A new perspective on in vitro assessment method for evaluating quantum dot toxicity by using microfluidics technology

In this study, we demonstrate a new perspective on in vitro assessment method for evaluating quantum dot (QD) toxicity by using microfluidics technology. A new biomimetic approach, based on the flow exposure condition, was applied in order to characterize the cytotoxic potential of QD. In addition, the outcomes obtained from the flow exposure condition were compared to those of the static exposure condition. An in vitro cell array system was established that used an integrated multicompartmented microfluidic device to develop a sensitive flow exposure condition. QDs modified with cetyltrimethyl ammonium bromide∕trioctylphosphine oxide were used for the cytotoxicity assessment. The results suggested noticeable differences in the number of detached and deformed cells and the viability percentages between two different exposure conditions. The intracellular production of reactive oxygen species and release of cadmium were found to be the possible causes of QD-induced cytotoxicity, irrespective of the types of exposure condition. In contrast to the static exposure, the flow exposure apparently avoided the gravitational settling of particles and probably assisted in the homogeneous distribution of nanoparticles in the culture medium during exposure time. Moreover, the flow exposure condition resembled in vivo physiological conditions very closely, and thus, the flow exposure condition can offer potential advantages for nanotoxicity research.     

何以成为真正的图书馆员

“真正的图书馆员”是指完全具备专业或职业素养的图书馆员,其中隐含着“图书馆员这一职业是一种专门职业”的内涵。图书馆职业资质由专业资质、个人资质和核心资质构成。一个真正的图书馆员应该具备专业资质、职业使命、继续学习、专业团体、职业伦理、个人品质、价值观这七种素质。图2。参考文献31。     

A Longitudinal and Multidimensional Examination of the Associations Between Temperament and Self-Restraint During Toddlerhood

Developing self-restraint, or the inhibition of behavior in response to a prohibition, is an important process during toddlerhood. The objective of this study was to gain a better understanding of individual differences in the development of self-restraint during toddlerhood by examining stable elements and growth of temperament (i.e., attentional control, behavioral inhibition, negative emotionality), general intelligence, and self-restraint. Participants were 412 same-sex twin pairs (approximately 90% European American) from predominately middle-class households in Colorado. Data were collected at 14, 20, 24, and 36 months. Results indicated that higher behavioral inhibition, attentional control, and intelligence were independently associated with better self-restraint, whereas higher negative emotionality was an independent predictor of lower self-restraint. The associations between temperament and self-restraint generally appeared to be stable from 14 to 36 months.     

Genres and genre repertoires of user and use information sources in U.S. state archival and records management appraisal practice

Many archival researchers and practitioners have claimed that appraisal practitioners should utilize users and use of records as a factor in appraisal practice. However, little is known about what sources appraisal practitioners utilize to collect user and use information. This study is the first to explore and analyze the genres of user and use information sources utilized as appraisal tools. It applies the concepts of genre, genre repertoire, and structuration theory to examine the relationships between the sources of user and use information and the organizational structure and function of U.S. state archives and records management programs. This study recommends ways to improve sources of user and use information for appraisal practice, and it also presents some topics in need of further study.