160 research outputs found

    Study on the Antioxidant Activity Hetao Wheat Germ Polypeptides

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    In this experiment, the peptides were obtained by enzymatic digestion of wheat germ proteins from river sets using neutral protease, trypsin and pepsin. In vitro antioxidant capacity of samples was determined and their polypeptides distribution was determined using polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that germ protein and polypeptides concentrations were positively correlated with antioxidant capacity.The antioxidant capacity of the peptides obtained by enzymatic digestion of neutral protease at different concentrations was significantly higher than that obtained by enzymatic digestion of pepsin and trypsin (P<0.05), and their reducing capacity, 2,2-biazo-bis(3-ethyl-benzothiazole- 6-sulfonic acid) diammonium salt (ABTS+), 1,1-diphenyl-2-picrylhydrazyl (DPPH) clearance was up to (1.17±0.004) 1.0 mg/mL, (84.82%±0.87%) 1.5 mg/mL and (55.01%±0.01%) 1.0 mg/mL, respectivety, and their ABTS+ and DPPH radical scavenging rates were significantly higher than those of germ proteins (p<0.05). In addition, for the hydrolysis capacity of different proteases differs, pepsin had the greatest hydrolysis capacity while neutral protease had the least. The antioxidant capacity of germ protein polypeptides correlated with their molecular weight, but it is not necessarily the case that the smaller the molecular weight of a protein peptide had the better antioxidant effect. The results of these experiments provide a theoretical basis for further research on the antioxidant polypeptides of wheat germ in the Hetao

    Electrosynthesis of Glycerol Carbonate from CO2 and Glycerol

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    在常温常压下,采用电化学方法,以丙三醇和CO2为原料合成了丙三醇碳酸酯,并详细考察了各种条件对该反应的影响规律. 择优条件下,目标碳酸酯的产率可达73%,远远高于普通的催化方法. 并借助循环伏安曲线研究了反应体系的电化学行为,分析了整个反应的可能历程.Glycerol carbonate was obtained from glycerol and carbon dioxide under room temperature and normal pressure by electrochemical method. The effects of synthesis conditions, such as cathode, charge, current density and temperature, on the reaction of glycerol and carbon dioxide have been investigated. The yields of 73% were produced by electrosynthesis of carbonate under the optimized condition, which is much higher than that by common catalysis method. The electrochemical behavior of the reaction system has been studied by cyclic voltammetry, through which the reaction process has been proposed.国家自然科学基金项目(No. 211730885,No. 21203066)资助作者联系地址:上海市绿色化学与化工过程绿色化重点实验室,华东师范大学化学系,上海 200062Author's Address: Shanghai Key Laboratory of Green Chemistry and Chemical Process, Department of Chemistry, East China Normal University, Shanghai 200062, China通讯作者E-mail:[email protected]

    Cadmium-Induced Oxidative Stress and Apoptotic Changes in the Testis of Freshwater Crab, Sinopotamon henanense

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    Cadmium (Cd), one of the most toxic environmental and industrial pollutants, is known to exert gonadotoxic and spermiotoxic effects. In the present study, we examined the toxic effect of Cd on the testis of freshwater crab, Sinopotamon henanense. Crabs were exposed to different Cd concentrations (from 0 to 116.00 mg·L−1) for 7 d. Oxidative stress and apoptotic changes in the testes were detected. The activities of SOD, GPx and CAT initially increased and subsequently decreased with increasing Cd concentrations, which was accompanied with the increase in malondialdehyde (MDA) and H2O2 content in a concentration-dependent manner. Typical morphological characteristic and physiological changes of apoptosis were observed using a variety of methods (HE staining, AO/EB double fluorescent staining, Transmission Electron Microscope observation and DNA fragmentation analysis), and the activities of caspase-3 and caspase-9 were increased in a concentration-dependent manner after Cd exposure. These results led to the conclusion that Cd could induced oxidative damage as well as apoptosis in the testis, and the apoptotic processes may be mediated via mitochondria-dependent apoptosis pathway by regulating the activities of caspase-3 and caspase-9

    TRPM2 Channel in Microglia as a New Player in Neuroinflammation Associated With a Spectrum of Central Nervous System Pathologies

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    Microglial cells in the central nervous system (CNS) are crucial in maintaining a healthy environment for neurons to function properly. However, aberrant microglial cell activation can lead to excessive generation of neurotoxic proinflammatory mediators and neuroinflammation, which represents a contributing factor in a wide spectrum of CNS pathologies, including ischemic stroke, traumatic brain damage, Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, psychiatric disorders, autism spectrum disorders, and chronic neuropathic pain. Oxidative stress is a salient and common feature of these conditions and has been strongly implicated in microglial cell activation and neuroinflammation. The transient receptor potential melastatin-related 2 (TRPM2) channel, an oxidative stress-sensitive calcium-permeable cationic channel, is highly expressed in microglial cells. In this review, we examine the recent studies that provide evidence to support an important role for the TRPM2 channel, particularly TRPM2-mediated Ca2+ signaling, in mediating microglial cell activation, generation of proinflammatory mediators and neuroinflammation, which are of relevance to CNS pathologies. These findings lead to a growing interest in the TRPM2 channel, a new player in neuroinflammation, as a novel therapeutic target for CNS diseases

    Potential of Core-Collapse Supernova Neutrino Detection at JUNO

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    JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

    Detection of the Diffuse Supernova Neutrino Background with JUNO

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    As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO
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