2,556 research outputs found

    Development of CGLARE: Design, Fabrication and Characterisation

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    Fibre Metal Laminates (FMLs) are hybrid materials consisting of metal layers bonded to fibre-reinforced polymer layers. CGLARE is an FML developed at NAL consisting of thin aluminum foil combined with carbon-epoxy and glass-epoxy prepreg materials. CGLARE is proposed as the candidate material for the leading edges of wing and empennage of an aircraft as it has superior characteristics in terms of shape retention (due to highly linearly elastic material like carbon/epoxy), energy absorption capability (due to layered structure and plastic deformation), lightning protection (due to the presence of aluminum layers), and also due to its cost effectiveness (lightweight construction and simple production techniques). This paper describes the issues regarding the development of CGLARE such as surface preparation of aluminum foils and bonding of aluminum with glass. Tensile, Compression, ILSS and Flexure testing of ASTM standard CGLARE specimens for different layups have been done. An important design issue is the internal residual stresses built into the laminate during curing due to differential coefficients of thermal expansion of the different material systems. The paper presents these results that indicate some properties of these material systems that could be exploited for energy absorption in the leading edges of the aircraft

    On the moment limit of quantum observables, with an application to the balanced homodyne detection

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    We consider the moment operators of the observable (i.e. a semispectral measure or POM) associated with the balanced homodyne detection statistics, with paying attention to the correct domains of these unbounded operators. We show that the high amplitude limit, when performed on the moment operators, actually determines uniquely the entire statistics of a rotated quadrature amplitude of the signal field, thereby verifying the usual assumption that the homodyne detection achieves a measurement of that observable. We also consider, in a general setting, the possibility of constructing a measurement of a single quantum observable from a sequence of observables by taking the limit on the level of moment operators of these observables. In this context, we show that under some natural conditions (each of which is satisfied by the homodyne detector example), the existence of the moment limits ensures that the underlying probability measures converge weakly to the probability measure of the limiting observable. The moment approach naturally requires that the observables be determined by their moment operator sequences (which does not automatically happen), and it turns out, in particular, that this is the case for the balanced homodyne detector.Comment: 22 pages, no figure

    HYPERPHOSPHATEMIA IN END STAGE RENAL DISEASE: PREVALENCE AND PATIENTS CHARACTERISTICS OF MULTIETHNIC POPULATION OF UNITED ARAB EMIRATES

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    Objective: Hyperphosphatemia is significantly associated with increased mortality among end stage renal disease (ESRD) patients on hemodialysis. There is paucity of data on hyperphosphatemia in ESRD patients of the multiethnic population of United Arab Emirates (UAE). The study aimed to investigate the prevalence and characteristics of hyperphosphatemia in ESRD patients of the multiethnic population of UAE undergoing maintenance hemodialysis.Methods: Adults ESRD patients undergoing maintenance hemodialysis for more than six months at the study site were included. Demographic, clinical and biological data of the patients were collected. Patient characteristics were compared as per the serum phosphate level, between patients with or without hyperphosphatemia. Univariate and multivariate logistic regression analyses were carried out to identify the predictors of hyperphosphatemia.Results: Hyperphosphatemia was present in 73.8% of the study population, while 31.3% presented with high calcium-phosphate product. Univariate logistic analysis revealed that hyperphosphatemia was inversely correlated with age, hemoglobin, serum calcium, and hypertensive nephropathy as cause of renal disease, and positively correlated with female gender, expatriate status, body mass index (BMI), higher number of comorbidities, calcium-phosphate product and parathyroid hormone (PTH). Multivariate logistic regression model revealed that only age, BMI, hemoglobin and PTH independently correlated with hyperphosphatemia.Conclusion: We report a high prevalence of hyperphosphatemia in multiethnic study population undergoing maintenance hemodialysis at a secondary care hospital in UAE. In this study population, only age, BMI, hemoglobin and PTH were identified as independent predictors of hyperphosphatemia

    Women's Experiences and Views about Costs of Seeking Malaria Chemoprevention and other Antenatal Services: A Qualitative Study from two Districts in Rural Tanzania.

