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101.
由于人体组织中存在血液对流传热和代谢产热,当皮肤表面绝热后,皮肤表面的温度将上升,体表温升值是人体组织中血液灌注率和动脉血温度的函数,根据实际测量的体表温升与时间的关系就可以测出活体组织的血液灌注率和动脉血温度。根据一维Pennes生物传热方程,推导出了体表绝热后人体组织中及皮肤表面温度分布的解析解,并对人体组织中的血液灌注率及动脉血温度进行了实验测量。由于测量过程中利用的只是皮肤表面的温度信息,无须引入外加热源,对人体组织完全不会造成损伤,亦避免了干扰人体组织的正常生理状态,整个测量系统也比较简单。  相似文献   
102.
We comment on the target article by Weingardt (this issue), which discusses recent advances in instructional design and technology (IDT) and their implications for dissemination of evidence-based practices. These arguments are extended to the topic of psychological intervention design, and possibilities for new intervention structures are briefly explored. Finally, comments are offered on maintaining a careful balance between technological and social processes in the effort to promote the dissemination of innovative and evidence-based psychological procedures.  相似文献   
103.
The paper deals with computer simulations of ‘silicon neurons’, which are assemblies of CMOS circuits that generate the equivalents of the ionic currents and of the action potentials of real (biological) neurons. The circuit simulation program SPICE is used to simulate the generation of action potentials by a silicon neuron. Moreover, the equivalent circuits of silicon synapses are described and the behaviours of simple two- and three-neuron networks are analysed. Implications for the areas of neurobiology and formal neural networks are briefly considered.  相似文献   
104.
105.
BACKGROUND: Overgrowth of bacteria in the birth canal is associated with an increased risk of late miscarriage, preterm labour, post-partum endometritis and low birthweight. Conception rates in assisted reproduction treatments (ART) remain frustratingly low. We examined whether the nature of bacterial flora, found in the uterine cervical canal at embryo transfer, is associated with the rate of conception in ART. METHODS: We sampled for bacteriological culture the cervical canal of 204 patients who underwent embryo transfer. Of these, 139 (68%) were of fresh embryos, following recent vaginal oocyte retrieval and prophylactic antibiotic therapy, and 65 (32%) of frozen-thawed embryos, without any vaginal intervention in the preceding days. Bacteriological work-up included identification, colony count and antibiotic susceptibility profile. Conception was correlated with bacterial type and colony count. RESULTS: In 75 patients (36.8%) sterile cervical cultures or lactobacillus were recorded. Of these 75 patients, 23 (30.7%) conceived, whereas among the 129 in whom any pathogenic micro-organism was recovered only 21 (16.3%) conceived (P = 0.002). No difference in colonization was found between women who underwent frozen-thawed versus fresh embryo transfer (57 and 67% respectively). Any Gram-negative colonization was associated with no conception. All Gram-positive, and 90% of the Gram-negative bacteria, were sensitive to augmentin. CONCLUSIONS: Failure to conceive in ART is significantly associated with bacterial colonization of the uterine cervix.  相似文献   
106.
目的探讨重点理工科学校大一新生焦虑状况及相关因素,为进行针对性的干预提供依据。方法以广东某重点理工高校2007级的大一学生为研究对象,采用自行设计一般项目调查表、状态-特质焦虑量表(STAI)、匹兹堡睡眠质量指数量表(PSQI)、应付方式问卷进行测评。结果测查学生不论男女状态焦虑、特质焦虑分均显著高于地方常模;19.29%的学生睡眠质量较差;高状态焦虑组和高特质焦虑组解决问题、求助应付因子分均显著低于低状态焦虑组和低特质焦虑组,而自责、幻想、退避应付因子分则显著高于低状态焦虑组和低特质焦虑组;多元逐步回归分析说明,学生如常采用解决问题应付方式,在一定程度上可避免焦虑的产生,而睡眠质量差、采用自责应对方式则可加重焦虑水平。结论采取有效的认知应对策略其意义是使学生改变应激源,以使其变得威胁较小或变成挑战,把情绪基调训练成兴奋、期待和征服。  相似文献   
107.
