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   2270991篇
  免费   174841篇
  国内免费   4090篇
耳鼻咽喉   31749篇
儿科学   74973篇
妇产科学   64732篇
基础医学   322035篇
口腔科学   65710篇
临床医学   197619篇
内科学   445739篇
皮肤病学   48542篇
神经病学   183234篇
特种医学   90954篇
外国民族医学   767篇
外科学   348438篇
综合类   54455篇
现状与发展   3篇
一般理论   768篇
预防医学   173209篇
眼科学   52595篇
药学   168834篇
  3篇
中国医学   4291篇
肿瘤学   121272篇
  2018年   21552篇
  2016年   18691篇
  2015年   21537篇
  2014年   30013篇
  2013年   46157篇
  2012年   62183篇
  2011年   65719篇
  2010年   39087篇
  2009年   37431篇
  2008年   62935篇
  2007年   66579篇
  2006年   67462篇
  2005年   65685篇
  2004年   64328篇
  2003年   61662篇
  2002年   60557篇
  2001年   104147篇
  2000年   107716篇
  1999年   91540篇
  1998年   25230篇
  1997年   23052篇
  1996年   22864篇
  1995年   22043篇
  1994年   20757篇
  1993年   19683篇
  1992年   74849篇
  1991年   72464篇
  1990年   70844篇
  1989年   68626篇
  1988年   63754篇
  1987年   62876篇
  1986年   60066篇
  1985年   57730篇
  1984年   43344篇
  1983年   37106篇
  1982年   21998篇
  1981年   19518篇
  1980年   18444篇
  1979年   40876篇
  1978年   28533篇
  1977年   24007篇
  1976年   22665篇
  1975年   24305篇
  1974年   29542篇
  1973年   28404篇
  1972年   26275篇
  1971年   24611篇
  1970年   22954篇
  1969年   21522篇
  1968年   20000篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
We examined several possible causes for the high incidence of poor sensory acuity in the limbs of 176 patients with moderate to severe peripheral vascular insufficiency. We investigated the relationships of diabetes, alcoholism, and smoking, as well as the severity of peripheral vascular disease, to the integrity of basic sensory modalities such as two-point discrimination and perception of light touch. The presence or absence of diabetes exerted the strongest effect on peripheral sensation. In patients who did not have diabetes, sensation in the limbs was most strongly affected by whether the patient was an alcoholic. Smoking did not have a significant effect on limb sensation. Among nondiabetic, nonalcoholic patients, there was a weak residual effect related to the severity of the peripheral vascular insufficiency. Even among these patients, however, systemic factors predominated in determining the loss of sensation. We also examined the extent to which loss of sensation might be related to the development of ulcers. Among patients who were not diabetic, there was a highly significant relationship between loss of sensation and the presence of limb ulceration. Surprisingly, however, there was no discernable relationship between the presence of ulcers in diabetic patients and the degree of loss of peripheral sensation. This result suggests that a large percentage of ulcers seen in diabetic patients are not of neurogenic origin.  相似文献   
994.
995.
Survey involved 84 workers matched for age, socio-occupational and families status and divided into 3 groups : A : 27 shift workers on 3 days rotating shift, B : 47 shift workers on 5 days rotating shift, C : 20 days workers. Each subject was submitted to dietary survey by means of 24 hours recall, realised 3 times for shift workers and once for control. All workers were interviewed about caloric intake of the preceding day off caloric intake. Annual weight gain was studied through the use of occupational health service records. There was no significant difference between the 3 groups for working day caloric intake. Day-off intake was lower (p less than 0.05) in group A (day-off any day of the week). Annual weight gain was not different between the 3 groups. Shift workers with faster weight gain had a higher caloric intake on day-off and after evening meal.  相似文献   
996.
Obsessive-compulsive disorder is increasingly recognized in patients of different age groups. Serotonergic agents, such as clomipramine, have been recently found to be useful in the management of this condition. However, unexpected side effects, such as dysphoria, aggressiveness, and paranoid ideation, may occur with therapeutic doses of this compound, as evidenced in the cases of two male adolescents presented here. Possible pathogenetic factors, involving serotonin and serotonin-receptor abnormalities are discussed. Management of these side effects is based on adequate dose reduction and monitorization.  相似文献   
997.
It is estimated that there are currently 10 million women in the United States who are taking oral contraceptives on a daily basis. Although the actual number is not known, it is also estimated that a large number of these same women are on concomitant drug therapy. In recent years, there has been a number of published reports linking a loss of contraceptive efficacy with the concurrent administration of other drugs, including antibiotics. Because of the common practice of prescribing antibiotics in dentistry, oral healthcare providers should be aware of the possibility of oral contraceptive failure with antibiotic treatment. Since it is often the dental hygienist who interviews patients and assists them in completing their health questionnaire, she or he can play an important role in educating and counseling these patients in possible drug interactions. This article reviews the published incidence of oral contraceptive/antibiotic interaction, along with a discussion of the possible mechanisms by which this interaction occurs. Recommendations are also presented for the oral health management of women taking oral contraceptives and other prescribed drugs.  相似文献   
998.
Coexistent primary hyperparathyroidism and monoclonal gammopathy, although rare, has been reported previously by a number of investigators. We report four patients with such an occurrence who were seen between 1976 and 1988. Another patient with primary hyperparathyroidism also had multiple myeloma and was in remission for 12 years. These patients represent approximately 1% of the 386 patients with primary hyperparathyroidism seen during the same 12-year period. Although several mechanisms have been proposed to explain this concurrence, we believe it is the result of a chance occurrence. A review of the literature, an estimate of the chance occurrence of coincidental monoclonal gammopathy, benign or malignant, in patients with primary hyperparathyroidism, and some practical implications of this interesting coexistence are presented.  相似文献   
999.
Encephalo-myelo-radiculo-ganglionitis presenting as pandysautonomia   总被引:2,自引:0,他引:2  
A 68-year-old man developed pandysautonomia with severe orthostatic dysfunction, fixed heart rate, low serum levels of norepinephrine and epinephrine, absent sympathetic skin responses, and pupillary abnormalities. CSF protein was 92 mg/dl. In spite of a good recovery following corticosteroid administration, a relapse occurred, with accompanying sensory symptoms confined to both arms. Fatal sudden cardiac arrest occurred after 4 months. Autopsy revealed numerous lymphocytic infiltrates, predominantly in autonomic and sensory ganglia and, to a lesser extent, in the nerve roots, spinal cord, and brainstem without evidence for an underlying tumor. This case provides histopathologic evidence for an inflammatory etiology of panautonomic neuropathy in some patients.  相似文献   
1000.
We conducted a randomized, double-blind, crossover trial of two anticholinergic agents--trihexyphenidyl and tridihexethyl chloride (a quaternary anticholinergic that does not cross the blood-brain barrier)--in patients with acquired nystagmus and measured visual acuity and nystagmus before and at the end of 1 month on each medication. Of the 10 patients admitted to the study, only five completed trials of both drugs due to intolerance of medication or intercurrent illness. Of six patients who completed the trial of trihexyphenidyl, only one showed improvement. Of six patients who completed a trial of tridihexethyl chloride, four showed improvement. We conclude that (1) trihexyphenidyl is not a reliable treatment for acquired nystagmus, although occasional patients may benefit; (2) anticholinergic agents may suppress nystagmus by peripheral rather than central mechanisms; and (3) the side effects of anticholinergic agents limit their effectiveness in the treatment of nystagmus.  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