全文获取类型
收费全文 | 1464篇 |
免费 | 172篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 24篇 |
妇产科学 | 14篇 |
基础医学 | 172篇 |
口腔科学 | 70篇 |
临床医学 | 144篇 |
内科学 | 187篇 |
皮肤病学 | 6篇 |
神经病学 | 109篇 |
特种医学 | 72篇 |
外国民族医学 | 1篇 |
外科学 | 217篇 |
综合类 | 136篇 |
预防医学 | 226篇 |
眼科学 | 36篇 |
药学 | 110篇 |
中国医学 | 38篇 |
肿瘤学 | 101篇 |
出版年
2024年 | 4篇 |
2023年 | 79篇 |
2022年 | 76篇 |
2021年 | 143篇 |
2020年 | 106篇 |
2019年 | 103篇 |
2018年 | 84篇 |
2017年 | 69篇 |
2016年 | 40篇 |
2015年 | 57篇 |
2014年 | 82篇 |
2013年 | 118篇 |
2012年 | 62篇 |
2011年 | 65篇 |
2010年 | 42篇 |
2009年 | 79篇 |
2008年 | 61篇 |
2007年 | 49篇 |
2006年 | 45篇 |
2005年 | 36篇 |
2004年 | 41篇 |
2003年 | 33篇 |
2002年 | 31篇 |
2001年 | 20篇 |
2000年 | 13篇 |
1999年 | 9篇 |
1998年 | 16篇 |
1997年 | 12篇 |
1996年 | 16篇 |
1995年 | 10篇 |
1994年 | 14篇 |
1993年 | 3篇 |
1992年 | 12篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 7篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1982年 | 1篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 2篇 |
排序方式: 共有1676条查询结果,搜索用时 15 毫秒
1.
《European journal of surgical oncology》2022,48(5):1062-1067
BackgroundSurgical resection is recommended for patients with resectable acinar cell carcinoma (ACC). The aim of this study was to investigate the clinical characteristics and surgical outcomes of resectable ACC in comparison to pancreatic ductal adenocarcinoma (PDAC).MethodA retrospective analysis was performed on all patients who consecutively underwent radical resection with pathologically confirmed ACC and PDAC from December 2011 to December 2018. Clinicopathologic characteristics and follow-up information were analyzed. A 1:3 propensity score matching (PSM) method was used to minimize the bias between ACC and PDAC.ResultsA total of 26 patients with ACC and 1351 with PDAC were included. Compared to PDAC, ACC tended to be larger (4.5 vs. 3.0 cm; p < 0.001) and more frequently located in the pancreatic body/tail (61.5% vs. 36.6%, p = 0.009), with lower total bilirubin levels, lower neutrophil lymphocyte ratio (NLR) levels and lower carbohydrate antigen 19-9 (CA19-9) levels and carcinoembryonic antigen (CEA) levels. There was no difference in postoperative morbidities in patients with ACC and PDAC. The median OS and RFS were longer in ACC when compared to PDAC (OS: 43.5 mo vs. 19.0 mo, p = 0.004; RFS: 24.5 mo vs. 11.6 mo, p = 0.023). After the 1:3 PSM, ACC remained to be a better histological type for OS (p = 0.024), but had comparable RFS with PDAC (p = 0.164).ConclusionPatients with ACC after radical resection had better OS than that with PDAC. However, ACC is also an aggressive tumor with a similar trend of RFS with PDAC after the matching, necessitating the multidisciplinary treatment for resectable ACC disease. 相似文献
2.
3.
《The Journal of thoracic and cardiovascular surgery》2023,165(2):634-644.e5
BackgroundProsthetic choice for mitral valve replacement is generally driven by patient age and patient and surgeon preference, and current guidelines do not discriminate between different etiologies of mitral valve disease. Our objective was to assess and compare short- and long-term outcomes after mitral valve replacement among patients with biological or mechanical prostheses in the setting of severe ischemic mitral regurgitation.MethodsBetween 2000 and 2016, 424 patients underwent mitral valve replacement for severe ischemic mitral regurgitation at our institution, using biological prosthesis in 188 (44%) and mechanical prosthesis in 236 (56%). A 1:1 propensity score match (n = 126 per group) and inverse probability of treatment weighting were used to compare groups. Short-term outcomes included in-hospital mortality and other cardiovascular adverse events. Long-term outcomes included survival and hospital readmission for cardiovascular causes, stroke, and major bleeding.ResultsIn-hospital mortality and early postoperative adverse events were similar between groups in the propensity score match and inverse probability of treatment weighting cohorts. Overall long-term survival was similar at 5 and 9 years, but mechanical prosthesis recipients were more frequently readmitted to hospital for cardiovascular causes, including stroke and non-neurological bleeding in propensity score matching and inverse probability of treatment weighting analyses (all P values < .004). Type of prosthesis did not independently influence all-cause mortality (hazard ratio, 1.01; 95% confidence interval, 0.71-1.43; P = .959), but placement of a mechanical prosthesis was associated with increased risk of readmission for cardiovascular events (hazard ratio, 1.65; 95% confidence interval, 1.17-2.32; P = .004) among matched patients.ConclusionsThe type of prosthesis has no influence on long-term survival among patients with severe ischemic mitral regurgitation undergoing mitral valve replacement. There may be an increased risk of neurologic events and serious bleeding associated with mechanical prostheses. 相似文献
4.
