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   2726篇
  免费   120篇
  国内免费   9篇
耳鼻咽喉   9篇
儿科学   176篇
妇产科学   90篇
基础医学   416篇
口腔科学   61篇
临床医学   229篇
内科学   559篇
皮肤病学   40篇
神经病学   173篇
特种医学   57篇
外科学   190篇
综合类   77篇
一般理论   3篇
预防医学   202篇
眼科学   66篇
药学   284篇
  1篇
中国医学   29篇
肿瘤学   193篇
  2022年   42篇
  2021年   74篇
  2020年   42篇
  2019年   58篇
  2018年   80篇
  2017年   43篇
  2016年   68篇
  2015年   67篇
  2014年   86篇
  2013年   131篇
  2012年   211篇
  2011年   199篇
  2010年   117篇
  2009年   72篇
  2008年   157篇
  2007年   172篇
  2006年   140篇
  2005年   134篇
  2004年   118篇
  2003年   123篇
  2002年   84篇
  2001年   50篇
  2000年   56篇
  1999年   44篇
  1998年   21篇
  1997年   12篇
  1996年   15篇
  1995年   12篇
  1994年   14篇
  1993年   16篇
  1992年   25篇
  1991年   20篇
  1990年   24篇
  1989年   24篇
  1988年   10篇
  1987年   27篇
  1986年   21篇
  1985年   17篇
  1984年   18篇
  1983年   11篇
  1982年   15篇
  1981年   10篇
  1977年   10篇
  1976年   13篇
  1974年   12篇
  1973年   15篇
  1972年   12篇
  1971年   10篇
  1970年   13篇
  1969年   17篇
排序方式: 共有2855条查询结果,搜索用时 343 毫秒
1.
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Heavy metal concentrations in surface soils of Reserved Forests (RFs) have a significant impact on...  相似文献   
2.
3.
4.
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   
5.
Zero-order release of oxprenolol hydrochloride was obtained by controlling the swelling and erosion of the matrix. This formulation involves only mixing of drug, hydroxypropylmethylcellulose (HPMC), and sodium carboxymethylcellulose (Na CMC) at the ratio of 1:0.4:1.6, respectively, and compressing the mixture directly into tablets. The in vitro release pattern from this optimized matrix tablet was reproducible. Accelerated stability studies revealed that the optimized formulation remains stable for an approximately 2-year shelf life. This sustained-release (SR) tablet was evaluated in dogs, and for comparison a conventional (CV) formulation was also given at the same dose level. Plasma oxprenolol levels were monitored by a sensitive and specific high-performance liquid chromatographic (HPLC) method. Significant differences in the pharmacokinetic parameters, i.e., lower C max, higher values of t max, MRT, AUC, and plasma concentration at 24 hr, and nearly constant plasma levels over 12 hr, indicated that the SR matrix tablet is superior to the CV rapid-releasing formulation. The in vitro release parameters and in vivo pharmacokinetics correlated well.  相似文献   
6.
7.
Intravascular papillary endothelial hyperplasia (IPEH) is an unusual vascular lesion of proliferating endothelial cells. It is more frequently seen in the extremities, particularly in the fingers. Oral IPEH has been reported with the common sites being lip, tongue, and buccal mucosa. In this article, we present a case of oral IPEH of the floor of the mouth, an unusual location, presenting in a 9-month-old male. The histogenesis, histologic features, and ultrastructural features are also reviewed. A misdiagnosis of angiosarcoma can be made in a case of IPEH due to similar histopathologic features. It is imperative to rule out this error by an elaborate histopathologic evaluation ofthese lesions.  相似文献   
8.
The alterations in the oesophageal epithelium were studied in mice after a single whole-body exposure to 7.5 Gy of Co-60 gamma rays in presence or absence of 2-mercaptopropionyl glycine. The epithelium showed an increase in the thickness which reached a maximum on the third day and then decreased gradually up to seventh day after irradiation in the non-drug treated group. In the 2-mercaptopropionyl glycine treated animals the epithelial thickness remained in the normal range except on the day 7 when it was significantly lower than normal. The total cell population registered a steady decline from one to seven days post-irradiation in both groups, but the number of cells was more in the 2-mercaptopropionyl glycine treated group. The number of pycnotic nuclei showed an inverse relationship to the total cell population, it increased continuously up to seven days in both the protected and non-protected groups. However, pycnotic nuclei were significantly lower in the protected group on days 3, 5 and 7 in non-protected group.  相似文献   
9.
In the brain, nitric oxide (NO) has been identified as a messenger molecule and a mediator of excitatory amino acid-induced neurotoxicity. In this study, the effects of NO on serum-induced mitogenesis and cell proliferation of the cerebellar glial cells were assessed. NO-generating agent, S-nitroso-N-acetylpenicillamine (SNAP) increased intracellular cyclic guanosine monophosphate (cGMP) levels. Furthermore, 2 chemically dissimilar NO-generating agents, SNAP and sodium nitroprusside (SNP) inhibited serum-induced thymidine incorporation and cell proliferation. The antimitogenic effect of NO was mimicked by 8-bromo-cGMP and blocked by hemoglobin, a known inhibitor of NO. The effect of NO was not cytotoxic, since the cells were not stained with Trypan blue and did not show increased release of lactate dehydrogenase in the culture supernatants. However, NO-treated cells showed decreased conversion of tetrazolium to blue formazan suggesting that NO inhibited mitochondrial activity in the glial cells. These results demonstrate that NO inhibits serum-induced mitogenesis and cell proliferation of cultured rat cerebellar glial cells.  相似文献   
10.
Two children out of three siblings of a family presented with tiredness, fatigue, and breathlessness for more than 6 months. Examination of peripheral blood smear, bone marrow aspirate, and a positive acidified serum test (HEMPAS) revealed these children to be a case of congenital dyserythropoietic anemia type II. This case is reported because of its rarity.  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