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Bionic lightweight design of limb leg units for hydraulic quadruped robots by additive manufacturing and topology optimization

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Bio-Design and Manufacturing 2024年第1期7卷 1-13页

作者： Huaizhi Zong junhui zhang Lei Jiang Kun zhang jun Shen Zhenyu Lu Ke Wang Yanli Wang Bing Xu The State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310058China Unmanned Vehicle Research and Development Center China North Vehicle Research InstituteBeijing 100072China School of Mechatronic Engineering Nanchang UniversityNanchang 330031China Auclean High-Tech Ltd. Wuxi 214108China

Galloping cheetahs,climbing mountain goats,and load hauling horses all show desirable locomotion capability,which motivates the development of quadruped robots.Among various quadruped robots,hydraulically driven quadruped robots show great potential in unstructured environments due to their discrete landing positions and large payloads.As the most critical movement unit of a quadruped robot,the limb leg unit(LLU)directly affects movement speed and reliability,and requires a compact and lightweight design.Inspired by the dexterous skeleton–muscle systems of cheetahs and humans,this paper proposes a highly integrated bionic actuator system for a better dynamic performance of an LLU.We propose that a cylinder barrel with multiple element interfaces and internal smooth channels is realized using metal additive manufacturing,and hybrid lattice structures are introduced into the lightweight design of the piston rod.In addition,additive manufacturing and topology optimization are incorporated to reduce the redundant material of the structural parts of the LLU.The mechanical properties of the actuator system are verified by numerical simulation and experiments,and the power density of the actuators is far greater than that of cheetah muscle.The mass of the optimized LLU is reduced by 24.5%,and the optimized LLU shows better response time performance when given a step signal,and presents a good trajectory tracking ability with the increase in motion frequency.

关键词： Additive manufacturing Bionic lightweight design Limb leg unit Quadruped robot Trajectory tracking

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Evaluating combined bevacizumab and XELOX in advanced colorectal cancer: Serum markers carcinoembryonic antigen, carbohydrate antigen 125, carbohydrate antigen 199 analysis

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World Journal of Clinical Cases 2024年第1期12卷 15-23页

作者： Dong-Bing Zhou jun Cheng Xiong-hui zhang Department of Gastroenterology The Second People's Hospital of Jingzhou HubeiJingzhou 434000Hubei ProvinceChina Department of Gastrointestinal Surgery Qianjiang Central HospitalQianjing 433100Hubei ProvinceChina Department of Gastroenterology Xiantao First People's Hosepital Affiliated to Yangtze UniversityXiantao 433000Hubei ProvinceChina

BACKGROUND Colorectal cancer ranks third and second among common and fatal cancers.The treatment of metastatic colorectal cancer(mCRC)is generally based on XELOX in clinical practice,which includes capecitabine(CAP)and oxaliplatin.Serum tumor markers carcinoembryonic antigen(CEA),carbohydrate antigen(CA)125 and CA199 are prognostic factors for various tumors.AIM To investigate evaluating combined bevacizumab(BEV)and XELOX in advanced colorectal cancer:Serum markers CEA,CA125,CA199 analysis.METHODS In this retrospective study,a total of 94 elderly patients diagnosed with mCRC were recruited and subsequently categorized into two groups based on the distinct treatment modalities they received.The control group was treated with XELOX plus CAP(n=47),while the observation group was treated with XELOX plus CAP and BEV(n=47).Several indexes were assessed in both groups,including disease control rate(DCR),incidence of adverse effects,serum marker levels(CEA,CA125,and CA19)and progression-free survival(PFS).RESULTS After 9 wk of treatment,the serum levels of CEA,CA199 and CA125 in the observation group were significantly lower than those in the control group(P0.05).CONCLUSION On the basis of XELOX treatment,the combination of BEV and CAP can reduce serum tumor marker levels and prolong PFS in patients with mCRC.

