全文获取类型
收费全文 | 2327篇 |
免费 | 91篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 95篇 |
妇产科学 | 20篇 |
基础医学 | 434篇 |
口腔科学 | 78篇 |
临床医学 | 270篇 |
内科学 | 514篇 |
皮肤病学 | 121篇 |
神经病学 | 49篇 |
特种医学 | 268篇 |
外科学 | 181篇 |
综合类 | 52篇 |
预防医学 | 153篇 |
眼科学 | 25篇 |
药学 | 135篇 |
中国医学 | 1篇 |
肿瘤学 | 47篇 |
出版年
2016年 | 24篇 |
2015年 | 29篇 |
2014年 | 28篇 |
2013年 | 85篇 |
2012年 | 37篇 |
2011年 | 38篇 |
2010年 | 51篇 |
2009年 | 46篇 |
2008年 | 36篇 |
2007年 | 50篇 |
2006年 | 52篇 |
2005年 | 32篇 |
2004年 | 21篇 |
2003年 | 26篇 |
2001年 | 32篇 |
2000年 | 22篇 |
1999年 | 39篇 |
1998年 | 81篇 |
1997年 | 94篇 |
1996年 | 105篇 |
1995年 | 70篇 |
1994年 | 73篇 |
1993年 | 76篇 |
1992年 | 42篇 |
1991年 | 39篇 |
1990年 | 44篇 |
1989年 | 71篇 |
1988年 | 60篇 |
1987年 | 48篇 |
1986年 | 51篇 |
1985年 | 38篇 |
1984年 | 55篇 |
1983年 | 27篇 |
1982年 | 31篇 |
1981年 | 37篇 |
1980年 | 49篇 |
1979年 | 23篇 |
1978年 | 27篇 |
1977年 | 35篇 |
1976年 | 38篇 |
1975年 | 36篇 |
1972年 | 24篇 |
1971年 | 21篇 |
1970年 | 23篇 |
1965年 | 50篇 |
1964年 | 50篇 |
1963年 | 47篇 |
1962年 | 41篇 |
1961年 | 40篇 |
1960年 | 65篇 |
排序方式: 共有2448条查询结果,搜索用时 31 毫秒
41.
42.
43.
de Wind Astrid van der Beek Allard J. Boezeman Edwin J. Swenneker Rosalie Anema Johannes R. de Boer Angela G. E. M. Beckerman Heleen Hoving Jan L. Nieuwenhuijsen Karen Scharn Micky Stam Mariska Terwee Caroline B. Frings-Dresen Monique H. W. Tamminga Sietske J. 《Quality of life research》2019,28(8):2233-2246
Quality of Life Research - The purpose of this study was to improve the measurement of participation. Research questions were as follows: (1) What constitutes participation according to adults? (2)... 相似文献
44.
45.
Diffuse large cell lymphoma in a patient with hairy cell leukemia: immunoglobulin gene analysis reveals separate clonal origins 总被引:1,自引:0,他引:1
A 75-year-old man with hairy cell leukemia (HCL) was found to have an immunoblastic lymphoma of the small bowel. Immunologic and genotypic characterization of these neoplasms revealed both the HCL and the immunoblastic lymphoma to be of the B cell lineage. The HCL expressed the HCL-associated antigens detected by the monoclonal antibodies HC-1 and HC-2, whereas the immunoblastic lymphoma failed to react with these antibodies. In addition, surface immunoglobulin light chains could not be accurately determined for the hairy cells, whereas the immunoblastic lymphoma was shown to express only kappa immunoglobulin light chains. These immunophenotype differences were compatible with either the clonal evolution of the HCL into the immunoblastic lymphoma or a separate clonal origin for these two neoplasms. An analysis of tumor DNA by Southern blot hybridization revealed different heavy-chain and kappa light-chain gene rearrangements in these two malignancies. Thus the occurrence of the large cell lymphoma most likely represents the emergence of a second clonally unrelated B cell malignancy. 相似文献
46.
JohnE. WoodsWilliamJ. Johnson CarlF. AndersonFrankJ. Leary PasqualeJ. PalumboPeterP. Frohnert JamesV. Donadio JR.JamesH. Deweerd 《Lancet》1972
Experience with renal transplantation in eight patients with overt diabetes mellitus suggests that renal transplantation from living related donors is not contraindicated as treatment for end-stage nephropathy. 相似文献
47.
Intestinal Mucosal Mechanisms Controlling Iron Absorption 总被引:13,自引:1,他引:13
Radioautographic studies provide evidence to support a concept of themechanism whereby the small intestine controls absorption of iron. Threedifferent states of the bodys iron stores have been considered in this regard:iron excess, iron deficiency and normal iron repletion. As the columnarepithelial cells of the duodenal villi are formed they incorporate a portion ofintrinsic iron from the bodys iron store, the amount depending upon thebodys requirement for new iron. It is predicated that with iron excess theiron-receptor mechanism in these cells is saturated with intrinsic iron; thisthen prevents the cell from accepting dietary iron. In the normal state ofiron repletion the receptor mechanism remains partly unsaturated, allowingsmall amounts of dietary iron to enter the cell. Part of this proceeds into thebody to satisfy any metabolic requirement for iron. Part is retained in themucosal epithelial cells to complete the saturation of the iron-receptormechanism. This bound iron is subsequently lost when the epithelial cellsare sloughed at the end of their life cycle. In iron deficiency it is postulatedthat the receptor system is inactive or diminished so that entry of dietary ironinto the body is relatively uninhibited. Submitted on February 12, 1963 Accepted on April 3, 1963 相似文献
48.
