全文获取类型
收费全文 | 3129篇 |
免费 | 359篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 158篇 |
妇产科学 | 105篇 |
基础医学 | 332篇 |
口腔科学 | 89篇 |
临床医学 | 432篇 |
内科学 | 568篇 |
皮肤病学 | 79篇 |
神经病学 | 248篇 |
特种医学 | 289篇 |
外科学 | 319篇 |
综合类 | 84篇 |
一般理论 | 1篇 |
预防医学 | 255篇 |
眼科学 | 59篇 |
药学 | 177篇 |
1篇 | |
肿瘤学 | 296篇 |
出版年
2021年 | 29篇 |
2020年 | 24篇 |
2019年 | 43篇 |
2018年 | 37篇 |
2017年 | 27篇 |
2016年 | 44篇 |
2015年 | 56篇 |
2014年 | 67篇 |
2013年 | 107篇 |
2012年 | 116篇 |
2011年 | 134篇 |
2010年 | 115篇 |
2009年 | 109篇 |
2008年 | 110篇 |
2007年 | 116篇 |
2006年 | 114篇 |
2005年 | 107篇 |
2004年 | 94篇 |
2003年 | 88篇 |
2002年 | 89篇 |
2001年 | 83篇 |
2000年 | 87篇 |
1999年 | 87篇 |
1998年 | 107篇 |
1997年 | 94篇 |
1996年 | 83篇 |
1995年 | 66篇 |
1994年 | 57篇 |
1993年 | 70篇 |
1992年 | 56篇 |
1991年 | 71篇 |
1990年 | 65篇 |
1989年 | 92篇 |
1988年 | 95篇 |
1987年 | 67篇 |
1986年 | 63篇 |
1985年 | 63篇 |
1984年 | 52篇 |
1983年 | 44篇 |
1982年 | 46篇 |
1981年 | 27篇 |
1980年 | 40篇 |
1979年 | 29篇 |
1978年 | 41篇 |
1977年 | 31篇 |
1976年 | 31篇 |
1975年 | 25篇 |
1972年 | 22篇 |
1971年 | 22篇 |
1970年 | 21篇 |
排序方式: 共有3508条查询结果,搜索用时 15 毫秒
1.
Satellite cells express distinct patterns of myogenic proteins in immature skeletal muscle. 总被引:1,自引:0,他引:1
Edward Schultz Connie Chamberlain Kathleen M McCormick Paul E Mozdziak 《Developmental dynamics》2006,235(12):3230-3239
Satellite cells are the myogenic cells lying between the myofiber sarcolemma and basal lamina. The objective of this study was to determine the expression patterns of MyoD, myogenin, and Pax7 within the satellite cell population in the growing rat soleus and extensor digitorum longus (EDL) muscles. Secondly, the expression of the myogenic markers was also studied within the interstitial cell compartment and myonuclei. It was discovered that the soleus contained a higher number of Pax7, MyoD, or myogenin-positive nuclei compared with the EDL. Similarly, myogenin was expressed at a lower level in the myonuclei of the soleus compared with the EDL, and myogenin was expressed at a higher level in the interstitial compartment of the soleus compared with the EDL. When interstitial nuclei, myonuclei, and double-labeled nuclei were used in the estimate of the satellite cell population, it was discovered that approximately of 13% of the myofibers in a transverse section of the soleus muscle and 4.1% of EDL myofibers exhibit a labeled satellite cell nucleus. Overall, results from this study suggest that expression patterns of these markers vary predictably among muscles with different growth dynamics and phenotypic characteristics. 相似文献
2.
3.
