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排序方式: 共有3468条查询结果,搜索用时 312 毫秒
1.
Stewart Shapiro Dimitris N. Tatakis Dr. Rosemary Dziak 《Calcified tissue international》1990,46(1):60-62
Summary Tumor necrosis factor α (10−10–10−8M) had no effects on cyclic AMP production by the osteoblastic osteosarcomal cells, Saos-2 and G292, or normal rat calvarial
cells. The cytokine did, however, inhibit the parathyroid hormone (PTH)-induced effect on cyclic AMP in the Saos-2 and normal
rat osteoblastic cells. This inhibitory effect did not occur on prostaglandin E2-induced cyclic AMP increases in the osteoblastic cells. Interleukin-1 (10 U/ml −100 U/ml) did not produce any effect on basal
levels or PTH-induced cyclic AMP increases in these cells. 相似文献
2.
A binocular machine vision system for three-dimensional surface measurement of small objects 总被引:1,自引:0,他引:1
Rendering three-dimensional information of a scene from optical measurements is very important for a wide variety of applications. However, computer vision advancements have not yet achieved the accurate three-dimensional reconstruction of objects smaller than 1 cm diameter. This paper describes the development of a novel volumetric method for small objects, using a binocular machine vision system. The achieved precision is high, providing a standard deviation of 0.04 mm. The robustness, of the system, issues from the lab prototype imaging system with the crucial z-axis movement without the need of further calibration and the fully automated volumetric algorithms. 相似文献
3.
Emmanouil I Kapetanakis Athanassios S Antonopoulos Theofani A Antoniou Kassiani A Theodoraki Dimitrios A Zarkalis Peter D Sfirakis Despina A Chilidou Peter A Alivizatos 《The Journal of heart and lung transplantation》2005,24(5):526-532
BACKGROUND: Early, rapid bone loss and fractures after cardiac transplantation are well-documented complications of steroid administration; therefore, we undertook this study on the effects of long-term calcitonin on steroid-induced osteoporosis. METHODS: Twenty-three heart transplant recipients on maintenance immunosuppression with cyclosporine, mycophenolate mofetil and prednisone were retrospectively studied. All patients received long-term prophylactic treatment with elemental calcium and vitamin D. Twelve (52.2%) patients also received long-term intranasal salmon calcitonin, whereas 11 (47.8%) received none. Bone mineral density and vertebral fractures were assessed at yearly intervals. Statistical comparisons between each group's bone loss during the first year and in the early (1 to 3 years), intermediate (4 to 6 years) and late (7+ years) post-transplantation periods were done. RESULTS: Lumbar spine bone loss was significant during the early follow-up period in the group not receiving calcitonin (0.744 +/- 0.114 g/cm(2) vs 0.978 +/- 0.094 g/cm(2) [p = 0.002]). The calcitonin group showed bone mineral density (BMD) levels within normal average values throughout the study period. BMD increased in the no-calcitonin group during the intermediate (4 to 6 years) and late (7+ years) follow-up periods, with values approaching normal average and no significant difference between the 2 groups (0.988 +/- 0.184 g/cm(2) vs 0.982 +/- 0.088 g/cm(2) [p = 0.944] and 0.89 +/- 0.09 g/cm(2) vs 1.048 +/- 0.239 g/cm(2) [p = 0.474], respectively). CONCLUSIONS: Prophylactic treatment with intranasal salmon calcitonin prevents rapid bone loss associated with high-dose steroids early after cardiac transplantation. Long-term administration does not seem warranted in re-establishing BMD. 相似文献
4.
Clio Mamalaki Marianna Murdjeva Mauro Tolaini Trisha Norton Phillip Chandler Alain Townsend Elizabeth Simpson Dimitris Kioussis 《Clinical & developmental immunology》1995,4(4):299-315
Influenza nucleoprotein (NP)-specific T-cell receptor transgenic mice (F5) were crossed
with transgenic mice expressing the cognate antigenic protein under the control of the H-
2Kb promoter. Double-transgenic mice show negative selection of thymocytes at the
CD4+8+TCR10 to CD4+8+TCRhi transition stage. A few CD8 T cells, however, escape clonal
deletion, and in the peripheral lymphoid organs of these mice, they exhibit low levels of
the transgenic receptor and upregulated levels of the CD44 memory marker. Such cells do
not proliferate upon exposure to antigen stimulation in vivo or ex vivo, however, they can
develop low but detectable levels of antigen-specific cytotoxic function after stimulation
in vitro in the presence of IL-2. 相似文献
5.
