分阶段微创治疗胫骨近端粉碎性骨折

目的探讨分阶段微创治疗胫骨近端粉碎性骨折的临床应用。方法选取自2003年12月至2007年12月94例胫骨中上段粉碎性骨折患者,其中合并开放伤70例,均采用分阶段微创方法治疗。结果随访6～13个月,94例骨折均在术后2～6个月愈合,患肢功能根据Johner—wruhs关节功能评定标准进行评价,优63例,良25例,可6例,优良率93．6％。结论分阶段微创治疗胫骨近段粉碎性骨折,尤其合并开放伤者,疗效满意。     

A new method of STR interpretation using inferential logic -development of a criminal intelligence database

Abstract A short tandem repeat (STR) system consisting of seven multiplexed loci has recently been introduced in the UK to support a National strategy to create large DNA databases for criminal intelligence purposes. The process uses automated sequencers, employing dye-labelled primers. Identification of tetrameric loci such as HUMTH01 are straightforward. Sizing windows are estimated by running a series of control allelic ladders on several gels and unknown samples are designated if they fall within a defined window. However, utilisation of complex STRs (eg. D21 S 11) characteristically have common variants which differ by just 2 bp. In addition, rare alleles are encountered which may differ by just 1 by from a common variant. To assist with the identification of alleles, we have introduced a series of allelic ladders, so that direct comparisons with unknown samples can be made on the same gel. To designate an allele, it should be within 0.5 by of an allelic ladder marker. Not all alleles (in particular rare alleles) can be included within an allelic ladder, however their expected positions can be easily calculated by reference to existing alleles in the ladder. Measurement of band shift is also a useful diagnostic tool. A series of guidelines are described to enable reliable allelic identification. These guidelines can be converted into computer programmes, which form the basis of an expert system.     

WebDISCO: a web service for distributed cox model learning without patient-level data sharing

Objective The Cox proportional hazards model is a widely used method for analyzing survival data. To achieve sufficient statistical power in a survival analysis, it usually requires a large amount of data. Data sharing across institutions could be a potential workaround for providing this added power.Methods and materials The authors develop a web service for distributed Cox model learning (WebDISCO), which focuses on the proof-of-concept and algorithm development for federated survival analysis. The sensitive patient-level data can be processed locally and only the less-sensitive intermediate statistics are exchanged to build a global Cox model. Mathematical derivation shows that the proposed distributed algorithm is identical to the centralized Cox model.Results The authors evaluated the proposed framework at the University of California, San Diego (UCSD), Emory, and Duke. The experimental results show that both distributed and centralized models result in near-identical model coefficients with differences in the range 10^?15 to 10^?12. The results confirm the mathematical derivation and show that the implementation of the distributed model can achieve the same results as the centralized implementation.Limitation The proposed method serves as a proof of concept, in which a publicly available dataset was used to evaluate the performance. The authors do not intend to suggest that this method can resolve policy and engineering issues related to the federated use of institutional data, but they should serve as evidence of the technical feasibility of the proposed approach.Conclusions WebDISCO (Web-based Distributed Cox Regression Model; https://webdisco.ucsd-dbmi.org:8443/cox/) provides a proof-of-concept web service that implements a distributed algorithm to conduct distributed survival analysis without sharing patient level data.     

前正中切口联合微创内固定系统双钢板固定C3型股骨远端骨折的疗效分析

目的 探讨前正中切口联合微创内固定系统(less invasive stabilization systems,LISS)双钢板固定AO-C3型股骨远端骨折的临床疗效.方法 筛选2014年6月至2017年3月我科采用膝关节置换术中常用的前正中切口联合LISS双钢板固定治疗AO-C3型股骨远端骨折的患者18例,其中男性12例,女性6例,年龄19 ～ 62岁.包括交通伤11例,高坠伤7例;6例为开放性骨折,12例为闭合性骨折.最后1次随访中采用Kolment和Wulff(1982)治疗评价标准评定内固定术后膝关节功能.结果 18例患者手术时间平均145(110 ～ 200) min,术后均获得17.5(12 ～25)个月随访,术后骨折平均愈合时间22(20 ～26)周,骨折全部愈合,未出现骨折不愈合、感染、骨髓炎及神经血管损伤等并发症.对末次随访患者按照Kolment和Wulff(1982)治疗评价标准进行评估:优6例,良9例,可2例,差1例,优良率达83.33％.结论 采用的膝关节前正中切口可充分暴露股骨远端关节面,术中显露清晰,便于关节面骨折的解剖复位,可一期处理关节内结构损伤,同时联合LISS双钢板牢固固定骨折,避免对骨折断段软组织的过多剥离,允许术后即刻进行有效的早期功能锻炼,可以取得良好的疗效.     

七氟醚麻醉下瑞芬太尼抑制小儿气管插管心血管反应的半数有效血浆靶浓度

目的 确定七氟醚麻醉下瑞芬太尼抑制小儿气管插管心血管反应的半数有效血浆靶浓度(Cp<50).方法 择期全麻手术患儿,年龄2～5岁,ASA Ⅰ或Ⅱ级.初始七氟醚吸入浓度为8%,氧流量3 L/min,待患儿意识消失后调整七氟醚吸入浓度,使呼气末七氟醚浓度为2.5%(1 MAC),2 min后采用Minto药代动力学模型靶控输注瑞芬太尼,10 min后进行气管插管.瑞芬太尼血浆靶浓度按序贯法确定,瑞芬太尼血浆靶浓度从6μg/L开始,相邻浓度的比值为1.2,气管插管心血管反应的标准:插管后2 min内MAP和/或HR较插管前升高≥15%.结果 瑞芬太尼抑制气管插管心血管反应的Cp50为3.6μg/L,95%可信区间为3.1～4.0μg/L.结论 七氟醚1 MAC麻醉下瑞芬太尼抑制小儿气管插管心血管反应的Cp50为3.6 μg/L,95%可信区间为3.1～4.0μg/L.     

