1,654 research outputs found

    Evaluation of the CERES-Rice version 3.0 model for the climate conditions of the state of Kerala, India

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    The CERES-Rice version 3.0 crop growth simulation model was calibrated and evaluated for the agroclimatic conditions of the state of Kerala in India. Genetic coefficients were developed for the rice crop variety Jaya and used for the model evaluation studies. In four experiments using different transplanting dates during the virippu season (June to September) under rainfed conditions (i.e. no irrigation), the flowering date was predicted within an error of four days and date of crop maturity within an error of two days. The model was found to predict the phenological events of the crop fairly well. The grain yield predicted by the model was within an error of 3 for all the transplanting dates, but the straw yield prediction was within an error of 27. The high accuracy of the grain yield prediction showed the ability of the model to simulate the growth of the crop in the agroclimatic conditions of Kerala. It can be concluded from this study that the model can be used for making various strategic and tactical decisions related to agricultural planning in the state

    Instruments of RT-2 Experiment onboard CORONAS-PHOTON and their test and evaluation II: RT-2/CZT payload

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    Cadmium Zinc Telluride (CZT) detectors are high sensitivity and high resolution devices for hard X-ray imaging and spectroscopic studies. The new series of CZT detector modules (OMS40G256) manufactured by Orbotech Medical Solutions (OMS), Israel, are used in the RT-2/CZT payload onboard the CORONAS-PHOTON satellite. The CZT detectors, sensitive in the energy range of 20 keV to 150 keV, are used to image solar flares in hard X-rays. Since these modules are essentially manufactured for commercial applications, we have carried out a series of comprehensive tests on these modules so that they can be confidently used in space-borne systems. These tests lead us to select the best three pieces of the 'Gold' modules for the RT-2/CZT payload. This paper presents the characterization of CZT modules and the criteria followed for selecting the ones for the RT-2/CZT payload. The RT-2/CZT payload carries, along with three CZT modules, a high spatial resolution CMOS detector for high resolution imaging of transient X-ray events. Therefore, we discuss the characterization of the CMOS detector as well.Comment: 26 pages, 19 figures, Accepted for publication in Experimental Astronomy (in press

    Management of Acute Myocardial Infarction During the COVID-19 Pandemic.

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    The worldwide pandemic caused by the novel acute respiratory syndrome coronavirus 2 (SARS-CoV2) has resulted in a new and lethal disease termed coronavirus disease 2019 (COVID-19). Although there is an association between cardiovascular disease and COVID-19, the majority of patients who need cardiovascular care for the management of ischemic heart disease may not be infected with COVID-19. The objective of this document is to provide recommendations for a systematic approach for the care of patients with an acute myocardial infarction (AMI) during the COVID-19 pandemic. There is a recognition of two major challenges in providing recommendations for AMI care in the COVID-19 era. Cardiovascular manifestations of COVID-19 are complex with patients presenting with AMI, myocarditis simulating a ST-elevation MI presentation, stress cardiomyopathy, non-ischemic cardiomyopathy, coronary spasm, or nonspecific myocardial injury and the prevalence of COVID-19 disease in the US population remains unknown with risk of asymptomatic spread. This document addresses the care of these patients focusing on 1) the varied clinical presentations; 2) appropriate personal protection equipment (PPE) for health care workers; 3) role of the Emergency Department, Emergency Medical System and the Cardiac Catheterization Laboratory; and 4) Regional STEMI systems of care. During the COVID-19 pandemic, primary PCI remains the standard of care for STEMI patients at PCI capable hospitals when it can be provided in a timely fashion, with an expert team outfitted with PPE in a dedicated CCL room. A fibrinolysis-based strategy may be entertained at non-PCI capable referral hospitals or in specific situations where primary PCI cannot be executed or is not deemed the best option

    Exploring the Free Energy Landscape: From Dynamics to Networks and Back

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    The knowledge of the Free Energy Landscape topology is the essential key to understand many biochemical processes. The determination of the conformers of a protein and their basins of attraction takes a central role for studying molecular isomerization reactions. In this work, we present a novel framework to unveil the features of a Free Energy Landscape answering questions such as how many meta-stable conformers are, how the hierarchical relationship among them is, or what the structure and kinetics of the transition paths are. Exploring the landscape by molecular dynamics simulations, the microscopic data of the trajectory are encoded into a Conformational Markov Network. The structure of this graph reveals the regions of the conformational space corresponding to the basins of attraction. In addition, handling the Conformational Markov Network, relevant kinetic magnitudes as dwell times or rate constants, and the hierarchical relationship among basins, complete the global picture of the landscape. We show the power of the analysis studying a toy model of a funnel-like potential and computing efficiently the conformers of a short peptide, the dialanine, paving the way to a systematic study of the Free Energy Landscape in large peptides.Comment: PLoS Computational Biology (in press

