车-人碰撞事故中行人胫骨撞击响应的二维数值分析

目的基于两相多孔弹性胫骨模型,建立一种车-人碰撞事故中行人胫骨撞击响应的二维数值分析方法。方法选用健康成年男性胫骨行CT分层扫描,结合数值插值方法获得胫骨的结构参数;在两相饱和多孔弹性理论的框架内,建立胫骨动力学控制方程组;采用自行开发的流-固耦合两相多孔介质有限元数值分析程序,数值模拟小汽车车头从侧向撞击行人下肢的动力学过程,并计算撞击载荷作用下0-200ms内行人胫骨的动力学响应。结果胫骨的弯曲变形主要集中在撞击载荷作用的区域;胫骨骨干上节点107处的侧向位移响应,约在75ms时刻出现峰值位移（-6mm）,对撞击载荷有明显的时间滞后;胫骨骨干上单元E77中心处的轴向应力响应,约在30ms时刻出现峰值应力（140MPa）,对撞击载荷也有明显的时间滞后。结论本研究所建立的对车-人碰撞事故中行人胫骨撞击响应的二维数值分析方法,能够近似地模拟胫骨撞击区的弯曲变形、侧向位移响应和轴向应力响应以及胫骨中骨髓流体组分对骨架固体组分动力学特性的影响。下一步研究将在现有初步结果的基础上提高胫骨动力学模型的生物仿真性。     

小剂量阿托伐他汀治疗老年高血压伴血脂异常的疗效观察

高血压 ,总胆固醇 (TC)及低密度脂蛋白胆固醇 (LDL C)是冠心病的主要危险因子 ,本文旨在探讨对高血压合并轻中度高胆固醇患者在降压治疗的同时给予小剂量阿托伐他汀 ,对血脂异常的治疗作用及临床意义。1　对象及方法1.1　病例选择　来自门诊的 64例原发性高血压患者 ,男 3 6例 ,女 2 8例 ,年龄 65～ 76岁 ,平均 (69 2± 3 3 )岁 ,高血压史 9～ 18年 ,平均 (14 2± 5 3 )年 ,血压 (14 5～182 ) /(94～ 118)mmHg ,平均 15 8/10 2mmHg。保持平常饮食 ,2周内空腹静脉采血 2次 ,取平均值 ,TC >5 72mmol·L-1的患者入选。排除肝肾疾病 ,…     

Animal study on Iung injury caused by simulant segmented shock waves

OBJECTIVE: To study the lung injury caused by segmented shock waves. METHODS: A total of 60 rabbits and 20 rats were used in this study. The process of transmission of shock waves was divided into three phases, i.e., the recompression phase (RP), the decompression phase (DP) and the underpressure phase (UP). And the recompression wave (RW), the decompression wave (DW) a nd the underpressure wave (UW) simulated the three phases, respectively, generated by the equipment designed by us. The RW test, DW test and UW test were respectively applied to the animals. And lung injuries caused by segmented shock waves were discussed. RESULTS: Under the experimental conditions, the RW did not cause obvious lung injury, but the DW could cause different severities of lung injuries. The greater the decompression ranged and the shorter the decompression duration was adopted, the more severe the lung injury was observed. The UW, to some extent, could cause obvious lung injury. CONCLUSIONS: It suggests that lung injury under shock waves probably occurs during the DP primarily. It probably does not cause direct obvious lung injury during the RP, but significantly influences the capability of causing lung injury during the DP.     

松质骨内液体渗透特性研究

通过把松质骨材料复杂结构简化形成立方框架结构,利用简化的等效单元流道,考虑固体网架表面对孔间骨髓等流体的摩擦阻力作用,得到了在高孔隙率松质骨中的压力降与流速的关系式及松质骨材料渗透率的估计式。通过专用的实验装置测定了两种不同孔径松质骨的渗透率。结果表明,根据所给模型理论预测的结果和实验值一致性较好,在松质骨力学行为研究中能够提供渗透特性的相关数据。     

Histological and enzymohistochemical observation of experimental muscle sprain

In the fields of orthopedics and sport medicine, there are more reports about injury and repair of bones, cartilages, tendons and few report about skeletal muscle injury[1－ 3].Most of the reports about skeletal muscle injury are about contusion,abrasion and delayed muscle aching pain.But in sports training, muscle sprain ,especially partial muscle sprain,is more common[4].Histological and enzymohistochemical changes after sprain were observed and the foundation of advanced research on prevent…     

Rabbit lung injury induced by explosive decompression

Objective:To study the mechanism of rabbit lung injury caused by explosive decompression.Methos:A total of 42 rabbits and 10 rats were werved as the experimental animals.A slow recompression-decompression test and an explosive decompression test were applied to the animals,respectively.And the effects of the given tests on the animals were discussed.Results:The slow recompression-decompression did not cause an obvious lung injury,but the explosive decompression did cause lung injuries in different degrees.The greater the decompression range was,the shorter the decompression duration was,and the heavier the lung injuries were.Conclusions:Explosive decompression can cause a similar lung injury as shock wave does.The primary mechanical causes of the lung injury might be a tensile strain or stress in the alveolar wall and the pulmonary surface‘s impacts on the inside wall of the chest.     

