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   611篇
  免费   31篇
耳鼻咽喉   2篇
儿科学   7篇
妇产科学   7篇
基础医学   55篇
口腔科学   10篇
临床医学   30篇
内科学   151篇
皮肤病学   19篇
神经病学   73篇
特种医学   52篇
外科学   96篇
综合类   5篇
预防医学   13篇
眼科学   10篇
药学   70篇
中国医学   11篇
肿瘤学   31篇
  2023年   5篇
  2022年   7篇
  2021年   17篇
  2020年   7篇
  2019年   17篇
  2018年   14篇
  2017年   11篇
  2016年   13篇
  2015年   19篇
  2014年   23篇
  2013年   25篇
  2012年   49篇
  2011年   26篇
  2010年   19篇
  2009年   24篇
  2008年   25篇
  2007年   27篇
  2006年   36篇
  2005年   24篇
  2004年   25篇
  2003年   22篇
  2002年   19篇
  2001年   21篇
  2000年   13篇
  1999年   16篇
  1998年   4篇
  1996年   4篇
  1995年   7篇
  1994年   6篇
  1993年   2篇
  1992年   7篇
  1991年   10篇
  1990年   10篇
  1989年   10篇
  1988年   6篇
  1987年   12篇
  1986年   10篇
  1985年   12篇
  1984年   4篇
  1983年   2篇
  1981年   2篇
  1979年   4篇
  1978年   2篇
  1976年   2篇
  1971年   3篇
  1970年   3篇
  1969年   2篇
  1968年   2篇
  1967年   2篇
  1965年   4篇
排序方式: 共有642条查询结果,搜索用时 15 毫秒
1.
Immune agglutinin or precipitin loses its reactivity with the corresponding antigen by heating or some chemicals. A. Se group saliva or M group blood stain was sensitized with human IgM anti-A or rabbit IgG anti-M serum, respectively. After being washed with saline, the stains were heated or treated with formalin or 2-mercaptoethanol (2-ME) of various concentrations. The immunoreactivity of the antibodies in the state of immunecomplex was examined by the mixed agglutination or elution test, indicating IgM and IgG antibodies in the state of immunecomplex were proof against heating up to 150 degrees C for 10 min and against formalin and 2-ME of high concentrations. It is considered that IgM and IgG acquire a new property of heat and chemical stability by formation of immunecomplex although they are substantially heat and chemical labile.  相似文献   
2.
The present experiments were carried out to determine the regrowth of endothelial cells (EC) after balloon denudation of the rabbit carotid artery and the changes in responsiveness of the artery with regenerated EC. Scanning electron microscopic findings revealed that 28.8% of the luminal surface was covered with regenerated EC at week 1. The regrowth of EC proceeded progressively, and a full lining was achieved at week 6. Regenerated EC were morphologically different from native ones; they were elongated (weeks 1 and 2) and irregularly oriented (weeks 4 and 6), and their numbers had significantly increased. Light microscopy revealed the intimal thickening and proliferation of smooth muscle cells. No accumulation of lipids in the vascular wall could be detected at any observation time. The experiments in an organ bath demonstrated that the altered appearance of EC was accompanied by depressed endothelium-dependent relaxations to acetylcholine, ADP and A23187. However, sodium nitroprusside-induced relaxation and contractile responses to noradrenaline, serotonin and histamine remained unchanged in the normal and denuded preparations, indicating that the dysfunction of the endothelium occurs at a time when the ability of the underlying vascular smooth muscle to relax or contract was unchanged. In addition, it is suggested that the impairment of the endothelium-dependent relaxation may be partly due to impairment of the synthesis and/or release of endothelium-derived relaxing factor(s) in EC.  相似文献   
3.
