全文获取类型
收费全文 | 2375285篇 |
免费 | 195077篇 |
国内免费 | 4220篇 |
专业分类
耳鼻咽喉 | 34293篇 |
儿科学 | 72761篇 |
妇产科学 | 62948篇 |
基础医学 | 334924篇 |
口腔科学 | 67562篇 |
临床医学 | 215612篇 |
内科学 | 468637篇 |
皮肤病学 | 47935篇 |
神经病学 | 200824篇 |
特种医学 | 95978篇 |
外国民族医学 | 887篇 |
外科学 | 360485篇 |
综合类 | 56234篇 |
现状与发展 | 1篇 |
一般理论 | 977篇 |
预防医学 | 190718篇 |
眼科学 | 55482篇 |
药学 | 177567篇 |
4篇 | |
中国医学 | 4367篇 |
肿瘤学 | 126386篇 |
出版年
2018年 | 24221篇 |
2016年 | 20584篇 |
2015年 | 23294篇 |
2014年 | 33554篇 |
2013年 | 50857篇 |
2012年 | 68767篇 |
2011年 | 72317篇 |
2010年 | 42492篇 |
2009年 | 40883篇 |
2008年 | 68793篇 |
2007年 | 73132篇 |
2006年 | 74021篇 |
2005年 | 72067篇 |
2004年 | 69357篇 |
2003年 | 67034篇 |
2002年 | 66284篇 |
2001年 | 112465篇 |
2000年 | 116538篇 |
1999年 | 98343篇 |
1998年 | 27865篇 |
1997年 | 25529篇 |
1996年 | 25450篇 |
1995年 | 24613篇 |
1994年 | 23162篇 |
1993年 | 21557篇 |
1992年 | 79393篇 |
1991年 | 76410篇 |
1990年 | 73588篇 |
1989年 | 70855篇 |
1988年 | 65868篇 |
1987年 | 64816篇 |
1986年 | 61338篇 |
1985年 | 58409篇 |
1984年 | 44229篇 |
1983年 | 37667篇 |
1982年 | 22895篇 |
1981年 | 20338篇 |
1980年 | 19037篇 |
1979年 | 41307篇 |
1978年 | 28989篇 |
1977年 | 24348篇 |
1976年 | 22838篇 |
1975年 | 23966篇 |
1974年 | 29641篇 |
1973年 | 28043篇 |
1972年 | 26229篇 |
1971年 | 24153篇 |
1970年 | 22755篇 |
1969年 | 21088篇 |
1968年 | 19136篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Evanescent arthralgias and myalgias are common early symptoms of Lyme disease. Transient, intermittent episodes of monoarticular, oligoarticular, or sometimes migratory polyarticular arthritis, lasting weeks to months, with disease-free intervals, are frequently observed in untreated patients with erythema chronicum migrans. A minority of patients develop chronic joint involvement, most commonly affecting the knee. Antibiotic therapy given during erythema chronicum migrans is often protective with regard to late joint manifestations. In chronic Lyme arthritis, however, the response to antibiotics is variable. 相似文献
993.
A Goldfarb J Weinreb W G Daniel I Kronzon 《Journal of the American Society of Echocardiography》1989,2(5):350-353
A patient who had right and left atrial membranes was examined. The diagnosis and the hemodynamic significance of both membranes were detailed by transesophageal echocardiography and were confirmed by magnetic resonance imaging. Transesophageal imaging was found to be superior to routine echocardiography in visualization of these atrial structures. 相似文献
994.
995.
A preliminary report of the short-term effect of carbonated beverage consumption on calcium metabolism in normal women 总被引:2,自引:0,他引:2
S Smith J Swain E M Brown G Wyshak T Albright V A Ravnikar I Schiff 《Archives of internal medicine》1989,149(11):2517-2519
A variety of nutritional factors influence the bioavailability of calcium and increase a woman's risk of osteoporosis. Eight healthy women completed an 8-week metabolic study designed to investigate the effect of nonalcoholic carbonated beverage consumption on calcium metabolism. Compared with women receiving a control diet, women consuming a diet high in nonalcoholic carbonated beverages demonstrated similar mean serum levels of calcium, ionized calcium, phosphorus, alkaline phosphatase, parathyroid hormone, 1,25-dihydroxyvitamin D3, and osteocalcin. Twenty-four-hour urine volume, creatinine clearance, calcium-creatinine ratio, and phosphorus-creatinine ratio were similar during consumption of the diet high in nonalcoholic carbonated beverages and the control diet. Twenty-four-hour cyclic adenosine monophosphate-creatinine ratio was significantly lower in women consuming the diet high in nonalcoholic carbonated beverage compared with women receiving the control diet (342 +/- 27.4 nmol/mmol vs 409 +/- 22.1 nmol/mmol). Consumption of a diet high in nonalcoholic carbonated beverages on a short-term basis does not appear to affect adversely the serum or urinary markers of calcium metabolism. 相似文献
996.
