火灾损伤后公路预应力空心板残余承载能力的试验研究

结合辽宁某高速公路桥梁受火后的承载能力试验，分析受火灾后预应力空心板的性能变化情况，总结初步确定火灾损伤后公路预应力空心板梁残余承载能力的一种方法。     

缺血预适应对大鼠移植小肠的早期保护作用

目的　研究缺血预适应 (IPC)对大鼠移植小肠上皮细胞和细胞外基质的早期保护作用。方法　SD大鼠随机分为正常对照组 (假手术组 ,S组 ,n =6 ) ,小肠移植组 (SBT组 ,n =12 )和缺血预适应加小肠移植组 (ISBT ,n =12 )。建立大鼠异位节段小肠移植模型。移植肠血管重建成功之后 ,再灌注 1h各组取材。免疫组化定量检测层粘连蛋白 (lami nin ,LN)表达。原位末端标记检测移植小肠上皮细胞凋亡。透射电子显微镜观察各组小肠上皮基底膜结构变化。结果　S组、SBT组、ISBT组LN表达分别为 39.5 2± 2 .6 0 ,13.5 3± 0 .4 4 ,2 5 .4 0± 1.79,SBT组明显低于S组 (P <0 .0 5 ) ,而ISBT组明显高于SBT组 (P <0 .0 5 )。S组、SBT组、ISBT组上皮细胞凋亡指数 (AI)分别为 2 .2± 0 .83,30 .8± 3.2 ,13.2± 2 .86 ,SBT组明显高于S组 (P <0 .0 5 ) ,ISBT组明显低于SBT组 (P <0 .0 5 )。透射电镜观察显示S组小肠上皮基底膜呈线性连续完整的结构 ,而SBT组基底膜分解断裂、甚至消失 ,ISBT组上皮基底膜破坏程度比SBT组为轻。结论　IPC对大鼠移植小肠上皮细胞和细胞外基质均有早期保护作用。IPC抑制细胞凋亡可能是其保护移植小肠上皮细胞的机制之一     

STUDY ON LIQUID-LIQUID EXTRACTION OF RESVERATROL FROM GIANT KNOTWEED AND ITS PROTECTIVE EFFECT ON MYOCARDIUM INJURY

Ｒｅｓｖｅｒａｔｒｏｌｈａｓｂｅｅｎｆｏｕｎｄｉｎｍａｎｙｐｌａｎｔｓａｎｄｈａｓａｌｏｔｏｆｖａｌｕａｂｌｅｅｆｆｅｃｔｓｕｃｈａｓａｎｔｉ ｔｕｍｏｒ,ａｎｔｉ ｉｎｆｌａｍ ｍａｔｉｏｎ ,ｔｒｅａｔｍｅｎｔｏｆｃａｒｄｉｏ ｖａｓｃｕｌａｒｄｉｓｅａｓｅｓ[1] .Ｔｈｅｍｅｃｈａｎｉｓｍｉｓｒｅｌａｔｅｄｔｏｔｈｅｑｕｅｎｃｈｉｎｇｏｆｌｉｐｉｄｐｅｒｏｘｉｄａ ｔｉｏｎ[2 ,3] .Ｍａｎｙｐａｐｅｒｓｒｅｐｏｒｔｅｄｔｈａｔｒｅｓｖｅｒａｔｒｏｌｗａｓｅｘ ｔｒａｃｔｅｄｆｒｏｍｇｒａｐｅ .Ｈｏｗｅｖ…     

PLC及IP_3R拮抗剂对弥漫性轴索损伤后继发性脑损伤的治疗作用

目的研究弥漫性轴索损伤(diffuse axonal injury,DAI)后PLC及IP3R抑制剂对DAI引发的脑水肿及神经元变性、损伤程度的影响,阐明PLC及IP3R抑制剂对DAI后继发性损伤的治疗作用。方法采用头颅冠状面瞬间加速旋转装置,制作大鼠颅脑DAI模型,并使用侧脑室穿刺给药的方法注射PLC抑制剂U73122及IP3R抑制剂光溜海绵素C(Xestospongin,XeC)。采用干湿重法测量脑组织含水量,ELISA测量脑脊液及动脉血中血清白蛋白(Alb)浓度并计算比值(QAlb),免疫组化法测量β-淀粉样前体蛋白(β-APP)的阳性面积及Western blot方法测量PLC的磷酸化程度。结果 DAI后6h大鼠脑组织含水量已明显增加,24h到达顶点,之后逐步下降,在5d时恢复到损伤前水平,XeC及U73122干预明显降低了损伤后24h脑组织含水量。ELISA结果显示DAI后6h及24h脑脊液中Alb浓度及QAlb明显升高,之后下降至损伤前水平,XeC及U73122干预对DAI引起的脑脊液中Alb浓度及QAlb升高无明显影响。免疫组化结果显示DAI后24h的β-APP的阳性面积较损伤前明显升高,XeC及U73122干预显著降低了DAI后24h的β-APP阳性面积。结论 DAI后脑水肿的形成是由细胞毒性水肿及血管源性水肿共同构成的;PLC及IP3R抑制剂降低了DAI后的细胞毒性水肿及神经元变性、损伤程度,对DAI后的继发性脑损伤具有治疗作用。     

