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   2168729篇
  免费   152230篇
  国内免费   3122篇
耳鼻咽喉   30223篇
儿科学   66119篇
妇产科学   58154篇
基础医学   315478篇
口腔科学   63169篇
临床医学   194952篇
内科学   419456篇
皮肤病学   46973篇
神经病学   173254篇
特种医学   84420篇
外国民族医学   359篇
外科学   327618篇
综合类   42256篇
现状与发展   3篇
一般理论   815篇
预防医学   162039篇
眼科学   50244篇
药学   162655篇
  10篇
中国医学   4281篇
肿瘤学   121603篇
  2018年   22938篇
  2017年   17901篇
  2016年   20219篇
  2015年   23135篇
  2014年   30918篇
  2013年   46341篇
  2012年   63755篇
  2011年   66725篇
  2010年   39044篇
  2009年   36952篇
  2008年   64105篇
  2007年   68227篇
  2006年   68711篇
  2005年   67330篇
  2004年   64739篇
  2003年   62446篇
  2002年   60884篇
  2001年   104089篇
  2000年   106689篇
  1999年   89962篇
  1998年   23606篇
  1997年   21042篇
  1996年   21217篇
  1995年   19745篇
  1994年   18367篇
  1993年   17088篇
  1992年   68958篇
  1991年   67029篇
  1990年   65026篇
  1989年   63183篇
  1988年   58163篇
  1987年   56767篇
  1986年   53615篇
  1985年   50788篇
  1984年   37705篇
  1983年   32475篇
  1982年   18410篇
  1981年   16395篇
  1979年   35148篇
  1978年   24942篇
  1977年   21046篇
  1976年   18976篇
  1975年   20960篇
  1974年   25363篇
  1973年   24469篇
  1972年   23284篇
  1971年   21884篇
  1970年   20709篇
  1969年   19591篇
  1968年   18124篇
排序方式: 共有10000条查询结果,搜索用时 28 毫秒
91.
To examine the prevalence of Internet sex networking among men who have sex with men (MSM) in Hong Kong and risk behaviors associated with the behavior, a telephone survey of 15,230 Hong Kong Chinese men aged 18-60 was conducted. Of the 283 active MSM (having engaged in some MSM behaviors in the last 6 months) identified, 17.7% had networked for MSM partners via the Internet in the last 6 months. Younger age (odds ratio [OR] for age < or = 25 vs. age >25 = 4.67, 95% confidence interval [CI] = 2.35-9.28) and being an anal-sex MSM (OR = 4.72, 95% CI=2.36-9.44) were independent predictors of Internet sex networking. Being an Internet sex networker was associated with some risk behaviors such as having contracted a sexually transmitted disease (adjusted OR = 4.79, 95% CI = 1.34-17.11), having had > or = 3 MSM partners (adjusted OR = 4.74, 95% CI = 2.20-10.23), and having engaged in anal sex (adjusted OR = 3.95, 95% CI = 1.89-8.23). HIV prevention programs for MSM should thereby include Internet-based interventions.  相似文献   
92.
The incidence of asthma has been reported to be associated with obesity. An alternative analysis, of net change in prevalence, does not require exclusion of those with asthma at baseline. Follow-up data were obtained from 9,552 participants in the European Community Respiratory Health Survey and the Swiss cohort Study on Air Pollution and Lung Disease in Adults. Incidence of asthma was analysed by proportional hazards regression, and net changes in symptoms and asthma status by generalised estimating equations, by obesity group. Incidence and net change in ever having had asthma were greater in females than in males, and in participants who remained obese compared with those who were never obese (hazard ratio 2.00, 95% confidence interval 1.25-3.20; excess net change 2.8%, 0.4-5.3% per 10 yrs). The effect of being obese on net change in diagnosed asthma was greater in females than in males, but for net change in wheeze without a cold it was greater in males. The present results are consistent with asthma being more frequently diagnosed in females, especially obese females. These findings may help to explain the reports of a stronger association between asthma and obesity in females than in males.  相似文献   
93.
Atherosclerotic renal artery stenosis (ARAS) may cause hypertension, progressive renal failure, and recurrent pulmonary edema. It typically occurs in high risk patients with coexistent vascular disease elsewhere. Most patients with ARAS are likely to die from coronary heart disease or stroke before end-stage renal failure occurs. Recent controlled trials have shown that most patients undergoing angioplasty to treat renovascular hypertension still need antihypertensive agents 6 or 12 months after the procedure. Nevertheless, the number of antihypertensive agents required to control blood pressure adequately is lower following angioplasty than for medication alone. Trials assessing the value of revascularization for preserving renal function or preventing clinical events are only in the early recruitment phase. Revascularization should be undertaken in patients with ARAS and resistant hypertension or heart failure, and probably in those with rapidly deteriorating renal function or with an increase in plasma creatinine levels during angiotensin-converting enzyme inhibition. With or without revascularization, medical therapy using antihypertensive, hypolipidemic and antiplatelet agents is necessary in almost all cases.  相似文献   
94.
