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   1564篇
  免费   92篇
  国内免费   9篇
耳鼻咽喉   43篇
儿科学   27篇
妇产科学   66篇
基础医学   196篇
口腔科学   63篇
临床医学   100篇
内科学   345篇
皮肤病学   26篇
神经病学   73篇
特种医学   42篇
外科学   321篇
综合类   33篇
一般理论   1篇
预防医学   55篇
眼科学   20篇
药学   89篇
中国医学   6篇
肿瘤学   159篇
  2024年   5篇
  2023年   19篇
  2022年   51篇
  2021年   94篇
  2020年   49篇
  2019年   57篇
  2018年   93篇
  2017年   51篇
  2016年   54篇
  2015年   52篇
  2014年   82篇
  2013年   95篇
  2012年   130篇
  2011年   144篇
  2010年   77篇
  2009年   61篇
  2008年   70篇
  2007年   76篇
  2006年   73篇
  2005年   63篇
  2004年   58篇
  2003年   46篇
  2002年   43篇
  2001年   12篇
  2000年   11篇
  1999年   12篇
  1998年   4篇
  1997年   8篇
  1996年   8篇
  1994年   4篇
  1993年   3篇
  1992年   6篇
  1991年   5篇
  1990年   4篇
  1989年   5篇
  1988年   5篇
  1986年   1篇
  1984年   2篇
  1983年   2篇
  1982年   3篇
  1981年   3篇
  1975年   1篇
  1974年   3篇
  1973年   3篇
  1972年   2篇
  1971年   4篇
  1970年   5篇
  1969年   3篇
  1968年   1篇
  1966年   1篇
排序方式: 共有1665条查询结果,搜索用时 31 毫秒
41.
42.

Background

Patients with chronic pancreatitis are prone to frequent readmissions. The aim of this study is to evaluate the rate and predictors of 30-day readmissions in patients with chronic pancreatitis using the Nationwide Readmission Database (NRD).

Methods

We performed a retrospective analysis of all adult patients with the principal discharge diagnosis of chronic pancreatitis from 2010 through 2014. We excluded patients who died during the hospitalization. Multivariate Cox proportional hazard regression was performed to identify demographic, clinical, and hospital factors that associated with 30-day unplanned readmissions.

Results

During the study period, 25,259 patients had the principal discharge diagnosis of chronic pancreatitis and survived the index hospitalization. Of these, 6477 (26.7%) were readmitted within 30 days. Younger age group, males, length of stay >5 days, admission to a large, metropolitan hospital, and several comorbidities (renal failure, rheumatic disease, chronic anemia, heart failure, depression, drug abuse, psychosis, and diabetes) were independently associated with increased risk of 30-day readmission. ERCP, pancreatic surgery, and obesity were associated with lower risk. The most common reasons for readmissions were acute pancreatitis (30%), chronic pancreatitis (17%), pseudocyst (2%), and abdominal pain (6%).

Conclusions

One in four patients with chronic pancreatitis is readmitted within 30 days (26.7%). Pancreatic disease accounts for at least half of all readmissions. Several baseline comorbidities and characteristics are associated with 30-day readmission risk after index admission. Knowledge of these predictors can help design interventions to target high-risk patients and reduce readmissions and costs of care.  相似文献   
43.
Objective:To compare personality traits, attitude toward orthodontic treatment, and pain perception and experience before and after orthodontic treatment.Materials and Methods:One hundred subjects (50 male and 50 female) were included in this study. The mean (SD) age was 17.5 (2.05) years at T1 and 19.15 (2.32) years at T2. The instruments for data collection were questionnaires that included assessment of patients'' personality traits, attitudes toward orthodontic treatment, and pain perception/experience. Subjects completed the questionnaires at two different times: before orthodontic treatment (T1) and after fixed orthodontic treatment (T2). Subjects were treated by fixed orthodontic appliances for an average (SD) period of 18.64 (0.35) months. Paired sample t-test and chi-square test were used to detect any differences.Results:Significant changes in personality traits were detected after orthodontic treatment irrespective of gender. Neuroticism, openness, agreeableness, and conscientiousness scores were improved (P < .001). A positive attitude toward orthodontic treatment was reported at T1 (4.31 [±1.26]) and improved at T2 (3.98 [±1.16]) irrespective of gender (P < .05). The average (SD) expected pain score (T1) was 4.73 (1.88) and the average (SD) experienced pain score (T2) was 4.63 (1.58). Significant difference in the expected and experienced pain scores was not detected (P  =  .11).Conclusions:Personality traits and attitude toward orthodontic treatment improved after orthodontic treatment. Reported actual pain experience during orthodontic treatment was similar to that expected before treatment.  相似文献   
44.
Background:The aim of this study is to compare the safety and efficacy of conventional laparotomy with those of robotic and laparoscopic approaches to hepatectomy.Database:Independent reviewers conducted a systematic review of publications in PubMed and Embase, with searches limited to comparative articles of laparoscopic hepatectomy with either conventional or robotic liver approaches. Outcomes included total operative time, estimated blood loss, length of hospitalization, resection margins, postoperative complications, perioperative mortality rates, and cost measures. Outcome comparisons were calculated using random-effects models to pool estimates of mean net differences or of the relative risk between group outcomes. Forty-nine articles, representing 3702 patients, comprise this analysis: 1901 (51.35%) underwent a laparoscopic approach, 1741 (47.03%) underwent an open approach, and 60 (1.62%) underwent a robotic approach. There was no difference in total operative times, surgical margins, or perioperative mortality rates among groups. Across all outcome measures, laparoscopic and robotic approaches showed no difference. As compared with the minimally invasive groups, patients undergoing laparotomy had a greater estimated blood loss (pooled mean net change, 152.0 mL; 95% confidence interval, 103.3–200.8 mL), a longer length of hospital stay (pooled mean difference, 2.22 days; 95% confidence interval, 1.78–2.66 days), and a higher total complication rate (odds ratio, 0.5; 95% confidence interval, 0.42–0.57).Conclusion:Minimally invasive approaches to liver resection are as safe as conventional laparotomy, affording less estimated blood loss, shorter lengths of hospitalization, lower perioperative complication rates, and equitable oncologic integrity and postoperative mortality rates. There was no proven advantage of robotic approaches compared with laparoscopic approaches.  相似文献   
45.
46.
47.
48.

