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   10616篇
  免费   958篇
  国内免费   61篇
耳鼻咽喉   31篇
儿科学   149篇
妇产科学   209篇
基础医学   1181篇
口腔科学   261篇
临床医学   884篇
内科学   1430篇
皮肤病学   136篇
神经病学   427篇
特种医学   521篇
外科学   878篇
综合类   151篇
预防医学   894篇
眼科学   85篇
药学   455篇
  5篇
中国医学   43篇
肿瘤学   3895篇
  2024年   40篇
  2023年   1108篇
  2022年   1314篇
  2021年   1410篇
  2020年   1333篇
  2019年   747篇
  2018年   482篇
  2017年   557篇
  2016年   479篇
  2015年   511篇
  2014年   795篇
  2013年   351篇
  2012年   217篇
  2011年   114篇
  2010年   403篇
  2009年   402篇
  2008年   113篇
  2007年   131篇
  2006年   85篇
  2005年   63篇
  2004年   30篇
  2003年   42篇
  2002年   57篇
  2001年   85篇
  2000年   43篇
  1999年   81篇
  1998年   98篇
  1997年   51篇
  1996年   75篇
  1995年   71篇
  1994年   42篇
  1993年   33篇
  1992年   21篇
  1991年   21篇
  1990年   29篇
  1989年   29篇
  1988年   27篇
  1987年   35篇
  1986年   23篇
  1985年   9篇
  1984年   14篇
  1983年   11篇
  1982年   13篇
  1981年   14篇
  1980年   12篇
  1979年   3篇
  1978年   4篇
  1977年   3篇
  1976年   3篇
  1972年   1篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
91.
92.
93.
BackgroundGeneral medical wards admit high-risk patients. Artificial intelligence algorithms can use big data for developing models to assess patients’ risk stratification. The aim of this study was to develop a mortality prediction machine learning model using data available at the time of admission to the medical ward.MethodsWe included consecutive patients (ages 18-100) admitted to medical wards at a single medical center (January 1, 2013-December 31, 2018). We constructed a machine learning model using patient characteristics, comorbidities, laboratory tests, and patients’ emergency department (ED) management. The model was trained on data from the years 2013 to 2017 and validated on data from the year 2018. The area under the curve (AUC) for mortality prediction was used as an outcome metric. Youden index was used to find an optimal sensitivity-specificity cutoff point.ResultsOf the 118,262 patients admitted to the medical ward, 6311 died (5.3%). The single variables with the highest AUCs were medications administered in the ED (AUC = 0.74), ED diagnosis (AUC = 0.74), and albumin (AUC = 0.73). The machine learning model yielded an AUC of 0.924 (95% confidence interval [CI]: 0.917-0.930). For Youden index, a sensitivity of 0.88 (95% CI: 0.86-0.89) and specificity of 0.83 (95% CI: 0.83–0.83) were observed. This corresponds to a false-positive rate of 1:5.9 and negative predictive value of 0.99.ConclusionA machine learning model outperforms single variables predictions of in-hospital mortality at the time of admission to the medical ward. Such a decision support tool has the potential to augment clinical decision-making regarding level of care needed for admitted patients.  相似文献   
94.
95.
96.
97.
98.
《Pancreatology》2022,22(7):838-845
Acute pancreatitis is characterized by necrosis of its parenchymal cells and influx and activation of inflammatory cells that further promote injury and necrosis. This review is intended to discuss the central role of disorders of calcium metabolism and mitochondrial dysfunction in the mechanism of pancreatitis development. The disorders are placed in context of calcium and mitochondria in physiologic function of the pancreas. Moreover, we discuss potential therapeutics for preventing pathologic calcium signals that injure mitochondria and interventions that promote the removal of injured mitochondria and regenerate new and heathy populations of mitochondria.  相似文献   
99.
《Pancreatology》2022,22(7):959-964
BackgroundEndoplasmic reticulum (ER) stress-inducing variants in several pancreatic secretory enzymes have been associated with pancreatic disease. Multiple variants in CEL, encoding carboxyl ester lipase, are known to cause maturity-onset diabetes of the young (MODY8) but have not been implicated in pancreatic cancer risk.MethodsThe prevalence of ER stress-inducing variants in the CEL gene was compared among pancreatic cancer cases vs. controls. Variants were identified by next-generation sequencing and confirmed by Sanger sequencing. Variants of uncertain significance (VUS) were assessed for their effect on the secretion of CEL protein and variants with reduced protein secretion were evaluated to determine if they induced endoplasmic reticulum stress.ResultsER stress-inducing CEL variants were found in 34 of 986 cases with sporadic pancreatic ductal adenocarcinoma, and 21 of 1045 controls (P = 0.055). Most of the variants were either the CEL-HYB1 variant, the I488T variant, or the combined CEL-HYB1/I488T variant; one case had a MODY8 variant.ConclusionThis case/control analysis finds ER stress-inducing CEL variants are not associated with an increased likelihood of having pancreatic cancer.  相似文献   
100.
《Pancreatology》2022,22(6):810-816
BackgroundIncreased postoperative serum amylase has been recently reported to be associated with increased postoperative morbidity, but studies on postoperative serum lipase are limited. The aim of this study was to evaluate the value of postoperative serum lipase in predicting clinically relevant postoperative pancreatic fistula (CR-POPF) after pancreaticoduodenectomy (PD).MethodA retrospective analysis was performed on 212 patients who underwent PD from September 2018 and March 2021, focusing on the association between postoperative day (POD) 1 serum lipase and CR-POPF.ResultsOverall, 108 (50.9%) patients had elevated serum lipase levels (>68 U/L) on POD 1. Patients with elevated serum lipase exhibited a significantly higher incidence of CR-POPF (37.0% vs. 6.7%, p < 0.001). Receiver operating characteristic (ROC) analyses showed improved diagnostic accuracy for POD 1 serum lipase compared with POD 1 serum amylase in predicting CR-POPF (AUC: 0.801 vs. 0.745, p = 0.029). Elevated serum lipase on POD 1 and elevated serum CRP on POD 3 were identified as independent predictors of CR-POPF. A simple early postoperative model, consisting of POD 1 serum lipase levels and POD 3 serum CRP levels, showed good discrimination (AUC 0.76, 95% CI 0.69–0.83) to identify the onset of CR-POPF.ConclusionSerum lipase on POD 1 outperformed serum amylase on POD 1 in predicting CR-POPF after PD. The combination of POD 1 serum lipase and POD 3 serum CRP provides a reliable predicting model for CR-POPF.  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