全文获取类型
收费全文 | 1743篇 |
免费 | 98篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 98篇 |
妇产科学 | 20篇 |
基础医学 | 138篇 |
口腔科学 | 43篇 |
临床医学 | 125篇 |
内科学 | 477篇 |
皮肤病学 | 88篇 |
神经病学 | 89篇 |
特种医学 | 42篇 |
外科学 | 223篇 |
综合类 | 32篇 |
一般理论 | 2篇 |
预防医学 | 53篇 |
眼科学 | 94篇 |
药学 | 149篇 |
中国医学 | 5篇 |
肿瘤学 | 123篇 |
出版年
2023年 | 18篇 |
2022年 | 39篇 |
2021年 | 60篇 |
2020年 | 24篇 |
2019年 | 48篇 |
2018年 | 76篇 |
2017年 | 40篇 |
2016年 | 42篇 |
2015年 | 33篇 |
2014年 | 54篇 |
2013年 | 106篇 |
2012年 | 149篇 |
2011年 | 126篇 |
2010年 | 65篇 |
2009年 | 72篇 |
2008年 | 80篇 |
2007年 | 105篇 |
2006年 | 62篇 |
2005年 | 72篇 |
2004年 | 70篇 |
2003年 | 70篇 |
2002年 | 69篇 |
2001年 | 26篇 |
2000年 | 35篇 |
1999年 | 35篇 |
1998年 | 14篇 |
1997年 | 14篇 |
1996年 | 11篇 |
1995年 | 7篇 |
1993年 | 6篇 |
1992年 | 20篇 |
1991年 | 16篇 |
1990年 | 20篇 |
1989年 | 12篇 |
1988年 | 12篇 |
1987年 | 13篇 |
1986年 | 9篇 |
1985年 | 8篇 |
1984年 | 8篇 |
1983年 | 6篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 4篇 |
1976年 | 6篇 |
1975年 | 8篇 |
1974年 | 10篇 |
1973年 | 7篇 |
1972年 | 4篇 |
1971年 | 11篇 |
排序方式: 共有1846条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Piceatannol (3,4,3',5'-tetrahydroxy-trans-stilbene) (NSC 365798) has recently been isolated and was subsequently synthesized for NCI tumor panel testing as a new antileukemic natural product from the seeds of Euphorbia lagascae. During the synthesis, a bioactive reaction mixture of several partially O-methylated piceatannol analogues was obtained. This mixture has now been maximized and subjected to bioactivity-directed fractionation, using brine shrimp lethality, to yield 3,3',5'-tri-O-methylpiceatannol (NSC 381281); this new compound has improved stability and better bioactivity in several systems than piceatannol itself. To confirm the structure, 5 was synthesized from vanillin. In addition, the isovanillin analogue, 4,3',5'-tri-O-methylpiceatannol (NSC 381864), another new compound, was synthesized and found to be bioactive. 相似文献
5.
Bioactive stilbenes of Scirpus maritimus 总被引:1,自引:0,他引:1
6.
7.
In the present work we report our studies on IgG separated from the serum of lepromatous patients and non-lepromatous leprosy cases using Laser Raman Spectroscopy. Striking spectral changes in LL cases have been observed in the following special regions: (a) the amide I and III, (b) the S-S and C-S stretching (c) the skeletal bending and (d) skeletal stretching regions. These changes indicate a decrease in the amount of beta-structure and a transition towards alpha-helical conformation. 相似文献
8.
R. Srinivas Reddy S. Bajaj A. R. Tolat J. Compson 《European journal of orthopaedic surgery & traumatology : orthopedie traumatologie》2007,17(4):373-376
Neurofibromas in the hand are uncommon and constitute less than 5% of all hand tumours. Accurate diagnosis and appropriate management are important because malignant transformation has been reported, especially in Von Recklinghausen’s neurofibromatosis. We report a case of a large neurofibroma in the right hand of an 18-year-old girl of Afro-Caribbean origin. She was symptomatic with complaints of pain and weakness of grip. General examination revealed multiple café-au-lait spots on the trunk and one nodular swelling in the forearm. The swelling was excised through a palmar approach and histology proved it to be a neurofibroma. The case is being reported for its rarity and it emphasizes the importance of general examination. Histopathological examination is vital in excluding malignant transformation. 相似文献
9.
Van Buskirk Glenn A. González Mario A. Shah Vinod P. Barnhardt Scott Barrett Colin Berge Stephen Cleary Gary Chan Keith Flynn Gordon Foster Thomas Gale Robert Garrison Raymond Gochnour Scott Gotto Amanda Govil Sharad Gray Vivian A. Hammar James Harder Samuel Hoiberg Charles Hussain Ajaz Karp Carol Llanos Hector Mantelle Juan Noonan Patrick Swanson David Zerbe Horst 《Pharmaceutical research》1997,14(7):848-852
Pharmaceutical Research - 相似文献
10.
Manjula K. Gupta Karen Seifarth Sharad D. Deodhar O. P. Schumacher 《Journal of clinical laboratory analysis》1987,1(1):124-128
A sensitive, simultaneous sandwich enzyme immunoassay for TSH was evaluated especially for its ability to distinguish hyperthyroid patients from the euthyroid population. A total of 140 patient samples was analzyed by this assay as well as with a two-step sandwich radioimmunoassay. The diagnostic sensitivity of the thyrotropin assay was 92.5% and the specificity was 88%. False negatives by thyrotropin assay included two patients with Graves' disease who were being treated with propranolol at the time of testing and one patient who was considered hyperthyroid while receiving synthroid. Twelve patients with elevated free thyroxine index levels were considered euthyroid and 50% of these had thyrotropin values that were undetectable; most were elderly patients with nonthyroidal illnesses. Although the thyrotropin enzyme immunoassay had good sensitivity and precision for the detection of hyperthyroidism, our data suggest the limitation of a single thyrotropin determination in establishing the euthyroid state, especially in elderly patients with associated nonthyroidal illnesses and hyperthyroxinemia. 相似文献