A study on interaction of Aluminium with rat intestinal brush border membrane

The present studies with aluminium chloride given in drinking water showed marked inhibition in the activities of intestinal brush border membrane marker enzymes, namely alkaline phosphatase, acetyl cholinesterase, γ-glutamyl transpeptidase and sucrase. Moreover, a significant depression in the levels of membrane constituents, viz phospholipids, cholesterol, hexoses and sialic acid following aluminium chloride treatment was also observed. On the basis of these studies it may be concluded that if aluminium is taken in high quantities it may alter the structure and functioning of the intestinal brush border membrane, which in turn may lead to the improper digestion and reduced nutrient uptake from the small intestine.     

Clodronate-superparamagnetic iron oxide-containing liposomes attenuate renal injury in rats with severe acute pancreatitis

Background and objective

It has been shown that macrophages play an important role in the development of severe acute pancreatitis (SAP), and eventually lead to multiple organ failure (MOF). Clodronate-liposome selectively depleted macrophages. This study was to investigate the role of renal macrophage infiltration in acute renal injury in rats with SAP and to evaluate the potential of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) for diagnosis.

Methods

Superparamagnetic Fe₃O₄ nanoparticles were prepared by chemical coprecipitation. SPIO-liposomes and SPIO-clodronate-liposomes were prepared by the thin film method. SAP models were prepared by injection of sodium taurocholate into the subcapsular space of rat pancreas. Sprague-Dawley rats were randomly divided into a control group, SAP plus SPIO-liposome (P) group, and SAP plus SPIO-clodronate-containing liposome (T) group. Kidney injury was evaluated by T2-weighted MRI scan. The levels of serum amylase (SAM), blood urea nitrogen (BUN), and serum creatinine (SCr) were measured by an automated enzymatic method. Serum tumor necrosis factor-α (TNF-α) was measured by enzyme-linked immunosorbent assay (ELISA). Pathological changes in the pancreas and kidney were observed using hematoxylin and eosin (H&E) staining, while cell apoptosis was detected with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. In addition, the macrophage markers (CD68) of the renal tissue were detected with immunohistochemistry.

Results

The pathological changes in the pancreas and kidneys of rats in the T group were milder than those in the P group. The MRI signal intensity of the kidneys in the P and T groups was significantly lower than that in the control group. There were significant changes in the two experimental groups (P<0.01). The levels of SAM, Bun, SCr, and TNF-α in rats in the P group were higher than those in the control group (P<0.01) and in the T group (P<0.01). The apoptosis of the kidney in the T group was higher than that in the P group at 2 and 6 h (P<0.01).

Conclusions

Clodronate-containing liposomes protected against renal injury in SAP rats, and SPIO can be used as a tracer for MRI examination to detect renal injury in SAP rats. SPIO-aided MRI provided an efficient non-invasive way to monitor the migration of macrophages after renal injury in rats with SAP.     

反复张力下V形切口圆条的表面裂纹的疲劳扩展

研究目的：在相同的反复张力下,研究V形切口圆条表面裂纹的疲劳扩展规律。研究方法：1.构建V形切口圆条模型（图1）,基于线性二次元将模型表面离散成一个个网格点（图2）;2.以AZ-6A-T5镁合金为例,利用J积分计算应力强度因数,利用NASGRO裂纹增长率模拟裂纹的疲劳扩展;3.通过研究不同的裂纹纵横比和对应的应力强度因数之间的相关性来研究裂纹的扩展。重要结论：1.在裂纹扩展时裂纹纵横比的初始值对断裂形状的发展有重要影响;2.裂纹纵横比对疲劳负荷寿命的作用比缺口半径更加明显;3.当裂纹前缘演变成一条直线形时可观察到不稳定的裂纹扩展;4.裂纹深度一定时,断裂纵横比越小,疲劳负荷寿命越短;5.当裂纹纵横比为0.6-0.7时,出现了不稳定的裂纹扩展。     

Risk of Eating Disorders Among Female College Athletes and Nonathletes

This study compared the prevalence of eating disorder behaviors between female collegiate athletes (n = 206) and female college nonathletes (n = 197). Although female nonathletes had somewhat higher average scores on the Eating Attitudes Test 26, the proportion at risk for disordered eating was not different in the 2 groups. There was no significant difference among female athletes in different sports. Younger women were found to have more symptoms of disordered eating than did older women.     

