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1.
皮质抑素是1996年发现的一种小分子的生物活性神经肽,是生长抑素家族的新成员,CST及其受体在人体多种组织中均有表达.CST与3种受体结合后能表现出多样的生物学效应：具有抑制运动、诱导睡眠、影响学习记忆等神经调节作用及一定的神经保护作用;并参与免疫系统和内分泌系统的调节,强效抑制炎症因子的表达,对缺血性损伤的心血管具有代偿性的保护作用. 相似文献
2.
连翘苷对小鼠非特异性免疫及应激作用的实验研究 总被引：1，自引：0，他引：1
刘静 《陕西教育学院学报》2008,24(3):59-61
通过测定小鼠的碳粒吞噬能力、迟发性超敏反应和在常压缺氧条件下小鼠的存活时间等指标来评价连翘苷对非特异性免疫及应激反应的影响。可知连翘苷能提高小鼠吞噬碳粒的能力,吞噬指数和吞噬百分率增加,减轻小鼠迟发超敏反应时两耳重量之差,延长小鼠在常压缺氧条件下的存活时间。说明连翘苷可调节小鼠非特异性免疫功能并且有一定的抗应激能力。 相似文献
3.
Objective: To investigate the in-vitro antitumor immune responses of dendritoma formed by mouse hepatocellular carcinoma (HCC) cells and lymphotactin (Lptn) gene modified dendritic cells (DCs). Method: DCs prepared from mouse bone marrow were genetically modified by lymphotactin adenovirus, and fused with H22 cells by polyethylene glycol (PEG). RT-PCR and ELISA were employed to identify lymphotactin expression at mRNA and protein level. Cell phenotypes and fusion efficiency was detected by FACS. The stimulatory effect of DC on T cells was detected by mixed lymphocyte reaction. The cytotoxicity activity against H22 cells was assayed by LDH method. Results: Lymphotactin could be efficiently expressed by DCLptn/H22 hybridoma. DCLptn/H22 cells could induce potent T cell proliferation effect and generate strong cytotoxic T lymphocyte (CTL) reaction against allogenic H22 cells. Conclusion: Lymphotactin genetic modification could enhance the in vitro immune activity of the dendritoma. 相似文献
4.
Preschool process quality and activity setting are considered important aspects influencing child engagement. As such, it is important to understand how educational settings can promote engagement, particularly for children with disabilities and/or at risk. This observational study describes process quality and activity setting in inclusive preschools, analyzing its predictive role for child engagement. Participants were 184 children attending 39 preschools. Three groups of children, nested within classrooms, were considered: with disabilities (n = 45), at risk (n = 59), typically developing (n = 80). Child Observation in Preschool assessed engagement and activity setting; Classroom Assessment Scoring System assessed quality of teacher–child interactions. Research Findings: Results from multilevel regressions show that classroom emotional support and organization and more time in free play were positively predicting child engagement, whereas more time in whole group was a negative predictor of engagement. Besides these main effects, an interaction effect between child developmental functioning and activity settings was found. For at-risk children, more time in whole-group activities had greater negative effects on child engagement. For children with disabilities, more time in free-play had greater positive effects on child engagement. Practice or Policy: Results contribute to inform teachers regarding the importance of individualizing interactions and planning activity settings to promote engagement and participation in inclusive preschools. 相似文献
5.
