全文获取类型
收费全文 | 1643篇 |
免费 | 115篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 34篇 |
妇产科学 | 38篇 |
基础医学 | 269篇 |
口腔科学 | 87篇 |
临床医学 | 142篇 |
内科学 | 395篇 |
皮肤病学 | 45篇 |
神经病学 | 179篇 |
特种医学 | 57篇 |
外科学 | 118篇 |
综合类 | 3篇 |
一般理论 | 1篇 |
预防医学 | 110篇 |
眼科学 | 53篇 |
药学 | 112篇 |
中国医学 | 4篇 |
肿瘤学 | 120篇 |
出版年
2023年 | 15篇 |
2022年 | 48篇 |
2021年 | 66篇 |
2020年 | 38篇 |
2019年 | 56篇 |
2018年 | 61篇 |
2017年 | 64篇 |
2016年 | 56篇 |
2015年 | 64篇 |
2014年 | 89篇 |
2013年 | 95篇 |
2012年 | 142篇 |
2011年 | 159篇 |
2010年 | 80篇 |
2009年 | 61篇 |
2008年 | 85篇 |
2007年 | 89篇 |
2006年 | 91篇 |
2005年 | 105篇 |
2004年 | 68篇 |
2003年 | 64篇 |
2002年 | 46篇 |
2001年 | 15篇 |
2000年 | 11篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 8篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1981年 | 6篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1974年 | 3篇 |
1969年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有1772条查询结果,搜索用时 0 毫秒
141.
Iacobucci I Galletti L Amabile M Soverini S Baccarani M Martinelli G 《Haematologica》2007,92(3):429-430
In order to overcome the problem of different control genes for BCR-ABL normalization, we used a linear regression equation to compare our results previously obtained using B2M as the control gene with those calculated using the ABL gene and validated the slope as a factor to convert from B2M to ABL results. 相似文献
142.
Marrazzo J 《Topics in HIV medicine : a publication of the International AIDS Society, USA》2007,15(1):11-16
An ongoing resurgence of syphilis and continued transmission of other common sexually transmitted diseases (STDs) in HIV-infected patients is fueled by a number of factors, including "prevention burnout" resulting from fatigue with long-term, safer-sex behavior, use of recretional drugs (notably methamphetamine), and false sense of security associated with HIV serosorting and elevated CD4+ cell count. Annual screening for common STDs is recommended for HIV-infected patients. Issues in syphilis and herpes simplex virus-2 (HSV-2) diagnosis and treatment are discussed. New problems are briefly reviewed, which include the increased reporting of lymphogranuloma venereum and the increased frequency of fluoroquinolone-resistant gonorrhea. The recently revised Centers for Disease Control and Prevention guidelines for treatment of syphilis, HSV-2 infection, chlamydial infection, and gonorrhea are summarized. This article summarizes a presentation on syphilis and other STDs made by Jeanne Marrazzo, MD, MPH, at the International AIDS Society-USA Continuing Medical Education course in New York, in October 2006. The original presentation is available as a Webcast at www.iasusa.org. 相似文献
143.
Kemp PM Hoffmann SA Tossici-Bolt L Fleming JS Holmes C 《Nuclear medicine communications》2007,28(6):451-456
OBJECTIVE: To assess the utility of the appearances of occipital lobe perfusion on HMPAO SPECT in the diagnosis of dementia with Lewy bodies (DLB) using the 123I-FP-CIT findings as the diagnostic 'gold standard'. METHODS: Eighty-four consecutive patients underwent both HMPAO SPECT and 123I-FP-CIT as part of their routine investigations for suspected DLB. RESULTS: Thirty-nine of the 84 FP-CIT scans were abnormal indicating a prevalence of 44% of patients with DLB in this series. In those patients classified as DLB, 28% of HMPAO SPECT scans demonstrated occipital hypoperfusion. In those patients with a dementia other than DLB 31% of patients demonstrated occipital hypoperfusion (P=0.8). CONCLUSION: Occipital lobe hypoperfusion as demonstrated by HMPAO SPECT in patients with suspected Lewy body dementia does not appear to be able to either rule in, or rule out, the diagnosis of DLB. 相似文献
144.
