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Simulation of Impurity Diffusion in a Strained Nanowire Using Off-Lattice KMC

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Communications in Computational physics 2007年第1期2卷 164-176页

作者： Weidong Guo tim p.schulze Weinan E Department of Mathematics University of TennesseeKnoxvilleTN 37996-1300USA Department of Mathematics and program in Applied and Computational Mathematics Princeton UniversityPrincetonNJ 08544-1000USA.

Kinetic Monte Carlo(KMC)is a stochastic model used to simulate crystal ***,most KMC models rely on a pre-defined lattice that neglects dislocations,lattice mismatch and strain *** this paper,we investigate the use of a 3D off-lattice KMC *** test this method by investigating impurity diffusion in a strained FCC *** faster than a molecular dynamics simulation,the most general implementation of off-lattice KMC is much slower than a lattice-based *** improved procedure is achieved for weakly strained systems by precomputing approximate saddle point locations based on unstrained lattice *** this way,one gives up some of the flexibility of the general method to restore some of the computational speed of lattice-based *** addition to providing an alternative approach to nano-materials simulation,this type of simulation will be useful for testing and calibrating methods that seek to parameterize the variation in the transition rates for lattice-based KMC using continuum modeling.

关键词： Off-lattice KMC nanowire strain rate impurity diffusion.

Inverted List Kinetic Monte Carlo with Rejection Applied to Directed Self-Assembly of Epitaxial Growth

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Communications in Computational physics 2009年第8期6卷 553-564页

作者： Michael A.Saum tim p.schulze Christian Ratsch Department of Mathematics University of TennesseeKnoxvilleTennessee 37996USA Department of Mathematics and Institute for pure and Applied Mathematics University of California in Los AngelesLos AngelesCalifornia 90095USA

We study the growth of epitaxial thin films on pre-patterned substrates that influence the surface diffusion of subsequently deposited material using a kinetic Monte Carlo algorithm that combines the use of inverted lists with *** resulting algorithm is well adapted to systems with spatially heterogeneous hopping *** evaluate the algorithm’s performance we compare it with an efficient,binary-tree based algorithm.A key finding is that the relative performance of the inverted list algorithm improves with increasing system size.

关键词： Epitaxial growth kinetic Monte Carlo binary-tree search

The Influence of Edge Energy on Step Flow Instability for Crystals with Bravais Versus Non-Bravais Lattice Structures

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Communications in Computational physics 2020年第1期27卷 70-86页

作者： tim Krumwiede Khoa D.Dinh Christian Ratsch tim p.schulze Department of Mathematics Bringham Young UniversityUT 84602USA Department of Mathematics University of TennesseeTennessee 37996USA Institute for pure and Applied Mathematics and Department of Mathematics University of CaliforniaLos AngelesCA 90095-1555USA

We examine the meandering instability for prismatic lattices formed from triangles,squares and hexagons using a nearest neighbor kinetic Monte Carlo *** the first two cases,which are Bravais lattices,we find that facets with the orientation favored in the equilibrium shape of isolated islands are most prone to this instability,while the analogous facet for the hexagonal lattice is the least *** argue that this is due to a significant difference in the reconstructed/equilibrium versus the non-reconstructed edge energy for non-Bravais ***/edge energy is typically modeled as a single-valued function of *** put forward a simple geometric argument that suggests this picture is inadequate for crystals with a non-Bravais lattice *** the case of a hexagonally structured lattice,our arguments indicate that the non-reconstructed edge energy can be viewed as both discontinuous and multi-valued for a subset of orientations that are commensurate with the crystal *** support these conclusions with density functional theory calculations that also reveal multivalued surface energies for the set of singular orientations.

关键词： KMC surface energy epitaxy

Intraoperative application of three-dimensional printed guides in total hip arthroplasty: A systematic review

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World Journal of Orthopedics 2024年第7期15卷 660-667页

作者： tim p Crone Bart M W Cornelissen Jakob Van Oldenrijk pieter Koen Bos Ewout S Veltman Department of Orthopedic Surgery and Sports Medicine Erasmus Medical CenterRotterdam 3015 GDNetherlands Department of Oral and Maxillofacial Surgery Erasmus Medical CenterRotterdam 3015 GDNetherlands

BACKGROUND Acetabular component positioning in total hip arthroplasty(THA)is of key importance to ensure satisfactory post-operative outcomes and to minimize the risk of *** majority of acetabular components are aligned freehand,without the use of navigation *** specific instruments(pSI)and three-dimensional(3D)printing of THA placement guides are increasingly used in primary THA to ensure optimal *** To summarize the literature on 3D printing in THA and how they improve acetabular component *** pubMed was used to identify and access scientific studies reporting on different 3D printing methods used in *** studies with 236 hips in 228 patients were *** studies could be divided into two main categories;3D printed models and 3D printed *** 3D printing in THA helped improve preoperative cup size planning and post-operative Harris hip scores between intervention and control groups(p=0.019,p=0.009).Otherwise,outcome measures were heterogeneous and thus difficult to *** overarching consensus between the studies is that the use of 3D guidance tools can assist in improving THA cup positioning and reduce the need for revision THA and the associated *** The implementation of 3D printing and pSI for primary THA can significantly improve the positioning accuracy of the acetabular cup component and reduce the number of complications caused by malpositioning.

