic counselling before conception was a very important benefit of community carrier screening. Two-thirds felt that general practice was the most appropriate place in which to offer it, and similar proportions that the most appropriate times to do so were when a close relative was diagnosed and when seeking family planning. About half wanted to offer community carrier screening themselves; this was related to experience with CF patients and CF carrier testing, and estimates of the numbers of CF carriers in the practice. CONCLUSIONS: There is considerable support among GPs for community carrier screening for CF in general practice, particularly in the context of family planning services. Knowledge and experience of CF increase GPs' willingness to offer it themselves. PMID:8762747

  15. Screening system and method of using same

    DOEpatents

    Jones, David A; Gresham, Christopher A; Basiliere, Marc L; Spates, James J; Rodacy, Philip J

    2014-04-15

    An integrated apparatus and method for screening an object for a target material is provided. The integrated apparatus comprises a housing and an integrated screener. The housing is positionable adjacent the object, and has a channel therethrough. The integrated screener is positionable in the housing, and comprises a fan, at least one filter, a heater and an analyzer. The fan is for drawing air carrying particles and vapor through the channel of the housing. The filter(s) is/are positionable in the channel of the housing for passage of the air therethrough. The filter(s) comprise(s) at least one metal foam having a plurality of pores therein for collecting and adsorbing a sample from the particles and vapor passing therethrough. The heater is for applying heat to the at least one metal foam whereby the collected sample is desorbed from the metal foam. The analyzer detects the target material from the desorbed sample.

  16. Display screen and method of manufacture therefor

    NASA Technical Reports Server (NTRS)

    Dubin, Matthew B. (Inventor); Larson, Brent D. (Inventor)

    2001-01-01

    A screen assembly that combines an angle re-distributing prescreen with a conventional diffusion screen is disclosed. The prescreen minimizes or eliminates the sensitivity of the screen assembly to projector location. The diffusion screen provides other desirable screen characteristics. The prescreen is preferably formed by a collection of light transmitting and refracting elements, preferably spheres 80, partially embedded in a light blocking layer. Toward the back of the spheres 80 are effective apertures 82 where the light blocking layer 81 is absent or at least thinner than in other regions toward the side of the spheres. The projected image enters spheres 80 through the effective apertures 82, and exits the spheres 80 centered orientationally about the normal to the lens axis. The re-oriented light rays then enter the diffusion screen for viewing.

  17. Generalizing Screen Inferiority--Does the Medium, Screen versus Paper, Affect Performance Even with Brief Tasks?

    ERIC Educational Resources Information Center

    Sidi, Yael; Ophir, Yael; Ackerman, Rakefet

    2016-01-01

    Screen inferiority in performance and metacognitive processes has been repeatedly found with text learning. Common explanations for screen inferiority relate to technological and physiological disadvantages associated with extensive reading on screen. However, recent studies point to lesser recruitment of mental effort on screen than on paper.…

  18. [Selective screening for hypercholesterolemia. Results from a screening model in general practice].

    PubMed

    Agner, E; Christensen, T E; Mahnfeldt, M S; Baastrup, A; Jacobsen, K; Jensen, S E

    1990-11-01

    At present, it appears to be probable that both dietary changes and medicinal treatment can reduce the risk of development of coronary disease in middle-aged men with moderately to severely raised blood cholesterol values. Internationally, the limits for cholesterol intervention are considerably lower than in Denmark. Extensive cholesterol screening is, however, very expensive and the identified persons with high cholesterol values will frequently be found in sex and age groups where the beneficial effect of intervention is probably limited. A model for selective cholesterol screening in high risk groups in general practice is described here. In 20 general practices, all of the men aged 45-59 years belonging to the practice were invited to examination of cholesterol and blood pressure. Plasma cholesterol was measured by means of a Reflotron (results are available within three minutes) and the blood pressure and tobacco consumption were registered. After this, the patient's own general practitioner calculated with each of the persons the risk for development of myocardial infarction within the next ten years and intervention could be commenced immediately. 41% of those invited came for examination. Out of these, 29% had cholesterol values greater than or equal to 7.0 mmol/l (Danish limiting value), 44% greater than or equal to 6.5 mmol/l (limiting value in the remainder of Western Europe), and 5% greater than or equal to 9.0 mmol/l (severe hypercholesterolaemia) while only 18% had completely normal cholesterol less than 5.2 mmol/l. In every practice, two patients on an average were found with severe hypercholesterolaemia greater than or equal to 9.0 mmol/l. 28% of the participants had at least two of the three risk factors investigated. (ABSTRACT TRUNCATED AT 250 WORDS) PMID:2238223

  19. Touch screen computer health assessment in Australian general practice patients: a cross-sectional study protocol

    PubMed Central

    Carey, Mariko Leanne; Sanson-Fisher, Robert William; Russell, Grant; Mazza, Danielle; Makeham, Meredith; Paul, Christine Louise; Inder, Kerry Jane; D'Este, Catherine

    2012-01-01

    Introduction Cardiovascular disease (CVD) and cancer are leading causes of death globally. Early detection of cancer and risk factors for CVD may improve health outcomes and reduce mortality. General practitioners (GPs) are accessed by the majority of the population and play a key role in the prevention and early detection of chronic disease risk factors. This cross-sectional study aims to assess the acceptability of an electronic method of data collection in general practice patients. The study will describe the proportion screened in line with guidelines for CVD risk factors and cancer as well as report the prevalence of depression, lifestyle risk factors, level of provision of preconception care, cervical cancer vaccination and bone density testing. Lastly, the study will assess the level of agreement between GPs and patients perception regarding presence of risk factors and screening. Methods and analysis The study has been designed to maximise recruitment of GPs by including practitioners in the research team, minimising participation burden on GPs and offering remuneration for participation. Patient recruitment will be carried out by a research assistant located in general practice waiting rooms. Participants will be asked regarding the acceptability of the touch screen computer and to report on a range of health risk and preventive behaviours using the touch screen computer. GPs will complete a one-page survey indicating their perception of the presence of risk behaviours in their patients. Descriptive statistics will be generated to describe the acceptability of the touch screen and prevalence of health risk behaviours. Cohen's κ will be used to assess agreement between GP and patient perception of presence of health risk behaviours. Ethics and dissemination This study has been approved by the human research committees in participating universities. Findings will be disseminated via peer-reviewed publications, conference presentations as well as practice

  20. SAR Ice Classification Using Fuzzy Screening Method

    NASA Astrophysics Data System (ADS)

    Gill, R. S.

    2003-04-01

    A semi-automatic SAR sea ice classification algorithm is described. It is based on combining the information in the original SAR data with those in the three 'image' products derived from it, namely Power-to-Mean Ratio (PMR), the Gamma distribution and the second order texture parameter entropy, respectively. The latter products contain information which is often useful during the manual interpretation of the images. The technique used to fuse the information in these products is based on a method c lled Multi Experts Multi Criteria Decision Making fuzzy a screening. The Multiple Experts in this case are the above four 'image' products. The two criteria used currently for making decisions are the Kolmogorov-Smirnov distribution matching and the statistical mean of different surface classes. The algorithm classifies an image into any number of predefined classes of sea ice and open water. The representative classes of these surface types are manually identified by the user. Further, as SAR signals from sea ice covered regions and open water are ambiguous, it was found that a minimum of 4 pre-identified surface classes (calm and turbulent water and sea ice with low and high backscatter values) are required to accurately classify an image. Best results are obtained when a total of 8 surface classes (2 each of sea ice and open water in the near range and a similar number in the far range of the SAR image) are used. The main advantage of using this image classification scheme is that, like neural networks, no prior knowledge is required of the statistical distribution of the different surface types. Furthermore, unlike the methods based on neural networks, no prior data sets are required to train the algorithm. All the information needed for image classification by the method is contained in the individual SAR images and associated products. Initial results illustrating the potential of this ice classification algorithm using the RADARSAT ScanSAR Wide data are presented

  1. Wafer screening device and methods for wafer screening

    DOEpatents

    Sopori, Bhushan; Rupnowski, Przemyslaw

    2014-07-15

    Wafer breakage is a serious problem in the photovoltaic industry because a large fraction of wafers (between 5 and 10%) break during solar cell/module fabrication. The major cause of this excessive wafer breakage is that these wafers have residual microcracks--microcracks that were not completely etched. Additional propensity for breakage is caused by texture etching and incomplete edge grinding. To eliminate the cost of processing the wafers that break, it is best to remove them prior to cell fabrication. Some attempts have been made to develop optical techniques to detect microcracks. Unfortunately, it is very difficult to detect microcracks that are embedded within the roughness/texture of the wafers. Furthermore, even if such detection is successful, it is not straightforward to relate them to wafer breakage. We believe that the best way to isolate the wafers with fatal microcracks is to apply a stress to wafers--a stress that mimics the highest stress during cell/module processing. If a wafer survives this stress, it has a high probability of surviving without breakage during cell/module fabrication. Based on this, we have developed a high throughput, noncontact method for applying a predetermined stress to a wafer. The wafers are carried on a belt through a chamber that illuminates the wafer with an intense light of a predetermined intensity distribution that can be varied by changing the power to the light source. As the wafers move under the light source, each wafer undergoes a dynamic temperature profile that produces a preset elastic stress. If this stress exceeds the wafer strength, the wafer will break. The broken wafers are separated early, eliminating cost of processing into cell/module. We will describe details of the system and show comparison of breakage statistics with the breakage on a production line.

  2. TranScreen-N: Method for rapid screening of trans-ungual drug delivery enhancers.

    PubMed

    Murthy, S Narasimha; Vaka, Siva Ram Kiran; Sammeta, Srinivasa Murthy; Nair, Anroop B

    2009-11-01

    Topical monotherapy of nail diseases such as onychomycosis and nail psoriasis has been less successful due to poor permeability of the human nail plate to topically administered drugs. Chemical enhancers are utilized to improve the drug delivery across the nail plate. Choosing the most effective chemical enhancers for the given drug and formulation is highly critical in determining the efficacy of topical therapy of nail diseases. Screening the large pool of enhancers using currently followed diffusion cell experiments would be tedious and expensive. The main objective of this study is to develop TranScreen-N, a high throughput method of screening trans-ungual drug permeation enhancers. It is a rapid microwell plate based method which involves two different treatment procedures; the simultaneous exposure treatment and the sequential exposure treatment. In the present study, several chemicals were evaluated by TranScreen-N and by diffusion studies in the Franz diffusion cell (FDC). Good agreement of in vitro drug delivery data with TranScreen-N data provided validity to the screening technique. In TranScreen-N technique, the enhancers can be grouped according to whether they need to be applied before or simultaneously with drugs (or by either procedures) to enhance the drug delivery across the nail plate. TranScreen-N technique can significantly reduce the cost and duration required to screen trans-ungual drug delivery enhancers. PMID:19363796

  3. Method to determine the speckle characteristics of front projection screens.

    PubMed

    Riechert, Falko; Glöckler, Felix; Lemmer, Uli

    2009-03-01

    We present a method to determine the speckle properties of front projection screens. Seven different screens are investigated in a backscattering geometry for 808 nm light. The speckle contrast reduction that results from polarization scrambling and reduced temporal coherence is modeled for the case of volume scattering in the screens. For this purpose, the screen's volume scattering path length distributions and depolarization characteristics are determined. This is done via a streak camera setup to measure the temporal broadening of ultrashort 50 fs light pulses scattered in the screens. We show that it is essential to properly select a projection screen with large volume roughness in order to achieve low speckle contrast values for moderate illumination bandwidths. PMID:19252632

  4. Improvement of screening methods for silicon planar semiconductor devices

    NASA Technical Reports Server (NTRS)

    Berger, W. M.

    1972-01-01

    The results of the program for the development of a more sensitive method for selecting silicon planar semiconductor devices for long life applications are reported. The manufacturing technologies (MOS and Bipolar) are discussed along with the screening procedures developed as a result of the tests and evaluations, and the effectiveness of the MOS and Bilayer screening procedures are evaluated.

  5. High Throughput Screening and Selection Methods for Directed Enzyme Evolution

    PubMed Central

    2015-01-01

    Successful evolutionary enzyme engineering requires a high throughput screening or selection method, which considerably increases the chance of obtaining desired properties and reduces the time and cost. In this review, a series of high throughput screening and selection methods are illustrated with significant and recent examples. These high throughput strategies are also discussed with an emphasis on compatibility with phenotypic analysis during directed enzyme evolution. Lastly, certain limitations of current methods, as well as future developments, are briefly summarized. PMID:26074668

  6. The roles of general and technology-related parenting in managing youth screen time.

    PubMed

    Sanders, Wesley; Parent, Justin; Forehand, Rex; Breslend, Nicole Lafko

    2016-08-01

    This study examines the associations of 2 types of parenting practices-general adaptive parenting and technology-related strategies-with youth screen time. We hypothesized that technology-related parenting focused on behavioral control would relate directly to screen time and serve to link general parenting to screen time. Participants were 615 parents drawn from 3 community samples of families with children across 3 development stages: young childhood (3-7 years; n = 210), middle childhood (8-12 years; n = 200), and adolescents (13-17 years; n = 205). Using structural equation modeling, we found that general adaptive parenting was not related to child screen time but was positively related to technology-related parenting strategies for all 3 samples. For the young and, to some extent, middle childhood samples, but not for the adolescent sample, general adaptive parenting was positively linked to youth screen time through technology-related parenting strategies. (PsycINFO Database Record PMID:26751759

  7. FIELD ANALYTICAL SCREENING PROGRAM: PCP METHOD - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    EPA Science Inventory

    This innovative technology evaluation report (ITER) presents information on the demonstration of the U.S. Environmental Protection Agency (EPA) Region 7 Superfund Field Analytical Screening Program (FASP) method for determining pentachlorophenol (PCP) contamination in soil and wa...

  8. FIELD ANALYTICAL SCREENING PROGRAM PCB METHOD: INNOVATIVE TECHNOLOGY EVALUATION REPORT

    EPA Science Inventory

    This innovative technology evaluation report (ITER) presents information on the demonstration of the U.S. Environmental Protection Agency (EPA) Region 7 Superfund Field Analytical Screening Program (FASP) method for determining polychlorinated biphenyl (PCB) contamination in soil...

  9. FIELD ANALYTICAL SCREENING PROGRAM: PCB METHOD - INNOVATIVE TECHNOLOGY REPORT

    EPA Science Inventory

    This innovative technology evaluation report (ITER) presents information on the demonstration of the U.S. Environmental Protection Agency (EPA) Region 7 Superfund Field Analytical Screening Program (FASP) method for determining polychlorinated biphenyl (PCB) contamination in soil...

  10. Outcomes of hepatitis C screening programs targeted at risk groups hidden in the general population: a systematic review

    PubMed Central

    2014-01-01

    Background Effective screening programs are urgently needed to provide undiagnosed hepatitis C virus (HCV)-infected individuals with therapy. This systematic review of characteristics and outcomes of screening programs for HCV focuses on strategies to identify HCV risk groups hidden in the general population. Methods We conducted a comprehensive search of MEDLINE and EMBASE databases for articles published between 1991–2010, including studies that screened the general population using either a newly developed (nonintegrated) screening program or one integrated in existing health care facilities. Look-back studies, prevalence studies, and programs targeting high-risk groups in care (e.g., current drug users) were excluded. Results After reviewing 7052 studies, we identified 67 screening programs: 24 nonintegrated; 41 programs integrated in a variety of health care facilities (e.g., general practitioner); and 2 programs with both integrated and nonintegrated strategies. Together, these programs identified approximately 25,700 HCV-infected individuals. In general, higher HCV prevalence was found in programs in countries with intermediate to high HCV prevalence, in psychiatric clinics, and in programs that used a prescreening selection based on HCV risk factors. Only 6 programs used a comparison group for evaluation purposes, and 1 program used theory about effective promotion for screening. Comparison of the programs and their effectiveness was hampered by lack of reported data on program characteristics, clinical follow-up, and type of diagnostic test. Conclusions A prescreening selection based on risk factors can increase the efficiency of screening in low-prevalence populations, and we need programs with comparison groups to evaluate effectiveness. Also, program characteristics such as type of diagnostic test, screening uptake, and clinical outcomes should be reported systematically. PMID:24450797

  11. A New Screening Programme for Autism in a General Population of Swedish Toddlers

    ERIC Educational Resources Information Center

    Nygren, Gudrun; Sandberg, Eva; Gillstedt, Fredrik; Ekeroth, Gunnar; Arvidsson, Thomas; Gillberg, Christopher

    2012-01-01

    The evidence from early intervention studies of autism has emphasised the need for early diagnosis. Insight into the early presentation of autism is crucial for early recognition, and routine screening can optimise the possibility for early diagnosis. General population screening was conducted for 2.5-year-old children at child health centres in…

  12. A comparison between Pap and HPV screening tests and screening methods

    PubMed Central

    Altobelli, Emma; Scarselli, Giorgio; Lattanzi, Amedeo; Fortunato, Carmine; Profeta, Valerio F.

    2016-01-01

    The present study assesses the results of cervical cancer (CC) screening over two 3-year periods (2008–2010 and 2011–2013) by comparing two screening tests [Papanicolaou (Pap) and human papillomavirus (HPV) tests] and two screening methods (organized and spontaneous). The study population includes women aged 25–64 years who underwent CC screening between 2008 and 2010 and/or 2011 and 2013, divided into those who responded to an invitation letter (organized screening) and those who spontaneously underwent testing at a public or private facility (non-programmed screening). Between 2008 and 2010, the response rates increased from 27.7% in 2008 to 44.5% in 2009 and 67.6% in 2010 (P<0.001). Women aged 25–34 years had the lowest response rate, whereas respondents were more frequent among women aged 35–44 and 45–54 years. Significant differences (P<0.001) were identified between organized and spontaneous screening test results with regard to diagnostic categories high-grade squamous intraepithelial lesion (50.5 vs. 49.5%), low-grade squamous intraepithelial lesion (42.8 vs. 57.2%) and undetermined lesion atypical glandular cells (AGC; 57.5 vs. 42.5%) or atypical squamous cells of undetermined significance (ASC-US; 54.2 vs. 45.8%). Compared with spontaneous screening, the organized programme resulted in a larger number of women screened for CC; it reduced the frequency of undetermined diagnoses (AGC, ASC-US), and identified a larger number of high-grade lesions. PMID:27446578

  13. Item Selection Methods for the Adolescent Domain Screening Inventory

    ERIC Educational Resources Information Center

    Corrigan, Matthew J.

    2009-01-01

    Objective: The purpose of this article is to describe the method of item selection tested in the development of the Adolescent Domain Screening Inventory. Method: The convenience sampling frame used for these analyses consisted of 26,781 Communities That Care Youth Surveys. The three item selection methods were used to assess known instrument,…

  14. Generalized model screening potentials for Fermi-Dirac plasmas

    NASA Astrophysics Data System (ADS)

    Akbari-Moghanjoughi, M.

    2016-04-01

    In this paper, some properties of relativistically degenerate quantum plasmas, such as static ion screening, structure factor, and Thomson scattering cross-section, are studied in the framework of linearized quantum hydrodynamic theory with the newly proposed kinetic γ-correction to Bohm term in low frequency limit. It is found that the correction has a significant effect on the properties of quantum plasmas in all density regimes, ranging from solid-density up to that of white dwarf stars. It is also found that Shukla-Eliasson attractive force exists up to a few times the density of metals, and the ionic correlations are seemingly apparent in the radial distribution function signature. Simplified statically screened attractive and repulsive potentials are presented for zero-temperature Fermi-Dirac plasmas, valid for a wide range of quantum plasma number-density and atomic number values. Moreover, it is observed that crystallization of white dwarfs beyond a critical core number-density persists with this new kinetic correction, but it is shifted to a much higher number-density value of n0 ≃ 1.94 × 1037 cm-3 (1.77 × 1010 gr cm-3), which is nearly four orders of magnitude less than the nuclear density. It is found that the maximal Thomson scattering with the γ-corrected structure factor is a remarkable property of white dwarf stars. However, with the new γ-correction, the maximal scattering shifts to the spectrum region between hard X-ray and low-energy gamma-rays. White dwarfs composed of higher atomic-number ions are observed to maximally Thomson-scatter at slightly higher wavelengths, i.e., they maximally scatter slightly low-energy photons in the presence of correction.

  15. Method For Screening Microcrystallizations For Crystal Formation

    DOEpatents

    Santarsiero, Bernard D. , Stevens, Raymond C. , Schultz, Peter G. , Jaklevic, Joseph M. , Yegian, Derek T. , Cornell, Earl W. , Nordmeyer, Robert A.

    2003-10-07

    A method is provided for performing array microcrystallizations to determine suitable crystallization conditions for a molecule, the method comprising: forming an array of microcrystallizations, each microcrystallization comprising a drop comprising a mother liquor solution whose composition varies within the array and a molecule to be crystallized, the drop having a volume of less than 1 microliter; storing the array of microcrystallizations under conditions suitable for molecule crystals to form in the drops in the array; and detecting molecule crystal formation in the drops by taking images of the drops.

  16. EVALUATION OF POHC AND PIC SCREENING METHODS

    EPA Science Inventory

    A recurring theme in environmental work is the need to characterize emissions to the maximum extent at the minimum cost. Unfortunately, many projects have been carried out In the past with little thought or planning concerning the optimum application of analytical methods availab...

  17. NEW METHODS TO SCREEN FOR DEVELOPMENTAL NEUROTOXICITY.

    EPA Science Inventory

    The development of alternative methods for toxicity testing is driven by the need for scientifically valid data (i.e. predictive of a toxic effect) that can be obtained in a rapid and cost-efficient manner. These predictions will enable decisions to be made as to whether further ...

  18. An alternative method to screen for pepper spray residue.

    PubMed

    Gillis, Trevor D; Kubic, Thomas A; De Forest, Peter R

    2003-01-01

    A method was developed to screen for pepper spray residue using instruments and methods other than those techniques commonly employed to analyze chemical residue (i.e.. gas chromatography mass spectrometry-GCMS or liquid chromatography mass spectrometry-LCMS). The method employed gas chromatography (GC), thin layer chromatography (TLC), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) to screen for dried pepper spray stains. Pepper sprays from nine different manufacturers were investigated. Capsaicin and dihydrocapsaicin were identified and unique IR reflectance spectra are presented. An additional five compounds were presumptively found. Results showed that a particular stain could be characterized as a pepper-based stain. PMID:12570209

  19. The Implementation of an Integrated Information System for Substance Use Screening in General Medical Settings

    PubMed Central

    Sorensen-Alawad, A.; Carney, B.L.; Persand, I.; Cruz, A.; Botticelli, M.; Pressman, K.; Adams, W.G.; Brolin, M.; Alford, D.P.

    2014-01-01

    Summary The Massachusetts Screening, Brief Intervention and Referral to Treatment (MASBIRT) Program, a substance use screening program in general medical settings, created a web-based, point-of-care (POC), application – the MASBIRT Portal (the “Portal”) to meet program goals. Objectives We report on development and implementation of the Portal. Methods Five year program process outcomes recorded by an independent evaluator and an anonymous survey of Health Educator’s (HEs) adoption, perceptions and Portal use with a modified version of the Technology Readiness Index are described. [8] Specific management team members, selected based on their roles in program leadership, development and implementation of the Portal and supervision of HEs, participated in semi-structured, qualitative interviews. Results At the conclusion of the program 73% (24/33) of the HEs completed a survey on their experience using the Portal. HEs reported that the Portal made recording screening information easy (96%); improved planning their workday (83%); facilitated POC data collection (84%); decreased time dedicated to data entry (100%); and improved job satisfaction (59%). The top two barriers to use were “no or limited wireless connectivity” (46%) and “the tablet was too heavy/bulky to carry” (29%). Qualitative management team interviews identified strategies for successful HIT implementation: importance of engaging HEs in outlining specifications and workflow needs, collaborative testing prior to implementation and clear agreement on data collection purpose, quality requirements and staff roles. Discussion Overall, HEs perceived the Portal favorably with regard to time saving ability and improved workflow. Lessons learned included identifying core requirements early during system development and need for managers to institute and enforce consistent behavioral work norms. Conclusion Barriers and HEs’ views of technology impacted the utilization of the MASBIRT Portal

  20. Generalization of the ERIT principle and method.

    SciTech Connect

    Ruggiero,A.G.

    2007-11-04

    The paper describes the generalization of the method to produce secondary particles with a low-energy and low-intensity primary beam circulating in a Storage Ring with the Emittance-Recovery by Internal-Target (ERIT).

  1. Generalization of the ERIT Principle and Method

    SciTech Connect

    Ruggiero,A.

    2008-02-01

    The paper describes the generalization of the method to produce secondary particles with a low-energy and low-intensity primary beam circulating in a Storage Ring with the Emittance-Recovery by Internal-Target (ERIT).

  2. PHOTOACTIVATED LUMINESCENCE METHOD FOR RAPID SCREENING OF POLYCHLORINATED BIPHENYLS

    EPA Science Inventory

    The U.S. Department of Energy and the U.S. Environmental Protection Agency have a strong need for screening capabilities for hazardous materials. his paper describes a new method based on enhanced photoactivated luminescence (ELP) for rapid detection of PCBs. he EPL method descri...

  3. FIELD ANALYTICAL SCREENING PROGRAM: PCP METHOD - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    EPA Science Inventory

    The Field Analytical Screening Program (FASP) pentachlorophenol (PCP) method uses a gas chromatograph (GC) equipped with a megabore capillary column and flame ionization detector (FID) and electron capture detector (ECD) to identify and quantify PCP. The FASP PCP method is design...

  4. Method for forming electromagnetic-wave-screening composite

    NASA Astrophysics Data System (ADS)

    1984-12-01

    A number of ways to give plastic parts the ability to screen out high frequency electromagnetic waves are outlined. Another method which consists of a one stage injection molding process for forming a thermoplastic sandwich whose plastic core, containing metal flakes, is coated with a surface layer of ABS is introduced. The method employs the Battenfeld two component injection molding machine.

  5. Down syndrome screening methods in Iranian pregnant women

    PubMed Central

    Farshbaf Khalili, Azizeh; Shahnazi, Mahnaz; Hajizadeh, Khadijeh; Shekari Khaniani, Mahmoud

    2012-01-01

    Introduction: Down syndrome is one of the most prevalent genetic diseases. Screening methods for this syndrome are easy and safe and are recommended to all pregnant women particularly mothers over 35 years of age. This study aimed to review the status of Down syndrome screening and related factors in Iranian pregnant women. Methods: This descriptive analytical study was carried out in 2011. It included 400 women who were randomly selected from those referring to Alzahra Hospital (Tabriz, Iran) during their third trimester of pregnancy. Data was collected through a question-naire whose reliability and validity have been approved. The data was analyzed by chi-square test in SPSS13. Results: The results showed that while 28 and 26 women imple-mented screening tests during the first and second trimesters, respectively, only 5 sub-jects benefited from both (integrated test). Chi-square test showed significant correla-tions between the implementation of screening methods and age, education level, in-come, and the location of prenatal care (p < 0.05). Conclusion: The findings of the present study showed women to poorly implement Down syndrome screening methods. Therefore, the necessity of providing appropriate educational programs for health staff and mothers seems undeniable. Moreover, paying attention to the related factors such as income, educational level, and adequate training of mothers during pregnancy is essential. PMID:25276689

  6. Standardization of a screening instrument (PHQ-15) for somatization syndromes in the general population

    PubMed Central

    2013-01-01

    Background The PHQ-15 is widely used as an open access screening instrument for somatization syndromes in different health care settings, thus far, normative data from the general population are not available. The objectives of the study were to generate normative data and to further investigate the construct validity of the PHQ-15 in the general population. Methods Nationally representative face-to face household surveys were conducted in Germany between 2003 and 2008 (n=5,031). The survey questionnaires included, the 15-item somatization module from the Patient Health Questionnaire (PHQ-15), the 9-item depression module (PHQ-9), the Satisfaction With Life Scale (SWLS), the SF-12 for the measurement of health related quality of life, and demographic characteristics. Results Normative data for the PHQ-15 were generated for both genders and different age levels including 5031 subjects (53.6% female) with a mean age (SD) of 48.9 (18.1) years. Somatization syndromes occured in 9.3% of the general population. Women had significantly higher mean (SD) scores compared with men [4.3 (4.1) vs. 3.4 (4.0)]. Intercorrelations with somatization were highest with depression, followed by the physical component summary scale of health related quality of life. Conclusions The normative data provide a framework for the interpretation and comparisons of somatization syndromes with other populations. Evidence supports reliability and validity of the PHQ-15 as a measure of somatization syndromes in the general population. PMID:23514436

  7. Estimating rotavirus vaccine effectiveness in Japan using a screening method.

    PubMed

    Araki, Kaoru; Hara, Megumi; Sakanishi, Yuta; Shimanoe, Chisato; Nishida, Yuichiro; Matsuo, Muneaki; Tanaka, Keitaro

    2016-05-01

    Rotavirus gastroenteritis is a highly contagious, acute viral disease that imposes a significant health burden worldwide. In Japan, rotavirus vaccines have been commercially available since 2011 for voluntary vaccination, but vaccine coverage and effectiveness have not been evaluated. In the absence of a vaccination registry in Japan, vaccination coverage in the general population was estimated according to the number of vaccines supplied by the manufacturer, the number of children who received financial support for vaccination, and the size of the target population. Patients with rotavirus gastroenteritis were identified by reviewing the medical records of all children who consulted 6 major hospitals in Saga Prefecture with gastroenteritis symptoms. Vaccination status among these patients was investigated by reviewing their medical records or interviewing their guardians by telephone. Vaccine effectiveness was determined using a screening method. Vaccination coverage increased with time, and it was 2-times higher in municipalities where the vaccination fee was supported. In the 2012/13 season, vaccination coverage in Saga Prefecture was 14.9% whereas the proportion of patients vaccinated was 5.1% among those with clinically diagnosed rotavirus gastroenteritis and 1.9% among those hospitalized for rotavirus gastroenteritis. Thus, vaccine effectiveness was estimated as 69.5% and 88.8%, respectively. This is the first study to evaluate rotavirus vaccination coverage and effectiveness in Japan since vaccination began. PMID:26680277

  8. Estimating rotavirus vaccine effectiveness in Japan using a screening method

    PubMed Central

    Araki, Kaoru; Hara, Megumi; Sakanishi, Yuta; Shimanoe, Chisato; Nishida, Yuichiro; Matsuo, Muneaki; Tanaka, Keitaro

    2016-01-01

    abstract Rotavirus gastroenteritis is a highly contagious, acute viral disease that imposes a significant health burden worldwide. In Japan, rotavirus vaccines have been commercially available since 2011 for voluntary vaccination, but vaccine coverage and effectiveness have not been evaluated. In the absence of a vaccination registry in Japan, vaccination coverage in the general population was estimated according to the number of vaccines supplied by the manufacturer, the number of children who received financial support for vaccination, and the size of the target population. Patients with rotavirus gastroenteritis were identified by reviewing the medical records of all children who consulted 6 major hospitals in Saga Prefecture with gastroenteritis symptoms. Vaccination status among these patients was investigated by reviewing their medical records or interviewing their guardians by telephone. Vaccine effectiveness was determined using a screening method. Vaccination coverage increased with time, and it was 2-times higher in municipalities where the vaccination fee was supported. In the 2012/13 season, vaccination coverage in Saga Prefecture was 14.9% whereas the proportion of patients vaccinated was 5.1% among those with clinically diagnosed rotavirus gastroenteritis and 1.9% among those hospitalized for rotavirus gastroenteritis. Thus, vaccine effectiveness was estimated as 69.5% and 88.8%, respectively. This is the first study to evaluate rotavirus vaccination coverage and effectiveness in Japan since vaccination began. PMID:26680277

  9. [Formalized dietary advice in hypercholesterolemia. Results in 110 men diagnosed by selective screening in general practice].

    PubMed

    Agner, E; Christensen, T E; Jacobsen, K; Baastrup, A; Mahnfeldt, M S; Jensen, S E

    1990-11-01

    In connection with a screening investigation for high blood cholesterol in middle-aged men in general practice in the Municipality of Copenhagen, all participants with cholesterol values greater than or equal to 7.5 mmol/l were given brief advice by their own general practitioner and were invited to come for fasting blood lipid tests approximately ten days later. In cases with continued cholesterol greater than or equal to 6.8 mmol/l, the participants together with wives or partners were invited to formalized dietary advice in small groups. Already before the formalized dietary advice, an average decrease in serum cholesterol of 10% was observed. This was attributed to biological variation, absence of fasting, the degree of error between the measuring methods and also a genuine decrease on the basis of the brief dietary advice by the general practitioner. On control after dietary advice, a further decrease in cholesterol of 15% was observed while low density lipoprotein cholesterol fell by 20% and triglycerides by 23%. These decreases must be considered to result mainly from the dietary advice. It is concluded that a single but professional session of dietary advice in small groups and with involvement of the wives or partners is an effective method of treatment in hypercholesterolaemia. If the decrease in cholesterol obtained can be maintained, the literature suggests that the risk of development of ischaemic heart disease during the subsequent 5-7 years is reduced by 20-30%. PMID:2238224

  10. In vitro evaluation method for screening of candidate prebiotic foods.

    PubMed

    Date, Yasuhiro; Nakanishi, Yumiko; Fukuda, Shinji; Nuijima, Yumi; Kato, Tamotsu; Umehara, Mikihisa; Ohno, Hiroshi; Kikuchi, Jun

    2014-01-01

    The aim of this work was to develop a simple and rapid in vitro evaluation method for screening and discovery of uncharacterised and untapped prebiotic foods. Using a NMR-based metabolomic approach coupled with multivariate statistical analysis, the metabolic profiles generated by intestinal microbiota after in vitro incubation with feces were examined. The viscous substances of Japanese bunching onion (JBOVS) were identified as one of the candidate prebiotic foods by this in vitro screening method. The JBOVS were primarily composed of sugar components, especially fructose-based carbohydrates. Our results suggested that ingestion of JBOVS contributed to lactate and acetate production by the intestinal microbiota, and were accompanied by an increase in the Lactobacillus murinus and Bacteroidetes sp. populations in the intestine and fluctuation of the host-microbial co-metabolic process. Therefore, our approach should be useful as a rapid and simple screening tool for potential prebiotic foods. PMID:24444934

  11. A General Symbolic Method with Physical Applications

    NASA Astrophysics Data System (ADS)

    Smith, Gregory M.

    2000-06-01

    A solution to the problem of unifying the General Relativistic and Quantum Theoretical formalisms is given which introduces a new non-axiomatic symbolic method and an algebraic generalization of the Calculus to non-finite symbolisms without reference to the concept of a limit. An essential feature of the non-axiomatic method is the inadequacy of any (finite) statements: Identifying this aspect of the theory with the "existence of an external physical reality" both allows for the consistency of the method with the results of experiments and avoids the so-called "measurement problem" of quantum theory.

  12. Nonlocal exchange correlation in screened-exchange densityfunctional methods

    SciTech Connect

    Lee, Byounghak; Wang, Lin-Wang; Spataru, Catalin D.; Louie,Steven G.

    2007-04-22

    We present a systematic study on the exchange-correlationeffects in screened-exchange local density functional method. Toinvestigate the effects of the screened-exchange potential in the bandgap correction, we have compared the exchange-correlation potential termin the sX-LDA formalism with the self-energy term in the GWapproximation. It is found that the band gap correction of the sX-LDAmethod primarily comes from the downshift of valence band states,resulting from the enhancement of bonding and the increase of ionizationenergy. The band gap correction in the GW method, on the contrary, comesin large part from the increase of theconduction band energies. We alsostudied the effects of the screened-exchange potential in the totalenergy by investigating the exchange-correlation hole in comparison withquantum Monte Carlo calculations. When the Thomas-Fermi screening isused, the sX-LDA method overestimates (underestimates) theexchange-correlation hole in short (long) range. From theexchange-correlation energy analysis we found that the LDA method yieldsbetter absolute total energy than sX-LDA method.

  13. General practitioners' perceptions of private health screening: too much paper, anxiety, and reassurance.

    PubMed Central

    Paynton, D; Dunleavey, J; Smith, H

    1998-01-01

    There is no evidence to support the practice of screening consultations that include general physical examinations and batteries of tests; however, many patients may choose, or be sent by their employers, to have private full health screening (FHS). General practitioners (GPs) are routinely sent the results of these screening examinations and are expected to deal with any subsequent care required. GPs recognize some positive aspects of FHS, but in our survey there was a groundswell of dislike for these examinations because of uncertainty about patient benefit (raised anxiety or false assurance) and a potential to irritate the GP. The implications for workload were minimal but resented. GPs would welcome a precise summary of significant findings and for the screening doctor to take greater responsibility for follow-up. PMID:9747551

  14. Spectral Methods in General Relativistic MHD Simulations

    NASA Astrophysics Data System (ADS)

    Garrison, David

    2012-03-01

    In this talk I discuss the use of spectral methods in improving the accuracy of a General Relativistic Magnetohydrodynamic (GRMHD) computer code. I introduce SpecCosmo, a GRMHD code developed as a Cactus arrangement at UHCL, and show simulation results using both Fourier spectral methods and finite differencing. This work demonstrates the use of spectral methods with the FFTW 3.3 Fast Fourier Transform package integrated with the Cactus Framework to perform spectral differencing using MPI.

  15. Screening Methods for Metal-Containing Nanoparticles in Water

    EPA Science Inventory

    Screening-level analysis of water for metal-containing nanoparticles is achieved with single particle-inductively coupled plasma mass spectrometry (SP-ICPMS). This method measures both the concentration of nanoparticles containing an analyte metal and the mass of the metal in eac...

  16. FIELD SCREENING METHODS FOR HAZARDOUS WASTES AND TOXIC CHEMICALS

    EPA Science Inventory

    The purpose of this document is to present the technical papers that were presented at the Second International Symposium on Field Screening Methods for Hazardous Wastes and Toxic Chemicals. ixty platform presentations were made and included in one of ten sessions: hemical sensor...

  17. Carotenoid analysis using the puree absorbance method for germplasm screening

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many fruits and vegetables contain health-promoting compounds which require labor intensive analyses to detect. This is the case with quantifying carotenoids in fresh fruits and vegetables. Carotenoid content can vary significantly between varieties; therefore a method to rapidly screen germplasm ...

  18. Using the Screened Coulomb Potential to Illustrate the Variational Method

    ERIC Educational Resources Information Center

    Zuniga, Jose; Bastida, Adolfo; Requena, Alberto

    2012-01-01

    The screened Coulomb potential, or Yukawa potential, is used to illustrate the application of the single and linear variational methods. The trial variational functions are expressed in terms of Slater-type functions, for which the integrals needed to carry out the variational calculations are easily evaluated in closed form. The variational…

  19. FIELD SCREENING METHOD FOR POLYCHLORINATED BIPHENYL COMPOUNDS IN WATER

    EPA Science Inventory

    The U.S. Environmental Protection Agency has been exploring the complexation of silver ions with certain organic pollutants as part of a search for alternative low-cost, rapid, field screening methods. he result is a rapid, easy, and inexpensive procedure for determining polychlo...

  20. Optimal assignment methods for ligand-based virtual screening

    PubMed Central

    2009-01-01

    Background Ligand-based virtual screening experiments are an important task in the early drug discovery stage. An ambitious aim in each experiment is to disclose active structures based on new scaffolds. To perform these "scaffold-hoppings" for individual problems and targets, a plethora of different similarity methods based on diverse techniques were published in the last years. The optimal assignment approach on molecular graphs, a successful method in the field of quantitative structure-activity relationships, has not been tested as a ligand-based virtual screening method so far. Results We evaluated two already published and two new optimal assignment methods on various data sets. To emphasize the "scaffold-hopping" ability, we used the information of chemotype clustering analyses in our evaluation metrics. Comparisons with literature results show an improved early recognition performance and comparable results over the complete data set. A new method based on two different assignment steps shows an increased "scaffold-hopping" behavior together with a good early recognition performance. Conclusion The presented methods show a good combination of chemotype discovery and enrichment of active structures. Additionally, the optimal assignment on molecular graphs has the advantage to investigate and interpret the mappings, allowing precise modifications of internal parameters of the similarity measure for specific targets. All methods have low computation times which make them applicable to screen large data sets. PMID:20150995

  1. The Edinburgh randomised trial of screening for breast cancer: description of method.

    PubMed Central

    Roberts, M. M.; Alexander, F. E.; Anderson, T. J.; Forrest, A. P.; Hepburn, W.; Huggins, A.; Kirkpatrick, A. E.; Lamb, J.; Lutz, W.; Muir, B. B.

    1984-01-01

    Edinburgh was selected as one of the centres in the UK Seven-year Trial of Breast Screening of women aged 45-65 which began in 1979. Subsequently, our study was extended to a randomised trial with its own control population within the city. Half the practices were randomly allocated for screening, giving a cluster sampling of women. The total number in the trial is 65,000. Women with previously diagnosed breast cancer are excluded. Women allocated for screening are invited to the clinic and screened according to the procedures specified in the U.K. protocol, having clinical examination every year and mammography on alternate years. The two modalities of screening are assessed independently and the role of nurses is being evaluated. Breast cancer incidence is monitored by pathology register and the local cancer registry office and deaths from the General Register office. Long-term follow-up will be obtained through flagging at NHS Central Register. To determine the value of screening, standard statistical methods will be used to compare breast cancer mortality rates in the whole of the screening population with that of the controls. This trial has a power of 83% of detecting a reduction in mortality of 35% after 7 years of follow-up and a power of 95% of detecting a similar reduction at 10 years (alpha = 0.05, one-sided test). PMID:6743506

  2. Indicators of depression in elderly and different screening methods

    PubMed Central

    Matias, Amanda Gilvani Cordeiro; Fonsêca, Marília de Andrade; Gomes, Maria de Lourdes de Freitas; Matos, Marcos Antonio Almeida

    2016-01-01

    ABSTRACT Objective To determine the prevalence of depressive symptoms among elderly and correlate the agreement between the screening methods used. Methods A cross-section study of 137 elderly attending the Programa Vivendo a Terceira Idade [Living for the Elderly Program]. Depressive symptoms were screened by the Patient Health Questionnaire-9 and the 15-item Geriatric Depression Scale, by Yesavage. Cohen´s kappa analyzed the degree of agreement of these scales. Results The prevalence of depressive symptoms screened by the Patient Health Questionnaire-9 was 62.8% and, by the Geriatric Depression Scale, 52.6%. The Spearman correlation between the results of scales obtained rho=0.387, p<0.000. The Kappa reliability coefficient was 0.41 and significance level of p<0.001. The screening methods showed sensitivity of 80% and specificity of 44%. Conclusion Both scales showed moderate agreement and were useful for detecting a relevant prevalence of the target outcome of depression among the elderly. PMID:27074227

  3. The 12-Item General Health Questionnaire as an Effective Mental Health Screening Tool for General Korean Adult Population

    PubMed Central

    Kim, Young Ju; Cho, Maeng Je; Park, Subin; Hong, Jin Pyo; Sohn, Jee Hoon; Bae, Jae Nam; Jeon, Hong Jin; Chang, Sung Man; Lee, Hae Woo

    2013-01-01

    Objective The 12-item General Health Questionnaire (GHQ-12) has been used extensively in various settings across different cultures. This study was conducted to determine the thresholds associated with optimum sensitivity and specificity for the GHQ-12 in Korean adults. Methods Data was acquired from a sample of 6,510 Korean adults, ages 18 to 64 years old, who were selected from the 2005 Census (2,581 men and 3,929 women). Participants completed the GHQ-12 and the Korean Composite International Diagnostic Interview (K-CIDI). Receiver Operating Characteristic (ROC) curve analysis was conducted. Results The mean GHQ-12 score for the total sample was 1.63 (SD 1.98). The internal consistency of the GHQ-12 was good (Cronbach's α=0.72). Results from the ROC curve indicated that the GHQ-12 yielded greater accuracy when identifying mood and anxiety disorders than when identifying all mental disorders as a whole. The optimal threshold of the GHQ-12 was either 1/2 or 2/3 point depending on the disorder, but was mainly 2/3. Conclusion The Korean version of the GHQ-12 could be used to screen for individuals at high risk of mental disorders, namely mood and anxiety disorders. PMID:24474983

  4. Modeling granular phosphor screens by Monte Carlo methods

    SciTech Connect

    Liaparinos, Panagiotis F.; Kandarakis, Ioannis S.; Cavouras, Dionisis A.; Delis, Harry B.; Panayiotakis, George S.

    2006-12-15

    The intrinsic phosphor properties are of significant importance for the performance of phosphor screens used in medical imaging systems. In previous analytical-theoretical and Monte Carlo studies on granular phosphor materials, values of optical properties, and light interaction cross sections were found by fitting to experimental data. These values were then employed for the assessment of phosphor screen imaging performance. However, it was found that, depending on the experimental technique and fitting methodology, the optical parameters of a specific phosphor material varied within a wide range of values, i.e., variations of light scattering with respect to light absorption coefficients were often observed for the same phosphor material. In this study, x-ray and light transport within granular phosphor materials was studied by developing a computational model using Monte Carlo methods. The model was based on the intrinsic physical characteristics of the phosphor. Input values required to feed the model can be easily obtained from tabulated data. The complex refractive index was introduced and microscopic probabilities for light interactions were produced, using Mie scattering theory. Model validation was carried out by comparing model results on x-ray and light parameters (x-ray absorption, statistical fluctuations in the x-ray to light conversion process, number of emitted light photons, output light spatial distribution) with previous published experimental data on Gd{sub 2}O{sub 2}S:Tb phosphor material (Kodak Min-R screen). Results showed the dependence of the modulation transfer function (MTF) on phosphor grain size and material packing density. It was predicted that granular Gd{sub 2}O{sub 2}S:Tb screens of high packing density and small grain size may exhibit considerably better resolution and light emission properties than the conventional Gd{sub 2}O{sub 2}S:Tb screens, under similar conditions (x-ray incident energy, screen thickness)

  5. Rapid screening methods for beta-emitters in food samples.

    PubMed

    Vos van Avezathe, A; Brandhoff, P N; van Bourgondiën, M J; Krijger, G C

    2015-03-01

    In case of a nuclear emergency, many samples need to be measured in a short time period. Therefore, it is of vital importance to have a quick and reliable (screening)method. Most methods to determine total beta activity are time-consuming because of extensive sample preparation, such as ashing. In this article three different rapid screening methods for beta emitting nuclides in agriculture, livestock and fishery products were tested and compared to each other, and to an accurate but more time consuming reference method. The goal was to find the method with the optimal trade-off between accuracy, speed and minimal detectable activity (MDA). All of the methods rely on liquid scintillation counting (LSC) or Cerenkov counting, and differ mainly in sample preparation. For matrices with little or no colour, the direct LSC-method is the most accurate and fastest option, while for darker coloured samples this method is not suitable because of high colour quenching. For such samples, two additional methods using a microwave digestion during sample preparation, produced good results. PMID:25577324

  6. On the order of general linear methods.

    SciTech Connect

    Constantinescu, E. M.; Mathematics and Computer Science

    2009-09-01

    General linear (GL) methods are numerical algorithms used to solve ODEs. The standard order conditions analysis involves the GL matrix itself and a starting procedure; however, a finishing method (F) is required to extract the actual ODE solution. The standard order analysis and stability are sufficient for the convergence of any GL method. Nonetheless, using a simple GL scheme, we show that the order definition may be too restrictive. Specifically, the order for GL methods with low order intermediate components may be underestimated. In this note we explore the order conditions for GL schemes and propose a new definition for characterizing the order of GL methods, which is focused on the final result--the outcome of F--and can provide more effective algebraic order conditions.

  7. High Throughput Screening Method to Explore Protein Interactions with Nanoparticles.

    PubMed

    Nasir, Irem; Fatih, Warda; Svensson, Anja; Radu, Dennis; Linse, Sara; Cabaleiro Lago, Celia; Lundqvist, Martin

    2015-01-01

    The interactions of biological macromolecules with nanoparticles underlie a wide variety of current and future applications in the fields of biotechnology, medicine and bioremediation. The same interactions are also responsible for mediating potential biohazards of nanomaterials. Some applications require that proteins adsorb to the nanomaterial and that the protein resists or undergoes structural rearrangements. This article presents a screening method for detecting nanoparticle-protein partners and conformational changes on time scales ranging from milliseconds to days. Mobile fluorophores are used as reporters to study the interaction between proteins and nanoparticles in a high-throughput manner in multi-well format. Furthermore, the screening method may reveal changes in colloidal stability of nanomaterials depending on the physicochemical conditions. PMID:26313757

  8. High Throughput Screening Method to Explore Protein Interactions with Nanoparticles

    PubMed Central

    Nasir, Irem; Fatih, Warda; Svensson, Anja; Radu, Dennis; Linse, Sara; Cabaleiro Lago, Celia; Lundqvist, Martin

    2015-01-01

    The interactions of biological macromolecules with nanoparticles underlie a wide variety of current and future applications in the fields of biotechnology, medicine and bioremediation. The same interactions are also responsible for mediating potential biohazards of nanomaterials. Some applications require that proteins adsorb to the nanomaterial and that the protein resists or undergoes structural rearrangements. This article presents a screening method for detecting nanoparticle-protein partners and conformational changes on time scales ranging from milliseconds to days. Mobile fluorophores are used as reporters to study the interaction between proteins and nanoparticles in a high-throughput manner in multi-well format. Furthermore, the screening method may reveal changes in colloidal stability of nanomaterials depending on the physicochemical conditions. PMID:26313757

  9. The Promise and Peril of Genomic Screening in the General Population

    PubMed Central

    Adams, Michael C.; Evans, James P.; Henderson, Gail E.; Berg, Jonathan S.

    2015-01-01

    Purpose Utilization of sequencing to screen the general population for preventable monogenic conditions is receiving substantial attention due to its potential to decrease morbidity and mortality. However, the selection of which variants to return is a serious implementation challenge. Procedures must be investigated to ensure optimal test characteristics and avoidance of harm from false positive test results. Methods We scanned exome sequences from 478 well-phenotyped individuals for potentially pathogenic variants in 17 genes representing 11 conditions that are among the most medically actionable Mendelian disorders in adults. We developed 5 variant selection algorithms with increasing sensitivity and measured their specificity in these 17 genes. Results Variant selection algorithms with increasing sensitivity exhibited decreased specificity, and performance was highly dependent on the genes analyzed. The most sensitive algorithm ranged from 88.8% to 99.6% specificity among the 17 genes. Conclusion For very low prevalence conditions, small reductions in specificity greatly increase false positives. This inescapable test characteristic governs the predictive value of genomic sequencing in the general population. To address this issue, test performance must be evaluated systematically for each condition so that the false negatives and false positives can be tailored for optimal outcomes, depending on the downstream clinical consequences. PMID:26540154

  10. Hilbert's axiomatic method and Carnap's general axiomatics.

    PubMed

    Stöltzner, Michael

    2015-10-01

    This paper compares the axiomatic method of David Hilbert and his school with Rudolf Carnap's general axiomatics that was developed in the late 1920s, and that influenced his understanding of logic of science throughout the 1930s, when his logical pluralism developed. The distinct perspectives become visible most clearly in how Richard Baldus, along the lines of Hilbert, and Carnap and Friedrich Bachmann analyzed the axiom system of Hilbert's Foundations of Geometry—the paradigmatic example for the axiomatization of science. Whereas Hilbert's axiomatic method started from a local analysis of individual axiom systems in which the foundations of mathematics as a whole entered only when establishing the system's consistency, Carnap and his Vienna Circle colleague Hans Hahn instead advocated a global analysis of axiom systems in general. A primary goal was to evade, or formalize ex post, mathematicians' 'material' talk about axiom systems for such talk was held to be error-prone and susceptible to metaphysics. PMID:26386526

  11. Screening for hyperglycaemia in pregnancy: analysis of two screening protocols and review of current methods.

    PubMed

    Hearty, R T; Traub, A I; Hadden, D R

    2000-05-01

    We assessed the ability of two screening protocols to detect varying degrees of hyperglycaemia in pregnancy and to compare fetal outcome in those found to have normal and abnormal glucose metabolism by either protocol. 493 pregnant women were identified by one of two screening protocols to be at risk of hyperglycaemia in pregnancy. Pregnancy complications, induction of labour, method of delivery, birth weight, incidence of congenital anomalies and neonatal complications were assessed; there were no significant differences between those with normal and abnormal glucose metabolism detected by either protocol apart from a significant linear trend for the incidence of large for gestational infants with increasing hyperglycaemia in both groups. Protocol B was as effective in detecting new hyperglycaemia in pregnancy as Protocol A. It involved the use of a breakfast meal profile in the initial assessment of those screened positive, reducing the need for glucose tolerance tests in the vast majority of cases. In the population studied, hyperglycaemia in pregnancy was not associated with adverse fetal outcome. PMID:10881644

  12. 7 CFR 361.2 - Preemption of State and local laws; general restrictions on the importation of seed and screenings.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... restrictions on the importation of seed and screenings. 361.2 Section 361.2 Agriculture Regulations of the... IMPORTATION OF SEED AND SCREENINGS UNDER THE FEDERAL SEED ACT § 361.2 Preemption of State and local laws; general restrictions on the importation of seed and screenings. (a) The regulations in this part...

  13. 7 CFR 361.2 - Preemption of State and local laws; general restrictions on the importation of seed and screenings.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... restrictions on the importation of seed and screenings. 361.2 Section 361.2 Agriculture Regulations of the... IMPORTATION OF SEED AND SCREENINGS UNDER THE FEDERAL SEED ACT § 361.2 Preemption of State and local laws; general restrictions on the importation of seed and screenings. (a) The regulations in this part...

  14. 7 CFR 361.2 - Preemption of State and local laws; general restrictions on the importation of seed and screenings.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... restrictions on the importation of seed and screenings. 361.2 Section 361.2 Agriculture Regulations of the... IMPORTATION OF SEED AND SCREENINGS UNDER THE FEDERAL SEED ACT § 361.2 Preemption of State and local laws; general restrictions on the importation of seed and screenings. (a) The regulations in this part...

  15. 7 CFR 361.2 - Preemption of State and local laws; general restrictions on the importation of seed and screenings.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... restrictions on the importation of seed and screenings. 361.2 Section 361.2 Agriculture Regulations of the... IMPORTATION OF SEED AND SCREENINGS UNDER THE FEDERAL SEED ACT § 361.2 Preemption of State and local laws; general restrictions on the importation of seed and screenings. (a) The regulations in this part...

  16. 7 CFR 361.2 - Preemption of State and local laws; general restrictions on the importation of seed and screenings.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... restrictions on the importation of seed and screenings. 361.2 Section 361.2 Agriculture Regulations of the... IMPORTATION OF SEED AND SCREENINGS UNDER THE FEDERAL SEED ACT § 361.2 Preemption of State and local laws; general restrictions on the importation of seed and screenings. (a) The regulations in this part...

  17. A screened automated structural search with semiempirical methods

    NASA Astrophysics Data System (ADS)

    Ota, Yukihiro; Ruiz-Barragan, Sergi; Machida, Masahiko; Shiga, Motoyuki

    2016-03-01

    We developed an interface program between a program suite for an automated search of chemical reaction pathways, GRRM, and a program package of semiempirical methods, MOPAC. A two-step structural search is proposed as an application of this interface program. A screening test is first performed by semiempirical calculations. Subsequently, a reoptimization procedure is done by ab initio or density functional calculations. We apply this approach to ion adsorption on cellulose. The computational efficiency is also shown for a GRRM search. The interface program is suitable for the structural search of large molecular systems for which semiempirical methods are applicable.

  18. Prenatal screening for fetal aneuploidies with cell-free DNA in the general pregnancy population: a cost-effectiveness analysis

    PubMed Central

    Fairbrother, Genevieve; Burigo, John; Sharon, Thomas; Song, Ken

    2016-01-01

    Abstract Objective: To estimate the cost-effectiveness of fetal aneuploidy screening in the general pregnancy population using non-invasive prenatal testing (NIPT) as compared to first trimester combined screening (FTS) with serum markers and NT ultrasound. Methods: Using a decision-analytic model, we estimated the number of fetal T21, T18, and T13 cases identified prenatally, the number of invasive procedures performed, corresponding normal fetus losses, and costs of screening using FTS or NIPT with cell-free DNA (cfDNA). Modeling was based on a 4 million pregnant women cohort, which represents annual births in the U.S. Results: For the general pregnancy population, NIPT identified 15% more trisomy cases, reduced invasive procedures by 88%, and reduced iatrogenic fetal loss by 94% as compared to FTS. The cost per trisomy case identified with FTS was $497 909. At a NIPT unit, cost of $453 and below, there were cost savings as compared to FTS. Accounting for additional trisomy cases identified by NIPT, a NIPT unit cost of $665 provided the same per trisomy cost as that of FTS. Conclusions: NIPT in the general pregnancy population leads to more prenatal identification of fetal trisomy cases as compared to FTS and is more economical at a NIPT unit cost of $453. PMID:26000626

  19. Potential screening and early diagnosis method for cancer: Tongue diagnosis

    PubMed Central

    HAN, SHUWEN; YANG, XI; QI, QUAN; PAN, YUEFEN; CHEN, YONGCHAO; SHEN, JUNJUN; LIAO, HAIHONG; JI, ZHAONING

    2016-01-01

    Tongue diagnosis, as a unique method of traditional Chinese medicine (TCM), was used to discriminate physiological functions and pathological conditions by observing the changes of the tongue and tongue coating. The aims of the present study were to explore a potential screening and early diagnosis method of cancer through evaluating the differences of the images of tongue and tongue coating and the microbiome on the tongue coating. The DS01-B tongue diagnostic information acquisition system was used to photograph and analyze the tongue and tongue coating. The next-generation sequencing technology was used to determine the V2-V4 hypervariable regions of 16S rDNA to investigate the microbiome on the tongue coating. Bioinformatics and statistical methods were used to analyze the microbial community structure and diversity. Comparing with the healthy people, the number of mirror-like tongue, thick tongue coating and the moisture of tongue were increased in cancers. The dominant color of the tongue in the healthy people was reddish while it was purple in the cancers. The relative abundance of Neisseria, Haemophilus, Fusobacterium and Porphyromonas in the healthy people were higher than that in the cancers. We also found 6 kinds of special microorganisms at species level in cancers. The study suggested that tongue diagnosis may provide potential screening and early diagnosis method for cancer. PMID:27035407

  20. Potential screening and early diagnosis method for cancer: Tongue diagnosis.

    PubMed

    Han, Shuwen; Yang, Xi; Qi, Quan; Pan, Yuefen; Chen, Yongchao; Shen, Junjun; Liao, Haihong; Ji, Zhaoning

    2016-06-01

    Tongue diagnosis, as a unique method of traditional Chinese medicine (TCM), was used to discriminate physiological functions and pathological conditions by observing the changes of the tongue and tongue coating. The aims of the present study were to explore a potential screening and early diagnosis method of cancer through evaluating the differences of the images of tongue and tongue coating and the microbiome on the tongue coating. The DS01-B tongue diagnostic information acquisition system was used to photograph and analyze the tongue and tongue coating. The next-generation sequencing technology was used to determine the V2-V4 hypervariable regions of 16S rDNA to investigate the microbiome on the tongue coating. Bioinformatics and statistical methods were used to analyze the microbial community structure and diversity. Comparing with the healthy people, the number of mirror-like tongue, thick tongue coating and the moisture of tongue were increased in cancers. The dominant color of the tongue in the healthy people was reddish while it was purple in the cancers. The relative abundance of Neisseria, Haemophilus, Fusobacterium and Porphyromonas in the healthy people were higher than that in the cancers. We also found 6 kinds of special microorganisms at species level in cancers. The study suggested that tongue diagnosis may provide potential screening and early diagnosis method for cancer. PMID:27035407

  1. Method for making generally cylindrical underground openings

    DOEpatents

    Routh, J.W.

    1983-05-26

    A rapid, economical and safe method for making a generally cylindrical underground opening such as a shaft or a tunnel is described. A borehole is formed along the approximate center line of where it is desired to make the underground opening. The borehole is loaded with an explodable material and the explodable material is detonated. An enlarged cavity is formed by the explosive action of the detonated explodable material forcing outward and compacting the original walls of the borehole. The enlarged cavity may be increased in size by loading it with a second explodable material, and detonating the second explodable material. The process may be repeated as required until the desired underground opening is made. The explodable material used in the method may be free-flowing, and it may be contained in a pipe.

  2. A general method to determine twinning elements

    PubMed Central

    Zhang, Yudong; Li, Zongbin; Esling, Claude; Muller, Jacques; Zhao, Xiang; Zuo, Liang

    2010-01-01

    The fundamental theory of crystal twinning has been long established, leading to a significant advance in understanding the nature of this physical phenomenon. However, there remains a substantial gap between the elaborate theory and the practical determination of twinning elements. This paper proposes a direct and simple method – valid for any crystal structure and based on the minimum shear criterion – to calculate various twinning elements from the experimentally determined twinning plane for Type I twins or the twinning direction for Type II twins. Without additional efforts, it is generally applicable to identify and predict possible twinning modes occurring in a variety of crystalline solids. Therefore, the present method is a promising tool to characterize twinning elements, especially for those materials with complex crystal structure. PMID:22477779

  3. Screening for celiac disease in the general population and in high-risk groups

    PubMed Central

    Card, Timothy R; Kaukinen, Katri; Bai, Julio; Zingone, Fabiana; Sanders, David S; Murray, Joseph A

    2015-01-01

    Background Celiac disease (CD) occurs in approximately 1% of the Western population. It is a lifelong disorder that is associated with impaired quality of life (QOL) and an excessive risk of comorbidity and death. Objectives To review the literature on screening for CD in relation to the current World Health Organization (WHO) criteria for mass screening. Methods We performed a PubMed search to identify indexed papers on CD screening with a publication date from 1900 until 1 June 2014. When we deemed an abstract relevant, we read the corresponding paper in detail. Results CD fulfills several WHO criteria for mass screening (high prevalence, available treatment and difficult clinical detection), but it has not yet been established that treatment of asymptomatic CD may reduce the excessive risk of severe complications, leading to higher QOL nor that it is cost-effective. Conclusions Current evidence is not sufficient to support mass screening for CD, but active case-finding may be appropriate, as we recognize that most patients with CD will still be missed by this strategy. Although proof of benefit is still lacking, screening for CD may be appropriate in high-risk groups. PMID:25922671

  4. Hori method for generalized canonical systems

    NASA Astrophysics Data System (ADS)

    da Silva Fernandes, Sandro

    2009-01-01

    In this paper, some special features on the canonical version of Hori method, when it is applied to generalized canonical systems (systems of differential equations described by a Hamiltonian function linear in the momenta), are presented. Two different procedures, based on a new approach for the integration theory recently presented for the canonical version, are proposed for determining the new Hamiltonian and the generating function for systems whose differential equations for the coordinates describe a periodic system with one fast phase. These procedures are equivalent and they are directly related to the canonical transformations defined by the general solution of the integrable kernel of the Hamiltonian. They provide the same near-identity transformation for the coordinates obtained through the non-canonical version of Hori method. It is also shown that these procedures are connected to the classic averaging principle through a canonical transformation. As examples, asymptotic solutions of a non-linear oscillations problem and of the elliptic perturbed problem are discussed.

