1,356 research outputs found

    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

    Diagnostic Molecular Markers for Phosphine Resistance in US Populations of Tribolium castaneum and Rhyzopertha dominica

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    Citation: Chen, Z., Schlipalius, D., Opit, G., Subramanyam, B., & Phillips, T. W. (2015). Diagnostic Molecular Markers for Phosphine Resistance in US Populations of Tribolium castaneum and Rhyzopertha dominica. Plos One, 10(3), 14. doi:10.1371/journal.pone.0121343Stored product beetles that are resistant to the fumigant pesticide phosphine (hydrogen phosphide) gas have been reported for more than 40 years in many places worldwide. Traditionally, determination of phosphine resistance in stored product beetles is based on a discriminating dose bioassay that can take up to two weeks to evaluate. We developed a diagnostic cleaved amplified polymorphic sequence method, CAPS, to detect individuals with alleles for strong resistance to phosphine in populations of the red flour beetle, Tribolium castaneum, and the lesser grain borer, Rhyzopertha dominica, according to a single nucleotide mutation in the dihydrolipoamide dehydrogenase (DLD) gene. We initially isolated and sequenced the DLD genes from susceptible and strongly resistant populations of both species. The corresponding amino acid sequences were then deduced. A single amino acid mutation in DLD in populations of T. castaneum and R. dominica with strong resistance was identified as P45S in T. castaneum and P49S in R. dominica, both collected from northern Oklahoma, USA. PCR products containing these mutations were digested by the restriction enzymes MboI and BstNI, which revealed presence or absence, respectively of the resistant (R) allele and allowed inference of genotypes with that allele. Seven populations of T. castaneum from Kansas were subjected to discriminating dose bioassays for the weak and strong resistance phenotypes. Application of CAPS to these seven populations confirmed the R allele was in high frequency in the strongly resistant populations, and was absent or at a lower frequency in populations with weak resistance, which suggests that these populations with a low frequency of the R allele have the potential for selection of the strong resistance phenotype. CAPS markers for strong phosphine resistance will help to detect and confirm resistant beetles and can facilitate resistance management actions against a given pest population

    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

    Effect of copper and manganese on free amino acid content of Neurospora crassa

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    Effect of copper and manganese on free amino acid content of Neurospora crass

    Steady-state pharmacokinetics of Nevirapine in HIV-1 infected adults in India

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    Background and Objectives: A variety of demographic factors, sex, and degree of immunosuppression can influence antiretroviral drug concentratians. The authors studied the influence of immune status, sex, and body mass index (BMI) on the steady-state pharmacokinetics of nevirapine delivered as a fixed-dose combination in HIV-1-infected patients in India. Methods: Twenty-six HIV-l-infected adult patients undergoing treatment with nevirapine-based highly active antiretroviral therapy regimens participated in the study. Pharmacokinetic variables were compared between patients divided based an CD4 cell counts, sex, and BMI. Results: Patients with higher BMI had lower peak and trough concentration and exposure of nevirapine than those with lower BMI; none of the differences in the pharmacokinetic variables of nevirapine between the various patient groups was statistically significant. Conclusions: Patients' immune status, sex, or BMI had no impact on the pharmacokinetics of nevirapine. Plasma nevirapine concentrations were maintained within the therapeutic range of the drug in the majority of the patients

