检索结果-南通市图书馆

Stress injuries and autophagy in mouse hippocampus after chronic cold exposure

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2017年第3期12卷 440-446页

作者： Ting-ting qu Jie-xin Deng Rui-ling Li Zhan-jun Cui xiao-qing Wang Lai Wang Jin-bo Deng Institute of Neurobiology College of Life ScienceHenan University Nursing College Henan Vocational College of Applied Technology

Cold exposure is an external stress factor that causes skin frostbite as well as a variety of *** might participate in neuroprotection after cold exposure,but its precise mechanism remains *** this study,mice were exposed to 10°C for 7 days and 0–4°C for 30 days to induce a model of chronic cold *** showed that oxidative stress-related c-fos and cyclooxygenase 2 expressions,MAP1LC3-labeled autophagic cells,Iba1-labeled activated microglia,and interleukin-1β-positive pyramidal cells were increased in the hippocampal CA1 *** cold exposure markedly elevated the levels of estrogen in the blood and the estrogen receptor,G protein-coupled receptor *** results indicate that neuroimmunoreactivity is involved in chronic cold exposure-induced pathological alterations,including oxidative stress,neuronal autophagy,and ***,estrogen exerts a neuroprotective effect on cold exposure.

关键词： nerve regeneration chronic cold exposure oxidative stress autophagy microglial cells neuroimmunoreactivity hippocampal CA1 area estrogen neural regeneration

Isolation and Characterization of Two Novel Gene Encoded Alkaline Esterases from an Alkaline Soil Metagenomic Library

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2010年第4期26卷 583-590页

作者： LU Yang LIU Xiang-guo YU Ying qu He-zhi YANG Shuo NING bo WANG xiao-ping HAO Dong-yun Key Laboratory for Molecular Enzymology and Engineering Ministry of Education Jilin University Changchun 130021 P. R. China College of Life Science Jilin University Changchun 130012 P. R. China Biotechnology Research Centre Jilin Academy of Agricultural Sciences Changchun 130033 P. R. China

The development of industrial biotechnology has created an increasing demand for alkaline lipolytic enzymes with functional diversity. In this study, an alkaline soil metagenomic library was constructed to search for new lipolytic enzymes. Two novel gene encoded alkaline esterases（designated as estA and estB） were isolated by functional screening from the library. The estA gene consisted of 834 bp and coded for 277 amino acids with a molecular mass of 29998. Amino acid sequence homology analysis indicates that EstA belongs to α/β hydrolase fold family 4.4（abH4.4）, with EstA being the smallest member of that family yet reported. The estB gene consisted of 1185 bp and encoded 394 amino acids with a theoretical molecular mass of 40090. Its conserved domain analysis shows that EstB belongs to the GDSL hydrolase superfamily. both EstA and EstB exhibit only moderate identity（〈38%） in amino acid sequence to the known lipolytic enzyme genes in the database. The two genes were respectively expressed in Escherichia coli and the protein products were purified for functional characterization. While the expressed EstA did not exhibit the functional properties that were superior to those of other esterases previously reported, the EstB was stable at temperature up to 45 ℃ and its maximum activity was measured to be 53.6 U/mg at pH=10. both the en- zymes have further enriched the diversity of the lipolytic enzymes database and also appear to be promising biocatalysts for potential biotechnological application.