关键词： Total hip arthroplasty Three-dimensional printing Hip replacement surgery Three-dimensional planning Surgical guides

Spatiotemporal mapping of(ultra‐)mafic magmatic mine areas:Implications of economic and political realities in China

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Deep Underground Science and Engineering 2024年第1期3卷 91-102页

作者： Heling Li Liang Tang tim T.Werner Zhengmeng Hou Fan Meng Jingjing Li College of Earth Sciences Chengdu University of TechnologyChengduChina Institute of Subsurface Energy Systems Clausthal University of TechnologyClausthal ZellerfeldGermany School of Geography Earth and Atmospheric SciencesFaculty of ScienceThe University of MelbourneMelbourneVictoriaAustralia

The spatiotemporal extension/expansion of mine areas is affected by multiple *** far,very little has been done to examine the interaction between mine areas and political or economic ***(ultra‐)mafic magmatic mines in China played a specific role in supporting national development and providing an ideal research subject for monitoring their *** this study,remote sensing and mining‐related GIS data were used to identify and analyze 1233(ultra‐)mafic magmatic mine area polygons in China,which covered approximately 322.96 km2 of land and included a V–Ti–Fe mine,a copper–nickel mine,a chromite mine,an asbestos mine,and a diamond *** was found that(1)the areal expansion of mines is significantly related to the mine types,perimeter,topography,and population density.(2)The mine area variation also reflects market and policy *** temporal expansion of the mine area from 2010 to 2020 followed an S‐shaped pattern(with the turning point occurring in 2014),closely related to iron overcapacity and tightened mining policies.(3)The complexity(D)of the mine area may reflect mine design and excavation *** be specific,lower D indicates early‐stage or artisanal/small‐scale mining,whereas higher D represents large‐scale *** study demonstrates that the detailed mapping of mine land can serve as an indicator to implement miningrelated market and policy ***(ultra‐)mafic mines area data set can be accessed at https://***/record/7636616#.Y-p0uXaZOa0.

关键词： complexity mine area mining and socioeconomic interaction spatiotemporal distribution (ultra‐)mafic magmatic mine

Impact of preoperative chemotherapy on surgical results in 139 patients with locally advanced pancreatic cancer

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Hepatobiliary Surgery and Nutrition 2024年第3期13卷 460-471页

作者： Marvin petrikowski tim Fahlbusch Anke Reinacher-Schick Giedre Kucinskaite Andrea Tannapfel Waldemar Uhl Orlin Belyaev Department of General and Visceral Surgery St.Josef-Hospital BochumRuhr-University BochumBochumGermany Department of Hematology and Oncology with palliative Medicine St.Josef-Hospital BochumRuhr-University BochumBochumGermany Department of Radiology and Nuclear Medicine St.Josef-Hospital BochumRuhr-University BochumBochumGermany Institute of pathology Ruhr-University BochumBochumGermany

Background:The establishment of preoperative chemotherapy(pCT)with FOLFIRINOX and gemcitabine/nab-paclitaxel in recent years has enabled resectability in many patients with initially locally advanced pancreatic cancer(LApC).Nevertheless,information about the impact of pCT on surgical results is ***:All patients with initial LApC who received surgery after chemotherapy at the high-volume centre for pancreatic surgery of ***-Hospital Bochum between 2015 and 2022 were included in this retrospective cohort ***:A total of 139 patients underwent surgery after pre-treatment with FOLFIRINOX(76.3%),gemcitabine/nab-paclitaxel(11.5%),both(5.8%)and other regimens(6.5%).Eighty-five tumors(61.2%)were resectable after pCT.R0 resection was achieved in 92.9%,R1 in 7.1%and R2 in 0%of ***-four tumors were still not resectable at the time of *** results of the patients did not show increased postoperative mortality and morbidity compared to the literature *** 30-day mortality was 1.4%.Rates for pancreas-specific complications[postoperative pancreatic fistula(pOpF),delayed gastric emptying(DGE),postpancreatectomy hemorrhage(ppH),and others]were not *** occurred in 10.5%and DGE in 26.3%after *** distal pancreatectomy,pOpF was detected in 37.5%and DGE in 12.5%.Median postoperative survival(31 vs.13 months)and overall survival after initial diagnosis(40 vs.20 months)were significantly longer in resected patients(ppostoperative recurrence-free survival in resected patients amounted to 12 ***:This study underlines that pCT allows resectability of primarily unresectable patients with LApC without increasing perioperative mortality and *** may lead to a significant prolongation of recurrence-free and overall survival in resected patients after pCT.