Jie Ren Ying-Mu Tong Rui-Xia Cui Zi Wang Qing-Lin Li Wei Liu Kai Qu Jing-Yao Zhang Chang Liu Yong Wan 《World journal of gastrointestinal oncology》2020,12(12):1394-1406
BACKGROUNDDue to the special clinical features and biologic characteristics of adolescent and young adult (AYA) cancers, AYA cancers are different from cancers in children and elderly individuals. However, there are few reports on AYA hepatocellular carcinoma (HCC).AIMTo investigate the overall survival (OS) of AYA (15-39 years) and elderly (40-74 years) patients with HCC.METHODSThe data of all the HCC cases were extracted from the Surveillance, Epidemiology, and End Results database from 2004 to 2015 and were then divided into two groups based on age: AYA group (15-39 years) and older group (40-74 years). Kaplan-Meier curves and log-rank tests were used to compare the OS of the two groups. Propensity score matching (PSM) was employed to analyze the OS difference between the two groups. The Cox proportional hazards regression model was used to perform multivariate analysis to explore the risk factors for OS of HCC patients.RESULTSCompared to elderly cancer patients, AYA patients with HCC had a worse Surveillance, Epidemiology, and End Results stage, including the distant stage (22.1% vs 15.4%, P < 0.001), and a more advanced American Joint Committee on Cancer (AJCC) stage, including AJCC III and IV (49.2% vs 38.3%, P < 0.001), and were more likely to receive surgery (64.5% vs 47.5%, P < 0.001). Before PSM, the AYA group had a longer survival in months (median: 20.00, interquartile range [IQR]: 5.00-62.50) than the older group (median: 15.00, IQR: 4.00-40.00) (P < 0.001). After PSM, the AYA group still had a longer survival in months (median: 21.00, IQR: 5.00-64.50) than the older group (median: 18.00, IQR: 6.00-53.00) (P < 0.001). The Cox proportional hazards regression model showed that advanced age (hazard ratio [HR] = 1.405, 95%CI: 1.218-1.621, P < 0.001) was a risk factor for OS of HCC patients. In the subgroup analysis, the Cox proportional hazards regression model showed that in AJCC I/II HCC patients, advanced age (HR = 1.749, 95%CI: 1.352-2.263, P < 0.001) was a risk factor for OS, while it was not a risk factor in AJCC III/IV HCC patients (HR = 1.186, 95%CI: 0.997-1.410, P = 0.054) before PSM. After PSM, advanced age (HR = 1.891, 95%CI: 1.356-2.637, P < 0.001) was still a risk factor for OS in AJCC I/II HCC patients, but was not a risk factor for OS in AJCC III/IV HCC patients (HR = 1.192, 95%CI: 0.934-1.521, P = 0.157) after PSM.CONCLUSIONAYA patients with HCC have different clinical characteristics from older adults. In different AJCC stages, the two groups of patients have different OS: In AJCC I/II HCC patients, advanced age is a risk factor for OS, but it is not a risk factor for OS in the AJCC III/IV HCC patient group. 相似文献
5.
6.
7.
