全文获取类型
收费全文 | 1696844篇 |
免费 | 123773篇 |
国内免费 | 3793篇 |
专业分类
耳鼻咽喉 | 21751篇 |
儿科学 | 55659篇 |
妇产科学 | 46157篇 |
基础医学 | 241407篇 |
口腔科学 | 48777篇 |
临床医学 | 151403篇 |
内科学 | 333863篇 |
皮肤病学 | 38670篇 |
神经病学 | 131267篇 |
特种医学 | 63940篇 |
外国民族医学 | 242篇 |
外科学 | 257658篇 |
综合类 | 38952篇 |
现状与发展 | 4篇 |
一般理论 | 531篇 |
预防医学 | 124263篇 |
眼科学 | 40233篇 |
药学 | 123693篇 |
7篇 | |
中国医学 | 4488篇 |
肿瘤学 | 101445篇 |
出版年
2021年 | 12813篇 |
2019年 | 13547篇 |
2018年 | 19975篇 |
2017年 | 15234篇 |
2016年 | 16633篇 |
2015年 | 18976篇 |
2014年 | 26231篇 |
2013年 | 37976篇 |
2012年 | 52810篇 |
2011年 | 55488篇 |
2010年 | 32819篇 |
2009年 | 30743篇 |
2008年 | 51611篇 |
2007年 | 54906篇 |
2006年 | 55359篇 |
2005年 | 52636篇 |
2004年 | 50827篇 |
2003年 | 48242篇 |
2002年 | 46446篇 |
2001年 | 91841篇 |
2000年 | 93662篇 |
1999年 | 77011篇 |
1998年 | 19750篇 |
1997年 | 17287篇 |
1996年 | 17413篇 |
1995年 | 16763篇 |
1994年 | 15298篇 |
1993年 | 14078篇 |
1992年 | 57408篇 |
1991年 | 55294篇 |
1990年 | 52994篇 |
1989年 | 50781篇 |
1988年 | 46158篇 |
1987年 | 44961篇 |
1986年 | 42246篇 |
1985年 | 40005篇 |
1984年 | 29368篇 |
1983年 | 24923篇 |
1982年 | 13906篇 |
1979年 | 25537篇 |
1978年 | 17580篇 |
1977年 | 14906篇 |
1976年 | 13876篇 |
1975年 | 14565篇 |
1974年 | 17633篇 |
1973年 | 16950篇 |
1972年 | 15679篇 |
1971年 | 14457篇 |
1970年 | 13436篇 |
1969年 | 12517篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
171.
H Murakami M Togawa S Takahashi N Kasahara J Yamamoto N Matsuura Y Koshiyama Y Ino M Oda 《Arzneimittel-Forschung》1990,40(12):1352-1358
The effects of FUT-187 (6-amidino-2-naphthyl 4-[(4,5-dihydro-1H-imidazol-2-yl)amino]benzoate dimethanesulfonate, CAS 103926-82-5), a novel synthetic protease inhibitor, were examined in experimental rat and canine models of pancreatitis. 1. FUT-187 significantly increased the survival of rats with trypsin- and phospholipase A2-induced pancreatitis in a dose-dependent manner (10-100 mg/kg, p.o.). 2. FUT-187 decreased plasma enzymatic activity reflecting the degree of pancreatitis in rats with ethionine-induced pancreatitis, and showed a tendency to ameliorate histopathological changes in the pancreas (10-100 mg/kg p.o.). 3. FUT-187 (10 mg/kg) produced an obvious improvement of various biochemical parameters of pancreatitis and also reduced histopathological changes in the pancreas in animals with experimental pancreatitis produced by the closed duodenal loop method. In addition, FUT-187 significantly increased the survival of dogs when given by direct administration into the lumen of the closed duodenal loop. The therapeutic effects of FUT-187 in experimental pancreatitis were nearly equal in most instances to those of camostat mesilate. Thus, FUT-187 would appear to be an effective new agent for the treatment of pancreatitis. 相似文献
172.
Multicentricity of hepatocellular carcinoma (HCC) is considered, especially in patients with liver cirrhosis. This paper describes an operative case of a male patient with probable multicentric development of HCC in precirrhotic fibrosis. The main tumors inside the capsule were completely necrotic due to transarterial embolization (TAE). Histologic examination disclosed discrete tiny nodules of HCC that were not detected grossly. They showed highly differentiated trabecular arrangements: Edmondson I. A scirrhous type was noted in the center of the tumors. At the borders of the tumors the carcinoma cells exhibited replacing growth patterns and it was thought that they developed multicentrically. Partial resection must be performed as extensively as possible in a case such as the present one. 相似文献
173.
S Yamada 《Journal of UOEH》1988,10(2):211-218
Physical activity and nutrition are the most important factors in preserving and/or improving health conditions. The relationship between exercise and nutrition is focused on two different directions: one is the direction toward health promoting, the other is for performance of a long heavy muscular work. For preserving and/or promoting health conditions, energy balance between intake and expenditure must be taken into account. The amount of glycogen stored in muscles is the essential factor to promote a long distance performance of working muscles. Topics that influence the energy balance and glycogen loading used by endurance athletes to improve performance are reviewed. 相似文献
174.