关键词： pancreatic cancer preoperative chemotherapy(pCT) postoperative complications mortality overall survival

Variability and trends of near-surface wind speed over the Tibetan plateau:The role played by the westerly and Asian monsoon

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Advances in Climate Change Research 2024年第3期15卷 525-536页

作者： Gang-Feng ZHANG Cesar AZORIN-MOLINA Deliang CHEN tim RMCVICAR Jose AGUIJARRO Kai-Qiang DENG Lorenzo MINOLA Jaeyeon LEE Seok-Woo SON Heng MA pei-Jun SHI State Key Laboratory of Earth Surface processes and Resource Ecology Beijing Normal UniversityBeijing 100875China Engineering Center of Desertification and Blown-Sand Control of Ministry of Education Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Key Laboratory of Environmental Change and Natural Disaster of Ministry of Education Beijing Normal UniversityBeijing 100875China Centro de Investigaciones Sobre Desertificaci'on Consejo Superior de Investigaciones Cientı'ficas(CIDECSIC-UV-Generalitat alenciana)ClimateAtmosphere and Ocean Laboratory(Climatoc-Lab)Moncada 46113Spain Regional Climate Group Department of Earth SciencesUniversity of GothenburgGothenburg 40530Sweden CSIRO Environment CanberraACT 2600Australia Australian Research Council Centre of Excellence for Climate Extremes CanberraACT 2600Australia State Meteorological Agency Balearic Islands OfficePalma de Mallorca 07015Spain School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 519082China Interuniversity Department of Regional and Urban Studies and planning(DIST) Politecnico and University of TurinTurin 10125Italy School of Earth and Environmental Sciences Seoul National UniversitySeoul 08826South Korea Atmospheric and Oceanic Sciences program Princeton UniversityPrinceton NJ 08544USA Geophysical Fluid Dynamics Laboratory NOAAPrinceton NJ 08544USA

Near-surface wind speed exerts profound impacts on many environmental issues,while the long-term(≥60 years)trend and multidecadal variability in the wind speed and its underlying causes in global high-elevation and mountainous areas(e.g.,Tibetan plateau)remain largely ***,by examining homogenized wind speed data from 104 meteorological stations over the Tibetan plateau for 1961-2020 and ERA5 reanalysis datasets,we investigated the variability and long-term trend in the near-surface wind speed and revealed the role played by the westerly and Asian *** results show that the homogenized annual wind speed displays a decreasing trend(-0.091 m s^(−1)per decade,ppring(-0.131 m s^(−1)per decade,pper decade,ppeed,which manifested in an prominent increase in 1961-1970,a sustained decrease in 1970-2002,and a consistent increase in *** observed decadal variations are likely linked to large-scale atmospheric circulation,and the correlation analysis unveiled a more important role of westerly and East Asian winter monsoon in modulating near-surface wind changes over the Tibetan *** potential physical processes associated with westerly and Asian monsoon changes are in concordance with wind speed change,in terms of overall weakened horizontal air flow(i.e.,geostrophic wind speed),declined vertical thermal and dynamic momentum transfer(i.e.,atmospheric stratification thermal instability and vertical wind shear),and varied Tibetan plateau *** indicates that to varying degrees these processes may have contributed to the changes in near-surface wind speed over the Tibetan *** study has implications for wind power production and soil wind erosion prevention in the Tibetan plateau.

关键词： Tibetan plateau Wind speed Decadal change Atmospheric circulation physical processes

piezo1 expression in chondrocytes controls endochondral ossification and osteoarthritis development

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Bone Research 2024年第1期12卷 199-214页

作者： Laura J.Brylka Assil-Ramin Alimy Miriam E.A.Tschaffon-Müller Shan Jiang Tobias Malte Ballhause Anke Baranowsky Simon von Kroge Julian Delsmann Eva pawlus Kian Eghbalian Klaus püschel Astrid Schoppa Melanie Haffner-Luntzer David J.Beech Frank timo Beil Michael Amling Johannes Keller Anita Ignatius timur A.Yorgan tim Rolvien Thorsten Schinke Department of Osteology and Biomechanics University Medical Center Hamburg-Eppendorf20246 HamburgGermany Department of Trauma and Orthopedic Surgery University Medical Center Hamburg-Eppendorf20246 HamburgGermany Institute of Orthopedic Research and Biomechanics University Medical Center UlmBadenWürttemberg89081 UlmGermany Department Legal Medicine University Medical Center Hamburg-Eppendorf20246 HamburgGermany Leeds Institute of Cardiovascular and Metabolic Medicine School of MedicineUniversity of LeedsLS29JT LeedsUK

