四溴二苯醚与高氯酸盐联合暴露对成年斑马鱼肝脏抗氧化系统的影响          下载免费PDF全文

任新  赵雪松  段小月  刘萍  贾晨梦  庞蒙蒙 《唐山学院学报》2018,31(3):29-34

实验选择四溴二苯醚（BDE-47）与高氯酸盐（PER）作为研究对象,系统研究了二者联合暴露对成年斑马鱼肝脏抗氧化系统的影响。实验设置（BDE-47 8.5+PER 335） mg/L,（BDE-47 0.85+PER 33.5） mg/L,（BDE-47 0.085+PER 3.35） mg/L三种联合暴露组及二者各自单一的暴露组。暴露14天后,分别测定雌雄斑马鱼肝脏内超氧化物歧化酶（SOD）活性、过氧化氢酶（CAT）活性、谷胱甘肽过氧化物酶（Gpx）活性以及脂质过氧化物（MDA）水平。结果显示,与两种物质单一暴露相比,联合暴露致使肝脏内SOD,CAT的活性增加,MDA水平增加,而GSH活性降低,实验说明,PER诱导加剧了BDE-47对成年斑马鱼肝脏抗氧化酶的影响,进一步产生了氧化应激。  相似文献   

The Notion of Creativity in Art and the Influence of Cultural Exposure     

Neville John Ellis  Tay-Koay Siew Luan 《Asia Pacific Journal of Education》1995,15(2):52-63

This study investigates how art teachers judge the creativity of student art work. Both conceptual and operational definitions given by teachers were studied. Furthermore, cultural exposure as measured by a teacher's exposure to non-Asian cultures, was studied to see how it might influence art teachers' judgements. Two instruments were developed for the purpose of this study. One instrument was a questionnaire designed to collect qualitative data from the respondents. The second instrument was used to measure art teachers' ratings of creativity. The data revealed that the conceptual definitions given by art teachers varied considerably. However, when asked to rate subjectively the creativity of art products, moderate agreement was reached among art teachers. Exposure to non-Asian cultures did not seem to have an effect on an art teachers' operational definition of creativity. Results of the study imply that the usefulness of the term creativity needs to be reviewed in general usage and in documents such as curricula. It would seem that there is not a clear notion among art teachers as to what constitutes creativity and a creative product.  相似文献   

The Successful Treatment of Specific Phobia in a College Counseling Center     

《Journal of College Student Psychotherapy》2013,27(1):56-66

Specific phobias are highly prevalent among college students and can be quite debilitating. However, students often do not present for treatment for phobias and, when they do, often do not receive effective treatment. This article will present a case study of the effective treatment of specific phobia using cognitive-behavioral therapy with an emphasis on in vivo exposure. It will provide a template for how to conduct this efficient and effective therapy and suggest several benefits of incorporating this treatment into the repertoire offered by a college counseling center.  相似文献   

试论新曝光冲突性事实在舆论逆转中的作用     

刘冲  李杰 《沧州师专学报》2013,29(3):91-93

舆论逆转是舆论变化的特殊形式,其根本原因是出现新曝光的冲突性事实.舆论逆转对当前舆论引导工作的启示是:作为媒体部门,在报道新闻事件时要做到真实全面;作为舆论的主体也就是广大受众,应提高信息辨别能力、公众媒介素养和媒介信息处理能力;监管部门应营造自由宽松的舆论大环境,使舆论真正发挥其作用.  相似文献   

Reduction in public speaking state anxiety during performance as a function of sensitization processes     

Chris R. Sawyer  Ralph R. Behnke 《Communication quarterly》2013,61(1):110-121

Recently, scholars have suggested that biological factors, such as temperament, influence human social behavior, particularly in the formation of traits, such as communication apprehension. Despite progress in this area, the relationship between temperament and states, such as speech anxiety, remains unclear. Theories of temperament predict that the rate at which subjects habituate to stress varies inversely with the degree to which they are sensitized during initial confrontation with stress‐producing stimuli. The inverse relationship between habituation and sensitization, in the context of public speaking state anxiety, is examined in this report. In two separate studies, using both physiological and psychological measures of state anxiety, the inverse relationship between sensitization and habituation was confirmed. Specifically, sensitization accounted for 69.1% and 50.3% of the variance in physiological and psychological habituation, respectively.  相似文献   

Survey on skin aging status and related influential factors in Southeast China     

Yi-na Wang  Hong Fang  Wei-fang Zhu 《Journal of Zhejiang University. Science. B》2009,10(1):57-66

