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   1364868篇
  免费   102929篇
  国内免费   4361篇
耳鼻咽喉   17227篇
儿科学   44273篇
妇产科学   36796篇
基础医学   201804篇
口腔科学   36833篇
临床医学   132727篇
内科学   264322篇
皮肤病学   26783篇
神经病学   114417篇
特种医学   49073篇
外国民族医学   366篇
外科学   188342篇
综合类   29417篇
现状与发展   1篇
一般理论   499篇
预防医学   117481篇
眼科学   29752篇
药学   100726篇
  31篇
中国医学   3224篇
肿瘤学   78064篇
  2021年   11762篇
  2019年   12192篇
  2018年   16952篇
  2017年   12771篇
  2016年   13769篇
  2015年   15767篇
  2014年   21608篇
  2013年   33151篇
  2012年   45872篇
  2011年   48481篇
  2010年   27972篇
  2009年   25761篇
  2008年   44081篇
  2007年   46558篇
  2006年   46621篇
  2005年   45114篇
  2004年   42913篇
  2003年   40764篇
  2002年   39449篇
  2001年   61459篇
  2000年   63058篇
  1999年   52818篇
  1998年   14888篇
  1997年   13567篇
  1996年   13392篇
  1995年   12701篇
  1994年   11859篇
  1993年   11128篇
  1992年   42022篇
  1991年   41142篇
  1990年   39811篇
  1989年   37720篇
  1988年   34914篇
  1987年   34034篇
  1986年   32485篇
  1985年   30957篇
  1984年   23322篇
  1983年   19814篇
  1982年   11949篇
  1979年   21063篇
  1978年   15023篇
  1977年   12226篇
  1976年   12014篇
  1975年   12268篇
  1974年   15002篇
  1973年   14640篇
  1972年   13524篇
  1971年   12556篇
  1970年   11627篇
  1969年   10556篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Interferon-alpha (IFN-alpha) has proved effective in the treatment of hemangiomas, hemangioblastomas, and Kaposi's sarcoma. To investigate the ability of IFNs to inhibit angiosarcoma, we used two transformed murine endothelial cell lines that form angiosarcomas in vivo. SVR and MS1-VEGF cell lines express oncogenic H-ras or vascular endothelial growth factor (VEGF), respectively. IFN-alpha1,8, which is active against murine and human cells, inhibited SVR and MS1-VEGF proliferation in vitro by 40% at 10(3) U/mL (p = 0.028). In vivo, IFN-alpha1,8 inhibited SVR tumor volume by 71% (p = 0.047) and MS1-VEGF volume by 79% (p = 0.003). Tumor-induced angiogenesis was decreased in SVR tumors by 52% (p = 0.005) and in MS1-VEGF tumors by 58% (p = 0.001). Sera from IFN-alpha1,8-treated mice bearing either SVR or MS1-VEGF tumors demonstrated a 5-fold increase in IP-10/CXCL10 (p = 0.001), an IFN-induced antiangiogenic protein. Both recombinant IP-10 and IFN-alpha1,8 inhibited human umbilical vein endothelial cell (HUVEC) vessel formation in the fibrin gel assay, a three-dimensional culture model of angiogenesis, by 56% at 25 ng/mL and 50% at 1.2 ng/mL, respectively (p < 0.001). An IP-10 blocking antibody restored vessel formation to 80% of untreated controls (p = 0.001). Given the magnitude of the in vivo response, these data suggested that the antitumor effects of IFN-alpha1,8 were likely mediated through angiogenesis inhibition rather than solely by direct inhibition of tumor cell proliferation.  相似文献   
72.
Relationship-centered care reflects both knowing and feeling: the knowledge that physician and patient bring from their respective domains of expertise, and the physician’s and patient’s experience, expression, and perception of emotions during the medical encounter. These processes are conveyed and reciprocated in the care process through verbal and nonverbal communication. We suggest that the emotional context of care is especially related to nonverbal communication and that emotion-related communication skills, including sending and receiving nonverbal messages and emotional self-awareness, are critical elements of high-quality care. Although nonverbal behavior has received far less study than other care processes, the current review argues that it holds significance for the therapeutic relationship and influences important outcomes including satisfaction, adherence, and clinical outcomes of care.  相似文献   
73.
