检索结果-南通市图书馆

A Novel 5-level Flying Capacitor Bridgeless PFC Converter Based on Cost-effective Low-voltage eGaN FETs

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electrical Engineering 2020年第3期6卷 56-64页

作者： Yuanyuan Xu Jun Wang Kun XIONG Geng Yin College of Electrical and Information Engineering Hunan UniversityChangsha 410082China

In this study,a type of multilevel flying capacitor bridgeless PFC converter is proposed that permits the use of economical and efficient 100 V GaN transistors.Compared with the popular two-level totem-pole bridgeless PFC converters achieved using the much more expensive 650 V GaN devices,this new design has several distinct advantages:lower component costs,lower dv/dt,lower power losses,and reduced concerns about device reliability.A 1.6 kW,5-level PFC converter prototype is designed and fabricated with an efficiency of 99.18%and a power factor of 0.99,which are experimentally demonstrated.The operation principle,design considerations,control strategy and experimental results are discussed.

关键词： Bridgeless PFC converters flying capacitor GaN multilevel topology

Expression signatures of long non-coding RNA and mRNA in human traumatic brain injury

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2019年第4期14卷 632-641页

作者： Li-Xiang Yang Li-kun Yang Jie Zhu Jun-Hui Chen Yu-Hai Wang Kun XIONG Department of Neurosurgery 101st Hospital of People's Liberation Army Department of Anatomy and Neurobiology School of Basic Medical Sciences Central South University

Long non-coding RNAs(lncRNAs) play a key role in craniocerebral disease, although their expression profiles in human traumatic brain injury are still unclear. In this regard, in this study, we examined brain injury tissue from three patients of the 101 st Hospital of the People's Liberation Army, China(specifically, a 36-year-old male, a 52-year-old female, and a 49-year-old female), who were diagnosed with traumatic brain injury and underwent brain contusion removal surgery. Tissue surrounding the brain contusion in the three patients was used as control tissue to observe expression characteristics of lncRNAs and mRNAs in human traumatic brain injury tissue. Volcano plot filtering identified 99 lncRNAs and 63 mRNAs differentially expressed in frontotemporal tissue of the two groups(P 1.2). Microarray analysis showed that 43 lncRNAs were up-regulated and 56 lncRNAs were down-regulated. Meanwhile, 59 mRNAs were up-regulated and 4 mRNAs were down-regulated. Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) analyses revealed 27 signaling pathways associated with target genes and, in particular, legionellosis and influenza A signaling pathways. Subsequently, a lncRNA-gene network was generated, which showed an absolute correlation coefficient value > 0.99 for 12 lncRNA-mRNA pairs. Finally, quantitative real-time polymerase chain reaction confirmed different expression of the five most up-regulated mRNAs within the two groups, which was consistent with the microarray results. In summary, our results show that expression profiles of mRNAs and lncRNAs are significantly different between human traumatic brain injury tissue and surrounding tissue, providing novel insight regarding lncRNAs' involvement in human traumatic brain injury. All participants provided informed consent. This research was registered in the Chinese Clinical Trial Registry(registration number: ChiCTR-TCC-13004002) and the protocol version number is 1.0.

关键词： nerve regeneration human traumatic brain injuries long noncoding RNA messenger RNA GO analysis real-time quantitative polymerase chain reaction biomarkers microarray analysis biological processes medical informatics neural regeneration

Copper Metabolism and Cuproptosis:Molecular Mechanisms and Therapeutic Perspectives in Neurodegenerative Diseases

在线全文

学校读者我要写书评

暂无评论

Current Medical Science 2024年第1期44卷 28-50页

作者： Xiao-xia BAN Hao WAN Xin-xing WAN Ya-ting TAN Xi-min HU Hong-xia BAN Xin-yu CHEN kun HUANG Qi ZHANG Kun XIONG Department of Human Anatomy and Neurobiology School of Basic Medical ScienceCentral South UniversityChangsha 430013China Department of Endocrinology Third Xiangya HospitalCentral South UniversityChangsha 430013China Department of Dermatology Xiangya HospitalCentral South UniversityChangsha 430013China Affiliated Hospital Inner Mongolia Medical UniversityHohhot 010050China Key Laboratory of Emergency and Trauma of Ministry of Education Hainan Medical UniversityHaikou 571199China Hunan Key Laboratory of Ophthalmology Changsha 430013China

Copper is an essential trace element,and plays a vital role in numerous physiological processes within the human body.During normal metabolism,the human body maintains copper homeostasis.Copper deficiency or excess can adversely affect cellular function.Therefore,copper homeostasis is stringently regulated.Recent studies suggest that copper can trigger a specific form of cell death,namely,cuproptosis,which is triggered by excessive levels of intracellular copper.Cuproptosis induces the aggregation of mitochondrial lipoylated proteins,and the loss of iron-sulfur cluster proteins.In neurodegenerative diseases,the pathogenesis and progression of neurological disorders are linked to copper homeostasis.This review summarizes the advances in copper homeostasis and cuproptosis in the nervous system and neurodegenerative diseases.This offers research perspectives that provide new insights into the targeted treatment of neurodegenerative diseases based on cuproptosis.