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    The Tanzanian government recommends women who attend antenatal care (ANC) clinics to accept receiving intermittent preventive treatment against malaria during pregnancy (IPTp) and vouchers for insecticide-treated nets (ITNs) at subsidized prices. Little emphasis has been paid to investigate the ability of pregnant women to access and effectively utilize these services. To describe the experience and perceptions of pregnant women about costs and cost barriers for accessing ANC services with emphasis on IPTp in rural Tanzania. Qualitative data were collected in the districts of Mufindi in Iringa Region and Mkuranga in Coast Region through 1) focus group discussions (FGDs) with pregnant women and mothers to infants and 2) exit-interviews with pregnant women identified at ANC clinics. Data were analyzed manually using qualitative content analysis methodology. FGD participants and interview respondents identified the following key limiting factors for women's use of ANC services: 1) costs in terms of money and time associated with accessing ANC clinics, 2) the presence of more or less official user-fees for some services within the ANC package, and 3) service providers' application of fines, penalties and blame when failing to adhere to service schedules. Interestingly, the time associated with travelling long distances to ANC clinics and ITN retailers and with waiting for services at clinic-level was a major factor of discouragement in the health seeking behaviour of pregnant women because it seriously affected their domestic responsibilities. A variety of resource-related factors were shown to affect the health seeking behaviour of pregnant women in rural Tanzania. Thus, accessibility to ANC services was hampered by direct and indirect costs, travel distances and waiting time. Strengthening of user-fee exemption practices and bringing services closer to the users, for example by promoting community-directed control of selected public health services, including IPTp, are urgently needed measures for increasing equity in health services in Tanzania

    Effect of Post Weld Heat Treatments on the Elevated Temperature Mechanical Properties of Ti6Al4V Friction Welds

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    The {\alpha}+\b {eta} titanium alloy (Ti6Al4V) has been successfully joined using rotary friction welding. To investigate the influence of post weld heat treatments on the microstructure and mechanical properties of the welds, the weld joints were heat treated in {\alpha}+\b {eta} and\b {eta} regions, followed by air cooling and furnace cooling. Subsequent to heat treatment, the specimens were subjected to stress relieving treatment. The heat treatment temperatures were selected keeping in view the beta transus temperature of the alloy. Mechanical properties of the welds are evaluated in the as-welded and post weld heat treated conditions at the working temperature of this alloy. The results reported are an average of the values obtained from three tests carried out at a given set of condition. Joints produced exhibited better mechanical properties when compared to the parent metal. Coarse transgranular microstructure and coarse grains in general exhibit better creep and stress rupture properties, while finer microstructures exhibit better tensile strengthsThe {\alpha}+\b {eta} titanium alloy (Ti6Al4V) has been successfully joined using rotary friction welding. To investigate the influence of post weld heat treatments on the microstructure and mechanical properties of the welds, the weld joints were heat treated in {\alpha}+\b {eta} and\b {eta} regions, followed by air cooling and furnace cooling. Subsequent to heat treatment, the specimens were subjected to stress relieving treatment. The heat treatment temperatures were selected keeping in view the beta transus temperature of the alloy. Mechanical properties of the welds are evaluated in the as-welded and post weld heat treated conditions at the working temperature of this alloy. The results reported are an average of the values obtained from three tests carried out at a given set of condition. Joints produced exhibited better mechanical properties when compared to the parent metal. Coarse transgranular microstructure and coarse grains in general exhibit better creep and stress rupture properties, while finer microstructures exhibit better tensile strength

    Design, synthesis, molecular modelling and in vitro screening of monoamine oxidase inhibitory activities of novel quinazolyl hydrazine derivatives

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    Funding: Deanship of Scientific Research at Taibah University, Al-Madinah Al-Munawarah, Saudi Arabia (project # 7101).A new series of N'-substituted benzylidene-2-(4-oxo-2-phenyl-1,4-dihydroquinazolin-3(2H)-yl)acetohydrazide (5a-5h) has been synthesized, characterized by FT-IR, NMR spectroscopy and mass spectrometry and tested against human monoamine oxidase (MAO) A and B. Only (3-methoxy-4-hydroxy)benzoyl substituted compounds gave submicromolar inhibition of MAO-A and MAO-B. Changing the phenyl substituent to methyl on the unsaturated quinazoline ring (12a-12d) decreased inhibition but a less flexible linker (14a-14d) resulted in selective micromolar inhibition of hMAO B providing insight for ongoing design.Publisher PDFPeer reviewe

