全文获取类型
收费全文 | 542739篇 |
免费 | 38771篇 |
国内免费 | 14123篇 |
专业分类
耳鼻咽喉 | 5224篇 |
儿科学 | 16779篇 |
妇产科学 | 8012篇 |
基础医学 | 46052篇 |
口腔科学 | 11477篇 |
临床医学 | 59629篇 |
内科学 | 94411篇 |
皮肤病学 | 7057篇 |
神经病学 | 44008篇 |
特种医学 | 13888篇 |
外国民族医学 | 35篇 |
外科学 | 52300篇 |
综合类 | 78229篇 |
现状与发展 | 42篇 |
一般理论 | 40篇 |
预防医学 | 50955篇 |
眼科学 | 7521篇 |
药学 | 44357篇 |
554篇 | |
中国医学 | 38191篇 |
肿瘤学 | 16872篇 |
出版年
2023年 | 9261篇 |
2022年 | 15867篇 |
2021年 | 23782篇 |
2020年 | 22165篇 |
2019年 | 25384篇 |
2018年 | 23311篇 |
2017年 | 20294篇 |
2016年 | 18137篇 |
2015年 | 17353篇 |
2014年 | 34003篇 |
2013年 | 37219篇 |
2012年 | 29926篇 |
2011年 | 32379篇 |
2010年 | 25862篇 |
2009年 | 24239篇 |
2008年 | 23893篇 |
2007年 | 24072篇 |
2006年 | 21296篇 |
2005年 | 18067篇 |
2004年 | 14974篇 |
2003年 | 13054篇 |
2002年 | 10560篇 |
2001年 | 9392篇 |
2000年 | 7784篇 |
1999年 | 6725篇 |
1998年 | 5869篇 |
1997年 | 5391篇 |
1996年 | 4747篇 |
1995年 | 4445篇 |
1994年 | 4200篇 |
1993年 | 3450篇 |
1992年 | 3406篇 |
1991年 | 2963篇 |
1990年 | 2520篇 |
1989年 | 2204篇 |
1988年 | 2074篇 |
1987年 | 1825篇 |
1986年 | 1659篇 |
1985年 | 4494篇 |
1984年 | 5378篇 |
1983年 | 3697篇 |
1982年 | 4230篇 |
1981年 | 3897篇 |
1980年 | 3432篇 |
1979年 | 3142篇 |
1978年 | 2712篇 |
1977年 | 2061篇 |
1976年 | 2272篇 |
1975年 | 1678篇 |
1974年 | 1474篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
《Clinical neurophysiology》2020,131(7):1444-1452
ObjectiveTo investigate cognitive functions in non-demented patients with early-onset Parkinson's disease (PD), and to compare PARK2 gene mutation carriers and non-carriers by means of event-related brain potentials (ERPs).MethodsThe participants comprised patients with early-onset PD (EOPD) and healthy controls (HC). Patients with EOPD were divided into two groups as carriers of known pathogenic variants of PARK2 gene (EOPD-PC) and non-carriers of genes involved in familial PD (EOPD-NC). ERP data were collected during auditory oddball and visual continuous performance test (CPT).ResultsBoth EOPD groups (EOPD-PC and EOPD-NC) displayed reduced and delayed P3 in response to oddball target and CPT NoGo. CPT Go P3 was reduced in EOPD-NC but not in EOPD-PC. Oddball target N1 was reduced and P2 was enhanced in both EOPD-PC and EOPD-NC. In both cognitive tasks, RTs were prolonged and accuracy was lower in EOPD-PC and EOPD-NC.ConclusionsWe found several EOPD-related neurophysiologic changes, implying impairments in cognitive functions. Pairwise comparisons between EOPD-PC and EOPD-NC revealed no significant ERP marker.SignificanceIn this study, the confounding effect of normative aging was somewhat excluded compared with many previous studies. In contrast with the many oddball studies in non-demented PD, we clearly observed reduced and prolonged P3 in early-onset PD. Our NoGo P3 findings also contribute to the limited ERP research concerning response inhibition. 相似文献
122.
123.
《Journal of vascular and interventional radiology : JVIR》2020,31(6):869-875
This paper describes country-wide special measures undertaken for interventional radiology staff during the current coronavirus disease 2019 (COVID-19) pandemic. Although each interventional radiology service around the world faces unique challenges, the principles outlined in this article will be useful when designing or strengthening individual practices and integrating them within wider hospital and national measures. Moving beyond the current outbreak, these measures will be useful for any future infectious diseases which are likely to arise. 相似文献
124.
《Journal of vascular and interventional radiology : JVIR》2020,31(12):1993-1997
PurposeTo examine the long-term clinical outcomes of patients with anti-centromere antibody (ACA)-positive critical limb-threatening ischemia (CLTI) who were treated with endovascular therapy (EVT).Materials and MethodsThis was a retrospective analysis using a database of 423 consecutive CLTI patients (543 limbs, Rutherford class 4–6) who underwent EVT between January 2011 and March 2013. The patients were divided into 2 groups: an ACA-positive group (10 limbs, 8 patients) and a control group (46 limbs, 43 patients). The control group was defined as female, non-dialysis, and those who were able to obtain a below-knee angiogram.ResultsNone of the 8 ACA-positive CLTI patients had previously been diagnosed as ACA positive. No significant difference was observed in the below-the-knee lesion distribution and severity between the ACA-positive group and the control group. The median observational period was 51 months. The survival rate was 54% in the ACA-positive group and 76% in the control group at 5 years after EVT (P = .732). The freedom from major amputation rate was 60% in the ACA-positive group and 91% in the control group at 5 years after EVT (P = .029). The technical EVT success rate in the ACA-positive group was 70% (7/10). Of the successful EVT cases, 71% (5/7) of patients achieved complete wound healing or rest pain relief; however, 60% (3/5) had a recurrence of wounds.ConclusionsIn a series of ACA-positive patients with CLTI, successful EVT had acceptable outcomes with respect to wound healing with short-term results. However, the major amputation rate for ACA-positive patients was high in long-term follow-up. 相似文献
125.
126.
127.
128.
129.
Osric A. Forrest Daniel M. Chopyk Yael Gernez Milton R. Brown Carol K. Conrad Richard B. Moss Vin Tangpricha Limin Peng Rabindra Tirouvanziam 《Journal of cystic fibrosis》2019,18(1):64-70
Background
Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.Methods
Resistin levels were measured in plasma and sputum from three retrospective CF cohorts spanning a wide range of disease. We also assessed the ability of neutrophils to secrete resistin upon activation in vitro. Finally, we constructed a multivariate model assessing the relationship between resistin levels and lung function.Results
Plasma resistin levels were only marginally higher in CF than in healthy control subjects. By contrast, sputum resistin levels were very high in CF, reaching 50–100 fold higher levels than in plasma. Among CF patients, higher plasma resistin levels were associated with allergic bronchopulmonary aspergillosis, and higher sputum resistin levels were associated with CF-related diabetes. Mechanistically, in vitro release of neutrophil primary granules was concomitant with resistin secretion. Overall, sputum resistin levels were negatively correlated with CF lung function, independently of other variables (age, sex, and genotype).Conclusions
Our data establish relationships between resistin levels in the plasma and sputum of CF patients that correlate with disease status, and identify resistin as a novel mechanistic link between neutrophilic inflammation and lung disease in CF. 相似文献130.