全文获取类型
收费全文 | 8051篇 |
免费 | 384篇 |
国内免费 | 65篇 |
专业分类
耳鼻咽喉 | 105篇 |
儿科学 | 152篇 |
妇产科学 | 69篇 |
基础医学 | 1304篇 |
口腔科学 | 191篇 |
临床医学 | 494篇 |
内科学 | 2207篇 |
皮肤病学 | 141篇 |
神经病学 | 572篇 |
特种医学 | 340篇 |
外科学 | 1300篇 |
综合类 | 16篇 |
预防医学 | 186篇 |
眼科学 | 100篇 |
药学 | 443篇 |
中国医学 | 27篇 |
肿瘤学 | 853篇 |
出版年
2023年 | 44篇 |
2022年 | 60篇 |
2021年 | 142篇 |
2020年 | 75篇 |
2019年 | 112篇 |
2018年 | 140篇 |
2017年 | 128篇 |
2016年 | 141篇 |
2015年 | 182篇 |
2014年 | 233篇 |
2013年 | 321篇 |
2012年 | 410篇 |
2011年 | 422篇 |
2010年 | 251篇 |
2009年 | 238篇 |
2008年 | 399篇 |
2007年 | 497篇 |
2006年 | 498篇 |
2005年 | 457篇 |
2004年 | 490篇 |
2003年 | 460篇 |
2002年 | 496篇 |
2001年 | 174篇 |
2000年 | 151篇 |
1999年 | 177篇 |
1998年 | 128篇 |
1997年 | 112篇 |
1996年 | 101篇 |
1995年 | 90篇 |
1994年 | 100篇 |
1993年 | 80篇 |
1992年 | 117篇 |
1991年 | 106篇 |
1990年 | 81篇 |
1989年 | 79篇 |
1988年 | 51篇 |
1987年 | 83篇 |
1986年 | 78篇 |
1985年 | 50篇 |
1984年 | 45篇 |
1983年 | 40篇 |
1982年 | 46篇 |
1981年 | 53篇 |
1980年 | 41篇 |
1979年 | 36篇 |
1978年 | 35篇 |
1977年 | 30篇 |
1976年 | 29篇 |
1975年 | 29篇 |
1973年 | 28篇 |
排序方式: 共有8500条查询结果,搜索用时 15 毫秒
61.
M. Kohmoto T. Miyazawa E. Sato K. Uetsuka Y. Nishimura Y. Ikeda G. Inada K. Doi T. Mikami 《Archives of virology》1998,143(9):1839-1845
Summary. Following establishment, via the vaginal route, of infection with an AP-1 binding-site deleted mutant (ΔAP-1) of feline immunodeficiency
virus (FIV), cats were challenged with a homologous intact strain (TM2) of FIV. The cats were observed for 23 weeks to evaluate
the efficacy of the ΔAP-1 against the homologous TM2 strain challenge. These two viruses were differentiated by Southern blotting
after amplification of proviral DNA by semi-nested polymerase chain reaction in DNAs of peripheral blood mononuclear cells
and tissues. A TM2-specific band was detected in one cat exposed to but not infected with ΔAP-1, but not in two ΔAP-1-infected.
These results indicate that ΔAP-1 could protect against subsequent challenge with homologous FIV TM2 strain.
Received December 23, 1998 Accepted March 31, 1998 相似文献
62.
63.
Isolation, sequence and expression of a cDNA encoding the alpha-chain of the feline CD8. 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M R Pecoraro Y Kawaguchi T Miyazawa J Norimine K Maeda T Toyosaki Y Tohya C Kai T Mikami 《Immunology》1994,81(1):127-131
We have cloned, sequenced and expressed a cDNA encoding the alpha-chain of feline CD8. This clone, named FT8-10, has an open reading frame with 720 nucleotides in length encoding a protein with 239 amino acid residues. Sequence analysis has revealed that the feline CD8 alpha-chain (CD8 alpha) shares significant homology with human (T8/Leu-2), bovine (BoCD8), rat (MRC OX8) and mouse (Lyt-2) CD8 alpha subunits. Cysteine residues as well as the tyrosine kinase p56lck binding site are well conserved. Besides, no putative N-linked glycosylation site was found. Interestingly, immunofluorescence analysis of COS-7 cells transfected with feline CD8 alpha expression plasmid driven by SR alpha promoter showed that the expressed feline CD8 alpha cross-reacted with an anti-human CD8 alpha monoclonal antibody OKT8, but did not react with an anti-feline monoclonal antibody, FT-2, which is thought to recognize the feline analogue of the human T8/Leu-2 and murine Lyt-2 molecules expressed on cytotoxic/suppressor T cells. 相似文献
64.
