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81.
Shin EH Kim DH Lin A Lee JW Kim HJ Ahn MH Chai JY 《The Korean journal of parasitology》2008,46(1):45-48
To evaluate the usefulness of the Korean Isolate-1 (KI-1) antigen for serodiagnosis of toxoplasmosis, antigen profiles of KI-1 tachyzoites were analyzed in comparison with RH tachyzoites by SDS-PAGE and immunoblotting. ELISA was performed on latex agglutination (LA)-positive and negative serum samples using KI-1 and RH antigens. Immunoblotting of the KI-1 antigen showed multiple antigen bands with molecular sizes of 22-105 kDa. Among them, 1 and 6 common bands were noted against a KI-1-infected and a RH-infected human serum, respectively, which represented differences in antigenic profiles between KI-1 and RH tachyzoites. However, all 9 LA-positive human sera were found positive by ELISA, and all 12 LA-negative sera were negative by ELISA; the correlation between the ELISA titers and LA titers was high (r = 0.749). Our results suggest that tachyzoites of KI-1 may be useful for serodiagnosis of human toxoplasmosis. 相似文献
82.
A block synthetic approach is presented for the synthesis of the pentasaccharide repeating unit of the O-antigen of E. coli O83:K24:H31 strain, present in the “Colifant” vaccine. The target pentasaccharide has been synthesized by coupling a disaccharide
with a trisaccharide in excellent yield. Yields are quite satisfactory in all intermediate steps.
A concise synthesis of the pentasaccharide repeating unit of the O-antigen of E. coli O83:K24:H31 strain, present in the COLINFANT vaccine is presented. The target pentasaccharide has been synthesized following
a block synthetic strategy by coupling a disaccharide with a trisaccharide in excellent yield. 相似文献
83.
Polyunsaturated fatty acids (PUFAs), notably of the n-3 series, have immunosuppressive effects which make these molecules candidates for treating inflammatory symptoms associated with cardiovascular disease, obesity, arthritis, and asthma. However, immunosuppression by PUFAs could increase susceptibility to bacterial and viral infection. A detailed molecular picture is required in order to understand the balance between the benefits and risks of utilizing PUFAs as adjuvant immunosuppressants. Here we review evidence that incorporation of PUFAs into membrane lipids of antigen presenting cells (APCs) downregulates APC function. We propose that PUFAs modulate antigen presentation by altering the organization of lipid and protein molecules of the plasma membrane and endomembranes; this alters recognition and responses by T cells. The foundation of our hypothesis is built on data from artificial bilayer experiments which provide the physical principles by which PUFA acyl chains affect membrane architecture. This review also reconciles conflicting results in the literature by discussing the advantages and disadvantages of differing methods of PUFA treatment of cells. We suggest that membrane modulation of immune cells may be an important and overlooked mechanism of immunomodulation. In addition, we propose that mechanistic studies with defined experimental protocols will speed the translation of laboratory studies on PUFAs to the clinic. 相似文献
84.
Thompson JA Srivastava MK Bosch JJ Clements VK Ksander BR Ostrand-Rosenberg S 《Cancer immunology, immunotherapy : CII》2008,57(3):389-398
Activation of tumor-reactive T lymphocytes is a promising approach for the prevention and treatment of patients with metastatic
cancers. Strategies that activate CD8+ T cells are particularly promising because of the cytotoxicity and specificity of CD8+ T cells for tumor cells. Optimal CD8+ T cell activity requires the co-activation of CD4+ T cells, which are critical for immune memory and protection against latent metastatic disease. Therefore, we are developing
“MHC II” vaccines that activate tumor-reactive CD4+ T cells. MHC II vaccines are MHC class I+ tumor cells that are transduced with costimulatory molecules and MHC II alleles syngeneic to the prospective recipient. Because
the vaccine cells do not express the MHC II-associated invariant chain (Ii), we hypothesized that they will present endogenously synthesized tumor peptides that are not presented by professional Ii+ antigen presenting cells (APC) and will therefore overcome tolerance to activate CD4+ T cells. We now report that MHC II vaccines prepared from human MCF10 mammary carcinoma cells are more efficient than Ii+ APC for priming and boosting Type 1 CD4+ T cells. MHC II vaccines consistently induce greater expansion of CD4+ T cells which secrete more IFNγ and they activate an overlapping, but distinct repertoire of CD4+ T cells as measured by T cell receptor Vβ usage, compared to Ii+ APC. Therefore, the absence of Ii facilitates a robust CD4+ T cell response that includes the presentation of peptides that are presented by traditional APC, as well as peptides that
are uniquely presented by the Ii− vaccine cells. 相似文献
85.
José Guilherme Chaui-Berlinck José Alexandre Marzagão Barbuto Luiz Henrique Alves Monteiro 《Theorie in den Biowissenschaften》2004,123(2):195-208
Summary A continuous harvest effort can lead a population to extinction. How an “unconscious” immune system would perpetrate such
an effort in order to eliminate a self-replicating antigen (a pathogen) becomes an intriguing problem if the system responses
are functions of the pathogen population: the responses cannot be a continuous effort as the pathogen vanishes. On theoretical
grounds, we show some qualities an immune response must have to support pathogen elimination. Then, three specific mechanisms
are addressed: a pathogen-independent positive feedback loop among the responding cells of the system (e.g., B-lymphocyte
and T-helper); the persistence of antigen bound to presenting cells; and the programmed expansion/contraction of a pool of
responding cells. The maintenance of responding cells due to these mechanisms is the essential feature to the effective clearance
of self-replicating agents. Thus, evolutionarily, the primary function of a helper lymphocyte would be to amplify a response
and the primary function of memory would be the very elimination of pathogens. 相似文献
86.
