全文获取类型
收费全文 | 619篇 |
免费 | 45篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 34篇 |
妇产科学 | 8篇 |
基础医学 | 64篇 |
口腔科学 | 53篇 |
临床医学 | 58篇 |
内科学 | 112篇 |
皮肤病学 | 7篇 |
神经病学 | 56篇 |
特种医学 | 65篇 |
外科学 | 68篇 |
综合类 | 12篇 |
预防医学 | 27篇 |
眼科学 | 5篇 |
药学 | 31篇 |
肿瘤学 | 34篇 |
出版年
2023年 | 5篇 |
2022年 | 2篇 |
2021年 | 17篇 |
2020年 | 10篇 |
2019年 | 16篇 |
2018年 | 16篇 |
2017年 | 9篇 |
2016年 | 11篇 |
2015年 | 15篇 |
2014年 | 24篇 |
2013年 | 25篇 |
2012年 | 34篇 |
2011年 | 40篇 |
2010年 | 30篇 |
2009年 | 36篇 |
2008年 | 29篇 |
2007年 | 42篇 |
2006年 | 29篇 |
2005年 | 30篇 |
2004年 | 20篇 |
2003年 | 18篇 |
2002年 | 13篇 |
2001年 | 18篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 18篇 |
1997年 | 12篇 |
1996年 | 13篇 |
1995年 | 10篇 |
1994年 | 12篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 10篇 |
1986年 | 10篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 6篇 |
1968年 | 3篇 |
1942年 | 2篇 |
排序方式: 共有676条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
Anderson RA; Wallace AM; Kicman AT; Wu FC 《Human reproduction (Oxford, England)》1997,12(8):1657-1662
Administration of supraphysiological doses of testosterone to normal men
causes inhibition of spermatogenesis, but while most become azoospermic,
30-55% maintain a low rate of spermatogenesis. We have investigated whether
there are differences in endogenous androgen production, of testicular and
adrenal origin, which may be related to the degree of suppression of
spermatogenesis. Thirty-three healthy Caucasian men were given weekly i.m.
injections of 200 mg testosterone oenanthate (TE), 18 became azoospermic,
while 15 remained oligozoospermic. Urinary excretion of epitestosterone, a
specific testicular product, was reduced to <10% of pretreatment values,
with no differences between the groups. Similar results were obtained for
other markers of testicular steroidogenesis. Urinary and plasma adrenal
androgens were also reduced during TE treatment: a statistically
significant decrease in both (P < 0.001 and P < 0.05 respectively)
was seen in the azoospermic but not oligozoospermic responders. These
results suggest that testicular steroidogenesis is decreased to <10% by
the administration of supraphysiological doses of exogenous testosterone.
Differences in the degree of ongoing steroidogenesis in the testis do not
appear to account for incomplete suppression of spermatogenesis, thus
differences in androgen metabolism may underlie this heterogeneous
response. A small but significant reduction in secretion of adrenal
androgens was also detectable, the relevance of which is unclear.
相似文献
5.
Since exogenous hemin has been shown to exert a variety of stimulatory effects on erythroid cells, including the augmentation of hemoglobin synthesis, we determined its effect on early stages of erythroid development by employing clonal cells assays. The addition of hemin at a concentration of 2 X 10(-4) M to cultures of normal murine marrow substantially increased the observed number of primitive BFU-E, which was in contrast to its lack of an effect on more mature erythroid colony-forming cells. This cell-specific enhancement of primitive BFU-E resulted in marrow frequencies equivalent to or exceeding those reported in the presence of "burst-promoting activity." In the presence of hemin, the number of BFU-E was also observed to be linearly related to the number of cells plated at very low plating densities, and the cell titration curve was observed to extrapolate to the origin. The evidence suggests that hemin may be a primary growth regulator of early developmental stages of erythroid progenitor cells. 相似文献
6.
7.
Fernando Moreno Antón Javier Sastre Valera Belén Loboff de León Sara López-Tarruella Luis Ortega Medina Eduardo Díaz-Rubio 《Clinical & translational oncology》2005,7(7):321-323
Metastastic tumours involving the epididymis are rare and most often found in patients with disseminated disease. It is even more unusual when the metastasis of the epididymis is the first sign of tumour recurrence. We report a case of an asymptomatic recurrent colon carcinoma presenting as metastasis in the epididymis. Although metastatic cancer presenting as an intra-scrotal mass is extremely rare, it should be considered as a possibility in patients who present with a mass involving the testicle or epididymis. 相似文献
8.
Edgard Eduard Engel MD PhD María Sol Brassesco PhD Elvis Terci Valera MD PhD Marcello Henrique Nogueira‐Barbosa MD PhD Maurício Eiji de Almeida Santos Yamashita MD Carlos Alberto Scrideli MD PhD Luiz Gonzaga Tone MD PhD 《Pediatric blood & cancer》2012,59(7):1320-1323
Malignant triton tumor (MTT) is an aggressive peripheral nerve sheath tumor with rhabdomyoblastic differentiation. Less than 100 cases have been described, being mostly male children with type 1 neurofibromatosis. We report a 6‐year‐old female with MTT and no diagnostic criteria for neurofibromatosis type 1. Cytogenetic analysis showed a 46,X,‐X[4]/46,XX[16] karyotype. She underwent a transfemoral amputation and chemotherapy and is free of disease 15 months after diagnosis. The few cytogenetic studies of MTT described in the literature have been inconclusive. Further cytogenetic analyses are needed to understand the role of chromosome X monosomy in the pathogenesis of this rare tumor. Pediatr Blood Cancer 2012; 59: 1320–1323. © 2012 Wiley Periodicals, Inc. 相似文献
9.
10.
Chiang Jannifer O. Azevedo Rafael S. Justino Maria C. A. Matos Haroldo J. Cabeça Hideraldo L. S. Silva Sandro P. Henriques Daniele F. Silva Eliana V. P. Andrade Gabriela S. S. Vasconcelos Pedro FC. Martins Lívia C. Azevedo Raimunda S. S. 《Journal of neurovirology》2021,27(4):626-630
Journal of NeuroVirology - We describe two neurological cases of Oropouche virus infection in northern Brazil, where the virus is endemic but neglected as a pathogen. This study reiterates the... 相似文献