piezo proteins are mechanically activated ion channels,which are required for mechanosensing functions in a variety of cell *** we and others have previously demonstrated that the expression of piezo1 in osteoblast lineage cells is essential for boneanabolic processes,there was only suggestive evidence indicating a role of piezo1 and/or piezo2 in *** we addressed the question if and how chondrocyte expression of the mechanosensitive proteins piezo1 or piezo2 controls physiological endochondral ossification and pathological osteoarthritis(OA)*** with chondrocyte-specific inactivation of piezo1(piezo1^(Col2a1Cre)),but not of piezo2,developed a near absence of trabecular bone below the chondrogenic growth plate ***,all piezo1^(Col2a1Cre) animals displayed multiple fractures of rib bones at 7 days of age,which were located close to the growth *** skeletal growth was only mildly affected in these mice,OA pathologies were markedly less pronounced compared to littermate controls at 60 weeks of ***,when OA was induced by anterior cruciate ligament transection,only the chondrocyte inactivation of piezo1,not of piezo2,resulted in attenuated articular cartilage ***,osteophyte formation and maturation were also reduced in piezo1^(Col2a1Cre) *** further observed increased piezo1 protein abundance in cartilaginous zones of human ***,we identified ptgs2 and Ccn2 as potentially relevant piezo1 downstream genes in ***,our data do not only demonstrate that piezo1 is a critical regulator of physiological and pathological endochondral ossification processes,but also suggest that piezo1 antagonists may be established as a novel approach to limit osteophyte formation in OA.

关键词： piezo1 markedly ossification

High formability Mg-Zn-Gd wire facilitates ACL reconstruction via its swift degradation to accelerate intra-tunnel endochondral ossification

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Journal of Magnesium and Alloys 2024年第1期12卷 295-315页

作者： Xuan He Ye Li Hongwei Miao Jiankun Xu Michael tim-yun Ong Chenmin Wang Lizhen Zheng Jiali Wang Le Huang Haiyue Zu Zhi Yao Jie Mi Bingyang Dai Xu Li patrick Shu-hang Yung Guangyin Yuan Ling Qin Musculoskeletal Research Laboratory of Department of Orthopaedics&Traumatology and Innovative Orthopaedic Biomaterial and Drug Translational Research Laboratory of Li Ka Shing Institute of Health Sciences The Chinese University of Hong KongHong KongChina National Engineering Research Center of Light Alloy Net Forming School of Materials Science&EngineeringShanghai Jiao Tong UniversityShanghaiChina Department of Orthopaedics and Traumatology Li Ka Shing Faculty of MedicineThe University of Hong KongHong KongChina Orthopaedic Department Peking University Third HospitalBeijingChina Department of Rehabilitation Sciences The Hong Kong Polytechnic UniversityHong KongChina

After reconstructing the anterior cruciate ligament(ACL),unsatisfactory bone tendon interface healing may often induce tunnel enlargement at the early healing *** good biological features and high formability,Magnesium-Zinc-Gadolinium(ZG21)wires are developed to bunch the tendon graft for matching the bone tunnel during ***,tensile strength,degradation,and cytotoxicity of ZG21 wire are *** rabbit model is used for assessing the biological effects of ZG21 wire by Micro-CT,histology,and mechanical *** SEM/EDS,immunochemistry,and in vitro assessments are performed to investigate the underlying *** tests demonstrate the high formability of ZG21 wire as surgical ***-CT shows ZG21 wire degradation accelerates tunnel bone formation,and histologically with earlier and more fibrocartilage regeneration at the healing *** mechanical test shows higher ultimate load in the ZG21 *** SEM/EDS presents ZG21 wire degradation triggered calcium phosphate(Ca-p)*** results demonstrate upregulation of Wnt3a,BMp2,and VEGF at the early phase and TGFβ3 and Type II collagen at the late phase of *** vitro tests also confirmed the Ca-p in the metal extract could elevate the expression of Wnt3a,βcatenin,ocn and opn to stimulate *** vivo tests of clinical samples indicated suturing with ZG21 wire did not weaken the ultimate loading of human tendon *** conclusion,the ZG21 wire is feasible for tendon graft *** degradation products accelerated intra-tunnel endochondral ossification at the early healing stage and therefore enhanced bone-tendon interface healing in ACL reconstruction.

关键词： Magnesium wire ACL reconstruction Magnesium alloy Biomaterials Endochondral ossification