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61.
Simona Picchietti Francesca Renata Terribili Lucia Mastrolia Giuseppe Scapigliati L. Abelli 《Brain structure & function》1997,196(6):457-463
The monoclonal antibodies DLT15 and DLIg3, which recognize antigenic determinants expressed by T cells and Ig-bearing cells, respectively, allowed the development of gut-associated lymphoid tissue of the teleost fish Dicentrarchus labrax (L.) to be studied. DLT15- immunoreactive cells were first detected in the epithelium of the stomach and intestine at day 30 post-hatching of fish maintained at 16° C. At that age, positive cells were found only in the thymus. Between day 44 and day 81 post-hatching, DLT15-immunoreactive cells became numerous, both in and under the gut epithelium. A gradient in the number of lymphocytes was present, concentrating them towards the anus. Until day 81 post-hatching, DLIg3-immunoreactive cells were not found in the gut, although they were present in the kidney, spleen and thymus earlier. Infrequent Ig-bearing cells were found in the gut mucosa of 1-year-old sea bass. This study showed that the gut-associated lymphoid tissue developed earlier than other lymphoid compartments. It also provided evidence of the predominance of T cells in the gut immune system of the sea bass. 相似文献
62.
For an effective radiotherapy the exact tumor location must be determined. The localization has to take into account patient's setup position as well as internal organ motion. Among the different localization methods, the use of a computer tomography (CT) scanner in the therapy room has been proposed recently. Achieving a CT with the patient on the therapy couch, a patient's treatment position is captured. We present a method to locate tumor considering internal organ motion and displacements due to respiration. We tested the method with prostate and lung patients. The method found the most probable tumor position as well as, for high-mobility tumors located in the lung, its trajectory during the respiratory cycle. The results of this novel method were validated by comparison with manually determined target position. 相似文献
63.
64.
Cytokeratin (CK) expression was investigated, by means of immunocytochemistry, in
the hamster thymic epithelium during ontogeny, as well as in primary cultures and
upon glucocorticoid hormone treatment in vivo. As compared to the distribution pattern
of distinct monoclonal antibody-defined cytokeratins in the normal adult thymus, CK
modulation was evidenced in the three situations studied. During thymus ontogeny,
both cytokeratins of simple lining epithelia, as CK8 and CK18, as well as the CK1/CK10
pair (typical marker of terminal stage of keratinization), were expressed since early
stages of thymus development. They were located in the central region of thymic lobules
preceding the cortical-medullary distinctions. This differed from what had been
previously shown for mouse thymus ontogeny, revealing that the interspecific diversity
in the distribution pattern of thymic cytokeratins occurred early in fetal life. A
modulation of CK expression was also detected when hamster thymic epithelial cells
(TEC) were led to grow in culture, with a down-regulation of CK19 contrasting with an
enhancement of CK18 expression. This diverged from the maintenance of the in situ
pattern when human TEC were cultured. Last, in vivo hydrocortisone treatment, known
to increase the numbers of KL1+ cells in the mouse thymus medulla, promoted a cortical
expression of the CK1/CK10 pair in the hamster thymus. Taken together, our findings
demonstrate a continuous plasticity of the thymic epithelium, at least regarding
cytokeratin expression, and enlarge the concept of interspecific diversity of intrathymic
CK distribution in conditions as morphogenesis, in vitro system, and responsiveness to
glucocorticoid hormone treatment. 相似文献
65.
