Does Preinterventional Flat-Panel Computer Tomography Pooled Blood Volume Mapping Predict Final Infarct Volume After Mechanical Thrombectomy in Acute Cerebral Artery Occlusion?

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

Wagner, Marlies, E-mail: marlies.wagner@kgu.de; Kyriakou, Yiannis, E-mail: yiannis.kyriakou@siemens.com; Mesnil de Rochemont, Richard du, E-mail: mesnil@em.uni-frankfurt.de

2013-08-01

PurposeDecreased cerebral blood volume is known to be a predictor for final infarct volume in acute cerebral artery occlusion. To evaluate the predictability of final infarct volume in patients with acute occlusion of the middle cerebral artery (MCA) or the distal internal carotid artery (ICA) and successful endovascular recanalization, pooled blood volume (PBV) was measured using flat-panel detector computed tomography (FPD CT).Materials and MethodsTwenty patients with acute unilateral occlusion of the MCA or distal ACI without demarcated infarction, as proven by CT at admission, and successful Thrombolysis in cerebral infarction score (TICI 2b or 3) endovascular thrombectomy were included. Cerebralmore » PBV maps were acquired from each patient immediately before endovascular thrombectomy. Twenty-four hours after recanalization, each patient underwent multislice CT to visualize final infarct volume. Extent of the areas of decreased PBV was compared with the final infarct volume proven by follow-up CT the next day.ResultsIn 15 of 20 patients, areas of distinct PBV decrease corresponded to final infarct volume. In 5 patients, areas of decreased PBV overestimated final extension of ischemia probably due to inappropriate timing of data acquisition and misery perfusion.ConclusionPBV mapping using FPD CT is a promising tool to predict areas of irrecoverable brain parenchyma in acute thromboembolic stroke. Further validation is necessary before routine use for decision making for interventional thrombectomy.« less

Heavy-Load Lifting: Acute Response in Breast Cancer Survivors at Risk for Lymphedema

PubMed Central

BLOOMQUIST, KIRA; OTURAI, PETER; STEELE, MEGAN L.; ADAMSEN, LIS; MØLLER, TOM; CHRISTENSEN, KARL BANG; EJLERTSEN, BENT; HAYES, SANDRA C.

2018-01-01

ABSTRACT Purpose Despite a paucity of evidence, prevention guidelines typically advise avoidance of heavy lifting in an effort to protect against breast cancer–related lymphedema. This study compared acute responses in arm swelling and related symptoms after low- and heavy-load resistance exercise among women at risk for lymphedema while receiving adjuvant taxane-based chemotherapy. Methods This is a randomized, crossover equivalence trial. Women receiving adjuvant taxane-based chemotherapy for breast cancer who had undergone axillary lymph node dissection (n = 21) participated in low-load (60%–65% 1-repetition maximum, two sets of 15–20 repetitions) and heavy-load (85%–90% 1-repetition maximum, three sets of 5–8 repetitions) upper-extremity resistance exercise separated by a 1-wk wash-out period. Swelling was determined by bioimpedance spectroscopy and dual-energy x-ray absorptiometry, with breast cancer–related lymphedema symptoms (heaviness, swelling, pain, tightness) reported using a numeric rating scale (0–10). Order of low- versus heavy-load was randomized. All outcomes were assessed before, immediately after, and 24 and 72 h after exercise. Generalized estimating equations were used to evaluate changes over time between groups, with equivalence between resistance exercise loads determined using the principle of confidence interval inclusion. Results The acute response to resistance exercise was equivalent for all outcomes at all time points irrespective of loads lifted, with the exception of extracellular fluid at 72 h after exercise with less swelling after heavy loads (estimated mean difference, −1.00; 95% confidence interval, −3.17 to 1.17). Conclusions Low- and heavy-load resistance exercise elicited similar acute responses in arm swelling and breast cancer–related lymphedema symptoms in women at risk for lymphedema receiving adjuvant taxane-based chemotherapy. These represent important preliminary findings, which can be used to

Baroreflex Responses to Acute Changes in Blood Volume in Humans

NASA Technical Reports Server (NTRS)

Thompson, Cynthia A.; Tatro, Dana L.; Ludwig, David A.; Convertino, Victor A.

1990-01-01

To test the hypothesis that acute changes in plasma volume affect the stimulus-response relations of high- and low- pressure baroreflexes, eight men (27-44 yr old) underwent measurements for carotid-cardiac and cardiopulmonary baro-reflex responses under the following three volemic conditions: hypovolemic, normovolemic, and hypervolemic. The stimulus- response relation of the carotid-cardiac response curve was generated using a neck cuff device, which delivered pressure changes between +40 and -65 mmHg in continuous steps of 15 mmHg. The stimulus-response relationship, of the cardio-pulmonary baroreflex were studied by measurements of Forearm Vascular Resistance (FVR) and Peripheral Venous Pressure (PVP) during low levels of lower body negative pressure (O to -20 mmHg). The results indicate greater demand for vasoconstriction for equal reductions in venous pressure during progressive hypovolemia; this condition may compromise the capacity to provide adequate peripheral resistance during severe orthostatic stress. Fluid loading before reentry after spaceflight may act to restore vasoconstrictive capacity of the cardiopulmonary baroreflex but may not be an effective countermeasure against potential post- flight impairment of the carotid-cardiac baroreflex.

Baroreflex Responses to Acute Changes in Blood Volume in Humans

NASA Technical Reports Server (NTRS)

Thompson, Cynthia A.; Tatro, Dana L.; Ludwig, David A.; Convertino, Victor A.

1990-01-01

To test the hypothesis that acute changes in plasma volume affect the stimulus-response relations of high- and low- pressure baroreflexes, eight men (27-44 yr old) underwent measurements for carotid-cardiac and cardiopulmonary baro- reflex responses under the following three volemic conditions: hypovolemic, normovolemic, and hypervolemic. The stimulus- response relation of the carotid-cardiac response curve was generated using a neck cuff device, which delivered pressure changes between +40 and -65 mmHg in continuous steps of 15 mmHg. The stimulus-response relationships of the cardiopulmonary baroreflex were studied by measurements of Forearm Vascular Resistance (FVR) and Peripheral Venotis Pressure (PVP) during low levels of lower body negative pressure (O to -20 mmHg). Altered vascular volume had no effect on response relations of the carotid-cardiac baroreflex but did alter the gain of the cardiopulmonary baroreflex (-7.93 q 1.71, -4.36 q 1.38, and -2.56 q 1.59 peripheral resistance units/mmHg for hypovolemic, normovolemic, and hypervolemic, respectively) independent of shifts in baseline FVR and PVP. These results indicate greater demand for vasoconstriction for equal reductions in venous pressure during progressive hypovolemia; this condition may compromise the capacity to provide adequate peripheral resistance during severe orthostatic stress. Fluid loading before reentry after spaceflight may act to restore vasoconstrictive capacity of the cardiopulnionary baroreflex but may not be an effective countermeasure against potential post- flight impairment of the carotid-cardiac baroreflex.

The contribution of volume, technique, and load to single-repetition and total-repetition kinematics and kinetics in response to three loading schemes.

PubMed

Crewther, Blair T; Cronin, John; Keogh, Justin W L

2008-11-01

This study examined the effect of volume, technique, and load upon single-repetition and total-repetition kinematics and kinetics during three loading schemes. Eleven recreationally trained males each performed a power (8 sets of 6 repetitions at 45% of one-repetition maximum [1RM], 3-minute rest periods, explosive and ballistic movements), hypertrophy (10 sets of 10 repetitions at 75% 1RM, 2-minute rest periods, controlled movements), and maximal strength (6 sets of 4 repetitions at 88% 1RM, 4-minute rest periods, explosive intent) scheme involving squats. Examination of repetition data showed that load intensity (% 1RM) generally had a direct effect on forces, contraction times, impulses, and work (i.e., increasing with load), whereas power varied across loads (p < 0.001). However, total-repetition forces, contraction times, impulses, work, and power were all greater in the hypertrophy scheme (p < 0.001), because of the greater number of repetitions performed (volume) as well as lifting technique. No differences in total forces were found between the equal-volume power and maximal strength schemes, but the former did produce greater total contraction times, work, and power (p < 0.001), which may also be attributed to repetition and technique differences. Total impulses were the only variable greater in the maximal strength scheme (p < 0.001). Thus, the interaction of load, volume, and technique plays an important role in determining the mechanical responses (stimuli) afforded by these workouts. These findings may explain disparities cited within research, regarding the effectiveness of different loading strategies for hypertrophy, maximal strength, and power adaptation.

The effects of acute stress and perceptual load on distractor interference.

PubMed

Sato, Hirotsune; Takenaka, Ippei; Kawahara, Jun I

2012-01-01

Selective attention can be improved under conditions in which a high perceptual load is assumed to exhaust cognitive resources, leaving scarce resources for distractor processing. The present study examined whether perceptual load and acute stress share common attentional resources by manipulating perceptual and stress loads. Participants identified a target within an array of nontargets that were flanked by compatible or incompatible distractors. Attentional selectivity was measured by longer reaction times in response to the incompatible than to the compatible distractors. Participants in the stress group participated in a speech test that increased anxiety and threatened self-esteem. The effect of perceptual load interacted with the stress manipulation in that participants in the control group demonstrated an interference effect under the low perceptual load condition, whereas such interference disappeared under the high perceptual load condition. Importantly, the stress group showed virtually no interference under the low perceptual load condition, whereas substantial interference occurred under the high perceptual load condition. These results suggest that perceptual and stress related demands consume the same attentional resources.

[Relationship between viral load of human bocavirus and clinical characteristics in children with acute lower respiratory tract infection].

PubMed

Ding, Xiao-Fang; Zhang, Bing; Zhong, Li-Li; Xie, Le-Yun; Xiao, Ni-Guang

2017-03-01

To investigate the prevalence of human bocavirus (HBoV) in children with acute lower respiratory tract infection and to explore the relationship between the viral load of HBoV and the clinical characteristics of acute lower respiratory tract infection in children. A total of 1 554 nasopharyngeal aspirates from children who were hospitalized due to acute lower respiratory tract infection between March 2011 and March 2014 were collected. Quantitative real-time PCR was used to detect 12 RNA and 2 DNA viruses, adenovirus (ADV) and HBoV, and to measure the viral load of HBoV in HBoV-positive children. A comprehensive analysis was performed with reference to clinical symptoms and indicators. In the 1 554 specimens, 1 212 (77.99%) were positive for viruses, and 275 (17.70%) were HBoV-positive. In HBoV-positive cases, 94.9% were aged <3 years, and there were more males than females. In the 275 HBoV-positive cases, 45 (16.36%) had single infection, and 230 (83.64%) had mixed infection. There was no significant difference in viral load between children with single infection and mixed infection (P>0.05). The patients with fever had a significantly higher viral load than those without fever (P<0.05). The children with wheezing had a significantly higher viral load than those without wheezing (P<0.05). There was no significant difference in viral load between children with mild, moderate, and severe acute lower respiratory tract infection (P>0.05). HBoV is one of the important pathogens of acute lower respiratory tract infection in children. Children with a higher viral load of HBoV are more likely to experience symptoms such as fever and wheezing. However, the severity of disease and mixed infection are not significantly related to viral load.

Ambient temperature and volume of perihematomal edema in acute intracerebral haemorrhage: the INTERACT1 study.

PubMed

Zheng, Danni; Arima, Hisatomi; Heeley, Emma; Karpin, Anne; Yang, Jie; Chalmers, John; Anderson, Craig S

2015-01-01

As no human data exist, we aimed to determine the relation between ambient temperature and volume of perihematomal 'cerebral' edema in acute spontaneous intracerebral haemorrhage (ICH) among Chinese participants of the pilot phase, Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage Trial (INTERACT1). INTERACT1 was a multicenter, open, blind outcome assessed, randomized controlled trial of intensive (systolic target <140 mmHg) vs. guideline-recommended (systolic target <180 mmHg) blood pressure (BP) lowering in 404 patients with acute ICH. Data on ambient temperature (mean, minimum, maximum, and range) on the day of each participant's ICH obtained from China Meteorological Data Sharing Service System were linked to other data including edema volumes. Multivariable regression analyses were performed to evaluate association between ambient temperature and edema volumes. A generalized linear regression model with a generalized estimating equations approach (GEE) was used to assess any association of ambient temperature and change in edema volume over 72 h. A total of 250 of all 384 Chinese participants had complete data that showed positive associations between ambient temperature (mean and minimum temperatures) and edema volumes at each time point over 72 h after hospital admission (all P < 0·05). All temperature parameters except diurnal temperature range were positively associated with edema volume after adjustment for confounding variables (all P < 0·02). An apparent positive association exists between ambient temperature and perihematomal edema volume in acute spontaneous ICH. © 2014 World Stroke Organization.

Reduced baroreflex sensitivity with volume loading in conscious dogs

NASA Technical Reports Server (NTRS)

Vatner, S. F.; Boettcher, D. H.; Heyndrickx, G. R.; Mcritchie, R. J.

1975-01-01

Results of studies of the Bainbridge reflex in intact conscious dogs are presented. They indicate that arterial baroreflex sensitivity is reduced progressively as atrial pressure is raised by volume loading; this observation explains how heart rate can rise markedly in the presence of an elevated arterial blood pressure.

Baroreflex sensitivity in acute hypoxia and carbohydrate loading.

PubMed

Klemenc, Matjaž; Golja, Petra

2011-10-01

Hypoxia decreases baroreflex sensitivity (BRS) and can be a sufficient cause for syncope in healthy individuals. Carbohydrate loading enhances efferent sympathetic activity, which affects cardiac contractility, heart rate and vascular resistance, the main determinants of blood pressure. Thus, in both normoxia and hypoxia, carbohydrate loading may be more than simply metabolically beneficial, as it may affect blood pressure regulation. We hypothesised that carbohydrate loading will, in both normoxia and hypoxia, alter the regulation of blood pressure, as reflected in a change in baroreflex sensitivity. Fourteen subjects participated in two experiments, composed of a 15-min normoxic period, after which the subjects ingested water or an equal amount of water with carbohydrates. A 30-min rest period was then followed by a 10-min second normoxic and a 30-min hypoxic period. Blood pressure and heart rate were monitored continuously during the experiment to determine BRS. Despite an increased sympathetic activation, reflected in increased heart rate (P < 0.001) BRS was lower (P < 0.01) after carbohydrate loading, as compared to the water experiment, in both normoxic [23.7 (12.4) versus 28.8 (13.8) ms/mmHg] and hypoxic [16.8 (11.0) versus 24.3 (12.3) ms/mmHg] phases of the present study. As BRS was decreased in acute hypoxic exposure, the results confirm that hypoxia interferes with blood pressure regulation. However, although oral carbohydrate loading induced sympathoexcitation, it did not improve blood pressure regulation in hypoxia, as evident from the BRS data. Baroreflex effects of other forms of carbohydrate loading, not causing postprandial blood shifts to digestive system, should therefore be investigated.

Clinical Factors and Viral Load Influencing Severity of Acute Hepatitis A.

PubMed

Lee, Hyun Woong; Chang, Dong-Yeop; Moon, Hong Ju; Chang, Hye Young; Shin, Eui-Cheol; Lee, June Sung; Kim, Kyung-Ah; Kim, Hyung Joon

2015-01-01

Clinical manifestations of hepatitis A virus (HAV) infection vary from mild to fulminant hepatic failure (FHF) in adults. We investigated the relationship between laboratory findings, including viral load, and clinical outcomes in patients with acute hepatitis A (AHA) and evaluated predictive factors for severe acute hepatitis (s-AH). We analyzed the clinical manifestations of AHA in 770 patients. Patients with a prothrombin time (PT) of less than 40% of normal were classified as s-AH and included 4 patients with FHF, 11 patients with acute renal failure, and 3 patients with prolonged jaundice (n = 128). Other patients were defined as mild acute hepatitis (m-AH) (n = 642). Serum samples were obtained from 48 patients with acute hepatitis A. Among them, 20 with s-AH, and 28 with m-AH, were tested for HAV RNA titer. In a multivariate analysis, age (HR = 1.042, P = 0.041), peak creatinine (HR = 4.014, P = 0.001), bilirubin (HR = 1.153, P = 0.003), alanine aminotransferase (ALT) (HR = 1.001, P < 0.001), initial lactate dehydrogenase (LDH) (HR = 1.000, P = 0.045) and total cholesterol (HR = 0.978, P < 0.001) were independent factors for s-AH. Serum HAV RNA was detected in 20/20 (100%) patients with s-AH and 22/28 (78.6%) patients with m-AH. In a multivariate analysis of the 48 patients who were tested for HAV RNA, peak ALT (HR = 1.001, P = 0.004) and HAV RNA titer (HR = 2.076, P = 0.012) were independent factors for s-AH. Clinical factors including age, peak creatinine, bilirubin, ALT, initial LDH and total cholesterol were independent factors for s-AH in a multivariate analysis. In particular, HAV load strongly correlated with the severity of hepatitis A.

Clinical Factors and Viral Load Influencing Severity of Acute Hepatitis A

PubMed Central

Lee, Hyun Woong; Chang, Dong-Yeop; Moon, Hong Ju; Chang, Hye Young; Shin, Eui-Cheol; Lee, June Sung; Kim, Kyung-Ah; Kim, Hyung Joon

2015-01-01

Background and Aims Clinical manifestations of hepatitis A virus (HAV) infection vary from mild to fulminant hepatic failure (FHF) in adults. We investigated the relationship between laboratory findings, including viral load, and clinical outcomes in patients with acute hepatitis A (AHA) and evaluated predictive factors for severe acute hepatitis (s-AH). Methods We analyzed the clinical manifestations of AHA in 770 patients. Patients with a prothrombin time (PT) of less than 40% of normal were classified as s-AH and included 4 patients with FHF, 11 patients with acute renal failure, and 3 patients with prolonged jaundice (n = 128). Other patients were defined as mild acute hepatitis (m-AH) (n = 642). Serum samples were obtained from 48 patients with acute hepatitis A. Among them, 20 with s-AH, and 28 with m-AH, were tested for HAV RNA titer. Results In a multivariate analysis, age (HR = 1.042, P = 0.041), peak creatinine (HR = 4.014, P = 0.001), bilirubin (HR = 1.153, P = 0.003), alanine aminotransferase (ALT) (HR = 1.001, P<0.001), initial lactate dehydrogenase (LDH) (HR = 1.000, P = 0.045) and total cholesterol (HR = 0.978, P<0.001) were independent factors for s-AH. Serum HAV RNA was detected in 20/20 (100%) patients with s-AH and 22/28 (78.6%) patients with m-AH. In a multivariate analysis of the 48 patients who were tested for HAV RNA, peak ALT (HR = 1.001, P = 0.004) and HAV RNA titer (HR = 2.076, P = 0.012) were independent factors for s-AH. Conclusions Clinical factors including age, peak creatinine, bilirubin, ALT, initial LDH and total cholesterol were independent factors for s-AH in a multivariate analysis. In particular, HAV load strongly correlated with the severity of hepatitis A. PMID:26090677

Virus Type and Genomic Load in Acute Bronchiolitis: Severity and Treatment Response With Inhaled Adrenaline.

PubMed

Skjerven, Håvard O; Megremis, Spyridon; Papadopoulos, Nikolaos G; Mowinckel, Petter; Carlsen, Kai-Håkon; Lødrup Carlsen, Karin C

2016-03-15

Acute bronchiolitis frequently causes infant hospitalization. Studies on different viruses or viral genomic load and disease severity or treatment effect have had conflicting results. We aimed to investigate whether the presence or concentration of individual or multiple viruses were associated with disease severity in acute bronchiolitis and to evaluate whether detected viruses modified the response to inhaled racemic adrenaline. Nasopharyngeal aspirates were collected from 363 infants with acute bronchiolitis in a randomized, controlled trial that compared inhaled racemic adrenaline versus saline. Virus genome was identified and quantified by polymerase chain reaction analyses. Severity was assessed on the basis of the length of stay and the use of supportive care. Respiratory syncytial virus (83%) and human rhinovirus (34%) were most commonly detected. Seven other viruses were present in 8%-15% of the patients. Two or more viruses (maximum, 7) were detected in 61% of the infants. Virus type or coinfection was not associated with disease severity. A high genomic load of respiratory syncytial virus was associated with a longer length of stay and with an increased frequency of oxygen and ventilatory support use. Treatment effect of inhaled adrenaline was not modified by virus type, load or coinfection. In infants hospitalized with acute bronchiolitis, disease severity was not associated with specific viruses or the total number of viruses detected. A high RSV genomic load was associated with more-severe disease. NCT00817466 and EudraCT 2009-012667-34. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

[Volume assessment in the acute heart and renal failure].

PubMed

Vujicić, Bozidar; Ruzić, Alen; Zaputović, Luka; Racki, Sanjin

2012-10-01

Acute kidney injury (AKI) is an important clinical issue, especially in the setting of critical care. It has been shown in multiple studies to be a key independent risk factor for mortality, even after adjustment for demographics and severity of illness. There is wide agreement that a generally applicable classification system is required for AKI which helps to standardize estimation of severity of renal disfunction and to predict outcome associated with this condition. That's how RIFLE (Risk-Injury-Failure-Loss-End-stage renal disease), and AKIN (Acute Kidney Injury Network) classifications for AKI were found in 2004 and 2007, respectively. In the clinical setting of heart failure, a positive fluid balance (often expressed in the literature as weight gain) is used by disease management programs as a marker of heart failure decompensation. Oliguria is defined as urine output less than 0,3 ml/kg/h for at least 24 h. Since any delay in treatment can lead to a dangerous progression of the AKI, early recognition of oliguria appears to be crucial. Critically ill patients with oliguric AKI are at increased risk for fluid imbalance due to widespread systemic inflammation, reduced plasma oncotic pressure and increased capillary leak. These patients are particulary at risk of fluid overload and therefore restrictive strategy of fluid administration should be used. Objective, rapid and accurate volume assessment is important in undiagnosed patients presenting with critical illness, as errors may result in interventions with fatal outcomes. The historical tools such as physical exam, and chest radiography suffer from significant limitations. As gold standard, radioisolopic measurement of volume is impractical in the acute care enviroment. Newer technologies offer the promise of both rapid and accurate bedside estimation of volume status with the potential to improve clinical outcomes. Blood assessment with bioimpendance vector analysis, and bedside ultrasound seem to be

Protective effect of magnolol-loaded polyketal microparticles on lipopolysaccharide-induced acute lung injury in rats.

PubMed

Tsai, Tsuimin; Kao, Chen-Yu; Chou, Chun-Liang; Liu, Lu-Chun; Chou, Tz-Chong

2016-08-01

Magnolol has shown inhibitory effects on NO production and TNF-alpha production in lipopolysaccharide (LPS)-activated macrophages and LPS-induced acute lung injury; however, the poor solubility of magnolol has hindered its clinical success. In this study, magnolol-loaded microparticles were prepared via single emulsion method from a polyketal polymer, termed PK3. The particle sizes of magnolol-loaded PK3 microparticle is 3.73 ± 0.41 μm, and was suitable for phagocytosis by macrophages and pulmonary drug delivery. PK3 microparticles exhibited excellent biocompatibility both in vitro and in vivo. More importantly, intratracheal delivery of these magnolol-loaded microparticles significantly reduced the lung inflammatory responses at low dosage of magnolol (0.5 mg/kg), and have great clinical potential in treating acute lung injury.

Scaling relationships between bed load volumes, transport distances, and stream power in steep mountain channels

NASA Astrophysics Data System (ADS)

Schneider, Johannes M.; Turowski, Jens M.; Rickenmann, Dieter; Hegglin, Ramon; Arrigo, Sabrina; Mao, Luca; Kirchner, James W.

2014-03-01

Bed load transport during storm events is both an agent of geomorphic change and a significant natural hazard in mountain regions. Thus, predicting bed load transport is a central challenge in fluvial geomorphology and natural hazard risk assessment. Bed load transport during storm events depends on the width and depth of bed scour, as well as the transport distances of individual sediment grains. We traced individual gravels in two steep mountain streams, the Erlenbach (Switzerland) and Rio Cordon (Italy), using magnetic and radio frequency identification tags, and measured their bed load transport rates using calibrated geophone bed load sensors in the Erlenbach and a bed load trap in the Rio Cordon. Tracer transport distances and bed load volumes exhibited approximate power law scaling with both the peak stream power and the cumulative stream energy of individual hydrologic events. Bed load volumes scaled much more steeply with peak stream power and cumulative stream energy than tracer transport distances did, and bed load volumes scaled as roughly the third power of transport distances. These observations imply that large bed load transport events become large primarily by scouring the bed deeper and wider, and only secondarily by transporting the mobilized sediment farther. Using the sediment continuity equation, we can estimate the mean effective thickness of the actively transported layer, averaged over the entire channel width and the duration of individual flow events. This active layer thickness also followed approximate power law scaling with peak stream power and cumulative stream energy and ranged up to 0.57 m in the Erlenbach, broadly consistent with independent measurements.

Factors associated with elevated plateau pressure in patients with acute lung injury receiving lower tidal volume ventilation.

PubMed

Prescott, Hallie C; Brower, Roy G; Cooke, Colin R; Phillips, Gary; O'Brien, James M

2013-03-01

Lung-protective ventilation with lower tidal volume and lower plateau pressure improves mortality in patients with acute lung injury and acute respiratory distress syndrome. We sought to determine the incidence of elevated plateau pressure in acute lung injury /acute respiratory distress syndrome patients receiving lower tidal volume ventilation and to determine the factors that predict elevated plateau pressure in these patients. We used data from 1398 participants in Acute Respiratory Distress Syndrome Network trials, who received lower tidal volume ventilation (≤ 6.5mL/kg predicted body weight). We considered patients with a plateau pressure greater than 30cm H2O and/or a tidal volume less than 5.5mL/kg predicted body weight on study day 1 to have "elevated plateau pressure." We used logistic regression to identify baseline clinical variables associated with elevated plateau pressure and to develop a model to predict elevated plateau pressure using a subset of 1,188 patients. We validated the model in the 210 patients not used for model development. Medical centers participating in Acute Respiratory Distress Syndrome Network clinical trials. None. Of the 1,398 patients in our study, 288 (20.6%) had elevated plateau pressure on day 1. Severity of illness indices and demographic factors (younger age, greater body mass index, and non-white race) were independently associated with elevated plateau pressure. The multivariable logistic regression model for predicting elevated plateau pressure had an area under the receiving operator characteristic curve of 0.71 for both the developmental and the validation subsets. acute lung injury patients receiving lower tidal volume ventilation often have a plateau pressure that exceeds Acute Respiratory Distress Syndrome Network goals. Race, body mass index, and severity of lung injury are each independently associated with elevated plateau pressure. Selecting a smaller initial tidal volume for non-white patients and patients

Constant load and constant volume response of municipal solid waste in simple shear.

PubMed

Zekkos, Dimitrios; Fei, Xunchang

2017-05-01

Constant load and constant volume simple shear testing was conducted on relatively fresh municipal solid waste (MSW) from two landfills in the United States, one in Michigan and a second in Texas, at respective natural moisture content below field capacity. The results were assessed in terms of two failure strain criteria, at 10% and 30% shear strain, and two interpretations of effective friction angle. Overall, friction angle obtained assuming that the failure plane is horizontal and at 10% shear strain resulted in a conservative estimation of shear strength of MSW. Comparisons between constant volume and constant load simple shear testing results indicated significant differences in the shear response of MSW with the shear resistance in constant volume being lower than the shear resistance in constant load. The majority of specimens were nearly uncompacted during specimen preparation to reproduce the state of MSW in bioreactor landfills or in uncontrolled waste dumps. The specimens had identical percentage of <20mm material but the type of <20mm material was different. The <20mm fraction from Texas was finer and of high plasticity. MSW from Texas was overall weaker in both constant load and constant volume conditions compared to Michigan waste. The results of these tests suggest the possibility of significantly lower shear strength of MSW in bioreactor landfills where waste is placed with low compaction effort and constant volume, i.e., "undrained", conditions may occur. Compacted MSW specimens resulted in shear strength parameters that are higher than uncompacted specimens and closer to values reported in the literature. However, the normalized undrained shear strength in simple shear for uncompacted and compacted MSW was still higher than the normalized undrained shear strength reported in the literature for clayey and silty soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

Acute Ischemic Stroke Infarct Topology: Association with Lesion Volume and Severity of Symptoms at Admission and Discharge.

PubMed

Payabvash, S; Taleb, S; Benson, J C; McKinney, A M

2017-01-01

Acute stroke presentation and outcome depend on both ischemic infarct volume and location. We aimed to determine the association between acute ischemic infarct topology and lesion volume and stroke severity at presentation and discharge. Patients with acute ischemic stroke who underwent MR imaging within 24 hours of symptom onset or last seen well were included. Infarcts were segmented and coregistered on the Montreal Neurological Institute-152 brain map. Voxel-based analyses were performed to determine the distribution of infarct lesions associated with larger volumes, higher NIHSS scores at admission and discharge, and greater NIHSS/volume ratios. A total of 238 patients were included. Ischemic infarcts involving the bilateral lentiform nuclei, insular ribbons, middle corona radiata, and right precentral gyrus were associated with larger infarct volumes (average, 76.7 ± 125.6 mL versus 16.4 ± 24.0 mL, P < .001) and higher admission NIHSS scores. Meanwhile, brain stem and thalami infarctions were associated with higher admission NIHSS/volume ratios. The discharge NIHSS scores were available in 218 patients, in whom voxel-based analysis demonstrated that ischemic infarcts of the bilateral posterior insular ribbons, middle corona radiata, and right precentral gyrus were associated with more severe symptoms at discharge, whereas ischemic lesions of the brain stem, bilateral thalami, and, to a lesser extent, the middle corona radiata were associated with higher ratios of discharge NIHSS score/infarct volume. Acute ischemic infarcts of the insulae, lentiform nuclei, and middle corona radiata tend to have larger volumes, more severe presentations, and worse outcomes, whereas brain stem and thalamic infarcts have greater symptom severity relative to smaller lesion volumes. © 2017 by American Journal of Neuroradiology.

Standardization of formulations for the acute amino acid depletion and loading test

PubMed Central

Badawy, Abdulla A-B; Dougherty, Donald M

2017-01-01

The acute tryptophan (Trp) depletion (ATD) and loading (ATL) and the acute tyrosine (Tyr) plus phenylalanine (Phe) depletion (ATPD) tests are powerful tools for studying the roles of cerebral monoamines in behaviour and symptoms related to various disorders. The tests use either amino acid mixtures or proteins. Current amino acid mixtures lack specificity in humans, but not in rodents, because of the faster disposal of branched-chain amino acids (BCAA) by the latter. The high content of BCAA (30-60%) is responsible for the poor specificity in humans and we recommend, in a 50g dose, the control formulation of Young et al. (1985) with a lowered BCAA content (18%) and minor modifications as a common control for the above tests. With protein-based formulations, α-lactalbumin is specific for ATL, whereas gelatine is only partially effective for ATD. We recommend the use of the whey protein fraction glycomacropeptide (GMP) as an alternative protein. Its BCAA content is ideal for specificity and the absence of Trp, Tyr and Phe render it suitable as a template for 7 formulations (separate and combined depletion or loading and a truly balanced control). We invite the research community to participate in standardization of the depletion and loading methodologies by using our recommended amino acid formulation and developing those based on GMP. PMID:25586395

Muscle volume, strength, endurance, and exercise loads during 6-month missions in space.

PubMed

Gopalakrishnan, Raghavan; Genc, Kerim O; Rice, Andrea J; Lee, Stuart M C; Evans, Harlan J; Maender, Christian C; Ilaslan, Hakan; Cavanagh, Peter R

2010-02-01

Decrements in muscular strength during long-duration missions in space could be mission-critical during construction and exploration activities. The purpose of this study was to quantify changes in muscle volume, strength, and endurance of crewmembers on the International Space Station (ISS) in the context of new measurements of loading during exercise countermeasures. Strength and muscle volumes were measured from four male ISS crewmembers (49.5 +/- 4.7 yr, 179.3 +/- 7.1 cm, 85.2 +/- 10.4 kg) before and after long-duration spaceflight (181 +/- 15 d). Preflight and in-flight measurements of forces between foot and shoe allowed comparisons of loading from 1-g exercise and exercise countermeasures on ISS. Muscle volume change was greater in the calf (-10 to 16%) than the thigh (-4% to -7%), but there was no change in the upper arm (+0.4 to -0.8%). Isometric and isokinetic strength changes at the knee (range -10.4 to -24.1%), ankle (range -4 to -22.3%), and elbow (range -7.5 to -16.7%) were observed. Although there was an overall postflight decline in total work (-14%) during the endurance test, an increase in postflight resistance to fatigue was observed. The peak in-shoe forces during running and cycling on ISS were approximately 46% and 50% lower compared to 1-g values. Muscle volume and strength were decreased in the lower extremities of crewmembers during long-duration spaceflight on ISS despite the use of exercise countermeasures. in-flight countermeasures were insufficient to replicate the daily mechanical loading experienced by the crewmembers before flight. Future exercise protocols need careful assessment both in terms of intensity and duration to maximize the "dose" of exercise and to increase loads compared to the measured levels.

The effects of contrast media volume on acute kidney injury after transcatheter aortic valve replacement: a systematic review and meta-analysis.

PubMed

Thongprayoon, Charat; Cheungpasitporn, Wisit; Podboy, Alexander J; Gillaspie, Erin A; Greason, Kevin L; Kashani, Kianoush B

2016-11-01

The goal of this systematic review was to assess the effects of contrast media volume on transcatheter aortic valve replacement-related acute kidney injury. A literature search was performed using Medline, EMbase, the Cochrane Database of Systematic Reviews, and clinicaltrials.gov from the inception of these databases through December 2015. Studies that reported relative risk, odds ratio, or hazard ratio comparing the risks of acute kidney injury following transcatheter aortic valve replacement in patients who received high contrast media volume were included. Pooled risk ratio (RR) and 95% confidence intervals (95% CI) were calculated using a random-effect, generic inverse variance method. Four cohort studies composed of 891 patients were included in the analyses to assess the risk of acute kidney injury after transcatheter aortic valve replacement in patients who received high contrast media volume. The pooled RR of acute kidney injury after transcatheter aortic valve replacement in patients who received a large volume of contrast media was 1.41 (95% CI, 0.87 to 2.28) compared with low contrast media volume. The meta-analysis was limited to studies using standard acute kidney injury definitions, and the pooled RR of acute kidney injury in patients who received high contrast media volume is 1.12 (95% CI, 0.78 to 1.62). Our meta-analysis shows no significant association between contrast media volume and risk of acute kidney injury after transcatheter aortic valve replacement. © 2016 Chinese Cochrane Center, West China Hospital of Sichuan University and John Wiley & Sons Australia, Ltd.

Acute Response of Circulating Vascular Regulating MicroRNAs during and after High-Intensity and High-Volume Cycling in Children.

PubMed

Kilian, Yvonne; Wehmeier, Udo F; Wahl, Patrick; Mester, Joachim; Hilberg, Thomas; Sperlich, Billy

2016-01-01

The aim of the present study was to analyze the response of vascular circulating microRNAs (miRNAs; miR-16, miR-21, miR-126) and the VEGF mRNA following an acute bout of HIIT and HVT in children. Twelve healthy competitive young male cyclists (14.4 ± 0.8 years; 57.9 ± 9.4 ml·min(-1)·kg(-1) peak oxygen uptake) performed one session of high intensity 4 × 4 min intervals (HIIT) at 90-95% peak power output (PPO), each interval separated by 3 min of active recovery, and one high volume session (HVT) consisting of a constant load exercise for 90 min at 60% PPO. Capillary blood from the earlobe was collected under resting conditions, during exercise (d1 = 20 min, d2 = 30 min, d3 = 60 min), and 0, 30, 60, 180 min after the exercise to determine miR-16, -21, -126, and VEGF mRNA. HVT significantly increased miR-16 and miR-126 during and after the exercise compared to pre-values, whereas HIIT showed no significant influence on the miRNAs compared to pre-values. VEGF mRNA significantly increased during and after HIIT (d1, 30', 60', 180') and HVT (d3, 0', 60'). RESULTS of the present investigation suggest a volume dependent exercise regulation of vascular regulating miRNAs (miR-16, miR-21, miR-126) in children. In line with previous data, our data show that acute exercise can alter circulating miRNAs profiles that might be used as novel biomarkers to monitor acute and chronic changes due to exercise in various tissues.

Precise determination of time to reach viral load set point after acute HIV-1 infection.

PubMed

Huang, Xiaojie; Chen, Hui; Li, Wei; Li, Haiying; Jin, Xia; Perelson, Alan S; Fox, Zoe; Zhang, Tong; Xu, Xiaoning; Wu, Hao

2012-12-01

The HIV viral load set point has long been used as a prognostic marker of disease progression and more recently as an end-point parameter in HIV vaccine clinical trials. The definition of set point, however, is variable. Moreover, the earliest time at which the set point is reached after the onset of infection has never been clearly defined. In this study, we obtained sequential plasma viral load data from 60 acutely HIV-infected Chinese patients among a cohort of men who have sex with men, mathematically determined viral load set point levels, and estimated time to attain set point after infection. We also compared the results derived from our models and that obtained from an empirical method. With novel uncomplicated mathematic model, we discovered that set points may vary from 21 to 119 days dependent on the patients' initial viral load trajectory. The viral load set points were 4.28 ± 0.86 and 4.25 ± 0.87 log10 copies per milliliter (P = 0.08), respectively, as determined by our model and an empirical method, suggesting an excellent agreement between the old and new methods. We provide a novel method to estimate viral load set point at the very early stage of HIV infection. Application of this model can accurately and reliably determine the set point, thus providing a new tool for physicians to better monitor early intervention strategies in acutely infected patients and scientists to rationally design preventative vaccine studies.

Estimation of Local Bone Loads for the Volume of Interest.

PubMed

Kim, Jung Jin; Kim, Youkyung; Jang, In Gwun

2016-07-01

Computational bone remodeling simulations have recently received significant attention with the aid of state-of-the-art high-resolution imaging modalities. They have been performed using localized finite element (FE) models rather than full FE models due to the excessive computational costs of full FE models. However, these localized bone remodeling simulations remain to be investigated in more depth. In particular, applying simplified loading conditions (e.g., uniform and unidirectional loads) to localized FE models have a severe limitation in a reliable subject-specific assessment. In order to effectively determine the physiological local bone loads for the volume of interest (VOI), this paper proposes a novel method of estimating the local loads when the global musculoskeletal loads are given. The proposed method is verified for the three VOI in a proximal femur in terms of force equilibrium, displacement field, and strain energy density (SED) distribution. The effect of the global load deviation on the local load estimation is also investigated by perturbing a hip joint contact force (HCF) in the femoral head. Deviation in force magnitude exhibits the greatest absolute changes in a SED distribution due to its own greatest deviation, whereas angular deviation perpendicular to a HCF provides the greatest relative change. With further in vivo force measurements and high-resolution clinical imaging modalities, the proposed method will contribute to the development of reliable patient-specific localized FE models, which can provide enhanced computational efficiency for iterative computing processes such as bone remodeling simulations.

Surfactant volume is an essential element in human toxicity in acute glyphosate herbicide intoxication.

PubMed

Seok, Su-Jin; Park, Jae-Seok; Hong, Joong-Rock; Gil, Hyo-Wook; Yang, Jong-Oh; Lee, Eun-Young; Song, Ho-Yeon; Hong, Sae-Yong

2011-12-01

Glyphosate, one of the most commonly used herbicides worldwide, has been considered as minimally toxic to humans. However, clinical toxicologists occasionally encounter cases of severe systemic toxicity. The purpose of this study was to determine the effect of glyphosate-surfactants ("glyphosate-surfactant toxicity") in patients with acute glyphosate intoxication. In all, 107 patients (69 men and 38 women, aged 52.3 ± 15.5 years) with acute glyphosate intoxication were enrolled in this study. From their medical records, we identified the formulation of ingested glyphosate products and derived clinical parameters, which focused on clinical outcome, admission days, duration in the intensive care unit, development of respiratory failure, cardiovascular deterioration, renal failure, altered mental status, and convulsions. The effect of surfactants on clinical complications was also assessed. For surfactant ingestion volumes of 8 mL, the incidence of clinical complications was (in rank order) as follows: hypotension, 47.1%; mental deterioration, 38.6%; respiratory failure, 30.0%; acute kidney injury, 17.1%; and arrhythmia, 10.0%. These complications were influenced by the volume of surfactant and not the type of surfactant-ingredient in the herbicide product. Two patients died of refractory shock, metabolic acidosis, and respiratory failure. However, the final clinical outcomes of the surviving patients were benign, and cardiovascular, respiratory, kidney, and mental functions were fully restored to normal levels. Our results indicate that treatment of patients with acute glyphosate herbicide intoxication should take into account the volume and not the type of surfactants in herbicide formulations.

Modal analysis of annual runoff volume and sediment load in the Yangtze river-lake system for the period 1956-2013.

PubMed

Chen, Huai; Zhu, Lijun; Wang, Jianzhong; Fan, Hongxia; Wang, Zhihuan

2017-07-01

This study focuses on detecting trends in annual runoff volume and sediment load in the Yangtze river-lake system. Times series of annual runoff volume and sediment load at 19 hydrological gauging stations for the period 1956-2013 were collected. Based on the Mann-Kendall test at the 1% significance level, annual sediment loads in the Yangtze River, the Dongting Lake and the Poyang Lake were detected with significantly descending trends. The power spectrum estimation indicated predominant oscillations with periods of 8 and 20 years are embedded in the runoff volume series, probably related to the El Niño Southern Oscillation (2-7 years) and Pacific Decadal Oscillation (20-30 years). Based on dominant components (capturing more than roughly 90% total energy) extracted by the proper orthogonal decomposition method, total change ratios of runoff volume and sediment load during the last 58 years were evaluated. For sediment load, the mean CRT value in the Yangtze River is about -65%, and those in the Dongting Lake and the Poyang Lake are -92.2% and -87.9% respectively. Particularly, the CRT value of the sediment load in the channel inflow of the Dongting Lake is even -99.7%. The Three Gorges Dam has intercepted a large amount of sediment load and decreased the sediment load downstream.

High-volume resistance training session acutely diminishes respiratory muscle strength.

PubMed

Hackett, Daniel A; Johnson, Nathan A; Chow, Chin-Moi

2012-01-01

This study investigated the effect of a high-volume compared to a low-volume resistance training session on maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP). Twenty male subjects with resistance training experience (6.2 ± 3.2 y), in a crossover trial, completed two resistance training protocols (high-volume: 5 sets per exercise; low-volume: 2 sets per exercise) and a control session (no exercise) on 3 separate occasions. MIP and MEP decreased by 13.6% (p < 0.01) and 14.7% (p < 0.01) respectively from pre-session MIP and MEP, following the high-volume session. MIP and MEP were unaffected following the low-volume or the control sessions. MIP returned to pre-session values after 40 minutes, whereas MEP remained significantly reduced after 60 minutes post-session by 9.2% compared to pre-session (p < 0.01). The findings suggest that the high-volume session significantly decreased MIP and MEP post-session, implicating a substantially increased demand on the respiratory muscles and that adequate recovery is mandatory following this mode of training. Key pointsRespiratory muscular strength performance is acutely diminished following a high-volume whole-body resistance training session.Greater ventilatory requirements and generation of IAP during the high-volume resistance training session may have contributed to the increased demand placed on the respiratory muscles.Protracted return of respiratory muscular strength performance to baseline levels may have implications for individuals prior to engaging in subsequent exercise bouts.

A Comparative Study of Pituitary Volume Variations in MRI in Acute Onset of Psychiatric Conditions.

PubMed

Soni, Brijesh Kumar; Joish, Upendra Kumar; Sahni, Hirdesh; George, Raju A; Sivasankar, Rajeev; Aggarwal, Rohit

2017-02-01

The growing belief that endocrine abnormalities may underlie many mental conditions has led to increased use of imaging and hormonal assays in patients attending to psychiatric OPDs. People who are in an acute phase of a psychiatric disorder show Hypothalamic Pituitary Adrenal (HPA) axis hyperactivity, but the precise underlying central mechanisms are unclear. To assess the pituitary gland volume variations in patients presenting with new onset acute psychiatric illness in comparison with age and gender matched controls by using MRI. The study included 50 patients, with symptoms of acute psychiatric illness presenting within one month of onset of illness and 50 age and gender matched healthy controls. Both patients and controls were made to undergo MRI of the Brain. A 0.9 mm slices of entire brain were obtained by 3 dimensional T1 weighted sequence. Pituitary gland was traced in all sagittal slices. Anterior pituitary and posterior pituitary bright spot were measured separately in each slice. Volume of the pituitary (in cubic centimetre- cm 3 ) was calculated by summing areas. Significance of variations in pituitary gland volumes was compared between the cases and controls using Analysis of Covariance (ANOVA). There were significantly larger pituitary gland volumes in the cases than the controls, irrespective of psychiatric diagnosis (ANOVA, f=15.56; p=0.0002). Pituitary volumes in cases were 15.36% (0.73 cm 3 ) higher than in controls. There is a strong likelihood of HPA axis overactivity during initial phase of all mental disorders along with increased pituitary gland volumes. Further studies including hormonal assays and correlation with imaging are likely to provide further insight into neuroanatomical and pathological basis of psychiatric disorders.

Effects of tidal volume on work of breathing during lung-protective ventilation in patients with acute lung injury and acute respiratory distress syndrome.

PubMed

Kallet, Richard H; Campbell, Andre R; Dicker, Rochelle A; Katz, Jeffrey A; Mackersie, Robert C

2006-01-01

To assess the effects of step-changes in tidal volume on work of breathing during lung-protective ventilation in patients with acute lung injury (ALI) or the acute respiratory distress syndrome (ARDS). Prospective, nonconsecutive patients with ALI/ARDS. Adult surgical, trauma, and medical intensive care units at a major inner-city, university-affiliated hospital. Ten patients with ALI/ARDS managed clinically with lung-protective ventilation. Five patients were ventilated at a progressively smaller tidal volume in 1 mL/kg steps between 8 and 5 mL/kg; five other patients were ventilated at a progressively larger tidal volume from 5 to 8 mL/kg. The volume mode was used with a flow rate of 75 L/min. Minute ventilation was maintained constant at each tidal volume setting. Afterward, patients were placed on continuous positive airway pressure for 1-2 mins to measure their spontaneous tidal volume. Work of breathing and other variables were measured with a pulmonary mechanics monitor (Bicore CP-100). Work of breathing progressively increased (0.86 +/- 0.32, 1.05 +/- 0.40, 1.22 +/- 0.36, and 1.57 +/- 0.43 J/L) at a tidal volume of 8, 7, 6, and 5 mL/kg, respectively. In nine of ten patients there was a strong negative correlation between work of breathing and the ventilator-to-patient tidal volume difference (R = -.75 to -.998). : The ventilator-delivered tidal volume exerts an independent influence on work of breathing during lung-protective ventilation in patients with ALI/ARDS. Patient work of breathing is inversely related to the difference between the ventilator-delivered tidal volume and patient-generated tidal volume during a brief trial of unassisted breathing.

The Impact of Hospital/Surgeon Volume on Acute Renal Failure and Mortality in Liver Transplantation: A Nationwide Cohort Study.

PubMed

Cheng, Chih-Wen; Liu, Fu-Chao; Lin, Jr-Rung; Tsai, Yung-Fong; Chen, Hsiu-Pin; Yu, Huang-Ping

2016-01-01

The aim of this study was to assess whether the case volume of surgeons and hospitals affects the rates of postoperative complications and survival after liver transplantation. This population-based retrospective cohort study included 2938 recipients of liver transplantation performed between 1998 and 2012, enrolled from the Taiwan National Health Insurance Research Database. They were divided into two groups, according to the cumulative case volume of their operating surgeons and the case volume of their hospitals. The duration of intensive care unit stay and post-transplantation hospitalization, postoperative complications, and mortality were analyzed. The results showed that, in the low and high case volume surgeons groups, respectively, acute renal failure occurred at the rate of 14.11% and 5.86% (p<0.0001), and the overall mortality rates were 19.61% and 12.44% (p<0.0001). In the low and high case volume hospital groups, respectively, acute renal failure occurred in 11% and 7.11% of the recipients (p = 0.0004), and the overall mortality was 18.44% and 12.86% (p<0.0001). These findings suggest that liver transplantation recipients operated on higher case volume surgeons or in higher case volume hospitals have a lower rate of acute renal failure and mortality.

White Matter Hyperintensity Volume and Outcome of Mechanical Thrombectomy With Stentriever in Acute Ischemic Stroke.

PubMed

Atchaneeyasakul, Kunakorn; Leslie-Mazwi, Thabele; Donahue, Kathleen; Giese, Anne-Katrin; Rost, Natalia S

2017-10-01

Finding of white matter hyperintensity (WMH) has been associated with an increased risk of parenchymal hematoma and poor clinical outcomes after mechanical thrombectomy using old-generation endovascular devices. Currently, no data exist with regard to the risk of mechanical thrombectomy using stentriever devices in patients with significant WMH. We hypothesized that WMH volume will not affect the hemorrhagic and clinical outcome in patients with acute ischemic stroke undergoing thrombectomy using new-generation devices. A retrospective cohort of consecutive acute ischemic stroke patients >18-year-old receiving mechanical thrombectomy with stentriever devices at a single academic center was examined. WMH volume was assessed by a semiautomated volumetric analysis on T2 fluid attenuated inversion recovery-magnetic resonance imaging. Outcomes included the rate of any intracerebral hemorrhage, 90-day modified Rankin Score (mRS), the rate of good outcome (discharge mRS ≤2), and the rate of successful reperfusion (thrombolysis in cerebral ischemia score 2b or 3). Between June 2012 and December 2015, 56 patients with acute ischemic stroke met the study criteria. Median WMH volume was 6.76 cm 3 (4.84-16.09 cm 3 ). Increasing WMH volume did not significantly affect the odds of good outcome (odds ratio [OR], 0.811; 95% confidence interval [CI], 0.456-1.442), intracerebral hemorrhage (OR, 1.055; 95% CI, 0.595-1.871), parenchymal hematoma (OR, 0.353; 95% CI, 0.061-2.057), successful recanalization (OR, 1.295; 95% CI, 0.704-2.383), or death (OR, 1.583; 95% CI, 0.84-2.98). Mechanical thrombectomy using stentrievers seems to be safe in selected patients with acute ischemic stroke with large vessel occlusion, nonwithstanding the severity of WMH burden in this population. Larger prospective studies are warranted to validate these findings. © 2017 American Heart Association, Inc.

Chronic and acute inspiratory muscle loading augment the effect of a 6-week interval program on tolerance of high-intensity intermittent bouts of running.

PubMed

Tong, Tom K; Fu, Frank H; Eston, Roger; Chung, Pak-Kwong; Quach, Binh; Lu, Kui

2010-11-01

This study examined the hypothesis that chronic (training) and acute (warm-up) loaded ventilatory activities applied to the inspiratory muscles (IM) in an integrated manner would augment the training volume of an interval running program. This in turn would result in additional improvement in the maximum performance of the Yo-Yo intermittent recovery test in comparison with interval training alone. Eighteen male nonprofessional athletes were allocated to either an inspiratory muscle loading (IML) group or control group. Both groups participated in a 6-week interval running program consisting of 3-4 workouts (1-3 sets of various repetitions of selected distance [100-2,400 m] per workout) per week. For the IML group, 4-week IM training (30 inspiratory efforts at 50% maximal static inspiratory pressure [P0] per set, 2 sets·d-1, 6 d·wk-1) was applied before the interval program. Specific IM warm-up (2 sets of 30 inspiratory efforts at 40% P0) was performed before each workout of the program. For the control group, neither IML was applied. In comparison with the control group, the interval training volume as indicated by the repeatability of running bouts at high intensity was approximately 27% greater in the IML group. Greater increase in the maximum performance of the Yo-Yo test (control: 16.9 ± 5.5%; IML: 30.7 ± 4.7% baseline value) was also observed after training. The enhanced exercise performance was partly attributable to the greater reductions in the sensation of breathlessness and whole-body metabolic stress during the Yo-Yo test. These findings show that the combination of chronic and acute IML into a high-intensity interval running program is a beneficial training strategy for enhancing the tolerance to high-intensity intermittent bouts of running.

Load research manual. Volume 3: Load research for advanced technologies

NASA Astrophysics Data System (ADS)

1980-11-01

Technical guidelines for electric utility load research are presented. Special attention is given to issues raised by the load reporting requirements of the Public Utility Regulatory Policies Act of 1978 and to problems faced by smaller utilities that are initiating load research programs. The manual includes guides to load research literature and glossaries of load research and statistical terms. Special load research procedures are presented for solar, wind, and cogeneration technologies.

Low Tidal Volume Ventilation in Patients without Acute Respiratory Distress Syndrome: A Paradigm Shift in Mechanical Ventilation

PubMed Central

Lipes, Jed; Bojmehrani, Azadeh; Lellouche, Francois

2012-01-01

Protective ventilation with low tidal volume has been shown to reduce morbidity and mortality in patients suffering from acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Low tidal volume ventilation is associated with particular clinical challenges and is therefore often underutilized as a therapeutic option in clinical practice. Despite some potential difficulties, data have been published examining the application of protective ventilation in patients without lung injury. We will briefly review the physiologic rationale for low tidal volume ventilation and explore the current evidence for protective ventilation in patients without lung injury. In addition, we will explore some of the potential reasons for its underuse and provide strategies to overcome some of the associated clinical challenges. PMID:22536499

Optimizing Preseason Training Loads in Australian Football.

PubMed

Carey, David L; Crow, Justin; Ong, Kok-Leong; Blanch, Peter; Morris, Meg E; Dascombe, Ben J; Crossley, Kay M

2018-02-01

To investigate whether preseason training plans for Australian football can be computer generated using current training-load guidelines to optimize injury-risk reduction and performance improvement. A constrained optimization problem was defined for daily total and sprint distance, using the preseason schedule of an elite Australian football team as a template. Maximizing total training volume and maximizing Banister-model-projected performance were both considered optimization objectives. Cumulative workload and acute:chronic workload-ratio constraints were placed on training programs to reflect current guidelines on relative and absolute training loads for injury-risk reduction. Optimization software was then used to generate preseason training plans. The optimization framework was able to generate training plans that satisfied relative and absolute workload constraints. Increasing the off-season chronic training loads enabled the optimization algorithm to prescribe higher amounts of "safe" training and attain higher projected performance levels. Simulations showed that using a Banister-model objective led to plans that included a taper in training load prior to competition to minimize fatigue and maximize projected performance. In contrast, when the objective was to maximize total training volume, more frequent training was prescribed to accumulate as much load as possible. Feasible training plans that maximize projected performance and satisfy injury-risk constraints can be automatically generated by an optimization problem for Australian football. The optimization methods allow for individualized training-plan design and the ability to adapt to changing training objectives and different training-load metrics.

Soil load above Hanford waste storage tanks (2 volumes)

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

Pianka, E.W.

1995-01-25

This document is a compilation of work performed as part of the Dome Load Control Project in 1994. Section 2 contains the calculations of the weight of the soil over the tank dome for each of the 75-feet-diameter waste-storage tanks located at the Hanford Site. The chosen soil specific weight and soil depth measured at the apex of the dome crown are the same as those used in the primary analysis that qualified the design. Section 3 provides reference dimensions for each of the tank farm sites. The reference dimensions spatially orient the tanks and provide an outer diameter formore » each tank. Section 4 summarizes the available soil surface elevation data. It also provides examples of the calculations performed to establish the present soil elevation estimates. The survey data and other data sources from which the elevation data has been obtained are printed separately in Volume 2 of this Supporting Document. Section 5 contains tables that provide an overall summary of the present status of dome loads. Tables summarizing the load state corresponding to the soil depth and soil specific weight for the original qualification analysis, the gravity load requalification for soil depth and soil specific weight greater than the expected actual values, and a best estimate condition of soil depth and specific weight are presented for the Double-Shell Tanks. For the Single-Shell Tanks, only the original qualification analysis is available; thus, the tabulated results are for this case only. Section 6 provides a brief overview of past analysis and testing results that given an indication of the load capacity of the waste storage tanks that corresponds to a condition approaching ultimate failure of the tank. 31 refs.« less

The effect of different volumes of acute resistance exercise on elderly individuals with treated hypertension.

PubMed

Scher, Luria M L; Ferriolli, Eduardo; Moriguti, Julio C; Scher, Ricardo; Lima, Nereida K C

2011-04-01

Acute resistance exercise can reduce the blood pressure (BP) of hypertensive subjects. The aim of this study was to evaluate the effect of different volumes of acute low-intensity resistance exercise over the magnitude and the extent of BP changes in treated hypertensive elderly individuals. Sixteen participants (7 men, 9 women), with mean age of 68 ± 5 years, performed 3 independent randomized sessions: Control (C: 40 minutes of rest), Exercise 1 (E1: 20 minutes, 1 lap in the circuit), and Exercise 2 (E2: 40 minutes, 2 laps in the circuit) with the intensity of 40% of 1 repetition maximum. Blood pressure was measured before (during 20 minutes) and after each session (every 5 minutes during 60 minutes) using both a mercury sphygmomanometer and a semiautomatic device (Omrom-HEM-431). After that, 24-hour ambulatory blood pressure monitoring was performed (Dyna-MAPA). Blood pressure decreased during the first 60 minutes (systolic: p < 0.01, diastolic: p < 0.05) after all exercise sessions. Only the highest volume session promoted a reduction of mean systolic 24-hour BP and awake BP (p < 0.05) after exercise, with higher diastolic BP during sleep (p < 0.05). Diastolic 24-hour BP and both systolic and diastolic BP during sleep were higher after E1 (p < 0.05). Concluding, acute resistive exercise sessions in a circuit with different volumes reduced BP during the first 60 minutes after exercise in elderly individuals with treated hypertension. However, only the highest volume promoted a reduction of mean 24-hour and awake systolic BP.

Effect of rowing ergometry and oral volume loading on cardiovascular structure and function during bed rest

PubMed Central

Hastings, Jeffrey L.; Krainski, Felix; Snell, Peter G.; Pacini, Eric L.; Jain, Manish; Bhella, Paul S.; Shibata, Shigeki; Fu, Qi; Palmer, M. Dean

2012-01-01

This study examined the effectiveness of a short-duration but high-intensity exercise countermeasure in combination with a novel oral volume load in preventing bed rest deconditioning and orthostatic intolerance. Bed rest reduces work capacity and orthostatic tolerance due in part to cardiac atrophy and decreased stroke volume. Twenty seven healthy subjects completed 5 wk of −6 degree head down bed rest. Eighteen were randomized to daily rowing ergometry and biweekly strength training while nine remained sedentary. Measurements included cardiac mass, invasive pressure-volume relations, maximal upright exercise capacity, and orthostatic tolerance. Before post-bed rest orthostatic tolerance and exercise testing, nine exercise subjects were given 2 days of fludrocortisone and increased salt. Sedentary bed rest led to cardiac atrophy (125 ± 23 vs. 115 ± 20 g; P < 0.001); however, exercise preserved cardiac mass (128 ± 38 vs. 137 ± 34 g; P = 0.002). Exercise training preserved left ventricular chamber compliance, whereas sedentary bed rest increased stiffness (180 ± 170%, P = 0.032). Orthostatic tolerance was preserved only when exercise was combined with volume loading (−10 ± 22%, P = 0.169) but not with exercise (−14 ± 43%, P = 0.047) or sedentary bed rest (−24 ± 26%, P = 0.035) alone. Rowing and supplemental strength training prevent cardiovascular deconditioning during prolonged bed rest. When combined with an oral volume load, orthostatic tolerance is also preserved. This combined countermeasure may be an ideal strategy for prolonged spaceflight, or patients with orthostatic intolerance. PMID:22345434

Peripheral Intravenous Volume Assessment (PIVA) for Quantitating Volume Overload in Patients Hospitalized with Acute Decompensated Heart Failure-a Pilot Study.

PubMed

Miles, Merrick; Alvis, Bret D; Hocking, Kyle; Baudenbacher, Franz; Guth, Christy; Lindenfeld, JoAann; Brophy, Colleen; Eagle, Susan

2018-05-16

To determine the feasibility of Peripheral Intravenous Volume Assessment (PIVA) of venous waveforms for assessing volume overload in patients admitted to the hospital with acute decompensated heart failure (ADHF). Venous waveforms were captured from a peripheral intravenous catheter in subjects admitted for ADHF and healthy age-matched controls. Admission PIVA signal, brain natriuretic peptide, and chest radiographic measurements were related to the net volume removed during diuresis. ADHF patients had a significantly greater PIVA signal on admission compared to the control group (P=0.0013, n=18). At discharge, ADHF patients had a PIVA signal similar to the control group. PIVA signal, not BNP or chest radiographic measures, accurately predicted the amount of volume removed during diuresis (R 2 =0.781, n=14). PIVA signal at time of discharge greater than 0.20, demonstrated 83.3% 120-day readmission rate. This study demonstrates the feasibility of PIVA for assessment of volume overload in patients admitted to the hospital with ADHF. Copyright © 2018. Published by Elsevier Inc.

Structures to Resist the Effects of Accidental Explosions. Volume 2. Blast, Fragment, and Shock Loads

DTIC Science & Technology

1986-12-01

IS. SUPPLEMENTARY NOTfS This report is Volume II of six volumes which will eventually be published as a tri-service design manual and was sponsored by...CLASSIFICAT ION OF THIS PAGE(When Date Entered) TABLE OF CONTENTS PAGE INTRODUCTION 2-I Purpose 1 2-2 Objective 1 2 3 Background 1 2-4 Scope of Manual ...2 2-5 Format of Manual 3 VOLUME CONTENTS 2-6 General EXPLOSION EFFECTS 2-7 Effects of Explosive Output 4 BLAST LOADS 2-8 Blast Phenomena 5 2-8.1

Hormonal and electrolyte responses to acute isohemic volume expansion in unanesthetized rats

NASA Technical Reports Server (NTRS)

Chenault, V. M.; Morris, M.; Lynch, C. D.; Maultsby, S. J.; Hutchins, P. M.

1993-01-01

This study was undertaken to explore the time course of the metabolic response to isohemic blood volume expansion (30%) in normotensive, unanesthetized Sprague-Dawley rats. Whole blood, drawn from a femoral artery catheter of conscious donor rats, was infused into the jugular vein of recipient rats. Blood samples were drawn from a carotid artery of recipient rats at time points beginning immediately post-volume expansion (IPVE) up through 5 days post-volume expansion (PVE). To characterize the attendant compensatory mechanisms, the plasma concentrations of electrolytes and fluid regulatory hormones were determined. Hematocrit began to raise IPVE and was significantly elevated above control IPVE 20, 30, 40, 60, and 90 min, and 2, 4, 6, 8, 12, and 24 hr PVE. Consistent with our current understanding of the hormonal response to excess volume, atrial natriuretic factor was significantly increased above the prevolume expansion (control) values 0-30 min PVE. Surprisingly, plasma aldosterone levels were significantly increased above control at 20 and 30 min and 6 hr PVE, whereas plasma renin activity was significantly decreased 30-40 min PVE. Plasma sodium was not changed from control values except for a significant increase at 6 hr post-volume expansion. Plasma potassium, osmolality, and arginine vasopressin levels were not altered by the volume expansion. These studies delineate the physiologic time scheme operative in the regulation of fluid volume during acute ischemic volume expansion.

Comparison of metabolic responses of United States Military Academy men and women in acute military load bearing.

PubMed

Stauffer, R W; McCarter, M; Campbell, J L; Wheeler, L F

1987-11-01

Twenty-four first year United States Military Academy (USMA) men and women were studied to compare metabolic response differences in seven horizontal walking velocities, under three military load bearing conditions. The treadmill protocol consisted of walking or jogging on a horizontal treadmill surface for 3-min intervals at velocities of 3, 3.5, 4, 4.5, 5, 5.5, and 6 mph. The three military load bearing conditions weighed 5, 12, and 20 kg. Metabolic measurements taken at each speed in each of the military load bearing conditions were: minute volume, tidal volume, respiratory rate, absolute and relative to body weight oxygen consumption, and respiratory quotient. Two three-way analyses of variance for repeated measures tests with main effects of gender, military load, and speed revealed that USMA men and women metabolically respond to different military load bearing conditions; they metabolically respond to different walking and jogging velocities under military load bearing conditions; and they have identifiable and quantifiable metabolic response differences to military load bearing. This study was designed to improve USMA physical and military training programs by providing information to equally and uniformly administer the USMA Doctrine of Comparable Training to men and women alike; and additionally to clarify the "...minimal essential adjustments...required because of physiological differences between male and female individuals ..." portion of Public Law 94-106 providing for the admission of women to America's Service Academies.

Whole-brain perfusion CT using a toggling table technique to predict final infarct volume in acute ischemic stroke.

PubMed

Schrader, I; Wilk, D; Jansen, O; Riedel, C

2013-09-01

To evaluate how accurately final infarct volume in acute ischemic stroke can be predicted with perfusion CT (PCT) using a 64-MDCT unit and the toggling table technique. Retrospective analysis of 89 patients with acute ischemic stroke who underwent CCT, CT angiography (CTA) and PCT using the "toggling table" technique within the first three hours after symptom onset. In patients with successful thrombolytic therapy (n = 48) and in those without effective thrombolytic therapy (n = 41), the infarct volume and the volume of the penumbra on PCT were compared to the infarct size on follow-up images (CT or MRI) performed within 8 days. The feasibility of complete infarct volume prediction by 8 cm cranio-caudal coverage was evaluated. The correlation between the volume of hypoperfusion on PCT defined by cerebral blood volume reduction and final infarct volume was strongest in patients with successful thrombolytic therapy with underestimation of the definite infarct volume by 8.5 ml on average. The CBV map had the greatest prognostic value. In patients without successful thrombolytic therapy, the final infarct volume was overestimated by 12.1 ml compared to the MTT map on PCT. All infarcts were detected completely. There were no false-positive or false-negative results. Using PCT and the "toggling table" technique in acute stroke patients is helpful for the rapid and accurate quantification of the minimal final infarct and is therefore a prognostic parameter which has to be evaluated in further studies to assess its impact on therapeutic decision. ▶ Using PCT and the “toggling table technique” allows accurate quantification of the infarct core and penumbra. ▶ It is possible to record dynamic perfusion parameters quickly and easily of almost the entire supratentorial brain volume on a 64-slice MDCT unit. ▶ The technique allows identification of those patients who could profit from thrombolytic therapy outside the established time intervals. © Georg Thieme Verlag

Relationships between static foot alignment and dynamic plantar loads in runners with acute and chronic stages of plantar fasciitis: a cross-sectional study

PubMed Central

Ribeiro, Ana P.; Sacco, Isabel C. N.; Dinato, Roberto C.; João, Silvia M. A.

2016-01-01

BACKGROUND: The risk factors for the development of plantar fasciitis (PF) have been associated with the medial longitudinal arch (MLA), rearfoot alignment and calcaneal overload. However, the relationships between the biomechanical variables have yet to be determined. OBJECTIVE: The goal of this study was to investigate the relationships between the MLA, rearfoot alignment, and dynamic plantar loads in runners with unilateral PF in acute and chronic phases. METHOD: Cross-sectional study which thirty-five runners with unilateral PF were evaluated: 20 in the acute phase (with pain) and 15 with previous chronic PF (without pain). The MLA index and rearfoot alignment were calculated using digital images. The contact area, maximum force, peak pressure, and force-time integral over three plantar areas were acquired with Pedar X insoles while running at 12 km/h, and the loading rates were calculated from the vertical forces. RESULTS: The multiple regression analyses indicated that both the force-time integral (R 2=0.15 for acute phase PF; R 2=0.17 for chronic PF) and maximum force (R 2=0.35 for chronic PF) over the forefoot were predicted by an elevated MLA index. The rearfoot valgus alignment predicted the maximum force over the rearfoot in both PF groups: acute (R 2=0.18) and chronic (R 2=0.45). The rearfoot valgus alignment also predicted higher loading rates in the PF groups: acute (R 2=0.19) and chronic (R 2=0.40). CONCLUSION: The MLA index and the rearfoot alignment were good predictors of plantar loads over the forefoot and rearfoot areas in runners with PF. However, rearfoot valgus was demonstrated to be an important clinical measure, since it was able to predict the maximum force and both loading rates over the rearfoot. PMID:26786073

Lung recruitment manoeuvres are effective in regaining lung volume and oxygenation after open endotracheal suctioning in acute respiratory distress syndrome

PubMed Central

Dyhr, Thomas; Bonde, Jan; Larsson, Anders

2003-01-01

Introduction Lung collapse is a contributory factor in the hypoxaemia that is observed after open endotracheal suctioning (ETS) in patients with acute lung injury and acute respiratory distress syndrome. Lung recruitment (LR) manoeuvres may be effective in rapidly regaining lung volume and improving oxygenation after ETS. Materials and method A prospective, randomized, controlled study was conducted in a 15-bed general intensive care unit at a university hospital. Eight consecutive mechanically ventilated patients with acute lung injury or acute respiratory distress syndrome were included. One of two suctioning procedures was performed in each patient. In the first procedure, ETS was performed followed by LR manoeuvre and reconnection to the ventilator with positive end-expiratory pressure set at 1 cmH2O above the lower inflexion point, and after 60 min another ETS (but without LR manoeuvre) was performed followed by reconnection to the ventilator with similar positive end-expiratory pressure; the second procedure was the same as the first but conducted in reverse order. Before (baseline) and over 25 min following each ETS procedure, partial arterial oxygen tension (PaO2) and end-expiratory lung volume were measured. Results After ETS, PaO2 decreased by 4.3(0.9–9.7)kPa (median and range; P < 0.005). After LR manoeuvre, PaO2 recovered to baseline. Without LR manoeuvre, PaO2 was reduced (P = 0.05) until 7 min after ETS. With LR manoeuvre end-expiratory lung volume was unchanged after ETS, whereas without LR manoeuvre end-expiratory lung volume was still reduced (approximately 10%) at 5 and 15 min after ETS (P = 0.01). Discussion A LR manoeuvre immediately following ETS was, as an adjunct to positive end-expiratory pressure, effective in rapidly counteracting the deterioration in PaO2 and lung volume caused by open ETS in ventilator-treated patients with acute lung injury or acute respiratory distress syndrome. PMID:12617741

Acute effects of heavy-load squats on consecutive squat jump performance.

