155 research outputs found

    Existence of Solutions for Nonhomogeneous A

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    We study the following nonhomogeneous A-harmonic equations: d*A(x,du(x))+B(x,u(x))=0,    x∈Ω,  u(x)=0,  x∈∂Ω, where Ω⊂ℝn is a bounded and convex Lipschitz domain, A(x,du(x)) and B(x,u(x)) satisfy some p(x)-growth conditions, respectively. We obtain the existence of weak solutions for the above equations in subspace 01,p(x)(Ω,Λl-1) of W01,p(x)(Ω,Λl-1)

    Calycosin regulates glucocorticoid-induced apoptosis via Nrf2/ARE signaling in MC3T3-E1 cells

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    Purpose: To determine the anti-osteoporotic effect of calycosin (CA) and investigate the mechanism involved.Methods: To establish a cell model of osteoporosis, MC3T3-E1 cells were treated with dexamethasone (DEX). Subsequently, the levels of accumulated reactive oxygen species (ROS) and subsequent apoptotic cell death (using flow cytometry) were determined. Relevant mRNA and protein expression levels were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunoblot respectively.Results: CA reduced the apoptosis and accumulation of ROS in DEX-treated cells. DEX induced the expression of caspase-3/-8/-9 in the cleavage of poly ADP-ribose polymerase (PARP), whereas CA treatment decreased expression levels of caspase-3/-8/-9 and PARP. In addition, DEX treatment significantly suppressed the expression of nuclear factor-erythroid 2-related factor 2 (Nrf2) as well as its downstream targets, viz, heme oxygenase-1 and quinone oxidoreductase-1. Interestingly, CA treatment reversed this suppressive effect. It was also found that Nrf2 small interfering RNA effectively inhibited the protective effects of CA against DEX-induced ROS overproduction as well as apoptosis.Conclusion: CA attenuates the cytotoxicity of DEX via inhibition of the generation of ROS and promotion of Nrf2 expression. These findings offer novel insights into a molecular approach to the treatment of glucocorticoid-induced osteoporosis via the application of natural compounds.Keywords: Calycosin, Osteoporosis, Nrf2, Antioxidant response elements, Apoptosi

    Breach of tolerance: primary biliary cirrhosis.

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    In primary biliary cirrhosis (PBC), the breach of tolerance that leads to active disease involves a disruption in several layers of control, including central tolerance, peripheral anergy, a liver tolerance effect, and the action of T regulatory cells and their related cytokines. Each of these control mechanisms plays a role in preventing an immune response against self, but all of them act in concert to generate effective protection against autoimmunity without compromising the ability of the host immune system to mount an effective response to pathogens. At the same time, genetic susceptibility, environmental factors, including infection agents and xenobiotics, play important roles in breach of tolerance in the development of PBC

    An overview of the material science and knowledge of nanomedicine, bioscaffolds, and tissue engineering for tendon restoration

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    Tendon wounds are a worldwide health issue affecting millions of people annually. Due to the characteristics of tendons, their natural restoration is a complicated and lengthy process. With the advancement of bioengineering, biomaterials, and cell biology, a new science, tissue engineering, has developed. In this field, numerous ways have been offered. As increasingly intricate and natural structures resembling tendons are produced, the results are encouraging. This study highlights the nature of the tendon and the standard cures that have thus far been utilized. Then, a comparison is made between the many tendon tissue engineering methodologies proposed to date, concentrating on the ingredients required to gain the structures that enable appropriate tendon renewal: cells, growth factors, scaffolds, and scaffold formation methods. The analysis of all these factors enables a global understanding of the impact of each component employed in tendon restoration, thereby shedding light on potential future approaches involving the creation of novel combinations of materials, cells, designs, and bioactive molecules for the restoration of a functional tendon

    O2ATH: An OpenMP Offloading Toolkit for the Sunway Heterogeneous Manycore Platform

