全文获取类型
收费全文 | 3738篇 |
免费 | 230篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 124篇 |
妇产科学 | 78篇 |
基础医学 | 603篇 |
口腔科学 | 40篇 |
临床医学 | 347篇 |
内科学 | 983篇 |
皮肤病学 | 75篇 |
神经病学 | 435篇 |
特种医学 | 77篇 |
外科学 | 270篇 |
综合类 | 5篇 |
预防医学 | 155篇 |
眼科学 | 37篇 |
药学 | 314篇 |
中国医学 | 2篇 |
肿瘤学 | 423篇 |
出版年
2024年 | 4篇 |
2023年 | 18篇 |
2022年 | 62篇 |
2021年 | 97篇 |
2020年 | 55篇 |
2019年 | 80篇 |
2018年 | 85篇 |
2017年 | 74篇 |
2016年 | 94篇 |
2015年 | 99篇 |
2014年 | 154篇 |
2013年 | 183篇 |
2012年 | 302篇 |
2011年 | 324篇 |
2010年 | 180篇 |
2009年 | 150篇 |
2008年 | 245篇 |
2007年 | 262篇 |
2006年 | 228篇 |
2005年 | 243篇 |
2004年 | 207篇 |
2003年 | 206篇 |
2002年 | 188篇 |
2001年 | 34篇 |
2000年 | 24篇 |
1999年 | 29篇 |
1998年 | 55篇 |
1997年 | 33篇 |
1996年 | 27篇 |
1995年 | 32篇 |
1994年 | 15篇 |
1993年 | 11篇 |
1992年 | 21篇 |
1991年 | 13篇 |
1990年 | 18篇 |
1989年 | 12篇 |
1988年 | 11篇 |
1987年 | 16篇 |
1986年 | 11篇 |
1985年 | 8篇 |
1984年 | 11篇 |
1983年 | 15篇 |
1982年 | 11篇 |
1981年 | 5篇 |
1980年 | 9篇 |
1979年 | 6篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1971年 | 4篇 |
1966年 | 3篇 |
排序方式: 共有3989条查询结果,搜索用时 0 毫秒
91.
Deoxyribonucleic acid damage in human lymphocytes after percutaneous transluminal coronary angioplasty 总被引:7,自引:0,他引:7
Andreassi MG Botto N Rizza A Colombo MG Palmieri C Berti S Manfredi S Masetti S Clerico A Biagini A 《Journal of the American College of Cardiology》2002,40(5):862-868
OBJECTIVES; We investigated the presence of oxidative deoxyribonucleic acid (DNA) damage in the peripheral lymphocytes of patients undergoing percutaneous transluminal coronary angioplasty (PTCA) by using the micronucleus test and comet assay, which are sensitive biomarkers of DNA damage. BACKGROUND; Although it has recognized that ischemia-reperfusion can induce oxidative DNA damage, its occurrence in patients undergoing PTCA has not yet been demonstrated. METHODS: Three groups of patients were enrolled: 30 patients with documented coronary heart disease who underwent elective PTCA (group I); 25 patients who underwent elective coronary angiography for diagnostic purpose (group II); and 27 healthy, age- and gender-matched subjects (group III). For each subject, the frequency of micronucleated binucleated (MNBN) cells, DNA single-strand breaks (SSBs), endonuclease III-sensitive sites, and sites sensitive to formamidopyrimidine glycosylase (FPG) were analyzed before and after diagnostic procedures. RESULTS:The mean basal values of MNBN cells (p = 0.04), DNA-SSBs (p = 0.001), endonuclease III-sensitive sites (p = 0.002), and FPG sites (p < 0.0001) were significantly higher in groups I and II than in group III. A high significant increase of MNBN cell frequency was observed in group I after the PTCA procedure (11.0 +/- 1.3 vs. 19.8 +/- 1.6, p < 0.0001), whereas no significant difference was observed in group II (10.2 +/- 1.3 vs. 12.9 +/- 1.4, p = 0.18). A significant positive correlation was observed between the increase in the MNBN cell rate and total inflation time during PTCA (R = 0.549, p = 0.0017). The levels of DNA-SSBs (11.7 +/- 1.4 vs. 26.5 +/- 3.0, p = 0.0003) and FPG sites (13.8 +/- 1.8 vs. 22.5 +/- 2.4, p = 0.01) were also higher after PTCA. CONCLUSIONS: Our results provide evidence for oxidative DNA damage after PTCA, likely related to ischemia-reperfusion injury. 相似文献
92.
Michele Salemi Concetta Barone Carmelo Romano Federico Ridolfo Cataldo Scavuzzo Rita Anna Cantarella Maria Grazia Salluzzo Aldo E. Calogero Corrado Romano Paolo Bosco 《Neurological sciences》2013,34(4):569-571
Down syndrome (DS) is a chromosomal disorder caused by chromosome 21 trisomy and is the most frequent genetic cause of intellectual disability. The gene for the kinesin family member 21A (KIF21A), is a member of the kinesin superfamily involved in the anterograde fast axonal transport. In this study, we have evaluated the possible differential expression of KIF21A mRNA, by qRT-PCR, in peripheral blood leukocytes of DS subjects and it compared with the normal population. In the assumption that changes in KIF21A gene expression levels may affect the axonal transport and the development of the nervous system of subjects with DS. In the present case–control study, KIF21A gene expression was increased in 72.72 % of DS samples compared with normal subjects. This finding suggests that changes in the expression levels of KIF21A in DS subjects may affect the axonal transport and the development of the nervous system. 相似文献
93.
