全文获取类型
收费全文 | 22198篇 |
免费 | 1384篇 |
国内免费 | 746篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 459篇 |
妇产科学 | 212篇 |
基础医学 | 5376篇 |
口腔科学 | 259篇 |
临床医学 | 2234篇 |
内科学 | 3800篇 |
皮肤病学 | 437篇 |
神经病学 | 1121篇 |
特种医学 | 417篇 |
外国民族医学 | 3篇 |
外科学 | 1402篇 |
综合类 | 3384篇 |
现状与发展 | 5篇 |
预防医学 | 1695篇 |
眼科学 | 155篇 |
药学 | 1640篇 |
8篇 | |
中国医学 | 235篇 |
肿瘤学 | 1445篇 |
出版年
2024年 | 27篇 |
2023年 | 263篇 |
2022年 | 629篇 |
2021年 | 733篇 |
2020年 | 590篇 |
2019年 | 577篇 |
2018年 | 547篇 |
2017年 | 565篇 |
2016年 | 603篇 |
2015年 | 631篇 |
2014年 | 975篇 |
2013年 | 1389篇 |
2012年 | 977篇 |
2011年 | 1116篇 |
2010年 | 821篇 |
2009年 | 840篇 |
2008年 | 850篇 |
2007年 | 947篇 |
2006年 | 836篇 |
2005年 | 850篇 |
2004年 | 786篇 |
2003年 | 753篇 |
2002年 | 627篇 |
2001年 | 573篇 |
2000年 | 563篇 |
1999年 | 452篇 |
1998年 | 474篇 |
1997年 | 489篇 |
1996年 | 440篇 |
1995年 | 517篇 |
1994年 | 475篇 |
1993年 | 431篇 |
1992年 | 413篇 |
1991年 | 400篇 |
1990年 | 335篇 |
1989年 | 235篇 |
1988年 | 254篇 |
1987年 | 204篇 |
1986年 | 162篇 |
1985年 | 316篇 |
1984年 | 207篇 |
1983年 | 144篇 |
1982年 | 95篇 |
1981年 | 68篇 |
1980年 | 37篇 |
1979年 | 32篇 |
1978年 | 31篇 |
1977年 | 13篇 |
1976年 | 9篇 |
1974年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
M. Shibuya F. Saito T. Miwa R. L. Davis C. B. Wilson T. Hoshino 《Acta neuropathologica》1992,84(2):178-183
Summary The growth potential of 65 pituitary adenomas was determined by histochemical analysis with Ki-67 and anti-DNA polymerase monoclonal antibodies, bromodeoxyuridine (BrdUdR) labeling, and counts of argyrophilic nucleolar organizer regions (Ag-NORs). The mean proliferating cell indices (PCIs) determined by Ki-67 and anti-DNA polymerase and the BrdUdR labeling index (LI) were generally very low [1.0±0.2%, 1.1±0.2%, and 0.5±0.1% (±SE), respectively]. Apart from adrenocorticotropic hormone-positive adenomas, which had significantly higher indices, there were no statistically significant differences in the indices among the other subtypes of pituitary adenomas. Recurrent tumors had higher Ki-67 and DNA polymerase PCIs and BrdUdR LIs (3.6%, 4.2%, 1.4%) than primary tumors (0.8%, 0.8%, 0.3%; P<0.005). The number of Ag-NORs did not correlated significantly with any of the three indices. The mean number of Ag-NORs was higher in nonfunctioning adenomas than in functioning adenomas (2.04 vs 1.66, P<0.005); among prolactin-positive adenomas, those treated preoperatively with bromocriptine had more Ag-NORs than untreated tumors (1.75 vs 1.57, P<0.005). These results suggest that the Ki-67 and DNA polymerase PCIs and the BrdUdR LI predict the growth potential of individual pituitary adenomas, whereas the number of Ag-NORs appears to correlate with hormone production rather than with the proliferative potential.Supported by grants CA-13525 and CA-50210 from the National Cancer Institute, by a grant from the Phi Beta Psi Sorority, and by Grant-in-Aid A 63771083 from the Ministry of Education, Science, and Culture of Japan 相似文献
102.
