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Analysis of new bone,cartilage,and fibrosis tissue in healing murine allografts using whole slide imaging and a new automated histomorphometric algorithm

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Bone Research 2015年第4期3卷 226-234页

作者： Longze Zhang Martin Chang christopher A Beck Edward M schwarz Brendan F Boyce Center for Musculoskeletal Research School of Medicine and DentistryUniversity of Rochester Medical Center

Histomorphometric analysis of histologic sections of normal and diseased bone samples,such as healing allografts and fractures,is widely used in bone ***,the utility of traditional semi-automated methods is limited because they are labor-intensive and can have high interobserver variability depending upon the parameters being assessed,and primary data cannot be re-analyzed *** histomorphometry has long been recognized as a solution for these issues,and recently has become more feasible with the development of digital whole slide imaging and computerized image analysis systems that can interact with digital ***,we describe the development and validation of an automated application（algorithm）using Visiopharm＇s image analysis system to quantify newly formed bone,cartilage,and fibrous tissue in healing murine femoral allografts in high-quality digital images of H＆E/alcian blue-stained decalcified histologic *** validate this algorithm,we compared the results obtained independently using OsteoMeasureTM and Visiopharm image analysis *** intraclass correlation coefficient between Visiopharm and OsteoMeasure was very close to one for all tissue elements tested,indicating nearly perfect reproducibility across *** new algorithm represents an accurate and labor-efficient method to quantify bone,cartilage,and fibrous tissue in healing mouse allografts.

关键词： cartilage slide automated healing fibrous Figure automatically sections segmentation quantify

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Retzius-sparing robotic radical prostatectomy

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Asian Journal of Andrology 2020年第2期22卷 149-151页

作者： christopher g Eden Department of Urology The Royal Surrey County HospitalGuildford GU27XXUK

Traditional approach to the prostate during radical prostatectomy(RP)when performed by open,laparoscopic,or robotic means has been from its anterior aspect first and has involved suture ligation and division of the dorsal vein complex(DVC),division of the puboprostatic ligaments,and incision of the endopelvic fascia on either side of the *** steps are necessary to liberate the prostate from its surrounding attachments,even though concern has always existed about the likely association between disruption of these structures and postprostatectomy incontinence(PPI).Although perineal prostatectomy leaves these structures intact,it has failed to become widely accepted because of the small incidence of postoperative fecal incontinence and the difficulty in performing a pelvic lymphadenectomy(PLND)when this is indicated.

关键词： robotic radical steps

mTORC1 signaling:what we still don’t know

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Journal of Molecular Cell Biology 2011年第4期3卷 206-220页

作者： Xuemin Wang christopher g.Proud School of Biological Sciences Life Sciences BuildingUniversity of SouthamptonSouthampton SO171BJUK

The mammalian target of rapamycin(mTOR)is a protein kinase that plays key roles in cellular *** forms complexes with additional *** best-understood one is mTOR complex 1(mTORC1).The regulation and cellular functions of mTORC1 have been the subjects of intense study;despite this,many questions remain to be *** include questions about the actual mechanisms by which mTORC1 signaling is stimulated by hormones and growth factors,which involves the small gTPase Rheb,and by amino acids,which involves other gTPase *** control of Rheb and the mechanism by which it activates mTORC1 remain incompletely *** it has been known for many years that rapamycin interferes with some functions of mTORC1,it is not known how it does this,or why only some functions of mTORC1 are ***1 regulates diverse cellular *** mTORC1 substrates are now known,although in several cases their physiological roles are poorly or incompletely *** the case of several processes,although it is clear that they are regulated by mTORC1,it is not known how mTORC1 does ***,mTORC1 is implicated in ageing,but again it is unclear what mechanisms account for *** the importance of mTORC1 signaling both for cellular functions and in human disease,it is a high priority to gain further insights into the control of mTORC1 signaling and the mechanisms by which it controls cellular functions and animal physiology.

