全文获取类型
收费全文 | 2414442篇 |
免费 | 179848篇 |
国内免费 | 6002篇 |
专业分类
耳鼻咽喉 | 32876篇 |
儿科学 | 81201篇 |
妇产科学 | 65694篇 |
基础医学 | 350213篇 |
口腔科学 | 65777篇 |
临床医学 | 224527篇 |
内科学 | 469633篇 |
皮肤病学 | 49931篇 |
神经病学 | 197397篇 |
特种医学 | 91563篇 |
外国民族医学 | 917篇 |
外科学 | 348986篇 |
综合类 | 51978篇 |
现状与发展 | 3篇 |
一般理论 | 867篇 |
预防医学 | 199852篇 |
眼科学 | 53236篇 |
药学 | 177968篇 |
7篇 | |
中国医学 | 5233篇 |
肿瘤学 | 132433篇 |
出版年
2019年 | 19761篇 |
2018年 | 27623篇 |
2017年 | 20899篇 |
2016年 | 22887篇 |
2015年 | 26157篇 |
2014年 | 36229篇 |
2013年 | 55367篇 |
2012年 | 76467篇 |
2011年 | 80975篇 |
2010年 | 47486篇 |
2009年 | 44659篇 |
2008年 | 75203篇 |
2007年 | 79861篇 |
2006年 | 80002篇 |
2005年 | 77473篇 |
2004年 | 74229篇 |
2003年 | 71320篇 |
2002年 | 69193篇 |
2001年 | 109999篇 |
2000年 | 113643篇 |
1999年 | 96164篇 |
1998年 | 27555篇 |
1997年 | 24800篇 |
1996年 | 24921篇 |
1995年 | 23624篇 |
1994年 | 22252篇 |
1993年 | 20776篇 |
1992年 | 76842篇 |
1991年 | 75182篇 |
1990年 | 72915篇 |
1989年 | 69478篇 |
1988年 | 64245篇 |
1987年 | 63018篇 |
1986年 | 59403篇 |
1985年 | 56862篇 |
1984年 | 42842篇 |
1983年 | 36311篇 |
1982年 | 21448篇 |
1981年 | 19370篇 |
1979年 | 38594篇 |
1978年 | 27189篇 |
1977年 | 22654篇 |
1976年 | 21695篇 |
1975年 | 22855篇 |
1974年 | 27282篇 |
1973年 | 26557篇 |
1972年 | 24469篇 |
1971年 | 22540篇 |
1970年 | 21124篇 |
1969年 | 19149篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Laterality of cross-modal spatial processing 总被引:1,自引:0,他引:1
J O Adams P D Duda 《Cortex; a journal devoted to the study of the nervous system and behavior》1986,22(4):539-552
This study examined the laterality of spatial-form perception in normal adults using a cross-modal matching paradigm involving visual and tactile processing. Randomly generated eight-point and 12-point Vanderplas and Garvin (1959) patterns were used as the stimuli. In a visual-to-tactile task, a lateralized visual pattern was followed immediately by a haptic task requiring subjects to discriminate which of two simultaneously felt shapes matched the visual pattern. In a tactile-to-visual task, subjects decided which of two simultaneously felt shapes matched a lateralized visual pattern presented after haptic manipulation. There were no main effects for laterality or for sex differences. Matching accuracy was better in the visual-to-tactile task and for less complex stimuli. A visual field by feeling hand interaction showed best recognition accuracy when visual-feeling hand combinations on the same side of the body were used in the two matching tasks. These data reflect a stimulus-response compatibility explanation of spatial-form perception that is consistent with a behavioral and not a cerebral asymmetry model. 相似文献
992.
D Mabin J P Borsotti S Tea J C Le Mevel J Clavier 《Revue d'électroencéphalographie et de neurophysiologie clinique》1986,15(4):341-348
Eleven patients with bronchial epidermoid carcinoma and undergoing treatment with cis-D.D.P. (II) were kept under electrophysiological and clinical surveillance. No other neurotoxic medication was added. The total dose of cis-D.D.P. was 300 mg/m2 over a period of three months: namely, three courses of 100 mg/m2 distributed over 5 days. Following the pretreatment check-up, the patients were divided into two groups: those without any electrophysiological abnormality (group A), and those without clinical abnormality but with a delayed latency H of the Hoffmann Reflex (group B). Patients in group A showed a slowing down of the motor nerve conduction velocity of the Median and Peroneal Nerves after a course of 100 mg, without accompanying worsening of the conduction velocity after 300 mg/m2, and prolongation of the distal latency of the sensory Median Nerve after 300 mg/m2; in group B, no significant change of electrophysiological clinical features were noted. In the two groups a non-significant reduction in amplitude of evoked responses were noted. These findings are more consistent with an axonal injury than with functional myelin injury. The authors review the existing literature and discuss the physiopathologic mechanisms of cis-D.D.P. peripheral neuropathies. 相似文献
993.
