家兔动脉瘤模型的刚性及弹性结构数值模拟的对比分析

目的 应用计算流体力学软件模拟家兔的动脉瘤模型,对比刚性及弹性两种结构模型的区别.方法 应用家兔建立侧方及顶端动脉瘤动物模型,测取所需参数.应用系列软件对动脉瘤模型分刚性及弹性结构进行数值模拟,并应用流体力学软件计算出两种模型结构的血流流速值,进行对比分析.结果 基于弹性及刚性结构的家兔动脉瘤的血液动力学参数明显不同,统计学结果显示在动脉瘤的流出道处的差异更加明显(P＜0.05).结论 动脉瘤的刚性及弹性结构的血液动力学参数存在明显差异,弹性结构更加科学合理.     

Understanding the biopsychosocial model

The biopsychosocial model has emerged from the need of a better understanding of the human being as a unit, with his biological, psychological and sociological perspective as well as from recent research findings suggesting the difficulties of working with one of these areas without dealing with the others. Even when the need of such a model has been extensively described, the model itself and its practical applications had been poorly defined, lacking specially theoretical explanations of the interaction of biological, psychological and social factors in producing medical and psychiatric illness. The author attempts in this paper to give a theoretical explanation of the interaction of these factors by applying the concept of multicausality of illness and the concept of vulnerability of systems. The practical application of this framework is also shown in a case example.     

Subarachnoid hemorrhage model in the rat: modification of the endovascular filament model

The present study describes modifications to the endovascular filament model of subarachnoid hemorrhage (SAH) in rats. Specifically, we sought to improve the percentage yield of SAH, reduce mortality rates and better simulate human cerebral aneurysmal rupture. Instead of using a 4-0 prolene suture to induce SAH in the existing endovascular filament model, a hollow and flexible polyetrafluoroethylene (PTFE) tube was maneuvered into the proximal anterior cerebral artery (ACA) to ensure that advancement occurred without producing trauma to the vessels. SAH was induced by advancing a tungsten wire through this tube, perforating the ACA at the desired location. These modifications produced significant improvements over the endovascular filament model. Mortality rate declined from 46 to 19%, and SAH was produced more frequently. With the prolene suture, only 48% of our attempts produced a SAH, and unsuccessful attempts typically resulted in an acute subdural hematoma (ASDH). In contrast, the wire/tubing technique was 90% successful at inducing SAH, and led to a significant reduction of ASDH incidence from 44 to 6%. Additionally, the modified technique produced vasospasm in basilar and middle cerebral arteries post-SAH as well as pseudoaneurysms in the proximal ACA which indicated the location of vessel perforation.     

加性与广义加性模型回归分析

本文目的是介绍加性与广义加性模型回归分析的概念、作用以及用软件实现计算的方法。先介绍有关的基本概念,再介绍基本原理,最后通过一个实例并基于SAS软件演示如何实施加性模型回归分析。结果表明:相对于引入派生变量进行常规多重线性回归分析而言,加性与广义加性模型回归分析能够更好地提升模型对资料的拟合效果。     

精神分裂症亚型划分的数学模型：一.数学模型的建立

应用Ａｎｄｒｅｓｅｎ的精神分裂症阳性型，混合型，阴性型分型标准的金标准，并对金标准筛选的三类病人进行简明精神病症状评定量表（ＢＰＲＳ）评定，由此得到阴性症状Ｘ１，阳性症状Ｘ２，和非特异症Ｘ３，以模糊数学隶属度为方法，求得数学模型为μ（Ｇｊ）（Ｘｉ）＝３∑ｉ＝１ＷｉｊμＧｊ（Ｘｉｊ），（ｉ＝１，２，３，ｊ＝１，２，３．），将原金标准病例Ｘ１，Ｘ２，Ｘ３代入后发现该模型对阳性型的符合率为８２．６１％。     

A new model of bilateral hemispheric ischemia in the rat--three vessel occlusion model

A new model of bilateral hemispheric ischemia was created in the rat by occluding the common carotid arteries and the basilar artery; this resulted in consistent and severe impairment of the cerebral blood flow. The procedure for producing this model is described, and the results of EEG and autoradiography obtained by this model are compared to those obtained by the four-vessel occlusion model.     

大鼠股骨开放截骨模型与闭合骨折模型制作的比较

背景：骨折动物模型无疑是研究骨折愈合的基石，其中开放截骨模型与闭合骨折模型是较成熟的两种长骨干骨折模型。就作者所查文献，未见关于大鼠两种模型比较研究的报道。 目的：比较大鼠股骨开放截骨模型与闭合骨折模型的制作过程，并通过X射线摄片比较二者的骨折愈合情况。 设计、时间及地点：随机对照动物实验，于2007-01/05在苏州大学附属第二医院骨科实验室完成。 材料：SPF级雄性SD大鼠40只，体质量(220±30) g，随机分为开放截骨模型组与闭合骨折模型组，每组20只。电动摆锯；自行改良设计的闭合骨折模型打击器。 方法：开放组行开放截骨术造成股骨中段横行骨折，逆行克氏针固定；闭合组行逆行克氏针固后，使用造模支架致股骨中段闭合骨折。 主要观察指标：比较两组的平均造模时间，造模成功率及术后2，3，4，8周骨折愈合的X射线情况。 结果：开放截骨模型每只造模成功率90%,平均造摸时间为17 min，骨折畸形愈合及不愈合率40%；闭合骨折模型每只造模成功率85%，平均造模时间12 min，未见畸形愈合及不愈合。术后2，3，4周X射线评分开放组均低于闭合组(P < 0.05)，8周时开放组X射线评分仍较闭合组低，但差异无显著性意义(P > 0.05)。 结论：开放截骨模型造模时间长，骨折畸形愈合不愈合发生率高，近中期骨折愈合明显滞后，不适于近中期骨折愈合的研究。     

A model of the functional psychoses

A model of the functional psychoses is described which accounts for their existence, answers certain questions about them and generates refutable predictions.     

