全文获取类型
收费全文 | 218460篇 |
免费 | 49859篇 |
国内免费 | 637篇 |
专业分类
耳鼻咽喉 | 2922篇 |
儿科学 | 7751篇 |
妇产科学 | 3170篇 |
基础医学 | 35111篇 |
口腔科学 | 7694篇 |
临床医学 | 27278篇 |
内科学 | 52894篇 |
皮肤病学 | 9709篇 |
神经病学 | 27693篇 |
特种医学 | 7424篇 |
外国民族医学 | 11篇 |
外科学 | 33953篇 |
综合类 | 1609篇 |
一般理论 | 107篇 |
预防医学 | 15493篇 |
眼科学 | 3381篇 |
药学 | 15003篇 |
中国医学 | 1199篇 |
肿瘤学 | 16554篇 |
出版年
2023年 | 922篇 |
2022年 | 1676篇 |
2021年 | 4436篇 |
2020年 | 6828篇 |
2019年 | 13379篇 |
2018年 | 13337篇 |
2017年 | 13651篇 |
2016年 | 14699篇 |
2015年 | 14928篇 |
2014年 | 16074篇 |
2013年 | 18206篇 |
2012年 | 13748篇 |
2011年 | 13787篇 |
2010年 | 14308篇 |
2009年 | 10409篇 |
2008年 | 10672篇 |
2007年 | 10125篇 |
2006年 | 9502篇 |
2005年 | 9233篇 |
2004年 | 8633篇 |
2003年 | 7965篇 |
2002年 | 7899篇 |
2001年 | 2963篇 |
2000年 | 2756篇 |
1999年 | 2318篇 |
1998年 | 1773篇 |
1997年 | 1489篇 |
1996年 | 1173篇 |
1995年 | 1167篇 |
1994年 | 998篇 |
1993年 | 906篇 |
1992年 | 1367篇 |
1991年 | 1273篇 |
1990年 | 1202篇 |
1989年 | 1131篇 |
1988年 | 1011篇 |
1987年 | 922篇 |
1986年 | 991篇 |
1985年 | 962篇 |
1984年 | 809篇 |
1983年 | 722篇 |
1982年 | 715篇 |
1981年 | 603篇 |
1980年 | 513篇 |
1979年 | 595篇 |
1978年 | 486篇 |
1977年 | 445篇 |
1975年 | 399篇 |
1974年 | 427篇 |
1973年 | 397篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
Jing‐Ping Zhang Limin Zheng Jiang‐Hai Wang Karl‐Eric Magnusson Xin Liu 《Phytotherapy research : PTR》2009,23(6):844-850
Ganoderma sinensis has been used widely in Oriental countries for the prevention and treatment of various diseases including cancer. Previous studies have shown that the lipid extract from Ganoderma exhibits direct cytotoxicity against tumor cells. Here, it is reported that the lipid extract from germinating G. sinensis spores, at lower concentrations that have no direct tumoricidal activity, induce potent antitumor immune responses in human monocytes/macrophages. Upon stimulation with the lipid extract, monocytes/macrophages exhibited markedly increased production of proinflammatory cytokines and surface expression of costimulatory molecules. Conditioned medium from stimulated cells effectively suppressed the growth of tumor cells. Apparently, the lipid extract triggered macrophage activation via a mechanism different from that associated with LPS. Moreover, it was observed that the lipid extract could partially re‐establish the antitumor activity of the immunosuppressive tumor‐associated macrophages. These results indicated that in addition to its direct tumoricidal activity, the lipid extract from G. sinensis spores could exert antitumor activity by stimulating the activation of human monocytes/macrophages. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
54.
