Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
177
result(s) for
"Gao, Xiao-Yun"
Sort by:
Gartanin Protects Neurons against Glutamate-Induced Cell Death in HT22 Cells: Independence of Nrf-2 but Involvement of HO-1 and AMPK
Oxidative stress mediates the pathogenesis of neurodegenerative disorders. Gartanin, a natural xanthone of mangosteen, possesses multipharmacological activities. Herein, the neuroprotection capacity of gartanin against glutamate-induced damage in HT22 cells and its possible mechanism(s) were investigated for the first time. Glutamate resulted in cell death in a dose-dependent manner and supplementation of 1–10 µM gartanin prevented the detrimental effects of glutamate on cell survival. Additional investigations on the underlying mechanisms suggested that gartanin could effectively reduce glutamate-induced intracellular ROS generation and mitochondrial depolarization. We further found that gartanin induced HO-1 expression independent of nuclear factor erythroid-derived 2-like 2 (Nrf2). Subsequent studies revealed that the inhibitory effects of gartanin on glutamate-induced apoptosis were partially blocked by small interfering RNA-mediated knockdown of HO-1. Finally, the protein expression of phosphorylation of AMP-activated protein kinase (AMPK) and its downstream signal molecules, Sirtuin activator (SIRT1) and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), increased after gartanin treatment. Taken together, these findings suggest gartanin is a potential neuroprotective agent against glutamate-induced oxidative injury partially through increasing Nrf-2-independed HO-1 and AMPK/SIRT1/PGC-1α signaling pathways.
Journal Article
Structural Strength and Reliability Analysis of Important Parts of Marine Diesel Engine Turbocharger
Supercharging is the main method to improve the output power of marine diesel engines. Nowadays, most marine diesel engines use turbocharging technology, which increases the air pressure and density into the cylinder and the amount of fuel injected correspondingly so as to achieve the purpose of improving the power. In a marine diesel engine, the turbocharger has become an indispensable part. The performance of turbochargers in a harsh working environment of high temperature and high pressure for a long time will directly affect the performance of diesel engine. Based on the market feedback data from manufacturers, the failure modes of compressor impeller, turbine blade, and turbine disk of marine diesel turbocharger are analyzed, and the statistical model of random factors is established. Using DOE design, the structural strength simulation data of 46 compressors and 62 turbines are obtained, and the response surface model is constructed. On this basis, Monte Carlo sampling is carried out to analyze the reliability of the compressor and turbine. The reliability of the compressor is good, while that of the turbine disk is 0.943 and that of the turbine blade is 0.96, which still has the potential of reliability optimization space. Therefore, a multiobjective optimization method based on the NSGA-II genetic algorithm is proposed to obtain the multiobjective optimization scheme data with the reliability and processing cost of turbine disk and blade as the objective function. After optimization, the reliability of turbine disk and blade is 1, the stress value of turbine blade is optimized by 4.7941%, the stress value of turbine disk is optimized by 3.0136%, the machining cost of the turbine blade is reduced by 15.5087%, and the machining cost of turbine disk is reduced by 3.9907%. At the same time, it is verified by simulation, the data based on NSGA-II multiobjective genetic algorithm are more accurate and have practical engineering reference value. The optimized data based on NSGA-II multiobjective genetic algorithm are used to manufacture new turbine samples, and the accelerated test of simulation samples is carried out. The cycle life of the optimized turbine can reach 101,697 cycles and 118,687 cycles, which is 51.75% and 77.11% longer than that of the unoptimized turbine. It can be seen that the optimized turbine can meet the requirements of the reliability index while reducing the manufacturing cost.
Journal Article
Genomic sequence analysis of a new reassortant infectious bursal disease virus from commercial broiler flocks in central China
We report the complete nucleotide sequence of a reassortant infectious bursal disease (IBD) virus (IBDV) HN isolate from commercial broiler flocks in central China. The genome consisted of 3,232 and 2,652 nucleotides in the coding regions of segments A and B, respectively. Alignment of both nucleotide and deduced amino acid sequences and phylogenetic analysis revealed that the genome segments A and B of HN were derived from the attenuated strain B87 and the VV strain OKYM. This is a new reassortant IBDV strain that has emerged in nature, involving segment A of a cell-culture-adapted attenuated vaccine strain B87.
Journal Article
The Study of the Architectural Beam Construction Cracks’ Condition on the Features of the Force-Electricity Functional Conversion Composite Materials
The technology monitoring the operating state of the architecture construction is always hot topics in civil engineering. In this paper, attempts using the NiTiSMA film/ferroelectric ceramics PZT composite materials with the function of force - electricity conversion are introduced to the design of structural safety monitoring system. The sensing materials based on the function of force - electricity conversion, directly perceive the stress changes of architectural structure under the vibration loads, monitoring the state changes of internal cracks in the architectural structure. The results show that the safety monitoring system of architectural beam structure,on the sense of NiTiSMA film / ferroelectric ceramics PZT composite materials, possesses reaction speed in milliseconds, response frequency at 0-1000 Hz. It is suitable for monitoring the damage status of cracks in the architecture construction.
