Gravity-oriented microfluidic device for uniform and massive cell spheroid formation

We propose a simple method for forming massive and uniform three-dimensional (3-D) cell spheroids in a multi-level structured microfluidic device by gravitational force. The concept of orienting the device vertically has allowed spheroid formation, long-term perfusion, and retrieval of the cultured spheroids by user-friendly standard pipetting. We have successfully formed, perfused, and retrieved uniform, size-controllable, well-conditioned spheroids of human embryonic kidney 293 cells (HEK 293) in the gravity-oriented microfluidic device. We expect the proposed method will be a useful tool to study in-vitro 3-D cell models for the proliferation, differentiation, and metabolism of embryoid bodies or tumours.     

The Colorado Learning Attitudes about Science Survey (CLASS) for use in Biology

This paper describes a newly adapted instrument for measuring novice-to-expert-like perceptions about biology: the Colorado Learning Attitudes about Science Survey for Biology (CLASS-Bio). Consisting of 31 Likert-scale statements, CLASS-Bio probes a range of perceptions that vary between experts and novices, including enjoyment of the discipline, propensity to make connections to the real world, recognition of conceptual connections underlying knowledge, and problem-solving strategies. CLASS-Bio has been tested for response validity with both undergraduate students and experts (biology PhDs), allowing student responses to be directly compared with a consensus expert response. Use of CLASS-Bio to date suggests that introductory biology courses have the same challenges as introductory physics and chemistry courses: namely, students shift toward more novice-like perceptions following instruction. However, students in upper-division biology courses do not show the same novice-like shifts. CLASS-Bio can also be paired with other assessments to: 1) examine how student perceptions impact learning and conceptual understanding of biology, and 2) assess and evaluate how pedagogical techniques help students develop both expertise in problem solving and an expert-like appreciation of the nature of biology.     

Double jeopardy: poorer social-emotional outcomes for children in the NICHD SECCYD experiencing home and child-care environments that confer risk

Using data from the National Institute of Child Health and Human Development Early Child Care Research Network (NICHD SECCYD), the authors examined whether interactions between home and child-care quality affect children's social-emotional adjustment at 24, 36, and 54 months (N = 771). Triadic splits on quality of home and child care were used to examine children in specific ecological niches, with a focus on those who experience the double jeopardy of poor quality home and child-care environments. Children in this niche exhibited the highest levels of mother-reported problem behavior and the lowest levels of prosocial behavior. However, there was evidence that children from lower quality home environments were able to benefit from the compensatory influence of high-quality child care. These results suggest policies aimed at the cross-context influences of protective and risky settings.     

An undergraduate course to bridge the gap between textbooks and scientific research

This article reports on a one-semester Advanced Cell Biology course that endeavors to bridge the gap between gaining basic textbook knowledge about cell biology and learning to think and work as a researcher. The key elements of this course are 1) learning to work with primary articles in order to get acquainted with the field of choice, to learn scientific reasoning, and to identify gaps in our current knowledge that represent opportunities for further research; 2) formulating a research project with fellow students; 3) gaining thorough knowledge of relevant methodology and technologies used within the field of cell biology; 4) developing cooperation and leadership skills; and 5) presenting and defending research projects before a jury of experts. The course activities were student centered and focused on designing a genuine research program. Our 5-yr experience with this course demonstrates that 1) undergraduate students are capable of delivering high-quality research designs that meet professional standards, and 2) the authenticity of the learning environment in this course strongly engages students to become self-directed and critical thinkers. We hope to provide colleagues with an example of a course that encourages and stimulates students to develop essential research thinking skills.     

Inclusive instruction and learning for deaf students in postsecondary education

This article explores how students who are deaf and their instructors experience mainstream college classes. Both quantitative and qualitative procedures were used to examine student access to information and their sense of belonging and engagement in learning. Instructors were asked to discuss their approach to teaching and any instructional modifications made to address the needs of deaf learners. Results indicate that deaf students viewed classroom communication and engagement in a similar manner as their hearing peers. Deaf students were more concerned about the pace of instruction and did not feel as much a part of the 'university family' as did their hearing peers. Faculty generally indicated that they made few if any modifications for deaf students and saw support service faculty as responsible for the success or failure of these students. We discuss results of these and additional findings with regard to barriers to equal access and strategies for overcoming these barriers.     

On-demand electrostatic droplet charging and sorting

This study reports a droplet-based microfluidic device for on-demand electrostatic droplet charging and sorting. This device combines two independent modules: one is a hydrodynamic flow focusing structure to generate water-in-oil droplets, and the other is the two paired-electrodes for charging and sorting of the droplets. Depending on the polarity on charging electrodes, water-in-oil droplets can be electrostatically charged positively or negatively, followed by automatic real-time electric sorting. This approach will be useful when preformed droplets, with a positive, a negative, or with no charge, need to be manipulated for further on-chip droplet manipulation.     

排名前10的与预防运动和体育活动猝死相关的关键问题

参加有组织的体育运动和休闲活动存在发生严重伤病甚至死亡的内在风险。虽然造成体育运动或体育活动中猝死的原因有很多,但运动医学和循证标准治疗方面的进展已使临床医生得以更有效地预防、发现和治疗可能致死的伤患。随着研究与技术不断发展进步,当前的治疗标准正在不断发展以更好地改善患者的治疗效果。本文提出了10个与运动和体育活动中猝死的主要原因及其治疗手段有关的关键问题,未来开展的研究将提高运动员和休闲运动爱好者参与运动的安全度。当前证据表明,如采取正确的预防策略或最佳治疗方案,绝大多数的死亡案例是可以避免的。     

语义计算的本体和约束

语义计算的目的是在用户和计算机共享的涵义和词汇的基础上设计和操作信息系统.它旨在缩小语义差距,使用户和信息系统能更好地协同工作,从而在语义学意义上使我们的生活更加丰富.文章将探讨以本体和约束为主要技术来实现用户和信息系统之间的涵义共享.     

Decrease in Ammonia Excretion by Boleophthalmus Boddaerti(Mudskipper) Exposed to Cyanide

ThetoleranceofthemudskipperBoleophthalmusboddaertitocyanideishigherthanthoseofotherfishes[1].Suchahightolerancetocyanidedoesnotinvoveareductionofmetabolicrateoranenhancedanaerobicmetabolism,oracyanide-insensitiverespiratorypathway.Instead,itisaresultofthepresenceofasurplusofcytochromeoxidaseandinduciblecyanide-detoxifyingmechanisms,tumingcyanideinthiocyanate,inthismudskipper[1].ThoughCN-isdetoxifiedtoSCN-,realizingbiomembranesaremorepermeabletoHCNthanCN-,wedecidedtoinvestigateiftheprotondi…