首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   264篇
  免费   7篇
  国内免费   1篇
教育   178篇
科学研究   43篇
各国文化   6篇
体育   10篇
文化理论   3篇
信息传播   32篇
  2024年   1篇
  2023年   1篇
  2022年   7篇
  2021年   6篇
  2020年   7篇
  2019年   10篇
  2018年   20篇
  2017年   27篇
  2016年   26篇
  2015年   10篇
  2014年   15篇
  2013年   41篇
  2012年   10篇
  2011年   8篇
  2010年   11篇
  2009年   7篇
  2008年   5篇
  2007年   4篇
  2006年   2篇
  2005年   6篇
  2004年   6篇
  2003年   2篇
  2002年   2篇
  2000年   4篇
  1999年   4篇
  1998年   7篇
  1997年   3篇
  1996年   2篇
  1995年   1篇
  1994年   4篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1990年   1篇
  1989年   3篇
  1984年   1篇
  1982年   1篇
  1975年   1篇
  1973年   1篇
  1964年   1篇
排序方式: 共有272条查询结果,搜索用时 15 毫秒
41.
This study evaluated the effects of comorbid disorders of diabetes and hyperthyroidism in the adult male mice. In total, 32 ICR strain mice were equally distributed into four groups: control (C), diabetic (D), diabetic-plushyperthyroid (DH), and hyperthyroid (H). Mice allocated for diabetes received a single intraperitoneal injection of streptozotocin (STZ) at 200 mg/kg body weight. At the onset of diabetes, one group of mice was concomitantly injected levothyroxine (LT4; 0.3 mg/kg body weight) and the other set of animals received the same treatment independently on a daily basis. The body weight, as well as the testicular and epididymal weights, was reduced markedly in D and DH mice. Higher trends of blood glucose levels were seen in the DH group, in comparison to euthyroid diabetic mice. Thyroid hormones could exert a transient effect on blood glucose homeostasis by altering the serum blood glucose level in diabetic patients. Histomorphometric analysis showed increased luminal sizes of seminiferous tubules, along with decreased epithelial height and atrophic changes in germinal stem cells in the testis of DH and H mice. Caput epididymis of DH mice showed extensive compaction of principal cells, loss of stereocilia, lipid vacuolization, and inflammatory infiltrations; however, damaged tubular integrity, packed clear cells, exfoliated cells, and round spermatids were profoundly noticed in the cauda epididymis. Hyperthyroidism elevated the serum testosterone levels in H and DH mice and produced critical damages to the histoarchitecture of the epididymis. Collectively, this experiment endeavored to mimic the polyglandular autoimmune syndrome, which will be helpful to better understand the reasons for male infertility in diabetic-cum-hyperthyroid patients.  相似文献   
42.
Assessment has been defined as an authentic method that plays an important role in evaluating students’ learning attitude in acquiring lifelong knowledge. Traditional methods of assessment including the Computer-Aided Assessment (CAA) for mathematics show limited ability to assess students’ full work unless multi-step questions are sub-divided into sub questions. This issue persisted significant drawback especially within the notion of method marking approach. To address this issue, the aim of the study is to develop a methodological framework that will create an information and communications technology (ICT) artefact prototype. The prototype (termed as method marking assessment (MMA) artefact) implements a method-marking assessment concept to assess through multi-step questions. Extensive literature reviews have revealed that there are features in common between complex-problem solution characteristics and multi-steps questions assessment using ICT; therefore complex problems paradigm is used in the study for developing the MMA prototype.  相似文献   
43.
This paper reports the results of a study examining the role of early reading instruction on the nonword reading strategies employed by beginning readers. Three groups of children given different styles of reading instruction were asked to read a list of nonwords presented (a) in isolation and (b) using the clue word technique (Goswami, 1986, 1988). The three groups of children were following either (i) the Early Reading Research project (small units instruction), (ii) the National Literacy Project (instruction emphasising onset‐rime and rhyme awareness), or (iii) usual classroom practice (combined large and small units instruction). Children given small units instruction (Early Reading Research) were found to make significant use of grapheme‐phoneme correspondences (GPCs) and were more accurate than the other two groups of children at reading the nonword items. The National Literacy Project children demonstrated a preference for a rime‐based strategy, once familiarity with the analogous words was controlled, and made significantly more use of this strategy than the Early Reading Research children. The results suggest that early reading instruction does have a significant impact on early reading strategies and should be taken into account in future studies of this type.  相似文献   
44.
