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   755篇
  免费   41篇
耳鼻咽喉   5篇
儿科学   89篇
妇产科学   21篇
基础医学   122篇
口腔科学   20篇
临床医学   46篇
内科学   106篇
皮肤病学   10篇
神经病学   76篇
特种医学   8篇
外科学   66篇
综合类   7篇
预防医学   56篇
眼科学   25篇
药学   66篇
中国医学   3篇
肿瘤学   70篇
  2023年   2篇
  2022年   4篇
  2021年   21篇
  2020年   9篇
  2019年   8篇
  2018年   14篇
  2017年   15篇
  2016年   16篇
  2015年   20篇
  2014年   26篇
  2013年   48篇
  2012年   72篇
  2011年   69篇
  2010年   41篇
  2009年   26篇
  2008年   41篇
  2007年   56篇
  2006年   39篇
  2005年   35篇
  2004年   29篇
  2003年   40篇
  2002年   26篇
  2001年   6篇
  2000年   6篇
  1999年   10篇
  1998年   10篇
  1996年   7篇
  1995年   4篇
  1994年   5篇
  1993年   7篇
  1992年   2篇
  1991年   3篇
  1990年   5篇
  1989年   7篇
  1987年   9篇
  1986年   3篇
  1984年   3篇
  1983年   2篇
  1982年   9篇
  1981年   5篇
  1980年   5篇
  1976年   3篇
  1974年   2篇
  1973年   2篇
  1972年   2篇
  1971年   3篇
  1970年   2篇
  1969年   4篇
  1968年   4篇
  1966年   2篇
排序方式: 共有796条查询结果,搜索用时 390 毫秒
1.
2.
India is called the land of villages. In 1951, 82.7% of the Indian population lived in rural areas. Sanskritisation and urbanisation have changed the pattern. It is expected that by the year 2020 this percentage would come down to 55%. These villagers are relocating in urban slums. Thus from the rehabilitation point of view both problems pose challenges. An Indian village community is a political, economic and cultural unit. At the urban slum area at Malwani and in small villages near Juchandra, community rehabilitation programmes were found to be most pragmatic. Community education and preventive occupational therapy are found to be essential steps in rural rehabilitation. Therapists have to work on ‘disability, attitude and beliefs’ and change the behaviour to deal with the grass root (basic) causes. It is felt that for longer sustainment, community-based rehabilitation should originate within the community. Heath professionals must recognise the capabilities of individuals within the support structure of the family and community, while helping individuals to improve the quality of their lives.  相似文献   
3.
4.
Purpose: To determine if adequate anaesthesia and akinesia could be obtained using an inferonasal quadrant sub-Tenons anaesthesia for cataract surgery.
Methods: The sub-Tenons method of local anaesthesia was used in 50 patients undergoing extracapsular cataract extraction and lens implantation. The technique followed was that described by JD Stevens in his study of 50 patients. Posterior sub-Tenons space was approached through a conjunctival incision in the inferonasal quadrant and the anaesthetic solution delivered by an irrigating cannula. The patients were assessed for residual ocular movements just before surgery. Effectiveness of anaesthesia was assessed during surgery using a verbal pain rating score. Scoring was based on the concept of a visual analogue pain score chart.
Results: Total akinesia was obtained in 20% patients and total anaesthesia in 24% patients. The remainder of the patients had adequate akinesia and anaesthesia to proceed with and complete the surgery.
Conclusion: This method provides satisfactory anaesthesia for cataract surgery.  相似文献   
5.
Ascorbic acid metabolism was studied in guinea pigs and rats after the administration of ethanol and a high dose of ascorbic acid (AA). Male guinea pigs were maintained for 30 days as follows: (1) controls (1 mg AA/100 g body wt.); (2) ethanol (1 mg AA/100 g body wt. + 900 mg ethanol/100 g body wt); (3) ascorbic acid (25 mg AA/100 g body wt.); (4) ascorbic acid + ethanol (25 mg AA/100 g body wt. + 900 mg ethanol/100 g body wt.). Rats were also grouped into four groups as in the case of guinea pigs, but the dose of AA was 200 mg/100 g body weight. Rats adjusted to ethanol intoxication by enhancing the biosynthesis of ascorbate as evidenced by elevated activity of L-gulono lactone oxidase (GLO). Hence ascorbate levels were not lowered in rats after administration of alcohol. However, alcohol administration lowered tissue levels of ascorbate in guinea pigs. But the supplementation of ascorbate along with alcohol raised the tissue level of this vitamin. Guinea pigs responded to the ascorbate deficiency during alcohol administration by lowering the degradation of ascorbate, as seen by the lower activity of the degrading enzyme gulono lactone hydrolase. It is concluded that on the administration of alcohol, guinea pigs are dependent upon additional exogenous supplies of ascorbic acid, whereas rats are not.  相似文献   
6.
