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   22305篇
  免费   1694篇
  国内免费   61篇
耳鼻咽喉   274篇
儿科学   727篇
妇产科学   543篇
基础医学   3168篇
口腔科学   347篇
临床医学   2137篇
内科学   4359篇
皮肤病学   373篇
神经病学   2149篇
特种医学   705篇
外科学   2988篇
综合类   683篇
现状与发展   1篇
一般理论   32篇
预防医学   1745篇
眼科学   628篇
药学   1585篇
中国医学   53篇
肿瘤学   1563篇
  2023年   143篇
  2022年   347篇
  2021年   548篇
  2020年   316篇
  2019年   491篇
  2018年   603篇
  2017年   353篇
  2016年   466篇
  2015年   504篇
  2014年   656篇
  2013年   1025篇
  2012年   1420篇
  2011年   1288篇
  2010年   804篇
  2009年   745篇
  2008年   1191篇
  2007年   1223篇
  2006年   1113篇
  2005年   1163篇
  2004年   1160篇
  2003年   1054篇
  2002年   946篇
  2001年   375篇
  2000年   382篇
  1999年   353篇
  1998年   230篇
  1997年   176篇
  1996年   178篇
  1995年   171篇
  1994年   128篇
  1993年   158篇
  1992年   260篇
  1991年   232篇
  1990年   247篇
  1989年   237篇
  1988年   224篇
  1987年   203篇
  1986年   212篇
  1985年   233篇
  1984年   178篇
  1983年   142篇
  1982年   150篇
  1981年   162篇
  1980年   135篇
  1979年   120篇
  1977年   98篇
  1976年   120篇
  1975年   103篇
  1974年   131篇
  1973年   104篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Between June and September, 1986, an outbreak of measles occurred in Pilkhi Primary Health Centre area (population 56,000) in Tehri Garhwal district, Uttar Pradesh, India. Overall, 1092 cases were identified and 62 died; case-fatality ratio was 5.7%. Illness was restricted primarily to children below 15 years of age; 38% cases were in children under 5 and 58% between 5-14 years of age. To better characterize the outbreak, a survey was conducted in 13 affected villages. The age of the cases ranged from 5 months to 19 years (median = 7.0 years). The age-specific attack rates were 22.4%, 54.5%, 46.2% and 35.3% for children under 1, 1-4, 5-9, 10-14 years of age respectively. In as many as four villages, the attack rate in children below ten was 80% or more. Secondary attack rate among family members was 70%. Overall, 82% of children with measles developed complications which consisted mainly of pneumonia, diarrhoea and dysentery. The age-specific case-fatality ratios in infants and children 1-4 years of age were 23.1% and 11.5% respectively; thereafter the rates tended to decline with increasing age and was higher in females than in males (less than 0.05). Pneumonia which was a complication in 39% of measles cases contributed to 56% of deaths. Traditional beliefs and customs in the area were strong and did not encourage treatment of measles cases. Although a measles vaccination programme has been launched in India since 1985, only 30 districts could be covered during the first year and another 90 during 1986.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
2.
3.
Mammalian fatty acid synthase (FASE) overexpression has been shown in a number of human malignancies including colonic adenocarcinoma. Since FASE synthesizes only saturated fatty acids, we hypothesized that cancer cells have a greater proportion of long-chain saturated fatty acids. We studied and found an unequivocal increase in saturated C18 fatty acid (stearic acid) in colonic adenocarcinoma compared to adjacent normal colonic mucosa. The increase is even more striking when measured as a ratio of stearic acid to the unsaturated C18 fatty acids (oleic acid and linoleic acid). This change in fatty acid composition of the cancer cells should significantly alter their physical and biological properties. The increase in relative proportion of saturated fatty acids should make the cancer cells more susceptible to cryodamage and measurement of fatty acid composition of cancer cells may help individualize the temperature for cryotherapy. Also, the lipid alterations may affect the structure and functions of lipid rafts, which may enable the cancer cells to affect signaling mechanisms such as those involved in cell growth and apoptosis. Dietary or therapeutic interventions targeting lipid rafts may thus be an option for cancer treatment.  相似文献   
4.
5.
6.
7.
Originally described by Rosen in 1983, syringomatous nipple adenoma (SAN) is a tumor of disputed histogenesis, which can be problematic both diagnostically and therapeutically. 1 It is a benign primary tumor of breast epithelium with histology similar to that of the syringoma. In the current case, we describe a 40-year-old female with this lesion occurring within a supernumerary breast. This case represents, to our knowledge, the first such reported case, and represents a significant finding as its presence could lend some confusion as to whether or not this represents a benign primary process of breast or a potentially infiltrative tumor of the skin.  相似文献   
8.
9.
Alemtuzumab is a powerful lymphocyte depleting antibody currently being evaluated in solid organ transplantation. This paper describes 5-year results of a single center study of alemtuzumab as induction in renal transplantation. Thirty-three renal transplant recipients received 20 mg alemtuzumab on day 0 and 1, followed by half-dose cyclosporin monotherapy (trough concentration 75-125 ng/mL) from day 3. They were compared in a retrospective contemporaneous-controlled manner with 66 kidney transplant recipients transplanted in the same period and center who received conventional immunosuppression with cyclosporin, azathioprine and prednisolone. In the alemtuzumab group 12% of recipients died compared to 17% in the control group (p = 0.48); likewise graft loss was similar in both groups (21% vs. 26%, respectively, p = 0.58). Incidence of acute rejection was also comparable at 5 years (31.5% vs. 33.6%), although the pattern of rejection was different with 14% patients in the alemtuzumab group experiencing rejection over 1 year post-transplant compared to none in the control group. There was no significant difference between groups in terms of infection or serious adverse events. While acknowledging the limitations of a relatively small single-center study, results suggest that alemtuzumab induction allowed satisfactory long-term patient and graft survival equivalent to that seen with standard triple immunosuppression, while avoiding steroid therapy.  相似文献   
10.
The red eye     
A red eye is a cardinal sign of ocular inflammation. Most cases are benign and can be managed by the primary care provider. The key is recognizing cases requiring ophthalmological consultation by differentiating between ciliary and conjunctival injection. Ciliary injection indicates inflammation of the cornea, iris, or ciliary body, whereas conjunctival injection mainly affects the posterior conjunctival blood vessels. The author has stated that he does not have a significant financial interest or other relationship with any product manufacturer or provider of services discussed in this article. The author also does not discuss the use of off-label products, which includes unlabeled, unapproved, or investigative products or devices.  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