95.
96.
97.
Decreases in sex hormone levels with menopause may bring about a number of consequences in women's general health and sexual well-being, especially when levels decline suddenly and prematurely, as in surgical menopause. In addition to the well-established role of estrogens in preserving the biological basis of sexual response, there is emerging evidence that androgens are significant independent determinants affecting sexual desire, activity and satisfaction, as well as mood, energy and other components of women's health. Hypoactive sexual desire disorder (HSDD), a persistent absence of sexual fantasies or thoughts and/or desire for and receptivity to sexual activity that causes personal distress, is experienced by some postmenopausal women. Even though conventional hormone therapy with estrogens or estrogens and progestogens may be effective for vaginal atrophy, increasing vaginal lubrication and reducing dyspareunia, it has not been shown to consistently increase sexual desire or activity and many women with sexual dysfunction remain unresponsive. Several recent, large, phase III studies have shown that the addition of transdermal testosterone to conventional hormone therapy can be helpful in surgically menopausal women presenting with HSDD. After 24 weeks of treatment in these studies, testosterone-treated women experienced significantly greater increases in satisfying sexual activity and sexual desire, and greater decreases in distress, than placebo-treated women. Accurate clinical assessment and individualized management of sexual symptoms are fundamentally important for all menopausal women with HSDD or other sexual problems.  相似文献   
98.
We report a case of a prepubertal girl with juvenile primary hypothyroidism presenting as ovarian cysts and precocious puberty. The 7-year-old female was referred to our clinic because of a pelvic/abdominal mass and vaginal bleeding. Besides these findings, on physical examination we noticed the thyroid gland globally increased and the presence of secondary sexual characteristics. Based upon the clinical profile and investigations, the patient was diagnosed with juvenile primary hypothyroidism due to autoimmune thyroiditis. The cysts and precocious puberty resolved spontaneously after the simple replacement of thyroid hormone. It is important to bear in mind hypothyroidism in cases of girls presenting ovarian cysts and precocious puberty in order to avoid unnecessary surgery on the ovaries.  相似文献   
99.
AIM: To compare the effects of 17beta-estradiol given intranasally (intranasal E2) and raloxifene on serum lipid profile and fibrinogen in hypercholesterolemic postmenopausal women. METHODS: The study population consisted of 46 women after menopause. The placebo group (n = 11) was given calcium, while the intervention groups were given intranasal E2 (Aerodiol; Servier, Chambray-les-Tours, France) (n = 16) or raloxifene (Evista; Lilly SA, Madrid, Spain) (n = 19). Blood lipids and fibrinogen were compared between groups at baseline and after 3 months of treatment. RESULTS: The group receiving intranasal E2 showed a significant decrease in triglyceride levels (p<0.05) and a marked increase in high-density lipoprotein cholesterol levels (p<0.05). No changes in lipid profile were observed in the raloxifene and placebo groups. Raloxifene caused a significant decrease in fibrinogen levels (p<0.05). CONCLUSION: Intranasal E2 exerts significant effects on lipid profile in hypercholesterolemic postmenopausal women. Raloxifene has a greater impact on fibrinogen than intranasal E2 application.  相似文献   
100.
Rehabilitative and palliative measures in the follow-up care of pancreatic cancer patients will remain the dominant medical focus as long as potentially curative measures (recurrence prophylaxis, early detection and therapy of recurrence) have failed to show a significant survival benefit. Rehabilitative measures are possible for patients undergoing potentially curative as well as palliative treatment. Their aim is to alleviate the negative effects of the cancer and its therapy, not only physically, but also psychologically, socially and vocationally. The spectrum of possible somatic handicaps ranges from metabolic disorders, malnutrition and under-nutrition, as well as gastrointestinal symptoms to pain. Assistance in coping with illness, alleviating fears and depression and strengthening compliance are the main areas which are dealt with in psycho-oncology. Assessment of vocational fitness and the capacity to work depends on tumor location, whether R0 or R1 resection has taken place, the extent of pancreas resection, accompanying illnesses, whether or not adjuvant therapy has been given, and the physical condition of the patient  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