Rho/ROCK通路在大鼠实验性弥漫性轴索损伤中的作用

目的研究RhoA和Nogo-A在弥漫性轴索损伤(diffuse axonal injury,DAI)后的动态表达,并探讨Rho/ROCK通路抑制对DAI后脑内Nogo-A表达的调控及其在DAI中的作用。方法用头颅瞬间旋转损伤装置制作大鼠DAI模型。观察DAI后RhoA和Nogo-A表达的时间依赖性和严重程度依赖性,并用辛伐他汀和Y27632药理性抑制RhoA/ROCK通路的活性,观察该通路在DAI后神经修复中的作用。用HE染色和PTAH染色指示DAI后脑组织病理学改变。Western blot检测RhoA和Nogo-A的表达,并检测β-APP的表达来指示轴突的损伤程度。并用免疫荧光染色指示RhoA和Nogo-A表达的空间相关性。结果 DAI后均出现明显的神经细胞坏死和轴突变性、断裂等病理改变;DAI后RhoA和Nogo-A的表达趋势一致,两者的表达量均随着DAI后时间的延长而增加,同时也随着损伤程度加重而增加,经免疫荧光双染色显示两者在脑内的表达有显著的同一性;用辛伐他汀和Y27632抑制RhoA/ROCK通路后能明显改善DAI后神经功能,并降低β-APP的表达,同时两者也能明显减少Nogo-A的表达。结论DAI后脑内RhoA和Nogo-A的表达有高度相关性,抑制Rho/ROCK通路可改善神经功能并减轻轴突损伤。     

The effects of lighting on driver's injury severity at highway‐rail grade crossings

This study estimates the safety effect of illumination on accidents at highway‐rail grade crossings in the United States, using data from exhaustive data from Federal Railroad Administration database covering the period 2002–2011. Using mixed logit modeling approach, the study explores the determinants of driver injury severity at unlighted highway‐rail grade crossings compared with lighted highway‐rail grade crossings in the United States. Several key issues are explored including availability of relevant highway‐rail grade crossing accident inventory data; relevant data element structures; specification and estimation of models to estimate driver's injury severity with lighting and without lighting; and techniques to interpret model parameters. Overall, highway‐rail grade crossing lighting improves safety by reducing the probability of high‐level injury severity through improvements in driver's visibility compared with unlighted intersections. Copyright © 2015 John Wiley & Sons, Ltd.     

基于有限元模型的汽车-行人碰撞事故重构研究

利用Hypermesh和Pamcrash软件,建立第50百分位行人下肢有限元模型和简化的厢式货车有限元模型,重构厢式货车倒车时与行人碰撞的交通事故案例,通过将模拟得到的行人损伤情况,比较韧带和骨骼的损伤,与医院给出的伤者诊断结果进行对比来确定初始参数,得出有限元仿真模拟碰撞事故的有效方法.结果表明,通过有限元仿真进行碰...     

Non-fatal spine injuries resulting from motorcycle crashes

This study aims to determine spinal injury patterns and identify crash factors commonly associated with serious spinal injury as a result of motorcycle crashes. Data was retrospectively collected from motorcyclists sustaining spinal injuries from road crashes treated at Kuala Lumpur Hospital, Malaysia, over the 5-year period from 2005 to 2009. Each patient's injuries were analyzed by reviewing his or her medical records for radiographic imaging and computed tomography scans.A total of 151 patients were included in this study, of which, males accounted for over 87%. The first lower lumbar (L1) was the most commonly injured vertebral level, followed by the adjacent thoracic vertebra (T12). Fracture to the vertebral body without dislocation was found to be the most frequently observed spinal injury pattern. Injury severities for a majority of patients (65%) were measured at Maximum Abbreviated Injury Scale (MAIS) of 2. Serious spinal injury was associated with thorax or upper-extremity injury.Prevalence of lumbar spinal injury in the study reflects a predominantly low-speed crash among the motorcyclist in the region. Motorcyclists are at greater odd to sustain severe spinal injury when directly striking an object compare to striking the ground during the crash event.     

前置护体式安全座椅布置参数优化研究

建立了Q系列3岁假人的正面碰撞仿真模型,以前置护体安装高度位置(相对于假人H点位置)、前置护体自身高度、前置护体加强肋板刚度以及泡沫材料刚度4个因素为研究对象,运用正交试验设计和方差分析筛选优化参数,并采用基于遗传算法的多目标优化方法进行求解。经过优化求解得知,当前置护体安装高度位置为0 mm(相对于假人H点位置),前置护体自身高度为190 mm时,对儿童乘员的保护效果最佳。此时最大腹部压力较初始值降低了16.3%,胸部3 ms加速度较初始值降低了9.1%。综合分析可知,在正面碰撞中减小儿童腹部与胸部损伤的关键之处在于,前置护体需约束在儿童乘员的盆骨部位,避免在碰撞过程中儿童出现"下潜"现象;通过将约束部位扩散到儿童胸部的方式可以有效分散碰撞冲击载荷,从而减小儿童乘员的腹部和胸部损伤。