Core-shell hydrogel beads with extracellular matrix for tumor spheroid formation     

L. Yu  S. M. Grist  S. S. Nasseri  E. Cheng  Y.-C. E. Hwang  C. Ni  K. C. Cheung 《Biomicrofluidics》2015,9(2)

Creating multicellular tumor spheroids is critical for characterizing anticancer treatments since they may provide a better model of the tumor than conventional monolayer culture. Moreover, tumor cell interaction with the extracellular matrix can determine cell organization and behavior. In this work, a microfluidic system was used to form cell-laden core-shell beads which incorporate elements of the extracellular matrix and support the formation of multicellular spheroids. The bead core (comprising a mixture of alginate, collagen, and reconstituted basement membrane, with gelation by temperature control) and shell (comprising alginate hydrogel, with gelation by ionic crosslinking) were simultaneously formed through flow focusing using a cooled flow path into the microfluidic chip. During droplet gelation, the alginate acts as a fast-gelling shell which aids in preventing droplet coalescence and in maintaining spherical droplet geometry during the slower gelation of the collagen and reconstituted basement membrane components as the beads warm up. After droplet gelation, the encapsulated MCF-7 cells proliferated to form uniform spheroids when the beads contained all three components: alginate, collagen, and reconstituted basement membrane. The dose-dependent response of the MCF-7 cell tumor spheroids to two anticancer drugs, docetaxel and tamoxifen, was compared to conventional monolayer culture.  相似文献   

Referee acknowledgment for 2014     

Hsueh-Chia Chang  Leslie Y. Yeo 《Biomicrofluidics》2015,9(1)

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题目：一种支持产品平台设计的多准则模块划分方法   总被引：2，自引：0，他引：2  

Wei WEI  Ang LIU  Stephen C.Y.LU  Thorsten WUEST 《浙江大学学报(A卷英文版)》2015,(1):1-10

目的：研究多准则约束下的产品模块划分方法,为企业建立稳健的模块化产品平台奠定基础。方法：采用改进的多目标进化算法对建立的多准则模块划分数学模型求解,并采用模糊集合评价机制进行最优解的寻取,得到基于多准则模块划分方法的产品模块划分结果。结论：通过改进的多目标进化算法求解多准则模块划分模型,能够得到有效支持产品平台设计的产品模块划分方案。通过与已有优化方法的比较验证了本文提出的多准则模块划分方法的优越性。  相似文献   

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

Semsar K  Knight JK  Birol G  Smith MK 《CBE life sciences education》2011,10(3):268-278

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.  相似文献   

倾斜金标试纸图像的线宽测量方法     

周律  陈正伟  朱建华  刘铁兵 《实验室研究与探索》2015,(3):146-149

基于显微图像的金标试纸条测试线线宽参数的测量方法具备操作方便、测量速度快、分辨率高等优点,然而图像采集系统采集到的金标试纸条的显微图像不可避免地会发生倾斜,这为后续的图像分割和参数测量带来了困难,因此需要对倾斜的金标试纸条显微图像进行校正。根据霍夫变换法和最小二乘法在直线检测中的优点和适用条件,拟采用一种结合霍夫变换法和最小二乘法的直线检测算法来求得金标试纸条图像的边缘线和边缘线的倾斜角度参数,并采用图像旋转变换算法实现对原图像的倾斜校正。实验表明,所采用的倾斜校正算法具备计算量小、占用内存小、校正精度高的优点,通过倾斜校正可以准确测量倾斜金标试纸图像的线宽参数。  相似文献   

Relationship Reciprocation Modulates Resource Allocation in Adolescent Social Networks: Developmental Effects          下载免费PDF全文

Stephanie Burnett Heyes  Yeou‐Rong Jih  Per Block  Chii‐Fen Hiu  Emily A. Holmes  Jennifer Y. F. Lau 《Child development》2015,86(5):1489-1506

Adolescence is characterized as a period of social reorientation toward peer relationships, entailing the emergence of sophisticated social abilities. Two studies (Study 1: N = 42, ages 13–17; Study 2: N = 81, ages 13–16) investigated age group differences in the impact of relationship reciprocation within school‐based social networks on an experimental measure of cooperation behavior. Results suggest development between mid‐ and late adolescence in the extent to which reciprocation of social ties predicted resource allocation. With increasing age group, investment decisions increasingly reflected the degree to which peers reciprocated feelings of friendship. This result may reflect social‐cognitive development, which could facilitate the ability to navigate an increasingly complex social world in adolescence and promote positive and enduring relationships into adulthood.  相似文献   

Research on teaching practicum – a systematic review     

Tony Lawson  Melek Çakmak  Müge Gündüz  Hugh Busher 《欧洲师范教育杂志》2015,38(3):392-407

The aim of the present study is to conduct a systematic review research which focuses on research studies into the school practicum. In order to identify the main issues and also to provide a contemporary picture of practicum, 114 studies published on the topic are reviewed and analysed in terms of: (i) aims, (ii) main participants, (iii) methodology used and (iv) the main outcomes emerging. Many of the reviewed studies take pre-service teachers as their main participants. The review also shows that many practicum studies are relatively small-scale studies since they are mainly qualitative focused and findings derived from a relatively small sample. This suggests that more large-scale studies are needed in the field in order to provide greater insight into teaching practicum. Finally, this systematic review provides some food for thought in the area of practicum research and promotes further studies in this complex field.  相似文献   

论苏童笔下的“颂莲”式女性     

周茜  王艳芳 《乐山师范学院学报》2015,(7)

苏童是少数几个尤其擅长写女性的男性作家。他对女性的心理描写和细节把握都处理得恰到好处,非常自然。他笔下的女性一改过往的温柔善良、知书达理,相反的,大多都阴暗猥琐、粗俗野蛮、善于妒忌,非常具有特色,成为中国当代女性小说的独有景观。苏童的几个从女性视角描写的女主人公具有很多的共同特征,他将这些女性称为“颂莲”式女性。  相似文献   

The Effect of Planetariums on Teaching Specific Astronomy Concepts     

Cumhur Türk  Hüseyin Kalkan 《Journal of Science Education and Technology》2015,24(1):1-15

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Differential effects of reading trainings on reading processes: a comparison in Grade 2     

Bettina?MüllerEmail author  Axel?Mayer  Tobias?Richter  Ana?Kri?an  Teresa?Hecht  Marco?Ennemoser 《Zeitschrift für Erziehungswissenschaft》2015,18(3):489-512

Phonics, fluency, and reading strategy trainings are evidence-based interventions that foster the reading skills of poor readers in primary school. The purpose of the present study was to compare differential effects of the three types of trainings on the efficiency of component processes on word, sentence, and text level immediately after the training and at a 3-month follow-up. The 235 poor readers were randomly allocated to one of the reading interventions or to a control condition. All interventions consisted of 25 sessions that were scheduled twice a week and lasted 45 min. Results indicated short-term effects of the phonics training and the strategy training on the efficiency of a broad range of word-level and sentence-level processes. None of the treatment effects persisted over the long term, indicating the need for instructional efforts to regularly practice the acquired skills after the actual training.  相似文献