    Clinical profile of patients with cardiac syndrome X in a tertiary care hospital

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    Background: Abnormalities in coronary microcirculation may lead to symptoms of chest pain which mimics angina. Symptoms of chest pain along with evidence of ischemia on non-invasive tests like electrocardiography (ECG), echocardiography or treadmill test (TMT) but with normal coronary angiogram (CAG) is referred to as cardiac syndrome X (CSX). Previous studies have shown favourable prognosis in such patients. However recent studies have not shown good prognosis. We intend to understand whether such adverse cardiovascular outcomes could be secondary to any change in the clinical characteristics of patients with CSX in the current era.Methods: This is a retrospective study which was conducted at a tertiary care hospital. CAG of patients who underwent coronary angiography between November 2013 and October 2016, for suspected ischemic heart disease was reviewed. Clinical characteristics of patients with normal or non-obstructive coronaries (less than 50% stenosis) in angiography with chest pain were analyzed. Further clinical characteristics, ECG, echocardiography, treadmill test and CAG findings were compared among males and females.Results: 410 patients were included in the study. 212 were females and 198 were males. Mean age of presentation was 53.46±10.5 years for males and 55.04±9.3 years for females. Patients presenting with atypical chest pain were higher (70.7%). There were 195 subjects with systemic hypertension, 103 with diabetes mellitus and 57 had dyslipidemia. In the study, most 260 subjects had ST-T changes on ECG. Abnormal echocardiography was seen in only 35 patients. 30.5% patients showed positive stress test for inducible ischemia.Conclusions: CSX is prevalent in significant number of patients who present with symptoms of chest pain. Unlike previous studies, there is no significant difference among males and females, in prevalence and risk factors for this syndrome. Further non-obstructive lesions were found to be higher in females

    Some observations on the effect of Daflon (micronized purified flavonoid fraction of Rutaceae aurantiae) in bancroftian filarial lymphoedema

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    BACKGROUND: Morbidity management is a core component of the global programme for the elimination of lymphatic filariasis. In a double-blind clinical trial, the tolerability and efficacy of Daflon (500 mg) + DEC (25 mg) or DEC (25 mg) alone, twice daily for 90 days, was studied in 26 patients with bancroftian filarial lymphoedema. RESULTS: None of the patients in either drug group reported any adverse reaction throughout the treatment period (90 days). Haematological and biochemical parameters were within normal limits and there was no significant difference between the pre-treatment (day 0) and post-treatment (day 90) values. The group receiving Daflon showed significant reduction in oedema volume from day 90 (140.6 ± 18.8 ml) to day 360 (71.8 ± 20.7 ml) compared to the pre-treatment (day 0, 198.4 ± 16.5 ml) value. This accounted for a 63.8% reduction in oedema volume by day 360 (considering the pre-treatment (day 0) as 100%). In the DEC group, the changes in oedema volume (between day 1 and day 360) were not significant when compared to the pre-treatment (day 0) value. The percentage reduction at day 360 was only 9%, which was not significant (P > 0.05). CONCLUSION: This study has shown that Daflon (500 mg, twice a day for 90 days) is both safe and efficacious in reducing oedema volume in bancroftian filarial lymphoedema. Further clinical trials are essential for strengthening the evidence base on the role of this drug in the morbidity management of lymphatic filariasis

    Data-Driven Robust Beamforming for Initial Access

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    We consider a robust beamforming problem where large amount of downlink (DL) channel state information (CSI) data available at a multiple antenna access point (AP) is used to improve the link quality to a user equipment (UE) for beyond-5G and 6G applications such as environment-specific initial access (IA) or wireless power transfer (WPT). As the DL CSI available at the current instant may be imperfect or outdated, we propose a novel scheme which utilizes the (unknown) correlation between the antenna domain and physical domain to localize the possible future UE positions from the historical CSI database. Then, we develop a codebook design procedure to maximize the minimum sum beamforming gain to that localized CSI neighborhood. We also incorporate a UE specific parameter to enlarge the neighborhood to robustify the link further. We adopt an indoor channel model to demonstrate the performance of our solution, and benchmark against a usually optimal (but now sub-optimal due to outdated CSI) maximum ratio transmission (MRT) and a subspace based method.We numerically show that our algorithm outperforms the other methods by a large margin. This shows that customized environment-specific solutions are important to solve many future wireless applications, and we have paved the way to develop further data-driven approaches.Comment: 6 pages, 6 figures, Accepted in IEEE GLOBECOM 202
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