  5. A novel method for screening beta-glucosidase inhibitors

    PubMed Central

    2013-01-01

    Background Few beta-glucosidase inhibitors have so far been reported from microorganisms due to the practical difficulties in performing the inhibition tests and subsequent interpretation of results. In an effort to investigate marine microbial extracts for β-glucosidase inhibitors, we developed a new protocol, using esculin as substrate in an agar plate based assay, to screen a large number of microbial extracts in a short span of time. Results With the new method, pale yellowish zones against the blackish brown background could be visually observed with more clarity in sample extracts where β-glucosidase inhibitor was present. The new method was compared with the closest existing method and established beyond doubt. This agar plate based procedure required about one hour for minimum 12 samples and the throughput increases with the size of the agar gel plate used. Conclusions The new protocol was simple, rapid and effective in detecting beta-glucosidase inhibitors in microbial extracts. PMID:23497098

  6. Generalized HPC method for the Poisson equation

    NASA Astrophysics Data System (ADS)

    Bardazzi, A.; Lugni, C.; Antuono, M.; Graziani, G.; Faltinsen, O. M.

    2015-10-01

    An efficient and innovative numerical algorithm based on the use of Harmonic Polynomials on each Cell of the computational domain (HPC method) has been recently proposed by Shao and Faltinsen (2014) [1], to solve Boundary Value Problem governed by the Laplace equation. Here, we extend the HPC method for the solution of non-homogeneous elliptic boundary value problems. The homogeneous solution, i.e. the Laplace equation, is represented through a polynomial function with harmonic polynomials while the particular solution of the Poisson equation is provided by a bi-quadratic function. This scheme has been called generalized HPC method. The present algorithm, accurate up to the 4th order, proved to be efficient, i.e. easy to be implemented and with a low computational effort, for the solution of two-dimensional elliptic boundary value problems. Furthermore, it provides an analytical representation of the solution within each computational stencil, which allows its coupling with existing numerical algorithms within an efficient domain-decomposition strategy or within an adaptive mesh refinement algorithm.

  7. Design of a general-purpose European compound screening library for EU-OPENSCREEN.

    PubMed

    Horvath, Dragos; Lisurek, Michael; Rupp, Bernd; Kühne, Ronald; Specker, Edgar; von Kries, Jens; Rognan, Didier; Andersson, C David; Almqvist, Fredrik; Elofsson, Mikael; Enqvist, Per-Anders; Gustavsson, Anna-Lena; Remez, Nikita; Mestres, Jordi; Marcou, Gilles; Varnek, Alexander; Hibert, Marcel; Quintana, Jordi; Frank, Ronald

    2014-10-01

    This work describes a collaborative effort to define and apply a protocol for the rational selection of a general-purpose screening library, to be used by the screening platforms affiliated with the EU-OPENSCREEN initiative. It is designed as a standard source of compounds for primary screening against novel biological targets, at the request of research partners. Given the general nature of the potential applications of this compound collection, the focus of the selection strategy lies on ensuring chemical stability, absence of reactive compounds, screening-compliant physicochemical properties, loose compliance to drug-likeness criteria (as drug design is a major, but not exclusive application), and maximal diversity/coverage of chemical space, aimed at providing hits for a wide spectrum of drugable targets. Finally, practical availability/cost issues cannot be avoided. The main goal of this publication is to inform potential future users of this library about its conception, sources, and characteristics. The outline of the selection procedure, notably of the filtering rules designed by a large committee of European medicinal chemists and chemoinformaticians, may be of general methodological interest for the screening/medicinal chemistry community. The selection task of 200K molecules out of a pre-filtered set of 1.4M candidates was shared by five independent European research groups, each picking a subset of 40K compounds according to their own in-house methodology and expertise. An in-depth analysis of chemical space coverage of the library serves not only to characterize the collection, but also to compare the various chemoinformatics-driven selection procedures of maximal diversity sets. Compound selections contributed by various participating groups were mapped onto general-purpose self-organizing maps (SOMs) built on the basis of marketed drugs and bioactive reference molecules. In this way, the occupancy of chemical space by the EU-OPENSCREEN library could

  8. Autoradiographic method to screen for soil microorganisms which accumulate zinc

    SciTech Connect

    Zamani, B.; Knezek, B.D.; Flegler, S.L.; Beneke, E.S.; Dazzo, F.B.

    1985-01-01

    An autoradiographic method was developed to screen for and isolate soil microorganisms which accumulate zinc (ZN). Diluted soil samples (pH 5.9) were plated on soil extract-glucose agar containing radioactive /sup 65/Zn. After 7 days of incubation, individual colonies which accumulated sufficient /sup 65/Zn could be detected by autoradiography. These colonies were isolated and confirmed as Zn accumulators in pure culture by using the autoradiographic plate technique. Most Zn accumulators were filamentous fungi, identified as Penicillium janthinellum, Aspergillus fumigatus, and Paecilomyces sp. Isolates of Penicillium janthinellum were the most common Zn accumulators. The most abundant Zn-accumulating bacteria were Bacillus spp. The validity of the autoradiographic plate technique to differentiate soil microbes which accumulate Zn was examined independently by energy dispersive X-ray analysis in a scanning electron microscope. This method confirmed that fungal isolates which gave positive autoradiographic responses in the plate assay bioaccumulated more Zn in their biomass than fungal isolates from the same soil sample which gave negative autoradiographic responses. Thus, this technique can be applied to specifically screen for and isolate microbes from the environment which bioaccumulate Zn.

  9. Method for in vitro screening of aquatic fungicides

    USGS Publications Warehouse

    Bailey, T.A.

    1983-01-01

    Methods were developed for in vitro screening of candidate aquatic fungicides for efficacy against Achlya fiagellata, A. racemosa, Saprolegnia hypogyna and S. megasperma. Agar plugs containing fungal hyphae, removed from the edge of actively growing colonies, were placed in the depressions of spot plates containing 1a??0, 10a??0 and 100 mg/I of the candidate compounds for 15 or 60 min. After exposure, the plugs were transferred on to filter papers (0a??45-A?m pore) in a holder, rinsed, and then placed on cornmeal agar medium in tri-petri dishes. The plates were checked for mycelial growth after 48, 96 and 168 h of incubation in a lighted (400-800 A?m) environmental control chamber at 20A?2A?C. Criteria for the acceptance or rejection of candidate aquatic fungicides for further study were based on the antifungal spectrum index (ASI) comparisons between respective compounds and malachite green after 48 h and the concentration level producing complete growth inhibition. Candidate compounds whose ASI was less than 50% that of malachite green after 48 h or did not inhibit growth at levels less than 100 mg/l were rejected. This method provides a base from which in vivo and definitive test regimens can be developed. Preliminary in vitro screening of candidate fungicides reduces the need for costly in vivo tests on compounds that have low antifungal activity.

  10. Rapid Screening Method for Detection of Bacteria in Platelet Concentrates

    PubMed Central

    Ribault, S.; Harper, K.; Grave, L.; Lafontaine, C.; Nannini, P.; Raimondo, A.; Faure, I. Besson

    2004-01-01

    Public awareness has long focused on the risks of the transmission of viral agents through blood product transfusion. This risk, however, pales in comparison to the less publicized danger associated with the transfusion of blood products contaminated with bacteria, in particular, platelet concentrates. Up to 1,000 cases of clinical sepsis after the transfusion of platelet concentrates are reported annually in the United States. The condition is characterized by acute reaction symptoms and the rapid onset of septicemia and carries a 20 to 40% mortality rate. The urgent need for a method for the routine screening of platelet concentrates to improve patient safety has long been recognized. We describe the development of a rapid and highly sensitive method for screening for bacteria in platelet concentrates for transfusion. No culture period is required; and the entire procedure, from the time of sampling to the time that the final result is obtained, takes less than 90 min. The method involves three basic stages: the selective removal of platelets by filtration following activation with a monoclonal antibody, DNA-specific fluorescent labeling of bacteria, and concentration of the bacteria on a membrane surface for enumeration by solid-phase cytometry. The method offers a universal means of detection of live, nondividing, or dead gram-negative and gram-positive bacteria in complex cellular blood products. The sensitivity is higher than those of the culture-based methods available at present, with a detection limit of 10 to 102 CFU/ml, depending upon the bacterial strain. PMID:15131147

  11. Rapid screening method for detection of bacteria in platelet concentrates.

    PubMed

    Ribault, S; Harper, K; Grave, L; Lafontaine, C; Nannini, P; Raimondo, A; Faure, I Besson

    2004-05-01

    Public awareness has long focused on the risks of the transmission of viral agents through blood product transfusion. This risk, however, pales in comparison to the less publicized danger associated with the transfusion of blood products contaminated with bacteria, in particular, platelet concentrates. Up to 1,000 cases of clinical sepsis after the transfusion of platelet concentrates are reported annually in the United States. The condition is characterized by acute reaction symptoms and the rapid onset of septicemia and carries a 20 to 40% mortality rate. The urgent need for a method for the routine screening of platelet concentrates to improve patient safety has long been recognized. We describe the development of a rapid and highly sensitive method for screening for bacteria in platelet concentrates for transfusion. No culture period is required; and the entire procedure, from the time of sampling to the time that the final result is obtained, takes less than 90 min. The method involves three basic stages: the selective removal of platelets by filtration following activation with a monoclonal antibody, DNA-specific fluorescent labeling of bacteria, and concentration of the bacteria on a membrane surface for enumeration by solid-phase cytometry. The method offers a universal means of detection of live, nondividing, or dead gram-negative and gram-positive bacteria in complex cellular blood products. The sensitivity is higher than those of the culture-based methods available at present, with a detection limit of 10 to 10(2) CFU/ml, depending upon the bacterial strain. PMID:15131147

  12. The views of general practitioners and practice nurses towards the barriers and facilitators of proactive, internet-based chlamydia screening for reaching young heterosexual men

    PubMed Central

    2014-01-01

    Background Chlamydia trachomatis is a common bacterial sexually transmitted infection (STI), which disproportionately affects young people under 25 years. Commonly, more women are offered screening than men. This study obtained the views of general practitioners and practice nurses towards Internet-based screening and assessed levels of support for the development of proactive screening targeting young heterosexual men via the Internet. Methods Semi-structured telephone interviews with 10 general practitioners and 8 practice nurses, across Central Scotland. Topics covered: experience of screening heterosexual men for chlamydia, views on the use of the Internet as a way to reach young men for chlamydia screening, beliefs about the potential barriers and facilitators to Internet-based screening. Transcripts from audio recordings were analysed with Framework Analysis, using QSR NVivo10. Results Experiences of chlamydia screening were almost exclusively with women, driven by the nature of consultations and ease of raising sexual health issues with female patients; few practice nurses reported seeing men during consultations. All participants spoke in favour of Internet-based screening for young men. Participants reported ease of access and convenience as potential facilitators of an Internet-based approach but anonymity and confidentiality could be potential barriers and facilitators to the success of an Internet approach to screening. Concerns over practical issues as well as those pertaining to gender and socio-cultural issues were raised. Conclusions Awareness of key barriers and facilitators, such as confidentiality, practicality and socio-cultural influences, will inform the development of an Internet-based approach to screening. However, this approach may have its limits in terms of being able to tackle wider social and cultural barriers, along with shifts in young people’s and health professionals’ attitudes towards screening. Nevertheless, employing

  13. Methods for external event screening quantification: Risk Methods Integration and Evaluation Program (RMIEP) methods development

    SciTech Connect

    Ravindra, M.K.; Banon, H.

    1992-07-01

    In this report, the scoping quantification procedures for external events in probabilistic risk assessments of nuclear power plants are described. External event analysis in a PRA has three important goals; (1) the analysis should be complete in that all events are considered; (2) by following some selected screening criteria, the more significant events are identified for detailed analysis; (3) the selected events are analyzed in depth by taking into account the unique features of the events: hazard, fragility of structures and equipment, external-event initiated accident sequences, etc. Based on the above goals, external event analysis may be considered as a three-stage process: Stage I: Identification and Initial Screening of External Events; Stage II: Bounding Analysis; Stage III: Detailed Risk Analysis. In the present report, first, a review of published PRAs is given to focus on the significance and treatment of external events in full-scope PRAs. Except for seismic, flooding, fire, and extreme wind events, the contributions of other external events to plant risk have been found to be negligible. Second, scoping methods for external events not covered in detail in the NRC`s PRA Procedures Guide are provided. For this purpose, bounding analyses for transportation accidents, extreme winds and tornadoes, aircraft impacts, turbine missiles, and chemical release are described.

  14. Methods for external event screening quantification: Risk Methods Integration and Evaluation Program (RMIEP) methods development

    SciTech Connect

    Ravindra, M.K.; Banon, H. )

    1992-07-01

    In this report, the scoping quantification procedures for external events in probabilistic risk assessments of nuclear power plants are described. External event analysis in a PRA has three important goals; (1) the analysis should be complete in that all events are considered; (2) by following some selected screening criteria, the more significant events are identified for detailed analysis; (3) the selected events are analyzed in depth by taking into account the unique features of the events: hazard, fragility of structures and equipment, external-event initiated accident sequences, etc. Based on the above goals, external event analysis may be considered as a three-stage process: Stage I: Identification and Initial Screening of External Events; Stage II: Bounding Analysis; Stage III: Detailed Risk Analysis. In the present report, first, a review of published PRAs is given to focus on the significance and treatment of external events in full-scope PRAs. Except for seismic, flooding, fire, and extreme wind events, the contributions of other external events to plant risk have been found to be negligible. Second, scoping methods for external events not covered in detail in the NRC's PRA Procedures Guide are provided. For this purpose, bounding analyses for transportation accidents, extreme winds and tornadoes, aircraft impacts, turbine missiles, and chemical release are described.

  15. Treecode-based generalized Born method

    NASA Astrophysics Data System (ADS)

    Xu, Zhenli; Cheng, Xiaolin; Yang, Haizhao

    2011-02-01

    We have developed a treecode-based O(Nlog N) algorithm for the generalized Born (GB) implicit solvation model. Our treecode-based GB (tGB) is based on the GBr6 [J. Phys. Chem. B 111, 3055 (2007)], an analytical GB method with a pairwise descreening approximation for the R6 volume integral expression. The algorithm is composed of a cutoff scheme for the effective Born radii calculation, and a treecode implementation of the GB charge-charge pair interactions. Test results demonstrate that the tGB algorithm can reproduce the vdW surface based Poisson solvation energy with an average relative error less than 0.6% while providing an almost linear-scaling calculation for a representative set of 25 proteins with different sizes (from 2815 atoms to 65456 atoms). For a typical system of 10k atoms, the tGB calculation is three times faster than the direct summation as implemented in the original GBr6 model. Thus, our tGB method provides an efficient way for performing implicit solvent GB simulations of larger biomolecular systems at longer time scales.

  16. A walk-in screening of dementia in the general population in Taiwan.

    PubMed

    Chen, Chun-Hung; Wang, Ling-Chun; Ma, Tzu-Chiao; Yang, Yuan-Han

    2014-01-01

    Alzheimer's disease (AD) has increased in its prevalence due to the increasing aged population. Currently there is no updated data on the prevalence of dementia including its very mild stage in Taiwan. Under the extensive coverage of Mentality Protection Center (MPC), Fo Guang Shan, Taiwan, the volunteers of MPC have conducted the medicine-related services and the screening of dementia by AD8 (ascertainment of dementia 8) that can screen the dementia even at its very mild stage in general population in all Taiwan. From 2011 to 2013, in total, 2,171 participants, 368 in the northern, 549 in the central, 877 in the southern, and 377 in the eastern part, were recruited with the mean age being 66.9 ± 10.2 years old. The ratio of suspected dementia patients, AD8 score greater than or equal to 2, was 13.6% of all recruited participants with their mean AD8 score being 2.9 ± 1.3, mean age being 69.4 ± 10.8 years old, and female predominance being 73.0%. Although this is a screening study, it has extensive coverage of all Taiwan and the use of AD8 is capable of screening very mild dementia. A further study with a randomized sampling to examine the prevalence and incidence of dementia including its very mild stage is encouraged. PMID:24883363

  17. SLCA/IP power alternative screening method (SPASM)

    SciTech Connect

    Palmer, S.C. |; Ancrile, J.D.

    1995-03-01

    This report describes the SLCA/IP Power Alternative Screening Method (SPASM), which was used to screen 784 possible combinations of electric power marketing alternatives and dam operational scenarios to provide a representative range for analysis in the Western Area Power Administration Salt Lake City Area Integrated Projects (SLCA/IP) Electric Power Marketing Environmental Impact Statement (EIS). Each combination consists of one energy and capacity commitment level and one operational scenario for each of the hydroelectric facilities at Glen Canyon Dam, Flaming Gorge Dam, and the Aspinall Unit. The total annual cost to the SLCA/IP firm power customers of each of the 784 combinations is estimated and included in a relative frequency distribution. A relative frequency distribution is also generated for each marketing alternative. The number of combinations is reduced to 12 by taking the mean value and endpoint value for each of four marketing alternatives. Some minor deviations from this procedure, which are made for political purposes, are explained. 9 figs., 14 tabs.

  18. Current utility of the ankle-brachial index (ABI) in general practice: implications for its use in cardiovascular disease screening

    PubMed Central

    2014-01-01

    Background Peripheral arterial disease (PAD) is a marker of systemic atherosclerosis and associated with a three to six fold increased risk of death from cardiovascular causes. Furthermore, it is typically asymptomatic and under-diagnosed; this has resulted in escalating calls for the instigation of Primary Care PAD screening via Ankle Brachial Index (ABI) measurement. However, there is limited evidence regarding the feasibility of this and if the requisite core skills and knowledge for such a task already exist within primary care. This study aimed to determine the current utility of ABI measurement in general practices across Wales, with consideration of the implications for its use as a cardiovascular risk screening tool. Method A self-reporting questionnaire was distributed to all 478 General Practices within Wales, sent via their responsible Health Boards. Results The survey response rate was 20%. ABI measurement is primarily performed by nurses (93%) for the purpose of wound management (90%). It is infrequently (73% < 4 times per month) and often incorrectly used (42% out of compliance with current ABI guidance). Only 52% of general practitioners and 16% of nurses reported that patients with an ABI of ≤ 0.9 require aggressive cardiovascular disease risk factor modification (as recommended by current national and international guidelines). Conclusion ABI measurement is an under-utilised and often incorrectly performed procedure in the surveyed general practices. Prior to its potential adoption as a formalised screening tool for cardiovascular disease, there is a need for a robust training programme with standardised methodology in order to optimise accuracy and consistency of results. The significance of a diagnosis of PAD, in terms of associated increased cardiovascular risk and the necessary risk factor modification, needs to be highlighted. PMID:24742018

  19. Screening for posttraumatic stress disorder in a general psychiatric outpatient setting.

    PubMed

    Sheeran, Thomas; Zimmerman, Mark

    2002-08-01

    Posttraumatic stress disorder (PTSD) may affect survivors of a number of accidents and illnesses, in addition to violence victims and combat veterans. Prior research suggests that PTSD may be underdiagnosed when trauma is not the presenting problem. Thus, a PTSD screening scale might have utility in routine clinical settings. The authors evaluated the screening performance of the Posttraumatic Diagnostic Scale (PDS) in a general psychiatric setting. Results indicated that the PDS performed as well in this setting as it did in the original trauma-focused validation studies, independent of PTSD status as a primary, versus secondary, reason for presenting. A simple cutoff score was adequate for case identification. There were no gender effects, and the scale performed equally well among patients with, versus without, a depressive diagnosis. PMID:12182279

  20. Antibody screening & identification in the general patient population at a tertiary care hospital in New Delhi, India

    PubMed Central

    Makroo, Raj Nath; Bhatia, Aakanksha; Hegde, Vikas; Chowdhry, Mohit; Thakur, Uday Kumar; Rosamma, N.L.

    2014-01-01

    Background & objectives: The development of alloantibodies can significantly complicate transfusion therapy and results in difficulties in cross-matching of blood. Most literature on alloimmunization is limited to multitransfused individuals, with very few studies on the general hospital patients. This study was aimed at assessing the frequency and type of unexpected red cell antibodies in the general patient population at a multispecialty tertiary care centre in New Delhi, India. Methods: The results of 49,077 antibody screening tests carried out on patients, from January 2009 to December 2012 were analyzed. The clinical and transfusion records were reviewed. The data were compiled and statistically analysed. Results: A total of 49,077 (29,917; 60.96% males and 19,160; 39.04% females) patient samples were screened for the presence of unexpected antibodies. Antibody screening was positive in 403 patients (0.82%). In the serum samples of 164 patients only autoantibodies were identified, 27 revealed autoantibodies with one or more underlying alloantibodies, while 212 patients had only alloantibody/ies in their serum. The overall alloimmunization rate was 0.49 per cent. Antibodies against the Rh system were the most frequent (64.1%), the most common alloantibody identified being anti E (37.2%), followed by anti D (19.2%). Interpretation & conclusions: Since clinically significant antibodies are frequently detected in our patient population, antibody screening and if required, identification is the need of the hour. Since antibodies against the common Rh and Kell blood group antigens are the most frequent, provision of Rh and Kell matched red cells may be of protective value. PMID:25366208

  1. SCREENING METHODS FOR SELECTION OF SURFACTANT FORMULATIONS FOR IOR FROM FRACTURED CARBONATE RESERVOIRS

    SciTech Connect

    William A. Goddard III; Yongchun Tang; Patrick Shuler; Mario Blanco; Yongfu Wu; Seung Soon Jang

    2005-07-01

    This topical report presents details of the laboratory work performed to complete Task 1 of this project; developing rapid screening methods to assess surfactant performance for IOR (Improved Oil Recovery) from fractured carbonate reservoirs. The desired outcome is to identify surfactant formulations that increase the rate and amount of aqueous phase imbibition into oil-rich, oil-wet carbonate reservoir rock. Changing the wettability from oil-wet to water-wet is one key to enhancing this water-phase imbibition process that in turn recovers additional oil from the matrix portion of a carbonate reservoir. The common laboratory test to evaluate candidate surfactant formulations is to measure directly the aqueous imbibition rate and oil recovery from small outcrop or reservoir cores, but this procedure typically requires several weeks. Two methods are presented here for the rapid screening of candidate surfactant formulations for their potential IOR performance in carbonate reservoirs. One promising surfactant screening protocol is based on the ability of a surfactant solution to remove aged crude oil that coats a clear calcite crystal (Iceland Spar). Good surfactant candidate solutions remove the most oil the quickest from the chips, plus change the apparent contact angle of the remaining oil droplets on the surface that thereby indicate increased water-wetting. The other fast surfactant screening method is based on the flotation behavior of powdered calcite in water. In this test protocol, first the calcite power is pre-treated to make the surface oil-wet. The next step is to add the pre-treated powder to a test tube and add a candidate aqueous surfactant formulation; the greater the percentage of the calcite that now sinks to the bottom rather than floats, the more effective the surfactant is in changing the solids to become now preferentially water-wet. Results from the screening test generally are consistent with surfactant performance reported in the literature.

  2. Screening portal, system and method of using same

    DOEpatents

    Linker, Kevin L.; Hunter, John A.; Brusseau, Charles A.

    2013-04-30

    A portal, system and method for screening an object for a target substance is provided. The portal includes an inflatable bladder expandable to form a test space for receiving the object and a plurality of nozzles positioned about the inflatable bladder. The nozzles are in fluid communication with a fluid source for directing air over the object whereby samples are removed from the object for examination. A collector is operatively connected to the inflatable bladder for collecting the samples removed from the object. A detector is operatively connected to the collector for examining the removed samples for the presence of the target substance. At least one preconcentrator may be operatively connected to the collector for concentrating the samples collected thereby.

  3. A Method for Universal Screening of Elementary School Students: Development of the Social Challenges Screening Questionnaire

    ERIC Educational Resources Information Center

    Smith, Christopher J.; Pollard, Elena; Stein, Alexander J.; Ober-Reynolds, Sharman; Kirwan, Janet; Malligo, Amanda; Matthews, Nicole L.; Openden, Daniel; Melmed, Raun D.

    2015-01-01

    Schools regularly screen students for hearing and vision impairments because they present impediments to academic progress. For the same reason, schools should consider adding a universal screening for social challenges, which may also impede the learning process. This study reports on the development of the Social Challenges Screening…

  4. A Desktop Screen Sharing System based on Various Connection Methods

    NASA Astrophysics Data System (ADS)

    Negishi, Yuya; Kawaguchi, Nobuo

    Recently it became very common to use information devices such as PCs during presentations and discussions. In these situations, a need arises for techniques that allow a smooth switch of presenters without changing cables, or an easy screen sharing in case of remote videoconferences. In this paper, we propose a desktop screen sharing system that can be used for such purposes and situations. For that, we designed an automatic control of connections in the VNC system that can be operated remotely over the network. We also suggested an interface that assigns a role such as “Screen sender" or “Screen receiver" to each terminal. In the proposed system, while sharing a screen between multiple terminals, one can easily display and browse the screen without having to understand how the others are connected. We also implemented a “role card" using contactless IC card, where roles are assigned only by placing the card in the IC reader.

  5. Screening methods to identify TALEN-mediated knockout mice.

    PubMed

    Nakagawa, Yoshiko; Yamamoto, Takashi; Suzuki, Ken-Ichi; Araki, Kimi; Takeda, Naoki; Ohmuraya, Masaki; Sakuma, Tetsushi

    2014-01-01

    Genome editing with site-specific nucleases, such as zinc-finger nucleases or transcription activator-like effector nucleases (TALENs), and RNA-guided nucleases, such as the CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated) system, is becoming the new standard for targeted genome modification in various organisms. Application of these techniques to the manufacture of knockout mice would be greatly aided by simple and easy methods for genotyping of mutant and wild-type pups among litters. However, there are no detailed or comparative reports concerning the identification of mutant mice generated using genome editing technologies. Here, we genotyped TALEN-derived enhanced green fluorescent protein (eGFP) knockout mice using a combination of approaches, including fluorescence observation, heteroduplex mobility assay, restriction fragment length polymorphism analysis and DNA sequencing. The detection sensitivities for TALEN-induced mutations differed among these methods, and we therefore concluded that combinatorial testing is necessary for the screening and determination of mutant genotypes. Since the analytical methods tested can be carried out without specialized equipment, costly reagents and/or sophisticated protocols, our report should be of interest to a broad range of researchers who are considering the application of genome editing technologies in various organisms. PMID:24521866

  6. Screening Methods to Identify TALEN-Mediated Knockout Mice

    PubMed Central

    Nakagawa, Yoshiko; Yamamoto, Takashi; Suzuki, Ken-Ichi; Araki, Kimi; Takeda, Naoki; Ohmuraya, Masaki; Sakuma, Tetsushi

    2014-01-01

    Genome editing with site-specific nucleases, such as zinc-finger nucleases or transcription activator-like effector nucleases (TALENs), and RNA-guided nucleases, such as the CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated) system, is becoming the new standard for targeted genome modification in various organisms. Application of these techniques to the manufacture of knockout mice would be greatly aided by simple and easy methods for genotyping of mutant and wild-type pups among litters. However, there are no detailed or comparative reports concerning the identification of mutant mice generated using genome editing technologies. Here, we genotyped TALEN-derived enhanced green fluorescent protein (eGFP) knockout mice using a combination of approaches, including fluorescence observation, heteroduplex mobility assay, restriction fragment length polymorphism analysis and DNA sequencing. The detection sensitivities for TALEN-induced mutations differed among these methods, and we therefore concluded that combinatorial testing is necessary for the screening and determination of mutant genotypes. Since the analytical methods tested can be carried out without specialized equipment, costly reagents and/or sophisticated protocols, our report should be of interest to a broad range of researchers who are considering the application of genome editing technologies in various organisms. PMID:24521866

  7. A Screening Method for the ALK Fusion Gene in NSCLC.

    PubMed

    Murakami, Yoshiko; Mitsudomi, Tetsuya; Yatabe, Yasushi

    2012-01-01

    Lung cancer research has recently made significant progress in understanding the molecular pathogenesis of lung cancer and in developing treatments for it. Such achievements are directly utilized in clinical practice. Indeed, the echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (ALK) fusion gene was first described in non-small cell lung cancer in 2007, and a molecularly targeted drug against the fusion was approved in 2011. However, lung cancer with the ALK fusion constitutes only a small fraction of lung cancers; therefore, efficient patient selection is crucial for successful treatment using the ALK inhibitor. Currently, RT-PCR, fluorescent in situ hybridization (FISH), and immunohistochemistry are commonly used to detect the ALK fusion. Although FISH is currently the gold standard technique, there are no perfect methods for detecting these genetic alterations. In this article, we discuss the advantages and disadvantages of each method and the possible criteria for selecting patients who are more likely to have the ALK fusion. If we can successfully screen patients, then ALK inhibitor treatment will be the best example of personalized therapy in terms of selecting patients with an uncommon genotype from a larger group with the same tumor phenotype. In other words, the personalized therapy may offer a new challenge for current clinical oncology. PMID:22655265

  8. A Screening Method for the ALK Fusion Gene in NSCLC

    PubMed Central

    Murakami, Yoshiko; Mitsudomi, Tetsuya; Yatabe, Yasushi

    2012-01-01

    Lung cancer research has recently made significant progress in understanding the molecular pathogenesis of lung cancer and in developing treatments for it. Such achievements are directly utilized in clinical practice. Indeed, the echinoderm microtubule-associated protein-like 4–anaplastic lymphoma kinase (ALK) fusion gene was first described in non-small cell lung cancer in 2007, and a molecularly targeted drug against the fusion was approved in 2011. However, lung cancer with the ALK fusion constitutes only a small fraction of lung cancers; therefore, efficient patient selection is crucial for successful treatment using the ALK inhibitor. Currently, RT-PCR, fluorescent in situ hybridization (FISH), and immunohistochemistry are commonly used to detect the ALK fusion. Although FISH is currently the gold standard technique, there are no perfect methods for detecting these genetic alterations. In this article, we discuss the advantages and disadvantages of each method and the possible criteria for selecting patients who are more likely to have the ALK fusion. If we can successfully screen patients, then ALK inhibitor treatment will be the best example of personalized therapy in terms of selecting patients with an uncommon genotype from a larger group with the same tumor phenotype. In other words, the personalized therapy may offer a new challenge for current clinical oncology. PMID:22655265

  9. A new method for screening and isolation of hypersecretion mutants in Aspergillus niger.

    PubMed

    Weenink, Xavier O; Punt, Peter J; van den Hondel, Cees A M J J; Ram, Arthur F J

    2006-02-01

    Although filamentous fungi have a unique property of secreting a large amount of homologous extracellular proteins, the use of filamentous fungi as hosts for the production of heterologous proteins is limited because of the low production levels that are generally reached. Here, we report a general screening method for the isolation of mutants with increased protein production levels. The screening method makes use of an Aspergillus niger strain that lacks the two major amylolytic enzymes, glucoamylase (GlaA) and acid amylase (AamA). The double-mutant strain grows poorly on starch and its growth is restored after reintroducing the catalytic part of the glucoamylase gene (GlaA512). We show that the fusion of a heterologous protein, a laccase from Pleurotus ostreatus (Pox2), to the catalytic part of glucoamylase (GlaA512-Pox2) severely hampers efficient production of the glucoamylase protein, resulting in a slow-growth phenotype on starch. Laccase-hypersecreting mutants were obtained by isolating mutants that displayed improved growth on starch plates. The mutant with the highest growth rate on starch displayed the highest laccase activity, indicating that increased glucoamylase protein levels are correlated with higher laccase production levels. In principle, our method can be applied to any low-produced heterologous protein that is secreted as a fusion with the glucoamylase protein. PMID:16021486

  10. Inhibition screening method of microsomal UGTs using the cocktail approach.

    PubMed

    Gradinaru, Julieta; Romand, Stéphanie; Geiser, Laurent; Carrupt, Pierre-Alain; Spaggiari, Dany; Rudaz, Serge

    2015-04-25

    A rapid method for the simultaneous determination of the in vitro activity of the 10 major human liver UDP-glucuronosyltransferase (UGT) enzymes was developed based on the cocktail approach. Specific substrates were first selected for each UGT: etoposide for UGT1A1, chenodeoxycholic acid for UGT1A3, trifluoperazine for UGT1A4, serotonin for UGT 1A6, isoferulic acid for UGT1A9, codeine for UGT2B4, azidothymidine for UGT2B7, levomedetomidine for UGT2B10, 4-hydroxy-3-methoxymethamphetamine for UGT2B15 and testosterone for UGT2B17. Optimal incubation conditions, including time-based experiments on cocktail metabolism in pooled HLMs that had been performed, were then investigated. A 45-min incubation period was found to be a favorable compromise for all the substrates in the cocktail. Ultra-high pressure liquid chromatography coupled to an electrospray ionization time-of-flight mass spectrometer was used to separate the 10 substrates and their UGT-specific glucuronides in less than 6 min. The ability of the cocktail to highlight the UGT inhibitory potential of xenobiotics was initially proven by using well-known UGT inhibitors (selective and nonselective) and then by relating some of the screening results obtained by using the cocktail approach with morphine glucuronidation (substrate highly glucuronidated by UGT 2B7). All the results were in agreement with both the literature and with the expected effect on morphine glucuronidation. PMID:25684194

  11. Recombinant methods for screening human DNA excision repair proficiency

    SciTech Connect

    Athas, W.F.

    1988-01-01

    A method for measuring DNA excision repair in response to ultraviolet radiation (UV)-induced DNA damage has been developed, validated, and field-tested in cultured human lymphocytes. The methodology is amenable to population-based screening and should facilitate future epidemiologic studies seeking to investigate associations between excision repair proficiency and cancer susceptibility. The impetus for such endeavors derives from the belief that the high incidence of skin cancer in the genetic disorder xeroderma pigmentosum (XP) primarily is a result of the reduced capacity of patients cells to repair UV-induced DNA damage. For assay, UV-irradiated non-replicating recombinant plasmid DNA harboring a chloramphenicol acetyltransferase (CAT) indicator gene is introduced into lymphocytes using DEAE-dextran short-term transfection conditions. Exposure to UV induces transcriptionally-inactivating DNA photoproducts in the plasmid DNA which inactivate CAT gene expression. Excision repair of the damaged CAT gene is monitored indirectly as a function of reactivated CAT enzyme activity following a 40 hour repair/expression incubation period.

  12. Use of unbalanced laminates as a screening method for microcracking

    NASA Technical Reports Server (NTRS)

    Papadopoulos, Demetrios S.; Bowles, Kenneth J.

    1990-01-01

    State-of-the-art, high temperature polyimide matrix composites, reinforced with continuous graphite fibers are known to be susceptible to intraply cracking when thermally cycled over their useful service temperature range. It is believed that the transply cracking, in part, results from residual stresses caused by differences in coefficients of thermal expansion (CTE) between the polymer matrix and the reinforcement. Thermal cycling tests to investigate this phenomenon involve expensive time and energy consuming programs which are not economically feasible for use as a part of a materials screening process. As an alternative to thermal cycling studies, a study of unbalanced crossply graphite fiber reinforcement composites was conducted to assess the effect of the composite ply layup and surface condition on the residual stresses that remain after the processing of these materials. The residual stresses were assessed by measuring the radii of curvature of the types of laminates that were studied. The temperature at which stress-free conditions existed were determined and a dye penetrant method was used to observe surface damage resulting from excessive residual stress buildup. These results are compared with some published results of thermal cycling tests that were previously conducted on balanced polyimide composites.

  13. Predicting Child Physical Activity and Screen Time: Parental Support for Physical Activity and General Parenting Styles

    PubMed Central

    Crain, A. Lauren; Senso, Meghan M.; Levy, Rona L.; Sherwood, Nancy E.

    2014-01-01

    Objective: To examine relationships between parenting styles and practices and child moderate-to-vigorous physical activity (MVPA) and screen time. Methods: Participants were children (6.9 ± 1.8 years) with a body mass index in the 70–95th percentile and their parents (421 dyads). Parent-completed questionnaires assessed parental support for child physical activity (PA), parenting styles and child screen time. Children wore accelerometers to assess MVPA. Results: Parenting style did not predict MVPA, but support for PA did (positive association). The association between support and MVPA, moreover, varied as a function of permissive parenting. For parents high in permissiveness, the association was positive (greater support was related to greater MVPA and therefore protective). For parents low in permissiveness, the association was neutral; support did not matter. Authoritarian and permissive parenting styles were both associated with greater screen time. Conclusions: Parenting practices and styles should be considered jointly, offering implications for tailored interventions. PMID:24812256

  14. Screening of the arrestin gene in dogs afflicted with generalized progressive retinal atrophy

    PubMed Central

    Dekomien, Gabriele; Epplen, Jörg Thomas

    2002-01-01

    Background Intronic DNA sequences of the canine arrestin (SAG) gene was screened to identify potential disease causing mutations in dogs with generalized progressive retinal atrophy (gPRA). The intronic sequences flanking each of the 16 exons were obtained from clones of a canine genomic library. Results Using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and DNA sequence analyses we screened affected and unaffected dogs of 23 breeds with presumed autosomal recessively (ar) transmitted gPRA. In the coding region of the SAG gene 12 nucleotide exchanges were identified, 5 of which lead to amino acid substitutions (H14C; A111V; A113T; D259T; A379E). 7 other exonic substitutions represent silent polymorphisms (C132C; Q199Q; H225H; V247V; P264P; T288T and L293L). 16 additional sequence variations were observed in intronic regions of different dog breeds. Conclusions In several breeds, these polymorphisms were found in homozygous state in unaffected and in heterozygous state in affected animals. Consequently these informative substitutions provide evidence to exclude mutations in the SAG gene as causing retinal degeneration in 14 of the 23 dog breeds with presumed ar transmitted gPRA. PMID:12123530

  15. Screening of Potential Remediation Methods for the 200-ZP-1 Operable Unit at the Hanford Site

    SciTech Connect

    Truex, Michael J.; Nimmons, Michael J.; Johnson, Christian D.; Dresel, P EVAN.; Murray, Christopher J.

    2006-08-07

    A screening-level evaluation of potential remediation methods for application to the contaminants of concern (COC) in the 200-ZP-1 Operable Unit at the Hanford Site was conducted based on the methods outlined in the Guidance for Conducting Remedial Investigations and Feasibility Studies under CERCLA Interim Final. The scope of this screening was to identify the most promising remediation methods for use in the more detailed analysis of remediation alternatives that will be conducted as part of the full feasibility study. The screening evaluation was conducted for the primary COC (potential major risk drivers). COC with similar properties were grouped for the screening evaluation. The screening evaluation was conducted in two primary steps. The initial screening step evaluated potential remediation methods based on whether they can be effectively applied within the environmental setting of the 200-ZP-1 Operable Unit for the specified contaminants. In the second step, potential remediation methods were screened using scoping calculations to estimate the scale of infrastructure, overall quantities of reagents, and conceptual approach for applying the method for each defined grouping of COC. Based on these estimates, each method was screened with respect to effectiveness, implementability, and relative cost categories of the CERCLA feasibility study screening process defined in EPA guidance.

  16. Screening the fifth force in the Horndeski's most general scalar-tensor theories

    SciTech Connect

    Kase, Ryotaro; Tsujikawa, Shinji E-mail: shinji@rs.kagu.tus.ac.jp

    2013-08-01

    We study how the Vainshtein mechanism operates in the most general scalar-tensor theories with second-order equations of motion. The field equations of motion, which can be also applicable to most of other screening scenarios proposed in literature, are generally derived in a spherically symmetric space-time with a matter source. In the presence of a field coupling to the Ricci scalar, we clarify conditions under which the Vainshtein mechanism is at work in a weak gravitational background. We also obtain the solutions of the field equation inside a spherically symmetric body and show how they can be connected to exterior solutions that accommodate the Vainshtein mechanism. We apply our general results to a number of concrete models such as the covariant/extended Galileons and the DBI Galileons with Gauss-Bonnet and other terms. In these models the fifth force can be suppressed to be compatible with solar-system constraints, provided that non-linear field kinetic terms coupled to the Einstein tensor do not dominate over other non-linear field self-interactions.

  17. Generalization of the Engineering Method to the UNIVERSAL METHOD.

    ERIC Educational Resources Information Center

    Koen, Billy Vaughn

    1987-01-01

    Proposes that there is a universal method for all realms of knowledge. Reviews Descartes's definition of the universal method, the engineering definition, and the philosophical basis for the universal method. Contends that the engineering method best represents the universal method. (ML)

  18. Visual screening: an alternative method for reducing stereotypic behaviors.

    PubMed

    McGonigle, J J; Duncan, D; Cordisco, L; Barrett, R P

    1982-01-01

    Visual screening, a mildly aversive response suppression procedure, was evaluated across two studies for its effectiveness in reducing topographically similar and dissimilar stereotypic behaviors of four developmentally disabled children. In the first study, a multiple baseline design across subjects and behaviors was used to assess the effectiveness of the procedure as a treatment for reducing the visual and auditory self-stimulatory responses of two 9-yr-old mentally retarded and behaviorally disturbed children. A multiple baseline design across subjects was used in the second study to evaluate the effectiveness of visual screening as a treatment for reducing stereotypic fabric pulling and self-mutilative ear bending, respectively, of two 13-yr-old mentally retarded, autisticlike adolescents. Long-term follow-up data for both studies were reported. The results suggested that visual screening was an easily administered, effective, and exceptionally durable treatment procedure for controlling a variety of stereotypic behaviors commonly associated with the developmentally disabled. PMID:7142063

  19. System and method for obtaining wide screen Schlieren photographs

    NASA Technical Reports Server (NTRS)

    Parthasarathy, S. P. (Inventor)

    1979-01-01

    A system for use in Schlieren photography includes (1) a viewing screen adjacently related to a large grating; (2) a small grating disposed in spaced relation with the large grating; (3) a transparent retainer for confining a transparent medium between the gratings; and (4) optics for imaging the small grating on the large grating. A light source and optically aligned lens are used to project a beam of light along axes extending through the small grating and strike the large grating, subsequent to passing through the medium. A Schlieren image of striations resulting from distortions of light rays proposed by the medium are formed on the screen. A camera is used to photograph the Schlieren image projected on the large screen.

  20. Eliminating health disparities: innovative methods to improve cervical cancer screening in a medically underserved population.

    PubMed

    Bharel, Monica; Santiago, Emely R; Forgione, Sanju Nembang; León, Casey K; Weinreb, Linda

    2015-07-01

    Homeless women have disproportionately lower rates of cervical cancer screening and higher rates of cervical cancer. In 2008, only 19% of the homeless women seen by Boston Health Care for the Homeless Program (BHCHP) were screened for cervical cancer. To improve screening, BHCHP implemented a 6-part intervention that incorporates point-of-care service, multidisciplinary screening, improved health maintenance forms, population management, process improvement, and increased provider and patient education. This resulted in a significant increase in cervical cancer screening, from 19% in 2008 to 50% in 2013. When compared with national and local cervical cancer screening trends, BHCHP surpassed improvement rates seen in other vulnerable populations. Simple and innovative interventions proved to be the most effective and practical methods of improving screening. PMID:25905832

  1. Eliminating Health Disparities: Innovative Methods to Improve Cervical Cancer Screening in a Medically Underserved Population

    PubMed Central

    Bharel, Monica; Santiago, Emely R.; Forgione, Sanju Nembang; Weinreb, Linda

    2015-01-01

    Homeless women have disproportionately lower rates of cervical cancer screening and higher rates of cervical cancer. In 2008, only 19% of the homeless women seen by Boston Health Care for the Homeless Program (BHCHP) were screened for cervical cancer. To improve screening, BHCHP implemented a 6-part intervention that incorporates point-of-care service, multidisciplinary screening, improved health maintenance forms, population management, process improvement, and increased provider and patient education. This resulted in a significant increase in cervical cancer screening, from 19% in 2008 to 50% in 2013. When compared with national and local cervical cancer screening trends, BHCHP surpassed improvement rates seen in other vulnerable populations. Simple and innovative interventions proved to be the most effective and practical methods of improving screening. PMID:25905832

  2. Postal urine specimens: are they a feasible method for genital chlamydial infection screening?

    PubMed Central

    Macleod, J; Rowsell, R; Horner, P; Crowley, T; Caul, E O; Low, N; Smith, G D

    1999-01-01

    BACKGROUND: A United Kingdom (UK) screening programme for Chlamydia trachomatis has recently been announced. Pilot projects involving the opportunistic testing of women attending health facilities are due to commence in several sites. There is a danger that this approach will fail to obtain adequate population coverage. The alternative--true systematic population screening--is generally assumed to be unfeasible. Studies in Denmark using postal urine specimens have challenged this assumption. No such studies have been reported from the UK. AIM: To assess the potential of urine specimens sent by post as the basis for a UK population screening strategy for genital chlamydial infection. METHOD: Two hundred patients (100 men, 100 women) aged 18 to 45 years were randomly sampled from the list of one urban group practice. Subjects were mailed an explanatory letter, a urine sample container, a sexual lifestyle questionnaire, and a prepaid return envelope. Non-responders were contacted by telephone; persistent non-responders were visited at home. Samples were tested for Chlamydia by DNA amplification and enzyme immunoassay. RESULTS: Sixty-four (32%) subjects were no longer living at their GP registered address. Of the remaining 136, 126 (93%) responded to the survey and 113 (83%) accepted the request for a urine sample and completed a questionnaire. Acceptance rates were similar for men and women and across age groups. Four samples (3%) were Chlamydia positive. CONCLUSION: Home mailed urine specimen collection in conjunction with a self-completed postal questionnaire is feasible. This could provide a viable basis both for determining population Chlamydia prevalence and for a UK Chlamydia population screening strategy. Overall cost effectiveness of such a strategy will depend on the cost of the test used. Comparative performance characteristics of the different currently available tests in this setting have yet to be fully determined. PMID:10562745

  3. Cross-screening: a new method to assemble clones rapidly and unambiguously into contigs.

    PubMed

    Locke, J; Rairdan, G; McDermid, H; Nash, D; Pilgrim, D; Bell, J; Roy, K; Hodgetts, R

    1996-02-01

    We have developed a new procedure that relies on an array of cross-hybridization tests to order a set of random clones into a contig. The method, called cross-screening, uses each clone as a target and its end sequences as probes, in a matrix of reciprocal cross-hybridization tests performed on a single blot. The relationships among the clones are determined rapidly from the pairwise tests, allowing clone order to be determined directly. We have applied this technique to DNAs from a set of overlapping lambda clones from Drosophila chromosome 4. The location and orientation of each clone derived from the cross-screening data was that expected from the map assembled from overlapping restriction sites and chromosomal walking. The procedure provided additional information on a previously unknown, internally repeated DNA sequence. To demonstrate the general utility of the procedure, we have applied it to a previously described clone set within a contig in region 22q12 of human chromosome 22. The correct relative position and orientation of these clones were derived from the cross-screening data without knowledge of, or reference to, any nucleotide sequence or restriction site analysis of the DNA concerned. The cross-screening procedure is fast, economical, and robust and allows clone overlaps to be determined efficiently, with minimal interference from repeated DNA sequences. This new procedure is specifically designed for small groups of overlapping clones (tens to hundreds) and should facilitate the ordering of subclone libraries derived from small chromosomes or the large cloned inserts carried in YAC, BAC, and P1 vectors. PMID:8919694

  4. Adaptive multiscale model reduction with Generalized Multiscale Finite Element Methods

    NASA Astrophysics Data System (ADS)

    Chung, Eric; Efendiev, Yalchin; Hou, Thomas Y.

    2016-09-01

    In this paper, we discuss a general multiscale model reduction framework based on multiscale finite element methods. We give a brief overview of related multiscale methods. Due to page limitations, the overview focuses on a few related methods and is not intended to be comprehensive. We present a general adaptive multiscale model reduction framework, the Generalized Multiscale Finite Element Method. Besides the method's basic outline, we discuss some important ingredients needed for the method's success. We also discuss several applications. The proposed method allows performing local model reduction in the presence of high contrast and no scale separation.

  5. Mounting method improves electrical and vibrational characteristics of screen electrodes

    NASA Technical Reports Server (NTRS)

    Nelson, R. E.

    1969-01-01

    Electrical characteristics of the mesh or screen electrodes used in electron tubes are improved by decreasing the shunt capacitance of the tube while retaining the close spacing needed for the required resolution. Vibrational characteristics are enhanced by raising the natural resonant frequency.

  6. Methods and Procedures in Screening Gifted Mayan Students

    ERIC Educational Resources Information Center

    Escobedo, Pedro Sanchez

    2008-01-01

    Instruments, procedures, and criteria for the screening of Mayan students in Yucatan, Mexico are depicted and evaluated by analyzing the results of their use on 242 students in five different regions of Yucatan. These 242, 8th grade students were selected from a pool of 1,530 potentially gifted students. Participants responded to a variety of…

  7. [Diagnosis of Alzheimer's disease for general practitioners: screening instruments and early symptoms].

    PubMed

    Allegri, Ricardo F

    2010-01-01

    Despite the increasing prevalence and the potential benefits of early identification, dementias continue to be under-diagnosed. By some estimates, fewer than half of all dementia patients have been diagnosed. AD is particularly under-diagnosed in primary care settings perhaps because patients with early AD may appear entirely appropriate in the context of a brief office visit. This, coupled with increasingly abbreviated office visits and the lack of routine use of mental status exams, make identification of cognitive deficit challenging in the primary care setting. Detection of these patients must be made by the general practitioners, who must know the possibilities to detect and guide the study of them. Patients' screening must include discrimination of forgetfulness and use of mini mental examination. Once the cognitive impairment is suspected we need to continue with neuropsychological assessment for cognitive profile, ancillary studies and CT scan to exclude structural diseases. The appropriate knowledge and training of general practitioners will allow the early diagnosis of these patients and the beginning of preventive actions and adequate symptomatic treatment. PMID:21598736

  8. A Polytomous Extension of the Generalized Distance Discriminating Method

    ERIC Educational Resources Information Center

    Sun, Jianan; Xin, Tao; Zhang, Shumei; de la Torre, Jimmy

    2013-01-01

    This article proposes a generalized distance discriminating method for test with polytomous response (GDD-P). The new method is the polytomous extension of an item response theory (IRT)-based cognitive diagnostic method, which can identify examinees' ideal response patterns (IRPs) based on a generalized distance index. The similarities…

  9. Evaluation of a standard test method for screening fuels in soils

    SciTech Connect

    Sorini, S.S.; Schabron, J.F.

    1996-12-31

    A new screening method for fuel contamination in soils was recently developed as American Society for Testing and Materials (ASTM) Method D-5831-95, Standard Test Method for Screening Fuels in Soils. This method uses low-toxicity chemicals and can be sued to screen organic- rich soils, as well as being fast, easy, and inexpensive to perform. Fuels containing aromatic compounds, such as diesel fuel and gasoline, as well as other aromatic-containing hydrocarbon materials, such as motor oil, crude oil, and cola oil, can be determined. The screening method for fuels in soils was evaluated by conducting a Collaborative study on the method. In the Collaborative study, a sand and an organic soil spiked with various concentrations of diesel fuel were tested. Data from the Collaborative study were used to determine the reproducibility (between participants) and repeatability (within participants) precision of the method for screening the test materials. The Collaborative study data also provide information on the performance of portable field equipment (patent pending) versus laboratory equipment for performing the screening method and a comparison of diesel concentration values determined using the screening method versus a laboratory method.

  10. Comparison of three screening methods to select mixed-microbial inoculum for mixed-acid fermentations.

    PubMed

    Golub, Kristina W; Forrest, Andrea K; Wales, Melinda E; Hammett, Amy Jo M; Cope, Julia L; Wilkinson, Heather H; Holtzapple, Mark T

    2013-02-01

    Using a mixed culture of microorganisms, the carboxylate platform converts biomass into hydrocarbons and chemicals. To develop a method that identifies the highest performing inoculum for carboxylate fermentations, five bacterial communities were screened and ranked by three fermentation performance tests: (1) 30-day batch screen, (2) 28-day continuum particle distribution model (CPDM), and (3) 5-month continuous countercurrent fermentation trains. To screen numerous inocula sources, these tests were used sequentially in an aseptic environment. For the batch-fermentation screen, Inoculum 1 achieved the highest conversion. For the CPDM evaluation, the operating map for Inoculum 1 had the highest performance. For the continuous countercurrent fermentation, the train resulting from Inoculum 1 was among the best performers. This study suggests that the three screens are a useful and predictive method for choosing optimal inocula sources. The bacterial community with optimal performance in these three screens could be considered for use in commercial-scale fermentations. PMID:23334035

  11. DEMONSTRATION BULLETIN: FIELD ANALYTICAL SCREENING PROGRAM: PCB METHOD - U.S. ENVIRONMENTAL PROTECTION AGENCY

    EPA Science Inventory

    The field analytical screening program (FASP) polychlorinated biphenyl (PCB) method uses a temperature-programmable gas chromatograph (GC) equipped with an electron capture detector (ECD) to identify and quantify PCBs. Gas chromatography is an EPA-approved method for determi...

  12. Knowledge-Based Methods To Train and Optimize Virtual Screening Ensembles

    PubMed Central

    2016-01-01

    Ensemble docking can be a successful virtual screening technique that addresses the innate conformational heterogeneity of macromolecular drug targets. Yet, lacking a method to identify a subset of conformational states that effectively segregates active and inactive small molecules, ensemble docking may result in the recommendation of a large number of false positives. Here, three knowledge-based methods that construct structural ensembles for virtual screening are presented. Each method selects ensembles by optimizing an objective function calculated using the receiver operating characteristic (ROC) curve: either the area under the ROC curve (AUC) or a ROC enrichment factor (EF). As the number of receptor conformations, N, becomes large, the methods differ in their asymptotic scaling. Given a set of small molecules with known activities and a collection of target conformations, the most resource intense method is guaranteed to find the optimal ensemble but scales as O(2N). A recursive approximation to the optimal solution scales as O(N2), and a more severe approximation leads to a faster method that scales linearly, O(N). The techniques are generally applicable to any system, and we demonstrate their effectiveness on the androgen nuclear hormone receptor (AR), cyclin-dependent kinase 2 (CDK2), and the peroxisome proliferator-activated receptor δ (PPAR-δ) drug targets. Conformations that consisted of a crystal structure and molecular dynamics simulation cluster centroids were used to form AR and CDK2 ensembles. Multiple available crystal structures were used to form PPAR-δ ensembles. For each target, we show that the three methods perform similarly to one another on both the training and test sets. PMID:27097522

  13. Knowledge-Based Methods To Train and Optimize Virtual Screening Ensembles.

    PubMed

    Swift, Robert V; Jusoh, Siti A; Offutt, Tavina L; Li, Eric S; Amaro, Rommie E

    2016-05-23

    Ensemble docking can be a successful virtual screening technique that addresses the innate conformational heterogeneity of macromolecular drug targets. Yet, lacking a method to identify a subset of conformational states that effectively segregates active and inactive small molecules, ensemble docking may result in the recommendation of a large number of false positives. Here, three knowledge-based methods that construct structural ensembles for virtual screening are presented. Each method selects ensembles by optimizing an objective function calculated using the receiver operating characteristic (ROC) curve: either the area under the ROC curve (AUC) or a ROC enrichment factor (EF). As the number of receptor conformations, N, becomes large, the methods differ in their asymptotic scaling. Given a set of small molecules with known activities and a collection of target conformations, the most resource intense method is guaranteed to find the optimal ensemble but scales as O(2(N)). A recursive approximation to the optimal solution scales as O(N(2)), and a more severe approximation leads to a faster method that scales linearly, O(N). The techniques are generally applicable to any system, and we demonstrate their effectiveness on the androgen nuclear hormone receptor (AR), cyclin-dependent kinase 2 (CDK2), and the peroxisome proliferator-activated receptor δ (PPAR-δ) drug targets. Conformations that consisted of a crystal structure and molecular dynamics simulation cluster centroids were used to form AR and CDK2 ensembles. Multiple available crystal structures were used to form PPAR-δ ensembles. For each target, we show that the three methods perform similarly to one another on both the training and test sets. PMID:27097522

  14. Challenges to implementation of developmental screening in urban primary care: a mixed methods study

    PubMed Central

    2014-01-01

    Background Research is needed to identify challenges to developmental screening and strategies for screening in an urban pediatric setting. Methods Parents of young children and clinicians at four urban pediatric practices participated in focus groups prior to implementation of screening. Participants were queried regarding attitudes, social norms, and barriers to developmental screening. Using information from the focus groups, workflow strategies were developed for implementing screening. Referral rates and satisfaction with screening were gathered at the conclusion. Results Six focus groups of parents and clinicians were conducted. Major themes identified included 1) parents desired greater input on child development and increased time with physicians, 2) physicians did not fully trust parental input, 3) physicians preferred clinical acumen over screening tools, and 4) physicians lacked time and training to conduct screening. For the intervention, developmental screening was implemented at the 9-, 18-, 24-, and 30-month well visits using the Ages & Stages Questionnaire-II and the Modified Checklist for Toddlers. 1397 (98% of eligible) children under 36 months old were enrolled, and 1184 (84%) were screened at least once. 1002 parents (85%) completed a survey at the conclusion of the screening trial. Most parents reported no difficulty completing the screens (99%), felt the screens covered important areas of child development (98%), and felt they learned about their child’s strengths and limitations (88%). Conclusions Developmental screening in urban low-income practices is feasible and acceptable, but requires strategies to capture parental input, provide training, facilitate referrals, and develop workflow procedures and electronic decision support. PMID:24447411

  15. Novel screening method for potential skin-whitening compounds by a luciferase reporter assay.

    PubMed

    Shirasugi, Ichiro; Sakakibara, Yoichi; Yamasaki, Masao; Nishiyama, Kazuo; Matsui, Takashi; Liu, Ming-Cheh; Suiko, Masahito

    2010-01-01

    Measurement of the melanin content by using B16 melanoma cells is generally applied to find novel skin-whitening agents. However, this measurement method using B16 melanoma cells has such disadvantages, as the time taken, its sensitivity, and troublesomeness. We therefore attempted in the present study to establish a reporter assay system by measuring the tyrosinase promoter activity to use for convenient, high-throughput screening of new melanogenesis inhibitors. We first confirmed the validity of this reporter assay system by using such known skin-whitening agents, as arbutin, sulforaphane, and theaflavin 3,3'-digallate. We then compared the effect of 56 compounds on the tyrosinase promoter activity to test this reporter assay system. Carnosol, and rottlerin strongly inhibited the tyrosinase promoter activity. Moreover, carnosol and rottlerin decreased melanin synthesis and tyrosinase expression in a dose-dependent manner when using B16 melanoma cells. These results indicate this new luciferase reported assay system to be an effective and convenient method for screening potential skin-whitening compounds. PMID:21071833

  16. High-throughput method for optimum solubility screening for homogeneity and crystallization of proteins

    DOEpatents

    Kim, Sung-Hou; Kim, Rosalind; Jancarik, Jamila

    2012-01-31

    An optimum solubility screen in which a panel of buffers and many additives are provided in order to obtain the most homogeneous and monodisperse protein condition for protein crystallization. The present methods are useful for proteins that aggregate and cannot be concentrated prior to setting up crystallization screens. A high-throughput method using the hanging-drop method and vapor diffusion equilibrium and a panel of twenty-four buffers is further provided. Using the present methods, 14 poorly behaving proteins have been screened, resulting in 11 of the proteins having highly improved dynamic light scattering results allowing concentration of the proteins, and 9 were crystallized.

  17. Interventional Education Methods for Increasing Women's Participation in Breast Cancer Screening Program.

    PubMed

    Seven, Memnun; Akyüz, Aygül; Robertson, Lyn B

    2015-06-01

    The purpose of this study was to evaluate the impact of the three methods of education-individual, individual with an educational brochure for spouses, and group-on participation on breast cancer screening in Turkey. A total of 550 home visits were made and 446 women were interviewed to accrue 327 women for the study, 26.7% of whom reported receiving a screening mammogram within the past 2 years. Participants were divided into one of the three educational groups, and following the educational session, they were invited to attend a breast cancer screening program. The results indicated that the decision to have a screening mammogram was influenced by the method of education and the knowledge score. Women, who were educated, within a group scored the highest. These results demonstrate that group education is an effective method of increasing breast cancer knowledge and screening awareness. PMID:25077769

  18. A weak Galerkin generalized multiscale finite element method

    DOE PAGESBeta

    Mu, Lin; Wang, Junping; Ye, Xiu

    2016-03-31

    In this study, we propose a general framework for weak Galerkin generalized multiscale (WG-GMS) finite element method for the elliptic problems with rapidly oscillating or high contrast coefficients. This general WG-GMS method features in high order accuracy on general meshes and can work with multiscale basis derived by different numerical schemes. A special case is studied under this WG-GMS framework in which the multiscale basis functions are obtained by solving local problem with the weak Galerkin finite element method. Convergence analysis and numerical experiments are obtained for the special case.

  19. Terbium-sensitized luminescence screening method for fluoroquinolones in beef serum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enrofloxacin is one of only two fluoroquinolone antibiotics approved for use in cattle in the U.S. Microbial screening methods commonly used for monitoring veterinary drug residues are not sensitive or selective for fluoroquinolones. In this work, a luminescence-based screening assay was developed...

  20. Time-resolved luminescence screening method for enrofloxacin in beef serum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enrofloxacin is one of only two fluoroquinolone antibiotics approved for use in cattle in the U.S. Microbial screening methods currently used in the U.S. for monitoring veterinary drug residues are not sensitive or selective for fluoroquinolones. In this work, a luminescence-based screening assay ...

  1. Effect of reminders mailed to general practitioners on colorectal cancer screening adherence: a cluster-randomized trial.

