全文获取类型
收费全文 | 1337429篇 |
免费 | 96014篇 |
国内免费 | 2936篇 |
专业分类
耳鼻咽喉 | 19729篇 |
儿科学 | 40261篇 |
妇产科学 | 38689篇 |
基础医学 | 187531篇 |
口腔科学 | 39883篇 |
临床医学 | 112849篇 |
内科学 | 263161篇 |
皮肤病学 | 30238篇 |
神经病学 | 106701篇 |
特种医学 | 53759篇 |
外国民族医学 | 435篇 |
外科学 | 208928篇 |
综合类 | 31066篇 |
现状与发展 | 6篇 |
一般理论 | 440篇 |
预防医学 | 92203篇 |
眼科学 | 31383篇 |
药学 | 100245篇 |
4篇 | |
中国医学 | 2994篇 |
肿瘤学 | 75874篇 |
出版年
2018年 | 11798篇 |
2015年 | 11936篇 |
2014年 | 16766篇 |
2013年 | 25346篇 |
2012年 | 33160篇 |
2011年 | 35031篇 |
2010年 | 20830篇 |
2009年 | 20317篇 |
2008年 | 33728篇 |
2007年 | 36840篇 |
2006年 | 37431篇 |
2005年 | 36148篇 |
2004年 | 35221篇 |
2003年 | 34218篇 |
2002年 | 33771篇 |
2001年 | 63727篇 |
2000年 | 65429篇 |
1999年 | 55465篇 |
1998年 | 14695篇 |
1997年 | 13488篇 |
1996年 | 12966篇 |
1995年 | 12243篇 |
1994年 | 11491篇 |
1992年 | 42820篇 |
1991年 | 41331篇 |
1990年 | 40596篇 |
1989年 | 39606篇 |
1988年 | 37001篇 |
1987年 | 36446篇 |
1986年 | 34924篇 |
1985年 | 33121篇 |
1984年 | 24837篇 |
1983年 | 21072篇 |
1982年 | 12676篇 |
1981年 | 11578篇 |
1980年 | 10781篇 |
1979年 | 23937篇 |
1978年 | 17083篇 |
1977年 | 14842篇 |
1976年 | 13398篇 |
1975年 | 15283篇 |
1974年 | 18085篇 |
1973年 | 17580篇 |
1972年 | 16829篇 |
1971年 | 15736篇 |
1970年 | 14923篇 |
1969年 | 14361篇 |
1968年 | 13466篇 |
1967年 | 12020篇 |
1966年 | 11263篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
Artificial dopamine agonists are widely employed for the treatment of idiopathic parkinsonism. Pleuropulmonary disease has previously been reported to occur with the use of bromocriptine and mesulergine. We report similar adverse effects induced by the newer agonists lisuride and cabergoline. All these agents are tetracyclic ergot derivatives. This suggests a causal link between ergot-derived dopamine agonists and pleuropulmonary disease. 相似文献
962.
Postencephalitic acquired Tourette-like syndrome in a child. 总被引:1,自引:0,他引:1
We report a 6-year-old girl who developed a Tourette-like syndrome following presumed herpes encephalitis. This case suggests that tics can be acquired in childhood and may be associated with lesions involving basal ganglia or limbic circuitry. 相似文献
963.
964.
Forty-two therapists conducting individual psychotherapy with schizophrenic outpatients in a public mental health system responded to a questionnaire that focused on the types of interventions used and the issues and problems encountered in therapy. The therapists spent 59 percent of their time in supportive, problem-solving work and only 32 percent in traditional psychotherapeutic interventions, such as providing insight. The most common issues in therapy were relationship problems, family concerns, depression, losses, and the role of medications in the client's life. The most significant impediments to therapeutic work were the lack of community resources, the client's noncompliance with medications and lack of motivation, and dual diagnoses. Suggestions are offered for improving psychotherapy with schizophrenic outpatients in the public mental health system. 相似文献
965.
966.
H Karppanen 《Annals of medicine》1991,23(3):299-305
The mineral elements sodium, potassium, calcium and magnesium play a central role in the normal regulation of blood pressure. In particular, these mineral elements have important interrelationships in the control of arterial resistance. These elements, especially sodium and potassium, also regulate the fluid balance of the body and, hence, influence the cardiac output. Evidence shows that the present levels of intake of mineral elements are not optimum for maintaining normal blood pressure but predispose to the development of arterial hypertension. Research results suggest that without sodium chloride (common salt) and other sodium compounds being added to the diet arterial hypertension would be virtually non existent. Moreover, blood pressure would not rise with age. In communities with a high consumption of added sodium, a high intake of potassium and, possibly, magnesium seem to protect against the development of arterial hypertension and the rise of blood pressure with age. A marked reduction of sodium intake is effective in treating even severe hypertension. A moderate restriction of sodium intake or an increase in potassium intake exert remarkable antihypertensive effects, at least in some hypertensive patients. Magnesium and possibly also calcium supplements may be effective in reducing blood pressure in some hypertensives. In hypertensive patients treated with drugs sodium restriction and potassium and magnesium supplementation enhance the therapeutic effect, reduce the number and dosage, and lessen the adverse effects of prescribed antihypertensive drugs. Hence, a fall in sodium consumption and increases in potassium and magnesium consumption are useful in preventing and treating arterial hypertension. 相似文献
967.
