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   26612篇
  免费   2282篇
  国内免费   58篇
耳鼻咽喉   291篇
儿科学   988篇
妇产科学   703篇
基础医学   3604篇
口腔科学   415篇
临床医学   3787篇
内科学   4980篇
皮肤病学   270篇
神经病学   2966篇
特种医学   677篇
外国民族医学   2篇
外科学   2479篇
综合类   468篇
一般理论   44篇
预防医学   3431篇
眼科学   451篇
药学   1516篇
中国医学   13篇
肿瘤学   1867篇
  2023年   153篇
  2022年   227篇
  2021年   472篇
  2020年   296篇
  2019年   454篇
  2018年   552篇
  2017年   439篇
  2016年   475篇
  2015年   547篇
  2014年   751篇
  2013年   1163篇
  2012年   1569篇
  2011年   1648篇
  2010年   926篇
  2009年   812篇
  2008年   1495篇
  2007年   1598篇
  2006年   1617篇
  2005年   1530篇
  2004年   1398篇
  2003年   1340篇
  2002年   1342篇
  2001年   491篇
  2000年   469篇
  1999年   446篇
  1998年   320篇
  1997年   253篇
  1996年   249篇
  1995年   209篇
  1994年   199篇
  1993年   210篇
  1992年   314篇
  1991年   275篇
  1990年   292篇
  1989年   285篇
  1988年   282篇
  1987年   275篇
  1986年   229篇
  1985年   245篇
  1984年   210篇
  1983年   171篇
  1982年   164篇
  1981年   163篇
  1980年   159篇
  1979年   163篇
  1978年   151篇
  1977年   152篇
  1976年   132篇
  1975年   138篇
  1974年   135篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Maternal and Child Health Journal - Early life exposures can have an impact on a child’s developmental trajectory and children born late preterm (34–36 weeks gestational age)...  相似文献   
3.
Aims: In neuropsychological evaluations, it is often difficult to ascertain whether poor performance on measures of validity is due to poor effort or malingering, or whether there is genuine cognitive impairment. Dunham and Denney created an algorithm to assess this question using the Medical Symptom Validity Test (MSVT). We assessed the ability of their algorithm to detect poor validity versus probable impairment, and concordance of failure on the MSVT with other freestanding tests of performance validity.

Methods: Two previously published datasets (n?=?153 and n?=?641, respectively) from outpatient neuropsychological evaluations were used to test Dunham and Denney’s algorithm, and to assess concordance of failure rates with the Test of Memory Malingering and the forced choice measure of the California Verbal Learning Test, two commonly used performance validity tests.

Results: In both datasets, none of the four cutoff scores for failure on the MSVT (70%, 75%, 80%, or 85%) identified a poor validity group with proportionally aligned failure rates on other freestanding measures of performance validity. Additionally, the protocols with probable impairment did not differ from those with poor validity on cognitive measures.

Conclusions: Despite what appeared to be a promising approach to evaluating failure on the easy MSVT subtests when clinical data are unavailable (as recommended in the advanced interpretation program, or advanced interpretation [AI], of the MSVT), the current findings indicate the AI remains the gold standard for doing so. Future research should build on this effort to address shortcomings in measures of effort in neuropsychological evaluations.  相似文献   

4.
5.
6.
Purpose

The development of Laparoscopic Linear Endostaplers (LLES) is crucial in minimally invasive approaches in bariatric surgery, but there have been very few published studies comparing 6-row LLES in Laparoscopic Sleeve Gastrectomy (LSG). The objective of this study was to compare two 6-row LLES in LSG.

Methods

A total of 60 patients were prospectively randomized to undergo LSG with either Medtronic Endo GIA? Tri-Staple technology (MTS) or AEON ? Endostapler(Lexington Medical) LLES. The measured parameters included patient demographics, comorbidity indices, LLES and specimen characteristics, postoperative symptoms, hospital stay, and total adverse events (AEs). Intraoperative bleeding was evaluated using five laparoscopic and corresponding endoscopic images of staple line before clip application, compared with a 1–5 Visual Analogue Scale (VAS), assessed by an independent bariatric surgeon who was blinded to the LLES used. Images of all cases were reviewed on the same day to increase test–retest reliability.

Results

Both groups were similar in patient demographics. Compared to MTS, AEON LLES group had significantly lower bleeding VAS scores in 4/5 laparoscopic images (pre-pyloric: 1.7?±?0.7 vs. 2.36?±?0.76, p?=?0.0007, mid-sleeve: 1.46?±?0.62 vs. 1.86?±?0.68, p?=?0.019, proximal sleeve: 1.6?±?0.77 vs. 2.0?±?0.83, p?=?0.038, gastro-esophageal junction: 1.43?±?0.67 vs. 1.86?±?0.77, p?=?0.014) and 3/5 endoscopic images (pre-pyloric: 1.56?±?0.56 vs. 2.36?±?0.76, p?=?0.006, incisura: 1.66?±?0.54 vs. 2.0?±?0.52, p?=?0.021, mid-sleeve: 1.63?±?0.49 vs. 2.0?±?0.45, p?=?0.005). There was no statistical difference in other parameters.

Conclusion

Both devices were equally safe and effective in terms of LLES and specimen characteristics, patient symptoms, hospital stay, and AEs. Bleeding VAS scores were significantly lower, favoring the AEON LLES.

Graphical abstract
  相似文献   
7.
8.
9.
10.
In the United States, renal cell carcinoma (RCC) incidence and the prevalence of obesity, an established risk factor for RCC, have been increasing for several decades. RCC is more common among older individuals. We sought to quantify the contribution of excess adiposity to the rising incidence of RCC among individuals 60 years or older. National Institutes of Health-American Association of Retired Persons Diet and Health Study data (n = 453 859 participants, enrolled in 1995-1996, age at enrollment 50-71 years) were used to estimate multivariable-adjusted hazard ratios (HRs) for RCC across body mass index categories and HRs associated with smoking. Population attributable fractions (PAFs) were calculated using estimated HRs and annual overweight/obesity prevalence from the National Health Interview Survey (1985-2008). PAF estimates were combined with RCC incidence from Surveillance, Epidemiology and End Results-13 to calculate annual percent changes in RCC incidence attributable (and unrelated) to overweight/obesity. We found that between 1995 and 2018, among individuals aged 60 years and older, PAF for overweight/obesity increased from 18% to 29% for all RCCs. In comparison, the PAF for smoking declined from 12% to 9%. RCC incidence increased 1.8% per year (95% confidence interval [CI] 1.5%-2.1%) overall, while RCC incidence attributable to overweight/obesity increased 3.8% per year (95%CI 3.5%-4.2%) and RCC incidence unrelated to overweight/obesity increased 1.2% per year (95% CI 0.9%-1.4%). In conclusion, overweight/obesity appears to have contributed importantly to the rising incidence of RCC in the United States since the mid-1990s. Public health interventions focused on reducing overweight and obesity could help substantially in curbing this trend.  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