110 research outputs found

    Cardioprotective Effects of Salvianolic Acid A on Myocardial Ischemia-Reperfusion Injury In Vivo and In Vitro

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    Salvianolic acid A (SAA), one of the major active components of Danshen that is a traditional Chinese medicine, has been reported to possess protective effect in cardiac diseases and antioxidative activity. This study aims to investigate the cardioprotection of SAA in vivo and in vitro using the model of myocardial ischemia-reperfusion in rat and hydrogen peroxide (H2O2)-induced H9c2 rat cardiomyoblasts apoptosis. It was found that SAA significantly limited infarct size of ischemic myocardium when given immediately prior to reperfusion. SAA also significantly suppressed cellular injury and apoptotic cell death. Additionally, the results of western blot and phospho-specific antibody microarray analysis showed that SAA could up-regulate Bcl-2 expression and increase the phosphorylation of proteins such as Akt, p42/p44 extracellular signal-related kinases (Erk1/2), and their related effectors. The phosphorylation of those points was related to suppress apoptosis. In summary, SAA possesses marked protective effect on myocardial ischemia-reperfusion injury, which is related to its ability to reduce myocardial cell apoptosis and damage induced by oxidative stress. The protection is achieved via up-regulation of Bcl-2 expression and affecting protein phosphorylation. These findings indicate that SAA may be of value in cardioprotection during myocardial ischemia-reperfusion injury, which provide pharmacological evidence for clinical application

    Highly efficient mixed-metal spinel cobaltite electrocatalysts for the oxygen evolution reaction

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    Cation substitution in spinel cobaltites (e.g., ACo2O4, in which A = Mn, Fe, Co, Ni, Cu, or Zn) is a promising strategy to precisely modulate their electronic structure/properties and thus im-prove the corresponding electrochemical performance for water splitting. However, the fun-damental principles and mechanisms are not fully understood. This research aims to systemat-ically investigate the effects of cation substitution in spinel cobaltites derived from mixed-metal-organic frameworks on the oxygen evolution reaction (OER). Among the obtained ACo2O4 catalysts, FeCo2O4 showed excellent OER performance with a current density of 10 mAcm–2 at an overpotential of 164 mV in alkaline media. Both theoretical calculations and ex-perimental results demonstrate that the Fe substitution in the crystal lattice of ACo2O4 can sig-nificantly accelerate charge transfer, thereby achieving enhanced electrochemical properties. The crystal field of spinel ACo2O4, which determines the valence states of cations A, is identified as the key factor to dictate the OER performance of these spinel cobaltites

    Multiple evaluations, risk assessment, and source identification of heavy metals in surface water and sediment of the Golmud River, northeastern Qinghai-Tibet Plateau, China

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    The water quality of the Golmud River is essential for environmental preservation and economic growth of Golmud city and Qarhan Salt Lake in China. Thirty-four samples of surface water and sediment from seventeen places in the Golmud River and thirty-two dustfall samples in the Qaidam Basin were collected. The concentrations of heavy metals (HMs) were measured; water quality, risk assessment, and multiple source analysis were applied. Concentrations of HMs in water were Zn > Cu > Ni > As > Pb > Cd > Hg, and in sediment were Ni > Zn > Pb > As > Cu > Cd > Hg. In water, the Nemerow pollution index (NP) values indicated that most of the sampling points seemly were seriously polluted; other water quality assessment results suggested no pollution. In sediment, the concentrations of 27% HMs exceeded the background values of soil in Qinghai; 48% exceeded the Earth crust background values, which were As, Hg, and Cd. The single factor index method (Pi), geological accumulation index (Igeo), and contamination factor (CF) revealed that As pollution is serious, followed by Hg and Cd; the pollution load index (PLI) and modified pollution index (mCd) values indicated that 64% and 57% of samples were polluted. NP values are shown serious pollution. The ecological risk results demonstrated a low risk in water and a medium risk in sediment. The average total hazard quotient values in sediment and water for adults and children revealed low non-carcinogenic risks. Carcinogenic risk indicated Ni in water and sediment, and As in sediment may be involved in cancer risk. Multivariate statistics showed that the HMs mainly came from nature, and human activities will also impact them. The upper continental crust values indicated that As and Hg have high background values. The saline dust storm was one of the essential sources of HMs, especially Hg. Various provenances constituted the material cycling of HMs in the surface environment

