全文获取类型
收费全文 | 7694篇 |
免费 | 335篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 28篇 |
儿科学 | 127篇 |
妇产科学 | 104篇 |
基础医学 | 868篇 |
口腔科学 | 242篇 |
临床医学 | 535篇 |
内科学 | 1931篇 |
皮肤病学 | 108篇 |
神经病学 | 636篇 |
特种医学 | 405篇 |
外国民族医学 | 1篇 |
外科学 | 1586篇 |
综合类 | 34篇 |
预防医学 | 221篇 |
眼科学 | 129篇 |
药学 | 477篇 |
中国医学 | 9篇 |
肿瘤学 | 608篇 |
出版年
2023年 | 44篇 |
2022年 | 57篇 |
2021年 | 147篇 |
2020年 | 71篇 |
2019年 | 114篇 |
2018年 | 134篇 |
2017年 | 109篇 |
2016年 | 109篇 |
2015年 | 131篇 |
2014年 | 174篇 |
2013年 | 182篇 |
2012年 | 328篇 |
2011年 | 318篇 |
2010年 | 191篇 |
2009年 | 171篇 |
2008年 | 333篇 |
2007年 | 308篇 |
2006年 | 325篇 |
2005年 | 338篇 |
2004年 | 313篇 |
2003年 | 309篇 |
2002年 | 331篇 |
2001年 | 245篇 |
2000年 | 248篇 |
1999年 | 222篇 |
1998年 | 94篇 |
1997年 | 80篇 |
1996年 | 55篇 |
1995年 | 54篇 |
1994年 | 54篇 |
1993年 | 48篇 |
1992年 | 186篇 |
1991年 | 210篇 |
1990年 | 195篇 |
1989年 | 175篇 |
1988年 | 167篇 |
1987年 | 171篇 |
1986年 | 137篇 |
1985年 | 142篇 |
1984年 | 115篇 |
1983年 | 102篇 |
1982年 | 50篇 |
1979年 | 81篇 |
1978年 | 52篇 |
1975年 | 51篇 |
1971年 | 49篇 |
1969年 | 53篇 |
1968年 | 53篇 |
1967年 | 42篇 |
1966年 | 52篇 |
排序方式: 共有8049条查询结果,搜索用时 125 毫秒
71.
72.
Lethal anemia caused by interferon-beta produced in mouse embryos carrying undigested DNA 总被引:1,自引:0,他引:1
The livers of DNase II-deficient mouse embryos contain many macrophages carrying undigested DNA, and the embryos die in utero. Here we report that erythroid precursor cells underwent apoptosis in the livers of DNase II-deficient embryos and that in the liver, interferon-beta mRNA was expressed by the resident macrophages. When the DNase II-deficient mice were crossed with mice deficient in type I interferon receptor, the resultant 'double-mutant' mice were born healthy. The double-mutant embryos expressed interferon-beta mRNA, but the expression of a subset of the interferon-responsive genes dysregulated in DNase II-deficient embryos was restored to normal. These results indicate that the inability to degrade DNA derived from erythroid precursors results in interferon-beta production that induces expression of a specific set of interferon-responsive genes associated with embryonic lethality in DNase II-deficient mice. 相似文献
73.
Akagi T Higashi A Tsugami H Sakamoto H Masuda Y Hishikawa Y 《Physics in medicine and biology》2003,48(22):N301-N312
At the Hyogo Ion Beam Medical Center (HIBMC) we have developed a new design method for the bar ridge filter used in proton therapy, taking into consideration the scattering and nuclear interaction effects within the filter itself, which are introduced in the design. In our beam delivery system, the bar ridge filter is employed as the range modulator. It is combined with the wobbler system, and produces a three-dimensionally uniform spread-out Bragg peak (SOBP). The design program predicts the three-dimensional dose distribution. Ridge filters of 3-12 cm SOBP in 1 cm increments were designed in the maximum radiation field for 150 MeV and 190 MeV proton beams so that a uniform physical dose area is obtained in the SOBP region three-dimensionally. Measurements were performed with the constructed ridge filters to verify the uniformity and these were compared with the predictions of the design program. The predictions and measurements were found to be in agreement except for the 12 cm SOBP. The uniformities were better than +/- 3.0% for all SOBPs produced. The ridge filters are now clinically in use. 相似文献
74.