Our previous studies demonstrated that sodium glucose cotransporter 1 (SGLT-1) was induced in the remnant ileum of total colectomized rats via the action of factors other than hyperaldosteronism. The aim of the present study was to clarify whether fecal stream is required for the enhancement of SGLT-1-mediated sodium transport. Twenty-seven pairs of ileal tissues were obtained from the proximal and distal side, respectively, of loop ileostomy after total proctocolectomy. Mucosae were mounted in an Ussing chamber to evaluate glucose-coupled sodium transport. Levels of SGLT-1 mRNA in proximal and distal mucosae were compared by Northern blotting. Villous height and crypt depth were measured to test for correlations between mucosal structure and SGLT-1-mediated sodium transport or mRNA expression levels. Both glucose-coupled sodium transport and expression of SGLT-1 mRNA were significantly lower in distal mucosae relative to proximal mucosae. In distal mucosae, villous height, but not crypt depth, was significantly lower than in proximal mucosae, demonstrating a positive correlation between villous height and SGLT-1 function and expression. Comparative studies of proximal and distal mucosae demonstrated that in addition to hormonal changes, fecal stream is required for full induction of the sodium transport system (which includes SGLT-1-mediated transport) in the remnant ileum following total proctocolectomy. Presented in part at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–19, 2005 (poster presentation). This work was supported by Grants-in-Aid for Scientific Research 10557118 and 14657295 from the Ministry of Education, Science and Culture of Japan to K. Fukushima, and by Kanae Foundation to K. Fukushima.  相似文献   
4.
Our research group aims to develop an osteochondral composite using type II collagen gel with hydroxyapatite (HAp) deposited on one side. Soaking gels in Ca2+ and phosphate solution is indispensable to HAp deposition, so relationships between cell behavior and Ca2+ concentration were examined in two- and three-dimensional cultures. The present results indicate that 2-4 mM Ca2+ is suitable for proliferation and survival of osteoblasts, whereas slightly higher concentrations (6-8 mM) favor osteoblast differentiation and matrix mineralization in both 2- and 3-dimensional cultures. Higher concentrations (>10 mM) are cytotoxic. Purely from the perspective of calcium deposition, higher concentrations lead to increased accumulation of Ca2+. Culturing cells in phosphate-containing gel in media with Ca2+ also leads to time-dependent formation of HAp in the gel. Considering the viability of embedded cells, culturing scaffolds in media with Ca2+ concentrations around 5mM is useful for both HAp deposition and osteoblast behavior.  相似文献   
5.
Cyclin‐dependent kinase 4 and 6 (CDK4/6) plays an important role in cell cycle progression, and the CDK4/6–cyclin D1 complex controls the cell cycle transition from G1 phase to S phase. CDK4 is enhanced in several types of cancers and CDK4/6 inhibitors attenuate the proliferation of several types of cancer in vitro/in vivo. The purpose of our study was to investigate the expression pattern of CDK4 and evaluate its clinical importance in extramammary Paget's disease (EMPD). Almost all EMPD tissues were positive for CDK4, and metastatic lesions had a similar immunostaining intensity to primary lesions. In addition, CDK4 protein levels were positively correlated with those of cyclin D1 protein. Taken together, CDK4 may assume a crucial role in EMPD progression.  相似文献   
6.
Reports have described how psychiatric patients respond to disasters. However, previous reports on the response depending on diagnostic categories have provided no clear consensus. Here we analyzed response to the Great East Japan Earthquake of March 11, 2011, among psychiatric patients in light of severity of pre-existing psychiatric illness. We studied psychiatric change among a population of psychiatric outpatients in Tochigi prefecture, located ∼160 km (∼100 miles) southeast of the Fukushima nuclear power plant, in an area that suffered moderate damage from the earthquake and radiation. A total of 294 psychiatric outpatients was assessed using the Global Assessment of Functioning (GAF-F). A change of ≥10 points in the GAF-F score was counted as a change in symptoms. The data were stratified by disease category, gender, and GAF-F score and analyzed using the Fisher's exact test. In the 2 months after the earthquake, 5.4% of patients showed evidence of a change in symptoms, with 4.1% worsening and 1.4% improving. Compared with patients having a GAF-F score ≤50, significantly more patients with a score >50 showed evidence of worsening symptoms. No significant difference was found with respect to gender or diagnostic category for patients with worsened or improved symptoms. Our findings reveal that a relatively small percent of patients with pre-existing psychiatric diseases showed evidence of a change in symptoms and that patients with mild-to-moderate psychiatric illness are potentially vulnerable to the impacts of a natural disaster.  相似文献   
7.
