130,745 research outputs found
Comment on Elangovan H et al. Vitamin D in liver disease: Current evidence and potential directions. Biochim Biophys Acta 2017;1863(4):907-916
No full textElangovan H et al. recently published a review summarizing the role of vitamin D in liver diseases, with a particular focus on vitamin D supplementation in hepatopathies.
In the section on Clinical studies in non-alcoholic fatty liver disease (6.3), among others, the authors commented the monocentric, randomized, double blind, placebo controlled trial which we conducted on 55 patients with type 2 diabetes and NAFLD (number 2011-003010-17, www.clinicaltrialsregister.eu) at Sapienza University of Rome, Italy
Design and Implementation of Soft Switched High Gain Current Fed Full Bridge DC-DC Converter for Fuel Cell Applications
No full textAbstractThis paper proposes the analysis and design of new current fed full bridge high gain isolated dc-dc converter for fuel cell application. The proposed converter uses voltage multiplier cells on the secondary side. The objective of the proposed converter is to generate DC link voltage for three phase grid from fuel cell. Current fed Converter reduces the input current ripple at the fuel cell input. The converter utilizes the energy stored in the transformer leakage and parasitic capacitance to maintain zero-current-switching (ZCS) over wide range. Soft switching permits higher switching frequency operation, reducing the size, weight and cost of the magnetic components and improve the converter efficiency. A new design method of half-wave Cockcroft–Walton Voltage Multiplier (H-W C-W VM) that lays on the calculation of the optimal number of stages, which is necessary to produce the desired output voltage with the minimum total capacitance value, is also presented. The operating frequency of the converter is 100kHz. The Analysis, simulation and experimental results of the proposed converter are presented. The proposed converter with three stage voltage multiplier is simulated for two different cases full load and half load conditions and the results were analysed. The hardware model for an input voltage of 30V and input current of 5 Amps was designed, the output from the inverter is 40V and output from the voltage multiplier of three stages is 240V and 0.6 Amps
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Loss of E-cadherin Activates a Targetable IGF1R Pathway in Invasive Lobular Breast Carcinoma
No full textInvasive Ductal Carcinoma (IDC) and Invasive Lobular Carcinoma (ILC) are two major subtypes of breast cancer with significant differences in their histological and molecular underpinnings. ILC has a unique hallmark of loss of E-cadherin (CDH1) in 90% of the cases, which we have previously demonstrated as a negative regulator of Insulin-like Growth Factor 1 (IGF1) receptor, IGF1R through a comprehensive analysis of cell line models and tumor samples on TCGA. We propose that the loss of E-cadherin in ILC sensitizes cells to growth factor signaling and thus alters their susceptibility to growth factor signaling inhibition. We generated CDH1 knockout (KO) IDC cell lines to investigate the mechanism by which E-cadherin loss activates IGF pathway and its subsequent effectors while also assessing its targetability in patients. CDH1 KO cells exhibited anchorage independent growth in suspension culture and altered p120 catenin localization as seen in ILC cells. Through in vitro studies, we observed increased signaling sensitivity to IGF/ insulin ligands where the high activation levels are sustained for an extended duration in the KO cells. In addition, there was higher migratory potential in the CDH1 KO cells, which was further enhanced as a chemotactic response to IGF1 or serum and as a haptotactic response to Collagen I. This phenotype was reversed with an IGF1R inhibitor to exhibit phenotype specificity. Despite no consistent differences in membranous IGF1R levels, higher ligand-receptor interaction was observed with E-cadherin loss. Our results currently demonstrate IGF1R’s increased availability for ligand binding which in turn allows for an enhanced signaling activation. As an extension to the pathway activation, increased susceptibility to IGF1R, PI3K, AKT and MEK inhibitors was also observed in T47D CDH1 KO cells. With about 90% of ILC cases being ER+, we investigated and showed the additive effect of Fulvestrant with Akt inhibitors in KO cells. Although a clear susceptibility to Akt inhibitor was not seen in ILC patient-derived organoids (PDO), a favorable trend was observed when compared to IDC PDOs. Our findings elucidated IGF1 signaling repression by E-cadherin in ILC, thus supporting the use of E-cadherin loss as a stratification method for improved targeted therapy approaches
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Parameter Estimation of Organic Photovoltaic Cells - A Three-Diode Approach Using Wind-Driven Optimization Algorithm
No full textModeling a reliable electrical equivalent circuit to simulate the output I-V characteristics of organic solar PV (OPV) cells still prevails as a challenging task. This is because, estimating unknown parameters from the transcendental current equation determining the nonlinear OPV characteristics is extremely difficult. More importantly, predicting the parameters for dynamic changes in irradiation profile demands reliable optimization-based models. Therefore, this article proposes the application of adaptive wind-driven optimization (WDO) algorithm for a three-diode electrical equivalent model to estimate the OPV circuit parameters. Application of WDO algorithm has produced precise PV parameters to reproduce the exact I-V characteristics. In particular, the ability to replicate the kink effect in OPV characteristics is a noticeable improvement. Compared to its counterparts, various factors that enable WDO to enhance its compatibility towards nonlinear OPV modeling are: i) unique velocity update strategy via Coriolis and Gravitational forces, ii) excellent tradeoff between exploration and exploitation of control variables, iii) adaptive capability to maintain solutions within the search space even if the limits are breached, and iv) easiness in parameter tuning. For the validation, extensive testing has been conducted to reproduce the widely used characteristics of nav100 OPV cell at various operating conditions. Quantitatively, WDO method showcases excellent accuracy with an individual absolute error value in the order of 10-6 and convergence within the first 50 iterations itself, demonstrating its supremacy to solve OPV parameter identification problem
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Scholarly Communication and Publishing Lunch and Learn Talk #11: The ULS Open Access Author Fee Fund
No full textAt the May 2014 talk, you will learn about the ULS Open Access Author Fee Fund--what it is, why we do it, how it works, and how the program is going so far
- …
