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111.
INTRODUCTIONDuetotheirwideapplicationsinengineer ing ,piezoelectriccrystalplatesattractedmuchattentionandhadbeenextensivelystudiedasre ported .However,mostworkswerebasedonva rioustwo dimensionalapproximations (Dokmeci,1 980 ;Lawson ,1 942 ;Mindlin ,1 952 … 相似文献
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作为“中国摇滚乐之父”,崔健的艺术实践一直是在“商”与“狂”之间自由地穿梭,其不仅具有我们通常认为的先锋性特质,同时也具有注重商业性、娱乐性和技术性的大众化品格。用崔健的话说,这其实是一种充满世俗化人文关怀的“名副其实的大众艺术”。 相似文献
114.
Bilal Ashraf Akansha Singh Germaine Uwimpuhwe Steven Higgins Adetayo Kasim 《British Educational Research Journal》2021,47(6):1675-1699
Meta-analysis is the synthesis of findings from research projects, which enables an estimate of the average or pooled effect across various studies. This study presents findings from the intention to treat analysis for a series of educational evaluations in England using a two-stage meta-analysis with standardised outcome data and individual participant data meta-analyses. The research estimates the overall impact of educational trials on pupils eligible for Free School Meals (FSM) and the attainment gap in literacy and mathematics performance between FSM and non-FSM pupils based on analysis of 88 trials and data from over half a million pupils. For the meta-analyses, frequentist and Bayesian multilevel models were used to estimate the individual and pooled effect size across categories of explanatory variables such as age groups (key stages in England) and aspects of the type of interventions (one-to-one, small group, whole class). Results indicated that the overall impact of interventions on the literacy outcomes of FSM pupils was positive, with a pooled effect size of 0.06 (0.03, 0.08). However, for mathematics, no overall effect on FSM pupils was observed. Analysis of the attainment gap indicated that literacy outcomes for FSM pupils were improved by interventions marginally more than for non-FSM pupils (pooled attainment gap 0.01 (−0.01, 0.04)). The risk of bias assessment showed that estimates were consistent across different methodological approaches. Overall, evidence from this study can be used to identify, test and scale educational interventions in schools to improve educational outcomes for disadvantaged pupils. 相似文献
115.
Ramesh Chander A. K. Khanna Kanwal Raj A. K. Rastogi 《Indian journal of clinical biochemistry : IJCB》2005,20(1):153-159
Indian black tea; CTC leaf and dust, produced by Tata Tea Limited, Kolkata, (India) was studiedin vitro as potential scavenger of oxygen free radicals. Super oxide anions were generated in a system containing xanthine—xanthine
oxidase (enzymic system) and by NADH- phenozine methosulphate (non enzymic system). Anions were assayed in terms of uric acid
formation and reduction of nitroblue tetrazolium salt, which were shown to be suppressed by tea extracts. Extracts from both
leaf and dust also inhibted the formation of hydroxyl radicalsin vitro in the enzymic system comprising hypoxanthine—Cu+2—sodium ascorbate and xanthine oxidase and in non enzymic system of deoxyribose—Cu+2—sodium ascorbate and H2O2 as well as the Cu+2 induced lipid peroxidation in human low density lipoprotein. Feeding with black tea in normal rats for sixty days increased
their antioxidant activity and their liver microsomes were shown to be protected against peroxidation of lipids as stimulated
by metal ions with enzymic or non enzymic reactants. Furthermore feeding with tea extracts in normal as well as triton WR—1339
induced hyperlipidemic rats caused decrease in their plasma levels of total cholesterol, phospholipids and triglycerides.
