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51.
Prevention of ultraviolet radiation- or chemical carcinogen-induced morphologic transformation and inhibition of tumor-producing transformed cell growth by lymphotoxin and by normal spleen leukocytes were quantitatively compared to define the antineoplastic activity spectra of these natural immune mediators. When Syrian golden hamster embryo cells seeded for colony formation in culture dishes were treated simultaneously with carcinogen and lymphotoxin, the number of morphologically transformed cell colonies was irreversibly reduced by 50% in the presence of 6 units of lymphotoxin/ml. Lymphotoxin inhibition of tumor cell growth, however, was reversible and 50% reduction in tumor cell growth in three transformed lines required 124, 330, and 477 units/ml. Thus, the anticarcinogenic activity of lymphotoxin can be 20-fold or more greater than its tumor growth-inhibitory activity. Similarly spleen leukocytes also were more effective as an anticarcinogen than as an inhibitor of tumor cell growth, consistent with previous observations that naturally occurring spleen leukocyte antineoplastic activity may result from lymphotoxin secretion. 相似文献
52.
53.
Summary We have determined the DNA sequence of a BALB/cTla region class I gene from the major histocompatibility complex (MHC) that had been identified previously as encoding a murine antigen by DNA-mediated gene transfer. Analysis of the DNA sequence shows, however, that this gene, the T1c gene from theTla
c genotype, could not encode a TL antigen or any other functional class I molecule due to the presence of numerous stop codons and frameshift mutations in the coding regions. This result suggests that the earlier transformation data may have been incorrect or perhaps that the clone containing the T1c gene contains sequences that induced expression of a serologically reactiveTla gene in the genome of the recipient L cell. The T1c gene is structurally related to the previously sequenced T13c gene that encodes a serologically defined TL antigen. The 3 half of the T1c gene including exons 4, 5, 6, and the 3 untranslated region has about 85% nucleotide similarity (including introns) with the corresponding parts of the T13c gene; however, the 5 half of the T1c gene has little homology with the T13c gene. There is a sharp line of demarcation between the homologous and nonhomologous regions, and this border occurs precisely at a B2 Alu repeat sequence present in the T13c gene. This suggests that a recombination event took place here and that an Alu repeat sequence that is known to have characteristics of transposable elements played some role in a recombination or gene conversion event. 相似文献
54.
Fritz Rudert Wolfgang Zimmermann John A. Thompson 《Journal of molecular evolution》1989,29(2):126-134
Summary Various rodent and primate DNAs exhibit a stronger intra- than interspecies cross-hybridization with probes derived from the N-terminal domain exons of human and rat carcinoembryonic antigen (CEA)-like genes. Southern analyses also reveal that the human and rat CEA gene families are of similar complexity. We counted at least 10 different genes per human haploid genome. In the rat, approximately seven to nine different N-terminal domain exons that presumably represent different genes appear to be present. We were able to assign the corresponding genomic restriction endonuclease fragments to already isolated CEA gene family members of both human and rat. Highly similar subgroups, as found within the human CEA gene family, seem to be absent from the rat genome. Hybridization with an intron probe from the human nonspecific cross-reacting antigen (NCA) gene and analysis of DNA sequence data indicate the conservation of noncoding regions among CEA-like genes within primates, implicating that whole gene units may have been duplicated. With the help of a computer program and by calculating the rate of synonymous substitutions, evolutionary trees have been derived. From this, we propose that an independent parallel evolution, leading to different CEA gene families, must have taken place in, at least, the primate and rodent orders. 相似文献
55.
56.
本文对国内流行的猪肠毒素源性大肠杆菌K88ac抗原的结构基因的核苷酸序列进行了测定。该基因由849对核苷酸组成,编码了283个氨基酸的蛋白亚单位及21个氨基酸的信号肽。与国外报道的K88ac序列的不同是我们发现一个碱基的点突变,导致在抗原决定簇内一个氨基酸的改变。从核苷酸序列推导出的氨基酸序列与另两种亚型进行了比较。 相似文献
57.
A chemiluminescent assay for hepatitis-B surface antigen is described which used an isoluminol derivative as the label. The assay is precise intra-assay CV, 1.96-2.45%; inter-assay CV, 5.26-8.11% and has a lower detection limit for hepatitis-B surface antigen of 1.3U/I. 相似文献
58.