关键词： Alkaline esterase Enzymatic characterization Metagenome

Development of pot-cover effect apparatus with freezing-thawing cycles

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2019年第9期62卷 1636-1648页

作者： LUO Ting CHEN Han YAO YangPing WANG NaiDong qu xiao School of Transportation Science and Engineering Beihang University

‘Pot-cover effect’ refers to the phenomenon of moisture accumulation beneath the pavement under condensation or desublimation because the vapor transfer in the soil is blocked by the pavement. To study this phenomenon in the laboratory, we have developed the pot-cover effect apparatus with freezing-thawing cycles(PEAFC), which consists of three parts, namely, the vapor transfer system, the temperature control system, and the temperature and water content monitoring system. The major functions of this apparatus include: simulation of both vapor transfer and freezing-thawing cycling in the soil, real-time monitoring of the temperature and the water content in soil samples, and one-dimensional heat and moisture transfer in the samples. The FDR(frequency domain reflectometry) sensors of the apparatus are calibrated and a calibration formula is proposed to eliminate the water content measurement errors induced by temperature changes. Constant temperature difference tests and a freezing-thawing cycling test are conducted with the apparatus. Results indicate that the apparatus can control the water replenishment in the soil samples, monitor the vapor transfer in the samples in real time, and simulate the vapor transfer process under the condition of the freezing-thawing cycling in the soil. These tests verify the effectiveness and reliability of the apparatus, which indicates that the development purpose is achieved.

关键词： pot-cover effect apparatus vapor transfer freezing-thawing cycle water content

A driving pulse edge modulation technique and its complex programming logic devices implementation

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2015年第12期16卷 1088-1098页

作者： xiao CHEN Dong-chang qu Yong GUO Guo-zhu CHEN Electrical Engineering Department Zhejiang University School of Automation and Electrical Engineering Zhejiang University of Science and Technology

With the continual increase in switching speed and rating of power semiconductors, the switching voltage spike becomes a serious problem. This paper describes a new technique of driving pulse edge modulation for insulated gate bipolar transistors(IGBTs). By modulating the density and width of the pulse trains, without regulating the hardware circuit, the slope of the gate driving voltage is controlled to change the switching speed. This technique is used in the driving circuit based on complex programmable logic devices(CPLDs), and the switching voltage spike of IGBTs can be restrained through software, which is easier and more flexible to adjust. Experimental results demonstrate the effectiveness and practicability of the proposed method.

关键词： Driving pulse edge modulation Switching voltage spike Complex programmable logic device(CPLD) Active gate drive

Enhanced photoelectrocatalytic degradation of ammonia by in situ photoelectrogenerated active chlorine on TiO_2 nanotube electrodes

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2016年第12期28卷 103-108页

作者： Shuhu xiao Dongjin Wan Kun Zhang Hongbin qu Jianfeng Peng State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences School of Chemistry and Chemical Engineering Henan University of Technology

TiO2 nanotube （TINT） electrodes anodized in fluorinated organic solutions were successfully prepared on Ti sheets. Field-emission scanning electron microscopy （FE-SEM） and X-ray diffraction （XRD） were performed to characterize the TiNT electrodes. The linear voltammetry results under irradiation showed that the TiNT electrode annealed at 450℃ presented the highest photoelectrochemical activity. By combining photocatalytic with electrochemical process, a significantly synergetic effect on ammonia degradation was observed with Na2SO4 as supporting electrolyte at pH 10.7. Furthermore, the photoelectrocatalytic efficiency on the ammonia degradation was greatly enhanced in presence of chloride ions without the limitation ofpH. The degradation rate was improved by 14.8 times reaching 4.98 × 10^-2 min^-1 at pH 10.7 and a faster degradation rate of 6.34 × 10^-2 min^-1 was obtained at pH 3.01. The in situ photoelectrocatalytic generated active chlorine was proposed to be responsible for the improved efficiency. On the other hand, an enhanced degradation of ammonia using TiNT electrode fabricated in fluorinated organic solution was also confirmed compared to TiNT electrode anodized in fluorinated water solution and TiO2 film electrode fabricated by sol-gel method. Finally, the effect of chloride concentration was also discussed.