The antioxidant and lipid lowering activities of both extracts from CTC leaf and dust tea was comparable and may be due to
the presence of natural products like catechin and others. 相似文献
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Biswajit Majumdar Susri Ray Chaudhuri Arun Ray Sandip K Bandyopadhyay 《Indian journal of clinical biochemistry : IJCB》2002,17(1):49-57
Pretreatment of an ethanolic extract of leaf ofPiper betle linn at a dose of 200mg/kg body weight, orally administered to rats for ten consecutive days, was found to possess a significant
protective action against gastric lesions induced by indomethacin. The extract pretreatment resulted in significant increase
in superoxide dismutase (SOD) and catalase (CAT) activity, increase in mucus, hexosamine and total thiol group content, but
marked reduction in oxidatively damaged protein and peroxidised lipid levels as compared to untreated ulcerated control. The
extract was also found to possess both superoxide and hydroxyl free radical scavenging action. The present observations establish
the efficacy of the extract in prevention of experimentally induced peptic ulcer by indomethacin and antioxidant property
appears to be predominantly responsible for such cytoprotective activity in the experimental model. 相似文献
118.
J. J. Fleming S. Rajaratnam M. S. Seshadri A. S. Kanagasabapathy 《Indian journal of clinical biochemistry : IJCB》2001,16(1):95-100
An audit of 2509 patient specimens analyzed for both total thyroxine (TT4) and free thyroxine (FT4) by the ACS-180 automated
chemiluminescence immunoassay analyzer revealed that there were 219 discrepancies (8.7% of the total). A discrepancy was defined
as one analyte within its reference range and the other outside. The discrepant results were divided into 4 groups: group
A: normal TT4, but decreased FT4, 101 patients (4.0%); group B: increased TT4, normal FT4, 78 patients (3.1%); group C: decreased
TT4, normal FT4, 34 patients (1.4%); and group D: normal TT4, increased FT4, 6 patients (0.2%). TSH measurements were available,
by a 3rd generation chemiluminescent assay, in 142 of these patients, and were consistent with the FT4 result in 72 patients, with
TT4 in 61 cases and with neither in 9 patients. The clinical diagnosis was investigated in a subgroup of 43 endocrine patients.
Thirteen of the 20 endocrine patients in group A were diagnosed as hypothyroid, with a measured serum TSH, in 11 of them,
of median 14.6, range 1.2 to 46.2 μlU/ml. Eleven of the 19 endocrine patients in group B were on thyroid replacement, with
a measured serum TSH, in 7 of them of <0.01 μlU/ml. The audit of current laboratory practice led to a suggestion to replace
the current thyroid function screening strategy of measuring both TT4 and FT4 by the combination of FT4 and TSH. The reasons
for the discrepancies and the alternative strategies for screening of thyroid function are discussed. 相似文献
119.
Farhana Zahir Shameem J Rizvi Soghra K Haq Rizwan H Khan 《Indian journal of clinical biochemistry : IJCB》2006,21(2):149-152
Mercury pollution and acute neurotoxicity of mercury is well known. The recent reports suggest the adverse effect of low dose
mercury, though the available literature is still silent on its mechanism. This study was therefore undertaken to probe the
effect of low dose methyl mercury induced heavy metal toxicity on free radical stress and its impact on behaviour of male
albino rats. Male albino rats were exposed to 1 mg/kg body wt of methylmercury chloride for seven days, on day 8 they were
tested for motor and memory functions. They were sacrificed later for biochemical estimations for rate of lipid peroxidation,
nucleic acids, proteins in cerebrum, cerebellum and brain stem. There was an increase in the rate of lipid peroxidation showing
methyl mercury induced free radical stress. The motor and memory functions demonstrated a clear decline, besides there was
a lowering in the levels of nucleic acids and proteins as compared to controls. The results are important in view of recent
reports that methyl mercury induced free radical stress results in early ageing and may serve as an initiating factor more
specifically for neurodegenerative disorders like Alzeihemer's disease and dementias. The current findings support the notion
that incorporating dietary antioxidants like curcumin, ascorbic acid and α-tocopherol in routine diet from early age may help
combat the risk of developing such disorders in ensuing years. 相似文献
120.