Anti-HIV effects of chloroquine: inhibition of viral particle glycosylation and synergism with protease inhibitors 总被引:2,自引:0,他引:2
Savarino A Lucia MB Rastrelli E Rutella S Golotta C Morra E Tamburrini E Perno CF Boelaert JR Sperber K Cauda R 《Journal of acquired immune deficiency syndromes (1999)》2004,35(3):223-232
OBJECTIVE: We tested the effects of chloroquine (CQ) on glycosylation of HIV particles and in combination with protease inhibitors (PIs) on HIV replication and on P-glycoprotein (P-gp)/multidrug resistance protein-1 (MRP1). DESIGN: CD4 cell lines were infected with laboratory strains and peripheral blood mononuclear cells were infected with primary isolates for evaluation of the anti-HIV effects. Peripheral blood lymphocytes were evaluated for of P-gp and MRP1 functions. METHODS: HIV replication was assessed by enzyme-linked immunosorbent assay. HIV glycosylation was measured by metabolic labeling of viral particles with [H] glucosamine. Synergism was tested using isobolograms. P-gp and MRP1 functions were assayed using rhodamine 123 (Rh123) and carboxyfluorescein (CF) efflux assays, respectively. RESULTS: CQ alone inhibited HIV replication and glycosylation in a dose-dependent manner. In combination with indinavir (IDV), ritonavir, or saquinavir (SQV), CQ had a synergistic effect at concentrations found in plasma of subjects receiving malaria prophylaxis. CQ decreased the 50% effective concentration of IDV in primary isolates from Africa and restored the response to IDV or SQV in 3 PI-resistant isolates. CQ increased the block of Rh123 and CF efflux activity exerted by PIs. CONCLUSION: The inhibitory effects of CQ on HIV glycosylation are associated with synergistic effects in combination with PIs. The CQ/PI combination exerts combined inhibitory effects on P-gp and MRP1 function. 相似文献
66.
Synaptic transmission from cones is faster than transmission from rods. Using paired simultaneous recordings from photoreceptors and second-order neurones in the salamander retina, we studied the contributions of rod–cone differences in glutamate receptor properties and synaptic release rates to shaping postsynaptic responses. Depolarizing steps evoked sustained calcium currents in rods and cones that in turn produced transient excitatory postsynaptic currents (EPSCs) in horizontal and OFF bipolar cells. Cone-driven EPSCs rose and decayed faster than rod-driven EPSCs, even when comparing inputs from a rod and cone onto the same postsynaptic neurone. Thus, rod–cone differences in EPSCs reflect properties of individual rod and cone synapses. Experiments with selective AMPA and KA agonists and antagonists showed that rods and cones both contact pharmacologically similar AMPA receptors. Spontaneous miniature EPSCs (mEPSCs) exhibited unimodal distributions of amplitude and half-amplitude time width and there were no rod–cone differences in mEPSC properties. To examine how release kinetics shape the EPSC, we convolved mEPSC waveforms with empirically determined release rate functions for rods and cones. The predicted EPSC waveform closely matched the actual EPSC evoked by cones, supporting a quantal release model at the photoreceptor synapse. Convolution with the rod release function also produced a good match in rod-driven cells, although the actual EPSC was often somewhat slower than the predicted EPSC, a discrepancy partly explained by rod–rod coupling. Rod–cone differences in the rates of exocytosis are thus a major factor in producing faster cone-driven responses in second-order retinal neurones. 相似文献
67.
Prosperini G Spicuzza L Polosa R 《The Journal of allergy and clinical immunology》2003,111(6):1416; author reply 1416-1416; author reply 1417
68.