关键词： TiO2 nanotube electrodes Ammonia Photoelectrocatalytic process Enhanced degradation

Measurement and characterization of bulk nanobubbles by nanoparticle tracking analysis method

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2022年第6期34卷 1121-1133页

作者： xiao-tong Ma Ming-bo Li Chao Sun Center for Combustion Energy Key Laboratory for Thermal Science and Power Engineering of Ministry of EducationDepartment of Energy and Power EngineeringTsinghua UniversityBeijing100084China

The size of the bulk nanobubbles(typically 100 nm-200 nm in diameter)is below the optical resolution of the typical microscopes,which makes it difficult to make a direct observation of them and differentiate between the nanoparticles and the *** this work,a nanoparticle tracking analysis(NTA)system is developed for tracking and sizing the bulk nanobubbles,and more broadly,the Brownian diffusing *** demonstrate the capabilities of the NTA in characterizing the nanoparticles through systematic validation of accuracy and *** particularly exhibit its unique advantages in detecting the polydisperse nanoparticle *** the nucleation and the thermodynamic stability of the bulk nanobubbles are systematically studied by the NTA *** bulk nanobubbles smaller than 600 nm in size are generated via the ultrasonication *** is shown that both the ultrasonic cavitation treatment time and amplitude,essentially,the energy input,favor the nucleation of the bulk nanobubbles with a more concentrated size distribution,a higher concentration,and a smaller hydrodynamic *** temperature dependence of the bulk nanobubbles over a wide range from 25°C to 70°C is *** is found that the nanobubble first shrinks in size significantly and then the size keeps approximately constant with the increasing temperature,showing a narrow size *** transition temperature is around 45°***,as an open system,the NTA is a potential tool in the study of the dynamic behavior of the bulk nanobubbles in situ,such as the coalescence and the collapse.

关键词： Nanoparticle tracking analysis bulk nanobubble light scattering hydrodynamic size number concentration

Elevated levels of interleukin-1β, interleukin-6, tumor necrosis factor-α and vascular endothelial growth factor in patients with knee articular cartilage injury

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2019年第11期7卷 1262-1269页

作者： Zhen-Wei Wang Le Chen xiao-Rui Hao Zhen-An qu Shi-bo Huang xiao-Jun Ma Jian-Chuan Wang Wei-Ming Wang Department of Sports Medicine Affiliated Zhongshan Hospital of Dalian University

BACKGROUND Inflammatory cytokines play a vital role in the occurrence of osteoarticular injury and inflammation. Whether inflammation-associated factors interleukin-1β(IL- 1β), IL-6, tumor necrosis factor-α(TNF-α) and vascular endothelial growth factor (VEGF) are involved in the pathogenesis of keen articular cartilage injury remains poorly understood. AIM To measure the levels of inflammatory factors [IL-1β, IL-6, TNF-α and VEGF] in patients with knee articular cartilage injury. METHODS Fifty-five patients with knee articular cartilage injury were selected as patient groups, who were divided into three grades [mild (n = 20), moderate (n = 19) and severe (n = 16)] according to disease severity and X-ray examinations. Meanwhile, 30 healthy individuals who underwent physical examination were selected as the control group. The levels of IL-1β, IL-6, TNF-α and VEGF were measured by ELISA and immunohistochemical staining. RESULTS Compared with the control group, patient groups displayed significantly higher levels of IL-1β, IL-6, TNF-α and VEGF, and the extent of increase was directly proportional to the severity of injury (P < 0.05). In addition, the number of cells with positive staining of IL-1β, IL-6, TNF-α and VEGF in the synovial membrane were significantly increased, along with increased disease severity (P < 0.05). After treatment, the scores of visual analogue scale and the Western Ontario and McMaster University of Orthopaedic Index in patient groups were 2.26 ± 1.13 and 15.56 ± 7.12 points, respectively, which were significantly lower than those before treatment (6.98 ± 1.32 and 49.48 ± 8.96). Correlation analysis suggested that IL-1β and TNF-α were positively correlated with VEGF. CONCLUSION IL-1β, IL-6, TNF-α and VEGF levels are increased in patients with knee articular cartilage injury, and are associated with the disease severity, indicating they might play an important role in the occurrence and development of knee articular cartilage injury. Furthermore,

