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   1086781篇
  免费   102066篇
  国内免费   3576篇
耳鼻咽喉   15234篇
儿科学   36853篇
妇产科学   30607篇
基础医学   147342篇
口腔科学   32510篇
临床医学   114656篇
内科学   215833篇
皮肤病学   26026篇
神经病学   90405篇
特种医学   41526篇
外国民族医学   305篇
外科学   165584篇
综合类   23867篇
现状与发展   40篇
一般理论   386篇
预防医学   90035篇
眼科学   24659篇
药学   72788篇
  14篇
中国医学   2040篇
肿瘤学   61713篇
  2021年   9383篇
  2020年   9322篇
  2019年   9026篇
  2018年   16784篇
  2017年   14958篇
  2016年   16611篇
  2015年   17886篇
  2014年   23930篇
  2013年   33061篇
  2012年   32211篇
  2011年   33840篇
  2010年   24684篇
  2009年   25748篇
  2008年   31779篇
  2007年   32480篇
  2006年   34038篇
  2005年   31407篇
  2004年   30140篇
  2003年   28733篇
  2002年   27665篇
  2001年   48645篇
  2000年   49090篇
  1999年   41833篇
  1998年   13081篇
  1997年   11851篇
  1996年   11952篇
  1995年   11318篇
  1994年   10068篇
  1993年   9341篇
  1992年   32948篇
  1991年   32049篇
  1990年   31515篇
  1989年   30383篇
  1988年   27655篇
  1987年   27689篇
  1986年   25780篇
  1985年   24896篇
  1984年   18636篇
  1983年   15801篇
  1982年   9494篇
  1979年   16927篇
  1978年   12348篇
  1977年   10431篇
  1976年   9855篇
  1975年   10251篇
  1974年   12390篇
  1973年   11912篇
  1972年   10967篇
  1971年   10169篇
  1970年   9440篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
The epidemiologic correlation of chronic dietary salt intake among populations with the prevalence of hypertension has resulted in the concept that sodium plays an etiologic role in the development of essential hypertension (EH). However, the association of sodium intake with blood pressure in individuals within populations has been difficult to demonstrate. The differing human responses to sodium intake are dependent upon the individual level of sodium sensitivity or sodium resistance. Factors associated with sodium sensitivity are race, age, and other dietary factors. More recent investigations have pursued the interaction of sodium intake with other physiologic parameters including neurogenic activity, vascular structure, renal function, and other cations such as potassium and calcium. The observations that some humans demonstrate very little increase in blood pressure despite high levels of sodium intake supports the concept that a high sodium intake alone is not a single causal factor in hypertension. Sodium intake appears to interact with renal excretory capacity and vascular compliance. These varying physiologic functions must be delineated to characterize sodium sensitivity.  相似文献   
92.
In transmitting the body's weight, the ankle is subject to frequent static and dynamic injury due to concentrated stresses during standing and movement. The frequency of athletic ankle injuries ranges from 10 to 90 percent, with the highest rate occurring in basketball players. There is prolonged disability and recurrent instability for months to years for 25 to 40 per cent of these patients. Because most of this trauma is handled by primary care physicians, this review presents the mechanism of injury, relevant anatomy, physical examination, and appropriate therapeutic intervention in the acute and rehabilitative phases.  相似文献   
93.
Recurrent erosion   总被引:1,自引:0,他引:1  
  相似文献   
94.
Chorioretinal folds have been reported as a result of many intraocular and extraocular inflammatory processes or tumors. Visual loss is usually secondary to a combination of the underlying process and chorioretinal folds involving the macula. We report a patient who developed decreased vision, metamorphopsia, chorioretinal folds, and a lamellar macular hole secondary to global compression by a bone fragment. The chorioretinal folds regressed and his vision stabilized following surgical decompression. Chorioretinal folds and lamellar macular hold formation are previously unrecognized complications of reconstructive craniofacial surgery.  相似文献   
95.
