首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   16427篇
  免费   911篇
  国内免费   147篇
耳鼻咽喉   207篇
儿科学   317篇
妇产科学   372篇
基础医学   1890篇
口腔科学   626篇
临床医学   1269篇
内科学   4211篇
皮肤病学   209篇
神经病学   1917篇
特种医学   617篇
外科学   2769篇
综合类   39篇
一般理论   2篇
预防医学   576篇
眼科学   266篇
药学   875篇
中国医学   17篇
肿瘤学   1306篇
  2023年   179篇
  2022年   188篇
  2021年   601篇
  2020年   415篇
  2019年   567篇
  2018年   610篇
  2017年   469篇
  2016年   508篇
  2015年   564篇
  2014年   745篇
  2013年   996篇
  2012年   1430篇
  2011年   1491篇
  2010年   783篇
  2009年   751篇
  2008年   1082篇
  2007年   1075篇
  2006年   931篇
  2005年   917篇
  2004年   890篇
  2003年   692篇
  2002年   637篇
  2001年   82篇
  2000年   43篇
  1999年   60篇
  1998年   101篇
  1997年   95篇
  1996年   69篇
  1995年   72篇
  1994年   70篇
  1993年   51篇
  1992年   32篇
  1991年   27篇
  1990年   36篇
  1989年   32篇
  1988年   16篇
  1987年   14篇
  1986年   22篇
  1985年   9篇
  1984年   18篇
  1983年   18篇
  1982年   24篇
  1981年   12篇
  1980年   16篇
  1979年   7篇
  1978年   6篇
  1976年   4篇
  1973年   3篇
  1972年   2篇
  1892年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
BackgroundContrast associated-acute kidney injury (CA-AKI) has been associated with adverse outcomes after ST-segment elevation myocardial infarction (STEMI). However, early markers of CA-AKI are still needed to improve risk stratification. We investigated the association between elevated serum uric acid (eSUA) and CA-AKI in patients with STEMI treated with primary percutaneous coronary intervention (pPCI).Methods and resultsSerum creatinine (Scr) was measured at admission and 24, 48 and 72 h after pPCI. CA-AKI was defined as an increase of 25% (CA-AKI 25%) or 0.5 mg/dl (CA-AKI 0.5) of Scr level above the baseline after 48 h following contrast administration. Multivariable analyses to investigate CA-AKI predictors were performed by binary logistic regression and multivariable backward logistic regression model.In the 3023 patients considered, CA-AKI was more frequent among patients with eSUA as compared with patients with normal SUA levels, considering both CA-AKI definitions (CA-AKI25%: 20.8% vs 16.2%, p < 0.012; CA-AKI 0.5: 10.1% vs 5.8%, p < 0.001). The association between eSUA and CA-AKI was confirmed at multivariable analyses (CA-AKI 25%: odd ratio 1.32, 95% CI 1.03–1.69, p = 0.027; CA-AKI 0.5: odd ratio 1.76, 95% CI 1.11–2.79, p = 0.016).ConclusionElevated serum uric acid is associated with CA-AKI after reperfusion in patients with STEMI treated with pPCI.  相似文献   
6.
7.

Background

In a pooled analysis of the phase 3 Controlled Myelofibrosis Study With Oral JAK Inhibitor Treatment I (COMFORT-I) and COMFORT-II clinical trials, adult patients with intermediate-2 or high-risk myelofibrosis who received oral ruxolitinib at randomization or after crossover from placebo or best available therapy (BAT) had improved overall survival (OS).

Methods

This post hoc analysis of pooled COMFORT data examined relevant disease outcomes based on the disease duration (≤12 or >12 months from diagnosis) before ruxolitinib initiation.

Results

The analysis included 525 patients (ruxolitinib: ≤12 months, n = 84; >12 months, n = 216; placebo/BAT: ≤12 months, n = 66; >12 months, n = 159); the median age was 65.0–70.0 years. Fewer thrombocytopenia and anemia events were observed among patients who initiated ruxolitinib treatment earlier. At Weeks 24 and 48, the spleen volume response (SVR) was higher for patients who initiated ruxolitinib earlier (47.6% vs. 32.9% at Week 24, p = .0610; 44.0% vs. 26.9% at Week 48, p = .0149). In a multivariable analysis of factors associated with spleen volume reduction, a logistic regression model that controlled for confounding factors found that a significantly greater binary reduction was observed among patients with shorter versus longer disease duration (p = .022). At Week 240, OS was significantly improved among patients who initiated ruxolitinib earlier (63% [95% CI, 51%‒73%] vs. 57% [95% CI, 49%‒64%]; hazard ratio, 1.53; 95% CI, 1.01‒2.31; p = .0430). Regardless of disease duration, a longer OS was observed for patients who received ruxolitinib versus those who received placebo/BAT.

