短期模拟失重大鼠不同部位动脉血管反应性变化的比较

目的为深入探讨失重对动脉血管系统功能的影响，观察短期模拟失重大鼠不同部位动脉血管反应性的变化。方法将１６只雄性ＳＤ大鼠分为对照组与尾部悬吊呈头低３０°２周模拟失重组。利用离体动脉血管环，比较模拟失重对大鼠不同部位动脉血管反应性的影响。结果模拟失重大鼠腹主动脉与股动脉对氯化钾（１０ｍｍｏｌ／Ｌ～８０ｍｍｏｌ／Ｌ）与苯肾上腺素（１０－９ｍｏｌ／Ｌ～１０－４ｍｏｌ／Ｌ）的收缩反应均减弱，而颈总动脉对氯化钾与苯肾上腺素的反应无明显变化；腹主动脉对乙酰胆碱（１０－９ｍｏｌ／Ｌ～１０－４ｍｏｌ／Ｌ）的舒张反应在悬吊大鼠明显减弱；三处动脉对硝普钠的舒张反应均无明显变化。结论短期模拟失重可能减弱了动脉血管平滑肌的收缩能力与内皮介导的舒张能力，此变化主要局限于后半身动脉。     

表面修饰煅烧骨的制备及其理化性质的研究

探讨一种新的仿生骨材料表面修饰煅烧牛松质骨的制备方法,以提高煅烧牛松质骨作为组织工程骨的活性。将制备好的大小一致的煅烧牛松质骨随机分成两组,分别浸泡在配制好的单倍模拟体液(SBF)和1.5倍SBF中。每组材料的浸泡时间均为7、14和21d共3个时间点。浸泡结束干燥后用扫描电镜(SEM)观察材料表面形态并分析材料表面矿化成分。通过比较筛选出效果最理想的表面修饰煅烧牛松质骨材料,研究其孔径、孔隙率、抗压和抗折强度等理化性质,并与未经表面修饰的煅烧骨材料进行比较。研究表明,煅烧骨材料在1.5倍SBF中浸泡14d可以获得最佳表面修饰效果,同时保留了原有煅烧骨材料的基本理化特性。     

高仿真生理驱动模拟系统在麻醉管理培训中的应用

目的 探讨高仿真生理驱动模拟系统(HPS)在麻醉管理培训中的应用以及存在的问题.方法 采用美国MFTI公司HPS,自主设计高级生理驱动程序12项,分别模拟12类危重病人的麻醉情景,针对中高级职称麻醉医师进行危重病人麻醉管理综合模拟训练.培训形式为"简短授课+单项训练+HPS综合训练+录像反馈总结".培训对象16人,其中中级职称12人,高级职称4人.建立危重病人高仿真模拟培训评价量表,分析HPS培训的应用意义.结果 高仿真模拟危重病人麻醉培训与临床相似性评分(8.8±0.7)分,对综合能力培养方面必要性评分(9.3±0.6)分,与单一理论授课相比获益性评分(9.6±0.6)分,在麻醉教学领域的作用评分(9.2±0.7)分.该项目主要问题有:高仿真模拟危重病人的训练时间短,与真实的临床病例仍有差距.结论 HPS可以有效构建临床麻醉中的多种危重情景,能有效地训练麻醉医师临床应急能力及危重病人的麻醉管理水平.     

模拟高原低氧对大鼠心肌力学影响的实验研究

目的:观察模拟高原低氧对大鼠心肌力学的影响,探讨红景天等组方中药复方合剂对其的作用。方法:雄性SD大鼠84只,随机分为平原对照组(PC)、模拟高原低氧1 d组(H1)、模拟高原低氧1 d加中药干预组(Z1)、模拟高原低氧3 d组(H3)、模拟高原低氧3 d加中药干预组(Z3)、模拟高原低氧7 d组(H7)、模拟高原低氧7 d加中药干预组(Z7),每组12只;采用MPA-心功能分析系统,记录大鼠HR、+dp/dt max、-dp/dt max。结果:H7组和Z7组大鼠心率加快,+dp/dt max、-dp/dt max均升高(P<0.01),且Z7组大鼠+dp/dt max、-dp/dt max明显高于H7组(P<0.01)。结论:模拟高原低氧可引起大鼠心脏收缩和舒张功能代偿性增强,红景天等组方中药复方合剂对大鼠心肌力学有一定的正性作用。     

解读美国密西根州立大学评估中心在护生综合能力培养中的经验

从课程设置、组织形式和开展方式等方面分析了美国密西根州立大学护理学院在该校评估中心的配合下开展模拟实验教学的特点;并针对我国目前护理实验教学的现状,在借鉴相关经验的基础上,提出改进建议,以期有效培养国内护生的综合能力,提高岗位胜任力。     

基于模拟教学法的卫生法课程实践化教学改革

模拟教学法是卫生法理论教学的必要补充,能满足卫生法教学的实践性改革需求,强化培养学生作为法律职业人应具备的素养.模拟教学法对师生、教学素材、组织管理等方面提出更高要求.在卫生法课程中实施模拟教学法需要注意情境设计、细节准备、实施活动和教学评价等实践环节.     