Ito Y Kawamura I Kohda C Tsuchiya K Nomura T Mitsuyama M 《International immunology》2005,17(12):1597-1606
Seeligeriolysin O (LSO), a member of cholesterol-dependent cytolysins of Listeria seeligeri, exhibits cytokine-inducing activity. In this study, we examined the profile of cytokines expressed in macrophages of mice after stimulation with full-length form of recombinant LSO (rLSO530), C-terminal-truncated protein (rLSO483) and two authentic cytokine-inducing Toll-like receptor (TLR) ligands from bacteria, peptidoglycan (PGN) and LPS. Both rLSO530 and rLSO483 were able to induce IL-12 p40 and IL-12 p70 more strongly in macrophages than PGN or LPS. In contrast, IFN-beta and nitric oxide were induced by LPS but not by rLSO530, rLSO483 or PGN. In the presence of exogenously added IFN-beta, IL-12 p40 and IL-12 p70 production was inhibited after LSO stimulation, but IL-12 p70 production was enhanced after PGN stimulation. Although LSO signaling appeared to be associated with both TLR2 and TLR4, the profile of cytokine production by LSO stimulation was distinct from those by stimulation with PGN or LPS. Thus, it was shown that LSO is a unique bacterial ligand that induces macrophage cytokine production in a manner different from PGN or LPS. 相似文献
75.
Hagihara K Yamane T Aoyama Y Nakamae H Hino M 《Annals of clinical and laboratory science》2005,35(1):31-36
In human immunodeficiency virus (HIV) infection, CD4 cell counts are useful in defining the disease state, monitoring antiviral treatment, and identifying patients at risk for opportunistic infections. Counting CD4 cells typically relies on traditional immuno-flow cytometric analyzers that require opening the tube for manipulation of the blood sample. In addition to automated blood cell counting, the CELL-DYN 4000 hematology analyzer performs a completely enclosed and automated analysis of the T lymphocyte subsets. We studied the performance characteristics of this method in blood samples containing low levels of CD4+ T cells. In one set of experiments, we emulated low level CD4 counts by use of a CD4 Positive Isolation Kit to deplete the CD4+ cells from blood samples. We used the FACScan analyzer for reference counts. Measurements were made exactly 12 hr after venepuncture in samples that were stored at room temperature. In normal samples and those with low CD4+ cell counts, there was excellent correlation between the results of the CELL-DYN and FACScan methods. Using the CELL-DYN 4000 analyzer, the precision of CD4+ and CD8+ T-cell counts was high (CV = 2 to 8%). The CD4+ T-cell count was linear over a wide range (35 to 1640 cells/microl). This study shows that CD4 and CD8 T cell counts using the CELL-DYN 4000 analyzer is suitable for normal samples and also for those with low CD4+ T cell counts. The method is rapid and automated, and blood specimens remain enclosed, minimizing the biohazard of exposure to blood of HIV patients. 相似文献
76.
H Horinouchi T Ishihara M Kawamura R Kato K Kikuchi K Kobayashi Y Maenaka C Torikata 《Journal of clinical pathology》1993,46(2):185-187
A case of epithelial myoepithelial tumour originating from the tracheal gland in a 57 year old woman is described. The tumour was removed by segmental tracheal resection and end-to-end anastomosis. Histologically, the tumour comprised clear cells and presented a monophasic pattern. Immunohistochemical analysis showed that the tumour cells were positive for both S-100 protein and smooth muscle actin. suggesting that this tumour resembles a subtype of epithelial-myoepithelial carcinoma described in the 1990 WHO international classification of salivary glands. Although some reports describe a clear cell dominant epithelial myoepithelial carcinoma, in this case local invasiveness or regional lymphnode metastasis was not proved through investigation. It is therefore concluded that this was an epithelial myoepithelial tumour rather than a carcinoma. 相似文献
77.
M Kawamura J Katahira M Fukasawa J Sakuragi K Ishikawa M Nakai J A Mingle M Osei-Kwasi V B Netty H Akari 《Virology》1992,188(2):850-853
A highly divergent HIV-2 designated as HIV-2[GH-2] was obtained from an AIDS-related complex (ARC) patient in Ghana. A full-length molecular clone of this isolate was obtained and a biologically active clone was constructed. Its restriction pattern differed from that of prototype HIV-2[GH-1] in 25 of 35 restriction sites, but was strikingly similar to a previously characterized HIV-2 isolate from a Ghanaian (HIV-2ALT). The conserved integrase region (288-bp fragment) previously displayed 95% identity with that of ALT but 17-20% divergence from the HIV-2 prototype member, and a new distinct subgroup (HIV-2b) of HIV-2 consisting of GH-2 and ALT was postulated (Miura et al. 1991.) These isolates, however, were biologically distinguishable from each other by its replication capacity in a monocyte line, U937, in which GH-2 could not grow but ALT grew well. In addition, the nucleotide sequence of the LTR of this new isolate displays 21% divergence from that of prototype HIV-2[GH-1], but the core enhancer, Sp1 binding sites and TATA box were conserved. Although the 3' half of the env gene sequence which is deleted in HIV-2ALT clone showed 27% diversity from the prototype, functional differences in the rev-responsive element were not observed. 相似文献
78.
