全文获取类型
收费全文 | 2112938篇 |
免费 | 152100篇 |
国内免费 | 5350篇 |
专业分类
耳鼻咽喉 | 28195篇 |
儿科学 | 63387篇 |
妇产科学 | 55797篇 |
基础医学 | 305966篇 |
口腔科学 | 60674篇 |
临床医学 | 196691篇 |
内科学 | 408789篇 |
皮肤病学 | 42711篇 |
神经病学 | 171172篇 |
特种医学 | 78930篇 |
外国民族医学 | 432篇 |
外科学 | 313120篇 |
综合类 | 43853篇 |
现状与发展 | 2篇 |
一般理论 | 677篇 |
预防医学 | 165518篇 |
眼科学 | 47184篇 |
药学 | 159480篇 |
9篇 | |
中国医学 | 4994篇 |
肿瘤学 | 122807篇 |
出版年
2019年 | 16519篇 |
2018年 | 23440篇 |
2017年 | 17835篇 |
2016年 | 19485篇 |
2015年 | 22318篇 |
2014年 | 30588篇 |
2013年 | 46609篇 |
2012年 | 63965篇 |
2011年 | 67583篇 |
2010年 | 39537篇 |
2009年 | 36756篇 |
2008年 | 63232篇 |
2007年 | 66504篇 |
2006年 | 67265篇 |
2005年 | 64821篇 |
2004年 | 62083篇 |
2003年 | 59279篇 |
2002年 | 57631篇 |
2001年 | 104553篇 |
2000年 | 107930篇 |
1999年 | 90322篇 |
1998年 | 23549篇 |
1997年 | 21129篇 |
1996年 | 20942篇 |
1995年 | 19737篇 |
1994年 | 18385篇 |
1993年 | 17105篇 |
1992年 | 70527篇 |
1991年 | 68469篇 |
1990年 | 66310篇 |
1989年 | 63755篇 |
1988年 | 58719篇 |
1987年 | 57172篇 |
1986年 | 54011篇 |
1985年 | 51666篇 |
1984年 | 38005篇 |
1983年 | 32274篇 |
1982年 | 18213篇 |
1979年 | 34233篇 |
1978年 | 23691篇 |
1977年 | 19791篇 |
1976年 | 18502篇 |
1975年 | 19520篇 |
1974年 | 23821篇 |
1973年 | 22892篇 |
1972年 | 21438篇 |
1971年 | 20183篇 |
1970年 | 18926篇 |
1969年 | 17496篇 |
1968年 | 16356篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Summary This study was undertaken to elucidate, using the Golgi method, the neuropathological change in the brain of the macular mutant mouse, whose hemizygote (Ml/y) is considered to be a model of Menkes kinky hair disease (MKHD). The hemizygote mice gradually lost weight after 10 days of age and died with emaciation and seizure around day 15. The normal littermate (+/y) was well developed. In the cerebrum, the arborization of pyramidal neurons in the layer V of the Ml/y was the same as that in the +/y on day 10. However, development of arborization in the Ml/y was delayed in comparison with that in the +/y on days 12 and 14. Purkinje cells with several somal sprouts were observed in the cerebellum in both the Ml/y and +/y on day 7. The somal sprouts in the +/y had regressed gradually by day 12, while they were still in the anterior and middle lobes of the Ml/y on day 14. Additionally, the trunks of Ml/y stem dendrites became thicker and a cactus formation was recognized on the branching portion of the dendrites on day 14. Arborization of these abnormal Purkinje cells was distinctly poor compared with that in the +/y. These results suggest that the growth of the neurons is delayed in the Ml/y and simultaneously their cytoskeletal developments are disturbed, especially in the Purkinje cells. There is a close similarity in many respects to the neuropathological change in MKHD. 相似文献
992.
Symptomatic HIV infection of the CNS in a patient without clinical evidence of immune deficiency 总被引:1,自引:0,他引:1
A Beckett P Summergrad T Manschreck H Vitagliano M Henderson M L Buttolph M Jenike 《The American journal of psychiatry》1987,144(10):1342-1344
Major depression with psychotic features, dementia, and focal neurologic abnormalities appeared in a Haitian man without AIDS or other syndromes of immune compromise. Neurologic evaluation, including brain biopsy, was nondiagnostic, but CSF culture revealed human immunodeficiency virus (HIV). 相似文献
993.
L M Cortese D W Greenberger P J Schneider J A Bourret 《American journal of hospital pharmacy》1987,44(11):2514-2518
Perceptions of job characteristics and job satisfaction of central-area technicians and drug-administration technicians at The Ohio State University Hospitals were analyzed. A questionnaire was administered to 79 pharmacy drug-administration technicians; 44 central-area technicians; 10 pharmacy residents, who served as objective raters (5 in the central area and 5 in the decentral area); 13 central-area pharmacists; and 17 decentral-area pharmacists. Perceived job characteristics were measured with the Job Characteristics Inventory; job satisfaction was measured by the Minnesota Job Satisfaction Questionnaire. The two groups of technicians differed significantly in their perceptions of task identity, task significance, and dealing with others. Significantly greater autonomy in technicians' jobs was perceived to exist by pharmacists and raters in both areas than by technicians. Significantly greater task identity was perceived by the central-area technicians than by their raters, and significantly greater task importance was perceived by both groups of technicians than by their pharmacists and raters. Friendship opportunities were perceived to exist to a significantly greater degree by decentral pharmacists and raters than by the drug-administration technicians. In the institution studied, both central-area and drug-administration technicians tended to be dissatisfied with their jobs. Central-area technicians' satisfaction was influenced most by the technicians' relationships with their supervisors and the feelings of accomplishment they gained. Drug-administration technicians were most satisfied if they believed they had opportunities to use their abilities. Efforts to increase job satisfaction among pharmacy technicians should focus on increasing feedback and task identity. 相似文献
994.