94.
Paolo Mazzone Fabrizio Stocchi Salvatore Galati Angelo Insola Maria Grazia Altibrandi Nicola Modugno Domenicantonio Tropepi Livia Brusa Alessandro Stefani 《Neuromodulation》2006,9(3):221-228
Objectives. Traditional deep brain stimulation (DBS) at the subthalamic nucleus (STN) has proved to be efficacious on core Parkinsonian symptoms. However, very disabling l ‐dopa–induced abnormal involuntary movements (AIMs) and axial signs are slightly affected, suggesting that we target less conventional targets. Our candidates for DBS were the globus pallidus internus (GPi) plus the intralaminar thalamic complex (Pf or CM), given its extensive functional links with basal ganglia nuclei. Materials and Methods. The routine utilization of our innovative stereotactic apparatus allows us to implant, at the same time, both the CM‐Pf complex together with the GPi in six Parkinson disease patients. Both intraoperative and postoperative neurophysiologic assessments helped us recognize functional subregions while optimizing implantation of electrodes. Unified Parkinson disease rating scale (UPDRS) motor scores, AIMs, and freezing were carefully blindly evaluated for each condition. Results. A significant amelioration of UPDRS scores was achieved by simultaneous activation of both targets. CM‐Pf activation was only slightly effective in reducing rigidity and akinesia, but more efficacious on freezing. Not surprisingly, AIMs were peculiarly decreased by the activation of the permanent electro‐catheter in the posteroventral GPi. Conclusions. These findings confirm that, in selected patients, it is conceivable to target structures other than the conventional STN in order to maximize clinical benefit. 相似文献
95.
Functional meaning of tryptophan-induced increase of 5-HT metabolism as clarified by in vivo voltammetry 总被引:3,自引:0,他引:3
Maria Grazia De Simoni Andrzej Sokola Fabio Fodritto Giuseppe Dal Toso Sergio Algeri 《Brain research》1987,411(1):89-94
Differential pulse voltammetry with carbon fiber electrodes was used to study serotonin (5-HT) metabolism in freely moving rats. The electrodes implanted in the striatum recorded the extracellular 5-hydroxyindoleacetic acid (5-HIAA) oxidation peak after oral tryptophan (150 mg/kg). This 5-HT precursor did not modify the 5-HIAA peak in any rat tested, but it raised 5-HIAA levels determined in total tissue by a classical biochemical method (HPLC). The administration of 5-hydroxytryptophan (5-HTP) (25 mg/kg i.p.) induced an increase of 5-HIAA detectable both in the extracellular medium by voltammetry and in tissue samples. As previously shown, dorsal raphe electrical stimulation raises extracellular 5-HIAA in the striatum and this effect is enhanced by pretreatment with tryptophan. The results suggest that tryptophan in 'normal' conditions enhances 5-HT metabolism without affecting 5-HT release unless such release is stimulated. 5-HTP increases 5-HT metabolism and release. 相似文献
96.
Antinori Andrea Cingolani Antonella Lorenzini Patrizia Giancola Maria Letizia Uccella Ilaria Bossolasco Simona Grisetti Susanna Moretti Francesca Vigo Beniamino Bongiovanni Marco Del Grosso Bruno Arcidiacono Maria Irene Fibbia Giovanni Carlo Mena Maurizio Finazzi Maria Grazia Guaraldi Giovanni Ammassari Adriana Monforte Antonella dArminio Cinque Paola De Luca Andrea 《Journal of neurovirology》2003,9(1):47-53
Human immunodeficiency virus (HIV)-associated progressive multifocal leukoencephalopathy (PML) remains a relevant clinical problem even in the era of highly active antiretroviral therapy (HAART). Aims of the study were to analyze clinical and treatment-related features and the survival probability of PML patients observed within the Italian Registry Investigative Neuro AIDS (IRINA) during a 29-month period of HAART. Intravenous drug use, the presence of focal signs, and the involvement of white matter at neuroradiology increased the risk of having PML. A reduced probability of PML was observed when meningeal signs were reported. Patients starting HAART at PML diagnosis and previously naïve for antiretrovirals showed significantly higher 1-year probability of survival (.58), compared to those continuing HAART (.24), or never receiving HAART (.00). Higher CD4 cell count were associated with a higher survival probability (.45). At multivariate analysis, a younger age, higher CD4, starting HAART at PML diagnosis, the absence of previous acquired immunodeficiency syndrome (AIDS)-defining events, and the absence of a severe neurologic impairment were all associated with a reduced hazard of death. The use of cidofovir showed a trend towards a reduced risk of death. 相似文献
97.
98.