Objectives

The optimal strategy for the reconstruction of the pancreas following pancreaticoduodenectomy (PD) is still debated. The aim of this study was to compare the outcomes of isolated Roux loop pancreaticojejunostomy (IRPJ) with those of pancreaticogastrostomy (PG) after PD.

Methods

Consecutive patients submitted to PD were randomized to either method of reconstruction. The primary outcome measure was the rate of postoperative pancreatic fistula (POPF). Secondary outcomes included operative time, day to resumption of oral feeding, postoperative morbidity and mortality, and exocrine and endocrine pancreatic functions.

Results

Ninety patients treated by PD were included in the study. The median total operative time was significantly longer in the IRPJ group (320 min versus 300 min; P = 0.047). Postoperative pancreatic fistula developed in nine of 45 patients in the IRPJ group and 10 of 45 patients in the PG group (P = 0.796). Seven IRPJ patients and four PG patients had POPF of type B or C (P = 0.710). Time to resumption of oral feeding was shorter in the IRPJ group (P = 0.03). Steatorrhea at 1 year was reported in nine of 42 IRPJ patients and 18 of 41 PG patients (P = 0.029). Albumin levels at 1 year were 3.6 g/dl in the IRPJ group and 3.3 g/dl in the PG group (P = 0.001).

Conclusions

Isolated Roux loop PJ was not associated with a lower rate of POPF, but was associated with a decrease in the incidence of postoperative steatorrhea. The technique allowed for early oral feeding and the maintenance of oral feeding even if POPF developed.  相似文献   
49.
Major bleeding is currently one of the most common non-cardiac complications observed in the treatment of patients with acute coronary syndrome (ACS). Hemorrhagic complications occur with a frequency of 1% to 10% during treatment for ACS. In fact, bleeding events are the most common extrinsic complication associated with ACS therapy. The identification of clinical characteristics and particularities of the antithrombin therapy associated with an increased risk of hemorrhagic complications would make it possible to adopt prevention strategies, especially among those exposed to greater risk. The international societies of cardiology renewed emphasis on bleeding risk stratification in order to decide strategy and therapy for patients with ACS. With this review, we performed an update about the ACS bleeding risk scores most frequently used in daily clinical practice.  相似文献   
50.
This investigation examines the role of carboxyl functionalized multi-walled carbon nanotubes (COOH-MWCNTs) in the on- and off-axis flexure and the shear responses of thin carbon woven fabric composite plates. The chemically functionalized COOH-MWCNTs were used to fabricate epoxy nanocomposites and, subsequently, carbon woven fabric plates to be tested on flexure and shear. In addition to the neat epoxy, three loadings of COOH-MWCNTs were examined: 0.5 wt%, 1.0 wt% and 1.5 wt% of epoxy. While no significant statistical difference in the flexure response of the on-axis specimens was observed, significant increases in the flexure strength, modulus and toughness of the off-axis specimens were observed. The average increase in flexure strength and flexure modulus with the addition of 1.5 wt% COOH-MWCNTs improved by 28% and 19%, respectively. Finite element modeling is used to demonstrate fiber domination in on-axis flexure behavior and matrix domination in off-axis flexure behavior. Furthermore, the 1.5 wt% COOH-MWCNTs increased the toughness of carbon woven composites tested on shear by 33%. Microstructural investigation using Fourier Transform Infrared Spectroscopy (FTIR) proves the existence of chemical bonds between the COOH-MWCNTs and the epoxy matrix.  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