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   9303篇
  免费   574篇
  国内免费   58篇
耳鼻咽喉   61篇
儿科学   263篇
妇产科学   223篇
基础医学   1440篇
口腔科学   281篇
临床医学   967篇
内科学   2038篇
皮肤病学   171篇
神经病学   1032篇
特种医学   195篇
外科学   695篇
综合类   38篇
一般理论   3篇
预防医学   789篇
眼科学   150篇
药学   681篇
中国医学   13篇
肿瘤学   895篇
  2024年   10篇
  2023年   86篇
  2022年   174篇
  2021年   319篇
  2020年   214篇
  2019年   230篇
  2018年   269篇
  2017年   211篇
  2016年   264篇
  2015年   295篇
  2014年   414篇
  2013年   533篇
  2012年   721篇
  2011年   741篇
  2010年   385篇
  2009年   348篇
  2008年   619篇
  2007年   673篇
  2006年   619篇
  2005年   533篇
  2004年   516篇
  2003年   474篇
  2002年   469篇
  2001年   50篇
  2000年   44篇
  1999年   67篇
  1998年   77篇
  1997年   78篇
  1996年   49篇
  1995年   55篇
  1994年   40篇
  1993年   35篇
  1992年   23篇
  1991年   21篇
  1990年   18篇
  1989年   26篇
  1988年   7篇
  1987年   9篇
  1986年   16篇
  1985年   16篇
  1984年   23篇
  1983年   24篇
  1982年   19篇
  1981年   19篇
  1980年   19篇
  1979年   15篇
  1978年   12篇
  1976年   8篇
  1975年   7篇
  1973年   6篇
排序方式: 共有9935条查询结果,搜索用时 15 毫秒
91.
When tissues are damaged, they usually heal. The cellular responses towards healing require the prior recognition that damage has occurred. High Mobility Group Box 1 protein (HMGB1) is a ubiquitous nuclear protein that is passively released by cells that have died in a traumatic, non-programmed way (necrosis). Several receptors for HMGB1 exist, and upon binding HMGB1 they alert leukocytes to extravasate from the blood into the affected tissue, trigger adaptive immunity and promote the migration and proliferation of cells (including stem cells) to repair the damaged tissue. Significantly, apoptotic cells modify their chromatin so as to bind HMGB1, which is not released. Several cell types (in particular inflammatory cells) when distressed have the ability to secrete HMGB1 actively, via a dedicated pathway, and thus produce a damage signal without dying. Because of its powerful activities, HMGB1 is involved in several disorders, including autoimmune ones.  相似文献   
92.
Abstract

An ELISA assay is described for the measurement of the smIgG. The method is based on the detection of cell-smIgG directly on the same microplate used for the culture. The cells, preincubated at 37°C for one hour, were cultured in the presence of S-ConA and serum-free medium for two days. Using this strategy, the background noise due to non specific adsorbtion of IgG to plastic wells and cytophilic antibodies was eliminated. The cells in the presence of S-ConA and serum-free medium adhered to the plastic wells, and the cell-smIgG were detected using an anti-human IgG covalently linked to alkaline phosphatase or its F(ab')2 fragment. The possibility of measuring the modulation of the expression of the cell-smIgG without any additional manipulation is stressed.  相似文献   
93.
94.
This article reviews recent developments in health care law, focusing on controversy at the intersection of health care law and culture. The article addresses: emerging issues in federal regulatory oversight of the rapidly developing market in direct-to-consumer genetic testing, including questions about the role of government oversight and professional mediation of consumer choice; continuing controversies surrounding stem cell research and therapies and the implications of these controversies for healthcare institutions; a controversy in India arising at the intersection of abortion law and the rights of the disabled but implicating a broader set of cross-cultural issues; and the education of U.S. health care providers and lawyers in the theory and practice of cultural competency.  相似文献   
95.
Humans may be exposed to pesticides such as fungicides, herbicides, and insecticides, during occupational and non‐occupational activities. Pesticides could be related to cancer development mainly because of their effects on the endocrine and immune systems and their cumulative effect. The present review evaluated in current literature evidence of an association between exposure to pesticides and the occurrence of head and neck cancer (HNC). A literature search for cohort studies was conducted in the PubMed, Web of science, and Cochrane databases. Methodological quality of each study was rated with the Scottish Intercollegiate Guidelines Network (SIGN) checklist. One thousand one hundred and thirty‐two studies were identified. Thirty‐two were included. Most of the studies found addressed occupational exposure to pesticides and were conducted in Europe and North America. Eleven high‐quality studies were found. Most of them found no association between exposure to pesticides and increased risk of HNC. Two studies found some evidence of a positive association between pesticide (malathion and atrazine) exposure and thyroid cancer. The literature review does not support a clear evidence for association between pesticides exposure and HNC. Only limited evidence points to a positive association between exposure to some pesticides and thyroid cancer. Further standardized studies based on appropriate designs are required to clarify the effect of pesticides on the genesis of HNC, considering dose, length of exposure, and type of pesticide.  相似文献   
96.
97.
The measurement of transepidermal water loss (TEWL) is important for evaluating the integrity of the barrier function of the stratum corneum. Normal TEWL values in healthy adults and in children ages 2 and older are well known, but few studies have been performed in infants and neonates. TEWL in healthy neonates younger than 24 hours old was assessed and compared with that of an adult study population. We also studied possible correlations between this parameter, gestational age, and mode of delivery. A prospective study was conducted in healthy newborns. The areas tested were the volar forearm and the popliteal fossa. Ninety‐nine healthy newborns were enrolled and 33 healthy adults were analyzed as controls. Statistically significant differences were noted between newborns and adults in TEWL (p < 0.01). Newborns had a much higher mean TEWL than adults. Differences in the morphology and physiology between newborn and mature skin can explain the higher TEWL in newborns. Higher TEWL could also be due to the sudden functional adaptation of the skin immediately after delivery, when the newborn transits from a liquid to the dry, gaseous extrauterine environment. Functional evaluation of the neonatal skin barrier is important mainly because maintaining skin integrity facilitates cutaneous adaptation.  相似文献   
98.
The genitalia may be the site of non-infectious inflammatory lesions that are generally manifested as balanoposthitis and vulvovaginitis. In men, these forms constitute 50% of all balanoposthitis forms, and in women, vulvovaginitis frequency is even higher. They consist of genital locations of general skin diseases, such as psoriasis, lichen planus, lichen sclerosus, and other clinical entities with their own physiognomy, such as Zoon’s balanitis-vulvitis. Diagnosis of genital non-infectious inflammatory lesions is usually made on clinical criteria. A biopsy is only necessary for the identification of clinical conditions that may simulate inflammatory form but are actually premalignant processes.  相似文献   
99.
100.
Investigation of causal interactions within brain networks using Granger causality analysis (GCA) is a key challenge in studying neural activity on the basis of functional magnetic resonance imaging (fMRI). The article describes an open-source software toolbox GMAC (Granger multivariate autoregressive connectivity) implementing multivariate spectral GCA. Available features are: fMRI data importing/exporting, network nodes definition, time series preprocessing, multivariate autoregressive modeling, spectral Granger causality indexes estimation, statistical significance assessment using surrogate data, network analysis and visualization of connectivity results. All functions have been integrated into a user-friendly graphical interface developed in the Matlab environment, easily accessible to both technical and clinical users.  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