关节镜治疗髋关节疾病的临床研究

目的:研究髋关节镜治疗髋关节疾病的方法、疗效及适应证,探讨髋关节镜在髋关节疾病中的临床价值。方法:研究对象为86例有明显髋关节疼痛的患者,包括股骨头坏死(osteonecrosis,ON)(43%)、盂唇损伤(20%)、退行性关节病变(degenerative joint disease,DJD)(10%)、股骨头骨骺缺血性坏死(Legg-Calve'-Perthes,LCP)(10%)、髋关节游离体(10%)、髋关节疼痛(100%)、机械性损伤(78%)、运动损伤(56%)。对患者采用仰卧位进行髋关节镜检查,使用牵引床,300或700,前外侧入口。观察不同疾病在治疗后的预后结果。结果:所有患者均无并发症,平均随访时间30个月,有60%的患者疼痛症状得到缓解。盂唇(91%,P0.003)或LCP(89%,P0.05)患者疗效较好,而ON和DJD患者疼痛症状缓解较差,改善率仅为40%和44%。在吻合血管游离腓骨移植(free-vascularized fibular graft,FVEG)的患者中有34%在随访期间得到改善(P=0.003)。其中18名患者(21%)进行了全髋关节置换术。结论:髋关节镜手术对于游离体、盂唇损伤、局灶性软骨病变、晚期LCP后遗症患者有良好的治疗效果;对股骨头坏死的治疗效果不佳。     

Dynamic conformational changes due to the ATP hydrolysis in the motor domain of myosin: 10-ns molecular dynamics simulations

Muscle contraction is caused by directed movement of myosin heads along actin filaments. This movement is triggered by ATP hydrolysis, which occurs within the motor domain of myosin. The mechanism for this intramolecular process remains unknown owing to a lack of ways to observe the detailed motions of each atom in the myosin molecule. We carried out 10-ns all-atom molecular dynamics simulations to investigate the types of dynamic conformational changes produced in the motor domain by the energy released from ATP hydrolysis. The results revealed that the thermal fluctuations modulated by perturbation of ATP hydrolysis are biased in one direction that is relevant to directed movement of the myosin head along the actin filament.     

近年来乌梁素海疣鼻天鹅种群数量变化及原因分析

为查清内蒙古乌梁素海湖泊湿地疣鼻天鹅(Cygnus olor)繁殖期和秋季迁徙前期种群数量,2014至2017年采用路线统计法和样点统计法对其进行精确计数统计,结合近十余年来的文献数据和监测记录,探讨了种群数量的变化及原因。结果显示,2015至2017年春季繁殖成鸟数量依次为84只、92只、80只,基本稳定;2014至2017年,秋季种群数量依次为411只、302只、281只、153只,逐年减少;近几年适宜繁殖地和觅食地面积不断缩小、天敌偷袭、捡蛋和投毒等因素影响亚成鸟和幼鸟的生存。根据文献和保护区监测数据,1996至2004年种群数量逐年增多,与自然保护区的建立、严禁捡蛋和没收猎枪有关,而2005至2013年因干旱缺水、水域被开发利用、芦苇(Phragmites australis)和宽叶香蒲(Typhalatifolia)面积扩增、水质恶化、富营养化加重等原因种群数量下降。研究表明,近几年乌梁素海被过度开发利用,人为干扰频繁,影响疣鼻天鹅正常繁殖栖息;栖息地的科学管理和严禁捡蛋及投毒行为,对该种群的生存及增长至关重要。     

Hazard function for cancer patients and cancer cell dynamics

The aim of the paper is to develop a procedure for an estimate of an analytical form of a hazard function for cancer patients. Although a deterministic approach based on cancer cell population dynamics yields the analytical expression, it depends on several parameters which should be estimated. On the other hand, a kernel estimate is an effective nonparametric method for estimating hazard functions. This method provides the pointwise estimate of the hazard function. Our procedure consists of two steps: in the first step we find the kernel estimate of the hazard function and in the second step the parameters in the deterministic model are obtained by the least squares method. A simulation study with different types of censorship is carried out and the developed procedure is applied to real data.     

A reliable Taylor series-based computational method for the calculation of dynamic sensitivities in large-scale metabolic reaction systems: Algorithm and software evaluation

Dynamic sensitivity analysis has become an important tool to successfully characterize all sorts of biological systems. However, when the analysis is carried out on large scale systems, it becomes imperative to employ a highly accurate computational method in order to obtain reliable values. Furthermore, the preliminary laborious mathematical operations required by current software before the computation of dynamic sensitivities makes it inconvenient for a significant number of unacquainted users. To satisfy these needs, the present work investigates a newly developed algorithm consisting of a combination of Taylor series method that can directly execute Taylor expansions for simultaneous non-linear-differential equations and a simple but highly-accurate numerical differentiation method based on finite-difference formulas. Applications to three examples of biochemical systems indicate that the proposed method makes it possible to compute the dynamic sensitivity values with highly-reliable accuracies and also allows to readily compute them by setting up only the differential equations for metabolite concentrations in the computer program. Also, it is found that the Padé approximation introduced in the Taylor series method shortens the computation time greatly because it stabilizes the computation so that it allows us to use larger stepsizes in the numerical integration. Consequently, the calculated results suggest that the proposed computational method, in addition to being user-friendly, makes it possible to perform dynamic sensitivity analysis in large-scale metabolic reaction systems both efficiently and reliably.     

