FEMLAB对OCT在脑外科手术中应用可行性的仿真分析

光学相干层析技术是一种高分辨率成像方法。它是一种无损伤、非介入、非离子辐射的探测技术，具有较高的空间分辨率。有限元分析（FEA）是用于工程科学的重要工具，FEMLAB（Finite Element Modeling Laboratory）是基于偏微分方程的对科学和工程问题进行建模和仿真计算的交互式系统。本文简要介绍了OCT成像技术的原理及FEMLAB的应用步骤，重点用FEMLAB软件对脑组织内光场的分布情况进行分析，从而利用分析结果论证OCT成像在脑外科手术中应用的可行性。     

青果微量元素的测定及其含量与功效的关系

用电感耦合等离子体发射光谱法(ICP—AES),同时测定了广州与潮州产青果中13种微量元素和宏量元素的含量,结果发现其含有多种人体必需和与乙型肝炎的发生发展有关的微量元素;初步讨论了它们与青果功效的关系。     

Otoconial alterations after embryonic development in hypergravity

The relation between prolonged hypergravity and structural adaptation of otoconia was studied in hamsters (n = 56). Three groups of hamsters (n = 27), were conceived and born in a centrifuge: group 1 (n = 10) 1 month under 2.5 G, group (2n = 9) 5 months under 2.5 G and 4 months under 1 G, group 3 (n = 8) 1 month under 2.5 G and 8 moths under 1 G. Control hamsters (n = 29) were conceived and born under 1 G (1 month old, n = 7; 9 months old, n = 22). Histological study of the otoconial layers (energy dispersive x-ray element analysis and scanning electron microscopy) showed similar calcium content, size, and shape in utricular and saccular otoconia in all groups. Different were the utricular otoconial size classes, large, medium-sized, a and small. The area with small otoconia increased in group 1 (p = 0.002). In group 2, the large otoconial area decreased (p < 0.001) and the medium-sized one increased (p < 0.001). In group 3, the large otoconial area decreased (p = 0.003) and the medium-sized one increased (p = 0.007). For age-related effects we found group 1 with an increased area of large otoconia (p = 0.001) and a decreased medium-sized one compared to groups 2 (p < 0.001) and 3 (p = 0.02). Hypergravity during formation of otoconia does not affect calcium content, size, or shape, but changes relative size of the areas with large, medium-sized, or small otoconia and the development of these areas. This resulted in a structural adaptation to hypergravity.     

Morphologic analysis of rat retinocollicular neuron terminals containing monoamine oxidase

The retino-collicular neuron terminals containing type A monoamine oxidase (MAO-A) in the stratum griseum superficiale of the rat superior colliculus were analyzed to provide a morphologic basis for the physiologic role of these neurons in the visual pathway. A computer-assisted, three-dimensional re-construction of the terminal complex associated with the MAO-A-positive terminals was performed. MAO-A-positive terminals originated in the retina and terminated in the stratum griseum superficiale. This was confirmed by tract tracing and enucleation experiments. The terminals were densely grouped in clusters of irregularly shaped swellings. Electron microscopy revealed that the MAO-A-positive terminals were located in a glomerulus-like structure. In this terminal complex, a significant proportion of the axonal profiles (42.96%) synapsed with the MAO-A-positive terminals. Most of the profiles (24.16%) resembled presynaptic dendrites, which represent intermediate elements between the retinal terminals and conventional dendrites. Unlike the glomerulus in the dorsal lateral geniculate body, the MAO-A-positive terminal swellings were not located in the central part of the terminal complex. The terminals had an irregular shape and were located in the complex. The terminal complex was partially ensheathed by glial processes. Furthermore, the membrane surfaces exhibiting synaptic specializations were very small compared with the total surface of the terminal swellings. The membrane length of the synaptic specialization was 5.38% of the total perimeter of the MAO-A-positive terminals.     

新生鼠和成年鼠脑7种微量元素含量的比较

利用高频电感耦合等离子体原子发射光谱法（ICP－AES）测定Sprunge－Dawley大鼠新生期大脑皮层、海马、小脑、间脑和脑桥等部位的锌、铁、铜、锰、铬、锶、钼等7种微量元素的含量，并与成年动物做了比较。结果表明：（1）新生期大鼠全脑7种微量元素含量的多寡依次为：锌、铁、铬、锶、锰、铜、钼；成年期时钢跃居第四位，总含量低于新生期。（2）脑内不同部位微量元素的含量不同。新生大鼠海马和小脑内多数元素含量高于其他脑区，钼在间脑和海马中含量较高。成年鼠皮层、海马微量元素含量较高，皮层内铜、锶、钼含量最低。     

Diagnostic imaging of orofacial malformations

Summary Two-dimensional conventional X-rays and computer tomographic imaging systems contribute to the diagnosis and surgical planning of patients with orofacial malformations. The ability to reformat CT scans into three-dimensional osseous and soft tissue surface images has a significant impact on the diagnosis and management of orofacial malformations. Cephalometric evaluation with teleradiography provides precise insight into both the skeletal structures and the soft parts, enabling the radiologist to assess the relationship among the different parts in a given subject, at any given time and in relation to the normal.      