Multiple pathways of cell invasion are regulated by multiple families of serine proteases 总被引:5,自引:0,他引:5
Del Rosso M Fibbi G Pucci M D'Alessio S Del Rosso A Magnelli L Chiarugi V 《Clinical & experimental metastasis》2002,19(3):193-207
The complex process of tumor invasion requires the coordinated expression and activity of cell-substratum adhesive interactions
and of cell-associated protease systems, which destroy the extracellular matrix (ECM), in order to enable the invading cells
to simultaneously grip and destroy the anatomical barriers that control cell spreading. A number of data indicate that such
a `grip and go' process may be performed by an enlarging series of cell membrane-associated serine proteases and serine protease
receptors, which provide the invasive cells with a functional unit (the protease and its receptor), able to mediate cell-substratum
adhesion through specific receptor domains, to proteolytically degrade ECM and to deliver into the cell signals that up-regulate
the expression either of the protease/receptor complex, or of other adhesion molecules, such as integrins. There is evidence
that some proteases and protease receptor expression are under the control of tumor hypoxia, which is the result of an imbalance
in oxygen supply and demand. The urokinase-type plasminogen activator (u-PA) receptor (u-PAR) is under hypoxic control and
cooperates with other serine proteases of the blood coagulation pathways that may extravasate in the tumor milieu as a result
of hypoxia-simulated increase of vessel permeability. Other serine proteases and their receptors cooperate with the cell-associated
fibrinolytic system to promote cell invasion. Among these, tissue factor and its ligand coagulation factor VII, thrombin and
its protease-activated receptors, and type II trans-membrane serine proteases seem to play a crucial role. This Review takes
into consideration the complex scenario of the single serine proteases and related receptors that are involved in cell invasion,
as well as the protease receptor/adhesion molecule interplay which is necessary to focus the cell surface-driven proteolysis
where adhesion provides a grip to the invading cell.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
69.
Frdric Vly Sylvain Olivero Lucia Olcese Alessandro Moretta Jacqueline E. Damen Ling Liu Gerald Krystal John C. Cambier Marc Daëron Eric Vivier 《European journal of immunology》1997,27(8):1994-2000
A novel family of inhibitory co-receptors has been recently defined according to the presence in their intracytoplasmic domain of immunoreceptor tyrosine-based inhibition motifs (ITIM). In particular, this family includes a low-affinity receptor for IgG, FcγRIIB, which is widely expressed on hematopoietic cells, as well as killer cell inhibitory receptors (KIR) for major histocompatibility complex (MHC) class I proteins, expressed on both T and natural killer (NK) lymphocytes. FcγRIIB and KIR inhibitory function depends upon the tyrosine phosphorylation of their respective ITIM. Phosphorylated FcγRIIB and KIR ITIM bind the tandem SH2 tyrosine phosphatases, SHP-1 and SHP-2. Recently, FcγRIIB has been shown to associate with a polyphosphate inositol 5-phosphatase, SHIP, which appears to be involved in its inhibitory function. Using cell lysate adsorption to phosphorylated ITIM peptides and surface plasmon resonance, we demonstrate here that, in contrast to FcγRIIB, KIR (CD158b: p58.2) do not bind to SHIP, and only recruit SHP-1 and SHP-2. In addition, we show that point mutation of the amino acid residue in position tyrosine-2 of FcγRIIB and KIR ITIM abolihes their binding to SHP-1 and SHP-2, but leaves intact the association of SHIP with FcγRIIB ITIM. These data contribute to the structural definition of ITIM and document a differential recruitment of phosphatases by distinct ITIM. These findings also reveal that diverse strategies of inhibition are used by distinct members of the ITIM-bearing co-receptor family. 相似文献
70.
Concepcin Martínez Lucia del Rio Agustín Portela Esteban Domingo Juan Ortín 《Virology》1983,130(2):539-545
The complete genetic information for the neuraminidase (NA) gene of influenza virus A/Bangkok/1/79 has been cloned by in vitro synthesis of dsDNA, insertion into pBR322 plasmid, and transformation of Escherichia coli. The nucleotide sequence of the NA gene has been determined by the Maxam and Gilbert method. It is 1466 nucleotides long and contains a single open reading frame with a coding capacity for 469 amino acids. When compared to the NA genes of the N2 strains A/Victoria/3/75, A/Udorn/72, A/NT/60/68, and A/RI/5-/57, 90% of the nucleotide positions and 87% of the amino acid positions remained invariant. Forty-two nucleotide changes and 14 amino acid changes accumulated in the period 1975-1979, but the general structure of the protein appeared to remain constant. 相似文献