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61.
Annals of Surgical Oncology - The liver-first approach in patients with synchronous colorectal liver metastases (CRLM) has gained wide consensus but its role is still to be clarified. We aimed to...  相似文献   
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We present a modeling framework designed for patient-specific computational hemodynamics to be performed in the context of large-scale studies. The framework takes advantage of the integration of image processing, geometric analysis and mesh generation techniques, with an accent on full automation and high-level interaction. Image segmentation is performed using implicit deformable models taking advantage of a novel approach for selective initialization of vascular branches, as well as of a strategy for the segmentation of small vessels. A robust definition of centerlines provides objective geometric criteria for the automation of surface editing and mesh generation. The framework is available as part of an open-source effort, the Vascular Modeling Toolkit, a first step towards the sharing of tools and data which will be necessary for computational hemodynamics to play a role in evidence-based medicine.  相似文献   
65.
Retinoids in embryonal development   总被引:30,自引:0,他引:30  
The key role of vitamin A in embryonal development is reviewed. Special emphasis is given to the physiological action of retinoids, as evident from the retinoid ligand knockout models. Retinoid metabolism in embryonic tissues and teratogenic consequences of retinoid administration at high doses are presented. Physiological and pharmacological actions of retinoids are outlined and explained on the basis of their interactions as ligands of the nuclear retinoid receptors. Immediate target genes and the retinoid response elements of their promoters are summarized. The fundamental role of homeobox genes in embryonal development and the actions of retinoids on their expression are discussed. The similarity of the effects of retinoid ligand knockouts to effects of compound retinoid receptor knockouts on embryogenesis is presented. Although much remains to be clarified, the emerging landscape offers exciting views for future research.  相似文献   
66.
Summary In ten patients with inclusion body myositis (IBM) five muscular biopsies showed profuse inflammatory exudates and three showed a few scattered inflammatory cells with partial invasion in some muscle fibers. No inflammatory cells were seen in two cases. In all patients, histopathological, histomorphometric and immunocytochemical studies were performed. Immunocytochemistry for the class I and class II major histocompatibility complex gene product (MHC) was performed in all cases and in ten control muscles including: normal muscles [3], dermatomyositis [3], polymyositis [3], scleroderma [1]. In the five cases of IBM with inflammatory exudates, subsets of lymphocytes were analyzed with a panel of monoclonal antibodies against B cells, T4 cells, T8 cells, K and natural killer cells and macrophages. Some muscle fibers expressed class I MHC antigens in the inflammatory cases of IBM. These fibers were near the inflammatory exudates and occasionally showed a partial invasion. No expression of class I MHC was found in normal muscles and in non-inflammatory cases of IBM. The antigen which triggers the mononuclear cells in the inflammatory forms of IBM is probably not the filamentous inclusions in rimmed vacuoles. In other inflammatory myopathies, expression of class I MHC was present on all fibers in polymyositis, only in the perifascicular area in dermatomyositis and in scleroderma. It could be suggested that the term inclusion body muscle disease be applied to cases with rimmed vacuoles and IBM-like filaments without inflammatory cells.  相似文献   
67.