Journal Article
Reliability analysis and optimization of turbocharger turbine of marine low speed diesel engine under complex load
In this paper, aiming at the reliability analysis and optimization of jth series marine low-speed diesel engine supercharger of Chongqing JIANGZENG Shipbuilding Heavy Industry Co., Ltd., a response surface mathematical model is constructed by using 62 groups of dispersive simulation analysis data to verify the accuracy and effectiveness of the mathematical model. Based on this, Monte Carlo sampling is carried out to obtain the reliability of turbine disk is 0.943, and the reliability of turbine blade is 0.96 Reliability optimization space. Based on NSGA-II multi-objective genetic algorithm, the reliability of turbine disk and turbine blade is optimized by taking the stress value and machining cost of turbine disk and turbine blade as the objective function. The reliability of turbine disk and turbine blade is 1, the stress value of turbine blade is optimized by 4.7941%, the stress value of turbine disk is optimized by 3.0136%, the machining cost of turbine blade is optimized by 15.5087%, and the machining cost of turbine disk is optimized by 3.9907%. Finally, the results of genetic algorithm and simulation analysis are compared, the difference is less than 5%, which shows that the data based on NSGA-II multi-objective genetic algorithm has practical application reference value.
Journal Article
Osthole, a Natural Coumarin Improves Cognitive Impairments and BBB Dysfunction After Transient Global Brain Ischemia in C57 BL/6J Mice: Involvement of Nrf2 Pathway
Oxidative stress and blood–brain barrier (BBB) disruption play important roles in cerebral ischemic pathogenesis and may represent targets for treatment. Earlier studies have shown that osthole, a main active constituent isolated from
Cnidium monnieri
(L.) Cusson, could be considered as an attractive therapeutic agent in the treatment of ischemic stroke. However, the mechanism underlying the protective effect remains vague. In this study we aimed to investigate the effect of osthole on transient cerebral ischemia as well as its mechanism(s) in C57 BL/6 J mice. Mice were subjected to transient global cerebral ischemia induced by bilateral common carotid artery occlusion for 25 min. Behavioral test was performed at 4 days after ischemia, followed by assessment of neuronal loss in hippocampal CA1 region. Osthole significantly improved the cognitive ability and enhanced the survival of pyramidal neurons in the CA1 region of mice after lesion. Further studies showed that osthole attenuated the permeation of BBB, which may contribute to antioxidative effect by increasing the superoxide dismutase activity and decreasing the malondialdehyde level in model mice. Further studies revealed that osthole obviously up-regulated the protein levels of nuclear factor erythroid 2-related factor 2/heme oxygenase 1 in HT22 cells. In conclusion, our findings indicated that osthole exerts neuroprotective effects against global cerebral ischemia injury by reducing oxidative stress injury and reserving the disruption of BBB, which may be attributed to elevating the protein levels of Nrf2 and HO-1.
Journal Article
Demand analysis of the Pacific Coast pear industry
Demand for Pacific Coast pears is analyzed by means of a simultaneous equation model which separately identifies Bartlett and winter pears in fresh and processed uses. The model is applied to annual data for the 1960–1989 period and is used to determine optimal allocations for historical periods and to forecast price effects under alternative future scenarios. Demand shifts have been favorable for fresh winter pears, but unfavorable for processed winter pears and for both fresh and processed Bartlett pears. Expected increases in production may threaten the profitability of the industry without prompt remedial action.© 1992 John Wiley & Sons, Inc.
Journal Article
Effects of the dust size distribution in one-dimensional quantum dusty plasma
The effects of the dust size distribution in ultracold quantum dusty plasmas are investigated. The amplitude φm and width ω of quantum dust acoustic waves are studied with different dust size distributions in the system. The φm and ω of the quantum dust acoustic waves are found to increase as the total number density increases. The φm and ω are greater for unusual dusty plasmas than for typical dusty plasmas. Moreover, as the Fermi temperature of the dust grains increases, the φm of the wave decreases. The ω of quantum dust acoustic waves increases as the speed u0 of the wave increases
Journal Article
Genome-scale detection of hypermethylated CpG islands in circulating cell-free DNA of hepatocellular carcinoma patients
Despite advances in DNA methylome analyses of cells and tissues, current techniques for genome-scale profiling of DNA methylation in circulating cell-free DNA （ccfDNA） remain limited. Here we describe a methylated CpG tan- dems amplification and sequencing （MCTA-Seq） method that can detect thousands of hypermethylated CpG islands simultaneously in ccfDNA. This highly sensitive technique can work with genomic DNA as little as 7.5 pg, which is equivalent to 2.5 copies of the haploid genome. We have analyzed a cohort of tissue and plasma samples （n = 151） of hepatocellular carcinoma （HCC） patients and control subjects, identifying dozens of high-performance markers in blood for detecting smaU HCC （≤ 3 cm）. Among these markers, 4 （RGS10, ST8SIA6, RUNX2 and VIM） are mostly specific for cancer detection, while the other 15, classified as a novel set, are already hypermethylated in the normal liver tissues. Two corresponding classifiers have been established, combination of which achieves a sensitivity of 94% with a specificity of 89% for the plasma samples from HCC patients （n = 36） and control subjects including cirrho- sis patients （n = 17） and normal individuals （n = 38）. Notably, all 15 alpha-fetoprotein-negative HCC patients were successfully identified. Comparison between matched plasma and tissue samples indicates that both the cancer and noncancerous tissues contribute to elevation of the methylation markers in plasma. MCTA-Seq will facilitate the development of ccfDNA methylation biomarkers and contribute to the improvement of cancer detection in a clinical setting.
Journal Article