Effect of simulated microgravity on salivary and serum oxidants, antioxidants, and periodontal status

Background: Microgravity is associated with an increase in peroxidative damage. The effect is more pronounced after long‐duration space flights and can even last for several weeks after landing. The objective of the study is to determine the influence of simulated microgravity on the periodontal status and salivary and serum oxidant/antioxidant status of the body in simulated microgravity (?6° head‐down‐tilt [HDT) bed rest). Methods: Twenty healthy male volunteers were studied before and after 60 days of simulated microgravity (?6° HDT bed rest). We measured salivary and serum oxidative markers, such as malondialdehyde (MDA), 8‐oxo‐7,8 dihydro‐2 deoxyguanosine (8‐OHdG), and vitamins C and E, and clinical periodontal parameters (probing depth [PD] and clinical attachment level [CAL]). Results: Serum and salivary vitamin C and E concentrations were significantly decreased, whereas MDA and 8‐OHdG levels were significantly increased after 60 days of simulated microgravity. Serum and salivary markers showed a strong and significant correlation. CAL and PD were higher but not statistically significant in simulated microgravity. Conclusions: This study suggests that oxidative stress in the microgravity environment was increased but did not significantly influence periodontal parameters after 2 months. Also, this study indicates the possibility that the findings may have a broader clinical relevance to patients on bed rest or who are physically inactive. Studies on larger patient samples and follow‐up for a longer time are required to verify the relationship between antioxidant status in the space microgravity condition and periodontal health.     

The influence of simulated masticatory loading regimes on the bi-axial flexure strength and reliability of a Y-TZP dental ceramic

OBJECTIVES: The purpose of the current study was to examine the influence of simulated masticatory loading regimes, to which all-ceramic crown or bridge restorations will routinely be subjected during their service-life, on the performance of a yttria-stabilised tetragonal zirconia polycrystalline (Y-TZP) dental ceramic. METHODS: Ten sets of 30 Y-TZP ceramic discs (13 mm diameter, 1.48-1.54 mm thickness) supplied by the manufacturer were randomly selected. Six groups were loaded for 2000 cycles at 500 N (383-420 MPa), 700N (536-588 MPa) and 800 N (613-672 MPa) with three groups maintained dry and the remaining three groups loaded while immersed in water at 37+/-1 degrees C. A further two groups underwent extended simulated masticatory loading regimes at 80 N (61-67 MPa) for 10(4) and 10(5)cycles under dry conditions. The mean bi-axial flexure strengths, standard deviations and associated Weibull moduli (m) were determined. The surface hardness was also determined using the Vickers hardness indentation technique. RESULTS: No significant difference (P>0.05) was identified in the bi-axial flexure strength of the simulated masticatory loading regimes and the control specimens loaded dry or wet. A significant increase in m was identified for the Y-TZP specimens following loading while immersed in water (8.6+/-1.6, 8.5+/-1.6 and 10.3+/-1.9) compared with the control (7.1+/-1.3). However, the extended loading regime to 10(5)cycles resulted in a significant reduction in the m of the Y-TZP specimens (5.3+/-1.0) compared with the control. Localised areas of increased surface hardness were identified to occur directly beneath the spherical indenter. CONCLUSIONS: The occurrence of localised areas of increased surface hardness could be the result of either a transformation toughening mechanism or crushing and densification of the material beneath the indentor manifested as the formation of a surface layer of compressive stresses that counteracted the tensile field generated at the tip of a propagating crack which increased the Weibull modulus of the Y-TZP specimens. The reduced reliability of the Y-TZP specimens loaded to 80 N for 10(5)cycles was associated with the accumulation of subcritical damage as a result of the extended nature of loading.     

A Markerless Motion Capture System to Study Musculoskeletal Biomechanics: Visual Hull and Simulated Annealing Approach

Human motion capture is frequently used to study musculoskeletal biomechanics and clinical problems, as well as to provide realistic animation for the entertainment industry. The most popular technique for human motion capture uses markers placed on the skin, despite some important drawbacks including the impediment to the motion by the presence of skin markers and relative movement between the skin where the markers are placed and the underlying bone. The latter makes it difficult to estimate the motion of the underlying bone, which is the variable of interest for biomechanical and clinical applications. A model-based markerless motion capture system is presented in this study, which does not require the placement of any markers on the subject's body. The described method is based on visual hull reconstruction and an a priori model of the subject. A custom version of adapted fast simulated annealing has been developed to match the model to the visual hull. The tracking capability and a quantitative validation of the method were evaluated in a virtual environment for a complete gait cycle. The obtained mean errors, for an entire gait cycle, for knee and hip flexion are respectively 1.5° (±3.9°) and 2.0° (±3.0°), while for knee and hip adduction they are respectively 2.0° (±2.3°) and 1.1° (±1.7°). Results for the ankle and shoulder joints are also presented. Experimental results captured in a gait laboratory with a real subject are also shown to demonstrate the effectiveness and potential of the presented method in a clinical environment.     

Inertial measurements of upper limb motion

We present an inertial sensor based monitoring system for measuring upper limb movements in real time. The purpose of this study is to develop a motion tracking device that can be integrated within a home-based rehabilitation system for stroke patients. Human upper limbs are represented by a kinematic chain in which there are four joint variables to be considered: three for the shoulder joint and one for the elbow joint. Kinematic models are built to estimate upper limb motion in 3-D, based on the inertial measurements of the wrist motion. An efficient simulated annealing optimisation method is proposed to reduce errors in estimates. Experimental results demonstrate the proposed system has less than 5% errors in most motion manners, compared to a standard motion tracker.This work was supported by the UK EPSRC under Grant GR/S29089/01.