Lymphocyte subpopulations of regional lymph nodes in human colon and gastric adenocarcinomas 总被引:3,自引:0,他引:3
Beatriz Lores-Vazquez Margarita Pacheco-Carracedo Josefina Oliver-Morales Purificación Parada-Gonzalez F. Gambón-Deza 《Cancer immunology, immunotherapy : CII》1996,42(6):339-342
In order to study the host immune response to tumours, previous knowledge of the cellular composition of regional draining
lymph nodes is necessary. Enlarged regional lymph nodes are a common finding in colon and gastric adenocarcinomas. We have
studied the cellular composition of normal non-reactive and of regional draining lymph nodes of colon and gastric adenocarcinomas.
In normal non-reactive lymph nodes, T lymphocytes (CD2+, CD7+) constituted the largest fraction of the lymphoreticular cells. These lymphocytes were mainly CD4+, and there were more cells expressing the CD45RA isoform of the CD45 antigen than CD45RO. Reactive lymph nodes presented
a decreased proportion of CD4+ CD45RA+ cells and an increased number of B cells. Although most of the T cells in the reactive nodes were CD4+ CD45RO+, their proportion was similar to that found in normal non-reactive nodes. We studied the presence of the molecules CD28 and
CD80 involved in the processes of interaction and activation of T and B lymphocytes. The CD28 molecule was found in all the
T lymphocytes, while the CD80 molecule was weakly expressed on the B lymphocyte membrane.
Received: 4 January 1996 / Accepted: 28 May 1996 相似文献
59.
Elizabeth A. Kingsley Teresa E. Carter Kevin D. Barrow Pamela J. Russell 《Cancer immunology, immunotherapy : CII》1996,41(6):348-354
A monoclonal antibody, BLCA-8, was raised against the human bladder cancer cell line, UCRU-BL-17CL. By flow cytometry and immunoperoxidase staining, this antibody was found to possess high specificity for bladder tumours, some reactivity with fetal tissues, and no reactivity with normal bladder, or any normal or malignant tissue. This high specificity and the stability of the antigen to the urinary environment suggest that BLCA-8 may have potential for use as an anti-bladder-cancer therapeutic agent. By thin-layer chromatography and autoradiography, BLCA-8 was found to bind four components within the neutral lipid fraction of a bladder cancer cell line, UCRU-BL-17/23. These components hadR
F values of 0.22, 0.16/0.15 (doublet), 0.12 and 0.08, and migrated below globoside, indicating the presence of more than four sugars. By enzyme-linked immunosorbant assay and thin-layer chromatography it was found that the binding of BLCA-8 to the lipid extract was increased by both mild alkaline hydrolysis and enzymatic treatments, indicating that adjacent phospholipids and glycolipids interfere with the accessibility of the antibody-binding site. Full biochemical characterisation of the BLCA-8 antigen is currently underway. 相似文献
60.
Shigenori Goto Sumitaka Sakai Jiro Kera Yukie Suma Gen-Ichiro Soma Shoshichi Takeuchi 《Cancer immunology, immunotherapy : CII》1996,42(4):255-261
Lipopolysaccharide (LPS) has been recognized as a potent antitumor agent in animal tumor models; however, its use in human
cancer therapy has been limited to only one trial, in which LPS from Salmonella was given intravenously. It was not very successful because of poor tumor response and was also toxic. We originally developed
LPS prepared from Pantoea agglomerans (LPSp), and this was a well-purified, small-molecular-mass (5 kDa) agent. We chose intradermal rather than intravenous administration
in the hope that the former would release LPS slowly into the bloodstream, and thus be less toxic while preserving antitumor
activity. In our animal tumor models, intradermal administration was indeed less toxic and more beneficial for tumor regression
than intravenous administration. We made a pilot study with intradermal administration of LPSp on the treatment of ten advanced
cancer patients. Five of them had evaluable tumor, which had failed earlier to respond to conventional chemotherapy. Cyclophosphamide
was also administered in this trial, in anticipation of its synergistic effect with LPSp. In this study LPSp was injected
intradermally into each patient twice a week, starting with an initial dose of 0.4 ng/kg, and raising it to 600 or 1800 ng/kg.
A 400-mg/m2 dose of cyclophosphamide was given intravenously every 2 weeks. After completion of the dose escalation, the treatment was
continued for at least 4 months, and it was found that 1800 ng/kg LPSp was well tolerated. A significant level of cytokines
was observed in the sera for at least 8 h. These results indicate higher tolerable doses and remarkably more continuous induction
of the cytokines than were reported in a previous study by others using intravenous administration. Three of the five evaluable
tumors showed a significant response to our combined therapy. Intradermally administered, LPS was less toxic and elicited
a tumor response in combination with cyclophosphamide; it can thus can be applied to cancer treatment even in humans.
Received: 3 August 1995 / Accepted: 2 April 1996 相似文献