中等强度冲击波负压暴露后豚鼠内耳损伤的治疗

目的 探讨豚鼠中等强度冲击波负压重复暴露后,高压氧和（或）地塞米松＋甲钴铵对内耳损伤的治疗效果。方法 32只豚鼠于实验性冲击波负压重复暴露3次后,立即分别给予高压氧治疗、肌注地塞米松＋甲钴胺治疗、肌注地塞米松＋甲钴胺＋高压氧治疗,对照组不接受任何治疗。各治疗组动物于治疗前、治疗后2小时-21天分别测试听性脑干反应（ABR）阈值,在光镜和扫描电镜下观察耳蜗毛细胞形态学改变,并将其与对照组进行对比分析。结果 实验性冲击波负压重复暴露后即刻,各治疗组动物ABR阈值明显升高（P〈0．01）,治疗21天后呈部分恢复。治疗21天后,各治疗组动物耳蜗毛细胞缺失少于对照组。在上述3种治疗方案中,以地塞米松＋甲钴胺＋高压氧联合应用对听器损伤的治疗效果最为明显。结论 在中等强度冲击波负压重复暴露造成豚鼠内耳损伤后,及时给予高压氧吸入及地塞米松和甲钴胺2种药物联合治疗,可有效促进听力功能的恢复并减轻耳蜗毛细胞损害程度。     

豚鼠冲击波负压暴露后耳蜗毛细胞损害定量观察

目的 探讨冲击波负压（blast underpressure,BUP）暴露后豚鼠耳蜗毛细胞损害特点.方法将豚鼠暴露实验性BUP 14天后处死,硝酸银染色硬铺片法计数观察耳蜗基底膜毛细胞损伤情况.结果压力峰值介于-22.4kPa和-63.3kPa之间的实验性BUP暴露后,豚鼠耳蜗外毛细胞出现了明显的病理性改变,损伤的程度以第二转最重,第二排和第三排的病变比第一排更为严重.BUP强度越高,毛细胞损害越重.各实验组动物的外毛细胞总缺失率明显高于正常对照组（P＜0.01）;重复暴露3次的动物外毛细胞缺失率明显高于暴露1次的动物（P＜0.01）.结论BUP暴露可引起明显的豚鼠耳蜗外毛细胞缺失等损害,其损害程度与负压峰值及暴露次数密切相关;毛细胞损害越重,ABR阈移也就越明显.     

汽车侧面碰撞交通伤的伤情特点实验研究

目的探讨猪轿车实车侧面90°碰撞交通伤的发生情况和伤情特点。方法分别以坐姿将大白猪固定于轿车驾驶员及前排乘员座椅上,在计算机控制下,牵引系统以50km/h的速度驱动台车碰撞正前方横停的轿车,以90°角撞击轿车左侧车体。观察现场至伤后24小时动物存活情况,采用解剖学、病理学方法观察形态改变,评判撞击伤发生和伤情特点。结果汽车侧撞致伤后,驾驶员座位猪的伤情重于前排乘员座位猪,24小时内死亡率75%。前排乘员座位猪伤后全部存活24小时以上。主要死亡原因为呼吸衰竭、失血性休克及多脏器损伤。结论车辆侧面90°高速碰撞,车内驾驶员位置乘员更易致伤,而且伤情较前排乘员严重且死亡率高。     

基于纹理分析和深度学习的肝纤维化研究进展

【摘要】肝纤维化的早期诊断和治疗,对于防治肝硬化、肝癌有重要价值,肝纤维化的非创伤性影像学诊断一直以来都是肝纤维化研究的重点。近年来,针对目前影像学检查包含的大量多模态图像信息,利用影像组学和深度学习等人工智能方法,通过分析图像中的人眼不能直接识别的海量图像信息实现辅助临床诊断受到社会各界的广泛关注。目前纹理分析和深度学习等方法在肝纤维化无创性诊断方面已经取得有效的临床进展。