全文获取类型
收费全文 | 231581篇 |
免费 | 21696篇 |
国内免费 | 15349篇 |
专业分类
耳鼻咽喉 | 1928篇 |
儿科学 | 2337篇 |
妇产科学 | 2921篇 |
基础医学 | 27471篇 |
口腔科学 | 4155篇 |
临床医学 | 30696篇 |
内科学 | 33529篇 |
皮肤病学 | 2614篇 |
神经病学 | 11929篇 |
特种医学 | 8279篇 |
外国民族医学 | 135篇 |
外科学 | 23227篇 |
综合类 | 38870篇 |
现状与发展 | 50篇 |
一般理论 | 23篇 |
预防医学 | 15468篇 |
眼科学 | 6364篇 |
药学 | 25020篇 |
224篇 | |
中国医学 | 14130篇 |
肿瘤学 | 19256篇 |
出版年
2024年 | 923篇 |
2023年 | 3784篇 |
2022年 | 9818篇 |
2021年 | 12414篇 |
2020年 | 9277篇 |
2019年 | 7895篇 |
2018年 | 8368篇 |
2017年 | 7610篇 |
2016年 | 7142篇 |
2015年 | 11004篇 |
2014年 | 13423篇 |
2013年 | 12180篇 |
2012年 | 17826篇 |
2011年 | 19416篇 |
2010年 | 12170篇 |
2009年 | 9570篇 |
2008年 | 12552篇 |
2007年 | 12044篇 |
2006年 | 11703篇 |
2005年 | 11423篇 |
2004年 | 7384篇 |
2003年 | 6738篇 |
2002年 | 5641篇 |
2001年 | 4715篇 |
2000年 | 4974篇 |
1999年 | 5112篇 |
1998年 | 3123篇 |
1997年 | 3102篇 |
1996年 | 2387篇 |
1995年 | 2299篇 |
1994年 | 1979篇 |
1993年 | 1199篇 |
1992年 | 1647篇 |
1991年 | 1412篇 |
1990年 | 1162篇 |
1989年 | 1065篇 |
1988年 | 969篇 |
1987年 | 787篇 |
1986年 | 591篇 |
1985年 | 495篇 |
1984年 | 233篇 |
1983年 | 204篇 |
1982年 | 110篇 |
1981年 | 143篇 |
1980年 | 94篇 |
1979年 | 123篇 |
1978年 | 52篇 |
1977年 | 53篇 |
1976年 | 42篇 |
1974年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Lei Ding Christopher Wilke Bobby Xu Xiaoliang Xu Wim van Drongelen Michael Kohrman Bin He 《Journal of clinical neurophysiology》2007,24(2):130-136
SUMMARY: It is desirable to estimate epileptogenic zones with both location and extent information from noninvasive EEG. In the present study, the authors use a subspace source localization method (FINE), combined with a local thresholding technique, to achieve such tasks. The performance of this method was evaluated in interictal spikes from three pediatric patients with medically intractable partial epilepsy. The thresholded subspace correlation, which is obtained from FINE scanning, is a favorable marker, which implies the extents of current sources associated with epileptic activities. The findings were validated by comparing the results with invasive electrocorticographic (ECoG) recordings of interictal spike activity. The surgical resections in these three patients correlated well with the epileptogenic zones identified from both EEG sources and ECoG potential distributions. The value of the proposed noninvasive technique for estimating epileptiform activity was supported by satisfactory surgery outcomes. 相似文献
72.
73.
Jiyou Li Yuquan Xie Guizhi Shi Heling Sun Xinhua Ji Maolin Jin Boqin Yang Mingsheng Wang 《中国癌症研究》1992,4(2):10-12
In order to investigate the antagonistic effect of Glycyrrhiza Uralensis Fish (GUF) and Chelidonium maJus L (CML) on gastrccarcinogenesis
induced by MNNG in Wastar rats, we treated the rats with MNNG alone (group 1) and with MNNG plus GUF and CML (group 2 and
3) respectively. The incidence of infiltrating adenocarcinoma of the glandular stomach and duodenum in group 2 was significantly
lower than that in group 1 (26.7% vs. 67.8%). The differentiation and aggressivenees of carcinomas occured in group 2 were
much better and mild than those in group 1. Present study also demonstrated that the inhibitory effect of CML on proliferation
of human stomach carcinoma cell line MGC-803 was very remarkable; in addition, GUF and CML were able to antagonise the mutagenic
activation of MNNG. These results suggest that GUF and CML may be empoyed in prevention of gastric carcinoma. 相似文献
74.
