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31.
R J Klaassen W H Ouwehand T W Huizinga C P Engelfriet A E von dem Borne 《Journal of immunology (Baltimore, Md. : 1950)》1990,144(2):599-606
FcRIII is not present on peripheral blood monocytes, but becomes expressed upon culturing and can be demonstrated on tissue macrophages. We studied the expression of FcRIII of cultured monocytes in detail and compared its structure with FcRIII of neutrophils and NK cells. The cell density of FcRIII reached a plateau within 3 days of culturing. During that time, the expression of FcRI and FcRIIa, also present on monocytes, did not change significantly. FcRIII on cultured monocytes lacked, as did NK cell FcRIII, the NA1-allotypic variant of the NA system present on the neutrophil FcRIII. Studies with glycosyl-phosphatidyl-inositol-specific phospholipase C and analysis of cells of patients with paroxysmal nocturnal hemoglobinuria revealed that FcRIII on cultured monocytes is not anchored by phosphatidyl-inositol-glycan in the cell membrane. Similarly, FcRIII on NK cells was resistant to glycosyl-phosphatidyl-inositol-specific phospholipase C treatment, suggesting that NK cell FcRIII is also not anchored by a phosphatidyl-inositol-glycan moiety, in contrast to neutrophil FcRIII. Analysis by SDS-PAGE showed that the FcRIII of cultured monocytes had a similar mobility as the FcRIII on NK cells, but was clearly distinct from neutrophil FcRIII. Treatment with N-glycanase showed that the protein backbone of deglycosylated FcRIII of cultured monocytes was similar to that of FcRIII of NK cells, but deglycosylated neutrophil FcRIII was different. Specific blocking of FcRIII of cultured monocytes with an anti-FcRIII mAb did not reduced the lytic action of the cultured monocytes towards sensitized erythrocytes. However, FcRIII was modulated from the cell surface by incubation with sensitized E, whereas non-FcR Ag were not. These findings indicate that FcRIII is involved in binding of immune complexes, but does not act as a trigger molecule for extracellular lysis of sensitized E. 相似文献
32.
Summary The kinetics of replication of the inactive (late replicating) X chromosome (LRX) were studied in karyotypically normal lymphocytes and human amniotic fluid cells. Both cell types were successively pulse labeled with 1-h or 1/2-h thymidine pulses in an otherwise BrdU-substituted S phase after partial synchronization of the cultures at G1/S. For the first time with this technique, the entire sequence of replication was analyzed for the LRX from the beginning to the end of the S phase, with special reference to mid S (R-band to G-band transition replication). The inactive X is the last chromosome of the metaphase to start replication, with a delay of 1 or 2h, after which time a thymidine pulse results in R-type patterns. In mid S, the inactive X is the first chromosome to switch to G-type replication (without overlapping of both types and without any detectable replication pause). Until the end of S, a thymidine pulse results in G-type patterns. To rule out artifacts that might arise by the synchronization of cultures in these experiments, controls were carried out with BrdU pulses and the BrdU antibody technique without synchronization. In the course of replication, no fundamental difference was seen between the two different cell types examined. In contrast to studies using continuos labeling, this study did not reveal an interindividual difference of replication kinetics in the LRXs of the seven individuals studied; thus it is concluded that the inactive X chromosome shows only one characteristic course of replication. 相似文献
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34.
Sabine P. Kuhn Robert M. Pfister 《Journal of industrial microbiology & biotechnology》1990,6(2):123-128
Summary
Zoogloea ramigera 115 was immobilized into beads of calcium-alginate and placed into batch air-bubbled column reactors. In the absence of any added nutrients the immobilized bacterium adsorbed Cd from solutions containing levels of 2 and 20 g ml–1 per day, over a period of 21 and 20 days, respectively. Adsorption of Cd from solutions containing 20 g ml–1 Cd was better than 90% for 16 days. Beads treated with Cd at 2 g ml–1 never adsorbed less than 95% of the metal. Alginate adsorbed Cd as well, but inclusion of cells changed the effectiveness of adsorption. Of a 250 g ml–1 Cd solution, alginate adsorbed 70.4% Cd in 60 min whereas alginate plus cells adsorbed 90.5% in the same time span. Temperature had no effect on adsorption by immobilized cells at levels of 2 and 10 g ml–1 Cd. However at higher concentrations, binding was enhanced as temperature increased.Z. ramigera beads were stable during all treatments and for prolonged periods of time (21 days). 相似文献
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37.