BACKGROUND. Studies have documented the potential contributions of preventive health care programs. Yet little is known about which screening tests should be included in public health programs for older persons. This study offers recommendations regarding these tests. METHODS. The recommendations come from synthesizing the findings of the US Preventive Services Task Force, the literature, and the consensus of experts in geriatrics, gerontology, and health policy research. The literature was evaluated to identify methodologically sound studies of the prevalence of selected disorders and benefits and availability of screening procedures for those disorders. Experts from various fields specializing in the care of the elderly formed panels to assist in evaluating the literature and providing further information from gerontological and public health perspectives. RESULTS. We recommend vision testing for refractive error; inspection of the skin surface for fungal infection and skin cancer, drug eruptions, and xerosis; a history for symptoms of xerosis; audiometric testing for presbycusis; surveys for hearing loss; otoscopic inspection for cerumen impaction; dental examination for caries; measurement of blood pressure for hypertension; and breast examination and mammography for cancer. CONCLUSIONS. Our study suggests that these screening procedures are useful for public health screening programs. More information is needed on the effects of screening services on the health and functioning of older persons. 相似文献
968.
Involving patients in do not resuscitate (DNR) decisions: an old issue raising its ugly head.
下载免费PDF全文
![点击此处可从《Journal of medical ethics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
E H Loewy 《Journal of medical ethics》1991,17(3):156-160
A recent paper in this journal (1) suggests that involving terminally ill patients in choices concerned with Cardio-Pulmonary Resuscitation (CPR) produces 'psychological pain' and therefore is ill-advised. Such a claim rests on anecdotal observations made by the authors. In this paper I suggest that drawing conclusions in ethics, no less than in science, requires a rigorous framework and cannot be relegated to personal observation of a few cases. The paper concludes by suggesting that patients, if we acknowledge their valid interest in making their own choices, must themselves be allowed to make a prior choice about choosing. Those who may not wish to choose may properly be relieved of this burden and may allow another to choose for them. Routinely allowing others to make choices for competent adults, however, is likely to decrease communication with the dying patient and to introduce an atmosphere of suspicion and fear and to exclude the competent patient from his/her rightful place in the community. 相似文献
969.
Two boys born in September 1949 played on uranium mill tailings from about ages 8 to 12. One of these boys was diagnosed as having leukemia at age 15.5. The 226Ra body burden of the survivor was measured at age 38. The whole-body 226Ra content measured by counting in vivo was 0 +/- 17 Bq and independently by Rn breath analysis as 4.3 +/- 2.1 Bq. At the same time, a control subject with no known exposure to 226Ra, matched in age, height, and weight, was also measured. The whole-body content was estimated as 4 +/- 15 Bq and independently by Rn breath analysis as 5.5 +/- 3.7 Bq. The body burden of the control subject was not significantly different from that of the exposed person. The radiation dose to the marrow-free skeleton assuming a constant 226Ra:Ca ratio since birth was 0.49 and 1.33 mGy at ages 14 and 38, respectively. The radiation dose to the marrow-free skeleton assuming 226Ra intake only between ages 8 to 12 was 1.4 and 2.8 mGy at ages 14 and 38, respectively. The best estimate is the mean of these two estimates: 0.9 and 2.1 mGy at ages 14 and 38, respectively. The alpha-particle dose to the red marrow from 226Ra and its decay products was 0.05 mGy at age 14 and 0.10 mGy at age 38. Since no excess was found for the radium dial painters whose doses were much higher, the induction of leukemia by doses of this magnitude would seem quite unlikely. 相似文献
970.
Accumulation of 64Cu in the 14-d mouse fetus was measured following intravenous injection of the dam with 64CuHis2. Concentration of 64Cu in the placenta increased rapidly over the first 4 h, thereafter remaining constant. Transfer to the fetus was linear over 48 h with little evidence of storage in the liver. Maternal serum levels decreased initially, concurrently with increased 64Cu levels in the maternal liver, but did not subsequently increase. Immediately following injection, as much as 40% of the radioactivity was in the nonalbumin fraction, and approximately 37% of that fraction (18% of total) was greater than 30,000 molecular weight. After 24 h, up to 60% of the 64Cu was still found in the albumin peak. The data suggest that the fetus can obtain its Cu from maternal ceruloplasmin but does not exclude the possibility that transfer occurs from the exchangeable (albumin/amino acid) Cu pool of the maternal plasma. In a second experiment, mice at different stages of gestation were injected with 64Cu and killed 4 h later. Total Cu levels and 64Cu uptake into the maternal tissues or into the placenta did not change with increasing gestation. Both total Cu and 64Cu uptake in the fetus and fetal liver increased to a maximum on d 16. Levels in the liver decreased thereafter to term, whereas levels in the rest of the fetus remained approximately constant. The pattern was similar whether the results were expressed per organ or per gram of fresh weight.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献