Tetsuo Takaishi Takashi Ono Yoshifumi Yasuda 《European journal of applied physiology》1992,65(4):335-339
Summary The surface electromyogram (EMG) from active muscle and oxygen uptake (
) were studied simultaneously to examine changes of motor unit (MU) activity during exercise tests with different ramp increments. Six male subjects performed four exhausting cycle exercises with different ramp slopes of 10, 20, 30 and 40 W · min–1 on different days. The EMG signals taken from the vastus lateralis muscle were stored on a digital data recorder and converted to obtain the integrated EMG (iEMG). The
was measured, with 20-s intervals, by the mixing chamber method. A non-linear increase in iEMG against work load was observed for each exercise in all subjects. The break point of the linear relationship of iEMG was determined by the crossing point of the two regression lines (iEMGbp). Significant differences were obtained in the exercise intensities corresponding to maximal oxygen uptake (
) and the iEMGbp between 10 and 30, and 10 and 40 W · min –1 ramp exercises (P < 0.05). However, no significant differences were obtained in
and
corresponding to the iEMGbp during the four ramp exercises. With respect to the relationship between
and exercise intensity during the ramp increments, the
-exercise intensity slope showed significant differences only for the upper half (i.e. above iEMGbp). These results demonstrated that the
and
at which a nonlinear increase in iEMG was observed were not varied by the change of ramp slopes but by the exercise intensity corresponding to
and the iEMGbp was varied by the change of ramp slopes. In addition, the significant differences in the
exercise intensity slopes for the upper half of the tests would suggest that the recruitment patterns of MU and/or muscle metabolic state might be considerably altered depending upon the ramp slope increments. 相似文献
65.
Tumorous necrotic nodule in the liver: unexpected effect of the microwave tissue coagulator. 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Journal of clinical pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The microwave tissue coagulator (MTC) is used in hepatectomy because it provides excellent haemostasis during the procedure. A 59 year old man underwent partial hepatic lobectomy with MTC, for metastasis from colon cancer. A tumorous necrotic nodule was discovered in the liver. The nodule measured 2.5 cm at its largest diameter. Microscopically, it showed extensive coagulation necrosis and massive sinusoidal dilatation. To date, such a necrotic mass clinically mimicking neoplasm has not been reported as a complication of hepatectomy using MTC. Although it is unknown how the rounded necrotic nodule was formed in this case, clinicians should be aware of this phenomenon to avoid unnecessary operations. Likewise, pathologists should recognise such histological changes and review the clinical history of the patient when coagulation necrosis with massive sinusoidal dilatation is observed in a biopsy or hepatectomy specimen. 相似文献
66.
Tetsuo Kodaka Ryoichi Mori Akihiko Hirayama Tsuneyoshi Sano 《Medical Electron Microscopy》2003,36(4):272-281
We investigated the fine structure and mineral components of 29 stonelike masses obtained from the mesenteries of four adult cadavers, using optical microscopy, backscattered electron imaging, scanning electron microscopy, energy-dispersive X-ray microanalysis, and X-ray diffraction. Although the overall appearance of the stonelike masses measuring about 5–20mm in diameter and 0.06–3.1g in dry weight was roughly grouped into smooth bulb- and uneven bulk-shaped types, all the calcified masses basically consisted of core and mantle regions. The smooth bulb-shaped masses had a broad mantle with many concentric rings, whereas the uneven bulk-shaped masses contained a large core. In their core regions, spherulitic and short bundle-shaped deposits composed of needle-shaped apatite crystals were mainly found among loose collagen fibers. Their mantle regions, on the other hand, showed the concentric structures of dense collagen fibers in the intra- and/or extrafibrous calcification with fine sandy grain-shaped deposits. The mineral elements were mainly Ca and P, and the major crystals were hydroxyapatite. Hexahedral whitlockite containing Mg was a minor component. The fiber-rich mantle regions showed lower calcification and lesser crystallization than the fiber-poor core region. When necrotic or some tumor adipose tissues and necrotic lymphoid tissues that might have been caused by some digestive diseases are recognized as foreign matter, their tissues occasionally will be calcified and grow into stonelike masses. These stonelike masses tend to occur more often in women than in men. 相似文献
67.