关键词： Metastatic colorectal cancer Bevacizumab Capecitabine XELOX Tumor markers

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Effects of Acupotomy on Immobilization-Induced Gastrocnemius Contracture and Fibrosis in Rats via Wnt/β-Catenin Signaling

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Chinese Journal of Integrative Medicine 2024年第7期30卷 633-642页

作者： HU Rui PAN jun-kang LI Jia-hui zhang Han LI Shao-rong zhang Yi School of Acupuncture-Moxibustion and Tuina Beijing University of Chinese Medicine Acupuncture Department Kunming Municipal Hospital of Traditional Chinese Medicine

Objective: To determine whether acupotomy ameliorates immobilization-induced muscle contracture and fibrosis via Wnt/β-catenin signaling pathway. Methods: Thirty Wistar rats were randomly divided into 5 groups(n=6) by a random number table, including control, immobilization, passive stretching, acupotomy, and acupotomy 3 weeks(3-w) groups. The rat model of gastrocnemius contracture was established by immobilizing the right hind limb in plantar flexion for 4 weeks. Rats in the passive stretching group received passive stretching at gastrocnemius, a daily series of 10 repetitions for 30 s each at 30-s intervals for 10 consecutive days. Rats in the acupotomy and acupotomy 3-w groups received acupotomy once and combined with passive stretching at gastrocnemius a daily series of 10 repetitions for 30 s each at 30-s intervals for 10 consecutive days. Additionally, rats in the acupotomy 3-w group were allowed to walk freely for 3 weeks after 10-day therapy. After treatment, range of motion(ROM), gait analysis [i.e., paw area, stance/swing and maximum ratio of paw area to paw area duration(Max dA/dT)], gastrocnemius wet weight and the ratio of muscle wet weight to body weight(MWW/BW) were tested. Gastrocnemius morphometric and muscle fiber cross-sectional area(CSA) were assessed by hematoxylin-eosin staining. Fibrosis-related mRNA expressions(i.e., Wnt 1, β-catenin, axin-2, α-smooth muscle actin, fibronectin, and types Ⅰ and Ⅲ collagen) were measured using real-time quantitative polymerase chain reactions. Wnt 1, β-catenin and fibronectin concentrations were measured by enzyme-linked immunosorbent assay. Types Ⅰ and Ⅲ collagen in the perimysium and endomysium were analyzed using immunofluorescence. Results: Compared with the control group, ROM, gait function, muscle weight, MWW/BW and CSA were significantly decreased in the immobilization group(all P <0.01), while protein levels of types Ⅰ and Ⅲ collagen, Wnt 1, β-catenin, fibronectin and mRNA levels of fibrosis-related genes were obviously increased(all P<0.01). Treatme

关键词： acupotomy immobilization muscle contracture muscle fibrosis Wnt/β-catenin signaling

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Designing ultrastrong and thermally stable FeCrAl alloys with the fine-grained structure

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Journal of Materials Science & Technology 2024年第4期171卷 198-208页

作者： Shuaiyang Liu Jinyu zhang hui Wang Gang Liu Xiangdong Ding jun Sun State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of ChinaChengdu 610041China

Designing microstructurally stable FeCrAl alloys with excellent strength-ductility synergy is highly desir-able for their engineering applications.However,due to the preference nucleation of precipitates at grain boundaries(GBs),the improved precipitation strengthening of these alloys is usually accompanied by in-tergranular embrittlement.Here,we propose a novel thermomechanical processing route coupled with the Si alloying strategy via precipitation of coherent deformable Laves precipitates inside equiaxed fine-grains to achieve FeCrAl alloys with ultrahigh yield strength over∼992 MPa,excellent uniform elongation of∼7.6%at room temperature,and superior thermal stability at temperature∼1200℃.The Si alloying not only decreases the stacking fault energy of Laves precipitates favorable for their stacking-fault-mediated deformation but also hinders grain coarsening at 1200℃due to the Si-enrichment favorable for GB pin-ning effects.Our results prove the possibility of achieving the collaborative enhancement of mutually exclusive properties in alloys,such as strength-ductility-thermal stability via nanoprecipitation engineer-ing,and offer a promising route to prepare dispersion-strengthened materials.