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    The next generation Sunway supercomputer employs the SW26010pro processor, which features a specialized on-chip heterogeneous architecture. Applications with significant hotspots can benefit from the great computation capacity improvement of Sunway many-core architectures by carefully making intensive manual many-core parallelization efforts. However, some legacy projects with large codebases, such as CESM, ROMS and WRF, contain numerous lines of code and do not have significant hotspots. The cost of manually porting such applications to the Sunway architecture is almost unaffordable. To overcome such a challenge, we have developed a toolkit named O2ATH. O2ATH forwards GNU OpenMP runtime library calls to Sunway's Athread library, which greatly simplifies the parallelization work on the Sunway architecture.O2ATH enables users to write both MPE and CPE code in a single file, and parallelization can be achieved by utilizing OpenMP directives and attributes. In practice, O2ATH has helped us to port two large projects, CESM and ROMS, to the CPEs of the next generation Sunway supercomputers via the OpenMP offload method. In the experiments, kernel speedups range from 3 to 15 times, resulting in 3 to 6 times whole application speedups.Furthermore, O2ATH requires significantly fewer code modifications compared to manually crafting CPE functions.This indicates that O2ATH can greatly enhance development efficiency when porting or optimizing large software projects on Sunway supercomputers.Comment: 15 pages, 6 figures, 5 tables

    Studies on Chemical Characterization of Ginkgo Amillaria Oral Solution and Its Drug–Drug Interaction With Piceatannol 3′-O-β-D-Glucopyranoside for Injection

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    Ginkgo Amillaria oral solution (GAO) is commonly used for the treatment of cardiovascular and cerebrovascular diseases in China. Piceatannol-3′-O-β-D-glucopyranoside for injection (PGI) is mainly used for the prevention and treatment of ischemic cerebrovascular diseases. With the spread of cerebrovascular disease, the possibility of combining the two drugs has increased; however, there is no research on the drug–drug interaction (DDI) between these two medicines. In this paper, an ultrahigh-performance liquid chromatography/quadrupole–orbitrap mass spectrometry (UHPLC/Q-Orbitrap MS) method was established to characterize the chemical constituents of GAO first; 62 compounds were identified or tentatively identified based on their retention time (RT), MS, and MS/MS data. Nine main compounds were determined by ultrahigh-performance liquid chromatography/triple quadrupole mass spectrometry (UPLC-QQQ-MS). Furthermore, incubation with liver microsomes in vitro was fulfilled; the results showed that GAO had a significant inhibitory effect on UGT1A9 and UGT2B7 (p < 0.05), and PGI was mainly metabolized by UGT1A9. The identification results of in vivo metabolites of PGI showed that PGI mainly undergoes a phase II binding reaction mediated by UDP-glucuronosyltransferase (UGT) and sulfotransferase (SULT) in vivo. Therefore, pharmacokinetic studies were performed to investigate the DDI between GAO and PGI. The results showed that the AUC (p < 0.05) and T1/2 (p < 0.05) of PGI in vivo were significantly increased when administered together with GAO, whereas the CL was significantly decreased (p < 0.05). The exploration of in vitro and in vivo experiments showed that there was a DDI between GAO and PGI

    Mutant Kras- and p16-regulated NOX4 activation overcomes metabolic checkpoints in development of pancreatic ductal adenocarcinoma

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    Kras activation and p16 inactivation are required to develop pancreatic ductal adenocarcinoma (PDAC). However, the biochemical mechanisms underlying these double alterations remain unclear. Here we discover that NAD(P)H oxidase 4 (NOX4), an enzyme known to catalyse the oxidation of NAD(P)H, is upregulated when p16 is inactivated by looking at gene expression profiling studies. Activation of NOX4 requires catalytic subunit p22phox, which is upregulated following Kras activation. Both alterations are also detectable in PDAC cell lines and patient specimens. Furthermore, we show that elevated NOX4 activity accelerates oxidation of NADH and supports increased glycolysis by generating NAD+, a substrate for GAPDH-mediated glycolytic reaction, promoting PDAC cell growth. Mechanistically, NOX4 was induced through p16-Rb-regulated E2F and p22phox was induced by KrasG12V-activated NF-κB. In conclusion, we provide a biochemical explanation for the cooperation between p16 inactivation and Kras activation in PDAC development and suggest that NOX4 is a potential therapeutic target for PDAC

    Atomic-layer-deposited ultrafine MoS2 nanocrystals on cobalt foam for efficient and stable electrochemical oxygen evolution