    The role of micro-cavitation on EHL: a study using a multiscale mass conserving approach

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    The role of micro-cavitation in Elastohydrodynamic Lubrication is numerically investigated using a multiscale approach whereby both the small scale topographical features and the micro-cavitation of the lubricant due to the features are resolved. Micro-cavitation and the fluid׳s shear-thinning property are modelled at the small scale of topological feature. The effects of topographical features on the film thickness of the line contact bearings and friction coefficient are presented with a focus on the role of micro-cavitation. This highlights how a mass conserving small scale model can be used to model both micro-cavitation and cavitation occurring at the bearing scale, and how topological features can be designed to reduce friction while maintaining bearing load

    Construction and progress of Chinese terrestrial ecosystem carbon, nitrogen and water fluxes coordinated observation

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    Transversalis fascia suture reinforcement may facilitate the performance of electrospun P(LLA-CL) nanoscale fibrinogen mesh in inguinal hernia repair: a prospective single-center cohort study

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    Abstract The aim of this study was to evaluate a new electrospun P(LLA-CL) nanoscale fibrinogen mesh performance in real-world clinical practice. A prospective, single-center evaluation of Lichtenstein inguinal hernia repair using electrospun P(LLA-CL) nanoscale fibrinogen mesh in elderly patients with comorbid diseases was conducted between 2020 and 2022. A suture reinforcement of transversalis fascia was applied before mesh implantation. Hernia recurrence, pain score and overall complication rate were measured. A total of 52 inguinal hernias in 48 patients were included. The age of patients ranged from 33 to 95 years, with a median of 78 years. Comorbid conditions included cardiopulmonary disease, organ dysfunction, anticoagulant use, diabetes and smoking. By optimizing the physical condition perioperatively, all patients finished treatment successfully. Four cases recurred secondary to direct hernias or combined hernias and were diagnosed in the first 24 case cohort during follow-up. With surgical procedural modification involving strengthening the posterior inguinal floor by reef-up suturing of the transversalis fascia and the inferior edge of mesh slit to accommodate the spermatic cord, no further recurrence was diagnosed. Postoperative pain was mild and the pain score decreased three months after surgery compared to 1 week after surgery (p = 0.0099). No severe complications occurred, while seroma occurred in six cases. Electrospun P(LLA-CL) nanoscale fibrinogen mesh is safe and effective in repairing inguinal hernias in elderly patients with comorbid disease. A strengthening of the transversalis fascia by suturing may enhance the performance of this mesh

    Multivisual Animation Character 3D Model Design Method Based on VR Technology

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    For VR systems, one of its core parts is to present people with a real and immersive 3D simulation environment. This paper uses real-time computer graphics technology, three-dimensional modeling technology, and binocular stereo vision technology to study the multivisual animation character objects in virtual reality technology; designs a binocular stereo vision animation system; designs and produces a three-dimensional model; and develops a virtual multivisual animation scene application. The main research content and work performed in the text include the research of the basic graphics rendering pipeline process and the analysis and research of each stage of the rendering pipeline. It mainly analyzes the 3D graphics algorithm used in the three-dimensional geometric transformation of computer graphics and studies the basic texture technology, basic lighting model, and other image output processes used in the fragment processing stage. Combined with the development needs of the subject, the principles of 3D animation rendering production software and 3D graphics modeling are studied, and the solid 3D model displayed in the virtual reality scene is designed and produced. This article also reflects the application of virtual reality in multivisual animation character design from the side, so it has realistic value and application prospects
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