Workplace status and risk of hypertension among hourly and salaried aluminum manufacturing employees
Jane Ellen Clougherty Ellen A. Eisen Martin D. Slade Ichiro Kawachi Mark R. Cullen 《Social science & medicine (1982)》2009
An inverse relationship between workplace status and morbidity is well established; higher job status has been associated with reduced risks of heart disease, hypertension, and injury. Most research on job status, however, has focused on salaried populations, and it remains unclear whether job status operates similarly among hourly workers. Our objectives were to examine whether hourly status itself influences risk of hypertension after adjustment for socioeconomic confounders, and to explore the role of fine-scale job grade on hypertension incidence within hourly and salaried groups. We examined data for 14,999 aluminum manufacturing employees in 11 plants across the U.S., using logistic regression with adjustment for age, sex, race/ethnicity and other individual characteristics. Propensity score restriction was used to identify comparable groups of hourly and salaried employees, reducing confounding by sociodemographic characteristics. Job grade (coded 1 through 30, within hourly and salaried groups) was examined as a more refined measure of job status. Hourly status was associated with an increased risk of hypertension, after propensity restriction and adjustment for confounders. The observed effect of hourly status was stronger among women, although the propensity-restricted cohort was disproportionately male (96%). Among salaried workers, higher job grade was not consistently associated with decreased risk; among hourly employees, however, there was a significant trend, with higher job grades more protective against hypertension. Increasing the stringency of hypertension case criteria also increased the risk of severe or persistent hypertension for hourly employees. 相似文献
55.
56.
57.
58.
Marie Maguire 《British Journal of Psychotherapy》2005,22(1):3-20
ABSTRACT I explore a bisexual male patient's need to differentiate highly problematic'feminine'identifications - originating in childhood sexual abuse and impingement by men as well as women - from identifications with more admired aspects of his mother. My main focus is on the patient's sexual identity - the personal meaning he gave to being male - rather than on his bisexuality - his desire for both sexes. In psychoanalytic literature powerful opposite-sex identifications are usually associated either with psychotic confusion or celebrated as a source of psychic strength. The co-existence of problematic and highly valued cross-sex identifications is rarely discussed. I also look at how this patient re-negotiated his identity through the transference relationship with a female psychotherapist, given that his'masculinity'derived mainly from childhood experiences of 'stealing'his mother's phallic power. Through a wideranging theoretical review I conclude that we need to draw together opposing psychoanalytic perspectives about maternal and paternal power, opening up new ways of thinking about triangular relationships in the transference. 相似文献
59.
Henry Ho‐Lung Chan 《Clinical & experimental optometry》2005,88(6):410-414
The first‐order kernel analysis in multifocal electroretinogram (mfERG) using low contrast stimulation is suggested as a way to detect the inner retinal responses in animal studies. In this case report, this protocol is applied to human patients with glaucoma to demonstrate the possibility of using mfERG as a tool to detect glaucomatous damage. Two patients with glaucoma were recruited and had mfERG measurements with the 103‐scaled hexagonal stimulus pattern at low (50 per cent) contrast. Their responses were analysed and compared with those from normal subjects with the mfERG measured under the same condition. In the normal subjects, there were obvious oscillatory components on the ascending and descending limbs of the first‐order kernel response to 50 per cent contrast. In the glaucomatous patients, the oscillatory component on the descending limb was obviously diminished. In addition, this component was significantly diminished in the quadrant with a glaucomatous visual field defect. This suggests that the low‐contrast stimulation condition in mERG measurement may provide a good way to detect glaucomatous damage and this may help in clinical diagnosis of glaucoma. 相似文献
60.
Jean Marie Jully Marie Christine Béné Gérard Martin Gilbert Faure 《Journal of clinical periodontology》1986,13(3):223-227
The cellular infiltrate present in human diseased gingiva was analyzed in biopsies from 12 patients with gingivitis or periodontitis. The samples studied had been obtained in the course of surgery at inflammatory sites remaining after institution of periodontal treatment. Histological and immunological techniques were used to identify macrophages, B-cells, plasma-cells, T-cells and T cell subsets, as well as cells expressing class II HLA membrane antigens. T-cells appeared as the predominant population, but plasma-cells were also visualized in nearly all samples. Both OKT4+ and OKT8+ cells were seen in all cases, the latter being more numerous in periodontitis patients. Interdigitating-like cells were observed, positively labelled for class II antigens, as well as macrophages which were more numerous in periodontitis patients. These results suggest the participation of all components of the immune response in gingival disease, in a way resembling chronic recurrent inflammatory diseases. 相似文献