全文获取类型
收费全文 | 2516295篇 |
免费 | 191903篇 |
国内免费 | 4848篇 |
专业分类
耳鼻咽喉 | 34143篇 |
儿科学 | 84063篇 |
妇产科学 | 70213篇 |
基础医学 | 360905篇 |
口腔科学 | 73025篇 |
临床医学 | 223947篇 |
内科学 | 490310篇 |
皮肤病学 | 56078篇 |
神经病学 | 204800篇 |
特种医学 | 97127篇 |
外国民族医学 | 822篇 |
外科学 | 374693篇 |
综合类 | 58523篇 |
现状与发展 | 3篇 |
一般理论 | 943篇 |
预防医学 | 199848篇 |
眼科学 | 57623篇 |
药学 | 186150篇 |
6篇 | |
中国医学 | 4980篇 |
肿瘤学 | 134844篇 |
出版年
2018年 | 28825篇 |
2017年 | 21789篇 |
2016年 | 23935篇 |
2015年 | 27285篇 |
2014年 | 36189篇 |
2013年 | 55698篇 |
2012年 | 77671篇 |
2011年 | 81462篇 |
2010年 | 47170篇 |
2009年 | 43512篇 |
2008年 | 76273篇 |
2007年 | 80684篇 |
2006年 | 80822篇 |
2005年 | 78482篇 |
2004年 | 76407篇 |
2003年 | 72796篇 |
2002年 | 70632篇 |
2001年 | 111213篇 |
2000年 | 114928篇 |
1999年 | 97233篇 |
1998年 | 26805篇 |
1997年 | 24333篇 |
1996年 | 24090篇 |
1995年 | 23474篇 |
1994年 | 21972篇 |
1993年 | 20675篇 |
1992年 | 79026篇 |
1991年 | 76954篇 |
1990年 | 75585篇 |
1989年 | 72817篇 |
1988年 | 67296篇 |
1987年 | 66779篇 |
1986年 | 63106篇 |
1985年 | 60951篇 |
1984年 | 45801篇 |
1983年 | 39213篇 |
1982年 | 23240篇 |
1981年 | 20844篇 |
1979年 | 43341篇 |
1978年 | 30542篇 |
1977年 | 25836篇 |
1976年 | 24267篇 |
1975年 | 25599篇 |
1974年 | 31349篇 |
1973年 | 30216篇 |
1972年 | 27742篇 |
1971年 | 26170篇 |
1970年 | 24133篇 |
1969年 | 22661篇 |
1968年 | 20816篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
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
992.
993.
B A Brockway 《Journal of the American Society of Echocardiography》1989,2(6):425-430
This article reviews the utility of noninvasive echocardiography in the detection of early cardiac transplant rejection before and after the use of cyclosporine. It addresses the use of Doppler and two-dimensional echocardiography in the routine cardiac evaluation of the heart-transplant patient, including the use of two-dimensional echocardiography in guiding the endomyocardial biopsy procedure. 相似文献
994.
995.
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
996.
A case is presented of severe pregnancy-induced hypertension that was complicated by oliguria and managed with the aid of a pulmonary artery catheter. This case illustrates that urinary diagnostic indices may be unreliable in predicting the etiology of oliguria. Although urinary diagnostic tests are advocated routinely as reliable in the nonobstetric literature, possible misinterpretation of these values in severe pre-eclampsia with oliguria may require confirmation with hemodynamic data obtained from a pulmonary artery catheter. 相似文献
997.
998.
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
999.
Bone and joint sepsis 总被引:1,自引:0,他引:1
1000.
R Vihko A Alanko V Isomaa A Kauppila 《Medical oncology and tumor pharmacotherapy》1986,3(3-4):197-210
The predictive value of female sex steroid, estrogen and progesterone, receptor (ER and PR, respectively) assays in breast, endometrial and ovarian cancer is reviewed with emphasis on comparative aspects of these malignant tumors in relation to their hormone dependency. The endocrine etiology of these three tumor types seems to be at least partly different, and so is the expression of these receptors in normal and malignant tissues of the breast, endometrium and ovary. There is a tendency for decreased receptor concentrations and disappearance of these receptors in association with advancement of these malignancies. There is also a decrease in the presence and concentrations of ER and PR in relation to loss of differentiation in breast and endometrial cancer. Receptor analyses have an established position in the selection of patients with advanced breast cancer for endocrine treatment, and they give promise of a similar application in endometrial cancer and in endometrioid cancer of the ovary. It is not clear whether the disease-free interval is related to the presence or concentrations of ER or PR as such in the tumor tissue. There is better survival in breast cancer patients with receptor-positive tumors, which might be due to a response to endocrine treatment. The same seems to be true for patients with endometrial cancer. Future progress in the application of female sex steroid receptor analyses in breast, endometrial and ovarian cancer needs additional controlled clinical trials and more highly developed receptor assays. 相似文献