Summary Experiments have been performed to determine whether the antisecretory (antidiarrhoeal) actions of difenoxin and loperamide are mediated by enteric neurones. An iso-osmotic perfusion solution was circulated around the lumen of the jejunum of anaesthetised rats. Vasoactive intestinal peptide was infused intra-arterially to induce net fluid secretion which was inhibited by difenoxin (ED50, 0.23 mg/kg) and loperamide (ED50, 0.5 mg/kg). However, neither were able to restore the fluid transport rate to the control level of absorption.The antisecretory effects of difenoxin (0.77 mg/kg) and loperamide (0.6 mg/kg) were blocked by the opiate receptor antagonist naloxone (2 mg/kg). Their effects were also abolished by pretreatment with the 5-HT synthesis inhibitor p-chlorophenylalanine (PCPA; 200 mg/kg; with desmethylimipramine given beforehand to protect noradrenergic nerves and enhance 5-HT depletion). The effect of difenoxin was blocked with methiothepin (1 mg/kg) and methysergide (30 g/kg) but not ketanserin (30 g/kg), ritanserin (30 mg/kg), ondansetron (10 g/kg) or ICS 205-930 (3 mg/kg). None of the above 5-HT receptor antagonists modified the antisecretory effect of loperamide. The antisecretory effect of difenoxin but not loperamide was prevented by phentolamine (2 mg/kg) and by pretreatment with 6-hydroxydopamine (150 mg/kg) total.It is concluded that both difenoxin and loperamide inhibit net fluid secretion by indirect mechanisms. It is proposed that the initial action is on enteric -opiate receptors and that this results in the release of 5-HT. In the case of difenoxin, the 5-HT may act on 5-HT1-like receptors to release noradrenaline. However, the major difference in the mechanism of action of loperamide compared to difenoxin is that it does not utilize noradrenaline as the final mediator of its antisecretory action.Correspondence to A. De Luca at the above address  相似文献   
68.
Summary The interaction of locally perfused cholecystokinin-8 (sulphated) with systemically administered apomorphine was studied on the release of dopamine and its metabolites using microdialysis in the neostriatum of the halothane-anaesthetized male rat. Dialysate levels of dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid were assayed by high performance liquid chromatography in combination with electrochemical detection. Perfusion with cholecystokinin-8 (100 M but not 1 M or 10 nM) increased the dialysate levels of dopamine without affecting those of DOPAC or HVA. At low concentrations (1 M and 10 nM but not 1 nM), cholecystokinin-8 counteracted the inhibitory effect of apomorphine (0.05 mg/kg, s. c.) on dopamine release. This counteraction was antagonized by perfusion with the cholecystokinin-8 antagonist proglumide (3 M). At this concentration, proglumide perfused alone was without effect on basal or apomorphine-reduced levels of dopamine. The results indicate a facilitatory effect of cholecystokinin-8 on dopamine release in rat neostriatum only at high concentrations. At lower concentrations, cholecystokinin-8 appears to modulate dopamine release by an inhibitory effect on dopamine autoreceptors possibly involving an intramembrane interaction between presynaptic cholecystokinin-8 receptors and dopamine autoreceptors. Send offprint requests to K. Fuxe at the above address  相似文献   
69.
Germline p53 mutations are associated with cancer predisposition in Li-Fraumeni families as well as in individuals with component tumors of the syndrome. In the majority of cases these mutations have been shown to be inherited rather than de novo. We screened 59 children with primary bone or soft tissue sarcomas. Germline p53 mutations were identified in 2 patients. Interestingly, analysis revealed that both mutations were de novo. Although the frequency of germline p53 mutations in primary pediatric sarcoma patients is low, there is evidence for the importance of considering pediatric patients for testing for de novo mutations.  相似文献   
70.
Monoclonal antibody SP-2, which binds to a 90,000 daltons tumor-associated antigen termed 90K, was generated by mouse immunization with proteins released by human breast cancer cells into the culture medium (Iacobelli et al: Cancer Res 46: 3005-3010, 1986). Elevated 90K levels have been previously reported in the serum of patients with various malignancies. We investigated whether the circulating levels of 90K antigen might be related to prognosis of patients with Non-Hodgkin's Lymphomas (NHL). Serum samples were obtained from 50 apparently healthy blood donors and 81 patients with NHL. Circulating serum 90K concentrations (U/ml) were determined by a solid-phase immunoradiometric assay (IRMA) by a two-step procedure. Serum 90K levels were significantly higher in patients with NHL than in healthy controls (p=0.004). The Kaplan-Meier analysis of overall survival showed that patients with 90K-negative (serum 90K levels less than or equal to 16 U/ml) survived longer than patients with 90K-positive sera (less than or equal to 16 U/ml) (p=0.004). Multivariate regression analysis revealed that serum levels of LDH and 90K were the two independent prognostic variables for predicting overall survival. We propose that an elevated 90K antigen level in sera is a predictor of poor prognosis in NHL.  相似文献   
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