1,138 research outputs found
Efficient metal halide perovskite light-emitting diodes with significantly improved light extraction on nanophotonic substrates.
Metal halide perovskite has emerged as a promising material for light-emitting diodes. In the past, the performance of devices has been improved mainly by optimizing the active and charge injection layers. However, the large refractive index difference among different materials limits the overall light extraction. Herein, we fabricate efficient methylammonium lead bromide light-emitting diodes on nanophotonic substrates with an optimal device external quantum efficiency of 17.5% which is around twice of the record for the planar device based on this material system. Furthermore, optical modelling shows that a high light extraction efficiency of 73.6% can be achieved as a result of a two-step light extraction process involving nanodome light couplers and nanowire optical antennas on the nanophotonic substrate. These results suggest that utilization of nanophotonic structures can be an effective approach to achieve high performance perovskite light-emitting diodes
Loss to Follow-Up from HIV Screening to ART Initiation in Rural China.
BackgroundPatients who are newly screened HIV positive by EIA are lost to follow-up due to complicated HIV testing procedures. Because this is the first step in care, it affects the entire continuum of care. This is a particular concern in rural China.Objective(s)To assess the routine HIV testing completeness and treatment initiation rates at 18 county-level general hospitals in rural Guangxi.MethodsWe reviewed original hospital HIV screening records. Investigators also engaged with hospital leaders and key personnel involved in HIV prevention activities to characterize in detail the routine care practices in place at each county.Results699 newly screened HIV-positive patients between January 1 and June 30, 2013 across the 18 hospitals were included in the study. The proportion of confirmatory testing across the 18 hospitals ranged from 14% to 87% (mean of 43%), and the proportion of newly diagnosed individuals successfully initiated antiretroviral treatment across the hospitals ranged from 3% to 67% (mean of 23%). The average interval within hospitals for individuals to receive the Western Blot (WB) and CD4 test results from HIV positive screening (i.e. achieving testing completion) ranged from 14-116 days (mean of 41.7 days) across the hospitals. The shortest interval from receiving a positive EIA screening test result to receiving WB and CD4 testing and counseling was 0 day and the longest was 260 days.ConclusionThe proportion of patients newly screened HIV positive that completed the necessary testing procedures for HIV confirmation and received ART was very low. Interventions are urgently needed to remove barriers so that HIV patients can have timely access to HIV/AIDS treatment and care in rural China
The effect of fog on the probability density distribution of the ranging data of imaging laser radar
This paper outlines theoretically investigations of the probability density distribution (PDD) of ranging data for the imaging laser radar (ILR) system operating at a wavelength of 905 nm under the fog condition. Based on the physical model of the reflected laser pulses from a standard Lambertian target, a theoretical approximate model of PDD of the ranging data is developed under different fog concentrations, which offer improved precision target ranging and imaging. An experimental test bed for the ILR system is developed and its performance is evaluated using a dedicated indoor atmospheric chamber under homogeneously controlled fog conditions. We show that the measured results are in good agreement with both the accurate and approximate models within a given margin of error of less than 1%
Expression of relative-protein of hypoxia-inducible factor-1α in vasculogenesis of mouse embryo
Distributed constraint optimization for discrete-time multiagent systems with event-triggered communication
This paper investigates the distributed optimization problem (DOP) with equality constraint in discrete-time multiagent systems (MASs) in which the global optimization objective is constituted by the summation of local objective functions. Firstly, by employing the Lagrange multiplier method, we convert the convex optimization problem with equality constraint into a consensus problem of MASs. Secondly, to reduce the communication burden, a type of event-triggered control protocol is proposed to enable all agents achieving consensus. Thirdly, by employing the Lyapunov function method and a set of inequality techniques, we establish some sufficient conditions to ensure that all agents converge to consensus and successfully solve the original DOP. Finally, a numerical simulation example is presented to validate the effectiveness of the theoretical analysis
Pharmacologic suppression of JAK1/2 by JAK1/2 inhibitor AZD1480 potently inhibits IL-6-induced experimental prostate cancer metastases formation.
