基于网络西部民族院校开放式立体化实验教学模式探析

通过对西部高校及其本校的物理学实验教学现状的分析,针对目前已建设的各级精品课程网络资源,提出基于校园网环境下医用物理学开放式立体化的实验教学模式,以期全面有效地提高实验教学的水平和质量,充分发挥学生学习的自主性,探索能够更大限度地发挥实验教学培养和提高学生动手能力和科学素质的有效途径,并在教学实践中加以实施和总结。     

多媒体技术在医药院校物理实验中的应用

分析医药院校物理实验教学的现状,说明在医药院校采用多媒体技术辅助实验教学的必要性。论述多媒体技术在物理实验预习、课堂教学、仿真实验中的应用。     

在《放射物理与防护》教学中要及时渗透STS教育

我们对我校2009级医学影像专业影像1班的<放射物理与防护>的教学中及时渗透STS教育,而将该年级影像专业影像2班的<放射物理与防护>全部采用传统教学作为对照班,进行了教学效果比较,取得了比较满意的效果,并为以后的教学提供了可参考的依据.     

Filament rigidity causes F-actin depletion from nonbinding surfaces

Proximity to membranes is required of actin networks for many key cell functions, including mechanics and motility. However, F-actin rigidity should hinder a filament''s approach to surfaces. Using confocal microscopy, we monitor the distribution of fluorescent actin near nonadherent glass surfaces. Initially uniform, monomers polymerize to create a depletion zone where F-actin is absent at the surface but increases monotonically with distance from the surface. At its largest, depletion effects can extend >35 μm, comparable with the average, mass-weighted filament length. Increasing the rigidity of actin filaments with phalloidin increases the extent of depletion, whereas shortening filaments by using capping protein reduces it proportionally. In addition, depletion kinetics are faster with higher actin concentrations, consistent with faster polymerization and faster Brownian-ratchet-driven motion. Conversely, the extent of depletion decreases with actin concentration, suggesting that entropy is the thermodynamic driving force. Quantitatively, depletion kinetics and extent match existing actin kinetics, rigidity, and lengths. However, explaining depletion profiles and concentration dependence (power-law of −1) requires modifying the rigid rod model. Within cells, surface depletion should slow membrane-associated F-actin reactions another ≈10-fold beyond hydrodynamically slowed diffusion of filaments (≈10-fold). In addition, surface depletion should cause membranes to bend spontaneously toward filaments. Such depletion principles underlie the thermodynamics of all surface-associated reactions with mechanical structures, ranging from DNA to filaments to networks. For various functions, cells must actively resist the thermodynamics of depletion.     

Physical manipulation of the Escherichia coli chromosome reveals its soft nature

Replicating bacterial chromosomes continuously demix from each other and segregate within a compact volume inside the cell called the nucleoid. Although many proteins involved in this process have been identified, the nature of the global forces that shape and segregate the chromosomes has remained unclear because of limited knowledge of the micromechanical properties of the chromosome. In this work, we demonstrate experimentally the fundamentally soft nature of the bacterial chromosome and the entropic forces that can compact it in a crowded intracellular environment. We developed a unique “micropiston” and measured the force-compression behavior of single Escherichia coli chromosomes in confinement. Our data show that forces on the order of 100 pN and free energies on the order of 10⁵ k_BT are sufficient to compress the chromosome to its in vivo size. For comparison, the pressure required to hold the chromosome at this size is a thousand-fold smaller than the surrounding turgor pressure inside the cell. Furthermore, by manipulation of molecular crowding conditions (entropic forces), we were able to observe in real time fast (approximately 10 s), abrupt, reversible, and repeatable compaction–decompaction cycles of individual chromosomes in confinement. In contrast, we observed much slower dissociation kinetics of a histone-like protein HU from the whole chromosome during its in vivo to in vitro transition. These results for the first time provide quantitative, experimental support for a physical model in which the bacterial chromosome behaves as a loaded entropic spring in vivo.     

基于静态图像的互动虚拟现实技术在医学物理学教学中的应用研究

目的:探讨基于静态图像的互动虚拟现实技术在医学物理学教学中的应用及其作用。方法:分析互动虚拟现实技术在医学物理学教学中应用的必要性,阐述互动虚拟现实技术的特点及其在相关教学过程中的应用优势,以软件VRObjectWorx为开发工具,介绍互动虚拟仪器设备展示实例的制作方法及其在医学物理学教学中的应用。结果:基于静态图像的互动虚拟现实技术可以灵活运用于现代化医疗设备展示、实验仪器设备的展示以及立体空间的构建与展示等相关医学物理学教学内容。结论:将互动虚拟现实技术应用于教学过程,可极大地改变传统教学观念和思维方式,突破教学难点,吸引学生的注意力,激发学习兴趣,加深学生对相应教学内容的理解和掌握,使教学过程更具有科学性,具有广阔的发展和应用前景。     

对亚健康人群脑功能活动状态的分析

目的：研究分析亚健康人群的脑功能活动状态。方法：按照物理学理论、耗能理论、脑生理及脑电脑象图活动的特点，对实验组和对照组分别检测3种状态的脑电脑象图，经SPSS8．0统计软件对选样进行统计学处理（χ^2检验）。结果：两组逃逸系数、稳定水平、重力系数、2项指标的P值均＜0．05，有显著差异，亚健康群体的脑功能活动不同于健康群体。结论：脑电脑象图可以测评亚健康状态，亚健康是脑的亚健康，人的高级神经活动可以有物理学和数学方式表达；中医药对亚健康的干预将起到积极作用。     

医学物理实验考核的改革与探索

探讨在医学院物理实验教学中,根据学生实际情况和每个实验的不同特点,编制不同的考核标准和设置考核方法,并对考核方法和考核内容进行改革,从而达到提高教学质量的目的。     

添加载银抗菌剂的藻酸盐印模材料抗菌性能及物理性能研究

目的:对添加磷酸锆载银抗菌剂的藻酸盐印模材料抗菌性能及物理性能进行测试和评价,为口腔抗菌印模材料的研制奠定实验基础。方法:以1%添加比将磷酸锆载银抗菌剂加入到藻酸盐印模材料,采用薄膜密着法,测试添加抗菌剂后印模材料的抗菌活性,并参照相关标准对材料的结固时间,压应变等物理性能进行测试和评价。结果:添加磷酸锆载银抗菌剂的藻酸盐印模材料对金黄色葡萄球菌和大肠杆菌的抗菌率分别为99.85%和99.83%。添加抗菌剂对藻酸盐印模材料主要物理性能没有显著影响(P>0.05)。结论:以1%的比例添加磷酸锆载银抗菌剂可赋予藻酸盐印模材料强抗菌性能。添加抗菌剂对藻酸盐印模材料的主要物理性能没有显著影响,可满足临床应用要求。     

A critical evaluation of the theory and practice of therapeutic touch

Abstract In this paper, the theory and practice of therapeutic touch (TT) is scrutinized from a number of perspectives. Firstly, the alleged close relationship between TT and Martha Rogers’ Science of Unitary Human Beings is evaluated. Secondly, the employment of the language of modern physics in Rogers’ theory and TT is critically examined. The authors then review the research literature on TT's efficacy, completing their critique by discussing the ethical issues involved in the practice of TT. As each of the perspectives considered reveals some concerns, the paper concludes that TT is a questionable intervention, underpinned by a very weak theoretical, clinical and research base.