全文获取类型
收费全文 | 31452篇 |
免费 | 2610篇 |
国内免费 | 72篇 |
专业分类
耳鼻咽喉 | 544篇 |
儿科学 | 1253篇 |
妇产科学 | 1014篇 |
基础医学 | 4311篇 |
口腔科学 | 832篇 |
临床医学 | 2748篇 |
内科学 | 7344篇 |
皮肤病学 | 747篇 |
神经病学 | 3254篇 |
特种医学 | 996篇 |
外国民族医学 | 3篇 |
外科学 | 3899篇 |
综合类 | 534篇 |
一般理论 | 43篇 |
预防医学 | 2301篇 |
眼科学 | 633篇 |
药学 | 1769篇 |
中国医学 | 8篇 |
肿瘤学 | 1901篇 |
出版年
2021年 | 413篇 |
2020年 | 271篇 |
2019年 | 454篇 |
2018年 | 507篇 |
2017年 | 363篇 |
2016年 | 405篇 |
2015年 | 461篇 |
2014年 | 642篇 |
2013年 | 971篇 |
2012年 | 1266篇 |
2011年 | 1338篇 |
2010年 | 789篇 |
2009年 | 682篇 |
2008年 | 1209篇 |
2007年 | 1307篇 |
2006年 | 1303篇 |
2005年 | 1234篇 |
2004年 | 1237篇 |
2003年 | 1123篇 |
2002年 | 1192篇 |
2001年 | 1096篇 |
2000年 | 1167篇 |
1999年 | 982篇 |
1998年 | 365篇 |
1997年 | 306篇 |
1996年 | 320篇 |
1995年 | 295篇 |
1994年 | 289篇 |
1993年 | 303篇 |
1992年 | 863篇 |
1991年 | 805篇 |
1990年 | 685篇 |
1989年 | 728篇 |
1988年 | 676篇 |
1987年 | 708篇 |
1986年 | 650篇 |
1985年 | 676篇 |
1984年 | 536篇 |
1983年 | 465篇 |
1982年 | 300篇 |
1980年 | 259篇 |
1979年 | 457篇 |
1978年 | 307篇 |
1977年 | 258篇 |
1976年 | 280篇 |
1975年 | 268篇 |
1974年 | 297篇 |
1973年 | 294篇 |
1972年 | 267篇 |
1971年 | 261篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
The use of a limited list to restrict the range and type of medication used by medical institutions that operate under the auspices of the provincial authorities has been mooted as one possible method of cost containment. This study discusses the implementation of such measures in other countries and then quantifies the cost savings that might be obtained in the South African case. The possible savings are somewhat offset by other costs such a measure would introduce. 相似文献
53.
Nasal provocation with ragweed pollen extract was performed on ragweed-sensitive and non-atopic subjects. Nasal lavage fluids were collected 15 min after saline and allergen challenges, and assayed for total protein, albumin, potassium, lysozyme activity and peroxidase activity. There was no statistically significant increase in any of these lavage fluid constituents in non-atopic subjects after allergen provocation, compared with after saline provocation. The lavage fluids of ragweed-sensitive subjects had significant rises in each of the constituents following allergen provocation. This method provides a simple mechanism for quantitating the nasal secretory response to allergen provocation. 相似文献
54.
55.
56.
Neurologic causes of learning disabilities 总被引:1,自引:0,他引:1
B H Cohen 《Seminars in neurology》1991,11(1):7-13
57.
A rare case of a large myxofibroma of the maxilla is presented. Computerized tomographic features, in conjunction with clinical appearance, were highly suggestive of a definitive diagnosis. Computerized tomography may play an important role in the planning of surgical management of this tumor known for its local aggressiveness and high recurrence rate. 相似文献
58.