X. He C. J. Wikstrand P. Fredman J.-E. Månsson L. Svennerholm D. D. Bigner 《Acta neuropathologica》1989,79(3):317-325
Summary Seven monoclonal antibodies (mAbs) reactive with ganglioside II3(NeuAc)2-LacCer (GD3) were generated; four of these mAbs (DMAb-21, DMAb-22, DMAb-23, and DMAb-24) by immunizing mice with GD3 adsorbed to Salmonella minnesota and the remaining three (DMAb-7, DMAb-8, and DMAb-17) with melanoma line SK-MEL 28, which contains 1.4 nmol sialic acid of GD3 per mg protein. The specificities of the mAbs were defined by high-performance thin-layer chromatography (HPTLC) immunostain and solid-phase radioimmunoassay (SP-RIA) with a panel of purified gangliosides. DMAb-7 and DMAb-8 reacted with GD3, IV3(NeuAc)2nLcOse4Cer(3,8-LD1), and very weakly with IV3(NeuAc)2II3NeuAc-GgOse4Cer (GTla), but not with II3NeuAc-LacCer (GM3), II3NeuAcGgOse3Cer(GM2), II3NeuAc-GgOse4Cer(GM1), II3NeuAc, IV3NeuAcGgOse4Cer (GD1a), II3(NeuAc)2GgOse3(GD2), II3(NeuAc)2GgOse4Cer (GD1b), IV3NeuAcII3(NeuAc)2, GgOse4Cer(GT1b), suggesting the binding epitope to be a terminal tetrasaccharide NeuAc2-8NeuAc2-3Gal1-4(Glc or GlcNAc). DMAb-7 and DMAb-8 were used to investigate the expression of GD3 on cultured human tumor cells of neuroectodermal origin. Thirteen of 19 gliomas, 3 of 5 medulloblastomas, 5 of 5 neuroblastomas, 2 of 2 melanomas, and 1 of 3 teratomas were shown to react with DMAb-8 and/or DMAb-7 by cell surface-RIA (CS-RIA) and immunofluorescence (IF) assays. HPTLC and densitometric analysis confirmed these results, as positive immunostains in the GD3 region were obtained with oligoganglioside fractions from 9 glioma, 1 medulloblastoma, 2 neuroblastoma, 1 melanoma, and 1 teratoma cell line. Glioma cell line U-105 MG and medulloblastoma cell line Daoy contain GD3 as shown by HPTLC immunostain analysis of extracts, although GD3 was undetectable on the cell surface as determined by CS-RIA and IF. There was no detectable GD3 found in gangliosides isolated from cell lines U-373 MG, D-54 MG, TE-671, and PA-1, which were negative for both DMAb-7 and DMAb-8 by CS-RIA and IF assay. Our results provide evidence that GD3 is expressed extensively with significant quantitative heterogeneity on cultured human neuroectodermal tumor cells including glioma, medulloblastoma, neuroblastoma, and melanoma.Supported by NIH grants R37 CA11898, NS 20023, and CA32672 and by grants from the Swedish Medical Research Council (project no. 03X-627), Swedish Cancer Society (project no. 2260-B88-01X) and the National Swedish Board for Technical Development (project no. 84-4667) 相似文献
103.
Flow cytometry immunolabeling, tube agglutination tests, and thin-layer chromatography immunostaining with two different anti-A
monoclonal antibodies (anti-A mAb1 and anti-A mAb2) and one anti-B mAb were used to demonstrate differences in expression
of the A and B antigens among erythrocytes from type A and four different type AB cats. Although the flow cytometric patterns
of reactivity and agglutination scores for erythrocytes from types A and B cats detected with the anti-A and anti-B mAbs were
consistent, reactivity among erythrocytes of different type AB cats was variable. By flow cytometric analysis, 99.9% of type
A erythrocytes, no type B erythrocytes, 2.5–4.0% of erythrocytes from type AB cats 1, 3, and 4, and 60.7% of erythrocytes
from type AB cat 2 had detectable A antigen when anti-A mAb1 was used. In contrast, 86.4% of type A erythrocytes, no type
B erythrocytes, 20.2–38.0% of erythrocytes from type AB cats 1, 3, and 4, and 68.5% of erythrocytes from type AB cat 2 had
detectable A antigen when anti-A mAb2 was used. In addition, 86.9% of type B erythrocytes, no type A erythrocytes, 83.1–96.8%
of erythrocytes from type AB cats 1, 3, and 4, and 73.0% of erythrocytes from type AB cat 2 had detectable B antigen when
the anti-B mAb was used. Agglutination scores of type AB cats were comparable to the percent binding on flow cytometry. Thin-layer
chromatography immunostains confirmed differences in the amount of A antigen between erythrocyte glycolipids of type A and
AB cats and those of type AB cats 1 and 2. These results suggest that at least two different phenotypes exist within the feline
AB blood type, which differ in the amount of A antigen expressed on the erythrocyte surface. 相似文献
104.
105.
Comparative study of pituitary and bacteria-derived human growth hormone by monoclonal antibodies 总被引:1,自引:0,他引:1
We have established hybridoma lines which secrete mouse monoclonal antibodies (Mabs) to human pituitary growth hormone, hGH. Using indirect competitive ELISA and indirect passive hemagglutination inhibition twelve different Mabs were characterized with regard to cross-reactivity with the hGH-related hormones, human chorionic somatomammotropin, hCS, and human prolactin, hPRL. The reactivity of these Mabs with pituitary hGH was compared to that with either bacterially-produced methionyl-hGH or to that of reduced and S-carboxymethylated hGH, which has an altered conformation. None of the Mabs reacted with hPRL. Four did not react with hCS whereas the others showed varying degree of cross-reactivity with hCS. All Mabs reacted more weakly with reduced and S-carboxymethylated hGH than with the native form of the hormone, which was not seen with conventional rabbit antisera to hGH. Thus in the case of hGH the Mabs are superior to conventional antisera in revealing small conformational differences. However the pituitary and bacterially-derived methionyl-hGH were indistinguishable as determined by the 12 Mabs. 相似文献
106.