Megakaryocyte Maturation Rate in Thrombocytopenic Rats 总被引:3,自引:0,他引:3
49.
Pedro Magalh?es Edgar JR Sanhangala Isildro M Dombele Henrique SN Ulundo Daniel P Capingana Amílcar BT Silva 《Cardiovascular journal of Africa》2015,26(2):57-62
High salt (sodium chloride) consumption is an important determinant of high blood pressure and cardiovascular risk. According to World Health Organisation (WHO) statistics, over 80% of cardiovascular disease (CVD) deaths take place in low-and middle-income countries, and elevated blood pressure levels were a major cause of these CVD deaths in those countries.1 Lifestyle factors such as unhealthy diet, physical inactivity, tobacco use and harmful use of alcohol have been considered the most important behavioural risk factors for heart disease and stroke.2Among dietary factors, high salt intake has been the most strongly associated with raised blood pressure and increased risk of stroke and CVD.3 Therefore dietary sodium restriction has been recommended as a non-pharmacological approach to blood pressure lowering,4-6 and for the prevention and control of non-communicable diseases at the population level.7,8Cumulative evidence has shown that even a modest reduction in salt intake was associated with blood pressure lowering and therefore with a significant reduction in incidence of cardiovascular events.9-12 Furthermore, data from the most recent systematic review and meta-analyses has shown the benefit of lowering sodium intake in apparently healthy adults and children,13 and in both hypertensive and normotensive individuals, irrespective of gender and ethnic group.9Since hypertension is associated with CVD worldwide, a public health intervention to reduce high blood pressure must target the role of lifestyle, particularly reduced sodium intake.7 Therefore, several countries have initiated strategies to reduce dietary salt intake in the general population by a combination of various procedures such as public education, food labelling, and collaboration with the food industry to reduce the salt content of processed food.14Among sub-Saharan African countries, only Nigeria and South Africa have developed dietary guidelines regarding salt intake.15 Recently, the South African government implemented important specific legislation towards decreasing salt intake in the population by reducing sodium content of processed foods by industries.16 Therefore, the current public health recommendation is that countries should launch national initiatives to reduce the over-consumption of salt as part of non-communicable disease prevention and healthy nutrition policies for limiting salt intake to less than 5 g/day for the general population including children.7 Despite of this guideline, however, high sodium intake remains prevalent around the world, with average daily salt intake varying from 5 to 18 g/day per person.17Although processed foods have been found to be the principal source of excessive dietary salt intake,18 sources of dietary sodium vary largely worldwide and may be influenced by cultural context and dietary habits of the population.19 In sub-Saharan African countries experiencing demographic and epidemiological transition, the rapid rise in prevalence of CVD (chiefly hypertension) has been attributed to lifestyle change, including high dietary sodium intake.20,21 However, consistent data from studies on risk factors are lacking for the majority of these countries.With regard to Angola, available data from a cross-sectional study reported a high prevalence of multiple cardiovascular risk factors, such as hypertension, sedentary lifestyle, electrocardiographic left ventricular hypertrophy,22 and high rate of the metabolic syndrome23 in an apparently healthy middle-aged population of university public employees living in urban and peri-urban areas.Determining the level of sodium intake in the population is crucial to establish intervention strategies and policy on reduction of sodium intake. For medical students in particular, it is very important to assess their awareness regarding dietary salt intake, since they are the future providers of healthcare information for the counselling of people about the need to reduce salt consumption. The aim of this study was to determine salt intake and to assess the knowledge, attitude and behaviour regarding dietary salt among medical students. 相似文献
50.
Diagnostic Specificity of Sucrose Hemolysis Test for Paroxysmal Nocturnal Hemoglobinuria 总被引:3,自引:0,他引:3
The diagnostic specificity of the various modifications of the sucrose hemolysis test for PNH was examined in detail. In whole blood screening tests thegreatest specificity was achieved using citrated or oxalated blood and roomtemperature incubation (23°). Defibrinated whole blood should not be usedsince "false positive" hemolysis may occur in blood disorders other than PNH.Mechanisms were suggested for this phenomenon. The validity of the confirmatory sucrose hemolysis test employing normal serum was further reported.Because of the clear, colorless character of serum-sucrose mixtures, an insignificant degree of hemolysis (i.e., less than 5%) is more readily visible thanin other PNH hemolytic tests employing undiluted serum. Definitive instructions and criteria for interpretation were given for both the whole bloodscreening test and the confirmatory sucrose hemolysis test. Submitted on June 18, 1969 Accepted on December 8, 1969 相似文献