全文获取类型
收费全文 | 237265篇 |
免费 | 11237篇 |
国内免费 | 405篇 |
专业分类
耳鼻咽喉 | 3102篇 |
儿科学 | 7390篇 |
妇产科学 | 4810篇 |
基础医学 | 34044篇 |
口腔科学 | 5666篇 |
临床医学 | 18791篇 |
内科学 | 52385篇 |
皮肤病学 | 6291篇 |
神经病学 | 21089篇 |
特种医学 | 7072篇 |
外国民族医学 | 102篇 |
外科学 | 29334篇 |
综合类 | 1004篇 |
一般理论 | 62篇 |
预防医学 | 21637篇 |
眼科学 | 4617篇 |
药学 | 16654篇 |
中国医学 | 716篇 |
肿瘤学 | 14141篇 |
出版年
2023年 | 1261篇 |
2022年 | 910篇 |
2021年 | 3524篇 |
2020年 | 2102篇 |
2019年 | 3953篇 |
2018年 | 7551篇 |
2017年 | 4953篇 |
2016年 | 4951篇 |
2015年 | 5545篇 |
2014年 | 5805篇 |
2013年 | 9375篇 |
2012年 | 16248篇 |
2011年 | 16266篇 |
2010年 | 8088篇 |
2009年 | 6010篇 |
2008年 | 13965篇 |
2007年 | 14918篇 |
2006年 | 13744篇 |
2005年 | 13562篇 |
2004年 | 12740篇 |
2003年 | 11625篇 |
2002年 | 10999篇 |
2001年 | 6152篇 |
2000年 | 6247篇 |
1999年 | 5541篇 |
1998年 | 906篇 |
1997年 | 753篇 |
1996年 | 715篇 |
1992年 | 3215篇 |
1991年 | 2881篇 |
1990年 | 2751篇 |
1989年 | 2506篇 |
1988年 | 2374篇 |
1987年 | 2206篇 |
1986年 | 2099篇 |
1985年 | 1890篇 |
1984年 | 1410篇 |
1983年 | 1201篇 |
1982年 | 696篇 |
1979年 | 1216篇 |
1978年 | 857篇 |
1977年 | 803篇 |
1975年 | 811篇 |
1974年 | 992篇 |
1973年 | 1001篇 |
1972年 | 946篇 |
1971年 | 926篇 |
1970年 | 863篇 |
1969年 | 912篇 |
1968年 | 791篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Long-term effects of physical exercise on working capacity and pulmonary function in cystic fibrosis 总被引:1,自引:0,他引:1
B Andréasson B Jonson R Kornf?lt E Nordmark S Sandstr?m 《Acta paediatrica Scandinavica》1987,76(1):70-75
Seven patients with cystic fibrosis aged 6 to 20 were enrolled for 30 months in a daily exercise program. After 12 months conventional chest physiotherapy was withdrawn. Patients with low initial Shwachman scores improved as regards maximal working capacity. Spirometric data and volume of trapped gas indicated opening of closed airways. We suggest that physical exercise in general should be the basis of pulmonary therapy in cystic fibrosis. Other forms of physiotherapy are advisable when hard physical exercise is not feasible. 相似文献
72.
Heloísio de Rezende Leite Guilherme Silvério de Oliveira Hélio Henrique de Araújo Brito 《American journal of orthodontics and dentofacial orthopedics》2005,128(2):241-251
This case report demonstrates how extracting a maxillary deciduous canine affects the eruption path of a labially displaced ectopically erupting permanent canine. A long-term follow-up is presented, and the biologic mechanisms are discussed. 相似文献
73.
74.
75.
