全文获取类型
收费全文 | 26401篇 |
免费 | 1330篇 |
国内免费 | 97篇 |
专业分类
耳鼻咽喉 | 424篇 |
儿科学 | 490篇 |
妇产科学 | 326篇 |
基础医学 | 3594篇 |
口腔科学 | 666篇 |
临床医学 | 1828篇 |
内科学 | 6520篇 |
皮肤病学 | 651篇 |
神经病学 | 1792篇 |
特种医学 | 1056篇 |
外国民族医学 | 1篇 |
外科学 | 4383篇 |
综合类 | 143篇 |
一般理论 | 2篇 |
预防医学 | 701篇 |
眼科学 | 323篇 |
药学 | 1977篇 |
4篇 | |
中国医学 | 77篇 |
肿瘤学 | 2870篇 |
出版年
2023年 | 158篇 |
2022年 | 289篇 |
2021年 | 459篇 |
2020年 | 288篇 |
2019年 | 339篇 |
2018年 | 426篇 |
2017年 | 344篇 |
2016年 | 423篇 |
2015年 | 412篇 |
2014年 | 609篇 |
2013年 | 698篇 |
2012年 | 1134篇 |
2011年 | 1227篇 |
2010年 | 683篇 |
2009年 | 670篇 |
2008年 | 1086篇 |
2007年 | 1257篇 |
2006年 | 1159篇 |
2005年 | 1240篇 |
2004年 | 1174篇 |
2003年 | 1036篇 |
2002年 | 1009篇 |
2001年 | 1021篇 |
2000年 | 961篇 |
1999年 | 897篇 |
1998年 | 309篇 |
1997年 | 212篇 |
1996年 | 236篇 |
1995年 | 190篇 |
1994年 | 160篇 |
1993年 | 187篇 |
1992年 | 628篇 |
1991年 | 546篇 |
1990年 | 533篇 |
1989年 | 528篇 |
1988年 | 512篇 |
1987年 | 483篇 |
1986年 | 459篇 |
1985年 | 426篇 |
1984年 | 311篇 |
1983年 | 256篇 |
1982年 | 158篇 |
1979年 | 245篇 |
1977年 | 184篇 |
1973年 | 177篇 |
1972年 | 186篇 |
1971年 | 190篇 |
1970年 | 172篇 |
1969年 | 186篇 |
1968年 | 170篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
Kazuma Ohyashiki Mitsuo Oshimura Takayo Toyoda Nobuhiko Sakai Hisao Ito Kohtaro Yamamoto Akira Tonomura 《Cancer Genetics and Cytogenetics》1984,11(2):215-219
We encountered a 38-year-old Japanese male patient with chronic myelogenous leukemia (CML), whose bone marrow and peripheral blood cells during the chronic and blastic phases contained a complex Ph1 translocation and an extra Y chromosome [i.e., 47,XYY,t(9;22;13)(q34;q11;q14)]. A karyotypic analysis of PHA-stimulated lymphocytes showed the constitutional karyotype to be 47,XYY. Thus, it was considered that CML with a complex Ph1 translocation developed in an XYY male; such a case has not been reported, so far. A B-lymphocyte cell line with the complex Ph1 translocation was established by the procedure of Epstein-Barr virus transformation. The presence of the complex Ph1 translocation in the B-lymphocyte cell line suggests that some of the B lymphocytes in this patient originated from the CML clone. 相似文献
152.
Y Ito Y Nishiyama K Shimokata H Takeyama A Kunii 《The Journal of general virology》1978,41(1):129-134
Cytochalasin D is thought to impair microfilament function. The present study has investigated its effects on four different systems in which interferon is formed, namely (1) mouse fibroblasts induced with virus (2) mouse spleen cells induced with virus, or (3) with endotoxin or (4) by allogeneic stimulation. Cytochalasin D did not suppress formation of interferon by fibroblasts (L cells) or spleen cells stimulated with either HVJ or NDV. However it did suppress production of interferon by spleen cells in response to endotoxin or an allogeneic stimulation; here its action was apparently not on the secretion of interferon, but on some earlier event. It also suppressed the production of interferon by mouse spleen cells induced with HVJ if this had been u.v. irradiated for more than 15 min: this suggests that cytochalasin D sensitive structures do play some role in interferon production by mouse spleen cells when stimulated with HVJ, as well as when they are stimulated with endotoxin or an allogeneic stimulus. 相似文献
153.
154.
Johnson et al [1983] reported on a large family with alopecia-anosmia-deafness-hypogonadism syndrome. We report the detailed findings of an unrelated, affected individual and emphasize the presence of hypohidrosis in our case. Our case indicates that this syndrome is not a private syndrome. 相似文献
155.
Two cases of fusion of the musculocutaneous and median nerves 总被引:1,自引:0,他引:1
156.