Aim: The efficacy of a mechanical, gravity‐independent resistance exercise (RE) system to induce strength gains and muscle hypertrophy was validated. Designed for space crew in orbit, this technique offers resistance during coupled concentric and eccentric actions by utilizing the inertia of a rotating flywheel(s), set in motion by the trainee. Methods: Ten middle‐aged (30–53 years) men and women performed four sets of seven maximal, unilateral (left limb) knee extensions two or three times weekly for 5 weeks. Knee extensor force and electromyographic (EMG) activity of the three superficial quadriceps muscles were measured before and after this intervention. In addition, with the use of magnetic resonance imaging (MRI), volume of individual knee extensor and ankle plantar flexor muscles was assessed. Results: Over the 12 training sessions, the average concentric (CON) and eccentric (ECC) force generated during exercise increased by 11% (P < 0.05). Likewise, maximal isometric strength (maximal voluntary contraction, MVC) at 90 and 120° knee angle increased by (P < 0.05) 11 and 12% respectively, after training. Neither individual quadriceps muscle showed a change (P > 0.05) in maximal integrated EMG (iEMG) activity. Quadriceps muscle volume increased by 6.1% (P < 0.05). Although the magnitude of response varied, all individual quadriceps muscles showed increased (P < 0.05) volume after training. As expected, ankle plantar flexor volume of the trained limb was unchanged (P > 0.05). Likewise, MVC, CON and ECC force, iEMG and knee extensor and plantar flexor muscle volume were unaltered (P > 0.05) in the right, non‐trained limb. Conclusion: The results of this study show that the present RE regimen produces marked muscle hypertrophy and important increases in maximal voluntary strength and appears equally effective as RE paradigms using gravity‐dependent weights, in this regard.  相似文献   
108.
髋臼骨关节面形态特征的研究   总被引:8,自引:0,他引:8  
髋臼骨关节面生物形态特征的研究将有助于通过建立更为精确的髋臼三维模型来分析髋关节的生物力学性能 ,具有重要的临床意义。但在以往的研究中 ,髋臼骨关节面大多被简单认定为一球面。本研究通过三维激光扫描获取髋臼的三维形态数据 -点云数据 ,运用反球工程技术结合优化拟合算法 ,分别用球面和旋转椭球面逐步逼近原始的髋臼骨关节面 ,获得最佳的髋臼骨关节面匹配模型 ,分析比较此二项匹配模型间的匹配误差。对 15例髋骨的统计测量结果表明 ,旋转椭球面的匹配误差显著小于球面的匹配误差 ,其中拟合球半径平均值为 2 4 .37±2 .2 2 mm,拟合旋转椭球面长轴 (髋臼左右方向 )平均值为 2 6 .0 2± 2 .76 mm,短轴 (髋臼前后方向 )平均值为 2 4 .17± 2 .16 mm。该项研究首次对髋臼骨关节面形态作了定量的分析 ,有助于我们对髋臼骨形态的重新认识 ,进而为一系列以其为基础的相关研究及应用提供重要的参考  相似文献   
109.
A recently reported device, the sorbent suspension reciprocating dialyser (SSRD), was investigated for use as a test system for biocompatibility of dialyser components. The device is easy to assemble and operate, and allows minimal blood contact with foreign material outside of dialyser components. Its constant pressure/ variable flow rate operation allows quantification of degree of clotting of dialyser versus time. The effect of heparinization of the blood distribution gaskets (BDG) of the device on performance and dialyser lifetime was investigated. Heparin was bound to the surface of polyethylene gaskets by immersion in a solution of tridodecylmethylammonium chloride (TDMAC)-heparin complex for several hours. Gaskets were then assembled in an SSRD which was then used for experimental dialysis in dogs with AV shunts. Dialysers assembled using non-heparinized gaskets were used as controls. Blood coagulation tendency was quantified by the activated clotting time (ACT) and partial thromboplastin time (PTT), and these values correlated with the rate of clotting of the device. Heparinization of the gaskets resulted in the prevention of clotting in the dialyser until the final minutes of dialysis in all cases, in contrast to the constant decay of blood fill volume and evidence of clotting in the non-heparinized cases. However, dialyser lifetime was not significantly increased by gasket heparinization. At normal initial values of ACT (80–95 s) dialyser clotting occurred in 10–15 mia In tests with non-heparinized gaskets and systemically heparinized dogs, values obtained in the ACT test were observed to decrease during dialysis, indicating the disappearance of heparin from the blood. Both ACT and PTT tests show promise as predictors of dialyser lifetime.  相似文献   
110.
Synthetic dyes were extracted from syrups, oral suspensions, tablets, gelatin capsules, suppositories and granules by ion-pair formation with tri-n-octylamine (TnOA) and back-extracted with perchlorate ions. Identification was performed by TLC on cellulose layers and by reversed phase ion-pair HPLC.  相似文献   
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