Metastatic prostate cancer is lethal and lacks effective strategies for prevention or treatment, requiring novel therapeutic approaches. Interleukin-6 (IL-6) is a cytokine that has been linked with prostate cancer pathogenesis by multiple studies. However, the direct functional roles of IL-6 in prostate cancer growth and progression have been unclear. In the present study, we show that IL-6 is produced in distant metastases of clinical prostate cancers. IL-6-activated signaling pathways in prostate cancer cells induced a robust 7-fold increase in metastases formation in nude mice. We further show that IL-6 promoted migratory prostate cancer cell phenotype, including increased prostate cancer cell migration, microtubule reorganization, and heterotypic adhesion of prostate cancer cells to endothelial cells. IL-6-driven metastasis was predominantly mediated by Stat3 and to lesser extent by ERK1/2. Most importantly, pharmacologic inhibition of Jak1/2 by AZD1480 suppressed IL-6-induced signaling, migratory prostate cancer cell phenotypes, and metastatic dissemination of prostate cancer in vivo in nude mice. In conclusion, we demonstrate that the cytokine IL-6 directly promotes prostate cancer metastasis in vitro and in vivo via Jak-Stat3 signaling pathway, and that IL-6-driven metastasis can be effectively suppressed by pharmacologic targeting of Jak1/2 using Jak1/2 inhibitor AZD1480. Our results therefore provide a strong rationale for further development of Jak1/2 inhibitors as therapy for metastatic prostate cancer
Rating Inflation versus Deflation: On Procyclical Credit Ratings
Credit rating agencies play a crucial role in financial markets. There are two competing views regarding their behavior: some argue that they engage in rating inflation, while others suggest that they deflate ratings. This article offers a rationale that reconciles the two opposite arguments. We find that both rating inflation and rating deflation can occur in equilibrium. Furthermore, we show
that credit rating is procyclical: rating inflation is more likely to happen in a boom while rating deflation is more likely to happen in a recession
Study on Modern Bridge Structure Health Monitoring System Based on Damage Identification
With the rapid growth of traffic, the loads\u27 design of many existing bridges can no longer meet the current vehicle load requirements, and the structural safety is seriously threatened. To ensure the structural safety of the bridge, it is necessary to monitor the bridge health and establish an early warning mechanism to prevent major accidents. The modern concrete bridge structure health monitoring based on damage identification proposed in this paper carried out principal component analysis of modern concrete bridges, and then this paper used principal component analysis (PCA) to locate the nonlinear damage source of the experimental model, which obtained the following conclusions. The maximum shear stress of the steel beam web is about 80 MPa,and the bulk stress of steel is reached at 7.5 MPa. Furthermore, to reduce the original data\u27s dimensionality, PCA effectively retains the characteristic information of the original data; empirical examples from external factor are presented. The major advantage of applying this framework is that the structural damage identification is simple and reliable with its advantages of dimensionality reduction, noise reduction, and exclusion of out-of-bounds interference factors
Rating Inflation versus Deflation: On Procyclical Credit Ratings
Credit rating agencies play a crucial role in financial markets. There are two competing views regarding their behavior: some argue that they engage in rating inflation, while others suggest that they deflate ratings. This article offers a rationale that reconciles the two opposite arguments. We find that both rating inflation and rating deflation can occur in equilibrium. Furthermore, we show
that credit rating is procyclical: rating inflation is more likely to happen in a boom while rating deflation is more likely to happen in a recession
Novelties of solid-liquid phase transfer catalyzed synthesis of benzyl diethyl phosphate from the sodium salt of diethyl phosphate
Solid-liquid phase transfer catalysis coupled with mixed solvents, which could be recycled, as a green chemistry procedure, was applied to the synthesis of phosphate from the sodium salt of diethyl phosphate. The benzyl diethyl phosphate was synthesized in good yield via one-pot method from the reaction of the industrial by-product sodium salt of diethyl phosphate with benzyl chloride in solid-liquid phase transfer catalysis and toluene-water mixed solvents. The effects of catalyst structure, the amounts of catalyst, the raw material molar ratio, water loading, and reaction temperature on the conversion of the reaction were investigated. The structure of the benzyl diethyl phosphate generated was confirmed by Elemental Analysis, IR, 1H NMR and GC/MS
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