Vascular smooth muscle cell culture in microfluidic devices     

Y. C. Wei  F. Chen  T. Zhang  D. Y. Chen  X. Jia  J. B. Wang  W. Guo  J. Chen 《Biomicrofluidics》2014,8(4)

This paper presents a microfluidic device enabling culture of vascular smooth muscle cells (VSMCs) where extracellular matrix coating, VSMC seeding, culture, and immunostaining are demonstrated in a tubing-free manner. By optimizing droplet volume differences between inlets and outlets of micro channels, VSMCs were evenly seeded into microfluidic devices. Furthermore, the effects of extracellular matrix (e.g., collagen, poly-l-Lysine (PLL), and fibronectin) on VSMC proliferation and phenotype expression were explored. As a platform technology, this microfluidic device may function as a new VSMC culture model enabling VSMC studies.  相似文献   

A microfluidic shear device that accommodates parallel high and low stress zones within the same culturing chamber     

X. Zhang  D. J. Huk  Q. Wang  J. Lincoln  Y. Zhao 《Biomicrofluidics》2014,8(5)

Fluid shear stress (FSS) plays a critical role in regulating endothelium function and maintaining vascular homeostasis. Current microfluidic devices for studying FSS effects on cells either separate high shear stress zone and low shear stress zone into different culturing chambers, or arranging the zones serially along the flow direction, which complicates subsequent data interpretation. In this paper, we report a diamond shaped microfluidic shear device where the high shear stress zone and the low shear stress zone are arranged in parallel within one culturing chamber. Since the zones with different shear stress magnitudes are aligned normal to the flow direction, the cells in one stress group are not substantially affected by the flow-induced cytokine/chemokine releases by cells in the other group. Cell loading experiments using human umbilical vein endothelial cells show that the device is able to reveal stress magnitude-dependent and loading duration-dependent cell responses. The co-existence of shear stress zones with varied magnitudes within the same culturing chamber not only ensures that all the cells are subject to the identical culturing conditions, but also allows the resemblance of the differential shear stress pattern in natural arterial conditions. The device is expected to provide a new solution for studying the effects of heterogeneous hemodynamic patterns in the onset and progression of various vascular diseases.  相似文献   

Modelica扩展建模的故障诊断技术研究     

邱晓红  龚姚腾  邱晓辉 《科技通报》2011,27(5)

故障诊断技术是提高故障检测和隔离能力,提高任务可靠性的重要手段,基于模型的故障诊断分析方法得到了广泛应用,但难以用于实时检测诊断,难以计算虚警率等设计指标。本文提出扩展多领域物理系统建模语言Modelica,将多种故障模态嵌入模型中,利用基于假设的真值维护系统(ATMS)方法分析了测试集的生成算法。理论上分析了计算虚警率的可行方案,体现了新模型的优势。  相似文献   

Aspects of financing non-formal education     

Francisco X. Swett Morales 《Prospects》1983,13(1):55-60

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Experimental laboratory apparatus to analyze kinematics and 3D kinetics in rowing     

P. Pudlo  A. Pinti  F. X. Lepoutre 《Sports Engineering》2005,8(1):39-46

In order to quantify internal forces and articular moments, by the inverse dynamics method, specially at lumbar level, an experimental laboratory apparatus to analyze kinematics and 3D kinetics of rowers was developed. It comprised a 3D motion analysis system, a Type C Concept II ergometer, three force-plates, six axes and two miniature mono-dimensional force transducers. The apparatus was designed for each hand, with two miniature transducers integrated into new steel handles to measure the force developed by each hand. Furthermore, the apparatus was also designed for each foot. Two force platforms were placed under two new foot stretchers to measure force and moment developed by each foot. The ergometer also has a sliding seat under which was placed a miniature force platform. A study of the rowing movement of a regional level competition rower demonstrated the relevance of the data. This study was concerned with the 3D kinetics parameters expressed in the medio-lateral, anterio-posterior and vertical axes. Some obtained data are novel or rarely associated together and enable a better understanding of the rower movement.  相似文献   

硬盘自举过程及常见错误修复方法     

崔卫东  王永乐  徐书欣 《商丘师范学院学报》2001,17(2):71-74

硬盘以其容量大，速度快等特点倍受微机用户的青睐，已成为当前微机配置必不可少的外部设备，但由于其使用率高，若有误操作，维护不当，病毒攻击或环境影响等方面的因素时，常出现硬盘不能自举的软故障，在此情况下，均令不少用户感到无从下手，唯有重做硬盘，这样既浪费了大量宝贵时间，又可能丢失许多有用的数据，同时也会缩短硬盘的寿命，实际上，若了解了系统自举过程，根据错误提示，就可对症下药，采取相应的对策进行修复。本文第一部分首先给出了硬盘自举过程的机理及系统自举过程中可能由于某种软故障而给出的错误提示；第二部分逐一给出根据不同的错误提示信息所做的相应故障分析及修复方法。  相似文献   