谷氨酸兴奋性毒性模型的研究

目的探讨谷氨酸兴奋性毒性模型培养液各成分中谷氨酸的含量及模型培养前后培养液中谷氨酸的变化。方法应用脊髓器官型培养模型,随机分成对照组和苏-羟天冬氨酸(THA)组,用免疫组化法检测运动神经元数目,用多功能酶标仪检测培养基中谷氨酸的含量。结果最小基础培养基和马血清中均含有谷氨酸。经过4w培养后,THA组培养液中谷氨酸的含量明显高于对照组(P<0.05),运动神经元数目较对照组减少(P<0.05)。结论 THA诱导的脊髓器官型培养模型可以模拟肌萎缩侧索硬化运动神经元变性,作为谷氨酸兴奋性毒性模型,我们在应用它时一定要严格检测培养液中谷氨酸的含量,每一个处理因素都要考虑其对谷氨酸的影响。     

Yohimbine and the model anxiety state

Ten subjects were treated with 30 and 60 mg oral doses of yohimbine hydrochloride or placebo under controlled clinical conditions to determine if such doses would create a "model anxiety state." Some evidence of anxiety was found on various rating scales, especially after the 60 mg dose. However, maximum anxiety produced by this dose of the drug exceeded that which occurred during placebo testing in only 5 of the 10 subjects. The 60 mg dose produced substantial increases in systolic blood pressure and less increase in diastolic blood pressure and pulse rate. It was concluded that yohimbine does not produce a very good model of anxiety.     

Testing the autogenous-reactive model of obsessions

Two independent studies were conducted to examine the autogenous-reactive subtype model of obsessions [Lee and Kwon, 2003]. Study 1 demonstrated that 30 obsessive-compulsive (OCD) patients' responses to autogenous versus reactive obsessions differed significantly with respect to emotional reactions, cognitive appraisals, and control strategies. Study 2 compared OCD patients whose primary obsessions were of the autogenous subtype (n=13) with OCD patients whose primary obsessions were of the reactive subtype (n=14). Results revealed significant differences between these two groups on several OCD-related domains including OCD symptom profiles, perfectionistic personality features, and dysfunctional beliefs. Theoretical and clinical implications are discussed.     

A new human experimental pain model: the heat/capsaicin sensitization model.

The heat/capsaicin sensitization model is a new human experimental pain model that synergistically combines non-invasive physical and chemical methods of nociceptor stimulation to produce stable and long-lasting hyperalgesia with a low potential for skin injury. In 10 healthy volunteers the forearm was stimulated with a 45 degrees C thermode for 5 min to produce an area of secondary hyperalgesia. Applying capsaicin cream for 30 min further expanded the area of secondary hyperalgesia. Periodically heating the treated skin with a previously non-painful temperature of 40 degrees C re-kindled the sensitization enough to maintain stable areas of secondary hyperalgesia for 4h. The evoked pain was moderate and well tolerated. The heat/capsaicin sensitization model should be well suited for studying pain mechanisms and testing new analgesics.     

Extending the demand-control model to informal caregiving

OBJECTIVE: Karasek's demand-control model of job strain was used in an attempt to extend previous work examining the psychological impact of informal caregiving in stroke. METHOD: Data were gathered from 138 informal caregivers/patient dyads at two time points. The dependent variables were the caregiver's anxiety and depression [Hospital Anxiety and Depression Scale (HADS)]. The predictor variables were caregiver demand (stroke survivor's assessment of their physical and psychosocial functional limitations) and control (caregiver's perceived control over stroke survivor's recovery). RESULTS: In a cross-sectional analysis of Times 1 and 2 data, main effects for demand and/or control were detected for anxiety and depression. Contrary to prediction, in longitudinal analysis of change, it was found that decreasing control, along with increasing demand, was associated with reduced distress. CONCLUSION: The model was moderately successful in predicting emotional distress. The relative importance of caregiver demand and control in predicting outcomes changed over time in these data. Attempts to replicate these findings are recommended.     

A neurodynamic model of the attentional blink

A brain-based neural model of attention is used to simulate results for the 'attentional blink', observed when a subject is exposed to a rapid stream of stimuli and required to monitor for two successive targets in the stream. The 'blink' occurs when the time between the first and second targets is 200-500 ms, when there is reduced accuracy for report of the second target. The model gives a qualitative explanation of the phenomenon, especially of how attention is bolstered, during the processing to report of a given stimulus, in order to defend reportable information from attack by distracters.