8.
Although side-to-side isoperistaltic anastomosis is a useful strictureplasty technique when long segments of intestinal stenosis complicate Crohns disease, concerns have been raised regarding disease recurrence adjacent to the anastomosis. We performed side-to-side isoperistaltic anastomosis without spatulated intestinal ends as a method of reconstruction after intestinal resection for Crohns disease; both intestinal ends were transversely closed like a Heineke-Mikulicz-type strictureplasty. With this procedure, the luminal diameter proximal and distal to the anastomosis became wider than the original diameter of the intestine. This new procedure, which we refer to as the modified side-to-side isoperistaltic anastomosis with double Heineke-Mikulicz procedure could become an alternative operation after intestinal resection in persons with Crohns disease, although long-term outcome analysis is necessary.  相似文献   
9.
Cachexia frequently occurs in the late stages of cancer, and is difficult to manage. We previously reported that interleukin-6 (IL-6) cDNA transfection into Lewis lung carcinoma (LLC-IL6) induced cachexia-like symptoms in C57BL/6 mice. This was thought to be a useful experimental model of cancer cachexia. We have examined the effects of two eicosanoids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), in order to evaluate whether they could relieve cachexia. LLC-IL6-bearing animals were divided into three treatment groups receiving DHA, EPA or water as the control; 80-l samples of these compounds (purity>95%) were administered orally by catheter daily starting 7 days after tumor transplantation. Tumor growth curves were similar in the three groups. There were no differences in water or food intake in the three groups. However, body weight, a marker of cachexia, was significantly higher in treated mice than in the control group. Sixteen days after tumor transplantation, the mean body weight was 17.45 g (P<0.05), 17.2 g and 16.41 g in the groups receiving DHA, EPA and water respectively. The eicosanoids did not affect serum levels of IL-6. Ubiquitination of muscle protein, a marker of proteolysis coupled to cachexia, was compared in LLC-IL6-and LLC-transplanted mice. The eicosanoids prevented the ubiquitination of approximately 180 kDa protein. These results suggest that eicosanoids may prevent the cachexia mediated by IL-6.Abbreviations DHA docosahexaenoic acid - EPA eicosapentaenoic acid - LLC Lewis lung carcinoma - IL interleukin  相似文献   
10.
BACKGROUND: Adiponectin, which is a collagen-like plasma protein produced by adipose tissue, has anti-atherogenic and anti-inflammatory effects. Plasma adiponectin levels in patients with congestive heart failure (CHF) were determined, as well as relationships between the plasma levels of adiponectin and other hormones. METHODS AND RESULTS: The study group comprised 90 patients with CHF and 20 control subjects, who were divided into 4 subgroups according to New York Heart Association (NYHA) functional class. Plasma levels of adiponectin, tumor necrosis factor (TNF)-alpha and brain natriuretic peptide (BNP) and cardiac hemodynamics were determined. Plasma adiponectin levels were significantly increased according to the severity of NYHA class in the patients with CHF; control: 6.2+/-1.0; NYHA I: 8.5+/-1.9, NYHA II: 12.0+/-2.2, NYHA III: 13.0+/-2.7, NYHA IV: 14.9+/-2.7 microg/ml (p=0.0008). Similarly, plasma BNP levels were significantly increased in accordance with the NYHA class. Plasma adiponectin levels correlated positively with BNP (r=0.40, p=0.0002) and TNF-alpha (r=0.49, p=0.0001), and correlated negatively with cardiac index (r=-0.27, p=0.05). In 24 of 46 patients in the NYHA III and IV subgroups, according to the prompt improvement in cardiac function, levels of both plasma adiponectin and BNP were significantly reduced (p<0.0001). CONCLUSION: Plasma adiponectin levels increased according to the severity of CHF and, moreover, they correlated with the plasma levels of BNP and TNF-alpha. These results indicate that augmented release of adiponectin is involved in the pathogenesis of CHF and further study is needed to elucidate its exact role.  相似文献   
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