Nicolás Pino-James 《Educational Action Research》2018,26(3):456-479
Current research suggests that student engagement with academic schoolwork in secondary school classrooms is often insufficient. This issue is of relevance because student engagement is a prerequisite for acquiring knowledge and skills and is also a mediator of achievement and important life outcomes. In response to this, the present study evaluates a pedagogical model for stimulating student engagement in learning activities in secondary school contexts through an action research approach. This model is composed of five facilitators of engagement that, when considered in both the design and implementation of learning activities, can potentially contribute to stimulating behavioural, emotional and cognitive engagement in such activities. Nineteen Year 9 students of Spanish from a state school in England, their teacher and the researcher participated in two long-term, learning activities designed using the proposed pedagogical model. Data were collected over two school terms through qualitative student self-reports, interviews with students and their teacher and the researcher’s journal. Thematic analyses were used to examine the effects of the learning activities on student behavioural, emotional and cognitive engagement. The results seem to confirm that the application of the proposed pedagogical model could help promote thorough student engagement in learning activities. Findings also suggest that failing to support the model’s facilitators of engagement may have detrimental effects on overall student engagement in learning activities. The study contributes to the improvement of student engagement with academic schoolwork internationally by proposing an assessed pedagogical solution that could be implemented by secondary school teachers with relative ease. 相似文献
6.
Coordinating attention to people and objects in mother-infant and peer-infant interaction 总被引：7，自引：0，他引：7
In a longitudinal study, infants 6-18 months of age were observed in their homes playing with their mothers and with peers. Of primary concern was how they coordinated their attention to people and objects. Observations were coded using a state-based scheme that included a state of coordinated joint engagement as well as states of person engagement, object engagement, onlooking, and passive joint engagement. All developmental trends observed were similar regardless of partner: person engagement declined with age, while coordinated joint engagement increased. Passive joint engagement, object engagement, and onlooking did not change with age. However, the absolute amount of some engagement states was affected by partner: both passive and coordinated joint engagement were much more likely when infants played with mothers. We conclude that mothers may indeed support or "scaffold" their infants' early attempts to embed objects in social interaction, but that as attentional capabilities develop even quite unskilled peers may be appropriate partners for the exercise of these capacities. 相似文献
7.
Tong-liang Bu Yu-dong Jia Jin-xing Lin Yu-ling Mi Cai-qiao Zhang 《Journal of Zhejiang University. Science. B》2012,13(4):318-326
As a component of diesel exhaust particles, 3-methyl-4-nitrophenol (4-nitro-m-cresol, PNMC) is also a metabolite of the insecticide fenitrothion and imposes hazardous effects on human health. In the
present study, the alleviative effect of a common antioxidant flavonoid quercetin on mouse germ cells intoxicated by PNMC
was investigated. Results showed that a single intraperitoneal injection of PNMC at 100 mg/kg induced severe testicular damage
after one week. PNMC-treated mice showed a significant loss of germ cells (approximate 40% loss of round germ cells). PNMC
caused an increase of hydroxyl radical and hydrogen peroxide production and lipid peroxidation, as well as a decrease in glutathione
level, superoxide dismutase and glutathione peroxidase activities. Furthermore, treatment of PNMC increased expression of
the pro-apoptotic protein Bax and decreased expression of the anti-apoptotic protein Bcl-XL in germ cells. In addition, testicular
caspase-3 activity was significantly up-regulated and germ cell apoptosis was significantly increased in the PNMC-treated
mice. In contrast, combined administration of quercetin at 75 mg/kg significantly attenuated PNMC-induced testicular toxicity.
These results indicate that the antioxidant quercetin displays a remarkable protective effect on PNMC-induced oxidative damage
in mouse testes and may represent an efficient supplement to attenuate reproductive toxicity by environmental toxicants to
ensure healthy sperm production. 相似文献
8.
Yan-long Zhao Pu-xun Tian Feng Han Jin Zheng Xin-xin Xia Wu-jun Xue Xiao-ming Ding Chen-guang Ding 《Journal of Zhejiang University. Science. B》2017,18(12):1055-1063
Macrophages have a diverse set of functions based upon their activation states. The activation states, including resting (M0) and polarizing (M1 and M2) states, of macrophages derived from the mouse bone marrow, spleen, and peritoneal cavity (BMs, SPMs, and PCMs, respectively) were compared. We evaluated the macrophage yield per mouse and compared the surface markers major histocompatibility complex (MHC) II and CD86 by flow cytometry. The relative mRNA levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, mannose receptor (MR), and Ym1 in the M0, M1, and M2 states were also compared using real-time polymerase chain reaction (PCR) analysis. Bone marrow yielded the most macrophages with the best homogeneity, but they were polarized toward the M2 phenotype. All three types of macrophages had the capacity to polarize into the M1 and M2 states, but SPMs had a stronger capacity to polarize into M1. The three types of macrophages showed no differences in their capacity to polarize into the M2 state. Therefore, the three types of macrophages have distinct characteristics regardless of their resting or polarizing states. Although bone marrow can get large amounts of homogeneous macrophages, the macrophages cannot replace tissue-derived macrophages. 相似文献
9.