A system effective in the early diagnosis of Dengue virus infection was developed. The time course kinetics of Dengue virus type 2 (D-2) antigen in vitro were analyzed by Flow Cytometry. Early profiles of D-2 were also studied quantitatively through this method of analysis. The early events of host cell and virus interaction were investigated: attachment, internalization and replication. From these early profiles, the time at which new viral synthesis was detectable differed with each individual trial. These different times were found to be dependent of the phase of the cell cycle. From these results we could detect newly synthesized viral antigen within 10 h after infection. 相似文献
157.
Naoki Tanaka Kensaku Ito Hiromi Kitano 《Macromolecular chemistry and physics.》1994,195(10):3369-3380
The Raman spectra of solutions of poly(N-vinyl-2-pyrrolidone) (PVP; M?w = 1 000, 10 000, 40 000 and 360 000) in D2O and dimethyl sulfoxide (DMSO) were measured at various concentrations. PVP is hydrated by D2O in a manner different from N-ethyl-2-pyrrolidone (NEP) and N-methyl-2-pyrrolidone (NMP), monomer analogues of PVP. The self-association of DMSO molecules in the solution of PVP was found to be different from that in the solution of NMP by using difference spectroscopy. These phenomena were attributed to a net-like structure of concentrated solutions of PVP. 相似文献
158.
Two molecules that regulate cell fusion have been identified and designated fusion regulatory protein-1 (FRP-1) and FRP-2. FRP-1 is a complex composed of a glycosylated heavy chain and a nonglycosylated light chain that are disulfide linked. FRP-1 heavy chain is identical to 4F2/CD98 heavy chain, whereas FRP-2 is identical to integrin alpha3 subunit. The FRP-1 heavy chain is a multifunctional molecule: that is, fusion regulator, amino acid transporter, integrin regulator, comitogenic factor, Na+-Ca2+ exchanger, oncogenic protein, and so on. Several aspects of the structure and function of the FRP-1 system are reviewed: fusion regulatory molecular mechanisms, cross-talk between the FRP-1 and integrin, the FRP-1 system as amino acid transporter, and FRP-1-mediated T-cell activation. The FRP-1 system is involved in virus-mediated cell fusion and multinucleated giant cell formation of blood monocytes. Monoclonal antibodies against human FRP-1 heavy chain induce polykaryocytes that have properties as osteoclasts. Multiple steps participate in molecular mechanisms regulating cell fusion. The FRP-1 heavy chain supports amino acid transport activity and the FRP-1 light chains have recently been cloned as amino acid transporters that require association with the heavy chain to exhibit their activity. Novel pathways for monocyte-dependent regulation of T-cell activation have recently been found that are mediated by the FRP-1 system. In conclusion, the FRP-1 molecules are essential factors for basic cellular functions. 相似文献
159.
Eleven monoclonal antibodies (MAbs) directed against the large (L) protein of human parainfluenza type 2 virus (hPIV-2) were prepared to examine the interactions of the L protein with other viral proteins. Coimmunoprecipitation assays using these MAbs revealed that the L protein directly interacted with the phospho- (P) and nucleocapsid (NP) proteins in vivo and in vitro. Mutational analysis of the P or NP protein was performed to identify the region(s) on these proteins interacting with L protein, indicating that amino acids 278-353 on the P protein and amino acids 403-494 on the NP protein are essential for the binding to the L protein. 相似文献
160.
Handa H Aihara H Kinoshita K Ohmoto T Ito T Kinugasa K Kamata I Asari S 《Acta medica Okayama》1999,53(1):45-53
The aim of this study was to determine suitable image parameters and an analytical method for phase-contrast magnetic resonance imaging (PC-MRI) as a means of measuring cerebral blood flow volume. This was done by constructing an experimental model and applying the results to a clinical application. The experimental model was constructed from the aorta of a bull and circulating isotonic saline. The image parameters of PC-MRI (repetition time, flip angle, matrix, velocity rate encoding, and the use of square pixels) were studied with percent flow volume (the ratio of actual flow volume to measured flow volume). The most suitable image parameters for accurate blood flow measurement were as follows: repetition time, 50 msec; flip angle, 20 degrees; and a 512 x 256 matrix without square pixels. Furthermore, velocity rate encoding should be set ranging from the maximum flow velocity in the vessel to five times this value. The correction in measuring blood flow was done with the intensity of the region of interest established in the background. With these parameters for PC-MRI, percent flow volume was greater than 90%. Using the image parameters for PC-MRI and the analytical method described above, we evaluated cerebral blood flow volume in 12 patients with occlusive disease of the major cervical arteries. The results were compared with conventional xenon computed tomography. The values found with both methods showed good correlation. Thus, we concluded that PC-MRI was a noninvasive method for evaluating cerebral blood flow in patients with occlusive disease of the major cervical arteries. 相似文献