642 research outputs found

    Enhancement of magnetoresistance in manganite multilayers

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    Magnanite multilayers have been fabricated using La0.67Ca0.33MnO3 as the ferromagnetic layer and Pr0.7Ca0.3MnO3 and Nd0.5Ca0.5MnO3 as the spacer layers. All the multilayers were grown on LaAlO3 (100) by pulse laser deposition. An enhanced magnetoresistnace (defined (RH- R0)/R0) of more than 98% is observed in these multilayers. Also a low field magnetoresistance of 41% at 5000 Oe is observed in these multilayer films. The enhanced MR is attributed to the induced double exchange in the spacer layer, which is giving rise to more number of conducting carriers. This is compared by replacing the spacer layer with LaMnO3 where Mn exists only in 3+ state and no enhancement is observed in the La0.67Ca0.33MnO3 / LaMnO3 multilayers as double exchange mechanism can not be induced by external magnetic fields.Comment: 13 pages, 5 Figure

    C-band superconductor/semiconductor hybrid field-effect transistor amplifier on a LaAlO3 substrate

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    A single-stage C-band superconductor/semiconductor hybrid field-effect transistor amplifier was designed, fabricated, and tested at 77 K. The large area (1 inch x 0.5 inches) high temperature superconducting Tl-Ba-Ca-Cu-O (TBCCO) thin film was rf magnetron sputtered onto a LaAlO3 substrate. The film had a transition temperature of about 92 K after it was patterned and etched. The amplifier showed a gain of 6 dB and a 3 dB bandwidth of 100 MHz centered at 7.9 GHz. An identical gold amplifier circuit was tested at 77 K, and these results are compared with those from the hybrid amplifier

    Enhancement of magnetoresistance in manganite multilayers

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    Magnanite multilayers have been fabricated using La0.67Ca0.33MnO3 as the ferromagnetic layer and Pr0.7Ca0.3MnO3 and Nd0.5Ca0.5MnO3 as the spacer layers. All the multilayers were grown on LaAlO3 (100) by pulse laser deposition. An enhanced magnetoresistnace (defined (RH- R0)/R0) of more than 98% is observed in these multilayers. Also a low field magnetoresistance of 41% at 5000 Oe is observed in these multilayer films. The enhanced MR is attributed to the induced double exchange in the spacer layer, which is giving rise to more number of conducting carriers. This is compared by replacing the spacer layer with LaMnO3 where Mn exists only in 3+ state and no enhancement is observed in the La0.67Ca0.33MnO3 / LaMnO3 multilayers as double exchange mechanism can not be induced by external magnetic fields.Comment: 13 pages, 5 Figure

    Hypovitamanosis D and non cardiac chest pain

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    Background: Recurrent atypical chest pain not due to cardiac illness is a very common condition in medical outpatient departments. Authors found that people consulting for atypical chest pain often have significant Vitamin D deficiency and correction of Vitamin D deficiency relieved patient symptoms. Hence authors carried out this study.Methods: Persons aged below 50 years were taken up for study. Those attending medical clinics with complaints of chest pain occurring more than two times were taken up for study. Cardiac illness was excluded by clinical examination and investigations. Those found to have low Vitamin D were taken up for study. 60,000 international units Vitamin D was administered orally weekly for 8 weeks. They were followed up twice weekly for three months and once monthly for three months.Results: Results were analyzed and charted. 120 subjects were taken up for study and duration of study was three years. Average age of the study group was 37.50 years and the average Vitamin D level was 15.75 nanogram/ml (ngm/ml). Duration of chest pain ranged from one week to one year. Most of the patients had migratory chest pain.Conclusions: As Vitamin D deficiency is a treatable medical condition it may be prudent to check Vitamin D levels in the patients presenting with recurrent atypical pain in the chest. It reduces the burden on the health care system and relieves the suffering of the patient. It may not be futile to check Vitamin D levels even in the patients with coronary artery disease who are suffering from atypical chest pain