Alan M. Mellow Trey Sunderland Robert M. Cohen Brian A. Lawlor James L. Hill Paul A. Newhouse Martin R. Cohen Dennis L. Murphy 《Psychopharmacology》1989,98(3):403-407
Thyrotropin releasing hormone (TRH) was administered intravenously to ten patients with Alzheimer's Disease (AD) in a high-dose paradigm, thought to maximize central nervous system effects and potentially produce facilitation of cholinergic function, a known property of the neuropeptide. Acute effects of TRH on behavioral, cognitive and physiologic measures were assessed after patients received 0.1 mg/kg TRH, 0.3 mg/kg TRH and placebo, the higher TRH dose and placebo being given in a randomized, double-blind fashion. Patients showed statistically significant increases in arousal and improvement in affect, as well as a modest improvement in semantic memory, all after receiving the higher TRH dose. Both TRH doses produced transient rises in systolic blood pressure, with no effect on diastolic blood pressure, heart rate or temperature. This study suggests that high-dose TRH can be safely administered to AD patients and is neurobehaviorally active; further studies are needed to determine the extent and mechanism of the cognitive and psychobiological properties of this peptide in AD and other neuropsychiatric disorders. 相似文献
59.
We have reviewed some of the factors which contribute to lung damage by various toxicants. These include disposition of the chemical, its metabolism, individual cell type susceptibility and the potential for the tissue to repair. We have discussed the use of biochemical parameters to measure the functional activity of individual cell types in order to predict the damage to specific cell types and concluded that careful morphological analysis of lung tissue is likely to provide a more sensitive and informative measure of specific cell type injury. However, in order to investigate the mechanism of toxicity of pulmonary toxicants it is essential to establish the primary biochemical event that leads to cell damage and morphological change. The importance of separating the relevant biochemical change(s) from the cascade of biochemical events associated with dead and dying cells and the reparative response of the lung is emphasised.This report results from a discussion sponsored and organised by the Advisory Subgroup in Toxicology (AST) of the European Science Foundation's Standing Committee for the European Medical Research Councils and held at the Medical Research Council Toxicology Unit, Carshalton, U. K. Those taking part were: W. N. Aldridge (AST; as above); J. Bignon (Unit for Research in Renal and Pulmonary Pathology, University of Paris, Creteil, France); P. H. Burri (Section of Developmental Biology, Institute of Anatomy, University of Berne, Switzerland); G. M. Cohen (as above); D. Dinsdale (MRC Toxicology Unit, Carshalton U. K.); P. Hedqvist (Dept. of Physiology, Karolinska Institute, Stockholm, Sweden); D. Henschler (AST; Dept. of Toxicology and Pharmacology, University of Wurzburg, FDR); G. J. Laurent (Biochemistry Unit, Cardiothoracic Institute, University of London, London, U. K.); R. Lauwerys (AST Industrial and Medical Toxicology Unit, University of Louvain, Brussels, Belgium); F. Lembeck (AST; Dept. for Experimental and Clinical Pharmacology, University of Graz, Austria); N. Lery (AST; Poison Control Centre, Lyon, France); P. Moldeus (Dept. of Forensic Medicine, Karolinska Institute, Stockholm, Sweden); B. Nemery (MRC Toxicology Unit, Carshalton, U. K.); A. Saria (Dept. for Experimental and Clinical Pharmacology, University of Graz, Austria); L. L. Smith (as above);B. Terracini (AST; Dept. of Pathology and Cancer Epidemiology, University of Turin, Italy) 相似文献
60.
A Golik D Modai J Weissgarten N Cohen Z Averbukh E Sigler R Zaidenstein U Shaked 《Clinical pharmacology and therapeutics》1987,42(1):42-44
Serum zinc levels and urinary zinc excretion were compared in 15 patients with essential hypertension taking chronically a combination of hydrochlorothiazide and amiloride as monotherapy, eight patients maintained with hydrochlorothiazide alone, and eight control subjects. Serum zinc values were statistically comparable in all three groups. However, urinary zinc excretion was abnormally elevated in the two patient groups. In the dosage used, amiloride did not have a zinc-sparing effect. 相似文献