Psychological Consequences of Food Restriction   总被引:1,自引:0,他引:1  
A review of the literature and research on food restriction indicates that inhibiting food intake has consequences that may not have been anticipated by those attempting such restriction. Starvation and self-imposed dieting appear to result in eating binges once food is available and in psychological manifestations such as preoccupation with food and eating, increased emotional responsiveness and dysphoria, and distractibility. Caution is thus advisable in counseling clients to restrict their eating and diet to lose weight, as the negative sequelae may outweigh the benefits of restraining one's eating. Instead, healthful, balanced eating without specific food restrictions should be recommended as a long-term strategy to avoid the perils of restrictive dieting. J Am Diet Assoc. 1996; 96:589-592.  相似文献   
96.
97.
Eighty-nine cases of chronic bronchitis were matched against167 asymptomatic controls from the glass bangle industry ofFirozabad. Factors of age, social status, smoking habit andduration of exposure were studied. Duration of exposure wasfound to be a factor contributing significantly to the causationof disease. Requests for reprints should be addressed to: Dr B. N. Gupta, Division of Epidemilogy, Industrial Toxicology Research Centre, Mahatma Gandhi Marg, Lucknow P.O. Box 80, 226001, India  相似文献   
98.
The composition of the clientele from an ophthalmological practitioner's office is described with special reference to the occurrence of glaucoma and disc haemorrhages (h in singular; hh in plural). This study could not be planned as an epidemiological survey and gives no clue to sensitivity or specificity of hh in glaucoma. During a period of about 10 years ending with 1986 there were 731 patients with h and/or glaucoma. When detected, 185 patients had h but no glaucoma, 33 had both h and glaucoma and 513 had glaucoma but no h. During the follow-up period hh were detected in 83 cases of glaucoma, and glaucoma developed in 27 cases with hh. The detection rate of hh among glaucoma was low but steady, indicating that hh may occur at any stage of the glaucoma process. This study shows no predilection for hh in cases with general hypertension or diabetes, nor is the frequency of hh among pseudoexfoliation cases significantly lower than among cases without this stigma.  相似文献   
99.
Isotretinoin (Accutane Capsules) is a synthetic vitamin A compound used for treatment of recalcitrant cystic acne. It has numerous ocular toxic side effects which include anterior segment inflammation, dry eye syndrome, contact lens intolerance, altered refraction, photosensitivity, and reduced night vision. Eye care practitioners should be aware of these potential side effects and be prepared to communicate with the prescribing physician if side effects present.  相似文献   
100.
Summary: This is the first report of the largest study of blood pressure measurement in pregnancy in a New Zealand population using standardized definitions and methodology. Over 3,800 women who delivered in an 8-month period in the Wellington region were included in the study. Blood pressure measurement and the presence of oedema and proteinuria were recorded from booking until delivery and in the puerperium. Only 2.7% of women were unable to be contacted after delivery for details on outcomes. The results established normal ranges for blood pressure throughout pregnancy. The data show that Mood pressure greater than 140/90 until 35 weeks' gestation is outside 2 standard deviations at all gestations and justifies using these measurements as the definition of hypertension in pregnancy. The fall in blood pressure in the 2nd trimester was less than 1 mm Ffg per week in both the systolic and diastolic pressures. This fall was smaller than previously recorded in other studies. Gestational hypertension was the commonest blood pressure abnormality occurring in 15.2% of the population. This represented 69% of the pregnant women with a hypertensive disorder. The overall incidence of both gestational hypertension and preeclampsia was 18.5% which is higher than reported in other parts of the world. In this study obesity was significantly associated with hypertensive disorders in pregnancy. An arm circumference of >33 cm, one of the measurements of obesity, was found in 6.8% of the study population. Even after the effect of arm circumference was taken into account, hypertensive disorders were also more common in Pacific Island women. Ankle oedema was significantly associated with the development of both gestational hypertension and preeclampsia but the incidence of oedema was noted in only 11.9% of the subjects.  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