全文获取类型
收费全文 | 32849篇 |
免费 | 1793篇 |
国内免费 | 222篇 |
专业分类
耳鼻咽喉 | 247篇 |
儿科学 | 757篇 |
妇产科学 | 499篇 |
基础医学 | 3987篇 |
口腔科学 | 769篇 |
临床医学 | 2253篇 |
内科学 | 8705篇 |
皮肤病学 | 599篇 |
神经病学 | 2703篇 |
特种医学 | 1069篇 |
外科学 | 5509篇 |
综合类 | 191篇 |
一般理论 | 1篇 |
预防医学 | 889篇 |
眼科学 | 479篇 |
药学 | 2315篇 |
中国医学 | 56篇 |
肿瘤学 | 3836篇 |
出版年
2023年 | 229篇 |
2022年 | 445篇 |
2021年 | 736篇 |
2020年 | 410篇 |
2019年 | 551篇 |
2018年 | 772篇 |
2017年 | 500篇 |
2016年 | 672篇 |
2015年 | 744篇 |
2014年 | 901篇 |
2013年 | 1068篇 |
2012年 | 1738篇 |
2011年 | 1876篇 |
2010年 | 1055篇 |
2009年 | 871篇 |
2008年 | 1553篇 |
2007年 | 1762篇 |
2006年 | 1623篇 |
2005年 | 1687篇 |
2004年 | 1554篇 |
2003年 | 1396篇 |
2002年 | 1493篇 |
2001年 | 1016篇 |
2000年 | 972篇 |
1999年 | 922篇 |
1998年 | 395篇 |
1997年 | 323篇 |
1996年 | 337篇 |
1995年 | 222篇 |
1994年 | 227篇 |
1993年 | 197篇 |
1992年 | 562篇 |
1991年 | 521篇 |
1990年 | 529篇 |
1989年 | 480篇 |
1988年 | 462篇 |
1987年 | 455篇 |
1986年 | 392篇 |
1985年 | 412篇 |
1984年 | 304篇 |
1983年 | 210篇 |
1979年 | 220篇 |
1978年 | 149篇 |
1977年 | 148篇 |
1974年 | 133篇 |
1971年 | 136篇 |
1970年 | 132篇 |
1969年 | 128篇 |
1968年 | 140篇 |
1967年 | 141篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Mitsuru Takahashi Hidenobu Takahashi Tetsushi Itoh Masaharu Nomura Akihiko Ogata Sachio Maehara Harubumi Kato 《Annals of thoracic and cardiovascular surgery》2006,12(1):50-52
Postoperative empyema and aspergillosis were diagnosed in a 66-year-old man. Since non-operative therapy was not effective, we performed surgery. On the 8th postoperative day, a covered Ultraflex expandable stent (Boston Scientific, Galway, Ireland) was implanted to make a one-way airway for blocking a major air leak from a bronchopleural fistula causing respiratory distress. His general condition improved gradually, and he was discharged 30 days after stenting. In conclusion, we used a covered Ultraflex expandable stent to make an airway to block an air leak. This may be a new application for this stent. 相似文献
12.
Factors associated with levels of physical activity at work and during leisure time were analyzed among 577 subjects who had been selected as population controls for a case-control study by random selection from telephone directories. The intensity of physical activity at work was inversely associated with body mass index, the proportion of professionals & managers, consumption of western style breakfast, coffee, butter/margarine, and whisky; and positively associated with rice intake. Frequency of physical activities during leisure time was positively associated with consumption of vegetables, fruits, mushrooms, milk, cheese and coffee, and moderation in eating; and inversely associated with rice intake and the prevalence of gastrointestinal symptoms and medication. The association of physical activity with these factors should be considered in studying its relationship to disease risk. 相似文献
13.
Tadashi Kato 《Seishin shinkeigaku zasshi》2002,104(6):509-512
14.
15.
16.
17.
18.
Thyroid function tests were studied in 105 severely disabled children. Fifty-four cases (53%) showed following abnormalities. Serum TSH concentration was increased in 2 cases. Both serum T4 and T3 levels were decreased in 18 cases (17%). Only the serum T4 level was decreased in 25 cases (24%). Only the serum T3 level was decreased in 10 cases (9.5%). Two patients showed primary hypothyroidism. Two patients (monozygotic twins) were suspected to have subclinical hypothalamic-pituitary hypothyroidism caused by septo-optic-dysplasia. Abnormal thyroid functions were caused by anticonvulsants in most patients. The serum T4 level was correlated with the number of anticonvulsants, but not correlated with motor performance (daily activity) or feeding function. Four patients who had low T4 level or low T4 and T3 levels were received L-thyroxine supplementation, but no clinical improvement was observed. The serum TSH concentration was decreased and the TRH test showed hyporeaction in all of these cases. The low T3 level and normal T4 level were not related to anticonvulsant administration. Two of these patients were in poor nutritional condition, resulting in so called low T3 syndrome. 相似文献
19.
20.
Cloning of regions required for contact hemolysis and entry into LLC-MK2 cells from Shigella sonnei form I plasmid: virF is a positive regulator gene for these phenotypes. 总被引:10,自引:5,他引:5 下载免费PDF全文
Two distinct regions required for both contact hemolysis and entry into LLC-MK2 cells were cloned into Escherichia coli from the Shigella sonnei form I plasmid, pSS120. The first region was cloned into an E. coli HB101 strain containing noninvasive Tn1 insertion mutants of the form I plasmid, and expression of ipa (invasion plasmid antigen) gene products was restored. The plasmid carrying the first region was then transformed into E. coli lacking the form I plasmid, and additional DNA fragments from the form I plasmid were cloned into the same recipient on compatible vectors. Five of these double transformants were found to be positive for contact hemolysis activity. Restriction analysis of these five clones indicated that the previously reported ipa locus and the invA locus were present on the second plasmid region. Only the strains carrying both of these regions were active in contact hemolysis and cell invasion assays. Several proteins, including the a, b, c, and d proteins encoded by the ipa genes, were detected in the double transformants by Western blot (immunoblot) analysis with serum of a monkey convalescing from shigellosis. A positive regulator was suggested to exist in the first region, since the amounts of most of these proteins were simultaneously increased in the presence of this region. Subcloning and nucleotide sequencing indicated that this positive regulator gene was virF. Product analysis of the virF gene with minicells showed that two peptides (30 and 21 kilodaltons) were synthesized and that at least the 30-kilodalton protein was essential for regulation of the ipa genes. 相似文献