Antonella Di Poto Maria S. Sbarra Giulio Provenza Livia Visai Pietro Speziale 《Biomaterials》2009,30(18):3158-3166
Staphylococcus aureus is one of the most important etiological agents of infections associated with medical devices. This is in part due to the ability of the organism to form biofilm, which provides a microenvironment that protects from attack by the host's immune system and by antibiotics. In this study we examined the structure of polysaccharide intercellular adhesin (PIA)-dependent or protein-based S. aureus biofilms. We defined new strategies aimed at treatment of mature established biofilms using photodynamic treatment (PDT) combined with chemotherapy or phagocytosis. Significant inactivation of bacteria was observed when structurally distinct biofilms were exposed to the cationic porphyrin, tetra-substituted N-methyl-pyridyl-porphine (TMP), and simultaneously to visible light. Moreover, PDT-treated biofilms exposed to vancomycin or subjected to the phagocytic action of whole blood resulted in their almost complete eradication. The drastic reduction in staphylococcal survival and the disruption of biofilms were confirmed by confocal laser scanning microscopy and scanning electron microscopy. The results suggest that PDT combined with vancomycin and the host defences may be a useful approach for the inactivation of staphylococcal biofilms adhering to medical implant surfaces. 相似文献
145.
Ami A. Shah Antony Rosen Laura Hummers Fredrick Wigley Livia Casciola‐Rosen 《Arthritis \u0026amp; Rheumatology》2010,62(9):2787-2795
Objective
This study was undertaken to examine the temporal relationship between scleroderma development and malignancy, and to evaluate whether this differs by autoantibody status among affected patients.Methods
Study participants had a diagnosis of scleroderma, a diagnosis of cancer, cancer, an available serum sample, and a cancer pathology specimen. Sera were tested for autoantibodies against topoisomerase I, centromere, and RNA polymerase I/III by immunoprecipitation and/or enzyme‐linked immunosorbent assay. Clinical and demographic characteristics were compared across autoantibody categories. Expression of RNA polymerases I and III was evaluated by immunohistochemistry using cancerous tissue from patients with anti–RNA polymerase antibodies.Results
Twenty‐three patients were enrolled. Six patients tested positive for anti–RNA polymerase I/III, 5 for anti–topoisomerase I, and 8 for anticentromere, and 4 were not positive for any of these antigens. The median duration of scleroderma at cancer diagnosis differed significantly between groups (−1.2 years in the anti–RNA polymerase I/III group, +13.4 years in the anti–topoisomerase I group, +11.1 years in the anticentromere group, and +2.3 years in the group that was negative for all antigens tested) (P = 0.027). RNA polymerase III demonstrated a robust nucleolar staining pattern in 4 of 5 available tumors from patients with antibodies to RNA polymerase I/III. In contrast, nucleolar RNA polymerase III staining was not detected in any of 4 examined tumors from the RNA polymerase antibody–negative group (P = 0.048).Conclusion
Our findings indicate that there is a close temporal relationship between the onset of cancer and scleroderma in patients with antibodies to RNA polymerase I/III, which is distinct from scleroderma patients with other autoantibody specificities. In this study, autoantibody response and tumor antigen expression are associated. We propose that malignancy may initiate the scleroderma‐specific immune response and drive disease in a subset of scleroderma patients.146.
147.
