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Alanyl-glutamine dipeptide inhibits hepatic ischemiareperfusion injury in rats

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World Journal of Gastroenterology 2006年第9期12卷 1373-1378页

作者： Chang-Jun Jia Chao-Liu Dai xu Zhang Kai Cui Feng xu yong-qing xu Department of Hepatobiliary Surgery Shengjing Hospital China Medical University Shenyang 110004 Liaoning Province China Department of General Surgery Fengtian Hospital Shenyang Medical University Shenyang 110024 Liaoning Province China

AIM： To investigate the protective effect and mechanism of alanyl-glutamine dipeptide （Ala-GIn） against hepatic ischemia-reperfusion injury in rats. METHODS： Rats were divided into group C as normal control Group （/7=16） and group G as alanyl-glutamine pretreatment 07=16）. Rats were intravenously infused with 0.9% saline solution in group C and Ala-GIn -enriched （2% glutamine） 0.9% saline solution in group G via central venous catheter for three days. Then all rats underwent hepatic warm ischemia for 30 min followed by different periods of reperfusion. Changes in biochemical parameters, the content of glutathione （GSH） and the activity of superoxide dismutase （SOD） in liver tissue, Bcl-2 and Bax protein expression and morphological changes of liver tissue were compared between both groups. RESULTS： One hour after reperfusion, the levels of liver enzymes in group G were significantly lower than those in group C （P〈0.05）. Twenty-four hours after reperfusion, the levels of liver enzymes in both groups were markedly recovered and the levels of liver enzyme in group G were also significantly lower than those in group C （P〈0.01）. One and 24 h after reperfusion, GSH content in group G was significantly higher than that in group C （P 〈0.05）. There was no statistical difference in activities of SOD between the two groups. One and 24 h after reperfusion, the positive expression rate of Bcl-2 protein was higher in group G than in group C （P〈0.05） and the positive expression rate of Bax protein was lower in group G than in group C （P〈0.05）. Histological and ultrastructural changes of liver tissue were inhibited in group C compared to group G. CONCLUSION： Our results suggest that Ala-GIn pretreatment provides the rat liver with significant tolerance to warm ischemia-reperfusion injury, which may be mediated partially by enhancing GSH content and regulating the expression of Bcl-2 and Bax proteins in the liver tissue.

关键词： Alanine Transaminase Animals Dipeptides Glutathione Immunohistochemistry L-Lactate Dehydrogenase Liver Male Microscopy, Electron Proto-Oncogene Proteins c-bcl-2 Rats Rats, Wistar Reperfusion Injury Superoxide Dismutase bcl-2-Associated X Protein

Dynamic SLAM Visual Odometry Based on Instance Segmentation:A Comprehensive Review

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Computers, Materials & Continua 2024年第1期78卷 167-196页

作者： Jiansheng Peng qing Yang Dunhua Chen Chengjun Yang yong xu yong Qin College of Automation Guangxi University of Science and TechnologyLiuzhou545000China Department of Artificial Intelligence and Manufacturing Hechi UniversityHechi547000China

Dynamic Simultaneous Localization and Mapping(SLAM)in visual scenes is currently a major research area in fields such as robot navigation and autonomous ***,in the face of complex real-world envi-ronments,current dynamic SLAM systems struggle to achieve precise localization and map *** the advancement of deep learning,there has been increasing interest in the development of deep learning-based dynamic SLAM visual odometry in recent years,and more researchers are turning to deep learning techniques to address the challenges of dynamic *** to dynamic SLAM systems based on deep learning methods such as object detection and semantic segmentation,dynamic SLAM systems based on instance segmentation can not only detect dynamic objects in the scene but also distinguish different instances of the same type of object,thereby reducing the impact of dynamic objects on the SLAM system’s *** article not only introduces traditional dynamic SLAM systems based on mathematical models but also provides a comprehensive analysis of existing instance segmentation algorithms and dynamic SLAM systems based on instance segmentation,comparing and summarizing their advantages and *** comparisons on datasets,it is found that instance segmentation-based methods have significant advantages in accuracy and robustness in dynamic ***,the real-time performance of instance segmentation algorithms hinders the widespread application of dynamic SLAM *** recent years,the rapid development of single-stage instance segmentationmethods has brought hope for the widespread application of dynamic SLAM systems based on instance ***,possible future research directions and improvementmeasures are discussed for reference by relevant professionals.