Conducting Indigenous research in Western knowledge spaces: aligning theory and methodology

Walking simultaneously in two worlds as an Indigenous researcher, navigating Indigenous and Western epistemologies/methodologies can have its challenges. Indigenous methodologies have become an important element of qualitative research and have been increasingly taken up by both Indigenous and non-Indigenous researchers. Indigenous methodologies seek to ensure that the research is culturally safe and culturally respectful through recognition of Indigenous worldviews, respect, and accountability. It is no longer research on or about Indigenous people, rather it is becoming research for and with Indigenous people. In this paper, we reflect on the experiences of an Indigenous researcher working with a non-Indigenous supervisor within an overarching Western theoretical framework of poststructuralism while also using Indigenous methodologies. We discuss the tensions and points of connection that emerged in the research design process. We suggest that Indigenous and Western epistemologies/methodologies do not have to be used to the exclusion of each other; they can be used effectively to complement and support each other.     

A Practical Introduction to Authoring for Computer-Assisted Instruction. Part 5: PHILVAS

Interactive videodisc technology is likely to have a significant impact upon many aspects of education and training. However, before this medium can be effectively utilized considerable attention must be given to overcoming the present problems associated with courseware authoring. Solutions to these problems are to be found in the provision of suitable courseware development aids. In particular, there is a requirement for a powerful and easy-to-use author language. This paper describes the approach used by the PHILVAS authoring system.     

The effects of passive and active learning on student preference and performance in an undergraduate basic science course

Active learning is based on self-directed and autonomous teaching methods, whereas passive learning is grounded in instructor taught lectures. An animal physiology course was studied over a two-year period (Year 1, n = 42 students; Year 2, n = 30 students) to determine the effects of student-led seminar (andragogical) and lecture (pedagogical) teaching methods on students' retention of information and performance. For each year of the study, the course was divided into two time periods. The first half was dedicated to instructor-led lectures, followed by a control survey in which the students rated the efficiency of pedagogical learning on a five-point Likert scale from one (strongly disagree) to five (strongly agree). During the second period, students engaged in andragogical learning via peer-led seminars. An experimental survey was then administered to students using the same scale as above to determine students' preferred teaching method. Raw examination scores and survey results from both halves of the course were statistically analyzed by ANOVA with Newman-Keuls multiple comparison test. By the end of the study, student preference for peer-led seminars increased [mean ± SD: (2.47 ± 0.94)/(4.03 ± 1.36), P < 0.04], and examination scores significantly increased [mean ± SD: (73.91% ± 13.18)/(85.77 ± 5.22), P < 0.001]. A majority of students (68.8%) preferred a method that contained peer-led seminars and instructor-led lectures. These results may indicate that integration of active and passive learning into undergraduate courses may have greater benefit in terms of student preference and performance than either method alone.     

Teacher evaluation practices in Malaysian primary schools: issues and challenges

This paper describes a qualitative case study that investigated the underlying issues in implementing school-based teacher evaluation practices in four Malaysian primary schools. The participants of the study comprised eight school administrators and sixteen teachers. Data obtained through interviews, observations, and document reviews were analyzed using the constant comparative method. The analysis captured four thematic constructs as key aspects of the school-based teacher evaluation system, namely: policy direction, evaluation methods, instruments, and utilization of evaluation results. The paper recommends revamping of the existing school-based teacher evaluation system along the emergent constructs identified in the study.     

How to Teach and to Ensure a Good,Sound Religious Education through a Multi‐faith Approach at the Primary School Level

If Religious Education is to have an effective place in education and is not objectionable to younger pupils, there would appear to be a case for laying a foundation of knowledge, while the attitude to the subject is favourable and learning is thus easier to achieve. Then pupils are more likely to be in a well‐informed position to discuss religion at the top of the school, than if teaching has already begun at an age when, although they were intellectually ready and able to undertake open debate, prejudice had already closed teenagers’ eyes to the whole matter (Attfield, 1974)

The school should be a community within which children should learn to live the ‘good life’... By example at first hand children can learn to love and care for others, to be generous, kind and courageous. Good experiences in personal relationships in early life will make a most important contribution to an understanding of spiritual and moral values when children are older. (The Plowden Report, 1967, Vol. 1, p. 206, para. 568)