全文获取类型
收费全文 | 48154篇 |
免费 | 4912篇 |
国内免费 | 156篇 |
专业分类
耳鼻咽喉 | 457篇 |
儿科学 | 1264篇 |
妇产科学 | 1142篇 |
基础医学 | 7079篇 |
口腔科学 | 1082篇 |
临床医学 | 5957篇 |
内科学 | 8751篇 |
皮肤病学 | 587篇 |
神经病学 | 4523篇 |
特种医学 | 1948篇 |
外国民族医学 | 57篇 |
外科学 | 6106篇 |
综合类 | 1293篇 |
一般理论 | 43篇 |
预防医学 | 5344篇 |
眼科学 | 1159篇 |
药学 | 3647篇 |
3篇 | |
中国医学 | 123篇 |
肿瘤学 | 2657篇 |
出版年
2021年 | 692篇 |
2020年 | 446篇 |
2019年 | 663篇 |
2018年 | 730篇 |
2017年 | 584篇 |
2016年 | 630篇 |
2015年 | 680篇 |
2014年 | 1014篇 |
2013年 | 1580篇 |
2012年 | 2134篇 |
2011年 | 2166篇 |
2010年 | 1325篇 |
2009年 | 1166篇 |
2008年 | 2087篇 |
2007年 | 2081篇 |
2006年 | 2103篇 |
2005年 | 2001篇 |
2004年 | 1995篇 |
2003年 | 1747篇 |
2002年 | 1727篇 |
2001年 | 1533篇 |
2000年 | 1647篇 |
1999年 | 1394篇 |
1998年 | 617篇 |
1997年 | 551篇 |
1996年 | 511篇 |
1995年 | 508篇 |
1994年 | 473篇 |
1993年 | 427篇 |
1992年 | 1077篇 |
1991年 | 1128篇 |
1990年 | 1039篇 |
1989年 | 1022篇 |
1988年 | 1028篇 |
1987年 | 896篇 |
1986年 | 876篇 |
1985年 | 865篇 |
1984年 | 721篇 |
1983年 | 592篇 |
1982年 | 387篇 |
1981年 | 365篇 |
1980年 | 356篇 |
1979年 | 665篇 |
1978年 | 518篇 |
1977年 | 446篇 |
1976年 | 418篇 |
1975年 | 389篇 |
1974年 | 438篇 |
1973年 | 436篇 |
1972年 | 377篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
11.
12.
Esophageal foreign body causing direct aortic injury. 总被引:4,自引:0,他引:4
Foreign bodies in the esophagus are uncommon causes of esophageal perforation. Many nonperforating cases are successfully managed by flexible gastroscopy. However, complicated foreign bodies such as those that result in esophageal perforation and vascular injury are best managed surgically. Gastroscopy remains the primary method of diagnosis. A case of a 59-year-old woman who developed retrosternal and intrascapular pain, odynophagia and hematemesis after eating fish is reported. Flexible gastroscopy showed arterial bleeding from the midthoracic esophagus. Computed tomography scan localized a 3 cm fish bone perforating the esophagus with surrounding hematoma. An aortogram did not reveal an actively bleeding aortoesophageal fistula. The fish bone was surgically removed and the patient recovered with no postoperative complications. This case illustrates the importance of early consideration for surgical intervention when confronted with a brisk arterial bleed from the esophagus with suggestive history of foreign body ingestion. 相似文献
13.
P F Plouin D L Clement H Boccalon J Dormandy I Durand-Zaleski G Fowkes L Norgren T Brown 《International angiology》2003,22(4):333-339
Atherosclerotic renal artery stenosis (ARAS) may cause hypertension, progressive renal failure, and recurrent pulmonary edema. It typically occurs in high risk patients with coexistent vascular disease elsewhere. Most patients with ARAS are likely to die from coronary heart disease or stroke before end-stage renal failure occurs. Recent controlled trials have shown that most patients undergoing angioplasty to treat renovascular hypertension still need antihypertensive agents 6 or 12 months after the procedure. Nevertheless, the number of antihypertensive agents required to control blood pressure adequately is lower following angioplasty than for medication alone. Trials assessing the value of revascularization for preserving renal function or preventing clinical events are only in the early recruitment phase. Revascularization should be undertaken in patients with ARAS and resistant hypertension or heart failure, and probably in those with rapidly deteriorating renal function or with an increase in plasma creatinine levels during angiotensin-converting enzyme inhibition. With or without revascularization, medical therapy using antihypertensive, hypolipidemic and antiplatelet agents is necessary in almost all cases. 相似文献
14.