PubMed

Weber, Kurt R; Brown, Lee E; Coburn, Jared W; Zinder, Steven M

2008-05-01

Postactivation potentiation (PAP) and complex training have generated interest within the strength and conditioning community in recent years, but much of the research to date has produced confounding results. The purpose of this study was to observe the acute effects of a heavy-load back squat [85% 1 repetition maximum (1RM)] condition on consecutive squat jump performance. Twelve in-season Division I male track-and-field athletes participated in two randomized testing conditions: a five-repetition back squat at 85% 1RM (BS) and a five-repetition squat jump (SJ). The BS condition consisted of seven consecutive squat jumps (BS-PRE), followed by five repetitions of the BS at 85% 1RM, followed by another set of seven consecutive squat jumps (BS-POST). The SJ condition was exactly the same as the BS condition except that five consecutive SJs replaced the five BSs, with 3 minutes' rest between each set. BS-PRE, BS-POST, SJ-PRE, and SJ-POST were analyzed and compared for mean and peak jump height, as well as mean and peak ground reaction force (GRF). The BS condition's mean and peak jump height and peak GRF increased 5.8% +/- 4.8%, 4.7% +/- 4.8%, and 4.6% +/- 7.4%, respectively, whereas the SJ condition's mean and peak jump height and peak GRF decreased 2.7% +/- 5.0%, 4.0% +/- 4.9%, and 1.3% +/- 7.5%, respectively. The results indicate that performing a heavy-load back squat before a set of consecutive SJs may enhance acute performance in average and peak jump height, as well as peak GRF.

In Vivo Administration of a JAK3 Inhibitor during Acute SIV Infection Leads to Significant Increases in Viral Load during Chronic Infection

PubMed Central

Takahashi, Yoshiaki; Byrareddy, Siddappa N.; Albrecht, Christina; Brameier, Markus; Walter, Lutz; Mayne, Ann E.; Dunbar, Paul; Russo, Robert; Little, Dawn M.; Villinger, Tara; Khowawisetsut, Ladawan; Pattanapanyasat, Kovit; Villinger, Francois; Ansari, Aftab A.

2014-01-01

The studies reported herein are the first to document the effect of the in vivo administration of a JAK3 inhibitor for defining the potential role of NK cells during acute SIV infection of a group of 15 rhesus macaques (RM). An additional group of 16 MHC/KIR typed RM was included as controls. The previously optimized in vivo dose regimen (20 mg/kg daily for 35 days) led to a marked depletion of each of the major NK cell subsets both in the blood and gastro-intestinal tissues (GIT) during acute infection. While such depletion had no detectable effects on plasma viral loads during acute infection, there was a significant sustained increase in plasma viral loads during chronic infection. While the potential mechanisms that lead to such increased plasma viral loads during chronic infection remain unclear, several correlates were documented. Thus, during acute infection, the administration of the JAK3 inhibitor besides depleting all NK cell subsets also decreased some CD8+ T cells and inhibited the mobilization of the plasmacytoid dendritic cells in the blood and their localization to the GIT. Of interest is the finding that the administration of the JAK3 inhibitor during acute infection also resulted in the sustained maintenance during chronic infection of a high number of naïve and central memory CD4+ T cells, increases in B cells in the blood, but decreases in the frequencies and function of NKG2a+ NK cells within the GIT and blood, respectively. These data identify a unique role for JAK3 inhibitor sensitive cells, that includes NK cells during acute infection that in concert lead to high viral loads in SIV infected RM during chronic infection without affecting detectable changes in antiviral humoral/cellular responses. Identifying the precise mechanisms by which JAK3 sensitive cells exert their influence is critical with important implications for vaccine design against lentiviruses. PMID:24603870

Load research manual. Volume 2: Fundamentals of implementing load research procedures

NASA Astrophysics Data System (ADS)

1980-11-01

This manual will assist electric utilities and state regulatory authorities in investigating customer electricity demand as part of cost-of-service studies, rate design, marketing research, system design, load forecasting, rate reform analysis, and load management research. Load research procedures are described in detail. Research programs at three utilities are compared: Carolina Power and Light Company, Long Island Lighting Company, and Southern California Edison Company. A load research bibliography and glossaries of load research and statistical terms are also included.

Deficiency of renal dopaminergic-dependent natriuretic response to acute sodium load in black salt-sensitive subjects in contrast to salt-resistant subjects.

PubMed

Damasceno, A; Santos, A; Serrão, P; Caupers, P; Soares-da-Silva, P; Polónia, J

1999-12-01

To evaluate the involvement of the renal dopaminergic system in the natriuretic responses to acute saline load in salt-resistant (SR) and salt-sensitive (SS) black normotensive (NT) and hypertensive (HT) subjects. We studied the relationship between the urinary excretion of dopa, dopamine (DA) and its metabolite DOPAC and the natriuretic responses to acute volume expansion (2 l NaCl 0.9% over 2 h) in 20 black NT subjects (12 SR and 8 SS) and 19 black HT subjects (10 SS and 9 SR). Subjects received a low salt (LS) diet (40 mmol sodium/day) for 1 week and a high salt (HS) diet (300 mmol sodium/day) for 1 week; the sequence of the dietary regimens was randomized. Comparisons were made between the results before the saline infusion (baseline) and the results 2 h after the infusion. In all the groups saline infusion induced significant increases in urinary volume (ml/4 h) of two- to three-fold and in urinary sodium excretion (mmol/4 h) of three- to ten-fold; these increases were significantly greater during the HS diet than during the LS diet. Saline infusion significantly increased the mean arterial pressure (MAP) by 5 mmHg in HT-SS subjects and by 4-5 mmHg in NT-SS subjects, but the MAP did not changed in the NT-SR and HT-SR groups. Under the LS diet, saline infusion changed the DA excretion (in nmol/4 h) by -49+/-89 in HT-SS subjects, by 17+/-52 in NT-SS subjects, by 235+/-72 in HT-SR subjects and by 220+/-86 in NT-SR subjects (P < 0.05 between SR and SS subjects). The saline infusion-induced changes in DA excretion correlated significantly with the increases in urinary sodium excretion (r = 0.71, P < 0.01) in the NT-SR and HT-SR subjects under the LS diet, but not in the SR groups on the HS diet nor in the SS groups (HT and NT) on either diet. Saline infusion significantly reduced the DA/dopa ratio in SS (NT and HT) but not SR (NT and HT) subjects, whereas the DA/DOPAC (dihydroxyphenylacetic acid) ratios were similar in all the groups. The urinary dopaminergic

Lung-Protective Ventilation With Low Tidal Volumes and the Occurrence of Pulmonary Complications in Patients Without Acute Respiratory Distress Syndrome: A Systematic Review and Individual Patient Data Analysis.

PubMed

Neto, Ary Serpa; Simonis, Fabienne D; Barbas, Carmen S V; Biehl, Michelle; Determann, Rogier M; Elmer, Jonathan; Friedman, Gilberto; Gajic, Ognjen; Goldstein, Joshua N; Linko, Rita; Pinheiro de Oliveira, Roselaine; Sundar, Sugantha; Talmor, Daniel; Wolthuis, Esther K; Gama de Abreu, Marcelo; Pelosi, Paolo; Schultz, Marcus J

2015-10-01

Protective mechanical ventilation with low tidal volumes is standard of care for patients with acute respiratory distress syndrome. The aim of this individual patient data analysis was to determine the association between tidal volume and the occurrence of pulmonary complications in ICU patients without acute respiratory distress syndrome and the association between occurrence of pulmonary complications and outcome in these patients. Individual patient data analysis. ICU patients not fulfilling the consensus criteria for acute respiratory distress syndrome at the onset of ventilation. Mechanical ventilation with low tidal volume. The primary endpoint was development of a composite of acute respiratory distress syndrome and pneumonia during hospital stay. Based on the tertiles of tidal volume size in the first 2 days of ventilation, patients were assigned to a "low tidal volume group" (tidal volumes ≤ 7 mL/kg predicted body weight), an "intermediate tidal volume group" (> 7 and < 10 mL/kg predicted body weight), and a "high tidal volume group" (≥ 10 mL/kg predicted body weight). Seven investigations (2,184 patients) were included. Acute respiratory distress syndrome or pneumonia occurred in 23% of patients in the low tidal volume group, in 28% of patients in the intermediate tidal volume group, and in 31% of the patients in the high tidal volume group (adjusted odds ratio [low vs high tidal volume group], 0.72; 95% CI, 0.52-0.98; p = 0.042). Occurrence of pulmonary complications was associated with a lower number of ICU-free and hospital-free days and alive at day 28 (10.0 ± 10.9 vs 13.8 ± 11.6 d; p < 0.01 and 6.1 ± 8.1 vs 8.9 ± 9.4 d; p < 0.01) and an increased hospital mortality (49.5% vs 35.6%; p < 0.01). Ventilation with low tidal volumes is associated with a lower risk of development of pulmonary complications in patients without acute respiratory distress syndrome.

Effect of fluid loading on left ventricular volume and stroke volume variability in patients with end-stage renal disease: a pilot study

PubMed Central

Kanda, Hirotsugu; Hirasaki, Yuji; Iida, Takafumi; Kanao-Kanda, Megumi; Toyama, Yuki; Kunisawa, Takayuki; Iwasaki, Hiroshi

2015-01-01

Purpose The aim of this study was to investigate fluid loading-induced changes in left ventricular end-diastolic volume (LVEDV) and stroke volume variability (SVV) in patients with end-stage renal disease (ESRD) using real-time three-dimensional transesophageal echocardiography and the Vigileo-FloTrac system. Patients and methods After obtaining ethics committee approval and informed consent, 28 patients undergoing peripheral vascular procedures were studied. Fourteen patients with ESRD on hemodialysis (HD) were assigned to the HD group and 14 patients without ESRD were assigned to the control group. Institutional standardized general anesthesia was provided in both groups. SVV was measured using the Vigileo-FloTrac system. Simultaneously, a full-volume three-dimensional transesophageal echocardiography dataset was acquired to measure LVEDV, left ventricular end-systolic volume, and left ventricular ejection fraction. Measurements were obtained before and after loading 500 mL hydroxyethyl starch over 30 minutes in both groups. Results In the control group, intravenous colloid infusion was associated with a significant decrease in SVV (13.8%±2.6% to 6.5%±2.6%, P<0.001) and a significant increase in LVEDV (83.6±23.4 mL to 96.1±28.8 mL, P<0.001). While SVV significantly decreased after infusion in the HD group (16.2%±6.0% to 6.2%±2.8%, P<0.001), there was no significant change in LVEDV. Conclusion Our preliminary data suggest that fluid responsiveness can be assessed not by LVEDV but also by SVV due to underlying cardiovascular pathophysiology in patients with ESRD. PMID:26527879

Role of cardiac volume receptors in the control of ADH release during acute simulated weightlessness in man

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Benjamin, B. A.; Keil, L. C.; Sandler, H.

1984-01-01

Hemodynamic responses and antidiuretic hormone (ADH) were measured during body position changes, designed to induce central blood volume shifts in ten cardiac and one heart-lung transplant recipients, to assess the contribution of cardiac volume receptors in the control of ADH release during the initial acute phase of exposure to weightlessness. Each subject underwent 15 min of a sitting-control period (C) followed by 30 min of 6 deg headdown tilt (T) and 30 min of resumed sitting (S). Venous blood samples and cardiac dimensions were taken at 0 and 15 min of C; 5, 15, and 30 min of T; and 5, 15, and 30 min of S. Blood samples were analyzed for hematocrit, plasma osmolality, plasma renin activity (PRA), and ADH. Heart rate and blood pressure were recorded every two min. Plasma osmolality was not altered by posture changes. Mean left ventricular end-diastolic volume increased (P less than 0.05) from 90 ml in C to 106 ml in T and returned to 87 ml in S. Plasma ADH was reduced by 20 percent (P less than 0.05) with T, and returned to control levels with S. These responses were similar in six normal cardiac-innervated control subjects. These data may suggest that cardiac volume receptors are not the primary mechanism for the control of ADH release during acute central volume shifts in man.

Association between feline immunodeficiency virus (FIV) plasma viral RNA load, concentration of acute phase proteins and disease severity.

PubMed

Kann, Rebecca K C; Seddon, Jennifer M; Kyaw-Tanner, Myat T; Henning, Joerg; Meers, Joanne

2014-08-01

Veterinarians have few tools to predict the rate of disease progression in FIV-infected cats. In contrast, in HIV infection, plasma viral RNA load and acute phase protein concentrations are commonly used as predictors of disease progression. This study evaluated these predictors in cats naturally infected with FIV. In older cats (>5 years), log10 FIV RNA load was higher in the terminal stages of disease compared to the asymptomatic stage. There was a significant association between log10 FIV RNA load and both log10 serum amyloid A concentration and age in unwell FIV-infected cats. This study suggests that viral RNA load and serum amyloid A warrant further investigation as predictors of disease status and prognosis in FIV-infected cats. Copyright © 2014 Elsevier Ltd. All rights reserved.

Prognostic implications of epicardial fat volume quantification in acute pericarditis.

PubMed

Lazaros, George; Antonopoulos, Alexios S; Oikonomou, Evangelos K; Vasileiou, Panagiotis; Oikonomou, Evangelos; Stroumpouli, Evangelia; Karavidas, Apostolos; Antoniades, Charalambos; Tousoulis, Dimitris

2017-02-01

The pathophysiology of acute pericarditis remains largely unknown, and biomarkers are needed to identify patients susceptible to complications. As adipose tissue has a pivotal role in cardiovascular disease pathogenesis, we hypothesized that quantification of epicardial fat volume (EFV) provides prognostic information in patients with acute pericarditis. Fifty (n = 50) patients with first diagnosis of acute pericarditis were enrolled in this study. Patients underwent a cardiac computerized tomography (CT) scan to quantify EFV on a dedicated workstation. Patients were followed up in hospital for atrial fibrillation (AF) development and up to 18 months for the composite clinical endpoint of development of constrictive, recurrent or incessant pericarditis or poor response to nonsteroidal anti-inflammatory drugs. Patients presenting with chest pain had lower EFV vs. patients without chest pain (167·2 ± 21·7 vs. 105·1 ± 11·1 cm 3 , respectively, P < 0·01); EFV (but not body mass index) was strongly positively correlated with pericardial effusion size (r = 0·395, P = 0·007) and associated with in-hospital AF. At follow-up, patients that reached the composite clinical endpoint had lower EFV (P < 0·05). After adjustment for age, EFV was associated with lower odds ratio for the composite clinical endpoint point of poor response to NSAIDs or the development of constrictive, recurrent or incessant pericarditis during follow-up (per 20 cm 3 increase in EFV: OR = 0·802 [0·656-0·981], P < 0·05). We report for the first time a significant association of EFV with the clinical features and the outcome of patients with acute pericarditis. Measurement of EFV by CT may have important prognostic implications in these patients. © 2016 Stichting European Society for Clinical Investigation Journal Foundation.

Low-Tidal-Volume Ventilation in the Acute Respiratory Distress Syndrome

PubMed Central

Malhotra, Atul

2008-01-01

A 55-year-old man who is 178 cm tall and weighs 95 kg is hospitalized with community-acquired pneumonia and progressively severe dyspnea. His arterial oxygen saturation while breathing 100% oxygen through a face mask is 76%; a chest radiograph shows diffuse alveolar infiltrates with air bronchograms. He is intubated and receives mechanical ventilation; ventilator settings include a tidal volume of 1000 ml, a positive end-expiratory pressure (PEEP) of 5 cm of water, and a fraction of inspired oxygen (FiO2) of 0.8. With these settings, peak airway pressure is 50 to 60 cm of water, plateau airway pressure is 38 cm of water, partial pressure of arterial oxygen is 120 mm Hg, partial pressure of carbon dioxide is 37 mm Hg, and arterial blood pH is 7.47. The diagnosis of the acute respiratory distress syndrome (ARDS) is made. An intensive care specialist evaluates the patient and recommends changing the current ventilator settings and implementing a low-tidal-volume ventilation strategy. PMID:17855672

High sulfur loading cathodes fabricated using peapodlike, large pore volume mesoporous carbon for lithium-sulfur battery.

PubMed

Li, Duo; Han, Fei; Wang, Shuai; Cheng, Fei; Sun, Qiang; Li, Wen-Cui

2013-03-01

Porous carbon materials with large pore volume are crucial in loading insulated sulfur with the purpose of achieving high performance for lithium-sulfur batteries. In our study, peapodlike mesoporous carbon with interconnected pore channels and large pore volume (4.69 cm(3) g(-1)) was synthesized and used as the matrix to fabricate carbon/sulfur (C/S) composite which served as attractive cathodes for lithium-sulfur batteries. Systematic investigation of the C/S composite reveals that the carbon matrix can hold a high but suitable sulfur loading of 84 wt %, which is beneficial for improving the bulk density in practical application. Such controllable sulfur-filling also effectively allows the volume expansion of active sulfur during Li(+) insertion. Moreover, the thin carbon walls (3-4 nm) of carbon matrix not only are able to shorten the pathway of Li(+) transfer and conduct electron to overcome the poor kinetics of sulfur cathode, but also are flexible to warrant structure stability. Importantly, the peapodlike carbon shell is beneficial to increase the electrical contact for improving electronic conductivity of active sulfur. Meanwhile, polymer modification with polypyrrole coating layer further restrains polysulfides dissolution and improves the cycle stability of carbon/sulfur composites.

[Low dose volume histogram analysis of the lungs in prediction of acute radiation pneumonitis in patients with esophageal cancer treated with three-dimensional conformal radiotherapy].

PubMed

Shen, Wen-bin; Zhu, Shu-chai; Gao, Hong-mei; Li, You-mei; Liu, Zhi-kun; Li, Juan; Su, Jing-wei; Wan, Jun

2013-01-01

To investigate the predictive value of low dose volume of the lung on acute radiation pneumonitis (RP) in patients with esophageal cancer treated with three-dimensional conformal radiotherapy (3D-CRT) only, and to analyze the relation of comprehensive parameters of the dose-volume V5, V20 and mean lung dose (MLD) with acute RP. Two hundred and twenty-two patients with esophageal cancer treated by 3D-CRT have been followed up. The V5-V30 and MLD were calculated from the dose-volume histogram system. The clinical factors and treatment parameters were collected and analyzed. The acute RP was evaluated according to the RTOG toxicity criteria. The acute RP of grade 1, 2, 3 and 4 were observed in 68 (30.6%), 40 (18.0%), 8 (3.6%) and 1 (0.5%) cases, respectively. The univariate analysis of measurement data:The primary tumor length, radiation fields, MLD and lung V5-V30 had a significant relationship with the acute RP. The magnitude of the number of radiation fields, the volume of GTV, MLD and Lung V5-V30 had a significant difference in whether the ≥ grade 1 and ≥ grade 2 acute RP developed or not. Binary logistic regression analysis showed that MLD, Lung V5, V20 and V25 were independent risk factors of ≥ grade 1 acute RP, and the radiation fields, MLD and Lung V5 were independent risk factors of ≥ grade 2 acute RP. The ≥ grade 1 and ≥ grade 2 acute RP were significantly decreased when MLD less than 14 Gy, V5 and V20 were less than 60% and 28%,respectively. When the V20 ≤ 28%, the acute RP was significantly decreased in V5 ≤ 60% group. When the MLD was ≤ 14 Gy, the ≥ 1 grade acute RP was significantly decreased in the V5 ≤ 60% group. When the MLD was >14 Gy, the ≥ grade 2 acute RP was significantly decreased in the V5 ≤ 60% group. The low dose volume of the lung is effective in predicting radiation pneumonitis in patients with esophageal cancer treated with 3D-CRT only. The comprehensive parameters combined with V5, V20 and MLD may increase the

Load and dynamic assessment of B-52B-008 carrier aircraft for finned configuration 1 space shuttle solid rocket booster deceleration subsystem drop test vehicle. Volume 4: Pylon load data

NASA Technical Reports Server (NTRS)

Quade, D. A.

1978-01-01

The pylon loading at the drop test vehicle and wing interface attack points is presented. The loads shown are determined using a stiffness method, which assumes the side stiffness of the forward hook guide and the fore and aft stiffness of each drag pin to be equal. The net effect of this assumption is that the forward hook guide reacts approximately 96% of the drop test vehicle yawing moment. For a comparison of these loads to previous X-15 analysis design loadings, see Volume 1 of this document.

Diagnosing acute HIV infection: The performance of quantitative HIV-1 RNA testing (viral load) in the 2014 laboratory testing algorithm.

PubMed

Wu, Hsiu; Cohen, Stephanie E; Westheimer, Emily; Gay, Cynthia L; Hall, Laura; Rose, Charles; Hightow-Weidman, Lisa B; Gose, Severin; Fu, Jie; Peters, Philip J

2017-08-01

New recommendations for laboratory diagnosis of HIV infection in the United States were published in 2014. The updated testing algorithm includes a qualitative HIV-1 RNA assay to resolve discordant immunoassay results and to identify acute HIV-1 infection (AHI). The qualitative HIV-1 RNA assay is not widely available; therefore, we evaluated the performance of a more widely available quantitative HIV-1 RNA assay, viral load, for diagnosing AHI. We determined that quantitative viral loads consistently distinguished AHI from a false-positive immunoassay result. Among 100 study participants with AHI and a viral load result, the estimated geometric mean viral load was 1,377,793copies/mL. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular Diagnosis of Chagas Disease in Colombia: Parasitic Loads and Discrete Typing Units in Patients from Acute and Chronic Phases

PubMed Central

Hernández, Carolina; Cucunubá, Zulma; Flórez, Carolina; Olivera, Mario; Valencia, Carlos; Zambrano, Pilar; León, Cielo; Ramírez, Juan David

2016-01-01

Background The diagnosis of Chagas disease is complex due to the dynamics of parasitemia in the clinical phases of the disease. The molecular tests have been considered promissory because they detect the parasite in all clinical phases. Trypanosoma cruzi presents significant genetic variability and is classified into six Discrete Typing Units TcI-TcVI (DTUs) with the emergence of foreseen genotypes within TcI as TcIDom and TcI Sylvatic. The objective of this study was to determine the operating characteristics of molecular tests (conventional and Real Time PCR) for the detection of T. cruzi DNA, parasitic loads and DTUs in a large cohort of Colombian patients from acute and chronic phases. Methodology/Principal Findings Samples were obtained from 708 patients in all clinical phases. Standard diagnosis (direct and serological tests) and molecular tests (conventional PCR and quantitative PCR) targeting the nuclear satellite DNA region. The genotyping was performed by PCR using the intergenic region of the mini-exon gene, the 24Sa, 18S and A10 regions. The operating capabilities showed that performance of qPCR was higher compared to cPCR. Likewise, the performance of qPCR was significantly higher in acute phase compared with chronic phase. The median parasitic loads detected were 4.69 and 1.33 parasite equivalents/mL for acute and chronic phases. The main DTU identified was TcI (74.2%). TcIDom genotype was significantly more frequent in chronic phase compared to acute phase (82.1% vs 16.6%). The median parasitic load for TcIDom was significantly higher compared with TcI Sylvatic in chronic phase (2.58 vs.0.75 parasite equivalents/ml). Conclusions/Significance The molecular tests are a precise tool to complement the standard diagnosis of Chagas disease, specifically in acute phase showing high discriminative power. However, it is necessary to improve the sensitivity of molecular tests in chronic phase. The frequency and parasitemia of TcIDom genotype in chronic

The function of the left anterior temporal pole: evidence from acute stroke and infarct volume

PubMed Central

Tsapkini, Kyrana; Frangakis, Constantine E.

2011-01-01

The role of the anterior temporal lobes in cognition and language has been much debated in the literature over the last few years. Most prevailing theories argue for an important role of the anterior temporal lobe as a semantic hub or a place for the representation of unique entities such as proper names of peoples and places. Lately, a few studies have investigated the role of the most anterior part of the left anterior temporal lobe, the left temporal pole in particular, and argued that the left anterior temporal pole is the area responsible for mapping meaning on to sound through evidence from tasks such as object naming. However, another recent study indicates that bilateral anterior temporal damage is required to cause a clinically significant semantic impairment. In the present study, we tested these hypotheses by evaluating patients with acute stroke before reorganization of structure–function relationships. We compared a group of 20 patients with acute stroke with anterior temporal pole damage to a group of 28 without anterior temporal pole damage matched for infarct volume. We calculated the average percent error in auditory comprehension and naming tasks as a function of infarct volume using a non-parametric regression method. We found that infarct volume was the only predictive variable in the production of semantic errors in both auditory comprehension and object naming tasks. This finding favours the hypothesis that left unilateral anterior temporal pole lesions, even acutely, are unlikely to cause significant deficits in mapping meaning to sound by themselves, although they contribute to networks underlying both naming and comprehension of objects. Therefore, the anterior temporal lobe may be a semantic hub for object meaning, but its role must be represented bilaterally and perhaps redundantly. PMID:21685458

Mechanisms of Decreased Plasma Volume During Acute Psychological Stress and Postural Change in Humans

DTIC Science & Technology

1993-09-14

follicular phase of their menstrual cycle as defined as 1 to 11 days post menses . Experimental Protocol Each subject was screened by telephone to...studies exist regarding possible gender differences in plasma volume changes during acute psychological stress. Menstrual cycle effects on physiologic...the different phases of the menstrual cycle (Strauss, Schultheiss, & Cohen, 1983; Carroll , ’I\\lrner I Lee I & Stephenson, 1984). Conflicting

A simple brain atrophy measure improves the prediction of malignant middle cerebral artery infarction by acute DWI lesion volume.

PubMed

Beck, Christoph; Kruetzelmann, Anna; Forkert, Nils D; Juettler, Eric; Singer, Oliver C; Köhrmann, Martin; Kersten, Jan F; Sobesky, Jan; Gerloff, Christian; Fiehler, Jens; Schellinger, Peter D; Röther, Joachim; Thomalla, Götz

2014-06-01

In patients with malignant middle cerebral artery infarction (MMI) decompressive surgery within 48 h improves functional outcome. In this respect, early identification of patients at risk of developing MMI is crucial. While the acute diffusion weighted imaging (DWI) lesion volume was found to predict MMI with high predictive values, the potential impact of preexisting brain atrophy on the course of space-occupying middle cerebral artery (MCA) infarction and the development of MMI remains unclear. We tested the hypothesis that the combination of the acute DWI lesion volume with simple measures of brain atrophy improves the early prediction of MMI. Data from a prospective, multicenter, observational study, which included patients with acute middle cerebral artery main stem occlusion studied by MRI within 6 h of symptom onset, was analyzed retrospectively. The development of MMI was defined according to the European randomized controlled trials of decompressive surgery. Acute DWI lesion volume, as well as brain and cerebrospinal fluid volume (CSF) were delineated. The intercaudate distance (ICD) was assessed as a linear brain atrophy marker by measuring the hemi-ICD of the intact hemisphere to account for local brain swelling. Binary logistic regression analysis was used to identify significant predictors of MMI. Cut-off values were determined by Classification and Regression Trees analysis. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the resulting models were calculated. Twenty-one (18 %) of 116 patients developed a MMI. Malignant middle cerebral artery infarctions patients had higher National Institutes of Health Stroke Scale scores on admission and presented more often with combined occlusion of the internal carotid artery and MCA. There were no differences in brain and CSF volume between the two groups. Diffusion weighted imaging lesion volume was larger (p < 0.001), while hemi-ICD was smaller (p = 0.029) in

Ratings of Perceived Exertion During Acute Resistance Exercise Performed at Imposed and Self-Selected Loads in Recreationally Trained Women.

PubMed

Cotter, Joshua A; Garver, Matthew J; Dinyer, Taylor K; Fairman, Ciaran M; Focht, Brian C

2017-08-01

Cotter, JA, Garver, MJ, Dinyer, TK, Fairman, CM, and Focht, BC. Ratings of perceived exertion during acute resistance exercise performed at imposed and self-selected loads in recreationally trained women. J Strength Cond Res 31(8): 2313-2318, 2017-Resistance exercise (RE) is commonly used to elicit skeletal muscle adaptation. Relative intensity of a training load links closely with the outcomes of regular RE. This study examined the rating of perceived exertion (RPE) responses to acute bouts of RE using imposed (40% and 70% of 1 repetition maximum [1RM]) and self-selected (SS) loads in recreationally trained women. Twenty physically active women (23.15 ± 2.92 years), who reported regular RE training of at least 3 weekly sessions for the past year, volunteered to participate. During the initial visit, participants completed 1RM testing on 4 exercises in the following order: leg extension, chest press, leg curl, and lat pull-down. On subsequent visits, the same exercises were completed at the SS or imposed loads. The RPE was assessed after the completion of each set of exercises during the 3 RE conditions using the Borg-15 category scale. Self-selected loads corresponded to an average of approximately 57%1RM (±7.62). Overall, RPE increased with load (40%1RM = 11.26 [±1.95]; SS 57%1RM = 13.94 [±1.58]; and, 70%1RM = 15.52 [±2.05]). Reflecting the linear pattern found between load and perceived effort, the present data provide evidence that RPE levels less than 15 likely equate to loads which are not consistent with contemporary American College of Sports Medicine (ACSM) guidelines for enhancing musculoskeletal health which includes strength and hypertrophy. Women desiring increases in strength and lean mass likely need to train at an exertion level at or surpassing a rating of 15 on the Borg-15 category. This article examined the modification of training load on perceived exertion, but other variables, such as the number of repetitions completed, may also be

Low load exercises targeting the gluteal muscle group acutely enhance explosive power output in elite athletes.

PubMed

Crow, Justin F; Buttifant, David; Kearny, Simon G; Hrysomallis, Con

2012-02-01

The purpose of this study was to investigate the acute effect of 3 warm-up protocols on peak power production during countermovement jump (CMJ) testing. The intention was to devise and compare practical protocols that could be applied as a warm-up immediately before competition matches or weight training sessions. A group of 22 elite Australian Rules Football players performed 3 different warm-up protocols over 3 testing sessions in a randomized order. The protocols included a series of low load exercises targeting the gluteal muscle group (GM-P), a whole-body vibration (WBV) protocol (WBV-P) wherein the subjects stood on a platform vibrating at 30 Hz for 45 seconds, and a no-warm-up condition (CON). The CMJ testing was performed within 5 minutes of each warm-up protocol on an unloaded Smith machine using a linear encoder to measure peak power output. Peak power production was significantly greater after the GM-P than after both the CON (p < 0.05) and WBV-P (p < 0.01). No significant differences in peak power production were detected between the WBV-P and CON. These results have demonstrated that a low load exercise protocol targeting the gluteal muscle group is effective at acutely enhancing peak power output in elite athletes. The mechanisms for the observed improvements are unclear and warrant further investigation. Coaches may consider incorporating low load exercises targeting the gluteal muscle group into the warm-up of athletes competing in sports requiring explosive power output of the lower limbs.

A Study of Intercellular Spaces in the Rabbit Jejunum during Acute Volume Expansion and after Treatment with Cholera Toxin

PubMed Central

DiBona, Donald R.; Chen, Lincoln C.; Sharp, Geoffrey W. G.

1974-01-01

The effects of acute volume expansion and of intraluminal administration of cholera toxin have been examined in rabbit jejunum. Acute volume expansion was shown to reverse the normal reabsorptive flux of water and cause significant fluid secretion. Phase and electronmicroscopic examination of the jejunal epithelium showed that marked distension of the intercellular spaces had occurred. Examination of the jejunal epithelium after treatment with cholera toxin showed that, in association with high rates of fluid secretion, the intercellular spaces were extremely small and lateral membranes of adjacent cells were in close apposition to one another. Thus the mechanisms of fluid secretion in these two situations would appear to be quite different. The secretion associated with volume expansion, and accompanied by a rise in venous pressure and bullous deformations of terminal junctions, could well be due to hydrostatic pressure applied through intercellular channels. The secretion of cholera appears to be unrelated to hydrostatic pressure and is more likely due to body-to-lumen active ion transport. Images PMID:4596506

A multi-scale cardiovascular system model can account for the load-dependence of the end-systolic pressure-volume relationship

PubMed Central

2013-01-01

Background The end-systolic pressure-volume relationship is often considered as a load-independent property of the heart and, for this reason, is widely used as an index of ventricular contractility. However, many criticisms have been expressed against this index and the underlying time-varying elastance theory: first, it does not consider the phenomena underlying contraction and second, the end-systolic pressure volume relationship has been experimentally shown to be load-dependent. Methods In place of the time-varying elastance theory, a microscopic model of sarcomere contraction is used to infer the pressure generated by the contraction of the left ventricle, considered as a spherical assembling of sarcomere units. The left ventricle model is inserted into a closed-loop model of the cardiovascular system. Finally, parameters of the modified cardiovascular system model are identified to reproduce the hemodynamics of a normal dog. Results Experiments that have proven the limitations of the time-varying elastance theory are reproduced with our model: (1) preload reductions, (2) afterload increases, (3) the same experiments with increased ventricular contractility, (4) isovolumic contractions and (5) flow-clamps. All experiments simulated with the model generate different end-systolic pressure-volume relationships, showing that this relationship is actually load-dependent. Furthermore, we show that the results of our simulations are in good agreement with experiments. Conclusions We implemented a multi-scale model of the cardiovascular system, in which ventricular contraction is described by a detailed sarcomere model. Using this model, we successfully reproduced a number of experiments that have shown the failing points of the time-varying elastance theory. In particular, the developed multi-scale model of the cardiovascular system can capture the load-dependence of the end-systolic pressure-volume relationship. PMID:23363818

Subcortical volume and cortical surface architecture in women with acute and remitted anorexia nervosa: An exploratory neuroimaging study.

PubMed

Miles, Amy E; Voineskos, Aristotle N; French, Leon; Kaplan, Allan S

2018-07-01

Anorexia nervosa (AN) is a highly heritable psychiatric disorder characterized by starvation and emaciation and associated with changes in brain structure. The precise nature of these changes remains unclear, as does their developmental time course and capacity for reversal with weight-restoration. In this comprehensive neuroimaging study, we sought to characterize these changes by measuring subcortical volume and cortical surface architecture in women with acute and remitted AN. Structural magnetic resonance imaging data was acquired from underweight women with a current diagnosis of AN (acAN: n = 23), weight-recovered women with a past diagnosis of AN (recAN: n = 24), and female controls (HC: n = 24). Subcortical segmentation and cortical surface reconstruction were performed with FreeSurfer 6.0.0, and group differences in regional volume and vertex-wise, cortex-wide thickness, surface area, and local gyrification index (LGI), a measure of folding, were tested with separate univariate analyses of covariance. Mean hippocampal and thalamic volumes were significantly reduced in acAN participants, as was mean cortical thickness in four frontal and temporal clusters. Mean LGI was significantly reduced in acAN and recAN participants in five frontal and parietal clusters. No significant group differences in cortical surface area were detected. Reductions in subcortical volume, cortical thickness, and right postcentral LGI were unique to women with acute AN, indicating state-dependence and pointing towards cellular remodeling and sulcal widening as consequences of disease manifestation. Reductions in bilateral frontal LGI were observed in women with acute and remitted AN, suggesting a role of atypical neurodevelopment in disease vulnerability. Copyright © 2018. Published by Elsevier Ltd.

Tidal volume in acute respiratory distress syndrome: how best to select it.

PubMed

Umbrello, Michele; Marino, Antonella; Chiumello, Davide

2017-07-01

Mechanical ventilation is the type of organ support most widely provided in the intensive care unit. However, this form of support does not constitute a cure for acute respiratory distress syndrome (ARDS), as it mainly works by buying time for the lungs to heal while contributing to the maintenance of vital gas exchange. Moreover, it can further damage the lung, leading to the development of a particular form of lung injury named ventilator-induced lung injury (VILI). Experimental evidence accumulated over the last 30 years highlighted the factors associated with an injurious form of mechanical ventilation. The present paper illustrates the physiological effects of delivering a tidal volume to the lungs of patients with ARDS, and suggests an approach to tidal volume selection. The relationship between tidal volume and the development of VILI, the so called volotrauma, will be reviewed. The still actual suggestion of a lung-protective ventilatory strategy based on the use of low tidal volumes scaled to the predicted body weight (PBW) will be presented, together with newer strategies such as the use of airway driving pressure as a surrogate for the amount of ventilatable lung tissue or the concept of strain, i.e., the ratio between the tidal volume delivered relative to the resting condition, that is the functional residual capacity (FRC). An ultra-low tidal volume strategy with the use of extracorporeal carbon dioxide removal (ECCO 2 R) will be presented and discussed. Eventually, the role of other ventilator-related parameters in the generation of VILI will be considered (namely, plateau pressure, airway driving pressure, respiratory rate (RR), inspiratory flow), and the promising unifying framework of mechanical power will be presented.

Tidal volume in acute respiratory distress syndrome: how best to select it

PubMed Central

Umbrello, Michele; Marino, Antonella

2017-01-01

Mechanical ventilation is the type of organ support most widely provided in the intensive care unit. However, this form of support does not constitute a cure for acute respiratory distress syndrome (ARDS), as it mainly works by buying time for the lungs to heal while contributing to the maintenance of vital gas exchange. Moreover, it can further damage the lung, leading to the development of a particular form of lung injury named ventilator-induced lung injury (VILI). Experimental evidence accumulated over the last 30 years highlighted the factors associated with an injurious form of mechanical ventilation. The present paper illustrates the physiological effects of delivering a tidal volume to the lungs of patients with ARDS, and suggests an approach to tidal volume selection. The relationship between tidal volume and the development of VILI, the so called volotrauma, will be reviewed. The still actual suggestion of a lung-protective ventilatory strategy based on the use of low tidal volumes scaled to the predicted body weight (PBW) will be presented, together with newer strategies such as the use of airway driving pressure as a surrogate for the amount of ventilatable lung tissue or the concept of strain, i.e., the ratio between the tidal volume delivered relative to the resting condition, that is the functional residual capacity (FRC). An ultra-low tidal volume strategy with the use of extracorporeal carbon dioxide removal (ECCO2R) will be presented and discussed. Eventually, the role of other ventilator-related parameters in the generation of VILI will be considered (namely, plateau pressure, airway driving pressure, respiratory rate (RR), inspiratory flow), and the promising unifying framework of mechanical power will be presented. PMID:28828362

Load and dynamic assessment of B-52B-008 carrier aircraft for finned configuration 1 space shuttle solid rocket booster decelerator subsystem drop test vehicle. Volume 3: Pylon load data method 1

NASA Technical Reports Server (NTRS)

Quade, D. A.

1978-01-01

The pylon loading at the drop test vehicle and wing interface attach points is presented. The loads shown are determined using a stiffness method, which assumes the side stiffness of the foreward hook guide to be one-fourth of the fore and aft stiffness of each drag pin. The net effect of this assumption is that the forward hook guide reacts approximately 85% of the drop test vehicle yawing moment. For a comparison of these loads to previous X-15 analysis design loadings, see Volume 1 of this document.

Reperfusion is a more accurate predictor of follow-up infarct volume than recanalization: a proof of concept using CT in acute ischemic stroke patients.

PubMed

Soares, Bruno P; Tong, Elizabeth; Hom, Jason; Cheng, Su-Chun; Bredno, Joerg; Boussel, Loic; Smith, Wade S; Wintermark, Max

2010-01-01

The purpose of this study was to compare recanalization and reperfusion in terms of their predictive value for imaging outcomes (follow-up infarct volume, infarct growth, salvaged penumbra) and clinical outcome in acute ischemic stroke patients. Twenty-two patients admitted within 6 hours of stroke onset were retrospectively included in this study. These patients underwent a first stroke CT protocol including CT-angiography (CTA) and perfusion-CT (PCT) on admission, and similar imaging after treatment, typically around 24 hours, to assess recanalization and reperfusion. Recanalization was assessed by comparing arterial patency on admission and posttreatment CTAs; reperfusion, by comparing the volumes of CBV, CBF, and MTT abnormality on admission and posttreatment PCTs. Collateral flow was graded on the admission CTA. Follow-up infarct volume was measured on the discharge noncontrast CT. The groups of patients with reperfusion, no reperfusion, recanalization, and no recanalization were compared in terms of imaging and clinical outcomes. Reperfusion (using an MTT reperfusion index >75%) was a more accurate predictor of follow-up infarct volume than recanalization. Collateral flow and recanalization were not accurate predictors of follow-up infarct volume. An interaction term was found between reperfusion and the volume of the admission penumbra >50 mL. Our study provides evidence that reperfusion is a more accurate predictor of follow-up infarct volume in acute ischemic stroke patients than recanalization. We recommend an MTT reperfusion index >75% to assess therapy efficacy in future acute ischemic stroke trials that use perfusion-CT.

The effects of load history and design variables on performance limit states of circular bridge columns - volume 1.

DOT National Transportation Integrated Search

2015-01-01

This report is the first of three volumes and presents interpretation of all experimental and numerical data and recommendations. In : total, 30 large scale reinforced concrete columns tests were conducted under a variety of loading conditions. Using...

Main rotor free wake geometry effects on blade air loads and response for helicopters in steady maneuvers. Volume 2: Program listings

NASA Technical Reports Server (NTRS)

Sadler, S. G.

1972-01-01

A mathematical model and computer program was implemented to study the main rotor free wake geometry effects on helicopter rotor blade air loads and response in steady maneuvers. Volume 1 (NASA CR-2110) contains the theoretical formulation and analysis of results. Volume 2 contains the computer program listing.

Kinetics of Epstein-Barr virus load and virus-specific CD8+ T cells in acute infectious mononucleosis.

PubMed

Hoshino, Yo; Nishikawa, Kazuo; Ito, Yoshinori; Kuzushima, Kiyotaka; Kimura, Hiroshi

2011-03-01

During the convalescent phase of acute infectious mononucleosis (AIM), Epstein-Barr virus (EBV) load shrinks rapidly in association with a rapid decline in the number of EBV-specific CD8(+) T cells. The actual contribution of EBV-specific CD8(+) T cells in reducing EBV load, however, is not known. To clarify the impact of EBV-specific CD8(+) T cells on the contraction of EBV load in AIM, we estimated half-lives of both EBV load and EBV-specific CD8(+) T cells. Blood was serially taken from five pediatric patients with AIM during the convalescent period, including the very early phase, and both EBV load and EBV-specific CD8(+) T cell numbers were assayed. EBV load declined rapidly (half-life 1.5 d) during the first 2 weeks after onset of symptoms. This half-life was seven-fold shorter than that reported for CD27(+) memory B cells. Subsequently, the EBV load declined much more slowly, with a half-life of 38.7 d. EBV-specific CD8(+) T cell numbers also declined concomitantly with the decrease in EBV load. The half-life of EBV-specific CD8(+) T cells during first 2 weeks was 2.9 d. The number of EBV-specific CD8(+) T cells and the rate of change of viral load correlated significantly (R(2) ≥ 0.8; p ≤ 0.02). The short half-life of EBV load, together with the strong correlation between the number of EBV-specific CD8(+) T cells and the rate of change of viral load indicates an active role for EBV-specific CD8(+) T cells in elimination of EBV in AIM. Copyright © 2010 Elsevier B.V. All rights reserved.

Load and dynamic assessment of B-52B-008 carrier aircraft for finned configuration 1 space shuttle solid rocket booster decelerator subsystem drop test vehicle. Volume 2: Airplane flutter and load analysis results

NASA Technical Reports Server (NTRS)

Quade, D. A.

1978-01-01

The airplane flutter and maneuver-gust load analysis results obtained during B-52B drop test vehicle configuration (with fins) evaluation are presented. These data are presented as supplementary data to that given in Volume 1 of this document. A brief mathematical description of airspeed notation and gust load factor criteria are provided as a help to the user. References are defined which provide mathematical description of the airplane flutter and load analysis techniques. Air-speed-load factor diagrams are provided for the airplane weight configurations reanalyzed for finned drop test vehicle configuration.

Acute effects of a loaded warm-up protocol on change of direction speed in professional badminton players.

PubMed

Maloney, Sean J; Turner, Anthony N; Miller, Stuart

2014-10-01

It has previously been shown that a loaded warm-up may improve power performances. We examined the acute effects of loaded dynamic warm-up on change of direction speed (CODS), which had not been previously investigated. Eight elite badminton players participated in three sessions during which they performed vertical countermovement jump and CODS tests before and after undertaking the dynamic warm-up. The three warm-up conditions involved wearing a weighted vest (a) equivalent to 5% body mass, (b) equivalent to 10% body mass, and (c) a control where a weighted vest was not worn. Vertical jump and CODS performances were then tested at 15 seconds and 2, 4, and 6 minutes post warm-up. Vertical jump and CODS significantly improved following all warm-up conditions (P < .05). Post warm-up vertical jump performance was not different between conditions (P = .430). Post warm-up CODS was significantly faster following the 5% (P = .02) and 10% (P < .001) loaded conditions compared with the control condition. In addition, peak CODS test performances, independent of recovery time, were faster than the control condition following the 10% loaded condition (P = .012). In conclusion, the current study demonstrates that a loaded warm-up augmented CODS, but not vertical jump performance, in elite badminton players.

Myocardial Extracellular Volume Estimation by CMR Predicts Functional Recovery Following Acute MI.

PubMed

Kidambi, Ananth; Motwani, Manish; Uddin, Akhlaque; Ripley, David P; McDiarmid, Adam K; Swoboda, Peter P; Broadbent, David A; Musa, Tarique Al; Erhayiem, Bara; Leader, Joshua; Croisille, Pierre; Clarysse, Patrick; Greenwood, John P; Plein, Sven

2017-09-01

In the setting of reperfused acute myocardial infarction (AMI), the authors sought to compare prediction of contractile recovery by infarct extracellular volume (ECV), as measured by T1-mapping cardiac magnetic resonance (CMR), with late gadolinium enhancement (LGE) transmural extent. The transmural extent of myocardial infarction as assessed by LGE CMR is a strong predictor of functional recovery, but accuracy of the technique may be reduced in AMI. ECV mapping by CMR can provide a continuous measure associated with the severity of tissue damage within infarcted myocardium. Thirty-nine patients underwent acute (day 2) and convalescent (3 months) CMR scans following AMI. Cine imaging, tissue tagging, T2-weighted imaging, modified Look-Locker inversion T1 mapping natively and 15 min post-gadolinium-contrast administration, and LGE imaging were performed. The ability of acute infarct ECV and acute transmural extent of LGE to predict convalescent wall motion, ejection fraction (EF), and strain were compared per-segment and per-patient. Per-segment, acute ECV and LGE transmural extent were associated with convalescent wall motion score (p < 0.01; p < 0.01, respectively). ECV had higher accuracy than LGE extent to predict improved wall motion (area under receiver-operating characteristics curve 0.77 vs. 0.66; p = 0.02). Infarct ECV ≤0.5 had sensitivity 81% and specificity 65% for prediction of improvement in segmental function; LGE transmural extent ≤0.5 had sensitivity 61% and specificity 71%. Per-patient, ECV and LGE correlated with convalescent wall motion score (r = 0.45; p < 0.01; r = 0.41; p = 0.02, respectively) and convalescent EF (p < 0.01; p = 0.04). ECV and LGE extent were not significantly correlated (r = 0.34; p = 0.07). In multivariable linear regression analysis, acute infarct ECV was independently associated with convalescent infarct strain and EF (p = 0.03; p = 0.04), whereas LGE was not (p = 0.29; p = 0.24). Acute infarct ECV

The Effect of Acute and Chronic Exposure to Hypobaric Hypoxia on Loaded Squat Jump Performance

PubMed Central

García-Ramos, Amador; Padial, Paulino; De la Fuente, Blanca; Argüelles-Cienfuegos, Javier; Bonitch-Góngora, Juan

2017-01-01

Abstract The present study aimed (1) to compare loaded squat jump performance after an acute and chronic exposure to a moderate natural altitude between normoxia and hypobaric hypoxia conditions, and (2) to analyze the effect of an altitude training camp on loaded jump squat development. Sixteen male swimmers (17.1 ± 0.8 years) took part in a 17-day training camp at a natural moderate altitude. They were randomly tested in counterbalanced order on days 1 and 3 in normoxia and hypoxia (pretest) and on days 15 and 17 again in normoxia and hypoxia (posttest). The peak velocity reached with loads equivalent to 25%, 50%, 75% and 100% of swimmers’ pretest body weight in the loaded squat jump exercise was the dependent variable analyzed. An overall increase in peak velocity during the test performed in hypoxia of 6.5% in pretest (p < 0.001, ES = 0.98) and 4.5% in posttest (p < 0.001, ES = 0.81) was observed. An overall increment in peak velocity of 4.0% considering the data for normoxia tests (p < 0.001, ES = 0.61) and 2.1% considering the data for hypoxia tests (p = 0.008, ES = 0.36) was achieved after the altitude training camp. These results highlight the beneficial effects of hypobaric hypoxia on jump performance after short and longer term exposure to a natural moderate altitude. The increase in loaded squat jump performance following the 17-day training camp suggests that altitude training could constitute a favorable stimulus in explosive strength. PMID:28469753

Estimating total maximum daily loads with the Stochastic Empirical Loading and Dilution Model

USGS Publications Warehouse

Granato, Gregory; Jones, Susan Cheung

2017-01-01

The Massachusetts Department of Transportation (DOT) and the Rhode Island DOT are assessing and addressing roadway contributions to total maximum daily loads (TMDLs). Example analyses for total nitrogen, total phosphorus, suspended sediment, and total zinc in highway runoff were done by the U.S. Geological Survey in cooperation with FHWA to simulate long-term annual loads for TMDL analyses with the stochastic empirical loading and dilution model known as SELDM. Concentration statistics from 19 highway runoff monitoring sites in Massachusetts were used with precipitation statistics from 11 long-term monitoring sites to simulate long-term pavement yields (loads per unit area). Highway sites were stratified by traffic volume or surrounding land use to calculate concentration statistics for rural roads, low-volume highways, high-volume highways, and ultraurban highways. The median of the event mean concentration statistics in each traffic volume category was used to simulate annual yields from pavement for a 29- or 30-year period. Long-term average yields for total nitrogen, phosphorus, and zinc from rural roads are lower than yields from the other categories, but yields of sediment are higher than for the low-volume highways. The average yields of the selected water quality constituents from high-volume highways are 1.35 to 2.52 times the associated yields from low-volume highways. The average yields of the selected constituents from ultraurban highways are 1.52 to 3.46 times the associated yields from high-volume highways. Example simulations indicate that both concentration reduction and flow reduction by structural best management practices are crucial for reducing runoff yields.

Resistance exercise load does not determine training-mediated hypertrophic gains in young men

PubMed Central

Mitchell, Cameron J.; Churchward-Venne, Tyler A.; West, Daniel W. D.; Burd, Nicholas A.; Breen, Leigh; Baker, Steven K.

2012-01-01

We have reported that the acute postexercise increases in muscle protein synthesis rates, with differing nutritional support, are predictive of longer-term training-induced muscle hypertrophy. Here, we aimed to test whether the same was true with acute exercise-mediated changes in muscle protein synthesis. Eighteen men (21 ± 1 yr, 22.6 ± 2.1 kg/m2; means ± SE) had their legs randomly assigned to two of three training conditions that differed in contraction intensity [% of maximal strength (1 repetition maximum)] or contraction volume (1 or 3 sets of repetitions): 30%-3, 80%-1, and 80%-3. Subjects trained each leg with their assigned regime for a period of 10 wk, 3 times/wk. We made pre- and posttraining measures of strength, muscle volume by magnetic resonance (MR) scans, as well as pre- and posttraining biopsies of the vastus lateralis, and a single postexercise (1 h) biopsy following the first bout of exercise, to measure signaling proteins. Training-induced increases in MR-measured muscle volume were significant (P < 0.01), with no difference between groups: 30%-3 = 6.8 ± 1.8%, 80%-1 = 3.2 ± 0.8%, and 80%-3= 7.2 ± 1.9%, P = 0.18. Isotonic maximal strength gains were not different between 80%-1 and 80%-3, but were greater than 30%-3 (P = 0.04), whereas training-induced isometric strength gains were significant but not different between conditions (P = 0.92). Biopsies taken 1 h following the initial resistance exercise bout showed increased phosphorylation (P < 0.05) of p70S6K only in the 80%-1 and 80%-3 conditions. There was no correlation between phosphorylation of any signaling protein and hypertrophy. In accordance with our previous acute measurements of muscle protein synthetic rates a lower load lifted to failure resulted in similar hypertrophy as a heavy load lifted to failure. PMID:22518835

Fluid-loading solutions and plasma volume: Astro-ade and salt tablets with water

NASA Technical Reports Server (NTRS)

Fortney, Suzanne M.; Seinmann, Laura; Young, Joan A.; Hoskin, Cherylynn N.; Barrows, Linda H.

1994-01-01

Fluid loading with salt and water is a countermeasure used after space flight to restore body fluids. However, gastrointestinal side effects have been frequently reported in persons taking similar quantities of salt and water in ground-based studies. The effectiveness of the Shuttle fluid-loading countermeasure (8 gms salt, 0.97 liters of water) was compared to Astro-ade (an isotonic electrolyte solution), to maintain plasma volume (PV) during 4.5 hrs of resting fluid restriction. Three groups of healthy men (n=6) were studied: a Control Group (no drinking), an Astro-ade Group, and a Salt Tablet Group. Changes in PV after drinking were calculated from hematocrit and hemoglobin values. Both the Salt Tablet and Astro-ade Groups maintained PV at 2-3 hours after ingestion compared to the Control Group, which had a 6 percent decline. Side effects (thirst, stomach cramping, and diarrhea) were noted in at least one subject in both the Astro-ade and Salt Tablet Groups. Nausea and vomiting were reported in one subject in the Salt Tablet Group. It was concluded that Astro-ade may be offered as an alternate fluid-loading countermeasure but further work is needed to develop a solution that is more palatable and has fewer side effects.

Early changes of parotid density and volume predict modifications at the end of therapy and intensity of acute xerostomia.

PubMed

Belli, Maria Luisa; Scalco, Elisa; Sanguineti, Giuseppe; Fiorino, Claudio; Broggi, Sara; Dinapoli, Nicola; Ricchetti, Francesco; Valentini, Vincenzo; Rizzo, Giovanna; Cattaneo, Giovanni Mauro

2014-10-01

To quantitatively assess the predictive power of early variations of parotid gland volume and density on final changes at the end of therapy and, possibly, on acute xerostomia during IMRT for head-neck cancer. Data of 92 parotids (46 patients) were available. Kinetics of the changes during treatment were described by the daily rate of density (rΔρ) and volume (rΔvol) variation based on weekly diagnostic kVCT images. Correlation between early and final changes was investigated as well as the correlation with prospective toxicity data (CTCAEv3.0) collected weekly during treatment for 24/46 patients. A higher rΔρ was observed during the first compared to last week of treatment (-0,50 vs -0,05HU, p-value = 0.0001). Based on early variations, a good estimation of the final changes may be obtained (Δρ: AUC = 0.82, p = 0.0001; Δvol: AUC = 0.77, p = 0.0001). Both early rΔρ and rΔvol predict a higher "mean" acute xerostomia score (≥ median value, 1.57; p-value = 0.01). Median early density rate changes for patients with mean xerostomia score ≥ / < 1.57 were -0.98 vs -0.22 HU/day respectively (p = 0.05). Early density and volume variations accurately predict final changes of parotid glands. A higher longitudinally assessed score of acute xerostomia is well predicted by higher rΔρ and rΔvol in the first two weeks of treatment: best cut-off values were -0.50 HU/day and -380 mm(3)/day for rΔρ and rΔvol respectively. Further studies are necessary to definitively assess the potential of early density/volume changes in identifying more sensitive patients at higher risk of experiencing xerostomia.

Effects of vertical positioning on gas exchange and lung volumes in acute respiratory distress syndrome.

PubMed

Richard, Jean-Christophe M; Maggiore, Salvatore Maurizio; Mancebo, Jordi; Lemaire, François; Jonson, Bjorn; Brochard, Laurent

2006-10-01

Supine position may contribute to the loss of aerated lung volume in patients with acute respiratory distress syndrome (ARDS). We hypothesized that verticalization increases lung volume and improves gas exchange by reducing the pressure surrounding lung bases. Prospective observational physiological study in a medical ICU. In 16 patients with ARDS we measured arterial blood gases, pressure-volume curves of the respiratory system recorded from positive-end expiratory pressure (PEEP), and changes in lung volume in supine and vertical positions (trunk elevated at 45 degrees and legs down at 45 degrees ). Vertical positioning increased PaO(2) significantly from 94+/-33 to 142+/-49 mmHg, with an increase higher than 40% in 11 responders. The volume at 20 cmH(2)O measured on the PV curve from PEEP increased using the vertical position only in responders (233+/-146 vs. -8+/-9 1ml in nonresponders); this change was correlated to oxygenation change (rho=0.55). End-expiratory lung volume variation from supine to vertical and 1 h later back to supine, measured in 12 patients showed a significant increase during the 1-h upright period in responders (n=7) but not in nonresponders (n=5; 215+/-220 vs. 10+/-22 ml), suggesting a time-dependent recruitment. Vertical positioning is a simple technique that may improve oxygenation and lung recruitment in ARDS patients.

Inflammatory responses and intestinal injury development during acute Trypanosoma cruzi infection are associated with the parasite load.

PubMed

Vazquez, Bruna Perez; Vazquez, Thaís Perez; Miguel, Camila Botelho; Rodrigues, Wellington Francisco; Mendes, Maria Tays; de Oliveira, Carlo José Freire; Chica, Javier Emílio Lazo

2015-04-03

Chagas disease is caused by the protozoan Trypanosoma cruzi and is characterized by cardiac, gastrointestinal, and nervous system disorders. Although much about the pathophysiological process of Chagas disease is already known, the influence of the parasite burden on the inflammatory process and disease progression remains uncertain. We used an acute experimental disease model to evaluate the effect of T. cruzi on intestinal lesions and assessed correlations between parasite load and inflammation and intestinal injury at 7 and 14 days post-infection. Low (3 × 10(2)), medium (3 × 10(3)), and high (3 × 10(4)) parasite loads were generated by infecting C57BL/6 mice with "Y"-strain trypomastigotes. Statistical analysis was performed using analysis of variance with Tukey's multiple comparison post-test, Kruskal-Wallis test with Dunn's multiple comparison, χ2 test and Spearman correlation. High parasite load-bearing mice more rapidly and strongly developed parasitemia. Increased colon width, inflammatory infiltration, myositis, periganglionitis, ganglionitis, pro-inflammatory cytokines (e.g., TNF-α, INF-γ, IL-2, IL-17, IL-6), and intestinal amastigote nests were more pronounced in high parasite load-bearing animals. These results were remarkable because a positive correlation was observed between parasite load, inflammatory infiltrate, amastigote nests, and investigated cytokines. These experimental data support the idea that the parasite load considerably influences the T. cruzi-induced intestinal inflammatory response and contributes to the development of the digestive form of the disease.

Multiple Pathways to Bacterial Load Reduction by Stormwater Best Management Practices: Trade-Offs in Performance, Volume, and Treated Area.

PubMed

Wolfand, Jordyn M; Bell, Colin D; Boehm, Alexandria B; Hogue, Terri S; Luthy, Richard G

2018-06-05

Stormwater best management practices (BMPs) are implemented to reduce microbial pollution in runoff, but their removal efficiencies differ. Enhanced BMPs, such as those with media amendments, can increase removal of fecal indicator bacteria (FIB) in runoff from 0.25-log 10 to above 3-log 10 ; however, their implications for watershed-scale management are poorly understood. In this work, a computational model was developed to simulate watershed-scale bacteria loading and BMP performance using the Ballona Creek Watershed (Los Angeles County, CA) as a case study. Over 1400 scenarios with varying BMP performance, percent watershed area treated, BMP treatment volume, and infiltrative capabilities were simulated. Incremental improvement of BMP performance by 0.25-log 10 , while keeping other scenario variables constant, reduces annual bacterial load at the outlet by a range of 0-29%. In addition, various simulated scenarios provide the same FIB load reduction; for example, 75% load reduction is achieved by diverting runoff from either 95% of the watershed area to 25 000 infiltrating BMPs with 0.5-log 10 removal or 75% of the watershed area to 75 000 infiltrating BMPs with 1.5-log 10 removal. Lastly, simulated infiltrating BMPs provide greater FIB reduction than noninfiltrating BMPs at the watershed scale. Results provide new insight on the trade-offs between BMP treatment volume, performance, and distribution.

Vital capacities in acute and chronic airway obstruction: dependence on flow and volume histories.

PubMed

Brusasco, V; Pellegrino, R; Rodarte, J R

1997-06-01

The aim of this study was to investigate whether measurements of vital capacity (VC) are affected by the direction of the manoeuvre (inspiratory vs expiratory) and by the rate of expiratory flow. The study was performed on 25 individuals with chronic airway obstruction (CAO) and a forced expiratory volume in one second (FEV1) (expressed in standardized residuals (SR)) of -2.0+/-1.4 SD (CAO group), and 10 asthmatic subjects with methacholine (MCh)-induced bronchoconstriction (FEV1 -23+/-1.02 SR) (MCh group). VCs were measured during fast inspiration following both slow (FIVCse) and forced (FIVCfe) expiration from end-tidal inspiration to residual volume (RV), and during slow (EVC) or forced (FVC) expiration from total lung capacity (TLC). In the CAO group, FVC was the smallest volume (3.75+/-1.03 L) and significantly different from the other three estimates of VC; FIVCse (4.03+/-0.91 L) was the largest volume and significantly different from FVC and FIVCfe (3.83+/-0.98 L). In the MCh group, FVC (4.16+/-0.94 L) and EVC (4.19+/-0.89 L) were the largest volumes, although only the difference between FVC and FIVCfe (3.76+/-0.81 L) reached statistical significance. These data suggest that both flow and volume histories contribute to decreased vital capacities during bronchoconstriction. However, whereas increasing expiratory flow always tends to decrease vital capacity, the volume history of full inflation has different effects in chronic and acute bronchoconstriction, probably due to different effects on airway calibre. These results stress the importance of using standardized manoeuvres in order to obtain comparable values of vital capacity.

[Experimental study of acute brain swelling under acute intracranial hypertension (author's transl)].

PubMed

Shigemori, M; Watanabe, M; Kuramoto, S

1976-12-01

There are many problems about the cause, pathophysiology and treatment of acute brain swelling under intracranial hypertension frequently encountered in the neurosurgical clinics. Generally, rapid increase of the cerebral vasoparesis caused by unknown etiology is thought to be the main cause of acute brain swelling under intracranial hypertension. Moreover, disturbance of the cerebral venous circulatory system is discussed recently by many authors. But, research from the point of systemic respiration and hemodynamics is necessary for resolving these problems. This experiment was designed to study the effects of respiration and hemodynamics on the cerebral vasoparesis. Using 22 adult dogs, acute intracranial hypertension was produced by epidural balloon inflation sustained at the level of 300 - 400 mmH2O. Simultaneously with measurement of intracranial pressure at the epidural space, superior sagittal sinus pressure, respirogram, systemic blood pressure (femoral artery), central venous pressure, common carotid blood flow, EKG and bipolar lead EEG were monitored continuously. The experimental group was divided by the respiratory loading into 5 groups as follows: control (6 cases), 10% CO2 hypercapnia (4 cases), 10% O2 hypoxia (4 cases), stenosis of airway (5 cases), 100% O2-controled respiration (3 cases). 1) Cerebral vasoparesis under acute intracranial hypertension took place earlier and showed more rapid progression in groups of stenosis of airway, hypercapnia and hypoxia than control group of spontaneous respiration in room air. No occurrence of cerebral vasoparesis was found out in a group of 100% O2 controlled respiration. It is proved that increased airway resistance or asphyxia, hypercapnia and hypoxia have strictly reference to the occurrence and progression of cerebral vasoparesis and for the prevention of cerebral vasoparesis, correct 100% O2 cont rolled respiration is effective. 2) From the hemodynamic change, the progression of rapid increase of cerebral

Structural Flight Loads Simulation Capability. Volume I.

DTIC Science & Technology

1980-11-01

actuators. Load cells sense the resulting loads and give the console operator a positive readout of the loads being applied. The operator’s console...qialn StesSa We Elmn 57. .......... C ’D D .... .. .-- --- -.. ... . ..114 .. ETF’ ’IFEFI,--EIJT :_I’F3L- EL4 ?O cl l c...3.20. (concluded). 127 ra E j214 CbC ob) C-H ea) 4p U) ’-4 r4 128 EL4 UA f r c www aw r. 0 ag 0 . 0 mo > 4-) 0 .4-) en 010 44 1*5 1 I .IA U * . a) Z

Cerebral collateral therapeutics in acute ischemic stroke: A randomized preclinical trial of four modulation strategies.

PubMed

Beretta, Simone; Versace, Alessandro; Carone, Davide; Riva, Matteo; Dell'Era, Valentina; Cuccione, Elisa; Cai, Ruiyao; Monza, Laura; Pirovano, Silvia; Padovano, Giada; Stiro, Fabio; Presotto, Luca; Paternò, Giovanni; Rossi, Emanuela; Giussani, Carlo; Sganzerla, Erik P; Ferrarese, Carlo

2017-10-01

Cerebral collaterals are dynamically recruited after arterial occlusion and highly affect tissue outcome in acute ischemic stroke. We investigated the efficacy and safety of four pathophysiologically distinct strategies for acute modulation of collateral flow (collateral therapeutics) in the rat stroke model of transient middle cerebral artery (MCA) occlusion. A composed randomization design was used to assign rats (n = 118) to receive phenylephrine (induced hypertension), polygeline (intravascular volume load), acetazolamide (cerebral arteriolar vasodilation), head down tilt (HDT) 15° (cerebral blood flow diversion), or no treatment, starting 30 min after MCA occlusion. Compared to untreated animals, treatment with collateral therapeutics was associated with lower infarct volumes (62% relative mean difference; 51.57 mm 3 absolute mean difference; p < 0.001) and higher chance of good functional outcome (OR 4.58, p < 0.001). Collateral therapeutics acutely increased cerebral perfusion in the medial (+40.8%; p < 0.001) and lateral (+19.2%; p = 0.016) MCA territory compared to pretreatment during MCA occlusion. Safety indicators were treatment-related mortality and cardiorespiratory effects. The highest efficacy and safety profile was observed for HDT. Our findings suggest that acute modulation of cerebral collaterals is feasible and provides a tissue-saving effect in the hyperacute phase of ischemic stroke prior to recanalization therapy.

Water quality of storm runoff and comparison of procedures for estimating storm-runoff loads, volume, event-mean concentrations, and the mean load for a storm for selected properties and constituents for Colorado Springs, southeastern Colorado, 1992

USGS Publications Warehouse

Von Guerard, Paul; Weiss, W.B.

1995-01-01

The U.S. Environmental Protection Agency requires that municipalities that have a population of 100,000 or greater obtain National Pollutant Discharge Elimination System permits to characterize the quality of their storm runoff. In 1992, the U.S. Geological Survey, in cooperation with the Colorado Springs City Engineering Division, began a study to characterize the water quality of storm runoff and to evaluate procedures for the estimation of storm-runoff loads, volume and event-mean concentrations for selected properties and constituents. Precipitation, streamflow, and water-quality data were collected during 1992 at five sites in Colorado Springs. Thirty-five samples were collected, seven at each of the five sites. At each site, three samples were collected for permitting purposes; two of the samples were collected during rainfall runoff, and one sample was collected during snowmelt runoff. Four additional samples were collected at each site to obtain a large enough sample size to estimate storm-runoff loads, volume, and event-mean concentrations for selected properties and constituents using linear-regression procedures developed using data from the Nationwide Urban Runoff Program (NURP). Storm-water samples were analyzed for as many as 186 properties and constituents. The constituents measured include total-recoverable metals, vola-tile-organic compounds, acid-base/neutral organic compounds, and pesticides. Storm runoff sampled had large concentrations of chemical oxygen demand and 5-day biochemical oxygen demand. Chemical oxygen demand ranged from 100 to 830 milligrams per liter, and 5.-day biochemical oxygen demand ranged from 14 to 260 milligrams per liter. Total-organic carbon concentrations ranged from 18 to 240 milligrams per liter. The total-recoverable metals lead and zinc had the largest concentrations of the total-recoverable metals analyzed. Concentrations of lead ranged from 23 to 350 micrograms per liter, and concentrations of zinc ranged from 110

Intraoperative intravascular volume optimisation and length of hospital stay after repair of proximal femoral fracture: randomised controlled trial.

PubMed Central

Sinclair, S.; James, S.; Singer, M.

1997-01-01

OBJECTIVES: To assess whether intraoperative intravascular volume optimisation improves outcome and shortens hospital stay after repair of proximal femoral fracture. DESIGN: Prospective, randomised controlled trial comparing conventional intraoperative fluid management with repeated colloid fluid challenges monitored by oesophageal Doppler ultrasonography to maintain maximal stroke volume throughout the operative period. SETTING: Teaching hospital, London. SUBJECTS: 40 patients undergoing repair of proximal femoral fracture under general anaesthesia. INTERVENTIONS: Patients were randomly assigned to receive either conventional intraoperative fluid management (control patients) or additional repeated colloid fluid challenges with oesophageal Doppler ultrasonography used to maintain maximal stroke volume throughout the operative period (protocol patients). MAIN OUTCOME MEASURES: Time declared medically fit for hospital discharge, duration of hospital stay (in acute bed; in acute plus long stay bed), mortality, perioperative haemodynamic changes. RESULTS: Intraoperative intravascular fluid loading produced significantly greater changes in stroke volume (median 15 ml (95% confidence interval 10 to 21 ml)) and cardiac output (1.2 l/min (0.1 to 2.3 l/min)) than in the conventionally managed group (-5 ml (-10 to 1 ml) and -0.4 l/min (-1.0 to 0.2 l/min)) (P < 0.001 and P < 0.05, respectively). One protocol patient and two control patients died in hospital. In the survivors, postoperative recovery was significantly faster in the protocol patients, with shorter times to being declared medically fit for discharge (median 10 (9 to 15) days v 15 (11 to 40) days, P < 0.05) and a 39% reduction in hospital stay (12 (8 to 13) days v 20 (10 to 61) days, P < 0.05). CONCLUSIONS: Proximal femoral fracture repair constitutes surgery in a high risk population. Intraoperative intravascular volume loading to optimal stroke volume resulted in a more rapid postoperative recovery and a

Population-specific influence of SLC2A9 genotype on the acute hyperuricaemic response to a fructose load.