    PubMed

    Le Breton, Julien; Ferrat, Émilie; Attali, Claude; Bercier, Sandrine; Le Corvoisier, Philippe; Brixi, Zahida; Veerabudun, Kalaivani; Renard, Vincent; Bastuji-Garin, Sylvie

    2016-09-01

    Reminders have been used in various settings, but failed to produce convincing evidence of benefits on patient adherence to colorectal cancer (CRC) screening. The aim of this study was to assess the effectiveness of sending general practitioners (GPs) printed reminders about CRC screening. We conducted a cluster-randomized controlled trial involving 144 GPs in the Val-de-Marne district (France), who provided care for any reason to 20 778 patients eligible for CRC screening between June 2010 and November 2011. Data were collected from the main statutory health-insurance programme and local cancer screening agency. GPs were randomly assigned in a 1 : 1 proportion to the intervention or the control group. Every 4 months, intervention-group GPs received a computer-generated printed list of patients who had not performed scheduled faecal occult blood test (FOBT) screening. The primary outcome was patient adherence to FOBT screening or exclusion from CRC screening for medical reasons. The screening adherence rate was 31.2% [95% confidence interval (CI) 30.3-32.1] in the control group and 32.9% (95% CI 32.0-33.8) in the intervention group [crude relative risk, 1.05 (95% CI 1.01-1.09), P<0.01]. This rate was not significantly different between groups by multilevel modelling accounting for clustering and confounding variables [adjusted relative risk, 1.07 (95% CI 0.95-1.20), P=0.27]. Computer-generated printed reminders sent to GPs did not significantly improve patient adherence to organized CRC screening by the FOBT. PMID:26340058

  2. Inexpensive Method for Selecting Receptor Structures for Virtual Screening.

    PubMed

    Huang, Zunnan; Wong, Chung F

    2016-01-25

    This article introduces a screening performance index (SPI) to help select from a number of experimental structures one or a few that are more likely to identify more actives among its top hits from virtual screening of a compound library. It achieved this by docking only known actives to the experimental structures without considering a large number of decoys to reduce computational costs. The SPI is calculated by using the docking energies of the actives to all the receptor structures. We evaluated the performance of the SPI by applying it to study eight protein systems: fatty acid binding protein adipocyte FABP4, serine/threonine-protein kinase BRAF, beta-1 adrenergic receptor ADRB1, TGF-beta receptor type I TGFR1, adenosylhomocysteinase SAHH, thyroid hormone receptor beta-1 THB, phospholipase A2 group IIA PA2GA, and cytochrome P450 3a4 CP3A4. We found that the SPI agreed with the results from other popular performance metrics such as Boltzmann-Enhanced Discrimination Receiver Operator Characteristics (BEDROC), Robust Initial Enhancement (RIE), Area Under Accumulation Curve (AUAC), and Enrichment Factor (EF) but is less expensive to calculate. SPI also performed better than the best docking energy, the molecular volume of the bound ligand, and the resolution of crystal structure in selecting good receptor structures for virtual screening. The implications of these findings were further discussed in the context of ensemble docking, in situations when no experimental structure for the targeted protein was available, or under circumstances when quick choices of receptor structures need to be made before quantitative indexes such as the SPI and BEDROC can be calculated. PMID:26651874

  3. Toward Harmonization of Performance Criteria for Mycotoxin Screening Methods: The EU Perspective.

    PubMed

    Lattanzio, Veronica M T

    2016-07-01

    Screening methods are defined as methods that are used to detect the presence of a substance or class of substances at the level of interest. These methods must have the capability of high sample throughput when being used to screen large numbers of samples for potential noncompliant results. Before using a screening method for practical applications, its fitness for the intended purpose needs to be demonstrated. This is normally achieved by conducting a validation study, comparing method performance against predefined criteria. Official guidelines recently established by the European Union for the evaluation of fitness-for-purpose performance parameters of screening methods to be used for the detection of mycotoxins in foods are presented and discussed herein. Practical applications of this evaluation scheme for single- and interlaboratory validation studies, as well as relevant information on screening method performances are reviewed, with emphasis on the impact of mycotoxin contamination in real samples on the fitness-for-purpose of the screening test. Lastly, validation follow-up is discussed in terms of extension of the scope of the method (increasing the range of application in terms of mycotoxin/matrix combinations), method implementation and verification, and evaluation of the method's applicability to modified mycotoxins. PMID:27455932

  4. General Practitioners’ Experiences of, and Responses to, Uncertainty in Prostate Cancer Screening: Insights from a Qualitative Study

    PubMed Central

    2016-01-01

    Background Prostate-specific antigen (PSA) testing for prostate cancer is controversial. There are unresolved tensions and disagreements amongst experts, and clinical guidelines conflict. This both reflects and generates significant uncertainty about the appropriateness of screening. Little is known about general practitioners’ (GPs’) perspectives and experiences in relation to PSA testing of asymptomatic men. In this paper we asked the following questions: (1) What are the primary sources of uncertainty as described by GPs in the context of PSA testing? (2) How do GPs experience and respond to different sources of uncertainty? Methods This was a qualitative study that explored general practitioners’ current approaches to, and reasoning about, PSA testing of asymptomatic men. We draw on accounts generated from interviews with 69 general practitioners located in Australia (n = 40) and the United Kingdom (n = 29). The interviews were conducted in 2013–2014. Data were analysed using grounded theory methods. Uncertainty in PSA testing was identified as a core issue. Findings Australian GPs reported experiencing substantially more uncertainty than UK GPs. This seemed partly explainable by notable differences in conditions of practice between the two countries. Using Han et al’s taxonomy of uncertainty as an initial framework, we first outline the different sources of uncertainty GPs (mostly Australian) described encountering in relation to prostate cancer screening and what the uncertainty was about. We then suggest an extension to Han et al’s taxonomy based on our analysis of data relating to the varied ways that GPs manage uncertainties in the context of PSA testing. We outline three broad strategies: (1) taking charge of uncertainty; (2) engaging others in managing uncertainty; and (3) transferring the responsibility for reducing or managing some uncertainties to other parties. Conclusion Our analysis suggests some GPs experienced uncertainties associated

  5. New strategies for blood donor screening for hepatitis B virus: nucleic acid testing versus immunoassay methods.

    PubMed

    Kuhns, Mary C; Busch, Michael P

    2006-01-01

    Serologic testing for hepatitis B virus (HBV) surface antigen (HBsAg) and antibody to HBV core antigen (anti-HBc) has historically been the foundation of blood screening, while HBV nucleic acid testing (NAT) was recently developed to detect HBsAg-negative, anti-HBc-negative blood units donated during early acute infection. Comparison data on seroconversion panels using HBsAg assays of varying sensitivities and pooled- or single-sample NAT, along with viral load estimates corresponding to HBsAg assay detection limits, have provided information on the theoretical benefits of NAT relative to HBsAg. Model-derived estimates have generally been predictive of the yields of DNA-positive, HBsAg-negative window period blood units detected in a number of studies from Europe, Japan, and the US. Studies indicate that the added benefit of pooled-sample NAT is relatively small in areas of low endemicity, with greater yields in areas highly endemic for HBV. Single-sample NAT would offer more significant early window period closure and could prevent a moderate number of residual HBV transmissions not detected by HBsAg assays; however, no fully automated single-sample HBV NAT systems are currently available.Even single-sample HBV NAT may not substitute for anti-HBc screening, as indicated by studies of donors with isolated anti-HBc who have extremely low DNA levels undetectable by standard single-sample NAT and who have been associated with transfusion-transmitted HBV. Moreover, HBsAg testing may still be needed even in the setting of combined anti-HBc and NAT screening. HBsAg-positive units from donors in the chronic stage of infection may contain very low or intermittently detectable DNA levels that single-sample NAT would miss. Although such donors are usually anti-HBc reactive and would be interdicted by anti-HBc screening, some lack anti-HBc. Extensive parallel testing will be needed to determine whether single-sample NAT in combination with anti-HBc might be sufficient to

  6. Feasibility of an electromagnetic compatibility method for MRgFUS using a wire mesh screen.

    PubMed

    Wu, Hao; Shen, Guofeng; Chen, Yazhu

    2016-12-01

    This study evaluated an electromagnetic compatibility method for high-intensity focused ultrasound (HIFU) and magnetic resonance (MR) imaging in an MR-guided focused ultrasound surgery using a conductive wire mesh screen. This screen has a good ultrasound transmission and shielding effectiveness. A hybrid acoustic simulation method was developed to analyze the effects of mesh parameters and the HIFU working frequency on the acoustic field. Experiments were performed to measure both acoustic pressure profile and radiated electromagnetic noise. With the proposed mesh screen, the electromagnetic radiation emission was reduced by 14dB at 128MHz while the acoustic focal intensity was reduced by less than 11% using one screen. This shielding method is easy to implement and requires no additional phase correction method. This method also improves the quality of MR images. PMID:27448456

  7. Optical method for the screening of doping substances

    NASA Astrophysics Data System (ADS)

    Lademann, J.; Shevtsova, J.; Patzelt, A.; Richter, H.; Gladkowa, N. D.; Gelikonov, V. M.; Gonchukov, S. A.; Sterry, W.; Blume-Peytavi, U.

    2008-12-01

    During the last years, an increased misuse of doping substances in sport has been observed. The action of doping substances characterized by the stimulation of blood flow and metabolic processes is also reflected in the hair structure. In the present study it was demonstrated that optical coherent tomography is well suited for the analysis of hair parameters influenced by doping. Analyzing 20 patients, systemically treated with steroids which also represent doping substances, it was found that in all cases a significant increase in the cross-section of the hairs could be detected. The results obtained in the study are not only important for the screening of doping substances but also for medical diagnostics and control of compliance of patients.

  8. Method for screening inhibitors of the toxicity of Bacillus anthracis

    DOEpatents

    Cirino, Nick M.; Jackson, Paul J.; Lehnert, Bruce E.

    2001-01-01

    The protective antigen (PA) of Bacillus anthracis is integral to the mechanism of anthrax poisoning. The cloning, expression and purification of a 32 kDa B. anthracis PA fragment (PA32) is described. This fragment has also been expressed as a fusion construct to stabilized green fluorescent protein (EGFP-PA32). Both proteins were capable of binding to specific cell surface receptors as determined by fluorescent microscopy and a flow cytometric assay. To confirm binding specificity in the flow cytometric assay, non-fluorescent PA83 or PA32 was used to competitively inhibit fluorescent EGFP-PA32 binding to cell receptors. This assay can be employed as a rapid screen for compounds which disrupts binding of PA to cells. Additionally, the high intracellular expression levels and ease of purification make this recombinant protein an attractive vaccine candidate or therapeutic treatment for anthrax poisoning.

  9. EVALUATION OF A FLUOROMETRIC SCREENING METHOD FOR PREDICTING TOTAL PAH CONCENTRATIONS IN CONTAMINATED SEDIMENTS

    EPA Science Inventory

    A flurorometric screening method was used to estimate total polycyclic aromatic hydrocarbon concentrations in sediments collected from the St. Louis River Area of Concern in northeastern Minnesota. Sediments were collected as part of a Regional Environmental Monitoring and Asses...

  10. DEMONSTRATION BULLETIN: FIELD ANALYTICAL SCREENING PROGRAM: PCP METHOD - U.S. ENVIRONMENTAL PROTECTION AGENCY

    EPA Science Inventory

    The Superfund Innovative Technology Evaluation (SITE) Program evaluates new technologies to assess their effectiveness. This bulletin summarizes results from the 1993 SITE demonstration of the Field Analytical Screening Program (FASP) Pentachlorophenol (PCP) Method to determine P...

  11. A Field Test of Web-Based Screening for Dry Eye Disease to Enhance Awareness of Eye Problems Among General Internet Users: A Latent Strategy to Promote Health

    PubMed Central

    Uchino, Miki; Kawazoe, Takashi; Kamiyashiki, Masaaki; Sano, Kokoro; Tsubota, Kazuo

    2013-01-01

    Background A Web-based self-check system including a brief questionnaire would seem to be a suitable tool for rapid disease screening. Objective The purpose of this preliminary study was to test a Web-based self-screening questionnaire for drawing attention to dry eye disease among general Internet users and identifying those with a higher risk of developing the condition. Methods A survey website was launched and used to recruit participants from general Internet users. In the first phase, volunteers were asked to complete a Web-based self-screening questionnaire containing 12 questions on dry eye symptoms. The second phase focused on the respondents who reported five or more dry eye symptoms and expressed their intention to seek medical attention. These participants performed the Schirmer test, for evaluating tear production, and completed a paper-based lifestyle questionnaire to provide relevant background data. Results Of the 1689 visitors to the website, 980 (58.0%) volunteers completed the Web-based self-screening questionnaire. Among these, 355 (36.2%) respondents reported five or more dry eye symptoms. Then, 99 (27.9%) of the symptomatic participants performed the Schirmer test and completed the paper-based lifestyle questionnaire. Out of these, 32 (32.2%) had abnormal tear production (≤5 mm). Conclusions The proposed Web-based self-screening questionnaire seems to be a promising tool for raising awareness of dry eye disease among general Internet users and identifying those with a higher risk of developing the condition, although further research is needed to validate its effectiveness. PMID:24072379

  12. Using pre-screening methods for an effective and reliable site characterization at megasites.

    PubMed

    Algreen, Mette; Kalisz, Mariusz; Stalder, Marcel; Martac, Eugeniu; Krupanek, Janusz; Trapp, Stefan; Bartke, Stephan

    2015-10-01

    This paper illustrates the usefulness of pre-screening methods for an effective characterization of polluted sites. We applied a sequence of site characterization methods to a former Soviet military airbase with likely fuel and benzene, toluene, ethylbenzene, and xylene (BTEX) contamination in shallow groundwater and subsoil. The methods were (i) phytoscreening with tree cores; (ii) soil gas measurements for CH4, O2, and photoionization detector (PID); (iii) direct-push with membrane interface probe (MIP) and laser-induced fluorescence (LIF) sensors; (iv) direct-push sampling; and (v) sampling from soil and from groundwater monitoring wells. Phytoscreening and soil gas measurements are rapid and inexpensive pre-screening methods. Both indicated subsurface pollution and hot spots successfully. The direct-push sensors yielded 3D information about the extension and the volume of the subsurface plume. This study also expanded the applicability of tree coring to BTEX compounds and tested the use of high-resolution direct-push sensors for light hydrocarbons. Comparison of screening results to results from conventional soil and groundwater sampling yielded in most cases high rank correlation and confirmed the findings. The large-scale application of non- or low-invasive pre-screening can be of help in directing and focusing the subsequent, more expensive investigation methods. The rapid pre-screening methods also yielded useful information about potential remediation methods. Overall, we see several benefits of a stepwise screening and site characterization scheme, which we propose in conclusion. PMID:25982981

  13. Predicting stages of adoption of mammography screening in a general population.

    PubMed

    Chamot, E; Charvet, A I; Perneger, T V

    2001-10-01

    This study assessed predictions of the Transtheoretical Model (TTM) of behaviour change applied to mammography screening in a random sample of 909 Swiss women aged 40-80 years. We examined stages of mammography adoption, positive and negative attitudes toward screening (pros, cons and decisional balance), and additional predisposing, enabling and reinforcing characteristics. The stage of mammography adoption was defined for 827 women, of whom 46.9% reported on-schedule screening (action 10.2%, maintenance 29.7%, relapse risk 7.0%) and 53% did not (precontemplation 23.1%, contemplation 13.5%, relapse 16.4%). Independent factors associated with more advanced stages (from precontemplation to maintenance) were high pros, low cons, belief that mammography screening is recommended every 2 years, high objective risk of breast cancer, being married and higher income. Independent correlates of stage regression (from action/maintenance to relapse) were high cons, belief that mammography screening is recommended every 4 years or not at all and not being married. Perceived utility of an organised screening programme and reluctance to pay for a mammogram were independently associated with only certain transitions between stages of adoption. Our results confirm the applicability of the TTM to mammography screening in a European context. They also suggest that constructs other than pros and cons may be useful in predicting mammography use. PMID:11576843

  14. Flow method and apparatus for screening chemicals using micro x-ray fluorescence

    DOEpatents

    Warner, Benjamin P.; Havrilla, George J.; Miller, Thomasin C.; Lewis, Cris; Mahan, Cynthia A.; Wells, Cyndi A.

    2011-04-26

    Method and apparatus for screening chemicals using micro x-ray fluorescence. A method for screening a mixture of potential pharmaceutical chemicals for binding to at least one target binder involves flow separating a solution of chemicals and target binders into separated components, exposing them to an x-ray excitation beam, detecting x-ray fluorescence signals from the components, and determining from the signals whether or not a binding event between a chemical and target binder has occurred.

  15. Flow method and apparatus for screening chemicals using micro x-ray fluorescence

    DOEpatents

    Warner, Benjamin P.; Havrilla, George J.; Miller, Thomasin C.; Lewis, Cris; Mahan, Cynthia A.; Wells, Cyndi A.

    2009-04-14

    Method and apparatus for screening chemicals using micro x-ray fluorescence. A method for screening a mixture of potential pharmaceutical chemicals for binding to at least one target binder involves flow-separating a solution of chemicals and target binders into separated components, exposing them to an x-ray excitation beam, detecting x-ray fluorescence signals from the components, and determining from the signals whether or not a binding event between a chemical and target binder has occurred.

  16. An improved generalized Newton method for absolute value equations.

    PubMed

    Feng, Jingmei; Liu, Sanyang

    2016-01-01

    In this paper, we suggest and analyze an improved generalized Newton method for solving the NP-hard absolute value equations [Formula: see text] when the singular values of A exceed 1. We show that the global and local quadratic convergence of the proposed method. Numerical experiments show the efficiency of the method and the high accuracy of calculation. PMID:27462490

  17. Integrating Multiple Teaching Methods into a General Chemistry Classroom.

    ERIC Educational Resources Information Center

    Francisco, Joseph S.; Nicoll, Gayle; Trautmann, Marcella

    1998-01-01

    Four different methods of teaching--cooperative learning, class discussions, concept maps, and lectures--were integrated into a freshman-level general chemistry course to compare students' levels of participation. Findings support the idea that multiple modes of learning foster the metacognitive skills necessary for mastering general chemistry.…

  18. IMMUNOTOXICOLOGICAL INVESTIGATIONS IN THE MOUSE: GENERAL APPROACH AND METHODS

    EPA Science Inventory

    The adverse effects of chemicals on the lymphoreticular system have generated considerable toxicological interest. In the series of papers, the effects of selected environmentally relevant compounds are reported. The first paper describes the methods and general approach used in ...

  19. Predicting High-Throughput Screening Results With Scalable Literature-Based Discovery Methods

    PubMed Central

    Cohen, T; Widdows, D; Stephan, C; Zinner, R; Kim, J; Rindflesch, T; Davies, P

    2014-01-01

    The identification of new therapeutic uses for existing agents has been proposed as a means to mitigate the escalating cost of drug development. A common approach to such repurposing involves screening libraries of agents for activities against cell lines. In silico methods using knowledge from the biomedical literature have been proposed to constrain the costs of screening by identifying agents that are likely to be effective a priori. However, results obtained with these methods are seldom evaluated empirically. Conversely, screening experiments have been criticized for their inability to reveal the biological basis of their results. In this paper, we evaluate the ability of a scalable literature-based approach, discovery-by-analogy, to identify a small number of active agents within a large library screened for activity against prostate cancer cells. The methods used permit retrieval of the knowledge used to infer their predictions, providing a plausible biological basis for predicted activity. PMID:25295575

  20. An expert system for screening enhanced oil recovery methods

    SciTech Connect

    Parkinson, W.J. ); Luger, G.F. . Dept. of Computer Science); Bretz, R.E.; Osowski, J.J. . Dept. of Petroleum Engineering)

    1990-01-01

    This paper demonstrates how a small expert system can be written with inexpensive shells (CLIPS and EXSHELL) and run on inexpensive personal computers. CLIPS is a forward-chaining rule-based system written in the C language. Rules are entered in a LISP-like format. EXSHELL is a backward-chaining rule-based system written in the PROLOG language. These shells were used to write a small expert system, an expert assistant, which is used to help petroleum engineers screen possible enhanced oil recovery candidate processes. Though the final candidate process is selected on the basis of an economic evaluation, the expert assistant greatly reduces the amount of work involved. The system selects the optimal collection of paths to the solutions and is easily updated as new data become available. This paper also demonstrates the utility and ease of use of these inexpensive shells, compares the approach used by each, and demonstrates the relative advantages of forward-chaining versus backward-chaining for this problem. 11 refs.

  1. A Method for Screening Climate Change-Sensitive Infectious Diseases

    PubMed Central

    Wang, Yunjing; Rao, Yuhan; Wu, Xiaoxu; Zhao, Hainan; Chen, Jin

    2015-01-01

    Climate change is a significant and emerging threat to human health, especially where infectious diseases are involved. Because of the complex interactions between climate variables and infectious disease components (i.e., pathogen, host and transmission environment), systematically and quantitatively screening for infectious diseases that are sensitive to climate change is still a challenge. To address this challenge, we propose a new statistical indicator, Relative Sensitivity, to identify the difference between the sensitivity of the infectious disease to climate variables for two different climate statuses (i.e., historical climate and present climate) in non-exposure and exposure groups. The case study in Anhui Province, China has demonstrated the effectiveness of this Relative Sensitivity indicator. The application results indicate significant sensitivity of many epidemic infectious diseases to climate change in the form of changing climatic variables, such as temperature, precipitation and absolute humidity. As novel evidence, this research shows that absolute humidity has a critical influence on many observed infectious diseases in Anhui Province, including dysentery, hand, foot and mouth disease, hepatitis A, hemorrhagic fever, typhoid fever, malaria, meningitis, influenza and schistosomiasis. Moreover, some infectious diseases are more sensitive to climate change in rural areas than in urban areas. This insight provides guidance for future health inputs that consider spatial variability in response to climate change. PMID:25594780

  2. A method for screening climate change-sensitive infectious diseases.

    PubMed

    Wang, Yunjing; Rao, Yuhan; Wu, Xiaoxu; Zhao, Hainan; Chen, Jin

    2015-01-01

    Climate change is a significant and emerging threat to human health, especially where infectious diseases are involved. Because of the complex interactions between climate variables and infectious disease components (i.e., pathogen, host and transmission environment), systematically and quantitatively screening for infectious diseases that are sensitive to climate change is still a challenge. To address this challenge, we propose a new statistical indicator, Relative Sensitivity, to identify the difference between the sensitivity of the infectious disease to climate variables for two different climate statuses (i.e., historical climate and present climate) in non-exposure and exposure groups. The case study in Anhui Province, China has demonstrated the effectiveness of this Relative Sensitivity indicator. The application results indicate significant sensitivity of many epidemic infectious diseases to climate change in the form of changing climatic variables, such as temperature, precipitation and absolute humidity. As novel evidence, this research shows that absolute humidity has a critical influence on many observed infectious diseases in Anhui Province, including dysentery, hand, foot and mouth disease, hepatitis A, hemorrhagic fever, typhoid fever, malaria, meningitis, influenza and schistosomiasis. Moreover, some infectious diseases are more sensitive to climate change in rural areas than in urban areas. This insight provides guidance for future health inputs that consider spatial variability in response to climate change. PMID:25594780

  3. Large-scale systematic analysis of 2D fingerprint methods and parameters to improve virtual screening enrichments.

    PubMed

    Sastry, Madhavi; Lowrie, Jeffrey F; Dixon, Steven L; Sherman, Woody

    2010-05-24

    A systematic virtual screening study on 11 pharmaceutically relevant targets has been conducted to investigate the interrelation between 8 two-dimensional (2D) fingerprinting methods, 13 atom-typing schemes, 13 bit scaling rules, and 12 similarity metrics using the new cheminformatics package Canvas. In total, 157 872 virtual screens were performed to assess the ability of each combination of parameters to identify actives in a database screen. In general, fingerprint methods, such as MOLPRINT2D, Radial, and Dendritic that encode information about local environment beyond simple linear paths outperformed other fingerprint methods. Atom-typing schemes with more specific information, such as Daylight, Mol2, and Carhart were generally superior to more generic atom-typing schemes. Enrichment factors across all targets were improved considerably with the best settings, although no single set of parameters performed optimally on all targets. The size of the addressable bit space for the fingerprints was also explored, and it was found to have a substantial impact on enrichments. Small bit spaces, such as 1024, resulted in many collisions and in a significant degradation in enrichments compared to larger bit spaces that avoid collisions. PMID:20450209

  4. The importance of screening and monitoring: the Standard Days Method and cycle regularity.

    PubMed

    Sinai, Irit; Jennings, Victoria; Arévalo, Marcos

    2004-03-01

    The Standard Days Method is a simple fertility awareness-based method of family planning with a correct-use pregnancy rate of 4.8 at 1 year and a typical-use pregnancy rate of 12. The protocol for providing the method includes guidelines for screening potential users for cycle regularity. There also are guidelines for monitoring users to determine continued method eligibility. This article explores the importance of these screening and monitoring procedures. A large existing dataset from a World Health Organization study of the Ovulation Method was used to estimate the theoretical probability of pregnancy using the Standard Days Method, with and without screening and monitoring. We used data from the efficacy study of the Standard Days Method to examine the effectiveness of current screening and monitoring procedures. Results suggest that current screening and monitoring procedures are useful in identifying women for whom the Standard Days Method is less effective. Strict adherence to these procedures is ideal, but even women who do not meet the cycle-regularity guidelines would have a relatively low probability of pregnancy. PMID:14969667

  5. Six Biophysical Screening Methods Miss a Large Proportion of Crystallographically Discovered Fragment Hits: A Case Study.

    PubMed

    Schiebel, Johannes; Radeva, Nedyalka; Krimmer, Stefan G; Wang, Xiaojie; Stieler, Martin; Ehrmann, Frederik R; Fu, Kan; Metz, Alexander; Huschmann, Franziska U; Weiss, Manfred S; Mueller, Uwe; Heine, Andreas; Klebe, Gerhard

    2016-06-17

    Fragment-based lead discovery (FBLD) has become a pillar in drug development. Typical applications of this method comprise at least two biophysical screens as prefilter and a follow-up crystallographic experiment on a subset of fragments. Clearly, structural information is pivotal in FBLD, but a key question is whether such a screening cascade strategy will retrieve the majority of fragment-bound structures. We therefore set out to screen 361 fragments for binding to endothiapepsin, a representative of the challenging group of aspartic proteases, employing six screening techniques and crystallography in parallel. Crystallography resulted in the very high number of 71 structures. Yet alarmingly, 44% of these hits were not detected by any biophysical screening approach. Moreover, any screening cascade, building on the results from two or more screening methods, would have failed to predict at least 73% of these hits. We thus conclude that, at least in the present case, the frequently applied biophysical prescreening filters deteriorate the number of possible X-ray hits while only the immediate use of crystallography enables exhaustive retrieval of a maximum of fragment structures, which represent a rich source guiding hit-to-lead-to-drug evolution. PMID:27028906

  6. Assessment of screening methods for the identification of genetically modified potatoes in raw materials and finished products.

    PubMed

    Jaccaud, Etienne; Höhne, Michaela; Meyer, Rolf

    2003-01-29

    Qualitative polymerase chain reaction methods for the detection of genetically modified potatoes have been investigated that can be used for screening purposes and identification of insect-resistant and virus-resistant potatoes in food. The presence of the nos terminator from Agrobacterium tumefaciens and the antibiotic marker gene nptII (neomycin-phosphotransferase II) was demonstrated in three commercialized Bt-potato lines (Monsanto Co., St. Louis, MO, USA) and one noncommercial GM-potato product (high amylopectin starch, AVEBE, Veendam, The Netherlands) and allows for general screening in foods. For further identification, specific primers for the FMV promoter derived from the figwort mosaic virus, the CryIIIA gene (delta-endotoxin from Bacillus thuringiensis subsp. tenebrionis), potato leafroll virus replicase gene, and the potato virus Y coat protein gene, were designed. The methods described were successfully applied to processed potato raw materials (dehydrated potato powders and flakes), starch samples, and finished products. PMID:12537422

  7. Pi sampling: a methodical and flexible approach to initial macromolecular crystallization screening

    SciTech Connect

    Gorrec, Fabrice Palmer, Colin M.; Lebon, Guillaume; Warne, Tony

    2011-05-01

    Pi sampling, derived from the incomplete factorial approach, is an effort to maximize the diversity of macromolecular crystallization conditions and to facilitate the preparation of 96-condition initial screens. The Pi sampling method is derived from the incomplete factorial approach to macromolecular crystallization screen design. The resulting ‘Pi screens’ have a modular distribution of a given set of up to 36 stock solutions. Maximally diverse conditions can be produced by taking into account the properties of the chemicals used in the formulation and the concentrations of the corresponding solutions. The Pi sampling method has been implemented in a web-based application that generates screen formulations and recipes. It is particularly adapted to screens consisting of 96 different conditions. The flexibility and efficiency of Pi sampling is demonstrated by the crystallization of soluble proteins and of an integral membrane-protein sample.

  8. Computationally efficient autoregressive method for generating phase screens with frozen flow and turbulence in optical simulations.

    PubMed

    Srinath, Srikar; Poyneer, Lisa A; Rudy, Alexander R; Ammons, S Mark

    2015-12-28

    We present a sample-based, autoregressive (AR) method for the generation and time evolution of atmospheric phase screens that is computationally efficient and uses a single parameter per Fourier mode to vary the power contained in the frozen flow and stochastic components. We address limitations of Fourier-based methods such as screen periodicity and low spatial frequency power content. Comparisons of adaptive optics (AO) simulator performance when fed AR phase screens and translating phase screens reveal significantly elevated residual closed-loop temporal power for small increases in added stochastic content at each time step, thus displaying the importance of properly modeling atmospheric "boiling". We present preliminary evidence that our model fits to AO telemetry are better reflections of real conditions than the pure frozen flow assumption. PMID:26831998

  9. Overview of Non-Volatile Testing and Screening Methods

    NASA Technical Reports Server (NTRS)

    Irom, Farokh

    2001-01-01

    Testing methods for memories and non-volatile memories have become increasingly sophisticated as they become denser and more complex. High frequency and faster rewrite times as well as smaller feature sizes have led to many testing challenges. This paper outlines several testing issues posed by novel memories and approaches to testing for radiation and reliability effects. We discuss methods for measurements of Total Ionizing Dose (TID).

  10. Optimal Multicomponent Analysis Using the Generalized Standard Addition Method.

    ERIC Educational Resources Information Center

    Raymond, Margaret; And Others

    1983-01-01

    Describes an experiment on the simultaneous determination of chromium and magnesium by spectophotometry modified to include the Generalized Standard Addition Method computer program, a multivariate calibration method that provides optimal multicomponent analysis in the presence of interference and matrix effects. Provides instructions for…

  11. A generalization of the method of harmonic balance

    NASA Technical Reports Server (NTRS)

    Mickens, R. E.

    1986-01-01

    A procedure is provided for generalizing the method of harmonic balance to obtain higher-order approximations to the periodic solutions of differential equations for two systems, one a conservative system and the other nonconservative. The procedure is currently being applied to investigate the possible solution behaviors of singular, nonlinear oscillators, where the usual perturbation methods do not work.

  12. [Research on the Screening Method of Soil Remediation Technology at Contaminated Sites and Its Application].

    PubMed

    Bai, Li-ping; Luo, Yun; Liu, Li; Zhou, You-ya; Yan, Zeng-guang; Li, Fa-sheng

    2015-11-01

    Soil remediation technology screening is an important procedure in the supervision of contaminated sites. The efficiency and costs of contaminated site remediation will be directly affected by the applicability of soil remediation technology. The influencing factors include characteristics of contaminants, site conditions, remediation time and costs should be considered to determine the most applicable remediation technology. The remediation technology screening was commonly evaluated by the experienced expert in China, which limited the promotion and application of the decision making method. Based on the supervision requirements of contaminated sites and the research status at home and abroad, the screening method includes preliminary screening and explicit evaluation was suggested in this paper. The screening index system was constructed, and the extension theory was used to divide the technology grade. The extension theory could solve the problem of human interference in the evaluation process and index value assignment. A chromium residue contaminated site in China was selected as the study area, and the applicable remediation technologies were suggested by the screening method. The research results could provide a scientific and technological support for the supervision and management of contaminated sites in China. PMID:26911012

  13. Recruitment methods employed in the prostate, lung, colorectal, and ovarian cancer screening trial

    PubMed Central

    Gren, Lisa; Broski, Karen; Childs, Jeffery; Cordes, Jill; Engelhard, Deborah; Gahagan, Betsy; Gamito, Eduard; Gardner, Vivien; Geisser, Mindy; Higgins, Darlene; Jenkins, Victoria; Lamerato, Lois; Lappe, Karen; Lowery, Heidi; McGuire, Colleen; Miedzinski, Mollie; Ogden, Sheryl; Tenorio, Sally; Watt, Gavin; Wohlers, Bonita; Marcus, Pamela

    2015-01-01

    Background The Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO) is a US National Cancer Institute (NCI)-funded randomized controlled trial designed to evaluate whether certain screening tests reduce mortality from prostate, lung, colorectal, and ovarian cancer. To obtain adequate statistical power, it was necessary to enroll over 150,000 healthy volunteers. Recruitment began in 1993 and ended in 2001. Purpose Our goal is to evaluate the success of recruitment methods employed by the 10 PLCO screening centers. We also provide estimates of recruitment yield and cost for our most successful strategy, direct mail. Methods Each screening center selected its own methods of recruitment. Methods changed throughout the recruitment period as needed. For this manuscript, representatives from each screening center provided information on methods utilized and their success. Results In the United States between 1993 and 2001, ten screening centers enrolled 154,934 study participants. Based on participant self-report, an estimated 95% of individuals were recruited by direct mail. Overall, enrollment yield for direct mail was 1.0%. Individual center enrollment yield ranged from 0.7% to 3.8%. Cost per enrolled participant was $9.64–35.38 for direct mail, excluding personnel costs. Limitations Numeric data on recruitment processes were not kept consistently at individual screening centers. Numeric data in this manuscript are based on the experiences of 5 of the 10 centers. Conclusions Direct mail, using rosters of names and addresses from profit and not-for-profit (including government) organizations, was the most successful and most often used recruitment method. Other recruitment strategies, such as community outreach and use of mass media, can be an important adjunct to direct mail in recruiting minority populations. PMID:19254935

  14. An Australian mixed methods pilot study exploring students performing patient risk screening.

    PubMed

    Gibson, Simone J; Golder, Janet; Cant, Robyn P; Davidson, Zoe E

    2016-06-01

    Clinical placement shortages and rising costs have created demand to provide low-resource, high value student learning opportunities. Malnutrition screening provides a vehicle for achieving this. A mixed methods explanatory sequential intervention study investigated time costs, and students' perceptions of preparedness after performing routine patient screening tasks, as well as students' overall views on their feelings of confidence and preparedness when commencing their first clinical placements. Pre-clinical student dietitians commencing initial placements participated (n=58), with 16 of these forming a subgroup who performed malnutrition screening tasks while the others attended usual placement orientation. The time saved when students undertook screening tasks usually assigned to nurses was substantial. Questionnaires revealed that student perceived confidence increased in the screening group when compared with controls. Focus group themes included "anxiety and confidence," "learning in the clinical learning environment," "communication skill development," and "the pre-placement screening experience." Students performing routine patient-screening tasks prior to initial clinical placement has potential cost savings for healthcare organizations and was perceived to be valuable for learning. PMID:26685779

  15. An analysis of highly viscous flow using Imai's complex function method with application to screen printing

    NASA Astrophysics Data System (ADS)

    Kawabata, Jun-ichi; Shi-igai, Hiroyoshi; Yabuno, Kohei; Saito, Tadayuki

    1992-06-01

    The complex function method is applied to screen printing flow with low Reynolds number assuming that the printing ink is Newtonian. The screen printing flow is expressed through a Taylor flow in the corner. The pressure distribution, vorticity distribution and stream lines of the Taylor flow can easily be obtained by using the complex function method. A new model of the flow which may better express the screen printing is obtained through this method by placing a sink at the origin of the Taylor flow. The appropriate corner angle for printing, theoretically derived from this method as 65.4°, corresponds to the empirical angle in industrial use. The pressure distribution of this model shows good agreement with the experimental results obtained in the present work.

  16. Toxicology screen

    MedlinePlus

    Barbiturates - screen; Benzodiazepines - screen; Amphetamines - screen; Analgesics - screen; Antidepressants - screen; Narcotics - screen; Phenothiazines - screen; Drug abuse screen; Blood alcohol test

  17. PATHOS: a quick screening method for assessing sexual addiction.

    PubMed

    Johnson, Pennie; Cashwell, Craig S; Cress, Jim; Barber, Tim; Dunn, Mary Clayton

    2013-01-01

    Pastors may understand that sex addiction exists and are frequently faced with people who need non-clinical and clinical services for the addiction. However, the pastoral counselors have no quick reliable method of assessing them. The purpose of this article is to define sexual addiction and provide information about a tool called PATHOS that can be used in clinical and non-clinical settings to identify potential sex addicts. PMID:24720235

  18. A robust general phase retrieval method for medical applications

    PubMed Central

    Yan, A.; Liu, H.

    2013-01-01

    From medical imaging perspective the robustness of a phase retrieval method is of critical importance. In this presentation we compare the robustness of two general phase retrieval methods, namely the transport of intensity equation inversion (TIE-inversion) method and the attenuation partition based (AP-based) method. We showed that the TIE-inversion method, regardless if being assisted with the Tikhonov regularization, failed to retrieve the phase maps in two experimental studies. The failure exposes this method’s weakness as being unstable against the noise. In contrast, the sample phase maps are retrieved successfully by using the AP-based method. The stark performance differences of the two methods are rooted in their different techniques dealing with the singularity problem. This comparison shows that the robust AP-based phase retrieval method will be superior to the TIE-inversion method for medical imaging applications where radiation doses are stringently limited. PMID:23894250

  19. Novel method for screening of enteric film coatings properties with magnetic resonance imaging.

    PubMed

    Dorożyński, Przemysław; Jamróz, Witold; Niwiński, Krzysztof; Kurek, Mateusz; Węglarz, Władysław P; Jachowicz, Renata; Kulinowski, Piotr

    2013-11-18

    The aim of the study is to present the concept of novel method for fast screening of enteric coating compositions properties without the need of preparation of tablets batches for fluid bed coating. Proposed method involves evaluation of enteric coated model tablets in specially designed testing cell with application of MRI technique. The results obtained in the testing cell were compared with results of dissolution studies of mini-tablets coated in fluid bed apparatus. The method could be useful in early stage of formulation development for screening of film coating properties that will shorten and simplify the development works. PMID:23994758

  20. On a New Numerical Method for Solving General Variational Inequalities

    NASA Astrophysics Data System (ADS)

    Bnouhachem, Abdellah; Noor, Muhammad Aslam; Khalfaoui, Mohamed; Sheng, Zhaohan

    In this paper, we suggest and analyze a new extragradient method for solving the general variational inequalities involving two operators. We also prove the global convergence of the proposed modified method under certain mild conditions. We used a self-adaptive technique to adjust parameter ρ at each iteration. It is proved theoretically that the lower-bound of the progress obtained by the proposed method is greater than that by the extragradient method. An example is given to illustrate the efficiency and its comparison with the extragradient method. Since the general variational inequalities include the classical variational inequalities and complementarity problems as special cases, our results obtained in this paper continue to hold for these problems. Results obtained in this paper may be viewed as an improvement and refinement of the previously known results in this field.

  1. [Screening for risk of child abuse and neglect. A practicable method?].

    PubMed

    Kindler, H

    2010-10-01

    Selective primary prevention programs for child abuse and neglect depend on risk screening instruments that have the goal of systematically identifying families who can profit most from early help. Based on a systematic review of longitudinal studies, a set of established risk factors for early child abuse and neglect is presented. Nearly half of the items included in screening instruments can be seen as validated. Available studies indicate a high sensitivity of risk screening instruments. Positive predictive values, however, are low. Overall, the use of risk screening instruments in the area of primary prevention for families at risk represents a feasible method, as long as stigmatizing effects can be avoided and participating families also benefit beyond preventing endangerment. PMID:20936452

  2. SARS-CoV protease inhibitors design using virtual screening method from natural products libraries.

    PubMed

    Liu, Bing; Zhou, Jiaju

    2005-04-15

    Two natural products databases, the marine natural products database (MNPD) and the traditional Chinese medicines database (TCMD), were used to find novel structures of potent SARS-CoV protease inhibitors through virtual screening. Before the procedure, the databases were filtered by Lipinski's ROF and Xu's extension rules. The results were analyzed by statistic methods to eliminate the bias in target-based database screening toward higher molecular weight compounds for enhancing the hit rate. Eighteen lead compounds were recommended by the screening procedure. They were useful for experimental scientists in prioritizing drug candidates and studying the interaction mechanism. The binding mechanism was also analyzed between the best screening compound and the SARS protein. PMID:15693056

  3. Micro x-ray fluorescence as a high throughput screening method for metal chelating compounds

    NASA Astrophysics Data System (ADS)

    Minogue, Edel M.; Havrilla, George J.; Taylor, Tammy P.; Burrell, Anthony K.; Warner, Benjamin P.

    2005-06-01

    Micro X-ray Fluorescence (MXRF) has proven to be a powerful tool in the rapid and quantitative means of screening oliogpeptides. MXRF is a non-destructive method of analysis, which can detect elemental composition of a sample by measuring its characteristic X-ray emission wavelengths or energies. An effective high throughput screening technique is described for the rapid screening of bead-based libraries by MXRF in order to identify suitable chelating agents that will bind metals found in radioactive dispersive devices. It is a sensitive technique which in conjunction with the wide range of chemistry inherent in peptide libraries (e.g. varying charge, length, hydrophobicity, aromaticity etc.), provides a rapid and quantitative means for screening chelator-ion binding. The method involves the selection of a suitable library of ligands; in this case it is a bead-based library of peptides. The library is exposed to the cation of interest and immobilized on to a microarray. The array is then analyzed by MXRF enabling rapid identification of chelating agents. This enables the screening of approximately 27,500 sequences per day. Initial experiments carried out successfully identified sequences that are selective for Co under certain binding conditions. This involved the screening of 8,400 sequences in adverse environmental conditions containing possible interferences (e.g. Ca, Fe, Al, Cs, Ir), which could be encountered in our application.

  4. Multiple-time-stepping generalized hybrid Monte Carlo methods

    NASA Astrophysics Data System (ADS)

    Escribano, Bruno; Akhmatskaya, Elena; Reich, Sebastian; Azpiroz, Jon M.

    2015-01-01

    Performance of the generalized shadow hybrid Monte Carlo (GSHMC) method [1], which proved to be superior in sampling efficiency over its predecessors [2-4], molecular dynamics and hybrid Monte Carlo, can be further improved by combining it with multi-time-stepping (MTS) and mollification of slow forces. We demonstrate that the comparatively simple modifications of the method not only lead to better performance of GSHMC itself but also allow for beating the best performed methods, which use the similar force splitting schemes. In addition we show that the same ideas can be successfully applied to the conventional generalized hybrid Monte Carlo method (GHMC). The resulting methods, MTS-GHMC and MTS-GSHMC, provide accurate reproduction of thermodynamic and dynamical properties, exact temperature control during simulation and computational robustness and efficiency. MTS-GHMC uses a generalized momentum update to achieve weak stochastic stabilization to the molecular dynamics (MD) integrator. MTS-GSHMC adds the use of a shadow (modified) Hamiltonian to filter the MD trajectories in the HMC scheme. We introduce a new shadow Hamiltonian formulation adapted to force-splitting methods. The use of such Hamiltonians improves the acceptance rate of trajectories and has a strong impact on the sampling efficiency of the method. Both methods were implemented in the open-source MD package ProtoMol and were tested on a water and a protein systems. Results were compared to those obtained using a Langevin Molly (LM) method [5] on the same systems. The test results demonstrate the superiority of the new methods over LM in terms of stability, accuracy and sampling efficiency. This suggests that putting the MTS approach in the framework of hybrid Monte Carlo and using the natural stochasticity offered by the generalized hybrid Monte Carlo lead to improving stability of MTS and allow for achieving larger step sizes in the simulation of complex systems.

  5. Multiple-time-stepping generalized hybrid Monte Carlo methods

    SciTech Connect

    Escribano, Bruno; Akhmatskaya, Elena; Reich, Sebastian; Azpiroz, Jon M.

    2015-01-01

    Performance of the generalized shadow hybrid Monte Carlo (GSHMC) method [1], which proved to be superior in sampling efficiency over its predecessors [2–4], molecular dynamics and hybrid Monte Carlo, can be further improved by combining it with multi-time-stepping (MTS) and mollification of slow forces. We demonstrate that the comparatively simple modifications of the method not only lead to better performance of GSHMC itself but also allow for beating the best performed methods, which use the similar force splitting schemes. In addition we show that the same ideas can be successfully applied to the conventional generalized hybrid Monte Carlo method (GHMC). The resulting methods, MTS-GHMC and MTS-GSHMC, provide accurate reproduction of thermodynamic and dynamical properties, exact temperature control during simulation and computational robustness and efficiency. MTS-GHMC uses a generalized momentum update to achieve weak stochastic stabilization to the molecular dynamics (MD) integrator. MTS-GSHMC adds the use of a shadow (modified) Hamiltonian to filter the MD trajectories in the HMC scheme. We introduce a new shadow Hamiltonian formulation adapted to force-splitting methods. The use of such Hamiltonians improves the acceptance rate of trajectories and has a strong impact on the sampling efficiency of the method. Both methods were implemented in the open-source MD package ProtoMol and were tested on a water and a protein systems. Results were compared to those obtained using a Langevin Molly (LM) method [5] on the same systems. The test results demonstrate the superiority of the new methods over LM in terms of stability, accuracy and sampling efficiency. This suggests that putting the MTS approach in the framework of hybrid Monte Carlo and using the natural stochasticity offered by the generalized hybrid Monte Carlo lead to improving stability of MTS and allow for achieving larger step sizes in the simulation of complex systems.

  6. General Methods for Quantifying Uncertainty in Discharge Measurements

    NASA Astrophysics Data System (ADS)

    Cohn, Tim; Kiang, Julie; Mason, Robert, Jr.

    2015-04-01

    Developing a general operational method for quantifying uncertainty in streamflow measurements has proven to be a difficult task. The Interpolated Variance Estimator (IVE), which can be applied to situations where sampling involves multiple verticals, has been shown to perform reasonably well at characterizing the nonsystematic errors associated with both irregular channel geometry and pulsating velocities. It is not obvious, however, how to generalize the procedure, or in fact find any alternative procedure, that can take advantage of the continuous current profiling associated with more sophisticated ADCP instruments. Developing a uniform and consistent operational method remains a tall and important order.

  7. An error embedded method based on generalized Chebyshev polynomials

    NASA Astrophysics Data System (ADS)

    Kim, Philsu; Kim, Junghan; Jung, WonKyu; Bu, Sunyoung

    2016-02-01

    In this paper, we develop an error embedded method based on generalized Chebyshev polynomials for solving stiff initial value problems. The solution and the error at each integration step are calculated by generalized Chebyshev polynomials of two consecutive degrees having overlapping zeros, which enables us to minimize overall computational costs. Further the errors at each integration step are embedded in the algorithm itself. In terms of concrete convergence and stability analysis, the constructed algorithm turns out to have the 6th order convergence and an almost L-stability. We assess the proposed method with several numerical results, showing that it uses larger time step sizes and is numerically more efficient.

  8. Recommendations for Developing Alternative Test Methods for Screening and Prioritization of Chemicals for Developmental Neurotoxicity

    EPA Science Inventory

    Developmental neurotoxicity testing (DNT) is perceived by many stakeholders to be an area in critical need of alternative methods to current animal testing protocols and gUidelines. An immediate goal is to develop test methods that are capable of screening large numbers of chemic...

  9. Development of a rapid method to isolate polyhydroxyalkanoates from bacteria for screening studies.

    PubMed

    Vizcaino-Caston, Isaac; Kelly, Catherine A; Fitzgerald, Annabel V L; Leeke, Gary A; Jenkins, Mike; Overton, Tim W

    2016-01-01

    We describe a novel method of Polyhydroxyalkanoate (PHA) extraction using dimethyl sulphoxide (DMSO) for use in screening studies. Compared to conventional chloroform extraction, the DMSO method was shown to release comparable quantities of PHA from Cupriavidus necator cells, with comparable properties as determined using Fourier transform infrared spectroscopy and differential scanning calorimetry. PMID:26143034

  10. Microbial screening and analytical methods for the production of polyol oils from soybean oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study is to develop a new useful method including microbial screening and product identification for a bioprocess to produce polyol oils from soybean oil. Methods for separating of product polyol oils from soybean oil substrate and free fatty acid byproducts using HPLC and TLC...

  11. A DNA method for screening hive debris for the presence of small hive beetle (Aethina tumida)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The small hive beetle (SHB) is a parasite and scavenger of honey bee colonies. It has recently become an invasive species creating the need for an efficient and reliable detection method. We present a method to screen hive debris for the presence of SHB using real-time PCR in conjunction with an aut...

  12. Cystic fibrosis: need for mass deployable screening methods.

    PubMed

    Sengar, Aditya Singh; Agarwal, Anirudh; Singh, Manish K

    2014-10-01

    Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. CFTR is a member of the adenosine triphosphate (ATP)-binding cassette superfamily of proteins and it functions as a chloride channel. CFTR largely controls the working of epithelial cells of the airways, the gastrointestinal tract, exocrine glands, and genitourinary system. Cystic fibrosis is responsible for severe chronic pulmonary disorders in children. Other maladies in the spectrum of this life-limiting disorder include nasal polyposis, pansinusitis, rectal prolapse, pancreatitis, cholelithiasis, insulin-dependent hyperglycemia, and cirrhosis. This review summarizes the recent state of art in the field of cystic fibrosis diagnostic methods with the help of CF literature published so far and proposes new research domains in the field of cystic fibrosis diagnosis. PMID:24880895

  13. A method for screening of plant species for space use

    NASA Technical Reports Server (NTRS)

    Goeschl, J. D.; Sauer, R. L.; Scheld, H. W.

    1986-01-01

    A cost-effective methodology which monitors numerous dynamic aspects of carbon assimilation and allocation kinetics in live, intact plants is discussed. Analogous methods can apply to nitrogen uptake and allocation. This methodology capitalizes on the special properties of the short-lived, positron-gamma emitting isotope C-11 especially when applied as CO2-11 in a special extended square wave (ESW) pattern. The 20.4 minute half-life allows for repeated or continuous experiments on the same plant over periods of minutes, hours, days, or weeks. The steady-state isotope equilibrium approached during the ESW experiments, and the parameters which can be analyzed by this technique are also direct results of that short half-life. Additionally, the paired .511 MeV gamma rays penetrate any amount of tissue and their 180 deg opposite orientation provides good collimation and allows coincidence counting which nearly eliminates background.

  14. An Alternative Field Method for Screening Soybean Genotypes for Resistance to Heterodera glycines

    PubMed Central

    Arantes, N. E.; Mauro, A. O.; Tihohood, D.

    1998-01-01

    The soybean cyst nematode (Heterodera glycines) has become an increasingly severe problem in soybean production areas in Brazil. The development and use of resistant cultivars is the most efficient method of minimizing losses due to this pathogen. Our objective was to test the efficiency of an alternative method for screening soybean genotypes for resistance to H. glycines in field plots. The alternative method was compared to the standard method of sowing the test genotypes in fields found to be infested during the previous crop season. In the alternative method, the test genotypes are sown in the furrow following the uprooting of 45-day-old infected plants. The alternative method resulted in twice the cyst population and fewer escapes, and more consistent results than the standard method. The major advantage of the alternative method is that it permits screening in a more homogeneous distribution of H. glycines in the soil. PMID:19274244

  15. Screening for Serious Mental Illness in the General Population with the K6 screening scale: Results from the WHO World Mental Health (WMH) Survey Initiative

    PubMed Central

    Kessler, Ronald C.; Green, Jennifer Greif; Gruber, Michael J.; Sampson, Nancy A.; Bromet, Evelyn; Cuitan, Marius; Furukawa, Toshi A.; Gureje, Oye; Hinkov, Hristo; Hu, Chi-yi; Lara, Carmen; Lee, Sing; Mneimneh, Zeina; Myer, Landon; Oakley-Browne, Mark; Posada-Villa, Jose; Sagar, Rajesh; Viana, Maria Carmen; Zaslavsky, Alan M.

    2013-01-01

    Data are reported on the background and performance of the K6 screening scale for serious mental illness (SMI) in the World Health Organization (WHO) World Mental Health (WMH) surveys. The K6 is a 6-item scale developed to provide a brief valid screen for DSM-IV SMI based on the criteria in the US ADAMHA Reorganization Act. Although methodological studies have documented good K6 validity in a number of countries, optimal scoring rules have never been proposed. Such rules are presented here based on analysis of K6 data in nationally or regionally representative WMH surveys in 14 countries (combined n = 41,770 respondents). Twelve-month prevalence of DSM-IV SMI was assessed with the fully-structured WHO Composite International Diagnostic Interview. Nested logistic regression analysis was used to generate estimates of the predicted probability of SMI for each respondent from K6 scores taking into consideration the possibility of variable concordance as a function of respondent age, gender, education, and country. Concordance, assessed by calculating the area under the receiver operating characteristic curve (AUC), was generally substantial (Median .83; Range .76-.89; Inter-quartile range .81-.85). Based on this result, optimal scaling rules are presented for use by investigators working with the K6 scale in the countries studied. PMID:20527002

  16. Screening of Potential Remediation Methods for the 200-BP-5 Operable Unit at the Hanford Site

    SciTech Connect

    Truex, Michael J.; Dresel, P. EVAN; Nimmons, Michael J.; Johnson, Christian D.

    2006-09-21

    A screening-level evaluation of potential remediation methods for application to the contaminants of concern (COC) in the 200-BP-5 Operable Unit at the Hanford Site was conducted based on the methods outlined in the Guidance for Conducting Remedial Investigations and Feasibility Studies under CERCLA Interim Final (EPA 1988). The scope of this screening was to identify the most promising remediation methods for use in the more detailed analysis of remediation alternatives that will be conducted as part of the full feasibility study. The screening evaluation was conducted for the primary COC (potential major risk drivers) identified in the groundwater sampling and analysis plan for the operable unit (DOE/RL-2001-49, Rev. 1) with additions.

  17. New screening method for lung cancer by detecting volatile organic compounds in breath.

    PubMed

    Belda-Iniesta, C; de Castro Carpeño, J; Carrasco, J A; Moreno, V; Casado Sáenz, E; Feliu, J; Sereno, M; García Río, F; Barriuso, J; González Barón, M

    2007-06-01

    Lung cancer is a frequent cause of cancer-related deaths in the world. There is no valid screening process and this limits its detection to the late stages, with consequently high mortality rates. Volatile organic compounds (VOC) are chemical compounds (mainly the products of cell catabolism) found as gases in the human breath. Different methods have been developed to analyse VOCs and to compare them in healthy subjects and lung cancer patients. In this review, we summarise the different techniques used to analyse VOC. Many reports have been published with promising results similar to those achieved with accepted screening methods such as mammography. These methods show good perspectives on lung cancer screening. PMID:17594950

  18. Survey of methods for calculating sensitivity of general eigenproblems

    NASA Technical Reports Server (NTRS)

    Murthy, Durbha V.; Haftka, Raphael T.

    1987-01-01

    A survey of methods for sensitivity analysis of the algebraic eigenvalue problem for non-Hermitian matrices is presented. In addition, a modification of one method based on a better normalizing condition is proposed. Methods are classified as Direct or Adjoint and are evaluated for efficiency. Operation counts are presented in terms of matrix size, number of design variables and number of eigenvalues and eigenvectors of interest. The effect of the sparsity of the matrix and its derivatives is also considered, and typical solution times are given. General guidelines are established for the selection of the most efficient method.

  19. Comparison Of Methods Used To Measure The Characteristic Curve Of Radiographic Screen/Film Systems

    NASA Astrophysics Data System (ADS)

    Wagner, Louis K.; Haus, Arthur G.; Barnes, Gary T.; Bencomo, Jose A.; Amtey, Sharad R.

    1980-08-01

    A systematic study was performed to investigate the accuracy and precision attained by four methods for determining the characteristic curve of radiographic screen/film systems. The four methods include: inverse square sensitometry, KVP adjusted bootstrap sensitometry step-wedge bootstrap sensitometry, and step wedge attenuation sensitometry. The inverse square method was used as the reference standard for accuracy. The extent of and the sources of the inaccurcies involved when using the alternative methods is discussed.

  20. Methods for contingency screening and ranking for voltage stability analysis of power systems

    SciTech Connect

    Ejebe, G.C.; Irisarri, G.D.; Mokhtari, S.; Obadina, O.; Ristanovic, P.; Tong, J.

    1996-02-01

    The comparison of performance of four methods for contingency screening and ranking for voltage stability analysis is presented. Three of the methods are existing methods, while a new method is proposed. The performance of all the methods is carried out by comparing with full solutions using a continuation power flow. It is shown that the newly proposed method has the best performance in terms of accuracy and computation time. All the methods are evaluated using a 234-bus system. Additional results using the best performing method are included for a 901-bus power system.

  1. Methods for contingency screening and ranking for voltage stability analysis of power systems

    SciTech Connect

    Ejebe, G.C.; Irisarri, G.D.; Mokhtari, S.; Obadina, O.; Ristanovic, P.; Tong, J.

    1995-12-31

    The comparison of performance of four methods for contingency screening and ranking for voltage stability analysis is presented. Three of the methods are existing methods, while a new method is proposed. The performance of all the methods is carried out by comparing with full solutions using a continuation power flow. It is shown that the newly proposed method has the best performance in terms of accuracy and computation time. All the methods are evaluated using a 234-bus system. Additional results using the best performing method are included for a 901-bus power system.

  2. Parental concerns based general developmental screening tool and autism risk: the Taiwan National Birth cohort study.

    PubMed

    Lung, For-Wey; Shu, Bih-Ching; Chiang, Tung-Liang; Lin, Shio-Jean

    2010-02-01

    Early detection of developmental delay and childhood disorders are important for early intervention. This study aimed to describe the distribution of responses in a large population-based survey, identify cutoff points for the parent concern checklist (PCC) suitable for the Chinese language and culture, and explore how many children were identified as having evidence of problems at age 18 mo different from those at age 6 mo. Using a national randomly selected sample, the overall development of 21,248 children was investigated using the Taiwan Birth Cohort study instrument, and the PCC, a problem-oriented screening instrument. The Newton-Raphson iteration showed that the PCC should be separated into three groups, those scoring 1-2 in the first group, 3- 6 in the second group, and 7- 8 in the third group.Structural equation models showed that 6-mo development was predictive of 18-mo development; additionally, 18-mo development and the PCC showed good concurrent validity. This study identified three groups with distinct developmental trajectories and two cutoff points of 2/3 and 6/7. Thus, the PCC can be used as a first-stage screening instrument in a two-stage window screening procedure. Further studies are needed to investigate the factors, which contribute to the differences among these groups;follow-up on the typical and atypical development of these children is necessary. PMID:20091940

  3. Design and Methods of Large-Scale RNA Interference Screens in Drosophila.

    PubMed

    Zhou, Jia; Tong, Chao

    2016-01-01

    Drosophila is an ideal model system for addressing important questions in biology. The use of RNA interference (RNAi) to knockdown gene expression in fly tissues is both very effective and relatively simple. In the past few decades, genome-wide UAS-RNAi transgenic libraries and thousands of Gal4 strains have been generated and have facilitated large-scale in vivo RNAi screening. Here, we discuss methods for the design and performance of a large-scale in vivo RNAi screen in Drosophila. Furthermore, methods for the validation of results and analysis of data will be introduced. PMID:27581292

  4. A reporter ligand NMR screening method for 2-oxoglutarate oxygenase inhibitors

    PubMed Central

    Leung, Ivanhoe K. H.; Demetriades, Marina; Hardy, Adam P.; Lejeune, Clarisse; Smart, Tristan J.; Szöllössi, Andrea; Kawamura, Akane; Schofield, Christopher J.; Claridge, Timothy D. W.

    2015-01-01

    The human 2-oxoglutarate (2OG) dependent oxygenases belong to a family of structurally related enzymes that play important roles in many biological processes. We report that competition-based NMR methods, using 2OG as a reporter ligand, can be used for quantitative and site-specific screening of ligand binding to 2OG oxygenases. The method was demonstrated using hypoxia inducible factor (HIF) hydroxylases and histone demethylases, and KD values were determined for inhibitors that compete with 2OG at the metal centre. This technique is also useful as a screening or validation tool for inhibitor discovery, as exemplified by work with protein-directed dynamic combinatorial chemistry (DCC). PMID:23234607

  5. Heavy meson mass-spectra by general relativistic methods (*)

    SciTech Connect

    Italiano, A.; Lattuada, M.; Maccarrone, G.D.; Recami, E.; Riggi, F.; Vinciguerra, D.

    1984-11-01

    By applying the classical methods of general relativity to elementary particles, one can get-in a natural way-the observed confinement of their constituents, avoiding any recourse to phenomenological models such as the bag model and allowing the deduction of the heavy meson (i.e., charmonium (J/psi) and bottomonium (..gamma..)) mass-spectra.

  6. The trace minimization method for the symmetric generalized eigenvalue problem

    NASA Astrophysics Data System (ADS)

    Sameh, Ahmed; Tong, Zhanye

    2000-11-01

    In this paper, the trace minimization method for the generalized symmetric eigenvalue problems proposed by Sameh and Wisniewski [35] is reviewed. Convergence of an inexact trace minimization algorithm is established and a variant of the algorithm that uses expanding subspaces is introduced and compared with the block Jacobi-Davidson algorithm.

  7. GENERAL CONSIDERATIONS FOR GEOPHYSICAL METHODS APPLIED TO AGRICULTURE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Geophysics is the application of physical quantity measurement techniques to provide information on conditions or features beneath the earth’s surface. With the exception of borehole geophysical methods and soil probes like a cone penetrometer, these techniques are generally noninvasive with physica...

  8. Assessing the feasibility of screening and providing brief advice for alcohol misuse in general dental practice: a clustered randomised control trial protocol for the DART study

    PubMed Central

    Ntouva, Antiopi; Porter, Jessie; Crawford, Mike J; Britton, Annie; Gratus, Christine; Newton, Tim; Tsakos, Georgios; Heilmann, Anja; Pikhart, Hynek; Watt, Richard G

    2015-01-01

    Introduction Alcohol misuse is a significant public health problem with major health, social and economic consequences. Systematic reviews have reported that brief advice interventions delivered in various health service settings can reduce harmful drinking. Although the links between alcohol and oral health are well established and dentists come into contact with large numbers of otherwise healthy patients regularly, no studies have been conducted in the UK to test the feasibility of delivering brief advice about alcohol in general dental settings. Methods and analysis The Dental Alcohol Reduction Trial (DART) aims to assess the feasibility and acceptability of screening for alcohol misuse and delivering brief advice in patients attending National Health Service (NHS) general dental practices in North London. DART is a cluster randomised control feasibility trial and uses a mixed methods approach throughout the development, design, delivery and evaluation of the intervention. It will be conducted in 12 NHS general dental practices across North London and will include dental patients who drink above the recommended guidance, as measured by the Alcohol Use Disorders Identification Test (AUDIT-C) screening tool. The intervention involves 5 min of tailored brief advice delivered by dental practitioners during the patient's appointment. Feasibility and acceptability measures as well as suitability of proposed primary outcomes of alcohol consumption will be assessed. Initial economic evaluation will be undertaken. Recruitment and retention rates as well as acceptability of the study procedures from screening to follow-up will be measured. Ethics and dissemination Ethical approval was obtained from the Camden and Islington Research Ethics Committee. Study outputs will be disseminated via scientific publications, newsletters, reports and conference presentations to a range of professional and patient groups and stakeholders. Based on the results of the trial

  9. Attempts to Improve the Method of Screening Cowpea Germplasm for Resistance to Cucumber Mosaic Virus and Blackeye Cowpea Mosaic Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Use of visual symptom screening for cowpea plants in field plots improved screening for Blackeye Cowpea Mosaic Virus (BICMV)-resistance. However, the method failed to improve the speed or accuracy of screening for Cucumber Mosaic Virus (CMV)-resistance. Plants that displayed few visual virus sympt...

  10. The effect on compliance of a health education leaflet in colorectal cancer screening in general practice in central England.