This study examines the effects of self-questioning on EFL students’ literary reading engagement. Two interventions were tested: (1) students generating questions while reading short stories, and then exploring their questions in small-groups; and (2) students generating questions while reading, and then reflecting through a free writing activity. Participants were 59 Vietnamese undergraduate students enrolled in an English as a foreign language course. A pre-test post-test control group design with switching replications was used, with a control condition in which the teacher (instead of the students) posed the questions. Students’ reading engagement was measured by a written response to a short story and a questionnaire. Results showed that both self-questioning interventions positively influenced students’ reading engagement compared to the control condition. A maintenance of effects was also observed. We conclude that self-questioning combined with group discussions or free writing promotes students’ reading engagement. 相似文献
10.
协作学习投入面临多维、动态数据采集与多元数据融合分析的挑战,而多模态交互分析能够提取并融合动态、多维度的投入信息,对表征协作学习交互过程具有重要价值。基于此,文章构建了基于多模态交互信息的协作学习投入分析指导框架,并从投入水平的整体性表征、投入状态的多维性分析和投入信息的时序性挖掘等角度,阐述了协作学习投入分析应考虑的关键问题。此外,文章还提出了包含多模态信息采集、多模态特征提取、多模态特征融合分析等三大模块构成的多模态交互信息分析路径。研究结论显示,多模态交互信息能实现对协作交互过程全方位、细粒度地记录,进而对小组协作学习投入的状态进行动态表征与持续分析。未来研究可能的方向在于基于智能语音处理技术的交互会话分析、基于仪表盘的投入信息可视化呈现以及基于智能代理的协作投入适应性支持。 相似文献
11.
ANNE PEAKER 《The International Journal of Art & Design Education》1994,13(1):57-64
The paper explores an important area of arts activity which falls between concepts of education and therapy. It examines the consequence of the increasing professionalisation of the arts in institutions which took place between 1950 and 1980, showing how it led to all arts activities in institutional settings being classified as therapy, training or rehabilitation. It charts the changes in attitude which have taken place over the past fifteen years and demonstrates that whilst freedom to become involved in creative activity should be seen as a basic human right, such engagement may, as a by-product, offer benefits of a therapeutic, educational, social, recreational and commercial nature. Important and innovatory work is being carried out by artists working on creative projects with people in institutions and effective techniques are being developed by them in order to draw adults, with no previous experience of this kind of activity, into arts education. 相似文献
12.
Respiratory sinus arrhythmia (RSA) and heart period were evaluated in 5-month-old infants (N = 40) during interaction challenges requiring affective adjustment. The paradigm consisted of four 2-min experimental conditions designed to elicit behavioral and autonomic responses to object-mediated (Picture Attention and Toy Attention) and person-mediated (Still Face and Social Interaction) engagement. The data demonstrated that autonomic state systematically changed during engagement and disengagement with the environment. During the object-mediated challenge, increases in RSA were uniquely related to positive engagement. During the person-mediated challenge, there was a more complex integration of autonomic and behavioral responses characterized by concordant increases and decreases in RSA, heart period, positive engagement, negative affect, and motor activity. When participants were partitioned into two groups, based on their RSA response pattern during the person-mediated challenge, only participants who exhibited a pattern of RSA decrease from Toy Attention to Still Face followed by a rapid recovery during Social Interaction demonstrated regulation of behavioral activity, including concordant recovery from stress. These findings provide additional empirical support for the role of vagal regulation of the heart in the modulation of affective adjustment and engagement behavior. 相似文献
13.