PubMed

Dalbeth, Nicola; House, Meaghan E; Gamble, Gregory D; Horne, Anne; Pool, Bregina; Purvis, Lauren; Stewart, Angela; Merriman, Marilyn; Cadzow, Murray; Phipps-Green, Amanda; Merriman, Tony R

2013-11-01

SLC2A9 is a strong genetic risk factor for hyperuricaemia and gout. SLC2A9 (GLUT9) is a high capacity urate transporter and reportedly transports glucose and fructose. Intake of fructose-containing beverages is associated with development of hyperuricaemia and gout. To determine whether genetic variation in SLC2A9 influences the acute serum urate response to a fructose load. Following an overnight fast, 76 healthy volunteers (25 Māori, 26 Pacific, 25 European Caucasian) drank a solution containing 64 g fructose. Serum and urine were obtained immediately before and then 30, 60, 120 and 180 min after ingestion. The SLC2A9 single nucleotide polymorphism (SNP) rs11942223 was genotyped and data were analysed based on the presence or absence of the gout protective minor allele (C). The rs11942223 C allele was present in 17 participants (22%). In the entire group, fructose intake led to an increase in serum urate, which peaked 60 min following fructose ingestion (analysis of variance p=0.006). The presence of the C allele was associated with an attenuated hyperuricaemic response (p(SNP)<0.0001) and increased fractional excretion of uric acid (FEUA) (p(SNP)<0.0001) following the fructose load. The effects of rs11942223 variants on serum urate and FEUA in response to fructose were present only in Caucasian ancestral subgroups but not in the Māori and Pacific ancestral subgroup. Variation in SLC2A9 influences acute serum urate and FEUA responses to a fructose load. SLC2A9 genotype may influence the development of gout on exposure to fructose-containing beverages, particularly in European Caucasian populations.

The effects of load history and design variables on performance limit states of circular bridge columns - volume 3 : analysis methods.

DOT National Transportation Integrated Search

2015-01-01

This report is the third of three volumes and presents the numerical portion of the research project on the impacts of loading history on : the behavior of reinforced concrete bridge columns. Two independent finite element methods were utilized to ac...

Effect of provider volume on the accuracy of hospital report cards: a Monte Carlo study.

PubMed

Austin, Peter C; Reeves, Mathew J

2014-03-01

Hospital report cards, in which outcomes after the provision of medical or surgical care are compared across healthcare providers, are being published with increasing frequency. However, the accuracy of such comparisons is controversial, especially when case volumes are small. The objective was to determine the relationship between hospital case volume and the accuracy of hospital report cards. Monte Carlo simulations were used to examine the influence of hospital case volume on the accuracy of hospital report cards in a setting in which true hospital performance was known with certainty, and perfect risk-adjustment was feasible. The parameters used to generate the simulated data sets were obtained from empirical analyses of data on patients hospitalized with acute myocardial infarction in Ontario, Canada, in which the overall 30-day mortality rate was 11.1%. We found that provider volume had a strong effect on the accuracy of hospital report cards. However, provider volume had to be >300 before ≥70% of hospitals were correctly classified. Furthermore, hospital volume had to be >1000 before ≥80% of hospitals were correctly classified. Producers and users of hospital report cards need to be aware that, even when perfect risk adjustment is possible, the accuracy of hospital report cards is, at best, modest for small to medium-sized case loads (i.e., 100-300). Hospital report cards displayed high degrees of accuracy only when provider volumes exceeded the typical annual hospital case load for many cardiovascular conditions and procedures.

Impacts of logging on storm peak flows, flow volumes and suspended sediment loads in Caspar Creek, California

Treesearch

Jack Lewis; Sylvia R. Mori; Elizabeth T. Keppeler; Robert R. Ziemer

2001-01-01

Abstract - Models are fit to 11 years of storm peak flows, flow volumes, and suspended sediment loads on a network of 14 stream gaging stations in the North Fork Caspar Creek, a 473-ha coastal watershed bearing a second-growth forest of redwood and Douglas-fir. For the first 4 years of monitoring, the watershed was in a relatively undisturbed state, having last been...

Automated cerebral infarct volume measurement in follow-up noncontrast CT scans of patients with acute ischemic stroke.

PubMed

Boers, A M; Marquering, H A; Jochem, J J; Besselink, N J; Berkhemer, O A; van der Lugt, A; Beenen, L F; Majoie, C B

2013-08-01

Cerebral infarct volume as observed in follow-up CT is an important radiologic outcome measure of the effectiveness of treatment of patients with acute ischemic stroke. However, manual measurement of CIV is time-consuming and operator-dependent. The purpose of this study was to develop and evaluate a robust automated measurement of the CIV. The CIV in early follow-up CT images of 34 consecutive patients with acute ischemic stroke was segmented with an automated intensity-based region-growing algorithm, which includes partial volume effect correction near the skull, midline determination, and ventricle and hemorrhage exclusion. Two observers manually delineated the CIV. Interobserver variability of the manual assessments and the accuracy of the automated method were evaluated by using the Pearson correlation, Bland-Altman analysis, and Dice coefficients. The accuracy was defined as the correlation with the manual assessment as a reference standard. The Pearson correlation for the automated method compared with the reference standard was similar to the manual correlation (R = 0.98). The accuracy of the automated method was excellent with a mean difference of 0.5 mL with limits of agreement of -38.0-39.1 mL, which were more consistent than the interobserver variability of the 2 observers (-40.9-44.1 mL). However, the Dice coefficients were higher for the manual delineation. The automated method showed a strong correlation and accuracy with the manual reference measurement. This approach has the potential to become the standard in assessing the infarct volume as a secondary outcome measure for evaluating the effectiveness of treatment.

Guaifenesin has no effect on sputum volume or sputum properties in adolescents and adults with acute respiratory tract infections.

PubMed

Hoffer-Schaefer, Agathe; Rozycki, Henry J; Yopp, Melissa A; Rubin, Bruce K

2014-05-01

Guaifenesin (glyceryl guaiacolate ether [GGE]) has been studied as a cough suppressant and as an expectorant; however, published studies to date have failed to find a consistent benefit. An 8-day multi-center clinical trial was conducted to study the effect of two 600-mg extended-release GGE tablets twice daily for 1 week on cold symptoms, sputum volume, and properties in adolescents and adults with productive cough from an acute respiratory tract infection (RTI). The study enrolled 378 subjects (GGE, n = 188; and placebo, n = 190) who were otherwise healthy and had an RTI for up to 5 days before enrollment. Subjects suffered from at least 2 of 3 symptoms of cough, thickened mucus, and chest congestion. A total of 151 GGE and 144 control subjects completed the full protocol. Single-sputum samples were collected from each subject on days 1, 3, 4, and 8 of the study. The rheology and interfacial tension of sputum were measured, and 24-h collected samples from days 1 and 4 were analyzed for total volume and hydration. Symptoms in both the GGE and placebo groups improved to a similar degree over time. There were no significant differences between the GGE and placebo groups for sputum volume (P = .41), percent solids (P = .69), interfacial tension (P = .88), elasticity (P = .71), viscosity (P = .45), or mechanical impedance (P = .75). The recommended dose of GGE had no measurable effect on sputum volume or properties and is unlikely to be an expectorant or mucolytic when used to treat acute RTI. (ClinicalTrials.gov registration NCT01046136.).

Does Stroke Volume Increase During an Incremental Exercise? A Systematic Review

PubMed Central

Vieira, Stella S.; Lemes, Brunno; de T. C. de Carvalho, Paulo; N. de Lima, Rafael; S. Bocalini, Danilo; A. S. Junior, José; Arsa, Gisela; A. Casarin, Cezar; L. Andrade, Erinaldo; J. Serra, Andrey

2016-01-01

Introduction: Cardiac output increases during incremental-load exercise to meet metabolic skeletal muscle demand. This response requires a fast adjustment in heart rate and stroke volume. The heart rate is well known to increase linearly with exercise load; however, data for stroke volume during incremental-load exercise are unclear. Our objectives were to (a) review studies that have investigated stroke volume on incremental load exercise and (b) summarize the findings for stroke volume, primarily at maximal-exercise load. Methods: A comprehensive review of the Cochrane Library’s, Embase, Medline, SportDiscus, PubMed, and Web of Sci-ence databases was carried out for the years 1985 to the present. The search was performed between February and June 2014 to find studies evaluating changes in stroke volume during incremental-load exercise. Controlled and uncontrolled trials were evaluated for a quality score. Results: The stroke volume data in maximal-exercise load are inconsistent. There is evidence to hypothesis that stroke volume increases during maximal-exercise load, but other lines of evidence indicate that stroke volume reaches a plateau under these circumstances, or even decreases. Conclusion: The stroke volume are unclear, include contradictory evidence. Additional studies with standardized reporting for subjects (e.g., age, gender, physical fitness, and body position), exercise test protocols, and left ventricular function are required to clarify the characteristics of stroke volume during incremental maximal-exercise load. PMID:27347221

In vivo tibiofemoral cartilage-to-cartilage contact area of females with medial osteoarthritis under acute loading using MRI.

PubMed

Shin, Choongsoo S; Souza, Richard B; Kumar, Deepak; Link, Thomas M; Wyman, Bradley T; Majumdar, Sharmila

2011-12-01

To investigate the effect of acute loading on in vivo tibiofemoral contact area changes in both compartments, and to determine whether in vivo tibiofemoral contact area differs between subjects with medial knee osteoarthritis (OA) and healthy controls. Ten subjects with medial knee OA (KL3) and 11 control subjects (KL0) were tested. Coronal three-dimensional spoiled gradient-recalled (3D-SPGR) and T(2) -weighted fast spin-echo FSE magnetic resonance imaging (MRI) of the knee were acquired under both unloaded and loaded conditions. Tibiofemoral cartilage contact areas were measured using image-based 3D models. Tibiofemoral contact areas in both compartments significantly increased under loading (P < 0.001) and the increased contact area in the medial compartment was significantly larger than in the lateral compartment (P < 0.05). Medial compartment contact area was significantly larger in KL3 subjects than KL0 subjects, both at unloaded and loaded conditions (P < 0.05). Contact areas measured from 3D-SPGR and T(2) -weighted FSE images were strongly correlated (r = 0.904). Females with medial OA increased tibiofemoral contact area in the medial compartment compared to healthy subjects under both unloaded and loaded conditions. The contact area data presented in this study may provide a quantitative reference for further cartilage contact biomechanics such as contact stress analysis and cartilage biomechanical function difference between osteoarthritic and healthy knees. Copyright © 2011 Wiley Periodicals, Inc.

Effect of Surface Impulsive Thermal Loads on Fatigue Behavior of Constant Volume Propulsion Engine Combustor Materials

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Fox, Dennis S.; Miller, Robert A.; Ghosn, Louis J.; Kalluri, Sreeramesh

2004-01-01

The development of advanced high performance constant-volume-combustion-cycle engines (CVCCE) requires robust design of the engine components that are capable of enduring harsh combustion environments under high frequency thermal and mechanical fatigue conditions. In this study, a simulated engine test rig has been established to evaluate thermal fatigue behavior of a candidate engine combustor material, Haynes 188, under superimposed CO2 laser surface impulsive thermal loads (30 to 100 Hz) in conjunction with the mechanical fatigue loads (10 Hz). The mechanical high cycle fatigue (HCF) testing of some laser pre-exposed specimens has also been conducted under a frequency of 100 Hz to determine the laser surface damage effect. The test results have indicated that material surface oxidation and creep-enhanced fatigue is an important mechanism for the surface crack initiation and propagation under the simulated CVCCE engine conditions.

Alteration of mean platelet volume in the pathogenesis of acute ischemic stroke: cause or consequence?

PubMed

Ayas, Zeynep Özözen; Can, Ufuk

2018-01-30

Platelets have a crucial role on vascular disease which are involved in pathogenesis of ischemic stroke. Platelet size is measured as mean platelet volume (MPV) and is a marker of platelet activity. Platelets contain more dense granules as the size increases and produce more serotonin and tromboglobulin (b-TG) than small platelets. In this study, the alteration of MPV values were investigated in patients with acute stroke, who had MPV values before stroke, during acute ischemic stroke and 7 days after the stroke. The relationship between this alteration and risk factors, etiology and localization of ischemic stroke were also investigated. Sixty-seven patients with clinically and radiologically established diagnoses of ischemic stroke were enrolled into the study and stroke etiology was classified by modified Trial of Org 10 172 in Acute Stroke Treatment (TOAST) classification and, modified Bamford classification was used for localization and stroke risk factors were also evaluated. The platelet counts and MPV values from patient files in patients who had values before stroke (at examination for another diseases), within 24 hours of symptom onset and after 7 further days were analysed. MPV values increased after stroke (10.59±2.26) compared with acute stroke values (9.84±1.64) and the values before stroke (9.59±1.72) (p<0.0001); this alteration of MPV values occured 7 days after stroke (p<0.016). There was a positive correlation between age and MPV values during acute stroke (r=0.270; p<0.05). Patients with atrial fibrillation had higher alteration in the time of MPV compared with patients without atrial fibrillation (p>0.006). We assessed for gender, men (n=38) had a higher alteration in the time of MPV compared with women (n=29) (p=0.013). Although there was no alteration of platelet counts, MPV values were increased 7 days after stroke in patients with acute ischemic stroke.

Limited reliability of computed tomographic perfusion acute infarct volume measurements compared with diffusion-weighted imaging in anterior circulation stroke.

PubMed

Schaefer, Pamela W; Souza, Leticia; Kamalian, Shervin; Hirsch, Joshua A; Yoo, Albert J; Kamalian, Shahmir; Gonzalez, R Gilberto; Lev, Michael H

2015-02-01

Diffusion-weighted imaging (DWI) can reliably identify critically ischemic tissue shortly after stroke onset. We tested whether thresholded computed tomographic cerebral blood flow (CT-CBF) and CT-cerebral blood volume (CT-CBV) maps are sufficiently accurate to substitute for DWI for estimating the critically ischemic tissue volume. Ischemic volumes of 55 patients with acute anterior circulation stroke were assessed on DWI by visual segmentation and on CT-CBF and CT-CBV with segmentation using 15% and 30% thresholds, respectively. The contrast:noise ratios of ischemic regions on the DWI and CT perfusion (CTP) images were measured. Correlation and Bland-Altman analyses were used to assess the reliability of CTP. Mean contrast:noise ratios for DWI, CT-CBF, and CT-CBV were 4.3, 0.9, and 0.4, respectively. CTP and DWI lesion volumes were highly correlated (R(2)=0.87 for CT-CBF; R(2)=0.83 for CT-CBV; P<0.001). Bland-Altman analyses revealed little systemic bias (-2.6 mL) but high measurement variability (95% confidence interval, ±56.7 mL) between mean CT-CBF and DWI lesion volumes, and systemic bias (-26 mL) and high measurement variability (95% confidence interval, ±64.0 mL) between mean CT-CBV and DWI lesion volumes. A simulated treatment study demonstrated that using CTP-CBF instead of DWI for detecting a statistically significant effect would require at least twice as many patients. The poor contrast:noise ratios of CT-CBV and CT-CBF compared with those of DWI result in large measurement error, making it problematic to substitute CTP for DWI in selecting individual acute stroke patients for treatment. CTP could be used for treatment studies of patient groups, but the number of patients needed to identify a significant effect is much higher than the number needed if DWI is used. © 2014 American Heart Association, Inc.

Dynamic equilibration of airway smooth muscle contraction during physiological loading.

PubMed

Latourelle, Jeanne; Fabry, Ben; Fredberg, Jeffrey J

2002-02-01

Airway smooth muscle contraction is the central event in acute airway narrowing in asthma. Most studies of isolated muscle have focused on statically equilibrated contractile states that arise from isometric or isotonic contractions. It has recently been established, however, that muscle length is determined by a dynamically equilibrated state of the muscle in which small tidal stretches associated with the ongoing action of breathing act to perturb the binding of myosin to actin. To further investigate this phenomenon, we describe in this report an experimental method for subjecting isolated muscle to a dynamic microenvironment designed to closely approximate that experienced in vivo. Unlike previous methods that used either time-varying length control, force control, or time-invariant auxotonic loads, this method uses transpulmonary pressure as the controlled variable, with both muscle force and muscle length free to adjust as they would in vivo. The method was implemented by using a servo-controlled lever arm to load activated airway smooth muscle strips with transpulmonary pressure fluctuations of increasing amplitude, simulating the action of breathing. The results are not consistent with classical ideas of airway narrowing, which rest on the assumption of a statically equilibrated contractile state; they are consistent, however, with the theory of perturbed equilibria of myosin binding. This experimental method will allow for quantitative experimental evaluation of factors that were previously outside of experimental control, including sensitivity of muscle length to changes of tidal volume, changes of lung volume, shape of the load characteristic, loss of parenchymal support and inflammatory thickening of airway wall compartments.

Acute glycaemic load breakfast manipulations do not attenuate cognitive impairments in adults with type 2 diabetes.

PubMed

Lamport, Daniel Joseph; Dye, Louise; Mansfield, Michael W; Lawton, Clare L

2013-04-01

Research on young healthy samples suggests that low glycaemic load foods can confer benefits for cognitive performance. The aim was to examine the effects of type 2 diabetes on cognitive function, and to investigate whether consumption of low glycaemic load breakfasts affects cognitive function in adults with type 2 diabetes. Memory, psychomotor skill and executive function were examined at two morning test sessions in 24 adults with type 2 diabetes and 10 adults with normal glucose tolerance (NGT) aged 45-77 years without dementia after water, low, and high glycaemic load breakfasts were consumed in accordance with a crossover, counterbalanced design. The type 2 diabetes and NGT groups were matched for education, depression, and IQ. Type 2 diabetes was associated with impairments in verbal memory, spatial memory, psychomotor skill, and executive function compared to adults with NGT. Consumption of the three breakfast conditions did not impact on cognitive performance in the type 2 diabetes or NGT participants. Abnormalities in glucose tolerance such as type 2 diabetes can have demonstrable negative effects on a range of cognitive functions. However, there was no evidence that low GL breakfasts administered acutely could confer benefits for cognitive function (ClincalTrials.gov identifier, NCT01047813). Copyright © 2012 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Effect of meal volume and calorie load on postprandial gastric function and emptying: studies under physiological conditions by combined fiber-optic pressure measurement and MRI.

PubMed

Kwiatek, Monika A; Menne, Dieter; Steingoetter, Andreas; Goetze, Oliver; Forras-Kaufman, Zsofia; Kaufman, Elad; Fruehauf, Heiko; Boesiger, Peter; Fried, Michael; Schwizer, Werner; Fox, Mark R

2009-11-01

This study assessed the effects of meal volume (MV) and calorie load (CL) on gastric function. MRI and a minimally invasive fiber-optic recording system (FORS) provided simultaneous measurement of gastric volume and pressure changes during gastric filling and emptying of a liquid nutrient meal in physiological conditions. The gastric response to 12 iso-osmolar MV-CL combinations of a multinutrient drink (MV: 200, 400, 600, 800 ml; CL: 200, 300, 400 kcal) was tested in 16 healthy subjects according to a factorial design. Total gastric volume (TGV) and gastric content volume (GCV = MV + secretion) were measured by MRI during nasogastric meal infusion and gastric emptying over 60 min. Intragastric pressure was assessed at 1 Hz by FORS. The dynamic change in postprandial gastric volumes was described by a validated three-component linear exponential model. The stomach expanded with MV, but the ratio of GCV:MV at t(0) diminished with increasing MV (P < 0.01). Postprandial changes in TGV followed those of GCV. Intragastric pressure increased with MV, and this effect was augmented further by CL (P = 0.02); however, the absolute pressure rise was <4 mmHg. A further postprandial increase of gastric volumes was observed early on before any subsequent volume decrease. This "early" increase in GCV was greater for smaller than larger MV (P < 0.01), indicating faster initial gastric emptying of larger MV. In contrast, volume change during filling and in the early postprandial period were unaffected by CL. In the later postprandial period, gastric emptying rate continued to be more rapid with high MVs (P < 0.001); however, at any given volume, gastric emptying was slowed by higher CL (P < 0.001). GCV half-emptying time decreased with CL at 18 +/- 6 min for each additional 100-kcal load (P < 0.001). These findings indicate that gastric wall stress (passive strain and active tone) provides the driving force for gastric emptying, but distal resistance to gastric outflow regulates

Acute Hyperglycemia Does Not Affect Brain Swelling or Infarction Volume After Middle Cerebral Artery Occlusion in Rats.

PubMed

McBride, Devin W; Matei, Nathanael; Câmara, Justin R; Louis, Jean-Sébastien; Oudin, Guillaume; Walker, Corentin; Adam, Loic; Liang, Xiping; Hu, Qin; Tang, Jiping; Zhang, John H

2016-01-01

Stroke disproportionally affects diabetic and hyperglycemic patients with increased incidence and is associated with higher morbidity and mortality due to brain swelling. In this study, the intraluminal suture middle cerebral artery occlusion (MCAO) model was used to examine the effects of blood glucose on brain swelling and infarct volume in acutely hyperglycemic rats and normo-glycemic controls. Fifty-four rats were distributed into normo-glycemic sham surgery, hyperglycemic sham surgery, normo-glycemic MCAO, and hyperglycemic MCAO. To induce hyperglycemia, 15 min before MCAO surgery, animals were injected with 50 % dextrose. Animals were subjected to 90 min of MCAO and sacrificed 24 h after reperfusion for hemispheric brain swelling and infarct volume calculations using standard equations. While normo-glycemic and hyperglycemic animals after MCAO presented with significantly higher brain swelling and larger infarcts than their respective controls, no statistical difference was observed for either brain swelling or infarct volume between normo-glycemic shams and hyperglycemic shams or normo-glycemic MCAO animals and hyperglycemic MCAO animals. The findings of this study suggest that blood glucose does not have any significant effect on hemispheric brain swelling or infarct volume after MCAO in rats.

Role of atrial natriuretic peptide in systemic responses to acute isotonic volume expansion

NASA Technical Reports Server (NTRS)

Watenpaugh, Donald E.; Yancy, Clyde W.; Buckey, Jay C.; Lane, Lynda D.; Hargens, Alan R.; Blomqvist, C. G.

1992-01-01

A hypothesis is proposed that a temporal relationship exists between increases in cardiac filling pressure and plasma artrial natriuretic peptide (ANP) concentration and also between ANP elevation and vasodilation, fluid movement from plasma to interstitium, and increased urine volume (UV). To test the hypothesis, 30 ml/kg isotonic saline were infused in supine male subjects over 24 min and responses were monitored for 3 h postinfusion. Results show that at end infusion, mean arterial pressure (RAP), heart rate and plasma volume exhibited peak increases of 146, 23, and 27 percent, respectively. Mean plasma ANP and UV peaked (45 and 390 percent, respectively) at 30 min postinfusion. Most cardiovascular variables had returned toward control levels by 1 h postinfusion, and net reabsorption of extravascular fluid ensued. It is concluded that since ANP was not significantly increased until 30 min postinfusion, factors other than ANP initiate responses to intravascular fluid loading. These factors include increased vascular pressures, baroreceptor-mediated vasolidation, and hemodilution of plasma proteins. ANP is suggested to mediate, in part, the renal response to saline infusion.

Acute toxicity study of tilmicosin-loaded hydrogenated castor oil-solid lipid nanoparticles.

PubMed

Xie, Shuyu; Wang, Fenghua; Wang, Yan; Zhu, Luyan; Dong, Zhao; Wang, Xiaofang; Li, Xihe; Zhou, Wenzhong

2011-11-20

Our previous studies demonstrated that tilmicosin-loaded hydrogenated castor oil solid lipid nanoparticles (Til-HCO-SLN) are a promising formulation for enhanced pharmacological activity and therapeutic efficacy in veterinary use. The purpose of this work was to evaluate the acute toxicity of Til-HCO-SLN. Two nanoparticle doses were used for the study in ICR mice. The low dose (766 mg/kg.bw) with tilmicosin 7.5 times of the clinic dosage and below the median lethal dose (LD(50)) was subcutaneously administered twice on the first and 7th day. The single high dose (5 g/kg.bw) was the practical upper limit in an acute toxicity study and was administered subcutaneously on the first day. Blank HCO-SLN, native tilmicosin, and saline solution were included as controls. After medication, animals were monitored over 14 days, and then necropsied. Signs of toxicity were evaluated via mortality, symptoms of treatment effect, gross and microscopic pathology, and hematologic and biochemical parameters. After administration of native tilmicosin, all mice died within 2 h in the high dose group, in the low dose group 3 died after the first and 2 died after the second injections. The surviving mice in the tilmicosin low dose group showed hypoactivity, accelerated breath, gloomy spirit and lethargy. In contrast, all mice in Til-HCO-SLN and blank HCO-SLN groups survived at both low and high doses. The high nanoparticle dose induced transient clinical symptoms of treatment effect such as transient reversible action retardation, anorexy and gloomy spirit, increased spleen and liver coefficients and decreased heart coefficients, microscopic pathological changes of liver, spleen and heart, and minor changes in hematologic and biochemical parameters, but no adverse effects were observed in the nanoparticle low dose group. The results revealed that the LD50 of Til-HCO-SLN and blank HCO-SLN exceeded 5 g/kg.bw and thus the nanoparticles are considered low toxic according to the toxicity

Acute toxicity study of tilmicosin-loaded hydrogenated castor oil-solid lipid nanoparticles

PubMed Central

2011-01-01

Background Our previous studies demonstrated that tilmicosin-loaded hydrogenated castor oil solid lipid nanoparticles (Til-HCO-SLN) are a promising formulation for enhanced pharmacological activity and therapeutic efficacy in veterinary use. The purpose of this work was to evaluate the acute toxicity of Til-HCO-SLN. Methods Two nanoparticle doses were used for the study in ICR mice. The low dose (766 mg/kg.bw) with tilmicosin 7.5 times of the clinic dosage and below the median lethal dose (LD50) was subcutaneously administered twice on the first and 7th day. The single high dose (5 g/kg.bw) was the practical upper limit in an acute toxicity study and was administered subcutaneously on the first day. Blank HCO-SLN, native tilmicosin, and saline solution were included as controls. After medication, animals were monitored over 14 days, and then necropsied. Signs of toxicity were evaluated via mortality, symptoms of treatment effect, gross and microscopic pathology, and hematologic and biochemical parameters. Results After administration of native tilmicosin, all mice died within 2 h in the high dose group, in the low dose group 3 died after the first and 2 died after the second injections. The surviving mice in the tilmicosin low dose group showed hypoactivity, accelerated breath, gloomy spirit and lethargy. In contrast, all mice in Til-HCO-SLN and blank HCO-SLN groups survived at both low and high doses. The high nanoparticle dose induced transient clinical symptoms of treatment effect such as transient reversible action retardation, anorexy and gloomy spirit, increased spleen and liver coefficients and decreased heart coefficients, microscopic pathological changes of liver, spleen and heart, and minor changes in hematologic and biochemical parameters, but no adverse effects were observed in the nanoparticle low dose group. Conclusions The results revealed that the LD50 of Til-HCO-SLN and blank HCO-SLN exceeded 5 g/kg.bw and thus the nanoparticles are considered low

Dietary sodium and plasma volume levels with exercise.

PubMed

Luetkemeier, M J; Coles, M G; Askew, E W

1997-05-01

Sodium is the major cation of the extracellular fluid and has a potent influence on fluid movement. Sodium has been likened to a sponge that draws fluids into the extracellular space, including the plasma volume, to equalize gradients in concentration. Conventional wisdom suggests limiting dietary intake of Na+ to decrease risk of hypertension. However, there are some extreme occupational or exercise-related conditions where sweat losses are great and Na+ losses may exceed normal dietary intake. This can occur acutely such as in an ultra-endurance event or chronically as in hard manual work in the hear. In such cases, additional Na+ in the form of a higher Na+ diet or adding Na+ to beverages used for fluid replacement may be warranted. A higher Na+ diet also appears to accelerate the cardiovascular and thermoregulatory adaptations that accompany heat acclimation or short term exercise training. Saline ingestion before exercise causes an expansion of plasma volume at rest and throughout the subsequent exercise bout. This expansion of plasma volume alters cardiovascular and thermoregulatory responses to exercise in ways that may lead to beneficial changes in endurance exercise performance. Plasma volume expansion also occurs with saline infusion during exercise, but exercise performance advantages have yet to be reported. The purpose of this article is to review the literature concerning dietary sodium and its influence on fluid balance, plasma volume and thermoregulation during exercise. It contains 2 major sections. First, we will discuss manipulations in daily Na+ intake initiated before or throughout an exercise regime. Second, we will examine studies where an acute Na+ load was administered immediately before or during an exercise trial. The dependent variables that we will discuss pertain to: (i) body water compartments, i.e. plasma volume; (ii) thermoregulatory variables, i.e. core temperature and sweat rate; (iii) cardiovascular variables, i.e. heart rate and

Correlation of symptom depression levels with mean platelet volume rate on patients of acute coronary syndrome

NASA Astrophysics Data System (ADS)

Hasugian, L.; Hanum, H.; Hanida, W.; Safri, Z.

2018-03-01

Patients with Depression and the acute coronary syndrome (ACS) is rarely detected, although in some studies say that depression can worsen cardiovascularly and increase mortality. From research, Canan F et al found that increasing levels of Mean platelet volume (MPV) as a risk factor for atherosclerosis and MPV was higher in patients with depression compared with patients without depression. In this study used observational methods of measurement of cross-sectional data. Research began in November 2015 - May 2016 against General Hospital inpatients H. Adam Malik Medan. There are 64 patients with a diagnosis of ACS were given quieter Beck Depression Inventory (BDI), then calculated a score of BDI patients and MPV levels were seen when they first entered the hospital before being given treatment. Patients answered quieter on days 3-7 after diagnosis ACS. ACS Patients were divided into 3 groups: acute myocardial infarction with ST elevation, acute myocardial infarction with non-ST elevation and unstable angina pectoris. The level of depression is grouped into not depression, mild depression, moderate depression and severe depression. Statistically significant with p-value<0.05Based on the linear correlation analysis, it was found a positive correlation with r=0.542. And the relationship is statistically significant with p-value 0.000003.

Solar Heating And Cooling Of Buildings (SHACOB): Requirements definition and impact analysis-2. Volume 3: Customer load management systems

NASA Astrophysics Data System (ADS)

Cretcher, C. K.; Rountredd, R. C.

1980-11-01

Customer Load Management Systems, using off-peak storage and control at the residences, are analyzed to determine their potential for capacity and energy savings by the electric utility. Areas broadly representative of utilities in the regions around Washington, DC and Albuquerque, NM were of interest. Near optimum tank volumes were determined for both service areas, and charging duration/off-time were identified as having the greatest influence on tank performance. The impacts on utility operations and corresponding utility/customer economics were determined in terms of delta demands used to estimate the utilities' generating capacity differences between the conventional load management, (CLM) direct solar with load management (DSLM), and electric resistive systems. Energy differences are also determined. These capacity and energy deltas are translated into changes in utility costs due to penetration of the CLM or DSLM systems into electric resistive markets in the snapshot years of 1990 and 2000.

Work of breathing during lung-protective ventilation in patients with acute lung injury and acute respiratory distress syndrome: a comparison between volume and pressure-regulated breathing modes.

PubMed

Kallet, Richard H; Campbell, Andre R; Dicker, Rochelle A; Katz, Jeffrey A; Mackersie, Robert C

2005-12-01

Pressure-control ventilation (PCV) and pressure-regulated volume-control (PRVC) ventilation are used during lung-protective ventilation because the high, variable, peak inspiratory flow rate (V (I)) may reduce patient work of breathing (WOB) more than the fixed V (I) of volume-control ventilation (VCV). Patient-triggered breaths during PCV and PRVC may result in excessive tidal volume (V(T)) delivery unless the inspiratory pressure is reduced, which in turn may decrease the peak V (I). We tested whether PCV and PRVC reduce WOB better than VCV with a high, fixed peak V (I) (75 L/min) while also maintaining a low V(T) target. Fourteen nonconsecutive patients with acute lung injury or acute respiratory distress syndrome were studied prospectively, using a random presentation of ventilator modes in a crossover, repeated-measures design. A target V(T) of 6.4 + 0.5 mL/kg was set during VCV and PRVC. During PCV the inspiratory pressure was set to achieve the same V(T). WOB and other variables were measured with a pulmonary mechanics monitor (Bicore CP-100). There was a nonsignificant trend toward higher WOB (in J/L) during PCV (1.27 + 0.58 J/L) and PRVC (1.35 + 0.60 J/L), compared to VCV (1.09 + 0.59 J/L). While mean V(T) was not statistically different between modes, in 40% of patients, V(T) markedly exceeded the lung-protective ventilation target during PRVC and PCV. During lung-protective ventilation, PCV and PRVC offer no advantage in reducing WOB, compared to VCV with a high flow rate, and in some patients did not allow control of V(T) to be as precise.

NT-pro-BNP levels in patients with acute pulmonary embolism are correlated to right but not left ventricular volume and function.

PubMed

Pasha, Sharif M; Klok, Frederikus A; van der Bijl, Noortje; de Roos, Albert; Kroft, Lucia J M; Huisman, Menno V

2012-08-01

N-terminal pro-Brain Natriuretic Peptide (NT-pro-BNP) is primarily secreted by left ventricular (LV) stretch and wall tension. Notably, NT-pro-BNP is a prognostic marker in acute pulmonary embolism (PE), which primarily stresses the right ventricle (RV). We sought to evaluate the relative contribution of the RV to NT-pro-BNP levels during PE. A post-hoc analysis of an observational prospective outcome study in 113 consecutive patients with computed tomography (CT)-proven PE and 226 patients in whom PE was clinically suspected but ruled out by CT. In all patients RV and LV function was established by assessing ECG-triggered-CT measured ventricular end-diastolic-volumes and ejection fraction (EF). NT-pro-BNP was assessed in all patients. The correlation between RV and LV end-diastolic-volumes and systolic function was evaluated by multiple linear regression corrected for known confounders. In the PE cohort increased RVEF (β-coefficient (95% confidence interval [CI]) -0.044 (± -0.011); p<0.001) and higher RV end-diastolic-volume (β-coefficient 0.005 (± 0.001); p<0.001) were significantly correlated to NT-pro-BNP, while no correlation was found with LVEF (β-coefficient 0.005 (± 0.010); p=0.587) and LV end-diastolic-volume (β-coefficient -0.003 (± 0.002); p=0.074). In control patients without PE we found a strong correlation between NT-pro-BNP levels and LVEF (β-coefficient -0.027 (± -0.006); p<0.001) although not LV end-diastolic-volume (β-coefficient 0.001 (± 0.001); p=0.418). RVEF (β-coefficient -0.002 (± -0.006); p=0.802) and RV end-diastolic-volume (β-coefficient <0.001 (± 0.001); p=0.730) were not correlated in patients without PE. In PE patients, lower RVEF and higher RV end-diastolic-volume were significantly correlated to NT-pro-BNP levels as compared to control patients without PE. These observations provide pathophysiological ground for the well-known prognostic value of NT-pro-BNP in acute PE.

Hospital Volume and 30-Day Mortality for Three Common Medical Conditions

PubMed Central

Ross, Joseph S.; Normand, Sharon-Lise T.; Wang, Yun; Ko, Dennis T.; Chen, Jersey; Drye, Elizabeth E.; Keenan, Patricia S.; Lichtman, Judith H.; Bueno, Héctor; Schreiner, Geoffrey C.; Krumholz, Harlan M.

2010-01-01

Background The association between hospital volume and the death rate for patients who are hospitalized for acute myocardial infarction, heart failure, or pneumonia remains unclear. It is also not known whether a volume threshold for such an association exists. Methods We conducted cross-sectional analyses of data from Medicare administrative claims for all fee-for-service beneficiaries who were hospitalized between 2004 and 2006 in acute care hospitals in the United States for acute myocardial infarction, heart failure, or pneumonia. Using hierarchical logistic-regression models for each condition, we estimated the change in the odds of death within 30 days associated with an increase of 100 patients in the annual hospital volume. Analyses were adjusted for patients’ risk factors and hospital characteristics. Bootstrapping procedures were used to estimate 95% confidence intervals to identify the condition-specific volume thresholds above which an increased volume was not associated with reduced mortality. Results There were 734,972 hospitalizations for acute myocardial infarction in 4128 hospitals, 1,324,287 for heart failure in 4679 hospitals, and 1,418,252 for pneumonia in 4673 hospitals. An increased hospital volume was associated with reduced 30-day mortality for all conditions (P<0.001 for all comparisons). For each condition, the association between volume and outcome was attenuated as the hospital's volume increased. For acute myocardial infarction, once the annual volume reached 610 patients (95% confidence interval [CI], 539 to 679), an increase in the hospital volume by 100 patients was no longer significantly associated with reduced odds of death. The volume threshold was 500 patients (95% CI, 433 to 566) for heart failure and 210 patients (95% CI, 142 to 284) for pneumonia. Conclusions Admission to higher-volume hospitals was associated with a reduction in mortality for acute myocardial infarction, heart failure, and pneumonia, although there was a

Ischemic Volume and Neurological Deficit: Correlation of Computed Tomography Perfusion with the National Institutes of Health Stroke Scale Score in Acute Ischemic Stroke.

PubMed

Furlanis, Giovanni; Ajčević, Miloš; Stragapede, Lara; Lugnan, Carlo; Ridolfi, Mariana; Caruso, Paola; Naccarato, Marcello; Ukmar, Maja; Manganotti, Paolo

2018-04-30

The National Institutes of Health Stroke Scale (NIHSS) is the most adopted stroke patients' evaluation tool in emergency settings to assess the severity of stroke and to determine the patients' eligibility for specific treatments. Computed tomography perfusion (CTP) is crucial to identify salvageable tissue that can benefit from the reperfusion treatment. The aim of this study is to identify the relation between the NIHSS scores and the hypoperfused volumes evaluated by CTP in patients with hyperacute ischemic stroke. This retrospective study was conducted on 105 patients with ischemic stroke who underwent NIHSS assessment and CTP in the hyperacute phase. Hypoperfused volume was evaluated by CTP maps processed with semi-automatic algorithm. An analysis was conducted to determine the degree of correlation between the NIHSS scores and the ischemic lesion volumes and to investigate the relation between the anterior and the posterior circulation strokes, as well as between the right and the left hemispheric strokes. A significant correlation was found between ischemic volume and NIHSS score at baseline (r = .82; P < .0001) in the entire cohort. A high NIHSS-volume correlation was identified in the anterior circulation stroke (r = .76; P < .0001); whereas, it was nonsignificant in the posterior circulation stroke. NIHSS score and volume correlated for the left and the right hemispheric strokes (r = .83 and .81; P < .0001), showing a slightly higher slope in the left. This study showed a strong correlation between the baseline NIHSS score and the ischemic volume estimated by CTP. We confirmed that NIHSS is a reliable predictor of perfusion deficits in acute ischemic stroke. CTP allows fast imaging assessment in the hyperacute phase. The results highlight the importance of these diagnostic tools in the assessment of stroke severity and in acute decision-making. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights

Hepatitis A viral load in relation to severity of the infection.

PubMed

Fujiwara, Keiichi; Kojima, Hiroshige; Yasui, Shin; Okitsu, Koichiro; Yonemitsu, Yutaka; Omata, Masao; Yokosuka, Osamu

2011-02-01

A correlation between hepatitis A virus (HAV) genomes and the clinical severity of hepatitis A has not been established. The viral load in sera of hepatitis A patients was examined to determine the possible association between hepatitis A severity and HAV replication. One hundred sixty-four serum samples from 91 Japanese patients with sporadic hepatitis A, comprising 11 patients with fulminant hepatitis, 10 with severe acute hepatitis, and 70 with self-limited acute hepatitis, were tested for HAV RNA. The sera included 83 serial samples from 20 patients. Viral load was measured by real-time RT-PCR. The detection rates of HAV RNA from fulminant, severe acute, and acute hepatitis were 10/11 (91%), 10/10 (100%), and 55/70 (79%), respectively. Mean values of HAV RNA at admission were 3.48 ± 1.30 logcopies/ml in fulminant, 4.19 ± 1.03 in severe acute, and 2.65 ± 1.64 in acute hepatitis. Patients with severe infection such as fulminant hepatitis and severe acute hepatitis had higher initial viral load than patients with less severe infection (P < 0.001). Viremia persisted for 14.2 ± 5.8 days in patients with severe infection and 21.4 ± 10.6 days in those with acute hepatitis after clinical onset (P = 0.19). HAV RNA was detectable quantitatively in the majority of the sera of hepatitis A cases during the early convalescent phase by real-time PCR. Higher initial viral replication was found in severely infected patients. An excessive host immune response might follow, reducing the viral load rapidly as a result of the destruction of large numbers of HAV-infected hepatocytes, and in turn severe disease might be induced. 2010 Wiley-Liss, Inc.

Dynamics of Viral and Proviral Loads of Feline Immunodeficiency Virus within the Feline Central Nervous System during the Acute Phase following Intravenous Infection

PubMed Central

Ryan, G.; Klein, D.; Knapp, E.; Hosie, M. J.; Grimes, T.; Mabruk, M. J. E. M. F.; Jarrett, O.; Callanan, J. J.

2003-01-01

Animal models of human immunodeficiency virus 1, such as feline immunodeficiency virus (FIV), provide the opportunities to dissect the mechanisms of early interactions of the virus with the central nervous system (CNS). The aims of the present study were to evaluate viral loads within CNS, cerebrospinal fluid (CSF), ocular fluid, and the plasma of cats in the first 23 weeks after intravenous inoculation with FIVGL8. Proviral loads were also determined within peripheral blood mononuclear cells (PBMCs) and brain tissue. In this acute phase of infection, virus entered the brain in the majority of animals. Virus distribution was initially in a random fashion, with more diffuse brain involvement as infection progressed. Virus in the CSF was predictive of brain parenchymal infection. While the peak of virus production in blood coincided with proliferation within brain, more sustained production appeared to continue in brain tissue. In contrast, proviral loads in the brain decreased to undetectable levels in the presence of a strengthening PBMC load. A final observation in this study was that there was no direct correlation between viral loads in regions of brain or ocular tissue and the presence of histopathology. PMID:12805447

Low-load resistance training with low relative pressure produces muscular changes similar to high-load resistance training.

PubMed

Kim, Daeyeol; Loenneke, Jeremy P; Ye, Xin; Bemben, Debra A; Beck, Travis W; Larson, Rebecca D; Bemben, Michael G

2017-12-01

This study compares the acute and chronic response of high-load resistance training (HL) to low-load resistance training with low blood flow restriction (LL-BFR) pressure. Participants completed elbow flexion with either HL or LL-BFR or nonexercise. In the chronic study, participants in the HL and LL-BFR groups were trained for 8 weeks to determine differences in muscle size and strength. The acute study examined the changes in pretesting/posttesting (Pre/Post) torque, muscle swelling, and blood lactate. In the chronic study, similar changes in muscle size and strength were observed for both HL and LL-BFR. In the acute study, Pre/Post changes in the torque, muscle swelling, and blood lactate were similar between HL and LL-BFR. Our findings indicate that pressure as low as 50% arterial occlusion can produce similar changes in muscle mass and strength compared with traditional HL. Muscle Nerve 56: E126-E133, 2017. © 2017 Wiley Periodicals, Inc.

Distinct Trajectories of Cortisol Response to Prolonged Acute Stress Are Linked to Affective Responses and Hippocampal Gray Matter Volume in Healthy Females

PubMed Central

Treadway, Michael T.; Valeri, Linda; Douglas, Samuel

2017-01-01

The development of robust laboratory procedures for acute stress induction over the last decades has greatly advanced our understanding of stress responses in humans and their underlying neurobiological mechanisms. Nevertheless, attempts to uncover linear relationships among endocrine, neural, and affective responses to stress have generally yielded inconsistent results. Here, 79 healthy females completed a well established laboratory procedure of acute stress induction that was modified to prolong its effect. Endocrinological and subjective affect assessments revealed stress-induced increases in cortisol release and negative affect that persisted 65 and 100 min after stress onset, respectively, confirming a relatively prolonged acute stress induction. Applying latent class linear mixed modeling on individuals' patterns of cortisol responses identified three distinct trajectories of cortisol response: the hyper-response (n = 10), moderate-response (n = 21), and mild-response (n = 48) groups. Notably, whereas all three groups exhibited a significant stress-induced increase in cortisol release and negative affect, the hyper-response and mild-response groups both reported more negative affect relative to the moderate-response group. Structural MRI revealed no group differences in hippocampal and amygdala volumes, yet a continuous measure of cortisol response (area under the curve) showed that high and low levels of stress-induced cortisol release were associated with less hippocampal gray matter volume compared with moderate cortisol release. Together, these results suggest that distinct trajectories of cortisol response to prolonged acute stress among healthy females may not be captured by conventional linear analyses; instead, quadratic relations may better describe links between cortisol response to stress and affective responses, as well as hippocampal structural variability. SIGNIFICANCE STATEMENT Despite substantial research, it is unclear whether and how

Distinct Trajectories of Cortisol Response to Prolonged Acute Stress Are Linked to Affective Responses and Hippocampal Gray Matter Volume in Healthy Females.

PubMed

Admon, Roee; Treadway, Michael T; Valeri, Linda; Mehta, Malavika; Douglas, Samuel; Pizzagalli, Diego A

2017-08-16

The development of robust laboratory procedures for acute stress induction over the last decades has greatly advanced our understanding of stress responses in humans and their underlying neurobiological mechanisms. Nevertheless, attempts to uncover linear relationships among endocrine, neural, and affective responses to stress have generally yielded inconsistent results. Here, 79 healthy females completed a well established laboratory procedure of acute stress induction that was modified to prolong its effect. Endocrinological and subjective affect assessments revealed stress-induced increases in cortisol release and negative affect that persisted 65 and 100 min after stress onset, respectively, confirming a relatively prolonged acute stress induction. Applying latent class linear mixed modeling on individuals' patterns of cortisol responses identified three distinct trajectories of cortisol response: the hyper-response ( n = 10), moderate-response ( n = 21), and mild-response ( n = 48) groups. Notably, whereas all three groups exhibited a significant stress-induced increase in cortisol release and negative affect, the hyper-response and mild-response groups both reported more negative affect relative to the moderate-response group. Structural MRI revealed no group differences in hippocampal and amygdala volumes, yet a continuous measure of cortisol response (area under the curve) showed that high and low levels of stress-induced cortisol release were associated with less hippocampal gray matter volume compared with moderate cortisol release. Together, these results suggest that distinct trajectories of cortisol response to prolonged acute stress among healthy females may not be captured by conventional linear analyses; instead, quadratic relations may better describe links between cortisol response to stress and affective responses, as well as hippocampal structural variability. SIGNIFICANCE STATEMENT Despite substantial research, it is unclear whether and how

Lung volume recruitment acutely increases respiratory system compliance in individuals with severe respiratory muscle weakness

PubMed Central

Molgat-Seon, Yannick; Hannan, Liam M.; Dominelli, Paolo B.; Peters, Carli M.; Fougere, Renee J.; McKim, Douglas A.; Sheel, A. William

2017-01-01

The aim of the present study was to determine whether lung volume recruitment (LVR) acutely increases respiratory system compliance (Crs) in individuals with severe respiratory muscle weakness (RMW). Individuals with RMW resulting from neuromuscular disease or quadriplegia (n=12) and healthy controls (n=12) underwent pulmonary function testing and the measurement of Crs at baseline, immediately after, 1 h after and 2 h after a single standardised session of LVR. The LVR session involved 10 consecutive supramaximal lung inflations with a manual resuscitation bag to the highest tolerable mouth pressure or a maximum of 50 cmH2O. Each LVR inflation was followed by brief breath-hold and a maximal expiration to residual volume. At baseline, individuals with RMW had lower Crs than controls (37±5 cmH2O versus 109±10 mL·cmH2O−1, p<0.001). Immediately after LVR, Crs increased by 39.5±9.8% to 50±7 mL·cmH2O−1 in individuals with RMW (p<0.05), while no significant change occurred in controls (p=0.23). At 1 h and 2 h post-treatment, there were no within-group differences in Crs compared to baseline (all p>0.05). LVR had no significant effect on measures of pulmonary function at any time point in either group (all p>0.05). During inflations, mean arterial pressure decreased significantly relative to baseline by 10.4±2.8 mmHg and 17.3±3.0 mmHg in individuals with RMW and controls, respectively (both p<0.05). LVR acutely increases Crs in individuals with RMW. However, the high airway pressures during inflations cause reductions in mean arterial pressure that should be considered when applying this technique. PMID:28326313

Changes in MR Relaxation Times of the Meniscus With Acute Loading: An In Vivo Pilot Study in Knee Osteoarthritis

PubMed Central

Subburaj, Karupppasamy; Souza, Richard B.; Wyman, Bradley T.; Le Graverand-Gastineau, Marie-Pierre Hellio; Li, Xiaojuan; Link, Thomas M.; Majumdar, Sharmila

2014-01-01

Purpose To prospectively evaluate changes in T1ρ and T2 relaxation times in the meniscal body with acute loading using MRI in osteoarthritic knees and to compare these findings with those of age-matched healthy controls. Materials and Methods Female subjects above 40 years of age with (N1 = 20) and without osteoarthritis (OA) (N2 = 10) were imaged on a 3 Tesla MR scanner using a custom made loading device. MR images were acquired, with the knee flexed at 20°, with and without a compressive load of 50% of the subject's bodyweight. The subjects were categorized based on the radiographic evidence of OA. Three different zones (outer, middle, and inner) of meniscus body were defined (each occupying 1/3rd the width). After adjusting for age and body mass index in the general linear regression model, repeated measures analysis of variance was used to detect significant differences in T1ρ and T2 with and without loading. Results In the unloaded condition, the average T1ρ and T2 times were elevated in the outer and middle zones of the medial meniscus in OA subjects compared with the controls. In the loaded condition, T1ρ and T2 times of the outer zone of the medial meniscus was significantly elevated in OA subjects compared with controls. Finally the change (from unloaded to loaded) was significantly higher in controls than OA subjects (15.1% versus 8.3%; P = 0.039 for ΔT1ρ, and 11.5% versus 6.9%, P = 0.049 for ΔT2). Conclusion These findings suggest that while the OA process appears to affect the relaxation times of all regions within the meniscus, it may affect some regions sooner or to a greater degree. Furthermore, the differences in the change in relaxation times between unloaded and loaded conditions may reveal evidence about load transmission failure of the outer zone of the medial meniscus in subjects with knee OA. It is possible that these metrics (ΔT1ρ and ΔT2) may be valuable as an early biomechanical biomarker, which could be used to predict load

Measurement of thrombus resolution using three-dimensional ultrasound assessment of deep vein thrombosis volume.

PubMed

Zhao, Limin; Prior, Steven J; Kampmann, Meghan; Sorkin, John D; Caldwell, Kevin; Braganza, Melita; McEvoy, Sue; Lal, Brajesh K

2014-04-01

Current imaging techniques are limited in their ability to quantify thrombus burden, progression, resolution, and organization over time in patients with acute deep vein thrombosis (DVT). These assessments are critical measures of therapeutic success when thrombolytic or thrombectomy treatment protocols are utilized for DVT. We evaluated the reliability of a new, commercially available method of acquiring and analyzing three-dimensional (3D) ultrasound images of DVTs that measures thrombus volume and echogenicity. We studied 25 consecutive hospital in-patients (18 male, seven female; age range, 37-87 years) with a first episode of acute DVT. Treatment decisions were not influenced by the study protocol. Scanning was performed independently by two sonographers, then the first sonographer repeated the scan. A combination of routine imaging in grayscale, color-flow, and power-Doppler modes (2D transducer) along with volumetric imaging (3D transducer) was performed. Patients underwent imaging at baseline and on one or more follow-up days 7, 14, 21 and 30. Image-processing software loaded on the ultrasound machine was used to obtain thrombus volume and echogenicity measurements. Thrombus volume was reliably determined by our protocol. The median volume of thrombus at baseline was 0.4 cm(3). Mean inter- and intraobserver differences in volume measurements were 0.006 ± 0.26 cm(3) and -0.12 ± 0.29 cm(3) (mean ± standard deviation). Thrombus resolved over time at a rate of -0.042 ± 0.01 cm(3)/day (P < .003). The median echogenicity of thrombus at baseline expressed as the grayscale median value was 59. There was a trend for thrombus organization (measured as echogenicity) to increase with time, +0.36 ± 0.23 grayscale median units/day (P < .13). Adjustment for the use of anticoagulation, gender of subject, or location of DVT in the upper vs lower extremity did not alter the relationship between time and volume or time and echogenicity. We describe a 3D

Challenges of Designing a 13-Hz High-Load Vibration Isolation System with Tight Volume Constraints: Lessons Learned and Path Forward

NASA Technical Reports Server (NTRS)

Dearing, Stella; Ruebsamen, Dale

2016-01-01

This paper describes the design of a passive isolation system using D-struts (Registered TradeMark) to isolate an optical payload from aircraft-borne jitter with challenging stroke per volume requirements. It discusses the use of viscoelastic-coated D-struts® that meet the customer performance and outgassing specification, NASA-1124. The result was a relatively soft isolation system, (where the first mode was 13 Hz), with each individual strut capable of withstanding loads on the order of magnitude of 623 N (140 lbf), weighing less than 910 g (2 lbm), fitting in a volume 5.1 cm (2 inches) in diameter and 12-cm (4.7-inches) long and capable of performing up to 1000 Hz without nonlinearities.

Influence of resistance load on neuromuscular response to vibration training.

PubMed

Luo, Jin; Clarke, Michael; McNamara, Brian; Moran, Kieran

2009-03-01

The purpose of this study was to examine the influence of resistance load on the acute and acute residual effects of vibration training, with vibration applied directly to the bicep tendon in a maximal-effort dynamic resistance exercise (3 sets of maximal-effort bicep curls). Eleven participants were exposed to 4 training conditions in random order: exercise with 1 of 2 different loads (40% 1-repetition maximum [RM] or 70% 1RM load) combined with 1 of 2 vibration conditions (vibration [1.2 mm, 65 Hz] or sham vibration). Five minutes before and after the exercise, a set of maximal-effort bicep curls with a load of either 40 or 70% 1RM was performed as the pre- and posttraining test. Concentric elbow joint angular velocity, moment and power, and bicep root mean square electromyography (EMGrms) were measured during training and in the pre- and posttraining tests. The results show that during training (acute effect) and at 5 minutes after training (acute residual effect), vibration did not induce a significant change in EMGrms, mean and peak angular velocities, moment and power, time to peak power, and initial power at 100 milliseconds after the start of the concentric phase for either resistance load. Therefore, in aiming to train neuromuscular output using maximal-effort dynamic contractions (40 and 70% 1RM), there is no benefit in employing direct vibration, at least with a 1.2-mm amplitude and 65-Hz frequency. However, the amplitude of 1.2 mm may be too high to effectively stimulate neuromuscular output in maximal-effort dynamic contractions per se.

Can mean platelet volume and neutrophil-to-lymphocyte ratio be biomarkers of acute exacerbation of bronchiectasis in children?

PubMed Central

Erdem, Semiha Bahceci; Karaman, Sait; Yazici, Selcuk; Can, Demet

2017-01-01

Introduction Bronchiectasis (BE) is a parenchymal lung disease evolving as a result of recurrent lung infections and chronic inflammation. Although it has been shown in adult studies that mean platelet volume (MPV) and neutrophil-to-lymphocyte ratio (NLR) can be used as biomarkers of airway inflammation, knowledge is limited in the paediatric age group. The aim of our study is to investigate the potential of MPV and NLR as biomarkers that may indicate acute exacerbations of non-cystic fibrosis BE in children. Material and methods Children with non-cystic fibrosis BE (n = 50), who were followed in the division of Paediatric Pulmonology of our hospital between June 2010 and July 2015, were involved in the present retrospective cross-sectional study. Haemogram values during acute exacerbations and non-exacerbation periods, and a control group were compared. Results In children with bronchiectasis, the average leukocyte count (p < 0.001), platelet count (p = 0.018), absolute neutrophil count (p < 0.001), and NLR (p < 0.001) were higher, as expected, when compared with the control group. NLR values, in the period of acute exacerbation were significantly higher than the values of both the non-exacerbation periods (p = 0.02) and the control group (p < 0.001). In contrast, MPV values in the period of acute exacerbation did not exhibit a significant difference from those of non-exacerbation periods (p = 0.530) and the control group (p = 0.103). Conclusions It was concluded that leukocyte count, platelet count, absolute neutrophil count, and NLR can be used to show chronic inflammation in BE, but only NLR and absolute neutrophil count can be used as biomarkers to show acute exacerbations. PMID:29472813

Convection enhanced delivery of panobinostat (LBH589)-loaded pluronic nano-micelles prolongs survival in the F98 rat glioma model

PubMed Central

Singleton, WG; Collins, AM; Bienemann, AS; Killick-Cole, CL; Haynes, HR; Asby, DJ; Butts, CP; Wyatt, MJ; Barua, NU; Gill, SS

2017-01-01

Background The pan-histone deacetylase inhibitor panobinostat is a potential therapy for malignant glioma, but it is water insoluble and does not cross the blood–brain barrier when administered systemically. In this article, we describe the in vitro and in vivo efficacy of a novel water-soluble nano-micellar formulation of panobinostat designed for administration by convection enhanced delivery (CED). Materials and methods The in vitro efficacy of panobinostat-loaded nano-micelles against rat F98, human U87-MG and M059K glioma cells and against patient-derived glioma stem cells was measured using a cell viability assay. Nano-micelle distribution in rat brain was analyzed following acute CED using rhodamine-labeled nano-micelles, and toxicity was assayed using immunofluorescent microscopy and synaptophysin enzyme-linked immunosorbent assay. We compared the survival of the bioluminescent syngenic F98/Fischer344 rat glioblastoma model treated by acute CED of panobinostat-loaded nano-micelles with that of untreated and vehicle-only-treated controls. Results Nano-micellar panobinostat is cytotoxic to rat and human glioma cells in vitro in a dose-dependent manner following short-time exposure to drug. Fluorescent rhodamine-labelled nano-micelles distribute with a volume of infusion/volume of distribution (Vi/Vd) ratio of four and five respectively after administration by CED. Administration was not associated with any toxicity when compared to controls. CED of panobinostat-loaded nano-micelles was associated with significantly improved survival when compared to controls (n=8 per group; log-rank test, P<0.001). One hundred percent of treated animals survived the 60-day experimental period and had tumour response on post-mortem histological examination. Conclusion CED of nano-micellar panobinostat represents a potential novel therapeutic option for malignant glioma and warrants translation into the clinic. PMID:28260886

Convection enhanced delivery of panobinostat (LBH589)-loaded pluronic nano-micelles prolongs survival in the F98 rat glioma model.

PubMed

Singleton, W G; Collins, A M; Bienemann, A S; Killick-Cole, C L; Haynes, H R; Asby, D J; Butts, C P; Wyatt, M J; Barua, N U; Gill, S S

2017-01-01

The pan-histone deacetylase inhibitor panobinostat is a potential therapy for malignant glioma, but it is water insoluble and does not cross the blood-brain barrier when administered systemically. In this article, we describe the in vitro and in vivo efficacy of a novel water-soluble nano-micellar formulation of panobinostat designed for administration by convection enhanced delivery (CED). The in vitro efficacy of panobinostat-loaded nano-micelles against rat F98, human U87-MG and M059K glioma cells and against patient-derived glioma stem cells was measured using a cell viability assay. Nano-micelle distribution in rat brain was analyzed following acute CED using rhodamine-labeled nano-micelles, and toxicity was assayed using immunofluorescent microscopy and synaptophysin enzyme-linked immunosorbent assay. We compared the survival of the bioluminescent syngenic F98/Fischer344 rat glioblastoma model treated by acute CED of panobinostat-loaded nano-micelles with that of untreated and vehicle-only-treated controls. Nano-micellar panobinostat is cytotoxic to rat and human glioma cells in vitro in a dose-dependent manner following short-time exposure to drug. Fluorescent rhodamine-labelled nano-micelles distribute with a volume of infusion/volume of distribution (Vi/Vd) ratio of four and five respectively after administration by CED. Administration was not associated with any toxicity when compared to controls. CED of panobinostat-loaded nano-micelles was associated with significantly improved survival when compared to controls (n=8 per group; log-rank test, P <0.001). One hundred percent of treated animals survived the 60-day experimental period and had tumour response on post-mortem histological examination. CED of nano-micellar panobinostat represents a potential novel therapeutic option for malignant glioma and warrants translation into the clinic.

Acute small bowel toxicity and preoperative chemoradiotherapy for rectal cancer: Investigating dose-volume relationships and role for inverse planning

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

Tho, Lye Mun; Glegg, Martin; Paterson, Jennifer

2006-10-01

Purpose: The relationship between volume of irradiated small bowel (VSB) and acute toxicity in rectal cancer radiotherapy is poorly quantified, particularly in patients receiving concurrent preoperative chemoradiotherapy. Using treatment planning data, we studied a series of such patients. Methods and Materials: Details of 41 patients with locally advanced rectal cancer were reviewed. All received 45 Gy in 25 fractions over 5 weeks, 3-4 fields three-dimensional conformal radiotherapy with daily 5-fluorouracil and folinic acid during Weeks 1 and 5. Toxicity was assessed prospectively in a weekly clinic. Using computed tomography planning software, the VSB was determined at 5 Gy dose intervalsmore » (V{sub 5}, V{sub 1}, etc.). Eight patients with maximal VSB had dosimetry and radiobiological modeling outcomes compared between inverse and conformal three-dimensional planning. Results: VSB correlated strongly with diarrheal severity at every dose level (p < 0.03), with strongest correlation at lowest doses. Median VSB differed significantly between patients experiencing Grade 0-1 and Grade 2-4 diarrhea (p {<=} 0.05). No correlation was found with anorexia, nausea, vomiting, abdominal cramps, age, body mass index, sex, tumor position, or number of fields. Analysis of 8 patients showed that inverse planning reduced median dose to small bowel by 5.1 Gy (p = 0.008) and calculated late normal tissue complication probability (NTCP) by 67% (p = 0.016). We constructed a model using mathematical analysis to predict for acute diarrhea occurring at V{sub 5} and V{sub 15}. Conclusions: A strong dose-volume relationship exists between VSB and acute diarrhea at all dose levels during preoperative chemoradiotherapy. Our constructed model may be useful in predicting toxicity, and this has been derived without the confounding influence of surgical excision on bowel function. Inverse planning can reduce calculated dose to small bowel and late NTCP, and its clinical role warrants

Acute decrease of left ventricular mechanical dyssynchrony and improvement of contractile state and energy efficiency after left ventricular restoration.

PubMed

Schreuder, Jan J; Castiglioni, Alessandro; Maisano, Francesco; Steendijk, Paul; Donelli, Andrea; Baan, Jan; Alfieri, Ottavio

2005-01-01

Surgical left ventricular restoration by means of endoventricular patch aneurysmectomy in patients with postinfarction aneurysm should result in acute improved left ventricular performance by decreasing mechanical dyssynchrony and increasing energy efficiency. Nine patients with left ventricular postinfarction aneurysm were studied intraoperatively before and after ventricular restoration with a conductance volume catheter to analyze pressure-volume relationships, energy efficiency, and mechanical dyssynchrony. The end-systolic elastance was used as a load-independent index of contractile state. Left ventricular energy efficiency was calculated from stroke work and total pressure-volume area. Segmental volume changes perpendicular to the long axis were used to calculate mechanical dyssynchrony. Statistical analysis was performed with the paired t test and least-squares linear regression. Endoventricular patch aneurysmectomy reduced end-diastolic volume by 37% (P < .001), with unchanged stroke volume. Systolic function improved, as derived from increased +dP/dt(max), by 42% (P < .03), peak ejection rate by 28% (P < .02), and ejection fraction by 16% (P < .0002). Early diastolic function improved, as shown by reduction of -dP/dt(max) by 34% (P < .006) and shortened tau by 30% (P < .001). Left ventricular end-systolic elastance increased from 1.2 +/- 0.6 to 2.2 +/- 1 mm Hg/mL (P < .001). Left ventricular energy efficiency increased by 36% (P < .002). Left ventricular mechanical dyssynchrony decreased during systole by 33% (P < .001) and during diastole by 20% (P < .005). Left ventricular restoration induced acute improvements in contractile state, energy efficiency, and relaxation, together with a decrease in left ventricular mechanical dyssynchrony.

Noninvasive, targeted gene therapy for acute spinal cord injury using LIFU-mediated BDNF-loaded cationic nanobubble destruction.

PubMed

Song, Zhaojun; Ye, Yongjie; Zhang, Zhi; Shen, Jieliang; Hu, Zhenming; Wang, Zhigang; Zheng, Jiazhuang

2018-02-12

Various gene delivery systems have been widely studied for the acute spinal cord injury (SCI) treatment. In the present study, a novel type of brain-derived neurotrophic factor (BDNF)-loaded cationic nanobubbles (CNBs) conjugated with MAP-2 antibody (mAb MAP-2 /BDNF/CNBs) was prepared to provide low-intensity focused ultrasound (LIFU)-targeted gene therapy. In vitro experiments, the ultrasound-targeted tranfection to BDNF overexpressioin in neurons and efficiently inhibition neuronal apoptosis have been demonstrated, and the elaborately designed mAb MAP-2 /BDNF/CNBs can specifically target to the neurons. Furthermore, in a acute SCI rat model, LIFU-mediated mAb MAP-2 /BDNF/CNBs transfection significantly increased BDNF expression, attenuated histological injury, decreased neurons loss, inhibited neuronal apoptosis in injured spinal cords, and increased BBB scores in SCI rats. LIFU-mediated mAb MAP-2 /BDNF/CNBs destruction significantly increase transfection efficiency of BDNF gene both in vitro and in vivo, and has a significant neuroprotective effect on the injured spinal cord. Therefore, the combination of LIFU irradiation and gene therapy through mAb MAP-2 /BDNF/CNBs can be considered as a novel non-invasive and targeted treatment for gene therapy of SCI. Copyright © 2018 Elsevier Inc. All rights reserved.

Diagnostic value of mean platelet volume (MPV) to troponin T inpatients with acute coronary syndrome

NASA Astrophysics Data System (ADS)

Aryanto, D.; Isnanta, R.; Safri, Z.; Hasan, R.

2018-03-01

Acute Coronary Syndrome (ACS) is used to describe the spectrum of coronary artery disease (CAD). Troponin T is the determinant of the most sensitive marker of ACS, but there aren’t all hospitals have this because of expensiveness. Mean Platelet Volume (MPV) is one of the components of a complete blood routine examination and relatively cheap as a marker in ACS. Determining the sensitivity and specificity of MPV in detecting cases of the acute coronary syndrome, 325 subjects’ medical records were from the period of July 2013 to June 2014; 228 ACS patients met the inclusion criteria. 228 subjects showed a risk factor for age ≥45years of more 195 (85.5%). 122 subjects with hypertension (53.5%) and subjects who smoked 118 (51.8%) that suffered most ACS. Subjects with risk factors for diabetes mellitus, obesity, menopause and dyslipidemia in this study was lower than non-diabetic 161 (70.6%), obese189 (82.9%), nonmenopause 196 (86%) and normal lipid 210 (92.1%). But there was norelation between risk factor with MPV and troponin T statistically. The results of diagnostic tests MPV for the evaluation of patients with ACS, sensitivity 92%, specificity 71%, positive predictive value 95% and negative predictive value 58%.

Effect of different seated positions on lung volume and oxygenation in acute respiratory distress syndrome.

PubMed

Dellamonica, J; Lerolle, N; Sargentini, C; Hubert, S; Beduneau, G; Di Marco, F; Mercat, A; Diehl, J L; Richard, J C M; Bernardin, G; Brochard, L

2013-06-01

Lung volume available for ventilation is markedly decreased during acute respiratory distress syndrome. Body positioning may contribute to increase lung volume and partial verticalization is simple to perform. This study evaluated whether verticalization had parallel effects on oxygenation and end expiratory lung volume (EELV). Prospective multicenter study in 40 mechanically ventilated patients with ALI/ARDS in five university hospital MICUs. We evaluated four 45-min successive trunk position epochs (supine slightly elevated at 15°; semi recumbent with trunk elevated at 45°; seated with trunk elevated at 60° and legs down at 45°; back to supine). Arterial blood gases, EELV measured using the nitrogen washin/washout, and static compliance were measured. Responders were defined by a PaO₂/FiO₂ increase >20 % between supine and seated position. Results are median [25th-75th percentiles]. With median PEEP = 10 cmH₂O, verticalization increased lung volume but only responders (13 patients, 32 %) had a significant increase in EELV/PBW (predicted body weight) compared to baseline. This increase persisted at least partially when patients were positioned back to supine. Responders had a lower EELV/PBW supine [14 mL/kg (13-15) vs. 18 mL/kg (15-27) (p = 0.005)] and a lower compliance [30 mL/cmH₂O (22-38) vs. 42 (30-46) (p = 0.01)] than non-responders. Strain decreased with verticalization for responders. EELV/PBW increase and PaO₂/FiO₂ increase were not correlated. Verticalization is easily achieved and improves oxygenation in approximately 32 % of the patients together with an increase in EELV. Nonetheless, effect of verticalization on EELV/PBW is not predictable by PaO₂/FiO₂ increase, its monitoring may be helpful for strain optimization.

Meta-Analysis of Ultrafiltration versus Diuretics Treatment Option for Overload Volume Reduction in Patients with Acute Decompensated Heart Failure.

PubMed

Barkoudah, Ebrahim; Kodali, Sindhura; Okoroh, Juliet; Sethi, Rosh; Hulten, Edward; Suemoto, Claudia; Bittencourt, Marcio Sommer

2015-05-01

Although diuretics are mainly used for the treatment of acute decompensated heart failure (ADHF), inadequate responses and complications have led to the use of extracorporeal ultrafiltration (UF) as an alternative strategy for reducing volume overloads in patients with ADHF. The aim of our study is to perform meta-analysis of the results obtained from studies on extracorporeal venous ultrafiltration and compare them with those of standard diuretic treatment for overload volume reduction in acute decompensated heart failure. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials databases were systematically searched using a pre‑specified criterion. Pooled estimates of outcomes after 48 h (weight change, serum creatinine level, and all-cause mortality) were computed using random effect models. Pooled weighted mean differences were calculated for weight loss and change in creatinine level, whereas a pooled risk ratio was used for the analysis of binary all-cause mortality outcome. A total of nine studies, involving 613 patients, met the eligibility criteria. The mean weight loss in patients who underwent UF therapy was 1.78 kg [95% Confidence Interval (CI): -2.65 to -0.91 kg; p < 0.001) more than those who received standard diuretic therapy. The post-intervention creatinine level, however, was not significantly different (mean change = -0.25 mg/dL; 95% CI: -0.56 to 0.06 mg/dL; p = 0.112). The risk of all-cause mortality persisted in patients treated with UF compared with patients treated with standard diuretics (Pooled RR = 1.00; 95% CI: 0.64-1.56; p = 0.993). Compared with standard diuretic therapy, UF treatment for overload volume reduction in individuals suffering from ADHF, resulted in significant reduction of body weight within 48 h. However, no significant decrease of serum creatinine level or reduction of all-cause mortality was observed.