Laura Castelnovo Antonio Tamburello Alfredo Lurati Eleonora Zaccara Maria Grazia Marrazza Micol Olivetti Nicola Mumoli Daniela Mastroiacovo Daniele Colombo Elisabetta Ricchiuti Paolo Vigano Faggioli Paola Antonino Mazzone 《Medicine》2021,100(1)
COVID-19 is causing a high influx of patients suffering from serious respiratory complications leading the necessity to find effective therapies. These patients seem to present with cytokine perturbation and high levels of IL6. Tocilizumab and sarilumab could be effective in this condition.We retrospectively collected data about 112 consecutive hospitalized in a single center.Fifty (IL6 group) treated with tocilizumab (8 mg/kg intravenously [IV], 2 infusions 12 hours apart) or sarilumab 400 mg IV once and 62 treated with the standard of care but not anti-cytokine drugs (CONTROL group).To determine whether anti-IL6 drugs are effective in improving prognosis and reducing hospitalization times and mortality in COVID-19 pneumonia.To date 84% (42/50) of IL6 group patients have already been discharged and only 2/50 are still recovered and intubated in intensive care. Six/fifty patients (12%) died: 5/6 due to severe respiratory failure within a framework of severe acute respiratory distress syndrome (ARDS), 1 suffered an acute myocardial infarction, and 1 died of massive pulmonary thromboembolism. There were no adverse treatment events or infectious complications. Compared to the CONTROL group they showed a lower mortality rate (12% versus 43%), for the same number of complications and days of hospitalization.Anti-IL6 drugs seem to be effective in the treatment of medium to severe forms of COVID-19 pneumonia reducing the risk of mortality due to multi-organ failure, acting at the systemic level and reducing inflammation levels and therefore microvascular complications. However, it is essential to identify the best time for treatment, which, if delayed, is rendered useless as well as counterproductive. Further studies and ongoing clinical trials will help us to better define patients eligible as candidates for more aggressive intervention. 相似文献
99.
Stefano Franchini Lorenzo Dagna Fulvio Salvo Patrizia Aiello Elena Baldissera Maria Grazia Sabbadini 《Arthritis \u0026amp; Rheumatology》2010,62(8):2530-2535
Objective
To evaluate the efficacy of antiinflammatory agents, steroids, immunosuppressants, and biologic agents in patients with adult‐onset Still's disease (AOSD) who have either chronic articular disease or nonchronic disease.Methods
Forty‐five patients with AOSD were seen and followed up for at least 2 years at our institution, from 1991 to 2008. The majority of patients were treated with several therapeutic regimens; a total of 152 efficacy trials were administered. Data regarding the type of medication, the dosage used, and the outcome of these trials were collected and analyzed.Results
Our data showed that the efficacy of monotherapy with a nonsteroidal antiinflammatory drug was very low (16%) and confirmed good efficacy of steroid therapy (63%), particularly in patients without chronic articular disease (78%). Patients whose disease did not respond to steroid therapy at the time of disease onset were at risk of the subsequent development of chronic arthritis. Disease‐modifying antirheumatic drug (DMARD) monotherapy was successful in controlling steroid‐resistant or steroid‐dependent disease in 60% of patients. Methotrexate and cyclosporine showed the best response rates. The combination of high‐dose steroids and cyclosporine was administered to successfully control some acute life‐threatening complications. Only 6 patients had disease that was both steroid resistant and DMARD resistant. Treatment with biologic agents eventually led to satisfactory control of disease manifestations in 5 (83%) of these 6 patients.Conclusion
Steroids were less effective in patients with chronic articular disease than in those with nonchronic disease. The administration of DMARDs early after disease onset could be beneficial in patients with steroid‐resistant disease who are at risk of the development of chronic articular disease. Biologic agents proved to be highly effective in both steroid‐resistant and DMARD‐resistant AOSD.100.
Revello MG Lilleri D Zavattoni M Furione M Genini E Comolli G Gerna G 《The Journal of infectious diseases》2006,193(2):269-276
BACKGROUND: The T cell-mediated immune response to human cytomegalovirus (HCMV) after primary infection, as well as the determinants of intrauterine transmission, are poorly understood. METHODS: Sequential peripheral blood leukocyte samples from 74 pregnant women and 29 nonpregnant individuals with primary infection were examined for HCMV-specific CD4+ T cells by cytokine flow cytometry (CFC) and lymphoproliferative response (LPR) analysis. Immunological results for 19 transmitter and 21 nontransmitter mothers were compared. RESULTS: Comparison of CFC and LPR analysis results showed that (1) there was no difference between pregnant and nonpregnant individuals; (2) HCMV-specific CD4+ T cells were detected by CFC, in the absence of an LPR to HCMV, in the great majority or the totality (according to different intervals) of samples collected from both pregnant and nonpregnant individuals during follow-up; and (3) LPR to HCMV was significantly (P<.001) lowered or delayed in transmitter mothers, compared with that in nontransmitter mothers. CONCLUSIONS: Pregnancy does not influence the HCMV-specific immune response. A dissociation between CFC response and LPR is commonly observed in patients with primary infections, and ad hoc studies aimed at understanding the mechanism(s) of the reduced LPR in transmitter mothers are warranted. 相似文献