    Photoconductivity of biased graphene

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    Graphene is a promising candidate for optoelectronic applications such as photodetectors, terahertz imagers, and plasmonic devices. The origin of photoresponse in graphene junctions has been studied extensively and is attributed to either thermoelectric or photovoltaic effects. In addition, hot carrier transport and carrier multiplication are thought to play an important role. Here we report the intrinsic photoresponse in biased but otherwise homogeneous graphene. In this classic photoconductivity experiment, the thermoelectric effects are insignificant. Instead, the photovoltaic and a photo-induced bolometric effect dominate the photoresponse due to hot photocarrier generation and subsequent lattice heating through electron-phonon cooling channels respectively. The measured photocurrent displays polarity reversal as it alternates between these two mechanisms in a backgate voltage sweep. Our analysis yields elevated electron and phonon temperatures, with the former an order higher than the latter, confirming that hot electrons drive the photovoltaic response of homogeneous graphene near the Dirac point

    Detected troponin elevation is associated with high early mortality after lung resection for cancer

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    BACKGROUND: Myocardial infarction can be difficult to diagnose after lung surgery. As recent diagnostic criteria emphasize serum cardiac markers (in particular serum troponin) we set out to evaluate its clinical utility and to establish the long term prognostic impact of detected abnormal postoperative troponin levels after lung resection. METHODS: We studied a historic cohort of patients with primary lung cancer who underwent intended surgical resection. Patients were grouped according to known postoperative troponin status and survival calculated by Kaplan Meier method and compared using log rank. Parametric survival analysis was used to ascertain independent predictors of mortality. RESULTS: From 2001 to 2004, a total of 207 patients underwent lung resection for primary lung cancer of which 14 (7%) were identified with elevated serum troponin levels within 30 days of surgery, with 9 (64%) having classical features of myocardial infarction. The median time to follow up (interquartile range) was 22 (1 to 52) months, and the one and five year survival probabilities (95% CI) for patients without and with postoperative troponin elevation were 92% (85 to 96) versus 60% (31 to 80) and 61% (51 to 71) versus 18% (3 to 43) respectively (p < 0.001). T stage and postoperative troponin elevation remained independent predictors of mortality in the final multivariable model. The acceleration factor for death of elevated serum troponin after adjusting for tumour stage was 9.19 (95% CI 3.75 to 22.54). CONCLUSION: Patients with detected serum troponin elevation are at high risk of early mortality with or without symptoms of myocardial infarction after lung resection

    Optimal reaction coordinate as a biomarker for the dynamics of recovery from kidney transplant.

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    The evolution of disease or the progress of recovery of a patient is a complex process, which depends on many factors. A quantitative description of this process in real-time by a single, clinically measurable parameter (biomarker) would be helpful for early, informed and targeted treatment. Organ transplantation is an eminent case in which the evolution of the post-operative clinical condition is highly dependent on the individual case. The quality of management and monitoring of patients after kidney transplant often determines the long-term outcome of the graft. Using NMR spectra of blood samples, taken at different time points from just before to a week after surgery, we have shown that a biomarker can be found that quantitatively monitors the evolution of a clinical condition. We demonstrate that this is possible if the dynamics of the process is considered explicitly: the biomarker is defined and determined as an optimal reaction coordinate that provides a quantitatively accurate description of the stochastic recovery dynamics. The method, originally developed for the analysis of protein folding dynamics, is rigorous, robust and general, i.e., it can be applied in principle to analyze any type of biological dynamics. Such predictive biomarkers will promote improvement of long-term graft survival after renal transplantation, and have potentially unlimited applications as diagnostic tools

    Effect of haemoglobin concentration on the clinical outcomes in patients with acute myocardial infarction and the factors related to haemoglobin

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    <p>Abstract</p> <p>Background</p> <p>The impact of haemoglobin concentrations on clinical outcomes is still a controversial issue. To determine the association between haemoglobin concentrations on admission and clinical outcomes and the related factors, this study was performed in a Chinese hospital.</p> <p>Findings</p> <p>We conducted a retrospective study on 1394 Chinese patients with acute myocardial infarction. Patients were categorized according to the haemoglobin concentration on admission, and data were evaluated to determine whether there was an association between the haemoglobin concentrations on admission and 30-day in-hospital MACEs (major cardiovascular events). Patients with hemoglobin values between 141 and 150 g/L were used as the reference, the MACEs increased as hemoglobin concentrations fell below 140 g/L or rose > 150 g/L, with an adjusted OR (odds ratio) of 5.96[95% CI (confidence interval) 2.00 to 17.68, p = 0.0013], 4.39(1.37 to 14.08, p = 0.0128), 3.99(1.46 to 10.92, p = 0.0071), 3.19(1.27 to 8.05, p = 0.0139), 2.37(0.94 to 6.01, p = 0.0687), 2.11(0.66 to 6.74, p = 0.2065), 2.01(0.60 to 6.68, p = 0.2559) in patients with haemoglobin concentrations <100 g/L, 101-110 g/L, 111-120 g/L, 121-130 g/L, 131-140 g/L, 151-160 g/L, and >160 g/L respectively. Partial correlation analysis showed that age, albumin and creatinine were significantly associated with hemoglobin concentration.</p> <p>Conclusions</p> <p>Our results demonstrated that haemoglobin concentration affected MACEs in patients with acute myocardial infarction, and that haemoglobin concentration was associated with age, albumin and creatinine.</p
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