Meta-Analysis of Ultrafiltration versus Diuretics Treatment Option for Overload Volume Reduction in Patients with Acute Decompensated Heart Failure

PubMed Central

Barkoudah, Ebrahim; Kodali, Sindhura; Okoroh, Juliet; Sethi, Rosh; Hulten, Edward; Suemoto, Claudia; Bittencourt, Marcio Sommer

2015-01-01

Introduction Although diuretics are mainly used for the treatment of acute decompensated heart failure (ADHF), inadequate responses and complications have led to the use of extracorporeal ultrafiltration (UF) as an alternative strategy for reducing volume overloads in patients with ADHF. Objective The aim of our study is to perform meta-analysis of the results obtained from studies on extracorporeal venous ultrafiltration and compare them with those of standard diuretic treatment for overload volume reduction in acute decompensated heart failure. Methods MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials databases were systematically searched using a pre‑specified criterion. Pooled estimates of outcomes after 48 h (weight change, serum creatinine level, and all-cause mortality) were computed using random effect models. Pooled weighted mean differences were calculated for weight loss and change in creatinine level, whereas a pooled risk ratio was used for the analysis of binary all-cause mortality outcome. Results A total of nine studies, involving 613 patients, met the eligibility criteria. The mean weight loss in patients who underwent UF therapy was 1.78 kg [95% Confidence Interval (CI): −2.65 to −0.91 kg; p < 0.001) more than those who received standard diuretic therapy. The post-intervention creatinine level, however, was not significantly different (mean change = −0.25 mg/dL; 95% CI: −0.56 to 0.06 mg/dL; p = 0.112). The risk of all-cause mortality persisted in patients treated with UF compared with patients treated with standard diuretics (Pooled RR = 1.00; 95% CI: 0.64–1.56; p = 0.993). Conclusion Compared with standard diuretic therapy, UF treatment for overload volume reduction in individuals suffering from ADHF, resulted in significant reduction of body weight within 48 h. However, no significant decrease of serum creatinine level or reduction of all-cause mortality was observed. PMID:25626761

Dynamic Patterns of Forces and Loading Rate in Runners with Unilateral Plantar Fasciitis: A Cross-Sectional Study

PubMed Central

Ribeiro, Ana Paula; João, Silvia Maria Amado; Dinato, Roberto Casanova; Tessutti, Vitor Daniel; Sacco, Isabel Camargo Neves

2015-01-01

Aim/Hypothesis The etiology of plantar fasciitis (PF) has been related to several risk factors, but the magnitude of the plantar load is the most commonly described factor. Although PF is the third most-common injury in runners, only two studies have investigated this factor in runners, and their results are still inconclusive regarding the injury stage. Objective Analyze and compare the plantar loads and vertical loading rate during running of runners in the acute stage of PF to those in the chronic stage of the injury in relation to healthy runners. Methods Forty-five runners with unilateral PF (30 acute and 15 chronic) and 30 healthy control runners were evaluated while running at 12 km/h for 40 meters wearing standardized running shoes and Pedar-X insoles. The contact area and time, maximum force, and force-time integral over the rearfoot, midfoot, and forefoot were recorded and the loading rate (20–80% of the first vertical peak) was calculated. Groups were compared by ANOVAs (p<0.05). Results Maximum force and force-time integral over the rearfoot and the loading rate was higher in runners with PF (acute and chronic) compared with controls (p<0.01). Runners with PF in the acute stage showed lower loading rate and maximum force over the rearfoot compared to runners in the chronic stage (p<0.01). Conclusion Runners with PF showed different dynamic patterns of plantar loads during running over the rearfoot area depending on the injury stage (acute or chronic). In the acute stage of PF, runners presented lower loading rate and forces over the rearfoot, possibly due to dynamic mechanisms related to pain protection of the calcaneal area. PMID:26375815

Pre-operative renal volume predicts peak creatinine after congenital heart surgery in neonates.

PubMed

Carmody, J Bryan; Seckeler, Michael D; Ballengee, Cortney R; Conaway, Mark; Jayakumar, K Anitha; Charlton, Jennifer R

2014-10-01

Acute kidney injury is common in neonates following surgery for congenital heart disease. We conducted a retrospective analysis to determine whether neonates with smaller pre-operative renal volume were more likely to develop post-operative acute kidney injury. We conducted a retrospective review of 72 neonates who underwent congenital heart surgery for any lesion other than patent ductus arteriosus at our institution from January 2007 to December 2011. Renal volume was calculated by ultrasound using the prolate ellipsoid formula. The presence and severity of post-operative acute kidney injury was determined both by measuring the peak serum creatinine in the first 7 days post-operatively and by using the Acute Kidney Injury Network scoring system. Using a linear change point model, a threshold renal volume of 17 cm³ was identified. Below this threshold, there was an inverse linear relationship between renal volume and peak post-operative creatinine for all patients (p = 0.036) and the subgroup with a single morphologic right ventricle (p = 0.046). There was a non-significant trend towards more acute kidney injury using Acute Kidney Injury Network criteria in all neonates with renal volume ≤17 cm³ (p = 0.11) and in the subgroup with a single morphologic right ventricle (p = 0.17). Pre-operative renal volume ≤17 cm³ is associated with a higher peak post-operative creatinine and potentially greater risk for post-operative acute kidney injury for neonates undergoing congenital heart surgery. Neonates with a single right ventricle may be at higher risk.

In vivo dynamic stiffness of the porcine lumbar spine exposed to cyclic loading: influence of load and degeneration.

PubMed

Kaigle, A; Ekström, L; Holm, S; Rostedt, M; Hansson, T

1998-02-01

The dynamic axial stiffness of the L2-3 motion segment subjected to vibratory loading under intact and injured states of the intervertebral disc was studied using an in vivo porcine model. Three groups of animals with the following states of the intervertebral discs were studied: intact disc, acutely injured disc, and degenerated disc. A miniaturized servo-hydraulic exciter was used to sinusoidally vibrate the motion segment from 0.05 to 25 Hz under a compressive load with a peak value of either 100 or 200 N. The dynamic axial stiffness of the intervertebral disc was calculated at 1-Hz intervals over the frequency range. The results showed that the dynamic axial stiffness was frequency dependent. A positive relationship was found between an increase in mean dynamic stiffness and load magnitude. An increase in mean stiffness with successive exposures at the same load magnitude was observed, despite the allowance of a recovery period between loading. The greatest difference was noted between the first and second load sets. No significant change in stiffness was found due to an acute disc injury, whereas a significant increase in mean stiffness was found for the degenerated disc group as compared with the intact group. The form of the frequency response curve, however, remained relatively unaltered regardless of the degenerated state of the disc. With heavier loads, repeated loading, and/or disc degeneration, the stiffness of the intervertebral disc increases. An increase in stiffness can mean a reduction in the amount of allowable motion within the motion segment or a potentially harmful increase in force to obtain the desired motion. This may locally result in greater stresses due to an altered ability of the disc to distribute loads.

Evaluation of pollutant loads from stormwater BMPs to receiving water using load frequency curves with uncertainty analysis.

PubMed

Park, Daeryong; Roesner, Larry A

2012-12-15

This study examined pollutant loads released to receiving water from a typical urban watershed in the Los Angeles (LA) Basin of California by applying a best management practice (BMP) performance model that includes uncertainty. This BMP performance model uses the k-C model and incorporates uncertainty analysis and the first-order second-moment (FOSM) method to assess the effectiveness of BMPs for removing stormwater pollutants. Uncertainties were considered for the influent event mean concentration (EMC) and the aerial removal rate constant of the k-C model. The storage treatment overflow and runoff model (STORM) was used to simulate the flow volume from watershed, the bypass flow volume and the flow volume that passes through the BMP. Detention basins and total suspended solids (TSS) were chosen as representatives of stormwater BMP and pollutant, respectively. This paper applies load frequency curves (LFCs), which replace the exceedance percentage with an exceedance frequency as an alternative to load duration curves (LDCs), to evaluate the effectiveness of BMPs. An evaluation method based on uncertainty analysis is suggested because it applies a water quality standard exceedance based on frequency and magnitude. As a result, the incorporation of uncertainty in the estimates of pollutant loads can assist stormwater managers in determining the degree of total daily maximum load (TMDL) compliance that could be expected from a given BMP in a watershed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Real-time volume rendering of 4D image using 3D texture mapping

NASA Astrophysics Data System (ADS)

Hwang, Jinwoo; Kim, June-Sic; Kim, Jae Seok; Kim, In Young; Kim, Sun Il

2001-05-01

Four dimensional image is 3D volume data that varies with time. It is used to express deforming or moving object in virtual surgery of 4D ultrasound. It is difficult to render 4D image by conventional ray-casting or shear-warp factorization methods because of their time-consuming rendering time or pre-processing stage whenever the volume data are changed. Even 3D texture mapping is used, repeated volume loading is also time-consuming in 4D image rendering. In this study, we propose a method to reduce data loading time using coherence between currently loaded volume and previously loaded volume in order to achieve real time rendering based on 3D texture mapping. Volume data are divided into small bricks and each brick being loaded is tested for similarity to one which was already loaded in memory. If the brick passed the test, it is defined as 3D texture by OpenGL functions. Later, the texture slices of the brick are mapped into polygons and blended by OpenGL blending functions. All bricks undergo this test. Continuously deforming fifty volumes are rendered in interactive time with SGI ONYX. Real-time volume rendering based on 3D texture mapping is currently available on PC.

Effects of cannabis and familial loading on subcortical brain volumes in first-episode schizophrenia.

PubMed

Malchow, Berend; Hasan, Alkomiet; Schneider-Axmann, Thomas; Jatzko, Alexander; Gruber, Oliver; Schmitt, Andrea; Falkai, Peter; Wobrock, Thomas

2013-11-01

Schizophrenia is a severe neuropsychiatric disorder with familial loading as heritable risk factor and cannabis abuse as the most relevant environmental risk factor up to date. Cannabis abuse has been related to an earlier onset of the disease and persisting cannabis consumption is associated with reduced symptom improvement. However, the underlying morphological and biochemical brain alterations due to these risk factors as well as the effects of gene-environmental interaction are still unclear. In this magnetic resonance imaging (MRI) study in 47 first-episode schizophrenia patients and 30 healthy control subjects, we investigated effects of previous cannabis abuse and increased familial risk on subcortical brain regions such as hippocampus, amygdala, caudate nucleus, putamen, thalamus and subsegments of the corpus callosum (CC). In a subsequent single-volume (1)H-magnetic resonance spectroscopy study, we investigated spectra in the left hippocampus and putamen to detect metabolic alterations. Compared to healthy controls, schizophrenia patients displayed decreased volumes of the left hippocampus, bilateral amygdala and caudate nucleus as well as an increased area of the midsagittal CC1 segment of the corpus callosum. Patients fulfilling the criteria for cannabis abuse at admission showed an increased area of the CC2 segment compared to those who did not fulfill the criteria. Patients with a family history of schizophrenia combined with previous cannabis abuse showed lower volumes of the bilateral caudate nucleus compared to all other patients, implicating an interaction between the genetic background and cannabis abuse as environmental factor. Patients with cannabis abuse also had higher ratios of N-acetyl aspartate/choline in the left putamen, suggesting a possible neuroprotective effect in this area. However, antipsychotic medication prior to MRI acquisition and gender effects may have influenced our results. Future longitudinal studies in first

Acute Effects of Elastic Bands on Kinetic Characteristics During the Deadlift at Moderate and Heavy Loads.

PubMed

Galpin, Andrew J; Malyszek, Kylie K; Davis, Kyle A; Record, Shaina M; Brown, Lee E; Coburn, Jared W; Harmon, RoQue A; Steele, Jeff M; Manolovitz, Adam D

2015-12-01

Loading a barbell with variable resistance positively alters kinetic characteristics during the back squat and bench press but has never been studied during the deadlift. The purpose of this project was to examine the acute effects of combining elastic bands and free weights during the deadlift at moderate and heavy loads. Twelve trained men (age: 24.08 ± 2.35 years, height: 175.94 ± 5.38 cm, mass: 85.58 ± 12.49 kg, deadlift 1 repetition maximum (RM): 188.64 ± 16.13 kg) completed 2 variable resistance (B1 and B2) and 1 traditional free-weight (NB) condition at both 60 and 85% 1RM on a force plate. B1 had 15% resistance from bands, with the remaining 85% from free weights. B2 had 35% bands and 65% free weights. NB used free weights only. Average resistance was equated for all conditions. Power and velocity generally increased, whereas force decreased with the addition of bands. The amount of band tension (B1 or B2) had little impact on power when lifting at 60% 1RM. However, greater resistance from bands resulted in greater peak and relative power when lifting at 85% 1RM. Adding elastic bands decreased time to peak force (PF), time between PF and peak power (PP), and time between PF and peak velocity (PV) when compared with NB at 60% 1RM (NB > B1 > B2). These differences only reached significance for NB > B2 when lifting at 85% 1RM. These same differences existed for time between PP and PV. Thus, the amount of tension from bands has less impact on interpeak variables at heavier absolute loads. Practitioners should consider using heavy bands when prescribing the deadlift for speed or power, but not maximal force.

Load Bearing Equipment for Bone and Muscle

NASA Technical Reports Server (NTRS)

Shackelford, Linda; Griffith, Bryan

2015-01-01

Resistance exercise on ISS has proven effective in maintaining bone mineral density and muscle mass. Exploration missions require exercise with similar high loads using equipment with less mass and volume and greater safety and reliability than resistance exercise equipment used on ISS (iRED, ARED, FWED). Load Bearing Equipment (LBE) uses each exercising person to create and control the load to the partner.

Clinical characteristics and viral load of respiratory syncytial virus and human metapneumovirus in children hospitaled for acute lower respiratory tract infection.

PubMed

Yan, Xiao-Li; Li, Yu-Ning; Tang, Yi-Jie; Xie, Zhi-Ping; Gao, Han-Chun; Yang, Xue-Mei; Li, Yu-Mei; Liu, Li-Jun; Duan, Zhao-Jun

2017-04-01

Respiratory syncytial virus (RSV) and human metapneumovirus (HMPV) are two common viral pathogens in acute lower respiratory tract infections (ALRTI). However, the association of viral load with clinical characteristics is not well-defined in ALRTI. To explore the correlation between viral load and clinical characteristics of RSV and HMPV in children hospitalized for ALRTI in Lanzhou, China. Three hundred and eighty-seven children hospitalized for ALRTI were enrolled. Nasopharyngeal aspirates (NPAs) were sampled from each children. Real-time PCR was used to screen RSV, HMPV, and twelve additional respiratory viruses. Bronchiolitis was the leading diagnoses both in RSV and HMPV positive patients. A significantly greater frequency of wheezing (52% vs. 33.52%, P = 0.000) was noted in RSV positive and negative patients. The RSV viral load was significant higher in children aged <1 year (P = 0.003), children without fever and wheezing (P = 0.015 and P = 0.000), days of illness <14 days (P = 0.002), children with bronchiolitis (P = 0.012) and children with RSV single infections (P = 0.000). No difference was found in the clinical features of HMPV positive and negative patients. The HMPV viral load had no correlation with any clinical characteristics. The incidences of severe disease were similar between single infection and coinfection for the two viruses (RSV, P = 0.221; HMPV, P = 0.764) and there has no statistical significance between severity and viral load (P = 0.166 and P = 0.721). Bronchiolitis is the most common disease caused by RSV and HMPV. High viral load or co-infection may be associated with some symptoms but neither has a significant impact on disease severity for the two viruses. J. Med. Virol. 89:589-597, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Dose-Volume Effects on Patient-Reported Acute Gastrointestinal Symptoms During Chemoradiation Therapy for Rectal Cancer

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

Chen, Ronald C.; Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts

2012-07-15

Purpose: Research on patient-reported outcomes (PROs) in rectal cancer is limited. We examined whether dose-volume parameters of the small bowel and large bowel were associated with patient-reported gastrointestinal (GI) symptoms during 5-fluorouracil (5-FU)-based chemoradiation treatment for rectal cancer. Methods and Materials: 66 patients treated at the Brigham and Women's Hospital or Massachusetts General Hospital between 2006 and 2008 were included. Weekly during treatment, patients completed a questionnaire assessing severity of diarrhea, urgency, pain, cramping, mucus, and tenesmus. The association between dosimetric parameters and changes in overall GI symptoms from baseline through treatment was examined by using Spearman's correlation. Potential associationsmore » between these parameters and individual GI symptoms were also explored. Results: The amount of small bowel receiving at least 15 Gy (V15) was significantly associated with acute symptoms (p = 0.01), and other dosimetric parameters ranging from V5 to V45 also trended toward association. For the large bowel, correlations between dosimetric parameters and overall GI symptoms at the higher dose levels from V25 to V45 did not reach statistical significance (p = 0.1), and a significant association was seen with rectal pain from V15 to V45 (p < 0.01). Other individual symptoms did not correlate with small bowel or large bowel dosimetric parameters. Conclusions: The results of this study using PROs are consistent with prior studies with physician-assessed acute toxicity, and they identify small bowel V15 as an important predictor of acute GI symptoms during 5-FU-based chemoradiation treatment. A better understanding of the relationship between radiation dosimetric parameters and PROs may allow physicians to improve radiation planning to optimize patient outcomes.« less

Empirical Model Development for Predicting Shock Response on Composite Materials Subjected to Pyroshock Loading. Volume 2, Part 1; Appendices

NASA Technical Reports Server (NTRS)

Gentz, Steven J.; Ordway, David O.; Parsons, David S.; Garrison, Craig M.; Rodgers, C. Steven; Collins, Brian W.

2015-01-01

The NASA Engineering and Safety Center (NESC) received a request to develop an analysis model based on both frequency response and wave propagation analyses for predicting shock response spectrum (SRS) on composite materials subjected to pyroshock loading. The model would account for near-field environment (approximately 9 inches from the source) dominated by direct wave propagation, mid-field environment (approximately 2 feet from the source) characterized by wave propagation and structural resonances, and far-field environment dominated by lower frequency bending waves in the structure. This document contains appendices to the Volume I report.

Poor Adherence to Lung-Protective Mechanical Ventilation in Pediatric Acute Respiratory Distress Syndrome.

PubMed

Ward, Shan L; Quinn, Carson M; Valentine, Stacey L; Sapru, Anil; Curley, Martha A Q; Willson, Douglas F; Liu, Kathleen D; Matthay, Michael A; Flori, Heidi R

2016-10-01

To determine the frequency of low-tidal volume ventilation in pediatric acute respiratory distress syndrome and assess if any demographic or clinical factors improve low-tidal volume ventilation adherence. Descriptive post hoc analysis of four multicenter pediatric acute respiratory distress syndrome studies. Twenty-six academic PICU. Three hundred fifteen pediatric acute respiratory distress syndrome patients. All patients who received conventional mechanical ventilation at hours 0 and 24 of pediatric acute respiratory distress syndrome who had data to calculate ideal body weight were included. Two cutoff points for low-tidal volume ventilation were assessed: less than or equal to 6.5 mL/kg of ideal body weight and less than or equal to 8 mL/kg of ideal body weight. Of 555 patients, we excluded 240 for other respiratory support modes or missing data. The remaining 315 patients had a median PaO2-to-FIO2 ratio of 140 (interquartile range, 90-201), and there were no differences in demographics between those who did and did not receive low-tidal volume ventilation. With tidal volume cutoff of less than or equal to 6.5 mL/kg of ideal body weight, the adherence rate was 32% at hour 0 and 33% at hour 24. A low-tidal volume ventilation cutoff of tidal volume less than or equal to 8 mL/kg of ideal body weight resulted in an adherence rate of 58% at hour 0 and 60% at hour 24. Low-tidal volume ventilation use was no different by severity of pediatric acute respiratory distress syndrome nor did adherence improve over time. At hour 0, overweight children were less likely to receive low-tidal volume ventilation less than or equal to 6.5 mL/kg ideal body weight (11% overweight vs 38% nonoverweight; p = 0.02); no difference was noted by hour 24. Furthermore, in the overweight group, using admission weight instead of ideal body weight resulted in misclassification of up to 14% of patients as receiving low-tidal volume ventilation when they actually were not. Low

Acute eosinophilic and neutrophilic pneumonia following transarterial chemoembolization with drug-eluting beads loaded with doxorubicin for hepatocellular carcinoma: a case report.

PubMed

Alifakioti, Dimitra; Daccord, Cécile; Lachenal, Yann; Fitting, Jean-William

2014-01-01

At an intermediate or advanced stage, i.e. stage B or C, based on the Barcelona Clinic Liver Cancer classification of hepatocellular carcinoma (HCC), transarterial chemoembolization (TACE) may be offered as a treatment of palliative intent. We report the case of a patient suffering from acute respiratory distress syndrome after TACE with drug-eluting beads loaded with doxorubicin for HCC. To our knowledge, this is the first case described where a bronchoalveolar lavage was performed, and where significant levels of alveolar eosinophilia and neutrophilia were evident, attributed to a pulmonary toxicity of doxorubicin following liver chemoembolization. © 2014 S. Karger AG, Basel.

Crack Growth Analysis for Arbitrary Spectrum Loading. Volume 1. Results and Discussion

DTIC Science & Technology

1974-10-01

amplitude growth without previous load history effects) the crack growth increments were increased. Many of the specimens were fitted with the Amsler...absolute magnitude of the maximum load.) Further, if S is defined as a function of the previous load history , then c h9 Equation (19) will predict...crack growth interaction effects. It remains then, to define S as a function of stress ratio and previous load history , and anyc other pertinent

Association between intravenous chloride load during resuscitation and in-hospital mortality among patients with SIRS.

PubMed

Shaw, Andrew D; Raghunathan, Karthik; Peyerl, Fred W; Munson, Sibyl H; Paluszkiewicz, Scott M; Schermer, Carol R

2014-12-01

Recent data suggest that both elevated serum chloride levels and volume overload may be harmful during fluid resuscitation. The purpose of this study was to examine the relationship between the intravenous chloride load and in-hospital mortality among patients with systemic inflammatory response syndrome (SIRS), with and without adjustment for the crystalloid volume administered. We conducted a retrospective analysis of 109,836 patients ≥ 18 years old that met criteria for SIRS and received fluid resuscitation with crystalloids. We examined the association between changes in serum chloride concentration, the administered chloride load and fluid volume, and the 'volume-adjusted chloride load' and in-hospital mortality. In general, increases in the serum chloride concentration were associated with increased mortality. Mortality was lowest (3.7%) among patients with minimal increases in serum chloride concentration (0-10 mmol/L) and when the total administered chloride load was low (3.5% among patients receiving 100-200 mmol; P < 0.05 versus patients receiving ≥ 500 mmol). After controlling for crystalloid fluid volume, mortality was lowest (2.6%) when the volume-adjusted chloride load was 105-115 mmol/L. With adjustment for severity of illness, the odds of mortality increased (1.094, 95% CI 1.062, 1.127) with increasing volume-adjusted chloride load (≥ 105 mmol/L). Among patients with SIRS, a fluid resuscitation strategy employing lower chloride loads was associated with lower in-hospital mortality. This association was independent of the total fluid volume administered and remained significant after adjustment for severity of illness, supporting the hypothesis that crystalloids with lower chloride content may be preferable for managing patients with SIRS.

Isolating Added Mass Load Components of CPAS Main Clusters

NASA Technical Reports Server (NTRS)

Ray, Eric S.

2017-01-01

The current simulation for the Capsule Parachute Assembly System (CPAS) lacks fidelity in representing added mass for the 116 ft Do ringsail Main parachute. The availability of 3-D models of inflating Main canopies allowed for better estimation the enclosed air volume as a function of time. This was combined with trajectory state information to estimate the components making up measured axial loads. A proof-of-concept for an alternate simulation algorithm was developed based on enclosed volume as the primary independent variable rather than drag area growth. Databases of volume growth and parachute drag area vs. volume were developed for several flight tests. Other state information was read directly from test data, rather than numerically propagated. The resulting simulated peak loads were close in timing and magnitude to the measured loads data. However, results are very sensitive to data curve fitting and may not be suitable for Monte Carlo simulations. It was assumed that apparent mass was either negligible or a small fraction of enclosed mass, with little difference in results.

Activation energy of the low-load NaCl transition from nanoindentation loading curves.

PubMed

Kaupp, Gerd

2014-01-01

Access to activation energies E(a) of phase transitions is opened by unprecedented analyses of temperature dependent nanoindentation loading curves. It is based on kinks in linearized loading curves, with additional support by coincidence of kink and electrical conductivity of silicon loading curves. Physical properties of B1, B2, NaCl and further phases are discussed. The normalized low-load transition energy of NaCl (Wtrans/µN) increases with temperature and slightly decreases with load. Its semi-logarithmic plot versus T obtains activation energy E(a)/µN for calculation of the transition work for all interesting temperatures and pressures. Arrhenius-type activation energy (kJ/mol) is unavailable for indentation phase transitions. The E(a) per load normalization proves insensitive to creep-on-load, which excludes normalization to depth or volume for large temperature ranges. Such phase transition E(a)/µN is unprecedented material's property and will be of practical importance for the compatibility of composite materials under impact and further shearing interactions at elevated temperatures. © 2014 Wiley Periodicals, Inc.

Inhalation of diethylamine--acute nasal effects and subjective response

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

Lundqvist, G.R.; Yamagiwa, M.; Pedersen, O.F.

1992-03-01

Adult volunteers were exposed to 25 ppm (75 mg/m3) diethylamine in a climate chamber for 15 min in order to study the acute nasal reactions to an exposure equivalent to the present threshold limit value-short-term exposure limit. Changes in nasal volume and nasal resistance were measured by acoustic rhinometry and by rhinomanometry. Acute change in nasal volume, usually seen as acute nasal mucosa response to thermal stimuli, was not observed, nor was an acute change in nasal airway resistance. In a subsequent experiment, the aim was to measure acute sensory effects. Exposure to a concentration increasing from 0 to 12more » ppm took place for 60 min, equal to an average concentration of 10 ppm (30 mg/m3). A moderate to strong olfactory response and distinct nasal and eye irritation were observed. In spite of considerable individual variation, the results were in agreement with sensory effect estimates obtained from animal studies.« less

Acute Effects of Static Stretching, Dynamic Exercises, and High Volume Upper Extremity Plyometric Activity on Tennis Serve Performance

PubMed Central

Gelen, Ertugrul; Dede, Muhittin; Bingul, Bergun Meric; Bulgan, Cigdem; Aydin, Mensure

2012-01-01

The purpose of this study was to compare the acute effects of static stretching; dynamic exercises and high volume upper extremity plyometric activity on tennis serve performance. Twenty-six elite young tennis players (15.1 ± 4.2 years, 167.9 ± 5.8 cm and 61.6 ± 8.1 kg) performed 4 different warm-up (WU) routines in a random order on non-consecutive days. The WU methods consisted of traditional WU (jogging, rally and serve practice) (TRAD); traditional WU and static stretching (TRSS); traditional WU and dynamic exercise (TRDE); and traditional WU and high volume upper extremity plyometric activity (TRPLYP). Following each WU session, subjects were tested on a tennis serve ball speed test. TRAD, TRSS, TRDE and TRPLYO were compared by repeated measurement analyses of variance and post-hoc comparisons. In this study a 1 to 3 percent increase in tennis serve ball speed was recorded in TRDE and TRPLYO when compared to TRAD (p< 0.05). However, no significant change in ball speed performance between TRSS and TRAD. (p> 0.05). ICCs for ball speed showed strong reliability (0.82 to 0.93) for the ball speed measurements.The results of this study indicate that dynamic and high volume upper extremity plyometric WU activities are likely beneficial to serve speed of elite junior tennis players. Key points After the traditional warm up in tennis, static stretching has no effect on serve speed. Tennis players should perform dynamic exercises and/or high volume upper extremity plyometric activities to improve their athletic performance. PMID:24150068

Interleukin-6 and associated cytokine responses to an acute bout of high-intensity interval exercise: the effect of exercise intensity and volume.

PubMed

Cullen, Tom; Thomas, Andrew W; Webb, Richard; Hughes, Michael G

2016-08-01

Acute increases in interleukin (IL)-6 following prolonged exercise are associated with the induction of a transient anti-inflammatory state (e.g., increases in IL-10) that is partly responsible for the health benefits of regular exercise. The purposes of this study were to investigate the IL-6-related inflammatory response to high-intensity interval exercise (HIIE) and to determine the impact of exercise intensity and volume on this response. Ten participants (5 males and 5 females) completed 3 exercise bouts of contrasting intensity and volume (LOW, MOD, and HIGH). The HIGH protocol was based upon standard HIIE protocols, while the MOD and LOW protocols were designed to enable a comparison of exercise intensity and volume with a fixed duration. Inflammatory cytokine concentrations were measured in plasma (IL-6, IL-10) and also determined the level of gene expression (IL-6, IL-10, and IL-4R) in peripheral blood. The plasma IL-6 response to exercise (reported as fold changes) was significantly greater in HIGH (2.70 ± 1.51) than LOW (1.40 ± 0.32) (P = 0.04) and was also positively correlated to the mean exercise oxygen uptake (r = 0.54, P < 0.01). However, there was no change in anti-inflammatory IL-10 or IL-4R responses in plasma or at the level of gene expression. HIIE caused a significant increase in IL-6 and was greater than that seen in low-intensity exercise of the same duration. The increases in IL-6 were relatively small in magnitude, and appear to have been insufficient to induce the acute systemic anti-inflammatory effects, which are evident following longer duration exercise.

Role of myocardial hypertrophy on acute and chronic right ventricular performance in relation to chronic volume overload in a porcine model: relevance for the surgical management of tetralogy of Fallot.

PubMed

Bove, Thierry; Vandekerckhove, Kristof; Bouchez, Stefaan; Wouters, Patrick; Somers, Pamela; Van Nooten, Guido

2014-06-01

The age for correction of tetralogy of Fallot has progressively declined to the postnatal period, often despite an increased rate of transannular patch repair. However, the long-term effect of premature exposure to chronic pulmonary insufficiency on the right ventricle remains unknown. On the basis of the relationship between the duration of pressure overload and age, the role of previous pressure load-related hypertrophy on right ventricular (RV) performance after chronic volume overload was investigated in a porcine model. RV hypertrophy (RVH), induced by pulmonary artery banding, was studied in pigs with (RVH plus pulmonary insufficiency [PI]) and without (RVH) subsequent PI. The effect of volume overload was compared between these 2 groups and pigs without RVH but with PI and controls (sham). Both acute and chronic effects on RV function were studied using conductance technology and validated using echocardiography. After chronic volume overload, the end-systolic and end-diastolic volumes were smaller in the RVH+PI group than in the PI group, including a lower pulmonary regurgitation fraction (25% ± 5% vs 35% ± 5%; P = .002). RVH resulted in better preserved systolic function, confirmed by an increased preload recruitable stroke work slope (14.7 ± 1.8 vs 9.3 ± 1.3 Mw.s/mL; P = .025) and higher RV ejection fraction (51% ± 3% vs 45% ± 4%; P = .05). Myocardial stiffness was impaired in the RVH+PI group versus the PI group (β, 0.19 ± 0.03 vs 0.12 ± 0.02 mL(-1); P = .001), presenting restrictive physiology only in the condition associating RVH and PI. The results of the present study have demonstrated that RVH attenuates the RV remodeling process related to chronic PI. It enables better preservation of contractility but at the cost of sustained diastolic impairment. These findings might help to determine the timing and strategy for repair of tetralogy of Fallot when RV outflow tract morphology indicates a definite need for transannular reconstruction

Effects of acute and chronic exercise on the osmotic stability of erythrocyte membrane of competitive swimmers.

PubMed

Paraiso, Lara Ferreira; Gonçalves-E-Oliveira, Ana Flávia Mayrink; Cunha, Lucas Moreira; de Almeida Neto, Omar Pereira; Pacheco, Adriana Garcia; Araújo, Karinne Beatriz Gonçalves; Garrote-Filho, Mário da Silva; Bernardino Neto, Morun; Penha-Silva, Nilson

2017-01-01

This study aimed to evaluate the influence of acute and chronic exercise on erythrocyte membrane stability and various blood indices in a population consisting of five national-level male swimmers, over 18 weeks of training. The evaluations were made at the beginning and end of the 1st, 7th, 13th and 18th weeks, when volume and training intensity have changed. The effects manifested at the beginning of those weeks were considered due to chronic adaptations, while the effects observed at the end of the weeks were considered due to acute manifestations of the exercise load of that week. Acute changes resulting from the exercise comprised increases in creatine kinase activity (CK) and leukocyte count (Leu), and decrease in hematocrit (Ht) and mean corpuscular volume (MCV), at the end of the first week; increase in the activities of CK and lactate dehydrogenase (LDH), in the uric acid (UA) concentration and Leu count, at the end of the seventh week; increases in CK and LDH activities and in the mean corpuscular hemoglobin concentration (MCHC), at the end of the 13th week; and decrease in the value of the osmotic stability index 1/H50 and increases in the CK activity and platelets (Plt) count, at the end of the 18th week. Chronic changes due to training comprised increase in the values of 1/H50, CK, LDH, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), serum iron (Fe), MCV and Plt. Although acute training has resulted in decrease in the osmotic stability of erythrocytes, possibly associated with exacerbation of the oxidative processes during intense exercise, chronic training over 18 weeks resulted in increased osmotic stability of erythrocytes, possibly by modulation in the membrane cholesterol content by low and high density lipoproteins.

Quantitative estimation of a ratio of intracranial cerebrospinal fluid volume to brain volume based on segmentation of CT images in patients with extra-axial hematoma.

PubMed

Nguyen, Ha Son; Patel, Mohit; Li, Luyuan; Kurpad, Shekar; Mueller, Wade

2017-02-01

Background Diminishing volume of intracranial cerebrospinal fluid (CSF) in patients with space-occupying masses have been attributed to unfavorable outcome associated with reduction of cerebral perfusion pressure and subsequent brain ischemia. Objective The objective of this article is to employ a ratio of CSF volume to brain volume for longitudinal assessment of space-volume relationships in patients with extra-axial hematoma and to determine variability of the ratio among patients with different types and stages of hematoma. Patients and methods In our retrospective study, we reviewed 113 patients with surgical extra-axial hematomas. We included 28 patients (age 61.7 +/- 17.7 years; 19 males, nine females) with an acute epidural hematoma (EDH) ( n = 5) and subacute/chronic subdural hematoma (SDH) ( n = 23). We excluded 85 patients, in order, due to acute SDH ( n = 76), concurrent intraparenchymal pathology ( n = 6), and bilateral pathology ( n = 3). Noncontrast CT images of the head were obtained using a CT scanner (2004 GE LightSpeed VCT CT system, tube voltage 140 kVp, tube current 310 mA, 5 mm section thickness) preoperatively, postoperatively (3.8 ± 5.8 hours from surgery), and at follow-up clinic visit (48.2 ± 27.7 days after surgery). Each CT scan was loaded into an OsiriX (Pixmeo, Switzerland) workstation to segment pixels based on radiodensity properties measured in Hounsfield units (HU). Based on HU values from -30 to 100, brain, CSF spaces, vascular structures, hematoma, and/or postsurgical fluid were segregated from bony structures, and subsequently hematoma and/or postsurgical fluid were manually selected and removed from the images. The remaining images represented overall brain volume-containing only CSF spaces, vascular structures, and brain parenchyma. Thereafter, the ratio between the total number of voxels representing CSF volume (based on values between 0 and 15 HU) to the total number of voxels

Functional adaptation to mechanical loading in both cortical and cancellous bone is controlled locally and is confined to the loaded bones.

PubMed

Sugiyama, Toshihiro; Price, Joanna S; Lanyon, Lance E

2010-02-01

In order to validate whether bones' functional adaptation to mechanical loading is a local phenomenon, we randomly assigned 21 female C57BL/6 mice at 19 weeks of age to one of three equal numbered groups. All groups were treated with isoflurane anesthesia three times a week for 2 weeks (approximately 7 min/day). During each anaesthetic period, the right tibiae/fibulae in the DYNAMIC+STATIC group were subjected to a peak dynamic load of 11.5 N (40 cycles with 10-s intervals between cycles) superimposed upon a static "pre-load" of 2.0 N. This total load of 13.5 N engendered peak longitudinal strains of approximately 1400 microstrain on the medial surface of the tibia at a middle/proximal site. The right tibiae/fibulae in the STATIC group received the static "pre-load" alone while the NOLOAD group received no artificial loading. After 2 weeks, the animals were sacrificed and both tibiae, fibulae, femora, ulnae and radii analyzed by three-dimensional high-resolution (5 mum) micro-computed tomography (microCT). In the DYNAMIC+STATIC group, the proximal trabecular percent bone volume and cortical bone volume at the proximal and middle levels of the right tibiae as well as the cortical bone volume at the middle level of the right fibulae were markedly greater than the left. In contrast, the left bones in the DYNAMIC+STATIC group showed no differences compared to the left or right bones in the NOLOAD or STATIC group. These microCT data were confirmed by two-dimensional examination of fluorochrome labels in bone sections which showed the predominantly woven nature of the new bone formed in the loaded bones. We conclude that the adaptive response in both cortical and trabecular regions of bones subjected to short periods of dynamic loading, even when this response is sufficiently vigorous to stimulate woven bone formation, is confined to the loaded bones and does not involve changes in other bones that are adjacent, contra-lateral or remote to them. (c) 2009 Elsevier Inc

Investigation of prediction methods for the loads and stresses of Apollo type spacecraft parachutes. Volume 1: Loads

NASA Technical Reports Server (NTRS)

Mickey, F. E.; Mcewan, A. J.; Ewing, E. G.; Huyler, W. C., Jr.; Khajeh-Nouri, B.

1970-01-01

An analysis was conducted with the objective of upgrading and improving the loads, stress, and performance prediction methods for Apollo spacecraft parachutes. The subjects considered were: (1) methods for a new theoretical approach to the parachute opening process, (2) new experimental-analytical techniques to improve the measurement of pressures, stresses, and strains in inflight parachutes, and (3) a numerical method for analyzing the dynamical behavior of rapidly loaded pilot chute risers.

A program for calculating load coefficient matrices utilizing the force summation method, L218 (LOADS). Volume 1: Engineering and usage

NASA Technical Reports Server (NTRS)

Miller, R. D.; Anderson, L. R.

1979-01-01

The LOADS program L218, a digital computer program that calculates dynamic load coefficient matrices utilizing the force summation method, is described. The load equations are derived for a flight vehicle in straight and level flight and excited by gusts and/or control motions. In addition, sensor equations are calculated for use with an active control system. The load coefficient matrices are calculated for the following types of loads: translational and rotational accelerations, velocities, and displacements; panel aerodynamic forces; net panel forces; shears and moments. Program usage and a brief description of the analysis used are presented. A description of the design and structure of the program to aid those who will maintain and/or modify the program in the future is included.

Short-Term Effects of Different Loading Schemes in Fitness-Related Resistance Training.

PubMed

Eifler, Christoph

2016-07-01

Eifler, C. Short-term effects of different loading schemes in fitness-related resistance training. J Strength Cond Res 30(7): 1880-1889, 2016-The purpose of this investigation was to analyze the short-term effects of different loading schemes in fitness-related resistance training and to identify the most effective loading method for advanced recreational athletes. The investigation was designed as a longitudinal field-test study. Two hundred healthy mature subjects with at least 12 months' experience in resistance training were randomized in 4 samples of 50 subjects each. Gender distribution was homogenous in all samples. Training effects were quantified by 10 repetition maximum (10RM) and 1 repetition maximum (1RM) testing (pre-post-test design). Over a period of 6 weeks, a standardized resistance training protocol with 3 training sessions per week was realized. Testing and training included 8 resistance training exercises in a standardized order. The following loading schemes were randomly matched to each sample: constant load (CL) with constant volume of repetitions, increasing load (IL) with decreasing volume of repetitions, decreasing load (DL) with increasing volume of repetitions, daily changing load (DCL), and volume of repetitions. For all loading schemes, significant strength gains (p < 0.001) could be noted for all resistance training exercises and both dependent variables (10RM, 1RM). In all cases, DCL obtained significantly higher strength gains (p < 0.001) than CL, IL, and DL. There were no significant differences in strength gains between CL, IL, and DL. The present data indicate that resistance training following DCL is more effective for advanced recreational athletes than CL, IL, or DL. Considering that DCL is widely unknown in fitness-related resistance training, the present data indicate, there is potential for improving resistance training in commercial fitness clubs.

A generalized threshold model for computing bed load grain size distribution

NASA Astrophysics Data System (ADS)

Recking, Alain

2016-12-01

For morphodynamic studies, it is important to compute not only the transported volumes of bed load, but also the size of the transported material. A few bed load equations compute fractional transport (i.e., both the volume and grain size distribution), but many equations compute only the bulk transport (a volume) with no consideration of the transported grain sizes. To fill this gap, a method is proposed to compute the bed load grain size distribution separately to the bed load flux. The method is called the Generalized Threshold Model (GTM), because it extends the flow competence method for threshold of motion of the largest transported grain size to the full bed surface grain size distribution. This was achieved by replacing dimensional diameters with their size indices in the standard hiding function, which offers a useful framework for computation, carried out for each indices considered in the range [1, 100]. New functions are also proposed to account for partial transport. The method is very simple to implement and is sufficiently flexible to be tested in many environments. In addition to being a good complement to standard bulk bed load equations, it could also serve as a framework to assist in analyzing the physics of bed load transport in future research.

Acute Toxicity Study of Zerumbone-Loaded Nanostructured Lipid Carrier on BALB/c Mice Model

PubMed Central

Rahman, Heshu Sulaiman; Rasedee, Abdullah; Othman, Hemn Hassan; Chartrand, Max Stanley; Namvar, Farideh; Abdul Samad, Nozlena; Andas, Reena Joys; Ng, Kuan Beng; How, Chee Wun

2014-01-01

Zerumbone- (ZER-) loaded nanostructure lipid carrier (NLC) (ZER-NLC) prepared for its antileukemia effect in vitro was evaluated for its toxicological effects by observing changes in the liver, kidney, spleen, lung, heart, and brain tissues, serum biochemical parameters, total haemogram, and bone marrow stem cells. The acute toxicity study for ZER-NLC was conducted by orally treating BALB/c mice with a single dose with either water, olive oil, ZER, NLC, or ZER-NLC for 14 days. The animals were observed for clinical and behavioral abnormalities, toxicological symptoms, feed consumption, and gross appearance. The liver, kidney, heart, lung, spleen, and brain tissues were assessed histologically. Total haemogram was counted by hemocytometry and microhematocrit reader. Bone marrow examination in terms of cellular morphology was done by Wright staining with bone marrow smear. Furthermore, serum biochemical parameters were determined spectrophotometrically. Grossly all treated mice, their investigated tissues, serum biochemical parameters, total haemogram, and bone marrow were normal. At oral doses of 100 and 200 mg/kg ZER-NLC there was no sign of toxicity or mortality in BALB/c mice. This study suggests that the 50% lethal dose (LD50) of ZER-NLC is higher than 200 mg/kg, thus, safe by oral administration. PMID:25276798

Acute toxicity study of zerumbone-loaded nanostructured lipid carrier on BALB/c mice model.

PubMed

Rahman, Heshu Sulaiman; Rasedee, Abdullah; Othman, Hemn Hassan; Chartrand, Max Stanley; Namvar, Farideh; Yeap, Swee Keong; Abdul Samad, Nozlena; Andas, Reena Joys; Muhammad Nadzri, Nabilah; Anasamy, Theebaa; Ng, Kuan Beng; How, Chee Wun

2014-01-01

Zerumbone- (ZER-) loaded nanostructure lipid carrier (NLC) (ZER-NLC) prepared for its antileukemia effect in vitro was evaluated for its toxicological effects by observing changes in the liver, kidney, spleen, lung, heart, and brain tissues, serum biochemical parameters, total haemogram, and bone marrow stem cells. The acute toxicity study for ZER-NLC was conducted by orally treating BALB/c mice with a single dose with either water, olive oil, ZER, NLC, or ZER-NLC for 14 days. The animals were observed for clinical and behavioral abnormalities, toxicological symptoms, feed consumption, and gross appearance. The liver, kidney, heart, lung, spleen, and brain tissues were assessed histologically. Total haemogram was counted by hemocytometry and microhematocrit reader. Bone marrow examination in terms of cellular morphology was done by Wright staining with bone marrow smear. Furthermore, serum biochemical parameters were determined spectrophotometrically. Grossly all treated mice, their investigated tissues, serum biochemical parameters, total haemogram, and bone marrow were normal. At oral doses of 100 and 200 mg/kg ZER-NLC there was no sign of toxicity or mortality in BALB/c mice. This study suggests that the 50% lethal dose (LD50) of ZER-NLC is higher than 200 mg/kg, thus, safe by oral administration.

Quantitative and volume, conductivity and scatter changes in leucocytes of patients with acute undifferentiated febrile illness: a pilot study.

PubMed

Kalra, Varun; Ahmad, Sohaib; Shrivastava, Vikas; Mittal, Garima

2016-05-01

A single diagnostic test for acute undifferentiated febrile illnesses (AUFI) is elusive. This pilot study was undertaken on the premise that leucocytes, being the main cells of defence, undergo quantitative, structural and functional changes in AUFI. We evaluated the potential of volume, conductivity and scatter (VCS) parameters of leucocytes, generated with the haemogram report by the Coulter auto-analyzer, in differentiating the common etiologies of AUFI. The haematological and VCS data obtained from 800 controls and 200 cases of AUFI (50 cases each of acute malaria, dengue, scrub typhus and enteric fever) were retrieved for analysis. The cases and controls differed significantly with respect to relative numbers and the VCS parameters of neutrophils, lymphocytes and monocytes (p<0.05). The neutrophil and lymphocyte were significantly voluminous in acute malaria and scrub typhus as compared to dengue and enteric fevers (p<0.05). Enteric fever significantly enhanced the conductivity of neutrophils as compared to other subgroups while lymphocyte conductivity significantly differed from dengue and scrub typhus. Lymphocyte and neutrophil scatter values in malaria and scrub typhus were comparable but differed significantly from that in enteric fever. Etiology-specific changes occur in leucocytes, both in numbers and their VCS properties which can be identified without additional cost. © The Author 2016. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The composite load spectra project

NASA Technical Reports Server (NTRS)

Newell, J. F.; Ho, H.; Kurth, R. E.

1990-01-01

Probabilistic methods and generic load models capable of simulating the load spectra that are induced in space propulsion system components are being developed. Four engine component types (the transfer ducts, the turbine blades, the liquid oxygen posts and the turbopump oxidizer discharge duct) were selected as representative hardware examples. The composite load spectra that simulate the probabilistic loads for these components are typically used as the input loads for a probabilistic structural analysis. The knowledge-based system approach used for the composite load spectra project provides an ideal environment for incremental development. The intelligent database paradigm employed in developing the expert system provides a smooth coupling between the numerical processing and the symbolic (information) processing. Large volumes of engine load information and engineering data are stored in database format and managed by a database management system. Numerical procedures for probabilistic load simulation and database management functions are controlled by rule modules. Rules were hard-wired as decision trees into rule modules to perform process control tasks. There are modules to retrieve load information and models. There are modules to select loads and models to carry out quick load calculations or make an input file for full duty-cycle time dependent load simulation. The composite load spectra load expert system implemented today is capable of performing intelligent rocket engine load spectra simulation. Further development of the expert system will provide tutorial capability for users to learn from it.

Weigh-in-motion (WIM) data for site-specific LRFR bridge load rating.

DOT National Transportation Integrated Search

2011-08-12

The live load factors in the Load and Resistant Factor Rating (LRFR) Manual are based on load data from Ontario : thought to be representative of traffic volumes nationwide. However, in accordance with the methodology for : developing site-specific l...

Distributed shared memory for roaming large volumes.

PubMed

Castanié, Laurent; Mion, Christophe; Cavin, Xavier; Lévy, Bruno

2006-01-01

We present a cluster-based volume rendering system for roaming very large volumes. This system allows to move a gigabyte-sized probe inside a total volume of several tens or hundreds of gigabytes in real-time. While the size of the probe is limited by the total amount of texture memory on the cluster, the size of the total data set has no theoretical limit. The cluster is used as a distributed graphics processing unit that both aggregates graphics power and graphics memory. A hardware-accelerated volume renderer runs in parallel on the cluster nodes and the final image compositing is implemented using a pipelined sort-last rendering algorithm. Meanwhile, volume bricking and volume paging allow efficient data caching. On each rendering node, a distributed hierarchical cache system implements a global software-based distributed shared memory on the cluster. In case of a cache miss, this system first checks page residency on the other cluster nodes instead of directly accessing local disks. Using two Gigabit Ethernet network interfaces per node, we accelerate data fetching by a factor of 4 compared to directly accessing local disks. The system also implements asynchronous disk access and texture loading, which makes it possible to overlap data loading, volume slicing and rendering for optimal volume roaming.

Bed load transport in gravel-bed rivers

Treesearch

Jeffrey J. Barry

2007-01-01

Bed load transport is a fundamental physical process in alluvial rivers, building and maintaining a channel geometry that reflects both the quantity and timing of water and the volume and caliber of sediment delivered from the watershed. A variety of formulae have been developed to predict bed load transport in gravel-bed rivers, but testing of the equations in natural...

[Role of hemodynamic factors and heart volume in the prognosis of acute cardiac insufficiency during the early postoperative period in patients with mitral valve stenosis].

PubMed

Guliamov, D S; Amanov, A A; Andres, Iu P; Bazhenova, T F

1983-07-01

Investigations performed in 172 patients have shown that the state of the myocardium (such parameters as the heart volume, degree of lung hypertension, end-diastolic pressure in the right and left ventricles) is of great importance in pathogenesis of the development of acute heart failure in the early postoperative period in patients with mitral stenosis of the IIIrd and IVth stage of the blood circulation insufficiency.

Crimean-Congo hemorrhagic fever: CXCL10 correlates with the viral load.

PubMed

Papa, Anna; Yagci Caglayık, Dilek; Christova, Iva; Tsergouli, Katerina; Korukluoglu, Gulay; Uyar, Yavuz

2015-06-01

Crimean-Congo hemorrhagic fever (CCHF) is a human disease with high fatality rate. Although its pathogenesis is not elucidated yet, it is considered that cytokines play a significant role in the progression and outcome of the disease. Serum CXCL10 levels were estimated in 35 patients with acute CCHF and were correlated with the viral load, and various demographic and clinical parameters. The mean CXCL10 concentration in the patients' group was higher compared to the respective value in the control group (4421.74 pg/ml vs. 28.47 pg/ml, P < 0.05). A strong positive correlation between CXCL10 and viral load was seen (rs = 0.57, P < 0.001), while the outcome of the disease was related with the viral load (rs = 0.47, P = 0.004) and the presence of hemorrhagic manifestations (P < 0.001). The study provides an insight into the strong correlation between CXCL10 and viral load in acute CCHF cases suggesting that it plays an important role in CCHF pathogenesis. © 2015 Wiley Periodicals, Inc.

The acute angiogenic signalling response to low-load resistance exercise with blood flow restriction.

PubMed

Ferguson, Richard A; Hunt, Julie E A; Lewis, Mark P; Martin, Neil R W; Player, Darren J; Stangier, Carolin; Taylor, Conor W; Turner, Mark C

2018-04-01

This study investigated protein kinase activation and gene expression of angiogenic factors in response to low-load resistance exercise with or without blood flow restriction (BFR). In a repeated measures cross-over design, six males performed four sets of bilateral knee extension exercise at 20% 1RM (reps per set = 30:15:15:continued to fatigue) with BFR (110 mmHg) and without (CON). Muscle biopsies were obtained from the vastus lateralis before, 2 and 4 h post-exercise. mRNA expression was determined using real-time RT-PCR. Protein phosphorylation/expression was determined using Western blot. p38MAPK phosphorylation was greater (p = 0.05) at 2 h following BFR (1.3 ± 0.8) compared to CON (0.4 ± 0.3). AMPK phosphorylation remained unchanged. PGC-1α mRNA expression increased at 2 h (5.9 ± 1.3 vs. 2.1 ± 0.8; p = 0.03) and 4 h (3.2 ± 0.8 vs. 1.5 ± 0.4; p = 0.03) following BFR exercise with no change in CON. PGC-1α protein expression did not change following either exercise. BFR exercise enhanced mRNA expression of vascular endothelial growth factor (VEGF) at 2 h (5.2 ± 2.8 vs 1.7 ± 1.1; p = .02) and 4 h (6.8 ± 4.9 vs. 2.5 ± 2.7; p = .01) compared to CON. mRNA expression of VEGF-R2 and hypoxia-inducible factor 1α increased following BFR exercise but only eNOS were enhanced relative to CON. Matrix metalloproteinase-9 mRNA expression was not altered in response to either exercise. Acute low-load resistance exercise with BFR provides a targeted angiogenic response potentially mediated through enhanced ischaemic and shear stress stimuli.

Analysis and predictive models of stormwater runoff volumes, loads, and pollutant concentrations from watersheds in the Twin Cities metropolitan area, Minnesota, USA.

PubMed

Brezonik, Patrick L; Stadelmann, Teresa H

2002-04-01

Urban nonpoint source pollution is a significant contributor to water quality degradation. Watershed planners need to be able to estimate nonpoint source loads to lakes and streams if they are to plan effective management strategies. To meet this need for the twin cities metropolitan area, a large database of urban and suburban runoff data was compiled. Stormwater runoff loads and concentrations of 10 common constituents (six N and P forms, TSS, VSS, COD, Pb) were characterized, and effects of season and land use were analyzed. Relationships between runoff variables and storm and watershed characteristics were examined. The best regression equation to predict runoff volume for rain events was based on rainfall amount, drainage area, and percent impervious area (R2 = 0.78). Median event-mean concentrations (EMCs) tended to be higher in snowmelt runoff than in rainfall runoff, and significant seasonal differences were found in yields (kg/ha) and EMCs for most constituents. Simple correlations between explanatory variables and stormwater loads and EMCs were weak. Rainfall amount and intensity and drainage area were the most important variables in multiple linear regression models to predict event loads, but uncertainty was high in models developed with the pooled data set. The most accurate models for EMCs generally were found when sites were grouped according to common land use and size.

Quantifying loading, toxic concentrations, and systemic persistence of chloride in a contemporary mixed-land-use watershed using an experimental watershed approach.

PubMed

Hubbart, J A; Kellner, E; Hooper, L W; Zeiger, S

2017-03-01

A nested-scale experimental watershed study was implemented to quantify loading and persistence of chloride in an urbanizing, mixed-land-use watershed. A Midwest USA (Missouri) watershed was partitioned into five sub-basins with contrasting dominant land use. Streamwater was tested for chloride concentration four days per week from October 2009 through May 2014 at each site. Monitoring sites included co-located gauging and climate stations recording variables at 30-minute intervals. Results indicate significant (p<0.01) differences in chloride concentrations and loading between sites. Loading consistently increased from the forested headwaters (average=507kgday -1 ) to primarily urban watershed terminus (average=7501kgday -1 ). Chloride concentrations were highest (average=83.9mgL -1 ) with the greatest frequency of acutely toxic conditions (i.e. 860mgL -1 ) mid-watershed. This finding is in-part attributable to the ratio of chloride application to streamflow volume (i.e. increasing flow volume with stream distance resulted in chloride dilution, offsetting increased percent urban land use with stream distance). Results highlight the important, yet often confounding, interactions between pollutant loading and flow dynamics. Chloride peaks occurred during late winter/early spring melting periods, implicating road salt application as the primary contributor to the chloride regime. Floodplain groundwater analysis indicated seasonal sink/source relationships between the stream and floodplain, which could contribute to chronic toxicity and persistent low Cl - concentrations in streamwater year-round. Results hold important implications for resource managers wishing to mitigate water quality and aquatic habitat degradation, and suggest important water quality limitations to stream restoration success in complex urban aquatic ecosystems. Copyright © 2017 Elsevier B.V. All rights reserved.

Changes in tendon spatial frequency parameters with loading.

PubMed

Pearson, Stephen J; Engel, Aaron J; Bashford, Gregory R

2017-05-24

To examine and compare the loading related changes in micro-morphology of the patellar tendon. Fifteen healthy young males (age 19±3yrs, body mass 83±5kg) were utilised in a within subjects matched pairs design. B mode ultrasound images were taken in the sagittal plane of the patellar tendon at rest with the knee at 90° flexion. Repeat images were taken whilst the subjects were carrying out maximal voluntary isometric contractions. Spatial frequency parameters related to the tendon morphology were determined within regions of interest (ROI) from the B mode images at rest and during isometric contractions. A number of spatial parameters were observed to be significantly different between resting and contracted images (Peak spatial frequency radius (PSFR), axis ratio, spatial Q-factor, PSFR amplitude ratio, and the sum). These spatial frequency parameters were indicative of acute alterations in the tendon micro-morphology with loading. Acute loading modifies the micro-morphology of the tendon, as observed via spatial frequency analysis. Further research is warranted to explore its utility with regard to different loading induced micro-morphological alterations, as these could give valuable insight not only to aid strengthening of this tissue but also optimization of recovery from injury and treatment of conditions such as tendinopathies. Copyright © 2017 Elsevier Ltd. All rights reserved.

High-repetition cyclic loading is a risk factor for a lumbar disorder.

PubMed

Navar, Daniel; Zhou, Bing-He; Lu, Yun; Solomonow, Moshe

2006-11-01

Epidemiological data suggest that prolonged exposure to cyclic lumbar flexion elicits a chronic neuromuscular disorder and disability in workers. This study provides a physiological and biomechanical assessment of various repetitions of cyclic lumbar flexion sessions as a risk factor for development of an acute neuromuscular disorder. An in vivo feline model was subjected to 10 minutes of cyclic (0.25-HZ) loading, followed by a 10-minute rest period, repeated three times in one experimental group, six times in a second group, and nine times in the third group, followed by rest for 7 hours. Displacement of the lumbar viscoelastic tissue and reflex electromyographic (EMG) activity from the lumbar multifidus muscle were monitored. Creep developed and accumulated during each load/rest period and partially recovered during the subsequent rest. Loading periods were characterized by a decrease in reflex EMG activity with superimposed spasms. In the 7-hour recovery period, initial hyperexcitability was present in all groups, whereas only the six- and nine-repetition groups displayed significant delayed hyperexcitability, indicating the presence of acute inflammation. The mathematical model developed fit the data reasonably well, as the R2 values were generally near 0.90. It was concluded that the resulting delayed muscular hyperexcitability constitutes an acute neuromuscular disorder associated with exposure to many repetitions of cyclic lumbar flexion. The acute disorder can become chronic if not allowed sufficient rest to resolve itself. Workers engaged in cyclic lumbar flexion (e.g., loading/unloading, assembly workers) should avoid long-term exposure in order to prevent the development of a chronic neuromuscular condition known as cumulative trauma disorder.

Use of continuous and grab sample data for calculating total maximum daily load (TMDL) in agricultural watersheds.

PubMed

Gulati, Shelly; Stubblefield, Ashley A; Hanlon, Jeremy S; Spier, Chelsea L; Stringfellow, William T

2014-03-01

Measuring the discharge of diffuse pollution from agricultural watersheds presents unique challenges. Flows in agricultural watersheds, particularly in Mediterranean climates, can be predominately irrigation runoff and exhibit large diurnal fluctuation in both volume and concentration. Flow and pollutant concentrations in these smaller watersheds dominated by human activity do not conform to a normal distribution and it is not clear if parametric methods are appropriate or accurate for load calculations. The objective of this study was to compare the accuracy of five load estimation methods to calculate pollutant loads from agricultural watersheds. Calculation of loads using results from discrete (grab) samples was compared with the true-load computed using in situ continuous monitoring measurements. A new method is introduced that uses a non-parametric measure of central tendency (the median) to calculate loads (median-load). The median-load method was compared to more commonly used parametric estimation methods which rely on using the mean as a measure of central tendency (mean-load and daily-load), a method that utilizes the total flow volume (volume-load), and a method that uses measure of flow at the time of sampling (instantaneous-load). Using measurements from ten watersheds in the San Joaquin Valley of California, the average percent error compared to the true-load for total dissolved solids (TDS) was 7.3% for the median-load, 6.9% for the mean-load, 6.9% for the volume-load, 16.9% for the instantaneous-load, and 18.7% for the daily-load methods of calculation. The results of this study show that parametric methods are surprisingly accurate, even for data that have starkly non-normal distributions and are highly skewed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Volume of Plasma Expansion and Functional Outcomes in Stroke.

PubMed

Miller, Joseph B; Lewandowski, Christopher; Wira, Charles R; Taylor, Andrew; Burmeister, Charlotte; Welch, Robert

2017-04-01

Plasma expansion in acute ischemic stroke has potential to improve cerebral perfusion, but the long-term effects on functional outcome are mixed in prior trials. The goal of this study was to evaluate how the magnitude of plasma expansion affects neurological recovery in acute stroke. This was a secondary analysis of data from the Albumin in Acute Stroke Part 2 trial investigating the relationship between the magnitude of overall intravenous volume infusion (crystalloid and colloid) to clinical outcome. The data were inclusive of 841 patients with a mean age of 64 years and a median National Institutes of Health Stroke Scale (NIHSS) of 11. In a multivariable-adjusted logistic regression model, this analysis tested the volume of plasma expansion over the first 48 h of hospitalization as a predictor of favorable outcome, defined as either a modified Rankin Scale score of 0 or 1 or a NIHSS score of 0 or 1 at 90 days. This model included all study patients, irrespective of albumin or isotonic saline treatment. Patients that received higher volumes of plasma expansion more frequently had large vessel ischemic stroke and higher NIHSS scores. The multivariable-adjusted model revealed that there was decreased odds of a favorable outcome for every 250 ml additional volume plasma expansion over the first 48 h (OR 0.91, 95 % CI, 0.88-0.94). The present study demonstrates an association between greater volume of plasma expansion and worse neurological recovery.

Correlation of Acute and Late Brainstem Toxicities With Dose-Volume Data for Pediatric Patients With Posterior Fossa Malignancies

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

Nanda, Ronica H., E-mail: rhazari@emory.edu; Ganju, Rohit G.; Schreibmann, Edward

Purpose: Radiation-induced brainstem toxicity after treatment of pediatric posterior fossa malignancies is incompletely understood, especially in the era of intensity modulated radiation therapy (IMRT). The rates of, and predictive factors for, brainstem toxicity after photon RT for posterior fossa tumors were examined. Methods and Materials: After institutional review board approval, 60 pediatric patients treated at our institution for nonmetastatic infratentorial ependymoma and medulloblastoma with IMRT were included in the present analysis. Dosimetric variables, including the mean and maximum dose to the brainstem, the dose to 10% to 90% of the brainstem (in 10% increments), and the volume of the brainstemmore » receiving 40, 45, 50, and 55 Gy were recorded for each patient. Acute (onset within 3 months) and late (>3 months of RT completion) RT-induced brainstem toxicities with clinical and radiographic correlates were scored using Common Terminology Criteria for Adverse Events, version 4.0. Results: Patients aged 1.4 to 21.8 years underwent IMRT or volumetric arc therapy postoperatively to the posterior fossa or tumor bed. At a median clinical follow-up period of 2.8 years, 14 patients had developed symptomatic brainstem toxicity (crude incidence 23.3%). No correlation was found between the dosimetric variables examined and brainstem toxicity. Vascular injury or ischemia showed a strong trend toward predicting brainstem toxicity (P=.054). Patients with grade 3 to 5 brainstem toxicity had undergone treatment to significant volumes of the posterior fossa. Conclusion: The results of the present series demonstrate a low, but not negligible, risk of brainstem radiation necrosis for pediatric patients with posterior fossa malignancies treated with IMRT. No specific dose-volume correlations were identified; however, modern treatment volumes might help limit the incidence of severe toxicity. Additional work investigating inherent biologic sensitivity might also

Determinants of acute mortality of Hippodamia convergens (Coleoptera: Coccinellidae) to ultra-low volume permethrin used for mosquito management

PubMed Central

Preftakes, Collin J.; Bodin, Jennifer L.; Brown, Christopher R.; Piccolomini, Alyssa M.; Schleier, Jerome J.

2016-01-01

There are relatively few experimental studies and risk assessments of the effects on non-target insects from ultra-low volume (ULV) insecticides used for management of adult mosquitoes. Therefore, we evaluated factors that may influence the ability of an insect to intercept the insecticide at the time of application by using Hippodamia convergens (Coleoptera: Coccinellidae) in field bioassay experiments in 2011 and 2015. Treatment factors included different distances, two cage heights (ground-level and 1.5 m above ground) to the point of the application, and covered vs. uncovered cage faces (2015 only). Insecticides used included a water-based formulation (Aqua-Reslin®) and an oil-based formulation (Permanone® 30-30) of permethrin. Cage height was highly significant both years, with much less acute (i.e., short-term exposure) mortality at ground-level compared with 1.5 m. In 2011, acute mortality was less at ground-level (mean = 3.2%, median = 0%) compared to 1.5 m (mean = 85.2%, median = 100%). Cage type also was highly significant, with less mortality in covered cages compared to uncovered cages. Mortality by cage height and cage type was as follows: ground level, covered cage (mean = 2.8%, median = 0.1%); ground level, uncovered cage (mean = 41.9%, median = 9.6%); 1.5 m, covered cage (mean = 6.8%, median = 0%); 1.5 m, uncovered cage (mean = 83.7%, median = 100%). Results suggest that acute mortality to non-target insects may vary considerably based on their height and their ability to directly intercept the insecticide as the aerosol passes through the area being sprayed. PMID:27366655

Changes to Hospital Inpatient Volume After Newspaper Reporting of Medical Errors.

PubMed

Fukuda, Haruhisa

2017-06-30

The aim of this study was to investigate the influence of medical error case reporting by national newspapers on inpatient volume at acute care hospitals. A case-control study was conducted using the article databases of 3 major Japanese newspapers with nationwide circulation between fiscal years 2012 and 2013. Data on inpatient volume at acute care hospitals were obtained from a Japanese government survey between fiscal years 2011 and 2014. Panel data were constructed and analyzed using a difference-in-differences design. Acute care hospitals in Japan. Hospitals named in articles that included the terms "medical error" and "hospital" were designated case hospitals, which were matched with control hospitals using corresponding locations, nurse-to-patient ratios, and bed numbers. Medical error case reporting in newspapers. Changes to hospital inpatient volume after error reports. The sample comprised 40 case hospitals and 40 control hospitals. Difference-in-differences analyses indicated that newspaper reporting of medical errors was not significantly associated (P = 0.122) with overall inpatient volume. Medical error case reporting by newspapers showed no influence on inpatient volume. Hospitals therefore have little incentive to respond adequately and proactively to medical errors. There may be a need for government intervention to improve the posterror response and encourage better health care safety.

Feasibility and Acute Toxicity of Hypofractionated Radiation in Large-breasted Patients

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

Dorn, Paige L., E-mail: pdorn@radonc.uchicago.edu; Corbin, Kimberly S.; Al-Hallaq, Hania

Purpose: To determine the feasibility of and acute toxicity associated with hypofractionated whole breast radiation (HypoRT) after breast-conserving surgery in patients excluded from or underrepresented in randomized trials comparing HypoRT with conventional fractionation schedules. Methods and Materials: A review was conducted of all patients consecutively treated with HypoRT at University of Chicago. All patients were treated to 42.56 Gy in 2.66 Gy daily fractions in either the prone or supine position. Planning was performed in most cases using wedges and large segments or a 'field-in-field' technique. Breast volume was estimated using volumetric measurements of the planning target volume (PTV). Dosimetricmore » parameters of heterogeneity (V105, V107, V110, and maximum dose) were recorded for each treatment plan. Acute toxicity was scored for each treated breast. Results: Between 2006 and 2010, 78 patients were treated to 80 breasts using HypoRT. Most women were overweight or obese (78.7%), with a median body mass index of 29.2 kg/m{sup 2}. Median breast volume was 1,351 mL. Of the 80 treated breasts, the maximum acute skin toxicity was mild erythema or hyperpigmentation in 70.0% (56/80), dry desquamation in 21.25% (17/80), and focal moist desquamation in 8.75% (7/80). Maximum acute toxicity occurred after the completion of radiation in 31.9% of patients. Separation >25 cm was not associated with increased toxicity. Breast volume was the only patient factor significantly associated with moist desquamation on multivariable analysis (p = 0.01). Patients with breast volume >2,500 mL experienced focal moist desquamation in 27.2% of cases compared with 6.34% in patients with breast volume <2,500 mL (p = 0.03). Conclusions: HypoRT is feasible and safe in patients with separation >25 cm and in patients with large breast volume when employing modern planning and positioning techniques. We recommend counseling regarding expected increases in skin toxicity in women

High Dietary Glycemic Load is Associated with Poor Functional Outcome in Patients with Acute Cerebral Infarction.

PubMed

Song, Tae Jin; Chang, Yoonkyung; Chun, Min Young; Lee, Chan Young; Kim, A Ram; Kim, Yuri; Kim, Yong Jae

2018-04-01

Elevated postprandial blood glucose is a critical risk factor for stroke. The dietary glycemic load (GL) and glycemic index (GI) are frequently used as markers of the postprandial blood glucose response to estimate the overall glycemic effect of diets. We hypothesized that high dietary GL, GI, or total carbohydrate intake is associated with a poor functional outcome in patients with acute ischemic stroke. We prospectively included 263 first-ever ischemic stroke patients who completed a semiquantitative food-frequency questionnaire. The dietary GL, GI, and total carbohydrate intake were investigated by examining the average frequency of intake during the previous year based on reference amounts for various food items. Poor functional outcome was defined as a score on the modified Rankin Scale (mRS) of ≥3 at 3 months after stroke. The patients were aged 65.4±11.7 years (mean±standard deviation), and 58.2% of them were male. A multivariate analysis adjusted for age, sex, marital status, prestroke mRS score, diabetes mellitus, hyperlipidemia, body mass index, triglycerides, low-density lipoprotein, hemoglobin A1c, stroke classification, and National Institutes of Health Stroke Scale score, early neurological deterioration, and high-grade white-matter hyperintensities revealed that the dietary GL and total carbohydrate intake were associated with a poor functional outcome, with odds ratios for the top quartile relative to the bottom quartile of 28.93 (95% confidence interval=2.82-296.04) and 36.84 (95% confidence interval=2.99-453.42), respectively (p for trend=0.002 and 0.002, respectively). In contrast, high dietary GI was not associated with a poor functional outcome (p for trend=0.481). Increased dietary GL and carbohydrate intake were associated with a poor short-term functional outcome after an acute ischemic stroke. Copyright © 2018 Korean Neurological Association.