Heather Nicholson Thomas J. Kehle Melissa A. Bray Jaci Van Heest 《Psychology in the schools》2011,48(2):198-213
A multiple baseline design was used to examine the effects of participation in antecedent physical activity on the academic engagement of four elementary‐school children diagnosed with autism spectrum disorder (ASD). The results indicated large effect sizes for academic engaged time for all four students. It was suggested that physical activity in the form of something as simple to implement as jogging may be efficacious in promoting academic achievement for students diagnosed with ASD. © 2010 Wiley Periodicals, Inc. 相似文献
14.
目的：研究不同浓度的制何首乌水煎浓缩液致小鼠网状内皮系统对血流中惰性炭粒的吞噬廓清能力的影响,探讨制何首乌调整免疫的最佳浓度。方法：以小鼠为实验对象,用2g/mL（大剂量）、1g/mL（中剂量）、0.5g/mL（小剂量）三种不同浓度的制何首乌水煎液给小鼠灌胃12d,采用炭粒廓清法来检测RES吞噬异物的能力。结果：大剂量能明显增强RES吞噬功能,中、小剂量组无显著性差异。结论：制何首乌浓度为2g/ml时可显著提高实验小鼠非特异性免疫功能,具有扶正固本的作用。 相似文献
15.
Xu Q Li ZX Peng HQ Sun ZW Cheng RL Ye ZM Li WX 《Journal of Zhejiang University. Science. B》2011,12(4):247-255
This paper aims to investigate the effects of artesunate (ART) on growth and apoptosis in human osteosarcoma HOS cell line
in vitro and in vivo and to explore the possible underlying mechanisms. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium
bromide (MTT) assay. The induction of apoptosis was detected by light and transmission electron microscopy and flow cytometry.
Western blot analysis was used to investigate the related mechanisms. Nude mice were further employed to investigate the antitumour
activity of ART in vivo. MTT assay results demonstrated that ART selectively inhibits the growth of HOS cells in a dose- and
time-dependent manner. Based on the findings of light and transmission electron microscopy, Hoechst 33258 staining, and fluorescein
isothiocyanate (FITC)-annexin V staining, the cytotoxicity of ART in HOS cells occurs through apoptosis. With ART treatment,
cytosolic cytochrome c was increased, Bax expression was gradually upregulated, Bcl-2 expression was downregulated, and caspase-9 and caspase-3
were activated. Thus, the intrinsic apoptotic pathway may be involved in ART-induced apoptosis. Cell cycle analysis by flow
cytometry indicated that ART may induce cell cycle arrest at G2/M phase. In nude mice bearing HOS xenograft tumours, ART inhibited tumour growth and regulated the expressions of cleaved
caspase-3 and survivin, in agreement with in vitro observations. ART has a selective antitumour activity against human osteosarcoma
HOS cells, which may be related to its effects on induction of apoptosis via the intrinsic pathway. The results suggest that
ART is a promising candidate for the treatment of osteosarcoma. 相似文献
16.
Robert L. Bangert-Drowns Curtis Pyke 《Educational technology research and development : ETR & D》2002,50(2):23-37
The quality of students' learning engagement may significantly influence their learning. Can teachers accurately judge student learning engagement with educational software? In this exploratory study, 3 fifth-grade teachers used a seven-level taxonomy to rate the frequency of different forms of engagement among 42 students interacting with different types of educational software. Teachers spontaneously treated the seven levels of engagement as a continuum, rating students highest on one level or a set of contiguous levels. Teachers generally agreed when ranking students by their typical levels of engagement, but disagreed regarding the actual frequencies of different engagement types. Ratings of software engagement conceived of as interpretive activity were correlated significantly with student reading test scores. Given the authentic classroom conditions in which this study took place, the results are promising for the classroom utility of the seven-level conception of student engagement with software. 相似文献
17.