Idiopathic scoliosis: biomechanics and biology

For whatever reason, right-left asymmetry has attracted an illogical proportion of research effort. Non-structural scoliosis, for example secondary to a leg length inequality, is indeed a problem of right-left asymmetry, but structural scoliosis is a complex three-dimensional deformity involving all planes. Biomechanical, biological and clinical evidence indicates clearly that the problem is one of front-back asymmetry and not right-left. The importanc of biological factors lies in their ability to bring the spinal column to and beyond its buckling threshold. Thus a taller and more slender spine is more liable to bend and, being stiffer in the sagittal plane, favours movement into other planes. This epitomises the spine of the scoliosis patient who is growing faster with a spinal template similar to other family members allowing idiopathic scoliosis to express itself genetically. It is the opposite condition to idiopathic hyperkyphosis (Scheuermann's disease), but this deformity is rotationally stable, thus remaining in the sagittal plane. The presence of an adjacent area of lordo-scoliosis below the region of hyperkyphosis testifies to the common nature of the pathogenesis of idiopathic scoliosis and Scheuermann's disease. It is the area of compensatory hyperlordosis below the Scheuermann's area that has obligatorily buckled and represents a human model supporting the lordosis theory, as does surgically tethering the back of the young growing human spine, which crankshafts accelerated progression. Similarly the only successful animal model of the formation of idopathic follows creation of a lordotic spinal segment in an otherwise kyphotic spine. For centuries, engineers have recognised that the mechanical behaviour of a column under load is influenced by geometry, as well as by material properties; it is clear that the spinal column also obeys these well-described laws.     

CBL教学联合三维成像技术在胸外科见习教学中的应用

目的 探讨以案例为基础的学习（case-based learning,CBL）联合三维成像技术在胸外科见习教学中的应用效果。方法 选取2019年在扬州大学附属医院胸外科见习的90名学生,按照随机数字表法分为常规理论授课组（A组）、CBL教学组（B组）和CBL教学联合三维成像技术组（C组）。其中A组行常规理论授课;B组行CBL教学;C组在CBL的基础上,使用三维成像软件利用CT数据对患者的影像资料进行三维重建。分别评估两组的理论考试成绩,并对学生进行问卷调查（包括教学是否有利于激发学习兴趣和热情、是否有利于临床思维的建立、教学方法优劣的评价、是否有利于理论知识的掌握）。采用 SPSS 20.0 进行方差分析、t 检验和卡方检验。结果 理论成绩A组（85.83±4.62）为3组最低;B组理论成绩（89.71±5.84）低于C组（94.60±6.28）;答题时间C组（286.68±77.56） s为3组最低,B组（359.78±80.55） s低于A组（423.31±83.53） s,差异有统计学意义（P<0.001）。在教学是否有利于激发学习兴趣和热情、是否有利于临床思维的建立、教学方法优劣的评价、是否有利于理论知识的掌握等方面C组优于B组和A组,B组又优于A组,差异有统计学意义（P<0.001）。结论 CBL教学联合三维重建技术,提高了胸外科见习学生对教学方法的认可度,提升了学生的理论成绩,激发了学生的学习兴趣和热情、培养了其临床思维,增加了其对理论知识的掌握。     

Kubicek每搏心输出量计算公式的三维有限元仿真研究

我们从 Kubicek模型三维有限元仿真的角度对 Kubicek每搏心输出量计算公式的临床应用价值进行了研究。在计算机仿真研究中 ,我们对比了模型仿真结果、具体采用 Kubicek每搏心输出量计算公式所得结果以及所设模型的理论计算结果。仿真结果表明 :模型中阻抗改变与主动脉中血液容积改变之间存在着近似的线性关系 ,证明了 Kubicek每搏心输出量计算公式具有一定的临床应用价值 ,同时也为心阻抗血流图基础理论提供了新的研究途径。     

Finite-element models of the human head

A review is presented of the existing finite-element (FE) models for the biomechanics of human head injury. Finite element analysis can be an important tool in describing the injury biomechanics of the human head. Complex geometric and material properties pose challenges to FE modelling. Various assumptions and simplifications are made in model development that require experimental validation. More recent models incorporate anatomic details with higher precision. The cervical vertebral column and spinal cord are included. Model results have been more qualitative than quantitative owing to the lack of adequate experimental validation. Advances include transient stress distribution in the brain tissue, frequency responses, effects of boundary conditions, pressure release mechanism of the foramen magnum and the spinal cord, verification of rotation and cavitation theories of brain injury, and protective effects of helmets. These theoretical results provide a basic understanding of the internal biomechanical responses of the head under various dynamic loading conditions. Basic experimental research is still needed to determine more accurate material properties and injury tolerance criteria, so that FE models can fully exercise their analytical and predictive power for the study and prevention of human head injury.