Monitoring of pulmonary mechanics in acute respiratory distress syndrome to titrate therapy.

PubMed

Gattinoni, Luciano; Eleonora, Carlesso; Caironi, Pietro

2005-06-01

This paper reviews recent findings regarding the respiratory mechanics during acute respiratory distress syndrome as a tool for tailoring its ventilatory management. The pressure-volume curve has been used for many years as a descriptor of the respiratory mechanics in patients affected by acute respiratory distress syndrome. The use of the sigmoidal equation introduced by Venegas for the analysis of the pressure-volume curve seems to be the most rigorous mathematical approach to assessing lung mechanics. Increasing attention has been focused on the deflation limb for titration of positive end-expiratory pressure. Based on physiologic reasoning, a novel parameter, the stress index, has been proposed for tailoring a safe mechanical ventilation, although its clinical impact has still to be proved. Evidence has confirmed that a variety of underlying pathologies may lead to acute respiratory distress syndrome, making unrealistic any attempt to unify the ventilatory approach. Although extensively proposed to tailor mechanical ventilation during acute respiratory distress syndrome, there is no evidence that the pressure-volume curve may be useful in setting a lung-protective strategy in the presence of different potentials for recruitment. The Venegas approach should be the standard analysis of pressure-volume curves. In any patient, the potential for recruitment should be assessed, as a basis for tailoring the most effective mechanical ventilation. Further studies are needed to clarify the potential use of the pressure-volume curve to guide a lung-protective ventilatory strategy.

Analysis of suture anchor eyelet position on suture failure load.

PubMed

Aktay, Sevima A; Kowaleski, Michael P

2011-06-01

To compare mechanical performance of 2 orientations of the 5 mm Corkscrew® suture anchor with #5 Fiberwire® . In vitro biomechanical study. Suture anchor-suture constructs (n=40). Acute and cyclic tensile loads were applied to suture threaded through eyelets of 40 anchors perpendicular to the long axis of the anchor. Eyelets were positioned so that the suture pull was in line with (anchor rotation angle of 0° [ARA 0]) or 90° (ARA 90) to the eyelet plane. Load at failure, stiffness, and cycles to failure were determined. All constructs failed by suture breakage at the eyelet. Mean load at failure was significantly higher in the ARA 90 group (634 ± 93 N) compared with the ARA 0 group (495 ± 52 N; P=.0015). No significant difference was found between groups for mean number of cycles to failure (270 ± 177 versus 178 ± 109; P=.2166) and stiffness (50 ± 4 versus 48 ± 5 N/mm; P=.3141). The Corkscrew® 5 mm suture anchor with Fiberwire® suture fails via suture breakage at the eyelet under higher acute loads if the suture is loaded at an angle of 90° compared with 0° with respect to the plane of the eyelet. © Copyright 2011 by The American College of Veterinary Surgeons.

A 5 kA pulsed power supply for inductive and plasma loads in large volume plasma device.

PubMed

Srivastava, P K; Singh, S K; Sanyasi, A K; Awasthi, L M; Mattoo, S K

2016-07-01

This paper describes 5 kA, 12 ms pulsed power supply for inductive load of Electron Energy Filter (EEF) in large volume plasma device. The power supply is based upon the principle of rapid sourcing of energy from the capacitor bank (2.8 F/200 V) by using a static switch, comprising of ten Insulated Gate Bipolar Transistors (IGBTs). A suitable mechanism is developed to ensure equal sharing of current and uniform power distribution during the operation of these IGBTs. Safe commutation of power to the EEF is ensured by the proper optimization of its components and by the introduction of over voltage protection (>6 kV) using an indigenously designed snubber circuit. Various time sequences relevant to different actions of power supply, viz., pulse width control and repetition rate, are realized through optically isolated computer controlled interface.

A 5 kA pulsed power supply for inductive and plasma loads in large volume plasma device

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

Srivastava, P. K., E-mail: pkumar@ipr.res.in; Singh, S. K.; Sanyasi, A. K.

This paper describes 5 kA, 12 ms pulsed power supply for inductive load of Electron Energy Filter (EEF) in large volume plasma device. The power supply is based upon the principle of rapid sourcing of energy from the capacitor bank (2.8 F/200 V) by using a static switch, comprising of ten Insulated Gate Bipolar Transistors (IGBTs). A suitable mechanism is developed to ensure equal sharing of current and uniform power distribution during the operation of these IGBTs. Safe commutation of power to the EEF is ensured by the proper optimization of its components and by the introduction of over voltagemore » protection (>6 kV) using an indigenously designed snubber circuit. Various time sequences relevant to different actions of power supply, viz., pulse width control and repetition rate, are realized through optically isolated computer controlled interface.« less

Role of angiotensin in renal sympathetic activation in cirrhotic rats.

PubMed

Voigt, M D; Jones, S Y; DiBona, G F

1999-08-01

Central nervous system (CNS) renin-angiotensin activity influences the basal level of renal sympathetic nerve activity (RSNA) and its reflex regulation. The effect of type 1 angiotensin II (ANG II)-receptor antagonist treatment (losartan) on cardiac baroreflex regulation of RSNA and renal sodium handling was examined in rats with cirrhosis due to common bile duct ligation (CBDL). Basal levels of heart rate, mean arterial pressure (MAP), RSNA, and urinary sodium excretion were not affected by intracerebroventricular administration of either losartan or vehicle to CBDL rats. After acute intravenous isotonic saline loading (10% body wt) in vehicle-treated CBDL rats, MAP was unchanged and the decrease in RSNA seen in normal rats did not occur. However, in losartan-treated CBDL rats, there were significant concurrent but transient decreases in MAP (-20 +/- 2 mmHg) and RSNA (-25 +/- 3%). The natriuretic response to acute volume loading in losartan-treated CBDL rats was significantly less than that in vehicle-treated CBDL rats only at those time points where there were significant decreases in MAP. Antagonism of CNS ANG II type 1 receptors augments the renal sympathoinhibitory response to acute volume loading in CBDL. However, the natriuretic response to the acute volume loading is not improved, likely due to the strong antinatriuretic influence of the concomitant marked decrease in MAP (renal perfusion pressure) mediated by widespread sympathetic withdrawal from the systemic vasculature.

Association between a high BK virus load in urine samples of patients with graft-versus-host disease and development of hemorrhagic cystitis after hematopoietic stem cell transplantation.

PubMed

Bogdanovic, G; Priftakis, P; Giraud, G; Kuzniar, M; Ferraldeschi, R; Kokhaei, P; Mellstedt, H; Remberger, M; Ljungman, P; Winiarski, J; Dalianis, T

2004-11-01

BK virus (BKV) load in urine alone or in combination with acute graft-versus-host disease (GVHD) was correlated to development of hemorrhagic cystitis (HC). BKV load in combination with acute GVHD discriminated the best, while BKV and viral load alone, but not GVHD, still showed predictive ability for HC.

Radiation Dose-Volume Effects in the Stomach and Small Bowel

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

Kavanagh, Brian D., E-mail: Brian.Kavanagh@ucdenver.ed; Pan, Charlie C.; Dawson, Laura A.

2010-03-01

Published data suggest that the risk of moderately severe (>=Grade 3) radiation-induced acute small-bowel toxicity can be predicted with a threshold model whereby for a given dose level, D, if the volume receiving that dose or greater (VD) exceeds a threshold quantity, the risk of toxicity escalates. Estimates of VD depend on the means of structure segmenting (e.g., V15 = 120 cc if individual bowel loops are outlined or V45 = 195 cc if entire peritoneal potential space of bowel is outlined). A similar predictive model of acute toxicity is not available for stomach. Late small-bowel/stomach toxicity is likely relatedmore » to maximum dose and/or volume threshold parameters qualitatively similar to those related to acute toxicity risk. Concurrent chemotherapy has been associated with a higher risk of acute toxicity, and a history of abdominal surgery has been associated with a higher risk of late toxicity.« less

Association between a High BK Virus Load in Urine Samples of Patients with Graft-Versus-Host Disease and Development of Hemorrhagic Cystitis after Hematopoietic Stem Cell Transplantation

PubMed Central

Bogdanovic, G.; Priftakis, P.; Giraud, G.; Kuzniar, M.; Ferraldeschi, R.; Kokhaei, P.; Mellstedt, H.; Remberger, M.; Ljungman, P.; Winiarski, J.; Dalianis, T.

2004-01-01

BK virus (BKV) load in urine alone or in combination with acute graft-versus-host disease (GVHD) was correlated to development of hemorrhagic cystitis (HC). BKV load in combination with acute GVHD discriminated the best, while BKV and viral load alone, but not GVHD, still showed predictive ability for HC. PMID:15528753

Evaluation of Geosynthetic-Reinforced Flexible Pavements using Static Plate Load Tests

DOT National Transportation Integrated Search

2010-01-01

This study focuses on the response of full-scale geogrid-reinforced flexible pavements to static surface loading. Specifically, static plate load (SPL) tests were performed on a low-volume, asphalt pavement frontage road in Eastern Arkansas, USA (the...

Volume-rendered hemorrhage-responsible arteriogram created by 64 multidetector-row CT during aortography: utility for catheterization in transcatheter arterial embolization for acute arterial bleeding.

PubMed

Minamiguchi, Hiroki; Kawai, Nobuyuki; Sato, Morio; Ikoma, Akira; Sanda, Hiroki; Nakata, Kouhei; Tanaka, Fumihiro; Nakai, Motoki; Sonomura, Tetsuo; Murotani, Kazuhiro; Hosokawa, Seiki; Nishioku, Tadayoshi

2014-01-01

Aortography for detecting hemorrhage is limited when determining the catheter treatment strategy because the artery responsible for hemorrhage commonly overlaps organs and non-responsible arteries. Selective catheterization of untargeted arteries would result in repeated arteriography, large volumes of contrast medium, and extended time. A volume-rendered hemorrhage-responsible arteriogram created with 64 multidetector-row CT (64MDCT) during aortography (MDCTAo) can be used both for hemorrhage mapping and catheter navigation. The MDCTAo depicted hemorrhage in 61 of 71 cases of suspected acute arterial bleeding treated at our institute in the last 3 years. Complete hemostasis by embolization was achieved in all cases. The hemorrhage-responsible arteriogram was used for navigation during catheterization, thus assisting successful embolization. Hemorrhage was not visualized in the remaining 10 patients, of whom 6 had a pseudoaneurysm in a visceral artery; 1 with urinary bladder bleeding and 1 with chest wall hemorrhage had gaze tamponade; and 1 with urinary bladder hemorrhage and 1 with uterine hemorrhage had spastic arteries. Six patients with pseudoaneurysm underwent preventive embolization and the other 4 patients were managed by watchful observation. MDCTAo has the advantage of depicting the arteries responsible for hemoptysis, whether from the bronchial arteries or other systemic arteries, in a single scan. MDCTAo is particularly useful for identifying the source of acute arterial bleeding in the pancreatic arcade area, which is supplied by both the celiac and superior mesenteric arteries. In a case of pelvic hemorrhage, MDCTAo identified the responsible artery from among numerous overlapping visceral arteries that branched from the internal iliac arteries. In conclusion, a hemorrhage-responsible arteriogram created by 64MDCT immediately before catheterization is useful for deciding the catheter treatment strategy for acute arterial bleeding.

Impact of Infarct Size on Blood Pressure in Young Patients with Acute Stroke.

PubMed

Bonardo, Pablo; Pantiú, Fátima; Ferraro, Martín; Chertcoff, Anibal; Bandeo, Lucrecia; Cejas, Luciana León; Pacha, Sol; Roca, Claudia Uribe; Rugilo, Carlos; Pardal, Manuel Maria Fernández; Reisin, Ricardo

2018-06-01

Hypertension can be found in up to 80% of patients with acute stroke. Many factors have been related to this phenomenon such as age, history of hypertension, and stroke severity. The aim of our study was to determine the relationship between infarct volume and blood pressure, at admission, in young patients with acute ischemic stroke. Patients younger than 55 years old admitted within 24 hours of ischemic stroke were included. Socio-demographic variables, systolic blood pressure, diastolic blood pressure, and infarct volume at admission were assessed. Statistical analysis: mean and SEM for quantitative variables, percentages for qualitative, and Spearman correlations ( p value < 0.05 was considered statistically significant). Twenty-two patients (12 men), mean age: 44.64 ± 1.62 years. The most frequent vascular risk factors were: hypertension, smoking, and overweight (40.9%). Mean systolic and diastolic blood pressure on admission were: 143.27 ± 6.57 mmHg and 85.14 ± 3.62 mmHg, respectively. Infarct volume: 11.55 ± 4.74 ml. Spearman correlations: systolic blood pressure and infarct volume: p = 0.15 r : -0.317; diastolic blood pressure and infarct volume: p = 0.738 r: -0.76. In our series of young patients with acute ischemic stroke, large infarct volume was not associated with high blood pressure at admission.

ESTIMATING URBAN WET WEATHER POLLUTANT LOADING

EPA Science Inventory

This paper presents procedures for estimating pollutant loads emanating from wet-weather flow discharge in urban watersheds. Equations are presented for: annual volume of litter and floatables; the quantity of sand from highway runoff; the quantity of dust-and-dirt accumulation ...

Chesapeake Bay Hypoxic Volume Forecasts and Results

USGS Publications Warehouse

Evans, Mary Anne; Scavia, Donald

2013-01-01

Given the average Jan-May 2013 total nitrogen load of 162,028 kg/day, this summer's hypoxia volume forecast is 6.1 km3, slightly smaller than average size for the period of record and almost the same as 2012. The late July 2013 measured volume was 6.92 km3.

Acute Stress and Perceptual Load Consume the Same Attentional Resources: A Behavioral-ERP Study

PubMed Central

Tiferet-Dweck, Chen; Hensel, Michael; Kirschbaum, Clemens; Tzelgov, Joseph; Friedman, Alon; Salti, Moti

2016-01-01

Stress and perceptual load affect selective attention in a paradoxical manner. They can facilitate selectivity or disrupt it. This EEG study was designed to examine the reciprocal relations between stress, load and attention. Two groups of subjects, one that performed the Trier Social Stress Test (TSST), and a control group, were asked to respond to a target letter under low and high perceptual load in the absence or presence of a distractor. In the control group, the distractor increased response times (RTs) for high and low load. In the TSST group, distractor increased RTs under low load only. ERPs showed that distractor’s presentation attenuated early visual P1 component and shortened its latency. In the TSST group, distractor reduced P1 component under high load but did not affect its latency. Source localization demonstrated reduced activation in V1 in response to distractors presence in the P1 time window for the TSST group compared to the control group. A behavioral replication revealed that in the TSST group distractors were less perceived under high load. Taken together, our results show that stress and perceptual load affect selectivity through the early stages of visual processing and might increase selectivity in a manner that would block conscious perception of irrelevant stimuli. PMID:27196027

Acute Effects of Nasal CPAP in Patients With Hypertrophic Cardiomyopathy.

PubMed

Nerbass, Flávia B; Salemi, Vera M C; Pedrosa, Rodrigo P; Portilho, Natanael de P; Ferreira-Filho, Julio C A; Moriya, Henrique T; Antunes, Murillo O; Arteaga-Fernández, Edmundo; Drager, Luciano F; Lorenzi-Filho, Geraldo

2016-11-01

Hypertrophic cardiomyopathy (HCM) is a common genetic disease that may cause left ventricular outflow tract (LVOT) obstruction, heart failure, and sudden death. Recent studies have shown a high prevalence of OSA among patients with HCM. Because the hemodynamics in patients with LVOT obstruction are unstable and depend on the loading conditions of the heart, we evaluated the acute effects of CPAP on hemodynamics and cardiac performance in patients with HCM. We studied 26 stable patients with HCM divided into nonobstructive HCM (n = 12) and obstructive HCM (n = 14) groups (LVOT gradient pressure lower or higher than 30 mm Hg, respectively). Patients in the supine position while awake were continuously monitored with beat-to-beat BP measurements and electrocardiography. Two-dimensional echocardiography was performed at rest (baseline) and after 20 min of nasal CPAP at 1.5 cm H 2 O and 10 cm H 2 O, which was applied in a random order interposed by 10 min without CPAP. BP, cardiac output, stroke volume, heart rate, left ventricular ejection fraction, and LVOT gradient did not change during the study period in either group. CPAP at 10 cm H 2 O decreased right atrial size and right ventricular relaxation in all patients. It also decreased left atrial volume significantly and decreased right ventricular outflow acceleration time, suggesting an increase in pulmonary artery pressure in patients with obstructive HCM. The acute application of CPAP is apparently safe in patients with HCM, because CPAP does not lead to hemodynamic compromise. Long-term studies in patients with HCM and sleep apnea and nocturnal CPAP are warranted. ClinicalTrials.gov; No. NCT01631006; URL: www.clinicaltrials.gov. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Striking volume intolerance is induced by mimicking arterial baroreflex failure in normal left ventricular function.

PubMed

Funakoshi, Kouta; Hosokawa, Kazuya; Kishi, Takuya; Ide, Tomomi; Sunagawa, Kenji

2014-01-01

Patients with heart failure and preserved ejection fraction (HFpEF) are supersensitive to volume overload, and a striking increase in left atrial pressure (LAP) often occurs transiently and is rapidly resolved by intravascular volume reduction. The arterial baroreflex is a powerful regulator of intravascular stressed blood volume. We examined whether arterial baroreflex failure (FAIL) mimicked by constant carotid sinus pressure (CSP) causes a striking increase in LAP and systemic arterial pressure (AP) by volume loading in rats with normal left ventricular (LV) function. In anesthetized Sprague-Dawley rats, we isolated bilateral carotid sinuses and controlled CSP by a servo-controlled piston pump. We mimicked the normal arterial baroreflex by matching CSP to instantaneous AP and FAIL by maintaining CSP at a constant value regardless of AP. We infused dextran stepwise (infused volume [Vi]) until LAP reached 15 mm Hg and obtained the LAP-Vi relationship. We estimated the critical Vi as the Vi at which LAP reached 20 mm Hg. In FAIL, critical Vi decreased markedly from 19.4 ± 1.6 mL/kg to 15.6 ± 1.6 mL/kg (P < .01), whereas AP at the critical Vi increased (194 ± 6 mm Hg vs 163 ± 6 mm Hg; P < .01). We demonstrated that an artificial arterial baroreflex system we recently developed could fully restore the physiologic volume intolerance in the absence of native arterial baroreflex. Arterial baroreflex failure induces striking volume intolerance in the absence of LV dysfunction and may play an important role in the pathogenesis of acute heart failure, especially in states of HFpEF. Copyright © 2014 Elsevier Inc. All rights reserved.

Comparison of DVH parameters and loading patterns of standard loading, manual and inverse optimization for intracavitary brachytherapy on a subset of tandem/ovoid cases.

PubMed

Jamema, Swamidas V; Kirisits, Christian; Mahantshetty, Umesh; Trnkova, Petra; Deshpande, Deepak D; Shrivastava, Shyam K; Pötter, Richard

2010-12-01

Comparison of inverse planning with the standard clinical plan and with the manually optimized plan based on dose-volume parameters and loading patterns. Twenty-eight patients who underwent MRI based HDR brachytherapy for cervix cancer were selected for this study. Three plans were calculated for each patient: (1) standard loading, (2) manual optimized, and (3) inverse optimized. Dosimetric outcomes from these plans were compared based on dose-volume parameters. The ratio of Total Reference Air Kerma of ovoid to tandem (TRAK(O/T)) was used to compare the loading patterns. The volume of HR CTV ranged from 9-68 cc with a mean of 41(±16.2) cc. Mean V100 for standard, manual optimized and inverse plans was found to be not significant (p=0.35, 0.38, 0.4). Dose to bladder (7.8±1.6 Gy) and sigmoid (5.6±1.4 Gy) was high for standard plans; Manual optimization reduced the dose to bladder (7.1±1.7 Gy p=0.006) and sigmoid (4.5±1.0 Gy p=0.005) without compromising the HR CTV coverage. The inverse plan resulted in a significant reduction to bladder dose (6.5±1.4 Gy, p=0.002). TRAK was found to be 0.49(±0.02), 0.44(±0.04) and 0.40(±0.04) cGy m(-2) for the standard loading, manual optimized and inverse plans, respectively. It was observed that TRAK(O/T) was 0.82(±0.05), 1.7(±1.04) and 1.41(±0.93) for standard loading, manual optimized and inverse plans, respectively, while this ratio was 1 for the traditional loading pattern. Inverse planning offers good sparing of critical structures without compromising the target coverage. The average loading pattern of the whole patient cohort deviates from the standard Fletcher loading pattern. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

[Ascites and acute kidney injury].

PubMed

Piano, Salvatore; Tonon, Marta; Angeli, Paolo

2016-07-01

Ascites is the most common complication of cirrhosis. Ascites develops as a consequence of an abnormal splanchnic vasodilation with reduction of effecting circulating volume and activation of endogenous vasoconstrictors system causing salt and water retention. Patients with ascites have a high risk to develop further complications of cirrhosis such as hyponatremia, spontaneous bacterial peritonitis and acute kidney injury resulting in a poor survival. In recent years, new studies helped a better understanding of the pathophysiology of ascites and acute kidney injury in cirrhosis. Furthermore, new diagnostic criteria have been proposed for acute kidney injury and hepatorenal syndrome and a new algorithm for their management has been recommended with the aim of an early diagnosis and treatment. Herein we will review the current knowledge on the pathophysiology, diagnosis and treatment of ascites and acute kidney injury in patients with cirrhosis and we will identify the unmet needs that should be clarified in the next years.

A program for calculating load coefficient matrices utilizing the force summation method, L218 (LOADS). Volume 2: Supplemental system design and maintenance document

NASA Technical Reports Server (NTRS)

Anderson, L. R.; Miller, R. D.

1979-01-01

The LOADS computer program L218 which calculates dynamic load coefficient matrices utilizing the force summation method is described. The load equations are derived for a flight vehicle in straight and level flight and excited by gusts and/or control motions. In addition, sensor equations are calculated for use with an active control system. The load coefficient matrices are calculated for the following types of loads: (1) translational and rotational accelerations, velocities, and displacements; (2) panel aerodynamic forces; (3) net panel forces; and (4) shears, bending moments, and torsions.

Chesapeake Bay hypoxic volume forecasts and results

USGS Publications Warehouse

Scavia, Donald; Evans, Mary Anne

2013-01-01

The 2013 Forecast - Given the average Jan-May 2013 total nitrogen load of 162,028 kg/day, this summer’s hypoxia volume forecast is 6.1 km3, slightly smaller than average size for the period of record and almost the same as 2012. The late July 2013 measured volume was 6.92 km3.

Acute hormonal responses in elite junior weightlifters.

PubMed

Kraemer, W J; Fry, A C; Warren, B J; Stone, M H; Fleck, S J; Kearney, J T; Conroy, B P; Maresh, C M; Weseman, C A; Triplett, N T

1992-02-01

To date, no published studies have demonstrated resistance exercise-induced increases in serum testosterone in adolescent males. Furthermore, few data are available on the effects of training experience and lifting performance on acute hormonal responses to weightlifting in young males. Twenty-eight junior elite male Olympic-style weightlifters (17.3 +/- 1.4 yrs) volunteered for the study. An acute weightlifting exercise protocol using moderate to high intensity loads and low volume, characteristic of many weightlifting training sessions, was examined. The exercise protocol was directed toward the training associated with the snatch lift weightlifting exercise. Blood samples were obtained from a superficial arm vein at 7 a.m. (for baseline measurements), and again at pre-exercise, 5 min post-, and 15 min post-exercise time points for determination of serum testosterone, cortisol, growth hormone, plasma beta-endorphin, and whole blood lactate. The exercise protocol elicited significant (p less than or equal to 0.05) increases in each of the hormones and whole blood lactate compared to pre-exercise measures. While not being significantly older, subsequent analysis revealed that subjects with greater than 2 years training experience exhibited significant exercise-induced increases in serum testosterone from pre-exercise to 5 min post-exercise (16.2 +/- 6.2 to 21.4 +/- 7.9 nmol.l-1), while those with less than or equal to 2 years training showed no significant serum testosterone differences. None of the other hormones or whole blood lactate appear to be influenced by training experience.(ABSTRACT TRUNCATED AT 250 WORDS)

Cellular pressure and volume regulation and implications for cell mechanics

NASA Astrophysics Data System (ADS)

Jiang, Hongyuan; Sun, Sean

2013-03-01

In eukaryotic cells, small changes in cell volume can serve as important signals for cell proliferation, death and migration. Volume and shape regulation also directly impacts the mechanics of the cell and multi-cellular tissues. Recent experiments found that during mitosis, eukaryotic cells establish a preferred steady volume and pressure, and the steady volume and pressure can robustly adapt to large osmotic shocks. Here we develop a mathematical model of cellular pressure and volume regulation, incorporating essential elements such as water permeation, mechano-sensitive channels, active ion pumps and active stresses in the actomyosin cortex. The model can fully explain the available experimental data, and predicts the cellular volume and pressure for several models of cell cortical mechanics. Furthermore, we show that when cells are subjected to an externally applied load, such as in an AFM indentation experiment, active regulation of volume and pressure leads to complex cellular response. We found the cell stiffness highly depends on the loading rate, which indicates the transport of water and ions might contribute to the observed viscoelasticity of cells.

Acute stress reactions after submarine accidents.

PubMed

Eid, Jarle; Johnsen, Bjørn Helge

2002-05-01

The aim of the present study was to explore contextual and individual factors associated with acute stress reactions in three Norwegian submarine crews exposed to different significant peacetime maneuver accidents. Approximately 2 to 3 weeks after the accidents, crew members completed the Coping Style Questionnaire, the General Health Questionnaire, the Impact of Event Scale, and the Post-Traumatic Symptom Scale. Although exposed subjects (N = 47) revealed more posttraumatic stress symptoms than nonexposed crew members on shore leave (N = 7), they showed less acute stress reactions than survivors from a surface ship accident in the Norwegian Navy. Inspection of individual cases revealed that 4% of the exposed submariners showed high loads of acute stress symptoms. Unit cohesion and habitual coping styles emerged as resilience factors, whereas previous exposure to critical incidents and personal experience of not coping in the accident situation emerged as vulnerability factors, explaining 32% of the acute stress reactions reported by submarine crew members.

Effects of Imbalanced Muscle Loading on Hip Joint Development and Maturation

PubMed Central

Ford, Caleb A.; Nowlan, Niamh C.; Thomopoulos, Stavros; Killian, Megan L.

2017-01-01

The mechanical loading environment influences the development and maturation of joints. In this study, the influence of imbalanced muscular loading on joint development was studied using localized chemical denervation of hip stabilizing muscle groups in neonatal mice. It was hypothesized that imbalanced muscle loading, targeting either gluteal muscles or quadriceps muscles, would lead to bilateral hip joint asymmetry, as measured by acetabular coverage, femoral head volume and bone morphometry, and femoral-acetabular shape. The contralateral hip joints as well as age-matched, uninjected mice were used as controls. Altered bone development was analyzed using micro-computed tomography, histology, and image registration techniques at postnatal days (P) 28, 56, and 120. This study found that unilateral muscle unloading led to reduced acetabular coverage of the femoral head, lower total volume, lower bone volume ratio, and lower mineral density, at all three time points. Histologically, the femoral head was smaller in unloaded hips, with thinner triradiate cartilage at P28 and thinner cortical bone at P120 compared to contralateral hips. Morphological shape changes were evident in unloaded hips at P56. Unloaded hips had lower trabecular thickness and increased trabecular spacing of the femoral head compared to contralateral hips. The present study suggests that decreased muscle loading of the hip leads to altered bone and joint shape and growth during postnatal maturation. Statement of Clinical Significance: Adaptations from altered muscle loading during postnatal growth investigated in this study have implications on developmental hip disorders that result from asymmetric loading, such as patients with limb-length inequality or dysplasia. PMID:27391299

Cognitive correlates of white matter lesion load and brain atrophy

PubMed Central

Dong, Chuanhui; Nabizadeh, Nooshin; Caunca, Michelle; Cheung, Ying Kuen; Rundek, Tatjana; Elkind, Mitchell S.V.; DeCarli, Charles; Sacco, Ralph L.; Stern, Yaakov

2015-01-01

Objective: We investigated white matter lesion load and global and regional brain volumes in relation to domain-specific cognitive performance in the stroke-free Northern Manhattan Study (NOMAS) population. Methods: We quantified white matter hyperintensity volume (WMHV), total cerebral volume (TCV), and total lateral ventricular (TLV) volume, as well as hippocampal and cortical gray matter (GM) lobar volumes in a subgroup. We used general linear models to examine MRI markers in relation to domain-specific cognitive performance, adjusting for key covariates. Results: MRI and cognitive data were available for 1,163 participants (mean age 70 ± 9 years; 60% women; 66% Hispanic, 17% black, 15% white). Across the entire sample, those with greater WMHV had worse processing speed. Those with larger TLV volume did worse on episodic memory, processing speed, and semantic memory tasks, and TCV did not explain domain-specific variability in cognitive performance independent of other measures. Age was an effect modifier, and stratified analysis showed that TCV and WMHV explained variability in some domains above age 70. Smaller hippocampal volume was associated with worse performance across domains, even after adjusting for APOE ε4 and vascular risk factors, whereas smaller frontal lobe volumes were only associated with worse executive function. Conclusions: In this racially/ethnically diverse, community-based sample, white matter lesion load was inversely associated with cognitive performance, independent of brain atrophy. Lateral ventricular, hippocampal, and lobar GM volumes explained domain-specific variability in cognitive performance. PMID:26156514

Low reflectance radio frequency load

DOEpatents

Ives, R. Lawrence; Mizuhara, Yosuke M

2014-04-01

A load for traveling microwave energy has an absorptive volume defined by cylindrical body enclosed by a first end cap and a second end cap. The first end cap has an aperture for the passage of an input waveguide with a rotating part that is coupled to a reflective mirror. The inner surfaces of the absorptive volume consist of a resistive material or are coated with a coating which absorbs a fraction of incident RF energy, and the remainder of the RF energy reflects. The angle of the reflector and end caps is selected such that reflected RF energy dissipates an increasing percentage of the remaining RF energy at each reflection, and the reflected RF energy which returns to the rotating mirror is directed to the back surface of the rotating reflector, and is not coupled to the input waveguide. Additionally, the reflector may have a surface which generates a more uniform power distribution function axially and laterally, to increase the power handling capability of the RF load. The input waveguide may be corrugated for HE11 mode input energy.

Instream wood loads in montane forest streams of the Colorado Front Range, USA

NASA Astrophysics Data System (ADS)

Jackson, Karen J.; Wohl, Ellen

2015-04-01

Although several studies examine instream wood loads and associated geomorphic effects in streams of subalpine forests in the U.S. Southern Rocky Mountains, little is known of instream wood loads in lower elevation, montane forests of the region. We compare instream wood loads and geomorphic effects between streams draining montane forest stands of differing age (old growth versus younger) and disturbance history (healthy versus infested by mountain pine beetles). We examined forest stand characteristics, instream wood load, channel geometry, pool volume, and sediment storage in 33 pool-riffle or plane-bed stream reaches with objectives of determining whether (i) instream wood and geomorphic effects differed significantly among old-growth, younger, healthy, and beetle-infested forest stands and (ii) wood loads correlated with valley and channel characteristics. Wood loads were standardized to drainage area, stream gradient, reach length, bankfull width, and floodplain area. Streams flowing through old-growth forests had significantly larger wood loads and logjam volumes (pairwise t-tests), as well as logjam frequencies (Kruskal-Wallis test), residual pool volume, and fine sediment storage around wood than streams flowing through younger forests. Wood loads in streams draining beetle-infested forest did not differ significantly from those in healthy forest stands, but best subset regression models indicated that elevation, stand age, and beetle infestation were the best predictors of wood loads in channels and on floodplains, suggesting that beetle infestation is affecting instream wood characteristics. Wood loads are larger than values from subalpine streams in the same region and jams are larger and more closely spaced. We interpret these differences to reflect greater wood piece mobility in subalpine zone streams. Stand age appears to exert the dominant influence on instream wood characteristics within pool-riffle streams in the study area rather than beetle

Cardiologist service volume, percutaneous coronary intervention and hospital level in relation to medical costs and mortality in patients with acute myocardial infarction: a nationwide study.

PubMed

Liu, C-Y; Lin, Y-N; Lin, C-L; Chang, Y-J; Hsu, Y-H; Tsai, W-C; Kao, C-H

2014-07-01

We explore whether cardiologist service volume, hospital level and percutaneous coronary intervention (PCI) are associated with medical costs and acute myocardial infarction (AMI) mortality. From the 1997-2010 Taiwan National Health Insurance Research Database of the National Health Research Institute, we identified AMI patients and performed multiple regression analyses to explore the relationships among the different hospital levels and treatment factors. We identified 2942 patients with AMI in medical centers and 4325 patients with AMI in regional hospitals. Cardiologist service volume, performing PCI and medical costs per patient were higher in medical centers than in regional hospitals (P < 0.0001). However, the two hospital levels did not differ significantly in in-hospital mortality (P = 0.1557). Post hoc analysis showed significant differences in in-hospital mortality rate and in medical costs among the eight groups subdivided on the basis of hospital level, cardiologist service volume, and whether PCI was performed (P < 0.001 and P = 0.001, respectively). These results highlight the importance of encouraging hospitals to develop PCI capability and increase their cardiologist service volume after taking medical costs into account. Transferring AMI patients to hospitals with higher cardiologist service volume and PCI performed can also be very important. © The Author 2014. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Neonatal mannequin comparison of the Upright self-inflating bag and snap-fit mask versus standard resuscitators and masks: leak, applied load and tidal volumes.

PubMed

Rafferty, Anthony Richard; Johnson, Lucy; Davis, Peter G; Dawson, Jennifer Anne; Thio, Marta; Owen, Louise S

2017-11-30

Neonatal mask ventilation is a difficult skill to acquire and maintain. Mask leak is common and can lead to ineffective ventilation. The aim of this study was to determine whether newly available neonatal self-inflating bags and masks could reduce mask leak without additional load being applied to the face. Forty operators delivered 1 min episodes of mask ventilation to a mannequin using the Laerdal Upright Resuscitator, a standard Laerdal infant resuscitator (Laerdal Medical) and a T-Piece Resuscitator (Neopuff), using both the Laerdal snap-fit face mask and the standard Laerdal size 0/1 face mask (equivalent sizes). Participants were asked to use pressure sufficient to achieve 'appropriate' chest rise. Leak, applied load, airway pressure and tidal volume were measured continuously. Participants were unaware that load was being recorded. There was no difference in mask leak between resuscitation devices. Leak was significantly lower when the snap-fit mask was used with all resuscitation devices, compared with the standard mask (14% vs 37% leak, P<0.01). The snap-fit mask was preferred by 83% of participants. The device-mask combinations had no significant effect on applied load. The Laerdal Upright Resuscitator resulted in similar leak to the other resuscitation devices studied, and did not exert additional load to the face and head. The snap-fit mask significantly reduced overall leak with all resuscitation devices and was the mask preferred by participants. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Sonographic assessment of changes in diaphragmatic kinetics induced by inspiratory resistive loading.

PubMed

Soilemezi, Eleni; Tsagourias, Matthew; Talias, Michael A; Soteriades, Elpidoforos S; Makrakis, Vasilios; Zakynthinos, Epaminondas; Matamis, Dimitrios

2013-04-01

Diaphragmatic breathing patterns under resistive loading remain poorly documented. To our knowledge, this is the first study assessing diaphragmatic motion under conditions of inspiratory resistive loading with the use of sonography. We assessed diaphragmatic motion during inspiratory resistive loading in 40 healthy volunteers using M-mode sonography. In phase I of the study, sonography was performed during normal quiet breathing without respiratory loading. In phase II, sonography was performed after application of a nose clip and connection of the subjects to a pneumotachograph through a mouth piece. In phase III, the participants were assessed while subjected to inspiratory resistive loading of 50 cm H(2)O/L/s. Compared with baseline, the application of a mouth piece and nose clip induced a significant increase in diaphragmatic excursion (from 1.7 to 2.3 cm, P < 0.001) and a decrease in respiratory rate (from 13.4 to 12.2, P < 0.01). Inspiratory resistive loading induced a further decrease in respiratory rate (from 12.2 to 8.0, P < 0.01) and a decrease in diaphragmatic velocity contraction (from 1.2 to 0.8 cm/s, P < 0.01), and also an increase in tidal volume (from 795 to 904 mL, P < 0.01); diaphragmatic excursion, however, did not change significantly. Inspiratory resistive loading induced significant changes in diaphragmatic contraction pattern, which mainly consisted of decreased velocity of diaphragmatic displacement with no change in diaphragmatic excursion. Tidal volume, increased significantly; the increase in tidal volume, along with the unchanged diaphragmatic excursion, provides sonographic evidence of increased recruitment of extradiaphragmatic muscles under inspiratory resistive loading. © 2013 The Authors. Respirology © 2013 Asian Pacific Society of Respirology.

Effect of rosuvastatin dose-loading on serum sLox-1, hs-CRP, and postoperative prognosis in diabetic patients with acute coronary syndromes undergoing selected percutaneous coronary intervention (PCI).

PubMed

Jiao, Yungen; Hu, Feng; Zhang, Zhengang; Gong, Kaizheng; Sun, Xiaoning; Li, Aihua; Liu, Naifeng

2015-01-01

To investigate the effect of rosuvastatin dose-loading on serum levels of lectin-like oxidized low-density lipoprotein receptor-1 (Lox-1) and high-sensitivity c-reactive protein (hs-CRP) and postoperative prognosis in patients with diabetes and non-ST segment elevation acute coronary syndromes (NSTEACS) undergoing selected percutaneous coronary intervention (PCI). A total of 72 patients with diabetes and NSTEACS were randomized to either the group treated with 20 mg rosuvastatin 12 hours prior to PCI with a second dose administered just before PCI (n = 33), or a control group treated with standard method according guideline (n = 39). Serum levels of sLox-1, hs-CRP, CK-MB, and cTnI were measured prior to PCI, and at 24 hours and 30 days after PCI. The 30-day incidence of major adverse cardiac events (MACE) was recorded in both groups. Compared to pre-PCI, serum levels of sLox-1 and hs-CRP of the two groups were increased at 24 hours after PCI (P < 0.05); the levels of CK-MB and cTnI were also improved (P < 0.01); however, the ascended values of sLox-1, hs-CRP, CK-MB, and cTnI were significantly lower in the loading-dose rosuvastatin-treated group than in the control-treated group. Serum levels of sLox-1 and hs-CRP were higher in the loading-dose rosuvastatin-treated group than in the control-treated group at 30 days after PCI (P < 0.05); compared to pre-PCI, the levels of TC and LDL-C were not changed at 24 hours after PCI (P > 0.05) until 30 days after PCI (P < 0.05), but there were no difference between the two groups. The levels of ALT and Scr had no significant difference between the two groups before and after PCI; the 30-day incidence of MACE occurred in 6.06% of patients in the loading-dose rosuvastatin-treated group and in 23.08% of patients in the control-treated group (P < 0.05). The therapy of dose-loading rosuvastatin for patients with diabetes and non-ST segment elevation acute coronary syndromes undergoing selected percutaneous coronary intervention

Prospective Study of Acute HIV-1 Infection in Adults in East Africa and Thailand.

PubMed

Robb, Merlin L; Eller, Leigh A; Kibuuka, Hannah; Rono, Kathleen; Maganga, Lucas; Nitayaphan, Sorachai; Kroon, Eugene; Sawe, Fred K; Sinei, Samuel; Sriplienchan, Somchai; Jagodzinski, Linda L; Malia, Jennifer; Manak, Mark; de Souza, Mark S; Tovanabutra, Sodsai; Sanders-Buell, Eric; Rolland, Morgane; Dorsey-Spitz, Julie; Eller, Michael A; Milazzo, Mark; Li, Qun; Lewandowski, Andrew; Wu, Hao; Swann, Edith; O'Connell, Robert J; Peel, Sheila; Dawson, Peter; Kim, Jerome H; Michael, Nelson L

2016-06-02

Acute human immunodeficiency virus type 1 (HIV-1) infection is a major contributor to transmission of HIV-1. An understanding of acute HIV-1 infection may be important in the development of treatment strategies to eradicate HIV-1 or achieve a functional cure. We performed twice-weekly qualitative plasma HIV-1 RNA nucleic acid testing in 2276 volunteers who were at high risk for HIV-1 infection. For participants in whom acute HIV-1 infection was detected, clinical observations, quantitative measurements of plasma HIV-1 RNA levels (to assess viremia) and HIV antibodies, and results of immunophenotyping of lymphocytes were obtained twice weekly. Fifty of 112 volunteers with acute HIV-1 infection had two or more blood samples collected before HIV-1 antibodies were detected. The median peak viremia (6.7 log10 copies per milliliter) occurred 13 days after the first sample showed reactivity on nucleic acid testing. Reactivity on an enzyme immunoassay occurred at a median of 14 days. The nadir of viremia (4.3 log10 copies per milliliter) occurred at a median of 31 days and was nearly equivalent to the viral-load set point, the steady-state viremia that persists durably after resolution of acute viremia (median plasma HIV-1 RNA level, 4.4 log10 copies per milliliter). The peak viremia and downslope were correlated with the viral-load set point. Clinical manifestations of acute HIV-1 infection were most common just before and at the time of peak viremia. A median of one symptom of acute HIV-1 infection was recorded at a median of two study visits, and a median of one sign of acute HIV-1 infection was recorded at a median of three visits. The viral-load set point occurred at a median of 31 days after the first detection of plasma viremia and correlated with peak viremia. Few symptoms and signs were observed during acute HIV-1 infection, and they were most common before peak viremia. (Funded by the Department of Defense and the National Institute of Allergy and Infectious

Prediction of infarction volume and infarction growth rate in acute ischemic stroke.

PubMed

Kamran, Saadat; Akhtar, Naveed; Alboudi, Ayman; Kamran, Kainat; Ahmad, Arsalan; Inshasi, Jihad; Salam, Abdul; Shuaib, Ashfaq; Qidwai, Uvais

2017-08-08

The prediction of infarction volume after stroke onset depends on the shape of the growth dynamics of the infarction. To understand growth patterns that predict lesion volume changes, we studied currently available models described in literature and compared the models with Adaptive Neuro-Fuzzy Inference System [ANFIS], a method previously unused in the prediction of infarction growth and infarction volume (IV). We included 67 patients with malignant middle cerebral artery [MMCA] stroke who underwent decompressive hemicraniectomy. All patients had at least three cranial CT scans prior to the surgery. The rate of growth and volume of infarction measured on the third CT was predicted with ANFIS without statistically significant difference compared to the ground truth [P = 0.489]. This was not possible with linear, logarithmic or exponential methods. ANFIS was able to predict infarction volume [IV3] over a wide range of volume [163.7-600 cm 3 ] and time [22-110 hours]. The cross correlation [CRR] indicated similarity between the ANFIS-predicted IV3 and original data of 82% for ANFIS, followed by logarithmic 70%, exponential 63% and linear 48% respectively. Our study shows that ANFIS is superior to previously defined methods in the prediction of infarction growth rate (IGR) with reasonable accuracy, over wide time and volume range.

Acute care hospitals' accountability to provincial funders.

PubMed

Kromm, Seija K; Ross Baker, G; Wodchis, Walter P; Deber, Raisa B

2014-09-01

Ontario's acute care hospitals are subject to a number of tools, including legislation and performance measurement for fiscal accountability and accountability for quality. Examination of accountability documents used in Ontario at the government, regional and acute care hospital levels reveals three trends: (a) the number of performance measures being used in the acute care hospital sector has increased significantly; (b) the focus of the health system has expanded from accountability for funding and service volumes to include accountability for quality and patient safety; and (c) the accountability requirements are misaligned at the different levels. These trends may affect the success of the accountability approach currently being used. Copyright © 2014 Longwoods Publishing.

Analyzing the effects of mechanical and osmotic loading on glycosaminoglycan synthesis rate in cartilaginous tissues.

PubMed

Gao, Xin; Zhu, Qiaoqiao; Gu, Weiyong

2015-02-26

The glycosaminoglycan (GAG) plays an important role in cartilaginous tissues to support and transmit mechanical loads. Many extracellular biophysical stimuli could affect GAG synthesis by cells. It has been hypothesized that the change of cell volume is a primary mechanism for cells to perceive the stimuli. Experimental studies have shown that the maximum synthesis rate of GAG is achieved at an optimal cell volume, larger or smaller than this level the GAG synthesis rate decreases. Based on the hypothesis and experimental findings in the literature, we proposed a mathematical model to quantitatively describe the cell volume dependent GAG synthesis rate in the cartilaginous tissues. Using this model, we investigated the effects of osmotic loading and mechanical loading on GAG synthesis rate. It is found our proposed mathematical model is able to well describe the change of GAG synthesis rate in isolated cells or in cartilage with variations of the osmotic loading or mechanical loading. This model is important for evaluating the GAG synthesis activity within cartilaginous tissues as well as understanding the role of mechanical loading in tissue growth or degeneration. It is also important for designing a bioreactor system with proper extracellular environment or mechanical loading for growing tissue at the maximum synthesis rate of the extracellular matrix. Copyright © 2015 Elsevier Ltd. All rights reserved.

Importance of viruses in acute otitis media.

PubMed

Nokso-Koivisto, Johanna; Marom, Tal; Chonmaitree, Tasnee

2015-02-01

Acute otitis media occurs as a complication of viral upper respiratory tract infection. Bacterial otopathogens and respiratory viruses interact and play important roles in acute otitis media development. A better understanding of viral and bacterial interactions may lead to innovative ways to lessen the burden of this common childhood disease. There has been increasing evidence that acute otitis media occurs during upper respiratory infection, even in the absence of nasopharyngeal bacterial colonization. Among the types of viruses associated with acute otitis media, respiratory syncytial virus continues to be the most commonly detected. It is still unclear whether viral load plays an important role in acute otitis media development, but symptomatic upper respiratory tract infection (as opposed to asymptomatic viral infection) is crucial. Widespread use of bacterial and viral vaccines in young children, including pneumococcal conjugate and influenza vaccines, has led to the reduction in otitis media-related healthcare use between 2001 and 2011. There has been no new vaccine against respiratory viruses other than influenza. Progress has been made toward the reduction of the burden of acute otitis media in the last decade. Success in reducing acute otitis media incidence will rely mainly on prevention of nasopharyngeal otopathogen colonization, as well as reduction in the incidence of viral upper respiratory tract infection.

An acute care surgery rotation contributes significant general surgical operative volume to residency training compared with other rotations.

PubMed

Stanley, Matthew D; Davenport, Daniel L; Procter, Levi D; Perry, Jacob E; Kearney, Paul A; Bernard, Andrew C

2011-03-01

Surgical resident rotations on trauma services are criticized for little operative experience and heavy workloads. This has resulted in diminished interest in trauma surgery among surgical residents. Acute care surgery (ACS) combines trauma and emergency/elective general surgery, enhancing operative volume and balancing operative and nonoperative effort. We hypothesize that a mature ACS service provides significant operative experience. A retrospective review was performed of ACGME case logs of 14 graduates from a major, academic, Level I trauma center program during a 3-year period. Residency Review Committee index case volumes during the fourth and fifth years of postgraduate training (PGY-4 and PGY-5) ACS rotations were compared with other service rotations: in total and per resident week on service. Ten thousand six hundred fifty-four cases were analyzed for 14 graduates. Mean cases per resident was 432 ± 57 in PGY-4, 330 ± 40 in PGY-5, and 761 ± 67 for both years combined. Mean case volume on ACS for both years was 273 ± 44, which represented 35.8% (273 of 761) of the total experience and exceeded all other services. Residents averaged 8.9 cases per week on the ACS service, which exceeded all other services except private general surgery, gastrointestinal/minimally invasive surgery, and pediatric surgery rotations. Disproportionately more head/neck, small and large intestine, gastric, spleen, laparotomy, and hernia cases occurred on ACS than on other services. Residents gain a large operative experience on ACS. An ACS model is viable in training, provides valuable operative experience, and should not be considered a drain on resident effort. Valuable ACS rotation experiences as a resident may encourage graduates to pursue ACS as a career. Copyright © 2011 by Lippincott Williams & Wilkins

Training loads and injury risk in Australian football—differing acute: chronic workload ratios influence match injury risk

PubMed Central

Carey, David L; Blanch, Peter; Ong, Kok-Leong; Crossley, Kay M; Crow, Justin; Morris, Meg E

2017-01-01

Aims (1) To investigate whether a daily acute:chronic workload ratio informs injury risk in Australian football players; (2) to identify which combination of workload variable, acute and chronic time window best explains injury likelihood. Methods Workload and injury data were collected from 53 athletes over 2 seasons in a professional Australian football club. Acute:chronic workload ratios were calculated daily for each athlete, and modelled against non-contact injury likelihood using a quadratic relationship. 6 workload variables, 8 acute time windows (2–9 days) and 7 chronic time windows (14–35 days) were considered (336 combinations). Each parameter combination was compared for injury likelihood fit (using R2). Results The ratio of moderate speed running workload (18–24 km/h) in the previous 3 days (acute time window) compared with the previous 21 days (chronic time window) best explained the injury likelihood in matches (R2=0.79) and in the immediate 2 or 5 days following matches (R2=0.76–0.82). The 3:21 acute:chronic workload ratio discriminated between high-risk and low-risk athletes (relative risk=1.98–2.43). Using the previous 6 days to calculate the acute workload time window yielded similar results. The choice of acute time window significantly influenced model performance and appeared to reflect the competition and training schedule. Conclusions Daily workload ratios can inform injury risk in Australian football. Clinicians and conditioning coaches should consider the sport-specific schedule of competition and training when choosing acute and chronic time windows. For Australian football, the ratio of moderate speed running in a 3-day or 6-day acute time window and a 21-day chronic time window best explained injury risk. PMID:27789430

[Perioperative acute kidney injury and failure].

PubMed

Chhor, Vibol; Journois, Didier

2014-04-01

Perioperative period is very likely to lead to acute renal failure because of anesthesia (general or perimedullary) and/or surgery which can cause acute kidney injury. Characterization of acute renal failure is based on serum creatinine level which is imprecise during and following surgery. Studies are based on various definitions of acute renal failure with different thresholds which skewed their comparisons. The RIFLE classification (risk, injury, failure, loss, end stage kidney disease) allows clinicians to distinguish in a similar manner between different stages of acute kidney injury rather than using a unique definition of acute renal failure. Acute renal failure during the perioperative period can mainly be explained by iatrogenic, hemodynamic or surgical causes and can result in an increased morbi-mortality. Prevention of this complication requires hemodynamic optimization (venous return, cardiac output, vascular resistance), discontinuation of nephrotoxic drugs but also knowledge of the different steps of the surgery to avoid further degradation of renal perfusion. Diuretics do not prevent acute renal failure and may even push it forward especially during the perioperative period when venous retourn is already reduced. Edema or weight gain following surgery are not correlated with the vascular compartment volume, much less with renal perfusion. Treatment of perioperative acute renal failure is similar to other acute renal failure. Renal replacement therapy must be mastered to prevent any additional risk of hemodynamic instability or hydro-electrolytic imbalance. Copyright © 2014 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

The effect of filler loading and morphology on the mechanical properties of contemporary composites.

PubMed

Kim, Kyo-Han; Ong, Joo L; Okuno, Osamu

2002-06-01

Little information exists regarding the filler morphology and loading of composites with respect to their effects on selected mechanical properties and fracture toughness. The objectives of this study were to: (1) classify commercial composites according to filler morphology, (2) evaluate the influence of filler morphology on filler loading, and (3) evaluate the effect of filler morphology and loading on the hardness, flexural strength, flexural modulus, and fracture toughness of contemporary composites. Field emission scanning electron microscopy/energy dispersive spectroscopy was used to classify 3 specimens from each of 14 commercial composites into 4 groups according to filler morphology. The specimens (each 5 x 2.5 x 15 mm) were derived from the fractured remnants after the fracture toughness test. Filler weight content was determined by the standard ash method, and the volume content was calculated using the weight percentage and density of the filler and matrix components. Microhardness was measured with a Vickers hardness tester, and flexural strength and modulus were measured with a universal testing machine. A 3-point bending test (ASTM E-399) was used to determine the fracture toughness of each composite. Data were compared with analysis of variance followed by Duncan's multiple range test, both at the P<.05 level of significance. The composites were classified into 4 categories according to filler morphology: prepolymerized, irregular-shaped, both prepolymerized and irregular-shaped, and round particles. Filler loading was influenced by filler morphology. Composites containing prepolymerized filler particles had the lowest filler content (25% to 51% of filler volume), whereas composites containing round particles had the highest filler content (59% to 60% of filler volume). The mechanical properties of the composites were related to their filler content. Composites with the highest filler by volume exhibited the highest flexural strength (120 to 129 MPa

Whole Arm Water Displacement Volumetry Is a Reliable and Sensitive Measure: A Pilot to Assess Acute Postburn Volume Change.

PubMed

Edgar, Dale W; Briffa, N Kathy; Wood, Fiona M

Water displacement volumetry (WDV) is a reliable method for measurement of wrist and hand volume in lymphedema patients. However, within session WDV reliability for the whole upper limb (UL) lacks comprehensive investigation, particularly in acute edema populations. This study aimed to confirm the reliability and investigate the impact of time between repeated trials on the sensitivity of WDV as a measure of whole UL volume change in an uninjured cohort and a burn injured pilot group. Within session, duplicate measures of whole UL WDV were recorded in two groups of noninjured volunteers and a group of burn patients. Each noninjured group differed only in the time between WDV repeats. The reliability trials were performed <10 minutes apart (T10) and 20 to 30 minutes apart (T20). The time between repetitions for burn patients was 20 to 30 minutes, based on the results of the noninjured participant trials. All trial groups demonstrated excellent correlation between trials (ICCT10 = 0.999, ICCT20 = 0.997). The minimum detectable difference calculated for WDV when measuring whole UL volume change of >50 ml for noninjured and >100 ml for burn patients. Despite this, a systematic bias was demonstrated between the T10 group means. The T20 group trials did not indicate such error on statistical testing (P = .297). The study confirms that WDV measurement of whole ULs is reliable and sensitive, if used at least 20 minutes apart. However, a significant and clinically relevant subject-by-method interaction was demonstrated. Researchers and clinicians are reminded to be aware of the performance of the technique when designing investigations in patient populations.

The effect of performance-volume limit on the DRG based acute care hospital financing in Hungary.

PubMed

Endrei, Dóra; Zemplényi, Antal; Molics, Bálint; Agoston, István; Boncz, Imre

2014-04-01

The aim of our paper is to analyse the effect of the so-called performance volume limit (PVL) financing method on acute hospital care. The data were derived from the nationwide administrative dataset of the National Health Insurance Fund Administration (OEP) covering the period 2003-2008. We analysed the trends in the DRG cost-weights, number of cases, case-mix, and average length of stay. We calculated the average annual reimbursement rate per DRG cost-weight with and without the application of PVL degression according to the hospital type and medical professions. Our results showed that although the national case mix (i.e., the sum of all of the DRG cost-weights produced in one year) did not change between 2003-2006, the trend of the annual number of cases increased, and the average length of stay decreased. During 2007-2008, a significant decline was found in each indicator. The introduction of the PVL resulted in a health insurance budget saving of 1.9% in 2004, 2.6% in 2005, 3.4% in 2006, 5.6% in 2007, and 3.2% in 2008. We found the lowest reimbursement rate per DRG cost-weight at the university medical schools (HUF 138,200 or € 550) and children's hospitals (HUF 132,547 or € 528), whereas the highest was at the county hospitals (HUF 143,451 or € 571) and city hospitals (HUF 142, 082 or € 565). The implementation of the PVL reduced the acute care hospital activity and reimbursement. The effect of the PVL was different on the different types of hospitals, and it had a serious disadvantageous effect on the university medical schools and children's hospitals. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Strategy for Alternative Occupant Volume Testing

DOT National Transportation Integrated Search

2009-10-20

This paper describes plans for a series of quasi-static : compression tests of rail passenger equipment. These tests are : designed to evaluate the strength of the occupant volume under : static loading conditions. The research plan includes a detail...

Development and in vitro evaluations of new decitabine nanocarriers for the treatment of acute myeloid leukemia

PubMed Central

Briot, Thomas; Roger, Emilie; Lautram, Nolwenn; Verger, Alexis; Clavreul, Anne; Lagarce, Frederic

2017-01-01

Decitabine is a hydrophilic drug that acts by hypomethylating DNA. Decitabine is used in Europe for the treatment of acute myeloid leukemia (AML) in patients aged ≥65 years. However, it can only be administered intravenously due to very low oral bioavailability and a large distribution volume. Oral administration would allow outpatient treatment, improving quality of life and reducing treatment costs. The present study proposes to develop lipid nanocapsules (LNCs), originally designed for lipophilic drugs, to encapsulate decitabine. Two different formulations of LNCs were designed: LNCs based on a high proportion of Transcutol® HP (THP-LNCs) and LNCs associated with a mixture of Transcutol® HP and Tween® 80 (THP-T80-LNCs). The second formulation had a diameter of 26.5±0.5 nm, high encapsulation efficiency (>85%), and a drug payload of 472±64 µg/mL. Decitabine-loaded THP-T80-LNC cytotoxicity was evaluated on two AML cell lines depending on their decitabine resistance: HEL (not resistant) and HL-60 (resistant). The permeability of decitabine-loaded THP-T80-LNCs was also evaluated on Caco-2 cell monolayers. Decitabine cytotoxicity against HEL and HL-60 was higher when decitabine was loaded in THP-T80-LNCs than when free. Apparent permeability on Caco-2 cell monolayers was also increased, suggesting a potentially useful formulation to increase the oral bioavailability of decitabine. PMID:29200853

Respiratory muscles stretching acutely increases expansion in hemiparetic chest wall.

PubMed

Rattes, Catarina; Campos, Shirley Lima; Morais, Caio; Gonçalves, Thiago; Sayão, Larissa Bouwman; Galindo-Filho, Valdecir Castor; Parreira, Verônica; Aliverti, Andrea; Dornelas de Andrade, Armèle

2018-08-01

Individuals post-stroke may present restrictive ventilatory pattern generated from changes in the functionality of respiratory system due to muscle spasticity and contractures. Objective was to assess the acute effects after respiratory muscle stretching on the ventilatory pattern and volume distribution of the chest wall in stroke subjects. Ten volunteers with right hemiparesis after stroke and a mean age of 60 ± 5.7 years were randomised into the following interventions: respiratory muscle stretching and at rest (control). The ventilatory pattern and chest wall volume distribution were evaluated through optoelectronic plethysmography before and immediately after each intervention. Respiratory muscle stretching promoted a significant acute increase of 120 mL in tidal volume, with an increase in minute ventilation, mean inspiratory flow and mean expiratory flow compared with the control group. Pulmonary ribcage increased 50 mL after stretching, with 30 mL of contribution to the right pulmonary rib cage (hemiparetic side) in comparison to the control group. Respiratory muscle stretching in patients with right hemiparesis post-stroke demonstrated that acute effects improve the expansion of the respiratory system during tidal breathing. NCT02416349 (URL: https://clinicaltrials.gov/ct2/show/ NCT02416349). Copyright © 2018 Elsevier B.V. All rights reserved.

Association of follow-up infarct volume with functional outcome in acute ischemic stroke: a pooled analysis of seven randomized trials.

PubMed

Boers, Anna M M; Jansen, Ivo G H; Beenen, Ludo F M; Devlin, Thomas G; San Roman, Luis; Heo, Ji Hoe; Ribó, Marc; Brown, Scott; Almekhlafi, Mohammed A; Liebeskind, David S; Teitelbaum, Jeanne; Lingsma, Hester F; van Zwam, Wim H; Cuadras, Patricia; du Mesnil de Rochemont, Richard; Beaumont, Marine; Brown, Martin M; Yoo, Albert J; van Oostenbrugge, Robert J; Menon, Bijoy K; Donnan, Geoffrey A; Mas, Jean Louis; Roos, Yvo B W E M; Oppenheim, Catherine; van der Lugt, Aad; Dowling, Richard J; Hill, Michael D; Davalos, Antoni; Moulin, Thierry; Agrinier, Nelly; Demchuk, Andrew M; Lopes, Demetrius K; Aja Rodríguez, Lucia; Dippel, Diederik W J; Campbell, Bruce C V; Mitchell, Peter J; Al-Ajlan, Fahad S; Jovin, Tudor G; Madigan, Jeremy; Albers, Gregory W; Soize, Sebastien; Guillemin, Francis; Reddy, Vivek K; Bracard, Serge; Blasco, Jordi; Muir, Keith W; Nogueira, Raul G; White, Phil M; Goyal, Mayank; Davis, Stephen M; Marquering, Henk A; Majoie, Charles B L M

2018-04-07

Follow-up infarct volume (FIV) has been recommended as an early indicator of treatment efficacy in patients with acute ischemic stroke. Questions remain about the optimal imaging approach for FIV measurement. To examine the association of FIV with 90-day modified Rankin Scale (mRS) score and investigate its dependency on acquisition time and modality. Data of seven trials were pooled. FIV was assessed on follow-up (12 hours to 2 weeks) CT or MRI. Infarct location was defined as laterality and involvement of the Alberta Stroke Program Early CT Score regions. Relative quality and strength of multivariable regression models of the association between FIV and functional outcome were assessed. Dependency of imaging modality and acquisition time (≤48 hours vs >48 hours) was evaluated. Of 1665 included patients, 83% were imaged with CT. Median FIV was 41 mL (IQR 14-120). A large FIV was associated with worse functional outcome (OR=0.88(95% CI 0.87 to 0.89) per 10 mL) in adjusted analysis. A model including FIV, location, and hemorrhage type best predicted mRS score. FIV of ≥133 mL was highly specific for unfavorable outcome. FIV was equally strongly associated with mRS score for assessment on CT and MRI, even though large differences in volume were present (48 mL (IQR 15-131) vs 22 mL (IQR 8-71), respectively). Associations of both early and late FIV assessments with outcome were similar in strength (ρ=0.60(95% CI 0.56 to 0.64) and ρ=0.55(95% CI 0.50 to 0.60), respectively). In patients with an acute ischemic stroke due to a proximal intracranial occlusion of the anterior circulation, FIV is a strong independent predictor of functional outcome and can be assessed before 48 hours, oneither CT or MRI. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Dynamic Loading Experiments In The Massive Exoplanet Regime

NASA Astrophysics Data System (ADS)

Swift, Damian; Hicks, D.; Eggert, J.; Milathianaki, D.; Rothman, S.; Rosen, P.; Collins, G.

2010-10-01

Exoplanets have been detected with masses and radii suggesting rocky and hydrogen-rich compositions up to 10 times the mass of the Earth and Jupiter, in similar volumes. The formation and evolution of such bodies, and the distribution and properties of brown dwarfs which are an important component of galactic structures, depend on the equation of state (EOS) and chemistry of constituent matter at pressures 2-200 TPa for Fe-rich and hydrogenic matter respectively. Electronic structure calculations can predict these properties, but experimental measurements are crucial to investigate their accuracy in this regime. Hohlraum-driven configurations at the National Ignition Facility can induce planar ramp or shock loading to 30 TPa, over volumes sufficient to enable percent accuracy in EOS measurements. We are designing configurations using convergent ramp and shock loading for EOS experiments to pressures in excess of 100 TPa.

Dynamic Characteristics of Green Sandstone Subjected to Repetitive Impact Loading: Phenomena and Mechanisms

NASA Astrophysics Data System (ADS)

Li, S. H.; Zhu, W. C.; Niu, L. L.; Yu, M.; Chen, C. F.

2018-06-01

A split Hopkinson pressure bar apparatus driven by a pendulum hammer was used to perform uniaxial compression tests to examine the degradation process of green sandstone subjected to repetitive impact loading. The acoustic characteristics, dissipated energy, deformation characteristics, and microstructure evolution were investigated. The representative stress-strain curve can be broken into five stages that were characterized by changes in the axial strain response during impact loading. Both the ultrasonic wave velocity and cumulative dissipated energy exhibited obvious three-stage behavior with respect to the impact number. As the impact number increased, more than one peak was observed in the frequency spectra, and the relative weight of the peak frequency increased in the low-frequency range. According to the evolution of the ultrasonic wave velocity, the degradation process was divided into three stages. By comparing the intact stage I and early stage II microcrack development patterns, the initiation of new cracks and elongation of existing cracks were identified as the main degradation mechanisms. Furthermore, a slight increase in the number of cracks was observed, and microcrack lengths steadily increased. Moreover, due to the low level of microcrack damage, the deformation mechanism was mainly characterized by volume compression during impact loading. In late stage II, the main degradation mechanism was the elongation of existing cracks. Additionally, as microcracks accumulated in the rock samples, cracks were arranged parallel to the loading direction, which led to volume dilation. In stage III, microcracks continued to elongate nearly parallel to the loading direction and then linked to each other, which led to intense degradation in the rock samples. In this stage, rock sample deformation was mainly characterized by volume dilation during impact loading. Finally, rock samples were split into blocks with fractures oriented subparallel to the loading

The effects of dynamic loading on the intervertebral disc.

PubMed

Chan, Samantha C W; Ferguson, Stephen J; Gantenbein-Ritter, Benjamin

2011-11-01

Loading is important to maintain the balance of matrix turnover in the intervertebral disc (IVD). Daily cyclic diurnal assists in the transport of large soluble factors across the IVD and its surrounding circulation and applies direct and indirect stimulus to disc cells. Acute mechanical injury and accumulated overloading, however, could induce disc degeneration. Recently, there is more information available on how cyclic loading, especially axial compression and hydrostatic pressure, affects IVD cell biology. This review summarises recent studies on the response of the IVD and stem cells to applied cyclic compression and hydrostatic pressure. These studies investigate the possible role of loading in the initiation and progression of disc degeneration as well as quantifying a physiological loading condition for the study of disc degeneration biological therapy. Subsequently, a possible physiological/beneficial loading range is proposed. This physiological/beneficial loading could provide insight into how to design loading regimes in specific system for the testing of various biological therapies such as cell therapy, chemical therapy or tissue engineering constructs to achieve a better final outcome. In addition, the parameter space of 'physiological' loading may also be an important factor for the differentiation of stem cells towards most ideally 'discogenic' cells for tissue engineering purpose.

Effects of imbalanced muscle loading on hip joint development and maturation.

PubMed

Ford, Caleb A; Nowlan, Niamh C; Thomopoulos, Stavros; Killian, Megan L

2017-05-01

The mechanical loading environment influences the development and maturation of joints. In this study, the influence of imbalanced muscular loading on joint development was studied using localized chemical denervation of hip stabilizing muscle groups in neonatal mice. It was hypothesized that imbalanced muscle loading, targeting either gluteal muscles or quadriceps muscles, would lead to bilateral hip joint asymmetry, as measured by acetabular coverage, femoral head volume and bone morphometry, and femoral-acetabular shape. The contralateral hip joints as well as age-matched, uninjected mice were used as controls. Altered bone development was analyzed using micro-computed tomography, histology, and image registration techniques at postnatal days (P) 28, 56, and 120. This study found that unilateral muscle unloading led to reduced acetabular coverage of the femoral head, lower total volume, lower bone volume ratio, and lower mineral density, at all three time points. Histologically, the femoral head was smaller in unloaded hips, with thinner triradiate cartilage at P28 and thinner cortical bone at P120 compared to contralateral hips. Morphological shape changes were evident in unloaded hips at P56. Unloaded hips had lower trabecular thickness and increased trabecular spacing of the femoral head compared to contralateral hips. The present study suggests that decreased muscle loading of the hip leads to altered bone and joint shape and growth during postnatal maturation. Statement of Clinical Significance: Adaptations from altered muscle loading during postnatal growth investigated in this study have implications on developmental hip disorders that result from asymmetric loading, such as patients with limb-length inequality or dysplasia. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1128-1136, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Structural Integrity of Normal Appearing White Matter and Sex-Specific Outcomes After Acute Ischemic Stroke.

PubMed

Etherton, Mark R; Wu, Ona; Cougo, Pedro; Giese, Anne-Katrin; Cloonan, Lisa; Fitzpatrick, Kaitlin M; Kanakis, Allison S; Boulouis, Gregoire; Karadeli, Hasan H; Lauer, Arne; Rosand, Jonathan; Furie, Karen L; Rost, Natalia S

2017-12-01

Women have worse poststroke outcomes than men. We evaluated sex-specific clinical and neuroimaging characteristics of white matter in association with functional recovery after acute ischemic stroke. We performed a retrospective analysis of acute ischemic stroke patients with admission brain MRI and 3- to 6-month modified Rankin Scale score. White matter hyperintensity and acute infarct volume were quantified on fluid-attenuated inversion recovery and diffusion tensor imaging MRI, respectively. Diffusivity anisotropy metrics were calculated in normal appearing white matter contralateral to the acute ischemia. Among 319 patients with acute ischemic stroke, women were older (68.0 versus 62.7 years; P =0.004), had increased incidence of atrial fibrillation (21.4% versus 12.2%; P =0.04), and lower rate of tobacco use (21.1% versus 35.9%; P =0.03). There was no sex-specific difference in white matter hyperintensity volume, acute infarct volume, National Institutes of Health Stroke Scale, prestroke modified Rankin Scale score, or normal appearing white matter diffusivity anisotropy metrics. However, women were less likely to have an excellent outcome (modified Rankin Scale score <2: 49.6% versus 67.0%; P =0.005). In logistic regression analysis, female sex and the interaction of sex with fractional anisotropy, radial diffusivity, and axial diffusivity were independent predictors of functional outcome. Female sex is associated with decreased likelihood of excellent outcome after acute ischemic stroke. The correlation between markers of white matter integrity and functional outcomes in women, but not men, suggests a potential sex-specific mechanism. © 2017 American Heart Association, Inc.

