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   1400篇
  免费   108篇
  国内免费   6篇
耳鼻咽喉   37篇
儿科学   34篇
妇产科学   44篇
基础医学   183篇
口腔科学   57篇
临床医学   125篇
内科学   279篇
皮肤病学   20篇
神经病学   72篇
特种医学   75篇
外科学   210篇
综合类   18篇
预防医学   99篇
眼科学   32篇
药学   121篇
中国医学   12篇
肿瘤学   96篇
  2024年   2篇
  2023年   25篇
  2022年   32篇
  2021年   74篇
  2020年   53篇
  2019年   73篇
  2018年   75篇
  2017年   56篇
  2016年   72篇
  2015年   57篇
  2014年   75篇
  2013年   93篇
  2012年   115篇
  2011年   109篇
  2010年   55篇
  2009年   41篇
  2008年   71篇
  2007年   82篇
  2006年   50篇
  2005年   30篇
  2004年   40篇
  2003年   34篇
  2002年   27篇
  2001年   19篇
  2000年   22篇
  1999年   18篇
  1998年   5篇
  1997年   2篇
  1996年   3篇
  1995年   3篇
  1994年   7篇
  1992年   3篇
  1991年   7篇
  1990年   4篇
  1989年   8篇
  1988年   10篇
  1987年   14篇
  1986年   8篇
  1985年   7篇
  1984年   4篇
  1983年   3篇
  1982年   5篇
  1981年   2篇
  1979年   2篇
  1973年   2篇
  1971年   3篇
  1970年   1篇
  1968年   3篇
  1967年   1篇
  1966年   1篇
排序方式: 共有1514条查询结果,搜索用时 15 毫秒
1.
Transplant atherosclerotic coronary disease remains the leading cause of death in heart transplant recipients. We report the first case of coronary stent implantation in a heart graft for epicardial focal stenosis. Due to the lower rate of restenosis after stenting in the native coronary artery, we suggest that coronary stenting be considered an acceptable, first intention therapeutic option instead of angioplasty alone whenever possible.  相似文献   
2.
3.
An attempt was made to investigate the proliferative effect of interleukin-7 (IL-7) on a rat Nb2 T-cell lymphoma line. It was demonstrated that both human and mouse IL-7 stimulated these cells to proliferate in a dose dependent fashion in culture medium containing 10% horse serum. The maximum activities of mIL-7 and hIL-7 were observed at 100 and 1000 units/ml with their half-maximal response of 10 and 50 units/ml, respectively. In a totally serum-free culture condition, mIL-7 produced a similar cellular proliferation, whereas hIL-7 was much less effective. The effectiveness of IL-7 on Nb2 cells was completely abolished by antibody to IL-7, but not by antibody to IL-2. Therefore, Nb2 cells may serve as a simple, convenient and sensitive assay for monitoring the biological activity of IL-7 in vitro. In addition, these cells are also useful for studying the lymphopoiesis of T-cell lineage regulated by IL-7.  相似文献   
4.
The present study was aimed at evaluating the acute effects of Calcium-Magnesium soft gels (CalMag) in morphine tolerant and dependent mice. Mice were rendered tolerant and dependent on morphine by subcutaneous injection of morphine over a fixed time period. Withdrawal signs were precipitated by injecting naloxone 2 h after the final injection of morphine. The tail-pinch assay was used to investigate the effects of various compounds on the development and reversal of morphine tolerance. Acute injection of CalMag (containing 50 mg/kg calcium and 25 mg/kg magnesium) significantly reduced the number of jumps, stands and fast breathing in morphine dependent mice. Co-administration of calcium (50 mg/kg) and magnesium (25 mg/kg) was also effective in preventing the development of morphine tolerance and dependence. Administration of calcium (up to 50 mg/kg) alone did not significantly block the development of tolerance and dependence. The mean latency to pain was significantly increased in animals pretreated with CalMag (containing 50 mg/kg calcium and 25 mg/kg magnesium). The mixture of calcium and magnesium at specific concentrations seem to be critical for preventing the development of morphine tolerance and dependence.  相似文献   
5.