Serum and urine samples from 513 patients clinically suspected of monoclonal gammopathies over a period of five years (1992–97) were subjected to various immunological procedures viz, electrophoresis, immunoelectrophoresis and immunoglobulin estimations. Laboratory investigations confirmed gammopathies in 10.33%. It was observed that overall age of incidence for monoclonal gammopathies in both sexes was between 42–72 years with a male to female ratio of 1.4∶1. Predominant paraprotein detected was IgG type (75.47%) followed by IgA (16.98%) and Bence Jones proteins (7.55%). Amongst positive patients, 64.16% were having kappa (k) type light chains and 35.84% lambda (δ) type light chains. 69.39% patients with serum M component (IgG and IgA) had Bence Jones proteinuria. Densitometric scanning revealed that majority of IgG type paraprotein was found in the slow gamma globulin region and majority of IgA type paraprotein was found equally distributed between beta and fast gamma globulin regions. Both types had decreased albumin and alpha-2-globulin concentrations as compared to normal controls. Immunoglobulin levels in patients with paraprotein had very high levels of serum IgG (6467.0 mg%) and IgA (2714.0 mg%) in respective types of monoclonal gammopathies; the rest of immunoglobulin classes were either at normal or decreased levels.  相似文献   
45.
Fasting samples of 1329 apparently healthy vegetarian Gujarati population were tested for total cholesterol, triglycerides and three major fractions of lipoproteins, i.e. high density lipoproteins, low density lipoproteins and very low density lipoproteins. All the values showed marked increase with the age. Except for serum triglycerides, values differ in males and females in the age group of above 45 years. Compared to Northern Indian population low density lipoprotein and high density lipoprotein values were higher, but values of triglycerides and very low density lipoproteins were lower. There is no significant difference in total cholesterol values. Compared to Southern Indian population low density lipoprotein and very low density lipoprotein values were higher but values of triglycerides, total cholesterol and high density lipoprotein were lower. All serum lipid values were significantly lower than the Westem population. The range of values for both the sexes is presented for different age groups.  相似文献   
46.
The study aimed to analyze the circulating levels of thrombotic and haemostatic components; tissue factor, tissue factor pathway inhibitor, tissue plasminogen activator and plasminogen activator inhibitor-1 in patients with acute myocardial infarction at presentation (Group 1, n=49), unstable angina and Non-ST elevated MI after treatment (Group 2, n=22), stable angina (Group 3, n=18) and healthy individuals (Group 4, n=31). Significant finding was increase in tissue factor not only in Group 1 (2.0 fold, P=0.001), Group 2 (2.2 fold, P=0.015) but also in Group 3 (1.8 fold, P=0.018) as compared to controls. In Group 1 Plasminogen activator inhibitor-1 increased significantly (35.8%, P=0.02). Tissue factor pathway inhibitor and tissue plasminogen activator demonstrated increase in Group 1 of age<40 years while insignificant changes in elder patients. Increased thrombotic and decreased fibrinolytic conditions in acute myocardial infarction patients were observed. Increase TF in stable angina demonstrates procoagulant status in these patients as well.  相似文献   
47.
The article outlines the life and work of Maryam Mirzakhani — the first and the only female winner of the Fields Medal since its inception in 1936. Mirzakhani is an inspiration to young women around the world, to believe in their own abilities and pursue their academic dreams.  相似文献   
48.
In this article, we suggest that we are witnessing a challenge to the hegemony of text-based knowledge in academic scholarship, brought about by newly available modes of expression, and a cultural shift in our notions of reading and writing, authorship, and networked knowledge production. The central question we address here concerns the implications of widening our ideas of acceptable forms of inquiry, analysis and representation in academic scholarship. As a collective of scholar-practitioners exploring new modes of expression and working both within and outside the formal structures of academia, we argue for the increasing significance of multimodal research in the contemporary context of academic inquiry. By more equitably valuing different ways of thinking, knowing and communicating, multimodal research can facilitate wider and more diverse participation in the production of knowledge, offer a more nuanced and ethical mode of inquiry, emphasize different ways of knowing and connecting, and make scholarship more broadly accessible beyond academic contexts. Here, we analyze the key opportunities facilitated by multimodal inquiry, as well as the obstacles that stand in the way of a wider adoption of this type of research in higher education.  相似文献   
49.
Hepcidin is a 25-amino acid peptide hormone produced by hepatocytes and plays a key role in body iron metabolism. Hepcidin deficiency is the cause of iron overload in hereditary hemochromatosis, iron-loading anemia, and its excess is associated with anemia of inflammation, chronic disease and iron deficiency anemia (IDA). The aims of this study was to evaluate HAMP gene mutation, namely IVS2 + 1(–G) (c.148–150 + 1del) and Gly71 Asp (c.212G > A (rs104894696) association with iron status in IDA conditions. Our study participants were 500 IDA patients and 550 age and sex-matched healthy controls. Hepcidin, ferritin and CRP analysis was done by ELISA method while ESR analysis was done according to Wintrobe method. CBC analysis was done by auto-analyzer. Two mutations in the HAMP genes were analysed by PCR RFLP method. Among the IDA patients, 7 were heterozygous for Met50del IVS2 + 1(–G) mutation. Nine IDA patients were heterozygous for G71D G–A mutation and homozygous were not identified in both mutations.Controls were showing heterozygous frequency 1.8 and 2.1% of Met50del IVS2 + 1(–G) and G71D G–A mutations respectively. Mutation of HAMP (Met50del IVS2 + 1(–G) and G71D G–A) were clinically associated with IDA and act as modulator of disease.  相似文献   
50.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号