关键词： mTORC1 protein synthesis cell signaling transcription cell growth autophagy metabolism

Heart failure in very elderly population-a profile of heart failure in patients over the age of eighty

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Journal of geriatric Cardiology 2007年第1期4卷 20-24页

作者： christopher V. Chien Dani Hackner Ernst R. schwarz Division of Cardiology and Comprehensive Transplant Center Department of Medicine Cedars Sinai Medical Center & University of California Los Angeles (UCLA) Los Angeles California USA

Objective Heart failure is an epidemic in the elderly, but there is a striking lack of data in this clinically important patient population. We investigated the demographics, cardiac performance, and medication management of a segment of the hospital popula- tion in at least their eighth decade of life. Methods We retrospectively reviewed 75 records of heart failure patients who were 80 years of age or older. Records were reviewed for demographic information, presence or absence of diastolic dysfunction, evaluation of ejection fraction, and medication usage including angiotensin-concerting enzyme (ACE) inhibitors, angiotensin receptor antagonists (ARBs), beta-adrenergic blockers, digoxin, and aldosterone antagonists. Assessment for contra-indications to ACE inhibitor or ARBs use was also performed to assess co-morbidities that limit treatment of heart failure. Results The population of very elderly with heart failure is heterogeneous. We found a higher proportion of females as well as higher rates of diastolic dysfunction in patients aged ≥ 90 years compared to patients between the ages of 80-89 years. Usage of ACE inhibitors, ARBs and beta-adrenergic blockers was strikingly low throughout the very elderly population. While co-morbid conditions limited use of agents in many cases, there was a lack of explicit contra-indication in most patients not on an ACE inhibitor or an ARB. Conclusions Heart failure is not a single disease processes, but a continuum of disease processes that vary with age. The elderly with heart failure are an undertreated population, in part due to the multitude of co-morbidities that affect them. Further prospective studies are needed to better understand the physiology and ideal treatment regiment in this growing population.

关键词： heart failure elderly octogenarians nonagenarians centenarians

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Modeling the impact of climate change on sediment transport and morphology in coupled watershed-coast systems:A case study using an integrated approach

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International Journal of Sediment Research 2014年第3期29卷 304-315页

作者： Achilleas g.SAMARAS christopher g KOUTITAS Research Fellow CIRI-ECFluid Dynamics Research UnitUniversity of BolognaVia del Lazzaretto 15/5Bologna 40131Italy Department of Civil Engineering Aristotle University of ThessalonikiUniversity Campus

Climate change is an issue of major concern *** impact on the natural and human environment is studied intensively,as the expected shift in climate will be significant in the next few *** experience shows that the effects will be critical in coastal areas,resulting in erosion and inundation phenomena *** addition to that,coastal areas are subject to "pressures" from upstream watersheds in terms of water quality and sediment *** present paper studies the impact of climate change on sediment transport and morphology in the aforementioned coupled *** study regards a sandy coast and its upstream watershed in Chalkidiki,North greece;it is based on:(a)an integrated approach for the quantitative correlation of the two through numerical modeling,developed by the authors,and(b)a calibrated application of the relevant models Soil and Water Assessment Tool(SWAT)and PELNCON-M,applied to the watershed and the coastal zone,*** examined climate change scenarios focus on a shift of the rainfall distribution towards fewer and more extreme rainfall events,and an increased frequency of occurrence of extreme wave *** indicate the significance of climatic pressures in wide-scale sediment dynamics,and are deemed to provide a useful perspective for researchers and policy planners involved in the study of coastal morphology evolution in a changing climate.

关键词： Climate change Sediment transport Coastal morphology Integrated approach Numerical modeling

Neighboring optimal control for periodic tasks for systems with discontinuous dynamics

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Science China(Information Sciences) 2011年第3期54卷 653-663页

作者： ATKESON christopher g. Robotics Institute Carnegie Mellon University

We propose a trajectory-based optimal control method for periodic tasks for systems with discontinuous dynamics. A general method, dynamic programming, suffers from the problem of dimensionality. We use local models of the optimal control law to construct a local controller. We combine a parametric trajectory optimization method and differential dynamic programming (DDP) to find the optimal periodic trajectory in a periodic task. By formulating the optimal control problem with an infinite time horizon, DDP generates time-invariant local models of the optimal control law. For DDP, the value function at dynamics discontinuities is approximated by a second order Taylor series. The utility of the proposed method is evaluated using simu- lated walking control of a five-link biped robot. The results show lower torques and more robustness from the proposed controller than a PD servo controller.