Allele fixation in a dynamic metapopulation: Founder effects vs refuge effects

The fixation of mutant alleles has been studied with models assuming various spatial population structures. In these models, the structure of the metapopulation that we call the “landscape” (number, size and connectivity of subpopulations) is often static. However, natural populations are subject to repetitive population size variations, fragmentation and secondary contacts at different spatiotemporal scales due to geological, climatic and ecological processes. In this paper, we examine how such dynamic landscapes can alter mutant fixation probability and time to fixation. We consider three stochastic landscape dynamics: (i) the population is subject to repetitive bottlenecks, (ii) to the repeated alternation of fragmentation and fusion of demes with a constant population carrying capacity, (iii) idem with a variable carrying capacity. We show by deriving a variance, a coalescent and a harmonic mean population effective size, and with simulations that these landscape dynamics generate repetitive founder effects which counteract selection, thereby decreasing the fixation probability of an advantageous mutant but accelerate fixation when it occurs. For models (ii) and (iii), we also highlight an antagonistic “refuge effect” which can strongly delay mutant fixation. The predominance of either founder effects or refuge effects determines the time to fixation and mainly depends on the characteristic time scales of the landscape dynamics.     

Sex determination of fetal and neonate skeletons by means of discriminant analysis

Facing the requirements of refined paleodemographical analyses, the access to the early ontogenetic sex ratio of skeletal populations is an important feature. Using raw data provided byFazekas & Kosa (1978) for a sample of known sex, discriminant functions are derived from hip and thigh bone dimensions that allow an almost unbiased classification of more than 70% of fetal and neonate individuals.     

PFNA内固定在老年人股骨转子间骨折的手术效果及对髋关节功能改善效果

目的:研究股骨近端螺旋刀片抗旋髓内钉(PFNA)内固定治疗老年股骨转子间骨折的效果及对髋关节功能影响。方法:研究对象选取我院2012年8月到2015年5月间收治的老年股骨转子间骨折患者86例,采用随机数字法将其分为对照组(43例)和观察组(43例)。对照组患者接受动力髋螺钉(DHS)内固定治疗,观察组患者接受PFNA内固定治疗。比较两组患者的手术效果和并发症发生率,同时术后随访,比较两组患者的髋关节功能评分和炎症因子表达水平。结果:在手术时间、术中出血量、卧床时间及骨折愈合时间方面,观察组均明显低于对照组(P0.01);观察组的总并发症发生率(4.66%)明显低于对照组(20.94%)(x~2=5.11,P=0.02);术后随访6个月,两组的Harris髋关节功能评分优良率比较无明显差异(P0.05);手术后,血清IL-6、IL-10、TNF-α表达水平,观察组均明显低于对照组(P0.01)。结论:PFNA治疗老年股骨转子间骨折的效果显著,手术创伤较小,术中出血量低,且并发症较低,且术后髋关节功能恢复效果较好,值得在临床推广。     

40多年来塔南策勒绿洲动态变化研究

 利用策勒绿洲1956、1990和1998年3个不同时期的遥感数据（航片、TM和SPOT）进行配准、解译与分类处理,比较分析绿洲40多年来的动态变化,并从自然和人为因素两个方面探讨绿洲变化的原因。结果表明,从1956年到1998年策勒绿洲西北部的景观格局发生了显著变化,绿洲面积增加了近20％;林地的分布明显改变;河道发生显著位移,据实地调查大约向北移动400 m。对1990年TM与1998年SPOT分类数据,用FRAGSTATS软件计算景观格局指数并比较分析,发现研究区的绿洲、绿洲 荒漠交错带、荒漠和沙丘4种景观类型发生了明显的变化。绿洲面积增加而斑块数减少了近一半;交错带面积减少而斑块数增加了35％;荒漠面积减少而斑块数增加了60％;沙丘面积基本没有变化但斑块数减少了20％。绿洲变化的总体趋势是人工绿洲的面积增大而绿洲 荒漠交错带的面积明显减少,同时整个绿洲的破碎度增加而连通性降低,绿洲的稳定性和自我调节的功能下降。     

Hierro intravenoso,recuperación funcional y delirium en pacientes con fractura de cadera. Estudio FEDEREF. Ensayo clínico unicéntrico aleatorizado,controlado con placebo,doble ciego. Número EudraCT: 2014-001923-53

Introduction

There are no previous studies evaluating the effect of intravenous iron therapy on functional and cognitive status of patients with hip fracture (HF).