Polynomial matrix solution of H2 optimal control problem for state‐space systems

A polynomial matrix solution to the H₂ output feedback optimal control problems is obtained for systems represented in state‐equation form. The proof does not invoke the separation principle but is obtained in the z‐domain. The cost function includes weighted states, which allows the so‐called standard system model problem to be solved. This encompasses the class of inferential control problems. The results also enable the two‐degree‐of‐freedom optimal control solution properties to be explored. Copyright © 2002 John Wiley & Sons, Ltd.     

靶控输注异丙酚意识消失时血浆和效应室浓度的EC50与脑电双频谱指数的关系多中心大样本临床研究

目的 研究择期手术患者靶控输注（TCI）异丙酚意识消失时血浆、效应室靶浓度的50%患者意识消失时的药物浓度（EC50）与脑电双频谱指数（BIS）的关系。方法 5家医疗中心405例择期手术患者（国人）,ASAⅠ或Ⅱ级。靶控输注异丙酚,以血浆靶浓度1．2μg/ml为起点,到达预期血浆靶浓度后每30秒递增0．3μg/ml,直至患者意识消失。采用概率单位回归分析计算患者意识消失时异丙酚血浆靶浓度、效应室靶浓度的EC05、EC50和EC95及其所对应的BIS。结果 择期手术患者TCI异丙酚意识消失时异丙酚血浆靶浓度EC05、EC50和EC95分别是2．9μg/ml、3．8μg/ml和4．8μg/ml,效应室靶浓度EC05、EC50和EC95分别是1．3μg/ml、2．2μg/ml和3．2μg/ml,50%患者意识消失的BIS是58,5%和95%患者意识消失的BIS分别是77和40。结论 择期手术患者TCI异丙酚意识消失时血浆靶浓度和效应室靶浓度EC50及95%置信区间分别是3．8μg/ml（3．8～3．9μg/ml）和2．2μg/ml（2．2～2．3μg/ml）, 50%患者意识消失的BIS用95%置信区间是58（58～59）。     

不同靶浓度瑞芬太尼对腹部手术患者七氟醚MACBAR的影响

目的比较不同血浆靶浓度瑞芬太尼对七氟醚抑制50%腹部手术患者切皮时血液动力学反应的最低肺泡有效浓度(MAC_(BAR))的影响。方法择期腹部手术患者75例,ASAⅠ级或Ⅱ级,年龄20～50岁,随机分为3组(n=25):不用瑞芬太尼组(R_0组)、瑞芬太尼靶浓度1 ng/ml组(R_1组)、瑞芬太尼靶浓度2 ng/ml组(R_2组)。3组均静脉注射异丙酚2 mg/kg、维库溴铵0.1 mg/kg及靶控输注瑞芬太尼(血浆靶浓度2 ng/ml)麻醉诱导,气管插管后吸入七氟醚维持麻醉.各组初始呼气末七氟醚浓度为3%。R_0组气管插管后立即停用瑞芬太尼,R_1组和R_2组血浆靶浓度分别改为1、2 ng/ml继续靶控输注。采用改良的序贯法根据手术切皮时患者HR或MAP的变化对每组切皮时七氟醚MAC_(BAR)进行观察。根据平衡点后面的呼气末七氟醚浓度,计算每组平均呼气末七氟醚浓度,即为每组的MAC_(BAR)。结果R_0组MAC_(BAR)为(3.16±0.07)%;R_1组为(1.51±0.08)%;R_2组为(0.85±0.03)%,3组间比较差异有统计学意义(P<0.01)。结论靶浓度1 ng/ml和2 ng/ml瑞芬太尼可分别降低腹部手术患者七氟醚MAC_(BAK)51%和74%。     

老年患者不同靶浓度罗库溴铵肌松效应的比较

目的比较老年患者不同靶浓度罗库溴铵的肌松效应。方法择期全麻老年患者100例,ASAⅡ级,随机分为4组(n=25),A组、B组和C组麻醉诱导气管插管时效应室靶浓度(Ce)为3μg/ ml,术中维持Ce分别为0.6、0.8、1.0μg/ml;D组麻醉诱导气管插管时Ce为3.3μg/ml,术中维持Ce为0_8μg/ml。记录肌松起效时间、恢复时间和恢复指数。评价气管插管条件和术中肌松程度。记录手术及TCI时间、罗库溴铵总用药量和期间用药量[总用药量,(体重×TCI时间)]。结果4组均可顺利完成气管插管,D组起效时间较A组、B组和C组缩短(P<0.05);A组肌松满意率低,B组、C组和D组均可维持满意肌松,但C组罗库溴铵用量较多,术中肌松程度较大,术后恢复时间较长(P<0.05)。结论麻醉诱导气管插管时罗库溴铵Ce为3.3μg/ml、术中麻醉维持Ce为0.8μg/ml,可产生满意的肌松条件,且有利于术后肌松恢复,是一种适用于老年患者合理的TCI给药方案。