    PubMed Central

    Hart, A R; Barone, T L; Gay, S P; Inglis, A; Griffin, L; Tallon, C A; Mayberry, J F

    1997-01-01

    OBJECTIVE: To raise compliance in a general practice based colorectal cancer screening programme by the use of a simple health educational leaflet. DESIGN: A randomised controlled trial of the leaflet's effect on completion of faecal occult blood tests. The leaflet explained the high frequency of colorectal cancer, the principles of screening, and addressed reasons for non-compliance. SETTING: The British town of Market Harborough where most of the population are registered with a single practice. PARTICIPANTS: These comprised 1571 residents aged 61 to 70 years registered with the practice. Residents were invited to receive a free faecal occult blood test in a colorectal cancer screening programme. Half the population were randomly assigned to receive the educational leaflet about screening. RESULTS: Compliance in test and control groups, positive rate of stool testing, and pathology detected were measured. Compliance was higher in men who received the leaflet in those aged 61 to 65 years (36% v 27%, chi2 = 4.0, p < 0.05) and in men aged 66 to 70 years (39% v 23%, chi2 = 9.7, p < 0.01). In women, use of the leaflet did not affect compliance in those aged either 61 to 65 years (38% v 36%, chi2 = 0.1, NS) or 66 to 70 years (31% v 31%, chi2 = 0.0, NS). The positive rate of stool testing in patients observing the required dietary restrictions was 1.6%. A significant lesion was detected in 1.4% of people tested (2 carcinomas and 5 patients with adenomatous polyps). CONCLUSIONS: Health education leaflets addressing reasons for non-compliance significantly increased compliance in men and should be used in screening programmes. Reasons for the lack of success of the leaflet in women should be investigated and other interventions for raising compliance should be developed. PMID:9196650

  11. Assessment of drugs against Cryptosporidium parvum using a simple in vitro screening method.

    PubMed

    Armson, A; Meloni, B P; Reynoldson, J A; Thompson, R C

    1999-09-15

    A rapid semi-quantitative screening method was devised for assessing the anticryptosporidial and cytotoxic effects of putative chemotherapeutic compounds. The method is suitable as an initial rapid screening procedure from which compounds demonstrating anticryptosporidial activity can be identified for further analysis. It has the advantages of speed, low cost and concurrent assessment of anticryptosporidial and cytotoxic effects and allows accurate determination of minimum lethal concentrations. Of the 71 compounds screened, six completely inhibited cryptosporidial growth at 1 microM (monensin, salinomycin, alborixin, lasalocid, trifluralin and nicarbazin) and a further eight showed significant anticryptosporidial activity at 1 or 20 microM (halquinol, bleomycin, suramin, mitomycin, doxycycline hydrochloride, toltrazuril, chloroquine phosphate and teniposide). Twelve compounds were found to have some degree of cytotoxicity at 1 microM and a further 12 at 20 microM. PMID:10499272

  12. Proposal of Screening Method of Sleep Disordered Breathing Using Fiber Grating Vision Sensor

    NASA Astrophysics Data System (ADS)

    Aoki, Hirooki; Nakamura, Hidetoshi; Nakajima, Masato

    Every conventional respiration monitoring technique requires at least one sensor to be attached to the body of the subject during measurement, thereby imposing a sense of restraint that results in aversion against measurements that would last over consecutive days. To solve this problem, we developed a respiration monitoring system for sleepers, and it uses a fiber-grating vision sensor, which is a type of active image sensor to achieve non-contact respiration monitoring. In this paper, we verified the effectiveness of the system, and proposed screening method of the sleep disordered breathing. It was shown that our system could equivalently measure the respiration with thermistor and accelerograph. And, the respiratory condition of sleepers can be grasped by our screening method in one look, and it seems to be useful for the support of the screening of sleep disordered breathing.

  13. Generalized directed loop method for quantum Monte Carlo simulations.

    PubMed

    Alet, Fabien; Wessel, Stefan; Troyer, Matthias

    2005-03-01

    Efficient quantum Monte Carlo update schemes called directed loops have recently been proposed, which improve the efficiency of simulations of quantum lattice models. We propose to generalize the detailed balance equations at the local level during the loop construction by accounting for the matrix elements of the operators associated with open world-line segments. Using linear programming techniques to solve the generalized equations, we look for optimal construction schemes for directed loops. This also allows for an extension of the directed loop scheme to general lattice models, such as high-spin or bosonic models. The resulting algorithms are bounce free in larger regions of parameter space than the original directed loop algorithm. The generalized directed loop method is applied to the magnetization process of spin chains in order to compare its efficiency to that of previous directed loop schemes. In contrast to general expectations, we find that minimizing bounces alone does not always lead to more efficient algorithms in terms of autocorrelations of physical observables, because of the nonuniqueness of the bounce-free solutions. We therefore propose different general strategies to further minimize autocorrelations, which can be used as supplementary requirements in any directed loop scheme. We show by calculating autocorrelation times for different observables that such strategies indeed lead to improved efficiency; however, we find that the optimal strategy depends not only on the model parameters but also on the observable of interest. PMID:15903632

  14. General guidelines for medically screening mixed population groups potentially exposed to nerve or vesicant agents

    SciTech Connect

    Watson, A.P.; Munro, N.B.; Sidell, F.R.; Leffingwell, S.S.

    1992-01-01

    A number of state and local planners have requested guidance on screening protocols and have expressed interest in sampling body fluids from exposed or potentially exposed individuals as a means of estimating agent dose. These guidelines have been developed to provide a clear statement that could be used by state and local emergency response personnel in the event of a nerve or vesicant agent incident resulting in off-post contamination; maximum protection from harm is the goal. The assumption is that any population group so exposed would be heterogeneous for age, gender, reproductive status, and state of health.

  15. General Characterization Methods for Photoelectrochemical Cells for Solar Water Splitting.

    PubMed

    Shi, Xinjian; Cai, Lili; Ma, Ming; Zheng, Xiaolin; Park, Jong Hyeok

    2015-10-12

    Photoelectrochemical (PEC) water splitting is a very promising technology that converts water into clean hydrogen fuel and oxygen by using solar light. However, the characterization methods for PEC cells are diverse and a systematic introduction to characterization methods for PEC cells has rarely been attempted. Unlike most other review articles that focus mainly on the material used for the working electrodes of PEC cells, this review introduces general characterization methods for PEC cells, including their basic configurations and methods for characterizing their performance under various conditions, regardless of the materials used. Detailed experimental operation procedures with theoretical information are provided for each characterization method. The PEC research area is rapidly expanding and more researchers are beginning to devote themselves to related work. Therefore, the content of this Minireview can provide entry-level knowledge to beginners in the area of PEC, which might accelerate progress in this area. PMID:26365789

  16. Perspectives on the provision of GDM screening in general practice versus the hospital setting: a qualitative study of providers and patients

    PubMed Central

    Tierney, Marie; O'Dea, Angela; Danyliv, Andrii; Carmody, Louise; McGuire, Brian E; Glynn, Liam G; Dunne, Fidelma

    2016-01-01

    Objective A novel gestational diabetes mellitus (GDM) screening programme which involved offering screening at the patient's general practitioner (GP) compared with the traditional hospital setting was trialled. This study investigates perspectives of involved stakeholders on the provision of GDM screening at both settings. Design Thematic analysis of the perspectives of stakeholders involved in the receiving and provision of GDM screening in both the GP and hospital settings drawn from focus groups and interviews. Participants 3 groups of participants are included in this research—patient participants, GP screening providers and hospital screening providers. All were recruited from a larger sample who participated in a randomised controlled screening trial. Purposeful sampling was utilised to select participants with a wide variety of perspectives on the provision of GDM screening. Setting Participants were recruited from a geographical area covered by 3 hospitals in Ireland. Results 4 themes emerged from thematic analysis—namely (1) travel distance, (2) best care provision, (3) sense of ease created and (4) optimal screening. Conclusions The influence of travel distance from the screening site is the most important factor influencing willingness to attend for GDM screening among women who live a considerable distance from the hospital setting. For patients who live equidistance from both settings, other factors are important; namely the waiting facilities including parking, perceived expertise of screening provider personnel, access to emergency treatment if necessary, accuracy of tests and access to timely results and treatment. Optimal screening for GDM should be specialist led, incorporate expert advice of GDM screening, treatment and management, should be provided locally, offer adequate parking and comfort levels, provide accurate tests, and timely access to results and treatment. Such a service should result in improved rates of GDM screening uptake

  17. Evaluation of three methods using deoxyribonuclease production as a screening test for Serratia marcescens

    PubMed Central

    Black, W. A.; Hodgson, R.; McKechnie, Ann

    1971-01-01

    Deoxyribonuclease (DNase) produced by Serratia marcescens is a characteristic feature which is useful in distinguishing this organism from closely related members of the Enterobacteriaceae. In an assessment of three methods of performing the DNase test as a screening procedure for Serratia marcescens, the conclusion was reached that the standard test was most suitable for use in the clinical bacteriology laboratory. PMID:4933661

  18. Validation of a GC-MS screening method for anabolizing agents in aqueous nutritional supplements.

    PubMed

    Thuyne, W Van; Delbeke, F T

    2005-01-01

    A sensitive and selective method for the screening of anabolizing agents in aqueous nutritional supplements is described and validated. A total of 28 different anabolizing agents are screened for, including testosterone and prohormones, nandrolone and prohormones, stanozolol, and metandienone. The different analytes are extracted from the aqueous nutritional supplements by liquid-liquid extraction with a mixture of pentane and freshly distilled diethylether (1:1) after the supplements have been made alkaline with a NaHCO3-K2CO3 (2:1) buffer. The anabolizing agents are derivatized with a mixture of MSTFA-NH4I-ethanethiol (320:1:2) as routinely used for the screening of anabolic steroids extracted from urine. The derivatives are analyzed by gas chromatography (GC)-mass spectrometry (MS) in the selective ion monitoring mode. The limits of detection range from 1 to 10 ng/mL. One aqueous nutritional supplement (creatine serum) was analyzed with this screening method and was found to contain dehydroepiandrosterone (DHEA) at very low concentrations. The presence of DHEA could be confirmed with GC-MS-MS. Results of the application of this method and a similar method for solid nutritional supplements previously described are given. PMID:15808000

  19. Optimization and visualization of the edge weights in optimal assignment methods for virtual screening

    PubMed Central

    2013-01-01

    Background Ligand‐based virtual screening plays a fundamental part in the early drug discovery stage. In a virtual screening, a chemical library is searched for molecules with similar properties to a query molecule by means of a similarity function. The optimal assignment of chemical graphs has proven to be a valuable similarity function for many cheminformatic tasks, such as virtual screening. The optimal assignment assumes all atoms of a query molecule to be equally important, which is not realistic depending on the binding mode of a ligand. The importance of a query molecule’s atoms can be integrated in the optimal assignment by weighting the assignment edges. We optimized the edge weights with respect to the virtual screening performance by means of evolutionary algorithms. Furthermore, we propose a visualization approach for the interpretation of the edge weights. Results We evaluated two different evolutionary algorithms, differential evolution and particle swarm optimization, for their suitability for optimizing the assignment edge weights. The results showed that both optimization methods are suited to optimize the edge weights. Furthermore, we compared our approach to the optimal assignment with equal edge weights and two literature similarity functions on a subset of the Directory of Useful Decoys using sophisticated virtual screening performance metrics. Our approach achieved a considerably better overall and early enrichment performance. The visualization of the edge weights enables the identification of substructures that are important for a good retrieval of ligands and for the binding to the protein target. Conclusions The optimization of the edge weights in optimal assignment methods is a valuable approach for ligand‐based virtual screening experiments. The approach can be applied to any similarity function that employs the optimal assignment method, which includes a variety of similarity measures that have proven to be valuable in various

  20. Sensitivity analysis and approximation methods for general eigenvalue problems

    NASA Technical Reports Server (NTRS)

    Murthy, D. V.; Haftka, R. T.

    1986-01-01

    Optimization of dynamic systems involving complex non-hermitian matrices is often computationally expensive. Major contributors to the computational expense are the sensitivity analysis and reanalysis of a modified design. The present work seeks to alleviate this computational burden by identifying efficient sensitivity analysis and approximate reanalysis methods. For the algebraic eigenvalue problem involving non-hermitian matrices, algorithms for sensitivity analysis and approximate reanalysis are classified, compared and evaluated for efficiency and accuracy. Proper eigenvector normalization is discussed. An improved method for calculating derivatives of eigenvectors is proposed based on a more rational normalization condition and taking advantage of matrix sparsity. Important numerical aspects of this method are also discussed. To alleviate the problem of reanalysis, various approximation methods for eigenvalues are proposed and evaluated. Linear and quadratic approximations are based directly on the Taylor series. Several approximation methods are developed based on the generalized Rayleigh quotient for the eigenvalue problem. Approximation methods based on trace theorem give high accuracy without needing any derivatives. Operation counts for the computation of the approximations are given. General recommendations are made for the selection of appropriate approximation technique as a function of the matrix size, number of design variables, number of eigenvalues of interest and the number of design points at which approximation is sought.

  1. A sensitive mutation screening method supporting cell line development for biotherapeutics.

    PubMed

    Valisheva, Ildana; Harris, Reed J; Zhu-Shimoni, Judith

    2016-07-15

    Random genetic mutations, which can occur during cell line development, can lead to sequence variants that comprise pharmaceutical product quality generated by recombinant technology. Mutation screening can minimize the probability of selecting clones harboring sequence variants. Here we report a polymerase chain reaction (PCR)-based mutation screening approach using high-resolution melting (HRM) analysis combined with a mutation enrichment step using limiting dilution to detect low-level mutations at 0.5%. The method allows unknown mutation discovery regardless of its location in a transgene as well as independent of its position in an HRM fragment, ranging from approximately 200 to 300 bp in size. PMID:27108188

  2. Generalization of the time-dependent numerical renormalization group method to finite temperatures and general pulses

    NASA Astrophysics Data System (ADS)

    Nghiem, H. T. M.; Costi, T. A.

    2014-02-01

    The time-dependent numerical renormalization group (TDNRG) method [Anders et al., Phys. Rev. Lett. 95, 196801 (2005), 10.1103/PhysRevLett.95.196801] offers the prospect of investigating in a nonperturbative manner the time dependence of local observables of interacting quantum impurity models at all time scales following a quantum quench. Here, we present a generalization of this method to arbitrary finite temperature by making use of the full density matrix approach [Weichselbaum et al., Phys. Rev. Lett. 99, 076402 (2007), 10.1103/PhysRevLett.99.076402]. We show that all terms in the projected full density matrix ρi →f=ρ+++ρ--+ρ+-+ρ-+ appearing in the time evolution of a local observable may be evaluated in closed form at finite temperature, with ρ+-=ρ-+=0. The expression for ρ-- is shown to be finite at finite temperature, becoming negligible only in the limit of vanishing temperatures. We prove that this approach recovers the short-time limit for the expectation value of a local observable exactly at arbitrary temperatures. In contrast, the corresponding long-time limit is recovered exactly only for a continuous bath, i.e., when the logarithmic discretization parameter Λ →1+. Since the numerical renormalization group approach breaks down in this limit, and calculations have to be carried out at Λ >1, the long-time behavior following an arbitrary quantum quench has a finite error, which poses an obstacle for the method, e.g., in its application to the scattering-states numerical renormalization group method for describing steady-state nonequilibrium transport through correlated impurities [Anders, Phys. Rev. Lett. 101, 066804 (2008), 10.1103/PhysRevLett.101.066804]. We suggest a way to overcome this problem by noting that the time dependence, in general, and the long-time limit, in particular, become increasingly more accurate on reducing the size of the quantum quench. This suggests an improved generalized TDNRG approach in which the system is time

  3. A General Method to Discover Epitopes from Sera

    PubMed Central

    Whittemore, Kurt; Johnston, Stephen Albert; Sykes, Kathryn; Shen, Luhui

    2016-01-01

    Antigen-antibody complexes are central players in an effective immune response. However, finding those interactions relevant to a particular disease state can be arduous. Nonetheless many paths to discovery have been explored since deciphering these interactions can greatly facilitate the development of new diagnostics, therapeutics, and vaccines. In silico B cell epitope mapping approaches have been widely pursued, though success has not been consistent. Antibody mixtures in immune sera have been used as handles for biologically relevant antigens, but these and other experimental approaches have proven resource intensive and time consuming. In addition, these methods are often tailored to individual diseases or a specific proteome, rather than providing a universal platform. Most of these methods are not able to identify the specific antibody’s epitopes from unknown antigens, such as un-annotated neo antigens in cancer. Alternatively, a peptide library comprised of sequences unrestricted by naturally-found protein space provides for a universal search for mimotopes of an antibody’s epitope. Here we present the utility of such a non-natural random sequence library of 10,000 peptides physically addressed on a microarray for mimotope discovery without sequence information of the specific antigen. The peptide arrays were probed with serum from an antigen-immunized rabbit, or alternatively probed with serum pre-absorbed with the same immunizing antigen. With this positive and negative screening scheme, we identified the library-peptides as the mimotopes of the antigen. The unique library peptides were successfully used to isolate antigen-specific antibodies from complete immune serum. Sequence analysis of these peptides revealed the epitopes in the immunized antigen. We present this method as an inexpensive, efficient method for identifying mimotopes of any antibody’s targets. These mimotopes should be useful in defining both components of the antigen

  4. Functional-based screening methods for lipases, esterases, and phospholipases in metagenomic libraries.

    PubMed

    Reyes-Duarte, Dolores; Ferrer, Manuel; García-Arellano, Humberto

    2012-01-01

    The use of metagenomic techniques for enzyme discovery constitutes a powerful approach. Functional screens, in contrast to sequence homology search, enable us to select enzymes based on their activity. It is noteworthy that they additionally guarantee the identification of genes coding for enzymes that exhibited no sequence similarity to known counterparts from public databases and that even do not match any putative catalytic residues, involved in the selected catalytic function. Therefore, this strategy not only provides new enzymes for new biotechnological applications, but also allows functional assignment of many proteins, found in abundance in the databases, currently designated as "hypothetical" or "conserved hypothetical" proteins. In the past decade, there has been an exponential increase in the design of functional screening programmes, the majority of them established for hydrolases and oxidoreductases. Here, functional screening methods that guarantee the greatest enzyme diversity, for mining esterases and lipases, are described. PMID:22426714

  5. A novel screening method to assess developability of antibody-like molecules

    PubMed Central

    Kohli, Neeraj; Jain, Nidhi; Geddie, Melissa L; Razlog, Maja; Xu, Lihui; Lugovskoy, Alexey A

    2015-01-01

    Monoclonal antibodies and antibody-like molecules represent a fast-growing class of bio-therapeutics that has rapidly transformed patient care in a variety of disease indications. The discovery of antibodies that bind to particular targets with high affinity is now a routine exercise and a variety of in vitro and in vivo techniques are available for this purpose. However, it is still challenging to identify antibodies that, in addition to having the desired biological effect, also express well, remain soluble at different pH levels, remain stable at high concentrations, can withstand high shear stress, and have minimal non-specific interactions. Many promising antibody programs have ultimately failed in development due to the problems associated with one of these factors. Here, we present a simple high-performance liquid chromatography (HPLC)-based screening method to assess these developability factors earlier in discovery process. This method is robust and requires only microgram quantities of proteins. Briefly, we show that for antibodies injected on a commercially available pre-packed Zenix HPLC column, the retention times are inversely related to their colloidal stability with antibodies prone to precipitation or aggregation retained longer on the column with broader peaks. By simply varying the salt content of running buffer, we were also able to estimate the nature of interactions between the antibodies and the column. We believe this approach should generally be applicable to assessment of the developability of other classes of bio-therapeutic molecules, and that the addition of this simple tool early in the discovery process will lead to selection of molecules with improved developability characteristics. PMID:25961854

  6. General finite state machine reasoning method for digital forensics

    NASA Astrophysics Data System (ADS)

    Chen, Long; Wang, Guoyin

    2008-04-01

    Digital forensics investigator faces the challenge of reliability of forensic conclusions. Formal automatic analysis method is helpful to deal with the challenge. The finite state machine analysis method tries to determine all possible sequences of events that could have happened in a digital system during an incident. Its basic idea is to model the target system using a finite state machine and then explore its all possible states on the condition of available evidence. Timed mealy finite state machine is introduced to model the target system, and the formalization of system running process and evidence is presented to match the system running with possible source evidence automatically. Based on Gladyshev's basic reasoning method, general reasoning algorithms with multi strategies are developed to find the possible real scenarios. Case study and experimental results show that our method is feasible and adaptable to possible cases and takes a further step to practical formal reasoning for digital forensics.

  7. Effective microwell plate-based screening method for microbes producing cellulase and xylanase and its application.

    PubMed

    Kim, Jennifer Jooyoun; Kwon, Young-Kyung; Kim, Ji Hyung; Heo, Soo-Jin; Lee, Youngdeuk; Lee, Su-Jin; Shim, Won-Bo; Jung, Won-Kyo; Hyun, Jung-Ho; Kwon, Kae Kyoung; Kang, Do-Hyung; Oh, Chulhong

    2014-11-28

    Cellulase and xylanase are main hydrolysis enzymes for the degradation of cellulosic and hemicellulosic biomass, respectively. In this study, our aim was to develop and test the efficacy of a rapid, high-throughput method to screen hydrolytic-enzyme-producing microbes. To accomplish this, we modified the 3,5-dinitrosalicylic acid (DNS) method for microwell plate-based screening. Targeted microbial samples were initially cultured on agar plates with both cellulose and xylan as substrates. Then, isolated colonies were subcultured in broth media containing yeast extract and either cellulose or xylan. The supernatants of the culture broth were tested with our modified DNS screening method in a 96-microwell plate, with a 200 μl total reaction volume. In addition, the stability and reliability of glucose and xylose standards, which were used to determine the enzymatic activity, were studied at 100°C for different time intervals in a dry oven. It was concluded that the minimum incubation time required for stable color development of the standard solution is 20 min. With this technique, we successfully screened 21 and 31 cellulase- and xylanase-producing strains, respectively, in a single experimental trial. Among the identified strains, 19 showed both cellulose and xylan hydrolyzing activities. These microbes can be applied to bioethanol production from cellulosic and hemicellulosic biomass. PMID:25085570

  8. Field-screening method for 2,4-dinitrotoluene in soil. Special report

    SciTech Connect

    Jenkins, T.F.; Walsh, M.E.

    1991-10-01

    2,4-Dinitrotoluene (2,4-DNT) is a major component of several munitions formulations used by the U.S. Army. It is also one of the major impurities in production grade TNT and is often found in contaminated soils at army ammunition plants, depots and explosive ordnance disposal areas. Since 2,4-DNT migrates rapidly through the soil to groundwater and is thought to be toxic in water at quite low concentrations, methods are needed to locate sources of this contaminant in the soil. Laboratory procedures to quantify the concentration of 2,4-DNT in soil samples have been developed but no rapid field method is currently available to screen for this contaminant. Field screening methods have recently been developed for TNT and RDX. The TNT method involves extraction of the soil with acetone and generation of the red-colored Janowsky complex by addition of potassium hydroxide and sodium sulfite.

  9. Development of quantitative duplex real-time PCR method for screening analysis of genetically modified maize.

    PubMed

    Oguchi, Taichi; Onishi, Mari; Minegishi, Yasutaka; Kurosawa, Yasunori; Kasahara, Masaki; Akiyama, Hiroshi; Teshima, Reiko; Futo, Satoshi; Furui, Satoshi; Hino, Akihiro; Kitta, Kazumi

    2009-06-01

    A duplex real-time PCR method was developed for quantitative screening analysis of GM maize. The duplex real-time PCR simultaneously detected two GM-specific segments, namely the cauliflower mosaic virus (CaMV) 35S promoter (P35S) segment and an event-specific segment for GA21 maize which does not contain P35S. Calibration was performed with a plasmid calibrant specially designed for the duplex PCR. The result of an in-house evaluation suggested that the analytical precision of the developed method was almost equivalent to those of simplex real-time PCR methods, which have been adopted as ISO standard methods for the analysis of GMOs in foodstuffs and have also been employed for the analysis of GMOs in Japan. In addition, this method will reduce both the cost and time requirement of routine GMO analysis by half. The high analytical performance demonstrated in the current study would be useful for the quantitative screening analysis of GM maize. We believe the developed method will be useful for practical screening analysis of GM maize, although interlaboratory collaborative studies should be conducted to confirm this. PMID:19602858

  10. Eddy Covariance Method: Overview of General Guidelines and Conventional Workflow

    NASA Astrophysics Data System (ADS)

    Burba, G. G.; Anderson, D. J.; Amen, J. L.

    2007-12-01

    Atmospheric flux measurements are widely used to estimate water, heat, carbon dioxide and trace gas exchange between the ecosystem and the atmosphere. The Eddy Covariance method is one of the most direct, defensible ways to measure and calculate turbulent fluxes within the atmospheric boundary layer. However, the method is mathematically complex, and requires significant care to set up and process data. These reasons may be why the method is currently used predominantly by micrometeorologists. Modern instruments and software can potentially expand the use of this method beyond micrometeorology and prove valuable for plant physiology, hydrology, biology, ecology, entomology, and other non-micrometeorological areas of research. The main challenge of the method for a non-expert is the complexity of system design, implementation, and processing of the large volume of data. In the past several years, efforts of the flux networks (e.g., FluxNet, Ameriflux, CarboEurope, Fluxnet-Canada, Asiaflux, etc.) have led to noticeable progress in unification of the terminology and general standardization of processing steps. The methodology itself, however, is difficult to unify, because various experimental sites and different purposes of studies dictate different treatments, and site-, measurement- and purpose-specific approaches. Here we present an overview of theory and typical workflow of the Eddy Covariance method in a format specifically designed to (i) familiarize a non-expert with general principles, requirements, applications, and processing steps of the conventional Eddy Covariance technique, (ii) to assist in further understanding the method through more advanced references such as textbooks, network guidelines and journal papers, (iii) to help technicians, students and new researchers in the field deployment of the Eddy Covariance method, and (iv) to assist in its use beyond micrometeorology. The overview is based, to a large degree, on the frequently asked questions

  11. Generalized slave-particle method for extended Hubbard models

    NASA Astrophysics Data System (ADS)

    Georgescu, Alexandru B.; Ismail-Beigi, Sohrab

    2015-12-01

    We introduce a set of generalized slave-particle models for extended Hubbard models that treat localized electronic correlations using slave-boson decompositions. Our models automatically include two slave-particle methods of recent interest, the slave-rotor and slave-spin methods, as well as a ladder of new intermediate models where one can choose which of the electronic degrees of freedom (e.g., spin or orbital labels) are treated as correlated degrees of freedom by the slave bosons. In addition, our method removes the aberrant behavior of the slave-rotor model, where it systematically overestimates the importance of electronic correlation effects for weak interaction strength, by removing the contribution of unphysical states from the bosonic Hilbert space. The flexibility of our formalism permits one to separate and isolate the effect of correlations on the key degrees of freedom.

  12. General method for quantifying base adducts in specific mammalian genes

    SciTech Connect

    Thomas, D.C.; Morton, A.G.; Bohr, V.A.; Sancar, A.

    1988-06-01

    A general method has been developed to measure the formation and removal of DNA adducts in defined sequences of mammalian genomes. Adducted genomic DNA is digested with an appropriate restriction enzyme, treated with Escherichia coli UvrABC excision nuclease (ABC excinuclease), subjected to alkaline gel electrophoresis, and probed for specific sequences by Southern hybridization. The ABC excinuclease incises DNA containing bulky adducts and thus reduces the intensity of the full-length fragments in Southern hybridization in proportion to the number of adducts present in the probed sequence. This method is similar to that developed by Bohr et al. for quantifying pyrimidine dimers by using T4 endonuclease V. Because of the wide substrate range of ABC exinuclease, however, our method can be used to quantify a large variety of DNA adducts in specific genomic sequences.

  13. School Locations and Traffic Emissions — Environmental (In)Justice Findings Using a New Screening Method

    PubMed Central

    Gaffron, Philine; Niemeier, Deb

    2015-01-01

    It has been shown that the location of schools near heavily trafficked roads can have detrimental effects on the health of children attending those schools. It is therefore desirable to screen both existing school locations and potential new school sites to assess either the need for remedial measures or suitability for the intended use. Current screening tools and public guidance on school siting are either too coarse in their spatial resolution for assessing individual sites or are highly resource intensive in their execution (e.g., through dispersion modeling). We propose a new method to help bridge the gap between these two approaches. Using this method, we also examine the public K-12 schools in the Sacramento Area Council of Governments Region, California (USA) from an environmental justice perspective. We find that PM2.5 emissions from road traffic affecting a school site are significantly positively correlated with the following metrics: percent share of Black, Hispanic and multi-ethnic students, percent share of students eligible for subsidized meals. The emissions metric correlates negatively with the schools’ Academic Performance Index, the share of White students and average parental education levels. Our PM2.5 metric also correlates with the traffic related, census tract level screening indicators from the California Communities Environmental Health Screening Tool and the tool’s tract level rate of asthma related emergency department visits. PMID:25679341

  14. A Novel Approach for Efficient Pharmacophore-based Virtual Screening: Method and Applications

    PubMed Central

    Dror, Oranit; Schneidman-Duhovny, Dina; Inbar, Yuval; Nussinov, Ruth; Wolfson, Haim J.

    2009-01-01

    Virtual screening is emerging as a productive and cost-effective technology in rational drug design for the identification of novel lead compounds. An important model for virtual screening is the pharmacophore. Pharmacophore is the spatial configuration of essential features that enable a ligand molecule to interact with a specific target receptor. In the absence of a known receptor structure, a pharmacophore can be identified from a set of ligands that have been observed to interact with the target receptor. Here, we present a novel computational method for pharmacophore detection and virtual screening. The pharmacophore detection module is able to: (i) align multiple flexible ligands in a deterministic manner without exhaustive enumeration of the conformational space, (ii) detect subsets of input ligands that may bind to different binding sites or have different binding modes, (iii) address cases where the input ligands have different affinities by defining weighted pharmacophores based on the number of ligands that share them, and (iv) automatically select the most appropriate pharmacophore candidates for virtual screening. The algorithm is highly efficient, allowing a fast exploration of the chemical space by virtual screening of huge compound databases. The performance of PharmaGist was successfully evaluated on a commonly used dataset of G-Protein Coupled Receptor alpha1A. Additionally, a large-scale evaluation using the DUD (directory of useful decoys) dataset was performed. DUD contains 2950 active ligands for 40 different receptors, with 36 decoy compounds for each active ligand. PharmaGist enrichment rates are comparable with other state-of-the-art tools for virtual screening. Availability The software is available for download. A user-friendly web interface for pharmacophore detection is available at http://bioinfo3d.cs.tau.ac.il/PharmaGist. PMID:19803502

  15. Rapid screening of guar gum using portable Raman spectral identification methods.

    PubMed

    Srivastava, Hirsch K; Wolfgang, Steven; Rodriguez, Jason D

    2016-01-25

    Guar gum is a well-known inactive ingredient (excipient) used in a variety of oral pharmaceutical dosage forms as a thickener and stabilizer of suspensions and as a binder of powders. It is also widely used as a food ingredient in which case alternatives with similar properties, including chemically similar gums, are readily available. Recent supply shortages and price fluctuations have caused guar gum to come under increasing scrutiny for possible adulteration by substitution of cheaper alternatives. One way that the U.S. FDA is attempting to screen pharmaceutical ingredients at risk for adulteration or substitution is through field-deployable spectroscopic screening. Here we report a comprehensive approach to evaluate two field-deployable Raman methods--spectral correlation and principal component analysis--to differentiate guar gum from other gums. We report a comparison of the sensitivity of the spectroscopic screening methods with current compendial identification tests. The ability of the spectroscopic methods to perform unambiguous identification of guar gum compared to other gums makes them an enhanced surveillance alternative to the current compendial identification tests, which are largely subjective in nature. Our findings indicate that Raman spectral identification methods perform better than compendial identification methods and are able to distinguish guar gum from other gums with 100% accuracy for samples tested by spectral correlation and principal component analysis. PMID:26609678

  16. Surface impedance based microwave imaging method for breast cancer screening: contrast-enhanced scenario

    NASA Astrophysics Data System (ADS)

    Güren, Onan; Çayören, Mehmet; Tükenmez Ergene, Lale; Akduman, Ibrahim

    2014-10-01

    A new microwave imaging method that uses microwave contrast agents is presented for the detection and localization of breast tumours. The method is based on the reconstruction of breast surface impedance through a measured scattered field. The surface impedance modelling allows for representing the electrical properties of the breasts in terms of impedance boundary conditions, which enable us to map the inner structure of the breasts into surface impedance functions. Later a simple quantitative method is proposed to screen breasts against malignant tumours where the detection procedure is based on weighted cross correlations among impedance functions. Numerical results demonstrate that the method is capable of detecting small malignancies and provides reasonable localization.

  17. Screening and referral to identify children at risk for FASD: Search for new methods 2006-2013.

    PubMed

    Koren, Gideon; Chudley, Albert; Loock, Christine; MacLeod, Stuart M; Orrbine, Elaine; Rosales, Ted; Rosenbaum, Charlotte; Sarkar, Moumita

    2014-01-01

    As part of the Canadian Association of Paediatric Health Centres Taskforce on FASD Screening commitment to further pilot, validate and evaluate the multiple components of the Canadian FASD Screening Tool Kit, it was deemed necessary that recent developments and/or improvements in FASD screening were identified and considered. In 2008 a literature review of methods for screening for FASD was published until 2006 and identified five tools which met pre-set criteria. A review of all new papers was published from the period January 2006 until July 1, 2013. Out of 1392 papers, two new screening methods met the inclusion criteria: Clarren et al's new norms for palpebral fissure length by age in Canada; and Breiner et al's extension of the Neurobehavioral Screening Test (NST) to age 4 years. Further work is needed to validate these methods in other settings.  PMID:25019303

  18. Optimal Methods to Screen Men and Women for Intimate Partner Violence: Results from an Internal Medicine Residency Continuity Clinic

    ERIC Educational Resources Information Center

    Kapur, Nitin A.; Windish, Donna M.

    2011-01-01

    Contradictory data exist regarding optimal methods and instruments for intimate partner violence (IPV) screening in primary care settings. The purpose of this study was to determine the optimal method and screening instrument for IPV among men and women in a primary-care resident clinic. We conducted a cross-sectional study at an urban, academic,…

  19. A general method for unsteady heat transfer on turbine blades

    NASA Technical Reports Server (NTRS)

    Cebeci, Tuncer; Platzer, Max F.

    1989-01-01

    The development of a general method for calculating unsteady heat transfer on turbine blades is described. It is based on the numerical solution of the boundary-layer equations for laminar, transitional, and turbulent flows. A novel procedure has been developed to account for the movement of the stagnation point caused by blade-passing wakes and has been applied to the stagnation region of three model flows with results which confirm its validity for laminar flows. It has also been applied to an experimental arrangement in which the average Nusselt number has been reported for turbulent flows and the results show considerable promise.

  20. Electrochemical estrogen screen method based on the electrochemical behavior of MCF-7 cells.

    PubMed

    Li, Jinlian; Song, Jia; Bi, Sheng; Zhou, Shi; Cui, Jiwen; Liu, Jiguang; Wu, Dongmei

    2016-08-01

    It was an urgent task to develop quick, cheap and accurate estrogen screen method for evaluating the estrogen effect of the booming chemicals. In this study, the voltammetric behavior between the estrogen-free and normal fragmented MCF-7 cell suspensions were compared, and the electrochemical signal (about 0.68V attributed by xanthine and guanine) of the estrogen-free fragmented MCF-7 cell suspension was obviously lower than that of the normal one. The electrochemistry detection of ex-secretion purines showed that the ability of ex-secretion purines of cells sharp decreased due to the removing of endogenous estrogen. The results indicated that the electrochemical signal of MCF-7 cells was related to the level of intracellular estrogen. When the level of intracellular estrogen was down-regulated, the concentrations of the xanthine and hypoxanthine decreased, which led to the electrochemical signal of MCF-7 cells fall. Based on the electrochemical signal, the electrochemical estrogen screen method was established. The estrogen effect of estradiol, nonylphenol and bisphenol A was evaluated with the electrochemical method, and the result was accordant with that of MTT assay. The electrochemical estrogen screen method was simple, quickly, cheap, objective, and it exploits a new way for the evaluation of estrogenic effects of chemicals. PMID:27108272

  1. An efficient screening method for simultaneous detection of recurrent copy number variants associated with psychiatric disorders.

    PubMed

    Rodriguez-Lopez, Julio; Carrera, Noa; Arrojo, Manuel; Amigo, Jorge; Sobrino, Beatriz; Páramo, Mario; Paz, Eduardo; Agra, Santiago; Ramos-Ríos, Ramón; Brenlla, Julio; Carracedo, Ángel; Costas, Javier

    2015-05-20

    Several recurrent copy number variants (CNVs) increasing risk to neuropsychiatric diseases have been identified in recent years. They show variable clinical expressivity, being associated with different disorders, and incomplete penetrance. However, due to its very low frequency, the full variety of clinical outcomes associated with each one of these CNVs is unknown. Current methods for detection of CNVs are labor intensive, expensive or not suitable for high throughput analysis. Quantitative interspecies competitive PCR linked to variant minisequencing and detection by mass-spectrometry may overcome these limitations. Here, we present two multiplex assays based on this method to screen for eleven psychiatric risk CNVs, such as 1q21, 16p11.2, 3q29, or 16p13.11 regions, among others. The assays were tested in our collection of 514 schizophrenia patients. Results were compared with MLPA at two CNVs. Additional positive results were confirmed by exome sequencing. A total of fourteen patients were CNV carriers. The method presents high sensitivity and specificity, showing its utility as a cheap, accurate, high throughput screening tool for recurrent CNVs. The method may be very useful for management of psychiatric patients as well as screening of different collections of samples to better identify the full spectrum of clinical variability. PMID:25797897

  2. A simple method for screening emission sources of carbonyl compounds in indoor air.

    PubMed

    Yamashita, Shohei; Kume, Kazunari; Horiike, Toshiyuki; Honma, Nobuyuki; Fusaya, Masahiro; Ohura, Takeshi; Amagai, Takashi

    2010-06-15

    Volatile organic compounds (VOCs) emitted from building and furnishing materials are frequently observed in high concentrations in indoor air. Nondestructive analytical methods that determine the main parameters influencing concentration of the chemical substances are necessary to screen for sources of VOC emissions. Toward this goal, we have developed a new flux sampler, referred to herein as an emission cell for simultaneous multi-sampling (ECSMS), that is used for screening indoor emission sources of VOCs and for determining the emission rates of these sources. Because the ECSMS is based on passive sampling, it can be easily used on-site at a low cost. Among VOCs, low-molecular-weight carbonyl compounds including formaldehyde are frequently detected at high concentrations in indoor environments. In this study, we determined the reliability of the ECSMS for the collection of formaldehyde and other carbonyl compounds emitted from wood-based composites of medium density fiberboards and particleboards. We then used emission rates determined by the ECSMS to predict airborne concentrations of formaldehyde emitted from a bookshelf in a large chamber, and these data were compared to formaldehyde concentrations that were acquired simultaneously by means of an active sampling method. The values obtained from the two methods were quite similar, suggesting that ECSMS measurement is an effective method for screening primary sources influencing indoor concentrations of formaldehyde. PMID:20149530

  3. Tripless control method for general-purpose inverters

    SciTech Connect

    Mutoh, N.; Ueda, A. . Hitachi Research Lab.); Nandoh, K.; Ibori, S. )

    1992-09-01

    In this paper a new control method is described. This method prevents general-purpose inverters without current regulators from tripping easily, i.e., to be tripless no matter how their load is varied, and enables motors to rotate stably at high frequencies. This control is performed using only current sensors and is a combination of PWM control and torque control. This approach for PWM control changes an asynchronized mode to a synchronized mode when the modulation ratio becomes more than one. This enables the carrier wave frequency to be continuously varied with the inverter frequency. As a result, motors can rotate stably over a wide frequency range. The torque control uses a real and reactive component detector, magnetic flux compensator, slip compensator, and current limit controller.

  4. [A generalized chemical-kinetic method for modeling gene networks].

    PubMed

    Likhoshvaĭ, V A; Matushkin, Iu G; Ratushnyĭ, A V; Anan'ko, E A; Ignat'eva, E V; Podkolodnaia, O A

    2001-01-01

    Development of methods for mathematical simulation of biological systems and building specific simulations is an important trend of bioinformatics development. Here we describe the method of generalized chemokinetic simulation generating flexible and adequate simulations of various biological systems. Adequate simulations of complex nonlinear gene networks--control system of cholesterol by synthesis in the cell and erythrocyte differentiation and maturation--are given as the examples. The simulations were expressed in terms of unit processes--biochemical reactions. Optimal sets of parameters were determined and the systems were numerically simulated under various conditions. The simulations allow us to study possible functional conditions of these gene networks, calculate consequences of mutations, and define optimal strategies for their correction including therapeutic ones. Graphical user interface for these simulations is available at http://wwwmgs.bionet.nsc.ru/systems/MGL/GeneNet/. PMID:11771132

  5. Application of EU guidelines for the validation of screening methods for veterinary drugs.

    PubMed

    Stolker, Alida A M Linda

    2012-08-01

    Commission Decision (CD) 2002/657/EC describes detailed rules for method validation within the framework of residue monitoring programmes. The approach described in this CD is based on criteria. For (qualitative) screening methods, the most important criteria is that the CCβ has to be below any regulatory limit. Especially when microbiological or immunochemical methods are involved, the approach described in the CD is not easily applied. For example, by those methods, a large number of analytes (all antibiotics) within several different matrices (meat, milk, fish, eggs, etc.) are detected. It is not completely clear whether all those analytes and all matrices have to be taken into account during method validation. To clarify this, a working group - from EU Reference Laboratories - came up with a practical approach to validate multi-analyte multi-matrix screening methods. It describes how many analyte/matrix combinations have to be tested and how these combinations are selected. Furthermore it describes how to determine CCβ for screening methods in relation to a large list of compounds and maximum residue limits (MRLs). First for each analyte/matrix combination the 'cut-off' level - i.e. the level at which the method separates blanks from contaminated samples - is established. The validation is preferably at the concentration of 50% of the regulatory limit. A minimum set of 20 different samples has to be tested. From the experiences with applying these guidelines it was concluded that the validation approach is very 'practical'; however, there are some remarks. One has to be careful with selecting 'representative' analytes and matrices and it is strongly recommended to collect additional validation data during the routine application of the method. PMID:22851358

  6. Microengineering Methods for Cell Based Microarrays and High-Throughput Drug Screening Applications

    PubMed Central

    Xu, Feng; Wu, JinHui; Wang, ShuQi; Durmus, Naside Gozde; Gurkan, Umut Atakan; Demirci, Utkan

    2011-01-01

    Screening for effective therapeutic agents from millions of drug candidates is costly, time-consuming and often face ethical concerns due to extensive use of animals. To improve cost-effectiveness, and to minimize animal testing in pharmaceutical research, in vitro monolayer cell microarrays with multiwell plate assays have been developed. Integration of cell microarrays with microfluidic systems have facilitated automated and controlled component loading, significantly reducing the consumption of the candidate compounds and the target cells. Even though these methods significantly increased the throughput compared to conventional in vitro testing systems and in vivo animal models, the cost associated with these platforms remains prohibitively high. Besides, there is a need for three-dimensional (3D) cell based drug-screening models, which can mimic the in vivo microenvironment and the functionality of the native tissues. Here, we present the state-of-the-art microengineering approaches that can be used to develop 3D cell based drug screening assays. We highlight the 3D in vitro cell culture systems with live cell-based arrays, microfluidic cell culture systems, and their application to high-throughput drug screening. We conclude that among the emerging microengineering approaches, bioprinting holds a great potential to provide repeatable 3D cell based constructs with high temporal, spatial control and versatility. PMID:21725152

  7. Methods for efficient high-throughput screening of protein expression in recombinant Pichia pastoris strains.

    PubMed

    Camattari, Andrea; Weinhandl, Katrin; Gudiminchi, Rama K

    2014-01-01

    The methylotrophic yeast Pichia pastoris is becoming one of the favorite industrial workhorses for protein expression. Due to the widespread use of integration vectors, which generates significant clonal variability, screening methods allowing assaying hundreds of individual clones are of particular importance. Here we describe methods to detect and analyze protein expression, developed in a 96-well format for high-throughput screening of recombinant P. pastoris strains. The chapter covers essentially three common scenarios: (1) an enzymatic assay for proteins expressed in the cell cytoplasm, requiring cell lysis; (2) a whole-cell assay for a fungal cytochrome P450; and (3) a nonenzymatic assay for detection and quantification of tagged protein secreted into the supernatant. PMID:24744029

  8. [Local straight line screening method for the detection of Chinese proprietary medicines containing undeclared prescription drugs].

    PubMed

    Li, Shu; Cao, Yan; Le, Jian; Chen, Gui-Liang; Chai, Yi-Feng; Lu, Feng

    2009-02-01

    The present paper constructs a new approach named local straight-line screening (LSLS) to detect Chinese proprietary medicines (CPM) containing undeclared prescription drugs (UPD). Different from traditional methods used in analysis of multi-component spectrum, LSLS is proposed according to the characteristics of original infrared spectra of the UPD and suspected CPM, without any pattern recognition or concentration model establishment. Spectrum-subtraction leads to the variance in local straight line, which serves as a key in discrimination of whether suspected CPD is adulterated or not. Sibutramine hydrochloride, fenfluramine hydrochloride, sildenafil citrate and lovastatin were used as reference substances of UPD to analyze 16 suspected CPM samples. The results show that LSLS can obtain an accurate quantitative and qualitative analysis of suspected CPM. It is possible for the method to be potentially used in the preliminary screening of CPM containing possible UPD. PMID:19445196

  9. A consolidated method for screening the endocrine activity of drinking water.

    PubMed

    Chevolleau, Sylvie; Debrauwer, Laurent; Stroheker, Thomas; Viglino, Liza; Mourahib, Issam; Meireles, Maria-Helena; Grimaldi, Marina; Balaguer, Patrick; di Gioia, Lodovico

    2016-12-15

    Endocrine activity of drinking water is a matter of growing interest for scientists as well as health authorities. A concentration technique for endocrine activity screening was developed, optimized, and transposed from 200mL to 10L water samples. To avoid any contamination during concentration, the method was developed using exclusively glass, Teflon and stainless steel materials. Any potential losses were tracked using three model radiolabeled molecules, namely BPA, DEHP and 4n-NP. The final method allowed 10L water samples to be concentrated 5000-fold, with good recovery and repeatability. After validation, by concentrating spiked and non-spiked 10L samples of EVIAN natural mineral water, 14 different drinking water samples were concentrated and screened for endocrine disrupting activity using bioluminescent assays. Samples consisting of bottled water, conditioned in various materials (glass, PET) and subjected to different storage conditions, had no hormone-like activities whereas estrogenic activity was found in the filtered tap water. PMID:27451182

  10. Histidine-containing peptide catalysts developed by a facile library screening method.

    PubMed

    Akagawa, Kengo; Sakai, Nobutaka; Kudo, Kazuaki

    2015-02-01

    Although peptide catalysts have a high potential for the use as organocatalysts, the optimization of peptide sequences is laborious and time-consuming. To address this issue, a facile screening method for finding efficient aminocatalysts from a peptide library has been developed. In the screening for the Michael addition of a malonate to an enal, a dye-labeled product is immobilized on resin-bound peptides through reductive amination to visualize active catalysts. This procedure allows for the monitoring of the reactivity of entire peptides without modifying the resin beads beforehand. Peptides containing histidine at an appropriate position were identified by this method. A novel function of the histidyl residue, which enhances the binding of a substrate to the catalyst by capturing an iminium intermediate, was indicated. PMID:25521645

  11. Simple screening method for molds producing intracellular mycotoxins in pure cultures.

    PubMed

    Filtenborg, O; Frisvad, J C; Svendsen, J A

    1983-02-01

    A simple screening method for molds producing the intracellular mycotoxins brevianamide A, citreoviridin, cyclopiazonic acid, luteoskyrin, penitrem A, roquefortine C, sterigmatocystin, verruculogen, viomellein, and xanthomegnin was developed. After removing an agar plug from the mold culture, the mycelium on the plug is wetted with a drop of methanol-chloroform (1:2). By this treatment the intracellular mycotoxins are extracted within seconds and transferred directly to a thin-layer chromatography plate by immediately placing the plug on the plate while the mycelium is still wet. After removal of the plug, known thin-layer chromatographic procedures are carried out. The substrate (Czapek yeast autolysate agar) and growth conditions (25 degrees C for 7 days) used by Penicillium taxonomists proved suitable for the production of the mycotoxins investigated when 60 known toxigenic isolates and 865 cultures isolated from foods and feedstuffs were tested with this screening method. PMID:6338829

  12. Simple screening method for molds producing intracellular mycotoxins in pure cultures.

    PubMed Central

    Filtenborg, O; Frisvad, J C; Svendsen, J A

    1983-01-01

    A simple screening method for molds producing the intracellular mycotoxins brevianamide A, citreoviridin, cyclopiazonic acid, luteoskyrin, penitrem A, roquefortine C, sterigmatocystin, verruculogen, viomellein, and xanthomegnin was developed. After removing an agar plug from the mold culture, the mycelium on the plug is wetted with a drop of methanol-chloroform (1:2). By this treatment the intracellular mycotoxins are extracted within seconds and transferred directly to a thin-layer chromatography plate by immediately placing the plug on the plate while the mycelium is still wet. After removal of the plug, known thin-layer chromatographic procedures are carried out. The substrate (Czapek yeast autolysate agar) and growth conditions (25 degrees C for 7 days) used by Penicillium taxonomists proved suitable for the production of the mycotoxins investigated when 60 known toxigenic isolates and 865 cultures isolated from foods and feedstuffs were tested with this screening method. PMID:6338829

  13. A simple method to generate adipose stem cell-derived neurons for screening purposes.

    PubMed

    Bossio, Caterina; Mastrangelo, Rosa; Morini, Raffaella; Tonna, Noemi; Coco, Silvia; Verderio, Claudia; Matteoli, Michela; Bianco, Fabio

    2013-10-01

    Strategies involved in mesenchymal stem cell (MSC) differentiation toward neuronal cells for screening purposes are characterized by quality and quantity issues. Differentiated cells are often scarce with respect to starting undifferentiated population, and the differentiation process is usually quite long, with high risk of contamination and low yield efficiency. Here, we describe a novel simple method to induce direct differentiation of MSCs into neuronal cells, without neurosphere formation. Differentiated cells are characterized by clear morphological changes, expression of neuronal specific markers, showing functional response to depolarizing stimuli and electrophysiological properties similar to those of developing neurons. The method described here represents a valuable tool for future strategies aimed at personalized screening of therapeutic agents in vitro. PMID:23468184

  14. Predict octane numbers using a generalized interaction method

    SciTech Connect

    Twu, C.H.; Coon, J.E.

    1996-02-01

    An interaction-based correlation using a new approach can be used to predict research and motor octane numbers of gasoline blends. An ultimately detailed analysis of the gasoline cut is not necessary. This correlation can describe blending behavior over the entire composition range of gasoline cuts. The component-oriented interaction approach is general and will accurately predict, without performing additional blending studies, blending behavior for new gasoline cuts. The proposed correlation fits the data quite closely for blends of many gasoline cuts. The regression gives realistic values for binary interaction parameters between components. A unique set of binary interaction parameters was found for the equation for predicting octane number of any gasoline blend. The binary interaction parameters between components contained in gasoline cuts have been converted to binary interaction parameters between gasoline cuts through a general equation to simplify the calculations. Because of the proposed method`s accuracy, optimum allocation of components among gasoline grades can be obtained and predicted values can be used for quality control of the octane number of marketed gasolines.

  15. Using stable isotopes to monitor forms of sulfur during desulfurization processes: A quick screening method

    USGS Publications Warehouse

    Liu, Chao-Li; Hackley, Keith C.; Coleman, D.D.; Kruse, C.W.

    1987-01-01

    A method using stable isotope ratio analysis to monitor the reactivity of sulfur forms in coal during thermal and chemical desulfurization processes has been developed at the Illinois State Geological Survey. The method is based upon the fact that a significant difference exists in some coals between the 34S/32S ratios of the pyritic and organic sulfur. A screening method for determining the suitability of coal samples for use in isotope ratio analysis is described. Making these special coals available from coal sample programs would assist research groups in sorting out the complex sulfur chemistry which accompanies thermal and chemical processing of high sulfur coals. ?? 1987.

  16. Spectral method for the Cornell and screened Cornell potentials in momentum space

    NASA Astrophysics Data System (ADS)

    Chen, Jiao-Kai

    2013-10-01

    We employ the Landé subtraction method and the spectral method to solve numerically the Schrödinger equation in momentum space with the Cornell and screened Cornell potentials in a unified approach. The calculated results are excellent, because singularities, especially the double-pole singularity, possessed by potentials are handled completely. Besides, we notice that the eigenvalues yielded by numerical methods have definite convergence directions. The convergence directions of the calculated eigenvalues are abnormal when potentials are singular and become normal as singularities are manipulated properly.

  17. Generalized Hartree-Fock method for electron-atom scattering

    SciTech Connect

    Rosenberg, L.

    1997-09-01

    In the widely used Hartree-Fock procedure for atomic structure calculations, trial functions in the form of linear combinations of Slater determinants are constructed and the Rayleigh-Ritz minimum principle is applied to determine the best in that class. A generalization of this approach, applicable to low-energy electron-atom scattering, is developed here. The method is based on a unique decomposition of the scattering wave function into open- and closed-channel components, so chosen that an approximation to the closed-channel component may be obtained by adopting it as a trial function in a minimum principle, whose rigor can be maintained even when the target wave functions are imprecisely known. Given a closed-channel trial function, the full scattering function may be determined from the solution of an effective one-body Schr{umlt o}dinger equation. Alternatively, in a generalized Hartree-Fock approach, the minimum principle leads to coupled integrodifferential equations to be satisfied by the basis functions appearing in a Slater-determinant representation of the closed-channel wave function; it also provides a procedure for optimizing the choice of nonlinear parameters in a variational determination of these basis functions. Inclusion of additional Slater determinants in the closed-channel trial function allows for systematic improvement of that function, as well as the calculated scattering parameters, with the possibility of spurious singularities avoided. Electron-electron correlations can be important in accounting for long-range forces and resonances. These correlation effects can be included explicitly by suitable choice of one component of the closed-channel wave function; the remaining component may then be determined by the generalized Hartree-Fock procedure. As a simple test, the method is applied to s-wave scattering of positrons by hydrogen. {copyright} {ital 1997} {ital The American Physical Society}

  18. Method for screening prevention and control measures and technologies based on groundwater pollution intensity assessment.

    PubMed

    Li, Juan; Yang, Yang; Huan, Huan; Li, Mingxiao; Xi, Beidou; Lv, Ningqing; Wu, Yi; Xie, Yiwen; Li, Xiang; Yang, Jinjin

    2016-05-01

    This paper presents a system for determining the evaluation and gradation indices of groundwater pollution intensity (GPI). Considering the characteristics of the vadose zone and pollution sources, the system decides which anti-seepage measures should be implemented at the contaminated site. The pollution sources hazards (PSH) and groundwater intrinsic vulnerability (GIV) are graded by the revised Nemerow Pollution Index and an improved DRTAS model, respectively. GPI is evaluated and graded by a double-sided multi-factor coupling model, which is constructed by the matrix method. The contaminated sites are categorized as prior, ordinary, or common sites. From the GPI results, we develop guiding principles for preventing and removing pollution sources, procedural interruption and remediation, and end treatment and monitoring. Thus, we can select appropriate prevention and control technologies (PCT). To screen the technological schemes and optimize the traditional analytical hierarchy process (AHP), we adopt the technique for order preference by the similarity to ideal solution (TOPSIS) method. Our GPI approach and PCT screening are applied to three types of pollution sites: the refuse dump of a rare earth mine development project (a potential pollution source), a chromium slag dump, and a landfill (existing pollution sources). These three sites are identified as ordinary, prior, and ordinary sites, respectively. The anti-seepage materials at the refuse dump should perform as effectively as a 1.5-m-thick clay bed. The chromium slag dump should be preferentially treated by soil flushing and in situ chemical remediation. The landfill should be treated by natural attenuation technology. The proposed PCT screening approach was compared with conventional screening methods results at the three sites and proved feasible and effective. The proposed method can provide technical support for the monitoring and management of groundwater pollution in China. PMID:26878632

  19. On the Use of Accelerated Aging Methods for Screening High Temperature Polymeric Composite Materials

    NASA Technical Reports Server (NTRS)

    Gates, Thomas S.; Grayson, Michael A.

    1999-01-01

    A rational approach to the problem of accelerated testing of high temperature polymeric composites is discussed. The methods provided are considered tools useful in the screening of new materials systems for long-term application to extreme environments that include elevated temperature, moisture, oxygen, and mechanical load. The need for reproducible mechanisms, indicator properties, and real-time data are outlined as well as the methodologies for specific aging mechanisms.

  20. Screening of plant extracts for antioxidant activity: a comparative study on three testing methods.

    PubMed

    Koleva, Irina I; van Beek, Teris A; Linssen, Jozef P H; de Groot, Aede; Evstatieva, Lyuba N

    2002-01-01

    Three methods widely employed in the evaluation of antioxidant activity, namely 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method, static headspace gas chromatography (HS-GC) and beta-carotene bleaching test (BCBT), have been compared with regard to their application in the screening of plant extracts. The strengths and limitations of each method have been illustrated by testing a number of extracts, of differing polarity, from plants of the genus Sideritis, and two known antioxidants (butylated hydroxytoluene and rosmarinic acid). The sample polarity was important for the exhibited activity in the BCBT and HS-GC methods but not for the DPPH method. The complex composition of the extracts and partition phenomena affected their activity in each assay. The value of the BCBT method appears to be limited to less polar samples. Although slow, the HS-GC method is preferable for assessing the antioxidant inhibitory properties on the formation of unwanted secondary volatile products. Being rapid, simple and independent of sample polarity, the DPPH method is very convenient for the quick screening of many samples for radical scavenging activity. PMID:11899609

  1. Novel Simplified and Rapid Method for Screening and Isolation of Polyunsaturated Fatty Acids Producing Marine Bacteria

    PubMed Central

    Tilay, Ashwini; Annapure, Uday

    2012-01-01

    Bacterial production of polyunsaturated fatty acids (PUFAs) is a potential biotechnological approach for production of valuable nutraceuticals. Reliable method for screening of number of strains within short period of time is great need. Here, we report a novel simplified method for screening and isolation of PUFA-producing bacteria by direct visualization using the H2O2-plate assay. The oxidative stability of PUFAs in growing bacteria towards added H2O2 is a distinguishing characteristic between the PUFAs producers (no zone of inhibition) and non-PUFAs producers (zone of inhibition) by direct visualization. The confirmation of assay results was performed by injecting fatty acid methyl esters (FAMEs) produced by selected marine bacteria to Gas Chromatography-Mass Spectrometry (GCMS). To date, this assay is the most effective, inexpensive, and specific method for bacteria producing PUFAs and shows drastically reduction in the number of samples thus saves the time, effort, and cost of screening and isolating strains of bacterial PUFAs producers. PMID:22934188

  2. Terbium-sensitised luminescence screening method for fluoroquinolones in beef serum.

    PubMed

    Schneider, Marilyn J; Yun, Limei; Lehotay, Steven J

    2013-01-01

    Enrofloxacin and danofloxacin are the only fluoroquinolone antibiotics approved for use in cattle in the United States. Microbial screening methods commonly used for monitoring veterinary drug residues are not sensitive or selective for fluoroquinolones. In this work, a luminescence-based screening assay was developed to detect fluoroquinolones in beef serum. This approach takes advantage of the DNA-enhanced luminescence signal of a fluoroquinolone-Tb⁺³ complex. In this method, serum samples were extracted with acidified acetonitrile in the presence of magnesium sulfate. After centrifugation, evaporation of the supernatant was followed by dissolution of the residue in buffer and filtration. Addition of Tb⁺³ and DNA then allowed a reading of the luminescence signal. The technique was illustrated using enrofloxacin, and provided good recoveries (73-88%) at 25, 50 and 100 ng ml⁻¹, with reasonable RSDs averaging at 11%. The LOD was 2.5 ng ml⁻¹ based on the variability of response of control serum samples from 18 different steers. The method provided no false-positive or false-negative results while screening blind samples for enrofloxacin and was demonstrated to be quantitative over a range of 0-100 ng ml⁻¹. PMID:23472630

  3. Population-based study of DNA image cytometry as screening method for esophageal cancer

    PubMed Central

    Zhao, Lin; Wei, Wen-Qiang; Zhao, De-Li; Hao, Chang-Qing; Lin, Dong-Mei; Pan, Qin-Jing; Li, Xin-Qing; Lei, Fu-Hua; Wang, Jin-Wu; Wang, Guo-Qing; Shang, Qi; Qiao, You-Lin

    2012-01-01

    AIM: To explore the DNA image cytometry (DNA-ICM) technique as a primary screening method for esophageal squamous precancerous lesions. METHODS: This study was designed as a population-based screening study. A total of 582 local residents aged 40 years-69 years were recruited from Linzhou in Henan and Feicheng in Shandong. However, only 452 subjects had results of liquid-based cytology, DNA-ICM and pathology. The sensitivity and specificity of DNA-ICM were calculated and compared with liquid-based cytology in moderate dysplasia or worse. RESULTS: Sensitivities of DNA-ICM ranging from at least 1 to 4 aneuploid cells were 90.91%, 86.36%, 79.55% and 77.27%, respectively, which were better than that of liquid-based cytology (75%). Specificities of DNA-ICM were 70.83%, 84.07%, 92.65% and 96.81%, but the specificity of liquid-based cytology was 91.91%. The sensitivity and specificity of a combination of liquid-based cytology and DNA-ICM were 84.09% and 85.78%, respectively. CONCLUSION: It is possible to use DNA-ICM technique as a primary screening method for esophageal squamous precancerous lesions. PMID:22294844

  4. A time-scale sensitometric method for evaluating screen-film systems.

    PubMed

    Góes, E G; Pelá, C A; Ghilardi, N T

    1997-10-01

    An x-ray sensitometer is used to measure the characteristic curve of radiographic films exposed with fluorescent intensifying screens. The series of relative exposures, necessary to cover the full density range of the film, can be obtained by either time-scale or intensity-scale sensitometric methods. We have developed a convenient method of exposing film-screen systems for time-scale sensitometry. In this method, during exposure the x-ray kilovoltage, tube current and x-ray intensity remain constant and a geometric series of exposures of the film is modulated by varying the exposure time. This time variation can be obtained when a lead disc with different sector openings is rotated in front of the film system by a stepping motor. The conditions normally used are 70 kVp x-rays, 3.5 mm Al total filtration at the tube, and 2.4 m focal spot-film distance. This exposure latitude gives a complete characteristic curve of film-screen systems. PMID:9364589

  5. A time-scale sensitometric method for evaluating screen - film systems

    NASA Astrophysics Data System (ADS)

    Góes, E. G.; Pelá, C. A.; Ghilardi, Netto T.

    1997-10-01

    An x-ray sensitometer is used to measure the characteristic curve of radiographic films exposed with fluorescent intensifying screens. The series of relative exposures, necessary to cover the full density range of the film, can be obtained by either time-scale or intensity-scale sensitometric methods. We have developed a convenient method of exposing film - screen systems for time-scale sensitometry. In this method, during exposure the x-ray kilovoltage, tube current and x-ray intensity remain constant and a geometric series of exposures of the film is modulated by varying the exposure time. This time variation can be obtained when a lead disc with different sector openings is rotated in front of the film system by a stepping motor. The conditions normally used are 70 kVp x-rays, 3.5 mm Al total filtration at the tube, and 2.4 m focal spot - film distance. This exposure latitude gives a complete characteristic curve of film - screen systems.