Cocaine-treated rats acquired a preference for cocaine-associated contextual stimuli (CS) relative to saline-injected control rats. However, when animals were given repeated tests for conditioned place preference intermittent between conditioning trials, they displayed an attenuation in strength of conditioning. This attenuation was not due to pharmacologic tolerance (Experiment 1), but rather reflected a disruption in learning due to exposure to the CS alone (Experiment 2). Like other examples of classical conditioning, the strength of the conditioned response (CR) as assessed by the conditioned place preference model may be influenced by partial reinforcement. 相似文献
994.
Forty patients suffering from asthmatic conditions, often accompanied by emphysema, were treated either with an extempore combination of salbutamol syrup plus 30-mg oxatomide tablets or with 30-mg oxatomide tablets alone for purposes of comparison. Greater efficacy was obtained with the combination, which produced positive results in terms of improved respiratory status, remission of clinical symptoms and reduced anti-asthma drug requirements in 90% of the cases treated, as against only 55% of satisfactory results obtained with oxatomide alone. The combination was very well tolerated with no incidence of adverse reactions, while the treatment with oxatomide alone, though on the whole well tolerated, gave rise to mild drowsiness in four cases. 相似文献
995.
Western transfer and immunoenzymatic staining with affinity-purified monospecific antiserum was used to detect a 38-Kd protein that bound to native and denatured DNA cellulose. This protein has previously been shown to be a delayed early herpes simplex virus type-2 specific protein. 相似文献
996.
Wheat germ agglutinin (WGA) was found to stimulate DNA synthesis in human peripheral blood mononuclear cells at relatively low concentrations and to inhibit DNA synthesis at higher concentrations. Both actions were inhibited by oligomers of N-acetyl-D-glucosamine. Significant mitogenic activity was dependent on the use of human (as opposed to fetal calf) serum to supplement the culture medium. Purified T cells responded to WGA very weakly and the incorporation of thymidine into non-T cells in response to WGA was less than the lectin-free control. The full ability of T cells to respond to WGA was restored by the addition of monocytes, but not by any other blood cells. Interleukin 2 partially restored the ability of T cells to respond to WGA; interleukin 1 was less effective. WGA displayed a strong synergistic action with the tumour promoter, 12-O-tetradecanoyl-13-acetate (TPA), in stimulating DNA synthesis in separated T (but not non-T) cell fractions, and in unfractioned mononuclear cells. These results reconcile most of the conflicting reports in the literature concerning the interaction of WGA with human lymphocytes. 相似文献
997.
A cohort of 1163 pregnant women in two small towns in South Wales, UK, was identified and followed until the children born to them were five years of age. Growth in these children is described and a number of determinants identified. Social-class differences were very small at birth but differences in height became clear by the age of two years and in head circumference before this. In height the differences were largely accounted for by greater growth in social class I, but there was a gradient in head circumference throughout all the social classes. The social class effects gradually increased as the children became older. Parity of the mothers had a small effect on size at birth but age of the mother had no effect once parity was allowed for. Data on illnesses in the children were collected but no effect on growth could be detected. By far the most important determinant of growth which could be controlled is maternal smoking. About 40% of the women smoked, about 17% heavily (15 or more cigarettes per day) and the prevalence of smoking altered little during pregnancy. There was a graded effect of smoking on growth up to a 9% deficit in birth-weight, a 2% deficit in length at birth and a 1.5% deficit in head circumference in the babies born to the mothers who smoked most heavily (25 or more cigarettes per day) compared with non-smokers. There effects decreased with age but there were still residual effects at age five years. 相似文献
998.
The Brief Symptom Inventory (BSI), a 53-item psychiatric symptom checklist, was administered to 57 alcoholic inpatients on days 2, 10, 18 and 26 of their 28-day stay in an alcoholism rehabilitation unit at a Veterans Administration hospital. The results of the test show a steady decline in the patients' psychiatric symptomatology from week 1 to week 4 with the most dramatic improvement evidenced between weeks 1 and 2. 相似文献
999.
R W Wulkan L Zwang T L Liem B G Blijenberg B Leijnse 《Zeitschrift für klinische Chemie und klinische Biochemie》1987,25(10):719-722
An expert system for evaluation of X-ray diffraction patterns of urinary calculi is described and evaluated. The software was developed using the PERSONAL CONSULTANT expert system shell from Texas Instruments. 相似文献
1000.
Activity of newer beta-lactam agents against clinical isolates of Bacteroides fragilis and other Bacteroides species. 总被引:7,自引:4,他引:3 下载免费PDF全文
J P O''''Keefe F R Venezio C A DiVincenzo K L Shatzer 《Antimicrobial agents and chemotherapy》1987,31(12):2002-2004
The in vitro activities of beta-lactam antibiotics against Bacteroides fragilis and B. fragilis group isolates are presented. Clinical isolates from 1986 were compared with strains from 1979 to 1982. Imipenem, ticarcillin-clavulanic acid, and ceftizoxime were the most active agents. Cefotetan was equivalent to cefoxitin against B. fragilis but less active against B. fragilis group isolates. Enhancement of cefotaxime by its desacetyl metabolite was minimal. 相似文献