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1.
Previous studies have demonstrated that culture supernatants of LPS-stimulated murine splenic B lymphocytes (BLPSSN) are able to inhibit the growth of freshly isolated B cells via an IgM antibody. In this work we investigated the progress of LPS-activated B lymphocytes through the cell cycle in the presence of this antibody. We found that the regulatory IgM did not affect the entry of LPS-stimulated B lymphocytes into G0*, as assessed by the increased expression of I-A antigens. Events that characterize the early G1 phase (G1A), such as cell enlargement and increased RNA synthesis, also occurred in the presence of the antibody. In contrast, events which mark the G1B phase, such as further cell enlargement and late RNA synthesis were inhibited. Moreover, a significant portion of the cells failed to incorporate [3H]thymidine and did not progress through S, G2, or M, as revealed by their DNA content. Therefore, our work points toward a well-defined stage of the early G1 phase at which the antibody inhibits the progression of B lymphocyte activation. This result shows a new insight into the mechanism of antibody-mediated down-regulation of polyclonal B cell responses. 相似文献
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Angiocentric lymphomatoid granulomatosis is a rare lymphoproliferative disease, mainly associated with pulmonary manifestation. Its origin is unknown, but Epstein-Barr virus may be one of the etiological factors. A 51-year-old male had an abdominal laparotomy in 1994 and a large granulomatous mass was removed from behind the cecum. No specific therapy was administered. In February 1998 multiple pulmonary lesions were found by X-ray and thoracoscopic biopsy was made. The histopathological diagnosis was angiocentric lymphomatoid granulomatosis. The patient received 6 cycles of CHOP chemotherapy, with which a complete remission was achieved. A consistent severe hypogammaglobulinaemia was detected, so the diagnosis of common variable immunodeficiency (CVID) was established. The diagnosed CVID was the probable causative factor of the angiocentric lymphomatoid granulomatosis. After the CHOP treatment, the patient is on intravenous immunoglobulin substitution and is well up to today. 相似文献
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Spontaneous and PHA-induced rosetting of human blood, tonsil lymphocytes and MLC blasts with sheep, human and horse erythrocytes. 下载免费PDF全文
Compared to peripheral blood lymphocytes the ability of human tonsil T cells and MLC blasts to bind sheep, human and horse erythrocytes was found to be increased. Tonsil and MLC T cells were able to bind sheep red blood cells without any cold incubation, i.e. they were 'early' rosettes, and higher percentage of human and horse erythrocyte rosettes were formed by these cells. Low doses of phytohaemagglutinin increased the proportion of rosettes between peripheral blood, tonsil, MLC cells and human and horse erythrocytes. PHA acted only on T cells, and not on B cells, lymphoblastoid B and other cell lines. On the ground of the stronger rosetting property of MLC blasts and tonsil cells, it is likely that the T cells responsible for binding of horse and human erythrocytes after PHA treatment are 'early' or 'active' rosetting cells. 相似文献
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Two-colour immunofluorescence studies on EBV-determined antigens 总被引:8,自引:0,他引:8
Two-colour fluorescence (TRITC and FITC) has been adapted for the direct visualization of Epstein-Barr virus (EBV)-determined membrane antigens (MA) and to study their relationship to genetically determined iso-antigens (HL-A type) and to viral capsid antigens (VCA, as defined by the Henle test). The following three postulates, based on indirect deductions from previous blocking, cross-blocking and absorption experiments, could be confirmed by direct visual observation:
(1) Membrane receptors of the HL-A and of the EBV determined MA type are distinct with regard to localization and antigenic specificity;
(2) Different subcomponents within the MA complex are part of the same macromolecular structure on the outer cell membrane;
(3) VCA and MA antigens are distinct with regard to specificity.
In addition, it has been shown that all VCA positive cells are also MA positive in EBV-carrier cultures, but that there exists, in such cultures, a 10-fold excess of MA positive, VCA negative cells.
相似文献6.
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Szládek G Juhász A Kardos G Szoke K Major T Sziklai I Tar I Márton I Kónya J Gergely L Szarka K 《Journal of clinical pathology》2005,58(4):402-405
BACKGROUND: The aetiology and factors leading to the progression of laryngeal cancer are still unclear. Although human papillomavirus (HPV) has been suggested to play a role, reports concerning the effect of HPV infection on tumour development are controversial. Recently, transfusion transmitted virus (TTV) was suggested to play a role in certain infections as a causative or coinfecting agent. AIMS: To investigate whether the development and progression of laryngeal squamous cell carcinoma is associated with coinfection with TTV and HPV. METHODS: The prevalence of TTV and HPV was investigated using the polymerase chain reaction in tissue samples from 40 healthy individuals, 10 patients with recurrent papillomatosis, five patients with papillomatosis with malignant transformation, and 25 patients with laryngeal carcinoma. The obtained prevalence data were compared and analysed statistically. RESULTS: In the 11 patients with carcinoma who had metastasis or relapse there was a high rate of coinfection with genogroup 1 TTV and HPV (eight of 11), whereas in the 14 without tumour progression no coinfection was found. Coinfection was associated with significantly lower tumour free survival in patients with carcinoma (p < 0.001). Furthermore, four of five patients who had papillomatosis with malignant transformation were coinfected with genogroup 1 TTV and HPV. CONCLUSIONS: Although the nature of cooperation between HPV and TTV needs to be investigated further, coinfection with genogroup 1 TTV and HPV appears to be associated with poor clinical outcome in laryngeal cancer. 相似文献
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Alternative pathway of complement activation by stimulated T lymphocytes. I. Binding of C3 fragments
Human blood lymphocytes cultured for 3 days with concanavalin A (Con A), phytohemagglutinin or pokeweed mitogen, in mixed lymphocyte culture with added interleukin 2 and stimulated by a lymphoblastoid cell line were found to activate and bind C3 molecules when exposed to human serum. The split products of C3 were detected in the supernatants and on the surface of the activated cells. The surface-attached C3 fragment on the Con A blast was identified as C3b by immune adherence i.e. binding of CR1 carrying human erythrocytes. In the Con A-stimulated population the majority of cells that activated and bound C3 were CD3 and Fc gamma receptor (CD16)-positive but complement receptor-negative blasts. In this cell subset both CD4 and CD8-positive cells were detected but their frequency suggested that a proportion of them carried both markers. 相似文献
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Csiszár A Nagy G Gergely P Pozsonyi T Pócsik E 《Clinical and experimental immunology》2000,122(3):464-470
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