936 research outputs found

    Pressure and force data for a flat wing and a warped conical wing having a shockless recompression at Mach 1.62

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    A conical nonlinear flow computer code was used to design a warped (cambered) wing which would produce a supercritical expansion and shockless recompression of the crossflow at a lift coefficient of 0.457, an angle of attack of 10 deg, and a Mach number of 1.62. This cambered wing and a flat wing the same thickness distribution were tested over a range of Mach numbers from 1.6 to 2.0. For both models the forward 60 percent is purely conical geometry. Results obtained with the cambered wing demonstrated the design features of a supercritical expansion and a shockless recompression, whereas results obtained with the flat wing indicated the presence of crossflow shocks. Tables of experimental pressure, force, and moment data are included, as well as selected oil flow photographs

    Importance of exposure route for behavioural responses in Lumbriculus variegatus Müller (Oligochaeta: Lumbriculida) in short-term exposures to Pb

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    Abstract Goal, Scope and Background Lumbriculus variegatus Müller (Oligochaeta), a common freshwater sediment-dweller, has frequently been used in toxicokinetic studies, although has been less used in ecotoxicity tests. Methods For the first time the Multispecies Freshwater Biomonitor® (MFB) was applied in a short-term whole-sediment toxicity test. The MFB automatically and quantitatively recorded the spontaneous locomotory behaviour of Lumbriculus variegatus in exposures with two compartments, water and sediment. The study questioned, whether the animals altered their locomotion depending on the compartment which was spiked with lead (Pb). Results and Discussion As in the exposures to Pb-contaminated water/clean sediment, the animals exposed to Pb-contaminated sediment/clean water showed higher activities in intermediate Pb-concentrations. This indicates, that spontaneous locomotory activity is affected by Pb-concentrations at sublethal levels regardless of whether the Pb-concentration is found in the water or in the sediment, because these animals use both environmental compartments simultaneously. However, within the same Pb-levels, the animals showed higher locomotory activity in contaminated water compared with contaminated sediment. This indicates a possible tendency to withdraw from (‘avoidance’) contaminated water into the clean sediment compartment, whereas there was no withdrawal from contaminated sediment into clean water. The latter might be explained by the fact that withdrawal from sediment to water might increase the risk of predation and drift in nature, whereas retracting to sediment might provide shelter. Conclusions The study showed that spontaneous locomotory responses of L. variegatus to Pb depend on whether the water or sediment is contaminated. The study also concluded that the Multispecies Freshwater Biomonitor® can be applied effectively in sediment toxicity testing. Recommendations and Perspectives More emphasis should be given to the interactions of water/sediment in sediment ecotoxicity tests to better simulate field conditions and increase ecological realism in risk assessment, especially as quantitative recording methods exisit

    Prospective Validation of Pooled Prognostic Factors in Women with Advanced Cervical Cancer Treated with Chemotherapy with/without Bevacizumab: NRG Oncology/GOG Study

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    PURPOSE: In the randomized phase III trial, Gynecologic Oncology Group (GOG) protocol 240, the incorporation of bevacizumab with chemotherapy significantly increased overall survival (OS) in women with advanced cervical cancer. A major objective of GOG-240 was to prospectively analyze previously identified pooled clinical prognostic factors known as the Moore criteria. EXPERIMENTAL DESIGN: Potential negative factors included black race, performance status 1, pelvic disease, prior cisplatin, and progression-free interval <365 days. Risk categories included low-risk (0-1 factor), mid-risk (2-3 factors), and high-risk (4-5 factors). Each test of association was conducted at the 5% level of significance. Logistic regression and survival analysis was used to determine whether factors were prognostic or could be used to guide therapy. RESULTS: For the entire population (n = 452), high-risk patients had significantly worse OS (P < 0.0001). The HRs of death for treating with topotecan in low-risk, mid-risk, and high-risk subsets are 1.18 [95% confidence interval (CI), 0.63-2.24], 1.11 (95% CI, 0.82-1.5), and 0.84 (95% CI, 0.50-1.42), respectively. The HRs of death for treating with bevacizumab in low-risk, mid-risk, and high-risk subsets are 0.96 (95% CI, 0.51-1.83; P = 0.9087), 0.673 (95% CI, 0.5-0.91; P = 0.0094), and 0.536 (95% CI, 0.32-0.905; P = 0.0196), respectively. CONCLUSIONS: This is the first prospectively validated scoring system in cervical cancer. The Moore criteria have real-world clinical applicability. Toxicity concerns may justify omission of bevacizumab in some low-risk patients where survival benefit is small. The benefit to receiving bevacizumab appears to be greatest in the moderate- and high-risk subgroups (5.8-month increase in median OS)

