全文获取类型
收费全文 | 3227篇 |
免费 | 114篇 |
国内免费 | 139篇 |
出版年
2024年 | 3篇 |
2023年 | 36篇 |
2022年 | 65篇 |
2021年 | 78篇 |
2020年 | 53篇 |
2019年 | 91篇 |
2018年 | 82篇 |
2017年 | 63篇 |
2016年 | 69篇 |
2015年 | 81篇 |
2014年 | 117篇 |
2013年 | 188篇 |
2012年 | 80篇 |
2011年 | 90篇 |
2010年 | 81篇 |
2009年 | 105篇 |
2008年 | 94篇 |
2007年 | 104篇 |
2006年 | 98篇 |
2005年 | 93篇 |
2004年 | 91篇 |
2003年 | 84篇 |
2002年 | 74篇 |
2001年 | 69篇 |
2000年 | 56篇 |
1999年 | 67篇 |
1998年 | 64篇 |
1997年 | 83篇 |
1996年 | 103篇 |
1995年 | 105篇 |
1994年 | 114篇 |
1993年 | 115篇 |
1992年 | 102篇 |
1991年 | 112篇 |
1990年 | 82篇 |
1989年 | 70篇 |
1988年 | 82篇 |
1987年 | 66篇 |
1986年 | 59篇 |
1985年 | 51篇 |
1984年 | 60篇 |
1983年 | 31篇 |
1982年 | 28篇 |
1981年 | 21篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1973年 | 3篇 |
1972年 | 2篇 |
排序方式: 共有3480条查询结果,搜索用时 15 毫秒
21.
Six monoclonal antibodies to Japanese monkey leukocytes were developed. These monoclonal antibodies, designated the U series, cover most kinds of leukocytes (pan T cells, CD8+ cells, CD8+ subset and granulocytes, CD16+ cells, monocytes/macrophages), and should be useful in the immunological analysis of primate models, such as tissue transplants and virus-related diseases, in particular, acquired immune deficiency syndrome (AIDS). 相似文献
22.
Biotyping of pathogenic yeasts and hyphomycetes based on their suceptibility to selected killer yeasts and their reactivity with monoclonal antibodies are described. Both methods were used to differentiate fungi isolated from patients providing valuable epidemiological information on mycotic infections. The functional biotyping obtained with the two systems and the conventional auxenographic biocoding approaches commercially available for opportunistic yeasts are comparatively evaluated. The potential for biotyping of industrial fungal isolates is also discussed. 相似文献
23.
Studies were carried out on glutamate dehydrogenase (GDH, EC 1.4.1.2) isolated from the SB1 and SB3 soybean (Glyciene max L. cv. Mandarin) cell cultures. The NAD(H) dependent enzyme from SB1 and SB3 cells was purified to homogeneity, and that from the SB3 cells studied in detail. It was shown to be activated by calcium. The molecular weight of the native enzyme was found to be 263 000 ± 12 000. The molecular weight of the subunits was shown to be 41 000 ± 2000, which indicates that the enzyme has a hexameric structure. Anti-GDH antibodies were produced in rabbits, to GDH purified to homogeneity from both cell cultures. Each antibody preparation reacted with the purified enzyme produced from either cell culture. Antibodies to GDH from SB3 cells were utilized to study the apparent induction of GDH, which occurs when these cells are grown in a medium with ammonium ions as the sole nitrogen source. The increase in GDH activity was shown to be due to de-novo protein synthesis. The anti-SB3-GDH antibody preparation was also tested for cross reactivity with crude GDH preparations from a number of plant sources, and purified GDH from a number of other organisms. The antibody was shown to cross react with a number of the GDH preparations. 相似文献
24.
Jürgen Markl Stefanie Winter 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1989,159(2):139-151
Summary Three murine hybridoma cell lines secreting IgG1 antibodies to 4×6 tarantula (Eurypelma californicum) hemocyanin were isolated, and the monoclonal antibodies Ec-7, Ec-8 and Ec-24 characterized by immunoblotting, immunoelectrophoresis and ELISA. WholeEurypelma hemocyanin, and the isolated subunitsa tog served as probes. For the subunits a novel, quick purification scheme on FPLC combined with immuno-affinity chromatography was established.Additionally, two cell lines secreting IgM antibodies were isolated. These antibodies showed irrelevant cross reactivities.Ec-7 strongly reacts with subunitd and weakly withb. Ec-8 and Ec-24 are specifically directed againstEurypelma subunitsa ande, respectively. The epitopes of Ec-7 and Ec-8 are sequence-dependent, whereas the Ec-24 epitope is conformation-dependent. Ec-8 and Ec-24 are specific forEurypelma hemocyanin. Ec-7 is not reactive to crustacean, centipede or gastropod hemocyanins, but binds to scorpion hemocyanin and to the immunological correlates of subunitsd andf in the hemocyanins of the spiderCupiennius salei and the xiphosuranLimulus polyphemus.In immunoblots with different polyclonal antisera,Eurypelma andAstacus hemocyanin cross-reacted with calliphorin, a larval serum protein from the blowflyCalliphora vicina. Calliphorin and chelicerate hemocyanins share the Ec-7 epitope. Sedimentation coefficients, pH stability regions, subunit size, and electron microscopical appearance of calliphorin are indiscernable from a typical 1×6 arthropod hemocyanin. This relationship is discussed in the context of hemocyanin evolution.Abbreviations
FPLC
fast performance liquid chromatography
-
PAGE
polyacrylamide gel electrophoresis
-
SDS
sodium dodecyl sulphate
A preliminary account of this work was presented in June 1987 at the annual meeting of the Deutsche Zoologische Gesellschaft at Ulm (Markl 1987a) 相似文献
25.