关键词： cuproptosis copper metabolism copper homeostasis neurodegeneration neurodegenerativedisease

Insight into Crosstalk Between Mitophagy and Apoptosis/Necroptosis:Mechanisms and Clinical Applications in Ischemic Stroke

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Medical Science 2022年第2期42卷 237-248页

作者： Yan-di YANG Zi-xin LI Xi-min HU Hao WAN Qi ZHANG Rui XIAO Kun XIONG Department of Anatomy and Neurobiology School of Basic Medical ScienceCentral South UniversityChangsha 410013China Clinical Medicine Eight-year Program 03 Class18 GradeXiangya School of MedicineCentral South UniversityChangsha 410013China Clinical Medicine Eight-Year Program 02 Class17 GradeXiangya School of MedicineCentral South UniversityChangsha 410013China Administrative Office the Third Xiangya HospitalCentral South UniversityChangsha 410013China Hunan Key Laboratory of Ophthalmology Changsha 410008China Key Laboratory of Emergency and Trauma Ministry of EducationCollege of Emergency and TraumaHainan Medical UniversityHaikou 571199China

Ischemic stroke is a serious cerebrovascular disease with high morbidity and mortality.As a result of ischemia-reperfusion,a cascade of pathophysiological responses is triggered by the imbalance in metabolic supply and demand,resulting in cell loss.These cellular injuries follow various molecular mechanisms solely or in combination with this disorder.Mitochondria play a driving role in the pathophysiological processes of ischemic stroke.Once ischemic stroke occurs,damaged cells would respond to such stress through mitophagy.Mitophagy is known as a conservatively selective autophagy,contributing to the removal of excessive protein aggregates and damaged intracellular components,as well as aging mitochondria.Moderate mitophagy may exert neuroprotection against stroke.Several pathways associated with the mitochondrial network collectively contribute to recovering the homeostasis of the neurovascular unit.However,excessive mitophagy would also promote ischemia-reperfusion injury.Therefore,mitophagy is a double-edged sword,which suggests that maximizing the benefits of mitophagy is one of the direction of future efforts.This review emphasized the role of mitophagy in ischemic stroke,and highlighted the crosstalk between mitophagy and apoptosis/necroptosis.

关键词： mitophagy ischemic stroke apoptosis necroptosis clinical application crosstalk

Multiple pretreatments can effectively improve the functionality of mesenchymal stem cells

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 Stem Cells 2024年第2期16卷 58-63页

作者： Xin-Xing Wan Xi-Min Hu Kun XIONG Department of Endocrinology Third Xiangya HospitalCentral South UniversityChangsha 410013Hunan ProvinceChina Department of Dermatology Xiangya HospitalCentral South UniversityChangsha 410008Hunan ProvinceChina Department of Anatomy and Neurobiology School of Basic Medical ScienceCentral South UniversityChangsha 410013Hunan ProvinceChina

In this editorial,we offer our perspective on the groundbreaking study entitled“Hypoxia and inflammatory factor preconditioning enhances the immunosup-pressive properties of human umbilical cord mesenchymal stem cells”,recently published in World Journal of Stem Cells.Despite over three decades of research on the clinical application of mesenchymal stem cells(MSCs),only a few therapeutic products have made it to clinical use,due to multiple preclinical and clinical challenges yet to be addressed.The study proved the hypoxia and inflammatory factor preconditioning led to higher immunosuppressive effects of MSCs without damaging their biological characteristics,which revealed the combination of inflammatory factors and hypoxic preconditioning offers a promising approach to enhance the function of MSCs.As we delve deeper into the intricacies of pretreat-ment methodologies,we anticipate a transformative shift in the landscape of MSC-based therapies,ultimately contributing to improved patient outcomes and advancing the field as a whole.

关键词： Mesenchymal stem cells Inflammatory factor Hypoxia Pretreatment

The existence of traveling wave solutions in an integro-difference competition-cooperation system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Biomathematics 2018年第1期11卷 203-224页

作者： kun Li xiong Li School of Mathematics and Computational ScienceHunan First Normal University Changsha 510205 P. R. China School of Mathematical Sciences Beijing Normal University Laboratory of Mathematics and Complex Systems Ministry of Education Beijing 100875 P. R. China

In this paper, we are devoted to establishing the existence of traveling wave solutions in an integro-difference competition-cooperation system with partial monotonicity by using Schauder\'s fixed point theorem, the cross-iteration and the upper and lower solutions method. To illustrate our result, we present an application to integrodifference competition-cooperation system with a special kernel by constructing a pair of upper and lower solutions, while the verification of upper and lower solutions is nontrivial.