  6. Parallel production and verification of protein products using a novel high-throughput screening method.

    PubMed

    Tegel, Hanna; Yderland, Louise; Boström, Tove; Eriksson, Cecilia; Ukkonen, Kaisa; Vasala, Antti; Neubauer, Peter; Ottosson, Jenny; Hober, Sophia

    2011-08-01

    Protein production and analysis in a parallel fashion is today applied in laboratories worldwide and there is a great need to improve the techniques and systems used for this purpose. In order to save time and money, a fast and reliable screening method for analysis of protein production and also verification of the protein product is desired. Here, a micro-scale protocol for the parallel production and screening of 96 proteins in plate format is described. Protein capture was achieved using immobilized metal affinity chromatography and the product was verified using matrix-assisted laser desorption ionization time-of-flight MS. In order to obtain sufficiently high cell densities and product yield in the small-volume cultivations, the EnBase® cultivation technology was applied, which enables cultivation in as small volumes as 150 μL. Here, the efficiency of the method is demonstrated by producing 96 human, recombinant proteins, both in micro-scale and using a standard full-scale protocol and comparing the results in regard to both protein identity and sample purity. The results obtained are highly comparable to those acquired through employing standard full-scale purification protocols, thus validating this method as a successful initial screening step before protein production at a larger scale. PMID:21681961

  7. A new antiviral screening method that simultaneously detects viral replication, cell viability, and cell toxicity.

    PubMed

    Matza-Porges, Sigal; Eisen, Kobi; Ibrahim, Hadeel; Haberman, Adva; Fridlender, Bertold; Joseph, Gili

    2014-11-01

    Viruses cause a variety of illnesses in humans, yet only a few antiviral drugs have been developed; thus, new antiviral drugs are urgently needed. Plants could be a good source of antiviral drugs, they do not have mobility and can only defend themselves by producing compounds against pathogens such as viruses in their own fix environment. These compounds may have the potential to inhibit animal and human viruses as well. In this study, a fast and reliable method for screening plant extracts for specific antiviral activity against Herpes simplex virus type-1 (HSV-1) was developed. This method distinguishes between host cell death due to infectivity and multiplicity of the virus versus toxicity of the plant extract. Extracts from 80 plant and plant organs were screened using this approach. Six plant extracts showed potential to exert specific HSV-1 growth inhibition activity. In two cases, different organs from the same plant showed similar active results. With this method it is possible to screen a large number of extracts in a rapid and accurate way to detect antiviral substances against HSV-I and other viruses. PMID:25152527

  8. Amyloid oligomer structure characterization from simulations: A general method

    SciTech Connect

    Nguyen, Phuong H.; Li, Mai Suan

    2014-03-07

    Amyloid oligomers and plaques are composed of multiple chemically identical proteins. Therefore, one of the first fundamental problems in the characterization of structures from simulations is the treatment of the degeneracy, i.e., the permutation of the molecules. Second, the intramolecular and intermolecular degrees of freedom of the various molecules must be taken into account. Currently, the well-known dihedral principal component analysis method only considers the intramolecular degrees of freedom, and other methods employing collective variables can only describe intermolecular degrees of freedom at the global level. With this in mind, we propose a general method that identifies all the structures accurately. The basis idea is that the intramolecular and intermolecular states are described in terms of combinations of single-molecule and double-molecule states, respectively, and the overall structures of oligomers are the product basis of the intramolecular and intermolecular states. This way, the degeneracy is automatically avoided. The method is illustrated on the conformational ensemble of the tetramer of the Alzheimer's peptide Aβ{sub 9−40}, resulting from two atomistic molecular dynamics simulations in explicit solvent, each of 200 ns, starting from two distinct structures.

  9. Generalized Bootstrap Method for Assessment of Uncertainty in Semivariogram Inference

    USGS Publications Warehouse

    Olea, R.A.; Pardo-Iguzquiza, E.

    2011-01-01

    The semivariogram and its related function, the covariance, play a central role in classical geostatistics for modeling the average continuity of spatially correlated attributes. Whereas all methods are formulated in terms of the true semivariogram, in practice what can be used are estimated semivariograms and models based on samples. A generalized form of the bootstrap method to properly model spatially correlated data is used to advance knowledge about the reliability of empirical semivariograms and semivariogram models based on a single sample. Among several methods available to generate spatially correlated resamples, we selected a method based on the LU decomposition and used several examples to illustrate the approach. The first one is a synthetic, isotropic, exhaustive sample following a normal distribution, the second example is also a synthetic but following a non-Gaussian random field, and a third empirical sample consists of actual raingauge measurements. Results show wider confidence intervals than those found previously by others with inadequate application of the bootstrap. Also, even for the Gaussian example, distributions for estimated semivariogram values and model parameters are positively skewed. In this sense, bootstrap percentile confidence intervals, which are not centered around the empirical semivariogram and do not require distributional assumptions for its construction, provide an achieved coverage similar to the nominal coverage. The latter cannot be achieved by symmetrical confidence intervals based on the standard error, regardless if the standard error is estimated from a parametric equation or from bootstrap. ?? 2010 International Association for Mathematical Geosciences.

  10. Logically rectangular mixed methods for Darcy flow on general geometry

    SciTech Connect

    Arbogast, T.; Keenan, P.T.; Wheeler, M.F.; Yotov, I.

    1995-12-31

    The authors consider an expanded mixed finite element formulation (cell centered finite difference) for Darcy flow with a tensor absolute permeability. The reservoir can be geometrically general with internal features, but the computational domain is rectangular. The method is defined on a curvilinear grid that need not be orthogonal, obtained by mapping the rectangular, computational grid. The original flow problem becomes a similar problem with a modified permeability on the computational grid. Quadrature rules turn the mixed method into a cell-centered finite difference method with a 9 point stencil in 2-D and 19 in 3-D. As shown by theory and experiment, if the modified permeability on the computational domain is smooth, then the convergence rate is optimal and both pressure and velocity are superconvergent at certain points. If not, Lagrange multiplier pressures can be introduced on boundaries of elements so that optimal convergence is retained. This modification presents only small changes in the solution process; in fact, the same parallel domain decomposition algorithms can be applied with little or no change to the code if the modified permeability is smooth over the subdomains. This Lagrange multiplier procedure can be used to extend the difference scheme to multi-block domains, and to give a coupling with unstructured grids. In all cases, the mixed formulation is locally conservative. Computational results illustrate the advantage and convergence of this method.

  11. Risks of Breast Cancer Screening

    MedlinePlus

    ... of Breast & Gynecologic Cancers Breast Cancer Screening Research Breast Cancer Screening (PDQ®)–Patient Version What is screening? Go ... cancer screening: Cancer Screening Overview General Information About Breast Cancer Key Points Breast cancer is a disease in ...

  12. Density functional theory based generalized effective fragment potential method

    SciTech Connect

    Nguyen, Kiet A. E-mail: ruth.pachter@wpafb.af.mil; Pachter, Ruth E-mail: ruth.pachter@wpafb.af.mil; Day, Paul N.

    2014-06-28

    We present a generalized Kohn-Sham (KS) density functional theory (DFT) based effective fragment potential (EFP2-DFT) method for the treatment of solvent effects. Similar to the original Hartree-Fock (HF) based potential with fitted parameters for water (EFP1) and the generalized HF based potential (EFP2-HF), EFP2-DFT includes electrostatic, exchange-repulsion, polarization, and dispersion potentials, which are generated for a chosen DFT functional for a given isolated molecule. The method does not have fitted parameters, except for implicit parameters within a chosen functional and the dispersion correction to the potential. The electrostatic potential is modeled with a multipolar expansion at each atomic center and bond midpoint using Stone's distributed multipolar analysis. The exchange-repulsion potential between two fragments is composed of the overlap and kinetic energy integrals and the nondiagonal KS matrices in the localized molecular orbital basis. The polarization potential is derived from the static molecular polarizability. The dispersion potential includes the intermolecular D3 dispersion correction of Grimme et al. [J. Chem. Phys. 132, 154104 (2010)]. The potential generated from the CAMB3LYP functional has mean unsigned errors (MUEs) with respect to results from coupled cluster singles, doubles, and perturbative triples with a complete basis set limit (CCSD(T)/CBS) extrapolation, of 1.7, 2.2, 2.0, and 0.5 kcal/mol, for the S22, water-benzene clusters, water clusters, and n-alkane dimers benchmark sets, respectively. The corresponding EFP2-HF errors for the respective benchmarks are 2.41, 3.1, 1.8, and 2.5 kcal/mol. Thus, the new EFP2-DFT-D3 method with the CAMB3LYP functional provides comparable or improved results at lower computational cost and, therefore, extends the range of applicability of EFP2 to larger system sizes.

  13. Flutter and Divergence Analysis using the Generalized Aeroelastic Analysis Method

    NASA Technical Reports Server (NTRS)

    Edwards, John W.; Wieseman, Carol D.

    2003-01-01

    The Generalized Aeroelastic Analysis Method (GAAM) is applied to the analysis of three well-studied checkcases: restrained and unrestrained airfoil models, and a wing model. An eigenvalue iteration procedure is used for converging upon roots of the complex stability matrix. For the airfoil models, exact root loci are given which clearly illustrate the nature of the flutter and divergence instabilities. The singularities involved are enumerated, including an additional pole at the origin for the unrestrained airfoil case and the emergence of an additional pole on the positive real axis at the divergence speed for the restrained airfoil case. Inconsistencies and differences among published aeroelastic root loci and the new, exact results are discussed and resolved. The generalization of a Doublet Lattice Method computer code is described and the code is applied to the calculation of root loci for the wing model for incompressible and for subsonic flow conditions. The error introduced in the reduction of the singular integral equation underlying the unsteady lifting surface theory to a linear algebraic equation is discussed. Acknowledging this inherent error, the solutions of the algebraic equation by GAAM are termed 'exact.' The singularities of the problem are discussed and exponential series approximations used in the evaluation of the kernel function shown to introduce a dense collection of poles and zeroes on the negative real axis. Again, inconsistencies and differences among published aeroelastic root loci and the new 'exact' results are discussed and resolved. In all cases, aeroelastic flutter and divergence speeds and frequencies are in good agreement with published results. The GAAM solution procedure allows complete control over Mach number, velocity, density, and complex frequency. Thus all points on the computed root loci can be matched-point, consistent solutions without recourse to complex mode tracking logic or dataset interpolation, as in the k and p

  14. Density functional theory based generalized effective fragment potential method.

    PubMed

    Nguyen, Kiet A; Pachter, Ruth; Day, Paul N

    2014-06-28

    We present a generalized Kohn-Sham (KS) density functional theory (DFT) based effective fragment potential (EFP2-DFT) method for the treatment of solvent effects. Similar to the original Hartree-Fock (HF) based potential with fitted parameters for water (EFP1) and the generalized HF based potential (EFP2-HF), EFP2-DFT includes electrostatic, exchange-repulsion, polarization, and dispersion potentials, which are generated for a chosen DFT functional for a given isolated molecule. The method does not have fitted parameters, except for implicit parameters within a chosen functional and the dispersion correction to the potential. The electrostatic potential is modeled with a multipolar expansion at each atomic center and bond midpoint using Stone's distributed multipolar analysis. The exchange-repulsion potential between two fragments is composed of the overlap and kinetic energy integrals and the nondiagonal KS matrices in the localized molecular orbital basis. The polarization potential is derived from the static molecular polarizability. The dispersion potential includes the intermolecular D3 dispersion correction of Grimme et al. [J. Chem. Phys. 132, 154104 (2010)]. The potential generated from the CAMB3LYP functional has mean unsigned errors (MUEs) with respect to results from coupled cluster singles, doubles, and perturbative triples with a complete basis set limit (CCSD(T)/CBS) extrapolation, of 1.7, 2.2, 2.0, and 0.5 kcal/mol, for the S22, water-benzene clusters, water clusters, and n-alkane dimers benchmark sets, respectively. The corresponding EFP2-HF errors for the respective benchmarks are 2.41, 3.1, 1.8, and 2.5 kcal/mol. Thus, the new EFP2-DFT-D3 method with the CAMB3LYP functional provides comparable or improved results at lower computational cost and, therefore, extends the range of applicability of EFP2 to larger system sizes. PMID:24985612

  15. Effect of screening and lifestyle counselling on incidence of ischaemic heart disease in general population: Inter99 randomised trial

    PubMed Central

    Jacobsen, Rikke Kart; Toft, Ulla; Aadahl, Mette; Glümer, Charlotte; Pisinger, Charlotta

    2014-01-01

    Objective To investigate the effect of systematic screening for risk factors for ischaemic heart disease followed by repeated lifestyle counselling on the 10 year development of ischaemic heart disease at a population level. Design Randomised controlled community based trial. Setting Suburbs of Copenhagen, Denmark Participants 59 616 people aged 30-60 years randomised with different age and sex randomisation ratios to an intervention group (n=11 629) and a control group (n=47 987). Intervention The intervention group was invited for screening, risk assessment, and lifestyle counselling up to four times over a five year period. All participants with an unhealthy lifestyle had individually tailored lifestyle counselling at all visits (at baseline and after one and three years); those at high risk of ischaemic heart disease, according to predefined criteria, were furthermore offered six sessions of group based lifestyle counselling on smoking cessation, diet, and physical activity. After five years all were invited for a final counselling session. Participants were referred to their general practitioner for medical treatment, if relevant. The control group was not invited for screening. Main outcome measures The primary outcome measure was incidence of ischaemic heart disease in the intervention group compared with the control group. Secondary outcome measures were stroke, combined events (ischaemic heart disease, stroke, or both), and mortality. Results 6091 (52.4%) people in the intervention group participated at baseline. Among 5978 people eligible at five year follow-up (59 died and 54 emigrated), 4028 (67.4%) attended. A total of 3163 people died in the 10 year follow-up period. Among 58 308 without a history of ischaemic heart disease at baseline, 2782 developed ischaemic heart disease. Among 58 940 without a history of stroke at baseline, 1726 developed stroke. No significant difference was seen between the intervention and control groups in the

  16. Study on measurement method for projectile location based on light screen

    NASA Astrophysics Data System (ADS)

    Han, Feng; Liu, QunHua; Sun, GuoBin

    2008-09-01

    In weapon-ammunition system, firing accuracy of projectile is major characteristic parameter weighing fire effect and capability of weapon-ammunition system for target. At present, firing accuracy of projectile is obtained by measuring the two-dimensional coordinates of projectile for target. In order to measure the parameters of two-dimensional coordinates of projectile for target, a new type of measurement system is proposed. The measurement system is composed of four high sensitivity light screens (known as target) with special geometrical frame. Light source of the screens is formed by special infrared LED array. The PIN infrared photodiodes array is used as the sensors. The longest effective distance between light source and sensors is 4m. It is impossible to achieve using traditional methods. Four light screens and high-precision timers are combined in order to acquire the value of time when the projectile flies across the position of four light screens. The real-time data acquirement and processing and display of two-dimensional coordinates and the projectile velocity can be realized. The principle of measurement system and the design of high sensitivity light screen are introduced emphatically. The measurement system was verified by using five kinds of small caliber pellets. As compared with the paper target sheet, the measurement system designed can meet the demand of check-up test of gun, bullet and ammunition. The firing testing in the target field has proved that the measurement system has the advantages of simple construction, easy operation and high precision and high sensitivity.

  17. Equivalence of the generalized Lie-Hori method and the method of averaging. [in celestial mechanics

    NASA Technical Reports Server (NTRS)

    Ahmed, A. H.; Tapley, B. D.

    1984-01-01

    In this investigation, a comparison is made of two methods for developing perturbation theories for non-canonical dynamical systems. The methods compared are the generalized Lie-Hori method and the method of averaging. In the comparison presented here, the equivalence of the methods up to the second order in the small parameter is shown. However, the approach used can be extended to demonstrate the equivalence for higher orders. To illustrate the equivalence Duffing's equation, the van der Pol equation and the oscillator with quadratic damping problem are solved using each method.

  18. High-Solids Enzymatic Saccharification Screening Method for Lignocellulosic Biomass (Poster)

    SciTech Connect

    Roche, C. M.; Stickel, J. J.

    2009-05-01

    The ability to screen new biomass pretreatments and advanced enzyme systems at process-relevant conditions is key to developing economically viable lignocellulosic ethanol. While much research is being invested in developing pretreatment technologies and enzyme systems that will more efficiently convert cellulosic biomass to sugars, the current standard reactor vessel, a shake flask, that is used for screening enzymatic saccharification of cellulosic biomass is inadequate at high-solids conditions. Shake flasks do not provide adequate mixing at high solids conditions. In this work, a roller bottle reactor was identified as a small-scale high-solids saccharification reaction vessel, and a method was developed for use in screening both pretreated biomass and enzyme systems at process-relevant conditions. This new method addresses mixing issues observed in high-solids saccharifications. In addition, yield calculations from sugar concentrations on a mass basis were used to account for the two-phase nature of the saccharification slurry, which eliminates discontinuities in comparing high-solids to low-solids saccharifications that occur when using concentrations on a volume basis. The roller bottle reactors out-performed the shake flasks by 5% for an initial insoluble solids loading of 15% and 140% for an initial soluble solids loading of 30%. The reactor system and method was compared at bench and floor scales and determined to be scalable for initial insoluble solids loading in the range of 15% to 30%. Pretreatment and enzyme screening results indicate that mid severity pretreated biomass is more digestible than the low and high severity biomass and GC220 is a superior enzyme to Spezyme CP.

  19. Primary prevention in general practice – views of German general practitioners: a mixed-methods study

    PubMed Central

    2014-01-01

    Background Policy efforts focus on a reorientation of health care systems towards primary prevention. To guide such efforts, we analyzed the role of primary prevention in general practice and general practitioners’ (GPs) attitudes toward primary prevention. Methods Mixed-method study including a cross-sectional survey of all community-based GPs and focus groups in a sample of GPs who collaborated with the Institute of General Practice in Berlin, Germany in 2011. Of 1168 GPs 474 returned the mail survey. Fifteen GPs participated in focus group discussions. Survey and interview guidelines were developed and tested to assess and discuss beliefs, attitudes, and practices regarding primary prevention. Results Most respondents considered primary prevention within their realm of responsibility (70%). Primary prevention, especially physical activity, healthy eating, and smoking cessation, was part of the GPs’ health care recommendations if they thought it was indicated. Still a quarter of survey respondents discussed reduction of alcohol consumption with their patients infrequently even when they thought it was indicated. Similarly 18% claimed that they discuss smoking cessation only sometimes. The focus groups revealed that GPs were concerned about the detrimental effects an uninvited health behavior suggestion could have on patients and were hesitant to take on the role of “health policing”. GPs saw primary prevention as the responsibility of multiple actors in a network of societal and municipal institutions. Conclusions The mixed-method study showed that primary prevention approaches such as lifestyle counseling is not well established in primary care. GPs used a selective approach to offer preventive advice based upon indication. GPs had a strong sense that a universal prevention approach carried the potential to destroy a good patient-physician relationship. Other approaches to public health may be warranted such as a multisectoral approach to population

  20. A general moment expansion method for stochastic kinetic models

    NASA Astrophysics Data System (ADS)

    Ale, Angelique; Kirk, Paul; Stumpf, Michael P. H.

    2013-05-01

    Moment approximation methods are gaining increasing attention for their use in the approximation of the stochastic kinetics of chemical reaction systems. In this paper we derive a general moment expansion method for any type of propensities and which allows expansion up to any number of moments. For some chemical reaction systems, more than two moments are necessary to describe the dynamic properties of the system, which the linear noise approximation is unable to provide. Moreover, also for systems for which the mean does not have a strong dependence on higher order moments, moment approximation methods give information about higher order moments of the underlying probability distribution. We demonstrate the method using a dimerisation reaction, Michaelis-Menten kinetics and a model of an oscillating p53 system. We show that for the dimerisation reaction and Michaelis-Menten enzyme kinetics system higher order moments have limited influence on the estimation of the mean, while for the p53 system, the solution for the mean can require several moments to converge to the average obtained from many stochastic simulations. We also find that agreement between lower order moments does not guarantee that higher moments will agree. Compared to stochastic simulations, our approach is numerically highly efficient at capturing the behaviour of stochastic systems in terms of the average and higher moments, and we provide expressions for the computational cost for different system sizes and orders of approximation. We show how the moment expansion method can be employed to efficiently quantify parameter sensitivity. Finally we investigate the effects of using too few moments on parameter estimation, and provide guidance on how to estimate if the distribution can be accurately approximated using only a few moments.

  1. A General Method of Empirical Q-matrix Validation.

    PubMed

    de la Torre, Jimmy; Chiu, Chia-Yi

    2016-06-01

    In contrast to unidimensional item response models that postulate a single underlying proficiency, cognitive diagnosis models (CDMs) posit multiple, discrete skills or attributes, thus allowing CDMs to provide a finer-grained assessment of examinees' test performance. A common component of CDMs for specifying the attributes required for each item is the Q-matrix. Although construction of Q-matrix is typically performed by domain experts, it nonetheless, to a large extent, remains a subjective process, and misspecifications in the Q-matrix, if left unchecked, can have important practical implications. To address this concern, this paper proposes a discrimination index that can be used with a wide class of CDM subsumed by the generalized deterministic input, noisy "and" gate model to empirically validate the Q-matrix specifications by identifying and replacing misspecified entries in the Q-matrix. The rationale for using the index as the basis for a proposed validation method is provided in the form of mathematical proofs to several relevant lemmas and a theorem. The feasibility of the proposed method was examined using simulated data generated under various conditions. The proposed method is illustrated using fraction subtraction data. PMID:25943366

  2. The Exoplanet Census: A General Method Applied to Kepler

    NASA Astrophysics Data System (ADS)

    Youdin, Andrew N.

    2011-11-01

    We develop a general method to fit the underlying planetary distribution function (PLDF) to exoplanet survey data. This maximum likelihood method accommodates more than one planet per star and any number of planet or target star properties. We apply the method to announced Kepler planet candidates that transit solar-type stars. The Kepler team's estimates of the detection efficiency are used and are shown to agree with theoretical predictions for an ideal transit survey. The PLDF is fit to a joint power law in planet radius, down to 0.5 R ⊕, and orbital period, up to 50 days. The estimated number of planets per star in this sample is ~0.7-1.4, where the range covers systematic uncertainties in the detection efficiency. To analyze trends in the PLDF we consider four planet samples, divided between shorter and longer periods at 7 days and between large and small radii at 3 R ⊕. The size distribution changes appreciably between these four samples, revealing a relative deficit of ~3 R ⊕ planets at the shortest periods. This deficit is suggestive of preferential evaporation and sublimation of Neptune- and Saturn-like planets. If the trend and explanation hold, it would be spectacular observational support of the core accretion and migration hypotheses, and would allow refinement of these theories.

  3. THE EXOPLANET CENSUS: A GENERAL METHOD APPLIED TO KEPLER

    SciTech Connect

    Youdin, Andrew N.

    2011-11-20

    We develop a general method to fit the underlying planetary distribution function (PLDF) to exoplanet survey data. This maximum likelihood method accommodates more than one planet per star and any number of planet or target star properties. We apply the method to announced Kepler planet candidates that transit solar-type stars. The Kepler team's estimates of the detection efficiency are used and are shown to agree with theoretical predictions for an ideal transit survey. The PLDF is fit to a joint power law in planet radius, down to 0.5 R{sub Circled-Plus }, and orbital period, up to 50 days. The estimated number of planets per star in this sample is {approx}0.7-1.4, where the range covers systematic uncertainties in the detection efficiency. To analyze trends in the PLDF we consider four planet samples, divided between shorter and longer periods at 7 days and between large and small radii at 3 R{sub Circled-Plus }. The size distribution changes appreciably between these four samples, revealing a relative deficit of {approx}3 R{sub Circled-Plus} planets at the shortest periods. This deficit is suggestive of preferential evaporation and sublimation of Neptune- and Saturn-like planets. If the trend and explanation hold, it would be spectacular observational support of the core accretion and migration hypotheses, and would allow refinement of these theories.

  4. Extended generalized Lagrangian multipliers for magnetohydrodynamics using adaptive multiresolution methods

    NASA Astrophysics Data System (ADS)

    Domingues, Margarete O.; Gomes, Anna Karina F.; Mendes, Odim; Schneider, Kai

    2013-10-01

    We present a new adaptive multiresoltion method for the numerical simulation of ideal magnetohydrodynamics. The governing equations, i.e., the compressible Euler equations coupled with the Maxwell equations are discretized using a finite volume scheme on a two-dimensional Cartesian mesh. Adaptivity in space is obtained via multiresolution analysis, which allows the reliable introduction of a locally refined mesh while controlling the error. The explicit time discretization uses a compact Runge-Kutta method for local time stepping and an embedded Runge-Kutta scheme for automatic time step control. An extended generalized Lagrangian multiplier approach with the mixed hyperbolic-parabolic correction type is used to control the incompressibility of the magnetic field. Applications to a two-dimensional problem illustrate the properties of the method. Memory savings and numerical divergences of the magnetic field are reported and the accuracy of the adaptive computations is assessed by comparing with the available exact solution. This work was supported by the contract SiCoMHD (ANR-Blanc 2011-045).

  5. Increasing chlamydia screening tests in general practice: a modified Zelen prospective Cluster Randomised Controlled Trial evaluating a complex intervention based on the Theory of Planned Behaviour

    PubMed Central

    McNulty, Cliodna A M; Hogan, Angela H; Ricketts, Ellie J; Wallace, Louise; Oliver, Isabel; Campbell, Rona; Kalwij, Sebastian; O'Connell, Elaine; Charlett, Andre

    2014-01-01

    Objective To determine if a structured complex intervention increases opportunistic chlamydia screening testing of patients aged 15–24 years attending English general practitioner (GP) practices. Methods A prospective, Cluster Randomised Controlled Trial with a modified Zelen design involving 160 practices in South West England in 2010. The intervention was based on the Theory of Planned Behaviour (TPB). It comprised of practice-based education with up to two additional contacts to increase the importance of screening to GP staff and their confidence to offer tests through skill development (including videos). Practical resources (targets, posters, invitation cards, computer reminders, newsletters including feedback) aimed to actively influence social cognitions of staff, increasing their testing intention. Results Data from 76 intervention and 81 control practices were analysed. In intervention practices, chlamydia screening test rates were 2.43/100 15–24-year-olds registered preintervention, 4.34 during intervention and 3.46 postintervention; controls testing rates were 2.61/100 registered patients prior intervention, 3.0 during intervention and 2.82 postintervention. During the intervention period, testing in intervention practices was 1.76 times as great (CI 1.24 to 2.48) as controls; this persisted for 9 months postintervention (1.57 times as great, CI 1.27 to 2.30). Chlamydia infections detected increased in intervention practices from 2.1/1000 registered 15–24-year-olds prior intervention to 2.5 during the intervention compared with 2.0 and 2.3/1000 in controls (Estimated Rate Ratio intervention versus controls 1.4 (CI 1.01 to 1.93). Conclusions This complex intervention doubled chlamydia screening tests in fully engaged practices. The modified Zelen design gave realistic measures of practice full engagement (63%) and efficacy of this educational intervention in general practice; it should be used more often. Trial registration The trial was

  6. Evaluation of a Fluorescence-Based Method for Antibabesial Drug Screening

    PubMed Central

    Guswanto, Azirwan; Sivakumar, Thillaiampalam; Rizk, Mohamed Abdo; Elsayed, Shimaa Abd Elsalam; Youssef, Mohamed Ahmed; ElSaid, ElSaid El Shirbini; Yokoyama, Naoaki

    2014-01-01

    In vitro evaluation of chemotherapeutic agents against Babesia and Theileria parasites has become routine, and the effectiveness of these chemicals is usually determined by comparing the parasitemia dynamics of untreated and treated parasites. Although microscopy is widely used to calculate parasitemia, several disadvantages are associated with this technique. The present study evaluated a fluorescence-based method using SYBR green I stain (SG I) to screen antibabesial agents in in vitro cultures of Babesia bovis. The linearity between relative fluorescence units (RFU) and parasitemia was found to be well correlated with a 0.9944 goodness-of-fit (r2) value. Subsequently, 50% inhibitory concentration (IC50) values were calculated for 3 antiprotozoan agents, diminazene aceturate, nimbolide, and gedunin, by this method. For diminazene aceturate and nimbolide, the IC50s determined by the fluorescence-based method (408 nM and 8.13 μM, respectively) and microscopy (400.3 nM and 9.4 μM, respectively) were in agreement. Furthermore, the IC50 of gedunin determined by the fluorescence-based method (19 μM) was similar to the recently described microscopy-based value (21.7 μM) for B. bovis. Additionally, the Z′ factor (0.80 to 0.90), signal-to-noise (S/N) ratio (44.15 to 87.64), coefficient of variation at the maximum signal (%CVmax) (0.50 to 2.85), and coefficient of variation at the minimum signal (%CVmin) (1.23 to 2.21) calculated for the fluorescence method using diminazene aceturate were comparable to those previously determined in malaria research for this assay. These findings suggest that the fluorescence-based method might be useful for antibabesial drug screening and may have potential to be developed into a high-throughput screening (HTS) assay. PMID:24914124

  7. Evaluation of a fluorescence-based method for antibabesial drug screening.

    PubMed

    Guswanto, Azirwan; Sivakumar, Thillaiampalam; Rizk, Mohamed Abdo; Elsayed, Shimaa Abd Elsalam; Youssef, Mohamed Ahmed; ElSaid, ElSaid El Shirbini; Yokoyama, Naoaki; Igarashi, Ikuo

    2014-08-01

    In vitro evaluation of chemotherapeutic agents against Babesia and Theileria parasites has become routine, and the effectiveness of these chemicals is usually determined by comparing the parasitemia dynamics of untreated and treated parasites. Although microscopy is widely used to calculate parasitemia, several disadvantages are associated with this technique. The present study evaluated a fluorescence-based method using SYBR green I stain (SG I) to screen antibabesial agents in in vitro cultures of Babesia bovis. The linearity between relative fluorescence units (RFU) and parasitemia was found to be well correlated with a 0.9944 goodness-of-fit (r(2)) value. Subsequently, 50% inhibitory concentration (IC50) values were calculated for 3 antiprotozoan agents, diminazene aceturate, nimbolide, and gedunin, by this method. For diminazene aceturate and nimbolide, the IC(50)s determined by the fluorescence-based method (408 nM and 8.13 μM, respectively) and microscopy (400.3 nM and 9.4 μM, respectively) were in agreement. Furthermore, the IC50 of gedunin determined by the fluorescence-based method (19 μM) was similar to the recently described microscopy-based value (21.7 μM) for B. bovis. Additionally, the Z' factor (0.80 to 0.90), signal-to-noise (S/N) ratio (44.15 to 87.64), coefficient of variation at the maximum signal (%CVmax) (0.50 to 2.85), and coefficient of variation at the minimum signal (%CVmin) (1.23 to 2.21) calculated for the fluorescence method using diminazene aceturate were comparable to those previously determined in malaria research for this assay. These findings suggest that the fluorescence-based method might be useful for antibabesial drug screening and may have potential to be developed into a high-throughput screening (HTS) assay. PMID:24914124

  8. An efficient iterative method for the generalized Stokes problem

    SciTech Connect

    Sameh, A.; Sarin, V.

    1996-12-31

    This paper presents an efficient iterative scheme for the generalized Stokes problem, which arises frequently in the simulation of time-dependent Navier-Stokes equations for incompressible fluid flow. The general form of the linear system is where A = {alpha}M + vT is an n x n symmetric positive definite matrix, in which M is the mass matrix, T is the discrete Laplace operator, {alpha} and {nu} are positive constants proportional to the inverses of the time-step {Delta}t and the Reynolds number Re respectively, and B is the discrete gradient operator of size n x k (k < n). Even though the matrix A is symmetric and positive definite, the system is indefinite due to the incompressibility constraint (B{sup T}u = 0). This causes difficulties both for iterative methods and commonly used preconditioners. Moreover, depending on the ratio {alpha}/{nu}, A behaves like the mass matrix M at one extreme and the Laplace operator T at the other, thus complicating the issue of preconditioning.

  9. New multiplex PCR methods for rapid screening of genetically modified organisms in foods.

    PubMed

    Datukishvili, Nelly; Kutateladze, Tamara; Gabriadze, Inga; Bitskinashvili, Kakha; Vishnepolsky, Boris

    2015-01-01

    We present novel multiplex PCR methods for rapid and reliable screening of genetically modified organisms (GMOs). New designed PCR primers targeting four frequently used GMO specific sequences permitted identification of new DNA markers, in particular 141 bp fragment of cauliflower mosaic virus (CaMV) 35S promoter, 224 bp fragment of Agrobacterium tumefaciens nopaline synthase (NOS) terminator, 256 bp fragment of 5-enolppyruvylshikimate-phosphate synthase (epsps) gene and 258 bp fragment of Cry1Ab delta-endotoxin (cry1Ab) gene for GMO screening. The certified reference materials containing Roundup Ready soybean (RRS) and maize MON 810 were applied for the development and optimization of uniplex and multiplex PCR systems. Evaluation of amplification products by agarose gel electrophoresis using negative and positive controls confirmed high specificity and sensitivity at 0.1% GMO for both RRS and MON 810. The fourplex PCR was developed and optimized that allows simultaneous detection of three common transgenic elements, such as: CaMV 35S promoter, NOS terminator, epsps gene together with soybean-specific lectin gene. The triplex PCR developed enables simultaneous identification of transgenic elements, such as: 35S promoter and cry1Ab gene together with maize zein gene. The analysis of different processed foods demonstrated that multiplex PCR methods developed in this study are useful for accurate and fast screening of GM food products. PMID:26257724

  10. Effects of semicore d-electrons in screened-exchange density functional methods

    NASA Astrophysics Data System (ADS)

    Lee, Byounghak; Wang, Lin-Wang

    2007-03-01

    We report a theoretical study on the role of shallow d states in the screened-exchange local density approximation (sX-LDA) band structure of binary semiconductor systems. We found that the inaccurate pseudo-wavefunctions can lead to 1) an overestimation of the screened-exchange interaction between the localized d states and the delocalized higher energy s and p states and 2) an underestimation of the screened-exchange interaction between the d states. The resulting sX-LDA band structures have substantially smaller band gaps compared with experiments. We correct the pseudo-wavefunctions of d states by including the s and p states of the same shell in the valence states. The correction of pseudo-wavefunctions yields band gaps and the d state binding energy in good agreement with experiments. Compared with the quasi-particle GW method, our sX-LDA results shows not only similar quality band gaps but also much better d state binding energy. As an example, we present sX-LDA results of s-d coupling in zinc-blende semiconductors and compare them with LDA+U results. We also present an efficient method to correct the pseudo-wavefunction exchange-integral error by using projection of wavefunctions onto atomic orbitals.

  11. Function-specific virtual screening for GPCR ligands using a combined scoring method

    PubMed Central

    Kooistra, Albert J.; Vischer, Henry F.; McNaught-Flores, Daniel; Leurs, Rob; de Esch, Iwan J. P.; de Graaf, Chris

    2016-01-01

    The ability of scoring functions to correctly select and rank docking poses of small molecules in protein binding sites is highly target dependent, which presents a challenge for structure-based drug discovery. Here we describe a virtual screening method that combines an energy-based docking scoring function with a molecular interaction fingerprint (IFP) to identify new ligands based on G protein-coupled receptor (GPCR) crystal structures. The consensus scoring method is prospectively evaluated by: 1) the discovery of chemically novel, fragment-like, high affinity histamine H1 receptor (H1R) antagonists/inverse agonists, 2) the selective structure-based identification of ß2-adrenoceptor (ß2R) agonists, and 3) the experimental validation and comparison of the combined and individual scoring approaches. Systematic retrospective virtual screening simulations allowed the definition of scoring cut-offs for the identification of H1R and ß2R ligands and the selection of an optimal ß-adrenoceptor crystal structure for the discrimination between ß2R agonists and antagonists. The consensus approach resulted in the experimental validation of 53% of the ß2R and 73% of the H1R virtual screening hits with up to nanomolar affinities and potencies. The selective identification of ß2R agonists shows the possibilities of structure-based prediction of GPCR ligand function by integrating protein-ligand binding mode information. PMID:27339552

  12. Novel microscopy-based screening method reveals regulators of contact-dependent intercellular transfer

    PubMed Central

    Michael Frei, Dominik; Hodneland, Erlend; Rios-Mondragon, Ivan; Burtey, Anne; Neumann, Beate; Bulkescher, Jutta; Schölermann, Julia; Pepperkok, Rainer; Gerdes, Hans-Hermann; Kögel, Tanja

    2015-01-01

    Contact-dependent intercellular transfer (codeIT) of cellular constituents can have functional consequences for recipient cells, such as enhanced survival and drug resistance. Pathogenic viruses, prions and bacteria can also utilize this mechanism to spread to adjacent cells and potentially evade immune detection. However, little is known about the molecular mechanism underlying this intercellular transfer process. Here, we present a novel microscopy-based screening method to identify regulators and cargo of codeIT. Single donor cells, carrying fluorescently labelled endocytic organelles or proteins, are co-cultured with excess acceptor cells. CodeIT is quantified by confocal microscopy and image analysis in 3D, preserving spatial information. An siRNA-based screening using this method revealed the involvement of several myosins and small GTPases as codeIT regulators. Our data indicates that cellular protrusions and tubular recycling endosomes are important for codeIT. We automated image acquisition and analysis to facilitate large-scale chemical and genetic screening efforts to identify key regulators of codeIT. PMID:26271723

  13. Pathophysiology, risk factors, and screening methods for prediabetes in women with polycystic ovary syndrome

    PubMed Central

    Gourgari, Evgenia; Spanakis, Elias; Dobs, Adrian Sandra

    2016-01-01

    Polycystic ovary syndrome (PCOS) is a syndrome associated with insulin resistance (IR), obesity, infertility, and increased cardiometabolic risk. This is a descriptive review of several mechanisms that can explain the IR among women with PCOS, other risk factors for the development of diabetes, and the screening methods used for the detection of glucose intolerance in women with PCOS. Few mechanisms can explain IR in women with PCOS such as obesity, insulin receptor signaling defects, and inhibition of insulin-mediated glucose uptake in adipocytes. Women with PCOS have additional risk factors for the development of glucose intolerance such as family history of diabetes, use of oral contraceptives, anovulation, and age. The Androgen Society in 2007 and the Endocrine Society in 2013 recommended using oral glucose tolerance test as a screening tool for abnormal glucose tolerance in all women with PCOS. The approach to detection of glucose intolerance among women with PCOS varies among health care providers. Large prospective studies are still needed for the development of guidelines with strong evidence. When assessing risk of future diabetes in women with PCOS, it is important to take into account the method used for screening as well as other risk factors that these women might have. PMID:27570464

  14. A New Versatile Microarray-based Method for High Throughput Screening of Carbohydrate-active Enzymes*

    PubMed Central

    Vidal-Melgosa, Silvia; Pedersen, Henriette L.; Schückel, Julia; Arnal, Grégory; Dumon, Claire; Amby, Daniel B.; Monrad, Rune Nygaard; Westereng, Bjørge; Willats, William G. T.

    2015-01-01

    Carbohydrate-active enzymes have multiple biological roles and industrial applications. Advances in genome and transcriptome sequencing together with associated bioinformatics tools have identified vast numbers of putative carbohydrate-degrading and -modifying enzymes including glycoside hydrolases and lytic polysaccharide monooxygenases. However, there is a paucity of methods for rapidly screening the activities of these enzymes. By combining the multiplexing capacity of carbohydrate microarrays with the specificity of molecular probes, we have developed a sensitive, high throughput, and versatile semiquantitative enzyme screening technique that requires low amounts of enzyme and substrate. The method can be used to assess the activities of single enzymes, enzyme mixtures, and crude culture broths against single substrates, substrate mixtures, and biomass samples. Moreover, we show that the technique can be used to analyze both endo-acting and exo-acting glycoside hydrolases, polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. We demonstrate the potential of the technique by identifying the substrate specificities of purified uncharacterized enzymes and by screening enzyme activities from fungal culture broths. PMID:25657012

  15. A new versatile microarray-based method for high throughput screening of carbohydrate-active enzymes.

    PubMed

    Vidal-Melgosa, Silvia; Pedersen, Henriette L; Schückel, Julia; Arnal, Grégory; Dumon, Claire; Amby, Daniel B; Monrad, Rune Nygaard; Westereng, Bjørge; Willats, William G T

    2015-04-01

    Carbohydrate-active enzymes have multiple biological roles and industrial applications. Advances in genome and transcriptome sequencing together with associated bioinformatics tools have identified vast numbers of putative carbohydrate-degrading and -modifying enzymes including glycoside hydrolases and lytic polysaccharide monooxygenases. However, there is a paucity of methods for rapidly screening the activities of these enzymes. By combining the multiplexing capacity of carbohydrate microarrays with the specificity of molecular probes, we have developed a sensitive, high throughput, and versatile semiquantitative enzyme screening technique that requires low amounts of enzyme and substrate. The method can be used to assess the activities of single enzymes, enzyme mixtures, and crude culture broths against single substrates, substrate mixtures, and biomass samples. Moreover, we show that the technique can be used to analyze both endo-acting and exo-acting glycoside hydrolases, polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. We demonstrate the potential of the technique by identifying the substrate specificities of purified uncharacterized enzymes and by screening enzyme activities from fungal culture broths. PMID:25657012

  16. New multiplex PCR methods for rapid screening of genetically modified organisms in foods

    PubMed Central

    Datukishvili, Nelly; Kutateladze, Tamara; Gabriadze, Inga; Bitskinashvili, Kakha; Vishnepolsky, Boris

    2015-01-01

    We present novel multiplex PCR methods for rapid and reliable screening of genetically modified organisms (GMOs). New designed PCR primers targeting four frequently used GMO specific sequences permitted identification of new DNA markers, in particular 141 bp fragment of cauliflower mosaic virus (CaMV) 35S promoter, 224 bp fragment of Agrobacterium tumefaciens nopaline synthase (NOS) terminator, 256 bp fragment of 5-enolppyruvylshikimate-phosphate synthase (epsps) gene and 258 bp fragment of Cry1Ab delta-endotoxin (cry1Ab) gene for GMO screening. The certified reference materials containing Roundup Ready soybean (RRS) and maize MON 810 were applied for the development and optimization of uniplex and multiplex PCR systems. Evaluation of amplification products by agarose gel electrophoresis using negative and positive controls confirmed high specificity and sensitivity at 0.1% GMO for both RRS and MON 810. The fourplex PCR was developed and optimized that allows simultaneous detection of three common transgenic elements, such as: CaMV 35S promoter, NOS terminator, epsps gene together with soybean-specific lectin gene. The triplex PCR developed enables simultaneous identification of transgenic elements, such as: 35S promoter and cry1Ab gene together with maize zein gene. The analysis of different processed foods demonstrated that multiplex PCR methods developed in this study are useful for accurate and fast screening of GM food products. PMID:26257724

  17. Designing specific protein–protein interactions using computation, experimental library screening, or integrated methods

    PubMed Central

    Chen, T Scott; Keating, Amy E

    2012-01-01

    Given the importance of protein–protein interactions for nearly all biological processes, the design of protein affinity reagents for use in research, diagnosis or therapy is an important endeavor. Engineered proteins would ideally have high specificities for their intended targets, but achieving interaction specificity by design can be challenging. There are two major approaches to protein design or redesign. Most commonly, proteins and peptides are engineered using experimental library screening and/or in vitro evolution. An alternative approach involves using protein structure and computational modeling to rationally choose sequences predicted to have desirable properties. Computational design has successfully produced novel proteins with enhanced stability, desired interactions and enzymatic function. Here we review the strengths and limitations of experimental library screening and computational structure-based design, giving examples where these methods have been applied to designing protein interaction specificity. We highlight recent studies that demonstrate strategies for combining computational modeling with library screening. The computational methods provide focused libraries predicted to be enriched in sequences with the properties of interest. Such integrated approaches represent a promising way to increase the efficiency of protein design and to engineer complex functionality such as interaction specificity. PMID:22593041

  18. Function-specific virtual screening for GPCR ligands using a combined scoring method.

    PubMed

    Kooistra, Albert J; Vischer, Henry F; McNaught-Flores, Daniel; Leurs, Rob; de Esch, Iwan J P; de Graaf, Chris

    2016-01-01

    The ability of scoring functions to correctly select and rank docking poses of small molecules in protein binding sites is highly target dependent, which presents a challenge for structure-based drug discovery. Here we describe a virtual screening method that combines an energy-based docking scoring function with a molecular interaction fingerprint (IFP) to identify new ligands based on G protein-coupled receptor (GPCR) crystal structures. The consensus scoring method is prospectively evaluated by: 1) the discovery of chemically novel, fragment-like, high affinity histamine H1 receptor (H1R) antagonists/inverse agonists, 2) the selective structure-based identification of ß2-adrenoceptor (ß2R) agonists, and 3) the experimental validation and comparison of the combined and individual scoring approaches. Systematic retrospective virtual screening simulations allowed the definition of scoring cut-offs for the identification of H1R and ß2R ligands and the selection of an optimal ß-adrenoceptor crystal structure for the discrimination between ß2R agonists and antagonists. The consensus approach resulted in the experimental validation of 53% of the ß2R and 73% of the H1R virtual screening hits with up to nanomolar affinities and potencies. The selective identification of ß2R agonists shows the possibilities of structure-based prediction of GPCR ligand function by integrating protein-ligand binding mode information. PMID:27339552

  19. Pathophysiology, risk factors, and screening methods for prediabetes in women with polycystic ovary syndrome.

    PubMed

    Gourgari, Evgenia; Spanakis, Elias; Dobs, Adrian Sandra

    2016-01-01

    Polycystic ovary syndrome (PCOS) is a syndrome associated with insulin resistance (IR), obesity, infertility, and increased cardiometabolic risk. This is a descriptive review of several mechanisms that can explain the IR among women with PCOS, other risk factors for the development of diabetes, and the screening methods used for the detection of glucose intolerance in women with PCOS. Few mechanisms can explain IR in women with PCOS such as obesity, insulin receptor signaling defects, and inhibition of insulin-mediated glucose uptake in adipocytes. Women with PCOS have additional risk factors for the development of glucose intolerance such as family history of diabetes, use of oral contraceptives, anovulation, and age. The Androgen Society in 2007 and the Endocrine Society in 2013 recommended using oral glucose tolerance test as a screening tool for abnormal glucose tolerance in all women with PCOS. The approach to detection of glucose intolerance among women with PCOS varies among health care providers. Large prospective studies are still needed for the development of guidelines with strong evidence. When assessing risk of future diabetes in women with PCOS, it is important to take into account the method used for screening as well as other risk factors that these women might have. PMID:27570464

  20. Methods to increase participation in organised screening programs: a systematic review

    PubMed Central

    2013-01-01

    Background The European Community recommends the implementation of population-based screening programmes for cervical, breast, and colorectal cancers. This recommendation is supported by many observational studies showing that organised programmes effectively reduce mortality and control the inappropriate use of screening tests. We conducted a systematic review of studies assessing the efficacy of interventions to increase participation in organised population-based screening programs. Methods We included all studies on interventions aimed at increasing screening participation published between 1/1999 and 7/2012. For those published before 1999, we considered the Jepson et al. (2000) review (Health Technol Assess 4:1-133, 2000). Results Including studies from the Jepson review, we found 69 with quantitative information on interventions in organised screening: 19 for cervical, 26 for breast, 20 colorectal cancers, and 4 for cervical and breast cancer together. Effective interventions were: postal (breast RR = 1,37 95% Confidence Interval (95% CI): 1.25-1.51; cervical RR = 1.71 95% CI: 1.60-1.83; colorectal RR = 1.33 95% CI: 1.17-1.51) and telephone reminders (with heterogeneous methods for implementation); GP’s signature on invitation letter (breast RR = 1.13 95% CI: 1.11-1.16; cervical RR = 1.20 95% CI: 1.10-1.30; colorectal RR = 1.15 95% CI: 1.07-1.24); scheduled appointment instead of open appointment (breast RR = 1.26 95% CI: 1.02-1.55; cervical RR = 1.49 95% CI: 1.27-1.75; colorectal RR = 1.79 95% CI: 1.65-1.93). Mailing a kit for self-sampling cervical specimens increased participation in non-responders (RR = 2.37 95% CI: 1.44-3.90). Conclusion Although some interventions did prove to be effective, some specific variables may influence their effectiveness in and applicability to organised population-based screening programs. PMID:23663511

  1. Case studies on screening soil samples for TNT and chlordane and practical aspects for bringing these field screening methods into the laboratory

    SciTech Connect

    Hooton, D.

    1995-12-31

    This paper shares specific experiences with screening soil samples for explosive (TNT) and pesticide (chlordane) residues. Suggestions for adapting analytical methods and associated QA/QC objectives for screening purposes are also discussed. Over the last several years, Midwest Research Institute (MRI) has analyzed hundreds of soil samples for environmental investigation programs. Quality control data are presented to show that reliable method performance (precision and recovery) has been achieved for this work. Comparative data are charted for representative samples which were subsequently reanalyzed using EPA methods to confirm non-contamination or to determine the exact concentration of the screened analytes. MRI has been successful in effectively controlling operational factors which impact cost and time for analysis completion. In the absence of a fully functional on-site laboratory, alternatives are suggested which make it possible to provide valid analysis results soon after sample collection. Sample documentation, data validation, and reporting are simplified using a 1-page form without sacrificing data quality and documentary evidence. Experimental data are presented which support the use of screening methods to improve a program`s effectiveness through evaluation of larger data sets and selective use of more rigorous and expensive EPA methods.

  2. Novel Methods for Communicating Plasma Science to the General Public

    NASA Astrophysics Data System (ADS)

    Zwicker, Andrew; Merali, Aliya; Wissel, S. A.; Delooper, John

    2012-10-01

    The broader implications of Plasma Science remains an elusive topic that the general public rarely discusses, regardless of their relevance to energy, the environment, and technology. Recently, we have looked beyond print media for methods to reach large numbers of people in creative and informative ways. These have included video, art, images, and music. For example, our submission to the ``What is a Flame?'' contest was ranked in the top 15 out of 800 submissions. Images of plasmas have won 3 out of 5 of the Princeton University ``Art of Science'' competitions. We use a plasma speaker to teach students of all ages about sound generation and plasma physics. We report on the details of each of these and future videos and animations under development.

  3. A genome-wide RNAi screening method to discover novel genes involved in virus infection.

    PubMed

    Panda, Debasis; Cherry, Sara

    2015-12-01

    Systematic and comprehensive analysis of host cell proteins involved in virus infection has been difficult in large part due to the lack of robust unbiased methods for their identification. Recent technological breakthroughs allowing development of cell-based genetic screens have greatly facilitated our understanding of virus-host interactions. These include instrumentation for processing in microtiter plates (e.g., 384 well), coupled with sensitive readers and off-the-shelf analysis and informatics pipelines. Because viruses are a significant threat to human health, a better understanding of the cellular factors that impact infection would pave the way for the development of new therapeutics. Here we describe the development and implementation of a genome-wide siRNA screen against a virus using human cells. PMID:26164699

  4. Surface-enhanced Raman spectroscopy + support vector machine: a new noninvasive method for prostate cancer screening?

    PubMed

    Li, Shaoxin; Guo, Zhouyi; Liu, Zhiming

    2015-01-01

    Prostate cancer is one of the most common malignancies of the older males worldwide. Early diagnosis and treatment are important to improve the survival of patients. Recently, we developed a new method for prostate cancer screening: by measuring the serum surface-enhanced Raman spectroscopy of prostate cancer patients and normal subjects, combining with classification algorithms of support vector machines, the measured surface-enhanced Raman spectroscopy spectra are successfully classified with accuracy of 98.1%. Although the practical application faces several difficulties, we believe that this label-free serum surface-enhanced Raman spectroscopy analysis technique combined with support vector machine diagnostic algorithms will become a powerful tool for noninvasive prostate cancer screening in the future. PMID:25525666

  5. Studies on bacterial cell wall inhibitors. VI. Screening method for the specific inhibitors of peptidoglycan synthesis.

    PubMed

    Omura, S; Tanaka, H; Oiwa, R; Nagai, T; Koyama, Y; Takahashi, Y

    1979-10-01

    A screening method was established for selecting new specific inhibitors of bacterial cell wall peptidoglycan synthesis. In the primary test, culture broths of soil isolates were selected based on relative microbial activity. A culture, to be retained, must be active against Bacillus subtilis and lack activities against Acholeplasma laidawii. In the secondary test, inhibitors of bacterial cell wall synthesis were identified by their ability to prevent the incorporation of meso-[3H]diaminopimelic acid but not to prevent the incorporation of L-[4C]leucine into the acid-insoluble macromolecular fraction of growing cells of Bacillus sp. ATCC 21206 (Dpm-). As the tertiary test, inhibitors with molecular weights under 1,000 were selected by passage through a Diaflo UM-2 membrane. By this screening procedure, six known antibiotics and one new one were picked out from ten thousand soil isolates. PMID:528376

  6. Method for rapid screening analysis of Sr-90 in edible plant samples collected near Fukushima, Japan.

    PubMed

    Amano, Hikaru; Sakamoto, Hideaki; Shiga, Norikatsu; Suzuki, Kaori

    2016-06-01

    A screening method for measuring (90)Sr in edible plant samples by focusing on (90)Y in equilibrium with (90)Sr is reported. (90)Y was extracted from samples with acid, co-precipitated with iron hydroxide, and precipitated with oxalic acid. The dissolved oxalate precipitate was loaded on an extraction chromatography resin, and the (90)Y-enriched eluate was analyzed by Cherenkov counting with a TDCR liquid scintillation counter. (90)Sr ((90)Y) concentration was determined in plant samples collected near the damaged Fukushima Daiichi Nuclear Power Plants with this method. PMID:27043171

  7. A method to screen and evaluate tissue adhesives for joint repair applications

    PubMed Central

    2012-01-01

    Background Tissue adhesives are useful means for various medical procedures. Since varying requirements cause that a single adhesive cannot meet all needs, bond strength testing remains one of the key applications used to screen for new products and study the influence of experimental variables. This study was conducted to develop an easy to use method to screen and evaluate tissue adhesives for tissue engineering applications. Method Tissue grips were designed to facilitate the reproducible production of substrate tissue and adhesive strength measurements in universal testing machines. Porcine femoral condyles were used to generate osteochondral test tissue cylinders (substrates) of different shapes. Viability of substrates was tested using PI/FDA staining. Self-bonding properties were determined to examine reusability of substrates (n = 3). Serial measurements (n = 5) in different operation modes (OM) were performed to analyze the bonding strength of tissue adhesives in bone (OM-1) and cartilage tissue either in isolation (OM-2) or under specific requirements in joint repair such as filling cartilage defects with clinical applied fibrin/PLGA-cell-transplants (OM-3) or tissues (OM-4). The efficiency of the method was determined on the basis of adhesive properties of fibrin glue for different assembly times (30 s, 60 s). Seven randomly generated collagen formulations were analyzed to examine the potential of method to identify new tissue adhesives. Results Viability analysis of test tissue cylinders revealed vital cells (>80%) in cartilage components even 48 h post preparation. Reuse (n = 10) of test substrate did not significantly change adhesive characteristics. Adhesive strength of fibrin varied in different test settings (OM-1: 7.1 kPa, OM-2: 2.6 kPa, OM-3: 32.7 kPa, OM-4: 30.1 kPa) and was increasing with assembly time on average (2.4-fold). The screening of the different collagen formulations revealed a substance with significant higher adhesive

  8. Development of colorimetric field screening methods for munitions compounds in soil

    SciTech Connect

    Jenkins, T.F.; Walsh, M.E.; Schumacher, P.W.; Thorne, P.G.

    1995-12-31

    Simple colorimetric tests have been developed to screen for the presence of TNT, TNB, DNT, DNB, tetryl, RDX, HMX, nitroglycerin (NG), PETN nitrocellulose (NC), nitroguanidine (NQ), picric acid and ammonia picrate in soil. Soils are extracted by manual shaking with acetone. For the nitroaromatics, the extracts are reacted with potassium hydroxide and sodium sulfite to form their colored Janowsky complexes. For RDX, HMX, NG, PETN, NC and NQ, extracts are passed through an anion exchange resin to remove nitrate, and then acidified with acetic acid; the nitramines and nitrate esters are educed with zinc to form nitrous acid. The nitrous acid is detected by the Griess reaction using a Hach Nitriver 3 powder pillow, which produces a highly colored azo dye. Detection of these analytes can be obtained visually and concentrations estimated from absorbance measurements at 540 nm for TNT, TNB and tetryl, 570 nm for DNTs and DNB, and at 510 nm for RDX, HMX, NG, PETN, NC and NQ. For picric acid/ammonium picrate, the acetone extract is passed through a basic ion-exchange column that retains picrate ion. The column is rinsed with methanol to elute interferences, and the picrate is desorbed with acetone containing several drops of sulfuric acid. The extract is diluted with deionized water, and the concentration of picrate is obtained from the absorbance at 400 nm. Detection limits are about 1 {micro}g/g for all analytes except NG, NC and NQ, which are slightly higher. Results from field screening at a number of sites have been correlated with laboratory analyses for TNT and RDX. The results indicate that the field screening methods do not suffer from false negatives and the rate of false positives is low. Concentration estimates from field screening compared favorably with results from the standard laboratory methods.

  9. Development of colorimetric field screening methods for munitions compounds in soil

    NASA Astrophysics Data System (ADS)

    Jenkins, Thomas F.; Walsh, Marianne E.; Schumacher, Patricia W.; Thorne, Philip G.

    1995-10-01

    Simple colorimetric tests have been developed to screen for the presence of TNT, TNB, DNT, DNB, tetryl, RDX, HMX, nitroglycerine (NG), PETN, nitrocellulose (NC), nitroguanidine (NQ), picric acid and ammonium picrate in soil. Soils are extracted by manual shaking with acetone. For the nitroaromatics, the extracts are reacted with potassium hydroxide and sodium sulfite to form their colored Janowsky complexes. For RDX, HMX, NG, PETN, NC and NQ, extracts are passed through an anion exchange resin to remove nitrate, and then acidified with acetic acid; the nitramines and nitrate esters are reduced with zinc to form nitrous acid. The nitrous acid is detected by the Griess reaction using a Hach Nitriver 3 powder pillow, which produces a highly colored azo dye. Detection of these analytes can be obtained visually and concentrations estimated from absorbance measurements at 540 nm for TNT, TNB and tetryl, 570 nm for DNTs and DNB, and at 510 nm for RDX, HMX, NG, PETN, NC and NQ. For picric acid/ammonium picrate, the acetone extract is passed through a basic ion-exchange column that retains picrate ion. The column is rinsed with methanol to elute interferences, and the picrate is desorbed with acetone containing several drops of sulfuric acid. The extract is diluted with deionized water, and the concentration of picrate is obtained from the absorbance at 400 nm. Detection limits are about 1 (mu) g/g for all analytes except NG, NC and NQ, which are slightly higher. Results from field screening at a number of sites have been correlated with laboratory analyses for TNT and RDX. The results indicate that the field screening methods do not suffer from false negatives and the rate of false positives is low. Concentration estimates from field screening compared favorably with results from the standard laboratory methods.

  10. A screening method of oil-soluble synthetic dyes in chilli products based on multi-wavelength chromatographic fingerprints comparison.

    PubMed

    Zhu, Yonghong; Wu, Yanlei; Zhou, Chunjie; Zhao, Bo; Yun, Wen; Huang, Siyu; Tao, Peng; Tu, Dawei; Chen, Shiqi

    2016-02-01

    A multi-wavelength HPLC fingerprint comparison method was proposed for the screening of oil-soluble synthetic dyes in chilli products. The screening was based on the fingerprint differences of normal unadulterated chilli sample with tested chilli samples. The samples were extracted with acetone and fingerprinted by HPLC under four visible light wavelengths (450 nm, 490 nm, 520 nm, and 620 nm). It was found that the fingerprints of different chilli product samples had a relatively fixed number of peaks and stable retention time. When 16 kinds of known synthetic dyes were used as model analytes to assess the screening efficiency, 14 of them could be screened using fingerprint comparison method, with LOD of 0.40-2.41 mg/kg. The new screening method was simple and had the possibility of finding existence of the adulterated dyes which could not be identified using known standard analytes as control. PMID:26304371

  11. An in vitro screening method to evaluate chemicals as potential chemotherapeutants to control Aeromonas hydrophila infection in channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using catfish gill cells G1B and four chemicals (hydrogen peroxide, sodium chloride, potassium permanganate, and D-mannose), the feasibility of using an in vitro screening method to identify potential effective chemotherapeutants was evaluated in this study. In vitro screening results revealed that,...

  12. A method to screen obstructive sleep apnea using multi-variable non-intrusive measurements.

    PubMed

    de Silva, S; Abeyratne, U R; Hukins, C

    2011-04-01

    Obstructive sleep apnea (OSA) is a serious sleep disorder. The current standard OSA diagnosis method is polysomnography (PSG) testing. PSG requires an overnight hospital stay while physically connected to 10-15 channels of measurement. PSG is expensive, inconvenient and requires the extensive involvement of a sleep technologist. As such, it is not suitable for community screening. OSA is a widespread disease and more than 80% of sufferers remain undiagnosed. Simplified, unattended and cheap OSA screening methods are urgently needed. Snoring is commonly associated with OSA but is not fully utilized in clinical diagnosis. Snoring contains pseudo-periodic packets of energy that produce characteristic vibrating sounds familiar to humans. In this paper, we propose a multi-feature vector that represents pitch information, formant information, a measure of periodic structure existence in snore episodes and the neck circumference of the subject to characterize OSA condition. Snore features were estimated from snore signals recorded in a sleep laboratory. The multi-feature vector was applied to a neural network for OSA/non-OSA classification and K-fold cross-validated using a random sub-sampling technique. We also propose a simple method to remove a specific class of background interference. Our method resulted in a sensitivity of 91 ± 6% and a specificity of 89 ± 5% for test data for AHI(THRESHOLD) = 15 for a database consisting of 51 subjects. This method has the potential as a non-intrusive, unattended technique to screen OSA using snore sound as the primary signal. PMID:21383492

  13. A combinatorial chemistry method for fast screening of perovskite-based NO oxidation catalyst.

    PubMed

    Yoon, Dal Young; Lim, Eunho; Kim, Young Jin; Cho, Byong K; Nam, In-Sik; Choung, Jin Woo; Yoo, Seungbeom

    2014-11-10

    A fast parallel screening method based on combinatorial chemistry (combichem) has been developed and applied in the screening tests of perovskite-based oxide (PBO) catalysts for NO oxidation to hit a promising PBO formulation for the oxidation of NO to NO2. This new method involves three consecutive steps: oxidation of NO to NO2 over a PBO catalyst, adsorption of NOx onto the PBO and K2O/Al2O3, and colorimetric assay of the NOx adsorbed thereon. The combichem experimental data have been used for determining the oxidation activity of NO over PBO catalysts as well as three critical parameters, such as the adsorption efficiency of K2O/Al2O3 for NO2 (α) and NO (β), and the time-average fraction of NO included in the NOx feed stream (ξ). The results demonstrated that the amounts of NO2 produced over PBO catalysts by the combichem method under transient conditions correlate well with those from a conventional packed-bed reactor under steady-state conditions. Among the PBO formulations examined, La0.5Ag0.5MnO3 has been identified as the best chemical formulation for oxidation of NO to NO2 by the present combichem method and also confirmed by the conventional packed-bed reactor tests. The superior efficiency of the combichem method for high-throughput catalyst screening test validated in this study is particularly suitable for saving the time and resources required in developing a new formulation of PBO catalyst whose chemical composition may have an enormous number of possible variations. PMID:25321326

  14. General flow field analysis methods for helicopter rotor aeroacoustics

    NASA Technical Reports Server (NTRS)

    Quackenbush, Todd R.; Lam, C. Gordon; Bliss, Donald B.

    1991-01-01

    Previous work in the analysis of rotor flow fields for aeroacoustic applications involved the preliminary development of an efficient and accurate Lagrangian simulation of the unsteady vorticity field in the vicinity of helicopter main rotor that could analyze a limited class of rotor/wake interactions. The capabilities of this analysis have subsequently been considerably enhanced to allow it to serve as the foundation for a general analysis of the rotor/wake interaction noise. This paper presents the details of these enhancements, which focus on the expansion of the reconstruction approach developed previously to handle arbitrary vortex wake interactions within three-dimensional regions located near or within the rotor disk. Also, the development of nearfield velocity corrections appropriate for the analysis of such interactions is described, as is a preliminary study of methods for using the new high-resolution flow field analysis for noise predictions. The results show that by employing this novel flow field reconstruction technique it is possible to employ full-span free wake analyses with temporal and spatial resolution suitable for acoustic applications while reducing the computation time required by one to two orders of magnitude relative to traditional methods.

  15. A generalized inversion method: Simultaneous source localization and environmental inversion

    NASA Astrophysics Data System (ADS)

    Neilsen, Tracianne B.; Knobles, David P.