Susanne Krmer Clio Mamalaki Ivan Horak Anneliese Schimpl Dimitris Kioussis Thomas Hünig 《European journal of immunology》1994,24(10):2317-2322
The requirement for interleukin-2 (IL-2) in repertoire selection and peripheral activation of CD8 T cells was tested in mice rendered IL-2 deficient by gene targeting and expressing a transgenic T cell receptor (TcR) (F5) specific for influenza nucleoprotein (NP) 366-374 + H-2Db. Positive selection of the transgenic F5 TcR into the CD8 compartment proceeded normally. Both in vivo and in vitro, the antigenic peptide induced depletion of immature thymocytes and proliferation of mature CD8 T cells regardless of the presence of an intact IL-2 gene. In contrast, cytotoxic T lymphocyte (CTL) activity was only generated by T cells from IL-2+ F5 transgenic mice. Exogenous IL-2 was able to fully restore the CTL response of IL-2?/? responder cells in vitro. Thus, both in vivo and in vitro, clonal expansion of CD8 T cells can proceed in the absence of IL-2, whereas in peptide-immunized F5 transgenic mice, induction of cytotoxic effector function is IL-2 dependent. 相似文献
6.
Tiniakos D Anagnostou V Stavrakis S Karandrea D Agapitos E Kittas C 《Anatomy and embryology》2004,209(1):41-47
We aimed to define, for the first time, the ontogeny of intrarenal innervation and to assess the distribution and nature of parenchymal nerves in the human fetal kidney. Our material consisted of routinely-processed renal tissue sections from 17 human fetuses, six of 20–24 gestational weeks (gw) and 11 of 25–40 gw, and three adults. We used immunohistochemistry with antibodies to the pan-neural markers neuron-specific enolase (NSE), neurofilaments (NF), PGP9.5, S100, and the adrenergic marker tyrosine hydroxylase (TH). NSE-, NF-, S100-, and PGP9.5-positive nerves, associated with arterial and venous vasculature, were identified in the renal cortex from 20 gw onwards, and their density appeared to increase with gestation, reaching adult levels at 28 gw. Most of the intrarenal nerves were TH-positive. Nerve fibers extended from the corticomedullary region to the outer cortex, reaching the renal capsule in the 3rd trimester. In detail, NSE-, NF-, S100-, PGP9.5-, and TH-immunoreactive fibers were observed in close apposition to the renal artery and its branches, occasionally reaching the afferent and efferent arteriole (3rd trimester). Nerve fibers were detected in close apposition to the juxtaglomerular apparatus in the 2nd and 3rd trimesters. In the renal medulla, NSE-, PGP9.5-, S100-, and TH-positive nerve fibers were detected close to tubular cells as early as 20 gw. However, their density gradually decreased during the 3rd trimester, and they were not observed in the medulla of the adult kidney. In conclusion, the human fetal kidney appears richly innervated during the 2nd and 3rd trimesters. There is a progressive increase in the density of parenchymal nerve fibers towards term from the corticomedullary region to the cortex. Most intrarenal nerves are adrenergic and have a predominant perivascular distribution, implying that renal innervation plays an important functional role during intrauterine life. 相似文献
7.
Papadimitriou GN Dikeos DG Souery D Del-Favero J Massat I Avramopoulos D Blairy S Cichon S Ivezic S Kaneva R Karadima G Lilli R Milanova V Nöthen M Oruc L Rietschel M Serretti A Van Broeckhoven C Stefanis CN Mendlewicz J 《Psychiatric genetics》2003,13(4):211-220
The co-segregation in one pedigree of bipolar affective disorder with Darier's disease whose gene is on chromosome 12q23-q24.1, and findings from linkage and association studies with the neighbouring gene of phospholipase A2 (PLA2) indicate that PLA2 may be considered as a candidate gene for affective disorders. All relevant genetic association studies, however, were conducted on bipolar patients. In the present study, the possible association between the PLA2 gene and unipolar affective disorder was examined on 321 unipolar patients and 604 controls (all personally interviewed), recruited from six countries (Belgium, Bulgaria, Croatia, Germany, Greece, and Italy) participating in the European Collaborative Project on Affective Disorders. After controlling for population group and gender, one of the eight alleles of the investigated marker (allele 7) was found to be more frequent among unipolar patients with more than three major depressive episodes than among controls (P<0.01); genotypic association was also observed, under the dominant model of genetic transmission (P<0.02). In addition, presence of allele 7 was correlated with a higher frequency of depressive episodes (P<0.02). These findings suggest that structural variations at the PLA2 gene or the chromosomal region around it may confer susceptibility for unipolar affective disorder. 相似文献
8.
