美国中东政策评析

美国在中东遇到大麻烦,主要战略目标未能实现。伊拉克安全形势持续严峻,巴以和谈停滞不前,伊朗核问题难以解决,压叙利亚屈服迄未奏效,恐怖活动越反越多,大中东改造计划受挫。美遇到的困难未超出其承受能力,美国在中东仍居主导地位,美中东政策在手法和策略上有所调整,实质上并无变化。     

实用型射野照相用标尺板的研制与应用

介绍一种实用型标尺板的研制方法,并将其应用在放疗射野照相工作中,从而得到了摆位误差的真实测量数据,有效地提高了放疗摆位中体位验证的精度,是加强放疗质量管理和质量控制的有效手段。     

改变产妇体位矫正胎儿方位的临床效果

目的:探讨产程中改变产妇体位以矫正胎位。方法:选择临产至宫口开全经B超及内诊检查为枕后位的初产妇200例,随机分为观察组与对照组各100例,在产程中指导观察组产妇取侧俯卧位,利用胎儿重力、羊水浮力、子宫间歇性收缩的合力作用,使胎头下降时逐渐从枕后位转至枕前位娩出,并与对照组比较。结果:观察组91例(91％)胎儿由枕后位转至枕前位经阴道分娩,剖宫产9例(9％);对照组经阴道分娩仅16例(16％),剖宫产84例(84％)。两组比较差异有显著性(P<0.01)。结论:在产程中指导产妇取侧俯卧位,用以矫正胎位不正是降低难产发生率的有效方法。     

颈椎前路钢板位置与术后颈肩痛的相关性影响

目的观察颈椎前路钢板内固定术后颈肩痛与钢板位置之间的关系。方法回顾分析1999年8月~2006年7月间实施的219例颈椎前路钢板内固定手术的临床和影像学资料。分别观察颈椎侧位X线片上钢板在上下位椎体的覆盖率,正位X线片评估其侧方移位和成角,应用视觉模拟评分(VAS)、颈椎活动障碍指数(NDI)评价手术前、后颈肩痛。应用Pearsons相关系数、线性回归分析进行统计学分析。结果平均随访16.8个月(6~42个月),钢板侧方偏移和成角与术后颈肩痛高度相关(相关系数P=0.417,P<0.001,n=87),线性回归分析显示钢板偏移和成角与术后VAS评分高度正相关(相关系数P=0.314,P<0.001,n=82),与术后NDI成正相关(相关系数P=0.379,P<0.001,n=66)。结论颈椎前路钢板侧方偏移和成角是术后颈肩痛的原因之一,术中应注意调整钢板位置,尽量避免侧方偏移和成角。     

基于永磁磁场的电子胶囊定位系统

为了确定可吞服式电子胶囊在人体内的位置,基于矩形永磁体空间磁场解析式,设计了定位系统,提出了相应的定位算法,并进行了实验。系统中两个三轴磁传感器封装在胶囊内,由胶囊和永磁体的空间位姿关系模型,建立了与传感器输出和胶囊位姿变量相关的一组非线性方程。对方程进行了数值求解,并和期望值进行了比较,结果发现该方法是切实可行的。     

Proprioception does not quickly drift during visual occlusion

Several perceptual studies have shown that the ability to estimate the location of the arm degrades quickly during visual occlusion. To account for this effect, it has been suggested that proprioception drifts when not continuously calibrated by vision. In the present study, we re-evaluated this hypothesis by isolating the proprioceptive component of position sense (i.e., the subjects were forced to rely exclusively on proprioception to locate their hand, which was not the case in earlier studies). Three experiments were conducted. In experiment 1, subjects were required to estimate the location of their unseen right hand, at rest, using a visual spot controlled by the left hand through a joystick. Results showed that the mean accuracy was identical whether the localization task was performed immediately after the positioning of the hand or after a 10-s delay. In experiments 2 and 3, subjects were required to point, without vision of their limb, to visual targets. These two experiments relied on the demonstration that biases in the perception of the initial hand location induced systematic variations of the movement characteristics (initial direction, final accuracy, end-point variability). For these motor tasks, the subjects did not pay attention to the initial hand location, which removed the possible occurrence of confounding cognitive strategies. Results indicated that movement characteristics were, on average, not affected when a 15-s or 20-s delay was introduced between the positioning of the arm at the starting point and the presentation of the target. When considered together, our results suggest that proprioception does not quickly drift in the absence of visual information. The potential origin of the discrepancy between our results and earlier studies is discussed.     