Muscle strips from the fundus, trigonum and distal ureters obtained from children at operations for vesico-ureteric reflux were studied using histochemical and immunohistochemical methods, and electrical nerve stimulation in an organ bath. A rich supply of cholinergic nerves was found and despite a partial atropine resistance the neurophysiological experiments indicated that the transmitter causing contraction of the detrusor muscle is acetylcholine. Imipramine, which is used in the treatment of enuresis, had no anticholinergic effect on the bladder in the doses used clinically. The adrenergic innervation was very sparse except around the ureter orifices. No contractile alpha-adrenoceptors could be detected but beta receptor mediated relaxation was found, which was neither of the beta 1 nor beta 2 type. A third type of beta receptor is postulated. Peptidergic nerves containing vasoactive intestinal peptide, VIP, were demonstrated in a few nerve terminals running along bundles of smooth muscle. No nerves containing enkephaline, somatostatine or substance P were found. VIP affected the detrusor muscle indicating a possible role as a modulator of transmitter action, while substance P had no effect. The anticholinergic and calcium antagonistic drug terodiline inhibited all muscle activity, whether it was induced by nerve stimulation, cholinergic drugs or a potassium rich solution, making it suitable for treatment of diurnal enuresis. 相似文献
76.
Early spontaneous hematoma in cerebral infarct: is primary cerebral hemorrhage overdiagnosed? 总被引:2,自引:0,他引:2
We identified 15 patients (63 +/- 8 years) in whom CT showed no bleeding within 6 hours of stroke onset but showed ganglionic or lobar hemorrhage less than 18 hours later, without visible underlying infarct (early spontaneous intra-infarct hematoma [ESIH]). No patient had antithrombotic therapy or a coagulation disorder, but eight had hypertension. The second CT was prompted by rapid worsening (in 10) or because the first CT was not available (in five). Prior transient ischemic attacks, silent infarcts on CT, and a potential cardiac source of embolism were more common in patients with ESIH than in 200 patients with primary cerebral hemorrhage (PCH) admitted during the same period. Distal occlusions were present in four of five patients who underwent intracranial studies within the first 2 days. Most of these patients probably had embolism with early and extensive bleeding in the ischemic area. Our findings suggest that ESIH may be under-recognized, while PCH may be overdiagnosed. 相似文献
77.
J Canet J Vallés P Vila F Vidal 《Revista espa?ola de anestesiología y reanimación》1990,37(6):366-369
Patients with morbid obesity present a series of functional and morphologic alterations and require a careful planning for anesthetic management. We report a case of a woman weighing 260 kg who was operated on twice for the treatment of her base condition. In the first operation, general anesthesia was carried out and in the second one, epidural anesthesia was conducted. Main complications included hypoxemia and hypercapnia which persisted during the first week after operation carried out under general anesthesia. 相似文献
78.
We studied 362 fractures of the femur that had occurred during the years 1950-57 and 1973-83, and 849 fractures of the tibia that occurred during the the years 1950-55 and 1980-83. There was an increase in age-specific incidence over aged 60 years. The risk of low-energy femoral shaft fractures also had increased in elderly women. Both fracture types shifted their age- and sex-specific incidence in the direction of a fragility pattern. There was no increase in the incidence of tibial shaft fractures. Fracture type, site, and degree of displacement of the tibial fractures remained unchanged during the 30 years, i.e, they were predominantly distal, longitudinal fractures with moderate displacement. 相似文献
79.
In order to clarify the physiological role in vivo of H2O2-detoxifying enzymes at low and high levels of O2 tension we studied catalase (CAT), glutathione peroxidases (GP), and in vivo peroxidation (TBA-RS) in the lung and heart of Rana perezi frogs chronically treated with hyperoxia, aminotriazole (AT) -a CAT inhibitor-, or both. Hyperoxia did not change CAT, GP or TBA-RS. Aminotriazole caused an almost complete depletion of CAT, a 30% decrease of GP and a 132% (lung) to 200% (heart) increase of TBA-RS. Changes similar to these were found in the group treated with AT in hyperoxia. No mortality or changes in total or organ weight occurred in the experimental groups. Main conclusions are: (1) The maximal hyperoxia tolerance showed by frogs among vertebrates does not need antioxidant enzyme induction from lung or heart and is probably related to the presence of high constitutive levels of GP in relation to metabolic rate. (2) Even in normoxia the tissues present significant amounts of H2O2, and CAT is needed to avoid oxidative damage. GP does not compensate its absence. The implications of these results in relation to oxygen toxicity in man is discussed. 相似文献
80.