Objective: To investigate cutaneous aging patterns of residents in Hangzhou, Zhejiang, China, and their contributing 2004. Results: Facial wrinkling first occurred at 21 years of age and skin elasticity began to lose at 22 years of age. In middle-aged and old people, facial wrinkling and looseness escalated with the increase of ultraviolet (UV)-exposure time, indicating the ac-celerating effect of a higher accumulative dose of UV radiation on skin aging. Only Fitzpatrick types Ⅱ, Ⅲ and Ⅳ were found in the skin phototypes of residents in Hangzhou area, and Fitzpatrick type Ⅱ seemed to be much more subject to severe wrinkling, elasticity destruction and skin tumors than types Ⅲ and Ⅳ. The oily skin was more protected against wrinkling and facial looseness than dry skin. However, as to concomitant cutaneous diseases, no difference was found among different skin types. Conclusion: Age, solar-exposure time, Fitzpatrick type and skin type are the associated forces in promoting skin aging, and emotional factor seems to be another independent risk factor. The age of 49 years and 2 h/d of solar-exposure time seem to be the turning points responsible for dramatic changes of cutaneous appearance in the process of skin aging in Southeast China.  相似文献   

蔬菜出口产地的农药使用行为及其对农民健康的影响——来自山东省莱阳、莱州和安丘三市的调研证据   总被引：4，自引：0，他引：4  

王志刚  吕冰 《中国软科学》2009,(11)

近年来,蔬菜的农药残留问题日益成为食品安全中备受关注的焦点.尽管国内外学者对此已有一定研究.但针对蔬菜出口产地的农药使用行为及其对农民健康影响方面的实证研究却相当缺乏.本文根据在山东省取得的调研数据,深入研究了蔬菜出口产地的农药使用行为及其对农民健康的危害.结果表明,农民在使用农药的过程中存在着未能严格按照标签对农药进行稀释等一系列不规范的使用行为;而且不规范地使用农药和缺乏相应的保护措施对农民的整体健康造成了不可忽视的负面影响,其中是否采取保护措施对农民的皮肤健康有着显著的影响;喷洒次数对农民的呼吸系统具有显著的负面影响.在此基础上,本文提出了加大力度宣传正确使用农药的方法以及强化对农药使用的监控措施等相关政策建议.  相似文献   

高解像度双面印刷电路板的穿通孔法制造工艺     

肖明 《茂名学院学报》1999,(3)

该文介绍采用PER—800液体感光抗蚀(镀)剂和PSR—550液体感光阻焊剂,生产制造具有高解像度的双面印刷电路板(PCB)的“穿通孔法”工艺技术;同时研究分析PER—800和PSR—550的使用方法和技术特性。  相似文献   

War-exposed newcomer adolescent immigrants facing daily life stressors in the United States     

《Int J Intercult Relat》2017

For adolescents new to the United States, the experience of war and acculturative stressors may play complex roles during early stages of adjustment to a new culture and country. The overall purpose of this study was to deepen understanding of the experiences of adolescents who are new to the United States, also called “newcomers”, through the examination of pre-migration war exposure and post-migration acculturative stressors as predictors of psychosocial adjustment and academic achievement. The study sample included newcomer immigrant and refugee youth (N = 184) with an average of 3.5 years in the United States. Triangulated data were collected from youth, teachers, and official school records. Results indicated that the participants who were exposed to war (N = 57) experienced more self-reported and teacher-reported anxiety, more self-reported conduct problems, and had lower academic achievement than participants who had not been exposed to war. Acculturative stressors also predicted more self-reported anxiety, conduct problems, and lower academic achievement, but only for those adolescents without war exposure, suggesting that exposure to traumatic events like war may change newcomer adolescents’ response to acculturative stressors. This may be related to the development of coping or growth that follows after trauma, which enable youth to navigate other life challenges. Understanding potential risk and resilience associated with war exposure among newly arrived students can assist clinicians, educators, and researchers in creating solutions to difficulties in psychosocial adjustment and academic performance.  相似文献   

光固化成型中曝光时间对成型质量的影响     

吴懋亮  方明伦  胡庆夕  戴春祥  卢秉恒 《上海大学学报(英文版)》2004,8(Z1)

A novel stereolithgraphy system with conventional UV light as a light source uses the 2D worktable as moving components, whose characteristics determine the accuracy of the prototyping parts. Many factors including mass of the worktable, elasticity and damp coefficients, speed and acceleration affect the non-uniform exposure time of the resin, and eventually influence the cured line shape and the curing accuracy. A light shuttle is used to eliminate the cure errors, greatly improving accuracy of the parts.  相似文献