关键词： FeCrAl alloys Si alloying Mechanical properties Thermal stability Laves phase

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Modeling of LF refining process:a review

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Journal of Iron and Steel Research(International) 2024年第2期31卷 289-317页

作者： Zi-cheng Xin Jiang-shan zhang Kai-xiang Peng jun-guo zhang Chun-hui zhang Qing Liu State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing100083China School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing100083China Tangshan Branch Hebei Iron and Steel Co.Ltd.Tangshan063000HebeiChina Xinjiang Bayi Iron and Steel Co. Ltd.Baosteel GroupWulumuqi830022XinjiangChina

With the increasing demand for energy conservation and emission reduction,more attentions have been paid to the intelligentization,greenization and low carbonization during the transformation and upgrading of steelmaking plants.Ladle furnace(LF)refining is one of the key procedures in steelmaking process and has been widely used in steelmaking plants for its high equipment matching degree,low equipment investment and outstanding refining performance.According to the main tasks of LF refining process,the modeling methods of temperature prediction model,slag-making model,alloying model,argon blowing model and model of inclusions behavior were systematically reviewed,and the advantages and disadvantages of each modeling method were summarized.In addition,the technical framework for the future has also been proposed based on existing works,including classification of raw materials,graphic representation of knowledge,introduction,upgradation and management of device/equipment,customization of steelmaking,modeling of refining process,synergy of models,intelligentization of decision-making,automation of control,and digitization of processes and operations,aiming to provide a reference for the modeling and intelligent development of LF refining process.

关键词： LF refining Temperature prediction Slag-making Alloying Argon blowing Inclusion behavior Modeling method

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Asymptotic Inference in the Random Coefficient Autoregressive Model with Time-functional Variance Noises

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 320-346页

作者： En-wen ZHU Zi-wei DENG Han-jun zhang jun CAO Xiao-hui LIU Department of Mathematics and Statistics Changsha University of Science and TechnologyChangsha 410114China School of Mathematics and Computational Science Xiangtan UniversityXiangtan 411105China School of Statistics and Data Science and Key Laboratory of Data Science in Finance and EconomicsJiangxi University of Finance and EconomicsNanchang 330013China

This paper considers the random coefficient autoregressive model with time-functional variance noises,hereafter the RCA-TFV model.We first establish the consistency and asymptotic normality of the conditional least squares estimator for the constant coefficient.The semiparametric least squares estimator for the variance of the random coefficient and the nonparametric estimator for the variance function are constructed,and their asymptotic results are reported.A simulation study is presented along with an analysis of real data to assess the performance of our method in finite samples.

关键词： random coefficient autoregressive model time-functional variance conditional least squares semiparametric least squares

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Efficacy and Safety of Bufei Jiedu Granules in Treating Multidrug-Resistant Pulmonary Tuberculosis: A Multi-center, Double-Blinded and Randomized Controlled Trial

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Chinese Journal of Integrative Medicine 2024年第7期30卷 579-587页

作者： zhang Shao-yan QIU Lei zhang Shun-xian XIAO He-ping CHU Nai-hui zhang Xia zhang hui-qiang ZHENG Pei-yong zhang hui-yong LU Zhen-hui Institute of Respiratory Diseases Longhua Hospital Shanghai University of Traditional Chinese Medicine Clinical Research Center Shanghai University of Traditional Chinese Medicine Department of Tuberculosis Shanghai Pulmonary HospitalTongji University Department of Tuberculosis Beijing Chest Hospital Capital Medical University Department of Tuberculosis the Second Hospital of Nanjing Department of Tuberculosis the First Hospital Affiliated to Xinxiang Medical College