关键词： trajectory optimization differential dynamic programming optimal control biped walking control

Constructing a taxonomy to support multi-document summarization of dissertation abstracts

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2005年第11期6卷 1258-1267页

作者： KHOO christopher S.g. gOH Dion H. Division of Information Studies School of Communication & Information Nanyang Technological University 639798 SingaporeDivision of Information Studies School of Communication & Information Nanyang Technological University 639798 Singapore

This paper reports part of a study to develop a method for automatic multi-document summarization. The current focus is on dissertation abstracts in the field of sociology. The summarization method uses macro-level and micro-level discourse structure to identify important information that can be extracted from dissertation abstracts, and then uses a variable-based framework to integrate and organize extracted information across dissertation abstracts. This framework focuses more on research concepts and their research relationships found in sociology dissertation abstracts and has a hierarchical structure. A taxonomy is constructed to support the summarization process in two ways：（1） helping to identify important concepts and relations expressed in the text, and （2） providing a structure for linking similar concepts in different abstracts. This paper describes the variable-based framework and the summarization process, and then reports the construction of the taxonomy for supporting the summarization process. An example is provided to show how to use the constructed taxonomy to identify important concepts and integrate the concepts extracted from different abstracts.

关键词： Text summarization Automatic multi-document summarization Variable-based framework Digital library

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Substrate mediated dissolution of redox active nanoparticles;electron transfer over long distances

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Nano Research 2022年第1期15卷 429-437页

作者： Ruo-Chen Xie christopher Batchelor-McAuley Minjun Yang Richard g.Compton Department of Chemistry Physical and Theoretical Chemistry LaboratoryUniversity of OxfordSouth Parks RoadOxford OXl 3QZUK

Reflective dark field microscopy is used to observe the decrease in the light scattered from Ag nanoparticles immobilised on differing solid *** nanoparticles are exposed to solutions containing halide ions,both at open circuit and under potentiostatic control,leading to the loss of the *** coupling optical and electrochemical techniques the physical origin of this transformation is demonstrated to be the electrochemical dissolution of the metal nanoparticles driven by electron transfer to ultra-trace dissolved *** dissolution kinetics of the surface-supported metal nanoparticles is compared on four substrate materials(i.e.,glass,indium titanium oxide,glassy carbon and platinum)with different electrical *** three conductive substrates catalyse the redox-driven dissolution of Ag nanoparticles with the electrons transferred from the nanoparticles,via the macroscopic electrode to the dioxygen electron acceptor.

关键词： substrate electrocatalysis oxidative dissolution metal nanoparticles optical microscopy electrochemistry

Koutecky-Levich analysis applied to nanoparticle modified rotating disk electrodes： Electrocatalysis or misinterpretation？

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Nano Research 2014年第1期7卷 71-78页

作者： Justus Masa christopher Batchelor-McAuley Wolfgang Schuhmann Richard g. Compton Department of Chemistry Physical and Theoretical Chemistry Laboratory University of Oxford South Parks Road Oxford OX13QZ UK Analytische Chemie and Center for Electrochemical Sciences-CES Ruhr-Universitat Bochum Universitatsstr 150 D-44780 Bochum Germany

The application of naive Koutecky-Levich analysis to micro- and nano-particle modified rotating disk electrodes of partially covered and non-planar geometry is critically analysed. Assuming strong overlap of the diffusion fields of the particles such that transport to the entire surface is time-independent and one-dimensional, the observed voltammetric response reflects an apparent electrochemical rate o constant koapp, equal to the true rate constant ko describing the redox reaction of interest on the surface of the nanoparticles and the ratio,ψ, of the total electroactive surface area to the geometric area of the rotating disk surface. It is demonstrated that Koutecky-Levich analysis is applicable and yields the expected plots of I-1 versus ω-1 where I is the current and ω is the rotation speed but that the values of the electrochemical rate constants inferred are thereof koapp, not ko. Thus, for ψ 〉 1 apparent electrocatalysis might be naively but wrongly inferred whereas for ψ 〈 1 the deduced electrochemical rate constant will be less than ko. Moreover, the effect of ψ on the observed rotating disk electrode voltammograms is significant, signalling the need for care in the overly simplistic application of Koutecky-Levich analysis to modified rotating electrodes, as is commonly applied for example in the analysis of possible oxygen reduction catalysts.

关键词： rotating disk electrodes nanoparticles electrocatalysis electrode kinetics electro-reduction ofoxygen Koutecky-Levich analysis