    Usage of Glimepiride/Metformin Fixed-dose Combination in Young Individuals with Type 2 Diabetes: The Indian Experience

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    Background: The prevalence of diabetes has been rising among the younger population and is a cause for concern. The present case-based questionnaire survey evaluated the treatment pattern and clinical experience of healthcare professionals (HCPs) in prescribing glimepiride/metformin fixed-dose combination (FDC) to young diabetes patients (up to 40 years of age) in the Indian setting. Material and methods: A retrospective, multicenter, observational, questionnaire-based survey was conducted in Indian healthcare centers using medical records of patients having type 2 diabetes mellitus (T2DM), who were prescribed different strengths of glimepiride/metformin FDCs. Data was collected from the patients’ medical records and were analyzed using statistical tests. Results: A total of 2,715 patients aged between 18 and 40 years were included in the study. Mean diabetes duration among the young patients was 2.76 ± 1.97 years. Among the young T2DM patients, 83.2% patients received glimepiride/metformin FDC as first-line therapy, and 16.8% received it as second-line therapy. Hypoglycemia at 6 months was noted in only 2.47% of the young patients. Mean glycated hemoglobin (HbA1c) before and after treatment was 8.7% ± 3.4% and 7.3% ± 3.9%, respectively. Mean fasting plasma glucose (FPG) was 171.8 ± 80.1 mg/dL in patients prior to treatment initiation and came down to 122.8 ± 41.8 mg/dL after treatment with glimepiride/metformin FDC. Mean postprandial plasma glucose (PPG) prior to combination therapy use was 248.7 ± 64.0 mg/dL and dropped to 177.2 ± 39.9 mg/dL after treatment. Good to excellent efficacy and tolerability were reported for 86% and 86.6% patients, respectively. Conclusion: This case-based questionnaire survey demonstrates the usage pattern of various strengths of glimepiride/metformin FDCs and the HCPs’ practice approach regarding the use of this combination in young T2DM patients in the Indian setting. The combination is commonly prescribed to young diabetes patients in India and is associated with beneficial effects on glycemic parameters

    Linking cohort-based data with electronic health records: a proof-of-concept methodological study in Hong Kong.

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    OBJECTIVES: Data linkage of cohort-based data and electronic health records (EHRs) has been practised in many countries, but in Hong Kong there is still a lack of such research. To expand the use of multisource data, we aimed to identify a feasible way of linking two cohorts with EHRs in Hong Kong. METHODS: Participants in the 'Children of 1997' birth cohort and the Chinese Early Development Instrument (CEDI) cohort were separated into several batches. The Hong Kong Identity Card Numbers (HKIDs) of each batch were then uploaded to the Hong Kong Clinical Data Analysis and Reporting System (CDARS) to retrieve EHRs. Within the same batch, each participant has a unique combination of date of birth and sex which can then be used for exact matching, as no HKID will be returned from CDARS. Raw data collected for the two cohorts were checked for the mismatched cases. After the matching, we conducted a simple descriptive analysis of attention deficit hyperactivity disorder (ADHD) information collected in the CEDI cohort via the Strengths and Weaknesses of ADHD Symptoms and Normal Behaviour Scale (SWAN) and EHRs. RESULTS: In total, 3473 and 910 HKIDs in the birth cohort and CEDI cohort were separated into 44 and 5 batches, respectively, and then submitted to the CDARS, with 100% and 97% being valid HKIDs respectively. The match rates were confirmed to be 100% and 99.75% after checking the cohort data. From our illustration using the ADHD information in the CEDI cohort, 36 (4.47%) individuals had ADHD-Combined score over the clinical cut-off in the SWAN survey, and 68 (8.31%) individuals had ADHD records in EHRs. CONCLUSIONS: Using date of birth and sex as identifiable variables, we were able to link the cohort data and EHRs with high match rates. This method will assist in the generation of databases for future multidisciplinary research using both cohort data and EHRs
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