A 19-item survey instrument was designed and mailed by the Infectious Diseases Society of America to its membership to determine the media preferred by infectious diseases physicians for continuing medical education on general topics and on antimicrobial resistance. The objective of the survey was to offer the developers of educational programs knowledge on which to base more-effective ways to deliver educational materials to physicians in this specialty.  相似文献   
74.
There are an estimated 200 million users of an illicit drug in the world today. In addition, an estimated 40 million people are infected with the human immunodeficiency virus (HIV) and an estimated 180 million people are infected with the hepatitis C virus (HCV). Both the use of an illicit drug and the co-occurrence of infections are associated with a multitude of medical and health consequences including hormonal and metabolic disorders. Thus, the National Institute on Drug Abuse (NIDA), a part of the National Institutes of Health (NIH) hosted a workshop on hormonal and metabolic disorders of HIV among substance abusers. A number of clinicians and scientists participated and discussed a wide range of issues concerning hormones, nutrition and metabolic complications in HIV and substance abuse. Their observations and the recommendations they made for future research are presented in these proceedings. The readers are encouraged to contact the NIH staff (JK, FV) for technical guidance and programmatic priorities on the subject and directly contact the individual authors for collaborations.  相似文献   
75.
Knowing Ron     
Spechko  Phyllis L. 《JAMA》2006,296(7):738
  相似文献   
76.
77.
BACKGROUND: Arterial hypertension and postmenopausal reduction of estrogen levels may be involved in modifications of the stiffness of large arteries. OBJECTIVES: To evaluate the pulse-wave velocity (PWV) and indirectly the arterial stiffness in hypertensive postmenopausal women submitted to hormone therapy with estradiol alone or combined with norethisterone acetate. SUBJECTS: Forty-five hypertensive postmenopausal women were double-blindly, randomly assigned to three arms of treatment: placebo (group I); estradiol 2 mg/day (group II); or estradiol 2 mg/day and norethisterone acetate 1 mg/day (group III). METHODS: Arterial stiffness was assessed from PWV measurements of the common carotid and femoral arteries (CF-PWV) and the common carotid and radial arteries (CR-PWV) obtained using the automatic Complior(R) device, taken at baseline and after 12 weeks of treatment. RESULTS: After the 12-week treatment, values of CF-PWV and CR-PWV were not significantly different (p = 0.910 and p = 0.736, respectively) among the groups. Systolic blood pressure showed a positive correlation with CF-PWV in groups II and III (p = 0.02 and p < 0.001, respectively). CONCLUSIONS: PWV and arterial stiffness in postmenopausal hypertensive women did not reduce over a 12-week treatment with estradiol alone compared with the same period of treatment with estradiol combined with norethisterone acetate.  相似文献   
78.
79.
80.
The prevalence of heavy alcohol consumption is a major problem of increasing proportions throughout the world. Although alcohol sensitizing drugs and more recently serotonin uptake inhibitors are drug interventions with some following, their long term beneficial consequences have yet to be demonstrated. In recent years, we have demonstrated that manipulating activity in the renin-angiotensin system will dramatically alter voluntary alcohol consumption in rats. Based on these findings, the present study evaluated the ability of a class of drugs known as the angiotensin converting enzyme inhibitors to reduce voluntary alcohol drinking in laboratory animals. These drugs prevent the conversion of angiotensin I to angiotensin II. They have been licensed for use in Europe and North America and are indicated in the treatment of hypertension. Our experiments showed that both captopril (Capoten, Squibb) and enalapril (Vasotec, Merck Sharpe & Dohme) can reduce alcohol drinking in both normotensive and hypertensive animals regardless of whether the pattern of intake is in a bout or of a less exaggerated nature. Furthermore, this change in alcohol intake can occur without concomitant changes in blood pressure, plasma renin activity, overall fluid balance, or the distribution and metabolism of alcohol. Taken together these findings suggest that the angiotensin converting enzyme inhibitors should be evaluated in a clinical setting for they may prove to be a useful new treatment or treatment adjunct for alcohol abuse in humans.  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