Objective: To assess the efficacy and safety of Bufei Jiedu(BFJD) Granules as adjuvant therapy for patients with multidrug-resistant pulmonary tuberculosis(MDR-PTB). Methods: A large-scale, multi-center, double-blinded, and randomized controlled trial was conducted in 18 sentinel hospitals in China from December 2012 to December 2016. A total of 312 MDR-PTB patients were randomly assigned to BFJD Granules or placebo groups(1:1) using a stratified randomization method, which both received the long-course chemotherapy regimen for 18 months(6 Am-Lfx-P-Z-Pto, 12 Lfx-P-Z-Pto). Meanwhile, patients in both groups also received BFJD Granules or placebo twice a day for a total of 18 months, respectively. The primary outcome was cure rate. The secondary outcomes included time to sputum-culture conversion, changes in lung cavities and quality of life(QoL) of patients. Adverse reactions were monitored during and after the trial. Results: A total of 216 cases completed the trial, 111 in the BFJD Granules group and 105 in the placebo group. BFJD Granules, as adjuvant treatment, increased the cure rate by 13.6% at the end of treatment, compared with the placebo(58.4% vs. 44.8%, P=0.02), and accelerated the median time to sputum-culture conversion(5 months vs. 11 months). The cavity closure rate of the BFJD Granules group(50.6%, 43/85) was higher than that of the placebo group(32.1%, 26/81; P=0.02) in patients who completed the treatment. At the end of the intensive treatment, according to the 36-item Short Form, the BFJD Granules significantly improved physical functioning, general health, and vitality of patients relative to the placebo group(all P<0.01). Overall, the death rates in the two groups were not significantly different; 5.1%(8/156) in the BFJD Granules group and 2.6%(4/156) in the placebo group. Conclusions: Supplementing BFJD Granules with the long-course chemotherapy regimen significantly increased the cure rate and cavity closure rate, and rapidly improved QoL of patients with MDR-PTB(Registration No. ChiCTR-TRC-

关键词： alternative medicine Chinese herbal formula Bufei Jiedu Granules multidrug-resistant tuberculosis long-course chemotherapy regimen randomized controlled trial

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Research on a Monte Carlo global variance reduction method based on an automatic importance sampling method

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Nuclear Science and Techniques 2024年第5期35卷 200-215页

作者： Yi-Sheng Hao Zhen Wu Shen-Shen Gao Rui Qiu hui zhang jun-Li Li Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Particle and Radiation Imaging of Ministry of Education Beijing 100084China Nuctech Company Limited Beijing 100084China

Global variance reduction is a bottleneck in Monte Carlo shielding calculations.The global variance reduction problem requires that the statistical error of the entire space is uniform.This study proposed a grid-AIS method for the global variance reduction problem based on the AIS method,which was implemented in the Monte Carlo program MCShield.The proposed method was validated using the VENUS-Ⅲ international benchmark problem and a self-shielding calculation example.The results from the VENUS-Ⅲ benchmark problem showed that the grid-AIS method achieved a significant reduction in the variance of the statistical errors of the MESH grids,decreasing from 1.08×10^(-2) to 3.84×10^(-3),representing a 64.00% reduction.This demonstrates that the grid-AIS method is effective in addressing global issues.The results of the selfshielding calculation demonstrate that the grid-AIS method produced accurate computational results.Moreover,the grid-AIS method exhibited a computational efficiency approximately one order of magnitude higher than that of the AIS method and approximately two orders of magnitude higher than that of the conventional Monte Carlo method.

关键词： Monte Carlo Global variance reduction Reactor shielding Automatic importance sampling

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Oligodendrocytes in central nervous system diseases:the effect of cytokine regulation

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Neural Regeneration Research 2024年第10期19卷 2132-2143页

作者： Chengfu zhang Mengsheng Qiu hui Fu Center for Cognition and Brain Disorders The Affiliated Hospital of Hangzhou Normal UniversityHangzhouZhejiang ProvinceChina Department of Psychiatry National Clinical Research Center for Mental Disordersand National Center for Mental DisordersThe Second Xiangya Hospital of Central South UniversityChangshaHunan ProvinceChina Institute of Life Sciences Key Laboratory of Organ Development and Regeneration of Zhejiang ProvinceCollege of Life and Environment SciencesHangzhou Normal UniversityHangzhouZhejiang ProvinceChina Key Laboratory of Aging and Cancer Biology of Zhejiang Province School of Basic Medical SciencesHangzhou Normal UniversityHangzhouZhejiang ProvinceChina