    2002-05-01

    The problem of localizing and tracking a source in the shallow ocean is often complicated by uncertainty in the environmental parameters. Likewise, the estimates of environmental parameters in the shallow ocean obtained by inversion methods can be degraded by incorrect information about the source location. To overcome both these common obstacles-environmental mismatch in matched field processing and incorrect source location in geoacoustic inversions-a generalized inversion scheme is developed that includes both source and environmental parameters as unknowns in the inversion. The new technique called systematic decoupling using rotated coordinates (SDRC) expands the original idea of rotated coordinates [M. D. Collins and L. Fishman, J. Acoust. Soc. Am. 98, 1637-1644 (1995)] by using multiple sets of coherent broadband rotated coordinates, each corresponding to a different set of bounds, to systematically decouple the unknowns in a series of simulated annealing inversions. The results of applying the SDRC inversion method to data from the Area Characterization Test II experiment performed on the New Jersey continental shelf are presented. [Work supported by ONR.

  16. Generalized method of eigenoscillations for near-field optical microscopy

    NASA Astrophysics Data System (ADS)

    Jiang, Bor-Yuan; Zhang, Lingfeng; Castro Neto, Antonio; Basov, Dimitri; Fogler, Michael

    2015-03-01

    Electromagnetic interaction between a sub-wavelength particle (the ``probe'') and a material surface (the ``sample'') is studied theoretically. The interaction is shown to be governed by a series of resonances (eigenoscillations), corresponding to surface polariton modes localized near the probe. The resonance parameters depend on the dielectric function and geometry of the probe, as well as the surface reflectivity of the material. Calculation of such resonances is carried out for several axisymmetric particle shapes (spherical, spheroidal, and pear-shaped). For spheroids an efficient numerical method is proposed, capable of handling cases of large or strongly momentum-dependent surface reflectivity. The method is applied to modeling near-field spectroscopy studies of various materials. For highly resonant materials such as aluminum oxide (by itself or covered with graphene) a rich structure of the simulated signal is found, including multi-peak spectra and nonmonotonic approach curves. These features have a strong dependence on physical parameters, e.g., the probe shape. For less resonant materials such as silicon oxide the dependence is weaker, and the spheroid model is generally applicable.

  17. General unknown screening, antioxidant and anti-inflammatory potential of Dendrobium macrostachyum Lindl.

    PubMed Central

    Sukumaran, Nimisha Pulikkal; Yadav, R. Hiranmai

    2016-01-01

    Context: D. macrostachyum is an epiphytic orchid abundant in Southern India and is reported for pain relief in folklore. Aims: The objective of the present study was to determine in vitro free radical scavenging and anti-inflammatory activity of D. macrostachyum and to perform LCMS based metabolic profiling of the plant. Settings and Design: Sequential stem and leaf extracts were assessed for its antioxidant and anti-inflammatory activity by in vitro methods. Materials and Methods: The antioxidant activity determined by assays based on the decolourization of the radical monocation of DPPH, ABTS and reducing power. Total amount of phenolics for quantitative analysis of antioxidative components was estimated. In vitro anti-inflammatory activity was evaluated using protein denaturation assay, membrane stabilization assay and proteinase inhibitory activity. Methanolic extract of plant was subjected to LCMS. Results: The stem ethanolic extracts exhibited significant IC50 value of 10.21, 31.54 and 142.97 μg/ml respectively for DPPH, ABTS radical scavenging and reducing power activity. The ethanol and water extract was highly effective as albumin denaturation inhibitors (IC50 = 114.13 and 135.818 μg/ml respectively) and proteinase inhibitors (IC50 = 72.49 and 129.681 μg/ml respectively). Membrane stabilization was also noticeably inhibited by the stem ethanolic extract among other extracts (IC50 = 89.33 μg/ml) but comparatively lower to aspirin standard (IC50 = 83.926 μg/ml). The highest total phenol content was exhibited by ethanolic stem and leaf extracts respectively at 20 and 16 mg of gallic acid equivalents of dry extract. On LCMS analysis 20 constituents were identified and it included chemotaxonomic marker for Dendrobium species. Conclusions: The results showed a relatively high concentration of phenolics, high scavenger activity and high anti-inflammatory activity of the stem extract compared to the leaf extract. The results indicate that the plant can be a

  18. A multidimensional screening method for the selection of two-photon enhanced fluorescent proteins

    NASA Astrophysics Data System (ADS)

    Stoltzfus, Caleb; Barnett, Lauren; Rebane, Aleksander; Hughes, Thomas; Drobizhev, Mikhail; Wicks, Geoffrey; Mikhailov, Alexandr

    2014-03-01

    Two-photon excitation of fluorescent proteins (FPs) is widely used in imaging whole organisms or living tissues. Many different FPs are now available but these proteins have only been optimized for their one-photon properties. We have developed a technique for screening entire libraries of E. coli colonies expressing FPs that utilizes multiple wavelengths of linear excitation as well as two-photon excitation. Single mutations in a particular protein that affect one or twophoton properties are easily identified, providing new views of structure/function relationships. An amplified femtosecond Ti:sapphire laser and a spectrally filtered lamp source are used to acquire the fluorescence signals of up to ~1000 E. coli colonies on a standard Petri dish. Automation of the analysis and acquisition of the fluorescent signals makes it feasible to rapidly screen tens of thousands of colonies. In a proof of principle experiment with the commonly used EGFP, we used two rounds of error prone PCR and selection to evolve new proteins with shifted absorption and increased two-photon cross sections at 790nm. This method of screening, coupled with careful measurements of photo bleaching dynamics and two-photon cross sections, should make it possible to optimize a wide variety of fluorescent proteins and biosensors for use in two-photon microscopes.

  19. High-throughput transformation method for Yarrowia lipolytica mutant library screening.

    PubMed

    Leplat, Christophe; Nicaud, Jean-Marc; Rossignol, Tristan

    2015-09-01

    As a microorganism of major biotechnological importance, the oleaginous yeast Yarrowia lipolytica is subjected to intensive genetic engineering and functional genomic analysis. Future advancements in this area, however, require a system that will generate a large collection of mutants for high-throughput screening. Here, we report a rapid and efficient method for high-throughput transformation of Y. lipolytica in 96-well plates. We developed plasmids and strains for the large-scale screening of overexpression mutant strains, using Gateway® vectors that were adapted for specific locus integration in Y. lipolytica. As an example, a collection of mutants that overexpressed the alkaline extracellular protease (AEP) was obtained in a single transformation experiment. The platform strain that we developed to receive the overexpression cassette was designed to constitutively express a fluorescent protein as a convenient growth reporter for screening in non-translucid media. An example of growth comparison in skim milk-based medium between AEP overexpression and deletion mutants is provided. PMID:26100263

  20. A 96-well electrochemical method for the screening of enzymatic activities.

    PubMed

    Abdellaoui, Sofiène; Noiriel, Alexandre; Henkens, Robert; Bonaventura, Celia; Blum, Loïc J; Doumèche, Bastien

    2013-04-01

    The rapid electrochemical screening of enzyme activities in bioelectronics is still a challenging issue. In order to solve this problem, we propose to use a 96-well electrochemical assay. This system is composed of 96 screen-printed electrodes on a printed circuit board adapted from a commercial system (carbon is used as the working electrode and silver chloride as the counter/reference electrode). The associated device allows for the measurements on the 96 electrodes to be performed within a few seconds. In this work, we demonstrate the validity of the screening method with the commercial laccase from the fungus Trametes versicolor. The signal-to-noise ratio (S/N) is found to be the best way to analyze the electrochemical signals. The S/N follows a saturation-like mechanism with a dynamic linear range of two decades ranging from 0.5 to 75 ng of laccase (corresponding to enzymatic activities from 62 × 10(-6) to 9.37 × 10(-3) μmol min(-1)) and a sensitivity of 3027 μg(-1) at +100 mV versus Ag/AgCl. Laccase inhibitors (azide and fluoride anions), pH optima, and interfering molecules could also be identified within a few minutes. PMID:23461701

  1. Pre-employment screening and health management for safety forces-methods and techniques.

    PubMed

    Mostardi, R A; Porterfield, J A; King, S; Urycki, S

    1990-01-01

    The purpose of this clinical report is to describe the process by which safety forces (police and fire) are tested prior to employment (pre-employment screening) and the periodic evaluations used to maintain such standards. The process began by testing 350 male police volunteers and developing a series of age stratified norms. These norms are used to compare incoming recruits such that candidates of a given age are compared to norms developed from police officers of the same age. The purposes of this report are to describe the clinical tests used in the pre-employment screening, to report the normative data and to describe the methods of comparing data obtained from applicants to the established norms. The proper management of high risk employees through pre-employment screening and intervention programs has been viewed as being necessary both for the individual employee in reducing injury and disease and for the municipality for cost saving purposes. J Orthop Sports Phys Ther 1990;11(9):398-401. PMID:18787271

  2. Kinase-interacting substrate screening is a novel method to identify kinase substrates

    PubMed Central

    Amano, Mutsuki; Hamaguchi, Tomonari; Shohag, Md. Hasanuzzaman; Kozawa, Kei; Kato, Katsuhiro; Zhang, Xinjian; Yura, Yoshimitsu; Matsuura, Yoshiharu; Kataoka, Chikako; Nishioka, Tomoki

    2015-01-01

    Protein kinases play pivotal roles in numerous cellular functions; however, the specific substrates of each protein kinase have not been fully elucidated. We have developed a novel method called kinase-interacting substrate screening (KISS). Using this method, 356 phosphorylation sites of 140 proteins were identified as candidate substrates for Rho-associated kinase (Rho-kinase/ROCK2), including known substrates. The KISS method was also applied to additional kinases, including PKA, MAPK1, CDK5, CaMK1, PAK7, PKN, LYN, and FYN, and a lot of candidate substrates and their phosphorylation sites were determined, most of which have not been reported previously. Among the candidate substrates for Rho-kinase, several functional clusters were identified, including the polarity-associated proteins, such as Scrib. We found that Scrib plays a crucial role in the regulation of subcellular contractility by assembling into a ternary complex with Rho-kinase and Shroom2 in a phosphorylation-dependent manner. We propose that the KISS method is a comprehensive and useful substrate screen for various kinases. PMID:26101221

  3. First screening method for the simultaneous detection of seven allergens by liquid chromatography mass spectrometry.

    PubMed

    Heick, J; Fischer, M; Pöpping, B

    2011-02-18

    The development of a multi-method for the detection of seven allergens based on liquid chromatography and triple-quadrupole tandem mass spectrometry in multiple reaction mode is described. It is based on extraction of the allergenic proteins from a food matrix, followed by enzymatic digestion with trypsin. The chosen marker peptides were implemented into one method that is capable of the simultaneous detection of milk, egg, soy, hazelnut, peanut, walnut and almond. This method has been used to detect all seven allergenic commodities from incurred reference bread material, which was baked according to a standard recipe from the baking industry. Detected concentrations ranged from 10 to 1000 μg/g, demonstrating that the mass spectrometric based method is a useful tool for allergen screening. PMID:21227428

  4. An objective method for screening and selecting personal cooling systems based on cooling properties.

    PubMed

    Elson, John; Eckels, Steve

    2015-05-01

    A method is proposed for evaluation and selection of a personal cooling system (PCS) incorporating PCS, subject, and equipment weights; PCS run time; user task time; PCS cooling power; and average metabolic rate. The cooling effectiveness method presented is derived from first principles and allows those who select PCSs for specific applications to compare systems based on their projected use. This can lower testing costs by screening for the most applicable system. Methods to predict cooling power of PCSs are presented and are compared to data taken through standard manikin testing. The cooling effectiveness ranking is presented and validated against human subject test data. The proposed method provides significant insight into the application of PCS on humans. However, the interaction a humans with a PCS is complex, especially considering the range of clothing ensembles, physiological issues, and end use scenarios, and requires additional analysis. PMID:25683529

  5. Studies with the USF/NASA toxicity screening test method - Exercise wheels and oxygen replenishment

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.

    1977-01-01

    Continuing efforts to improve the University of San Francisco/NASA toxicity screening test method have included the addition of exercise wheels to provide a different measure of incapacitation, and oxygen replenishment to offset any effect of oxygen depletion by the test animals. The addition of exercise wheels limited the number of animals in each test and doubled the required number of tests without any significant improvement in reproducibility. Oxygen replenishment appears to have an effect on survival in the last 5 minutes of the 30-minute test, but the effect is expected to be similar for most materials.

  6. Screening and selection of synthetic peptides for a novel and optimized endotoxin detection method.

    PubMed

    Mujika, M; Zuzuarregui, A; Sánchez-Gómez, S; Martínez de Tejada, G; Arana, S; Pérez-Lorenzo, E

    2014-09-30

    The current validated endotoxin detection methods, in spite of being highly sensitive, present several drawbacks in terms of reproducibility, handling and cost. Therefore novel approaches are being carried out in the scientific community to overcome these difficulties. Remarkable efforts are focused on the development of endotoxin-specific biosensors. The key feature of these solutions relies on the proper definition of the capture protocol, especially of the bio-receptor or ligand. The aim of the presented work is the screening and selection of a synthetic peptide specifically designed for LPS detection, as well as the optimization of a procedure for its immobilization onto gold substrates for further application to biosensors. PMID:25034430

  7. A Novel Method for Screening Children with Isolated Bicuspid Aortic Valve.

    PubMed

    Gharehbaghi, Arash; Dutoit, Thierry; Sepehri, Amir A; Kocharian, Armen; Lindén, Maria

    2015-12-01

    This paper presents a novel processing method for heart sound signal: the statistical time growing neural network (STGNN). The STGNN performs a robust classification by merging supervised and unsupervised statistical methods to overcome non-stationary behavior of the signal. By combining available preprocessing and segmentation techniques and the STGNN classifier, we build an automatic tool for screening children with isolated BAV, the congenital heart malformation which can lead to serious cardiovascular lesions. Children with BAV (22 individuals) and healthy condition (28 individuals) are subjected to the study. The performance of the STGNN is compared to that of a time growing neural network (CTGNN) and a conventional support vector (CSVM) machine, using balanced repeated random sub sampling. The average of the accuracy/sensitivity is estimated to be 87.4/86.5 for the STGNN, 81.8/83.4 for the CTGNN, and 72.9/66.8 for the CSVM. Results show that the STGNN offers better performance and provides more immunity to the background noise as compared to the CTGNN and CSVM. The method is implementable in a computer system to be employed in primary healthcare centers to improve the screening accuracy. PMID:26577485

  8. Efficient method for screening and identification of radical scavengers in the leaves of Olea europaea L.

    PubMed

    Wang, Xiaofei; Li, Chen; Liu, Yewei; Li, Hongbing; Di, Duolong

    2011-03-01

    In this article, an efficient method was developed to screen, isolate and identify the major radical scavengers in the leaves of Olea europaea L. by DPPH-HPLC-DAD, HSCCC and NMR. The method of DPPH-HPLC-DAD was used to screen the major radical scavengers. It was found that three major constituents (A, B, C) in the extract of the leaves of O. europaea L. possessed potential antioxidant activities. In order to identify the chemical structures of those compounds, the HSCCC method with a two-phase solvent system composed of petroleum ether-ethyl acetate-water at an optimized volume ratio of 6:600:700 (v/v/v) together with column chromatography was developed to isolate and purify the active compounds. Pure compounds A (225 mg), B (10 mg) and C (12 mg) with purities 92.6, 95.1 and 96.4%, respectively, were obtained from the crude sample (500 mg). Their structures were identified as oleuropein (A), luteolin-7-O-glucoside (B) and verbascoside (C) by (1) H-NMR and (13) C-NMR. PMID:21321972

  9. Detection of Inorganic Arsenic in Rice Using a Field Test Kit: A Screening Method.

    PubMed

    Bralatei, Edi; Lacan, Severine; Krupp, Eva M; Feldmann, Jörg

    2015-11-17

    Rice is a staple food eaten by more than 50% of the world's population and is a daily dietary constituent in most South East Asian countries where 70% of the rice export comes from and where there is a high level of arsenic contamination in groundwater used for irrigation. Research shows that rice can take up and store inorganic arsenic during cultivation, and rice is considered to be one of the major routes of exposure to inorganic arsenic, a class I carcinogen for humans. Here, we report the use of a screening method based on the Gutzeit methodology to detect inorganic arsenic (iAs) in rice within 1 h. After optimization, 30 rice commodities from the United Kingdom market were tested with the field method and were compared to the reference method (high-performance liquid chromatography-inductively coupled plasma-mass spectrometry, HPLC-ICP-MS). In all but three rice samples, iAs compound can be determined. The results show no bias for iAs using the field method. Results obtained show quantification limits of about 50 μg kg(-1), a good reproducibility for a field method of ±12%, and only a few false positives and negatives (<10%) could only be recorded at the 2015 European Commission (EC) guideline for baby rice of 100 μg kg(-1), while none were recorded at the maximum level suggested by the World Health Organization (WHO) and implemented by the EC for polished and white rice of 200 μg kg(-1). The method is reliable, fast, and inexpensive; hence, it is suggested to be used as a screening method in the field for preselection of rice which violates legislative guidelines. PMID:26506262

  10. Neonatal Screening Part 2: Neonatal Screening in Canada

    PubMed Central

    Morris, Brian A.P.

    1990-01-01

    Neonatal screening is a widely accepted, cost-effective method for early detection of various inborn errors of metabolism. This series of three articles examines different aspects of neonatal screening. In the first article, the author discussed general principles of screening and its function in the spectrum of diagnostic techniques for genetic disease. In this, the second article, the author reviews the history and current practices of neonatal screening in Canada. The individual diseases for which screening is used and particular points of interest for each of these diseases are briefly described. The author also outlines the benefits of screening and treatment. In the final article of this series, the author will examine controversial topics that represent the possible future of screening. PMID:21234041

  11. Directed Evolution Method in Saccharomyces cerevisiae: Mutant Library Creation and Screening.

    PubMed

    Viña-Gonzalez, Javier; Gonzalez-Perez, David; Alcalde, Miguel

    2016-01-01

    Directed evolution in Saccharomyces cerevisiae offers many attractive advantages when designing enzymes for biotechnological applications, a process that involves the construction, cloning and expression of mutant libraries, coupled to high frequency homologous DNA recombination in vivo. Here, we present a protocol to create and screen mutant libraries in yeast based on the example of a fungal aryl-alcohol oxidase (AAO) to enhance its total activity. Two protein segments were subjected to focused-directed evolution by random mutagenesis and in vivo DNA recombination. Overhangs of ~50 bp flanking each segment allowed the correct reassembly of the AAO-fusion gene in a linearized vector giving rise to a full autonomously replicating plasmid. Mutant libraries enriched with functional AAO variants were screened in S. cerevisiae supernatants with a sensitive high-throughput assay based on the Fenton reaction. The general process of library construction in S. cerevisiae described here can be readily applied to evolve many other eukaryotic genes, avoiding extra PCR reactions, in vitro DNA recombination and ligation steps. PMID:27077451

  12. Screening for antimicrobial resistance in fecal samples by the replica plating method.

    PubMed Central

    Osterblad, M; Leistevuo, T; Huovinen, P

    1995-01-01

    Replica plating can be used for the detection of antibiotic resistance in normal flora. We have evaluated this application of the replica plating method by comparing it with a five-colony method. The replica plating method uses a single plate for each antibiotic, with a concentration just above that for borderline resistance. By the five-colony method, five colonies per sample were picked, chosen to represent all different colony morphologies present, and MICs were determined by a standard agar dilution method. The gram-negative, aerobic floras of 131 fecal samples were screened for resistance to ampicillin, cefuroxime, nalidixic acid, trimethoprim, sulfamethoxazole, and tetracycline by both methods. The rate of resistance detection by the two methods did not differ statistically for any of the antibiotics tested. The breakpoint concentrations used for the replica plates in the study gave results similar to those produced by the agar dilution method and the breakpoint values of the National Committee for Clinical Laboratory Standards and can thus be recommended. As the only currently used resistance detection method, replica plating facilitates an exact determination of the percentage of resistant colonies/total number of colonies (between 1 and 100%) in a sample. This revealed an uneven distribution, with only 23% of the samples having resistance frequencies in the range of 10 to 85%; usually, the resistant flora either was a small minority or was very dominant in samples with resistance. This phenomenon was present for all of the antibiotics. PMID:8586690

  13. Convenient, Sensitive and High-Throughput Method for Screening Botanic Origin

    PubMed Central

    Yuan, Yuan; Jiang, Chao; Liu, Libing; Yu, Shulin; Cui, Zhanhu; Chen, Min; Lin, Shufang; Wang, Shu; Huang, Luqi

    2014-01-01

    In this work, a rapid (within 4–5 h), sensitive and visible new method for assessing botanic origin is developed by combining loop-mediated isothermal amplification with cationic conjugated polymers. The two Chinese medicinal materials (Jin-Yin-Hua and Shan-Yin-Hua) with similar morphology and chemical composition were clearly distinguished by gene SNP genotyping assays. The identification of plant species in Patented Chinese drugs containing Lonicera buds is successfully performed using this detection system. The method is also robust enough to be used in high-throughput screening. This new method is very helpful to identify herbal materials, and is beneficial for detecting safety and quality of botanic products. PMID:24953704

  14. Convenient, Sensitive and High-Throughput Method for Screening Botanic Origin

    NASA Astrophysics Data System (ADS)

    Yuan, Yuan; Jiang, Chao; Liu, Libing; Yu, Shulin; Cui, Zhanhu; Chen, Min; Lin, Shufang; Wang, Shu; Huang, Luqi

    2014-06-01

    In this work, a rapid (within 4-5 h), sensitive and visible new method for assessing botanic origin is developed by combining loop-mediated isothermal amplification with cationic conjugated polymers. The two Chinese medicinal materials (Jin-Yin-Hua and Shan-Yin-Hua) with similar morphology and chemical composition were clearly distinguished by gene SNP genotyping assays. The identification of plant species in Patented Chinese drugs containing Lonicera buds is successfully performed using this detection system. The method is also robust enough to be used in high-throughput screening. This new method is very helpful to identify herbal materials, and is beneficial for detecting safety and quality of botanic products.

  15. The 'GALS' locomotor screen.

    PubMed Central

    Doherty, M; Dacre, J; Dieppe, P; Snaith, M

    1992-01-01

    The locomotor system is complex and difficult to examine. A selective clinical process to detect important locomotor abnormalities and functional disability could prove valuable. A screen based on a tested 'minimal' history and examination system is described, together with a simple method of recording. The screen is fast and easy to perform. As well as providing a useful introduction to examination of the locomotor system, the screen includes objective observation of functional movements relevant to activities of daily living. Its inclusion in the undergraduate clerking repertoire could improve junior doctors' awareness and recognition of rheumatic disease and general disability. It could also provide a valuable screening test for use in general practice. Images PMID:1444632

  16. Powered by DFT: Screening methods that accelerate materials development for hydrogen in metals applications.

    PubMed

    Nicholson, Kelly M; Chandrasekhar, Nita; Sholl, David S

    2014-11-18

    CONSPECTUS: Not only is hydrogen critical for current chemical and refining processes, it is also projected to be an important energy carrier for future green energy systems such as fuel cell vehicles. Scientists have examined light metal hydrides for this purpose, which need to have both good thermodynamic properties and fast charging/discharging kinetics. The properties of hydrogen in metals are also important in the development of membranes for hydrogen purification. In this Account, we highlight our recent work aimed at the large scale screening of metal-based systems with either favorable hydrogen capacities and thermodynamics for hydrogen storage in metal hydrides for use in onboard fuel cell vehicles or promising hydrogen permeabilities relative to pure Pd for hydrogen separation from high temperature mixed gas streams using dense metal membranes. Previously, chemists have found that the metal hydrides need to hit a stability sweet spot: if the compound is too stable, it will not release enough hydrogen under low temperatures; if the compound is too unstable, the reaction may not be reversible under practical conditions. Fortunately, we can use DFT-based methods to assess this stability via prediction of thermodynamic properties, equilibrium reaction pathways, and phase diagrams for candidate metal hydride systems with reasonable accuracy using only proposed crystal structures and compositions as inputs. We have efficiently screened millions of mixtures of pure metals, metal hydrides, and alloys to identify promising reaction schemes via the grand canonical linear programming method. Pure Pd and Pd-based membranes have ideal hydrogen selectivities over other gases but suffer shortcomings such as sensitivity to sulfur poisoning and hydrogen embrittlement. Using a combination of detailed DFT, Monte Carlo techniques, and simplified models, we are able to accurately predict hydrogen permeabilities of metal membranes and screen large libraries of candidate alloys

  17. Microbial screening for quinolones residues in cow milk by bio-optical method.

    PubMed

    Appicciafuoco, Brunella; Dragone, Roberto; Frazzoli, Chiara; Bolzoni, Giuseppe; Mantovani, Alberto; Ferrini, Anna Maria

    2015-03-15

    The use of antibiotics on lactating cows should be monitored for the possible risk of milk contamination with residues. Accordingly, Maximum Residue Levels (MRLs) are established by the European Commission to guarantee consumers safety. As pointed out by Dec 2002/657/EC, screening is the first step in the strategy for antibiotic residue control, thus playing a key role in the whole control procedure. However, current routine screening methods applied in milk chain still fail to detect residues of quinolones at concentrations of interest. This paper reports the findings of a new bio-optical method for the screening of quinolones residues in bovine milk, based on E. coli ATCC 11303 growth inhibition. The effect of blank and spiked cow milk samples (aliquots equivalents to 0.8%, v/v) is evaluated in Mueller Hinton Broth (MHb) and MHb enriched with MgSO4 2% (MHb-Mg) inoculated with the test strain at the concentration of 10(4)CFU/mL. The presence of quinolones inhibits the cellular growth in MHb, while this effect is neutralized in MHb-Mg allowing both detection and presumptive identification of quinolones. Growth of the test strain is monitored at 37 °C in a Bioscreen C automated system, and Optical Density (OD) at 600 nm is recorded every 10 min after shaking for 10s. Growth curves (OD vs. time) of E. coli ATCC 11303 are assessed in milk samples, with and without quinolones, and their differences in terms of ΔOD (ΔOD600nm=ODMHb-Mg-ODMHb) are calculated. The presence of quinolones is detected by the cellular growth inhibition (OD vs time, none increase in the value OD) and presumptively identified through the increase of the slope of ΔOD600nm curve (ΔOD vs. time), after about 3h of incubation. The detection limit for ciprofloxacin and enrofloxacin is at the level of MRL, for marbofloxacin is at 2-fold the MRL whereas for danofloxacin is at 4-fold the MRL. Although the sensitivity of the method could be further improved and the procedure automated, it is a

  18. A Study of Applications of Machine Learning Based Classification Methods for Virtual Screening of Lead Molecules.

    PubMed

    Vyas, Renu; Bapat, Sanket; Jain, Esha; Tambe, Sanjeev S; Karthikeyan, Muthukumarasamy; Kulkarni, Bhaskar D

    2015-01-01

    The ligand-based virtual screening of combinatorial libraries employs a number of statistical modeling and machine learning methods. A comprehensive analysis of the application of these methods for the diversity oriented virtual screening of biological targets/drug classes is presented here. A number of classification models have been built using three types of inputs namely structure based descriptors, molecular fingerprints and therapeutic category for performing virtual screening. The activity and affinity descriptors of a set of inhibitors of four target classes DHFR, COX, LOX and NMDA have been utilized to train a total of six classifiers viz. Artificial Neural Network (ANN), k nearest neighbor (k-NN), Support Vector Machine (SVM), Naïve Bayes (NB), Decision Tree--(DT) and Random Forest--(RF). Among these classifiers, the ANN was found as the best classifier with an AUC of 0.9 irrespective of the target. New molecular fingerprints based on pharmacophore, toxicophore and chemophore (PTC), were used to build the ANN models for each dataset. A good accuracy of 87.27% was obtained using 296 chemophoric binary fingerprints for the COX-LOX inhibitors compared to pharmacophoric (67.82%) and toxicophoric (70.64%). The methodology was validated on the classical Ames mutagenecity dataset of 4337 molecules. To evaluate it further, selectivity and promiscuity of molecules from five drug classes viz. anti-anginal, anti-convulsant, anti-depressant, anti-arrhythmic and anti-diabetic were studied. The TPC fingerprints computed for each category were able to capture the drug-class specific features using the k-NN classifier. These models can be useful for selecting optimal molecules for drug design. PMID:26138573

  19. Chronic Kidney Disease Screening Methods and Its Implication for Malaysia: An in Depth Review

    PubMed Central

    Almualm, Yasmin; Huri, Hasniza Zaman

    2015-01-01

    Chronic Kidney Disease has become a public health problem, imposing heath, social and human cost on societies worldwide. Chronic Kidney Disease remains asymptomatic till late stage when intervention cannot stop the progression of the disease. Therefore, there is an urgent need to detect the disease early. Despite the high prevalence of Chronic Kidney Disease in Malaysia, screening is still lacking behind. This review discusses the strengths and limitations of current screening methods for Chronic Kidney Disease from a Malaysian point of view. Diabetic Kidney Disease was chosen as focal point as Diabetes is the leading cause of Chronic Kidney Disease in Malaysia. Screening for Chronic Kidney Disease in Malaysia includes a urine test for albuminuria and a blood test for serum creatinine. Recent literature indicates that albuminuria is not always present in Diabetic Kidney Disease patients and serum creatinine is only raised after substantial kidney damage has occurred. Recently, cystatin C was proposed as a potential marker for kidney disease but this has not been studied thoroughly in Malaysia. Glomerular Filtration Rate is the best method for measuring kidney function and is widely estimated using the Modification of Diet for Renal Disease equation. Another equation, the Chronic Kidney Disease Epidemiology Collaboration Creatinine equation was introduced in 2009. The new equation retained the precision and accuracy of the Modification of Diet for Renal Disease equation at GFR < 60ml/min/1.73m2, showed less bias and improved precision at GFR>60ml/min/1.73m2. In Asian countries, adding an ethnic coefficient to the equation enhanced its performance. In Malaysia, a multi-ethnic Asian population, the Chronic Kidney Disease Epidemiology Collaboration equation should be validated and the Glomerular Filtration Rate should be reported whenever serum creatinine is ordered. Reporting estimated Glomerular Filtration Rate will help diagnose patients who would have been

  20. An evaluation of industrial ventilation branch screening methods for obstructions in working exhaust systems.

    PubMed

    Booth, D W; Guffey, S E

    2001-01-01

    This research evaluated the effectiveness of screening methods in identifying obstructed branches in industrial ventilation systems. These methods were divided into two categories: pressure comparisons and pressure ratio comparisons. The first category contained techniques that compare measured static pressures with the corresponding design static pressures or with previously measured pressures. Certain aspects of the method suggested in the Industrial Ventilation Manual were also tested. The second category compares the ratios of two measured pressures and includes the new reference ratio method. Data were collected from six industrial ventilation systems. Four of the systems were used to control wood dust, and two were used to control metal shavings from a saw-sharpening operation. Each system was tested for naturally occurring or deliberately inserted obstructions. Appropriate static and velocity pressures were measured to calculate each troubleshooting method's parameter. The change in the parameter was compared with a range of thresholds for the test cases. Receiver operator characteristic curves and bootstrapping techniques were used to identify the best method for determining the presence of obstructions or alterations. The pressure ratio methods were found to be substantially superior to the pressure comparison methods at detecting obstructions. PMID:11549133

  1. Residual-driven online generalized multiscale finite element methods

    NASA Astrophysics Data System (ADS)

    Chung, Eric T.; Efendiev, Yalchin; Leung, Wing Tat

    2015-12-01

    The construction of local reduced-order models via multiscale basis functions has been an area of active research. In this paper, we propose online multiscale basis functions which are constructed using the offline space and the current residual. Online multiscale basis functions are constructed adaptively in some selected regions based on our error indicators. We derive an error estimator which shows that one needs to have an offline space with certain properties to guarantee that additional online multiscale basis function will decrease the error. This error decrease is independent of physical parameters, such as the contrast and multiple scales in the problem. The offline spaces are constructed using Generalized Multiscale Finite Element Methods (GMsFEM). We show that if one chooses a sufficient number of offline basis functions, one can guarantee that additional online multiscale basis functions will reduce the error independent of contrast. We note that the construction of online basis functions is motivated by the fact that the offline space construction does not take into account distant effects. Using the residual information, we can incorporate the distant information provided the offline approximation satisfies certain properties. In the paper, theoretical and numerical results are presented. Our numerical results show that if the offline space is sufficiently large (in terms of the dimension) such that the coarse space contains all multiscale spectral basis functions that correspond to small eigenvalues, then the error reduction by adding online multiscale basis function is independent of the contrast. We discuss various ways computing online multiscale basis functions which include a use of small dimensional offline spaces.

  2. Confinement and hadron-hadron interactions by general relativistic methods

    NASA Astrophysics Data System (ADS)

    Recami, Erasmo

    By postulating covariance of physical laws under global dilations, one can describe gravitational and strong interactions in a unified way. Namely, in terms of the new discrete dilational degree of freedom, our cosmos and hadrons can be regarded as finite, similar systems. And a discrete hierarchy of finite ``universes'' may be defined, which are governed by fields with strengths inversally proportional to their radii; in each universe an Equivalence Principle holds, so that the relevant field can be there geometrized. Scaled-down Einstein equations -with cosmological term- are assumed to hold inside hadrons (= strong micro-cosmoses); and they yield in a natural way classical confinement, as well as ``asymptotic freedom'', of the hadron constituents. In other words, the association of strong micro-universes of Friedmann type with hadrons (i.e., applying the methods of General Relativity to subnuclear particle physics) allows avoiding recourse to phenomenological models such as the Bag Model. Inside hadrons we have to deal with a tensorial field (= strong gravity), and hadron constituents are supposed to exchange spin-2 ``gluons''. Our approach allows us also to write down a tensorial, bi-scale field theory of hadron-hadron interactions, based on modified Einstein-type equations here proposed for strong interactions in our space. We obtain in particular: (i) the correct Yukawa behaviour of the strong scalar potential at the static limit and for r>~l fm; (ii) the value of hadron radii. As a byproduct, we derive a whole ``numerology'', connecting our gravitational cosmos with the strong micro-cosmoses (hadrons), such that it does imply no variation of G with the epoch. Finally, since a structute of the ``micro-universe'' type seems to be characteristic even of leptons, a hope for the future is including also weak interactions in our classical unification of the fundamental forces.

  3. Investigation of screening effects on the shape resonances in the electron-hydrogen system using the complex-scaling method

    NASA Astrophysics Data System (ADS)

    Jiao, Li-Guang; Ho, Y. K.

    2013-05-01

    In the present work we study the effects of screened Coulomb potentials on shape resonances in the electron-hydrogen system. Here we concentrate on the 1Se and 1Po shape resonances associated with and lying above, respectively, the H (N = 2), (N =3), (N =4), and (N = 5) thresholds. The complex-scaling method is used to extract resonance poles, together with employing correlated Hylleraas-type wave functions up to 1078 and 1771 terms for the S- and P-wave states, respectively, to represent the two-electron system. To model the screening effect we replace the pure Coulomb interaction term for any pair of charged particles by a screened Coulomb (or Yukawa-type) interaction term. Our un-screened shape resonances agree well with those in the literature. We will present our latest results for the screened cases at the meeting. Supported by the National Science Council of Taiwan.

  4. Two in vitro methods for screening potential parasiticides against Ichthyophthirius multifiliis using Tetrahymena thermophila.

    PubMed

    Xu, D-H; Zhang, Q-Z; Zhang, D

    2016-03-01

    Ichthyophthirius multifiliis (Ich) is a ciliate parasite that infects many species of freshwater fishes worldwide and causes heavy economic losses in aquaculture. Currently, parasiticides for controlling this parasite are limited, and few pond-practical chemical therapies exist. Hence, the search for new parasiticides is urgently needed. One challenge confronting the screening of potential parasiticides is the difficulty in raising enough parasite for efficacy testing as Ich is an obligate parasite. This study used species of Tetrahymena, Ich-related and cultivable ciliate protozoa, to evaluate two in vitro methods to test parasiticides. Plate counting and MTS assays (CellTiter 96® AQueous Non-Radioactive Cell Proliferation Assay) were used to compare lethal concentrations or median lethal concentrations (LC50) of copper sulphate, formalin and malachite green between T. thermophila and Ich theronts or between T. thermophila and Ich tomonts. The parasiticides that killed T. thermophila have been demonstrated to kill theronts or tomonts. These in vitro methods using T. thermophila can be used to screen novel parasiticides against Ich. PMID:25857201

  5. [Leaching of ores with heterotrophic microorganisms. Development of a screening method].

    PubMed

    Klages, D; Meyer, I; Schwartz, W; Näveke, R

    1981-01-01

    Besides leaching of sulfide ores with thiobacilli, a second way of microbial leaching is tested with carbon-heterotrophic fungi and bacteria for those types of ores, where thiobacilli fail to work. The active agents are metabolic products, f. i. organic acids, which are released into the medium producing water soluble compounds with heavy metals. A screening method is described for recognizing active strains in samples of soil, metal-containing sites, mining heaps and other biocoenoses, using the dilution method in plates with different media. The critical signs of supposed leaching activity are halo formations around growing colonies in turbid agar media with suspended particles of Ca carbonate or Ca phosphates of low solubility, and in a second group of experiments with insoluble compounds of heavy metals, f. i. oxides. The leaching activity was tested with metal compounds suspended in liquid media and inoculated with active strains of the screening program. First results were reached with oxides of copper (CuO), uranium (U3O8) and an uranium-containing phosphorite. PMID:7039150

  6. Screening method for selecting semiconductor substrates having defects below a predetermined level in an oxide layer

    DOEpatents

    Warren, W.L.; Vanheusden, K.J.R.; Schwank, J.R.; Fleetwood, D.M.; Shaneyfelt, M.R.; Winokur, P.S.; Devine, R.A.B.

    1998-07-28

    A method is disclosed for screening or qualifying semiconductor substrates for integrated circuit fabrication. The method comprises the steps of annealing at least one semiconductor substrate at a first temperature in a defect-activating ambient (e.g. hydrogen, forming gas, or ammonia) for sufficient time for activating any defects within on oxide layer of the substrate; measuring a defect-revealing electrical characteristic of at least a portion of the oxide layer for determining a quantity of activated defects therein; and selecting substrates for which the quantity of activated defects is below a predetermined level. The defect-revealing electrical characteristic may be a capacitance-versus voltage (C-V) characteristic or a current-versus-voltage (I-V) characteristic that is dependent on an electrical charge in the oxide layer generated by the activated defects. Embodiments of the present invention may be applied for screening any type of semiconductor substrate or wafer having an oxide layer formed thereon or therein. This includes silicon-on-insulator substrates formed by a separation by the implantation of oxygen (SIMOX) process or the bond and etch back silicon-on-insulator (BESOI) process, as well as silicon substrates having a thermal oxide layer or a deposited oxide layer. 5 figs.

  7. Screening method for selecting semiconductor substrates having defects below a predetermined level in an oxide layer

    DOEpatents

    Warren, William L.; Vanheusden, Karel J. R.; Schwank, James R.; Fleetwood, Daniel M.; Shaneyfelt, Marty R.; Winokur, Peter S.; Devine, Roderick A. B.

    1998-01-01

    A method for screening or qualifying semiconductor substrates for integrated circuit fabrication. The method comprises the steps of annealing at least one semiconductor substrate at a first temperature in a defect-activating ambient (e.g. hydrogen, forming gas, or ammonia) for sufficient time for activating any defects within on oxide layer of the substrate; measuring a defect-revealing electrical characteristic of at least a portion of the oxide layer for determining a quantity of activated defects therein; and selecting substrates for which the quantity of activated defects is below a predetermined level. The defect-revealing electrical characteristic may be a capacitance-versus-voltage (C-V) characteristic or a current-versus-voltage (I-V) characteristic that is dependent on an electrical charge in the oxide layer generated by the activated defects. Embodiments of the present invention may be applied for screening any type of semiconductor substrate or wafer having an oxide layer formed thereon or therein. This includes silicon-on-insulator substrates formed by a separation by the implantation of oxygen (SIMOX) process or the bond and etch back silicon-on-insulator (BESOI) process, as well as silicon substrates having a thermal oxide layer or a deposited oxide layer.

  8. Aluminium tolerance in barley (Hordeum vulgare L.): physiological mechanisms, genetics and screening methods*

    PubMed Central

    Wang, Jun-ping; Raman, Harsh; Zhang, Guo-ping; Mendham, Neville; Zhou, Mei-xue

    2006-01-01

    Aluminium (Al) toxicity is one of the major limiting factors for barley production on acid soils. It inhibits root cell division and elongation, thus reducing water and nutrient uptake, consequently resulting in poor plant growth and yield. Plants tolerate Al either through external resistance mechanisms, by which Al is excluded from plant tissues or internal tolerance mechanisms, conferring the ability of plants to tolerate Al ion in the plant symplasm where Al that has permeated the plasmalemma is sequestered or converted into an innocuous form. Barley is considered to be most sensitive to Al toxicity among cereal species. Al tolerance in barley has been assessed by several methods, such as nutrient solution culture, soil bioassay and field screening. Genetic and molecular mapping research has shown that Al tolerance in barley is controlled by a single locus which is located on chromosome 4H. Molecular markers linked with Al tolerance loci have been identified and validated in a range of diverse populations. This paper reviews the (1) screening methods for evaluating Al tolerance, (2) genetics and (3) mechanisms underlying Al tolerance in barley. PMID:16972319

  9. Toward the discovery of functional transthyretin amyloid inhibitors: application of virtual screening methods.

    PubMed

    Simões, Carlos J V; Mukherjee, Trishna; Brito, Rui M M; Jackson, Richard M

    2010-10-25

    Inhibition of amyloid fibril formation by stabilization of the native form of the protein transthyretin (TTR) is a viable approach for the treatment of familial amyloid polyneuropathy that has been gaining momentum in the field of amyloid research. The TTR stabilizer molecules discovered to date have shown efficacy at inhibiting fibrilization in vitro but display impairing issues of solubility, affinity for TTR in the blood plasma and/or adverse effects. In this study we present a benchmark of four protein- and ligand-based virtual screening (VS) methods for identifying novel TTR stabilizers: (i) two-dimensional (2D) similarity searches with chemical hashed, pharmacophore, and UNITY fingerprints, (ii) 3D searches based on shape, chemical, and electrostatic similarity, (iii) LigMatch, a new ligand-based method which uses multiple templates and combines 3D geometric hashing with a 2D preselection process, and (iv) molecular docking to consensus X-ray crystal structures of TTR. We illustrate the potential of the best-performing VS protocols to retrieve promising new leads by ranking a tailored library of 2.3 million commercially available compounds. Our predictions show that the top-scoring molecules possess distinctive features from the known TTR binders, holding better solubility, fraction of halogen atoms, and binding affinity profiles. To the best of our knowledge, this is the first attempt to rationalize the utilization of a large battery of in silico screening techniques toward the identification of a new generation of TTR amyloid inhibitors. PMID:20883031

  10. Solution of Ambrosio-Tortorelli model for image segmentation by generalized relaxation method

    NASA Astrophysics Data System (ADS)

    D'Ambra, Pasqua; Tartaglione, Gaetano

    2015-03-01

    Image segmentation addresses the problem to partition a given image into its constituent objects and then to identify the boundaries of the objects. This problem can be formulated in terms of a variational model aimed to find optimal approximations of a bounded function by piecewise-smooth functions, minimizing a given functional. The corresponding Euler-Lagrange equations are a set of two coupled elliptic partial differential equations with varying coefficients. Numerical solution of the above system often relies on alternating minimization techniques involving descent methods coupled with explicit or semi-implicit finite-difference discretization schemes, which are slowly convergent and poorly scalable with respect to image size. In this work we focus on generalized relaxation methods also coupled with multigrid linear solvers, when a finite-difference discretization is applied to the Euler-Lagrange equations of Ambrosio-Tortorelli model. We show that non-linear Gauss-Seidel, accelerated by inner linear iterations, is an effective method for large-scale image analysis as those arising from high-throughput screening platforms for stem cells targeted differentiation, where one of the main goal is segmentation of thousand of images to analyze cell colonies morphology.

  11. Reprint of Solution of Ambrosio-Tortorelli model for image segmentation by generalized relaxation method

    NASA Astrophysics Data System (ADS)

    D'Ambra, Pasqua; Tartaglione, Gaetano

    2015-04-01

    Image segmentation addresses the problem to partition a given image into its constituent objects and then to identify the boundaries of the objects. This problem can be formulated in terms of a variational model aimed to find optimal approximations of a bounded function by piecewise-smooth functions, minimizing a given functional. The corresponding Euler-Lagrange equations are a set of two coupled elliptic partial differential equations with varying coefficients. Numerical solution of the above system often relies on alternating minimization techniques involving descent methods coupled with explicit or semi-implicit finite-difference discretization schemes, which are slowly convergent and poorly scalable with respect to image size. In this work we focus on generalized relaxation methods also coupled with multigrid linear solvers, when a finite-difference discretization is applied to the Euler-Lagrange equations of Ambrosio-Tortorelli model. We show that non-linear Gauss-Seidel, accelerated by inner linear iterations, is an effective method for large-scale image analysis as those arising from high-throughput screening platforms for stem cells targeted differentiation, where one of the main goal is segmentation of thousand of images to analyze cell colonies morphology.

  12. A comparative study of variable selection methods in the context of developing psychiatric screening instruments.

    PubMed

    Lu, Feihan; Petkova, Eva

    2014-02-10

    The development of screening instruments for psychiatric disorders involves item selection from a pool of items in existing questionnaires assessing clinical and behavioral phenotypes. A screening instrument should consist of only a few items and have good accuracy in classifying cases and non-cases. Variable/item selection methods such as Least Absolute Shrinkage and Selection Operator (LASSO), Elastic Net, Classification and Regression Tree, Random Forest, and the two-sample t-test can be used in such context. Unlike situations where variable selection methods are most commonly applied (e.g., ultra high-dimensional genetic or imaging data), psychiatric data usually have lower dimensions and are characterized by the following factors: correlations and possible interactions among predictors, unobservability of important variables (i.e., true variables not measured by available questionnaires), amount and pattern of missing values in the predictors, and prevalence of cases in the training data. We investigate how these factors affect the performance of several variable selection methods and compare them with respect to selection performance and prediction error rate via simulations. Our results demonstrated that: (1) for complete data, LASSO and Elastic Net outperformed other methods with respect to variable selection and future data prediction, and (2) for certain types of incomplete data, Random Forest induced bias in imputation, leading to incorrect ranking of variable importance. We propose the Imputed-LASSO combining Random Forest imputation and LASSO; this approach offsets the bias in Random Forest and offers a simple yet efficient item selection approach for missing data. As an illustration, we apply the methods to items from the standard Autism Diagnostic Interview-Revised version. PMID:23934941

  13. Collaborative trial validation studies of real-time PCR-based GMO screening methods for detection of the bar gene and the ctp2-cp4epsps construct.

    PubMed

    Grohmann, Lutz; Brünen-Nieweler, Claudia; Nemeth, Anne; Waiblinger, Hans-Ulrich

    2009-10-14

    Polymerase Chain Reaction (PCR)-based screening methods targeting genetic elements commonly used in genetically modified (GM) plants are important tools for the detection of GM materials in food, feed, and seed samples. To expand and harmonize the screening capability of enforcement laboratories, the German Federal Office of Consumer Protection and Food Safety conducted collaborative trials for interlaboratory validation of real-time PCR methods for detection of the phosphinothricin acetyltransferase (bar) gene from Streptomyces hygroscopicus and a construct containing the 5-enolpyruvylshikimate-3-phosphate synthase gene from Agrobacterium tumefaciens sp. strain CP4 (ctp2-cp4epsps), respectively. To assess the limit of detection, precision, and accuracy of the methods, laboratories had to analyze two sets of 18 coded genomic DNA samples of events LLRice62 and MS8 with the bar method and NK603 and GT73 with the ctp2-cp4epsps method at analyte levels of 0, 0.02, and 0.1% GM content, respectively. In addition, standard DNAs were provided to the laboratories to generate calibration curves for copy number quantification of the bar and ctp2-cp4epsps target sequences present in the test samples. The study design and the results obtained are discussed with respect to the difficult issue of developing general guidelines and concepts for the collaborative trial validation of qualitative PCR screening methods. PMID:19807158

  14. Rapid determination of fluoroquinolone residues in honey by a microbiological screening method and liquid chromatography.

    PubMed

    Kanda, Maki; Kusano, Tomoto; Kanai, Setsuko; Hayashi, Hiroshi; Matushima, Yoko; Nakajima, Takayuki; Takeba, Kazue; Sasamoto, Takeo; Nagayma, Toshijiro

    2010-01-01

    A rapid and efficient method was developed for the simultaneous determination of seven fluoroquinolone (FQ) residues: norfloxacin, ciprofloxacin, danofloxacin, enrofloxacin, orbifloxacin, sarafloxacin, and difloxacin in honey. The samples were first screened with a microbiological method by using test plates made from metal-free purified agar seeded with Bacillus subtilis BGA. When a sample was found to contain FQ residues by using the microbiological method, it was analyzed by LC with fluorescence detection (LC/FL). FQs were extracted with Na2EDTA-McIlvaine buffer and purified by a dual SPE method in which a cation-exchange cartridge was connected to an anion-exchange cartridge. The overall recoveries of the seven FQs ranged from 70.0 to 92.1%. The intra-assay and interassay CVs were < or = 7.8 and < or = 5.1%, respectively. For the microbiological method, the LOD values ranged from 2 to 9 microg/kg. For LC/FL, the LOQ values ranged from 2 to 7 microg/kg. The developed method was used to analyze 70 honey samples. In 14 samples in which the microbiological method detected the presence of FQ residues, norfloxacin, ciprofloxacin, and enrofloxacin were identified by LC/FL. PMID:20922969

  15. A simple screening method using ion chromatography for the diagnosis of cerebral creatine deficiency syndromes.

    PubMed

    Wada, Takahito; Shimbo, Hiroko; Osaka, Hitoshi

    2012-08-01

    Cerebral creatine deficiency syndromes (CCDS) are caused by genetic defects in L-arginine:glycine amidinotransferase, guanidinoacetate methyltransferase or creatine transporter 1. CCDS are characterized by abnormal concentrations of urinary creatine (CR), guanidinoacetic acid (GA), or creatinine (CN). In this study, we describe a simple HPLC method to determine the concentrations of CR, GA, and CN using a weak-acid ion chromatography column with a UV detector without any derivatization. CR, GA, and CN were separated clearly with the retention times (mean ± SD, n = 3) of 5.54 ± 0.0035 min for CR, 6.41 ± 0.0079 min for GA, and 13.53 ± 0.046 min for CN. This new method should provide a simple screening test for the diagnosis of CCDS. PMID:22080216

  16. A simple colorimetric method to screen drug cytotoxicity against Leishmania using the dye Alamar Blue.

    PubMed

    Mikus, J; Steverding, D

    2000-01-01

    A quantitative colorimetric assay using the oxidation-reduction indicator Alamar Blue was developed to measure cytotoxicity of compounds against the protozoan parasite Leishmania. Absorbance increased linearly with the plating density of promastigotes of L. major MRHO/IR/76 vaccine strain up to at least 2.5 x 10(6) cells/ml when parasites were incubated for 72 h in the presence of 10% Alamar Blue. The 50% effective dose values of common drugs (amphotericin B, pentostam and paromomycin) obtained by this assay were in the same range as previously determined by other methods. The Alamar Blue assay permits a simple, reproducible and reliable method for screening antileishmanial drugs. PMID:11227767

  17. Advancement of Analysis Method for Electromagnetic Screening Effect of Viaducts for Railway

    NASA Astrophysics Data System (ADS)

    Okutani, Tamio; Nakamura, Nobuyuki; Terada, Natsuki; Tate, Yutaka; Inada, Satoshi; Ogawa, Tomoyuki; Son, Yoshio; Wakao, Shinji

    New method to estimate electromagnetic screening effect of rigid frame viaducts has been developed. Mutual relationship among the effects of electrical connecting manner of girding bridges; conductivity of the ground; and harmonic frequency was identified theoretically and numerically based on the results of multiple conductor circuit model simulations and field measurements using over 3km length test cables set on a viaduct section of Shinkansen line under construction. Adding, developed modeling method to simplify the equivalent circuit of vast amount of steel bars in the reinforced concrete accelerates the estimation process with enough accuracy. As the result, it became easy to calculate the induced voltage in the cables or in the track circuits with enough accuracy.

  18. [Screening methods for detection of metallo-beta-lactamase producing gram negative rods].

    PubMed

    Mereuţă, Ana-Irina; Poiati, Antonia; Tuchiluş, Cristina; Dorneanu, Olivia; Nistor, Silvia; Copăcianu, Brînduşa

    2005-01-01

    Modified Hodge test and a method using a disk with imipenem plus 1000 mg of EDTA were used to determine the presence of metallo-beta-lactamase producing gram-negative rods among 166 clinical isolates from hospitals in Iaşi and Galaţi. Of 9 imipenem resistant strains found, only one Pseudomonas aeruginosa gave positive results with both tests and other two P. aeruginosa clinical isolates gave negative results with both tests. The rest of the strains (2 P. aeruginosa, 2 Acinetobacter baumanii, 1 Sphingomonas paucimobilis) did not give conclusive results. These screening methods are useful, simple and accessible to clinical laboratories. PCR is needed to confirm the presence of metallo-beta-lactamase gene in bacteria and to determine the type of the enzymes. PMID:16607806

  19. Precise method for investigation of Lissajous generalized figures

    NASA Astrophysics Data System (ADS)

    Bednarek, Stanisław

    2014-07-01

    This article describes the Lissajous generalized figure and the original instrument for its investigation. Two specially prepared electrodynamic loudspeakers—a horizontal and a vertical—cause oscillations in two mirrors. It is possible to precisely control the motion of the mirrors, achieve a high frequency of oscillation and investigate anharmonic vibrations because loudspeakers are powered by electronic generators. Eccentric mounting, and rotation of a vertical loudspeaker, also allow composition of the oscillations in inclined directions, which generates Lissajous’ generalized figures.

  20. Ovarian Cancer Screening Method Fails to Reduce Deaths from the Disease

    Cancer.gov

    New results from the NCI-sponsored PLCO Cancer Screening Trial show that screening for ovarian cancer with transvaginal ultrasound (TVU) and the CA-125 blood test did not result in fewer deaths from the disease compared with usual care.

  1. Evaluating the merits of using brief measures of PTSD or general mental health measures in two-stage PTSD screening.

    PubMed

    Steele, Nicole M; Benassi, Helen P; Chesney, Catherine J; Nicholson, Cherie; Fogarty, Gerard J

    2014-12-01

    Psychological screening of large numbers of personnel returning from deployments should be as brief as possible without sacrificing the ability to detect individuals who are experiencing serious psychological difficulties. This study focused on screening for posttraumatic stress disorder (PTSD) symptomatology in 421 deployed male members of the Australian Army while they were on deployment and again 3 to 6 months after they returned home. The first aim was to evaluate the performance of the Primary Care--Posttraumatic Stress Disorder Screen (PC-PTSD) and a 4-item version of the 17-item Posttraumatic Stress Disorder Checklist (PCL). A second aim was to evaluate the role of the Kessler-10 (K10) in psychological screening. The results indicated that the short form of the PCL was a better substitute for the full PCL than the PC-PTSD. Other results suggested that a more efficient screening process can be achieved using an initial K10 screening followed by more intensive PTSD screening for people identified as high risk. An additional advantage of an initial K10 filter is that other forms of mental illness could also be targeted in the second-stage screening. PMID:25469974

  2. A real decoupled method and free interface component mode synthesis methods for generally damped systems

    NASA Astrophysics Data System (ADS)

    He, Huan; Wang, Tao; Chen, Guoping; Sun, Dongyang; Sun, Rujie

    2014-01-01

    This paper reports on the development of a new transformation method. In contrast to most existing mode transformation methods in which the first-order state-space equation of the damped vibration system is transformed into a decoupled form with complex coefficient matrices, using the decoupled method presented in this paper, the equation of the damped system can be decomposed into a decoupled equation with real coefficient matrices. Two new free interface component mode synthesis methods are also presented. The equivalent full-mode matrix of the damped structure is used to capture the effects of the higher-order modes. Additionally, this work modifies the compatibility conditions at the junctions that are employed in most of the previous component mode synthesis methods for generally damped systems. The first component mode synthesis method is performed in complex space, whereas the second method can be applied in real space. Because the coefficient matrices of the coupled equation constructed by the second component mode synthesis method are all real-valued, the solution of the eigenproblem for this coupled equation can be performed in real space as well. Additionally, numerical examples demonstrate the accuracy and validity of these two component mode synthesis methods.

  3. Accelerated screening methods for determining chemical and thermal stability of refrigerant-lubricant mixtures, Part 1: Method assessment. Final report

    SciTech Connect

    Kauffman, R.

    1993-04-01

    This report presents results of a literature search performed to identify analytical techniques suitable for accelerated screening of chemical and thermal stabilities of different refrigerant/lubricant combinations. Search focused on three areas: Chemical stability data of HFC-134a and other non-chlorine containing refrigerant candidates; chemical stability data of CFC-12, HCFC-22, and other chlorine containing refrigerants; and accelerated thermal analytical techniques. Literature was catalogued and an abstract was written for each journal article or technical report. Several thermal analytical techniques were identified as candidates for development into accelerated screening tests. They are easy to operate, are common to most laboratories, and are expected to produce refrigerant/lubricant stability evaluations which agree with the current stability test ANSI/ASHRAE (American National Standards Institute/American Society of Heating, Refrigerating, and Air-Conditioning Engineers) Standard 97-1989, ``Sealed Glass Tube Method to Test the Chemical Stability of Material for Use Within Refrigerant Systems.`` Initial results of one accelerated thermal analytical candidate, DTA, are presented for CFC-12/mineral oil and HCFC-22/mineral oil combinations. Also described is research which will be performed in Part II to optimize the selected candidate.

  4. Root-cubing and general root-powering methods for finding the zeros of polynomials

    NASA Technical Reports Server (NTRS)

    Bareiss, E. H.

    1969-01-01

    Mathematical analysis technique generalizes a root squaring and root cubing method into a general root powering method. The introduction of partitioned polynomials into this general root powering method simplifies the coding of the polynomial transformations into input data suitable for processing by computer. The method includes analytic functions.

  5. Current trends in virtual high throughput screening using ligand-based and structure-based methods.

    PubMed

    Sukumar, Nagamani; Das, Sourav

    2011-12-01

    High throughput in silico methods have offered the tantalizing potential to drastically accelerate the drug discovery process. Yet despite significant efforts expended by academia, national labs and industry over the years, many of these methods have not lived up to their initial promise of reducing the time and costs associated with the drug discovery enterprise, a process that can typically take over a decade and cost hundreds of millions of dollars from conception to final approval and marketing of a drug. Nevertheless structure-based modeling has become a mainstay of computational biology and medicinal chemistry, helping to leverage our knowledge of the biological target and the chemistry of protein-ligand interactions. While ligand-based methods utilize the chemistry of molecules that are known to bind to the biological target, structure-based drug design methods rely on knowledge of the three-dimensional structure of the target, as obtained through crystallographic, spectroscopic or bioinformatics techniques. Here we review recent developments in the methodology and applications of structure-based and ligand-based methods and target-based chemogenomics in Virtual High Throughput Screening (VHTS), highlighting some case studies of recent applications, as well as current research in further development of these methods. The limitations of these approaches will also be discussed, to give the reader an indication of what might be expected in years to come. PMID:21843144

  6. Generalized methods and solvers for noise removal from piecewise constant signals. II. New methods

    PubMed Central

    Little, Max A.; Jones, Nick S.

    2011-01-01

    Removing noise from signals which are piecewise constant (PWC) is a challenging signal processing problem that arises in many practical scientific and engineering contexts. In the first paper (part I) of this series of two, we presented background theory building on results from the image processing community to show that the majority of these algorithms, and more proposed in the wider literature, are each associated with a special case of a generalized functional, that, when minimized, solves the PWC denoising problem. It shows how the minimizer can be obtained by a range of computational solver algorithms. In this second paper (part II), using this understanding developed in part I, we introduce several novel PWC denoising methods, which, for example, combine the global behaviour of mean shift clustering with the local smoothing of total variation diffusion, and show example solver algorithms for these new methods. Comparisons between these methods are performed on synthetic and real signals, revealing that our new methods have a useful role to play. Finally, overlaps between the generalized methods of these two papers and others such as wavelet shrinkage, hidden Markov models, and piecewise smooth filtering are touched on. PMID:22003313

  7. Development of Screening Method for an Frail Elderly by Measurement Quantitative Lower Limb Muscular Strength

    NASA Astrophysics Data System (ADS)

    Yamashita, Kazuhiko; Iwakami, Yumi; Imaizumi, Kazuya; Sato, Mitsuru; Nakajima, Sawako; Ino, Shuichi; Kawasumi, Masashi; Ifukube, Tohru

    Falling is one of the most serious problems for the elderly. The aim of this study was to develop a screening method for identifying factors that increase the risk of falling among the elderly, particularly with regard to lower limb muscular strength. Subjects were 48 elderly volunteers, including 25 classed as healthy and 23 classed as frail. All subjects underwent measurement of lower limb muscular strength via toe gap force and measurement of muscle strength of the hip joint adductor via knee gap force. In the frail group, toe gap force of the right foot was 20% lower than that in the healthy group; toe gap force of the left foot in the frail group was 23% lower than that in the healthy group, while knee gap force was 20% lower. Furthermore, we found that combining left toe gap force and knee gap force gave the highest odds ratio (6.05) with 82.6% sensitivity and 56.0% specificity when the toe gap force was 24 N and the knee gap force was 100 N. Thus, lower limb muscular strength can be used for simple and efficient screening, and approaches to prevent falls can be based on quantitative data such as lower limb muscular strength.