关键词： Dynamic SLAM instance segmentation visual odometry

Variable projection algorithms with sparse constraint for separable nonlinear models

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Control Theory and Technology 2024年第1期22卷 135-146页

作者： Hui-Lang xu Guang-yong Chen Si-qing Cheng Min Gan Jing Chen College of Computer and Data Science Fuzhou UniversityFuzhou350116FujianChina Fujian Key Laboratory of Network Computing and Intelligent Information Processing Fuzhou UniversityFuzhou350116FujianChina Key Laboratory of Intelligent Metro of Universities in Fujian Fuzhou UniversityFuzhou350116FujianChina Engineering Research Center of Big Data Intelligence Ministry of EducationFuzhou UniversityFuzhou350116FujianChina School of Science Jiangnan UniversityWuxi214122JiangsuChina

Separable nonlinear models are widely used in various fields such as time series analysis, system modeling, and machine learning, due to their flexible structures and ability to capture nonlinear behavior of data. However, identifying the parameters of these models is challenging, especially when sparse models with better interpretability are desired by practitioners. Previous theoretical and practical studies have shown that variable projection (VP) is an efficient method for identifying separable nonlinear models, but these are based on \(L_2\) penalty of model parameters, which cannot be directly extended to deal with sparse constraint. Based on the exploration of the structural characteristics of separable models, this paper proposes gradient-based and trust-region-based variable projection algorithms, which mainly solve two key problems: how to eliminate linear parameters under sparse constraint;and how to deal with the coupling relationship between linear and nonlinear parameters in the model. Finally, numerical experiments on synthetic data and real time series data are conducted to verify the effectiveness of the proposed algorithms.

关键词： Variable projection(VP) Non-smooth constraint Separable nonlinear models

The Essential 2-rank for Classical Groups

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2169-2186页

作者： Jian Bei AN yong xu Department of Mathematics University of AucklandAucklandNew Zealand School of Mathematics and Statistics He’nan University of Science and TechnologyLuoyang 471023P.R.China

Let G be a symplectic or orthogonal group defined over a finite field with odd characteristic and let D≤G be a Sylow *** this paper,we classify the essential 2-subgroups and determine the essential 2-rank of the Frobenius category FD(G).Together with the results of An–Dietrich and Cao–An–Zeng,this completes the work of essential subgroups and essential ranks of classical groups.

关键词： Frobenius category conjugation families essential 2-rank symplectic groups orthogonal groups

A robust indium-organic framework with open tubular channels for efficient separation of acetylene

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Nano Research 2024年第4期17卷 3139-3146页

作者： yong-Zhi Li Gang-Ding Wang Fan xu qing Yin Danyang Zhao Jiqiu Qi Yanwei Sui Lei Hou Yao-Yu Wang School of Materials and Physics China University of Mining and TechnologyXuzhou 221116China Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education Shaanxi Key Laboratory of Physico-Inorganic ChemistryCollege of Chemistry&Materials ScienceNorthwest UniversityXi’an 710069China

Considering the tremendous applications and purification requirement of acetylene(C_(2)H_(2)),seeking appropriate adsorbents with high capacity and selectivity is a vital task and remains an enduring ***,we designed and synthesized a robust three-dimensional(3D)indium-organic framework([(Me)_(2)NH_(2)][In(L6)_(0.5)(IPA)_(0.5)]·DMA·2H_(2)O(In-L6-IPA,DMA=dimethylammonium,IPA=isopropyl alcohol))featuring two types of one-dimensional(1D)tubular *** activated In-L6-IPA displayed high loading for C_(2)H_(2)(104.4 cm^(3)·g^(-1),the second highest value among all reported indium-based metal-organic frameworks(MOFs))and simultaneously selective adsorption for C_(2)H_(2) over CO_(2),C_(2)H_(6),and ethylene(C_(2)H_(4))at 298 K under 100 *** modelling revealed that the porous wall of In-L6-IPA provides more and stronger multiple interactions for C_(2)H_(2) than CO_(2),C_(2)H_(6),and C_(2)H_(4) containing C–H···π,C–H···O,and O···π*** experiments validated the actual separation ability for various ratios of binary C_(2)H_(2)/C_(2)H_(4) and C_(2)H_(2)/CO_(2) mixtures as well as equimolar ternary C_(2)H_(2)/C_(2)H_(4)/CO_(2) and C_(2)H_(2)/C_(2)H_(4)/C_(2)H_(6) mixtures with excellent reusability.

