A multichannel acoustically driven microfluidic chip to study particle-cell interactions

Microfluidic devices have emerged as important tools for experimental physiology. They allow to study the effects of hydrodynamic flow on physiological and pathophysiological processes, e.g., in the circulatory system of the body. Such dynamic in vitro test systems are essential in order to address fundamental problems in drug delivery and targeted imaging, such as the binding of particles to cells under flow. In the present work an acoustically driven microfluidic platform is presented in which four miniature flow channels can be operated in parallel at distinct flow velocities with only slight inter-experimental variations. The device can accommodate various channel architectures and is fully compatible with cell culture as well as microscopy. Moreover, the flow channels can be readily separated from the surface acoustic wave pumps and subsequently channel-associated luminescence, absorbance, and/or fluorescence can be determined with a standard microplate reader. In order to create artificial blood vessels, different coatings were evaluated for the cultivation of endothelial cells in the microchannels. It was found that 0.01% fibronectin is the most suitable coating for growth of endothelial monolayers. Finally, the microfluidic system was used to study the binding of 1 μm polystyrene microspheres to three different types of endothelial cell monolayers (HUVEC, HUVECtert, HMEC-1) at different average shear rates. It demonstrated that average shear rates between 0.5 s⁻¹ and 2.25 s⁻¹ exert no significant effect on cytoadhesion of particles to all three types of endothelial monolayers. In conclusion, the multichannel microfluidic platform is a promising device to study the impact of hydrodynamic forces on cell physiology and binding of drug carriers to endothelium.     

谁曾见过风？

有个叫布罗迪的英国教师,在整理阁楼上的旧物时,发现了一叠练习册,它们是50年前皮特金幼儿园B（2）班31位孩子的春季作文,题目是“未来我是——”。     

Changing literacies—people,place and objects: a review essay

In this review essay, I refer to two recently published scholarly works that explore the notions of transcultural, mobile and placed literacies: in Languages and literacies as mobile and placed resources edited by Sue Nichols and Collette Snowden, and Literacy lives in transcultural times edited by Rahat Zaidi and Jennifer Rowsell. Much research in the field of literacy education has recently acknowledged how literacies are continually changing due to globalisation and transmobility. People move, places change, and objects shift in and through these spaces. Researchers and educators are, therefore, grappling with how best to address these diversities and engage learners in such environments. Through a review of the books mentioned above, two key questions are explored: what are the appropriate pedagogies for literacy education? Where and how is literacy education research leading us into the future? This review takes a socio-cultural perspective of literacy by presenting the contemporary research that attempts to answer these questions.     

The pleasure imperative? Reflecting on sexual pleasure’s inclusion in sex education and sexual health

This article offers an empirically grounded contribution to scholarship exploring the ways in which pleasure is ‘put to work’ in sex and sexuality education. Such research has cautioned against framing pleasure as a normative requirement of sexual activity and hence reproducing a ‘pleasure imperative’. This paper draws on interviews with sexual health and education practitioners who engaged with Pleasure Project resources and training between 2007 and 2016. Findings suggest that practitioners tend to understand pleasure within critical frameworks that allow them to avoid normalising and (re)enforcing a pleasure imperative. Accounts also show negotiations with, and strategic deployments of, values surrounding sexual pleasure in society and culture. While some accounts suggest that a pleasure imperative does run the risk of being reproduced by practitioners, notably this is when discussing more ‘contentious’ sexual practices. Interviews also demonstrate that practitioners attempting to implement a pleasure agenda are faced with a range of challenges. While some positive, holistic, and inclusive practice has been afforded by a pleasure approach, we argue that the importance of a critical framework needs to be (re)emphasised. The paper concludes by highlighting areas for further empirical research.     

Coping strategies at the ages 8, 10 and 12

The aim of the cross-sectional study was to reveal what coping strategies 8, 10- and 12-year-old Hungarian students (N?=?167) use in situations that are frustrating, either for themselves or their peers. The coping strategies in school situations were assessed by our own questionnaires. The instrument enables the investigation of the following behaviourally observable strategies: physical aggression, verbal aggression, resistance, venting/crying, avoidance, teacher-seeking, peer-seeking, following the norms and following teacher’s instructions. The coping strategies were assessed by teacher-report and self-report questionnaires developed especially for this purpose. The most important finding of this study is that the occurrence of overt aggression increases with age, which is supported by the results of both the self-report and the teacher-report questionnaires. Results obtained by the self-report and teacher-report instruments correlated significantly in all three cohorts (p?相似文献   

Effect of Non-Darcian Flow on Time Rate of Consolidation

The effect of non-Darcian flow on the consolidation behavior of clay soils is studied, and its role in the extrapolation of laboratory test results to field problems is evaluated. This is accomplished by postulating a reasonably general four-parameter velocity-gradient relationship which, by proper choice of parameters, is capable of characterizing much of the published experimental data; then, this relationship is combined with the standard assumptions of classical consolidation theory to develop a nonlinear parabolic partial differential equation, which is solved by use of a finite difference technique. The stability and convergence criteria for related linear and quasi-linear equations are empirically extended to the associated nonlinear equations, and a comparison is made between various explicit and implicit finite difference schemes, with the result that a sufficiently accurate and more economical numerical solution is obtained by use of an explicit scheme. Typical solutions for various specific cases confirm and offer an explanation for the well-known phenomenon wherein the time rate of consolidation is found to decrease as the load increment decreases; also, the thickness of the consolidating layer is shown to affect the dimensionless time rate of consolidation. These conditions indicate that laboratory consolidation test results can be applied to a field situation only if appropriate stress and thickness corrections are made.     

Achievement and school behavior among children with epilepsy

The school-related behavior of 15 epileptic children (7 boys and 8 girls) whose average age was approximately 10 years was compared with that of matched groups of diabetic and healthy children. Data were derived from the Piers-Harris Children's Self-concept Scale, the Multidimensional Measure of Children's Perception of Control, and the Rochester Adaptive Behavior Inventory. The epileptic children were found to be more likely to attribute the success or failure of their school performance to unknown sources of control, and to hold less positive feelings about school and about their own self-worth within the school setting than were their diabetic or healthy peers. The implications of these findings are discussed, and recommendations for remediation are offered.