全文获取类型
收费全文 | 33399篇 |
免费 | 1858篇 |
国内免费 | 125篇 |
专业分类
耳鼻咽喉 | 378篇 |
儿科学 | 1663篇 |
妇产科学 | 919篇 |
基础医学 | 4036篇 |
口腔科学 | 675篇 |
临床医学 | 2286篇 |
内科学 | 7246篇 |
皮肤病学 | 945篇 |
神经病学 | 2378篇 |
特种医学 | 886篇 |
外科学 | 3935篇 |
综合类 | 822篇 |
一般理论 | 23篇 |
预防医学 | 2234篇 |
眼科学 | 1620篇 |
药学 | 2876篇 |
中国医学 | 217篇 |
肿瘤学 | 2243篇 |
出版年
2023年 | 206篇 |
2022年 | 476篇 |
2021年 | 1203篇 |
2020年 | 623篇 |
2019年 | 830篇 |
2018年 | 998篇 |
2017年 | 704篇 |
2016年 | 841篇 |
2015年 | 874篇 |
2014年 | 1310篇 |
2013年 | 1596篇 |
2012年 | 2341篇 |
2011年 | 2525篇 |
2010年 | 1360篇 |
2009年 | 1135篇 |
2008年 | 1833篇 |
2007年 | 1888篇 |
2006年 | 1827篇 |
2005年 | 1588篇 |
2004年 | 1404篇 |
2003年 | 1228篇 |
2002年 | 1159篇 |
2001年 | 745篇 |
2000年 | 724篇 |
1999年 | 595篇 |
1998年 | 279篇 |
1997年 | 197篇 |
1996年 | 166篇 |
1995年 | 179篇 |
1994年 | 131篇 |
1993年 | 123篇 |
1992年 | 379篇 |
1991年 | 382篇 |
1990年 | 347篇 |
1989年 | 337篇 |
1988年 | 289篇 |
1987年 | 262篇 |
1986年 | 241篇 |
1985年 | 236篇 |
1984年 | 178篇 |
1983年 | 142篇 |
1981年 | 103篇 |
1979年 | 159篇 |
1978年 | 102篇 |
1977年 | 88篇 |
1975年 | 84篇 |
1974年 | 101篇 |
1973年 | 96篇 |
1972年 | 121篇 |
1970年 | 81篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
A. R. Mridha M. C. Sharma C. Sarkar V. Suri A. Rishi A. Garg A. Suri 《Child's nervous system》2007,23(10):1209-1213
Introduction Myxopapillary ependymomas are low grade tumours that are known to recur locally even after complete excision, but metastasis
to distant sites is extremely uncommon.
Case report We report an unusual case of lumbo-sacral myxopapillary ependymoma in a 13-year-old boy with metastasis to both cerebellopontine
angles. To the best of our knowledge, this is the youngest patient of metastatic myxopapillary ependymoma. 相似文献
73.
Christopher D Wells Russell I Heigh Virender K Sharma Michael D Crowell Suryakanth R Gurudu Jonathan A Leighton Nora Mattek David E Fleischer 《BMC gastroenterology》2007,7(1):19
Background
Many factors impacting cecal intubation rates have been examined in detail; however, little information exists regarding the effect of the timing of the procedure. We sought to examine any difference in cecal intubation rates between morning and afternoon colonoscopies and identify factors contributing to a discrepancy. 相似文献74.
75.
76.
Neerja Sharma 《Early child development and care》1990,58(1):71-79
The infant is the youngest but perhaps the most valuable member of society. It has been unequivocally established through research that the period up to two years is the most potent for forming and establishing the basis of later development. This paper summarizes the findings of two research studies on infant care in India that began in July 1988 and culminated in March 1989 under my guidance. The two studies are linked in their final implications for infant stimulation and in their role in providing insights into changing trends in infant-care in India.
In study I patterns of infant caregiving practiced by fathers were investigated. Study II looked into infant-care practices in Punjabi families where the grandmother lived with the young parents. 相似文献
In study I patterns of infant caregiving practiced by fathers were investigated. Study II looked into infant-care practices in Punjabi families where the grandmother lived with the young parents. 相似文献
77.
This communication highlights scleral dellen as an unusual complication of strabismus surgery in a 55-year-old hypertensive male. The clinical significance, differential diagnosis and management of this condition has been discussed. 相似文献
78.
S D Black P K Sharma J C Gallucci A C Blackburn J W Downs S J Rinderle D T Witiak 《Carcinogenesis》1992,13(8):1337-1343
1,2,3,4-Tetrahydro-7,12-dimethylbenz[a]anthracene (THDMBA) is an animal carcinogen which lacks an aromatic bay-region and shows promise as a model to investigate non-classical mechanisms of carcinogenesis. The fluorine-substituted derivatives at positions 5 and 6 on the B-ring exhibit a striking range of oncogenic potential wherein the 6F-THDMBA is twice as potent as the parent carcinogen, but the 5F-THDMBA is virtually inactive. To study structure-reactivity relationships for these fluorine regioisomers, we have determined the three-dimensional structures of the compounds by single-crystal X-ray diffraction. These crystal structures are the first such to be reported for any monofluoro anthracene (or pyrene) derivative. The partially-reduced A-ring exists in both enantiomeric half-chair conformers in the crystalline state, and the compounds have quasi-planar anthracene ring systems which exhibit a right-handed twist in the 'beta'-conformer, with the expected opposite twist in the other. A complete analysis of bond lengths, bond angles and torsion angles is presented. Preliminary electrostatic potentials have been derived from the X-ray data sets, and the results indicate significant differences in potential between 5F- and 6F-THDMBA at positions near the partially reduced bay region. Such results are likely to be of importance in the understanding of metabolic activation to reactive intermediates capable of bonding covalently to DNA. 相似文献
79.
We describe herein the rare case of a hydatid cyst found in the breast of a 26-year-old woman. Clinically, the mass was at
first suspected of being a fibroadenoma, but fine needle aspiration cytology (FNAC) yielded clear fluid only. Histopathologic
examination of the resected speciman confirmed that it was a hydatid cyst. 相似文献
80.
S. Shaikh D. A. Collier P. Sham L. Pilowsky T. Sharma L. K. Lin M. A. Crocq M. Gill R. Kerwin 《American journal of medical genetics. Part A》1995,60(6):541-545
We have examined the hypothesis that a variable number of tandem repeats in the third cytoplasmic loop of the dopamine D4 receptor influences clinical response to clozapine using a sample of 189 schizophrenic patients. Alleles of the 48-bp repeat, which range from two to ten copies in the normal human population, were analysed by the polymerase chain reaction using genomic DNA as template. Association between these alleles and response to clozapine was tested using the difference in pre-and post-treatment GAS scores as a measure of response. We found no statistically significant variation between genotypic groups and response by analysis of variance. We conclude that the variation of the number of 48-bp repeats alone does not determine response to clozapine. Larger studies are underway to determine if there is a more subtle relationship with sequence variation within the repeats or at other polymorphic sites within the gene that may provide evidence for a component of clozapine's action being at D4 receptors. © 1995 Wiley-Liss, Inc. 相似文献