直视下经尿道内切开术治疗尿道狭窄

目的：探讨直视下经尿道内次切开术治疗尿道狭窄的有效性和安全性。方法：总结直视下经尿道内切开术治疗68例尿道狭窄和闭锁患者的疗效和经验，63例1次手术成功；3例行2次、2例行3次成功。结果：68例中，57例术后随访3～71个月，平均28．3个月，43例(75％)均排尿通畅；2例暂时性尿失禁者分别于术后3～6月内恢复。结论：直视下经尿道内切开术创伤小，并发症少，疗效确切，是尿道狭窄和闭锁的首选治疗方法。     

椎弓根钉内固定治疗胸腰椎骨折

目的：探讨脊柱胸腰段骨折椎弓根钉内固定治疗效果。方法：临床收治脊柱胸腰段骨折72例，均采用后路减压，Dick或RF系统钉内固定手术治疗。比较手术前后骨折复位及神经功能恢复情况。结果：术后椎体高度完全或基本恢复占95．8％，神经功能有Frankel一级以上改善，不完全截瘫占90％，完全截瘫占53．1％。随访3—38个月，无螺钉折断、后退及脊柱矫正度丢失。结论：开放复位后路椎弓根钉内固定是治疗胸腰椎骨折的有效方法。     

影响髋臼骨折治疗效果的各种因素

许多因素可以影响髋臼骨折的治疗效果。据文献可归纳为:①伤前相关因素:骨骼质量,患者年龄,身体的其他疾病情况及病人对功能的期望;②受伤相关因素:骨折类型,是否有神经损伤,股骨头脱位及股骨头软骨损伤情况,软组织损伤程度及其他并发损伤;③手术因素:损伤与手术间隔的时间,手术复位的精确度与术后髋关节的稳定性,手术医师的经验,手术入路选择的合理性,医院条件,手术并发症等。     

经舟骨月骨周围脱位的早期手术治疗

目的　研究经舟骨月骨周围脱位早期复位并进行切开内固定和修复损伤的腕掌侧关节囊和韧带的治疗方法。方法　从1995年 6月～ 2 0 0 1年 6月 ,共 7例经舟骨月骨周围脱位患者接受这种治疗方法。手术均在受伤后 2周内进行 ,所有患者均为后脱位。结果　 7例都得到随访 ,平均随访时间 2 0 5个月。 6例舟骨骨折愈合 ,腕关节功能恢复良好 ;1例出现骨不连 ,腕关节功能部分受限。尚未发现月骨坏死者。采用Cooney评分法 :优 2例、良 3例、可 1例和差 1例 ,优良率 71 4 %。结论　经舟骨月骨周围脱位应早期复位及切开内固定治疗 ,同时修复损伤的腕掌侧关节囊、桡舟头韧带和桡舟月韧带。可早期提供腕舟骨稳固的固定 ,有利于舟骨近段和月骨血供的恢复。     

切开复位内固定治疗股骨髁间骨折

目的探讨股骨髁间骨折的切开复位内固定临床价值。方法自1995年7月～2001年12月,采用切开复位,普通钢板、95°角钢板、DCS或髁部支撑钢板等内固定治疗股骨髁间骨折32例。根据AO/ASIF分类,C1型13例,C2型10例,C3型9例。根据术前术后X线片及术后膝关节功能恢复情况评价内固定效果。结果27例获得随访,随访时间9个月～7年,根据Sanders评分标准,优14例,良9例,差4例。结论切开复位内固定是治疗股骨髁间骨折的理想选择。     

双凤尾钢板植骨内固定治疗胸腰椎爆裂骨折的生物力学测试

目的 对双凤尾钢板治疗胸腰椎爆裂骨折进行生物力学评价和临床应用观察。方法 取成年男性尸体脊柱标本(T12-L2),制成8具L1椎体爆裂骨折模型。按实际手术方法放置双凤尾钢板。对试件分别进行轴向和弯曲扭转加载测试。临床观察应用双凤尾钢板治疗胸腰椎爆裂骨折的效果。结果 压缩实验和弯曲扭转实验中,各点应变值与载荷均呈线性关系。当轴向载荷达到600N或扭矩达到600N·cm时,这种线性关系未改变。弯扭矩与模型两端之间相对扭转角的增加呈线性关系。弯扭矩达到600N·cm时,扭转角只有6.26°。临床观察表明双凤尾钢板固定可靠。结论 双凤尾钢板固定具有良好的稳定性,表现出高弹性,符合生物学固定的原则。值得临床推广应用。     

