707 research outputs found

    Plasmonic backscattering enhanced inverted photovoltaics

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98669/1/ApplPhysLett_99_113306.pd

    Customer Behavior Analysis for Social Media

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    It is essential for a business organization to get the customer feedback in order to grow as a company. Business organizations are collecting customer feedback using various methods. But the question is ‘are they efficient and effective?' In the current context, there is more of a customer oriented market and all the business organizations are competing to achieve customer delight through their products and services. Social Media plays a huge role in one's life. Customers tend to reveal their true opinion about certain brands on social media rather than giving routine feedback to the producers or sellers. Because of this reason, it is identified that social media can be used as a tool to analyze customer behavior. If relevant data can be gathered from the customers' social media feeds and if these data are analyzed properly, a clear idea to the companies what customers really think about their brand can be provided

    Estimating the risk of mortality attributable to recent late HIV diagnosis following admission to the intensive care unit: A single-centre observational cohort study

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    OBJECTIVES: Despite improvements in survival of people with HIV admitted to the intensive care unit (ICU), late diagnosis continues to contribute to in-ICU mortality. We quantify the population attributable fraction (PAF) of in-ICU mortality for recent late diagnosis among people with HIV admitted to a London ICU. METHODS: Index ICU admissions among people with HIV were considered from 2000 to 2019. Recent late diagnosis was a CD4 T-cell count < 350 cells/μL and/or AIDS-defining illness at/within 6 months prior to ICU admission. Univariate comparisons were conducted using Wilcoxon rank-sum/Cochran-Armitage/χ2 /Fisher's exact tests. We used Poisson regression (robust standard errors) to estimate unadjusted/adjusted (age, sex, calendar year of ICU admission) risk ratios (RRs) and regression standardization to estimate the PAF. RESULTS: In all, 207 index admissions were included [median (interquartile range) age: 46 (38-53) years; 72% male]; 58 (28%) had a recent late diagnosis, all of whom had a CD4 count < 350 cells/μL, and 95% had advanced HIV (CD4 count < 200 cells/μL and/or AIDS at admission) as compared with 57% of those who did not have a recent late diagnosis (p < 0.001). In-ICU mortality was 27% (55/207); 38% versus 22% in those who did and did not have a recent late diagnosis, respectively (p = 0.02). Recent late diagnosis was independently associated with increased in-ICU mortality risk (adjusted RR = 1.75) (95% confidence interval: 1.05-2.91), with 17.08% (16.04-18.12%) of deaths being attributable to this. CONCLUSIONS: There is a need for improved public health efforts focused on HIV testing and reporting of late diagnosis to better understand potentially missed opportunities for earlier HIV diagnosis in healthcare services

    Evaluation of in-vivo and in-vitro microbiological methods for testing the efficacy of parenteral antibiotics: A Review

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    Antibiotics are available as innovators and generics. An innovator or branded drug is a medicine that is discovered, developed and marketed by a pharmaceutical company which also holds the patent for that drug. Generics only become available after the patent on the innovator expires. Generic drugs are required to have the same active ingredient, strength, dosage form, and route of administration as the innovator product. Generics should be bioequivalent to the innovator and when used, should have the same efficacy and safety profile. This is crucial for parenteral antibiotics because according to the World Health Organization and U.S. Food and Drug Administration criteria, parenteral generic products do not need to provide evidence for in-vivo bioavailability or bioequivalence before they can be marketed. Published evidence shows that there is a disparity in the efficacy of different generic antibiotic products. In-vitro microbiological methods of efficacy testing have been recognized as a standardized and cost-effective approach to clarify doubts regarding the efficacy of generic parenteral antibiotics. However, in-vitro methods used alone, might not be a good measurement of antibiotic efficacy as several studies have shown disparities between in-vitro and in-vivo efficacy of parenteral antibiotics.</p

    Monte-Carlo simulations of the recombination dynamics in porous silicon

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    A simple lattice model describing the recombination dynamics in visible light emitting porous Silicon is presented. In the model, each occupied lattice site represents a Si crystal of nanometer size. The disordered structure of porous Silicon is modeled by modified random percolation networks in two and three dimensions. Both correlated (excitons) and uncorrelated electron-hole pairs have been studied. Radiative and non-radiative processes as well as hopping between nearest neighbor occupied sites are taken into account. By means of extensive Monte-Carlo simulations, we show that the recombination dynamics in porous Silicon is due to a dispersive diffusion of excitons in a disordered arrangement of interconnected Si quantum dots. The simulated luminescence decay for the excitons shows a stretched exponential lineshape while for uncorrelated electron-hole pairs a power law decay is suggested. Our results successfully account for the recombination dynamics recently observed in the experiments. The present model is a prototype for a larger class of models describing diffusion of particles in a complex disordered system.Comment: 33 pages, RevTeX, 19 figures available on request to [email protected]