    Development of Single Serum ELISA and Flow Through Assay for Infectious Bursal Disease of Poultry

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    The infectious bursal disease (IBD) is an age-limiting viral disease of chicken affecting both broiler and layer chicks between 3 – 6 weeks of age characterized by severe immunosuppression and high mortality. The maternally derived antibodies protect chicks till they develop age – resistance, hence breeder flocks immune status monitoring regularly helps in ensuring adequate levels of maternal antibodies transfer to hatchlings and fine tuning of vaccination schedule. The conventional virus neutralization test (VNT) though gold standard, is time consuming and cumbersome. Hence, alternate immunodiagnostic tests which are simple and relatively easy to perform viz., single serum dilution enzyme linked immunosorbent assay (ELISA) for antibody titre and flow through assay (FTA) for antigen detection were developed. A standard curve was constructed by using regression analysis which helped in derivation of an equation and that allowed to demonstrate correlation between observed titre and predicted titre. At a dilution of 1:2000 of serum there was a linear relationship between predicted titres at single serum dilution and observed titre. The FTA was able to detect 200 ng / µl concentrations of IBDV. The FTA can be performed as, on spot test for detection of IBDV in suspected cases

    Indigenous Health and Socioeconomic Status in India

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    BACKGROUND: Systematic evidence on the patterns of health deprivation among indigenous peoples remains scant in developing countries. We investigate the inequalities in mortality and substance use between indigenous and non-indigenous, and within indigenous, groups in India, with an aim to establishing the relative contribution of socioeconomic status in generating health inequalities. METHODS AND FINDINGS: Cross-sectional population-based data were obtained from the 1998–1999 Indian National Family Health Survey. Mortality, smoking, chewing tobacco use, and alcohol use were four separate binary outcomes in our analysis. Indigenous status in the context of India was operationalized through the Indian government category of scheduled tribes, or Adivasis, which refers to people living in tribal communities characterized by distinctive social, cultural, historical, and geographical circumstances. Indigenous groups experience excess mortality compared to non-indigenous groups, even after adjusting for economic standard of living (odds ratio 1.22; 95% confidence interval 1.13–1.30). They are also more likely to smoke and (especially) drink alcohol, but the prevalence of chewing tobacco is not substantially different between indigenous and non-indigenous groups. There are substantial health variations within indigenous groups, such that indigenous peoples in the bottom quintile of the indigenous-peoples-specific standard of living index have an odds ratio for mortality of 1.61 (95% confidence interval 1.33–1.95) compared to indigenous peoples in the top fifth of the wealth distribution. Smoking, drinking alcohol, and chewing tobacco also show graded associations with socioeconomic status within indigenous groups. CONCLUSIONS: Socioeconomic status differentials substantially account for the health inequalities between indigenous and non-indigenous groups in India. However, a strong socioeconomic gradient in health is also evident within indigenous populations, reiterating the overall importance of socioeconomic status for reducing population-level health disparities, regardless of indigeneity

    Is Economic Growth Associated with Reduction in Child Undernutrition in India?

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    An analysis of cross-sectional data from repeated household surveys in India, combined with data on economic growth, fails to find strong evidence that recent economic growth in India is associated with a reduction in child undernutrition

    High sensitivity C-reactive protein levels across spectrum and severity of coronary artery disease

