全文获取类型
收费全文 | 1074823篇 |
免费 | 71748篇 |
国内免费 | 1366篇 |
专业分类
耳鼻咽喉 | 15015篇 |
儿科学 | 34621篇 |
妇产科学 | 28623篇 |
基础医学 | 153401篇 |
口腔科学 | 29555篇 |
临床医学 | 94910篇 |
内科学 | 203643篇 |
皮肤病学 | 24391篇 |
神经病学 | 81453篇 |
特种医学 | 42964篇 |
外国民族医学 | 201篇 |
外科学 | 163096篇 |
综合类 | 21702篇 |
现状与发展 | 1篇 |
一般理论 | 263篇 |
预防医学 | 74601篇 |
眼科学 | 24535篇 |
药学 | 86106篇 |
7篇 | |
中国医学 | 2805篇 |
肿瘤学 | 66044篇 |
出版年
2019年 | 7756篇 |
2018年 | 11293篇 |
2017年 | 8906篇 |
2016年 | 10094篇 |
2015年 | 11263篇 |
2014年 | 15267篇 |
2013年 | 22200篇 |
2012年 | 30545篇 |
2011年 | 32289篇 |
2010年 | 18953篇 |
2009年 | 17814篇 |
2008年 | 29949篇 |
2007年 | 32069篇 |
2006年 | 32701篇 |
2005年 | 31031篇 |
2004年 | 29720篇 |
2003年 | 28550篇 |
2002年 | 27529篇 |
2001年 | 60026篇 |
2000年 | 61477篇 |
1999年 | 50927篇 |
1998年 | 12446篇 |
1997年 | 11000篇 |
1996年 | 11014篇 |
1995年 | 10323篇 |
1994年 | 9341篇 |
1993年 | 8859篇 |
1992年 | 37788篇 |
1991年 | 36273篇 |
1990年 | 35747篇 |
1989年 | 34289篇 |
1988年 | 30867篇 |
1987年 | 29989篇 |
1986年 | 28217篇 |
1985年 | 26448篇 |
1984年 | 19185篇 |
1983年 | 16114篇 |
1982年 | 8823篇 |
1979年 | 17029篇 |
1978年 | 11404篇 |
1977年 | 10229篇 |
1976年 | 8837篇 |
1975年 | 10068篇 |
1974年 | 11651篇 |
1973年 | 11273篇 |
1972年 | 10754篇 |
1971年 | 10092篇 |
1970年 | 9252篇 |
1969年 | 8939篇 |
1968年 | 7919篇 |
排序方式: 共有10000条查询结果,搜索用时 7 毫秒
941.
Simultaneous immunoelectron microscopic localization of human chorionic gonadotropin (HCG) and human placental lactogen (HPL) was examined on the same ultrathin section of human chorionic villi by means of the double labeling technique. Using specific rabbit antisera against HCG and HPL followed by goat anti-rabbit IgG-coated colloidal gold of different sizes (15 nm and 5 nm), immunoreactions of HCG were concentrated on middle-sized secretory granules of 200-300 nm and large dense bodies of 500-1000 nm, while those of HPL were exclusively located on small secretory granules of 80-180 nm. The present experiment provides direct evidence for our previous data that HCG and HPL seem to be stored in different granular components in the syncytiotrophoblast. 相似文献
942.
The formation of lens alpha-neoprotein molecules which are built by the association of A and B subunit chains of alpha-crystallin but have a different quaternary structure than the native protein is a posttranslational process that progresses through the life span. Alpha-neoproteins occur regularly in all mature mammalian lenses tested. The mechanisms that have been identified for the formation of alpha neoproteins are imbalance in the biosynthesis of A- to B-chains, which leads to a ratio of less than 2A-chains to 1B-chain, and derivation of the chains after their initial association into native alpha-crystallin. In terms of quantity of neoproteins, no significant differences have been found between lenses with developing cataracts and normal control lenses of corresponding age. The possibility that there are structural differences between alpha-neoproteins in normal and cataractous lenses of the same age, as well as potential differences among alpha-neoproteins isolated from normal lenses of different ages, are presently under investigation. 相似文献
943.
P E Kaiser S K Narang J A Seawright D L Kline 《Journal of the American Mosquito Control Association》1988,4(4):494-499
A new member, species C, of the Anopheles quadrimaculatus complex was recently found in collections from the northwest coast of Florida. This new species cannot be differentiated from the other 2 species with available taxonomic keys. Evidence for this taxon as a sibling species includes data on hybrid sterility and distorted sex ratios in the progeny of crosses to species A and B, chromosomal differences, and diagnostic allozymes. 相似文献
944.
Progressive peripheral cone dysfunction 总被引:1,自引:0,他引:1
A 22-year-old man had a three-year history of progressive day blindness, most notably peripherally, and denied difficulty with central vision or color vision. Visual function studies demonstrated a diffuse dysfunction of the photopic system and normal scotopic function. The central cone function, however, was essentially normal. Visual acuity was 20/20 in each eye, results on AO-HRR and Ishihara color plate testing were normal, color naming visual fields demonstrated color discrimination in the central 10 degrees, and foveal adaptation was normal. 相似文献
945.
946.
947.
The relationship between intestinal Campylobacter species isolated from animals and humans as determined by BRENDA 总被引:4,自引:0,他引:4
Intestinal thermophilic Campylobacter species produce stable patterns when subjected to bacterial restriction endonuclease DNA analysis (BRENDA); this technique is therefore of considerable value in epidemiological studies. BRENDA was used to examine thermophilic Campylobacter species from humans, wild and domestic animals. One hundred and ninety-four (61%) of 316 isolates of Campylobacter jejuni from humans had BRENDA patterns which could be matched to those of animal isolates. Poultry appear to be a major source of infection for C. jejuni in humans with nearly half (49.7%) of the human isolates giving patterns which were indistinguishable from those isolated from poultry. A total of 60 BRENDA types were identified from 316 human isolates and 11 of these had the same pattern as those isolated from poultry. One of the three Campylobacter coli BRENDA types recovered from poultry was indistinguishable from a human isolate type. Pigs appear to be only a minor source of C. coli infection for humans in New Zealand. Rats were found to be infected with strains of C. jejuni with BRENDA patterns indistinguishable from those infecting humans, poultry and a horse. None of the 102 isolates of Campylobacter species from wild birds gave BRENDA patterns similar to those of isolates from humans. 相似文献
948.
On the basis of a series of 500 patients the authors describe the development of silicone oil surgery, the surgical technique, and present-day indications for it, as well as the results that can be achieved with this procedure. The postoperative problems (cataract, glaucoma, and keratopathy) are analyzed and guidelines presented for reducing the complication rate. 相似文献
949.
950.
Ocular manifestations of childhood leukemia 总被引:1,自引:0,他引:1
K Ohkoshi 《Nippon Ganka Gakkai zasshi》1988,92(11):1787-1796