T.-N. Wu Chen-Yang Shen Saou-Hsing Liou Guang-Yang Yang K.-N. Ko Show-Lin Chao Chao-Chun Hsu P.-Y. Chang 《International archives of occupational and environmental health》1997,69(6):386-391
To monitor the lead hazards in industries and to investigate the prevalence of elevated blood lead levels (BLLs) in lead-exposed
workers, a lead surveillance system (PRESS-BLLs) has been established and operated in Taiwan, Republic of China, since July
1993. A cohort of lead-exposed workers who received a periodic annual health examination at 55 accredited hospital laboratories
was constructed. A total of 9807 separate BLL measurements were reported to the system in 1994. The mean BLL was 15.8 μg/dl
in male workers and 11.6 μg/dl in female workers. The mean BLL of lead-exposed workers was significantly (P<0.05, z-test) higher than that of the general Taiwanese population (8.6 μg/dl for males and 6.7 μg/dl for females). In addition,
the BLLs of 983 (10.0%) workers exceeded the regulatory action level (40 μg/dl for males; 30 μg/dl for females). The workplaces
and homes of 57% of the workers with elevated BLLs were thoroughly investigated to determine the sources of lead contamination.
These actions identified the causes of elevated BLLs and set up strategies to reduce workers’ lead exposure. The establishment
of this occupational lead surveillance system represents a method for monitoring of lead hazards from occupational and environmental
settings to prevent lead poisoning. The information acquired from the system can help in the setting up of a priority of prevention
and the development of control measures. It is also useful for further monitoring of changes in the BLLs of the lead-exposed-worker
cohort. The Health Department of Taiwan can use this information to evaluate the effectiveness of current industrial hygiene
practice. Subjects with elevated BLLs have been medically treated and placed on long-term follow-up for sequelae.
Received: 2 September 1996/Accepted: 29 November 1996 相似文献
75.
76.
77.
本文报告了1990年5月以来脑干区大型、复杂占位病变15例.其中,位于脑干内3例,脚间窝2例,岩尖部4例,全岩骨区1例,全斜坡区2例,第四脑室内3例.本组采用以扩大了的岩骨入路为主的联合入路,行肿瘤全切除8例,次全切除5例.2例仅作了活检加减压术.除1例死亡外,均恢复良好.本文结合文献,对脑干区手术入路进行了讨论. 相似文献
78.
79.
Penetration of Schistosoma japonicum cercaria into host skin. 总被引:1,自引:0,他引:1
The anterior part of Schistosoma japonicum cercaria is a specialized head organ which can slightly stretch out and retract. There are three different types of large unicellular glands in cercarial body, consisting of one head gland, 2 pairs of pre- and 3 pairs of postacetabular glands. These glands differ in position, gross feature, histochemistry and functions. Both polysaccharase and protease activities are demonstrated in the secretions from these glands. Mode of cercarial penetration is described in detail and the penetration is effected by a combination of lytic secretions and mechanical movements. The schematic representation of the process of cercarial penetration is presented. The dynamic distributions of schistosomula in skin at different time intervals after skin penetration in various mammalian hosts are shown. Some newly transformed schistosomula die while penetrating into the skin of 7 mammalian species and the mortality rate varies with the host species, and that can also be affected by the age of cercariae following emergence from the snail. Some physiological aspects between cercariae and newly transformed schistosomula are compared. In contrast to cercariae, schistosomula are saline-adapted and water-intolerant. They were modified histochemically and antigenically.
相似文献
80.