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   2165篇
  免费   226篇
  国内免费   9篇
耳鼻咽喉   36篇
儿科学   68篇
妇产科学   39篇
基础医学   352篇
口腔科学   114篇
临床医学   214篇
内科学   374篇
皮肤病学   73篇
神经病学   103篇
特种医学   164篇
外国民族医学   48篇
外科学   220篇
综合类   64篇
预防医学   223篇
眼科学   21篇
药学   77篇
中国医学   1篇
肿瘤学   209篇
  2022年   15篇
  2021年   25篇
  2020年   15篇
  2019年   20篇
  2018年   32篇
  2017年   28篇
  2016年   31篇
  2015年   41篇
  2014年   34篇
  2013年   54篇
  2012年   65篇
  2011年   86篇
  2010年   57篇
  2009年   64篇
  2008年   79篇
  2007年   81篇
  2006年   70篇
  2005年   67篇
  2004年   80篇
  2003年   63篇
  2002年   63篇
  2001年   56篇
  2000年   56篇
  1999年   61篇
  1998年   68篇
  1997年   80篇
  1996年   72篇
  1995年   56篇
  1994年   59篇
  1993年   59篇
  1992年   67篇
  1991年   43篇
  1990年   56篇
  1989年   57篇
  1988年   53篇
  1987年   54篇
  1986年   57篇
  1985年   42篇
  1984年   24篇
  1983年   24篇
  1982年   31篇
  1981年   17篇
  1980年   19篇
  1979年   23篇
  1978年   13篇
  1977年   15篇
  1976年   19篇
  1975年   16篇
  1973年   11篇
  1967年   10篇
排序方式: 共有2400条查询结果,搜索用时 0 毫秒
1.
2.
3.
Selachyl alcohol (SA) is a mono-oleyl glyceryl ether. It has certain biologic activities similar to those of the antihypertensive neutral renomedullary lipid (ANRL) derived from the renal papilla and its renomedullary interstitial cells (RIC). These include a vaso-depressor effect following bolus injection and a requirement for hepatic activation for the development of biological activity. In view of this similarity to ANRL, it appeared worthwhile to test the antihypertensive action of SA when given via the GI tract. Accordingly, pure SA was given either by gavage or by tube into the stomach or duodenum of one-kidney, one-clip hypertensive rats (5-10 mg per dose). The role of hepatic activation was demonstrated by comparing the BP response to bolus injection of SA and ANRL with and without the presence of an intact circulation to the liver. Administration of SA via the GI tract resulted in a significant decline in BP without tachycardia or weight loss. In the absence of a circulation to the liver, neither SA nor ANRL was active. SA appears to be an effective antihypertensive agent when given via the GI tract.  相似文献   
4.
5.
6.
Cases of AIDS among women of reproductive age have increased dramatically since 1981; nearly a third of all cases among females were reported in 1990 alone. Surveillance of human immunodeficiency virus (HIV) infection among women is essential for monitoring the spread of HIV over time and identifying specific populations and geographic areas in need of HIV counseling, testing, and prevention services. Blinded (unlinked) serologic surveys were conducted in the United States and Puerto Rico in sentinel clinics providing reproductive health services to women, including family planning, prenatal care, and abortion services. Seventy-eight of 94 clinics (83%) in 30 cities conducting surveys during 1988 and 1989 detected at least one HIV-positive woman. Clinic-specific prevalence ranged from 0-2.28% (median 0.22%), with rates over 1% occurring in clinics predominantly on the East Coast and in Puerto Rico. Seroprevalence varied by primary type of service, race-ethnicity, and age group. Median rates were higher in clinics offering prenatal services and lower in abortion and family planning clinics in the same cities. In general, women 25-29 years of age showed the highest median rate of infection (0.32%), and rates were higher among black women (median 0.34%) than among Hispanic (median 0.11%) and white women (median 0%). Our data indicate the need to educate women about recognizing and reducing their risk of HIV infection. Reproductive health clinics with high seroprevalence should implement voluntary HIV counseling and testing with appropriate follow-up clinical evaluation and referral for infected women. Clinics with low prevalence should seize the opportunity to enhance HIV education and prevention efforts.  相似文献   
7.
The A chain of the toxin ricin has been conjugated by a disulfide bond to a murine monoclonal antibody that recognizes the CD5 (T,p67) antigen present on 95% of peripheral blood T lymphocytes. This immunotoxin was used to treat a patient with severe grade III-IV, steroid-resistant, acute graft-vs-host disease (GvHD) after an allogeneic, human leukocyte antigen-identical bone marrow transplant for acute myelogenous leukemia. Immunotoxin therapy produced a complete clinical response in the skin and gastrointestinal tract. The patient tolerated a 14-day course without symptoms or signs of toxic effects. After two days of therapy, circulating T cells could not be demonstrated by indirect immunofluorescence. After therapy, acute GvHD did not recur. However, seven months after therapy the patient demonstrated mild signs of chronic GvHD that were easily controlled with low-dose immunosuppressive therapy. These findings indicate that an anti-T-cell ricin A chain immunotoxin can be given safely for treatment of acute GvHD and may be an effective therapy for this significant posttransplant complication.  相似文献   
8.
9.
A new syndrome is described in a patient with advanced renal insufficiency. This consists of severe and persistent hypotension causing weakness but associated with a clear mental status. Also present is evidence for decreased vascular reactivity. The hypotension was not orthostatic. The hypotension was associated with a circulating vasodepressor substance having the characteristics of medullipin I. The medullipin appears to have been derived from the remaining right kidney. Hypotension existed despite the presence of major prohypertensive mechanisms, including an endstage kidney, hyperreninemia and hyperaldosteronemia. It is likely that hypotension due to hypermedullipinemia is an entity occurring in the human being.  相似文献   
10.
Cutaneous metastasis of vaginal carcinoma is extremely rare. So far, the total number of reported skin metastasis of vaginal carcinoma is only one. We present another case with an unusual manifestation of vagina carcinoma metastasis: skin metastasis presenting as a leg ulcer on the lower leg.  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