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A sensitive isotope modification of the mixed haemadsorption test applicable to the study of prozone effects 总被引:3,自引:0,他引:3 下载免费PDF全文
Investigations of surface antigens of animal cells require sensitive and quantitative in vitro methods. A modification of the mixed haemadsorption technique (MHT) suitable for such purposes is presented. The indicator cells have been labelled with chromium-51. During studies of experimental conditions, including reproducibility and sensitivity, the technique was used in four model systems including histocompatibility (H-2, HL-A), species, organ and blood group antigens. Isotope labelling of the indicator cells has rendered the test more sensitive and in addition some qualitative properties of antigen—antibody interaction have been studied. The test procedure is simple and fast. 相似文献
4.
Eneslätt K Rantapää-Dahlqvist S Uddhammar A Sundqvist KG 《Journal of clinical immunology》2001,21(3):183-192
Monocytes and lymphocytes from patients with systemic lupus erythematosus (SLE) had a higher cell surface expression of FasL than the corresponding cells from healthy individuals. Inhibitors of metalloproteases upregulated the surface expression of FasL in peripheral blood lymphocytes (PBL), indicating that a metalloprotease is responsible for the cleavage of FasL. The level of sFasL in serum was slightly increased in the patient group compared to the controls. Therefore, the possible contribution of various mononuclear cell types to the release of FasL was analyzed. Isolated NK cells and T lymphocytes released FasL into the medium and the release was prevented by inhibitors of metalloproteases. In contrast, isolated monocytes did not release FasL. FasR expression was elevated in patients with inverted CD4/CD8 ratio, while FasL expression showed no relationship to CD4/CD8 ratio. The absence of FasL release by isolated cells and a high level of surface expression of FasL distinguish monocytes and T lymphocytes/NK cells. 相似文献
5.
Cytocidal and apoptotic effects of the ClyA protein from Escherichia coli on primary and cultured monocytes and macrophages 下载免费PDF全文
Lai XH Arencibia I Johansson A Wai SN Oscarsson J Kalfas S Sundqvist KG Mizunoe Y Sjöstedt A Uhlin BE 《Infection and immunity》2000,68(7):4363-4367
Cytolysin A (ClyA) is a newly discovered cytolytic protein of Escherichia coli K-12 that mediates a hemolytic phenotype. We show here that highly purified ClyA and ClyA-expressing E. coli were cytotoxic and apoptogenic to fresh as well as cultured human and murine monocytes/macrophages. 相似文献
6.
B. Wahren S. Nordlund A. Åkesson V.-A. Sundqvist B. Morein 《Medical microbiology and immunology》1987,176(1):13-19
Cell-mediated and humoral responses to cytomegalovirus were studied in a monkey model. Repeated low doses of virus antigen gave poor reactivities in both respects. High antigen doses gave a good humoral IgG response. When autologous monocytes were incubated with the CMV antigen as the immunizing injection, the specific cellular response to CMV antigen increased. The monocytes themselves did not contribute to the in vitro specific proliferation response. When iscoms were the carrier particles for CMV antigens, cellular response was even more strongly enhanced. In immunization schedules where specific cellular responses are important, we suggest that autologous monocytes or iscoms may be employed as antigen carriers. 相似文献
7.
Krokan Hans; Grafstrom Roland C.; Sundqvist Kristina; Esterbauer Hermann; Harris Curtis C. 《Carcinogenesis》1985,6(12):1755-1759
Lipid peroxidation aldehydes of the 4-hydroxy-, ß-unsaturatedtype, as well as the tobacco-smoke related , ß-unsaturatedaldehyde, acrolein, were highly cytotoxic and decreased theintracellular thiol content in cultured human bronchial fibroblastsafter treatment with micromolar concentrations. In comparison,formaldehyde and acetaldehyde were less toxic and 100- to 300-foldhigher doses were required to affect cell survival or thiollevels. The unsaturated aldehydes also markedly inhibited theDNA repair enzyme O6-methylguanine-DNA methyltransferase knownto have a cysteine residue in its active site, but had no effecton the activity of uracil-DNA glycosylase. Our results indicatethat reactive aldehydes of either exogenous or endogenous originhave direct cytotoxic effects and may also make cells more susceptibleto other toxic chemicals due to an impairment in cellular defensemechanisms, e.g., DNA repair and detoxification by systems requiringglutathione. 相似文献
8.