A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure

PubMed Central

Chang, Suchi; Shi, Jindong; Fu, Cuiping; Wu, Xu; Li, Shanqun

2016-01-01

Background COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Intensive care unit patients with acute exacerbations of COPD requiring mechanical ventilation have higher mortality rates than other hospitalized patients. Although mechanical ventilation is the most effective intervention for these conditions, invasive ventilation techniques have yielded variable effects. Objective We evaluated pressure-regulated volume control (PRVC) ventilation treatment efficacy and preventive effects on pulmonary barotrauma in elderly COPD patients with respiratory failure. Patients and methods Thirty-nine intubated patients were divided into experimental and control groups and treated with the PRVC and synchronized intermittent mandatory ventilation – volume control methods, respectively. Vital signs, respiratory mechanics, and arterial blood gas analyses were monitored for 2–4 hours and 48 hours. Results Both groups showed rapidly improved pH, partial pressure of oxygen (PaO2), and PaO2 per fraction of inspired O2 levels and lower partial pressure of carbon dioxide (PaCO2) levels. The pH and PaCO2 levels at 2–4 hours were lower and higher, respectively, in the test group than those in the control group (P<0.05 for both); after 48 hours, blood gas analyses showed no statistical difference in any marker (P>0.05). Vital signs during 2–4 hours and 48 hours of treatment showed no statistical difference in either group (P>0.05). The level of peak inspiratory pressure in the experimental group after mechanical ventilation for 2–4 hours and 48 hours was significantly lower than that in the control group (P<0.05), while other variables were not significantly different between groups (P>0.05). Conclusion Among elderly COPD patients with respiratory failure, application of PRVC resulted in rapid improvement in arterial blood gas analyses while maintaining

A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure.

PubMed

Chang, Suchi; Shi, Jindong; Fu, Cuiping; Wu, Xu; Li, Shanqun

2016-01-01

COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Intensive care unit patients with acute exacerbations of COPD requiring mechanical ventilation have higher mortality rates than other hospitalized patients. Although mechanical ventilation is the most effective intervention for these conditions, invasive ventilation techniques have yielded variable effects. We evaluated pressure-regulated volume control (PRVC) ventilation treatment efficacy and preventive effects on pulmonary barotrauma in elderly COPD patients with respiratory failure. Thirty-nine intubated patients were divided into experimental and control groups and treated with the PRVC and synchronized intermittent mandatory ventilation - volume control methods, respectively. Vital signs, respiratory mechanics, and arterial blood gas analyses were monitored for 2-4 hours and 48 hours. Both groups showed rapidly improved pH, partial pressure of oxygen (PaO2), and PaO2 per fraction of inspired O2 levels and lower partial pressure of carbon dioxide (PaCO2) levels. The pH and PaCO2 levels at 2-4 hours were lower and higher, respectively, in the test group than those in the control group (P<0.05 for both); after 48 hours, blood gas analyses showed no statistical difference in any marker (P>0.05). Vital signs during 2-4 hours and 48 hours of treatment showed no statistical difference in either group (P>0.05). The level of peak inspiratory pressure in the experimental group after mechanical ventilation for 2-4 hours and 48 hours was significantly lower than that in the control group (P<0.05), while other variables were not significantly different between groups (P>0.05). Among elderly COPD patients with respiratory failure, application of PRVC resulted in rapid improvement in arterial blood gas analyses while maintaining a low peak inspiratory pressure. PRVC can reduce pulmonary barotrauma

Training loads and injury risk in Australian football-differing acute: chronic workload ratios influence match injury risk.

PubMed

Carey, David L; Blanch, Peter; Ong, Kok-Leong; Crossley, Kay M; Crow, Justin; Morris, Meg E

2017-08-01

(1) To investigate whether a daily acute:chronic workload ratio informs injury risk in Australian football players; (2) to identify which combination of workload variable, acute and chronic time window best explains injury likelihood. Workload and injury data were collected from 53 athletes over 2 seasons in a professional Australian football club. Acute:chronic workload ratios were calculated daily for each athlete, and modelled against non-contact injury likelihood using a quadratic relationship. 6 workload variables, 8 acute time windows (2-9 days) and 7 chronic time windows (14-35 days) were considered (336 combinations). Each parameter combination was compared for injury likelihood fit (using R 2 ). The ratio of moderate speed running workload (18-24 km/h) in the previous 3 days (acute time window) compared with the previous 21 days (chronic time window) best explained the injury likelihood in matches (R 2 =0.79) and in the immediate 2 or 5 days following matches (R 2 =0.76-0.82). The 3:21 acute:chronic workload ratio discriminated between high-risk and low-risk athletes (relative risk=1.98-2.43). Using the previous 6 days to calculate the acute workload time window yielded similar results. The choice of acute time window significantly influenced model performance and appeared to reflect the competition and training schedule. Daily workload ratios can inform injury risk in Australian football. Clinicians and conditioning coaches should consider the sport-specific schedule of competition and training when choosing acute and chronic time windows. For Australian football, the ratio of moderate speed running in a 3-day or 6-day acute time window and a 21-day chronic time window best explained injury risk. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Gas loading apparatus for the Paris-Edinburgh press

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

Bocian, A.; Kamenev, K. V.; Bull, C. L.

2010-09-15

We describe the design and operation of an apparatus for loading gases into the sample volume of the Paris-Edinburgh press at room temperature and high pressure. The system can be used for studies of samples loaded as pure or mixed gases as well as for loading gases as pressure-transmitting media in neutron-scattering experiments. The apparatus consists of a high-pressure vessel and an anvil holder with a clamp mechanism. The vessel, designed to operate at gas pressures of up to 150 MPa, is used for applying the load onto the anvils located inside the clamp. This initial load is sufficient formore » sealing the pressurized gas inside the sample containing gasket. The clamp containing the anvils and the sample is then transferred into the Paris-Edinburgh press by which further load can be applied to the sample. The clamp has apertures for scattered neutron beams and remains in the press for the duration of the experiment. The performance of the gas loading system is illustrated with the results of neutron-diffraction experiments on compressed nitrogen.« less

Thaw weakening and load restriction practices on low volume roads

DOT National Transportation Integrated Search

2000-06-01

Low volume roads subjected to seasonal freezing are highly susceptible to damage from traffic during midwinter and spring thaws. Such traffic-induced damage can be minimized by a variety of design methods; however, most are not economically feasible....

A comparison of methods to quantify the in-season training load of professional soccer players.

PubMed

Scott, Brendan R; Lockie, Robert G; Knight, Timothy J; Clark, Andrew C; Janse de Jonge, Xanne A K

2013-03-01

To compare various measures of training load (TL) derived from physiological (heart rate [HR]), perceptual (rating of perceived exertion [RPE]), and physical (global positioning system [GPS] and accelerometer) data during in-season field-based training for professional soccer. Fifteen professional male soccer players (age 24.9 ± 5.4 y, body mass 77.6 ± 7.5 kg, height 181.1 ± 6.9 cm) were assessed in-season across 97 individual training sessions. Measures of external TL (total distance [TD], the volume of low-speed activity [LSA; <14.4 km/h], high-speed running [HSR; >14.4 km/h], very high-speed running [VHSR; >19.8 km/h], and player load), HR and session-RPE (sRPE) scores were recorded. Internal TL scores (HR-based and sRPE-based) were calculated, and their relationships with measures of external TL were quantified using Pearson product-moment correlations. Physical measures of TD, LSA volume, and player load provided large, significant (r = .71-.84; P < .01) correlations with the HR-based and sRPE-based methods. Volume of HSR and VHSR provided moderate to large, significant (r = .40-.67; P < .01) correlations with measures of internal TL. While the volume of HSR and VHSR provided significant relationships with internal TL, physical-performance measures of TD, LSA volume, and player load appear to be more acceptable indicators of external TL, due to the greater magnitude of their correlations with measures of internal TL.

Low reflectance high power RF load

DOEpatents

Ives, R. Lawrence; Mizuhara, Yosuke M.

2016-02-02

A load for traveling microwave energy has an absorptive volume defined by cylindrical body enclosed by a first end cap and a second end cap. The first end cap has an aperture for the passage of an input waveguide with a rotating part that is coupled to a reflective mirror. The inner surfaces of the absorptive volume consist of a resistive material or are coated with a coating which absorbs a fraction of incident RF energy, and the remainder of the RF energy reflects. The angle of the reflector and end caps is selected such that reflected RF energy dissipates an increasing percentage of the remaining RF energy at each reflection, and the reflected RF energy which returns to the rotating mirror is directed to the back surface of the rotating reflector, and is not coupled to the input waveguide. Additionally, the reflector may have a surface which generates a more uniform power distribution function axially and laterally, to increase the power handling capability of the RF load. The input waveguide may be corrugated for HE11 mode input energy.

Lowering bronchoaspiration rate in an acute stroke unit by means of a 2 volume/3 texture dysphagia screening test with pulsioximetry.

PubMed

Cocho, D; Sagales, M; Cobo, M; Homs, I; Serra, J; Pou, M; Perez, G; Pujol, G; Tantinya, S; Bao, P; Aloy, A; Sabater, R; Gendre, J; Otermin, P

During acute stroke, 30% of all patients present dysphagia and 50% of that subgroup will experience bronchoaspiration. Our aim was to compare mortality and bronchoaspiration rates associated with the water test compared to those associated with a 2 volume/3 texture test controlled with pulse oximetry (2v/3t-P test) in our stroke unit. Over a 5-year period, we performed a prospective analysis of all consecutive acute ischaemic stroke patients hospitalised in the Stroke Unit. Dysphagia was evaluated using the water test between 2008 and 2010 (group 0 or G0), and the 2v/3t-P test (group 1 or G1) between 2011 and 2012. We analysed demographic data, vascular risk factors, neurological deficit on the NIHSS, aetiological subtype according to TOAST criteria, clinical subtype according to the Oxfordshire classification, prevalence of dysphagia, percentage of patients with bronchoaspiration, and mortality. We examined 418 patients with acute stroke (G0=275, G1=143). There were significant differences between the 2 groups regarding the percentage of patients with TACI (17% in G0 vs. 29% in G1, P=.005) and median NIHSS score (4 points in G0 vs. 7 points in G1, P=.003). Since adopting the new swallowing test, we detected a non-significant increase in the percentage of dysphagia (22% in G0 vs. 25% in G1, P=.4), lower mortality (1.7% in G0 vs. 0.7% in G1, P=.3) and a significant decrease in the bronchoaspiration rate (6.2% in G0 vs. 2.1% in G1, P=.05). Compared to the water test used for dysphagia screening, the new 2v/3t-P test lowered bronchoaspiration rates in acute stroke patients. Copyright © 2014 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Image processing system for the measurement of timber truck loads

NASA Astrophysics Data System (ADS)

Carvalho, Fernando D.; Correia, Bento A. B.; Davies, Roger; Rodrigues, Fernando C.; Freitas, Jose C. A.

1993-01-01

The paper industry uses wood as its raw material. To know the quantity of wood in the pile of sawn tree trunks, every truck load entering the plant is measured to determine its volume. The objective of this procedure is to know the solid volume of wood stocked in the plant. Weighing the tree trunks has its own problems, due to their high capacity for absorbing water. Image processing techniques were used to evaluate the volume of a truck load of logs of wood. The system is based on a PC equipped with an image processing board using data flow processors. Three cameras allow image acquisition of the sides and rear of the truck. The lateral images contain information about the sectional area of the logs, and the rear image contains information about the length of the logs. The machine vision system and the implemented algorithms are described. The results being obtained with the industrial prototype that is now installed in a paper mill are also presented.

A Hydrostatic Bearing Test System for Measuring Bearing Load Using Magnetic-Fluid Lubricants.

PubMed

Weng, Huei Chu; Chen, Lu-Yu

2016-05-01

This paper conducts a study on the design of a hydrostatic bearing test system. It involves the determination of viscous properties of magnetic-fluid lubricants. The load of a hydrostatic thrust bearing using a water-based magnetite nanofluid of varying volume flow rate is measured under an applied external induction field via the test system. Results reveal that the presence of nanoparticles in a carrier liquid would cause an enhanced bearing load. Such an effect could be further magnified by increasing the lubricant volume flow rate or the external induction field strength.

A gas-loading system for LANL two-stage gas guns

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

Gibson, Lloyd Lee; Bartram, Brian Douglas; Dattelbaum, Dana Mcgraw

A novel gas loading system was designed for the specific application of remotely loading high purity gases into targets for gas-gun driven plate impact experiments. The high purity gases are loaded into well-defined target configurations to obtain Hugoniot states in the gas phase at greater than ambient pressures.The small volume of the gas samples is challenging, as slight changing in the ambient temperature result in measurable pressure changes. Therefore, the ability to load a gas gun target and continually monitor the sample pressure prior to firing provides the most stable and reliable target fielding approach. We present the design andmore » evaluation of a gas loading system built for the LANL 50 mm bore two-stage light gas gun. Targets for the gun are made of 6061 Al or OFHC Cu, and assembled to form a gas containment cell with a volume of approximately 1.38 cc. The compatibility of materials was a major consideration in the design of the system, particularly for its use with corrosive gases. Piping and valves are stainless steel with wetted seals made from Kalrez® and Teflon®. Preliminary testing was completed to ensure proper flow rate and that the proper safety controls were in place. The system has been used to successfully load Ar, Kr, Xe, and anhydrous ammonia with purities of up to 99.999 percent. The design of the system and example data from the plate impact experiments will be shown.« less

A gas-loading system for LANL two-stage gas guns

NASA Astrophysics Data System (ADS)

Gibson, L. L.; Bartram, B. D.; Dattelbaum, D. M.; Lang, J. M.; Morris, J. S.

2017-01-01

A novel gas loading system was designed for the specific application of remotely loading high purity gases into targets for gas-gun driven plate impact experiments. The high purity gases are loaded into well-defined target configurations to obtain Hugoniot states in the gas phase at greater than ambient pressures. The small volume of the gas samples is challenging, as slight changing in the ambient temperature result in measurable pressure changes. Therefore, the ability to load a gas gun target and continually monitor the sample pressure prior to firing provides the most stable and reliable target fielding approach. We present the design and evaluation of a gas loading system built for the LANL 50 mm bore two-stage light gas gun. Targets for the gun are made of 6061 Al or OFHC Cu, and assembled to form a gas containment cell with a volume of approximately 1.38 cc. The compatibility of materials was a major consideration in the design of the system, particularly for its use with corrosive gases. Piping and valves are stainless steel with wetted seals made from Kalrez® and Teflon®. Preliminary testing was completed to ensure proper flow rate and that the proper safety controls were in place. The system has been used to successfully load Ar, Kr, Xe, and anhydrous ammonia with purities of up to 99.999 percent. The design of the system and example data from the plate impact experiments will be shown.

Reassessment of HIV-1 acute phase infectivity: accounting for heterogeneity and study design with simulated cohorts.

PubMed

Bellan, Steve E; Dushoff, Jonathan; Galvani, Alison P; Meyers, Lauren Ancel

2015-03-01

The infectivity of the HIV-1 acute phase has been directly measured only once, from a retrospectively identified cohort of serodiscordant heterosexual couples in Rakai, Uganda. Analyses of this cohort underlie the widespread view that the acute phase is highly infectious, even more so than would be predicted from its elevated viral load, and that transmission occurring shortly after infection may therefore compromise interventions that rely on diagnosis and treatment, such as antiretroviral treatment as prevention (TasP). Here, we re-estimate the duration and relative infectivity of the acute phase, while accounting for several possible sources of bias in published estimates, including the retrospective cohort exclusion criteria and unmeasured heterogeneity in risk. We estimated acute phase infectivity using two approaches. First, we combined viral load trajectories and viral load-infectivity relationships to estimate infectivity trajectories over the course of infection, under the assumption that elevated acute phase infectivity is caused by elevated viral load alone. Second, we estimated the relative hazard of transmission during the acute phase versus the chronic phase (RHacute) and the acute phase duration (dacute) by fitting a couples transmission model to the Rakai retrospective cohort using approximate Bayesian computation. Our model fit the data well and accounted for characteristics overlooked by previous analyses, including individual heterogeneity in infectiousness and susceptibility and the retrospective cohort's exclusion of couples that were recorded as serodiscordant only once before being censored by loss to follow-up, couple dissolution, or study termination. Finally, we replicated two highly cited analyses of the Rakai data on simulated data to identify biases underlying the discrepancies between previous estimates and our own. From the Rakai data, we estimated RHacute = 5.3 (95% credibility interval [95% CrI]: 0.79-57) and dacute = 1.7 mo (95% Cr

Atrophy of Swallowing Muscles Is Associated With Severity of Dysphagia and Age in Patients With Acute Stroke.

PubMed

Sporns, Peter B; Muhle, Paul; Hanning, Uta; Suntrup-Krueger, Sonja; Schwindt, Wolfram; Eversmann, Julian; Warnecke, Tobias; Wirth, Rainer; Zimmer, Sebastian; Dziewas, Rainer

2017-07-01

Sarcopenia has been identified as an independent risk factor for dysphagia. Dysphagia is one of the most important and prognostically relevant complications of acute stroke. The role of muscle atrophy as a contributing factor for the occurrence of poststroke dysphagia is yet unclear. To assess whether there is a correlation between age and muscle volume and whether muscle volume is related to dysphagia in acute stroke patients. This retrospective, single-center study included 73 patients with acute ischemic or hemorrhagic stroke who underwent computed tomography angiography on admission and an objective dysphagia assessment by Fiberoptic Endoscopic Evaluation of Swallowing within 72 hours from admission. With the help of semiautomated muscle segmentation and 3-dimensional reconstruction volumetry of the digastric, temporal, and geniohyoid muscles was performed. For further analysis, participants were first divided into 4 groups according to their age (<61 years, n = 12; 61-75 years, n = 16; 76-85 years, n = 28; ≥86 years, n = 17), secondly into 3 different groups according to their dysphagia severity using the Fiberoptic Endoscopic Dysphagia Severity Scale (FEDSS) (FEDSS 1 and 2, n = 25; FEDSS 3 and 4, n = 32; FEDSS 5 and 6, n = 16). Correlation of muscle volumes with age and dysphagia severity. Muscle volumes of single muscles (except for geniohyoid and the right digastric muscles) as well as the sum muscle volume were significantly and inversely related to dysphagia severity. We found a significant decline of muscle volume with advancing age for most muscle groups and, in particular, for the total muscle volume. Apart from features being determined by the acute stroke itself (eg, site and size of stroke), also premorbid conditions, in particular age-related muscle atrophy, have an impact on the complex pathophysiology of swallowing disorders poststroke. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine

Impact of acute care surgery to departmental productivity.

PubMed

Barnes, Stephen L; Cooper, Christopher J; Coughenour, Jeffrey P; MacIntyre, Allan D; Kessel, James W

2011-10-01

The face of trauma surgery is rapidly evolving with a paradigm shift toward acute care surgery (ACS). The formal development of ACS has been viewed by some general surgeons as a threat to their practice. We sought to evaluate the impact of a new division of ACS to both departmental productivity and provider satisfaction at a University Level I Trauma Center. Two-year retrospective analysis of annual work relative value unit (wRVU) productivity, operative volume, and FTEs before and after establishment of an ACS division at a University Level I trauma center. Provider satisfaction was measured using a 10-point scale. Analysis completed using Microsoft Excel with a p value less than 0.05 significant. The change to an ACS model resulted in a 94% increase in total wRVU production (78% evaluation and management, 122% operative; p<0.05) for ACS, whereas general surgery wRVU production increased 8% (-15% evaluation and management, 14% operative; p<0.05). Operative productivity was substantial after transition to ACS, with 129% and 44% increases (p<0.05) in operative and elective case load, respectively. Decline in overall general surgery operative volume was attributed to reduction in emergent cases. Establishment of the ACS model necessitated one additional FTE. Job satisfaction substantially improved with the ACS model while allowing general surgery a more focused practice. The ACS practice model significantly enhances provider productivity and job satisfaction when compared with trauma alone. Fears of a productivity impact to the nontrauma general surgeon were not realized.

High Intensity Interval Training Leads to Greater Improvements in Acute Heart Rate Recovery and Anaerobic Power as High Volume Low Intensity Training.

PubMed

Stöggl, Thomas L; Björklund, Glenn

2017-01-01

The purpose of the current study was to explore if training regimes utilizing diverse training intensity distributions result in different responses on neuromuscular status, anaerobic capacity/power and acute heart rate recovery (HRR) in well-trained endurance athletes. Methods: Thirty-six male ( n = 33) and female ( n = 3) runners, cyclists, triathletes and cross-country skiers [peak oxygen uptake: (VO 2peak ): 61.9 ± 8.0 mL·kg -1 ·min -1 ] were randomly assigned to one of three groups (blocked high intensity interval training HIIT; polarized training POL; high volume low intensity oriented control group CG/HVLIT applying no HIIT). A maximal anaerobic running/cycling test (MART/MACT) was performed prior to and following a 9-week training period. Results: Only the HIIT group achieved improvements in peak power/velocity (+6.4%, P < 0.001) and peak lactate ( P = 0.001) during the MART/MACT, while, unexpectedly, in none of the groups the performance at the established lactate concentrations (4, 6, 10 mmol·L -1 ) was changed ( P > 0.05). Acute HRR was improved in HIIT (11.2%, P = 0.002) and POL (7.9%, P = 0.023) with no change in the HVLIT oriented control group. Conclusion: Only a training regime that includes a significant amount of HIIT improves the neuromuscular status, anaerobic power and the acute HRR in well-trained endurance athletes. A training regime that followed more a low and moderate intensity oriented model (CG/HVLIT) had no effect on any performance or HRR outcomes.

High Intensity Interval Training Leads to Greater Improvements in Acute Heart Rate Recovery and Anaerobic Power as High Volume Low Intensity Training

PubMed Central

Stöggl, Thomas L.; Björklund, Glenn

2017-01-01

The purpose of the current study was to explore if training regimes utilizing diverse training intensity distributions result in different responses on neuromuscular status, anaerobic capacity/power and acute heart rate recovery (HRR) in well-trained endurance athletes. Methods: Thirty-six male (n = 33) and female (n = 3) runners, cyclists, triathletes and cross-country skiers [peak oxygen uptake: (VO2peak): 61.9 ± 8.0 mL·kg−1·min−1] were randomly assigned to one of three groups (blocked high intensity interval training HIIT; polarized training POL; high volume low intensity oriented control group CG/HVLIT applying no HIIT). A maximal anaerobic running/cycling test (MART/MACT) was performed prior to and following a 9-week training period. Results: Only the HIIT group achieved improvements in peak power/velocity (+6.4%, P < 0.001) and peak lactate (P = 0.001) during the MART/MACT, while, unexpectedly, in none of the groups the performance at the established lactate concentrations (4, 6, 10 mmol·L−1) was changed (P > 0.05). Acute HRR was improved in HIIT (11.2%, P = 0.002) and POL (7.9%, P = 0.023) with no change in the HVLIT oriented control group. Conclusion: Only a training regime that includes a significant amount of HIIT improves the neuromuscular status, anaerobic power and the acute HRR in well-trained endurance athletes. A training regime that followed more a low and moderate intensity oriented model (CG/HVLIT) had no effect on any performance or HRR outcomes. PMID:28824457

Accumulated workloads and the acute:chronic workload ratio relate to injury risk in elite youth football players

PubMed Central

Bowen, Laura; Gross, Aleksander Stefan; Gimpel, Mo; Li, François-Xavier

2017-01-01

Aim The purpose of this study was to investigate the relationship between physical workload and injury risk in elite youth football players. Methods The workload data and injury incidence of 32 players were monitored throughout 2 seasons. Multiple regression was used to compare cumulative (1, 2, 3 and 4-weekly) loads and acute:chronic (A:C) workload ratios (acute workload divided by chronic workload) between injured and non-injured players for specific GPS and accelerometer-derived variables:total distance (TD), high-speed distance (HSD), accelerations (ACC) and total load. Workloads were classified into discrete ranges by z-scores and the relative risk was determined. Results A very high number of ACC (≥9254) over 3 weeks was associated with the highest significant overall (relative risk (RR)=3.84) and non-contact injury risk (RR=5.11). Non-contact injury risk was significantly increased when a high acute HSD was combined with low chronic HSD (RR=2.55), but not with high chronic HSD (RR=0.47). Contact injury risk was greatest when A:C TD and ACC ratios were very high (1.76 and 1.77, respectively) (RR=4.98). Conclusions In general, higher accumulated and acute workloads were associated with a greater injury risk. However, progressive increases in chronic workload may develop the players' physical tolerance to higher acute loads and resilience to injury risk. PMID:27450360

Clinical and microbiological characteristics of spontaneous acute prostatitis and transrectal prostate biopsy-related acute prostatitis: Is transrectal prostate biopsy-related acute prostatitis a distinct acute prostatitis category?

PubMed

Kim, Jong Wook; Oh, Mi Mi; Bae, Jae Hyun; Kang, Seok Ho; Park, Hong Seok; Moon, Du Geon

2015-06-01

This study aimed to compare the clinical and microbiological characteristics between acute bacterial prostatitis and transrectal biopsy-related acute prostatitis. We retrospectively reviewed the records of 135 patients hospitalized for acute prostatitis in three urological centers between 2004 and 2013. Acute bacterial prostatitis was diagnosed according to typical symptoms, findings of physical examination, and laboratory test results. Clinical variables, laboratory test results, and anti-microbial susceptibility results were reviewed. Patients were classified into the spontaneous acute prostatitis group (S-ABP) or biopsy-related acute prostatitis (Bx-ABP) for comparison of their clinical, laboratory, and microbiological findings. The mean age of all patients was 61.7 ± 12.9 years. Compared with S-ABP patients, Bx-ABP patients were significantly older, had larger prostate volumes, higher PSA values, higher peak fever temperatures, and higher incidence of septicemia and antibiotic-resistant bacteria. Overall, of the 135 patients, 57.8% had positive bacterial urine and/or blood cultures. Bx-ABP patients had a higher incidence of bacterial (urine and/or blood) positive cultures compared to S-ABP patients (66.7% versus 55.6%). Escherichia coli was the predominant organism in both groups, but it was more common in Bx-ABP (88.9%) than in S-ABP (66.7%). Extended spectrum beta-lactamase -producing bacteria accounted for 64.7% of culture-positive patients in the Bx-ABP group compared to 13.3% in the S-ABP group. Bx-ABP patients showed a higher incidence of septicemia and antibiotic-resistant bacteria than S-ABP patients. These results have important implications for the management and antimicrobial treatment of Bx-ABP, which may well deserve to be considered a distinct prostatitis category. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Prospective Study of Acute HIV-1 Infection in Adults in East Africa and Thailand

PubMed Central

Robb, Merlin L.; Eller, Leigh A.; Kibuuka, Hannah; Rono, Kathleen; Maganga, Lucas; Nitayaphan, Sorachai; Kroon, Eugene; Sawe, Fred K.; Sinei, Samuel; Sriplienchan, Somchai; Jagodzinski, Linda L.; Malia, Jennifer; Manak, Mark; de Souza, Mark S.; Tovanabutra, Sodsai; Sanders-Buell, Eric; Rolland, Morgane; Dorsey-Spitz, Julie; Eller, Michael A.; Milazzo, Mark; Li, Qun; Lewandowski, Andrew; Wu, Hao; Swann, Edith; O'Connell, Robert J.; Peel, Sheila; Dawson, Peter; Kim, Jerome H.; Michael, Nelson L.

2016-01-01

Background Acute human immunodeficiency virus type 1 (HIV-1) infection is a major contributor to transmission of HIV-1. An understanding of acute HIV-1 infection may be important in the development of treatment strategies to eradicate HIV-1 or achieve a functional cure. Methods We performed twice-weekly qualitative plasma HIV-1 RNA nucleic acid testing in 2276 volunteers who were at high risk for HIV-1 infection. For participants in whom acute HIV-1 infection was detected, clinical observations, quantitative measurements of plasma HIV-1 RNA levels (to assess viremia) and HIV antibodies, and results of immunophenotyping of lymphocytes were obtained twice weekly. Results Fifty of 112 volunteers with acute HIV-1 infection had two or more blood samples collected before HIV-1 antibodies were detected. The median peak viremia (6.7 log10 copies per milliliter) occurred 13 days after the first sample showed reactivity on nucleic acid testing. Reactivity on an enzyme immunoassay occurred at a median of 14 days. The nadir of viremia (4.3 log10 copies per milliliter) occurred at a median of 31 days and was nearly equivalent to the viral-load set point, the steady-state viremia that persists durably after resolution of acute viremia (median plasma HIV-1 RNA level, 4.4 log10 copies per milliliter). The peak viremia and downslope were correlated with the viral-load set point. Clinical manifestations of acute HIV-1 infection were most common just before and at the time of peak viremia. A median of one symptom of acute HIV-1 infection was recorded at a median of two study visits, and a median of one sign of acute HIV-1 infection was recorded at a median of three visits. Conclusions The viral-load set point occurred at a median of 31 days after the first detection of plasma viremia and correlated with peak viremia. Few symptoms and signs were observed during acute HIV-1 infection, and they were most common before peak viremia. (Funded by the Department of Defense and the National

[Morphological analysis of bone dynamics and metabolic bone disease. Effect of loading on bone tissue].

PubMed

Sakai, Akinori

2011-04-01

We developed a voluntarily climbing animal model to investigate the effect of skeletal loading on bone tissue. At the cross section of the mid-femur, climbing exercise increases outer diameter and area of cortical bone. The mechanical strength of the femur is increased. This change of cortical volume and structure is more marked in anti-gravity exercise, such as climbing and jumping, than aerobic exercise. At the bone marrow area, climbing exercise increases trabecular bone volume and osteoblast number, while it decreases fat volume and adipocyte number. Skeletal loading promotes differentiation from mesenchymal stem cells to osteoblasts and suppresses that to adipocytes by facilitating the signal through PTH÷PTHrP receptor.

Acute effects of volume-oriented incentive spirometry on chest wall volumes in patients after a stroke.

PubMed

Lima, Illia Ndf; Fregonezi, Guilherme Af; Melo, Rodrigo; Cabral, Elis Ea; Aliverti, Andrea; Campos, Tânia F; Ferreira, Gardênia Mh

2014-07-01

The aim of the present study was to assess how volume-oriented incentive spirometry applied to patients after a stroke modifies the total and compartmental chest wall volume variations, including both the right and left hemithoraces, compared with controls. Twenty poststroke patients and 20 age-matched healthy subjects were studied by optoelectronic plethysmography during spontaneous quiet breathing (QB), during incentive spirometry, and during the recovery period after incentive spirometry. Incentive spirometry was associated with an increased chest wall volume measured at the pulmonary rib cage, abdominal rib cage and abdominal compartment (P = .001) and under 3 conditions (P < .001). Compared with healthy control subjects, the tidal volume (VT) of the subjects with stroke was 24.7, 18.0, and 14.7% lower during QB, incentive spirometry, and postincentive spirometry, respectively. Under all 3 conditions, the contribution of the abdominal compartment to VT was greater in the stroke subjects (54.1, 43.2, and 48.9%) than in the control subjects (43.7, 40.8, and 46.1%, P = .039). In the vast majority of subjects (13/20 and 18/20 during QB and incentive spirometry, respectively), abdominal expansion precedes rib cage expansion during inspiration. Greater asymmetry between the right and left hemithoracic expansions occurred in stroke subjects compared with control subjects, but it decreased during QB (62.5%, P = .002), during incentive spirometry (19.7%), and postincentive spirometry (67.6%, P = .14). Incentive spirometry promotes increased expansion in all compartments of the chest wall and reduces asymmetric expansion between the right and left parts of the pulmonary rib cage; therefore, it should be considered as a tool for rehabilitation. Copyright © 2014 by Daedalus Enterprises.

Urinary free cortisol and cortisone excretion in healthy individuals: influence of water loading.

PubMed

Fenske, Martin

2006-11-01

The influence of water loading on urinary excretion of free cortisol and cortisone was investigated in healthy men. The results were as follows: water loading tests (intake of 0.25-1.5 L) in a single individual showed that a water load of 1.5 L reliably increased the excretion of urine, free cortisol and cortisone (p < 0.01). Regression analyses gave significant correlations of urine volume with free cortisol and free cortisone, and of free cortisol and free cortisone. Corresponding results were obtained when water loading tests were performed in males who ingested 1.5 L of water (n = 8): the excretion of urine, free cortisol and free cortisone were significantly augmented; correlated was urine volume with free cortisol and free cortisone, and free cortisol with free cortisone. In a third set of tests, volunteers collected one 5 h urine (10:00-15:00 h) after the intake of 3 x 0.1 or 0.5 L at 11:00, 12:00 and 14:00 h. Excretion of urine, free cortisol and free cortisone in males of the low water loading group (3 x 0.1 L) was 0.59 mL/min, and 8.2 or 15.0 microg/5 h; corresponding values in individuals ingesting 3 x 0.5 L of water were 1.5 mL/min (p < 0.01), 12.3 microg/5 h (p > 0.05) and 26.3 microg/5 h (p < 0.02). In summary, urinary free cortisol and cortisone excretion in healthy men depends on urine volume, especially during water diuresis. Thus, interpretation of free cortisol and especially of free cortisone excretion is only possible if subjects strictly control their fluid intake and if urine volume is considered an important pre-analytical parameter-otherwise, interpretation of urinary free cortisol results is difficult and of urinary free cortisone data remains tenuous at best.

Effects of Percutaneous LVAD Support on Right Ventricular Load and Adaptation.

PubMed

Yourshaw, Jeffrey P; Mishra, Prabodh; Armstrong, M Christopher; Ramu, Bhavadharini; Craig, Michael L; Van Bakel, Adrian B; Steinberg, Daniel H; DiSalvo, Thomas G; Tedford, Ryan J; Houston, Brian A

2018-04-30

Both operative and hemodynamic mechanisms have been implicated in right heart failure (RHF) following surgical left ventricular assist device (LVAD) implantation. We investigated the effects of percutaneous LVAD (pLVAD; Impella®, Abiomed) support on right ventricular (RV) load and adaptation. We reviewed all patients receiving a pLVAD for cardiogenic shock at our institution between July 2014 and April 2017, including only those with pre- and post-pLVAD invasive hemodynamic measurements. Hemodynamic data was recorded immediately prior to pLVAD implantation and up to 96 h post-implantation. Twenty-five patients were included. Cardiac output increased progressively during pLVAD support. PAWP improved early post-pLVAD but did not further improve during continued support. Markers of RV adaptation (right ventricular stroke work index, right atrial pressure (RAP), and RAP to pulmonary artery wedge pressure ratio (RAP:PAWP)) were unchanged acutely implant but progressively improved during continued pLVAD support. Total RV load (pulmonary effective arterial elastance; E A ) and resistive RV load (pulmonary vascular resistance; PVR) both declined progressively. The relationship between RV load and RV adaptation (E A /RAP and E A /RAP:PAWP) was constant throughout. Median vasoactive-inotrope score declined after pLVAD placement and continued to decline throughout support. Percutaneous LVAD support in patients with cardiogenic shock did not acutely worsen RV adaptation, in contrast to previously described hemodynamic effects of surgically implanted durable LVADs. Further, RV load progressively declined during support, and the noted RV adaptation improvement was load-dependent as depicted by constant E A /RA and E A /RAP:PAWP relationships. These findings further implicate the operative changes associated with surgical LVAD implantation in early RHF following durable LVAD.

Acute care surgery: impact on practice and economics of elective surgeons.

PubMed

Miller, Preston R; Wildman, Elizabeth A; Chang, Michael C; Meredith, J Wayne

2012-04-01

The creation of an acute care surgery service provides a rich operative experience for acute care surgeons. Elective surgeons typically have concerns about whether their practice volume will be restored with elective cases. Acute care surgery has financial implications for both groups. The aim of this project is to examine the impact in terms of work relative value units (wRVUs), collections, and cases in both groups with creation of an acute care surgery service at our institution. Work RVUs, collections, and case volume were examined from departmental records for 2 groups before and after acute care surgery service creation. The service began on September 1, 2008. Before this time, emergency surgical consults went to the general surgeon on call. After this date, all emergency consults were seen by acute care surgeons. The number of operations performed by the acute care surgery group increased significantly when the mean of the 2 years after institution of acute care surgery were compared with the mean of the 2 years preceding the service creation (1,639 vs 790/year; p = 0.007). There was no change in total operations done by the elective surgery group (2,763 vs 2,496/year: p = 0.13). Elective caseload, however, did increase by 23% in the elective surgery group. In the acute care surgery group, wRVUs increased by 140% and elective surgery group wRVUs decreased by 8%. Collections increased in both groups (acute care surgery 129%, elective surgery 7%) and the combined collections of the groups increased by $2,138,00 in the year after service creation. Acute care surgery service creation took emergency business from the elective surgery group, but this was almost immediately replaced with elective cases. This resulted in higher collections for both groups and a resultant significant increase in collections in aggregate. Copyright © 2012 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Reassessment of HIV-1 Acute Phase Infectivity: Accounting for Heterogeneity and Study Design with Simulated Cohorts

PubMed Central

Bellan, Steve E.; Dushoff, Jonathan; Galvani, Alison P.; Meyers, Lauren Ancel

2015-01-01

Background The infectivity of the HIV-1 acute phase has been directly measured only once, from a retrospectively identified cohort of serodiscordant heterosexual couples in Rakai, Uganda. Analyses of this cohort underlie the widespread view that the acute phase is highly infectious, even more so than would be predicted from its elevated viral load, and that transmission occurring shortly after infection may therefore compromise interventions that rely on diagnosis and treatment, such as antiretroviral treatment as prevention (TasP). Here, we re-estimate the duration and relative infectivity of the acute phase, while accounting for several possible sources of bias in published estimates, including the retrospective cohort exclusion criteria and unmeasured heterogeneity in risk. Methods and Findings We estimated acute phase infectivity using two approaches. First, we combined viral load trajectories and viral load-infectivity relationships to estimate infectivity trajectories over the course of infection, under the assumption that elevated acute phase infectivity is caused by elevated viral load alone. Second, we estimated the relative hazard of transmission during the acute phase versus the chronic phase (RHacute) and the acute phase duration (d acute) by fitting a couples transmission model to the Rakai retrospective cohort using approximate Bayesian computation. Our model fit the data well and accounted for characteristics overlooked by previous analyses, including individual heterogeneity in infectiousness and susceptibility and the retrospective cohort's exclusion of couples that were recorded as serodiscordant only once before being censored by loss to follow-up, couple dissolution, or study termination. Finally, we replicated two highly cited analyses of the Rakai data on simulated data to identify biases underlying the discrepancies between previous estimates and our own. From the Rakai data, we estimated RHacute = 5.3 (95% credibility interval [95% CrI]: 0

Variation in critical care unit admission rates and outcomes for patients with acute coronary syndromes or heart failure among high- and low-volume cardiac hospitals.

PubMed

van Diepen, Sean; Bakal, Jeffrey A; Lin, Meng; Kaul, Padma; McAlister, Finlay A; Ezekowitz, Justin A

2015-02-27

Little is known about cross-hospital differences in critical care units admission rates and related resource utilization and outcomes among patients hospitalized with acute coronary syndromes (ACS) or heart failure (HF). Using a population-based sample of 16,078 patients admitted to a critical care unit with a primary diagnosis of ACS (n=14,610) or HF (n=1467) between April 1, 2003 and March 31, 2013 in Alberta, Canada, we stratified hospitals into high (>250), medium (200 to 250), or low (<200) volume based on their annual volume of all ACS and HF hospitalization. The percentage of hospitalized patients admitted to critical care units varied across low, medium, and high-volume hospitals for both ACS and HF as follows: 77.9%, 81.3%, and 76.3% (P<0.001), and 18.0%, 16.3%, and 13.0% (P<0.001), respectively. Compared to low-volume units, critical care patients with ACS and HF admitted to high-volume hospitals had shorter mean critical care stays (56.6 versus 95.6 hours, P<0.001), more critical care procedures (1.9 versus 1.2 per patient, <0.001), and higher resource-intensive weighting (2.8 versus 1.5, P<0.001). No differences in in-hospital mortality (5.5% versus 6.2%, adjusted odds ratio 0.93; 95% CI, 0.61 to 1.41) were observed between high- and low-volume hospitals; however, 30-day cardiovascular readmissions (4.6% versus 6.8%, odds ratio 0.77; 95% CI, 0.60 to 0.99) and cardiovascular emergency-room visits (6.6% versus 9.5%, odds ratio 0.80; 95% CI, 0.69 to 0.94) were lower in high-volume compared to low-volume hospitals. Outcomes stratified by ACS or HF admission diagnosis were similar. Cardiac patients hospitalized in low-volume hospitals were more frequently admitted to critical care units and had longer hospitals stays despite lower resource-intensive weighting. These findings may provide opportunities to standardize critical care utilization for ACS and HF patients across high- and low-volume hospitals. © 2015 The Authors. Published on behalf of the American

Modular acute system for general surgery: hand over the operation, not the patient.

PubMed

Poole, Garth H; Glyn, Tamara; Srinivasa, Sanket; Hill, Andrew G

2012-03-01

Various models have been proposed to effectively provide acute surgical care in Australasia. Recently, General Surgeons Australia (GSA) has published a 12-point plan with guiding principles on this matter. This study describes a model of providing acute general surgical care in a high-volume institution, evaluates clinical outcomes and critically appraises the system against the GSA 12-point plan. The acute care system is qualitatively described with quantitative measures of workload. The outcomes of acute laparoscopic cholecystectomy were used as a proxy of system performance. The system was critically appraised against the GSA 12-point plan. Teams are on call once per week with each surgeon on call once per fortnight. The three key elements of acute management - collecting patients, post-acute ward round and operating - are treated as modules. The patient remains under the care of the admitting consultant but is often operated on by another team. From June 2009 to 2010, there were 7429 acute general surgical admissions (mean: 20.4 patients per day) with 2999 acute operations (mean: 8.4 operations per day). The other activities of the department were not compromised. In that time, 388 acute laparoscopic cholecystectomies were performed with a conversion rate of 1.3% and no major bile duct injury. The system is compatible with the GSA 12-point plan. This study describes an efficient and safe system for providing acute general surgical care in a high-volume setting with satisfactory clinical outcomes. It is compatible with the GSA 12-point plan. © 2012 The Authors. ANZ Journal of Surgery © 2012 Royal Australasian College of Surgeons.

Do Age and Anticoagulants Affect the Natural History of Acute Subdural Hematomas?

PubMed

Lucke-Wold, Brandon P; Turner, Ryan C; Josiah, Darnell; Knotts, Chelsea; Bhatia, Sanjay

2016-01-01

Acute subdural hematoma is a serious complication following traumatic brain injury. Large volume hematomas or those with underlying brain injury can cause mass effect, midline shift, and eventually herniation of the brain. Acute subdural hematomas in the young are associated with high-energy trauma and often have underlying contusions, while acute subdural hematomas in the elderly are associated with minor trauma and an absence of underlying contusions, even though the elderly are more likely to be on anticoagulants or anti-platelet therapy. In the young patients with high impact injuries the hematomas tend to be small and the underlying brain injury and swelling is responsible for the increased intracranial pressure and midline shift. In the elderly, the injuries are low impact (e.g fall from standing), the underlying brain is intact, and the volume of the hematoma itself produces symptoms. In addition the use of anticoagulants and antiplatelet agents in the elderly population has been thought to be a poor prognostic indicator and is considered to be responsible for larger hematomas and poor outcome. When managed conservatively, acute subdural hematomas can sometimes progress to chronic subdural hematoma formation, further enlargement, seizures, and progressive midline shift. Another potential difference in the young and the elderly is brain atrophy, which increases the potential space to accommodate a larger hematoma. It is not known if these two groups differ in other ways that might have implications for treatment or prognosis. In this paper, we investigate the clinical course of 80 patients admitted to our institution with acute subdural hematomas, to identify differences in patients above or below the age of 65 years. The natural progression/resolution of acute subdural hematomas was mapped by measuring volume expansion/regression over time. In this retrospective chart review, we investigated clinical baseline metrics and subsequent volumetric expansion

Do Age and Anticoagulants Affect the Natural History of Acute Subdural Hematomas?

PubMed Central

Lucke-Wold, Brandon P.; Turner, Ryan C.; Josiah, Darnell; Knotts, Chelsea; Bhatia, Sanjay

2016-01-01

Acute subdural hematoma is a serious complication following traumatic brain injury. Large volume hematomas or those with underlying brain injury can cause mass effect, midline shift, and eventually herniation of the brain. Acute subdural hematomas in the young are associated with high-energy trauma and often have underlying contusions, while acute subdural hematomas in the elderly are associated with minor trauma and an absence of underlying contusions, even though the elderly are more likely to be on anticoagulants or anti-platelet therapy. In the young patients with high impact injuries the hematomas tend to be small and the underlying brain injury and swelling is responsible for the increased intracranial pressure and midline shift. In the elderly, the injuries are low impact (e.g fall from standing), the underlying brain is intact, and the volume of the hematoma itself produces symptoms. In addition the use of anticoagulants and antiplatelet agents in the elderly population has been thought to be a poor prognostic indicator and is considered to be responsible for larger hematomas and poor outcome. When managed conservatively, acute subdural hematomas can sometimes progress to chronic subdural hematoma formation, further enlargement, seizures, and progressive midline shift. Another potential difference in the young and the elderly is brain atrophy, which increases the potential space to accommodate a larger hematoma. It is not known if these two groups differ in other ways that might have implications for treatment or prognosis. In this paper, we investigate the clinical course of 80 patients admitted to our institution with acute subdural hematomas, to identify differences in patients above or below the age of 65 years. The natural progression/resolution of acute subdural hematomas was mapped by measuring volume expansion/regression over time. In this retrospective chart review, we investigated clinical baseline metrics and subsequent volumetric expansion

Study of Abrasive Wear Volume Map for PTFE and PTFE Composites

NASA Astrophysics Data System (ADS)

Unal, H.; Sen, U.; Mimaroglu, A.

2007-11-01

The potential of this work is based on consideration of wear volume map for the evaluation of abrasive wear performance of polytetrafluoroethylene (PTFE) and PTFE composites. The fillers used in the composite are 25% bronze, 35% graphite and 17% glass fibre glass (GFR). The influence of filler materials, abrasion surface roughness and applied load values on abrasive wear performance of PTFE and PTFE composites were studied and evaluated. Experimental abrasive wear tests were carried out at atmospheric condition on pin-on-disc wear tribometer. Tests were performed under 4, 6, 8 and 10 N load values, travelling speed of 1 m/sec and abrasion surface roughness values of 5, 20 and 45 µm. Wear volume maps were obtained and the results showed that the lowest wear volume rate for PTFE is reached using GFR filler. Furthermore, the results also showed that the higher is the applied load and the roughness of the abrasion surface, the higher is the wear rate. Finally it is also concluded that abrasive wear process mechanism include ploughing and cutting mechanisms.

Acute severe asthma: performance of ventilator at simulated altitude.

PubMed

Tourtier, Jean-Pierre; Forsans, Emma; Leclerc, Thomas; Libert, Nicolas; Ramsang, Solange; Tazarourte, Karim; Man, Michel; Borne, Marc

2011-04-01

Exacerbation of asthma can be seen during air transport. Severe patients, not responding to conventional therapy, require ventilator support. We evaluated the performance of two transport ventilators, built with turbine technology, the T-birdVSO2 and the LTV-1000, for use during aeromedical evacuation of acute severe asthma. We have assessed the ability of both the ventilators to deliver to an acute severe asthma model a tidal volume (Vt) set at different simulated altitudes, by changing the ambient air pressure. The simulated cabin altitudes were 1500, 2500, and 3000 m (decompression chamber). Vt was set at 700 and 400 ml in an acute severe asthma lung model. Comparisons of the preset with the actual measured values were accomplished using a t-test. Comparisons between the actual delivered Vt and set Vt showed a significant difference starting at 1500 m for both the ventilators. The T-birdVSO2 showed a decrease in the volume delivered, with a negative variation of more than 10% compared with the Vt set. The LTV-1000 showed mostly an increase in the volume delivered. The delivered Vt remained within 10% of the set Vt. The accuracy of Vt delivery was superior with the LTV-1000 than with the T-birdVSO2, but the higher delivered Vt of the LTV-1000 are likely to be more harmful than lower delivered Vt of the T-birdVSO2.

Traffic load spectra development for the 2002 AASHTO design guide.

DOT National Transportation Integrated Search

2004-12-30

Accurate knowledge of traffic volumes and loading is essential to structural pavement design and performance. : Underestimation of design traffic can result in premature pavement failures and excessive rehabilitation costs. : Overestimation can resul...

The administration of a loading dose of aspirin to patients presenting with acute myocardial infarction while receiving chronic aspirin treatment reduces thromboxane A2-dependent platelet reactivity.

PubMed

Santos, Maria Teresa; Madrid, Isabel; Moscardo, Antonio; Latorre, Ana M; Bonastre, Juan; Ruano, Miguel; Valles, Juana

2014-01-01

Abstract The optimal dose of aspirin for patients presenting with acute myocardial infarction (AMI) while receiving chronic aspirin therapy has not been clearly established. We evaluated whether continued treatment with 100 mg of aspirin or a loading dose (200-500 mg) influences thromboxane A2 (TX) suppression or platelet reactivity. Sixty-four consecutive patients with AMI and 98 healthy subjects (82 aspirin-free and 16 receiving 100 mg daily for a week) were evaluated. Treatment was at the discretion of the attending physician. Collagen (1 µg/ml)-induced TX synthesis, (14)C-serotonin-release, platelet aggregation, and the PFA-100 assay were evaluated. The platelet TX synthesis of patients receiving a loading dose of aspirin was sixfold lower than that of patients receiving 100 mg of aspirin (p<0.005). This was associated with marked reductions in (14)C-serotonin-release and arachidonic-acid-induced aggregation and an increase in the PFA-100 closure time (p<0.01). Categorization of patients according to their TX synthesis (<95% or ≥ 95% inhibition vs. healthy aspirin-free subjects) revealed that 8% of the patients treated with loading doses had a poor response (<95% inhibition) vs. 53% of those treated with 100 mg (p<0.001). Patients with lower TX inhibition had higher serum NT-Pro-BNP (p<0.005), a marker of poor left ventricular systolic function. Administration of a loading dose of aspirin to patients with AMI during existing chronic aspirin treatment induced greater reductions in platelet TX synthesis and TX-dependent platelet reactivity than the continued treatment alone.

Pericardial adipose tissue and the metabolic syndrome is increased in patients with chronic major depressive disorder compared to acute depression and controls.

PubMed

Kahl, K G; Herrmann, J; Stubbs, B; Krüger, T H C; Cordes, J; Deuschle, M; Schweiger, U; Hüper, K; Helm, S; Birkenstock, A; Hartung, D

2017-01-04

Major depressive disorder (MDD) is associated with an estimated fourfold risk for premature death, largely attributed to cardiovascular disorders. Pericardial adipose tissue (PAT), a fat compartment surrounding the heart, has been implicated in the development of coronary artery disease. An unanswered question is whether people with chronic MDD are more likely to have elevated PAT volumes versus acute MDD and controls (CTRL). The study group consists of sixteen patients with chronic MDD, thirty-four patients with acute MDD, and twenty-five CTRL. PAT and adrenal gland volume were measured by magnetic resonance tomography. Additional measures comprised factors of the metabolic syndrome, cortisol, relative insulin resistance, and pro-inflammatory cytokines (interleukin-6; IL-6 and tumor necrosis factor-α, TNF-α). PAT volumes were significantly increased in patients with chronic MDD>patients with acute MDD>CTRL. Adrenal gland volume was slightly enlarged in patients with chronic MDD>acute MDD>CTRL, although this difference failed to reach significance. The PAT volume was correlated with adrenal gland volume, and cortisol concentrations were correlated with depression severity, measured by BDI-2 and MADRS. Group differences were found concerning the rate of the metabolic syndrome, being most frequent in chronic MDD>acute MDD>CTRL. Further findings comprised increased fasting cortisol, increased TNF-α concentration, and decreased physical activity level in MDD compared to CTRL. Our results extend the existing literature in demonstrating that patients with chronic MDD have the highest risk for developing cardiovascular disorders, indicated by the highest PAT volume and prevalence of metabolic syndrome. The correlation of PAT with adrenal gland volume underscores the role of the hypothalamus-pituitary-adrenal system as mediator for body-composition changes. Metabolic monitoring, health advices and motivation for the improvement of physical fitness may be recommended in

Combining creatinine and volume kinetics identifies missed cases of acute kidney injury following cardiac arrest

PubMed Central

2013-01-01

Introduction Fluid resuscitation in the critically ill often results in a positive fluid balance, potentially diluting the serum creatinine concentration and delaying diagnosis of acute kidney injury (AKI). Methods Dilution during AKI was quantified by combining creatinine and volume kinetics to account for fluid type, and rates of fluid infusion and urine output. The model was refined using simulated patients receiving crystalloids or colloids under four glomerular filtration rate (GFR) change scenarios and then applied to a cohort of critically ill patients following cardiac arrest. Results The creatinine concentration decreased during six hours of fluid infusion at 1 litre-per-hour in simulated patients, irrespective of fluid type or extent of change in GFR (from 0% to 67% reduction). This delayed diagnosis of AKI by 2 to 9 hours. Crystalloids reduced creatinine concentration by 11 to 19% whereas colloids reduced concentration by 36 to 43%. The greatest reduction was at the end of the infusion period. Fluid dilution alone could not explain the rapid reduction of plasma creatinine concentration observed in 39 of 49 patients after cardiac arrest. Additional loss of creatinine production could account for those changes. AKI was suggested in six patients demonstrating little change in creatinine, since a 52 ± 13% reduction in GFR was required after accounting for fluid dilution and reduced creatinine production. Increased injury biomarkers within a few hours of cardiac arrest, including urinary cystatin C and plasma and urinary Neutrophil-Gelatinase-Associated-Lipocalin (biomarker-positive, creatinine-negative patients) also indicated AKI in these patients. Conclusions Creatinine and volume kinetics combined to quantify GFR loss, even in the absence of an increase in creatinine. The model improved disease severity estimation, and demonstrated that diagnostic delays due to dilution are minimally affected by fluid type. Creatinine sampling should be delayed at least

Metals transport in the Sacramento River, California, 1996-1997; Volume 2: Interpretation of metal loads

USGS Publications Warehouse

Alpers, Charles N.; Antweiler, Ronald C.; Taylor, Howard E.; Dileanis, Peter D.; Domagalski, Joseph L.

2000-01-01

Metals transport in the Sacramento River, northern California, from July 1996 to June 1997 was evaluated in terms of metal loads from samples of water and suspended colloids that were collected on up to six occasions at 13 sites in the Sacramento River Basin. Four of the sampling periods (July, September, and November 1996; and May-June 1997) took place during relatively low-flow conditions and two sampling periods (December 1996 and January 1997) took place during high-flow and flooding conditions, respectively. This study focused primarily on loads of cadmium, copper, lead, and zinc, with secondary emphasis on loads of aluminum, iron, and mercury.Trace metals in acid mine drainage from abandoned and inactive base-metal mines, in the East and West Shasta mining districts, enter the Sacramento River system in predominantly dissolved form into both Shasta Lake and Keswick Reservoir. The proportion of trace metals that was dissolved (as opposed to colloidal) in samples collected at Shasta and Keswick dams decreased in the order zinc ≈ cadmium > copper > lead. At four sampling sites on the Sacramento River--71, 256, 360, and 412 kilometers downstream of Keswick Dam--trace-metal loads were predominantly colloidal during both high- and low-flow conditions. The proportion of total cadmium, copper, lead, and zinc loads transported to San Francisco Bay and the Sacramento-San Joaquin Delta estuary (referred to as the Bay-Delta) that is associated with mineralized areas was estimated by dividing loads at Keswick Dam by loads 412 kilometers downstream at Freeport and the Yolo Bypass. During moderately high flows in December 1996, mineralization-related total (dissolved + colloidal) trace-metal loads to the Bay-Delta (as a percentage of total loads measured downstream) were cadmium, 87 percent; copper, 35 percent; lead, 10 percent; and zinc, 51 percent. During flood conditions in January 1997 loads were cadmium, 22 percent; copper, 11 percent; lead, 2 percent; and zinc, 15

Evaluation of Propranolol Effect on Experimental Acute and Chronic Toxoplasmosis Using Quantitative PCR

PubMed Central

Montazeri, Mahbobeh; Ebrahimzadeh, Mohammad Ali; Ahmadpour, Ehsan; Sharif, Mehdi; Sarvi, Shahabeddin

2016-01-01

Current therapies against toxoplasmosis are limited, and drugs have significant side effects and low efficacies. We evaluated the potential anti-Toxoplasma activity of propranolol at a dose of 2 or 3 mg/kg of body weight/day in vivo in the acute and chronic phases. Propranolol as a cell membrane-stabilizing agent is a suitable drug for inhibiting the entrance of Toxoplasma gondii tachyzoites into cells. The acute-phase assay was performed using propranolol, pyrimethamine, and propranolol plus pyrimethamine before (pretreatment) and after (posttreatment) intraperitoneal challenge with 1 × 103 tachyzoites of the virulent T. gondii strain RH in BALB/c mice. Also, in the chronic phase, treatment was performed 12 h before intraperitoneal challenge with 1 × 106 tachyzoites of the virulent strain RH of T. gondii in rats. One week (in the acute phase) and 2 months (in the chronic phase) after postinfection, tissues were isolated and DNA was extracted. Subsequently, parasite load was calculated using quantitative PCR (qPCR). In the acute phase, in both groups, significant anti-Toxoplasma activity was observed using propranolol (P < 0.001). Propranolol in the pretreatment group showed higher anti-Toxoplasma activity than propranolol in posttreatment in brain tissues, displaying therapeutic efficiency on toxoplasmosis. Also, propranolol combined with pyrimethamine reduced the parasite load as well as significantly increased survival of mice in the pretreatment group. In the chronic phase, anti-Toxoplasma activity and decreased parasite load in tissues were observed with propranolol. In conclusion, the presented results demonstrate that propranolol, as an orally available drug, is effective at low doses against acute and latent murine toxoplasmosis, and the efficiency of the drug is increased when it is used in combination therapy with pyrimethamine. PMID:27645234

Determining volume sensitive waters in Beaufort County, SC tidal creeks

Treesearch

Andrew Tweel; Denise Sanger; Anne Blair; John Leffler

2016-01-01

Non-point source pollution from stormwater runoff associated with large-scale land use changes threatens the integrity of ecologically and economically valuable estuarine ecosystems. Beaufort County, SC implemented volume-based stormwater regulations on the rationale that if volume discharge is controlled, contaminant loading will also be controlled.

1995 Pacific Northwest Loads and Resources Study, Technical Appendix: Volume 1.

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

United States. Bonneville Power Administration.

1995-12-01

The Pacific Northwest Loads and Resources Study (WhiteBook), is published annually by BPA, and establishes the planning basis for supplying electricity to customers. It serves a dual purpose. First, the White Book presents projections of regional and Federal system load and resource capabilities, along with relevant definitions and explanations. Second, the White Book serves as a benchmark for annual BPA determinations made pursuant to the 1981 regional power sales contracts. Specifically, BPA uses the, information in the White Book for determining the notice required when customers request to increase or decrease the amount of power purchased from BPA. Aside frommore » these purposes, the White Book is used for input to BPA`s resource planning process. The White Book compiles information obtained from several formalized resource planning reports and data submittals, including those from the Northwest Power Planning Council (Council) and the Pacific Northwest Utilities Conference Committee (PNUCC).« less

Predictors of acute and persisting ischemic brain lesions in patients randomized to carotid stenting or endarterectomy.

PubMed

Rostamzadeh, Ayda; Zumbrunn, Thomas; Jongen, Lisa M; Nederkoorn, Paul J; Macdonald, Sumaira; Lyrer, Philippe A; Kappelle, L Jaap; Mali, Willem P Th M; Brown, Martin M; van der Worp, H Bart; Engelter, Stefan T; Bonati, Leo H

2014-02-01

We investigated predictors for acute and persisting periprocedural ischemic brain lesions among patients with symptomatic carotid stenosis randomized to stenting or endarterectomy in the International Carotid Stenting Study. We assessed acute lesions on diffusion-weighted imaging 1 to 3 days after treatment in 124 stenting and 107 endarterectomy patients and lesions persisting on fluid-attenuated inversion recovery after 1 month in 86 and 75 patients, respectively. Stenting patients had more acute (relative risk, 8.8; 95% confidence interval, 4.4-17.5; P<0.001) and persisting lesions (relative risk, 4.2; 95% confidence interval, 1.6-11.1; P=0.005) than endarterectomy patients. Acute lesion count was associated with age (by trend), male sex, and stroke as the qualifying event in stenting; high systolic blood pressure in endarterectomy; and white matter disease in both groups. The rate of conversion from acute to persisting lesions was lower in the stenting group (relative risk, 0.4; 95% confidence interval, 0.2-0.8; P=0.007), and was only predicted by acute lesion volume. Stenting caused more acute and persisting ischemic brain lesions than endarterectomy. However, the rate of conversion from acute to persisting lesions was lower in the stenting group, most likely attributable to lower acute lesion volumes. Clinical Trial Registration -URL: www.isrctn.org. Unique identifier: ISRCTN25337470.

Influence of occlusal loading on peri-implant clinical parameters. A pilot study

PubMed Central

Pellicer-Chover, Hilario; Viña-Almunia, José; Romero-Millán, Javier; Peñarrocha-Oltra, David; Peñarrocha-Diago, María

2014-01-01

Objectives: To investigate the relation between occlusal loading and peri-implant clinical parameters (probing depth, bleeding on probing, gingival retraction, width of keratinized mucosa, and crevicular fluid volume) in patients with implant-supported complete fixed prostheses in both arches. Material and Methods: This clinical study took place at the University of Valencia (Spain) dental clinic. It included patients attending the clinic for regular check-ups during at least 12 months after rehabilitation of both arches with implant-supported complete fixed ceramo-metallic prostheses. One study implant and one control implant were established for each patient using the T-Scan®III computerized system (Tesco, South Boston, USA). The maxillary implant closest to the point of maximum occlusal loading was taken as the study implant and the farthest (with least loading) as the control. Occlusal forces were registered with the T-Scan® III and then occlusal adjustment was performed to distribute occlusal forces correctly. Peri-implant clinical parameters were analyzed in both implants before and two and twelve months after occlusal adjustment. Results: Before occlusal adjustment, study group implants presented a higher mean volume of crevicular fluid (51.3±7.4 UP) than the control group (25.8±5.5 UP), with statistically significant difference. Two months after occlusal adjustment, there were no significant differences between groups (24.6±3.8 UP and 26±4.5 UP respectively) (p=0.977). After twelve months, no significant differences were found between groups (24.4±11.1 UP and 22.5±8.9 UP respectively) (p=0.323). For the other clinical parameters, no significant differences were identified between study and control implants at any of the study times (p>0.05). Conclusions: Study group implants receiving higher occlusal loading presented significantly higher volumes of crevicular fluid than control implants. Crevicular fluid volumes were similar in both groups two and

Discussion series on PURPA related topics: load management

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

Sturgeon, J I

The Discussion Series on PURPA Related Topics is composed of five volumes: Metering, Billing, Information to Customers, Load Management Techniques and Master Metering. These reports are based on twenty-five Demonstration and Implementation projects sponsored and directed during the past five years by the US Department of Energy, Office of Utility Systems. Each of the topics bears directly on one or more of the federal standards contained in the Public Utilities Regulatory Policies Act of 1978 (PURPA). This volume, Load Management Techniques, relates primarily to the Time-of-Day rates standard, PURPA IB(d)3. The experiences related in this report deal, in part, withmore » the procedures and equipment which are affected when time-of-day rates are implemented. One goal of this report is to describe how people in a variety of settings have dealt with the many practical issues in load management. Another is to highlight the lessons and summarize the experiences of the Project participants. This report does not stand as a manual nor provide prescriptive guidelines on how to deal with the topic. Rather it offers an account for those charged with the responsibility of implementing PURPA requirements to learn from the insights and problems which occurred during the Rate Demonstration projects.« less

Coupling between gamma-band power and cerebral blood volume during recurrent acute neocortical seizures.

PubMed

Harris, Sam; Ma, Hongtao; Zhao, Mingrui; Boorman, Luke; Zheng, Ying; Kennerley, Aneurin; Bruyns-Haylett, Michael; Overton, Paul G; Berwick, Jason; Schwartz, Theodore H

2014-08-15

Characterization of neural and hemodynamic biomarkers of epileptic activity that can be measured using non-invasive techniques is fundamental to the accurate identification of the epileptogenic zone (EZ) in the clinical setting. Recently, oscillations at gamma-band frequencies and above (>30 Hz) have been suggested to provide valuable localizing information of the EZ and track cortical activation associated with epileptogenic processes. Although a tight coupling between gamma-band activity and hemodynamic-based signals has been consistently demonstrated in non-pathological conditions, very little is known about whether such a relationship is maintained in epilepsy and the laminar etiology of these signals. Confirmation of this relationship may elucidate the underpinnings of perfusion-based signals in epilepsy and the potential value of localizing the EZ using hemodynamic correlates of pathological rhythms. Here, we use concurrent multi-depth electrophysiology and 2-dimensional optical imaging spectroscopy to examine the coupling between multi-band neural activity and cerebral blood volume (CBV) during recurrent acute focal neocortical seizures in the urethane-anesthetized rat. We show a powerful correlation between gamma-band power (25-90 Hz) and CBV across cortical laminae, in particular layer 5, and a close association between gamma measures and multi-unit activity (MUA). Our findings provide insights into the laminar electrophysiological basis of perfusion-based imaging signals in the epileptic state and may have implications for further research using non-invasive multi-modal techniques to localize epileptogenic tissue. Copyright © 2014. Published by Elsevier Inc.

Investigation of the effects of intravenous magnesium sulphate on cardiac rhythm in acute myocardial infarction.

PubMed Central

Roffe, C.; Fletcher, S.; Woods, K. L.

1994-01-01

OBJECTIVE--To examine the effect of doubling serum magnesium concentration on the incidence of arrhythmias in patients with suspected acute myocardial infarction. DESIGN--Randomised double blind clinical trial. SETTING--Coronary care unit of a teaching hospital. PATIENTS--Clinical data were collected on 2316 randomised patients with suspected acute myocardial infarction. Holter monitoring was performed in a subgroup of 70 patients and analysed in 48 patients in whom acute myocardial infarction was confirmed. INTERVENTIONS--By random allocation, patients received either an intravenous loading dose of 8 mmol magnesium sulphate over five minutes plus 65 mmol over the next 24 hours, or equal volumes of saline. MAIN OUTCOME MEASURES--(a) Clinically documented arrhythmias; (b) use of antiarrhythmic treatments, cardioversion, and insertion of a pacemaker; (c) incidence of all abnormal rhythms during Holter monitoring. RESULTS--In the main trial the incidence of rhythm disturbance while in the coronary care unit (expressed as the odds ratio (OR) for magnesium: placebo and its 95% confidence interval) was not significantly different between treatment groups for ventricular fibrillation (OR 0.74; 0.46 to 1.20), ventricular tachycardia (OR 0.87; 0.63 to 1.20), supraventricular tachycardia (OR 0.69; 0.38 to 1.26), atrial fibrillation (OR 0.92; 0.69 to 1.23), or heart block of any degree (OR 1.17; 0.83 to 1.65). Sinus bradycardia was significantly more common in the magnesium group (OR 1.38; 1.03 to 1.85; p = 0.02). These findings were corroborated by the use of treatments for rhythm disturbance and the data from Holter monitoring. CONCLUSION--The regimen of intravenous magnesium sulphate used here had no significant effect on arrhythmia in acute myocardial infarction. The reduction in mortality that has been shown with this form of treatment is not attributable to suppression of life threatening rhythm disturbances. PMID:8130021

Assessment of the Uniqueness of Wind Tunnel Strain-Gage Balance Load Predictions

NASA Technical Reports Server (NTRS)

Ulbrich, N.

2016-01-01

A new test was developed to assess the uniqueness of wind tunnel strain-gage balance load predictions that are obtained from regression models of calibration data. The test helps balance users to gain confidence in load predictions of non-traditional balance designs. It also makes it possible to better evaluate load predictions of traditional balances that are not used as originally intended. The test works for both the Iterative and Non-Iterative Methods that are used in the aerospace testing community for the prediction of balance loads. It is based on the hypothesis that the total number of independently applied balance load components must always match the total number of independently measured bridge outputs or bridge output combinations. This hypothesis is supported by a control volume analysis of the inputs and outputs of a strain-gage balance. It is concluded from the control volume analysis that the loads and bridge outputs of a balance calibration data set must separately be tested for linear independence because it cannot always be guaranteed that a linearly independent load component set will result in linearly independent bridge output measurements. Simple linear math models for the loads and bridge outputs in combination with the variance inflation factor are used to test for linear independence. A highly unique and reversible mapping between the applied load component set and the measured bridge output set is guaranteed to exist if the maximum variance inflation factor of both sets is less than the literature recommended threshold of five. Data from the calibration of a six{component force balance is used to illustrate the application of the new test to real-world data.

Engine System Loads Development for the Fastrac 60K Flight Engine

NASA Technical Reports Server (NTRS)

Frady, Greg; Christensen, Eric R.; Mims, Katherine; Harris, Don; Parks, Russell; Brunty, Joseph

2000-01-01

Early implementation of structural dynamics finite element analyses for calculation of design loads is considered common design practice for high volume manufacturing industries such as automotive and aeronautical industries. However, with the rarity of rocket engine development programs starts, these tools are relatively new to the design of rocket engines. In the new Fastrac engine program, the focus has been to reduce the cost to weight ratio; current structural dynamics analysis practices were tailored in order to meet both production and structural design goals. Perturbation of rocket engine design parameters resulted in a number of Fastrac load cycles necessary to characterize the impact due to mass and stiffness changes. Evolution of loads and load extraction methodologies, parametric considerations and a discussion of load path sensitivities are discussed.

Longitudinal Volume Quantification of Deep Medullary Veins in Patients with Cerebral Venous Sinus Thrombosis : Venous Volume Assessment in Cerebral Venous Sinus Thrombosis Using SWI.