J A Lowe N R Ling J A Forrester A J Cumber W C Ross 《Journal of immunological methods》1985,76(1):93-104
Conjugates of ricin A-chain with monoclonal anti-light chain antibodies specifically killed cells hearing kappa or lambda immunoglobulin (Ig) light chains. Exposure of cells from B-lymphoblastoid cell lines (B-LCL) to conjugate for less than 30 h had only a slight effect on cell growth, but on 48 h exposure a marked killing effect was achieved. After recovery of growth, cells were re-exposed to conjugate for 9-14 days. Treatment of cells from the EB4 line (sIgG lambda) in this way yielded 4 variants which showed a marked reduction in levels of surface Ig lambda and secreted Ig lambda with slight, or no, reduction in MHC class II expression and similar growth rates to the parent line. Variant lines retained their phenotype over long periods of culture. 相似文献
107.
A method is described based on crossed immunoelectrophoresis of a complex antigen mixture in agarose gel followed by incubation of the gel with the monoclonal antibody. The bound monoclonal antibody is detected by the use of a secondary enzyme-labelled antibody.Using this technique we have been able to identify the precipitate arc in crossed immunoelectrophoresis of major histocompatibility complex (MHC) class I molecules in a mixture of all detergent solubilized cell membrane molecules by means of a monoclonal antibody, the specificity of which was known independently to be against MHC class I molecules. In other experiments using the same technique we demonstrated the reaction of a monoclonal antibody specific for chicken Ig light chains. 相似文献
108.
慢性肾盂肾炎发病与巨细胞病毒感染关系初探 总被引:5,自引:0,他引:5
应用免疫酶斑点法检测慢性肾盂肾炎病人尿液中巨细胞颊毒,同时应用ELISA法检测血中HCMV抗体,检测结果表明,尿中HCMV阳性率为52.9%,血清中HCMV抗体为75.9%,与正常对照组相比,并差非常显著,证明慢性肾盂炎发病与HCMV感染有关。 相似文献
109.
N Yamaguchi Y Hitoshi S Takaki Y Murata M Migita T Kamiya J Minowada A Tominaga K Takatsu 《International immunology》1991,3(9):889-898
The murine interleukin 5 receptor (IL-5R) was identified by utilizing an immobilized IL-5 and an immobilized monoclonal antibody against the murein IL-5R (designated H7 mAb). The H7 mAb immunoaffinity-purified materials from the extract of cell-surface radioiodinated T88-M cells (an IL-5-dependent early B cell line) using 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) were reacted with an immobilized IL-5 matrix. SDS-PAGE of the adsorbed fraction revealed a single band at approximately 60 kDa. The binding of the 60 kDa protein to the immobilized IL-5 matrix was inhibited by the excess IL-5. The CHAPS-extract depleted of the 60 kDa protein by the absorption with H7 mAb did not contain any IL-5 binding proteins. Immunoaffinity procedure provided a final 7400-fold purification, based on an estimation of the content of the 60 kDa protein (approximate purity: 20%) from the silver-stained pattern of SDS-PAGE. Actin was copurified with the 60 kDa protein at an approximate ratio of 1:1, suggesting that the intracytoplasmic domain of the IL-5R may interact with actin. Furthermore, soluble IL-5R (molecular mass: 50 kDa) was purified by the H7 mAb-immunoaffinity chromatography. The purified soluble IL-5R was capable of inhibiting the binding of IL-5 to T88-M cells. Preparative SDS-PAGE followed by electroblotting onto a membrane permitted the determination of the N-terminal sequence of the IL-5R. The determined N-terminal sequence of the IL-5R and the deduced primary sequence from recently isolated cDNA were compared. 相似文献
110.
A protamine sulphate (PS) pretreated solid phase coated with different amounts of dsDNA has been used to develop a sensitive, specific and reproducible anti-dsDNA ELISA. Using low concentrations of a dsDNA coat 50% of SLE sera were found to be positive and false positive reactivity due to anti-PS reactivity was found in 3/40 patients with other auto-immune diseases (OAID). In contrast, when PS was saturated with higher concentrations of dsDNA 80% of SLE sera were detected, the reproducibility of the results was better and anti-PS reactivity of OAID patients with an anti-PS reactivity disappeared. The sera of three other OAID patients contained low avidity anti-dsDNA, measured after a salt elution step in the ELISA procedure, and 2/60 patients with non-auto-immune disease exhibited a false positive anti-dsDNA reactivity since they reacted with the solid phase even in the absence of PS and dsDNA. Thus an ELISA procedure using a PS pretreated solid phase permits the sensitive, specific and reproducible measurement of anti-dsDNA antibodies only if a high concentration of dsDNA is coated on the PS and appropriate controls are performed. 相似文献