关键词： Knee articular cartilage injury Interleukin-1β Interleukin-6 Tumor necrosis factor-α Vascular endothelial growth factor

Room-Temperature Phosphorescent Organic-Doped Inorganic Frameworks Showing Wide-Range and Multicolor LongPersistent Luminescence

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research 2021年第1期2021卷 1413-1423页

作者： Guowei xiao bo Zhou xiaoyu Fang Dongpeng Yan Beijing Key Laboratory of Energy Conversion and Storage Materials College of Chemistry Beijing Normal UniversityBeijing 100875China College of Chemistry Key Laboratory of RadiopharmaceuticalsMinistry of EducationBeijing Normal UniversityBeijing 100875China College of Chemistry and Molecular Engineering Zhengzhou UniversityZhengzhou 450001China

Long-persistent luminescence based on purely inorganic and/or organic compounds has recently attracted much attention in a wide variety of fields including illumination,biological imaging,and information ***,simultaneously tuning the static and dynamic afterglow performance still presents a *** this work,we put forward a new route of organic-doped inorganic framework to achieve wide-range and multicolor ultralong room-temperature phosphorescence(RTP).Through a facile hydrothermal method,phosphor(tetrafluoroterephthalic acid(TFTPA))into the CdCO_(3)(or Zn_(_(2))(OH)_(2)CO_(3))host matrix exhibits an excitation-dependent colorful RTP due to the formation of diverse molecular aggregations with multicentral *** RTP lifetime of the doped organic/inorganic hybrids is greatly enhanced(313 times)compared to the pristine *** high RTP quantum yield(43.9%)and good stability guarantee their easy visualization in both ambient and extreme conditions(such as acidic/basic solutions and an oxygen environment).Further codoped inorganic ions(Mn_(2)+and Pb_(2)+)afford the hybrid materials with a novel time-resolved tunable afterglow emission,and the excitation-dependent RTP color is highly adjustable from dark blue to red,covering nearly the whole visible spectrum and outperforming the current stateof-the-art RTP ***,this work not only describes a combined codoping and multicentral strategy to obtain statically and dynamically tunable long-persistent luminescence but also provides great opportunity for the use of organicinorganic hybrid materials in multilevel anticounterfeiting and multicolor display applications.

关键词： inorganic excitation luminescence

An Adaptive Padding Correlation Filter With Group Feature Fusion for Robust Visual Tracking

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2022年第10期9卷 1845-1860页

作者： Zihang Feng Liping Yan Yuanqing Xia bo xiao Key Laboratory of Intelligent Control and Decision of Complex Systems the School of AutomationBeijing Institute of TechnologyBeijing 100081China IEEE the School of Artificial Intelligence Beijing University of Posts and TelecommunicationsBeijing 100876China

In recent visual tracking research,correlation filter(CF)based trackers become popular because of their high speed and considerable *** methods mainly work on the extension of features and the solution of the boundary effect to learn a better correlation ***,the related studies are *** exploring the potential of trackers in these two aspects,a novel adaptive padding correlation filter(APCF)with feature group fusion is proposed for robust visual tracking in this paper based on the popular context-aware tracking *** the tracker,three feature groups are fused by use of the weighted sum of the normalized response maps,to alleviate the risk of drift caused by the extreme change of single ***,to improve the adaptive ability of padding for the filter training of different object shapes,the best padding is selected from the preset pool according to tracking precision over the whole video,where tracking precision is predicted according to the prediction model trained by use of the sequence features of the first several *** sequence features include three traditional features and eight newly constructed *** experiments demonstrate that the proposed tracker is superior to most state-of-the-art correlation filter based trackers and has a stable improvement compared to the basic trackers.

关键词： Adaptive padding context information correlation filter(CF) feature group fusion robust visual tracking