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Pro-pigmentary action of 5-fluorouracil through the stimulated secretion of CXCL12 by dermal fibroblasts

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chinese Medical Journal 2021年第20期134卷 2475-2482页

作者： Zhi-Kai Liao Shuang-Hai Hu Bin-Yu Han Xie Qiu Shan Jiang tie-chi lei Department of Dermatology Renmin Hospital of Wuhan UniversityWuhanHubei 430060China

Background:There is growing evidence that 5-fluorouracil(5-FU)combined with therapeutic trauma can effectively induce skin repigmentation in vitiligo patients who are unresponsive to conventional *** studies have mainly focused on identifying the antimitotic activity of 5-FU for the treatment of skin cancer,but few studies have investigated its extra-genotoxic actions favoring melanocyte ***:We utilized the full thickness excisional skin wound model in Dct-LacZ transgenic mice to dynamically assess the migration of melanocytes in the margins of wounds treated with or without ***-situ expression of CXCL12 was examined in the wound beds using immunofluorescence *** real-time polymerase chain reaction and Western blotting analyses were performed to detect the expression levels of CXCL12 mRNA and protein in primary mouse dermal fibroblasts treated with or without *** assays and fluorescein isothiocyanate(FITC)-phalloidin staining were used to observe cell migration and filamentous actin(F-actin)changes of melan-a murine ***:Whole mount and cryosection X-gal staining showed that the cell numbers of LacZ-positive melanocytes were much higher in the margins of dorsal and tail skin wounds treated with 5-FU compared with the ***,CXCL12 immunostaining was significantly increased in the dermal compartment of wounds treated with 5-FU(controlvs.5-FU,22.47±8.85vs.44.69±5.97,P<0.05).Moreover,5-FU significantly upregulated the expression levels of CXCL12 mRNA(controlvs.5-FU,1.00±0.08vs.1.54±0.06,P<0.05)and protein(controlvs.5-FU,1.00±0.06vs.2.93±0.10,P<0.05)in cultured *** of the CXCL12/CXCR4 axis suppressed melanocyte migrationin vitro using a CXCL12 small interfering RNA(siRNA)or a CXCR4 antagonist(AMD3100).Conclusion:5-FU possesses a pro-pigmentary activity through activation of the CXCL12/CXCR4 axis to drive the chemotactic migration of melanocytes.

关键词： Fluorouracil Melanocyte Migration Fibroblast Chemokine Vitiligo

Evidence of guide field magnetic reconnection in flapping current sheets

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Earth and Planetary Physics 2024年第4期8卷 650-658页

作者： YunTian Hou SuPing Duan lei Dai chi Wang State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Key Laboratory of Solar Activity and Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

Based on current sheet flapping motion on 27 August 2018 in the dusk flank magnetotail,as recorded by instruments aboard Magnetospheric Multiscale(MMS)spacecraft,we present the first study of guide field reconnection observed in the flux rope embedded in kink-like flapping current sheets near the dusk-side flank of the *** more common magnetotail reconnections,which are symmetric,these asymmetric small-scale(λ_(i)~650 km)reconnections were found in the highly twisted current sheet when the direction normal to the sheet changes from the Z direction into the Y *** unique feature of this unusual reconnection is that the reconnection jets are along the Z direction-different from outflow in the X direction,which is the more usual *** vertical reconnection jet is parallel or antiparallel to the up-and-down motion of the tail’s current *** normalized reconnection rate R is estimated to be~*** results indicate that such asymmetric reconnections can significantly enlarge current sheet flapping,with large oscillation *** letter presents direct evidence of guide field reconnection in a highly twisted current sheet,characterized by enlarged current sheet flapping as a consequence of the reconnection outflow.