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    Ultrafine molybdenum sulfide (MoS2) nanocrystals are grown on a porous cobalt (Co) foam current collector by atomic layer deposition (ALD) using molybdenum hexacarbonyl and hydrogen sulfide as precursors. When used to catalyze the oxygen evolution reaction (OER), the optimal Co@MoS2 electrode, even with a MoS2 loading as small as 0.06 mg cm-2, exhibits a large cathodic shift of ca. 200 mV in the onset potential (the potential at which the current density is 5 mA cm-2), a low overpotential of only 270 mV to attain an anodic current density of 10 mA cm-2, much smaller charge transfer resistance and substantially improved long-term stability at both low and high current densities, with respect to the bare Co foam electrode, showing substantial promise for use as an efficient, low-cost and durable anode in water electrolyzers.L. F. Liu acknowledges the support of the FCT Investigator grant (no. IF/01595/2014) and the Exploratory grant (No. IF/01595/2014/CP1247/CT0001) from the Portuguese Foundation of Science & Technology (FCT). D. H. Xiong and W. Li are thankful for the financial support from Marie Curie Action COFUND fellowships (NanoTrainforGrowth, Grant Agreement no. 600375) under the FP7 framework. D. H. Xiong also acknowledges the financial support from the China Postdoctoral Science Foundation (No. 2015 T80847). This work was partly funded by the European Commission Horizon 2020 project "CritCat" (Grant Agreement No. 686053).info:eu-repo/semantics/publishedVersio

    HCV Coinfection Associated with Slower Disease Progression in HIV-Infected Former Plasma Donors Naïve to ART

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    It remains controversial how HCV coinfection influences the disease progression during HIV-1 infection. This study aims to define the influence of HCV infection on the replication of HIV-1 and the disease progression in HIV-infected former plasma donors (FPDs) naïve to ART.168 HIV-1-infected FPDs were enrolled into a cohort study from Anhui province in central China, and thereafter monitored at month 3, 9, 15, 21 and 33. Fresh whole blood samples were used for CD4+ T-cell counting. Their plasma samples were collected and stored for quantification of HIV-1 viral loads and for determination of HCV and Toxoplasma. Out of 168 HIV-infected FBDs, 11.9% (20 cases), 80.4% (135 cases) and 7.7% (13 cases) were infected with HIV-1 alone, HIV-1/HCV and HIV/HCV/Toxoplasma, respectively. During the 33-month follow-up, only 35% (7 out of 20 cases) HIV-1 mono-infected subjects remained their CD4+ T-cell counts above 200 cells/µl and retained on the cohort study, which was significantly lower than 56% (75 out of 135 cases) for HIV/HCV group and 69% (9 out of 13 cases) for HIV/HCV/Toxoplasma group (p<0.05). CD4+ T cells in HIV mono infection group were consistently lower than that in HIV/HCV group (p = 0.04, 0.18, 0.03 and 0.04 for baseline, month 9, month 21 and month 33 visit, respectively). In accordance with those observations, HIV viral loads in HIV mono-infection group were consistently higher than that in HIV/HCV group though statistical significances were only reached at baseline (p = 0.04).These data indicated HCV coinfection with HIV-1 is associated with the slower disease progression at the very late stage when comparing with HIV-1 mono-infection. The coinfection of Toxoplasma with HIV and HCV did not exert additional influence on the disease progression. It will be highly interesting to further explore the underlying mechanism for this observation in the future

    Construction of a cross-species cell landscape at single-cell level.

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    Individual cells are basic units of life. Despite extensive efforts to characterize the cellular heterogeneity of different organisms, cross-species comparisons of landscape dynamics have not been achieved. Here, we applied single-cell RNA sequencing (scRNA-seq) to map organism-level cell landscapes at multiple life stages for mice, zebrafish and Drosophila. By integrating the comprehensive dataset of > 2.6 million single cells, we constructed a cross-species cell landscape and identified signatures and common pathways that changed throughout the life span. We identified structural inflammation and mitochondrial dysfunction as the most common hallmarks of organism aging, and found that pharmacological activation of mitochondrial metabolism alleviated aging phenotypes in mice. The cross-species cell landscape with other published datasets were stored in an integrated online portal-Cell Landscape. Our work provides a valuable resource for studying lineage development, maturation and aging
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