Exploring dimensions of social inclusion among alternative learning centres in the USA     

Dawn X. Henderson  Rachelle Redmond Barnes 《International Journal of Inclusive Education》2016,20(7):726-742

Increasing disparities in out-of-school suspension and dropout rates have led a number of school districts to develop alternative models of education to include alternative learning centres (ALCs). Using an exploratory mixed methods design, this study explores dimensions of social inclusion among ALCs, located in the southeastern region of the USA. In the first phase, case-study analyses across two sites contextualised student experiences from the perspective of students, teachers, and assistant principals. In the second phase, data explored student outcomes among a sample of 593 students across 28 ALCs in the school district. Qualitative findings revealed varying dimensions of social inclusion through access, success through empowerment, and participation and engagement. Quantitative findings revealed a majority of students transitioned back to the traditional school environment. There were no clear student or school advantages associated with student transitions; however, high school students were more likely to transition back to the traditional school environment than middle school students. Discussion centres on the challenges school districts experience in promoting social inclusion and implications for inclusive models of education.  相似文献   

The influence of a residential outdoor education programme to pupil’s environmental perception   总被引：1，自引：0，他引：1  

Franz X. Bogner 《European Journal of Psychology of Education - EJPE》2002,17(1):19-34

This empirical study finds support for the hypothesis that participation in a special residential education programme enhances facets of pupils’ environmental perception. A 4-day extra-curricular educational unit with a cognitive outdoors focus (established in a nature centre in France) was surveyed by using a two stage sampling design in a pre-post-treatment evaluation; the post-test was delayed for a one-month period after participation. All selected participating pupils (n=151) responded twice to the same perception questionnaire. The factorial structure of this questionnaire had been previously developed using a large European sample (n=4500) and separately validated in a smaller French pupil sample (n=900). The matched-pair pre-post-test survey showed significant differences in two of the five primary factors; both of them covered utilitarian preferences and scored in a way which indicated an increase in sensitivity to the environment. A pre-post-tested control group (n=78) revealed no significant difference. Possible reasons for the partial shift in primary factors are discussed, including a consideration of two related studies (in Germany and Switzerland) which were both monitored by the same measurement instrument.  相似文献   

Comparisons of adopted and nonadopted adolescents in a large, nationally representative sample     

Miller BC  Fan X  Christensen M  Grotevant HD  van Dulmen M 《Child development》2000,71(5):1458-1473

There are conflicting findings about whether adopted children have more psychological and behavioral problems than nonadoptees. Research results are discrepant partly because many previous studies were based on small clinical samples or on samples biased by self-selection. A nationally representative school survey (Add Health) was used to compare adopted (n = 1,587) and nonadopted adolescents (total N = 87,165) across a wide variety of measures. Standardized mean differences show that adopted adolescents are at higher risk in all of the domains examined, including school achievement and problems, substance use, psychological well-being, physical health, fighting, and lying to parents. Demographic and background variable breakdowns show that the effect sizes for differences between adopted and nonadopted adolescents were larger for males, younger or older adolescents, Hispanics or Asians, and adolescents living in group homes or with parents of low education. Distributional analyses revealed approximately a 1:1 ratio of adopted to nonadopted adolescents in the middle ranges of the outcome variables but a ratio of 3:1 or greater near the tails of the distributions. These data clearly show that more adopted adolescents have problems of various kinds than their nonadopted peers; effect sizes were small to moderate based on mean differences, but comparisons of distributions suggest much larger proportions of adopted than nonadopted adolescents at the extremes of salient outcome variables.  相似文献   

Environmental perception of French and some Western European secondary school students     

Franz X. Bogner  Michael Wiseman 《European Journal of Psychology of Education - EJPE》2002,17(1):3-18

This paper describes, by focusing on factor analytic structures, pupils’ reactions towards the utilisation and preservation of nature. A previously hypothesised model based on these two domains (comprised of 5 primary factors) was shown to be valid for four different Western European pupil samples: CH, D, DK, IRL. The empirical basis of this present paper comprises a survey of about 900 French pupils of both genders aged between 11 and 16 years from rural areas who responded to a paper-and-pencil questionnaire. Data from the remaining European samples added some 4000 respondents based on the same objective test each. The purpose of the present study was five-fold: Firstly, to test and confirm the hypothesised primary and secondary factor structure for the combined data set. Secondly, to apply the methods of linear structural relationship analysis to test the existence of two higher-order factors (the domains: “Preservation” and “Utilisation”). Thirdly, to investigate any age or gender effect in the primary factors. Fourthly, to provide an age-adjusted empirical instrument for evaluation purposes of educational programmes featuring conservation and environmental protection. Finally, to compare the means within-region factor scores in anticipation of substantial between-region differences. These differences followed a rather consistent pattern supporting the interpretation that “utilising” nature is negatively correlated with positive environmental reactions.  相似文献