关键词： magnetic reconnection magnetotail current sheet

Autonomy Evaluation of Unmanned Systems Based on Task Models

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Machine Intelligence Research 2024年第5期21卷 815-830页

作者： Yi Zou Zehao Ni Xun lei chi Zhang Key Laboratory of Complex Aviation Simulation System Beijing100076China State Key Laboratory of Multimodal Artificial Intelligence Systems(MAIS) Institute of AutomationChinese Academy of Sciences(CASIA)Beijing100190China Hong Kong Institute of Science&Innovation Chinese Academy of Sciences(HKISI CAS)Hong Kong999077China

In this study,relevant work on autonomy evaluation(AE)in recent years was comprehensively reviewed and classified from the perspective of task models,and a closed-loop task models based theoretical framework for AE was *** main contributions of this study are as follows.1)A taxonomy for AE based on task models was introduced to classify current theories,methods and standards.2)The limitations of the current autonomous evaluation methods were addressed to provide a theoretical framework for quantitative evaluation based on task models,and evaluation metrics for each stage were proposed based on the AE theoretical framework.3)Qualitative analyses of the superiority of the proposed AE framework based on the closed-loop task models were *** study attempts to provide a reference for researchers and engineers in the autonomous unmanned systems field and inspire future development of AE.

关键词： Unmanned system(UMS) autonomy evaluation task models closed-loop task models kill chain

Arbitrarily rotating polarization direction and manipulating phases in linear and nonlinear ways using programmable metasurface

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Light(Science & Applications) 2024年第9期13卷 1789-1800页

作者： Wei Liu Si Ran Wang Jun Yan Dai lei Zhang Qiao Chen Qiang Cheng tie Jun Cui State Key Laboratory of Millimeter Waves Southeast UniversityNanjing 210096China Institute of Electromagnetic Space Southeast UniversityNanjing 210096China Frontiers Science Center for Mobile Information Communication and Security Southeast UniversityNanjing 210096China Electrical Engineering Department Chalmers University of TechnologyGothenburg 41258Sweden

Independent controls of various properties of electromagnetic(EM)waves are crucially required in a wide range of *** metasurface is a promising candidate to provide an advanced platform for manipulating EM ***,we propose an approach that can arbitrarily control the polarization direction and phases of reflected waves in linear and nonlinear ways using a stacked programmable ***,we extend the space-timecoding theory to incorporate the dimension of polarization,which provides an extra degree of freedom for manipulating EM *** proof-of-principle application examples,we consider polarization rotation,phase manipulation,and beam steering at linear and nonlinear *** validation,we design,fabricate,and measure a metasurface *** experimental results show good agreement with theoretical predictions and *** proposed approach has a wide range of applications in various areas,such as imaging,data storage,and wireless communication.

关键词： surface. nonlinear rotating

Cobalt-nitrogen co-doped porous carbon sphere as highly efficient catalyst for liquid-phase cyclohexane oxidation with molecular oxygen and the active sites investigation

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Frontiers of Chemical Science and Engineering 2024年第3期18卷 101-112页

作者： lei Chen Yuan Sun Jinshan chi Wei Xiong Pingle Liu Fang Hao College of Chemical Engineering National&Local United Engineering Research Centre for Chemical Process Simulation and IntensificationXiangtan UniversityXiangtan411105China

The selective oxidation of cyclohexane to cyclohexanone and cyclohexanol(KA oil)is a challenging issue in the chemical *** present the industrial conversion of cyclohexane to cyclohexanone and cyclohexanol is normally controlled at less than 5%***,the development of highly active and stable catalysts for the aerobic oxidation of cyclohexane is necessary to overcome this low-efficiency ***,we have developed a cobalt-nitrogen co-doped porous sphere catalyst,Co-NC-x(x is the Zn/Co molar ratio,where x=0,0.5,1,2,and 4)by pyrolyzing resorcinol-formaldehyde resin *** achieved 88.28%cyclohexanone and cyclohexanol selectivity and a cyclohexane conversion of 8.88%under *** results showed that the introduction of zinc effectively alleviated the aggregation of Co nanoparticles and optimized the structural properties of the *** addition,Co0 and pyridinic-N are proposed to be the possible active species,and their proportion efficiently increased in the presence of Zn^(2+)*** this study,we developed a novel strategy to design highly active catalysts for cyclohexane oxidation.