Inhibitory effect of antiserum to surface antigen P50 of Babesia gibsoni on growth of parasites in severe combined immunodeficiency mice given canine red blood cells
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Fukumoto S Xuan X Takabatake N Igarashi I Sugimoto C Fujisaki K Nagasawa H Mikami T Suzuki H 《Infection and immunity》2004,72(3):1795-1798
The inhibitory effect of an antiserum to surface protein P50 of Babesia gibsoni on the growth of the parasite was determined with severe combined immunodeficiency mice given canine red blood cells. The antiserum to the recombinant P50 protein significantly inhibited the parasite growth, indicating that P50 might be a useful vaccine candidate. 相似文献
68.
J. Norimine T. Miyazawa Y. Kawaguchi K. Tomonaga Y. -S. Shin T. Toyosaki M. Kohmoto M. Niikura Y. Tohya T. Mikami 《Archives of virology》1993,130(1-2):171-178
Summary To investigate whether the feline CD 4 (fCD 4) molecules are involved in infections of highly lymphotropic feline immunodeficiency virus (FIV) isolates, we expressed fCD 4 stably on Crandell feline kidney cells andFelis catus whole foetus 4 cells by transfection of a cDNA encoding the fCD 4 glycoprotein, and then infected them with TM 1 and TM 2 strains of FIV, which are unable to infect these cells productively. In spite of fCD 4 being expressed on these cells, no virus production was observed. This result indicates that fCD 4 expression alone cannot induce a productive infection of the FIV TM 1 and TM 2 strains. 相似文献
69.
70.
Quantitative Analysis of Mycobacterial and Propionibacterial DNA in Lymph Nodes of Japanese and European Patients with Sarcoidosis 总被引:10,自引:0,他引:10
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yoshinobu Eishi Moritaka Suga Ikuo Ishige Daisuke Kobayashi Tetsuo Yamada Tamiko Takemura Touichiro Takizawa Morio Koike Shoji Kudoh Ulrich Costabel Josune Guzman Gianfranco Rizzato Marcello Gambacorta Ronald du Bois Andrew G. Nicholson Om P. Sharma Masayuki Ando 《Journal of clinical microbiology》2002,40(1):198-204
The cause(s) of sarcoidosis is unknown. Mycobacterium spp. are suspected in Europe and Propionibacterium spp. are suspected in Japan. The present international collaboration evaluated the possible etiological links between sarcoidosis and the suspected bacterial species. Formalin-fixed and paraffin-embedded sections of biopsy samples of lymph nodes, one from each of 108 patients with sarcoidosis and 65 patients with tuberculosis, together with 86 control samples, were collected from two institutes in Japan and three institutes in Italy, Germany, and England. Genomes of Propionibacterium acnes, Propionibacterium granulosum, Mycobacterium tuberculosis, Mycobacterium avium subsp. paratuberculosis, and Escherichia coli (as the control) were counted by quantitative real-time PCR. Either P. acnes or P. granulosum was found in all but two of the sarcoid samples. M. avium subsp. paratuberculosis was found in no sarcoid sample. M. tuberculosis was found in 0 to 9% of the sarcoid samples but in 65 to 100% of the tuberculosis samples. In sarcoid lymph nodes, the total numbers of genomes of P. acnes or P. granulosum were far more than those of M. tuberculosis. P. acnes or P. granulosum was found in 0 to 60% of the tuberculosis and control samples, but the total numbers of genomes of P. acnes or P. granulosum in such samples were less than those in sarcoid samples. Propionibacterium spp. are more likely than Mycobacteria spp. to be involved in the etiology of sarcoidosis, not only in Japanese but also in European patients with sarcoidosis. 相似文献