Using in vivo-induced antigen technology (IVIAT), a modified immunoscreening technique that circumvents the need for animal models, we directly identified immunogenic Escherichia coli O157:H7 (O157) proteins expressed either specifically during human infection but not during growth under standard laboratory conditions or at significantly higher levels in vivo than in vitro. IVIAT identified 223 O157 proteins expressed during human infection, several of which were unique to this study. These in vivo-induced (ivi) proteins, encoded by ivi genes, mapped to the backbone, O islands (OIs), and pO157. Lack of in vitro expression of O157-specific ivi proteins was confirmed by proteomic analysis of a mid-exponential-phase culture of E. coli O157 grown in LB broth. Because ivi proteins are expressed in response to specific cues during infection and might help pathogens adapt to and counter hostile in vivo environments, those identified in this study are potential targets for drug and vaccine development. Also, such proteins may be exploited as markers of O157 infection in stool specimens.  相似文献   
7.
Sephadex purified PPD and Con A induced mediator rich fractions (MRF) were applied to guinea-pig macrophages cultured in vitro. At varying times after the addition of the MRF, cells were removed from culture for morphological study and for cytochemical tests. Respiratory enzyme activity and lysosomal acid phos-phatase activity were estimated and the former was quantitated using an integrating microdensitometer. Early changes, 1 hr after MRF contact, were observed and subsequent alterations in activity up to 48 hr after the addition of MRF were also seen. These changes have been related to the inhibition of migration and subsequent `activation' of the macrophages which has been observed morphologically at times up to 3 weeks after MRF addition.

It is suggested that alterations in the cytochemistry of the macrophages after MRF contact could help explain changes in the behaviour of the cells under these experimental conditions.

  相似文献   
8.
We report a family heterozygous for a newly identified mutation in the tyrosine kinase I domain of the FGFR2 gene (1576A > G, encoding the missense substitution Lys526Glu), associated with variable expressivity of Crouzon syndrome, including clinical nonpenetrance. Our observations expand both the clinical and molecular spectrum of this unusual subset of FGFR2 mutations.  相似文献   
9.
Breast cancer progression depends upon the elaboration of a vasculature sufficient for the nourishment of the developing tumor. Breast tumor cells frequently contain a mutant form of p53 (mtp53), a protein which promotes their survival. The aim of this study was to determine whether combination therapy targeting mtp53 and anionic phospholipids (AP) on tumor blood vessels might be an effective therapeutic strategy for suppressing advanced breast cancer. We examined the therapeutic effects, singly, or in combination, of p53 reactivation and induction of massive apoptosis (PRIMA-1), which reactivates mtp53 and induces tumor cell apoptosis, and 2aG4, a monoclonal antibody that disrupts tumor vasculature by targeting AP on the surface of tumor endothelial cells and causes antibody-dependent destruction of tumor blood vessels, leading to ischemia and tumor cell death. Xenografts from two tumor cell lines containing mtp53, BT-474 and HCC-1428, were grown in nude mice to provide models of advanced breast tumors. After treatment with PRIMA-1 and/or 2aG4, regressing tumors were analyzed for vascular endothelial growth factor (VEGF) expression, blood vessel loss, and apoptotic markers. Individual drug treatment led to partial suppression of breast cancer progression. In contrast, combined treatment with PRIMA-1 and 2aG4 was extremely effective in suppressing tumor growth in both models and completely eradicated approximately 30% of tumors in the BT-474 model. Importantly, no toxic effects were observed in any treatment group. Mechanistic studies determined that PRIMA-1 reactivated mtp53 and also exposed AP on the surface of tumor cells as determined by enhanced 2aG4 binding. Combination treatment led to significant induction of tumor cell apoptosis, loss of VEGF expression, as well as destruction of tumor blood vessels. Furthermore, combination treatment severely disrupted tumor blood vessel perfusion in both tumor models. The observed in vitro PRIMA-1-induced exposure of tumor epithelial cell AP might provide a target for 2aG4 and contribute to the increased effectiveness of such combination therapy in vivo. We conclude that the combined targeting of mtp53 and the tumor vasculature is a novel effective strategy for combating advanced breast tumors.  相似文献   
10.
Diagnosis of articular cartilage pathology in the early disease stages using current clinical diagnostic imaging modalities is challenging, particularly because there is often no visible change in the tissue surface and matrix content, such as proteoglycans (PG). In this study, we propose the use of near infrared (NIR) spectroscopy to spatially map PG content in articular cartilage. The relationship between NIR spectra and reference data (PG content) obtained from histology of normal and artificially induced PG-depleted cartilage samples was investigated using principal component (PC) and partial least squares (PLS) regression analyses. Significant correlation was obtained between both data (R2 = 91.40%, p<0.0001). The resulting correlation was used to predict PG content from spectra acquired from whole joint sample, this was then employed to spatially map this component of cartilage across the intact sample. We conclude that NIR spectroscopy is a feasible tool for evaluating cartilage contents and mapping their distribution across mammalian joint.OCIS codes: (170.6510) Spectroscopy, tissue diagnostics; (170.6935) Tissue characterization; (170.3880) Medical and biological imaging  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