关键词： KA oil production cyclohexane selective oxidation cobalt-nitrogen co-doped porous carbon spheres metal-organic framework

Significant annealing-induced hardening effect in nanolaminate d-nanotwinne d(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8)me dium-entropy alloy by severe cold rolling

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Journal of Materials Science & Technology 2024年第3期170卷 156-166页

作者： Shuqing Yuan Hui Fu lei Qian chi Fai Cheung Xu-Sheng Yang State Key Laboratory of Ultra-precision Machining Technology Department of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518060China

Due to the easy coarsening caused by poor thermal stability,the verified annealing-induced hardening in nanograined metals can only maintain at a relatively low-temperature *** this study,a nanolam-inated(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8)medium-entropy alloy with an average lamellae thickness of∼20 nm embedded by thinner nanotwins was fabricated by severe cold rolling to achieve superior thermal *** with the conventional nanotwinned CrCoNi with nanotwins inside ultra-fined grains,the hier-archical nanolaminated-nanotwinned(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8) exhibits a significant annealing-induced hard-ening effect,i.e.,hardness increasing from∼250 HV in the original specimen to∼500 HV in the cold-rolled status and finally∼630 HV after annealing at 600℃for 1 *** microstructure characterizations reveal that the reduced dislocation density and formation of L1_(2)ordered domain are mainly responsible for such hardening effect,which is facilitated by the effectively suppressed coarsening with annealing temperature,i.e.,slow detwinning process and well-retained low-angle nanolamellar *** coarsening mechanisms from the cold-rolled nanolamellae to the fully recrystallized micro-equiaxed structures under the annealing temperatures ranging from 400 to 800℃ were also elucidated by atomic observations.

关键词： Annealing-induced hardening Thermal stability Nanolaminated-nanotwinned structure CrCoNi Detwinning Grain boundary migration

Gradient inflammation in the pancreatic stump after pancreaticoduodenectomy:Two case reports and review of literature

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World Journal of Clinical Cases 2024年第9期12卷 1649-1659页

作者： tie-Gong Wang Liang Tian Xiao-Ling Zhang lei Zhang Xiu-lei Zhao De-Shuai Kong Department of Surgery Cangzhou Central HospitalCangzhou 061000Hebei ProvinceChina Department of Pathology Cangzhou Central HospitalCangzhou 061000Hebei ProvinceChina

BACKGROUND Postoperative pancreatic fistula(POPF)contributes significantly to morbidity and mortality after pancreaticoduodenectomy(PD).However,the underlying mechanisms remain *** study explored this pathology in the pancreatic stumps and elucidated the mechanisms of POPF following *** SUMMARY Pathological analysis and 16S rRNA gene sequencing were performed on specimens obtained from two patients who underwent complete pancreatectomy for grade C POPF after *** inflammation is present in the pancreatic *** apoptosis was lower than that in the normal ***,neu-trophildominated inflammatory cells are concentrated in the ductal ***-tably,neutrophils migrated through the ductal wall in acinar duct metaplasia-formed ***,evidence indicates that gut microbes migrate from the digestive *** inflammation occurs in pancreatic stumps after *** The mechanisms underlying POPF include high biochemical activity in the pancreas,mechanical injury,and digestive *** prevent POPF and address pancreatic inflammation and reflux,breaking the link with anastomotic dehi-scence is practical.