  8. Benchmarking Methods and Data Sets for Ligand Enrichment Assessment in Virtual Screening

    PubMed Central

    Xia, Jie; Tilahun, Ermias Lemma; Reid, Terry-Elinor; Zhang, Liangren; Wang, Xiang Simon

    2014-01-01

    Retrospective small-scale virtual screening (VS) based on benchmarking data sets has been widely used to estimate ligand enrichments of VS approaches in the prospective (i.e. real-world) efforts. However, the intrinsic differences of benchmarking sets to the real screening chemical libraries can cause biased assessment. Herein, we summarize the history of benchmarking methods as well as data sets and highlight three main types of biases found in benchmarking sets, i.e. “analogue bias”, “artificial enrichment” and “false negative”. In addition, we introduced our recent algorithm to build maximum-unbiased benchmarking sets applicable to both ligand-based and structure-based VS approaches, and its implementations to three important human histone deacetylase (HDAC) isoforms, i.e. HDAC1, HDAC6 and HDAC8. The Leave-One-Out Cross-Validation (LOO CV) demonstrates that the benchmarking sets built by our algorithm are maximum-unbiased in terms of property matching, ROC curves and AUCs. PMID:25481478

  9. A fast and specific method to screen for intracellular amyloid inhibitors using bacterial model systems.

    PubMed

    Navarro, Susanna; Carija, Anita; Muñoz-Torrero, Diego; Ventura, Salvador

    2016-10-01

    The aggregation of a large variety of amyloidogenic proteins is linked to the onset of devastating human disorders. Therefore, there is an urgent need for effective molecules able to modulate the aggregative properties of these polypeptides in their natural environment, in order to prevent, delay or halt the progression of such diseases. On the one hand, the complexity and cost of animal models make them inefficient at early stages of drug discovery, where large chemical libraries are usually screened. On the other hand, in vitro aggregation assays in aqueous solutions hardly reproduce (patho)physiological conditions. In this context, because the formation of insoluble aggregates in bacteria shares mechanistic and functional properties with amyloid self-assembly in higher organisms, they have emerged as a promising system to model aggregation in the cell. Here we show that bacteria provide a powerful and cost-effective system to screen for amyloid inhibitors using fluorescence spectroscopy and flow cytometry, thanks to the ability of the novel red fluorescent ProteoStat dye to detect specifically intracellular amyloid-like aggregates. We validated the approach using the Alzheimer's linked Aβ40 and Aβ42 peptides and tacrine- and huprine-based aggregation inhibitors. Overall, the present method bears the potential to replace classical in vitro anti-aggregation assays. PMID:26608003

  10. Development of a screening method to identify regulators of MICA shedding.

    PubMed

    Kishikawa, Takahiro; Otsuka, Motoyuki; Ohno, Motoko; Yoshikawa, Takeshi; Sato, Masaya; Koike, Kazuhiko

    2015-10-01

    Immune cells, such as natural killer (NK) cells, recognize virally infected and transformed cells, and eliminate them through the interaction between NKG2D receptors on NK cells and NKG2D ligands on pathogenic cells. Shedding of NKG2D ligands is thought to be a type of counter-mechanism employed by pathogenic cells to evade from NKG2D-mediated immune surveillance. MHC class I polypeptide-related sequence A (MICA) is a prototypical NKG2D ligand. We previously reported that, in soluble form, MICA expression levels are significantly associated with hepatitis virus-induced hepatocellular carcinoma. Here, we report a MICA shedding assay that utilizes membrane-bound MICA tagged at its N-terminus with a nano-luciferase reporter to quantify MICA shedding into culture media. Using this method, we screened a compound library and identified putative regulators of MICA shedding that have the potential to enhance the immune reaction by simultaneously increasing cell surface MICA levels and decreasing soluble MICA levels. This shedding assay may be useful for screening regulators of cell surface molecule shedding. PMID:26299929

  11. A robust screening method for dietary agents that activate tumour-suppressor microRNAs

    PubMed Central

    Hagiwara, Keitaro; Gailhouste, Luc; Yasukawa, Ken; Kosaka, Nobuyoshi; Ochiya, Takahiro

    2015-01-01

    Certain dietary agents, such as natural products, have been reported to show anti-cancer effects. However, the underlying mechanisms of these substances in human cancer remain unclear. We recently found that resveratrol exerts an anti-cancer effect by upregulating tumour-suppressor microRNAs (miRNAs). In the current study, we aimed to identify new dietary products that have the ability to activate tumour-suppressor miRNAs and that therefore may serve as novel tools for the prevention and treatment of human cancers. We describe the generation and use of an original screening system based on a luciferase-based reporter vector for monitoring miR-200c tumour-suppressor activity. By screening a library containing 139 natural substances, three natural compounds — enoxolone, magnolol and palmatine chloride — were identified as being capable of inducing miR-200c expression in breast cancer cells at 10 μM. Moreover, these molecules suppressed the invasiveness of breast cancer cells in vitro. Next, we identified a molecular pathway by which the increased expression of miR-200c induced by natural substances led to ZEB1 inhibition and E-cadherin induction. These results indicate that our method is a valuable tool for a fast identification of natural molecules that exhibit tumour-suppressor activity in human cancer through miRNA activation. PMID:26423775

  12. The Trial of Drug Discovery using the In-Silico Screening Methods Developed by Pharmaceutical Innovation Value Chain

    NASA Astrophysics Data System (ADS)

    Inoue, Tsuyoshi; Matsumura, Hiroyoshi; Adachi, Hiroaki; Mori, Yusuke; Takano, Kazufumi; Murakami, Satoshi; Fukunishi, Yoshifumi; Nakamura, Haruki; Kinoshita, Takayoshi; Nakanishi, Isao; Okuno, Yasushi; Minakata, Satoshi; Mikami, Yoshiaki; Sakuma, Toshihiro; Kitajima, Masato; Fukuoka, Yoshitada; Takada, Toshikazu; Sakata, Tsuneaki

    We have recently established Pharmaceutical Innovation Value Chain collaborated by The SOSHO project (http://www.so-sho.jp) and The BioGrid Project (http://www.biogrid.jp/) to accelerate new drug development. The in-silico group calculated the matrices on the interaction between the proteins and chemical compounds, and developed the novel in-silico screening methods, Multiple Target Screening (MTS) and Docking score index (DSI), improving the hit rate of screening a lead compound. We have applied these methods for the two target enzymes; human hematopoietic prostaglandin D synthase (H-PGDS) and orotidine 5’-monophosphate decarboxylase from human malaria parasite plasmodium falciparum (PfOMPDC). The optimizing of HQL-79, one of the known inhibitors for human H-PGDS and the screening of lead compounds for both enzymes are in study.

  13. Screening for adverse events.

    PubMed

    Karson, A S; Bates, D W

    1999-02-01

    Adverse events (AEs) in medical patients are common, costly, and often preventable. Development of quality improvement programs to decrease the number and impact of AEs demands effective methods for screening for AEs on a routine basis. Here we describe the impact, types, and potential causes of AEs and review various techniques for identifying AEs. We evaluate the use of generic screening criteria in detail and describe a recent study of the sensitivity and specificity of individual generic screening criteria and combinations of these criteria. In general, the most sensitive screens were the least specific and no small sub-set of screens identified a large percentage of adverse events. Combinations of screens that were limited to administrative data were the least expensive, but none were particularly sensitive, although in practice they might be effective since routine screening is currently rarely done. As computer systems increase in sophistication sensitivity will improve. We also discuss recent studies that suggest that programs that screen for and identify AEs can be useful in reducing AE rates. While tools for identifying AEs have strengths and weaknesses, they can play an important role in organizations' quality improvement portfolios. PMID:10468381

  14. A cell–ECM screening method to predict breast cancer metastasis

    PubMed Central

    Barney, L.E.; Dandley, E.C.; Jansen, L.E.; Reich, N.G.; Mercurio, A.M.

    2015-01-01

    Breast cancer preferentially spreads to the bone, brain, liver, and lung. The clinical patterns of this tissue-specific spread (tropism) cannot be explained by blood flow alone, yet our understanding of what mediates tropism to these physically and chemically diverse tissues is limited. While the microenvironment has been recognized as a critical factor in governing metastatic colonization, the role of the extracellular matrix (ECM) in mediating tropism has not been thoroughly explored. We created a simple biomaterial platform with systematic control over the ECM protein density and composition to determine if integrin binding governs how metastatic cells differentiate between secondary tissue sites. Instead of examining individual behaviors, we compiled large patterns of phenotypes associated with adhesion to and migration on these controlled ECMs. In combining this novel analysis with a simple biomaterial platform, we created an in vitro fingerprint that is predictive of in vivo metastasis. This rapid biomaterial screen also provided information on how β1, α2, and α6 integrins might mediate metastasis in patients, providing insights beyond a purely genetic analysis. We propose that this approach of screening many cell–ECM interactions, across many different heterogeneous cell lines, is predictive of in vivo behavior, and is much simpler, faster, and more economical than complex 3D environments or mouse models. We also propose that when specifically applied toward the question of tissue tropism in breast cancer, it can be used to provide insight into certain integrin subunits as therapeutic targets. Insight, innovation, integration We developed a high-throughput method to rapidly screen cell adhesion, motility, and growth factor responses on biomaterial surfaces. This approach is analogous to systems biology, relying on cell phenotypes in lieu of genetics. We used this technique to reveal patterns of phenotypes associated with breast cancer metastasis to

  15. A Finger-Stick Whole-Blood HIV Self-Test as an HIV Screening Tool Adapted to the General Public

    PubMed Central

    Prazuck, Thierry; Karon, Stephen; Gubavu, Camelia; Andre, Jerome; Legall, Jean Marie; Bouvet, Elisabeth; Kreplak, Georges; Teglas, Jean Paul; Pialoux, Gilles

    2016-01-01

    Background In 2013, the French Health Authority approved the use of HIV self-tests in pharmacies for the general public. This screening tool will allow an increase in the number of screenings and a reduction in the delay between infection and diagnosis, thus reducing the risk of further infections. We previously compared 5 HIV-self test candidates (4 oral fluid and one whole blood) and demonstrated that the whole blood HIV test exhibited the optimal level of performance (sensitivity/specificity). We studied the practicability of an easy-to-use finger-stick whole blood HIV self-test “autotest VIH®”, when used in the general public. Methods and Materials This multicenter cross-sectional study involved 411 participants from the Parisian region (AIDES and HF association) between April and July 2014 and was divided into 2 separate studies: one evaluating the capability of participants to obtain an interpretable result using only the information notice, and a second evaluating the interpretation of test results, using a provided chart. Results A total of 411 consenting participants, 264 in the first study and 147 in the second, were included. All participants were over 18 years of age. In the first study, 99.2% of the 264 participants correctly administered the auto-test, and 21.2% needed, upon their request, telephone assistance. Ninety-two percent of participants responded that the test was easy/very easy to perform, and 93.5% did not find any difficulty obtaining a sufficient good quantity of blood. In the second study, 98.1% of the 147 participants correctly interpreted the results. The reading/interpretation errors concerned the negative (2.1%) or the indeterminate (3.3%) auto-tests. Conclusions The success rate of handling and interpretation of this self-test is very satisfactory, demonstrating its potential for use by the general public and its utility to increase the number of opportunities to detect HIV patients. PMID:26882229

  16. Screening for Depression in the General Population with the Center for Epidemiologic Studies Depression (CES-D): A Systematic Review with Meta-Analysis

    PubMed Central

    Vilagut, Gemma; Forero, Carlos G.; Barbaglia, Gabriela; Alonso, Jordi

    2016-01-01

    Objective We aimed to collect and meta-analyse the existing evidence regarding the performance of the Center for Epidemiologic Studies Depression (CES-D) for detecting depression in general population and primary care settings. Method Systematic literature search in PubMed and PsychINFO. Eligible studies were: a) validation studies of screening questionnaires with information on the accuracy of the CES-D; b) samples from general populations or primary care settings; c) standardized diagnostic interviews following standard classification systems used as gold standard; and d) English or Spanish language of publication. Pooled sensitivity, specificity, likelihood ratios and diagnostic odds ratio were estimated for several cut-off points using bivariate mixed effects models for each threshold. The summary receiver operating characteristic curve was estimated with Rutter and Gatsonis mixed effects models; area under the curve was calculated. Quality of the studies was assessed with the QUADAS tool. Causes of heterogeneity were evaluated with the Rutter and Gatsonis mixed effects model including each covariate at a time. Results 28 studies (10,617 participants) met eligibility criteria. The median prevalence of Major Depression was 8.8% (IQ range from 3.8% to 12.6%). The overall area under the curve was 0.87. At the cut-off 16, sensitivity was 0.87 (95% CI: 0.82–0.92), specificity 0.70 (95% CI: 0.65–0.75), and DOR 16.2 (95% CI: 10.49–25.10). Better trade-offs between sensitivity and specificity were observed (Sensitivity = 0.83, Specificity = 0.78, diagnostic odds ratio = 16.64) for cut-off 20. None of the variables assessed as possible sources of heterogeneity was found to be statistically significant. Conclusion The CES-D has acceptable screening accuracy in the general population or primary care settings, but it should not be used as an isolated diagnostic measure of depression. Depending on the test objectives, the cut-off 20 may be more adequate than the value

  17. Comparison of Adsorbed Mercury Screening Method With Cold-Vapor Atomic Absorption Spectrophotometry for Determination of Mercury in Soil

    NASA Technical Reports Server (NTRS)

    Easterling, Donald F.; Hovanitz, Edward S.; Street, Kenneth W.

    2000-01-01

    A field screening method for the determination of elemental mercury in environmental soil samples involves the thermal desorption of the mercury from the sample onto gold and then the thermal desorption from the gold to a gold-film mercury vapor analyzer. This field screening method contains a large number of conditions that could be optimized for the various types of soils encountered. In this study, the conditions were optimized for the determination of mercury in silty clay materials, and the results were comparable to the cold-vapor atomic absorption spectrophotometric method of determination. This paper discusses the benefits and disadvantages of employing the field screening method and provides the sequence of conditions that must be optimized to employ this method of determination on other soil types.

  18. Iterative methods for elliptic finite element equations on general meshes

    NASA Technical Reports Server (NTRS)

    Nicolaides, R. A.; Choudhury, Shenaz

    1986-01-01

    Iterative methods for arbitrary mesh discretizations of elliptic partial differential equations are surveyed. The methods discussed are preconditioned conjugate gradients, algebraic multigrid, deflated conjugate gradients, an element-by-element techniques, and domain decomposition. Computational results are included.

  19. Statistical methods for the analysis of a screening test for chronic beryllium disease

    SciTech Connect

    Frome, E.L.; Neubert, R.L.; Smith, M.H.; Littlefield, L.G.; Colyer, S.P.

    1994-10-01

    The lymphocyte proliferation test (LPT) is a noninvasive screening procedure used to identify persons who may have chronic beryllium disease. A practical problem in the analysis of LPT well counts is the occurrence of outlying data values (approximately 7% of the time). A log-linear regression model is used to describe the expected well counts for each set of test conditions. The variance of the well counts is proportional to the square of the expected counts, and two resistant regression methods are used to estimate the parameters of interest. The first approach uses least absolute values (LAV) on the log of the well counts to estimate beryllium stimulation indices (SIs) and the coefficient of variation. The second approach uses a resistant regression version of maximum quasi-likelihood estimation. A major advantage of the resistant regression methods is that it is not necessary to identify and delete outliers. These two new methods for the statistical analysis of the LPT data and the outlier rejection method that is currently being used are applied to 173 LPT assays. The authors strongly recommend the LAV method for routine analysis of the LPT.

  20. 21 CFR 130.12 - General methods for water capacity and fill of containers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false General methods for water capacity and fill of... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION FOOD STANDARDS: GENERAL General Provisions § 130.12 General methods for water capacity and fill of containers. For the purposes of regulations promulgated...

  1. 21 CFR 130.12 - General methods for water capacity and fill of containers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false General methods for water capacity and fill of containers. 130.12 Section 130.12 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION FOOD STANDARDS: GENERAL General Provisions § 130.12 General methods for water capacity and...

  2. A General Simulation Method for Multiple Bodies in Proximate Flight

    NASA Technical Reports Server (NTRS)

    Meakin, Robert L.

    2003-01-01

    Methods of unsteady aerodynamic simulation for an arbitrary number of independent bodies flying in close proximity are considered. A novel method to efficiently detect collision contact points is described. A method to compute body trajectories in response to aerodynamic loads, applied loads, and inter-body collisions is also given. The physical correctness of the methods are verified by comparison to a set of analytic solutions. The methods, combined with a Navier-Stokes solver, are used to demonstrate the possibility of predicting the unsteady aerodynamics and flight trajectories of moving bodies that involve rigid-body collisions.

  3. Health Screenings and Immunizations

    MedlinePlus

    ... your primary doctor. Blood Tests – A Common Screening Method (Source: National Heart, Lung, and Blood Institute) Click ... tests, see What Are Blood Tests? Other Screening Methods Doctors can't screen for all diseases and ...

  4. Evaluation of Stimulus Preference Assessment Methods with General Education Students

    ERIC Educational Resources Information Center

    Schanding, G. Thomas, Jr.; Tingstrom, Daniel H.; Sterling-Turner, Heather E.

    2009-01-01

    The current exploratory study examined the ability of three stimulus preference assessments to identify effective reinforcers for general education students. Four students from Grades K through 5 and their teachers participated. A student nomination, teacher nomination, and ongoing (daily) stimulus preference assessment were evaluated. The results…

  5. Precise Method for Investigation of Lissajous Generalized Figures

    ERIC Educational Resources Information Center

    Bednarek, Stanislaw

    2014-01-01

    This article describes the Lissajous generalized figure and the original instrument for its investigation. Two specially prepared electrodynamic loudspeakers--a horizontal and a vertical--cause oscillations in two mirrors. It is possible to precisely control the motion of the mirrors, achieve a high frequency of oscillation and investigate…

  6. Extending the alias Monte Carlo sampling method to general distributions

    SciTech Connect

    Edwards, A.L.; Rathkopf, J.A. ); Smidt, R.K. )

    1991-01-07

    The alias method is a Monte Carlo sampling technique that offers significant advantages over more traditional methods. It equals the accuracy of table lookup and the speed of equal probable bins. The original formulation of this method sampled from discrete distributions and was easily extended to histogram distributions. We have extended the method further to applications more germane to Monte Carlo particle transport codes: continuous distributions. This paper presents the alias method as originally derived and our extensions to simple continuous distributions represented by piecewise linear functions. We also present a method to interpolate accurately between distributions tabulated at points other than the point of interest. We present timing studies that demonstrate the method's increased efficiency over table lookup and show further speedup achieved through vectorization. 6 refs., 12 figs., 2 tabs.

  7. A novel method for screening of potential probiotics for high adhesion capability.

    PubMed

    Wang, Xin; Wu, Qinglong; Deng, Kan; Wei, Qiang; Hu, Ping; He, Jingjing; Liu, Huan; Zheng, Yong; Wei, Hua; Shah, Nagendra P; Chen, Tingtao

    2015-07-01

    To screen for potential probiotics with high adhesion capability, a chemostat model-based cultured human feces and denaturing gradient gel electrophoresis methods were applied, and the adhesion capability of the isolates was evaluated in vitro and in vivo. Lactobacillus plantarum (HM218749), Lactobacillus reuteri (EU547310), and Enterococcus faecalis (HM218543) were isolated from the slime on the chemostat wall, as these organisms could grow better at 37°C in an anaerobic environment and could resist harsh conditions (pH 1.5 and 0.30% bile salt). Lactobacillus plantarum, L. reuteri, and E. faecalis could adhere to HT-29 cells and reduce the adhesion of Shigella dysenteriae 2457, Staphylococcus aureus Cowan1, Enterobacter sakazakii 45401, and Escherichia coli 44102 to HT-29 cells. Moreover, the animal experiment showed that L. plantarum could adhere to mice intestine, increasing the number of lactobacilli and decreasing the number of enterococci. PMID:25912863

  8. Use of the dual-screen thru-tubing sand control method

    SciTech Connect

    Freiman, O.H.; Johnson, K.J.

    1995-12-31

    This paper will describe a new sand control method used in area of Ecuador, South America where workover rigs are not readily available. Sand production had been significantly affecting maintenance costs on surface and downhole production equipment and had impacted performance of the downhole jet pump, subsequently causing a decrease in well production. By installing a small-diameter, sintered metal gravel-pack screen across the perforation interval and placing the gravel-pack sand with coiled tubing, the sand production was successfully controlled. The procedure and equipment used to perform this technique as well as post job data that provide results obtained will also be presented. Noteworthy advantages, such as recompletion without removal of the existing production completion string and without use of a workover rig, will also be discussed.

  9. Use of the dual-screen thru-tubing sand control method

    SciTech Connect

    Freiman, O.H.; Johnson, K.J.

    1994-12-31

    This paper describes a new sand control method used in an area of Ecuador, South America where workover rigs are not readily available. Sand production had been significantly affecting maintenance costs on surface and downhole production equipment and had impacted performance of the downhole jet pump, subsequently causing a decrease in well production. By installing a small-diameter, sintered metal gravel-pack screen across the perforation interval and placing the gravel-pack sand with coiled tubing, the sand production was successfully controlled. The procedure and equipment used to perform this technique as well as post job data that provide results obtained is also presented. Noteworthy advantages, such as recompletion without removal of the existing production completion string and without use of a workover rig, is also discussed.

  10. Directed Differentiation of Embryonic Stem Cells Using a Bead-Based Combinatorial Screening Method

    PubMed Central

    Tarunina, Marina; Hernandez, Diana; Johnson, Christopher J.; Rybtsov, Stanislav; Ramathas, Vidya; Jeyakumar, Mylvaganam; Watson, Thomas; Hook, Lilian; Medvinsky, Alexander; Mason, Chris; Choo, Yen

    2014-01-01

    We have developed a rapid, bead-based combinatorial screening method to determine optimal combinations of variables that direct stem cell differentiation to produce known or novel cell types having pre-determined characteristics. Here we describe three experiments comprising stepwise exposure of mouse or human embryonic cells to 10,000 combinations of serum-free differentiation media, through which we discovered multiple novel, efficient and robust protocols to generate a number of specific hematopoietic and neural lineages. We further demonstrate that the technology can be used to optimize existing protocols in order to substitute costly growth factors with bioactive small molecules and/or increase cell yield, and to identify in vitro conditions for the production of rare developmental intermediates such as an embryonic lymphoid progenitor cell that has not previously been reported. PMID:25251366

  11. A new screening method for flunitrazepam in vodka and tequila by fluorescence spectroscopy.

    PubMed

    Leesakul, Nararak; Pongampai, Sirintip; Kanatharana, Proespichaya; Sudkeaw, Pravit; Tantirungrotechai, Yuthana; Buranachai, Chittanon

    2013-01-01

    A new screening method for flunitrazepam in colourless alcoholic beverages based on a spectroscopic technique is proposed. Absorption and steady-state fluorescence of flunitrazepam and its protonated form with various acids were investigated. The redshift of the wavelength of maximum absorption was distinctively observed in protonated flunitrazepam. An emissive fluorescence at 472 nm was detected in colourless spirits (vodka and tequila) at room temperature. 2-M perchloric acid was the most appropriated proton source. By using electron ionization mass spectrometry and time-dependent density functional theory calculations, the possible structure of protonated flunitrazepam was identified to be 2-nitro-N-methylacridone, an acridone derivative as opposed to 2-methylamino-5-nitro-2'-fluorobenzophenone, a benzophenone derivative. PMID:22354877

  12. Studies with the USF/NASA toxicity screening test method - Oxygen concentrations with various test conditions

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.; Solis, A. N.

    1977-01-01

    Continuing efforts to increase the versatility of the USF/NASA toxicity screening test method have included the use of different test conditions in order to simulate various fire environments. The use of air flow at flow rates of 16 to 48 ml/sec maintains oxygen concentrations above 19 percent throughout the 30 min exposure period, compared to above 16 percent without forced air flow. These levels of oxygen are well within the tolerance range of mice, and approach the oxygen levels found in many real fire situations. Proposed minimum oxygen levels based on experience with rats are unduly restrictive on the use of other species such as mice, and tend to eliminate the cost savings which may more than justify the selection of mice.

  13. Strategies and applications of combinatorial methods and high throughput screening to the discovery of non-noble metal catalyst

    NASA Astrophysics Data System (ADS)

    Bricker, Maureen L.; Sachtler, J. W. Adriaan; Gillespie, Ralph D.; McGonegal, Charles P.; Vega, Honorio; Bem, Dave S.; Holmgren, Jennifer S.

    2004-02-01

    The integrated End-to-End™ combinatorial process for catalyst preparation and screening, with emphasis on its capability to vary both process and compositional parameters will be demonstrated. Additionally, each step of the combinatorial screening process has been validated against results from traditional screening methods. The greatest challenge of all has been the adherence to the core concepts of the combinatorial approach. Catalyst libraries have been made and tested for naphthalene dehydrogenation chemistry. The preparation of these libraries has included the application of high throughput techniques for: metal impregnation; catalyst finishing; catalyst screening. The catalyst screening system has been used to find a non-noble metal catalyst system that can replace Pt in dehydrogenation applications in the petroleum industry. A proprietary catalytic composition was developed for the dehydrogenation of methylcyclohexane (MCH) to toluene starting with four non-noble metals of different proportions and four different supports (alumina, titania, zirconia and silica) prepared in different ways and applying a statistical design of experiments. These data demonstrate that all steps of catalyst preparation and screening are performed in a rapid, useful, high throughput manner. Data will be presented from the catalyst screening efforts will demonstrate that optimized metal composition is dependent on the support type.

  14. Noninvasive Assessment of Excessive Erythrocytosis as a Screening Method for Chronic Mountain Sickness at High Altitude.

    PubMed

    Vyas, Kaetan J; Danz, David; Gilman, Robert H; Wise, Robert A; León-Velarde, Fabiola; Miranda, J Jaime; Checkley, William

    2015-06-01

    Vyas, Kaetan J., David Danz, Robert H. Gilman, Robert A. Wise, Fabiola León-Velarde, J. Jaime Miranda, and William Checkley. Noninvasive assessment of excessive erythrocytosis as a screening method for chronic mountain sickness at high altitude. High Alt Med Biol 16:162-168, 2015.--Globally, over 140 million people are at risk of developing chronic mountain sickness, a common maladaptation to life at high altitude (>2500 meters above sea level). The diagnosis is contingent upon the identification of excessive erythrocytosis (EE). Current best practices to identify EE require a venous blood draw, which is cumbersome for large-scale surveillance. We evaluated two point-of-care biomarkers to screen for EE: noninvasive spot-check tests of total hemoglobin and oxyhemoglobin saturation (Pronto-7, Masimo Corporation). We conducted paired evaluations of total serum hemoglobin from a venous blood draw and noninvasive, spot-check testing of total hemoglobin and oxyhemoglobin saturation with the Pronto-7 in 382 adults aged ≥35 years living in Puno, Peru (3825 meters above sea level). We used the Bland-Altman method to measure agreement between the noninvasive hemoglobin assessment and the gold standard lab hemoglobin analyzer. Mean age was 58.8 years and 47% were male. The Pronto-7 test was unsuccessful in 21 (5%) participants. Limits of agreement between total hemoglobin measured via venous blood draw and the noninvasive, spot-check test ranged from -2.8 g/dL (95% CI -3.0 to -2.5) to 2.5 g/dL (95% CI 2.2 to 2.7), with a bias of -0.2 g/dL (95% CI -0.3 to -0.02) for the difference between total hemoglobin and noninvasive hemoglobin concentrations. Overall, the noninvasive spot-check test of total hemoglobin had a better area under the receiver operating characteristic curve compared to oxyhemoglobin saturation for the identification of EE as measured by a gold standard laboratory hemoglobin analyzer (0.96 vs. 0.82; p<0.001). Best cut-off values to screen for EE with

  15. Exact Solutions for The Generalized Zakharov-Kuznetsov Equation with Variable Coefficients Using The Generalized (G'/G)-expansion Method

    NASA Astrophysics Data System (ADS)

    Zayed, Elsayed M. E.; Abdelaziz, Mahmoud A. M.

    2010-09-01

    In this article, the generalized G'/G-expansion method using a generalized wave transformation is applied to find exact traveling wave solutions of the generalized Zakharov-Kuznetsov equation with variable coefficients. As a result, hyperbolic, trigonometric and rational function solutions with parameters are obtained. When these parameters are taken special values, the solitary wave solutions are derived from the hyperbolic function solution. It is shown that the proposed method is direct, effective and can be applied to many other nonlinear evolution equations in mathematical physics.

  16. SUDOSCAN: A Simple, Rapid, and Objective Method with Potential for Screening for Diabetic Peripheral Neuropathy

    PubMed Central

    Selvarajah, Dinesh; Cash, Tom; Davies, Jennifer; Sankar, Adithya; Rao, Ganesh; Grieg, Marni; Pallai, Shillo; Gandhi, Rajiv; Wilkinson, Iain D.; Tesfaye, Solomon

    2015-01-01

    Clinical methods of detecting diabetic peripheral neuropathy (DPN) are not objective and reproducible. We therefore evaluated if SUDOSCAN, a new method developed to provide a quick, non-invasive and quantitative assessment of sudomotor function can reliably screen for DPN. 70 subjects (45 with type 1 diabetes and 25 healthy volunteers [HV]) underwent detailed assessments including clinical, neurophysiological and 5 standard cardiovascular reflex tests (CARTs). Using the American Academy of Neurology criteria subjects were classified into DPN and No-DPN groups. Based on CARTs subjects were also divided into CAN, subclinical-CAN and no-CAN. Sudomotor function was assessed with measurement of hand and foot Electrochemical Skin Conductance (ESC) and calculation of the CAN risk score. Foot ESC (μS) was significantly lower in subjects with DPN [n = 24; 53.5(25.1)] compared to the No-DPN [77.0(7.9)] and HV [77.1(14.3)] groups (ANCOVA p<0.001). Sensitivity and specificity of foot ESC for classifying DPN were 87.5% and 76.2%, respectively. The area under the ROC curve (AUC) was 0.85. Subjects with CAN had significantly lower foot [55.0(28.2)] and hand [53.5(19.6)] ESC compared to No-CAN [foot ESC, 72.1(12.2); hand ESC 64.9(14.4)] and HV groups (ANCOVA p<0.001 and 0.001, respectively). ROC analysis of CAN risk score to correctly classify CAN revealed a sensitivity of 65.0% and specificity of 80.0%. AUC was 0.75. Both foot and hand ESC demonstrated strong correlation with individual parameters and composite scores of nerve conduction and CAN. SUDOSCAN, a non-invasive and quick test, could be used as an objective screening test for DPN in busy diabetic clinics, insuring adherence to current recommendation of annual assessments for all diabetic patients that remains unfulfilled. PMID:26457582

  17. Mitigating unwanted amorphisation: A screening method for the selection of suitable excipients.

    PubMed

    Amharar, Youness; Curtin, Vincent; Gallagher, Kieran H; O'Siochru, Eoin; O'Connell, Peter; Healy, Anne-Marie

    2016-01-01

    Co-processing an active pharmaceutical ingredient (API) with a low Tg excipient has been previously reported to be an effective strategy for preventing drug amorphisation on milling. This technique relies on the ability of the excipient to form a molecular dispersion with the amorphous API during the milling process. The presence of the excipient within the amorphous phase induces a reduction of the Tg. Hence, the molecular dispersion becomes less stable than the amorphous API alone and recrystallises upon milling. The objective of this study was to develop a screening method for the selection of suitable excipients to prevent amorphisation, based on two criteria: the Tg of the excipient and the solubility of the excipient in the amorphous API. The ability of the excipients to induce Tg reduction was first assessed by measuring the Tg of the amorphous composite by thermal analysis and comparing it with that of the pure API (griseofulvin). A predicted ability for mitigation of amorphisation upon milling was then deduced from these observations for each excipient and assessed against experimental results. The same excipients were then studied with regard to their expected solubility in another amorphous API (budesonide) by Hildebrand solubility parameter calculations in order to evaluate their capacity to form an amorphous composite with the drug. The predicted effects of the excipients on comilling were compared with the amorphous content of the processed API. The screening method as applied to both APIs showed good agreement with the experimental results and were shown to be efficient for the selection of the most appropriate excipient. This approach revealed that the two key parameters involved are the Tg of the excipient and the ability of the API to form an amorphous molecular dispersion with the excipients. This work confirms and completes our previously published results on the mitigation of the amorphisation by comilling with low Tg excipients and constitutes

  18. A method for fast safety screening of explosives in terms of crystal packing and molecular stability.

    PubMed

    Hu, Xiaohua; Chen, Nana; Li, Weichen

    2016-07-01

    Safety prediction is crucial to the molecular design or the material design of explosives, and the predictions based on any single factor alone will cause much inaccuracy, leading to a desire for a method on multi-bases. The presented proposes an improved method for fast screening explosive safety by combining a crystal packing factor and a molecular one, that is, steric hindrance against shear slide in crystal and molecular stability, denoted by intermolecular friction symbol (IFS) and bond dissociation energy (BDE) of trigger linkage respectively. Employing this BDE-IFS combined method, we understand the impact sensitivities of 24 existing explosives, and predict those of two energetic-energetic cocrystals of the observed CL-20/BTF and the supposed HMX/TATB. As a result, a better understanding is implemented by the combined method relative to molecular stability alone, verifying its improvement of more accurate predictions and the feasibility of IFS to graphically reflect molecular stacking in crystals. Also, this work verifies that the explosive safety is strongly related with its crystal stacking, which determines steric hindrance and influences shear slide. PMID:27365051

  19. Micellar electrokinetic chromatographic screening method for common sexual assault drugs administered in beverages.

    PubMed

    Bishop, Sandra C; Lerch, Margaret; McCord, Bruce R

    2004-04-20

    Recently, much attention has been given to benzodiazepines and gamma-hydroxybutyric acid (GHB) related compounds owing to their alleged widespread use as date-rape drugs. Toxicologists would greatly benefit from a screening method that allows for the simultaneous detection of both groups of substances. A new capillary electrophoresis (CE) method has been developed in the micellar mode to accomplish this separation in under 16 min using a sodium dodecyl sulfate (SDS)/sodium tetraborate/boric acid buffer with an acetonitrile organic modifier. Optimization of SDS and organic modifier concentration, along with pH, were performed on a set of standards containing eight benzodiazepines, GHB, gamma-butyrolactone, and the internal standard, sulfanilic acid. The method was shown to have a detection limit of less than 2 microg/ml for five out of eight benzodiazepines with a linear range of 2.5-100 microg/ml. The detection limit for GHB was 32 mg/ml with a linear range to 2500 microg/ml. This method was applied to the rapid analysis of spiked beverages. GHB spiked beverages were monitored after using a series of simple dilutions to determine the effects of time on the drug analysis. Possible interfering peaks from drugs of abuse and artifacts from a variety of different drink combinations were also studied in detail. A one-step liquid-liquid extraction was the only necessary sample pretreatment. PMID:15066708

  20. The Split-Spectrum Method for Differential InSAR Ionospheric Phase Screen Correction

    NASA Astrophysics Data System (ADS)

    Gomba, G.; Eineder, M.

    2015-12-01

    The differential ionospheric path delay is a major error source in L-band interferograms. It is superimposed to topography and ground deformation signals hindering the measurement of geophysical processes like earthquakes. Exploiting the ionosphere dispersive nature of the ionosphere, the method separates the ionospheric component of the interferometric phase from the non-dispersive component, related to topography, ground motion and tropospheric path delay. An implementation of the split-spectrum method is in this work exposed in detail and its performance is analyzed. We test the method using various ALOS PALSAR interferometric pairs with different characteristics: high to low coherence, moving and non-moving terrain, with and without topography and different ionosphere states. Ionospheric errors of almost one meter have been corrected to a centimeter or millimeter level. The results show how the method is able to systematically compensate the ionospheric phase in interferograms. In this work we also present ALOS PALSAR ionospheric-free interferograms and the related ionospheric phase screens for the 2015 Nepal earthquake, the 2008 Wenchuan earthquake, the 2008 Kyrgyzstan earthquake, and the 2011 Myanmar earthquke.

  1. A method for screening for the risk of chronic effects of surface water pollution.

    PubMed

    Soldán, Přemysl; Badurová, Jana

    2013-01-01

    The article describes a method for screening for the risk of chronic surface water pollution which was developed at the T. G. Masaryk Water Research Institute. The approach, which is based on exotoxicological analyses, can be classed as a rapid method of assessment. The degree of risk of chronic effects surface water pollution is determined from an evaluation of two major parameters-toxicity and genotoxicity. As the method utilizes relative simple procedures for sample collection, pretreatment of the sample, chemical analyses, bioassays and results assessment, this approach is suitable for widespread practical use. Extensive utilization of this approach for assessing river basins in the Czech Republic has proved its suitability for a more sophisticated detection of the biological impact of surface water pollution. This is documented in the article where the method is used in a study of the Bílina River, and in the overview of the results of the risk assessment of chronic effects of surface water pollution in selected sections of three international river basins in the Czech Republic. PMID:22318738

  2. A colony multiplex quantitative PCR-Based 3S3DBC method and variations of it for screening DNA libraries.

    PubMed

    An, Yang; Toyoda, Atsushi; Zhao, Chen; Fujiyama, Asao; Agata, Kiyokazu

    2015-01-01

    A DNA library is a collection of DNA fragments cloned into vectors and stored individually in host cells, and is a valuable resource for molecular cloning, gene physical mapping, and genome sequencing projects. To take the best advantage of a DNA library, a good screening method is needed. After describing pooling strategies and issues that should be considered in DNA library screening, here we report an efficient colony multiplex quantitative PCR-based 3-step, 3-dimension, and binary-code (3S3DBC) method we used to screen genes from a planarian genomic DNA fosmid library. This method requires only 3 rounds of PCR reactions and only around 6 hours to distinguish one or more desired clones from a large DNA library. According to the particular situations in different research labs, this method can be further modified and simplified to suit their requirements. PMID:25646755

  3. A Colony Multiplex Quantitative PCR-Based 3S3DBC Method and Variations of It for Screening DNA Libraries

    PubMed Central

    An, Yang; Toyoda, Atsushi; Zhao, Chen; Fujiyama, Asao; Agata, Kiyokazu

    2015-01-01

    A DNA library is a collection of DNA fragments cloned into vectors and stored individually in host cells, and is a valuable resource for molecular cloning, gene physical mapping, and genome sequencing projects. To take the best advantage of a DNA library, a good screening method is needed. After describing pooling strategies and issues that should be considered in DNA library screening, here we report an efficient colony multiplex quantitative PCR-based 3-step, 3-dimension, and binary-code (3S3DBC) method we used to screen genes from a planarian genomic DNA fosmid library. This method requires only 3 rounds of PCR reactions and only around 6 hours to distinguish one or more desired clones from a large DNA library. According to the particular situations in different research labs, this method can be further modified and simplified to suit their requirements. PMID:25646755

  4. 26 CFR 1.446-1 - General rule for methods of accounting.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 6 2013-04-01 2013-04-01 false General rule for methods of accounting. 1.446-1 Section 1.446-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Methods of Accounting § 1.446-1 General rule for methods of accounting. (a) General rule. (1)...

  5. 26 CFR 1.446-1 - General rule for methods of accounting.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 6 2014-04-01 2014-04-01 false General rule for methods of accounting. 1.446-1 Section 1.446-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Methods of Accounting § 1.446-1 General rule for methods of accounting. (a) General rule. (1)...

  6. UV-visible spectroscopy method for screening the chemical stability of potential antioxidants for proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Banham, Dustin; Ye, Siyu; Knights, Shanna; Stewart, S. Michael; Wilson, Mahlon; Garzon, Fernando

    2015-05-01

    A novel method based on UV-visible spectroscopy is reported for screening the chemical stability of potential antioxidant additives for proton exchange membrane fuel cells, and the chemical stabilities of three CeOx samples of varying crystallite sizes (6, 13, or 25 nm) are examined. The chemical stabilities predicted by this new screening method are compared to in-situ membrane electrode assembly (MEA) accelerated stress testing, with the results confirming that this rapid and inexpensive method can be used to accurately predict performance impacts of antioxidants.

  7. [A hybrid volume rendering method using general hardware].

    PubMed

    Li, Bin; Tian, Lianfang; Chen, Ping; Mao, Zongyuan

    2008-06-01

    In order to improve the effect and efficiency of the reconstructed image after hybrid volume rendering of different kinds of volume data from medical sequential slices or polygonal models, we propose a hybrid volume rendering method based on Shear-Warp with economical hardware. First, the hybrid volume data are pre-processed by Z-Buffer method and RLE (Run-Length Encoded) data structure. Then, during the process of compositing intermediate image, a resampling method based on the dual-interpolation and the intermediate slice interpolation methods is used to improve the efficiency and the effect. Finally, the reconstructed image is rendered by the texture-mapping technology of OpenGL. Experiments demonstrate the good performance of the proposed method. PMID:18693424

  8. Utilization of breast cancer screening methods in a developing nation: results from a nationally representative sample of Malaysian households.

    PubMed

    Dunn, Richard A; Tan, Andrew K G

    2011-01-01

    As is the case in many developing nations, previous studies of breast cancer screening behavior in Malaysia have used relatively small samples that are not nationally representative, thereby limiting the generalizability of results. Therefore, this study uses nationally representative data from the Malaysia Non-Communicable Disease Surveillance-1 to investigate the role of socio-economic status on breast cancer screening behavior in Malaysia, particularly differences in screening behaviour between ethnic groups. The decisions of 816 women above age 40 in Malaysia to screen for breast cancer using mammography, clinical breast exams (CBE), and breast self-exams (BSE) are modeled using logistic regression. Results indicate that after adjusting for differences in age, education, household income, marital status, and residential location, Malay women are less likely than Chinese and Indian women to utilize mammography, but more likely to perform BSE. Education level and urban residence are positively associated with utilization of each method, but these relationships vary across ethnicity. Higher education levels are strongly related to using each screening method among Chinese women, but have no statistically significant relationship to screening among Malays. PMID:21615819

  9. FMM-Yukawa: An adaptive fast multipole method for screened Coulomb interactions

    NASA Astrophysics Data System (ADS)

    Huang, Jingfang; Jia, Jun; Zhang, Bo

    2009-11-01

    A Fortran program package is introduced for the rapid evaluation of the screened Coulomb interactions of N particles in three dimensions. The method utilizes an adaptive oct-tree structure, and is based on the new version of fast multipole method in which the exponential expansions are used to diagonalize the multipole-to-local translations. The program and its full description, as well as several closely related packages are also available at http://www.fastmultipole.org/. This paper is a brief review of the program and its performance. Catalogue identifier: AEEQ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEQ_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GPL 2.0 No. of lines in distributed program, including test data, etc.: 12 385 No. of bytes in distributed program, including test data, etc.: 79 222 Distribution format: tar.gz Programming language: Fortran77 and Fortran90 Computer: Any Operating system: Any RAM: Depends on the number of particles, their distribution, and the adaptive tree structure Classification: 4.8, 4.12 Nature of problem: To evaluate the screened Coulomb potential and force field of N charged particles, and to evaluate a convolution type integral where the Green's function is the fundamental solution of the modified Helmholtz equation. Solution method: An adaptive oct-tree is generated, and a new version of fast multipole method is applied in which the "multipole-to-local" translation operator is diagonalized. Restrictions: Only three and six significant digits accuracy options are provided in this version. Unusual features: Most of the codes are written in

  10. Constraint factor graph cut–based active contour method for automated cellular image segmentation in RNAi screening

    PubMed Central

    CHEN, C.; LI, H.; ZHOU, X.; WONG, S. T. C.

    2010-01-01

    Summary Image-based, high throughput genome-wide RNA interference (RNAi) experiments are increasingly carried out to facilitate the understanding of gene functions in intricate biological processes. Automated screening of such experiments generates a large number of images with great variations in image quality, which makes manual analysis unreasonably time-consuming. Therefore, effective techniques for automatic image analysis are urgently needed, in which segmentation is one of the most important steps. This paper proposes a fully automatic method for cells segmentation in genome-wide RNAi screening images. The method consists of two steps: nuclei and cytoplasm segmentation. Nuclei are extracted and labelled to initialize cytoplasm segmentation. Since the quality of RNAi image is rather poor, a novel scale-adaptive steerable filter is designed to enhance the image in order to extract long and thin protrusions on the spiky cells. Then, constraint factor GCBAC method and morphological algorithms are combined to be an integrated method to segment tight clustered cells. Compared with the results obtained by using seeded watershed and the ground truth, that is, manual labelling results by experts in RNAi screening data, our method achieves higher accuracy. Compared with active contour methods, our method consumes much less time. The positive results indicate that the proposed method can be applied in automatic image analysis of multi-channel image screening data. PMID:18445146

  11. From CBCL to DSM: A Comparison of Two Methods to Screen for DSM-IV Diagnoses Using CBCL Data

    ERIC Educational Resources Information Center

    Krol, Nicole P. C. M.; De Bruyn, Eric E. J.; Coolen, Jolanda C.; van Aarle, Edward J. M.

    2006-01-01

    The screening efficiency of 2 methods to convert Child Behavior Checklist (CBCL) assessment data into Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]; American Psychiatric Association, 1994) diagnoses was compared. The Machine-Aided Diagnosis (MAD) method converts CBCL input data directly into DSM-IV symptom criteria. The…

  12. A general, mass-preserving Navier-Stokes projection method

    NASA Astrophysics Data System (ADS)

    Salac, David

    2016-07-01

    The conservation of mass is a common issue with multiphase fluid simulations. In this work a novel projection method is presented which conserves mass both locally and globally. The fluid pressure is augmented with a time-varying component which accounts for any global mass change. The resulting system of equations is solved using an efficient Schur-complement method. Using the proposed method four numerical examples are performed: the evolution of a static bubble, the rise of a bubble, the breakup of a thin fluid thread, and the extension of a droplet in shear flow. The method is capable of conserving the mass even in situations with morphological changes such as droplet breakup.

  13. Generalized multiscale finite element method. Symmetric interior penalty coupling

    NASA Astrophysics Data System (ADS)

    Efendiev, Y.; Galvis, J.; Lazarov, R.; Moon, M.; Sarkis, M.

    2013-12-01

    Motivated by applications to numerical simulations of flows in highly heterogeneous porous media, we develop multiscale finite element methods for second order elliptic equations. We discuss a multiscale model reduction technique in the framework of the discontinuous Galerkin finite element method. We propose two different finite element spaces on the coarse mesh. The first space is based on a local eigenvalue problem that uses an interior weighted L2-norm and a boundary weighted L2-norm for computing the “mass” matrix. The second choice is based on generation of a snapshot space and subsequent selection of a subspace of a reduced dimension. The approximation with these multiscale spaces is based on the discontinuous Galerkin finite element method framework. We investigate the stability and derive error estimates for the methods and further experimentally study their performance on a representative number of numerical examples.

  14. Rapid Methods for the Detection of General Fecal Indicators

    EPA Science Inventory

    Specified that EPA should develop: appropriate and effective indicators for improving detection in a timely manner of pathogens in coastal waters appropriate, accurate, expeditious and cost-effective methods for the timely detection of pathogens in coastal waters

  15. A Rapid and Quantitative Fluorimetric Method for Protein-Targeting Small Molecule Drug Screening.

    PubMed

    Yu, Yong; New, Siu Yee; Lin, Jiaxian; Su, Xiaodi; Tan, Yen Nee

    2015-01-01

    We demonstrate a new drug screening method for determining the binding affinity of small drug molecules to a target protein by forming fluorescent gold nanoclusters (Au NCs) within the drug-loaded protein, based on the differential fluorescence signal emitted by the Au NCs. Albumin proteins such as human serum albumin (HSA) and bovine serum albumin (BSA) are selected as the model proteins. Four small molecular drugs (e.g., ibuprofen, warfarin, phenytoin, and sulfanilamide) of different binding affinities to the albumin proteins are tested. It was found that the formation rate of fluorescent Au NCs inside the drug loaded albumin protein under denaturing conditions (i.e., 60 °C or in the presence of urea) is slower than that formed in the pristine protein (without drugs). Moreover, the fluorescent intensity of the as-formed NCs is found to be inversely correlated to the binding affinities of these drugs to the albumin proteins. Particularly, the higher the drug-protein binding affinity, the slower the rate of Au NCs formation, and thus a lower fluorescence intensity of the resultant Au NCs is observed. The fluorescence intensity of the resultant Au NCs therefore provides a simple measure of the relative binding strength of different drugs tested. This method is also extendable to measure the specific drug-protein binding constant (KD) by simply varying the drug content preloaded in the protein at a fixed protein concentration. The measured results match well with the values obtained using other prestige but more complicated methods. PMID:26555855

  16. LC-MS method for screening unknown microbial carotenoids and isoprenoid quinones.

    PubMed

    Kaiser, Philipp; Geyer, Roland; Surmann, Peter; Fuhrmann, Herbert

    2012-01-01

    The structure of secondary metabolites from microorganisms provides a useful tool for microbial characterization and chemotaxonomic classification. Microbial isoprenoid quinones, for example, are well described and used to distinguish among photosynthetic microorganism groups. In addition, isoprenoid quinones can also be found, together with carotenoids, in non-photosynthetic microorganisms. The aim of the present study was to develop a LC-MS/MS method which can analyze and identify these microbial isoprenoids. Positive atmospheric pressure chemical ionization (APCI) together with collisionally induced dissociation was applied for generation of informative fragment spectra by mass spectrometry. Enhanced product ion (EPI) scan in a linear ion trap with information dependent data acquisition (IDA) enabled generation of MS fragment data even from minor isoprenoids. The developed liquid chromatography method enabled separation of isoprenoid patterns from their ester derivatives. Discovery and structural characterization of isoprenoid quinones and carotenoids were carried out by comparing characteristics of fragment spectra from unknown compounds with fragment spectra of a range of isoprenoid standard compounds and using published data. Throughout the study 17 microorganisms (e.g., Acremonium butyri, Arthrobacter spp., Brevibacterium linens, Bullera variabilis, Exophiala dermatitidis, Lecythophora hoffmannii, Panthoea agglomerans, Rhodotorula spp., Xanthophyllomyces dendrorhous) were screened and probable structures of isoprenoid quinones and carotenoids were suggested. The method lays some foundations on the analysis of yet unknown isoprenoids in microorganisms by using LCMS/MS techniques. PMID:22036764

  17. Methods for transforming and expression screening of filamentous fungal cells with a DNA library

    SciTech Connect

    Teter, Sarah; Lamsa, Michael; Cherry, Joel; Ward, Connie

    2015-06-02

    The present invention relates to methods for expression screening of filamentous fungal transformants, comprising: (a) isolating single colony transformants of a DNA library introduced into E. coli; (b) preparing DNA from each of the single colony E. coli transformants; (c) introducing a sample of each of the DNA preparations of step (b) into separate suspensions of protoplasts of a filamentous fungus to obtain transformants thereof, wherein each transformant contains one or more copies of an individual polynucleotide from the DNA library; (d) growing the individual filamentous fungal transformants of step (c) on selective growth medium, thereby permitting growth of the filamentous fungal transformants, while suppressing growth of untransformed filamentous fungi; and (e) measuring activity or a property of each polypeptide encoded by the individual polynucleotides. The present invention also relates to isolated polynucleotides encoding polypeptides of interest obtained by such methods, to nucleic acid constructs, expression vectors, and recombinant host cells comprising the isolated polynucleotides, and to methods of producing the polypeptides encoded by the isolated polynucleotides.

  18. A fluorescence high throughput screening method for the detection of reactive electrophiles as potential skin sensitizers.

    PubMed

    Avonto, Cristina; Chittiboyina, Amar G; Rua, Diego; Khan, Ikhlas A

    2015-12-01

    Skin sensitization is an important toxicological end-point in the risk assessment of chemical allergens. Because of the complexity of the biological mechanisms associated with skin sensitization, integrated approaches combining different chemical, biological and in silico methods are recommended to replace conventional animal tests. Chemical methods are intended to characterize the potential of a sensitizer to induce earlier molecular initiating events. The presence of an electrophilic mechanistic domain is considered one of the essential chemical features to covalently bind to the biological target and induce further haptenation processes. Current in chemico assays rely on the quantification of unreacted model nucleophiles after incubation with the candidate sensitizer. In the current study, a new fluorescence-based method, 'HTS-DCYA assay', is proposed. The assay aims at the identification of reactive electrophiles based on their chemical reactivity toward a model fluorescent thiol. The reaction workflow enabled the development of a High Throughput Screening (HTS) method to directly quantify the reaction adducts. The reaction conditions have been optimized to minimize solubility issues, oxidative side reactions and increase the throughput of the assay while minimizing the reaction time, which are common issues with existing methods. Thirty-six chemicals previously classified with LLNA, DPRA or KeratinoSens™ were tested as a proof of concept. Preliminary results gave an estimated 82% accuracy, 78% sensitivity, 90% specificity, comparable to other in chemico methods such as Cys-DPRA. In addition to validated chemicals, six natural products were analyzed and a prediction of their sensitization potential is presented for the first time. PMID:26455772

  19. Identification of imprinted genes using a novel screening method based on asynchronous DNA replication

    SciTech Connect

    Kawame, H.; Hansen, R.S.; Gartler, S.M.

    1994-09-01

    Genomic imprinting refers to the process of epigenetic change that occurs during germ cell development that results in either maternal- or paternal-specific gene expression. Identification of imprinted genes is of primary importance to the understanding of imprinting mechanisms and the role of specific imprinted genes in human disease. Recently, it has been established that chromosomal regions known to contain imprinted genes replicate asynchronously. We propose a novel screening method to identify imprinted genes based on replication asynchrony as a marker for imprinted domains. Dividing human cells were pulse-labeled with BrdU and separated into different fractions of S-phase by flow cytometry. A library of late-replicating inter-Alu sequences should be enriched in gene-associated sequences that replicate early on one chromosome and late on the other homologue. Clones were analyzed for replication timing by hybridization to inter-Alu replication profiles. Candidates for replication asynchrony exhibited broad or biphasic replication timing, and these were analyzed for chromosomal location by hybridizations to inter-Alu products from a hybrid mapping panel. Initial screening of 123 clones resulted in 3 asynchronously-replicating clones that localized to single chromosomes. Chromosome 17 and chromosome 19 candidates might be located in regions thought to be imprinted by synteny with mouse chromosomes. A chromosome 15 clone was further characterized because of its possible localization to the Prader-Willi/Angelman locus. This sequence was localized outside the region deleted in Prader-Willi patients, and was found to be expressed in human cell lines. Replication asynchrony for this sequence appears to be polymorphic because cells derived from some individuals indicated synchronous replication. This appears to be the first example of a polymorphism in replication asynchrony.

  20. LC-MS/MS screening method for designer amphetamines, tryptamines, and piperazines in serum.

    PubMed

    Wohlfarth, Ariane; Weinmann, Wolfgang; Dresen, Sebastian

    2010-04-01

    Since the late 1990s and early 2000s, derivatives of well-known designer drugs as well as new psychoactive compounds have been sold on the illicit drug market and have led to intoxications and fatalities. The LC-MS/MS screening method presented covers 31 new designer drugs as well as cathinone, methcathinone, phencyclidine, and ketamine which were included to complete the screening spectrum. All but the last two are modified molecular structures of amphetamine, tryptamine, or piperazine. Among the amphetamine derivatives are cathinone, methcathinone, 3,4-DMA, 2,5-DMA, DOB, DOET, DOM, ethylamphetamine, MDDMA, 4-MTA, PMA, PMMA, 3,4,5-TMA, TMA-6 and members of the 2C group: 2C-B, 2C-D, 2C-H, 2C-I, 2C-P, 2C-T-2, 2C-T-4, and 2C-T-7. AMT, DPT, DiPT, MiPT, DMT, and 5MeO-DMT are contained in the tryptamine group, BZP, MDBP, TFMPP, mCPP, and MeOPP in the piperazine group. Using an Applied Biosystems LC-MS/MS API 365 TurboIonSpray it is possible to identify all 35 substances. After addition of internal standards and mixed-mode solid-phase extraction the analytes are separated using a Synergi Polar RP column and gradient elution with 1 mM ammonium formate and methanol/0.1% formic acid as mobile phases A and B. Data acquisition is performed in MRM mode with positive electro spray ionization. The assay is selective for all tested substances. Limits of detection were determined by analyzing S/N-ratios and are between 1.0 and 5.0 ng/mL. Matrix effects lie between 65% and 118%, extraction efficiencies range from 72% to 90%. PMID:20069283

  1. Choosing the optimal method in programmatic colorectal cancer screening: current evidence and controversies

    PubMed Central

    2015-01-01

    Colorectal cancer (CRC) is an important health problem all over the world, being the third most common cancer and the second leading cause of cancer-related death in Western countries. The most important strategy for CRC prevention is screening (i.e. secondary prevention). Since it is widely accepted that adenomas and serrated polyps are the precursors of the vast majority of CRC, early detection and removal of these lesions is associated with a reduction of CRC incidence and, consequently, mortality. Moreover, cancers detected by screening are usually diagnosed at early stages and, therefore, curable by endoscopic or surgical procedures. This review will be address CRC screening strategies in average-risk population, which is defined by those individuals, men and women, 50 years of age or older, without any additional personal or familial predisposing risk factor. In order to maximize the impact of screening and ensure high coverage and equity of access, only organized screening programs (i.e. programmatic screening) should be implemented, as opposed to case-finding or opportunistic screening. For that reason and considering that the optimal approach for colorectal screening may differ depending on the scenario, this review will be focused on the advantages and limitations of each screening strategy in an organized setting. PMID:26136839

  2. Physical methods of nucleic acid transfer: general concepts and applications

    PubMed Central

    Villemejane, Julien; Mir, Lluis M

    2009-01-01

    Physical methods of gene (and/or drug) transfer need to combine two effects to deliver the therapeutic material into cells. The physical methods must induce reversible alterations in the plasma membrane to allow the direct passage of the molecules of interest into the cell cytosol. They must also bring the nucleic acids in contact with the permeabilized plasma membrane or facilitate access to the inside of the cell. These two effects can be achieved in one or more steps, depending upon the methods employed. In this review, we describe and compare several physical methods: biolistics, jet injection, hydrodynamic injection, ultrasound, magnetic field and electric pulse mediated gene transfer. We describe the physical mechanisms underlying these approaches and discuss the advantages and limitations of each approach as well as its potential application in research or in preclinical and clinical trials. We also provide conclusions, comparisons, and projections for future developments. While some of these methods are already in use in man, some are still under development or are used only within clinical trials for gene transfer. The possibilities offered by these methods are, however, not restricted to the transfer of genes and the complementary uses of these technologies are also discussed. As these methods of gene transfer may bypass some of the side effects linked to viral or biochemical approaches, they may find their place in specific clinical applications in the future. This article is part of a themed section on Vector Design and Drug Delivery. For a list of all articles in this section see the end of this paper, or visit: http://www3.interscience.wiley.com/journal/121548564/issueyear?year=2009 PMID:19154421

  3. A new general 1-D vadose zone flow solution method

    NASA Astrophysics Data System (ADS)

    Ogden, Fred L.; Lai, Wencong; Steinke, Robert C.; Zhu, Jianting; Talbot, Cary A.; Wilson, John L.

    2015-06-01

    We have developed an alternative to the one-dimensional partial differential equation (PDE) attributed to Richards (1931) that describes unsaturated porous media flow in homogeneous soil layers. Our solution is a set of three ordinary differential equations (ODEs) derived from unsaturated flux and mass conservation principles. We used a hodograph transformation, the Method of Lines, and a finite water-content discretization to produce ODEs that accurately simulate infiltration, falling slugs, and groundwater table dynamic effects on vadose zone fluxes. This formulation, which we refer to as "finite water-content", simulates sharp fronts and is guaranteed to conserve mass using a finite-volume solution. Our ODE solution method is explicitly integrable, does not require iterations and therefore has no convergence limits and is computationally efficient. The method accepts boundary fluxes including arbitrary precipitation, bare soil evaporation, and evapotranspiration. The method can simulate heterogeneous soils using layers. Results are presented in terms of fluxes and water content profiles. Comparing our method against analytical solutions, laboratory data, and the Hydrus-1D solver, we find that predictive performance of our finite water-content ODE method is comparable to or in some cases exceeds that of the solution of Richards' equation, with or without a shallow water table. The presented ODE method is transformative in that it offers accuracy comparable to the Richards (1931) PDE numerical solution, without the numerical complexity, in a form that is robust, continuous, and suitable for use in large watershed and land-atmosphere simulation models, including regional-scale models of coupled climate and hydrology.

  4. Collaborative study of a microbiological screening method (three-plate) for the banned antimicrobial growth promotors tylosin, virginiamycin, spiramycin, zinc bacitracin and avoparcin in animal feed.

    PubMed

    Pol-Hofstad, I; Driessen-Van Lankveld, W; Tomassen, M; De Jong, J; Van Egmond, H

    2008-12-01

    A microbiological screening method (three-plate) for the detection of the antimicrobial growth promoters tylosin, spiramycin, virginiamycin, zinc bacitracin, and avoparcin in animal feed has been developed and validated successfully. A collaborative study involving 18 laboratories receiving 172 samples was carried out to verify the performance characteristics. The detection level for tylosin/virginiamycin/spiramycin, expressed in microbiological activity, was 1 mg kg(-1) (false-positives, 2%; false-negatives, 3, 0, and 6%, respectively). Avoparcin could be detected at 1 mg kg(-1) in feed in general (false-positives, 2%; false-negatives, 0%). However, in calf feed the sensitivity was lower. The percentages of false-negatives were found to be 12%, 7%, and 0% at 1, 3, and 5 mg kg(-1), respectively (false-positives, 4%). The limit of detection for zinc bacitracin was 3-5 mg kg(-1) (false-positives, 5-10%; false-negatives, 77% at 1 mg kg(-1), 45% at 2 mg kg(-1), 12% at 3 mg kg(-1), and 4% at 5 mg kg(-1)). The method allowed for a distinction to be made between the groups of antibiotics: avoparcin/zinc bacitracin versus tylosin/virginiamycin/spiramycin. This definitely gives added value to the method in the framework of a follow-up of positive screening results by post-screening and confirmatory analysis. PMID:19680856

  5. [General calculation method of diffraction efficiency of concave blazed gratings].

    PubMed

    Li, Ting; Huang, Yuan-Shen; Xu, Bang-Lian; Li, Bai-Cheng; Zhang, Da-Wei; Tao, Chun-Xian; Ling, Jin-Zhong; Zhuang, Song-Lin

    2013-07-01

    In order to make diffraction energy of concave gratings more concentrated in the desired order, the present paper puts forward that the concave blazed grating with variable groove angles could be fabricated on the concave substrates by mechanical ruling method, and the theoretical method of simultaneously calculating the diffraction efficiency in the main section and non-main section is deduced by using Fresnel-Kirchhoff's diffraction formula, which makes up the shortage of the diffraction efficiency calculated only in the main section. Finally, the diffraction efficiency curves varied with wavelength is simulated by Matlab software, and the variation laws of the diffraction efficiency are compared for different production methods and application parameters, which provides a valuable reference for the design and production of the concave gratings. PMID:24059218

  6. Generalized framework for context-specific metabolic model extraction methods

    PubMed Central

    Robaina Estévez, Semidán; Nikoloski, Zoran

    2014-01-01

    Genome-scale metabolic models (GEMs) are increasingly applied to investigate the physiology not only of simple prokaryotes, but also eukaryotes, such as plants, characterized with compartmentalized cells of multiple types. While genome-scale models aim at including the entirety of known metabolic reactions, mounting evidence has indicated that only a subset of these reactions is active in a given context, including: developmental stage, cell type, or environment. As a result, several methods have been proposed to reconstruct context-specific models from existing genome-scale models by integrating various types of high-throughput data. Here we present a mathematical framework that puts all existing methods under one umbrella and provides the means to better understand their functioning, highlight similarities and differences, and to help users in selecting a most suitable method for an application. PMID:25285097

  7. A General Interface Method for Aeroelastic Analysis of Aircraft

    NASA Technical Reports Server (NTRS)

    Tzong, T.; Chen, H. H.; Chang, K. C.; Wu, T.; Cebeci, T.

    1996-01-01

    The aeroelastic analysis of an aircraft requires an accurate and efficient procedure to couple aerodynamics and structures. The procedure needs an interface method to bridge the gap between the aerodynamic and structural models in order to transform loads and displacements. Such an interface method is described in this report. This interface method transforms loads computed by any aerodynamic code to a structural finite element (FE) model and converts the displacements from the FE model to the aerodynamic model. The approach is based on FE technology in which virtual work is employed to transform the aerodynamic pressures into FE nodal forces. The displacements at the FE nodes are then converted back to aerodynamic grid points on the aircraft surface through the reciprocal theorem in structural engineering. The method allows both high and crude fidelities of both models and does not require an intermediate modeling. In addition, the method performs the conversion of loads and displacements directly between individual aerodynamic grid point and its corresponding structural finite element and, hence, is very efficient for large aircraft models. This report also describes the application of this aero-structure interface method to a simple wing and an MD-90 wing. The results show that the aeroelastic effect is very important. For the simple wing, both linear and nonlinear approaches are used. In the linear approach, the deformation of the structural model is considered small, and the loads from the deformed aerodynamic model are applied to the original geometry of the structure. In the nonlinear approach, the geometry of the structure and its stiffness matrix are updated in every iteration and the increments of loads from the previous iteration are applied to the new structural geometry in order to compute the displacement increments. Additional studies to apply the aero-structure interaction procedure to more complicated geometry will be conducted in the second phase

  8. General Method to Determine Replica Symmetry Breaking Transitions

    NASA Astrophysics Data System (ADS)

    Marinari, E.; Naitza, C.; Zuliani, F.; Parisi, G.; Picco, M.; Ritort, F.

