全文获取类型
收费全文 | 2032篇 |
免费 | 172篇 |
国内免费 | 61篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 98篇 |
妇产科学 | 30篇 |
基础医学 | 287篇 |
口腔科学 | 60篇 |
临床医学 | 303篇 |
内科学 | 451篇 |
皮肤病学 | 35篇 |
神经病学 | 110篇 |
特种医学 | 259篇 |
外科学 | 147篇 |
综合类 | 77篇 |
一般理论 | 3篇 |
预防医学 | 136篇 |
眼科学 | 52篇 |
药学 | 119篇 |
中国医学 | 2篇 |
肿瘤学 | 91篇 |
出版年
2023年 | 7篇 |
2022年 | 14篇 |
2021年 | 34篇 |
2020年 | 20篇 |
2019年 | 21篇 |
2018年 | 43篇 |
2017年 | 28篇 |
2016年 | 27篇 |
2015年 | 49篇 |
2014年 | 46篇 |
2013年 | 80篇 |
2012年 | 75篇 |
2011年 | 92篇 |
2010年 | 53篇 |
2009年 | 35篇 |
2008年 | 57篇 |
2007年 | 117篇 |
2006年 | 69篇 |
2005年 | 78篇 |
2004年 | 85篇 |
2003年 | 67篇 |
2002年 | 55篇 |
2001年 | 54篇 |
2000年 | 51篇 |
1999年 | 45篇 |
1998年 | 63篇 |
1997年 | 48篇 |
1996年 | 78篇 |
1995年 | 62篇 |
1994年 | 54篇 |
1993年 | 67篇 |
1992年 | 24篇 |
1991年 | 32篇 |
1990年 | 49篇 |
1989年 | 51篇 |
1988年 | 53篇 |
1987年 | 64篇 |
1986年 | 48篇 |
1985年 | 45篇 |
1984年 | 30篇 |
1983年 | 18篇 |
1982年 | 17篇 |
1981年 | 27篇 |
1980年 | 25篇 |
1979年 | 12篇 |
1978年 | 13篇 |
1977年 | 19篇 |
1976年 | 11篇 |
1975年 | 11篇 |
1971年 | 6篇 |
排序方式: 共有2265条查询结果,搜索用时 156 毫秒
11.
Sixteen cases of histopathologically proved solitary rectal ulcer syndrome were encountered. Fifteen patients underwent barium enema study; in nine cases the findings--including rectal stricture, granularity of the mucosa, and thickened rectal folds-were nonspecific. In six cases the study was normal. All patients had a long history of defecation disorders, and defecography was performed in all. In seven cases, intussusception of the rectal wall was seen; in another case the intussusception was accompanied by a rectocele. One case showed rectal prolapse. In four cases, failed relaxation of the puborectalis occurred and prevented the passage of the bolus; in another case there was abnormal perineal descent. In two patients studies were normal. In patients with defecation disorders, the possibility of this syndrome should be considered. Defecography is the method of choice for establishing the diagnosis. 相似文献
12.
13.
14.
Dissecting aneurysms of the vertebral arteries following cervical manipulation: a case report. 总被引:1,自引:1,他引:0 下载免费PDF全文
J W Dunne G N Conacher M Khangure C G Harper 《Journal of neurology, neurosurgery, and psychiatry》1987,50(3):349-353
Neck manipulation may uncommonly be associated with serious and even fatal vascular complications. Although well recognised, the nature of the vascular injury has only rarely been directly established by pathological examination. The case is reported of a 43-year-old man who died following neck manipulation, and in whom multiple dissecting aneurysms within both vertebral arteries were demonstrated radiologically and found at necropsy. Bilateral dissecting aneurysms were found both at the level of atlanto-axial articulation and close to the origins of the vertebral arteries. No predisposition was found, other than early atheroma consistent with the patient's age. 相似文献
15.
16.
17.
18.
19.
Specific antibody responses to three schistosome-related carbohydrate structures in recently exposed immigrants and established residents in an area of Schistosoma mansoni endemicity 下载免费PDF全文
Naus CW van Remoortere A Ouma JH Kimani G Dunne DW Kamerling JP Deelder AM Hokke CH 《Infection and immunity》2003,71(10):5676-5681
By the use of surface plasmon resonance spectroscopy, immunoglobulin G (IgG) subclass and IgM antibodies against three schistosome-derived carbohydrate structures, FLDN (Fucalpha1-3GalNAcbeta1-4GlcNAcbeta1-3Galalpha1), LDN-DF [GalNAcbeta1-4(Fucalpha1-2Fucalpha1-3)GlcNAcbeta1], and LDNF [GalNAcbeta1-4(Fucalpha1-3)GlcNAcbeta1-3Galalpha1], were measured in 184 previously unexposed Kenyan immigrants who moved into the Masongaleni area, where Schistosoma mansoni is endemic. They were sampled within their first year of exposure and again 2 years later. A cohort selected out of the original residents of the area, who had been exposed for many years, served as controls. Associations with responses to S. mansoni worm, egg (SEA), and cercarial (CERC) antigens were examined. In addition, we measured responses to keyhole limpet hemocyanin, a glycoprotein which carries glycan epitopes that are also expressed by schistosomes. Specific IgG1 responses were most pronounced against FLDN and LDN-DF and strongly associated with those previously measured to SEA and CERC. Similarly to previously published age profiles of IgG1 and IgG2 responses to SEA, levels of IgG1 against LDN-DF decreased with age. In contrast, specific IgM responses against the three schistosome-derived carbohydrate structures were most marked against LDNF. Our results indicate that, of the three glycan structures tested, the acute response against schistosome glycoconjugate antigens in young children is mainly directed against the LDN-DF epitope. The response to LDN-DF in older individuals and the responses to the two other epitopes were similar in the two cohorts, suggesting that these antigens are recognized in the early stages of infection and that the immune response persists. The biological significance of these observations needs further elucidation. 相似文献
20.
Ghosh D; Stewart DR; Nayak NR; Lasley BL; Overstreet JW; Hendrickx AG; Sengupta J 《Human reproduction (Oxford, England)》1997,12(5):914-920
The present study was undertaken to assess the temporal association between
the profiles of serum concentrations of oestradiol-17beta, progesterone,
chorionic gonadotrophin (CG) and relaxin in pregnancies established
naturally, and after embryo transfer, as well as in failed pregnancies in
rhesus monkeys. In naturally mated cycles (group 1) a conception rate of
75% was obtained. In group 1, the mean day of CG detection in serum was
11.5 +/- 1.9 day post-ovulation, and for relaxin, 9.0 +/- 2.5 day
post-ovulation. In group 2, embryo transfer to synchronous, non-mated
surrogate recipients was performed; seven embryo transfer cycles yielded
three pregnancies which were allowed to continue to term and normal infants
were delivered. In embryo transfer cycles the mean day of CG detection was
14.8 +/- 1.8 day post- ovulation, and for relaxin, 11.4 +/- 2.6 day
post-ovulation. A delay of about 3 days was observed in the appearance in
circulation of CG (P < 0.05) and also of relaxin (P < 0.05) between
natural mated and embryo transfer conception cycles. Significant
differences (P < 0.05 for progesterone and P < 0.03 for oestradiol)
were obtained for the areas under the curves for progesterone and
oestradiol between days 12 and 16 in conception cycles compared with failed
pregnancies. These data provide the first observation of the normal
hormonal signals associated with maternal recognition of transferred
embryos during the peri- implantation period, and suggest that the use of
such an experimental primate embryo transfer model may help to elucidate
components of maternal and embryonic signal-response mechanisms during
embryo implantation.
相似文献