G. Kahlmeter D. F. J. Brown F. W. Goldstein A. P. MacGowan J. W. Mouton I. Odenholt A. Rodloff C-J. Soussy M. Steinbakk F. Soriano O. Stetsiouk 《Clinical microbiology and infection》2006,12(6):501-503
The main objectives of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) are to harmonise breakpoints for antimicrobial agents in Europe, and to act as the breakpoint committee for the European Medicines Agency (EMEA) during the registration of new antimicrobial agents. Detailed EUCAST procedures for harmonising and setting breakpoints for antimicrobial agents are available on the EUCAST website. Beginning with the current issue, a series of EUCAST Technical Notes will be published in CMI, based on the rationale documents produced by EUCAST for each of the antimicrobial agents studied, with the aim of highlighting important background information underlying decisions on breakpoints made by EUCAST. 相似文献
15.
16.
K Brown 《Environmental health perspectives》1996,104(3):276-278
17.
Although extracellular matrix (ECM) glycoproteins play important roles in neural development, their levels are generally believed to decrease in the adult brain. Immunohistochemical analysis indicates that the anti-adhesive ECM glycoprotein SPARC/osteonectin, which contains a follistatin ‘module’, is expressed in the adult rabbit nervous system. In the cerebellum, SPARC is present in Bergmann glia, with a strong signal along their radial fibres. SPARC, while enriched in membrane fractions, is not a transmembrane protein. In the hippocampus, colocalization of SPARC is observed in cells which express the astrocytic marker GFAP. The expression of SPARC by a subset of astrocytes, particularly in synaptic enriched areas, suggests a continuing role for the ECM in the adult brain. 相似文献
18.
Segregation analysis of leprosy in families of northern Thailand 总被引:4,自引:0,他引:4
Sixty-three families with multiple instances of leprosy were identified through a major leprosy treatment center in northern Thailand. Complex segregation analyses for single major genes or polygenic inheritance were performed using the maximum-likelihood routine POINTER to determine the most likely etiologic model of genetic susceptibility. Liability differences between men and women were considered in these models. When individuals were considered to be affected because they had any form of leprosy, a generalized major gene model with nearly dominant parameters on the liability scale, but additive penetrances, was found to be the most likely. When only those individuals who had tuberculoid forms of leprosy were considered to be affected, a recessive model was found to be the most likely; however, the discrimination between various models was poor. Further analyses are necessary to delineate genetic mechanisms to explain these apparently divergent results. In particular, methods of testing two locus models should be considered. 相似文献
19.
Reactive oxygen species and human spermatozoa: physiology and pathology 总被引:20,自引:1,他引:19
The role of reactive oxygen species (ROS) in the pathophysiology of human sperm function has been emphasized in recent years. ROS production in semen has been associated with loss of sperm motility, decreased capacity for sperm–oocyte fusion and loss of fertility. There is a current presumption that the most prolific source of ROS in sperm suspensions is an NADPH oxidase located in leukocytes or in spermatozoa which produces superoxide which is further converted to peroxide by the action of superoxide dismutase. Hydrogen peroxide has been recognized as the most toxic oxidizing species for human spermatozoa, which are very sensitive to lipid peroxidation owing to the high content of polyunsaturated fatty acids in their plasma membrane, though this is not the sole mechanism by which sperm function might be impaired by ROS. Although the excessive production of ROS is detrimental to human spermatozoa, there is a growing body of evidence which suggests that ROS are also involved in the physiological control of some sperm functions. This review focuses on the nature and source of the ROS generated by human spermataozoa as well as their operational mechanisms and their effects, which may be detrimental or beneficial. 相似文献
20.
Technetium-99-labelled methylene diphosphonate uptake scans in patients with dialysis arthropathy 总被引:1,自引:0,他引:1
Patients on long-term haemodialysis suffer from dialysis arthropathy due to the deposition of dialysis amyloid. We investigated the use of 99Tc-labelled methylene diphosphonate bone scans in 17 patients as a possible in vivo diagnostic technique. In most clinically affected joints, with the exception of shoulders and hands, there was increased radioisotope uptake consistent with uptake by periarticular bone. In addition, we describe intense soft-tissue uptake around some clinically affected large joints. In contrast, control groups of patients on haemodialysis without arthropathy and patients without renal failure did not have increased uptake. A semi-quantitative scale of uptake was devised, and the following correlations were significant: pain perception and isotope uptake score in the ankles and feet, and the number of radiological lesions and isotope uptake scores in the wrists and knees. The following sites where the radioisotope might bind in the affected joints are proposed: amyloid deposits, areas of soft-tissue calcification, or areas of increased bone turnover. It is concluded that whereas the scanning technique cannot make a definite diagnosis of amyloid and, therefore, cannot be expected to supersede histological diagnosis, it is a useful adjuvant investigation, of particular importance in those patients unable or unwilling to undergo biopsy. 相似文献