In vitro study of immunosuppressive effect of apoptotic cells 总被引：3，自引：0，他引：3
INTRODUCTION Apoptosis plays an important role in differen- tiation, development and pathophysiological proc- esses such as inflammation, neoplasia and autoim- mune diseases. For a long time, apoptotic cells per se and the clearance of apoptotic cells had been viewed as neutral in immune response. Recently many in- vestigations suggested that apoptotic cells actively regulate the immune response (Voll et al., 1997; Fadok et al., 1998; 2000; Byrne and Reen, 2002). Apoptotic cells release … 相似文献
18.
A person‐in‐context approach to student engagement in science: Examining learning activities and choice 
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下载免费PDF全文 Science education reform efforts in the Unites States call for a dramatic shift in the way students are expected to engage with scientific concepts, core ideas, and practices in the classroom. This new vision of science learning demands a more complex conceptual understanding of student engagement and research models that capture both the multidimensionality and contextual specificity of student engagement in science. In a unique application of person‐oriented analysis of experience sampling data, we employ cluster analysis to identify six distinct momentary engagement profiles representing different combinations of the behavioral, cognitive, and affective dimensions of student engagement in high school science classrooms. Students spend a majority of their classroom time in one of several engagement profiles characterized by high engagement on one dimension, but low levels on the others. Students exhibited low engagement across all three dimensions of engagement in about 22% of our observations. Full engagement, or high levels across all three dimensions, is the least frequent profile, occurring in only 11% of the observations. Students’ momentary engagement profiles are related in meaningful ways to both the learning activity in which students are engaged and the types of choices they are afforded. Laboratory activities provided especially polarized engagement experiences, producing full engagement, universally low engagement, and pleasurable engagement in which students are affectively engaged but are not engaged cognitively or behaviorally. Student choice is generally associated with more optimal engagement profiles and the specific type of choice matters in important ways. Choices about how to frame the learning activity have the most positive effects relative to other types of choices, such as choosing whom to work with or how much time to take. Results are discussed in terms of implications for practice and the utility of the methodological approach for evaluating the complexities of student engagement in science classrooms. © 2017 Wiley Periodicals, Inc. J Res Sci Teach 88: 19–43, 2018 相似文献
19.
Key voices influencing higher education are increasingly aware of engagement in effecting change. Public research universities
have missions compatible with engagement, but efforts to institutionalize it may conflict with their underlying values. Using
boundary expansion as the analytical framework, this study compared the institutionalization of engagement at two types of
public research universities. Land-grant universities implement engagement primarily through outreach and extension in specialized
units. At urban or metropolitan universities, engagement is more often a university-wide agenda, impacting teaching, research,
and partnerships. The difference between the two approaches can be explained by examining institutional capacity for boundary
reshaping and expansion.
Lorilee R. Sandmann is Associate Professor in the Department of Lifelong Education, Administration, and Policy at the University of Georgia. Her
research focuses on major institutional change processes to promote higher education community engagement and on criteria
to define and evaluate faculty engaged scholarship. She received her Ph.D. from the University of Wisconsin-Madison.
David J. Weerts is Assistant Professor, Department of Educational Policy and Administration, University of Minnesota, Minneapolis. His teaching,
research and scholarly interests include state financing of higher education, university-community engagement, and alumni
philanthropy and volunteerism. He received his Ph.D. from the University of Wisconsin-Madison. 相似文献
20.
Current trends in research on motivation in the classroom are based on theories that focus on the individual's intrapsychological traits or his or her cognitive and/or affective functioning. In contrast to this individualistic perspective, social constructivist theory provides a framework for conceptualizing motivation as socially negotiated by the participants in the classroom. In such a conceptualization, motivation is inseparable from the instructional process and the classroom environment. The culturally determined joint activity between student and social context results in an internal state of interest and cognitive and affective engagement, and motivated behaviors, both of which can be considered cultural norms. Implications of this perspective for understanding motivation, classroom instruction, and research are discussed. 相似文献