Immerstrand C Jager EW Magnusson KE Sundqvist T Lundström I Inganäs O Peterson KH 《Medical & biological engineering & computing》2003,41(3):357-364
Melanophores are dark-brown pigment cells located in the skin of amphibia, fish and many invertebrates. The skin colour of
these organisms is regulated by the translocation of pigment organelles, and the pigment distribution can be altered by external
stimuli. The ability to change colour in response to stimuli makes these cells of interest for biosensing applications. It
was investigated whether pigment aggregation in Xenopus laevis melanophores can be detected by impedance measurements performed
in transparent microvials. The results show that cell attachment, cell spreading and pigment aggregation all resulted in impedance
changes, seen particularly at the highest frequency tested (10 kHz). The mechanisms behind the impedance changes were investigated
by the addition of latrunculin or melatonin, both of which cause pigment aggregation. The latrunculin-induced aggregation
was associated with cell area decrease and filamentous actin (F-actin) breakdown, processes that can influence the impedance.
Lack of F-actin breakdown and an increase in cell area during melatonin-induced aggregation suggest that some other intracellular
process also contributes to the impedance decrease seen for melatonin. It was shown that impedance measurements reflect not
only cell attachment and cell spreading, but also intracellular events. 相似文献
9.
The majority of splenic lymphocytes were motile, showing lamellipodial activity almost immediately after purification. In contrast, fresh blood lymphocytes were non-motile and maintained their spherical suspension morphology. The number of motile blood lymphocytes increased markedly during a 2-day in vitro culture period. This increase was enhanced by high cell density and required a metabolically active cell with protein synthesis but not exogenous mitogens. The spontaneous development of motility in different subpopulations of blood lymphocytes was analysed by means of monoclonal antibodies. The results indicated that cells which were motile immediately after purification were almost exclusively non-T lymphocytes. Lymphocytes which became motile during in vitro culture included both T and non-T cells. Substrate adhesion mediated by concanavalin A (Con A) changed the morphology of motile T lymphocytes and instead of being polar, the cells flattened over the substratum and acquired a non-polar shape. Furthermore, the morphogenetic response induced by Con A-mediated substrate adhesion appeared to distinguish T and non-T lymphocytes. Thus, the length of the cell perimeter showing lamellar activity was greater in T than in non-T lymphocytes, and the degree of polarity was greater in non-T (with and without B-cell markers) than in T lymphocytes. 相似文献
10.
Infiltrative capacity was found to distinguish separate T leukemia cell lines. Of seven T-cell lines four exhibited capacity
to infiltrate Matrigel. Analysis of infiltration was performed at the single-cell level throughout the Matrigel using a depth
meter. Further, we examined differences in migration capacity and metalloproteinase production between infiltrating and non-infiltrating
T-cell lines. The capacity to infiltrate was not directly correlated to the capacity to adhere to the Matrigel or to migrate
on/to extracellular matrix components. It is concluded that infiltration capacity does not simply reflect capacity to migrate
but represents a distinct functional property. The production of metalloproteinases and their inhibitors by the separate T-cell
lines was analyzed using rt PCR, biosynthetic labelling, zymography, immunoprecipitation and ELISA. All T-cell lines with
capacity to infiltrate produced matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) while
non-infiltrating cell lines did not express MMP-9. Expression of MMP-1, 2, 3, 10, 14 and 17 showed no correlation to capacity
to infiltrate. Analysis of infiltration in the presence of a metalloprotease inhibitor showed an increased number of cells
within the gel. This enhancement of infiltration suggests that the function of MMPs and/or their inhibitors in lymphocyte
infiltration is more complex than previously thought.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献