《European journal of surgical oncology》2019,45(3):425-431
BackgroundAdvanced gastric cancer (AGC) causes debilitating malnutrition and leads to deterioration of the immune response. However, the concept of the prognostic nutritional index (PNI) is controversial when applied to patients with AGC. The aim of the present study was to evaluate the effect of the PNI after gastrectomy in patients with AGC.Materials and methodsA multicenter retrospective study was conducted using propensity score matching (PSM) in gastric adenocarcinoma patients who underwent resection via laparoscopic or open surgery between 2014 and 2017. To overcome selection bias, we performed 1:1 matching using 5 covariates.ResultsThe resection margins (P < 0.001) and LNM (P = 0.004) were significantly different between the two groups. In univariate analysis, poor tumor differentiation (P = 0.038) (R1+R2, P = 0.004), vascular and neural invasion (P < 0.001), and a PNI<50 (P < 0.001) were associated with poor recurrence-free survival (RFS). In multivariate analysis, a PNI<50 (hazard ratio (HR), 12.993; P < 0.001) was a risk factor for RFS. Univariate analysis for overall survival (OS) revealed that a PNI<50 (P < 0.001) (R1+R2,P = 0.006) and vascular and neural invasion (P < 0.001) were risk factors. In subsequent multivariate analysis, a PNI<50 (HR, 24.501; P < 0.001) was a significant risk factor for OS. Clinical assessments performed during a 12.34 (±5.050) month follow-up revealed that OS (P < 0.001) and RFS (P < 0.001) were worse in patients with a low PNI (<50) than in matched patients with a high PNI.ConclusionA low PNI is a strong predictor of unfavorable RFS and OS in patients with AGC. 相似文献
8.
Arianna Rigon Michelle W. Voss Lyn S. Turkstra Bilge Mutlu Melissa C. Duff 《Social neuroscience》2019,14(4):434-448
Although facial affect recognition deficits are well documented in individuals with moderate-to-severe traumatic brain injury (TBI), little research has examined the neural mechanisms underlying these impairments. Here, we use diffusion tensor imaging (DTI), specifically the scalars fractional anisotropy (FA), mean diffusivity (MD), and radial diffusivity (RD), to examine relationships between regional white-matter integrity and two facial affect sub-skills: perceptual affect recognition abilities (measured by an affect matching task) and verbal categorization of facial affect (measured by an affect labeling task). Our results showed that, within the TBI group, higher levels of white-matter integrity in tracts involved in affect recognition (inferior fronto-occipital, inferior longitudinal, and uncinate fasciculi) were associated with better performance on both tasks. Verbal categorization skills were specifically and positively correlated with integrity of the left uncinate fasciculus. Moreover, we observed a striking lateralization effect, with perceptual abilities having an almost exclusive relationship with integrity of right hemisphere tracts, while verbal abilities were associated with both left and right hemisphere integrity. The findings advance our understanding of the neurobiological mechanisms that underlie subcomponents of facial affect recognition and lead to different patterns of facial affect recognition impairment in adults with TBI. 相似文献
9.
《Research in social & administrative pharmacy》2022,18(11):3988-3994
BackgroundScarce data exists regarding United States (US) national-level work productivity loss among adults with Multiple Sclerosis (MS).ObjectiveTo address this significant knowledge gap, we examined the national-level productivity loss among adults (18≤ age ≤64 years) with MS compared to propensity score matched non-MS controls.MethodsWe adopted a retrospective, cross-sectional, matched cohort study design with pooled data from alternate years (2005/2007/2009/2011/2013/2015) of the Medical Expenditure Panel Survey (MEPS). We included adults who were employed and alive during the calendar year. Clinical Classification System code of “80” was used to identify individuals with MS. We matched adults with MS to non-MS adults utilizing propensity scores generated based on age, gender, and race/ethnicity using a greedy matching algorithm (8:1-digit matching). Missed workdays measured productivity loss of MEPS respondents. We selected Negative Binomial Regression (NBR) analysis as the count data model for this study. Analyses were conducted using SAS 9.4 and STATA 15.0 and accounted for the complex survey design of MEPS to generate US national-level estimates.ResultsThe final propensity-score matched sample consisted of 104 and 312 (unweighted) adults with and without MS, respectively. US national-level mean [Standard Error (SE)] annual missed workdays among individuals with MS [8.94 (SE:1.59)] was significantly higher (p = 0.001) compared to propensity score matched non-MS controls [3.15 (SE:0.40)]. After adjusting for several factors, NBR showed an approximately two-fold higher rate of missed work days among individuals with MS compared to propensity score matched non-MS controls (Incidence Rate Ratio: 1.98, 95% Confidence Interval: 1.18–3.33). Severity of pain, marital status, region, and hypertension also negatively impacted work productivity in this sample.ConclusionsIndividuals with MS in the US experience significantly higher productivity loss compared to propensity score matched non-MS controls. Interventions (e.g., improved management of MS symptoms) are warranted to reduce productivity loss among individuals with MS. 相似文献
10.