Terry Joe Sprinkle Julia F. Agee Russell B. Tippins C. Richard Chamberlain Guy B. Faguet George H. DeVries 《Brain research》1987,426(2):349-357
Monoclonal antibodies against human and bovine 2′:3′-cyclic nucleotide 3′-phosphodiesterase (CNPase) were generated by fusing FOX-NY myeloma cells with spleen cells from RBF/Dn mice previously immunized with the purified brain antigens. The enzyme isolated from bovine brain was quite basic, with an isoelectric point of 9.71 and both the bovine and human enzymes consisted of a closely spaced doublet at approximately 44 and 46 kDa on SDS-PAGE. Six monoclonals were identified as strongly recognizing the enzyme on both ELISA plates and on immunoblots of whole brain protein. Four monoclonals very weakly cross-reacted with guinea pig myelin basic protein. In contrast with two previous reports, some of our monoclonal antibodies did immunostain 2 or 3 protein bands in peripheral nerve, two bands closely corresponding to those immunostained in central nervous system (CNS) myelin, the Wolfgram protein fraction and in acetone powders of whole brain. Each of the 6 monoclonals reacting strongly on immunoblots recognized the enzyme in from 2 to 5 of the species examined (human, bovine, rat, mouse and rabbit). In addition, all 6 monoclonals that immunostained the enzyme in whole brain, myelin and Wolfgram protein immunoblots recognized both CNP1 (44 kDa) and CNP2 (46 kDa). The two closely spaced protein bands observed on SDS-PAGE and previously stained on immunoblots of CNS CNPase using polyvalent rabbit anti-bovine CNPase antisera, and now different monoclonal antibodies, appear to be immunologically related and to contain highly conserved sequences. 相似文献
4.
5.
6.
Pyomyositis: characteristics at CT and MR imaging 总被引:9,自引:0,他引:9
7.
8.
D De AJ Kanwar S Handa 《Journal of the European Academy of Dermatology and Venereology》2006,20(7):853-859
BACKGROUND: Diagnosis of atopic dermatitis (AD) depends on clinical features because no definitive diagnostic test exists. Criteria proposed by Hanifin and Rajka (Acta Derm Venereol (Stockh) 1980; Suppl 92: 44-47) were acceptable for hospital-based studies but were found not to be suitable for field studies. A UK working party formulated clinical diagnostic criteria that could be used in both hospital and epidemiological settings. Validation studies of the criteria showed widely variable results, probably due to different clinical settings and ethnicity. AIM AND OBJECTIVE: This study was undertaken to validate Hanifin and Rajka's criteria and to assess the comparative efficacy of their criteria and the UK working party's diagnostic criteria in the diagnosis of AD in a hospital setting in North India. SUBJECTS AND METHODS: This study serially included 101 patients with AD and 48 controls of paediatric age group. The study period was from July 2003 to December 2004. RESULTS: Hanifin and Rajka's criteria (sensitivity 96%, specificity 93.75%, positive predictive value 97% (PPV) and negative predictive value (NPV) 91.84%) had a statistical advantage over the UK working party's diagnostic criteria (sensitivity 86%, specificity 95.83%, PPV 97.75% and NPV 76.67%), with a P-value < 0.005. 相似文献
9.
Sajeel Chowdhary MD Lisa M. Chalmers PA-C Marc Chamberlain MD 《Journal of neuroimaging》2007,17(1):69-73
In the course of 1 year at a tertiary cancer center, 3 patients (2 men; 1 woman; age 51-75 years) were seen in neurological consultation (1.5% of all consultations). Clinical course in all patients was of a progressive neurologic disorder not consistent with either a primary or secondary malignancy. Magnetic resonance (MR) imaging was most informative with respect to diagnosis and subsequent management. Brain biopsy was performed in all patients to assist in both diagnosis and prognostication. All patients were determined to have progressive multifocal leukoencephalopathy (PML) by brain biopsy. 相似文献
10.
RASER: a new ultrafast magnetic resonance imaging method. 总被引:1,自引:0,他引:1
Ryan Chamberlain Jang-Yeon Park Curt Corum Essa Yacoub Kamil Ugurbil Clifford R Jack Michael Garwood 《Magnetic resonance in medicine》2007,58(4):794-799
A new MRI method is described to acquire a T(2)-weighted image from a single slice in a single shot. The technique is based on rapid acquisition by sequential excitation and refocusing (RASER). RASER avoids relaxation-related blurring because the magnetization is sequentially refocused in a manner that effectively creates a series of spin echoes with a constant echo time. RASER uses the quadratic phase produced by a frequency-swept chirp pulse to time-encode one dimension of the image. In another implementation the pulse can be used to excite multiple slices with phase-encoding and frequency-encoding in the other two dimensions. The RASER imaging sequence is presented along with single-shot and multislice images, and is compared to conventional spin-echo and echo-planar imaging sequences. A theoretical and empirical analysis of the spatial resolution is presented, and factors in choosing the spatial resolution for different applications are discussed. RASER produces high-quality single-shot images that are expected to be advantageous for a wide range of applications. 相似文献