PubMed

Dempfle, A K; Harloff, A; Schuchardt, F; Bäuerle, J; Yang, S; Urbach, H; Egger, K

2017-06-06

Susceptibility-weighted imaging (SWI) visualizes small cerebral veins with high sensitivity and could, thus, enable quantification of hemodynamics of deep medullary veins. We aimed to evaluate volume changes of deep medullary veins in patients with acute cerebral venous sinus thrombosis (CVST) over time in comparison to healthy controls. All magnetic resonance imaging (MRI) experiments were executed at 3 T using a 32-channel head coil. Based on SWI and semiautomatic postprocessing (statistical parametric mapping [SPM8] and ANTs), the volume of deep medullary veins was quantified in 14 patients with acute CVST at baseline and the 6‑month follow-up, as well as in 13 healthy controls undergoing repeated MRI examination with an interscan interval of at least 1 month. Deep medullary venous volume change over time was significantly different between healthy controls and patient groups (p < 0.001). Patients with superior sagittal sinus thrombosis (SSST) showed a significant decline from baseline to follow-up measurements (9.8 ± 4.9 ml versus 7.5 ± 4.2 ml; p = 0.02), whereas in patients with transverse sinus thrombosis (TST) and healthy controls no significant volume changes were observable. Venous volume quantification was feasible and reproducible both in healthy volunteers and in patients. The decrease of venous volume in patients over time represents improvement of venous drainage, reduction of congestion, and normalization of microcirculation due to treatment. Thus, quantification of venous microcirculation could be valuable for estimation of prognosis and guidance of CVST therapy in the future.

Comparison of fluid types for resuscitation after acute blood loss in mallard ducks (Anas platyrhynchos).

PubMed

Lichtenberger, Marla; Orcutt, Connie; Cray, Carolyn; Thamm, Douglas H; DeBehnke, Daniel; Page, Cheryl; Mull, Lori; Kirby, Rebecca

2009-10-01

The purpose of this study was to determine the LD(50) for acute blood loss in mallard ducks (Anas platyrhynchos), compare the mortality rate among 3 fluid resuscitation groups, and determine the time required for a regenerative RBC response. Prospective study. Medical College of Wisconsin Research facility. Eighteen mallard ducks were included for the LD(50) study and 28 for the fluid resuscitation study. Phlebotomy was performed during both the LD(50) and fluid resuscitation studies. Ducks in the fluid resuscitation study received a 5 mL/kg intravenous bolus of crystalloids, hetastarch (HES), or a hemoglobin-based oxygen-carrying solution (HBOCS). The LD(50) for acute blood loss was 60% of total blood volume. This blood volume was removed in the fluid resuscitation study to create a model of acute blood loss. Following fluid administration, 6 birds in the crystalloid group (66%), 4 birds in the HES group (40%), and 2 birds in the HBOCS group (20%) died. No statistical difference in mortality rate was seen among the 3 fluid resuscitation groups. Relative polychromasia evaluated post-phlebotomy demonstrated regeneration starting at 24 hours and continuing through 48 hours. The LD(50) for acute blood loss in mallard ducks was 60% of their total blood volume. Although no statistical difference in mortality rate was appreciated among the 3 fluid resuscitation groups, a trend of decreased mortality rate was observed in the HBOCS group. An early regenerative response was apparent following acute blood loss.

Preferential effects of low volume versus high volume replacement with crystalloid fluid in a hemorrhagic shock model in pigs.

PubMed

Ponschab, Martin; Schöchl, Herbert; Keibl, Claudia; Fischer, Henrik; Redl, Heinz; Schlimp, Christoph J

2015-10-06

Fluid resuscitation is a core stone of hemorrhagic shock therapy, and crystalloid fluids seem to be associated with lower mortality compared to colloids. However, as redistribution starts within minutes, it has been suggested to replace blood loss with a minimum of a three-fold amount of crystalloids. The hypothesis was that in comparison to high volume (HV), a lower crystalloid volume (LV) achieves a favorable coagulation profile and exerts sufficient haemodynamics in the acute phase of resuscitation. In 24 anaesthetized pigs, controlled arterial blood loss of 50 % of the estimated blood volume was either (n = 12) replaced with a LV (one-fold) or a HV (three-fold) volume of a balanced, acetated crystalloid solution at room temperature. Hemodynamic parameters, dilution effects and coagulation profile by standard coagulation tests and thromboelastometry at baseline and after resuscitation were determined in both groups. LV resuscitation increased MAP significantly less compared to the HV, 61 ± 7 vs. 82 ± 14 mmHg (p < 0.001) respectively, with no difference between lactate and base excess between groups. Haematocrit after fluid replacement was 0.20 vs. 0.16 (LV vs. HV, p < 0.001), suggesting a grade of blood dilution of 32 vs. 42 % (p < 0.001) compared to baseline values. Compared to LV, HV resulted in decreased core temperature (37.5 ± 0.2 vs. 36.0 ± 0.6 °C, p < 0.001), lower platelet count (318 ± 77 vs. 231 ± 53 K/μL, p < 0.01) and lower plasma fibrinogen levels (205 ± 19 vs. 168 ± 24 mg/dL, p < 0.001). Thromboelastometric measurements showed a significant impairment on viscoelastic clot properties following HV group. While prothrombin time index decreased significantly more in the HV group, activated partial thromboplastin time did not differ between both groups. HV did not result in hyperchloraemic acidosis. Coagulation parameters represented by plasma fibrinogen and ROTEM parameters were also less impaired with LV. With regrad to hematocrit, 60 % of LV

Left ventricular outflow tract mean systolic acceleration as a surrogate for the slope of the left ventricular end-systolic pressure-volume relationship

NASA Technical Reports Server (NTRS)

Bauer, Fabrice; Jones, Michael; Shiota, Takahiro; Firstenberg, Michael S.; Qin, Jian Xin; Tsujino, Hiroyuki; Kim, Yong Jin; Sitges, Marta; Cardon, Lisa A.; Zetts, Arthur D.;

High-volume plasma exchange in a patient with acute liver failure due to non-exertional heat stroke in a sauna.

PubMed

Chen, Kuan-Jung; Chen, Tso-Hsiao; Sue, Yuh-Mou; Chen, Tzay-Jinn; Cheng, Chung-Yi

2014-10-01

Heat stroke is a life-threatening condition characterized by an increased core body temperature (over 40°C) and a systemic inflammatory response, which may lead to a syndrome of multiple organ dysfunction. Heat stroke may be due to either strenuous exercise or non-exercise-induced exposure to a high environmental temperature. Current management of heat stroke is mostly supportive, with an emphasis on cooling the core body temperature and preventing the development of multiple organ dysfunction. Prognosis of heat stroke depends on the severity of organ involvement. Here, we report a rare case of non-exercise-induced heat stroke in a 73-year-old male patient who was suffering from acute liver failure after prolonged exposure in a hot sauna room. We successfully managed this patient by administering high-volume plasma exchange, and the patient recovered completely after treatment. © 2014 Wiley Periodicals, Inc.

MRKAd5 HIV-1 Gag/Pol/Nef Vaccine-Induced T-Cell Responses Inadequately Predict Distance of Breakthrough HIV-1 Sequences to the Vaccine or Viral Load

PubMed Central

Janes, Holly; Frahm, Nicole; DeCamp, Allan; Rolland, Morgane; Gabriel, Erin; Wolfson, Julian; Hertz, Tomer; Kallas, Esper; Goepfert, Paul; Friedrich, David P.; Corey, Lawrence; Mullins, James I.; McElrath, M. Juliana; Gilbert, Peter

2012-01-01

Background The sieve analysis for the Step trial found evidence that breakthrough HIV-1 sequences for MRKAd5/HIV-1 Gag/Pol/Nef vaccine recipients were more divergent from the vaccine insert than placebo sequences in regions with predicted epitopes. We linked the viral sequence data with immune response and acute viral load data to explore mechanisms for and consequences of the observed sieve effect. Methods Ninety-one male participants (37 placebo and 54 vaccine recipients) were included; viral sequences were obtained at the time of HIV-1 diagnosis. T-cell responses were measured 4 weeks post-second vaccination and at the first or second week post-diagnosis. Acute viral load was obtained at RNA-positive and antibody-negative visits. Findings Vaccine recipients had a greater magnitude of post-infection CD8+ T cell response than placebo recipients (median 1.68% vs 1.18%; p = 0·04) and greater breadth of post-infection response (median 4.5 vs 2; p = 0·06). Viral sequences for vaccine recipients were marginally more divergent from the insert than placebo sequences in regions of Nef targeted by pre-infection immune responses (p = 0·04; Pol p = 0·13; Gag p = 0·89). Magnitude and breadth of pre-infection responses did not correlate with distance of the viral sequence to the insert (p>0·50). Acute log viral load trended lower in vaccine versus placebo recipients (estimated mean 4·7 vs 5·1) but the difference was not significant (p = 0·27). Neither was acute viral load associated with distance of the viral sequence to the insert (p>0·30). Interpretation Despite evidence of anamnestic responses, the sieve effect was not well explained by available measures of T-cell immunogenicity. Sequence divergence from the vaccine was not significantly associated with acute viral load. While point estimates suggested weak vaccine suppression of viral load, the result was not significant and more viral load data would be needed to detect suppression. PMID

Quantifying vocal fatigue recovery: Dynamic vocal recovery trajectories after a vocal loading exercise

PubMed Central

Hunter, Eric J.; Titze, Ingo R.

2012-01-01

Objectives To quantify the recovery of voice following a 2-hour vocal loading exercise (oral reading). Methods 86 adult participants tracked their voice recovery using short vocal tasks and perceptual ratings after an initial vocal loading exercise and for the following two days. Results Short-term recovery was apparent with 90% recovery within 4-6 hours and full recovery at 12-18 hours. Recovery was shown to be similar to a dermal wound healing trajectory. Conclusions The new recovery trajectory highlighted by the vocal loading exercise in the current study is called a vocal recovery trajectory. By comparing vocal fatigue to dermal wound healing, this trajectory is parallel to a chronic wound healing trajectory (as opposed to an acute wound healing trajectory). This parallel suggests that vocal fatigue from the daily use of the voice could be treated as a chronic wound, with the healing and repair mechanisms in a state of constant repair. In addition, there is likely a vocal fatigue threshold at which point the level of tissue damage would shift the chronic healing trajectory to an acute healing trajectory. PMID:19663377

In-Hospital Outcomes of Dual Loading Antiplatelet Therapy in Patients 75 Years and Older With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention: Findings From the CCC-ACS (Improving Care for Cardiovascular Disease in China-Acute Coronary Syndrome) Project.

PubMed

Zhao, Guanqi; Zhou, Mengge; Ma, Changsheng; Huo, Yong; Smith, Sidney C; Fonarow, Gregg C; Ge, Junbo; Han, Yaling; Liu, Jing; Hao, Yongchen; Liu, Jun; Wang, Xiao; Taubert, Kathryn A; Morgan, Louise; Zhao, Dong; Nie, Shaoping

2018-03-30

Elderly patients with acute coronary syndrome (ACS) are at high risk for ischemic and bleeding events. This study aimed to evaluate the clinical effectiveness and safety of dual loading antiplatelet therapy for patients 75 years and older undergoing percutaneous coronary intervention for ACS. The Improving Care for Cardiovascular Disease in China-ACS project was a collaborative study of the American Heart Association and Chinese Society of Cardiology. A total of 5887 patients 75 years and older with ACS who had percutaneous coronary intervention and received dual antiplatelet therapy with aspirin and P2Y 12 inhibitors (clopidogrel or ticagrelor) between November 2014 and June 2017 were enrolled. The primary effectiveness and safety outcomes were in-hospital major adverse cardiovascular events and major bleeding. Hazard ratios (HRs) of in-hospital outcomes with different loading statuses of antiplatelet therapy were estimated using Cox proportional hazard models with multivariate adjustment. A propensity score-matched analysis was also conducted. Compared with patients receiving a dual nonloading dose, patients taking a dual loading dose had increased risks of both major adverse cardiovascular events (HR, 1.66, 95% confidence interval, 1.13-2.44; [ P =0.010]) and major bleeding (HR, 2.34, 95% confidence interval, 1.75-3.13; [ P <0.001]). Among 3284 propensity score-matched patients, a dual loading dose was associated with a 1.36-fold risk of major adverse cardiovascular events (HR, 1.36; 95% confidence interval, 0.88-2.11 [ P =0.168]) and a 2.08-fold risk of major bleeding (HR, 2.08; 95% confidence interval, 1.47-2.93 [ P <0.001]). A dual loading dose of antiplatelet therapy was associated with increased major bleeding risk but not with decreased major adverse cardiovascular events risk among patients 75 years and older undergoing percutaneous coronary intervention for ACS in China. URL: http://www.ClinicalTrials.gov. Unique identifier: NCT02306616. © 2018 The

Radiation dose-volume effects in the esophagus.

PubMed

Werner-Wasik, Maria; Yorke, Ellen; Deasy, Joseph; Nam, Jiho; Marks, Lawrence B

2010-03-01

Publications relating esophageal radiation toxicity to clinical variables and to quantitative dose and dose-volume measures derived from three-dimensional conformal radiotherapy for non-small-cell lung cancer are reviewed. A variety of clinical and dosimetric parameters have been associated with acute and late toxicity. Suggestions for future studies are presented. Copyright 2010 Elsevier Inc. All rights reserved.

Dysphagia Management in Acute and Sub-acute Stroke

PubMed Central

Vose, Alicia; Nonnenmacher, Jodi; Singer, Michele L.; González-Fernández, Marlís

2014-01-01

Swallowing dysfunction is common after stroke. More than 50% of the 665 thousand stroke survivors will experience dysphagia acutely of which approximately 80 thousand will experience persistent dysphagia at 6 months. The physiologic impairments that result in post-stroke dysphagia are varied. This review focuses primarily on well-established dysphagia treatments in the context of the physiologic impairments they treat. Traditional dysphagia therapies including volume and texture modifications, strategies such as chin tuck, head tilt, head turn, effortful swallow, supraglottic swallow, super-supraglottic swallow, Mendelsohn maneuver and exercises such as the Shaker exercise and Masako (tongue hold) maneuver are discussed. Other more recent treatment interventions are discussed in the context of the evidence available. PMID:26484001

Immunological and molecular epidemiological characteristics of acute and fulminant viral hepatitis A.

PubMed

Hussain, Zahid; Husain, Syed A; Almajhdi, Fahad N; Kar, Premashis

2011-05-23

Hepatitis A virus is an infection of liver; it is hyperendemic in vast areas of the world including India. In most cases it causes an acute self limited illness but rarely fulminant. There is growing concern about change in pattern from asymptomatic childhood infection to an increased incidence of symptomatic disease in the adult population. In-depth analysis of immunological, viral quantification and genotype of acute and fulminant hepatitis A virus. Serum samples obtained from 1009 cases of suspected acute viral hepatitis was employed for different biochemical and serological examination. RNA was extracted from blood serum, reverse transcribed into cDNA and amplified using nested PCR for viral quantification, sequencing and genotyping. Immunological cell count from freshly collected whole blood was carried out by fluorescence activated cell sorter. Fulminant hepatitis A was mostly detected with other hepatic viruses. CD8+ T cells count increases in fulminant hepatitis to a significantly high level (P = 0.005) compared to normal healthy control. The immunological helper/suppressor (CD4+/CD8+) ratio of fulminant hepatitis was significantly lower compared to acute cases. The serologically positive patients were confirmed by RT-PCR and total of 72 (69.2%) were quantified and sequenced. The average quantitative viral load of fulminant cases was significantly higher (P < 0.05). There was similar genotypic distribution in both acute and fulminant category, with predominance of genotype IIIA (70%) compared to IA (30%). Immunological factors in combination with viral load defines the severity of the fulminant hepatitis A. Phylogenetic analysis of acute and fulminant hepatitis A confirmed genotypes IIIA as predominant against IA with no preference of disease severity.

Immunological and molecular epidemiological characteristics of acute and fulminant viral hepatitis A

PubMed Central

2011-01-01

Background Hepatitis A virus is an infection of liver; it is hyperendemic in vast areas of the world including India. In most cases it causes an acute self limited illness but rarely fulminant. There is growing concern about change in pattern from asymptomatic childhood infection to an increased incidence of symptomatic disease in the adult population. Objective In-depth analysis of immunological, viral quantification and genotype of acute and fulminant hepatitis A virus. Methods Serum samples obtained from 1009 cases of suspected acute viral hepatitis was employed for different biochemical and serological examination. RNA was extracted from blood serum, reverse transcribed into cDNA and amplified using nested PCR for viral quantification, sequencing and genotyping. Immunological cell count from freshly collected whole blood was carried out by fluorescence activated cell sorter. Results Fulminant hepatitis A was mostly detected with other hepatic viruses. CD8+ T cells count increases in fulminant hepatitis to a significantly high level (P = 0.005) compared to normal healthy control. The immunological helper/suppressor (CD4+/CD8+) ratio of fulminant hepatitis was significantly lower compared to acute cases. The serologically positive patients were confirmed by RT-PCR and total of 72 (69.2%) were quantified and sequenced. The average quantitative viral load of fulminant cases was significantly higher (P < 0.05). There was similar genotypic distribution in both acute and fulminant category, with predominance of genotype IIIA (70%) compared to IA (30%). Conclusions Immunological factors in combination with viral load defines the severity of the fulminant hepatitis A. Phylogenetic analysis of acute and fulminant hepatitis A confirmed genotypes IIIA as predominant against IA with no preference of disease severity. PMID:21605420

ERic Acute StrokE Recanalization: A study using predictive analytics to assess a new device for mechanical thrombectomy.

PubMed

Siemonsen, Susanne; Forkert, Nils D; Bernhardt, Martina; Thomalla, Götz; Bendszus, Martin; Fiehler, Jens

2017-08-01

Aim and hypothesis Using a new study design, we investigate whether next-generation mechanical thrombectomy devices improve clinical outcomes in ischemic stroke patients. We hypothesize that this new methodology is superior to intravenous tissue plasminogen activator therapy alone. Methods and design ERic Acute StrokE Recanalization is an investigator-initiated prospective single-arm, multicenter, controlled, open label study to compare the safety and effectiveness of a new recanalization device and distal access catheter in acute ischemic stroke patients with symptoms attributable to acute ischemic stroke and vessel occlusion of the internal cerebral artery or middle cerebral artery. Study outcome The primary effectiveness endpoint is the volume of saved tissue. Volume of saved tissue is defined as difference of the actual infarct volume and the brain volume that is predicted to develop infarction by using an optimized high-level machine learning model that is trained on data from a historical cohort treated with IV tissue plasminogen activator. Sample size estimates Based on own preliminary data, 45 patients fulfilling all inclusion criteria need to complete the study to show an efficacy >38% with a power of 80% and a one-sided alpha error risk of 0.05 (based on a one sample t-test). Discussion ERic Acute StrokE Recanalization is the first prospective study in interventional stroke therapy to use predictive analytics as primary and secondary endpoint. Such trial design cannot replace randomized controlled trials with clinical endpoints. However, ERic Acute StrokE Recanalization could serve as an exemplary trial design for evaluating nonpivotal neurovascular interventions.

Regional Availability of Mechanical Embolectomy for Acute Ischemic Stroke in California, 2009 to 2010

PubMed Central

Choi, Jay Chol; Hsia, Renee Y.

2015-01-01

Background and Purpose— We sought to assess the geographic proximity of patients with stroke in California to centers that performed specific threshold volumes of mechanical embolectomy procedures each year. Methods— We identified all patients who were hospitalized for acute ischemic stroke at all nonfederal acute care hospitals in California from 2009 to 2010, and all hospitals that performed any mechanical embolectomy procedures by case volume during the same period, using nonpublic data from the Office of Statewide Health Planning and Development. We computed geographic service areas around each hospital on the basis of prespecified ground transport distance thresholds. We then calculated the proportion of hospitalized patients with stroke who lived within service areas for centers that performed a low volume and high volume of mechanical embolectomy procedures each year. Results— During the 2-year study period, 15% (53/360) of hospitals performed at least 1 mechanical embolectomy for acute stroke, but only 19% (10/53) performed >10 cases per year. Most hospitalized patients with stroke (94%) lived within a 2-hour transport time (65 miles) to a hospital that performed ≥1 procedure during the 2-year period. Approximately 93% of the patients with stroke who received mechanical embolectomy lived within 20 miles from an embolectomy-capable hospital compared with 7% of those who lived >20 miles. Conclusions— In California, most patients with stroke lived within reasonable ground transport distances from centers that performed ≥1 mechanical embolectomy in a 2-year period. The probability of receiving mechanical embolectomy for acute ischemic stroke was associated with living in close geographic proximity to these hospitals. PMID:25657180

Traffic load spectra development for the 2002 AASHTO pavement design guide

DOT National Transportation Integrated Search

2004-12-30

Accurate knowledge of traffic volumes and loading is essential to structural pavement design and performance. Underestimation of design traffic can result in premature pavement failures and excessive rehabilitation costs. Overestimation can result in...

Accelerated and enhanced bone formation on novel simvastatin-loaded porous titanium oxide surfaces.

PubMed

Nyan, Myat; Hao, Jia; Miyahara, Takayuki; Noritake, Kanako; Rodriguez, Reena; Kasugai, Shohei

2014-10-01

With increasing application of dental implants in poor-quality bones, the need for implant surfaces ensuring accelerated osseointegration and enhanced peri-implant bone regeneration is increased. A study was performed to evaluate the osseointegration and bone formation on novel simvastatin-loaded porous titanium oxide surface. Titanium screws were treated by micro-arc oxidation to form porous oxide surface and 25 or 50 μg of simvastatin was loaded. The nontreated control, micro-arc oxidized, and simvastatin-loaded titanium screws were surgically implanted into the proximal tibia of 16-week-old male Wistar rats (n = 36). Peri-implant bone volume, bone-implant contact, and mineral apposition rates were measured at 2 and 4 weeks. Data were analyzed by one-way analysis of variance followed by Tukey's post hoc test. New bone was formed directly on the implant surface in the bone marrow cavity in simvastatin-loaded groups since 2 weeks. Bone-implant contact values were significantly higher in simvastatin-loaded groups than control and micro-arc oxidized groups at both time points (p < .05). Peri-implant bone volume and mineral apposition rate of simvastatin-loaded groups were significantly higher than control and micro-arc oxidized groups at 2 weeks (p < .05). These data suggested that simvastatin-loaded porous titanium oxide surface provides faster osseointegration and peri-implant bone formation and it would be potentially applicable in poor-quality bones. © 2013 Wiley Periodicals, Inc.

The Preservation of Cued Recall in the Acute Mentally Fatigued State: A Randomised Crossover Study.

PubMed

Flindall, Ian Richard; Leff, Daniel Richard; Pucks, Neysan; Sugden, Colin; Darzi, Ara

2016-01-01

The objective of this study is to investigate the impact of acute mental fatigue on the recall of clinical information in the non-sleep-deprived state. Acute mental fatigue in the non-sleep-deprived subject is rarely studied in the medical workforce. Patient handover has been highlighted as an area of high risk especially in fatigued subjects. This study evaluates the deterioration in recall of clinical information over 2 h with cognitively demanding work in non-sleep-deprived subjects. A randomised crossover study involving twenty medical students assessed free (presentation) and cued (MCQ) recall of clinical case histories at 0 and 2 h under low and high cognitive load using the N-Back task. Acute mental fatigue was assessed through the Visual Analogue Scale, Stanford Scale and NASA-TLX Mental Workload Rating Scale. Free recall is significantly impaired by increased cognitive load (p < 0.05) with subjects demonstrating perceived mental fatigue during the high cognitive load assessment. There was no significant difference in the amount of information retrieved by cued recall under high and low cognitive load conditions (p = 1). This study demonstrates the loss of clinical information over a short time period involving a mentally fatiguing, high cognitive load task. Free recall for the handover of clinical information is unreliable. Memory cues maintain recall of clinical information. This study provides evidence towards the requirement for standardisation of a structured patient handover. The use of memory cues (involving recognition memory and cued recall methodology) would be beneficial in a handover checklist to aid recall of clinical information and supports evidence for their adoption into clinical practice.

An apparatus for altering the mechanical load of the respiratory system.

PubMed

Younes, M; Bilan, D; Jung, D; Kroker, H

1987-06-01

We describe an apparatus for altering the mechanical load against which the respiratory muscles operate in humans. A closed system incorporates a rolling seal spirometer. The spirometer piston shaft is coupled to a fast-responding linear actuator that develops force in proportion to desired command signals. The command signal may be flow (resistive loading or unloading), volume (elastic loading or unloading), constant voltage (continuous positive or negative pressure), or any external function. Combinations of loads can be applied. Logic circuits permit application of the load at specific times during the respiratory cycle, and the magnitude of the loads is continuously adjustable. Maximum pressure output is +/- 20 cmH2O. The apparatus permits loading or unloading over a range of ventilation extending from resting levels to those observed during high levels of exercise (over 100 l/min). In response to a square-wave input, pressure rises exponentially with a time constant of 20 ms.

Full Body Loading for Small Exercise Devices Project

NASA Technical Reports Server (NTRS)

Downs, Meghan; Hanson, Andrea; Newby, Nathaniel

2015-01-01

Protecting astronauts' spine, hip, and lower body musculoskeletal strength will be critical to safely and efficiently perform physically demanding vehicle egress, exploration, and habitat building activities necessary to expand human presence in the solar system. Functionally limiting decrements in musculoskeletal health are likely during Mars proving-ground and Earth-independent missions given extended transit times and the vehicle limitations for exercise devices (low-mass, small volume). Most small exercise device concepts are designed with single-cable loading, which inhibits the ability to perform full body exercises requiring two-point loading at the shoulders. Shoulder loading is critical to protect spine, hip, and lower body musculoskeletal strength. We propose a novel low-mass, low-maintenance, and rapid deploy pulley-based system that can attach to a single-cable small exercise device to enable two-point loading at the shoulders. This attachment could protect astronauts' health and save cost, space, and energy during all phases of the Journey to Mars.

Early low volume oral synbiotic/prebiotic supplemented enteral stimulation of the gut in patients with severe acute pancreatitis: a prospective feasibility study.

PubMed

Plaudis, H; Pupelis, G; Zeiza, K; Boka, V

2012-01-01

Experience with administration of synbiotics (prebiotics/probiotics) in patients with severe acute pancreatitis (SAP) has demonstrated immunomodulatory capacity. The aim of this trial was evaluation of the feasibility and perspective of early clinical application of oral synbiotic/prebiotic supplements in patients with SAP. 90 SAP patients were enrolled during the period from 2005-2008. Patients were stratified according to the feeding mode. CONTROL (n = 32) group received standard whole protein feeding formula. SYNBIO (n = 30) and FIBRE groups (n = 28) received early (within first 24-48 hours) synbiotic or prebiotic supplements. Oral administration of synbiotics or prebiotics was commenced when patients were able to sip water. Daily provided average volume and calories of synbiotic/prebiotic blends were smaller compared to the CONTROL, p = 0.001. Oral administration of synbiotic/prebiotic supplements was associated with lower infection rate (pancreatic and peripancreatic necrosis) compared to the CONTROL, (p = 0.03; p = 0.001), lower rate of surgical interventions, p = 0.005, shorter ICU (p = 0.05) and hospital stay (p = 0.03). Synbiotic supplemented enteral stimulation of the gut resulted in reduced mortality rate compared to the CONTROL, p = 0.02. Early low volume oral synbiotic/prebiotic supplemented enteral stimulation of the gut seems to be a potentially valuable complement to the routine treatment protocol of SAP.

Load and resistance factor rating (LRFR) in New York State : volume II.

DOT National Transportation Integrated Search

2011-09-01

This report develops a Load and Resistance Factor Rating (NYS-LRFR) methodology : for New York bridges. The methodology is applicable for the rating of existing : bridges, the posting of under-strength bridges, and checking Permit trucks. The : propo...

Load and resistance factor rating (LRFR) in New York State : volume I.

DOT National Transportation Integrated Search

2011-09-01

This report develops a Load and Resistance Factor Rating (NYS-LRFR) methodology : for New York bridges. The methodology is applicable for the rating of existing : bridges, the posting of under-strength bridges, and checking Permit trucks. The : propo...

Change of mean platelet volume values in asthmatic children as an inflammatory marker.

PubMed

Tuncel, T; Uysal, P; Hocaoglu, A B; Erge, D O; Karaman, O; Uzuner, N

2012-01-01

Asthma is the most common chronic disease of childhood in industrialised countries. T helper-2 (Th-2) cells, mast cells and eosinophils have a role in inflammation of asthma. Recently it was shown that platelets also play a role in asthma. Mean platelet volume shows platelet size and reflects platelet activation. The aim of this retrospective study is to evaluate levels of mean platelet volume in asthmatic patients during asymptomatic periods and exacerbations compared with healthy controls. The study consisted of 100 asthmatic patients (male/female: 55/45, mean age: 8.2±3.3) and 49 age and sex matched healthy children as a control group. Mean platelet volume values of asthmatic patients during asymptomatic period were 7.7±0.8fL while mean platelet volume values in asthmatics during exacerbation were 7.8±0.9fL. Comparison of mean platelet volume values of asthmatic patients and healthy controls both in acute asthmatic attack and asymptomatic period showed no difference (p>0.05). Comparison of mean platelet volume values at asthmatic attack and asymptomatic period also had no difference (p>0.05). The presence of atopy, infection, eosinophilia, elevated immunoglobulin E, and severity of acute asthmatic attack did not influence mean platelet volume values. The results of our study suggest that mean platelet volume values may not be used as a marker in bronchial asthma, although prospective studies with larger number of patients are needed to evaluate the role of mean platelet volume in asthma. Copyright © 2011 SEICAP. Published by Elsevier Espana. All rights reserved.

High tidal volume decreases adult respiratory distress syndrome, atelectasis, and ventilator days compared with low tidal volume in pediatric burned patients with inhalation injury.

PubMed

Sousse, Linda E; Herndon, David N; Andersen, Clark R; Ali, Arham; Benjamin, Nicole C; Granchi, Thomas; Suman, Oscar E; Mlcak, Ronald P

2015-04-01

Inhalation injury, which is among the causes of acute lung injury and acute respiratory distress syndrome (ARDS), continues to represent a significant source of mortality in burned patients. Inhalation injury often requires mechanical ventilation, but the ideal tidal volume strategy is not clearly defined in burned pediatric patients. The aim of this study was to determine the effects of low and high tidal volume on the number of ventilator days, ventilation pressures, and incidence of atelectasis, pneumonia, and ARDS in pediatric burned patients with inhalation injury within 1 year post burn injury. From 1986 to 2014, inhalation injury was diagnosed by bronchoscopy in pediatric burned patients (n = 932). Patients were divided into 3 groups: unventilated (n = 241), high tidal volume (HTV, 15 ± 3 mL/kg, n = 190), and low tidal volume (LTV, 9 ± 3 mL/kg, n = 501). High tidal volume was associated with significantly decreased ventilator days (p < 0.005) and maximum positive end expiratory pressure (p < 0.0001) and significantly increased maximum peak inspiratory pressure (p < 0.02) and plateau pressure (p < 0.02) compared with those in patients with LTV. The incidence of atelectasis (p < 0.0001) and ARDS (p < 0.02) was significantly decreased with HTV compared with LTV. However, the incidence of pneumothorax was significantly increased in the HTV group compared with the LTV group (p < 0.03). High tidal volume significantly decreases ventilator days and the incidence of both atelectasis and ARDS compared with low tidal volume in pediatric burned patients with inhalation injury. Therefore, the use of HTV may interrupt sequences leading to lung injury in our patient population. Copyright © 2015 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Value of Quantitative Collateral Scoring on CT Angiography in Patients with Acute Ischemic Stroke.

PubMed

Boers, A M M; Sales Barros, R; Jansen, I G H; Berkhemer, O A; Beenen, L F M; Menon, B K; Dippel, D W J; van der Lugt, A; van Zwam, W H; Roos, Y B W E M; van Oostenbrugge, R J; Slump, C H; Majoie, C B L M; Marquering, H A

2018-06-01

Many studies have emphasized the relevance of collateral flow in patients presenting with acute ischemic stroke. Our aim was to evaluate the relationship of the quantitative collateral score on baseline CTA with the outcome of patients with acute ischemic stroke and test whether the timing of the CTA acquisition influences this relationship. From the Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN) data base, all baseline thin-slice CTA images of patients with acute ischemic stroke with intracranial large-vessel occlusion were retrospectively collected. The quantitative collateral score was calculated as the ratio of the vascular appearance of both hemispheres and was compared with the visual collateral score. Primary outcomes were 90-day mRS score and follow-up infarct volume. The relation with outcome and the association with treatment effect were estimated. The influence of the CTA acquisition phase on the relation of collateral scores with outcome was determined. A total of 442 patients were included. The quantitative collateral score strongly correlated with the visual collateral score (ρ = 0.75) and was an independent predictor of mRS (adjusted odds ratio = 0.81; 95% CI, .77-.86) and follow-up infarct volume (exponent β = 0.88; P < .001) per 10% increase. The quantitative collateral score showed areas under the curve of 0.71 and 0.69 for predicting functional independence (mRS 0-2) and follow-up infarct volume of >90 mL, respectively. We found significant interaction of the quantitative collateral score with the endovascular therapy effect in unadjusted analysis on the full ordinal mRS scale ( P = .048) and on functional independence ( P = .049). Modification of the quantitative collateral score by acquisition phase on outcome was significant (mRS: P = .004; follow-up infarct volume: P < .001) in adjusted analysis. Automated quantitative collateral scoring in patients with acute ischemic

Physicochemical characterization and in vivo evaluation of triamcinolone acetonide-loaded hydroxyapatite nanocomposites for treatment of rheumatoid arthritis.

PubMed

Jafari, Samira; Maleki-Dizaji, Nasrin; Barar, Jaleh; Barzegar-Jalali, Mohammad; Rameshrad, Maryam; Adibkia, Khosro

2016-04-01

The current study was aimed to investigate the anti-inflammatory effect of triamcinolone acetonide-loaded hydroxyapatite (TA-loaded HAp) nanocomposites in the arthritic rat model. The HAp nanocomposites were synthesized through a chemical precipitation method and the drug was subsequently incorporated into the nanocomposites using an impregnation method. The physicochemical properties as well as cytotoxicity of the prepared nanoformulation were examined as well. To evaluate the therapeutic efficacy of the prepared nanoformulation, the various parameters such as paw volume, haematological parameters and histological studies were assessed in the arthritic rats. The nanocomposites with the particle size of 70.45 nm, pore size of 2.71 nm and drug loading of 41.94% were obtained in this study. The specific surface area (aBET) as well as the volume of nitrogen adsorbed on one gram of HAp to complete the monolayer adsorption (Vm) were decreased after the drug loading process. The prepared nanoformulation revealed the slower drug release profile compared to the pure drug. Furthermore, the obtained data from MTT assay showed that the TA-loaded nanocomposites had a lower cytotoxic effect on NIH-3T3 and CAOV-4 cell lines as compared to the pure drug. Furthermore, TA-loaded HAp nanocomposites demonstrated favorable effects on the paw volume as well as the haematological and histopathological abnormalities in the adjuvant-induced arthritic rats. Therefore, TA-loaded HAp nanocomposites are potentially suggested for treatment of rheumatoid arthritis after further required evaluations. Copyright © 2015 Elsevier B.V. All rights reserved.

Cyclic load magnitude is a risk factor for a cumulative lower back disorder.

PubMed

Le, Peter; Solomonow, Moshe; Zhou, Bing-He; Lu, Yun; Patel, Vikas

2007-04-01

Epidemiological data suggest that high loads lifted by workers engaged in static and cyclic daily activities may be a risk factor for low back disorder. Our previous research provided physiological and biomechanical validation of the epidemiological data for static load conditions. The objective of this report was to provide physiological and biomechanical experimental validation to the epidemiological data in cyclic (repetitive) load conditions. Three groups of in vivo feline models were subjected to 3 cyclic load levels in a series of 6 periods of 10 minutes of work spaced by 10 minutes of rest followed by 7 hours of rest. Multifidus electromyography (EMG) and lumbar displacement were statistically analyzed after processing. Delayed muscular hyperexcitability was observed only in moderate (40 N) and high (60 N) loads (P<0.0001) but was absent in low (20 N) loads. The magnitude of the delayed hyperexcitability was found to be higher (P<0.0001) in the high (60 N) loads compared with the moderate (40 N) loads. Exposure to moderate and high loads in cyclic (repetitive) work results in an acute neuromuscular disorder indicative of soft tissue inflammation that may become chronic with further exposure.

Load and resistance factor rating (LRFR) in NYS : volume II final report.

DOT National Transportation Integrated Search

2011-09-01

This report develops a Load and Resistance Factor Rating (NYS-LRFR) methodology for New York bridges. The methodology is applicable for the rating of existing bridges, the posting of under-strength bridges, and checking Permit trucks. The proposed LR...

Load and resistance factor rating (LRFR) in NYS : volume I final report.

DOT National Transportation Integrated Search

2011-09-01

This report develops a Load and Resistance Factor Rating (NYS-LRFR) methodology for New York bridges. The methodology is applicable for the rating of existing bridges, the posting of under-strength bridges, and checking Permit trucks. The proposed LR...

Haemodilution for acute ischaemic stroke

PubMed Central

Chang, Timothy S; Jensen, Matthew B

2014-01-01

Background Ischaemic stroke interrupts the flow of blood to part of the brain. Haemodilution is thought to improve the flow of blood to the affected areas of the brain and thus reduce infarct size. Objectives To assess the effects of haemodilution in acute ischaemic stroke. Search methods We searched the Cochrane Stroke Group Trials Register (February 2014), the Cochrane Central Register of Controlled Trials (Issue 1, 2014), MEDLINE (January 2008 to October 2013) and EMBASE (January 2008 to October 2013). We also searched trials registers, scanned reference lists and contacted authors. For the previous version of the review, the authors contacted manufacturers and investigators in the field. Selection criteria Randomised trials of haemodilution treatment in people with acute ischaemic stroke. We included only trials in which treatment was started within 72 hours of stroke onset. Data collection and analysis Two review authors assessed trial quality and one review author extracted the data. Main results We included 21 trials involving 4174 participants. Nine trials used a combination of venesection and plasma volume expander. Twelve trials used plasma volume expander alone. The plasma volume expander was plasma alone in one trial, dextran 40 in 12 trials, hydroxyethyl starch (HES) in five trials and albumin in three trials. Two trials tested haemodilution in combination with another therapy. Evaluation was blinded in 14 trials. Five trials probably included some participants with intracerebral haemorrhage. Haemodilution did not significantly reduce deaths within the first four weeks (risk ratio (RR) 1.10; 95% confidence interval (CI) 0.90 to 1.34). Similarly, haemodilution did not influence deaths within three to six months (RR 1.05; 95% CI 0.93 to 1.20), or death and dependency or institutionalisation (RR 0.96; 95% CI 0.85 to 1.07). The results were similar in confounded and unconfounded trials, and in trials of isovolaemic and hypervolaemic haemodilution. No

Twelve-month prostate volume reduction after MRI-guided transurethral ultrasound ablation of the prostate.

PubMed

Bonekamp, David; Wolf, M B; Roethke, M C; Pahernik, S; Hadaschik, B A; Hatiboglu, G; Kuru, T H; Popeneciu, I V; Chin, J L; Billia, M; Relle, J; Hafron, J; Nandalur, K R; Staruch, R M; Burtnyk, M; Hohenfellner, M; Schlemmer, H-P

2018-06-25

To quantitatively assess 12-month prostate volume (PV) reduction based on T2-weighted MRI and immediate post-treatment contrast-enhanced MRI non-perfused volume (NPV), and to compare measurements with predictions of acute and delayed ablation volumes based on MR-thermometry (MR-t), in a central radiology review of the Phase I clinical trial of MRI-guided transurethral ultrasound ablation (TULSA) in patients with localized prostate cancer. Treatment day MRI and 12-month follow-up MRI and biopsy were available for central radiology review in 29 of 30 patients from the published institutional review board-approved, prospective, multi-centre, single-arm Phase I clinical trial of TULSA. Viable PV at 12 months was measured as the remaining PV on T2-weighted MRI, less 12-month NPV, scaled by the fraction of fibrosis in 12-month biopsy cores. Reduction of viable PV was compared to predictions based on the fraction of the prostate covered by the MR-t derived acute thermal ablation volume (ATAV, 55°C isotherm), delayed thermal ablation volume (DTAV, 240 cumulative equivalent minutes at 43°C thermal dose isocontour) and treatment-day NPV. We also report linear and volumetric comparisons between metrics. After TULSA, the median 12-month reduction in viable PV was 88%. DTAV predicted a reduction of 90%. Treatment day NPV predicted only 53% volume reduction, and underestimated ATAV and DTAV by 36% and 51%. Quantitative volumetry of the TULSA phase I MR and biopsy data identifies DTAV (240 CEM43 thermal dose boundary) as a useful predictor of viable prostate tissue reduction at 12 months. Immediate post-treatment NPV underestimates tissue ablation. • MRI-guided transurethral ultrasound ablation (TULSA) achieved an 88% reduction of viable prostate tissue volume at 12 months, in excellent agreement with expectation from thermal dose calculations. • Non-perfused volume on immediate post-treatment contrast-enhanced MRI represents only 64% of the acute thermal ablation volume

The short-term effects of running on the deformation of knee articular cartilage and its relationship to biomechanical loads at the knee.

PubMed

Boocock, M; McNair, P; Cicuttini, F; Stuart, A; Sinclair, T

2009-07-01

To investigate the short-term effects of recreational running on the deformation of knee articular cartilage and to examine the relationship between changes in knee cartilage volume and biomechanical modulators of knee joint load. Twenty healthy volunteers participated in a two phase cross-sectional study. Session 1 involved Magnetic Resonance Imaging (MRI) of femoral and tibial cartilage volumes prior to and following a 30 min period of relaxed sitting, which was directly followed by a recreational run of 5000 steps. Subsequently, all participants undertook a laboratory study of their running gait to compare biomechanical derived measures of knee joint loading with changes in cartilage volume. Estimates of knee joint load were determined using a rigid-link segment, dynamic biomechanical model of the lower limbs and a simplified muscle model. Running resulted in significant deformation of the medial (5.3%, P<0.01) and lateral femoral cartilage (4.0%, P<0.05) and lateral aspect of the tibial cartilage (5.7%, P<0.01), with no significant differences between genders. Maximum compression stress was significantly correlated with percentage changes in lateral femoral cartilage volume (r(2)=0.456, P<0.05). No other biomechanical variables correlated with volume changes. Limited evidence was found linking biomechanical measures of knee joint loading and observed short-term deformation of knee articular cartilage volume following running. Further enhancement of knee muscle modelling and analysis of stress distribution across cartilage are needed if we are to fully understand the contribution of biomechanical factors to knee joint loading and the pathogenesis of knee osteoarthritis (OA).

A displacement pump procedure to load extracts for automated gel permeation chromatography.

PubMed

Daft, J; Hopper, M; Hensley, D; Sisk, R

1990-01-01

Automated gel permeation chromatography (GPC) effectively separates lipids from pesticides in sample extracts that contain fat. Using a large syringe to load sample extracts manually onto GPC models having 5 mL holding loops is awkward, slow, and potentially hazardous. Loading with a small-volume displacement pump, however, is convenient and fast (ca 1 loop every 20 s). And more importantly, the analyst is not exposed to toxic organic vapors because the loading pump and its connecting lines do not leak in the way that a syringe does.

Description of plastic deformation of structural materials in triaxial loading

NASA Astrophysics Data System (ADS)

Lagzdins, A.; Zilaucs, A.

2008-03-01

A model of nonassociated plasticity is put forward for initially isotropic materials deforming with residual changes in volume under the action of triaxial normal stresses. The model is based on novel plastic loading and plastic potential functions, which define closed, convex, every where smooth surfaces in the 6D space of symmetric second-rank stress tensors. By way of example, the plastic deformation of a cylindrical concrete specimen wrapped with a CFRP tape and loaded in axial compression is described.

Systemic vascular load in calcific degenerative aortic valve stenosis: insight from percutaneous valve replacement.

PubMed

Yotti, Raquel; Bermejo, Javier; Gutiérrez-Ibañes, Enrique; Pérez del Villar, Candelas; Mombiela, Teresa; Elízaga, Jaime; Benito, Yolanda; González-Mansilla, Ana; Barrio, Alicia; Rodríguez-Pérez, Daniel; Martínez-Legazpi, Pablo; Fernández-Avilés, Francisco

2015-02-10

Systemic arterial load impacts the symptomatic status and outcome of patients with calcific degenerative aortic stenosis (AS). However, assessing vascular properties is challenging because the arterial tree's behavior could be influenced by the valvular obstruction. This study sought to characterize the interaction between valvular and vascular functions in patients with AS by using transcatheter aortic valve replacement (TAVR) as a clinical model of isolated intervention. Aortic pressure and flow were measured simultaneously using high-fidelity sensors in 23 patients (mean 79 ± 7 years of age) before and after TAVR. Blood pressure and clinical response were registered at 6-month follow-up. Systolic and pulse arterial pressures, as well as indices of vascular function (vascular resistance, aortic input impedance, compliance, and arterial elastance), were significantly modified by TAVR, exhibiting stiffer vascular behavior post-intervention (all, p < 0.05). Peak left ventricular pressure decreased after TAVR (186 ± 36 mm Hg vs. 162 ± 23 mm Hg, respectively; p = 0.003) but remained at >140 mm Hg in 70% of patients. Wave intensity analysis showed abnormally low forward and backward compression waves at baseline, increasing significantly after TAVR. Stroke volume decreased (-21 ± 19%; p < 0.001) and correlated with continuous and pulsatile indices of arterial load. In the 48 h following TAVR, a hypertensive response was observed in 12 patients (52%), and after 6-month follow-up, 5 patients required further intensification of discharge antihypertensive therapy. Vascular function in calcific degenerative AS is conditioned by the upstream valvular obstruction that dampens forward and backward compression waves in the arterial tree. An increase in vascular load after TAVR limits the procedure's acute afterload relief. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Prognostic Significance of Hyponatremia in Acute Intracerebral Hemorrhage: Pooled Analysis of the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial Studies.

PubMed

Carcel, Cheryl; Sato, Shoichiro; Zheng, Danni; Heeley, Emma; Arima, Hisatomi; Yang, Jie; Wu, Guojun; Chen, Guofang; Zhang, Shihong; Delcourt, Candice; Lavados, Pablo; Robinson, Thompson; Lindley, Richard I; Wang, Xia; Chalmers, John; Anderson, Craig S

2016-07-01

To determine the association of hyponatremia at presentation with clinical and imaging outcomes in patients with acute intracerebral hemorrhage. Retrospective pooled analysis of prospectively collected data from 3,243 participants of the pilot and main phases of the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trials 1 and 2 (international, multicenter, open, blinded endpoint, randomized controlled trials designed to assess the effects of early intensive blood pressure lowering in patients with acute intracerebral hemorrhage). Clinical hospital sites in 21 countries. Patients with predominantly mild-moderate severity of spontaneous intracerebral hemorrhage within 6 hours of onset and elevated systolic blood pressure (150-220 mm Hg) were included in the study. Patients were assigned to receive intensive (target systolic blood pressure, < 140 mm Hg within 1 hr) or guideline-recommended (target systolic blood pressure, < 180 mm Hg) blood pressure-lowering therapy. Presentation hyponatremia was defined as serum sodium less than 135 mEq/L. The primary outcome was death at 90 days. Multivariable logistic regression was used to assess the association of hyponatremia with important clinical events. Of 3,002 patients with available data, 349 (12%) had hyponatremia. Hyponatremia was associated with death (18% vs 11%; multivariable-adjusted odds ratio, 1.81; 95% CI, 1.28-2.57; p < 0.001) and larger baseline intracerebral hemorrhage volume (multivariable adjusted, p = 0.046) but not with baseline perihematomal edema volume nor with growth of intracerebral hemorrhage or perihematomal edema during the initial 24 hours. Hyponatremia at presentation is associated with increased mortality in patients with predominantly deep and modest volume intracerebral hemorrhage through mechanisms that seem independent of growth in intracerebral hemorrhage or perihematomal edema.

Assessment of Composite Delamination Self-Healing Under Cyclic Loading

NASA Technical Reports Server (NTRS)

O'Brien, T. Kevin

2009-01-01

Recently, the promise of self-healing materials for enhanced autonomous durability has been introduced using a micro-encapsulation technique where a polymer based healing agent is encapsulated in thin walled spheres and embedded into a base polymer along with a catalyst phase. For this study, composite skin-stiffener flange debonding specimens were manufactured from composite prepreg containing interleaf layers with a polymer based healing agent encapsulated in thin-walled spheres. Constant amplitude fatigue tests in three-point bending showed the effect of self-healing on the fatigue response of the skin-stiffener flange coupons. After the cycling that created debonding, fatigue tests were held at the mean load for 24 hours. For roughly half the specimens tested, when the cyclic loading was resumed a decrease in compliance (increase in stiffness) was observed, indicating that some healing had occurred. However, with continued cycling, the specimen compliance eventually increased to the original level before the hold, indicating that the damage had returned to its original state. As was noted in a prevoius study conducted with specimens tested under monotonically increasing loads to failure, healing achieved via the micro-encapsulation technique may be limited to the volume of healing agent available relative to the crack volume.

Effect of high-dose rosuvastatin loading before percutaneous coronary intervention in Chinese patients with acute coronary syndrome: A systematic review and meta-analysis

PubMed Central

Su, Qiang; Guo, Wenqin; Dai, Weiran; Li, Hongqing; Yang, Huafeng; Li, Lang

2017-01-01

Background Acute coronary syndrome (ACS) is an important disease threatening human life and health. Many studies have shown that the loading dose of atorvastatin can significantly improve the prognosis of patients with ACS, and reduce the mortality. However, this conclusion is not consistent. Thus, we aimed to evaluate the effect of high-dose rosuvastatin loading before percutaneous coronary intervention (PCI) in Chinese patients with ACS using a meta-analysis based on a systematic review of published articles. Methods We systematically reviewed published studies, evaluating the effect of high-dose rosuvastatin loading before percutaneous coronary intervention in Chinese patients with ACS. The retrieval time is limited from inception to 2 November 2016, and the retrieved databases included PubMed, Embase, the Cochrane Library, Web of Science, CBM, CNKI, the VIP database and the Wang Fang database. Two researchers independently assessed the quality of the included studies and then extracted the data. Stata 11.0 was used for data analysis. Results In total, 11 articles, which included 802 patients, were included in our meta-analysis. Among these patients, 398 patients were in the high-dose group (20 mg/day) and 404 patients were in the conventional dose group (10 mg/day). Meta-analysis results showed that compared with the conventional dose group: 1) The loading dose of rosuvastatin can significantly reduce the hs-CRP level after PCI, including at 24 hours (SMD = -0.65, 95%CI -0.84 ~ -0.47, P = 0.000), 48 hours (SMD = -0.40, 95%CI -0.68 ~ -0.11, P = 0.006), and four weeks (SMD = -1.64, 95%CI -2.01 ~ -1.26, P = 0.000). 2) The loading dose of rosuvastatin can significantly reduce the levels of LDL-C and cTnT, including the level of LDL-C at 30 d after PCI (SMD = -0.89, 95%CI -1.10 ~ -0.69, P = 0.000), and the level of cTnT at 24 h after PCI (SMD = -1.93, 95%CI -2.28 ~ -1.59, P = 0.000), and increase the level of HDL-C at 48 h after PCI (SMD = 0.61, 95%CI 0.34 ~ 0.88, P

A Descriptive Study of the Temporal Patterns of Volume and Contents Change in Human Acute Burn Edema: Application in Evidence-Based Intervention and Research Design.

PubMed

Edgar, Dale W; Fear, Mark; Wood, Fiona M

2016-01-01

Edema after burn contributes significantly to burn wound depth conversion. In humans after burn injury, there is a lack of detailed understanding of the contents and temporal changes in volume of acute tissue edema. The novel findings of these studies relate to the collection of edema fluid after partial-thickness burn injury. Edema volume peaks on day 1 after burn without formal fluid resuscitation. The studies indicated that the peak was on day 2 for a resuscitated burn. In contrast, animal studies suggest that the peak of edema occurs by or before day 1 after injury. The findings confirm the pitfalls of evidence derived from animal models and assuming direct transference to humans. Postburn edema was demonstrated to be a high-protein fluid (ie, ≥10 g/L) for the duration of the inflammatory period. The presence of high-protein edema presents greater challenges to clinicians developing novel treatment options. The rate of volume change over time tapered to insignificant levels after day 4 following burn. Greater than 98% of the edema contents was fluid. However, the size of particulate matter did not preclude it passing through patent lymphatic collectors. The results indicate a necessity for urgent postburn intervention, which should incorporate the active stimulation of the lymphatic system to improve efficacy of edema removal.

Human respiratory syncytial virus load normalized by cell quantification as predictor of acute respiratory tract infection.

PubMed

Gómez-Novo, Miriam; Boga, José A; Álvarez-Argüelles, Marta E; Rojo-Alba, Susana; Fernández, Ana; Menéndez, María J; de Oña, María; Melón, Santiago

2018-05-01

Human respiratory syncytial virus (HRSV) is a common cause of respiratory infections. The main objective is to analyze the prediction ability of viral load of HRSV normalized by cell number in respiratory symptoms. A prospective, descriptive, and analytical study was performed. From 7307 respiratory samples processed between December 2014 to April 2016, 1019 HRSV-positive samples, were included in this study. Low respiratory tract infection was present in 729 patients (71.54%). Normalized HRSV load was calculated by quantification of HRSV genome and human β-globin gene and expressed as log10 copies/1000 cells. HRSV mean loads were 4.09 ± 2.08 and 4.82 ± 2.09 log10 copies/1000 cells in the 549 pharyngeal and 470 nasopharyngeal samples, respectively (P < 0.001). The viral mean load was 4.81 ± 1.98 log10 copies/1000 cells for patients under the age of 4-year-old (P < 0.001). The viral mean loads were 4.51 ± 2.04 cells in patients with low respiratory tract infection and 4.22 ± 2.28 log10 copies/1000 cells with upper respiratory tract infection or febrile syndrome (P < 0.05). A possible cut off value to predict LRTI evolution was tentatively established. Normalization of viral load by cell number in the samples is essential to ensure an optimal virological molecular diagnosis avoiding that the quality of samples affects the results. A high viral load can be a useful marker to predict disease progression. © 2018 Wiley Periodicals, Inc.

Prevention of contrast-induced acute kidney injury: is simple oral hydration similar to intravenous? A systematic review of the evidence.

PubMed

Hiremath, Swapnil; Akbari, Ayub; Shabana, Wael; Fergusson, Dean A; Knoll, Greg A

2013-01-01

Pre-procedural intravenous fluid administration is an effective prophylaxis measure for contrast-induced acute kidney injury. For logistical ease, the oral route is an alternative to the intravenous. The objective of this study was to compare the efficacy of the oral to the intravenous route in prevention of contrast-induced acute kidney injury. A systematic review and meta-analysis of randomised trials with a stratified analysis and metaregression. Databases included MEDLINE (1950 to November 23 2011), EMBASE (1947 to week 47 2011), Cochrane CENTRAL (3(rd) quarter 2011). Two reviewers identified relevant trials and abstracted data. SETTINGS AND POPULATION: Trials including patients undergoing a contrast enhanced procedure. Randomised controlled trial; adult (>18 years) population; comparison of oral versus intravenous volume expansion. Oral route of volume expansion compared to the intravenous route. Any measure of acute kidney injury, need for renal replacement therapy, hospitalization and death. Six trials including 513 patients met inclusion criteria. The summary odds ratio was 1.19 (95% CI 0.46, 3.10, p = 0.73) suggesting no difference between the two routes of volume expansion. There was significant heterogeneity (Cochran's Q = 11.65, p = 0.04; I(2) = 57). In the stratified analysis, inclusion of the five studies with a prespecified oral volume expansion protocol resulted in a shift towards oral volume expansion (OR 0.75, 95% CI 0.37, 1.50, p = 0.42) and also resolved the heterogeneity (Q = 3.19, P = 0.53; I(2) = 0). Small number of studies identified; lack of hard clinical outcomes. The oral route may be as effective as the intravenous route for volume expansion for contrast-induced acute kidney injury prevention. Adequately powered trials with hard endpoints should be done given the potential advantages of oral (e.g. reduced patient burden and cost) over intravenous volume expansion.

Protective effects of alginate–chitosan microspheres loaded with alkaloids from Coptis chinensis Franch. and Evodia rutaecarpa (Juss.) Benth. (Zuojin Pill) against ethanol-induced acute gastric mucosal injury in rats

PubMed Central

Wang, Qiang-Song; Zhu, Xiao-Ning; Jiang, Heng-Li; Wang, Gui-Fang; Cui, Yuan-Lu

2015-01-01

Zuojin Pill (ZJP), a traditional Chinese medicine formula, consists of Coptis chinensis Franch. and Evodia rutaecarpa (Juss.) Benth. in a ratio of 6:1 (w/w) and was first recorded in “Danxi’s experiential therapy” for treating gastrointestinal disorders in the 15th century. However, the poor solubility of alkaloids from ZJP restricted the protective effect in treating gastritis and gastric ulcer. The aim of the study was to investigate the protective mechanism of mucoadhesive microspheres loaded with alkaloids from C. chinensis Franch. and E. rutaecarpa (Juss.) Benth. on ethanol-induced acute gastric mucosal injury in rats. Surface morphology, particle size, drug loading, encapsulation efficiency, in vitro drug release, mucoadhesiveness, and fluorescent imaging of the microspheres in gastrointestinal tract were studied. The results showed that the mucoadhesive microspheres loaded with alkaloids could sustain the release of drugs beyond 12 hours and had gastric mucoadhesive property with 82.63% retention rate in vitro. The fluorescence tracer indicated high retention of mucoadhesive microspheres within 12 hours in vivo. The mucoadhesive microspheres loaded with alkaloids could reduce the gastric injury by decreasing the mucosal lesion index, increasing the percentage of inhibition and increasing the amount of mucus in the gastric mucosa in an ethanol-induced gastric mucosal injury rat model. Moreover, the mucoadhesive microspheres loaded with alkaloids reduce the inflammatory response by decreasing the levels of tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), downregulating the mRNA expression of inducible nitric oxide synthase, TNF-α, and IL-1β in gastric mucosa. All the results indicate that mucoadhesive microspheres loaded with alkaloids could not only increase the residence time of alkaloids in rat stomach, but also exert gastroprotective effects through reducing the inflammatory response on ethanol-induced gastric mucosal damage. Thus

High tidal volume ventilation induces NOS2 and impairs cAMP- dependent air space fluid clearance.

PubMed

Frank, James A; Pittet, Jean-Francois; Lee, Hyon; Godzich, Micaela; Matthay, Michael A

2003-05-01

Tidal volume reduction during mechanical ventilation reduces mortality in patients with acute lung injury and the acute respiratory distress syndrome. To determine the mechanisms underlying the protective effect of low tidal volume ventilation, we studied the time course and reversibility of ventilator-induced changes in permeability and distal air space edema fluid clearance in a rat model of ventilator-induced lung injury. Anesthetized rats were ventilated with a high tidal volume (30 ml/kg) or with a high tidal volume followed by ventilation with a low tidal volume of 6 ml/kg. Endothelial and epithelial protein permeability were significantly increased after high tidal volume ventilation but returned to baseline levels when tidal volume was reduced. The basal distal air space fluid clearance (AFC) rate decreased by 43% (P < 0.05) after 1 h of high tidal volume but returned to the preventilation rate 2 h after tidal volume was reduced. Not all of the effects of high tidal volume ventilation were reversible. The cAMP-dependent AFC rate after 1 h of 30 ml/kg ventilation was significantly reduced and was not restored when tidal volume was reduced. High tidal volume ventilation also increased lung inducible nitric oxide synthase (NOS2) expression and air space total nitrite at 3 h. Inhibition of NOS2 activity preserved cAMP-dependent AFC. Because air space edema fluid inactivates surfactant and reduces ventilated lung volume, the reduction of cAMP-dependent AFC by reactive nitrogen species may be an important mechanism of clinical ventilator-associated lung injury.

Loads and loads and loads: the influence of prospective load, retrospective load, and ongoing task load in prospective memory.

PubMed

Meier, Beat; Zimmermann, Thomas D

2015-01-01

In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load (OTL) can affect prospective memory performance. The existence of multiple target events increases prospective load (PL) and adding complexity to the to-be-remembered action increases retrospective load (RL). In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of PL on costs in the ongoing task for categorical targets (Experiment 2), but not for specific targets (Experiment 1). RL and OTL both affected remembering the retrospective component of the prospective memory task. We suggest that PL can enhance costs in the ongoing task due to additional monitoring requirements. RL and OTL seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially.

Loads and loads and loads: the influence of prospective load, retrospective load, and ongoing task load in prospective memory

PubMed Central

Meier, Beat; Zimmermann, Thomas D.

2015-01-01

In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load (OTL) can affect prospective memory performance. The existence of multiple target events increases prospective load (PL) and adding complexity to the to-be-remembered action increases retrospective load (RL). In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of PL on costs in the ongoing task for categorical targets (Experiment 2), but not for specific targets (Experiment 1). RL and OTL both affected remembering the retrospective component of the prospective memory task. We suggest that PL can enhance costs in the ongoing task due to additional monitoring requirements. RL and OTL seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially. PMID:26082709

Krypton-81m ventilation scanning: acute respiratory disease

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

Lavender, J.P.; Irving, H.; Armstrong, J.D. II

1981-02-01

From experience with 700 patients undergoing ventilation and perfusion lung scanning with krypton-81m/technetium-99m technique, 34 patients suffering from nonembolic acute respiratory disease were selected for review. In 16 patients with pneumonia, all had defects of ventilation corresponding to, or larger than, the radiologic consolidation. In 13 patients there was some preservation of perfusion in the consolidated region. In two of the three patients with matched defects, the pneumonia was of long standing. In seven patients with collapse or atelectasis and in 11 patients with acute reversible bronchial obstruction and normal volume lungs, a similar pattern or ventillation and perfusion wasmore » observed.« less

Altered baseline blood volume and the norepinephrine response to stress in humans

NASA Technical Reports Server (NTRS)

Vernikos, J.; Convertino, V. A.

1992-01-01

A hypothesis is proposed that a primary physiological purpose of the neural and endocrine response to stressors is the preservation of the blood volume/blood pressure relationship. Changes in blood volume caused by an adaptation to the environmental challenge serve to modulate the neural and endocrine responsiveness to stress. Relationships between changes in vascular volume, vasoconstriction, and norepinephrine (NE) responses during acute and chronic exposure to various stressors are examined. It is noted that the hypothesis is based on numerous observations rather than definitive cause-effect experiments and further investigation is required to prove it.

Paying for volume: British Columbia's experiment with funding hospitals based on activity.

PubMed

Sutherland, Jason M; Liu, Guiping; Crump, R Trafford; Law, Michael

2016-11-01

For decades, Canadian hospitals have been funded using global budgets, a lump sum for providing care irrespective of the volume or mix of patients. In 2010, British Columbia (BC) introduced a controversial, but limited, form of activity-based funding (ABF) for hospitals. This study uses a quasi-experimental design to evaluate the impact of the introduction of ABF funding in the province. Our analysis used the population of patient-level acute hospitalization and day surgery discharge summaries from BC's acute hospitals from April 1, 2008 to March 31, 2013. Our outcome measures focused on both the intended and unintended impacts of ABF including the volume of cases, the efficiency of care, and the quality of care delivered. Our analysis used interrupted time series analysis. There was an increase in the volume of inpatient surgical activity associated with the implementation of ABF. The volume of medical cases dropped, and medical patients' lengths of stays increased. There were no changes in measures of quality. Hospitals' measurable responses to ABF policies on a number of key performance measures were mixed. Though BC's experiment with ABF was not associated with increases in hospital volumes for all types of care, the experience provides key lessons that small magnitude and short-term reforms are unlikely to change hospitals' behaviors quickly. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Acute Brucella melitensis M16 infection model in mice treated with tumor necrosis factor-alpha inhibitors.

PubMed

Kutlu, Murat; Ergin, Çağrı; Şen-Türk, Nilay; Sayin-Kutlu, Selda; Zorbozan, Orçun; Akalın, Şerife; Şahin, Barboros; Çobankara, Veli; Demirkan, Neşe

2015-02-19

There is limited data in the literature about brucellosis related to an intracellular pathogen and anti-tumor necrosis factor alpha (anti-TNFα) medication. The aim of this study was to evaluate acute Brucella infections in mice receiving anti-TNFα drug treatment. Anti-TNFα drugs were injected in mice on the first and fifth days of the study, after which the mice were infected with B. melitensis M16 strain. Mice were sacrificed on the fourteenth day after infection. Bacterial loads in the liver and spleen were defined, and histopathological changes were evaluated. Neither the liver nor the spleen showed an increased bacterial load in all anti-TNFα drug groups when compared to a non-treated, infected group. The most significant histopathological findings were neutrophil infiltrations in the red pulp of the spleen and apoptotic cells with hepatocellular pleomorphism in the liver. There was no significant difference among the groups in terms of previously reported histopathological findings, such as extramedullary hematopoiesis and granuloma formation. There were no differences in hepatic and splenic bacterial load and granuloma formation, which indicate worsening of the acute Brucella infection in mice; in other words, anti-TNFα treatment did not exacerbate the acute Brucella spp. infection in mice.

[Treatment of acute respiratory distress syndrome using pressure and volume controlled ventilation with lung protective strategy].

PubMed

Ge, Ying; Wan, Yong; Wang, Da-qing; Su, Xiao-lin; Li, Jun-ying; Chen, Jing

2004-07-01

To investigate the significance and effect of pressure controlled ventilation (PCV) as well as volume controlled ventilation (VCV) by lung protective strategy on respiratory mechanics, blood gas analysis and hemodynamics in patients with acute respiratory distress syndrome (ARDS). Fifty patients with ARDS were randomly divided into PCV and VCV groups with permissive hypercapnia and open lung strategy. Changes in respiratory mechanics, blood gas analysis and hemodynamics were compared between two groups. Peak inspiration pressure (PIP) in PCV group was significantly lower than that in VCV group, while mean pressure of airway (MPaw) was significantly higher than that in VCV after 24 hours mechanical ventilation. After 24 hours mechanical ventilation, there were higher central venous pressure (CVP) and slower heart rate (HR) in two groups, CVP was significantly higher in VCV compared with PCV, and PCV group had slower HR than VCV group, the two groups had no differences in mean blood pressure (MBP) at various intervals. All patients showed no ventilator-induced lung injury. Arterial blood oxygenations were obviously improved in two groups after 24 hours mechanical ventilation, PCV group had better partial pressure of oxygen in artery (PaO2) than VCV group. Both PCV and VCV can improve arterial blood oxygenations, prevent ventilator-induced lung injury, and have less disturbance in hemodynamic parameters. PCV with lung protective ventilatory strategy should be early use for patients with ARDS.

Has the athlete trained enough to return to play safely? The acute:chronic workload ratio permits clinicians to quantify a player's risk of subsequent injury.

PubMed

Blanch, Peter; Gabbett, Tim J

2016-04-01

The return to sport from injury is a difficult multifactorial decision, and risk of reinjury is an important component. Most protocols for ascertaining the return to play status involve assessment of the healing status of the original injury and functional tests which have little proven predictive ability. Little attention has been paid to ascertaining whether an athlete has completed sufficient training to be prepared for competition. Recently, we have completed a series of studies in cricket, rugby league and Australian rules football that have shown that when an athlete's training and playing load for a given week (acute load) spikes above what they have been doing on average over the past 4 weeks (chronic load), they are more likely to be injured. This spike in the acute:chronic workload ratio may be from an unusual week or an ebbing of the athlete's training load over a period of time as in recuperation from injury. Our findings demonstrate a strong predictive (R(2)=0.53) polynomial relationship between acute:chronic workload ratio and injury likelihood. In the elite team setting, it is possible to quantify the loads we are expecting athletes to endure when returning to sport, so assessment of the acute:chronic workload ratio should be included in the return to play decision-making process. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Alpha Air Sample Counting Efficiency Versus Dust Loading: Evaluation of a Large Data Set

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

Hogue, M. G.; Gause-Lott, S. M.; Owensby, B. N.

Dust loading on air sample filters is known to cause a loss of efficiency for direct counting of alpha activity on the filters, but the amount of dust loading and the correction factor needed to account for attenuated alpha particles is difficult to assess. In this paper, correction factors are developed by statistical analysis of a large database of air sample results for a uranium and plutonium processing facility at the Savannah River Site. As is typically the case, dust-loading data is not directly available, but sample volume is found to be a reasonable proxy measure; the amount of dustmore » loading is inferred by a combination of the derived correction factors and a Monte Carlo model. The technique compares the distribution of activity ratios [beta/(beta + alpha)] by volume and applies a range of correction factors on the raw alpha count rate. The best-fit results with this method are compared with MCNP modeling of activity uniformly deposited in the dust and analytical laboratory results of digested filters. Finally, a linear fit is proposed to evenly-deposited alpha activity collected on filters with dust loading over a range of about 2 mg cm -2 to 1,000 mg cm -2.« less

Alpha Air Sample Counting Efficiency Versus Dust Loading: Evaluation of a Large Data Set

DOE PAGES

Hogue, M. G.; Gause-Lott, S. M.; Owensby, B. N.; ...

2018-03-03

Dust loading on air sample filters is known to cause a loss of efficiency for direct counting of alpha activity on the filters, but the amount of dust loading and the correction factor needed to account for attenuated alpha particles is difficult to assess. In this paper, correction factors are developed by statistical analysis of a large database of air sample results for a uranium and plutonium processing facility at the Savannah River Site. As is typically the case, dust-loading data is not directly available, but sample volume is found to be a reasonable proxy measure; the amount of dustmore » loading is inferred by a combination of the derived correction factors and a Monte Carlo model. The technique compares the distribution of activity ratios [beta/(beta + alpha)] by volume and applies a range of correction factors on the raw alpha count rate. The best-fit results with this method are compared with MCNP modeling of activity uniformly deposited in the dust and analytical laboratory results of digested filters. Finally, a linear fit is proposed to evenly-deposited alpha activity collected on filters with dust loading over a range of about 2 mg cm -2 to 1,000 mg cm -2.« less

Los Angeles Area Permit Holder Estimated Trash Load Reduction

EPA Pesticide Factsheets

The Los Angeles River has been designated as an impaired waterbody due to the large volume of trash it receives from the watershed. To address this problem a Total Maximum Daily Load (TMDL), which establishes baseline trash loads to the river from the watershed, has been incorporated into the area stormwater permit. The permit requires each permittee to implement trash reduction measures for discharges through the storm drain system with an emphasis on the installation of full capture devices. The stormwater permit incorporates progressive reductions in trash discharges to the Los Angeles River, reaching a zero level in 2016.

