缺血性心肌病的左心室几何变化与心功能关系

目的 探讨缺血性心肌病(ischemic cardiomyopathy,ICM)病人左心室几何形态学变化与其心功能的关系.方法 应用彩色多普勒超声测量ICM 65例及正常人30名左心室几何形态学及其有关左心室收缩功能和舒张功能指标;以左心室球形指数(sphericity index,SI)即左心室长径/短径比值(L/D)作为反映左心室几何构型的变化,比较ICM病人及正常人左心室射血分数(left ventricular ejection fraction,LVEF)、短轴缩短率(shortening fraction,FS)、心脏指数(cardiac index,CI)、收缩期左心室球形指数(left ventricular geometry sphericity index at the end of systole,SIs)、舒张期左心室球形指数(left ventricular geometry sphericity index at the end of diastole,SId)差异,并对各参数行相关分析.结果 ICM病人SI明显降低,SIs与LVEF呈正相关(r=0.7452),SId与EVI/AVI呈正相关(r=0.6597).结论 ICM左心室几何形态变化与其心功能密切相关,心功能愈差,左心室愈趋球形,心室球形化的程度可能预示心功能的减退程度.     

数字化塑形三维钛网早期修补颅骨缺损的临床应用体会

目的：探讨数字化三维钛网对颅骨缺损修补的临床效果。方法将92例颅骨缺损患者按修补方法分为手工塑形组和数字化三维塑形组。对比两组患者颅骨修复的情况、修复后的并发症、生物相容性等。结果手工塑形组部分患者在修补中出现了感染、钛网边缘翘起、皮下积液、癫痫、脑室积水等症状,修补满意度为70.8%。我们在数字化三维钛网塑形组只有3例患者出现了皮下积液,修补满意率为97.7%。结论数字化三维钛网对颅骨缺损的修补效果要好于手工塑形。     

Prerequisites for magnetic resonance image-guided interventions and endoscopic surgery

Summary

Our purpose was to evaluate technological prerequisites and predural principles that enable easy, precise and reproducible magnetic resonance imaging control of interventional procedures, such as biopsy and aspiration of neoplasm or local interstitial drug instillation in adequate time and with the required safety. New MR compatible needles, trocars/cannulae, endoscopes and ancillary equipment were developed or evaluated in collaboration with industry. Sequences, study protocols and the strategies of performing the procedure within the environment of an interventional MRI suite were conceptualized and tested. In 80 patients interventions such as aspiration biopsy, peridural corticoid injection at spinal nerve roots and intratumoural ethanol instillation were performed successfully.     

Incommensurate antiferromagnetism in a pure spin system via cooperative organization of local and itinerant moments

Materials with strong correlations are prone to spin and charge instabilities, driven by Coulomb, magnetic, and lattice interactions. In materials that have significant localized and itinerant spins, it is not obvious which will induce order. We combine electrical transport, X-ray magnetic diffraction, and photoemission studies with band structure calculations to characterize successive antiferromagnetic transitions in GdSi. GdSi has both sizable local moments and a partially nested Fermi surface, without confounding contributions from orbital effects. We identify a route to incommensurate order where neither type of moment dominates, but is rooted in cooperative feedback between them. The nested Fermi surface of the itinerant electrons induces strong interactions between local moments at the nesting vector, whereas the ordered local moments in turn provide the necessary coupling for a spin-density wave to form among the itinerant electrons. This mechanism echoes the cooperative interactions between electrons and ions in charge-density–wave materials, and should be germane across a spectrum of transition-metal and rare-earth intermetallic compounds.     

Thermally Activated Composite with Two-Way and Multi-Shape Memory Effects

The use of shape memory polymer composites is growing rapidly in smart structure applications. In this work, an active asymmetric composite called “controlled behavior composite material (CBCM)” is used as shape memory polymer composite. The programming and the corresponding initial fixity of the composite structure is obtained during a bending test, by heating CBCM above thermal glass transition temperature of the used Epoxy polymer. The shape memory properties of these composites are investigated by a bending test. Three types of recoveries are conducted, two classical recovery tests: unconstrained recovery and constrained recovery, and a new test of partial recovery under load. During recovery, high recovery displacement and force are produced that enables the composite to perform strong two-way actuations along with multi-shape memory effect. The recovery force confirms full recovery with two-way actuation even under a high load. This unique property of CBCM is characterized by the recovered mechanical work.     

鼎力健胶囊的安全性试验

背景与目的:鼎力健胶囊是由蚂蚁粉与中药组成的复方制剂,为确定其对人体健康是否会造成损害,对其进行食品安全性毒理学评价.材料与方法:用急性毒性试验、小鼠骨髓细胞微核试验、小鼠精子畸形试验和Ames试验方法对鼎力健胶囊的急性毒性和遗传毒性进行研究.结果:急性毒性试验大鼠、小鼠最大耐受剂量(maximum tolerated-dose,MTD)均＞20.0 g/kg体重,属无毒级物质;Ames试验、小鼠骨髓细胞微核试验和小鼠睾丸精子畸形试验结果均为阴性.结论:鼎力健胶囊无急性毒性和致突变性.     

Y形钢板加松质骨螺钉固定和尺神经前置治疗肱骨髁间骨折

目的:评价Y形钢板加松质骨螺钉固定及常规尺神经前置治疗肱骨髁间骨折的疗效。方法:2003年7月～2006年6月,采用Y形钢板加松质骨螺钉固定及常规尺神经前置的方式手术治疗肱骨髁间骨折31例。随访资料完整27例,男21例,女6例;年龄16～72岁,平均39岁。肱骨髁间骨折按AO/ASIF分型:C1型17例,C2型8例,C3型2例。除3例合并尺骨鹰嘴骨折经后侧骨折端入路,其余均采用Campbell后侧入路。术后早期肘关节CPM功能练习。结果:随访6～27个月,平均11.8个月,按Cassebaum方法评价疗效:优16例,良8例,可3例。优良率88.9%。3例术前尺神经挫伤随访8个月,1例神经功能恢复不全,另2例均完全恢复。肘关节功能良好。结论:肱骨髁间骨折应尽早解剖复位,尺神经前置可有效减少神经麻痹的发生,对于术前有尺神经挫伤者也有利于神经功能恢复。坚强的固定便于早期功能锻炼,有助于肘关节功能恢复。     

带形状参数的指数均匀B样条模型

本文给出了k(k≥2)阶带形状参数指数多项式的均匀B样条模型.该类模型具有很多与B样条模型相同的性质,并且具有一个可调节的形状参数.由该模型构造的曲线,通过改变形状参数的取值,可以调整曲线接近其控制多边形的程度.该模型可以应用于CAD/CAM领域,作为几何造型一种新的有效模型.