    Effect of lutein and antioxidant dietary supplementation on contrast sensitivity in age-related macular disease:A randomized controlled trial

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    Objective: The aim of the study is to determine the effect of lutein combined with vitamin and mineral supplementation on contrast sensitivity in people with age-related macular disease (ARMD). Design: A prospective, 9-month, double-masked randomized controlled trial. Setting: Aston University, Birmingham, UK and a UK optometric clinical practice. Subjects: Age-related maculopathy (ARM) and atrophic age-related macular degeneration (AMD) participants were randomized (using a random number generator) to either placebo (n = 10) or active (n=15) groups. Three of the placebo group and two of the active group dropped out. Interventions: The active group supplemented daily with 6 mg lutein combined with vitamins and minerals. The outcome measure was contrast sensitivity (CS) measured using the Pelli-Robson chart, for which the study had 80% power at the 5% significance level to detect a change of 0.3log units. Results: The CS score increased by 0.07 ± 0.07 and decreased by 0.02 ± 0.18 log units for the placebo and active groups, respectively. The difference between these values is not statistically significant (z = 0.903, P = 0.376). Conclusion: The results suggest that 6 mg of lutein supplementation in combination with other antioxidants is not beneficial for this group. Further work is required to establish optimum dosage levels

    Improving the repeatability of heterochromatic flicker photometry for measurement of macular pigment optical density

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    Background: Heterochromatic flicker photometry (HFP) is a psychophysical technique used to measure macular pigment optical density (MPOD). We used the MPS 9000 (MPS) HFP device. Our aim was to determine if the repeatability of the MPS could be improved to make it more suitable for monitoring MPOD over time. Methods: Intra-session repeatability was assessed in 25 participants (aged 20-50 years). The resulting data was explored in detail, e.g., by examining the effect of removal and adjustment of data with less than optimal quality parameters. A protocol was developed for improved overall reliability, which was then tested in terms of inter-session repeatability in a separate group of 27 participants (aged 19-52 years). Results: Removal and adjustment of data reduced the intra-session coefficient of repeatability (CR) by 0.04, on average, and the mean individual standard deviation by 0.004. Raw data observation offered further insight into ways of improving repeatability. The proposed protocol resulted in an inter-session CR of 0.08. Conclusions: Removal and adjustment of less than optimal data improved repeatability, and is therefore recommended. To further improve repeatability, in brief we propose that each patient perform each part of the test twice, and a third time where necessary (described in detail by the protocol). Doing so will make the MPS more useful in research and clinical settings. © 2012 Springer-Verlag

    The cross-sectional association of stressful life events with depression severity among patients with hypertension and diabetes in Malawi

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    Depressive disorders are a leading cause of global morbidity and remain disproportionately high in low- and middle-income settings. Stressful life events (SLEs) are known risk factors for depressive episodes and worsened depressive severity, yet are under-researched in comparison to other depression risk factors. As depression is often comorbid with hypertension, diabetes, and other noncommunicable diseases (NCDs), research into this relationship among patients with NCDs is particularly relevant to increasing opportunities for integrated depression and NCD care. This study aims to estimate the cross-sectional association between SLEs in the three months preceding baseline interviews and baseline depressive severity among patients with at least mild depressive symptoms who are seeking NCD care at 10 NCD clinics across Malawi. SLEs were measured by the Life Events Survey and depressive severity (mild vs. moderate to severe) was measured by the Patient Health Questionnaire-9. The study population (n = 708) was predominately currently employed, grand multiparous (5–8 children) women with a primary education level. Two thirds (63%) had mild depression while 26%, 8%, and 3% had moderate, moderately severe, and severe depression, respectively. Nearly all participants (94%) reported at least one recent SLE, with the most common reported SLEs being financial stress (48%), relationship changes (45%), death of a family member or friend (41%), or serious illness of a family member or friend (39%). Divorce/separation, estrangement from a family member, losing source of income, and major new health problems were significant predictors of greater (moderate or severe) depressive severity compared to mild severity. Having a major new health problem or experiencing divorce/separation resulted in particularly high risk of more severe depression. After adjustment, each additional SLE was associated with a 9% increased risk of moderate or worse depressive severity compared to mild depressive severity (RR: 1.09; (95% CI: 1.05, 1.13), p<0.0001). Among patients with NCDs with at least mild depressive symptoms, SLEs in the prior 3 months were associated with greater depressive severity. While many SLEs may not be preventable, this research suggests that assessment of SLEs and teaching of positive coping strategies when experiencing SLEs may play an important role in integrated NCD and depression treatment models

    An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

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    For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
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