关键词： indium-organic framework crystal structure gas adsorption acetylene(C_(2)H_(2))separation

Nonlinear Extrapolation Estimates of π

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 91-108页

作者： Wen-qing xu Sha-sha Wang Da-chuan xu Beijing Institute for Scientific and Engineering Computing Beijing University of TechnologyBeijing100124China Department of Mathematics and Statistics California State UniversityLong BeachCalifornia90840USA Department of Mathematics and Physics Shijiazhuang Tiedao UniversityShijiazhuang050043China

The classical Archimedean approximation of π uses the semiperimeter or area of regular polygons inscribed in or circumscribed about a unit circle in R~2 and it is well-known that by using linear combinations of these basic estimates,modern extrapolation techniques can greatly speed up the approximation ***,when n vertices are randomly selected on the circle,the semiperimeter and area of the corresponding random inscribed and circumscribing polygons are known to converge to π almost surely as n→∞,and by further applying extrapolation processes,faster convergence rates can also be achieved through similar linear combinations of the semiperimeter and area of these random *** this paper,we further develop nonlinear extrapolation methods for approximating π through certain nonlinear functions of the semiperimeter and area of such *** focus on two types of extrapolation estimates of the forms χ_n=S_n~αA_n~β and Y_n(p)=(αS_n~p+βA_n~p)~(1/p) where α+β=1,p≠0,and Sn and An respectively represents the semiperimeter and area of a random n-gon inscribed in the unit circle in R~2,and Xn may be viewed as the limit of Y_n(p) when p→*** deriving probabilistic asymptotic expansions with carefully controlled error estimates for Xn and Y_n(p),we show that the choice α=4/3,β=-1/3 minimizes the approximation error in both cases,and their distributions are also asymptotically normal.

关键词： Archimedean polygons random polygons approximations ofπ extrapolation processes asymptotic convergence

Anomalous thermal expansion and enhanced magnetocaloric effect in<001>-textured Mn_(x)Fe_(5-x)Si_(3) alloys

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Rare Metals 2024年第5期43卷 2263-2274页

作者： yong Gong xue-Fei Miao Tapas Samanta Chris Taake Jun Liu Feng-Jiao Qian Yan-Yan Shao Yu-Jing Zhang qing-yong Ren Luana Caron Feng xu MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials Technology School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing210094China Department of Physics Bielefeld University33501BielefeldGermany College of Physics Nanjing University of Aeronautics and AstronauticsNanjing210016China Institute of High Energy Physics Chinese Academy of SciencesBeijing100049China Spallation Neutron Source Science Center Dongguan523803China Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology Dongguan523803China Department of Physics Bielefeld University33501BielefeldGermany Helmholtz-Zentrum Berlin für Materialien und Energie12489BerlinGermany

The development of zero and negative therma expansion(i.e.,ZTE and NTE)materials is of crucial importance to the control of undesirable thermal expansion for high-precision *** the present work,ZTE and NTE were obtained in directionally-solidified Mn_(x)Fe_(5-x)Si_(3)alloys with a strongtexture,in striking contrast to positive thermal expansion in their isotropic counterparts Magnetometry and in-situ X-ray diffraction(XRD)measurements were performed to uncover the origin of the anomalous thermal *** measurements indicate a strong easy-plane magnetocrystalline anisotropy in the textured samples,where the magnetic moments are aligned within the ab plane of the hexagonal structure Temperature-dependent XRD on the x=1 sample reveals a ZTE character in the ab plane that is coupled to a ferromagnetic *** a result,the macroscopic ZTE(~0.22×10^(-6)K^(-1))in the x=1 sample can be attributed to the microscopic magneto volume effect within the ab plane,which is realized by the introduction of the-textured ***,the competition between antiferromagnetic and ferromagnetic exchange coupling leads to NTE in textured x=1.5 and 2 ***,textured x=1 sample displays enhanced magnetocaloric properties as compared to the conventional counterparts with randomly-oriented *** this work demonstrates a new strategy toward the exploration of anomalous thermal expansion properties as well as the enhancement of magnetocaloric properties for materials with a strong magnetocrystalline anisotropy.