Distribution of the largest neuron in mouse caudate-putamen nucleus: Its position in large-cell — Medium-cell clusters

Summary The position of the largest striatal neuron within territories delimited by medium-sized clustered neurons was charted in Nissl-stained sections through the mouse caudate-putamen nucleus. Medium-sized neuron somata occur in close proximity to this large cell at some point in the anteroposterior, mediolateral or dorsoventral extent of its soma. The size of the network of medium-sized neurons associated with the large cell may vary from two to 15 neurons. Even when this network is extensive, the large neuron is never completely surrounded. Most often, this cell also borders a fascicle of internal capsule fibers, and the entire cellular island may be aligned either parallel to or perpendicular to the orientation of these fibers. These findings suggest the hypothesis that cellular territories in the caudate-putamen nucleus have a very specific orientation in three dimensional space.     

Nondestructive evaluation of blood flow in a dialyzer using X-ray computed tomography

It is very important to observe the concentrations and flow patterns of blood through a dialyzer to evaluate its function and to obtain the most appropriate design. We established a visualization method for the blood flow pattern in a dialyzer using X-ray computed tomography, and investigated the so-called internal filtration phenomenon. The results obtained were as follows: (1) The influence of 5% BaSO₄, which was added to the blood as a contrast medium, on the filtration rate of the dialyzer was minimal. (2) The relationship between the concentration of BaSO₄ and the Hounsfield unit value was expressed by linear regression. (3) Hounsfield unit values increased massively just after blood entered the dialyzer and peak values increased with dialysate perfusion under the following conditions: the dialyzer (BS-1.6UL, polysulfone hollow fibers) was used, and bovine blood with 5% BaSO₄ added was used at a blood flow rate of 200ml/min. The dialysate flow rate was 500ml/min and the slice thickness of X-ray computed tomography was 1–10mm. (4) It was observed that blood flowed slightly faster in the center than the peripheral portion of the dialyzer, when the flow pattern was followed after pulse injection of blood containing 20% BaSO₄ into the dialyzer. It was concluded that this method could possibly be utilized not only qualitatively but also quantitatively for observation of the real state of blood flow and in designing dialyzers.     

A mixture of experts network structure for modelling Doppler ultrasound blood flow signals

Mixture of experts (ME) is a modular neural network architecture for supervised learning. This paper illustrates the use of ME network structure to guide modelling Doppler ultrasound blood flow signals. Expectation-Maximization (EM) algorithm was used for training the ME so that the learning process is decoupled in a manner that fits well with the modular structure. The ophthalmic and internal carotid arterial Doppler signals were decomposed into time-frequency representations using discrete wavelet transform and statistical features were calculated to depict their distribution. The ME network structures were implemented for diagnosis of ophthalmic and internal carotid arterial disorders using the statistical features as inputs. To improve diagnostic accuracy, the outputs of expert networks were combined by a gating network simultaneously trained in order to stochastically select the expert that is performing the best at solving the problem. The ME network structure achieved accuracy rates which were higher than that of the stand-alone neural network models.     

Pyrford钢丝环扎加张力带内固定治疗髌骨骨折的生物力学分析

目的　测试Pyrford钢丝环扎加张力带内固定治疗髌骨骨折的生物力学特性 ,为临床治疗提供理论依据。方法　采集新鲜牛尸体膝关节标本 6具 ,制成髌骨骨折模型 ,用Pyrford钢丝环扎加张力带固定 ,并与克氏针张力带、单纯钢丝环扎进行对照比较。结果　Pyrford钢丝环扎加张力带内固定完全符合髌骨的生物力学性能 ,与克氏针张力带相当 ,能满足膝关节的强度 ,符合人体正常生理功能要求。结论　Pyrford钢丝环扎加张力带固定治疗髌骨骨折 ,具有优越的生物力学性能 ,且能达到解剖复位 ,操作简便 ,固定牢固 ,适应早期功能锻炼的目的