6.
Usher syndrome is a heterogeneous autosomal recessive trait and the most common cause of hereditary deaf-blindness. Usher syndrome type I (USH1) is characterised by profound congenital sensorineural hearing loss, vestibular dysfunction, and prepubertal onset of retinitis pigmentosa. Of the at least six different loci for USH1, USH1B maps on chromosome 11q13, and the MYO7A gene has been shown to be defective in USH1B. MYO7A encodes myosin VIIA, an unconventional myosin, and it consists of 48 coding exons. In this study, MYO7A was analysed in 34 unrelated Usher type I patients by single-strand conformation polymorphism analysis and direct sequencing. We identified a total of 12 novel and unique mutations, all single base changes. In addition, we found a previously reported nonsense mutation (C31X) on nine alleles of a total of six patients from Denmark.  相似文献   
7.
We evaluate the performance of our novel hybrid optical coherence tomography (OCT) and scintillating probe, demonstrate simultaneous OCT imaging and scintillating detection, and validate the system using an atherosclerotic rabbit model. Preliminary data obtained from the rabbit model suggest that our prototype positron probe detects local uptake of fluorodeoxyglucose (FDG) labeled with 18F positron (beta) radionuclide emitter, and the high-uptake regions correlate with sites of injury and extensive atherosclerosis areas. Preliminary data also suggest that coregistered high-resolution OCT images provide imaging of detailed plaque microstructures, which cannot be resolved by positron detection.  相似文献   
8.
Infection with the human immunodeficiency virus HIV-1 is associated with the expansion of a CD14lowCD16high monocyte subset in peripheral blood. This subset, which represents a minor subpopulation of monocytes in healthy individuals, increases during HIV infection and, in patients with AIDS, may represent up to 40% of the total circulating monocyte cell population. The CD14lowCD16high circulating monocytes co-express MAX.1, p150,95 and HLADR which are typical of tissue macrophage markers. These cells also express higher levels of intracellular interleukin (IL)-1α and tumor necrosis factor (TNF)-α than the CD14highCD16low monocyte population from the same patients. The CD14lowCD16high cells also express low levels of CD35, CD11a and CD4 in common with normal monocytes. When cultured in vitro, monocytes from HIV-seropositive individuals differentiated within a few hours into an elongated fibroblastoid shape characteristic of migratory cells. Our results suggest that the expansion of the CD14lowCD16high monocyte subset, which produce high amounts of TNF-α and IL-1α, may participate in the immune dysfunction observed during HIV infection.  相似文献   
9.
Deficiency of the enzyme, galactokinase, is a recognized cause of "juvenile" lens opacities; these opacities are felt to be its only clinical expression. The deficiency itself is inherited as an autosomal recessive and as such is expected to be clinically manifest in the homozygote. We have recently demonstrated cataracts and associated bilateral macular deposits in a white male who is heterozygous for the deficiency of the enzyme and whose dietary intake of milk and its products is extremely high. To our knowledge, intraretinal deposits have not previously been described in patients with galactokinase deficiency, and their clinical significance and biochemical makeup can only be speculative. Dietary restriction of galactose is recommended for all individuals proven to be deficient in this enzyme, whether homozygous or heterozygous.  相似文献   
10.
The coronavirus disease 2019 (COVID-19) disease was first detected in December 2019 in Wuhan, China. This disease is currently one of the most important global health problems. The novel coronavirus COVID-19 is a respiratory illness, that has caused a deadly pandemic that is spreading rapidly around the world. It is not only a respiratory system virus that causes severe lung disease, but also a systemic disease agent that can affect all systems. People with COVID-19 disease usually have respiratory signs, however, the liver disorder is not an uncommon presentation. In addition, many studies around the world have revealed that the liver is injured to various degrees in patients with severe acute respiratory syndrome coronavirus 2 disease. This review mainly focuses on the impact of COVID-19 on Liver Injury at various ages.  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