仰俯卧位对早产儿肺炎患儿肺功能的影响

目的探讨仰俯卧位对早产儿肺炎患儿肺功能的影响.方法应用美国Bicore CP-100新生儿肺功能仪分别对30名不吸氧组(SaO2≥90%)和18名吸氧组(SaO2<90%)早产儿肺炎患儿的肺功能值进行检测.结果不吸氧组患儿俯卧位呼吸频率明显低于仰卧位(43.4±10.2 v 49.8±11.7);俯卧位潮气量明显高于仰卧位(3.11±0.92 v 2.48±0.77 ml/kg);俯卧位气道阻力明显低于仰卧位(98.6±50.1 v 117.4±41.5cm H2O/L/s,);俯卧位动态肺顺应性明显高于仰卧位(1.115±0.401 v 0.914±0.48ml/cm H2O/kg);俯卧位呼吸功明显高于仰卧位(8.0±3.8 v 5.9±2.7gm cm/kg).吸氧组患儿俯卧位呼吸频率明显低于仰卧位(52.7±10.2 v 56.1±12.4);潮气量明显高于仰卧位(2.13±0.42 v 1.79±0.66 ml/kg);俯卧位气道阻力明显低于仰卧位(290.4±107.0 v 319.1±104.1cm H2O/L/s);俯卧位动态肺顺应性明显高于仰卧位(0.562±0.192 v 0.488±0.217ml/cm H2O/kg);俯卧位呼吸功明显高于仰卧位(10.1±4.7 v 7.3±3.4gm cm/kg).结论无论吸氧与否俯卧位均可提高患儿的潮气量、动态肺顺应性和呼吸功,降低呼吸频率和气道阻力,俯卧位为早产儿肺炎患儿的适宜体位.     

高精度红外光点位置检测分析系统

高精度红外光点位置检测分析系统是基于光电位置敏感器件、立体测量学研制而成的运动物体分析系统。它能快速、准确地测出运动物体各特征点的瞬时位置，并在此基础上进行分析计算，给出三维坐标及针对具体应用领域的特征曲线和参数。该系统可应用于人体运动检测、外科手术定位等领域。     

Retention of successive position reversals in rats with septal and fronto-polar lesions

Eight successive position reversals were given preoperatively to establish position reversal sets in rats. Six animals received septal lesions, six fronto-polar cortex ablations, and six normals served as a control group. During a series of eight postoperative reversals, rats with septal lesions committed significantly more errors and approach errors than normals while fronto-polar ablations had no detectable effect.     

阈值校正方式对PET脑显像统计参数图分析显示结果的影响

目的 探讨各种阈值校正方法对统计参数图(SPM)软件统计比较结果显示的影响.方法 利用Hoffman标准脑模型制作缺损模型PET成像与正常模型PET成像,进行统计参数图的统计比较.并选取脑梗死患者与健康检查者进行统计参数图的统计比较.结果 校正与非校正产生的结果有差异,其中族错误率(FWE)校正(P=5×10-2)得到的统计分析结果激活区最少及最小,其次是错误发现率(FDR)校正(P=5×10-2),非校正方式(P=1×10-3)得到的激活区最多及最大.但FDR校正效果不稳定,有时不如不校正.结论 统计参数图软件中FWE校正方法可明显降低假阳性,得到的结果可信度稳定地高于非校正方法.