Conclusions

These findings suggest that earlier ruxolitinib initiation for adult patients with intermediate-2 and high-risk myelofibrosis may improve clinical outcomes, including fewer cytopenia events, durable SVR, and prolonged OS.

Plain Language Summary

  • Patients with myelofibrosis, a bone marrow cancer, often do not live as long as the general population. These patients may also have an enlarged spleen and difficult symptoms such as fatigue.
  • Two large clinical trials showed that patients treated with the drug ruxolitinib lived longer and had improved symptoms compared to those treated with placebo or other standard treatments.
  • Here it was examined whether starting treatment with ruxolitinib earlier (i.e., within a year of diagnosis) provided benefits versus delaying treatment.
  • Patients who received ruxolitinib within a year of diagnosis lived longer and experienced fewer disease symptoms than those whose treatment was delayed.
  相似文献   
8.
9.
ObjectiveThe objective of this study was to collect and critically analyze the current evidence on the modalities and results of treatment of descending thoracic aortic surgical graft (SG) and endograft (EG) infection, which represents a rare but dramatic complication after both surgical and endovascular aortic repair.MethodsA comprehensive electronic health database search (PubMed/MEDLINE, Scopus, Google Scholar, and the Cochrane Library) identified all articles that were published up to October 2017 reporting on thoracic aortic SG or EG infection. Observational studies, multicenter reports, single-center series and case reports, case-control studies, and guidelines were considered eligible if reporting specific results of treatment of descending thoracic aortic SG or EG infection. Comparisons of patients presenting with SG or EG infection and between invasive and conservative treatment were performed. Odds ratio (OR) meta-analyses were run when comparative data were available.ResultsForty-three studies reporting on 233 patients with infected SG (49) or EG (184) were included. Four were multicenter studies including 107 patients, all with EG infection, associated with a fistula in 91% of cases, with a reported overall survival at 2 years of 16% to 39%. The remaining 39 single-center studies included 49 patients with SG infection and 77 with EG infection. Association with aortoesophageal fistula was significantly more common with EG (60% vs 31%; P = .01). In addition, time interval from index procedure to infection was significantly shorter with EG (17 ± 21 months vs 32 ± 61 months; P = .03). Meta-analysis showed a trend of increased 1-year mortality in patients with SG infection compared with EG infection (pooled OR, 3.6; 95% confidence interval, 0.9-14.7; P = .073). Surgical management with infected graft explantation was associated with a trend toward lower 1-year mortality compared with graft preservation (pooled OR, 0.3; 95% confidence interval, 0.1-1.0; P = .056).ConclusionsThoracic aortic EG infection is likely to occur more frequently in association with aortoesophageal fistulas and in a shorter time compared with SG infection. Survival is poor in both groups, especially in patients with SG infection. Surgical treatment with graft explantation seems to be the preferable choice in fit patients.  相似文献   
10.
Aberrations of large‐scale brain networks are found in the majority of neurodegenerative disorders. The brain connectivity alterations underlying dementia with Lewy bodies (DLB) remain, however, still elusive, with contrasting results possibly due to the pathological and clinical heterogeneity characterizing this disorder. Here, we provide a molecular assessment of brain network alterations, based on cerebral metabolic measurements as proxies of synaptic activity and density, in a large cohort of DLB patients (N = 72). We applied a seed‐based interregional correlation analysis approach (p < .01, false discovery rate corrected) to evaluate large‐scale resting‐state networks' integrity and their interactions. We found both local and long‐distance metabolic connectivity alterations, affecting the posterior cortical networks, that is, primary visual and the posterior default mode network, as well as the limbic and attention networks, suggesting a widespread derangement of the brain connectome. Notably, patients with the lowest visual and attention cognitive scores showed the most severe connectivity derangement in regions of the primary visual network. In addition, network‐level alterations were differentially associated with the core clinical manifestations, namely, hallucinations with more severe metabolic dysfunction of the attention and visual networks, and rapid eye movement sleep behavior disorder with alterations of connectivity of attention and subcortical networks. These multiple network‐level vulnerabilities may modulate the core clinical and cognitive features of DLB and suggest that DLB should be considered as a complex multinetwork disorder.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号