Effect of anti-mosquito antibodies on the infectivity of the rodent malaria parasite Plasmodium berghei to Anopheles farauti 总被引:3,自引:0,他引:3
The effect of mouse anti-mosquito antibodies, present in the bloodmeal, on the infectivity of Plasmodium berghei Vincke to Anopheles farauti Laveran was investigated. Significantly fewer oocysts developed in mosquitoes feeding on mice immunized with sugar-fed mosquito midgut antigens than in mosquitoes feeding on control mice. Mosquitoes feeding on mice immunized with the midgut antigens derived from sugar-fed mosquitoes also showed reduced mortality and had lower infection rates than those fed on unimmunized mice. Blood-fed midgut antigen was less effective in producing these effects than sugar-fed midgut antigen. 相似文献
26.
Jamal Bayad Nicole Sabolovic Denyse Bagrel Athanase Visvikis Maria Wellman Gerard Siest 《Cell biology and toxicology》1990,6(2):157-170
Eighteen IgGl monoclonal antibodies (blabs) have been produced against gamma-glutamyl transferase (GGT) from rat kidney. They were specific to the light subunit of the enzyme with affinity constants ranging from 0.3 to 7.5 108 M–1, while they did not react with GGT from other sources i.e. human and pig kidney, rat and guinea pig liver, suggesting species and organ specificity. Two of the blabs (N° 11 and 21) lost their immunoreactivities towards rat kidney GGT in the presence of N-acetyl-neuraminic acid, while immunoreactivities of the other blabs were unchanged. Furthermore, Mabs No 11 and 21 did not react with desialylated rat kidney GGT. These findings suggest that N-acetyl-neuraminic acid is involved in the epitopes recognized by these two Mabs.Abbreviations ELISA
enzyme linked immunosorbent assay
- GGT
gamma-glutamyltransferase
- Mab
monoclonal antibody
- SDS-PAGE
sodium dodecyl sulfate-polyacrylamide gel electrophoresis 相似文献
27.
Mitoshi Yokota Yutaka Tagawa Daikichi Okada Tooru Yasutake Yoshikazu Mine Hiroshi Ishikawa Kousei Miyashita Masao Tomita Sumihiro Tabuchi 《Biotherapy》1990,2(3):207-212
Pre- and postoperative intradermal administration of OK-432 enhanced the SU-PS skin reaction in patients with gastric cancer, but failed to prevent a fall in the NK activity induced by the operation.The change in NK activity was not associated with a change in the proportion of Leu 7-positive cells, but was related to Leu 11a-positive cells. Intradermal injection of OK-432 increased the proportion of Leu 7-positive cells in the patients in whom they accounted for less than 20% of lymphocyte population. The case was the same with Leu 11a-positive cells.Intravenous injection of OK-432 tended to increase suppressor-inducer T cells (CD4+2HA+ cells), B cells and Leu 7-positive cells. Particularly, the proportions of OK-M1-positive cells and MHC class II antigen-positive cells increased in all patients. Immunotherapy with OK-432 given intravenously at a dose of 0.1 KE appeared to be safe because no side effects were essentially observed. 相似文献
28.
Summary We raised monoclonal antibodies against a membrane fraction ofXenopus neurulae in order to detect tissue-specific cell-surface markers. Here we describe a monoclonal antibody that recognizes an epithelial membrane-associated antigen (EMA) in immunohistological stainings. The tissue-specific and membrane-associated antigen detected in immunohistological stainings could serve as useful marker in epithelium differentiation and membrane organization of the early embryo. In tadpoles and adults EMA was found in specific epithelial tissues derived from different germ layers such as kidney, skin, gut, pancreas, epiphysis and choroid plexus. In the cleaving embryo this antibody stained newly formed membranes between blastomeres from the two-cell stage onwards. Cytoplasmic staining in large oocytes and early embryos was also observed. The possibility that the cytoplasmic signal represents a maternal store of membrane material is discussed. 相似文献
29.
Summary Monoclonal antibodies were raised against germinal vesicles which were isolated from fully grown oocytes of the ascidianHalocynthia roretzi. Immunoblot analyses revealed that one of the antibodies, designated Hgv-2, recognized a single band with a molecular weight of about 83 kDa. The antibody, visualized by indirect immunohistochemistry, reacted only with the germinal vesicles of oocytes and did not react with test cells, follicle cells, and other somatic cells of the gonad. During embryogenesis the antigenicity was found in interphase nuclei of all embryonic cells. The antibody did not react with chromosomes or the mitotic apparatus. The antigenicity was retained by interphase nuclei of larval cells, but it disappeared from nuclei of juveniles about 7 days after metamorphosis. 相似文献
30.
An antiserum raised against -fructosidase isolated from the cell walls of suspension-cultured carrot cells cross-reacts with many plant proteins and hemocyanin ofHelix pomatia. The shared epitope appears to be a small complex glycan with a (1–2)-linked xylose residue attached to the -linked mannose residue of the core of an asparagine-linked oligosaccharide. There is strong cross-reactivity with the proteins of many seed plants, molluscs and insects, and no cross-reactivity with the proteins of fungi, algae, mosses, ferns, or any of the vertebrates tested. Xylose-containing glycans appear to increase the immunogenicity of the proteins to which they are attached, and we suggest that they may be responsible for some allergic responses of people that are repeatedly exposed to plant or insect proteins. 相似文献