Hoch Brigitte Lutsch Gudrun Schlegel Wolfgang-Peter Stahl Joachim Wallukat Gerd Bartel Sabine Krause Ernst-Georg Benndorf Rainer Karczewski Peter 《Molecular and cellular biochemistry》1996,160(1):231-239
Recent investigations concentrate on the correlation between the myocardial expression of the inducible 70-kDa heat shock protein (HSP70i) by different stress conditions and its possible protective effects. Only few studies have focused on the involvement of small heat shock proteins in this process. We analyzed the location of the small heat shock protein HSP25 in isolated cardiomyocytes as well as its location and induction in isolated perfused hearts of rats. By immunofluorescence microscopy HSP25 was found to colocalize with actin in the I-band of myofibrils in cardiomyocytes of isolated perfused hearts as well as in isolated neonatal and adult cardiomyocytes. Hyperthermic perfusion of isolated hearts for 45 min resulted in modulation of different parameters of heart function and in induction of HSP25 and HSP70i. Temperatures higher than 43°C (44–46°C) were lethal with respect to the contractile function of the hearts. Compared to control hearts perfused at 37°C, significant increases during hyperthermic perfusion at 42°C and 43°C were obtained for heart rate, contraction velocity and relaxation velocity. In response to hyperthermia at 43°C and after subsequent normothermic perfusion for 135 min at 37°C, left ventricular pressure, contraction velocity and relaxation velocity remained significantly elevated. However, heart rate returned to control values immediately after the period of heat treatment. HSP25 is constitutively expressed even in normothermic perfused hearts as shown by Western blotting. Hyperthermia increased the content of HSP25 only in the left ventricular tissue. In contrast, HSP70i was strongly induced in all analyzed parts of the myocardium (left ventricle, right ventricle, septum). Our findings suggest a differential regulation of HSP25 and HSP70i expression in response to hyperthermia in isolated perfused hearts. The constitutively expressed HSP25 seems to be located adjacent to the myofibrils which implies a specific role of this protein even under unstressed conditions for the contractile function of the myocardium. 相似文献
38.
Kaumann Alberto J. Sanders Louise Lynham James A. Bartel Sabine Kuschel Meike Karczewski Peter Krause Ernst-Georg 《Molecular and cellular biochemistry》1996,163(1):113-123
Evidence from ventricular preparations of cat, sheep, rat and dog suggests that both 1-adrenoceptors (1AR) and 2-adrenoceptors (2AR) mediate positive inotropic effects but that only 1AR do it through activation of a cAMP pathway. On the other hand, our evidence has shown that both 1 AR and 2 AR hasten relaxation of isolated human myocardium consistent with a common cAMP pathway. We have now investigated in the isolated human right atrial appendage, a tissue whose -AR comprise around 2/3 of 1AR and 1/3 of 2AR, whether or not 2AR-mediated effects occur via activation of a cAMP pathway. We carried out experiments on atria obtained from patients without advanced heart failure undergoing open heart surgery. To activate 2AR, we used the 2AR-selective ligand zinterol. Experiments were carried out on paced atrial strips (1 Hz) and tissue homogenates and membrane particles. Zinterol caused positive inotropic and lusitropic (i.e. reduction of t1:2 of relaxation) effects with EC50 values of 3 and 2 nM, respectively. The zinterol-evoked effects were unaffected by the AR-selective antagonist CGP 20712A (300 nM) but blocked surmountably by the 2AR-selective antagonist ICI 118551 (50 nM) which reduced both EC50 values to 1 M. Zinterol stimulated adenylyl cyclase activity with an EC50 of 30 nM and intrinsic activity of 0.75 with respect to (–)-isoprenaline (600 M); the effects were resistant to blockade by CGP 20712A (300 nM) but antagonised surmountably by ICI 118551 (50 nM). Zinterol bound to membrane PAR labelled with (–)-[125I] cyanopindolol with higher affinity for 2AR than for - 1 AR; the binding to 2AR but not to - BAR was reduced by GTPyS (10 M). In the presence of CGP 20712A (300 nM) (–)-isoprenaline (400 M); (to activate both 1AR and 2AR maximally) and zinterol (10 M); increased contractile force 3.4-fold and 2.5-fold respectively and reduced relaxation tut by 32% and 18% respectively. These effects of (–)-isoprenaline and zinterol were associated (5 min incubation) with phosphorylation (pmol P/mg supernatant protein) of troponin I and C-protein to values of 8.4 ± 2.0 vs 12.4 ± 2.3 and 10.1 ± 2.5 vs 8.6 ± 1.6 respectively. (–)-Isoprenaline and zinterol also caused phosphorylation of phospholamban (1.8 ± 0.3 vs 0.4 ± 0.1 pmol P/mg respectively) specifically at serine residues. We conclude that in human atrial myocardium activation of both 1AR and 2AR leads to cAMP-dependent phosphorylation of proteins involved in augmenting both contractility and relaxation. 相似文献
39.
Sabine Kölle Fred Sinowatz Gudrun Boie Ines Totzauer Werner Amselgruber Johnna Plendl 《The Histochemical journal》1996,28(6):441-447
Summary The mRNA of the zona pellucida glycoprotein ZP3 was localized in frozen sections of pig ovaries, isolated oocytes and early embryos byin situ hybridization using biotinylated oligonucleotide probes. In follicles, the distribution of mRNA for ZP3 was correlated with the developmental stage: in primordial and primary follicles, the mRNA was shown to be predominantly localized in the oocyte. In secondary follicles, mRNA was found in both the oocyte and follicle cells. In tertiary and preovulatory follicles, the follicle cells showed distinct staining, whereas the oocyte was labelled weakly. In the early embryo, i.e. 2 days after fertilization, mRNA for ZP3 could not be demonstrated. Our results suggest that, in the pig, the zona pellucida protein ZP3 is synthesized by the oocyte and the follicle cells in sequence. After fertilization, synthesis of ZP3 is terminated. 相似文献