Hiroko Fujita Jianguo Meng Miyako Kawamura Noriko Tozuka Fumiyo Ishii Naoko Tanaka 《American journal of medical genetics. Part A》1992,44(4):434-436
We report on a 6-year-old boy with de novo 46, XY, del(3)(q12q23) and bilateral blepharo-phimosis, ptosis, epicanthus inversus, in addition to multiple other anomalies. Since 4 previously reported cases of interstitial deletion of 3q involving 3q23 band are clinically similar, we propose this blepharophimosis sequence due to 3q23 deletion as a further “contiguous gene syndrome”. 相似文献
79.
K. Kawamura M.D. T. Konno 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1979,35(1):161-175
Summary The retrograde labeling of cortical neurons with horseradish peroxidase (HRP) was used to investigate the morphological features of neurons in various cortical areas projecting to the superior colliculus in the cat.Corticotectal cells were found to be labeled in layer V of the entire cerebral cortex. The number of labeled cells and their locations varied according to the sites of injections of HRP in the colliculus. Most of the Corticotectal cells identified in the present study were small (9–20 m in diameter, 66%) and medium (20–40 urn, 30%) pyramidal neurons and only 4% of them were large (more than 40 m). The labeled cells, 261 in total number, had somal diameters of 20.8±8.0 m (mean and SD). The range of sizes of the labeled neurons was different in different cortical areas. For example, the labeled neurons in the Clare-Bishop area had a greater proportion of large diameter cells than in other areas.The present findings are largely in agreement with the previous data of anterograde degeneration methods with respect to the topographical correlation of the Corticotectal projections. However, in some cortical areas, e.g., the sensorimotor and the first visual (area 17) cortex of the lateral surface of the hemisphere, relatively small numbers of Corticotectal neurons appear to have been labeled by retrogradely transported HRP. The sparsity of the labeled neurons in certain cortical areas may reflect the existence of Corticotectal neurons with axon collaterals supplying brain structures other than the superior colliculus.Abbreviations A.c.
Aqueductus cerebri
- AEct
Gyrus ectosylvius anterior
- AEs
Sulcus ectosylvius anterior
- AI
Stratum album intermediale
- AL
Gyrus lateralis anterior
- AP
Stratum album profundum
- AS
Gyrus sylvius anterior
- Cd
Nucleus caudatus
- F.l.m.
Fasciculus longitudinalis medialis
- GI
Stratum griseum intermediale
- GP
Stratum griseum profundum
- GS
Stratum griseum superficiale
- Ic
Inferior colliculus
- L
Left
- MEct
Gyrus ectosylvius medius
- MS
Gyrus sylvius medius
- MSup
Gyrus suprasylvius medius
- N.r.
Nucleus ruber
- O
Stratum opticum
- P
Pontine nuclei
- P.c.
Pedunculus cerebri
- PEct
Gyrus ectosylvius posterior
- P.g.
Periaqueductal gray matter
- PSigm
Gyrus sigmoideus posterior
- PSup
Gyrus suprasylvius posterior
- R
Right
- Sc
Superior colliculus
- S.n.
Substantia nigra
- Z
Statum zonale
- II
Optic nerve
- III and IV
Motor nuclei of cranial nerves 相似文献
80.
K. Ito T. Watanabe R. Horie M. Shiota S. Kawamura S. Mori 《The American journal of pathology》1994,145(2):276-280
CD30 is a receptor-type membrane protein that belongs to the nerve growth receptor superfamily. It is expressed on Hodgkin's cells and activated lymphocytes, as well as in some human malignancies including malignant lymphomas, embryonal carcinomas, and other mesenchymal tumors. However, whether it is expressed in normal tissues remains unclear. To study the expression and biological function of CD30, we first examined various human tissues by immunohistochemistry. The monoclonal antibody Ber-H2 intensely stained the membranes of decidual and endometrial cells with decidual change in frozen sections. Western blots of these tissues with Ber-H2 revealed bands of 120, 105, and 90 kd as found on CD30-expressing cells. Northern blots of these tissues using a CD30 cDNA probe detected mRNAs of the same molecular mass and variety as those in the positive control cell line HUT 102. These results indicated that CD30 is expressed in human endometrial tissue with decidual change and imply that CD30 expression in endometrial tissue is induced by hormonal control. 相似文献