关键词： MnFeySis Magnetocaloric effect Magnetic phase transition Negative thermal expansion

Vertically grown MoS_(2)nanosheets on graphene with defect-rich structure for efficient sodium storage

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Rare Metals 2024年第3期43卷 1062-1071页

作者： Ying Wang Jia-Peng He Han-qing Pan qing-Peng Wang Lei Zhang yong-Chang Liu qing-Hong Wang School of Chemistry&Materials Science Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional MaterialsJiangsu Normal UniversityXuzhou221116China Institute of Biopharmaceutical Research Liaocheng UniversityLiaocheng252059China Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyState Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing100083China Centre for Catalysis and Clean Energy Gold Coast CampusGriffith UniversityGold CoastQLD4222Australia

The synthesis of a perpendicular growth structure of MoS_(2)nanosheets on graphene for efficient sodium storage is challenging yet ideal due to the benefits of open ion diffusion channels and high electronic *** this study,we have successfully fabricated a novel structure of vertical MoS_(2)nanosheets on graphene,with ZnS nanoparticles serving as bonding points(MoS_(2)/ZnS/G),through a facile hydrothermal *** the synthesis process,Zn^(2+)not only acts as a landing site for the vertical growth of MoS_(2)nanosheets but also triggers the formation of a defect-rich structure in the final *** unique architecture of MoS_(2)/ZnS/G effectively combines the advantages of a vertically aligned geometry and a defectrich structure for energy *** resulting structure displays shortened transport paths for electrons/ions,enhanced conductivity,improved structural integrity,and an increased number of active sites for promising electrochemical *** expected,when used as anode for sodium-ion batteries,the as-synthesize d MoS_(2)/ZnS/G exhibits excellent rate capability(high capacity of 298 mAh·g^(-1)at 5 A·g^(-1))and good cycling stability(a capacity decay of 0.056%per cycle after 500 cycles at 1 A·g^(-1)).According to the kinetic investigations,the electrochemical process of the MoS_(2)/ZnS/G sample is primarily governe d by a pseudocapacitive behavior,which enhances the charge/discharge kinetics and allows the MoS_(2)/ZnS/G structure to remain intact during cycling.

关键词： MoS_(2) Perpendicular growth Graphene Sodium storage Electrochemical performance

Prescribed Performance Tracking Control of Time-Delay Nonlinear Systems With Output Constraints

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1557-1565页

作者： Jin-Xi Zhang Kai-Di xu qing-Guo Wang IEEE the State Key Laboratory of Synthetical Automation for Process Industries Northeastern UniversityShenyang 110819China Institute of Artificial Intelligence and Future Networks Beijing Normal UniversityZhuhai 519087 Guangdong Key Laboratory of Artificial Intelligence and Multi-Modal Data Processing Beijing Normal University-Hong Kong Baptist University United International CollegeZhuhai 519087

The problem of prescribed performance tracking control for unknown time-delay nonlinear systems subject to output constraints is dealt with in this paper. In contrast with related works, only the most fundamental requirements, i.e., boundedness and the local Lipschitz condition, are assumed for the allowable time delays. Moreover, we focus on the case where the reference is unknown beforehand, which renders the standard prescribed performance control designs under output constraints infeasible. To conquer these challenges, a novel robust prescribed performance control approach is put forward in this ***, a reverse tuning function is skillfully constructed and automatically generates a performance envelop for the tracking error. In addition, a unified performance analysis framework based on proof by contradiction and the barrier function is established to reveal the inherent robustness of the control system against the time delays. It turns out that the system output tracks the reference with a preassigned settling time and good accuracy,without constraint violations. A comparative simulation on a two-stage chemical reactor is carried out to illustrate the above theoretical findings.

关键词： Nonlinear systems output constraints prescribed performance reference tracking time delays