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    Background: C-reactive protein (CRP) is an acute-phase reactant protein synthesized by the liver in response to acute\ud stress in a wide range of acute and chronic inflammatory conditions. In healthy subjects and patients presenting with\ud coronary artery disease (CAD), elevated levels of CRP has repeatedly been demonstrated to predict future cardiovascular\ud events.\ud Methods: We measured high sensitivity C-reactive protein (hs-CRP) levels in 382 consecutive patients with CAD and 60 healthy controls by immunoturbidimetry method. Risk factors like hypertension, diabetes mellitus, dyslipidaemia,smoking, obesity and family history of premature CAD were assessed.\ud Results: The mean age of patients with CAD was 53.5±11.8 years (303 males) and that of control group was 50.83±8.07(28 males). The patient group had significant higher concentration of mean hs-CRP levels when compared\ud with the healthy control group (1.8±1.9 mg/L vs 0.35±1.1 mg/L, p<0.001). The mean hs-CRP levels of unstable angina\ud (USA) and myocardial infarction (MI) patients was higher than chronic stable angina (CSA) patients (p<0.05). Based\ud on the disease severity, we found a significantly higher hs-CRP levels in patients of triple vessel disease when compared\ud to patients with single vessel disease (p=0.01).\ud Conclusions: Elevated serum hs-CRP levels provide a useful marker for cardiovascular risk which, when combined\ud with traditional risk factors, may help improve global risk prediction. Our study showed a significant contribution of\ud hs-CRP to coronary risk prediction with better discrimination

    Association between economic growth and early childhood undernutrition: evidence from 121 Demographic and Health Surveys from 36 low-income and middle-income countries

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    Background Economic growth is widely regarded as a necessary, and often suffi cient, condition for the improvement of population health. We aimed to assess whether macroeconomic growth was associated with reductions in early childhood undernutrition in low-income and middle-income countries. Methods We analysed data from 121 Demographic and Health Surveys from 36 countries done between Jan 1, 1990, and Dec 31, 2011. The sample consisted of nationally representative cross-sectional surveys of children aged 0–35 months, and the outcome variables were stunting, underweight, and wasting. The main independent variable was per-head gross domestic product (GDP) in constant prices and adjusted for purchasing power parity. We used logistic regression models to estimate the association between changes in per-head GDP and changes in child undernutrition outcomes. Models were adjusted for country fi xed eff ects, survey-year fi xed eff ects, clustering, and demographic and socioeconomic covariates for the child, mother, and household. Findings Sample sizes were 462 854 for stunting, 485 152 for underweight, and 459 538 for wasting. Overall, 35·6% (95% CI 35·4–35·9) of young children were stunted (ranging from 8·7% [7·6–9·7] in Jordan to 51·1% [49·1–53·1] in Niger), 22·7% (22·5–22·9) were underweight (ranging from 1·8% [1·3–2·3] in Jordan to 41·7% [41·1–42·3] in India), and 12·8% (12·6–12·9) were wasted (ranging from 1·2% [0·6–1·8] in Peru to 28·8% [27·5–30·0] in Burkina Faso). At the country level, no association was seen between average changes in the prevalence of child undernutrition outcomes and average growth of per-head GDP. In models adjusted only for country and survey-year fi xed eff ects, a 5% increase in perhead GDP was associated with an odds ratio (OR) of 0·993 (95% CI 0·989–0·995) for stunting, 0·986 (0·982–0·990) for underweight, and 0·984 (0·981–0·986) for wasting. ORs after adjustment for the full set of covariates were 0·996 (0·993–1·000) for stunting, 0·989 (0·985–0·992) for underweight, and 0·983 (0·979–0·986) for wasting. These fi ndings were consistent across various subsamples and for alternative variable specifi cations. Notably, no association was seen between per-head GDP and undernutrition in young children from the poorest household wealth quintile. ORs for the poorest wealth quintile were 0·997 (0·990–1·004) for stunting, 0·999 (0·991–1·008) for underweight, and 0·991 (0·978–1·004) for wasting. Interpretation A quantitatively very small to null association was seen between increases in per-head GDP and reductions in early childhood undernutrition, emphasising the need for direct health investments to improve the nutritional status of children in low-income and middle-income countries

    Fabrication and Analysis of Amorphous Silicon TFT

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    The display technology and large area electronics got momentum with the introduction of TFT devices. TFTs can be made using different semiconducting materials or organic conducting materials as the active layer. Each one of them differ in their performance depending on the material used for the active layer. In this paper, fabrication of amorphous silicon TFT using PECVD is carried out. Simulation of the a-Si: H TFT is also carried out with the dimensions similar to that of the masks used for the fabrication. The Id-Vd plot for both the simulation and fabrication is obtained and studied
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