We developed a method to measure the rupture forces between antibody and antigen by atomic force microscopy (AFM). Previous studies have reported that in the measurement of antibody–antigen interaction using AFM, the specific intermolecular forces are often obscured by nonspecific adhesive binding forces between antibody immobilized cantilever and substrate surfaces on which antigen or nonantigen are fixed. Here, we examined whether detergent and nonreactive protein, which have been widely used to reduce nonspecific background signals in ordinary immunoassay and immunoblotting, could reduce the nonspecific forces in the AFM measurement. The results showed that, in the presence of both nonreactive protein and detergent, the rupture forces between anti-ferritin antibodies immobilized on a tip of cantilever and ferritin (antigen) on the substrate could be successfully measured, distinguishing from nonspecific adhesive forces. In addition, we found that approach/retraction velocity of the AFM cantilever was also important in the reduction of nonspecific adhesion. These insights will contribute to the detection of specific molecules at nanometer scale region and the investigation of intermolecular interaction by the use of AFM. 相似文献
87.
Kawahito Y Ichinose S Sano H Tsubouchi Y Kohno M Yoshikawa T Tokunaga D Hojo T Harasawa R Nakano T Matsuda K 《Biochemical and biophysical research communications》2008,369(2):561-566
Mycoplasma fermentans has been suspected as one of the causative pathogenic microorganisms of rheumatoid arthritis (RA) however, the pathogenic mechanism is still unclear. We, previously, reported that glycolipid-antigens (GGPL-I and III) are the major antigens of M. fermentans. Monoclonal antibody against the GGPL-III could detect the existence of the GGPL-III antigens in synovial tissues from RA patients. GGPL-III antigens were detected in 38.1% (32/84) of RA patient’s tissues, but not in osteoarthritis (OA) and normal synovial tissues. Immunoelectron microscopy revealed that a part of GGPL-III antigens are located at endoplasmic reticulum. GGPL-III significantly induced TNF-α and IL-6 production from peripheral blood mononulear cells, and also proliferation of synovial fibroblasts. Further study is necessary to prove that M. fermentans is a causative microorganism of RA; however, the new mechanisms of disease pathogenesis provides hope for the development of effective and safe immunotherapeutic strategies based on the lipid-antigen, GGPL-III, in the near future. 相似文献
88.
记忆T细胞平行分化模型的理论研究 总被引:4,自引:0,他引:4
为了从理论上讨论T细胞记忆维持机制的问题,基于T细胞的平行分化假说建立了非线性理论模型,利用此模型,在不同的抗原初值下得到了三种不同类型的应答。用优化剂量的抗原免疫生物体并且抗原存在时记忆能持续很长的时间,而失去抗原的同时将失去记忆,得出记忆T细胞平行分化模型确有记忆机制;并发现记忆强度与剩余抗原量有直接的关系,还进一步讨论了记忆细胞寿命的问题,并对体外情况作了预言。 相似文献
89.
Summary The distributions of small cardioactive peptide (SCP)- and FMRFamide-like immunoreactivities in the central nervous system of the medicinal leech Hirudo medicinalis were studied. A subset of neurons in the segmental ganglia and brains was immunoreactive to an antibody directed against SCPB. Immunoreactive cell bodies were regionally distributed throughout the nerve cord, and occurred both as bilaterally paired and unpaired neurons. The majority of the unpaired cells displayed a tendency to alternate from side to side in adjacent ganglia. A small number of neurons were immunoreactive only in a minority of nerve cords investigated. Intracellular injections of Lucifer yellow dye and subsequent processing for immunocytochemistry revealed SCP-like immunoreactivity in heart modulatory neurons but not in heart motor neurons. FMRFamide-like immunoreactivity was also detected in cell bodies throughout the central nervous system. A subset of neurons contained both SCP- and FMRFamide-like immunoreactivities; others stained for only one or the other antigen. These data suggest that an antigen distinct from FMRFamide is responsible for at least part of the SCP-like immunoreactivity. This antigen likely bears some homology to the carboxyl terminal of SCPA and SCPB. 相似文献
90.
Dr. Kimie Fukuyama Yoshimasa Ito Kazuo Yabe William L. Epstein 《Cell and tissue research》1985,240(2):417-423
Summary Monospecific antibody directed to cysteine protease of 2-day-old rat epidermis recently characterized as being different from the proteases previously reported was produced in rabbits. By immunofluorescence microscopy and immunoperoxidase staining with an avidin-biotin-peroxidase method the protease was found to be present in the epidermis of rodents of different ages as well as that of humans, but not in the dermis. The staining in germinative cells was more intense than in cells in the superficial layers. It appeared as irregular patches in the nuclei and stained more diffusely in the cytoplasm where small granular components, strongly stained, were identified. The staining patterns in granular cells showed accumulation of the antigen in a granular form. The morphology and distribution of granules resembled those of keratohyalin-like granules in the nucleus and dense homogenous deposits in the cytoplasm. In cornified cells the reaction product was localized by the plasma membrane where concentration of the dense homogenous deposits occurred, suggesting that the cysteine protease is one component of the unique and characteristic structure of differentiated keratinocytes. In addition, the cysteine protease antigen having the same molecular weight as the epidermal enzyme was detected in liver, kidney and lung indicating a wider tissue distribution of the protease. The significance of the protease in regulation of cellular functions remains to be investigated. 相似文献