关键词：合作系统比赛波浪旅行 Schauder 应用程序

Detrimental impact of hyperlipidemia on the peripheral nervous system A novel target of medical epidemiological and fundamental research study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2012年第5期7卷 392-399页

作者： Song Wu Xu Cao Rongzhen He Kun XIONG Department of Orthopedics Third Xiangya Hospital of Central South University Changsha 410013 Hunan Province China Clinical Medicine Eight-year Program 01 Class 07 Grade Central South University Changsha 410013 Hunan Province China Department of Anatomy and Neurobiology Xiangya Medical School of Central South University Changsha 410013 Hunan Province China

Recently, epidemiological studies on the etiology of peripheral neuropathies have revealed that hyperlipidemia is a novel risk factor. Plasma lipid levels were confirmed to be associated with the incidence of many peripheral neuropathies including axonal distal polyneuropathy, vision and hearing loss, motor nerve system lesions and sympathetic nerve system dysfunction. Moreover, different lipid components such as cholesterol, triacylglycerols and lipoprotein are involved in the pathogenesis of these neuropathies. This review aimed to discuss the effect of hyperlipidemia on the peripheral nervous system and its association with peripheral neuropathies. Furthermore, a detailed discussion focusing on the explicit mechanisms related to hyperlipidemia-induced peripheral neuropathies is presented here. These mechanisms, including intracellular oxidative stress, inflammatory lesions, ischemia and dysregulation of local lipid metabolism, share pathways and interact mutually. In addition, we examined current information on clinical trials to prevent and treat peripheral neuropathies caused by hyperlipidemia, with a predictive discussion regarding the orientation of future investigations.

关键词： hyperlipidemia peripheral nervous system neuropathy reviews

Catalytic properties of Ru nanoparticles embedded on ordered mesoporous carbon with different pore size in Fischer-Tropsch synthesis

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2013年第4期22卷 560-566页

作者： Kun XIONG Yuhua Zhang Jinlin Li Kongyong Liew Key Laboratory of Catalysis and Materials Science of the State Ethnic Af fairs Commission & Ministry of Education South-Central University for Nationalities College of Chemistry and Chemical Engineering Chongqing University College of Chemistry Chemical Engineering and Materials ScienceSoochow University Faculty of Industrial Science and Technology Universiti Malaysia Pahang

A series of 3 wt% Ru embedded on ordered mesoporous carbon （OMC） catalysts with different pore sizes were prepared by autoreduction between ruthenium precursors and carbon sources at 1123 K. Ru nanoparticles were embedded on the carbon walls of OMC. Characterization technologies including power X-ray diffraction （XRD）, nitrogen adsorption-desorption, transmission electron microscopy （TEM）, and hydrogen temperature-programmed reduction （H2-TPR） were used to scrutinize the catalysts. The catalyst activity for Fischer-Tropsch synthesis （FTS） was measured in a fixed bed reactor. It was revealed that 3 wt% Ru-OMC catalysts exhibited highly ordered mesoporous structure and large surface area. Compared with the catalysts with smaller pores, the catalysts with larger pores were inclined to form larger Ru particles. These 3 wt% Ru-OMC catalysts with different pore sizes were more stable than 3 wt% Ru/AC catalyst during the FTS reactions because Ru particles were embedded on the carbon walls, suppressing particles aggregation, movement and oxidation. The catalytic activity and C5＋ selectivity were found to increase with the increasing pore size, however, CH4 selectivity showed the opposite trend. These changes may be explained in terms of the special environment of the active Ru sites and the diffusion of products in the pores of the catalysts, suggesting that the activity and hydrocarbon selectivity are more dependent on the pore size of OMC than on the Ru particle size.

关键词： Fischer-Tropsch synthesis ordered mesoporous carbon Ru nanoparticle size pore size embedded

Seismic failure modes and seismic safety of Hardfill dam

在线全文

学校读者我要写书评

暂无评论

Water Science and Engineering 2013年第2期6卷 199-214页

作者： Kun XIONG Yong-hong WENG Yun-long H Changjiang Institute of Survey Planning Design and Research National Dam Safety Research Center State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University

Based on microscopic damage theory and the finite element method, and using the Weibull distribution to characterize the random distribution of the mechanical properties of materials, the seismic response of a typical Hardfill dam was analyzed through numerical simulation during the earthquakes with intensities of 8 degrees and even greater. The seismic failure modes and failure mechanism of the dam were explored as well. Numerical results show that the Hardfill dam remains at a low stress level and undamaged or slightly damaged during an earthquake with an intensity of 8 degrees. During overload earthquakes, tensile cracks occur at the dam surfaces and extend to inside the dam body, and the upstream dam body experiences more serious damage than the downstream dam body. Therefore, under the seismic conditions, the failure pattern of the Hardfill dam is the tensile fracture of the upstream regions and the dam toe. Compared with traditional gravity dams, Hardfill dams have better seismic performance and ~reater seismic safety.

关键词： Hardfill dam, seismic failure mode, seismic safety microscopic damage model