Benevolo M Terrenato I Mottolese M Marandino F Carosi M Rollo F Ronchetti L Muti P Mariani L Sindico S Vocaturo G Vocaturo A 《Cancer causes & control : CCC》2011,22(6):869-875
The study aimed to assess the clinical utility in identifying CIN2 or worse (CIN2+), of the Pretect HPV-Proofer test for E6/E7 mRNA detection in Hybrid Capture 2 (HC2)-positive patients, who underwent colposcopy. In particular, the study analyzed the mRNA test performance as the third test in a subgroup of HC2+ patients with less severe than high-grade squamous intraepithelial lesions (HSIL-). We analyzed 464 cervico-vaginal samples by liquid-based cytology (LBC) and PreTect HPV-Proofer. Moreover 231 patients also had a biopsy at baseline and 75, with HSIL-, were followed up within 2 years by LBC, colposcopy, and histology when indicated. The highest sensitivity for CIN2+ belonged to the mRNA compared to LBC, at the HSIL+ threshold (72% vs. 58%), whereas the LBC showed the highest specificity and positive predictive value (PPV) (99 and 93% vs. 73 and 39%, respectively). Focusing on the 408 HSIL- patients, the mRNA positivity was significantly more associated with CIN2+ than CIN2- lesions (p < 0.0001). Moreover, among the 75 HSIL- followed up patients, the mRNA displayed high longitudinal Specificity (89%), even if the sensitivity and the PPV were low (50 and 20%, respectively). The present data suggest that the mRNA test may have a diagnostic and a potentially prognostic role in HC2+/HSIL- patients. 相似文献
148.
149.
Kelly E. Desino Rosario Pignatello Livia Basile Mary Lou Michaelis Kenneth L. Audus 《Biochemical pharmacology》2009,78(11):1412-1417
A variety of approaches have been taken to improve the brain penetration of pharmaceutical agents. The amphipathic character of a compound can improve its interaction with the lipid bilayer within cell membranes, and as a result improve permeability. Fatty acid chains or lipoamino acids of various lengths were attached to tranylcypromine (TCP), in an attempt to improve the blood-brain barrier (BBB) permeability by increasing the lipophilicity as well as the amphiphatic character of the drug. TCP-FA4, one of the derivatives containing a four carbon alkyl acid chain, showed the greatest improvement in permeability. This molecule was slightly neuroprotective in a β-amyloid-induced neurodegeneration assay and may also be capable of upregulating brain derived neurotrophic factor (BDNF), as indicated by cell culture assays using human umbilical vein endothelial cells. Since decreased levels of BDNF are observed in many CNS disorders, and direct injection of BDNF is not a viable option due to its poor permeability across the BBB, small molecules capable of regulating BDNF that also cross the BBB may be an interesting treatment option. 相似文献
150.
Riondino S Trifirò E Principessa L Mascioletti S Di Renzo L Gaudio C Biasucci LM Crea F Pulcinelli FM 《Thrombosis research》2008,122(3):359-365
INTRODUCTION: There is emerging evidence of a considerable variability of the impact of aspirin on clinical outcome and laboratory findings. Persistent TxA2 production seems to be the most likely reason. Aim of this study was to determine whether the mechanism responsible for TxA2 persistent production is, at least partially, dependent upon aspirin-insensitive platelet COX-2 enzymatic pathway. METHODS AND RESULTS: In 100 consecutive patients, under chronic aspirin anti-platelet treatment (100-160 mg/day) selected on the basis of detectable plasma salicylate levels, serum and Arachidonic Acid (AA)-induced platelet TxA2 production, immunoblot analysis of platelet COX-1/COX-2 expression and COX-2 activity were studied. Immunoblot revealed COX-2 expression in 46% patients, in an amount that was markedly lower than COX-1. In 10 COX-2 positive patients with TxA2 levels over the median, AA-induced TxA2 production performed in vitro in the presence of the COX-2 inhibitor CAY10404 and aspirin demonstrated that COX-2 dependent TxA2 production is less than 2%. CONCLUSION: Our data demonstrate that the inter-individual variability of platelet sensitivity to aspirin is due to a reduced efficacy of aspirin on platelet COX-1 despite ascertained patient compliance. We suggest that serum TxA2 assay might be performed in future clinical studies to improve our knowledge on the residual TxA2 production in aspirin-treated patients. 相似文献