    1998-08-01

    We introduce a new parameter to investigate replica symmetry breaking transitions using finite-size scaling methods. Based on exact equalities initially derived by F. Guerra this parameter is a direct check of the self-averaging character of the spin-glass order parameter. This new parameter can be used to study models with time reversal symmetry but its greatest interest lies in models where this symmetry is absent. We apply the method to long-range and short-range Ising spin-glasses with and without a magnetic field as well as short-range multispin interaction spin-glasses.

  9. A new magnetotelluric inversion scheme using generalized RRI method

    NASA Astrophysics Data System (ADS)

    Yamane, Kazunobu; Takasugi, Shinji; Lee, Ki Ha

    1996-09-01

    A new two-dimensional (2-D) magnetotelluric (MT) inversion scheme is proposed in this paper. This scheme is based on a locally 2-D analysis in order to minimize computational time and computer memory. The MT governing equation is linearized in terms of the magnetic field and electrical conductivity for the perturbation analysis. The perturbed equation is then multiplied by a test function and integrated over the cross-section. Integrating by parts and then substituting this test function with local magnetic fields, a new equation is obtained that is a 2-D variational integral for the electrical conductivity. The new equation is general in the sense that it can explicitly include the horizontal derivative of the magnetic field. If the horizontal derivative term is eliminated, the new equation becomes identical to the Rapid Relaxation Inversion (RRI) scheme proposed by Smith and Booker (J. Geophys. Res., 96: 3905-3922, 1991).

  10. Scalable Kernel Methods and Algorithms for General Sequence Analysis

    ERIC Educational Resources Information Center

    Kuksa, Pavel

    2011-01-01

    Analysis of large-scale sequential data has become an important task in machine learning and pattern recognition, inspired in part by numerous scientific and technological applications such as the document and text classification or the analysis of biological sequences. However, current computational methods for sequence comparison still lack…

  11. Projected Hybrid Orbitals: A General QM/MM Method

    PubMed Central

    2015-01-01

    A projected hybrid orbital (PHO) method was described to model the covalent boundary in a hybrid quantum mechanical and molecular mechanical (QM/MM) system. The PHO approach can be used in ab initio wave function theory and in density functional theory with any basis set without introducing system-dependent parameters. In this method, a secondary basis set on the boundary atom is introduced to formulate a set of hybrid atomic orbtials. The primary basis set on the boundary atom used for the QM subsystem is projected onto the secondary basis to yield a representation that provides a good approximation to the electron-withdrawing power of the primary basis set to balance electronic interactions between QM and MM subsystems. The PHO method has been tested on a range of molecules and properties. Comparison with results obtained from QM calculations on the entire system shows that the present PHO method is a robust and balanced QM/MM scheme that preserves the structural and electronic properties of the QM region. PMID:25317748

  12. A General Linear Method for Equating with Small Samples

    ERIC Educational Resources Information Center

    Albano, Anthony D.

    2015-01-01

    Research on equating with small samples has shown that methods with stronger assumptions and fewer statistical estimates can lead to decreased error in the estimated equating function. This article introduces a new approach to linear observed-score equating, one which provides flexible control over how form difficulty is assumed versus estimated…

  13. An indirect conductimetric screening method for the detection of antibiotic residues in bovine kidneys.

    PubMed

    Myllyniemi, Anna-Liisa; Sipilä, Hannu; Nuotio, Lasse; Niemi, Anneli; Honkanen-Buzalski, Tuula

    2002-09-01

    An indirect conductimetric screening method using three test bacterium-medium combinations was developed for rapid detection of antibiotic residues in bovine carcasses. The detection time (DT), i.e. the point when the growth of the test bacterium was detected, was determined by observing the rate of change in the conductance plotted against time. This detection time averaged half of the reference time recorded by the instrument software. Total change in conductance (TC) was used as a further measure of growth. Threshold values for DT and TC were determined with inhibitor-free kidney samples. The presence of a residue was indicated if the DT exceeded the respective threshold value and was confirmed if the TC remained below the TC threshold value. The limits of detection (LODs) determined with fortified samples were at about or below the MRLs for cephalexin, chlortetracycline, ciprofloxacin, dihydrostreptomycin, enrofloxacin, oxytetracycline and penicillin G. The LODs for penicillin G, oxytetracycline and the sum of enrofloxacin and ciprofloxacin were also estimated with incurred samples; these samples were also analysed using liquid chromatography. The LODs determined with fortified and incurred samples were in close agreement. Given its rapid detection, good sensitivity to a wide range of antibiotics and ease of performance, the indirect conductimetric method developed here would seem to offer an appealing alternative to agar diffusion tests. PMID:12375852

  14. Penile xenon (/sup 133/Xe) washout: a rapid method of screening for vasculogenic impotence

    SciTech Connect

    Nseyo, U.O.; Wilbur, H.J.; Kang, S.A.; Flesh, L.; Bennett, A.H.

    1984-01-01

    The radioactive inert gas xenon (/sup 133/Xe) is a well-established isotopic indicator used to assess vascular status in many organ systems. Xenon-133 was used to evaluate male impotence. Xenon-133 was injected subcutaneously at the level of the coronal sulcus in the detumescent state. Using the gamma camera, sequential images were obtained and computer-generated curves calculated. The clearance time for 50 per cent washout of the injected /sup 133/Xe (T1/2) was then calculated for each patient, as well as a control group. Preliminary findings indicate a correlation with such established techniques of evaluating erectile impotence as history, physical examination, penile pulse Doppler tracings, and brachial-penile blood pressure index. The xenon-133 washout study was a rapid, minimally invasive, reproducible, and cost-effective method of screening those impotent patients for vasculogenic etiology of their erectile impotence. We recommend the addition of this method to the surgeon engaged in the care of impotent males.

  15. A volumetric method for estimation of breast density on digitized screen-film mammograms.

    PubMed

    Pawluczyk, Olga; Augustine, Bindu J; Yaffe, Martin J; Rico, Dan; Yang, Jiwei; Mawdsley, Gordon E; Boyd, Norman F

    2003-03-01

    A method is described for the quantitative volumetric analysis of the mammographic density (VBD) from digitized screen-film mammograms. The method is based on initial calibration of the imaging system with a tissue-equivalent plastic device and the subsequent correction for variations in exposure factors and film processing characteristics through images of an aluminum step wedge placed adjacent to the breast during imaging. From information about the compressed breast thickness and technique factors used for taking the mammogram as well as the information from the calibration device, VBD is calculated. First, optical sensitometry is used to convert images to Log relative exposure. Second, the images are corrected for x-ray field inhomogeneity using a spherical section PMMA phantom image. The effectiveness of using the aluminum step wedge in tracking down the variations in exposure factors and film processing was tested by taking test images of the calibration device, aluminum step wedge and known density phantoms at various exposure conditions and also at different times over one year. Results obtained on known density phantoms show that VBD can be estimated to within 5% accuracy from the actual value. A first order thickness correction is employed to correct for inaccuracy in the compression thickness indicator of the mammography units. Clinical studies are ongoing to evaluate whether VBD can be a better indicator for breast cancer risk. PMID:12674236

  16. A modified bioautographic method for antibacterial component screening against anaerobic and microaerophilic bacteria.

    PubMed

    Kovács, Judit K; Horváth, Györgyi; Kerényi, Monika; Kocsis, Béla; Emődy, Levente; Schneider, György

    2016-04-01

    Direct bioautography is a useful method to identify antimicrobial compounds with potential therapeutic importance. Because of technical limitations till now, it has been applied only for aerobic bacteria. In this work we present the modification of the original method by which antimicrobial screening of bacteria requiring modified atmosphere became feasible by direct bioautography. Here we demonstrate its applicability by testing three anaerobic Clostridium perfringens and three microaerophilic Campylobacter jejuni strains against two essential oils, clove and thyme. Antimicrobial component profiles of clove and thyme essential oils against these two medically important pathogenic bacteria were compared and significant differences were revealed in their inhibition capacities. Linalool, a component of thyme essential oil exerted a more expressed antibacterial activity against C. perfringens than against C. jejuni. Our results demonstrate that direct bioautography is not only suitable for testing aerobic bacteria, but by applying the presently described modified version it can also contribute to the quest to find novel antimicrobial agents against multidrug resistant anaerobic and microaerophilic bacteria. PMID:26853123

  17. A rapid sample screening method for authenticity control of whiskey using capillary electrophoresis with online preconcentration.

    PubMed

    Heller, Melina; Vitali, Luciano; Oliveira, Marcone Augusto Leal; Costa, Ana Carolina O; Micke, Gustavo Amadeu

    2011-07-13

    The present study aimed to develop a methodology using capillary electrophoresis for the determination of sinapaldehyde, syringaldehyde, coniferaldehyde, and vanillin in whiskey samples. The main objective was to obtain a screening method to differentiate authentic samples from seized samples suspected of being false using the phenolic aldehydes as chemical markers. The optimized background electrolyte was composed of 20 mmol L(-1) sodium tetraborate with 10% MeOH at pH 9.3. The study examined two kinds of sample stacking, using a long-end injection mode: normal sample stacking (NSM) and sample stacking with matrix removal (SWMR). In SWMR, the optimized injection time of the samples was 42 s (SWMR42); at this time, no matrix effects were observed. Values of r were >0.99 for the both methods. The LOD and LOQ were better than 100 and 330 mg mL(-1) for NSM and better than 22 and 73 mg L(-1) for SWMR. The CE-UV reliability in the aldehyde analysis in the real sample was compared statistically with LC-MS/MS methodology, and no significant differences were found, with a 95% confidence interval between the methodologies. PMID:21662238

  18. Establishment of the method for screening the potential targets and effective components of huatuo reconstruction pill.

    PubMed

    Wu, Ke-Zhu; Jiang, Yun-Gen; Zuo, Ying; Li, Ai-Xiu

    2014-06-01

    Huatuo reconstruction pill (HTRP) is a traditional Chinese medicine prescription that mainly treats for hemiplegia and postoperation of brain stroke. Existing pharmacological studies have previously shown that HTRP could inhibit in vitro thrombosis, delay platelet adhesion, dilate blood vessels, and improve the microcirculation disturbances. In this paper, we chiefly concerned about the potential targets of HTRP and tried to figure out the active components of it. Computer-aided drug design method was emploied to search for the active components and explain the mechanism between the targets and the small molecules at molecular lever. The potential targets of this compound pharmaceutics were searched through relevant pharmacological studies and three pharmacophore models which involved the platelet activating factor (PAF) receptor, the angiotensin converting enzyme (ACE) and the 5-hydroxytryptamine receptor (5-HT2A) were constructed by Discotech method of Sybyl. Thus, the candidate compounds which agreed with the pharmacophore models were obtained by the virtual screening to the known ingredients of HTRP. Based on that, sequence and structure prediction of the unknown targets were realized by homology modeling which were used for molecular docking with those candidate compounds. Results showed that three compounds, which may prove to be valid to these targets, got higher scores than the existing corresponding inhibitors after molecular docking, including ferulic acid, onjixanthone I and albiflorin. And the three molecules may refer to the singificant substances to the total compounds of HTRP which were effective to the disease. PMID:25172450

  19. Evaluation of screening methods for demulsifying bacteria and characterization of lipopeptide bio-demulsifier produced by Alcaligenes sp.

    PubMed

    Huang, Xiang-Feng; Liu, Jia; Lu, Li-Jun; Wen, Yue; Xu, Jing-Cheng; Yang, Dian-Hai; Zhou, Qi

    2009-02-01

    In this paper, surface tension measurement, oil-spreading test and blood-plate hemolysis test were attempted in the screening of demulsifying bacteria. After the comparison to the screening results obtained in demulsification test, 50 mN/m of surface tension of culture was proposed as a preliminary screening standard for potential demulsifying bacteria. For the identification of efficient demulsifying strains, surface tension level was set at 40 mN/m. The detected strains were further verified in demulsification test. Compared to using demulsification test alone as screening method, the proposed screening protocol would be more efficient. From the screening, a highly efficient demulsifying stain, S-XJ-1, was isolated from petroleum-contaminated soil and identified as Alcaligenes sp. by 16S rRNA gene and physiological test. It achieved 96.5% and 49.8% of emulsion breaking ratio in W/O and O/W kerosene emulsion within 24h, respectively, and also showed 95% of water separation ratio in oilfield petroleum emulsion within 2h. The bio-demulsifier was found to be cell-wall combined. After soxhlet extraction and purification through silicon-gel column, the bio-demulsifier was then identified as lipopeptide biosurfactant by TLC and FT-IR. PMID:18799309

  20. Access to chronic disease care in general practice: the acceptability of implementing systematic waiting-room screening using computer-based patient-reported risk status

    PubMed Central

    Paul, Christine L; Carey, Mariko; Yoong, Sze Lin; D’Este, Catherine; Makeham, Meredith; Henskens, Frans

    2013-01-01

    Background Routine screening and advice regarding risky lifestyle behaviours is appropriate in the primary care setting, but often not implemented. Routine electronic collection of patients’ self-reported data may streamline the collection of such information. Aim To explore the perceptions of GPs and their attending patients regarding the acceptability of waiting-room touchscreen computers for the collection of health behaviour information. Uptake, ease of operation, and the perceived likelihood of future implementation were studied. Design and setting Cross-sectional health-risk survey. General practices in metropolitan areas in Australia. Method Practices were randomly selected by postcode. Consecutive patients who were eligible to take part in the study were approached in the waiting room and invited to do so. Participants completed the touchscreen health survey. A subsample of patients and GPs completed additional items regarding acceptability. Results Twelve general practices participated in the study, with 4058 patients (86%) and 51 of 68 (75%) GPs consenting to complete the health-risk survey, 596 patients and 30 GPs were selected to complete the acceptability survey. A majority of the 30 GPs indicated that the operation of the survey was not disruptive to practice and more than 90% of patients responded positively to all items regarding its operation. More than three-quarters of the patient sample were willing to consider allowing their responses to be kept on file and complete such surveys in the future. Conclusion As waiting-room-based collection of this information appears to be both feasible and acceptable, practitioners should consider collecting and incorporating routine patient-reported health behaviours for inclusion in the medical record. PMID:23998842

  1. Ovarian Cancer Screening Method Fails to Reduce Deaths from the Disease | Division of Cancer Prevention

    Cancer.gov

    New results from the NCI-sponsored Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial show that screening for ovarian cancer with transvaginal ultrasound (TVU) and the CA-125 blood test did not result in fewer deaths from the disease compared with usual care. |

  2. School-Based BMI and Body Composition Screening and Parent Notification in California: Methods and Messages

    ERIC Educational Resources Information Center

    Madsen, Kristine A.; Linchey, Jennifer

    2012-01-01

    Background: School-based body mass index (BMI) or body composition screening is increasing, but little is known about the process of parent notification. Since 2001, California has required annual screening of body composition via the FITNESSGRAM, with optional notification. This study sought to identify the prevalence of parental notification…

  3. Comparison of screening methods for antibiotics in beef kidney juice and serum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rapid screening tests can be used as part of an efficient program designed to monitor veterinary drug residues in cattle. In this work, three rapid tests designed to screen samples for the presence of antibiotic residues, the FAST, Premi® and KISTM tests, were compared using beef kidney juice and s...

  4. Screening of minor bioactive compounds from herbal medicines by in silico docking and the trace peak exposure methods.

    PubMed

    Wu, Bin; Song, Hui-Peng; Zhou, Xu; Liu, Xin-Guang; Gao, Wen; Dong, Xin; Li, Hui-Jun; Li, Ping; Yang, Hua

    2016-03-01

    Screening of high potent enzyme inhibitors from herbal medicines is always lacking of efficiency due to the complexity of chemicals. The constituents responsible for the holistic effect may be trace-level chemicals, but these chemicals were covered by highly abundant compositions. To challenge this bottleneck, a strategy for screening minor bioactive compounds was proposed. It generally included four steps, (1) preliminarily find the enzyme binders by ultrafiltration; (2) optimise and predict the potential inhibitors by docking analysis; (3) selectively identify and prepare trace compounds by segment and exposure approach; (4) validate the activity and summarize the structure-activity relationship. As a case study, α-glucosidase (AGH) and Ginkgo biloba extract were used as the experimental materials. By comprehensive screening, 11 trace flavones were screened out and identified as strong AGH inhibitors. Among them, AGH inhibitory activities of syringetin and sciadopitysin were reported for the first time. Their IC50 values were 36.80 and 8.29μM, respectively, which were lower than that of a positive control acarbose. In addition, the AGH inhibitory activities of the flavonoids could be ranked, based on a decreased order, as biflavone, flavone, flavone glycoside, flavone biglycoside. The strategy is expected to be practical and useful for screening bioactive molecules from herbal medicines, especially for the minor compounds, which will definitely accelerate the discovery of new drug candidates. PMID:26852619

  5. A general method to determine the stability of compressible flows

    NASA Technical Reports Server (NTRS)

    Guenther, R. A.; Chang, I. D.

    1982-01-01

    Several problems were studied using two completely different approaches. The initial method was to use the standard linearized perturbation theory by finding the value of the individual small disturbance quantities based on the equations of motion. These were serially eliminated from the equations of motion to derive a single equation that governs the stability of fluid dynamic system. These equations could not be reduced unless the steady state variable depends only on one coordinate. The stability equation based on one dependent variable was found and was examined to determine the stability of a compressible swirling jet. The second method applied a Lagrangian approach to the problem. Since the equations developed were based on different assumptions, the condition of stability was compared only for the Rayleigh problem of a swirling flow, both examples reduce to the Rayleigh criterion. This technique allows including the viscous shear terms which is not possible in the first method. The same problem was then examined to see what effect shear has on stability.

  6. Screening and confirmatory method for multiclass determination of 62 antibiotics in meat.

    PubMed

    Moretti, Simone; Dusi, Guglielmo; Giusepponi, Danilo; Pellicciotti, Simona; Rossi, Rosanna; Saluti, Giorgio; Cruciani, Gabriele; Galarini, Roberta

    2016-01-15

    A multiclass method for screening and confirmatory analysis of antimicrobial residues in muscle has been developed and validated, according to Commission Decision 2002/657/EC. Sixty-two antibiotics belonging to ten different drug families (amphenicols, beta-lactams, diamino-pyrimidine, lincosamides, macrolides, pleuromutilins, quinolones, rifamycins, sulfonamides and tetracyclines) have been included in the method. After the addition of an aqueous solution of EDTA, the minced muscle was extracted with acetonitrile/water mixture and, later, with pure acetonitrile. The extract was evaporated and redissolved in ammonium acetate buffer prior to LC injection. Instrumental determination was performed by liquid chromatography coupled to hybrid high resolution mass analyser (LC-HRMS/MS) operating in positive electrospray ionization mode. Chromatographic separation was optimized on a Poroshell 120 EC-C18 column (100 × 3.0 mm, 2.7 μm) with gradient using methanol and water containing 0.1% of formic acid as mobile phases. The method was validated in bovine muscle in the range 3.3-150 μg kg(-1) for all antibiotics; for some compounds with MRL higher than 100 μg kg(-1), the validation interval has been extended until 1500 μg kg(-1). The studied performance characteristics were selectivity, linearity, precision, trueness (recovery), decision limits, detection capabilities, detection and quantification limits. Satisfactory quantitative performances were obtained for all the analytes. Ruggedness tests demonstrated the applicability to swine and poultry muscle, too. Finally the wide participation in proficiency tests allowed to investigate in deep the method performances. PMID:26726937

  7. Fast extraction and dilution flow injection mass spectrometry method for quantitative chemical residue screening in food.

    PubMed

    Nanita, Sergio C; Stry, James J; Pentz, Anne M; McClory, Joseph P; May, John H

    2011-07-27

    A prototype multiresidue method based on fast extraction and dilution of samples followed by flow injection mass spectrometric analysis is proposed here for high-throughput chemical screening in complex matrices. The method was tested for sulfonylurea herbicides (triflusulfuron methyl, azimsulfuron, chlorimuron ethyl, sulfometuron methyl, chlorsulfuron, and flupyrsulfuron methyl), carbamate insecticides (oxamyl and methomyl), pyrimidine carboxylic acid herbicides (aminocyclopyrachlor and aminocyclopyrachlor methyl), and anthranilic diamide insecticides (chlorantraniliprole and cyantraniliprole). Lemon and pecan were used as representative high-water and low-water content matrices, respectively, and a sample extraction procedure was designed for each commodity type. Matrix-matched external standards were used for calibration, yielding linear responses with correlation coefficients (r) consistently >0.99. The limits of detection (LOD) were estimated to be between 0.01 and 0.03 mg/kg for all analytes, allowing execution of recovery tests with samples fortified at ≥0.05 mg/kg. Average analyte recoveries obtained during method validation for lemon and pecan ranged from 75 to 118% with standard deviations between 3 and 21%. Representative food processed fractions were also tested, that is, soybean oil and corn meal, yielding individual analyte average recoveries ranging from 62 to 114% with standard deviations between 4 and 18%. An intralaboratory blind test was also performed; the method excelled with 0 false positives and 0 false negatives in 240 residue measurements (20 samples × 12 analytes). The daily throughput of the fast extraction and dilution (FED) procedure is estimated at 72 samples/chemist, whereas the flow injection mass spectrometry (FI-MS) throughput could be as high as 4.3 sample injections/min, making very efficient use of mass spectrometers with negligible instrumental analysis time compared to the sample homogenization, preparation, and data

  8. Screening method for stimulants in urine by UHPLC-MS/MS: identification of isomeric compounds.

    PubMed

    Monfort, Núria; Martínez, Laura; Bergés, Rosa; Segura, Jordi; Ventura, Rosa

    2015-09-01

    A fast screening method for the detection of more than 60 stimulants in urine was developed. The method consisted of a dilution of the urine (1:5 v/v) and analysis by ultra high performance liquid chromatography coupled to tandem mass spectrometry, using a C18 column (1.7 µm particle size), a mobile phase containing deionized water and acetonitrile with formic acid, and gradient elution. The chromatographic run time was 5 min. The detection was performed in positive mode electrospray ionization, monitoring one or two specific ion transitions for each analyte. Appropriate repeatability was obtained, with relative standard deviation (RSD) values below 25% for most of the analytes. Regarding intermediate precision, estimated during routine work, higher RSDs were obtained, probably due to between-day differences in the status of the mass spectrometer and in the chromatographic system. Matrix effect ranged from 60 to 255% with RSD lower than 35% for the majority of compounds. Despite the matrix effect observed, the signal/noise ratio of the analytes spiked at 50 ng/mL was greater than three in all tested samples, allowing a correct detection of all substances at the minimum required performance levels required by the World Anti-Doping Agency and demonstrating the suitability of the method. The method was tested in administration study samples and satisfactorily in operation for more than one year with routine doping samples. The presence of isomeric stimulants with closely similar chromatographic and/or mass spectrometric properties did not allow the unequivocal identification of these compounds after the first analysis. Different possibilities for separation and identification of isomeric compounds are presented. PMID:25728759

  9. A general method for modeling population dynamics and its applications.

    PubMed

    Shestopaloff, Yuri K

    2013-12-01

    Studying populations, be it a microbe colony or mankind, is important for understanding how complex systems evolve and exist. Such knowledge also often provides insights into evolution, history and different aspects of human life. By and large, populations' prosperity and decline is about transformation of certain resources into quantity and other characteristics of populations through growth, replication, expansion and acquisition of resources. We introduce a general model of population change, applicable to different types of populations, which interconnects numerous factors influencing population dynamics, such as nutrient influx and nutrient consumption, reproduction period, reproduction rate, etc. It is also possible to take into account specific growth features of individual organisms. We considered two recently discovered distinct growth scenarios: first, when organisms do not change their grown mass regardless of nutrients availability, and the second when organisms can reduce their grown mass by several times in a nutritionally poor environment. We found that nutrient supply and reproduction period are two major factors influencing the shape of population growth curves. There is also a difference in population dynamics between these two groups. Organisms belonging to the second group are significantly more adaptive to reduction of nutrients and far more resistant to extinction. Also, such organisms have substantially more frequent and lesser in amplitude fluctuations of population quantity for the same periodic nutrient supply (compared to the first group). Proposed model allows adequately describing virtually any possible growth scenario, including complex ones with periodic and irregular nutrient supply and other changing parameters, which present approaches cannot do. PMID:24057917

  10. Strategies to Overcome Barriers to Implementation of Alcohol Screening and Brief Intervention in General Practice: a Delphi Study Among Healthcare Professionals and Addiction Prevention Experts.

    PubMed

    Abidi, L; Oenema, A; Nilsen, P; Anderson, P; van de Mheen, D

    2016-08-01

    Despite the evidence base, alcohol screening and brief intervention (ASBI) have rarely been integrated into routine clinical practice. The aim of this study is to identify strategies that could tackle barriers to ASBI implementation in general practice by involving primary healthcare professionals and addiction prevention experts. A three-round online Delphi study was carried out in the Netherlands. The first-round questionnaire consisted of open-ended questions to generate ideas about strategies to overcome barriers. In the second round, participants were asked to indicate how applicable they found each strategy. Items without consensus were systematically fed back with group median ratings and interquartile range (IQR) scores in the third-round questionnaire. In total, 39 out of 69 (57 %) invited participants enrolled in the first round, 214 participants completed the second round, and 144 of these (67 %) completed the third-round questionnaire. Results show that participants reached consensus on 59 of 81 strategies, such as the following: (1) use of E-learning technology, (2) symptom-specific screening by general practitioners (GPs) and/or universal screening by practice nurses, (3) reimbursement incentives, (4) supportive materials, (5) clear guidelines, (6) service provision of addiction care centers, and (7) more publicity in the media. This exploratory study identified a broad set of strategies that could potentially be used for overcoming barriers to ASBI implementation in general practice and paves the way for future research to experimentally test the identified implementation strategies using multifaceted approaches. PMID:27167074

  11. The Polish language version of the Confusion Assessment Method - a questionnaire for the screening of consciousness disorders.

    PubMed

    Świerzy, Krzysztof A; Pudlo, Robert; Wesołowski, Bartosz; Garbacz, Marcin; Morawski, Michał; Jaworska, Izabela; Sołtysik, Mariusz; Zembala, Marian

    2016-06-01

    Confusion on a somatic basis is a dangerous problem mainly related with aging of the population. Data says that consciousness disorders concern 10-15% of patients in general wards, and up to 50% of patients admitted to geriatric wards. The persistence of the symptoms of confusion results in increase of agitation, disorganization, fear, which increases the risk of self-injuries of patients, it causes the need for parenteral feeding and hydratation, as well as maintaining water balance, and also disturbs cooperation, worsening the course and prognosis of the primary disease. It is believed that consciousness disorders are one of the most difficult diagnostic problems and the most difficult therapy problem among psychotic disorders. So far in Poland there have been no screening evaluation tools to assess the occurrence of confusion on the somatic basis. The purpose of this paper is to introduce the Polish translation of the widely used scale to assess consciousness disorders, intended also for middle personnel of health care - Confusion Assessment Method (CAM). Numerous studies over 16 years established the position of CAM as an exceptionally effective standardized diagnostic test, specifying the sensitivity of 94-100%, specificity from 90-95%, positive predictive value of 91-94%, negative predictive value of 90-100%. The questionnaire and instructions of its interpretation have been translated by doctors with active help from the original creators of CAM. Further studies are required in order to validate and determine the effectiveness of the newly formed diagnostic tool. PMID:27516799

  12. The Polish language version of the Confusion Assessment Method – a questionnaire for the screening of consciousness disorders

    PubMed Central

    Pudlo, Robert; Wesołowski, Bartosz; Garbacz, Marcin; Morawski, Michał; Jaworska, Izabela; Sołtysik, Mariusz; Zembala, Marian

    2016-01-01

    Confusion on a somatic basis is a dangerous problem mainly related with aging of the population. Data says that consciousness disorders concern 10-15% of patients in general wards, and up to 50% of patients admitted to geriatric wards. The persistence of the symptoms of confusion results in increase of agitation, disorganization, fear, which increases the risk of self-injuries of patients, it causes the need for parenteral feeding and hydratation, as well as maintaining water balance, and also disturbs cooperation, worsening the course and prognosis of the primary disease. It is believed that consciousness disorders are one of the most difficult diagnostic problems and the most difficult therapy problem among psychotic disorders. So far in Poland there have been no screening evaluation tools to assess the occurrence of confusion on the somatic basis. The purpose of this paper is to introduce the Polish translation of the widely used scale to assess consciousness disorders, intended also for middle personnel of health care – Confusion Assessment Method (CAM). Numerous studies over 16 years established the position of CAM as an exceptionally effective standardized diagnostic test, specifying the sensitivity of 94-100%, specificity from 90-95%, positive predictive value of 91-94%, negative predictive value of 90-100%. The questionnaire and instructions of its interpretation have been translated by doctors with active help from the original creators of CAM. Further studies are required in order to validate and determine the effectiveness of the newly formed diagnostic tool. PMID:27516799

  13. Combustor flow computations in general coordinates with a multigrid method

    NASA Astrophysics Data System (ADS)

    Shyy, Wei; Braaten, Mark E.

    The computational approach presented for single-phase combusting turbulent flowfields balances the requirements of complex physical and chemical flow interactions with those of resolving the three-dimensional geometrical constraints of the combustor contours, film cooling slots, and circular dilution holes. Attention is given to the three-dimensional grid-generation algorithm, the two-dimensional adaptive grid method applied to recirculating turbulent reacting flows, and theory/data assessments for three-dimensional combusting flows in an annular gas turbine combustor.

  14. Collocation method for chatter avoidance of general turning operations

    NASA Astrophysics Data System (ADS)

    Urbicain, G.; Olvera, D.; Fernández, A.; Rodríguez, A.; López de Lacalle, L. N.

    2012-04-01

    An accurate prediction of the dynamic stability of a cutting system involves the implementation of tool geometry and cutting conditions on any model used for such purpose. This study presents a dynamic cutting force model based on the collocation method by Chebyshev polynomials taking advantage from its ability to consider tool geometry and cutting parameters. In the paper, a simple 1DOF model is used to forecast chatter vibrations due to the workpiece and tool, which are distinguished in separate sections. The proposed model is verified positively against experimental dynamic tests.

  15. Variational method for finding periodic orbits in a general flow.

    PubMed

    Lan, Yueheng; Cvitanović, Predrag

    2004-01-01

    A variational principle is proposed and implemented for determining unstable periodic orbits of flows as well as unstable spatiotemporally periodic solutions of extended systems. An initial loop approximating a periodic solution is evolved in the space of loops toward a true periodic solution by a minimization of local errors along the loop. The "Newton descent" partial differential equation that governs this evolution is an infinitesimal step version of the damped Newton-Raphson iteration. The feasibility of the method is demonstrated by its application to the Hénon-Heiles system, the circular restricted three-body problem, and the Kuramoto-Sivashinsky system in a weakly turbulent regime. PMID:14995703

  16. General unknown screening in hair by liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF-MS).

    PubMed

    Broecker, Sebastian; Herre, Sieglinde; Pragst, Fritz

    2012-05-10

    The retrospective investigation of the exposure to toxic substances by general unknown screening of hair is still a difficult task because of the large number of possible poisons, the low sample amount and the difficult sample matrix. In this study the use of liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) was tested as a promising technique for this purpose. In the optimized procedure, 20mg hair were decontaminated with water and acetone and two times extracted by 18h incubation with 0.5ml of a mixture of methanol/acetonitrile/H(2)O/ammonium formate at 37°C. A mixture of deuterated standards from different drug groups was added for quantification and method control. The united extracts were evaporated to a residue of 0.5ml and 5μl were injected without clean-up for LC-QTOF-MS measurement (instrument Agilent 6530) with positive electrospray ionization and in data dependent acquisition mode. For peak identification the accurate mass data base and spectral library of the authors was used which contains accurate mass CID spectra of more than 2500 and theoretically calculated accurate mass data of more than 7500 toxicologically relevant substances. Validation at the example of 24 illegal drugs, their metabolites and benzodiazepines resulted in limits of detection of 0.003-0.015ng/mg, and limits of quantification of 0.006-0.021ng/mg with good accuracy and intra- and interday reproducibility. The matrix effect by ion suppression/enhancement was 72-107% for basic drugs and 42-75% for benzodiazepines. Yields of the hair extraction above 90% were determined for 59 drugs or metabolites. The method was applied to hair samples from 30 drug fatalities and from 60 death cases with known therapeutic drug intake at life time. Altogether 212 substances were identified with a frequency per drug of 1-40 (mean 4.2) and per case of 2-33 (mean 10.2), between them 35 illegal drug related substances and 154 therapeutic drugs. Comparison with the

  17. Generalized spectral method for near-field optical microscopy

    NASA Astrophysics Data System (ADS)

    Jiang, B.-Y.; Zhang, L. M.; Castro Neto, A. H.; Basov, D. N.; Fogler, M. M.

    2016-02-01

    Electromagnetic interaction between a sub-wavelength particle (the "probe") and a material surface (the "sample") is studied theoretically. The interaction is shown to be governed by a series of resonances corresponding to surface polariton modes localized near the probe. The resonance parameters depend on the dielectric function and geometry of the probe as well as on the surface reflectivity of the material. Calculation of such resonances is carried out for several types of axisymmetric probes: spherical, spheroidal, and pear-shaped. For spheroids, an efficient numerical method is developed, capable of handling cases of large or strongly momentum-dependent surface reflectivity. Application of the method to highly resonant materials, such as aluminum oxide (by itself or covered with graphene), reveals a rich structure of multi-peak spectra and nonmonotonic approach curves, i.e., the probe-sample distance dependence. These features also strongly depend on the probe shape and optical constants of the model. For less resonant materials such as silicon oxide, the dependence is weak, so that the spheroidal model is reliable. The calculations are done within the quasistatic approximation with radiative damping included perturbatively.

  18. Noninvasive Assessment of Excessive Erythrocytosis as a Screening Method for Chronic Mountain Sickness at High Altitude

    PubMed Central

    Vyas, Kaetan J.; Danz, David; Gilman, Robert H.; Wise, Robert A.; León-Velarde, Fabiola; Jaime Miranda, J.

    2015-01-01

    Abstract Vyas, Kaetan J., David Danz, Robert H. Gilman, Robert A. Wise, Fabiola León-Velarde, J. Jaime Miranda, and William Checkley. Noninvasive assessment of excessive erythrocytosis as a screening method for chronic mountain sickness at high altitude. High Alt Med Biol 16:162–168, 2015.—Globally, over 140 million people are at risk of developing chronic mountain sickness, a common maladaptation to life at high altitude (>2500 meters above sea level). The diagnosis is contingent upon the identification of excessive erythrocytosis (EE). Current best practices to identify EE require a venous blood draw, which is cumbersome for large-scale surveillance. We evaluated two point-of-care biomarkers to screen for EE: noninvasive spot-check tests of total hemoglobin and oxyhemoglobin saturation (Pronto-7, Masimo Corporation). We conducted paired evaluations of total serum hemoglobin from a venous blood draw and noninvasive, spot-check testing of total hemoglobin and oxyhemoglobin saturation with the Pronto-7 in 382 adults aged ≥35 years living in Puno, Peru (3825 meters above sea level). We used the Bland-Altman method to measure agreement between the noninvasive hemoglobin assessment and the gold standard lab hemoglobin analyzer. Mean age was 58.8 years and 47% were male. The Pronto-7 test was unsuccessful in 21 (5%) participants. Limits of agreement between total hemoglobin measured via venous blood draw and the noninvasive, spot-check test ranged from −2.8 g/dL (95% CI −3.0 to −2.5) to 2.5 g/dL (95% CI 2.2 to 2.7), with a bias of −0.2 g/dL (95% CI −0.3 to −0.02) for the difference between total hemoglobin and noninvasive hemoglobin concentrations. Overall, the noninvasive spot-check test of total hemoglobin had a better area under the receiver operating characteristic curve compared to oxyhemoglobin saturation for the identification of EE as measured by a gold standard laboratory hemoglobin analyzer (0.96 vs. 0.82; p<0.001). Best cut-off values

  19. Multiparameter Screening on SlipChip Used for Nanoliter Protein Crystallization Combining Free Interface Diffusion and Microbatch Methods

    SciTech Connect

    Li, Liang; Du, Wenbin; Ismagilov, Rustem F.

    2010-08-04

    This paper describes two SlipChip-based approaches to protein crystallization: a SlipChip-based free interface diffusion (FID) method and a SlipChip-based composite method that simultaneously performs microbatch and FID crystallization methods in a single device. The FID SlipChip was designed to screen multiple reagents, each at multiple diffusion equilibration times, and was validated by screening conditions for crystallization of two proteins, enoyl-CoA hydratase from Mycobacterium tuberculosis and dihydrofolate reductase/thymidylate synthase from Babesia bovis, against 48 different reagents at five different equilibration times each, consuming 12 {micro}L of each protein for a total of 480 experiments using three SlipChips. The composite SlipChip was designed to screen multiple reagents, each at multiple mixing ratios and multiple equilibration times, and was validated by screening conditions for crystallization of two proteins, enoyl-CoA hydratase from Mycobacterium tuberculosis and dihydrofolate reductase/thymidylate synthase from Babesia bovis. To prevent cross-contamination while keeping the solution in the neck channels for FID stable, the plates of the SlipChip were etched with a pattern of nanowells. This nanopattern was used to increase the contact angle of aqueous solutions on the surface of the silanized glass. The composite SlipChip increased the number of successful crystallization conditions and identified more conditions for crystallization than separate FID and microbatch screenings. Crystallization experiments were scaled up in well plates using conditions identified during the SlipChip screenings, and X-ray diffraction data were obtained to yield the protein structure of dihydrofolate reductase/thymidylate synthase at 1.95 {angstrom} resolution. This free-interface diffusion approach provides a convenient and high-throughput method of setting up gradients in microfluidic devices and may find additional applications in cell-based assays.

  20. Production of monoclonal antibodies specific for Haemophilus ducreyi: a screening method to discriminate specific and cross-reacting antibodies.

    PubMed

    Odumeru, J A; Alfa, M J; Martin, C F; Ronald, A R; Jay, F T

    1989-06-01

    Haemophilus ducreyi is the etiological agent of chancroid. The organism shares extensive immunological cross-reactivity with other Haemophilus species. This presents substantial difficulties for the production of specific monoclonal antibodies (MAbs). A competition ELISA was devised for hybridoma screening which allowed the detection of H. ducreyi-specific antibody-producing hybridoma cultures during the initial screening process. With this screening method, seven MAbs specific for H. ducreyi were obtained in a single cell fusion exercise. The specificities of the 7 MAbs were demonstrated by direct ELISA and dot immunobinding assays against several strains each of H. influenzae, H. parainfluenzae and Neisseria gonorrhoeae. Five of the MAbs reacted against all ten strains of H. ducreyi. These MAbs may permit the development of rapid and efficient immunodiagnostics for chancroid. The principle of the competition ELISA for hybridoma screening should be widely applicable to the development of specific MAbs to other organisms in which immunological cross-reactivity is an impediment to hybridoma screening by conventional methods. PMID:2787274

  1. A general method for modeling biochemical and biomedical response

    NASA Astrophysics Data System (ADS)

    Ortiz, Roberto; Lerd Ng, Jia; Hughes, Tyler; Abou Ghantous, Michel; Bouhali, Othmane; Arredouani, Abdelilah; Allen, Roland

    2012-10-01

    The impressive achievements of biomedical science have come mostly from experimental research with human subjects, animal models, and sophisticated laboratory techniques. Additionally, theoretical chemistry has been a major aid in designing new drugs. Here we introduce a method which is similar to others already well known in theoretical systems biology, but which specifically addresses biochemical changes as the human body responds to medical interventions. It is common in systems biology to use first-order differential equations to model the time evolution of various chemical concentrations, and we as physicists can make a significant impact through designing realistic models and then solving the resulting equations. Biomedical research is rapidly advancing, and the technique presented in this talk can be applied in arbitrarily large models containing tens, hundreds, or even thousands of interacting species, to determine what beneficial effects and side effects may result from pharmaceuticals or other medical interventions.

  2. A meta-analysis and systematic review of the prevalence of mitochondrially encoded 12S RNA in the general population: Is there a role for screening neonates requiring aminoglycosides?

    PubMed Central

    Ibekwe, Titus S.; Bhimrao, Sanjiv K.; Westerberg, Brian D.; Kozak, Frederick K.

    2015-01-01

    Background: This was a meta-analysis and systematic review to determine the global prevalence of the mitochondrially encoded 12S RNA (MT-RNR1) genetic mutation in order to assess the need for neonatal screening prior to aminoglycoside therapy. Materials and Methods: A comprehensive search of MEDLINE, EMBASE, Ovid, Database of Abstracts of Reviews of Effect, Cochrane Library, Clinical Evidence and Cochrane Central Register of Trials was performed including cross-referencing independently by 2 assessors. Selections were restricted to human studies in English. Meta-analysis was done with MetaXL 2013. Results: Forty-five papers out of 295 met the criteria. Pooled prevalence in the general population for MT-RNR1 gene mutations (A1555G, C1494T, A7445G) was 2% (1–4%) at 99%. Conclusion: Routine screening for MT-RNR1 mutations in the general population prior to treatment with aminoglycosides appear desirable but poorly supported by the weak level of evidence available in the literature. Routine screening in high-risk (Chinese and Spanish) populations appear justified. PMID:26168747

  3. A bivariate binormal ROC methodology for comparing new methods to an existing standard for screening applications

    NASA Astrophysics Data System (ADS)

    Abbey, Craig K.; Insana, Michael F.; Eckstein, Miguel P.; Boone, John M.

    2007-03-01

    Validating the use of new imaging technologies for screening large patient populations is an important and very challenging area of diagnostic imaging research. A particular concern in ROC studies evaluating screening technologies is the problem of verification bias, in which an independent verification of disease status is only available for a subpopulation of patients, typically those with positive results by a current screening standard. For example, in screening mammography, a study might evaluate a new approach using a sample of patients that have undergone needle biopsy following a standard mammogram and subsequent work-up. This case sampling approach provides accurate independent verification of ground truth and increases the prevalence of disease cases. However, the selection criteria will likely bias results of the study. In this work we present an initial exploration of an approach to correcting this bias within the parametric framework of binormal assumptions. We posit conditionally bivariate normal distributions on the latent decision variable for both the new methodology as well as the screening standard. In this case, verification bias can be seen as the effect of missing data from an operating point in the screening standard. We examine the magnitude of this bias in the setting of breast cancer screening with mammography, and we derive a maximum likelihood approach to estimating bias corrected ROC curves in this model.

  4. Detection and screening of bovine leukocyte adhesion deficiency in Pakistan using molecular methods.

    PubMed

    Nasreen, Fozia; Altaf Malik, Naveed; Naeem Riaz, Muhammad; Anver Qureshi, Javed

    2009-05-01

    Bovine leukocyte adhesion deficiency (BLAD) is an autosomal recessive disease. Affected animals die because of extreme susceptibility to infections caused by the lack of a membrane glycoprotein called the leukocyte integrin beta-2 subunit of CD18. The present study was planned to standardize a technique for the diagnosis of BLAD and to get an estimation of BLAD allele in the Pakistani cattle population. The study was performed on 700 animals including Holstein-Friesian (HF) (n=280), Friesian-Sahiwal (FS) (n=120) Sahiwal (n=100) cows and HF calves (n=59) from Government as well as private farms. Similarly 141 bulls of Sahiwal (n=100), HF (n=18) and FS (n=23) from the Semen Production Unit Qadirabad and Kherimorat were also sampled. The identification of normal, carrier and affected animals were made by the PCR-RFLP method. No animal was found homozygous for BLAD while 10 animals including HF calve (n=1), FS bull (n=1), HF (n=6) and FS (n=2) cows were BLAD carrier. The Hardy-Weinberg frequency of the mutant allele in HF and FS population in Pakistan was calculated to 0.01. Thus there is a need of regular screening of the bulls used for artificial insemination to avoid the risk of spreading BLAD in the cattle population of Pakistan. PMID:19490168

  5. [The Reliability of Measurement Methods for Medical Examinations and Health Screening].

    PubMed

    Hosogaya, Shigemi

    2016-03-01

    Clinical laboratory data used in medical examinations and health screening need to have a guaranteed analytical reliability. To ensure the reliability of measurement data, each constituent is required to be compatible with its traceability chain, and any constituent whose traceability chain has yet to be established is required to be appropriately harmonized in the current measurement system. The inter-laboratory reproducibility of standardized measurement values obtained from the external quality assessments conducted by the Japan Medical Association and Japanese Association of Medical Technologists was estimated to evaluate the analytical reliability of clinical tests in Japan. The estimated inter-laboratory reproducibility was then compared with the permissible error limits which have been reported domestically and internationally based on inter- and intra-individual biological variations of healthy subjects. The results showed that most of the measurement uncertainties were sufficiently lower than the permissible limits. This study proposes that the measurement uncertainty of the standardized measurement method has the potential to be a new assessment standard for analytical reliability. PMID:27363220

  6. Device and method for screening crystallization conditions in solution crystal growth

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C. (Inventor)

    1995-01-01

    A device and method for detecting optimum protein crystallization conditions and for growing protein crystals in either 1g or microgravity environments comprising a housing, defining at least one pair of chambers for containing crystallization solutions is presented. The housing further defines an orifice therein for providing fluid communication between the chambers. The orifice is adapted to receive a tube which contains a gelling substance for limiting the rate of diffusive mixing of the crystallization solutions. The solutions are diffusively mixed over a period of time defined by the quantity of gelling substance sufficient to achieve equilibration and to substantially reduce density driven convection disturbances therein. The device further includes endcaps to seal the first and second chambers. One of the endcaps includes a dialysis chamber which contains protein solution in which protein crystals are grown. Once the endcaps are in place, the protein solution is exposed to the crystallization solutions wherein the solubility of the protein solution is reduced at a rate responsive to the rate of diffusive mixing of the crystallization solutions. This allows for a controlled approach to supersaturation and allows for screening of crystal growth conditions at preselected intervals.

  7. Device and Method for Screening Crystallization Conditions in Solution Crystal Growth

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C. (Inventor)

    1997-01-01

    A device and method for detecting optimum protein crystallization conditions and for growing protein crystals in either 1 g or microgravity environments comprising a housing defining at least one pair of chambers for containing crystallization solutions. The housing further defines an orifice therein for providing fluid communication between the chambers. The orifice is adapted to receive a tube which contains a gelling substance for limiting the rate of diffusive mixing of the crystallization solutions. The solutions are diffusively mixed over a period of time defined by the quantity of gelling substance sufficient to achieve equilibration and to substantially reduce density driven convection disturbances therein. The device further includes endcaps to seal the first and second chambers. One of the endcaps includes a dialysis chamber which contains protein solution in which protein crystals are grown. Once the endcaps are in place. the protein solution is exposed to the crystallization solutions wherein the solubility of the protein solution is reduced at a rate responsive to the rate of diffusive mixing of the crystallization solutions. This allows for a controlled approach to supersaturation and allows for screening of crystal growth conditions at preselected intervals.

  8. Screening instruments for a population of older adults: The 10-item Kessler Psychological Distress Scale (K10) and the 7-item Generalized Anxiety Disorder Scale (GAD-7).

    PubMed

    Vasiliadis, Helen-Maria; Chudzinski, Veronica; Gontijo-Guerra, Samantha; Préville, Michel

    2015-07-30

    Screening tools that appropriately detect older adults' mental disorders are of great public health importance. The present study aimed to establish cutoff scores for the 10-item Kessler Psychological Distress (K10) and the 7-item Generalized Anxiety Disorder (GAD-7) scales when screening for depression and anxiety. We used data from participants (n = 1811) in the Enquête sur la Santé des Aînés-Service study. Depression and anxiety were measured using DSM-V and DSM-IV criteria. Receiver operating characteristic (ROC) curve analysis provided an area under the curve (AUC) of 0.767 and 0.833 for minor and for major depression when using K10. A cutoff of 19 was found to balance sensitivity (0.794) and specificity (0.664) for minor depression, whereas a cutoff of 23 was found to balance sensitivity (0.692) and specificity (0.811) for major depression. When screening for an anxiety with GAD-7, ROC analysis yielded an AUC of 0.695; a cutoff of 5 was found to balance sensitivity (0.709) and specificity (0.568). No significant differences were found between subgroups of age and gender. Both K10 and GAD-7 were able to discriminate between cases and non-cases when screening for depression and anxiety in an older adult population of primary care service users. PMID:25956759

  9. 26 CFR 1.446-1 - General rule for methods of accounting.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... (a) General rule. (1) Section 446(a) provides that taxable income shall be computed under the method.... The term “method of accounting” includes not only the overall method of accounting of the taxpayer but... disbursements method, an accrual method, combinations of such methods, and combinations of the foregoing...

  10. Determination of Tolerance to Internal Shorts and Its Screening in Lithium-ion Cells NASA - JSC Method

    NASA Technical Reports Server (NTRS)

    Jeevarajan, Judith

    2009-01-01

    This slide presentation reviews the method developed by the NASA Johnson Space Center (JSC) to determine tolerances to internal shorts and screening for problems in commercial off the shelf (COTS) Lithium-ion batteries. The test apparatus is shown and several examples of the usage and results of the test are discussed.

  11. Rapid screening of anti-infective drug products for counterfeits using Raman spectral library-based correlation methods.

    PubMed

    Loethen, Yvette L; Kauffman, John F; Buhse, Lucinda F; Rodriguez, Jason D

    2015-11-01

    A new spectral library-based approach that is capable of screening a diverse set of finished drug products using only an active pharmaceutical ingredient spectral library is described in this paper. This approach obviates the need for a comprehensive drug product library, thereby streamlining the use of spectral library-based tests for anti-counterfeiting efforts, specifically to target finished drug products containing the wrong active ingredient or no active ingredient at all. Both laboratory-based and portable spectrometers are used in the study to demonstrate the usefulness and transferability of the spectral correlation method for field screening. The spectral correlation between the active pharmaceutical ingredient and finished drug product spectra is calculated using both full spectral analysis and targeted spectral regions analysis of six types of antimalarial, antibiotic and antiviral products. The spectral regions were determined using a moving window spectral correlation algorithm, and the use of specific spectral regions is shown to be crucial in screening finished drug products using only the active pharmaceutical ingredient spectrum. This comprehensive screening spectral correlation method is tested on seven different validation samples from different manufacturers as those used to develop the method, as well as simulated counterfeits which were prepared to mimic falsified drugs containing no active ingredient. The spectral correlation method is successful in correctly identifying 100% of the authentic products and simulated counterfeit samples tested. PMID:26401527

  12. Orthogonal analytical screening for liquid chromatography-mass spectrometry method development and preparative scale-up.

    PubMed

    Font, Luis M; Fontana, A; Galceran, M T; Iturrino, L; Perez, V

    2011-01-01

    An analytical HPLC-MS screening methodology has been developed to improve preparative RP-HPLC-MS purifications in medicinal chemistry laboratories. Although several approaches have been previously described to optimize analytical separations, none of them met our needs for the optimization of preparative conditions. Our screening protocol is based on searching among several orthogonal conditions to find the optimum preparative separation. Five different buffer conditions, from low to high pH, two organic solvents, acetonitrile and methanol, and five stationary phases of different polarities and characteristics were used. The orthogonality of the system was demonstrated using both, a standard mixture and mixtures from synthesis. To carry out the screening one of the analytical "open access" HPLC-MS systems was modified to perform the analytical screening while maintaining the open-access functionality for synthesis reaction monitoring. A software tool for automated sample programming and data reporting was also developed. PMID:21122868

  13. Biosensor-based screening method for the detection of aflatoxins B1-G1.

    PubMed

    Cuccioloni, Massimiliano; Mozzicafreddo, Matteo; Barocci, Simone; Ciuti, Francesca; Pecorelli, Ivan; Eleuteri, Anna Maria; Spina, Michele; Fioretti, Evandro; Angeletti, Mauro

    2008-12-01

    Aflatoxins are extremely toxic metabolites from Aspergillus species that can adulterate a wide range of human foodstuff. Herein, we propose a novel assay designed as an analytical test for aflatoxin B1 and G1 (AFB1 and AFG1, respectively) that could represent an alternative screening technique for this class of mycotoxins. The approach for the determination of these toxins is based on surface plasmon resonance using neutrophil porcine elastase as a "bait" for these aflatoxins. The selection and optimization of the analytical procedure involved a preliminary investigation on the type of inhibition by AFB1: the level of the protease inhibition exerted by AFB1 depended upon the incubation time and the concentration of the binding partners, showing the competitiveness and the reversibility of the inhibition. A posteriori, the nature of the interaction granted a rapid analysis, a single detection test requiring only a few minutes. For the development of the assay, the experimental conditions were evaluated and optimized with both calibration solution and aflatoxin-spiked samples. To apply this method to aflatoxin-contaminated maize, a rapid solid-phase extraction treatment was developed. The proposed assay for AFB1 and AFG1 was validated by comparison with both a chromatographic reference method and a standard enzyme linked immunosorbent assay procedure. This enzyme-based biosensor represents a new approach for the detection of aflatoxins based on the reversible interaction between a blocked macromolecule and a soluble ligand, having the major advantages in the relative rapidity, the reusability of the capturing surface, and low cost per single test. PMID:19551989

  14. Classification of findings in mammography screening--a method to minimise recall anxiety?

    PubMed Central

    Pamilo, M; Lönnqvist, J; Halttunen, A; Soiva, M; Suramo, I

    1991-01-01

    STUDY OBJECTIVE--The aim was to find out if it is possible, by classifying screening mammograms according to the likelihood of malignancy, to divide the recalled women to a group in which there is high suspicion of malignancy, most having breast cancers, and a group with more obscure findings. DESIGN--Screening mammograms of recalled women were classified according to the likelihood of malignancy. 0 = technically insufficient, 1 = normal, 2 = benign tumour, 3 = malignancy cannot be excluded, 4 = strongly suspicious for malignancy, 5 = malignant. SETTING--This study was a population based survey of mammography screening in Helsinki and surroundings in Finland. PATIENTS--21,417 women (aged 50-59 years) were invited to be screened, 18,012 (84.10%) participated. Of these 579 (3.21% of those screened) were recalled for further studies; 124 of these were referred for surgical biopsy and 82 had breast cancer. MEASUREMENTS AND MAIN RESULTS--All cases classified as 5, 60% of the cases classified as 4, 6.5% of the cases classified as 3, 0% of the cases classified as 2 or 1, and 1.2% of the cases classified as 0 proved to have breast cancers. However classification 5 represented 5.9% of all recalled women and 41.5% of all screening detected breast cancers; classification 4, 6.0% of all recalled women and 25.6% of all screening detected breast cancers; classification 3, 68.9% of all recalled women and 31.7% of all screening detected breast cancers; classification 2, 11.7% and classification 1, 2.9% of all recalled women. No breast cancers were detected with these classifications. Classification 0 represented 4.5% of all recalled women and 1.2% of all screening detected breast cancers. Classifications 5 and 4 represented only 11.9% of all recalled women but 67.1% of all screening detected breast cancers. CONCLUSIONS--By classifying screening mammograms according to the likelihood of malignancy, recalled women can be divided into two groups: (1) a quite small subgroup in which

  15. Comparison Between a Rapid Biological Screening Method (EPA 4425) for TCDDs/TCDFs and Chemical Analytical Methods

    SciTech Connect

    Anderson, Jack W.; Jones, Jennifer M.; McCoy, Daniel L.; Fujita, Akira; Yamamoto, Taichi; Iijima, Satoshi

    2003-08-01

    Seven polychlorinated dibenzo-p-dioxins (PCDDs), ten polychlorinated dibenzofurans (PCDFs) as well as twelve polychlorinated biphenyls (PCBs) are collectively referred to as dioxin-like compounds. The World Health Organization toxic equivalency factors (TEFs) for these persistent chlorinated organic compounds and their measured concentrations are used to produce the toxic equivalency quotient (TEQ) of a sample. TEF values are partially based on a common mechanism involving binding of the chemical to the aryl hydrocarbon receptor (AhR). Biological methods for the determination of TEQs are based on the assumption that all dioxin-related compounds act through the Ah receptor signal transduction pathway. Based on the biochemical response of CYP1A activation via the AhR, in vitro systems that utilize a reporter gene under transcriptional control of CYP1A have been developed. Several investigations have reported on the success of utilizing biological test systems to detect PCDDs, PCDFs, PCBs in environmental samples. The P450 Human Reporter Gene System assay (EPA Method 4425) utilizes a human hepatoma cell line (HepG2) in which a plasmid containing the human CYP1A1 promoter and 5'-flanking sequences with three xenobiotic responsive elements (XREs) fused to the luciferase reporter gene. The enzyme luciferase is produced in the presence of compounds that bind the XREs, and can be detected by a simple assay that measures relative light units with a luminometer. Method 4425, used by Columbia Analytical Services (CAS), has gained acceptance as a rapid and inexpensive approach for screening solvent extracts of environmental samples of soil, sediment, tissue, and water to detect compounds that activate the AhR. Investigations in the U. S. and Japan comparing the results of 4425 and standard high-resolution GC/MS (HRGC/HRMS) will be reported here. The purpose of making these comparisons is to determine if risk assessments for large dioxin sites both before and after remediation

  16. Screening procedure to evaluate air pollution effects on Class I wilderness areas. Forest Service general technical report (Final)

    SciTech Connect

    Fox, D.G.; Bartuska, A.M.; Byrne, J.G.; Cowling, E.; Fisher, R.

    1989-03-01

    The screening procedure is intended to help wilderness managers conduct Adverse impact determinations as part of Prevention of Significant Deterioration (PSD) applications for sources that emit air pollutants that might impact class I wildernesses. The process provides an initial estimate of susceptibility to critical loadings for sulfur, nitrogen, and ozone. It also provides a basis for requesting necessary additional information where potential adverse impacts are identified.

  17. Effects of scanning (routine health information exposure) on cancer screening and prevention behaviors in the general population.

    PubMed

    Hornik, Robert; Parvanta, Sarah; Mello, Susan; Freres, Derek; Kelly, Bridget; Schwartz, J Sanford

    2013-01-01

    Research on health information exposure focuses primarily on deliberate information-seeking behavior and its effects on health. By contrast, this study explores the complementary and perhaps more influential role of health information acquired through exposure to routinely used sources, called scanning. The authors hypothesized that scanning from nonmedical sources, both mediated and interpersonal, affects cancer screening and prevention decisions. The authors used a nationally representative longitudinal survey of 2,489 adults 40 to 70 years of age to analyze the effects of scanning on 3 cancer screening behaviors (mammography, prostate-specific antigen [PSA], and colonoscopy) and 3 prevention behaviors (exercising, eating fruits and vegetables, and dieting to lose weight). After adjustment for baseline behaviors and covariates, scanning at baseline predicted weekly exercise days 1 year later as well as daily fruit and vegetable servings 1 year later for those whose consumption of fruits and vegetables was already higher at baseline. Also, among those reporting timely screening mammogram behavior at baseline, scanning predicted repeat mammography. Scanning was marginally predictive of PSA uptake among those not reporting a PSA at baseline. Although there were strong cross-sectional associations, scanning did not predict dieting or colonoscopy uptake in longitudinal analyses. These analyses provide substantial support for a claim that routine exposure to health content from nonmedical sources affects specific health behaviors. PMID:24083417

  18. Comparative Evaluation of Ligation-Mediated PCR and Spoligotyping as Screening Methods for Genotyping of Mycobacterium tuberculosis Strains

    PubMed Central

    Bonora, Stefano; Gutierrez, M. Cristina; Di Perri, Giovanni; Brunello, Francesca; Allegranzi, Benedetta; Ligozzi, Marco; Fontana, Roberta; Concia, Ercole; Vincent, Veronique

    1999-01-01

    Spoligotyping has been suggested as a screening test in multistep genotyping of Mycobacterium tuberculosis strains. Relying on restriction fragment length polymorphism (RFLP) analysis with IS6110 (IS6110 RFLP analysis) as a “gold standard,” we performed a comparative evaluation of spoligotyping and ligation-mediated PCR (LMPCR), a recently described PCR-based typing method, as rapid screening tests for fingerprinting of 158 M. tuberculosis strains collected in Verona, Italy. LMPCR seemed to be comparable to spoligotyping in terms both of feasibility with rapidly extracted DNA and of generation of software-analyzable images. Moreover, LMPCR grouped considerably fewer strains than spoligotyping (38 versus 67%) and was found to reduce the cluster overestimation rate (26.3 versus 58%) and to give a better discriminatory index (0.992 versus 0.970) compared to spoligotyping. In our geographical region, where there was no evidence of clustered strains carrying fewer than six IS6110 copies, LMPCR was found to be more discriminatory than spoligotyping. We also evaluated two models of three-step typing strategies, involving the use of spoligotyping and LMPCR as screening methods and IS6110 RFLP analysis as a further supporting test. LMPCR proved to be a more effective first-step test than spoligotyping, significantly reducing the need for subtyping. LMPCR should be considered an alternative to spoligotyping as a rapid screening method for M. tuberculosis fingerprinting, particularly in areas with a low prevalence of M. tuberculosis strains carrying few copies of IS6110. PMID:10488164

  19. A Protocolised Once a Day Modified Early Warning Score (MEWS) Measurement Is an Appropriate Screening Tool for Major Adverse Events in a General Hospital Population

    PubMed Central

    Ludikhuize, Jeroen; Kramer, Mark H. H.

    2016-01-01

    Background The Modified Early Warning Score (MEWS) was developed to timely recognise clinically deteriorating hospitalised patients. However, the ability of the MEWS in predicting serious adverse events (SAEs) in a general hospital population has not been examined prospectively. The aims were to (1) analyse protocol adherence to a MEWS protocol in a real-life setting and (2) to determine the predictive value of protocolised daily MEWS measurement on SAEs: death, cardiac arrests, ICU-admissions and readmissions. Methods All adult patients admitted to 6 hospital wards in October and November 2015 were included. MEWS were checked each morning by the research team. For each critical score (MEWS ≥ 3), the clinical staff was inquired about the actions performed. 30-day follow-up for SAEs was performed to compare between patients with and without a critical score. Results 1053 patients with 3673 vital parameter measurements were included, 200 (19.0%) had a critical score. The protocol adherence was 89.0%. 18.2% of MEWS were calculated wrongly. Patients with critical scores had significant higher rates of unplanned ICU admissions [7.0% vs 1.3%, p < 0.001], in-hospital mortality [6.0% vs 0.8%, p < 0.001], 30-day readmission rates [18.6% vs 10.8%, p < 0.05], and a longer length of stay [15.65 (SD: 15.7 days) vs 6.09 (SD: 6.9), p < 0.001]. Specificity of MEWS related to composite adverse events was 83% with a negative predicting value of 98.1%. Conclusions Protocol adherence was high, even though one-third of the critical scores were calculated wrongly. Patients with a MEWS ≥ 3 experienced significantly more adverse events. The negative predictive value of early morning MEWS < 3 was 98.1%, indicating the reliability of this score as a screening tool. PMID:27494719

  20. 29 CFR 4281.17 - Asset valuation methods-in general.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Asset valuation methods-in general. 4281.17 Section 4281.17... MASS WITHDRAWAL Valuation of Plan Benefits and Plan Assets § 4281.17 Asset valuation methods—in general. (a) General rule. The plan sponsor shall value plan assets as of the valuation date, using...