L R?stam R V Luepker M B Mittelmark D M Murray J S Slater H Blackburn 《American journal of preventive medicine》1988,4(5):249-254
To determine the potential effect of screening on referral patterns, an adult population sample (4,404 men, 5,164 women, 20-69 years of age) was systematically recruited and screened for hypercholesterolemia and then analyzed by different cholesterol referral recommendations. Using levels suggested by the Lipid Research Clinics Coronary Primary Prevention Trial (greater than or equal to 265 mg/dL), 7.3% of men and 5.8% of women would be referred for follow-up. With the suggested recommendations of the National Cholesterol Education Program (NCEP), (greater than or equal to 200 mg/dL), 49.2% of men and 40.2% of women would be referred. The use of age-related definitions of the NIH Consensus Conference on Lipid Lowering results in 28.0% referrals in men and 21.8% in women. From this population, hypercholesterolemia subjects (greater than or equal to 265 mg/dL at screening; n = 624) were invited for a second cholesterol determination (58% returned), which found 36% below the 265 mg/dL level. Population screening for cholesterol is likely to produce large numbers of patients for follow-up, with the actual numbers strongly dependent on cutoff levels and age-sex distributions. Referral and follow-up of these patients may place a significant load on an unprepared health care community. 相似文献
175.
Ticks of the Ornithodoros moubata complex were collected from domestic pig sties and dwelling houses, and from a warthog habitat, and tested for the presence of African swine fever (ASF) virus. Collections were made in 9 of the 24 districts of Malawi, these being primarily the districts in which O. moubata is most numerous. ASF virus was isolated from ticks collected in both domestic pig sties and houses in certain villages in Mchinji district where ASF outbreaks had recently occurred. Mchinji district is in the centre of a large ASF enzootic area which stretches into other districts of Malawi and also into Zambia and Mozambique. The high titre of virus in some of the ticks demonstrates that O. moubata can act as a virus reservoir and potential vector of disease in the field situation in Malawi. 相似文献
176.
177.
178.
Integration and differentiation of human embryonic stem cells transplanted to the chick embryo. 总被引:3,自引:0,他引:3
Ronald S Goldstein Micha Drukker Benjamin E Reubinoff Nissim Benvenisty 《Developmental dynamics》2002,225(1):80-86
Human embryonic stem (ES) cells are pluripotent cells that can differentiate into a large array of cell types and, thus, hold promise for advancing our understanding of human embryology and for contributing to transplantation medicine. In this study, differentiation of human ES cells was examined in vivo by in ovo transplantation to organogenesis-stage embryos. Colonies of human ES cells were grafted into or in place of epithelial-stage somites of chick embryos of 1.5 to 2 days of development. The grafted human ES cells survived in the chick host and were identified by vital staining with carboxyfluorescein diacetate or use of a green fluorescent protein-expressing cells. Histologic analysis showed that human ES cells are easily distinguished from host cells by their larger, more intensely staining nuclei. Some grafted cells differentiated en masse into epithelia, whereas others migrated and mingled with host tissues, including the dorsal root ganglion. Colonies grafted directly adjacent to the host neural tube produced primarily structures with the morphology and molecular characteristics of neural rosettes. These structures contain differentiated neurons as shown by beta-3-tubulin and neurofilament expression in axons and cell bodies. Axons derived from the grafted cells penetrate the host nervous system, and host axons enter the structures derived from the graft. Our results show that human ES cells transplanted in ovo survive, divide, differentiate, and integrate with host tissues and that the host embryonic environment may modulate their differentiation. The chick embryo, therefore, may serve as an accessible and unique experimental system for the study of in vivo development of human ES cells. 相似文献
179.
M. Wensing A. H. Penninks† S. L. Hefle‡ J. H. Akkerdaas§ R. van Ree§ S. J. Koppelman† C. A. F. M. Bruijnzeel-Koomen A. C. Knulst 《Clinical and experimental allergy》2002,32(12):1757-1762
BACKGROUND: The risk for allergic reactions depends on the sensitivity of individuals and the quantities of offending food ingested. The sensitivity varies among allergic individuals, as does the threshold dose of a food allergen capable of inducing an allergic reaction. OBJECTIVE: This study aimed at determining the distribution of minimum provoking doses of hazelnut in a hazelnut-allergic population. METHODS: Thirty-one patients with a history of hazelnut-related allergic symptoms, a positive skin prick test to hazelnut and/or an elevated specific IgE level, were included. Double-blind, placebo-controlled food challenges (DBPCFC) were performed with seven increasing doses of dried hazelnut (1 mg to 1 g hazelnut protein) randomly interspersed with seven placebo doses. RESULTS: Twenty-nine patients had a positive challenge. Itching of the oral cavity and/or lips was the first symptom in all cases. Additional gastrointestinal symptoms were reported in five patients and difficulty in swallowing in one patient. Lip swelling was observed in two patients, followed by generalized urticaria in one of these. Threshold doses for eliciting subjective reactions varied from a dose of 1 mg up to 100 mg hazelnut protein (equivalent to 6.4-640 mg hazelnut meal). Extrapolation of the dose-response curve showed that 50% of our hazelnut-allergic population will suffer from an allergic reaction after ingestion of 6 mg (95% CI, 2-11 mg) of hazelnut protein. Objective symptoms were observed in two patients after 1 and 1,000 mg, respectively. CONCLUSION: DBPCFCs demonstrated threshold doses in half of the hazelnut-allergic patients similar to doses previously described to be hidden in consumer products. This stresses the need for careful labelling and strategies to prevent and detect contamination of food products with hazelnut residues. 相似文献
180.