关键词： Pancreaticoduodenectomy Postoperative pancreatic fistula Inflammation Digestive reflux Case report

Feasibility Study on Recovering Human-Occupied Vehicle with An Offshore Crane

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china Ocean Engineering 2024年第4期38卷 648-662页

作者： HAN Ming-yue XIE Peng XIAN Hao-yi ZHONG Xin-xin CHEN Sheng-lin SUN tie-rui SUN Feng-lei School of Ocean Engineering and Technology Sun Yat-Sen UniversityZhuhai 519082China Key Laboratory of Comprehensive Observation of Polar Environment(Sun Yat-sen University) Ministry of EducationZhuhai 519082China Guangzhou Marine Engineering Corporation Guangzhou 510250China

Launching and recovering human-occupied vehicles(HOVs)has always been a challenging *** current recovery process requires staff to manually complete the tethering task,which is inefficient and endangers the lives of *** paper suggests moving the recovery position from the surface to underwater at approximately half the wavelength of the water depth(30−50 m underwater),where the HOV experiences less environmental *** ROV equipped with a ultra-short baseline beacon(USBL)and a manipulator was used to complete the tethering ***,a shackle customized to the shape of the manipulator’s gripper is fitted to the end of the cable to simplify the tethering *** investigate the dynamic response of recovering the HOV using this suggested method,a comprehensive numerical model is developed in this *** effects of wind,surface waves,ocean currents,and nonlinear interaction between the installation vessel and the HOV are quantitatively *** results show that the proposed recovery method can reduce the motion amplitude of the HOV and that the wave has the greatest influence on the dynamic response of the HOV during the recovery *** model provides better insight into the proposed HOV recovery method and confirms the effectiveness of the heave compensation *** proposed approach aims to enhance safety and operational efficiency by reducing direct human involvement in the recovery process and mitigating potential *** finding holds particular significance,especially in environmentally sensitive areas,where reducing the impact on the surrounding ecosystem is crucial.

关键词： human-occupied vehicle recovery dynamic response active heave compensation

Assessing cutter-rock interaction during TBM tunnelling in granite:Large-scale standing rotary cutting tests and 3D DEM simulations

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3595-3615页

作者： Xin Huang Miaoyuan Tang Shuaifeng Wang Yixin Zhai Qianwei Zhuang chi Zhang Qinghua lei Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghaiChina College of Civil Engineering and Architecture Xinjiang UniversityUrumqiChina State Key Laboratory of Geotechnical Engineering Ministry of EducationTongji UniversityShanghaiChina china Shipbuilding NDRI Engineering Co. Ltd.ShanghaiChina Shanghai Tunnel Engineering Co. Ltd.ShanghaiChina Shanghai Shield Design and Experimental Research Center Co. Ltd.ShanghaiChina Department of Earth Sciences Uppsala UniversityUppsalaSweden

The widespread utilisation of tunnel boring machines(TBMs)in underground construction engineering requires a detailed investigation of the cutter-rock *** this paper,we conduct a series of largescale standing rotary cutting tests on granite in conjunction with high-fidelity numerical simulations based on a particle-type discrete element method(DEM)to explore the effects of key cutting parameters on the TBM cutter performance and the distribution of cutter-rock contact *** assessment results of cutter performance obtained from the cutting tests and numerical simulations reveal similar dependencies on the key cutting *** specifically,the normal and rolling forces exhibit a positive correlation with penetration but are slightly influenced by the cutting *** contrast,the side force decreases as the cutting radius ***,the side force shows a positive relationship with the penetration for smaller cutting radii but tends to become negative as the cutting radius *** cutter's relative effectiveness in rock breaking is significantly impacted by the penetration but shows little dependency on the cutting ***,an optimal penetration is identified,leading to a low boreability index and specific energy.A combined Hertz-Weibull function is developed to fit the cutter-rock contact stress distribution obtained in DEM simulations,whereby an improved CSM(Colorado School of Mines)model is proposed by replacing the original monotonic cutting force distribution with this combined Hertz-Weibull *** proposed model outperforms the original CSM model as demonstrated by a comparison of the estimated cutting forces with those from the tests/*** findings from this work that advance our understanding of TBM cutter performance have important implications for improving the efficiency and reliability of TBM tunnelling in granite.

关键词： Large-scale standing rotary cutting test Discrete element method(DEM)simulation Cutter-rock interaction Improved CSM(Colorado School of Mines) model Cutting force