    A composite index to measure the adoption level of healthcare waste management of base hospitals in Uwa Province of Sri Lanka

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    Healthcare wastes are highly infectious and management of healthcare waste is of great importance due to its potential environmental hazards and public health risks. In recent years, many efforts have been made by environmental regulatory agencies towards the better management of wastes through healthcare  facilities. But there is no valid criterion to assess the adoption level of standard method of waste care management. Therefore this study brings into focus to develop a Composite Index called Healthcare Waste Management Index (HWMI) to measure the adoption level of standard methods of waste collection and disposal methods based on the information obtained from the base hospitals of Uwa Province as a case study, in order to assess human and environmental risks due to their improper management. Eight main categories of waste management that were identified by the World Health organization were considered for the study. Information on these waste categories were circulated among 20 subject specialists and weightages were obtained for each categories depending   on its influence on human health and environment. Current practices of waste management for each category were obtained from hospitals and they were ranked from zero to three with respect to their adoption compare to the standard practices. Finally Composite Index was developed with the ratio of linear additive rank of each waste category by multiplying the relevant weightages and highest rank (which is 3 in this case) multiply by the total weightage. Calculated index value lie between 0 to 1 and value of  1 indicate the complete adoption of standard methods. Index value obtained for six hospitals lie in between 0.69 to 0.58, recording the highest Index value from Diyatalawa base hospital. This index could be used as basic tool for grading and ranking the status of healthcare management practices.Key words: Healthcare waste management, Healthcare Waste Management Index, Waste disposa

    Gapless spinons and a field-induced soliton gap in the hyper-honeycomb Cu oxalate framework compound [(C2_{2}H5_{5})3_{3}NH]2_{2}Cu2_{2}(C2_{2}O4_{4})3_{3}

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    We report a detailed study of the specific heat and magnetic susceptibility of single crystals of a spin liquid candidate: the hyper-honeycomb Cu oxalate framework compound [(C2_2H5_5)3_3NH]2_2Cu2_2(C2_2O4_4)3_3. The specific heat shows no anomaly associated with a magnetic transition at low temperatures down to TT\sim 180 mK in zero magnetic field. We observe a large linear-in-TT contribution to the specific heat γT\gamma T, γ=98(1)\gamma = 98(1) mK/mol K2^{2}, at low temperatures, indicative of the presence of fermionic excitations despite the Mott insulating state. The low-TT specific heat is strongly suppressed by applied magnetic fields HH, which induce an energy gap, Δ(H)\Delta (H), in the spin-excitation spectrum. We use the four-component relativistic density-functional theory (DFT) to calculate the magnetic interactions, including the Dzyaloshinskii-Moriya antisymmetric exchange, which causes an effective staggered field acting on one copper sublattice. The magnitude and field dependence of the field-induced gap, Δ(H)H2/3\Delta (H) \propto H^{2/3}, are accurately predicted by the soliton mass calculated from the sine-Gordon model of weakly coupled antiferromagnetic Heisenberg chains with all parameters determined by our DFT calculations. Thus our experiment and calculations are entirely consistent with a model of [(C2_2H5_5)3_3NH]2_2Cu2_2(C2_2O4_4)3_3 in which anisotropic magnetic exchange interactions due to Jahn-Teller distortion cause one copper sublattice to dimerize, leaving a second sublattice of weakly coupled antiferromagnetic chains. We also show that this model quantitatively accounts for the measured temperature-dependent magnetic susceptibility. Thus [(C2_2H5_5)3_3NH]2_2Cu2_2(C2_2O4_4)3_3 is a canonical example of a one-dimensional spin-1/2 Heisenberg antiferromagnet and not a resonating-valence-bond quantum spin liquid, as previously proposed.Comment: 8 pages, 6 figure

    Electrochemical integration of graphene with light absorbing copper-based thin films

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    We present an electrochemical route for the integration of graphene with light sensitive copper-based alloys used in optoelectronic applications. Graphene grown using chemical vapor deposition (CVD) transferred to glass is found to be a robust substrate on which photoconductive Cu_{x}S films of 1-2 um thickness can be deposited. The effect of growth parameters on the morphology and photoconductivity of Cu_{x}S films is presented. Current-voltage characterization and photoconductivity decay experiments are performed with graphene as one contact and silver epoxy as the other
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