There is evidence that leukocyte contaminating red blood cells and platelet concentrates are responsible for refractoriness to platelet transfusions. The efficacy of a cotton-wool filter to remove leukocytes from red blood cells has been documented previously. The present study was designed to evaluate whether the cotton-wool filters can effectively remove leukocytes from platelet concentrates. Sixty pools of random-donor platelets and single-donor plateletpheresis products were filtered through a cotton-wool filter. The efficacy of filtration was determined by measuring the absolute numbers of leukocytes and platelets and subpopulations of mononuclear cells. The average platelet loss was 8% per pool of random platelets and 10% per plateletpheresis product. The average leukocyte removal was 99% from a pool of random platelets and plateletpheresis concentrates collected by CS-3000 and 90% from plateletpheresis concentrates harvested by single-stage COBE/IBM-2997. The filtration removed 100% of granulocytes, 95% of monocytes, 90% of B-lymphocytes, and 85% of T-lymphocytes. We conclude that filtration through a cotton-wool filter is an efficient and cost-effective method for preparation of leukocyte-poor platelets. 相似文献
997.
998.
The acute recognition and management of CHF is challenging. A basic understanding of the determinants of cardiac performance and myocardial O2 consumption along with the pathophysiology of CHF is essential knowledge for the physician undertaking to treat this serious disorder. The basic value of the patient history and physical examination along with assessment of noninvasive tests remains unquestioned, but in addition much relevant and sophisticated information can be gained by invasive hemodynamic monitoring. The cardiopulmonary profile generated by such monitoring allows the physician to use specific hemodynamic and circulatory data for the purpose of manipulating these variables favorably for the heart and circulation. A wide array of therapeutic options is currently available, but, in general, respiratory support and pharmacotherapy are the mainstays of treatment. The traditional agents like digitalis and diuretics have assumed a lesser role during the last decade because of the availability of potent new vasodilator and inotropic agents. In addition, certain mechanical, procedural, and surgical options can be used if circumstances are urgent. In the final analysis, physicians who manage these patients must possess strong cognitive skills but also the clinical reflexes to carry them out: for every hemodynamic and circulatory action, they must be prepared to counter quickly and decisively with a clinical reaction which utilizes these principles to optimize cardiac function. It is hoped that the strategies presented in this article will allow them to perform in such a manner. 相似文献
999.
S G Gundersen A Bjoerneklett J N Bruun 《Scandinavian journal of infectious diseases》1989,21(2):225-228
A 41-year-old woman had acute hepatitis A infection complicated with severe anemia due to selective erythroblastopenia and hemolysis. A mechanism involving a cellular immune reaction is suggested. The hematological complications resolved during steroid treatment. She later developed a transient seropositive arthritis. 相似文献
1000.
John P Elliott Hugh S Miller Suzanne Coleman Debbie Rhea Diana Abril Karen Hallbauer Niki B Istwan Gary J Stanziano 《Journal of perinatology》2005,25(10):626-630
OBJECTIVE: To assess the impact of activity restriction (AR) on the incidence of preterm birth in women treated for preterm labor testing negative for fetal fibronectin (fFN). STUDY DESIGN: Women who were diagnosed with preterm labor and tocolyzed with magnesium sulfate were concurrently screened with fFN for the purpose of subsequent management. Included were consenting patients with negative fFN, gestational age 23 0/7-33 6/7 weeks, cervical dilation < or =3 cm, and minimal vaginal bleeding. Patients were randomized to AR or no AR. Primary study outcome was incidence of preterm delivery and interval from randomization to delivery. RESULTS: A total of 73 women with negative fFN were randomized (36 with AR, 37 without AR). The overall preterm birth rate was 40%, with 44.4% of patients with AR and 35.1% of patients without AR delivering preterm, p=0.478. CONCLUSION: Maternal AR did not impact pregnancy outcome. The incidence of preterm birth in symptomatic women testing fFN negative was higher than previously reported. 相似文献