In order to examine the cholecystohepatic circulation of trichloroethylene (TRI) and its metabolites, we injected the gallbladder with TRI and its metabolites, i.e. chloral hydrate (CH), free-trichloroethanol (F-TCE), trichloroacetic acid (TCA) and conjugated-trichloroethanol (Conj-TCE), using anesthetized dogs. The absorption rates of water from the gallbladder were 25-30% 2 h after administration for all substances. The absorption rates of substances were 65-70% in the CH, F-TCE and TRI groups, and 40-50% in the Conj-TCE and TCA groups 2 h after the administration. Conj-TCE in the blood absorbed from the gallbladder has a tendency to be directly transported to the venous system rather than to be taken into hepatocytes in the liver. All of the administered substances, in particular, F-TCE might be metabolized to other substances in the gallbladder. 相似文献
995.
996.
J B Ubbink W J Serfontein P J Becker L S de Villiers 《The American journal of clinical nutrition》1987,46(1):78-85
Plasma pyridoxal-5'-phosphate and pyridoxal levels increased significantly (p less than 0.05) when single, oral bolus doses of pyridoxine were increased from 10 to 25 and from 25 to 50 mg in nine female volunteers. However, when the dose was increased to 100 mg, plasma pyridoxal-5'-phosphate levels did not differ significantly from those recorded after the 50 mg dose. Within 3 h plasma pyridoxal levels rose with a factor of 3.85 compared with the 50 mg dose but high pyridoxal levels were eliminated from the circulation. Renal clearance of pyridoxal remained a constant, low percentage (less than 2.0%) of each pyridoxine supplement in spite of the observed very high circulating pyridoxal levels. Pyridoxine supplementation is discussed in relation to circulating pyridoxal-5'-phosphate and pyridoxal availability for cellular metabolism. 相似文献
997.
998.
Curative local excision of rectal adenocarcinoma 总被引:3,自引:0,他引:3
The records of all 28 patients with rectal adenocarcinoma treated by potentially curative local excision by one surgeon (A.M.C.) between 1970 and 1984 were reviewed. Patient age, sex, tumour size, site, degree of differentiation and level of invasion are reported. The procedure was associated with no mortality and minimal morbidity. Twenty-two patients, followed for an average of 51 months, have either died of other causes or remain free of recurrent or disseminated malignancy. Six patients have required further surgery for local recurrence. Of these, one patient has had a repeat local excision while the remaining five patients have had an abdominoperineal excision of the rectum. All six patients, followed since the second operation for an average of 50 months, are free of further recurrent or disseminated disease. The results reported in this review suggest that in a selected group of patients with rectal adenocarcinoma curative local excision may offer a safe alternative to more radical forms of surgery. 相似文献
999.
1000.
Delta hepatitis virus infection in China 总被引:1,自引:0,他引:1
D Q Wang H H Cheng G Y Minuk L H Liu C M Anand T C Stowe H X Wang D C Ying Y R Tu K A Buchan 《International journal of epidemiology》1987,16(1):79-83
To assess the prevalence, epidemiological features and prognostic implications of hepatitis D (Delta) in Sichuan Province, The People's Republic of China, 649 sera (515 from HBsAg positive patients and 134 from HBsAg negative subjects) were tested by radioimmunoassay (RIA) for antibody to the hepatitis D virus (anti-HD). Forty-seven sera (7.2%) showed some degree of reactivity. Serial dilutions of these sera indicated that prozoning was not responsible for the equivocal results. Thirty-four of the 47 sera were submitted under code to a second laboratory for independent analysis. According to those results anti-HD antibodies were detected in four of these sera. The overall prevalence of anti-HD in the HBsAg positive patients therefore was 0.8% (4/515). On the basis of clinical, biochemical and histological data 427 HBsAg positive sera were further divided into acute Type B hepatitis, chronic Type B hepatitis, healthy carrier state and hepatocellular carcinoma (HCC) subgroups. Two of 65 (3.1%) anti-HD positive sera belonged to the acute Type B hepatitis group; one of 104 (0.9%), the chronic Type B hepatitis group and one of 246 (0.4%), the healthy carrier group. No antibody was detected in sera from 12 HBsAg positive HCC patients. All HBsAg negative patients were negative for anti-HD antibody. The results of this study indicate that despite a high prevalence of hepatitis B virus infection, positive serology for delta virus is uncommon in Sichuan Province, The People's Republic of China. 相似文献