Lifetime Reliability Prediction of Ceramic Structures Under Transient Thermomechanical Loads

NASA Technical Reports Server (NTRS)

Nemeth, Noel N.; Jadaan, Osama J.; Gyekenyesi, John P.

2005-01-01

An analytical methodology is developed to predict the probability of survival (reliability) of ceramic components subjected to harsh thermomechanical loads that can vary with time (transient reliability analysis). This capability enables more accurate prediction of ceramic component integrity against fracture in situations such as turbine startup and shutdown, operational vibrations, atmospheric reentry, or other rapid heating or cooling situations (thermal shock). The transient reliability analysis methodology developed herein incorporates the following features: fast-fracture transient analysis (reliability analysis without slow crack growth, SCG); transient analysis with SCG (reliability analysis with time-dependent damage due to SCG); a computationally efficient algorithm to compute the reliability for components subjected to repeated transient loading (block loading); cyclic fatigue modeling using a combined SCG and Walker fatigue law; proof testing for transient loads; and Weibull and fatigue parameters that are allowed to vary with temperature or time. Component-to-component variation in strength (stochastic strength response) is accounted for with the Weibull distribution, and either the principle of independent action or the Batdorf theory is used to predict the effect of multiaxial stresses on reliability. The reliability analysis can be performed either as a function of the component surface (for surface-distributed flaws) or component volume (for volume-distributed flaws). The transient reliability analysis capability has been added to the NASA CARES/ Life (Ceramic Analysis and Reliability Evaluation of Structures/Life) code. CARES/Life was also updated to interface with commercially available finite element analysis software, such as ANSYS, when used to model the effects of transient load histories. Examples are provided to demonstrate the features of the methodology as implemented in the CARES/Life program.

Chronic baseline prostate inflammation is associated with lower tumor volume in men with prostate cancer on repeat biopsy: Results from the REDUCE study.

PubMed

Moreira, Daniel M; Nickel, J Curtis; Andriole, Gerald L; Castro-Santamaria, Ramiro; Freedland, Stephen J

2015-09-01

To evaluate whether baseline acute and chronic prostate inflammation among men with initial negative biopsy for prostate cancer (PC) is associated with PC volume at the 2-year repeat prostate biopsy in a clinical trial with systematic biopsies. Retrospective analysis of 886 men with negative baseline prostate biopsy and positive 2-year repeat biopsy in the Reduction by Dutasteride of PC Events (REDUCE) study. Acute and chronic inflammation and tumor volume were determined by central pathology. The association of baseline inflammation with 2-year repeat biopsy cancer volume was evaluated with linear and Poisson regressions controlling for demographics and laboratory variables. Chronic, acute inflammation, and both were detected in 531 (60%), 12 (1%), and 84 (9%) baseline biopsies, respectively. Acute and chronic inflammation were significantly associated with each other (P < 0.001). Chronic inflammation was associated with larger prostate (P < 0.001) and lower pre-repeat biopsy PSA (P = 0.01). At 2-year biopsy, baseline chronic inflammation was associated with lower mean tumor volume (2.07 µl vs. 3.15 µl; P = 0.001), number of biopsy cores involved (1.78 vs. 2.19; P < 0.001), percent of cores involved (17.8% vs. 22.8%; P < 0.001), core involvement (0.21 µl vs. 0.31 µl; P < 0.001), and overall percent tumor involvement (1.40% vs. 2.01%; P < 0.001). Results were unchanged in multivariable analysis. Baseline acute inflammation was not associated with any tumor volume measurement. In a cohort of men with 2-year repeat prostate biopsy positive for PC after a negative baseline biopsy, baseline chronic inflammation was associated with lower PC volume. © 2015 Wiley Periodicals, Inc.

Diffusion tensor imaging and neurocognition in survivors of childhood acute lymphoblastic leukaemia.

PubMed

Edelmann, Michelle N; Krull, Kevin R; Liu, Wei; Glass, John O; Ji, Qing; Ogg, Robert J; Sabin, Noah D; Srivastava, Deo Kumar; Robison, Leslie L; Hudson, Melissa M; Reddick, Wilburn E

2014-11-01

Survivors of childhood acute lymphoblastic leukaemia are at risk for neurocognitive impairment, though little information is available on its association with brain integrity, particularly for survivors treated without cranial radiation therapy. This study compares neurocognitive function and brain morphology in long-term adult survivors of childhood acute lymphoblastic leukaemia treated with chemotherapy alone (n = 36) to those treated with cranial radiation therapy (n = 39) and to healthy control subjects (n = 23). Mean (standard deviation) age at evaluation was 24.9 (3.6) years for the chemotherapy group and 26.7 (3.4) years for the cranial radiation therapy group, while time since diagnosis was 15.0 (1.7) and 23.9 (3.1) years, respectively. Brain grey and white matter volume and diffusion tensor imaging was compared between survivor groups and to 23 healthy controls with a mean (standard deviation) age of 23.1 (2.6) years. Survivors treated with chemotherapy alone had higher fractional anisotropy in fibre tracts within the left (P < 0.05), but not in the right, hemisphere when compared to controls. Survivors of acute lymphoblastic leukaemia, regardless of treatment, had a lower ratio of white matter to intracranial volume in frontal and temporal lobes (P < 0.05) compared with control subjects. Survivors of acute lymphoblastic leukaemia treated with chemotherapy alone performed worse in processing speed (P < 0.001), verbal selective reminding (P = 0.01), and academics (P < 0.05) compared to population norms and performed better than survivors treated with cranial radiation therapy on verbal selective reminding (P = 0.02), processing speed (P = 0.05) and memory span (P = 0.009). There were significant associations between neurocognitive performance and brain imaging, particularly for frontal and temporal white and grey matter volume. Survivors of acute lymphoblastic leukaemia treated with chemotherapy alone demonstrated significant long-term differences in

Geographic access to high capability severe acute respiratory failure centers in the United States.

PubMed

Wallace, David J; Angus, Derek C; Seymour, Christopher W; Yealy, Donald M; Carr, Brendan G; Kurland, Kristen; Boujoukos, Arthur; Kahn, Jeremy M

2014-01-01

Optimal care of adults with severe acute respiratory failure requires specific resources and expertise. We sought to measure geographic access to these centers in the United States. Cross-sectional analysis of geographic access to high capability severe acute respiratory failure centers in the United States. We defined high capability centers using two criteria: (1) provision of adult extracorporeal membrane oxygenation (ECMO), based on either 2008-2013 Extracorporeal Life Support Organization reporting or provision of ECMO to 2010 Medicare beneficiaries; or (2) high annual hospital mechanical ventilation volume, based 2010 Medicare claims. Nonfederal acute care hospitals in the United States. We defined geographic access as the percentage of the state, region and national population with either direct or hospital-transferred access within one or two hours by air or ground transport. Of 4,822 acute care hospitals, 148 hospitals met our ECMO criteria and 447 hospitals met our mechanical ventilation criteria. Geographic access varied substantially across states and regions in the United States, depending on center criteria. Without interhospital transfer, an estimated 58.5% of the national adult population had geographic access to hospitals performing ECMO and 79.0% had geographic access to hospitals performing a high annual volume of mechanical ventilation. With interhospital transfer and under ideal circumstances, an estimated 96.4% of the national adult population had geographic access to hospitals performing ECMO and 98.6% had geographic access to hospitals performing a high annual volume of mechanical ventilation. However, this degree of geographic access required substantial interhospital transfer of patients, including up to two hours by air. Geographic access to high capability severe acute respiratory failure centers varies widely across states and regions in the United States. Adequate referral center access in the case of disasters and pandemics will

Respiratory load perception in overweight and asthmatic children.

PubMed

MacBean, Victoria; Wheatley, Lorna; Lunt, Alan C; Rafferty, Gerrard F

2017-05-01

Overweight asthmatic children report greater symptoms than normal weight asthmatics, despite comparable airflow obstruction. This has been widely assumed to be due to heightened perception of respiratory effort. Three groups of children (healthy weight controls, healthy weight asthmatics, overweight asthmatics) rated perceived respiratory effort throughout an inspiratory resistive loading protocol. Parasternal intercostal electromyogram was used as an objective marker of respiratory load; this was expressed relative to tidal volume and reported as a ratio of the baseline value (neuroventilatory activity ratio (NVEAR)). Significant increases in perception scores (p<0.0001), and decreases in NVEAR (p<0.0001) were observed from lowest to highest resistive load. Higher BMI increased overall perception scores, with no influence of asthma or BMI-for-age percentile on the resistance-perception relationships. These data, indicating elevated overall respiratory effort in overweight asthmatic children but comparable responses to dynamic changes in load, suggest that the greater disease burden in overweight asthmatic children may be due to altered respiratory mechanics associated with increased body mass. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of Cyclic Thermo-Mechanical Loads on Fatigue Reliability in Polymer Matrix Composites

NASA Technical Reports Server (NTRS)

Shah, A. R.; Murthy, P. L. N.; Chamis, C. C.

1996-01-01

A methodology to compute probabilistic fatigue life of polymer matrix laminated composites has been developed and demonstrated. Matrix degradation effects caused by long term environmental exposure and mechanical/thermal cyclic loads are accounted for in the simulation process. A unified time-temperature-stress dependent multi-factor interaction relationship developed at NASA Lewis Research Center has been used to model the degradation/aging of material properties due to cyclic loads. The fast probability integration method is used to compute probabilistic distribution of response. Sensitivities of fatigue life reliability to uncertainties in the primitive random variables (e.g., constituent properties, fiber volume ratio, void volume ratio, ply thickness, etc.) computed and their significance in the reliability- based design for maximum life is discussed. The effect of variation in the thermal cyclic loads on the fatigue reliability for a (0/+/- 45/90)(sub s) graphite/epoxy laminate with a ply thickness of 0.127 mm, with respect to impending failure modes has been studied. The results show that, at low mechanical cyclic loads and low thermal cyclic amplitudes, fatigue life for 0.999 reliability is most sensitive to matrix compressive strength, matrix modulus, thermal expansion coefficient, and ply thickness. Whereas at high mechanical cyclic loads and high thermal cyclic amplitudes, fatigue life at 0.999 reliability is more sensitive to the shear strength of matrix, longitudinal fiber modulus, matrix modulus, and ply thickness.

Reduced microvascular volume and hemispherically deficient vasoreactivity to hypercapnia in acute ischemia: MRI study using permanent middle cerebral artery occlusion rat model

PubMed Central

Suh, J Y; Shim, Woo H; Cho, Gyunggoo; Fan, Xiang; Kwon, Seon J; Kim, Jeong K; Dai, George; Wang, Xiaoying; Kim, Young R

2015-01-01

Vasoreactivity to hypercapnia has been used for assessing cerebrovascular tone and control altered by ischemic stroke. Despite the high prognostic potential, traits of hypercapnia-induced hemodynamic changes have not been fully characterized in relation with baseline vascular states and brain tissue damage. To monitor cerebrovascular responses, T2- and T2*-weighted magnetic resonance imaging (MRI) images were acquired alternatively using spin- and gradient-echo echo plannar imaging (GESE EPI) sequence with 5% CO2 gas inhalation in normal (n=5) and acute stroke rats (n=10). Dynamic relative changes in cerebrovascular volume (CBV), microvascular volume (MVV), and vascular size index (VSI) were assessed from regions of interest (ROIs) delineated by the percent decrease of apparent diffusion coefficient (ADC). The baseline CBV was not affected by middle cerebral artery occlusion (MCAO) whereas the baseline MVV in ischemic areas was significantly lower than that in the rest of the brain and correlated with ADC. Vasoreactivity to hypercapnic challenge was considerably attenuated in the entire ipsilesional hemisphere including normal ADC regions, in which unsolicited, spreading depression-associated increases of CBV and MVV were observed. The lesion-dependent inhomogeneity in baseline MVV indicates the effective perfusion reserve for accurately delineating the true ischemic damage while the cascade of neuronal depolarization is probably responsible for the hemispherically lateralized changes in overall neurovascular physiology. PMID:25690471

Reduced microvascular volume and hemispherically deficient vasoreactivity to hypercapnia in acute ischemia: MRI study using permanent middle cerebral artery occlusion rat model.

PubMed

Suh, J Y; Shim, Woo H; Cho, Gyunggoo; Fan, Xiang; Kwon, Seon J; Kim, Jeong K; Dai, George; Wang, Xiaoying; Kim, Young R

2015-06-01

Vasoreactivity to hypercapnia has been used for assessing cerebrovascular tone and control altered by ischemic stroke. Despite the high prognostic potential, traits of hypercapnia-induced hemodynamic changes have not been fully characterized in relation with baseline vascular states and brain tissue damage. To monitor cerebrovascular responses, T2- and T2*-weighted magnetic resonance imaging (MRI) images were acquired alternatively using spin- and gradient-echo echo plannar imaging (GESE EPI) sequence with 5% CO2 gas inhalation in normal (n=5) and acute stroke rats (n=10). Dynamic relative changes in cerebrovascular volume (CBV), microvascular volume (MVV), and vascular size index (VSI) were assessed from regions of interest (ROIs) delineated by the percent decrease of apparent diffusion coefficient (ADC). The baseline CBV was not affected by middle cerebral artery occlusion (MCAO) whereas the baseline MVV in ischemic areas was significantly lower than that in the rest of the brain and correlated with ADC. Vasoreactivity to hypercapnic challenge was considerably attenuated in the entire ipsilesional hemisphere including normal ADC regions, in which unsolicited, spreading depression-associated increases of CBV and MVV were observed. The lesion-dependent inhomogeneity in baseline MVV indicates the effective perfusion reserve for accurately delineating the true ischemic damage while the cascade of neuronal depolarization is probably responsible for the hemispherically lateralized changes in overall neurovascular physiology.

Curvilinear steel elements in load-bearing structures of high-rise building spatial frames

NASA Astrophysics Data System (ADS)

Ibragimov, Alexander; Danilov, Alexander

2018-03-01

The application of curvilinear elements in load-bearing metal structures of high-rise buildings supposes ensuring of their bearing capacity and serviceability. There may exist a great variety of shapes and orientations of such structural elements. In particular, it may be various flat curves of an open or closed oval profile such as circular or parabolic arch or ellipse. The considered approach implies creating vast internal volumes without loss in the load-bearing capacity of the frame. The basic concept makes possible a wide variety of layout and design solutions. The presence of free internal spaces of large volume in "skyscraper" type buildings contributes to resolving a great number of problems, including those of communicative nature. The calculation results confirm the basic assumptions.

Space shuttle solid rocket booster recovery system definition. Volume 3: SRB water impact loads computer program, user's manual

NASA Technical Reports Server (NTRS)

1973-01-01

This user's manual describes the FORTRAN IV computer program developed to compute the total vertical load, normal concentrated pressure loads, and the center of pressure of typical SRB water impact slapdown pressure distributions specified in the baseline configuration. The program prepares the concentrated pressure load information in punched card format suitable for input to the STAGS computer program. In addition, the program prepares for STAGS input the inertia reacting loads to the slapdown pressure distributions.

Prediction of a Densely Loaded Particle-Laden Jet using a Euler-Lagrange Dense Spray Model

NASA Astrophysics Data System (ADS)

Pakseresht, Pedram; Apte, Sourabh V.

2017-11-01

Modeling of a dense spray regime using an Euler-Lagrange discrete-element approach is challenging because of local high volume loading. A subgrid cluster of droplets can lead to locally high void fractions for the disperse phase. Under these conditions, spatio-temporal changes in the carrier phase volume fractions, which are commonly neglected in spray simulations in an Euler-Lagrange two-way coupling model, could become important. Accounting for the carrier phase volume fraction variations, leads to zero-Mach number, variable density governing equations. Using pressure-based solvers, this gives rise to a source term in the pressure Poisson equation and a non-divergence free velocity field. To test the validity and predictive capability of such an approach, a round jet laden with solid particles is investigated using Direct Numerical Simulation and compared with available experimental data for different loadings. Various volume fractions spanning from dilute to dense regimes are investigated with and without taking into account the volume displacement effects. The predictions of the two approaches are compared and analyzed to investigate the effectiveness of the dense spray model. Financial support was provided by National Aeronautics and Space Administration (NASA).

Tensiomyographical responses to accelerometer loads in female collegiate basketball players.

PubMed

Peterson, Kyle D; Quiggle, Gabriela T

2017-12-01

The purpose of the present study was to characterise the relationship between relative versus absolute internal and external loads in collegiate basketball players throughout the course of a season. Five Division I basketball players wore triaxial accelerometers throughout the 2015-2016 season and were tensiomyographically assessed weekly. One-way repeated-measure analysis of variance (RM ANOVA) with least-significant-difference (LSD) pairwise comparisons was used to determine which absolute weekly loads were different across the season. Cohen's d was used to supplement the determination of meaningful relative load changes. Overall RM ANOVA models suggest absolute external load differences occurred (PlayerLoad™ F = 17.63; IMA™ F = 31.63). Two-way RM ANOVA models revealed main effect differences were revealed between muscle groups for Tc (F = 9.11) and Dm (F = 3.25). Meaningful relative load changes between weeks were observed for both external and internal. The present study observed that tensiomyography utilised as a tool to monitor internal load may be more suitable for detecting fatigue from relative external load changes versus absolute load attained. Limiting weekly training volume changes to ≤10% may maintain appropriate adaptation. Mediolateral plane IMA™ and adductor longus muscle group may be pertinent metrics when monitoring female collegiate basketball athletes.

Resistance Training with Single vs. Multi-joint Exercises at Equal Total Load Volume: Effects on Body Composition, Cardiorespiratory Fitness, and Muscle Strength.

PubMed

Paoli, Antonio; Gentil, Paulo; Moro, Tatiana; Marcolin, Giuseppe; Bianco, Antonino

2017-01-01

The present study aimed to compare the effects of equal-volume resistance training performed with single-joint (SJ) or multi-joint exercises (MJ) on VO 2 max, muscle strength and body composition in physically active males. Thirty-six participants were divided in two groups: SJ group ( n = 18, 182.1 ± 5.2, 80.03 ± 2.78 kg, 23.5 ± 2.7 years) exercised with only SJ exercises (e.g., dumbbell fly, knee extension, etc.) and MJ group ( n = 18, 185.3 ± 3.6 cm, 80.69 ± 2.98 kg, 25.5 ± 3.8 years) with only MJ exercises (e.g., bench press, squat, etc.). The total work volume (repetitions × sets × load) was equated between groups. Training was performed three times a week for 8 weeks. Before and after the training period, participants were tested for VO 2 max, body composition, 1 RM on the bench press, knee extension and squat. Analysis of covariance (ANCOVA) was used to compare post training values between groups, using baseline values as covariates. According to the results, both groups decreased body fat and increased fat free mass with no difference between them. Whilst both groups significantly increased cardiorespiratory fitness and maximal strength, the improvements in MJ group were higher than for SJ in VO 2 max (5.1 and 12.5% for SJ and MJ), bench press 1 RM (8.1 and 10.9% for SJ and MJ), knee extension 1 RM (12.4 and 18.9% for SJ and MJ) and squat 1 RM (8.3 and 13.8% for SJ and MJ). In conclusion, when total work volume was equated, RT programs involving MJ exercises appear to be more efficient for improving muscle strength and maximal oxygen consumption than programs involving SJ exercises, but no differences were found for body composition.

The impact of a 600-mg loading dose of clopidogrel in diabetic and non-diabetic patients undergoing elective PCI.

PubMed

Mohareb, Mina W; Abd Elghany, Mohamed; Sabry, Nirmeen A; Farid, Samar F

2016-08-01

High platelet reactivity (HPR) and suboptimal response to dual antiplatelet therapy (DAPT) may explain high recurrent rates of ischemic events in type 1 and 2 diabetes mellitus (DM) patients undergoing percutaneous coronary intervention (PCI). The aim of this study was to determine the effect of diabetes mellitus on clopidogrel activity in cardiac patients undergoing PCI. This is an observational study. Patients were categorized according to DM status into diabetic group (N.=30) and non-diabetic group (N.=33). All patients received clopidogrel in a loading dose of 600 mg before PCI. Platelet function was assessed using light transmittance aggregometry (LTA) technique at baseline (before clopidogrel administration), 24 hour after clopidogrel loading dose administration and 7-10 days after PCI. All patients were followed up for at least one year after PCI for recurrence of acute cardiac events. There was no statistically significant difference between the two groups with respect to 10 µm adenosine diphosphate (ADP)-induced platelet aggregation measured at baseline (P=0.64), 24 hours after PCI (P=0.874), and 7-10 days after PCI (0.643). Diabetics were not significantly different from non-diabetics in terms of post-PCI acute stent thrombosis (P=0.945), sub-acute stent thrombosis (P=0.945), unstable angina (P=0.29) and cardiac death (P=0.64). There was a statistically significant difference between patients with and without post-PCI acute events regarding ADP aggregation measured 24 hours and 7-10 days after PCI. The use of a high loading dose of clopidogrel (600 mg) in patients undergoing elective PCI can overcome the significant increase in post-PCI platelet aggregation and rate of acute cardiac events induced by diabetes mellitus as co-morbidity in those patients.

Effects of Gender and Load on Combative Movement Performance. Volume I

DTIC Science & Technology

1982-02-01

Discuss ion 49 References 51 Appendices A Clothing and Equipment Used in This Study 53 B ANOVA Summary Tables 63 b3 LIST OF FIGURES Page Figure 1...Performance Introduction This is the first of four studies on the biomechanics of load carrying behavior being carried out in the Biomechanics Laboratory at...were taken on each subject and the weights of their utility clothes , boots, and sneakers were determined and recorded. Direct measurements were made of

[Using carnosine and natural antioxidants for the prophylaxis of acute post-loading oxidative stress].

PubMed

Rozhkova, E A; Ordzhonikidze, Z G; Druzhinin, A E; Seĭfulla, N R; Paniushkin, V V; Kuznetsov, Iu M

2007-01-01

The effects of a submaximum single physical load with a mixed aerobic-anaerobic character (combined rowing test) on the intensity of lipid peroxidation (LPO) processes, antioxidant state of the organism, and rheological properties of blood have been studied in a group of athletes. The administration of natural antioxidants significantly decreased the LPO stress induced by the physical load, reduced the suppression of the antioxidant system of the organism, and normalized the LPO-disturbed hemorheological parameters. Antioxidants such as carnosine, cytamine, and apilac can be used as non-doping means for the accelerated recovery and increase in the physical work capacity in athletes.

Analyzing the uncertainty of suspended sediment load prediction using sequential data assimilation

NASA Astrophysics Data System (ADS)

Leisenring, Marc; Moradkhani, Hamid

2012-10-01

SummaryA first step in understanding the impacts of sediment and controlling the sources of sediment is to quantify the mass loading. Since mass loading is the product of flow and concentration, the quantification of loads first requires the quantification of runoff volume. Using the National Weather Service's SNOW-17 and the Sacramento Soil Moisture Accounting (SAC-SMA) models, this study employed particle filter based Bayesian data assimilation methods to predict seasonal snow water equivalent (SWE) and runoff within a small watershed in the Lake Tahoe Basin located in California, USA. A procedure was developed to scale the variance multipliers (a.k.a hyperparameters) for model parameters and predictions based on the accuracy of the mean predictions relative to the ensemble spread. In addition, an online bias correction algorithm based on the lagged average bias was implemented to detect and correct for systematic bias in model forecasts prior to updating with the particle filter. Both of these methods significantly improved the performance of the particle filter without requiring excessively wide prediction bounds. The flow ensemble was linked to a non-linear regression model that was used to predict suspended sediment concentrations (SSCs) based on runoff rate and time of year. Runoff volumes and SSC were then combined to produce an ensemble of suspended sediment load estimates. Annual suspended sediment loads for the 5 years of simulation were finally computed along with 95% prediction intervals that account for uncertainty in both the SSC regression model and flow rate estimates. Understanding the uncertainty associated with annual suspended sediment load predictions is critical for making sound watershed management decisions aimed at maintaining the exceptional clarity of Lake Tahoe. The computational methods developed and applied in this research could assist with similar studies where it is important to quantify the predictive uncertainty of pollutant load

Effect of initial conditions on combustion generated loads

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

Tieszen, S.R.

1991-01-01

This analytical study examines the effect of initial thermodynamic conditions on the loads generated by the combustion of homogeneous hydrogen-air-steam mixtures. The effect of initial temperature, pressure, hydrogen concentration, and steam concentration is evaluated for two cases, (1) constant volume and (2) constant initial pressure. For each case, the Adiabatic, Isochoric, Complete Combustion (AICC), Chapman-Jouguet (CJ), and normally reflected CJ pressures are calculated for a range of hydrogen and steam concentrations representative of the entire flammable regime. For detonation loads, pressure profiles and time-histories are also evaluated in one-dimensional Cartesian geometry. The results show that to a first approximation, themore » AICC and CJ pressures are directly proportional to the initial density. Increasing the hydrogen concentration up to stoichiometric concentrations significantly increases the AICC, CJ, and reflected CJ pressures. For the constant volume case, the AICC, CJ, and reflected CJ pressures increase with increasing hydrogen concentration on the rich side of stoichiometric concentrations. For the constant initial pressure case, the AICC, CJ and reflected CJ pressures decrease with increasing hydrogen concentration on the rich side of stoichiometric values. The addition of steam decreases the AICC, CJ and reflected CJ pressures for the constant initial pressure case, but increases them for the constant volume case. For detonations, the pressure time-histories can be normalized with the AICC pressure and the reverberation time for Cartesian geometry. 35 refs., 16 figs.« less

Multidisciplinary acute care research organization (MACRO): if you build it, they will come.

PubMed

Early, Barbara J; Huang, David T; Callaway, Clifton W; Zenati, Mazen; Angus, Derek C; Gunn, Scott R; Yealy, Donald M; Unikel, Daniel; Billiar, Timothy R; Peitzman, Andrew B; Sperry, Jason L

2013-07-01

Clinical research will increasingly play a core role in the evolution and growth of acute care surgery program development across the country. What constitutes an efficient and effective clinical research infrastructure in the current fiscal and academic environment remains obscure. We sought to characterize the effects of implementation of a multidisciplinary acute care research organization (MACRO) at a busy tertiary referral university setting. In 2008, to minimize redundancy and cost as well as to maximize existing resources promoting acute care research, MACRO was created, unifying clinical research infrastructure among the Departments of Critical Care Medicine, Emergency Medicine, and Surgery. During the periods 2008 to 2012, we performed a retrospective analysis and determined volume of clinical studies, patient enrollment for both observational and interventional trials, and staff growth since MACRO's origination and characterized changes over time. From 2008 to 2011, the volume of patients enrolled in clinical studies, which MACRO facilitates has significantly increased more than 300%. The percentage of interventional/observational trials has remained stable during the same period (50-60%). Staff has increased from 6 coordinators to 10, with an additional 15 research associates allowing 24/7 service. With this significant growth, MACRO has become financially self-sufficient, and additional outside departments now seek MACRO's services. Appropriate organization of acute care clinical research infrastructure minimizes redundancy and can promote sustainable, efficient growth in the current academic environment. Further studies are required to determine if similar models can be successful at other acute care surgery programs.

Performance of the BioPlex 2200 HIV Ag-Ab assay for identifying acute HIV infection.

PubMed

Eshleman, Susan H; Piwowar-Manning, Estelle; Sivay, Mariya V; Debevec, Barbara; Veater, Stephanie; McKinstry, Laura; Bekker, Linda-Gail; Mannheimer, Sharon; Grant, Robert M; Chesney, Margaret A; Coates, Thomas J; Koblin, Beryl A; Fogel, Jessica M

Assays that detect HIV antigen (Ag) and antibody (Ab) can be used to screen for HIV infection. To compare the performance of the BioPlex 2200 HIV Ag-Ab assay and two other Ag/Ab combination assays for detection of acute HIV infection. Samples were obtained from 24 individuals (18 from the US, 6 from South Africa); these individuals were classified as having acute infection based on the following criteria: positive qualitative RNA assay; two negative rapid tests; negative discriminatory test. The samples were tested with the BioPlex assay, the ARCHITECT HIV Ag/Ab Combo test, the Bio-Rad GS HIV Combo Ag-Ab EIA test, and a viral load assay. Twelve (50.0%) of 24 samples had RNA detected only ( > 40 to 13,476 copies/mL). Ten (43.5%) samples had reactive results with all three Ag/Ab assays, one sample was reactive with the ARCHITECT and Bio-Rad assays, and one sample was reactive with the Bio-Rad and BioPlex assays. The 11 samples that were reactive with the BioPlex assay had viral loads from 83,010 to >750,000 copies/mL; 9/11 samples were classified as Ag positive/Ab negative by the BioPlex assay. Detection of acute HIV infection was similar for the BioPlex assay and two other Ag/Ab assays. All three tests were less sensitive than a qualitative RNA assay and only detected HIV Ag when the viral load was high. The BioPlex assay detected acute infection in about half of the cases, and identified most of those infections as Ag positive/Ab negative. Copyright © 2018 Elsevier B.V. All rights reserved.

Intra-aortic balloon pumping in acute mitral regurgitation reduces aortic impedance and regurgitant fraction.

PubMed

Dekker, André L A J; Reesink, Koen D; van der Veen, Frederik H; van Ommen, G Vincent A; Geskes, Gijs G; Soemers, A Cecilia M; Maessen, Jos G

2003-04-01

Acute mitral regurgitation (MR) is present in 10% of patients presenting with cardiogenic shock. To stabilize these patients, intra-aortic balloon pumping (IABP) is recommended, but the mechanism of IABP support in these patients is unknown. This animal study was designed to describe the hemodynamic effect of intra-aortic balloon pumping during cardiogenic shock induced by acute MR. In eight calves, left ventricular pressure-volume loops, aortic and left atrial pressure, and aortic, carotid artery, and coronary blood flow were recorded. Acute MR (range 36%-79%) was created by placing a metal cage in the mitral valve. Hemodynamic data was obtained at control, during acute MR, and during acute MR with 1:1 IABP support. Acute MR caused a decrease in cardiac output (-32%, P = 0.018), blood pressure, and carotid artery flow, whereas left ventricular output (+127%, P = 0.018), end-diastolic volume, and left atrial pressure all significantly increased. Stroke work, ejection fraction, and coronary blood flow were not significantly changed, and no signs of ischemia were seen on the ECG. The IABP raised average cardiac output by 31% (P = 0.012) and significantly raised blood pressure and flow to the brain while decreasing systemic vascular resistance. Left ventricular function and mean coronary blood flow did not change, but diastolic coronary flow became more important as shown by the increase in diastolic fraction from 64% to 95%. (P = 0.028). Average MR dropped by 7.5% (P = 0.025). In conclusion, application of the IABP during acute MR lowers aortic impedance, resulting in less MR and more output toward the aorta without changing left ventricular function.

Load-based approaches for modelling visual clarity in streams at regional scale.

PubMed

Elliott, A H; Davies-Colley, R J; Parshotam, A; Ballantine, D

2013-01-01

Reduction of visual clarity in streams by diffuse sources of fine sediment is a cause of water quality impairment in New Zealand and internationally. In this paper we introduce the concept of a load of optical cross section (LOCS), which can be used for load-based management of light-attenuating substances and for water quality models that are based on mass accounting. In this approach, the beam attenuation coefficient (units of m(-1)) is estimated from the inverse of the visual clarity (units of m) measured with a black disc. This beam attenuation coefficient can also be considered as an optical cross section (OCS) per volume of water, analogous to a concentration. The instantaneous 'flux' of cross section is obtained from the attenuation coefficient multiplied by the water discharge, and this can be accumulated over time to give an accumulated 'load' of cross section (LOCS). Moreover, OCS is a conservative quantity, in the sense that the OCS of two combined water volumes is the sum of the OCS of the individual water volumes (barring effects such as coagulation, settling, or sorption). The LOCS can be calculated for a water quality station using rating curve methods applied to measured time series of visual clarity and flow. This approach was applied to the sites in New Zealand's National Rivers Water Quality Network (NRWQN). Although the attenuation coefficient follows roughly a power relation with flow at some sites, more flexible loess rating curves are required at other sites. The hybrid mechanistic-statistical catchment model SPARROW (SPAtially Referenced Regressions On Watershed attributes), which is based on a mass balance for mean annual load, was then applied to the NRWQN dataset. Preliminary results from this model are presented, highlighting the importance of factors related to erosion, such as rainfall, slope, hardness of catchment rock types, and the influence of pastoral development on the load of optical cross section.

Cerebral Blood Volume ASPECTS Is the Best Predictor of Clinical Outcome in Acute Ischemic Stroke: A Retrospective, Combined Semi-Quantitative and Quantitative Assessment.

PubMed

Padroni, Marina; Bernardoni, Andrea; Tamborino, Carmine; Roversi, Gloria; Borrelli, Massimo; Saletti, Andrea; De Vito, Alessandro; Azzini, Cristiano; Borgatti, Luca; Marcello, Onofrio; d'Esterre, Christopher; Ceruti, Stefano; Casetta, Ilaria; Lee, Ting-Yim; Fainardi, Enrico

2016-01-01

The capability of CT perfusion (CTP) Alberta Stroke Program Early CT Score (ASPECTS) to predict outcome and identify ischemia severity in acute ischemic stroke (AIS) patients is still questioned. 62 patients with AIS were imaged within 8 hours of symptom onset by non-contrast CT, CT angiography and CTP scans at admission and 24 hours. CTP ASPECTS was calculated on the affected hemisphere using cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) maps by subtracting 1 point for any abnormalities visually detected or measured within multiple cortical circular regions of interest according to previously established thresholds. MTT-CBV ASPECTS was considered as CTP ASPECTS mismatch. Hemorrhagic transformation (HT), recanalization status and reperfusion grade at 24 hours, final infarct volume at 7 days and modified Rankin scale (mRS) at 3 months after onset were recorded. Semi-quantitative and quantitative CTP ASPECTS were highly correlated (p<0.00001). CBF, CBV and MTT ASPECTS were higher in patients with no HT and mRS ≤ 2 and inversely associated with final infarct volume and mRS (p values: from p<0.05 to p<0.00001). CTP ASPECTS mismatch was slightly associated with radiological and clinical outcomes (p values: from p<0.05 to p<0.02) only if evaluated quantitatively. A CBV ASPECTS of 9 was the optimal semi-quantitative value for predicting outcome. Our findings suggest that visual inspection of CTP ASPECTS recognizes infarct and ischemic absolute values. Semi-quantitative CBV ASPECTS, but not CTP ASPECTS mismatch, represents a strong prognostic indicator, implying that core extent is the main determinant of outcome, irrespective of penumbra size.

Cerebral Blood Volume ASPECTS Is the Best Predictor of Clinical Outcome in Acute Ischemic Stroke: A Retrospective, Combined Semi-Quantitative and Quantitative Assessment

PubMed Central

Padroni, Marina; Bernardoni, Andrea; Tamborino, Carmine; Roversi, Gloria; Borrelli, Massimo; Saletti, Andrea; De Vito, Alessandro; Azzini, Cristiano; Borgatti, Luca; Marcello, Onofrio; d’Esterre, Christopher; Ceruti, Stefano; Casetta, Ilaria; Lee, Ting-Yim; Fainardi, Enrico

2016-01-01

Introduction The capability of CT perfusion (CTP) Alberta Stroke Program Early CT Score (ASPECTS) to predict outcome and identify ischemia severity in acute ischemic stroke (AIS) patients is still questioned. Methods 62 patients with AIS were imaged within 8 hours of symptom onset by non-contrast CT, CT angiography and CTP scans at admission and 24 hours. CTP ASPECTS was calculated on the affected hemisphere using cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) maps by subtracting 1 point for any abnormalities visually detected or measured within multiple cortical circular regions of interest according to previously established thresholds. MTT-CBV ASPECTS was considered as CTP ASPECTS mismatch. Hemorrhagic transformation (HT), recanalization status and reperfusion grade at 24 hours, final infarct volume at 7 days and modified Rankin scale (mRS) at 3 months after onset were recorded. Results Semi-quantitative and quantitative CTP ASPECTS were highly correlated (p<0.00001). CBF, CBV and MTT ASPECTS were higher in patients with no HT and mRS≤2 and inversely associated with final infarct volume and mRS (p values: from p<0.05 to p<0.00001). CTP ASPECTS mismatch was slightly associated with radiological and clinical outcomes (p values: from p<0.05 to p<0.02) only if evaluated quantitatively. A CBV ASPECTS of 9 was the optimal semi-quantitative value for predicting outcome. Conclusions Our findings suggest that visual inspection of CTP ASPECTS recognizes infarct and ischemic absolute values. Semi-quantitative CBV ASPECTS, but not CTP ASPECTS mismatch, represents a strong prognostic indicator, implying that core extent is the main determinant of outcome, irrespective of penumbra size. PMID:26824672

A magnetic resonance imaging study of abnormalities of the patella and patellar tendon that predispose children to acute patellofemoral dislocation.

PubMed

Yılmaz, Barış; Çiçek, Esin Derin; Şirin, Evrim; Özdemir, Güzelali; Karakuş, Özgün; Muratlı, Hasan Hilmi

This study compared 20 children hospitalised with acute patellofemoral dislocation with an age-matched healthy control group with no history of knee problems or patellar dislocation. The following morphological parameters were significantly different between the groups: the mean patellar width and length, mean sulcus depth, mean patellar tendon width and total patellar volume. The magnetic resonance imaging findings of this study suggested that structurally smaller than normal patella and patellar tendon volumes are predisposing factors for acute patellofemoral dislocation. Copyright © 2016 Elsevier Inc. All rights reserved.

Acute Effects of the Elevation Training Mask on Strength Performance in Recreational Weight lifters.

PubMed

Jagim, Andrew R; Dominy, Trevor A; Camic, Clayton L; Wright, Glenn; Doberstein, Scott; Jones, Margaret T; Oliver, Jonathan M

2018-02-01

Jagim, AR, Dominy, TA, Camic, CL, Wright, G, Doberstein, S, Jones, MT, and Oliver, JM. Acute effects of the elevation training mask on strength performance in recreational weightlifters. J Strength Cond Res 32(2): 482-489, 2018-The Elevation Training Mask 2.0 (ETM) is a novel device that purportedly simulates altitude training. The purpose of this study was to investigate the acute effects of the ETM on resistance exercise performance, metabolic stress markers, and ratings of mental fatigue. Twenty male recreational weight lifters completed 2 training sessions of back squat and bench press (6 sets of 10 repetitions at 85% of 5-repetition maximum and seventh set to failure) as well as a maximal effort sprint test (18% body mass) with the mask (ETM) and without the mask (NM). Training evaluation included baseline and postexercise blood lactate and oxygen saturation measures. Performance evaluation included peak and average velocity bar velocity, total volume load, total work, total repetitions completed, and sprint performance. Adverse side effects were reported in 12% (n = 3) of participants, which included feelings of light headedness, anxiety, and discomfort. No differences were found in repetitions or total workload in back squat (p = 0.07) or bench press (p = 0.08) between conditions. A lower peak velocity was identified during the back squat, bench press, and sprint test in the ETM condition (p = 0.04). Blood lactate values were lower after bench press and sprint during the ETM condition (p < 0.001). Significantly lower ratings of alertness and focus for task were found after squat, bench press, and sprint test in the ETM condition compared with the NM condition (p < 0.001). Wearing the ETM during bouts of resistance training did not hinder the ability to achieve desired training volumes during the resistance training session. However, wearing the ETM does seem to attenuate the ability to maintain working velocity during training bouts and negatively influence

Vibration and loads in hingeless rotors. Volume 1: Theoretical analyses

NASA Technical Reports Server (NTRS)

Watts, G. A.; London, R. J.

1972-01-01

Analytic methods are developed for calculating blade loads and shaft-transmitted vibratory forces in stiff bladed hingeless rotors operating at advance ratios from mu = .3 to mu = 2.0. Calculated shaft harmonic moments compared well with experimental values when the blade first flap frequency was in the region of two-per-revolution harmonic excitation. Calculated blade bending moment azimuthal distributions due to changes in cyclic pitch agreed well with experiment at radial stations near the blade root at values of the ratio of first flap frequency to rotor rotation rate from 1.5 to 5.0. At stations near the blade tip good agreement was only obtained at the higher values of frequency ratio.

In vivo anti-psoriatic activity, biodistribution, sub-acute and sub-chronic toxicity studies of orally administered methotrexate loaded chitin nanogel in comparison with methotrexate tablet.

PubMed

Panonnummal, Rajitha; Jayakumar, R; Anjaneyan, Gopikrishnan; Sabitha, M

2018-04-15

The anti-psoriatic efficacy of orally administered methotrexate loaded chitin nanogel (MCNG) was evaluated (two doses- 2.715 mg/kg and 5.143 mg/kg) and compared against orally administered methotrexate tablet MTX (5.143 mg/kg). MCNG at both dose levels of 2.715 mg/kg and 5.143 mg/kg exhibited significant anti-psoriatic activity which is very much comparable with MTX, caused normalization of histological features and inflammatory score associated with induced psoriasis. Biodistribution studies revealed the presence of drug in serum and in vital organs at all the three cases with highest amount in MCNG at 5.143 mg/kg dose, followed by MTX tablet and are lowest in MCNG at 2.715 mg/kg dose. MCNG at the highest dose of 5.143 mg/kg caused liver, lung and kidney toxicities on sub acute toxicity studies and MTX tablet was found to be toxic on liver and lung on sub chronic toxicity studies. MCNG 2.715 mg/kg was found to be safe on both sub acute and sub chronic administrations, suggesting that it can provide sufficient serum and tissue level of methotrexate necessary to clear psoriatic lesions, without inducing systemic toxicity and expected to be a better alternative for orally administered conventional methotrexate tablet for patients who need systemic medications for psoriasis. Copyright © 2018. Published by Elsevier B.V.

Engine System Loads Analysis Compared to Hot-Fire Data

NASA Technical Reports Server (NTRS)

Frady, Gregory P.; Jennings, John M.; Mims, Katherine; Brunty, Joseph; Christensen, Eric R.; McConnaughey, Paul R. (Technical Monitor)

2002-01-01

Early implementation of structural dynamics finite element analyses for calculation of design loads is considered common design practice for high volume manufacturing industries such as automotive and aeronautical industries. However with the rarity of rocket engine development programs starts, these tools are relatively new to the design of rocket engines. In the NASA MC-1 engine program, the focus was to reduce the cost-to-weight ratio. The techniques for structural dynamics analysis practices, were tailored in this program to meet both production and structural design goals. Perturbation of rocket engine design parameters resulted in a number of MC-1 load cycles necessary to characterize the impact due to mass and stiffness changes. Evolution of loads and load extraction methodologies, parametric considerations and a discussion of load path sensitivities are important during the design and integration of a new engine system. During the final stages of development, it is important to verify the results of an engine system model to determine the validity of the results. During the final stages of the MC-1 program, hot-fire test results were obtained and compared to the structural design loads calculated by the engine system model. These comparisons are presented in this paper.

Dynamic Magnetic Resonance Angiography Provides Collateral Circulation and Hemodynamic Information in Acute Ischemic Stroke.

PubMed

Hernández-Pérez, María; Puig, Josep; Blasco, Gerard; Pérez de la Ossa, Natalia; Dorado, Laura; Dávalos, Antoni; Munuera, Josep

2016-02-01

Contrary to usual static vascular imaging techniques, contrast-enhanced dynamic magnetic resonance angiography (dMRA) enables dynamic study of cerebral vessels. We evaluated dMRA ability to assess arterial occlusion, cerebral hemodynamics, and collateral circulation in acute ischemic stroke. Twenty-five acute ischemic stroke patients with proximal anterior circulation occlusion underwent dMRA on a 3T scanner within 12 hours of symptoms onset. Diffusion weighted imaging, Tmax6 s lesion volumes and hypoperfusion intensity ratio as volume of Tmax>6 s/volume of Tmax>10 s were measured. Site and grade of occlusion (Thrombolysis in Myocardial Infarction criteria) were evaluated on time-of-flight MRA and dMRA. Leptomeningeal collaterality (American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology [ASITN/SIR] Scale) and asymmetries in venous clearance were assessed exclusively on dMRA. Collateral filling was dichotomized into incomplete (ASITN/SIR 0-2) or complete (ASITN/SIR 3-4). On dMRA, site of occlusion was M1 in 21 patients, tandem internal carotid artery/M1 in 2 and tandem internal carotid artery/terminal internal carotid artery in 2 patients. Three tandem occlusions were not detected on time-of-flight-MRA. All patients had Thrombolysis in Myocardial Infarction 0 to 1 on time-of-flight-MRA, but three of them had Thrombolysis in Myocardial Infarction 2 on dMRA. Complete collateral filling (n=12, 48%) was associated with smaller diffusion weighted imaging lesion volume (P=0.039), smaller hypoperfused volume (P=0.018), and lower hypoperfusion intensity ratio (P=0.006). Patients with symmetrical clearance of transverse sinuses (52%) were more likely to have complete collateral filling (P=0.015). As a fast, direct, feasible, noninvasive, and reliable method to assess site of occlusion, collateral circulation and hemodynamic alterations, dMRA provides profound insights in acute stroke. © 2015 American Heart Association, Inc.

Nectar loads as fuel for collecting nectar and pollen in honeybees: adjustment by sugar concentration.

PubMed

Harano, Ken-Ichi; Nakamura, Jun

2016-06-01

When honeybee foragers leave the nest, they receive nectar from nest mates for use as fuel for flight or as binding material to build pollen loads. We examined whether the concentration of nectar carried from the nest changes with the need for sugar. We found that pollen foragers had more-concentrated nectar (61.8 %) than nectar foragers (43.8 %). Further analysis revealed that the sugar concentration of the crop load increased significantly with waggle duration, an indicator of food-source distance, in both groups of foragers. Crop volume also increased with waggle duration. The results support our argument that foragers use concentrated nectar when the need for sugar is high and suggest that they precisely adjust the amount of sugar in the crop by altering both volume and nectar concentrations. We also investigated the impact of the area where foragers receive nectar on the crop load concentration at departure. Although nectar and pollen foragers tend to load nectar at different areas in the nest, area did not have a significant effect on crop load concentration. Departing foragers showed an average of 2.2 momentary (<1 s) begging trophallactic contacts before leaving the nest. They might be rejecting nectar with inappropriate concentrations during these contacts.

Mass loading of the upper airway extraluminal tissue space in rabbits: effects on tissue pressure and pharyngeal airway lumen geometry.

PubMed

Kairaitis, Kristina; Howitt, Lauren; Wheatley, John R; Amis, Terence C

2009-03-01

Lateral pharyngeal fat pad compression of the upper airway (UA) wall is thought to influence UA size in patients with obstructive sleep apnea. We examined interactions between acute mass/volume loading of the UA extra-luminal tissue space and UA patency. We studied 12 supine, anesthetized, spontaneously breathing, head position-controlled (50 degrees ), New Zealand White rabbits. Submucosal extraluminal tissue pressures (ETP) in the anterolateral (ETPlat) and anterior (ETPant) pharyngeal wall were monitored with surgically inserted pressure transducer-tipped catheters (Millar). Tracheal pressure (Ptr) and airflow (V) were measured via a pneumotachograph and pressure transducer inserted in series into the intact trachea, with hypopharyngeal cross-sectional area (CSA) measured via computed tomography, while graded saline inflation (0-1.5ml) of a compliant tissue expander balloon in the anterolateral subcutaneous tissue was performed. Inspiratory UA resistance (Rua) at 20 ml/s was calculated from a power function fitted to Ptr vs. V data. Graded expansion of the anterolateral balloon increased ETPlat from 2.3 +/- 0.5 cmH(2)O (n = 11, mean +/- SEM) to 5.0 +/- 1.1 cmH(2)O at 1.5-ml inflation (P < 0.05; ANOVA). However, ETPant was unchanged from 0.5 +/- 0.5 cmH(2)O (n = 9; P = 0.17). Concurrently, Rua increased to 119 +/- 4.2% of baseline value (n = 12; P < 0.001) associated with a significant reduction in CSA between 10 and 70% of airway length to a minimum of 82.2 +/- 4.4% of baseline CSA at 40% of airway length (P < 0.05). We conclude that anterolateral loading of the upper airway extraluminal tissue space decreases upper airway patency via an increase in ETPlat, but not ETPant. Lateral pharyngeal fat pad size may influence UA patency via increased tissue volume and pressure causing UA wall compression.

Effect of Loading Dose of Atorvastatin Prior to Planned Percutaneous Coronary Intervention on Major Adverse Cardiovascular Events in Acute Coronary Syndrome: The SECURE-PCI Randomized Clinical Trial.

PubMed

Berwanger, Otavio; Santucci, Eliana Vieira; de Barros E Silva, Pedro Gabriel Melo; Jesuíno, Isabella de Andrade; Damiani, Lucas Petri; Barbosa, Lilian Mazza; Santos, Renato Hideo Nakagawa; Laranjeira, Ligia Nasi; Egydio, Flávia de Mattos; Borges de Oliveira, Juliana Aparecida; Dall Orto, Frederico Toledo Campo; Beraldo de Andrade, Pedro; Bienert, Igor Ribeiro de Castro; Bosso, Carlos Eduardo; Mangione, José Armando; Polanczyk, Carisi Anne; Sousa, Amanda Guerra de Moraes Rego; Kalil, Renato Abdala Karam; Santos, Luciano de Moura; Sposito, Andrei Carvalho; Rech, Rafael Luiz; Sousa, Antônio Carlos Sobral; Baldissera, Felipe; Nascimento, Bruno Ramos; Giraldez, Roberto Rocha Corrêa Veiga; Cavalcanti, Alexandre Biasi; Pereira, Sabrina Bernardez; Mattos, Luiz Alberto; Armaganijan, Luciana Vidal; Guimarães, Hélio Penna; Sousa, José Eduardo Moraes Rego; Alexander, John Hunter; Granger, Christopher Bull; Lopes, Renato Delascio

2018-04-03

The effects of loading doses of statins on clinical outcomes in patients with acute coronary syndrome (ACS) and planned invasive management remain uncertain. To determine if periprocedural loading doses of atorvastatin decrease 30-day major adverse cardiovascular events (MACE) in patients with ACS and planned invasive management. Multicenter, double-blind, placebo-controlled, randomized clinical trial conducted at 53 sites in Brazil among 4191 patients with ACS evaluated with coronary angiography to proceed with a percutaneous coronary intervention (PCI) if anatomically feasible. Enrollment occurred between April 18, 2012, and October 6, 2017. Final follow-up for 30-day outcomes was on November 6, 2017. Patients were randomized to receive 2 loading doses of 80 mg of atorvastatin (n = 2087) or matching placebo (n = 2104) before and 24 hours after a planned PCI. All patients received 40 mg of atorvastatin for 30 days starting 24 hours after the second dose of study medication. The primary outcome was MACE, defined as a composite of all-cause mortality, myocardial infarction, stroke, and unplanned coronary revascularization through 30 days. Among the 4191 patients (mean age, 61.8 [SD, 11.5] years; 1085 women [25.9%]) enrolled, 4163 (99.3%) completed 30-day follow-up. A total of 2710 (64.7%) underwent PCI, 333 (8%) underwent coronary artery bypass graft surgery, and 1144 (27.3%) had exclusively medical management. At 30 days, 130 patients in the atorvastatin group (6.2%) and 149 in the placebo group (7.1%) had a MACE (absolute difference, 0.85% [95% CI, -0.70% to 2.41%]; hazard ratio, 0.88; 95% CI, 0.69-1.11; P = .27). No cases of hepatic failure were reported; 3 cases of rhabdomyolysis were reported in the placebo group (0.1%) and 0 in the atorvastatin group. Among patients with ACS and planned invasive management with PCI, periprocedural loading doses of atorvastatin did not reduce the rate of MACE at 30 days. These findings do not support the routine use

Surface Damage Mechanism of Monocrystalline Si Under Mechanical Loading

NASA Astrophysics Data System (ADS)

Zhao, Qingliang; Zhang, Quanli; To, Suet; Guo, Bing

2017-03-01

Single-point diamond scratching and nanoindentation on monocrystalline silicon wafer were performed to investigate the surface damage mechanism of Si under the contact loading. The results showed that three typical stages of material removal appeared during dynamic scratching, and a chemical reaction of Si with the diamond indenter and oxygen occurred under the high temperature. In addition, the Raman spectra of the various points in the scratching groove indicated that the Si-I to β-Sn structure (Si-II) and the following β-Sn structure (Si-II) to amorphous Si transformation appeared under the rapid loading/unloading condition of the diamond grit, and the volume change induced by the phase transformation resulted in a critical depth (ductile-brittle transition) of cut (˜60 nm ± 15 nm) much lower than the theoretical calculated results (˜387 nm). Moreover, it also led to abnormal load-displacement curves in the nanoindentation tests, resulting in the appearance of elbow and pop-out effects (˜270 nm at 20 s, 50 mN), which were highly dependent on the loading/unloading conditions. In summary, phase transformation of Si promoted surface deformation and fracture under both static and dynamic mechanical loading.

Calcium Imaging of AM Dyes Following Prolonged Incubation in Acute Neuronal Tissue

PubMed Central

Morley, John W.; Tapson, Jonathan; Breen, Paul P.; van Schaik, André

2016-01-01

Calcium-imaging is a sensitive method for monitoring calcium dynamics during neuronal activity. As intracellular calcium concentration is correlated to physiological and pathophysiological activity of neurons, calcium imaging with fluorescent indicators is one of the most commonly used techniques in neuroscience today. Current methodologies for loading calcium dyes into the tissue require prolonged incubation time (45–150 min), in addition to dissection and recovery time after the slicing procedure. This prolonged incubation curtails experimental time, as tissue is typically maintained for 6–8 hours after slicing. Using a recently introduced recovery chamber that extends the viability of acute brain slices to more than 24 hours, we tested the effectiveness of calcium AM staining following long incubation periods post cell loading and its impact on the functional properties of calcium signals in acute brain slices and wholemount retinae. We show that calcium dyes remain within cells and are fully functional >24 hours after loading. Moreover, the calcium dynamics recorded >24 hrs were similar to the calcium signals recorded in fresh tissue that was incubated for <4 hrs. These results indicate that long exposure of calcium AM dyes to the intracellular cytoplasm did not alter the intracellular calcium concentration, the functional range of the dye or viability of the neurons. This data extends our previous work showing that a custom recovery chamber can extend the viability of neuronal tissue, and reliable data for both electrophysiology and imaging can be obtained >24hrs after dissection. These methods will not only extend experimental time for those using acute neuronal tissue, but also may reduce the number of animals required to complete experimental goals. PMID:27183102

Multifunctional Structures for High-Energy Lightweight Load-Bearing Storage

NASA Technical Reports Server (NTRS)

Loyselle, Patricia L.

2018-01-01

This is a pull-up banner of the Multifunctional Structures for High-Energy Lightweight Load-bearing Storage (M-SHELLS) technology that will be on display at the SciTech Conference in January 2018. Efforts in Multifunctional Structures for High Energy Load-Bearing Storage (M-Shells) are pushing the boundaries of development for hybrid electric propulsion for future commercial aeronautical transport. The M-Shells hybrid material would serve as the power/energy storage of the vehicle and provide structural integrity, freeing up usable volume and mass typically occupied by bulky batteries. The ultimate goal is to demonstrate a system-level mass savings with a multifunctional structure with energy storage.

The acute effects of body position strategies and respiratory therapy in paralyzed patients with acute lung injury

PubMed Central

Davis, Kenneth; Johannigman, Jay A; Campbell, Robert S; Marraccini, Ann; Luchette, Fred A; Frame, Scott B; Branson, Richard D

2001-01-01

Background: Routine turning of critically ill patients is a standard of care. In recent years, specialized beds that provide automated turning have been introduced. These beds have been reported to improve lung function, reduce hospital-acquired pneumonia, and facilitate secretion removal. This trial was designed to measure the physiological effects of routine turning and respiratory therapy in comparison with continuous lateral rotation (CLR). Methods: The study was a prospective, quasi-experimental, random assignment, trial with patients serving as their own controls. Paralyzed, sedated patients with acute respiratory distress syndrome were eligible for study. Patients were randomized to receive four turning and secretion management regimens in random sequence for 6 h each over a period of 24 h: (1) routine turning every 2 h from the left to right lateral position; (2) routine turning every 2 h from the left to right lateral position including a 15-min period of manual percussion and postural drainage (P&PD); (3) CLR with a specialized bed that turned patients from left to right lateral position, pausing at each position for 2 min; and (4) CLR with a specialized bed that turned patients from left to right lateral position pausing at each position for 2 min, and a 15-min period of percussion provided by the pneumatic cushions of the bed every 2 h. Results: Nineteen patients were entered into the study. There were no statistically significant differences in the measured cardiorespiratory variables. There was a tendency for the ratio of partial pressure of arterial oxygen to fractional inspired oxygen concentration (PaO2/FIO2) to increase (174 ± 31 versus 188 ± 36; P = 0.068) and for the ratio of deadspace to tidal volume (Vd/Vt) to decrease (0.62 ± 0.18 versus 0.59 ± 0.18; P = 0.19) during periods of CLR, but these differences did not achieve statistical significance. There were statistically significant increases in sputum volume during the periods of CLR. The

Shock Isolation Elements Testing for High Input Loadings. Volume II. Foam Shock Isolation Elements.

DTIC Science & Technology

SHOCK ABSORBERS ), (*GUIDED MISSILE SILOS, SHOCK ABSORBERS ), (*EXPANDED PLASTICS, (*SHOCK(MECHANICS), REDUCTION), TEST METHODS, SHOCK WAVES, STRAIN(MECHANICS), LOADS(FORCES), MATHEMATICAL MODELS, NUCLEAR EXPLOSIONS, HARDENING.

Micropollutant loads in the urban water cycle.

PubMed

Musolff, Andreas; Leschik, Sebastian; Reinstorf, Frido; Strauch, Gerhard; Schirmer, Mario

2010-07-01

The assessment of micropollutants in the urban aquatic environment is a challenging task since both the water balance and the contaminant concentrations are characterized by a pronounced variability in time and space. In this study the water balance of a central European urban drainage catchment is quantified for a period of one year. On the basis of a concentration monitoring of several micropollutants, a contaminant mass balance for the study area's wastewater, surface water, and groundwater is derived. The release of micropollutants from the catchment was mainly driven by the discharge of the wastewater treatment plant. However, combined sewer overflows (CSO) released significant loads of caffeine, bisphenol A, and technical 4-nonylphenol. Since an estimated fraction of 9.9-13.0% of the wastewater's dry weather flow was lost as sewer leakages to the groundwater, considerable loads of bisphenol A and technical 4-nonylphenol were also released by the groundwater pathway. The different temporal dynamics of release loads by CSO as an intermittent source and groundwater as well as treated wastewater as continuous pathways may induce acute as well as chronic effects on the receiving aquatic ecosystem. This study points out the importance of the pollution pathway CSO and groundwater for the contamination assessments of urban water resources.

Impact of case volume on survival of septic shock in patients with malignancies.

PubMed

Zuber, Benjamin; Tran, Thi-Chien; Aegerter, Philippe; Grimaldi, David; Charpentier, Julien; Guidet, Bertrand; Mira, Jean-Paul; Pène, Frédéric

2012-01-01

Septic shock is a frequent and severe complication in the course of malignancies. In a large multicenter cohort of septic shock patients with hematologic malignancies and solid tumors, we assessed the temporal trend in survival and the prognostic factors, with particular emphasis on case volume. A 12-yr multicenter retrospective cohort study of prospectively collected data. Cancer patients with septic shock were selected over a 12-yr period (1997-2008) from a French regional database (CUB-Réa). The following variables were extracted: demographic characteristics, type of malignancy, characteristics of infection, severity-of-illness score (Simplified Acute Physiology Score II), organ failure supports, and vital status. For each unit, a running mean annual volume of admissions was calculated for the purpose of categorization into volume tertiles. Prognostic factors were analyzed by a conditional multivariate logistic model after matching on a propensity score of being admitted to a high-volume unit and on the year of admission. None. A total of 3,437 patients were included in the study. The intensive care unit mortality rate dramatically dropped over time (from 70.4% in 1997 to 52.5% in 2008, relative decrease 25.4%, p < .001). Participating units were distributed into low-volume (< five patients per year), medium-volume (five to 12 patients per year), and high-volume (≥ 13 patients per year) tertiles. A medical cause for intensive care unit admission, Simplified Acute Physiology Score II, invasive mechanical ventilation, renal replacement therapy, fungal infections, and unknown microorganism were identified as poor prognostic factors. Case volume demonstrated a strong influence on survival, admission in a high-volume unit being associated with a marked decrease in mortality as compared to low-volume units (adjusted odds ratio 0.63; 95% confidence interval [0.46-0.87], p = .002). Survival of septic shock patients with malignancies markedly increased over the recent

The Molecular Basis for Load-Induced Skeletal Muscle Hypertrophy

PubMed Central

Marcotte, George R.; West, Daniel W.D.; Baar, Keith

2016-01-01

In a mature (weight neutral) animal, an increase in muscle mass only occurs when the muscle is loaded sufficiently to cause an increase in myofibrillar protein balance. A tight relationship between muscle hypertrophy, acute increases in protein balance, and the activity of the mechanistic target of rapamycin complex 1 (mTORC1) was demonstrated 15 years ago. Since then, our understanding of the signals that regulate load-induced hypertrophy has evolved considerably. For example, we now know that mechanical load activates mTORC1 in the same way as growth factors, by moving TSC2 (a primary inhibitor of mTORC1) away from its target (the mTORC activator) Rheb. However, the kinase that phosphorylates and moves TSC2 is different in the two processes. Similarly, we have learned that a distinct pathway exists whereby amino acids activate mTORC1 by moving it to Rheb. While mTORC1 remains at the forefront of load-induced hypertrophy, the importance of other pathways that regulate muscle mass are becoming clearer. Myostatin, is best known for its control of developmental muscle size. However, new mechanisms to explain how loading regulates this process are suggesting that it could play an important role in hypertrophic muscle growth as well. Lastly, new mechanisms are highlighted for how β2 receptor agonists could be involved in load-induced muscle growth and why these agents are being developed as non-exercise-based therapies for muscle atrophy. Overall, the results highlight how studying the mechanism of load-induced skeletal muscle mass is leading the development of pharmaceutical interventions to promote muscle growth in those unwilling or unable to perform resistance exercise. PMID:25359125

Loading the Saturn I S-IV Stage into Pregnant Guppy

NASA Technical Reports Server (NTRS)

1965-01-01

The photograph shows the loading operation of the Saturn I S-IV stage (second stage) into the Pregnant Guppy at the Redstone Airfield, Huntsville, Alabama. The Pregnant Guppy was a Boeing B-377 Stratocruiser modified to transport various stages of Saturn launch vehicles. The modification project called for lengthening the fuselage to accommodate the S-IV stage. After the flight test of that modification, phase two called for the enlargement of the plane's cabin section to approximately double its normal volume. The fuselage separated just aft of the wing's trailing edge to load and unload the S-IV and other cargoes.

The Chronic and Acute Effects of Exercise Upon Selected Blood Measures.

ERIC Educational Resources Information Center

Roitman, J. L.; Brewer, J. P.

This study investigated the effects of chronic and acute exercise upon selected blood measures and indices. Nine male cross-country runners were studied. Red blood count, hemoglobin, and hematocrit were measured using standard laboratory techniques; mean corpuscular volume (MCV), mean corpuscular hemoglobin, and mean corpuscular hemoglobin…

Evaluation of Occupant Volume Strength in Conventional Passenger Railroad Equipment

DOT National Transportation Integrated Search

2008-09-24

To ensure a level of occupant volume protection, passenger : railway equipment operating on mainline railroads in the : United States must be designed to resist an 800,000-lb : compressive load applied statically along the line of draft. An : alterna...

Key performance indicators in an acute surgical unit: have we made an impact?

PubMed

Hsee, Li; Devaud, Marcelo; Civil, Ian

2012-10-01

Timely access to acute surgery is a worldwide issue and New Zealand is similarly affected. Auckland City Hospital is one of the largest metropolitan public hospitals in New Zealand where more than 60 % of surgical admissions fit into the acute category. In January 2009, an Acute Surgical Unit (ASU) was set up to improve acute surgical flow. Key performance indicators (KPIs) were identified as valuable tools in evaluating ASU service performance. Our goals were to describe the current acute patient pathway, present the early trend of KPIs for the ASU and determine whether an impact has been made on acute surgical patients. A retrospective review of patients admitted with acute general surgical conditions from January 2008 (pre-ASU) to October 2010 was performed. Patient data were identified through hospital electronic records. KPIs assessed included: (1) time to assess referred patients from the emergency department (ED) and from GPs [where patient assessment occurs in the assessment and planning unit (APU)]; (2) preoperative length of stay (LOS[PO]); (3) length of stay of nonadmitted patients (LOS[NA]); (4) case volume "in h" (0730-1730) versus "after h"; and (5) readmission rate. Statistical analysis was performed with one-way ANOVA, regression, and χ(2) tests. Results show a reduction of mean time from referral to assessment from 2.28 to 1.6 h in the ED (p ≤ 0.001). Patients are seen in APU after GP referral sooner as well as the time from referral to assessment reducing from 2 to 1.76 h (p < 0.001). The LOS[PO] has not changed significantly overall (34.58 vs. 34.88 h, p = not significant [NS]). However, there are encouraging signs in high-volume procedures, such as appendicectomy. The mean LOS[PO] for appendicectomy was 7.81 h but is now 6.53 h (p ≤ 0.005). The LOS[NA] has decreased from 15.23 to 9.48 h (p < 0.005). Since the development of the ASU, the number of cases operated on "in hours" is increasing with a corresponding decrease in "after hours

Effectiveness of the Saline Load Test in Diagnosis of Traumatic Elbow Arthrotomies

DTIC Science & Technology

2011-11-01

load test for the knee, using 80 knees in patients undergoing elective knee arthroscopy . A fixed volume of 60 mL of saline was injected while observing... Arthroscopy . 1990;6:100–103. 10. Voit GA, Irvine G, Beals RK. Saline load test for penetration of periarticular lacerations. J Bone Joint Surg Br. 1996;78:732...318. 12. Plancher KD, Shariff KB. Basics of elbow arthroscopy : setup, portals, and technique. Tech Orthop. 2006;21:239–249. 13. Marvel JE, Marsh HO

Lipotoxicity Causes Multisystem Organ Failure and Exacerbates Acute Pancreatitis in Obesity

PubMed Central

Navina, Sarah; Acharya, Chathur; DeLany, James P.; Orlichenko, Lidiya S.; Baty, Catherine J.; Shiva, Sruti S.; Durgampudi, Chandra; Karlsson, Jenny M.; Lee, Kenneth; Bae, Kyongtae T.; Furlan, Alessandro; Behari, Jaideep; Liu, Shiguang; McHale, Teresa; Nichols, Larry; Papachristou, Georgios Ioannis; Yadav, Dhiraj; Singh, Vijay P.

2012-01-01

Obesity increases the risk of adverse outcomes during acute critical illnesses such as burns, severe trauma, and acute pancreatitis. Although individuals with more body fat and higher serum cytokines and lipase are more likely to experience problems, the roles that these characteristics play are not clear. We used severe acute pancreatitis as a representative disease to investigate the effects of obesity on local organ function and systemic processes. In obese humans, we found that an increase in the volume of intrapancreatic adipocytes was associated with more extensive pancreatic necrosis during acute pancreatitis and that acute pancreatitis was associated with multisystem organ failure in obese individuals. In vitro studies of pancreatic acinar cells showed that unsaturated fatty acids were proinflammatory, releasing intracellular calcium, inhibiting mitochondrial complexes I and V, and causing necrosis. Saturated fatty acids had no such effects. Inhibition of lipolysis in obese (ob/ob) mice with induced pancreatitis prevented a rise in serum unsaturated fatty acids and prevented renal injury, lung injury, systemic inflammation, hypocalcemia, reduced pancreatic necrosis, and mortality. Thus, therapeutic approaches that target unsaturated fatty acid–mediated lipotoxicity may reduce adverse outcomes in obese patients with critical illnesses such as severe acute pancreatitis. PMID:22049070

Moving in extreme environments: extreme loading; carriage versus distance.

PubMed

Lucas, Samuel J E; Helge, Jørn W; Schütz, Uwe H W; Goldman, Ralph F; Cotter, James D

2016-01-01

This review addresses human capacity for movement in the context of extreme loading and with it the combined effects of metabolic, biomechanical and gravitational stress on the human body. This topic encompasses extreme duration, as occurs in ultra-endurance competitions (e.g. adventure racing and transcontinental races) and expeditions (e.g. polar crossings), to the more gravitationally limited load carriage (e.g. in the military context). Juxtaposed to these circumstances is the extreme metabolic and mechanical unloading associated with space travel, prolonged bedrest and sedentary lifestyle, which may be at least as problematic, and are therefore included as a reference, e.g. when considering exposure, dangers and (mal)adaptations. As per the other reviews in this series, we describe the nature of the stress and the associated consequences; illustrate relevant regulations, including why and how they are set; present the pros and cons for self versus prescribed acute and chronic exposure; describe humans' (mal)adaptations; and finally suggest future directions for practice and research. In summary, we describe adaptation patterns that are often U or J shaped and that over time minimal or no load carriage decreases the global load carrying capacity and eventually leads to severe adverse effects and manifest disease under minimal absolute but high relative loads. We advocate that further understanding of load carrying capacity and the inherent mechanisms leading to adverse effects may advantageously be studied in this perspective. With improved access to insightful and portable technologies, there are some exciting possibilities to explore these questions in this context.

NASA Task Load Index (TLX). Volume 1.0; Computerized Version

NASA Technical Reports Server (NTRS)

Hart, Sandra G.

1986-01-01

This booklet and the accompanying diskette contain the materials necessary to collect subjective workload assessments with the NASA Task Load Index on IBM PC compatible microcomputers. This procedure for collecting workload ratings was developed by the Human Performance Group at NASA Ames Research Center during a three year research effort that involved more than 40 laboratory, simulation, and inflight experiments Although the technique is still undergoing evaluation, this package is being distributed to allow other researchers to use it in their own experiments Comments or suggestions about the procedure would be greatly appreciated This package is intended to fill a "nuts and bolts" function of describing the procedure. A bibliography provides background information about previous empirical findings and the logic that supports the procedure.

Safe Hydration Volume to Prevent Contrast-induced Acute Kidney Injury and Worsening Heart Failure in Patients With Heart Failure and Preserved Ejection Fraction After Cardiac Catheterization.

PubMed