Cytokines including tumor necrosis factor, interleukins, interferons, and chemokines are abundantly produced in various diseases. As pleiotropic factors, cytokines are involved in nearly every aspect of cellular functions such as migration, survival, proliferation, and differentiation. Oligodendrocytes are the myelin-forming cells in the central nervous system and play critical roles in the conduction of action potentials, supply of metabolic components for axons, and other functions. Emerging evidence suggests that both oligodendrocytes and oligodendrocyte precursor cells are vulnerable to cytokines released under pathological conditions. This review mainly summarizes the effects of cytokines on oligodendrocyte lineage cells in central nervous system diseases. A comprehensive understanding of the effects of cytokines on oligodendrocyte lineage cells contributes to our understanding of central nervous system diseases and offers insights into treatment strategies.

关键词： astrocyte central nervous system disease CXC chemokine cytokine interferonγ interleukin microglia oligodendrocyte oligodendrocyte precursor cell tumor necrosis factorα

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Self-assembly of differentiated dental pulp stem cells facilitates spheroid human dental organoid formation and prevascularization

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World Journal of Stem Cells 2024年第3期16卷 287-304页

作者： Fei Liu Jing Xiao Lei-hui Chen Yu-Yue Pan jun-zhang Tian Zhi-Ren zhang Xiao-Chun Bai School of Basic Medical Sciences Southern Medical UniversityGuangzhou 510515Guangdong ProvinceChina Department of Health Management Guangdong Second Provincial General HospitalGuangzhou 510317Guangdong ProvinceChina Guangdong Provincial Key Laboratory of Tumor Interventional Diagnosis and Treatment Zhuhai People’s Hospital Affiliated with Jinan UniversityZhuhai 519000Guangdong ProvinceChina Centre of Reproduction Development and AgingFaculty of Health SciencesUniversity of MacaoMacao 999078China Department of Stomatology Guangdong Second Provincial General HospitalGuangzhou 510317Guangdong ProvinceChina Zhuhai Institute of Translational Medicine Zhuhai Hospital Affiliated with Jinan UniversityZhuhai 519000Guangdong ProvinceChina Department of Cell Biology School of Basic Medical SciencesSouthern Medical UniversityGuangzhou 510515Guangdong ProvinceChina

BACKGROUND The self-assembly of solid organs from stem cells has the potential to greatly expand the applicability of regenerative medicine.Stem cells can self-organise into microsized organ units,partially modelling tissue function and regeneration.Dental pulp organoids have been used to recapitulate the processes of tooth development and related diseases.However,the lack of vasculature limits the utility of dental pulp organoids.AIM To improve survival and aid in recovery after stem cell transplantation,we demonstrated the three-dimensional(3D)self-assembly of adult stem cell-human dental pulp stem cells(hDPSCs)and endothelial cells(ECs)into a novel type of spheroid-shaped dental pulp organoid in vitro under hypoxia and conditioned medium(CM).METHODS During culture,primary hDPSCs were induced to differentiate into ECs by exposing them to a hypoxic environment and CM.The hypoxic pretreated hDPSCs were then mixed with ECs at specific ratios and conditioned in a 3D environment to produce prevascularized dental pulp organoids.The biological characteristics of the organoids were analysed,and the regulatory pathways associated with angiogenesis were studied.RESULTS The combination of these two agents resulted in prevascularized human dental pulp organoids(Vorganoids)that more closely resembled dental pulp tissue in terms of morphology and function.Single-cell RNA sequencing of dental pulp tissue and RNA sequencing of Vorganoids were integrated to analyse key regulatory pathways associated with angiogenesis.The biomarkers forkhead box protein O1 and fibroblast growth factor 2 were identified to be involved in the regulation of Vorganoids.CONCLUSION In this innovative study,we effectively established an in vitro model of Vorganoids and used it to elucidate new mechanisms of angiogenesis during regeneration,facilitating the development of clinical treatment strategies.

关键词： Human dental pulp stem cells Prevascularized organoids Integrated analyses Angiogenesis Forkhead box protein O1

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