Smyth LA Ardouin L Williams O Norton T Tybulewicz V Kioussis D 《European journal of immunology》2002,32(12):3386-3394
Interactions of T cells with MHC plus peptide in the peripheral lymphoid system are important for their survival. In this study we investigated further the molecular consequences of such interactions using F5 TCR transgenic mice and peptides previously shown to induce either negative or positive selection in the thymus. Following TCR ligation with the negatively selecting agonist peptide, mature CD8(+) cells proliferated and up-regulated the activation marker CD69. Interestingly, ligation of this TCR with MHC molecules loaded with high concentrations of the positively selecting peptide also resulted in the aforementioned changes, but with slower kinetics. Analysis of the biochemical changes that occur following stimulation with these peptides showed that phosphorylation of key signaling molecules, such as ZAP-70, CD3zeta, Vav, SLP-76, LAT, and ERK-1 and 2, could be detected after exposure to agonist but not antagonist peptide. Confocal microscopy, however, revealed infrequent phosphorylation 'patches' at the site of contact between T cells and APC presenting the antagonist peptide. Our data suggest that peptides capable of inducing positive selection in the thymus can be recognized by mature T cells and cause proliferation, up-regulation of CD69 and accumulation of phosphorylated proteins at the immunological synapse with low efficiency; however no phosphorylation of signaling molecules can be detected using conventional biochemical assays. 相似文献
9.
Apolipoprotein(a) phenotypes are reliable biomarkers for familial aggregation of coronary heart disease 总被引:2,自引:0,他引:2
Peros E Geroldi D D'Angelo A Falcone C Montagna L Carabela M Emanuele E 《International journal of molecular medicine》2004,13(2):243-247
Lipoprotein(a) [Lp(a)] is an atherogenic and prothrombotic molecule formed by the covalent binding of the highly polymorphic apolipoprotein(a) [apo(a)] to apoprotein B-100 of LDL. High Lp(a) concentrations are a recognized genetic risk factor for coronary heart disease (CHD) and have been shown to be related with a familial clustering of ischemic cardiac events. Nevertheless, the association between apolipoprotein(a) isoforms and a positive familial history of CHD has received far less attention. In this report, we explored the distribution of apo(a) phenotypes in 127 CHD subjects with a family history of coronary events and in 92 CHD patients without such a history. Twenty-two apo(a) isoforms were detected by a high-resolution immunoblotting method. In univariate analysis, the percentage of subjects with at least one small sized apo(a) isoform was significantly higher in CHD patients with a positive family history than in those without (P<0.01). Multivariate analysis showed that apo(a) isoforms of low molecular weight were the best predictors of familial aggregation of cardiac ischemia. We conclude that apo(a) size polymorphism is strongly associated with a familial history of CHD and is more efficient than Lp(a) plasma concentrations in predicting the familial clustering of coronary disease. When detected by high-resolution techniques, apo(a) phenotypes are objective laboratory markers that can substitute for a knowledge of a positive family history of CHD and should be used, together with Lp(a) levels, to better assess the familial predisposition to coronary events. 相似文献
10.
Theoharis C. Theoharides Duraisamy Kempuraj Michael Tagen Pio Conti Dimitris Kalogeromitros 《Immunological reviews》2007,217(1):65-78
Summary: Mast cells are well known for their involvement in allergic and anaphylactic reactions, during which immunoglobulin E (IgE) receptor (FcɛRI) aggregation leads to exocytosis of the content of secretory granules (1000 nm), commonly known as degranulation, and secretion of multiple mediators. Recent findings implicate mast cells also in inflammatory diseases, such as multiple sclerosis, where mast cells appear to be intact by light microscopy. Mast cells can be activated by bacterial or viral antigens, cytokines, growth factors, and hormones, leading to differential release of distinct mediators without degranulation. This process appears to involve de novo synthesis of mediators, such as interleukin-6 and vascular endothelial growth factor, with release through secretory vesicles (50 nm), similar to those in synaptic transmission. Moreover, the signal transduction steps necessary for this process appear to be largely distinct from those known in FcɛRI-dependent degranulation. How these differential mast cell responses are controlled is still unresolved. No clinically available pharmacological agents can inhibit either degranulation or mast cell mediator release. Understanding this process could help develop mast cell inhibitors of selective mediator release with novel therapeutic applications. 相似文献