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   1757篇
  免费   115篇
  国内免费   9篇
耳鼻咽喉   17篇
儿科学   34篇
妇产科学   34篇
基础医学   265篇
口腔科学   39篇
临床医学   126篇
内科学   393篇
皮肤病学   39篇
神经病学   131篇
特种医学   67篇
外科学   234篇
综合类   43篇
一般理论   2篇
预防医学   135篇
眼科学   7篇
药学   149篇
中国医学   27篇
肿瘤学   139篇
  2023年   9篇
  2022年   23篇
  2021年   69篇
  2020年   32篇
  2019年   64篇
  2018年   47篇
  2017年   36篇
  2016年   43篇
  2015年   56篇
  2014年   65篇
  2013年   75篇
  2012年   130篇
  2011年   118篇
  2010年   51篇
  2009年   51篇
  2008年   76篇
  2007年   78篇
  2006年   65篇
  2005年   61篇
  2004年   77篇
  2003年   83篇
  2002年   70篇
  2001年   62篇
  2000年   48篇
  1999年   45篇
  1998年   21篇
  1997年   23篇
  1996年   15篇
  1995年   20篇
  1994年   17篇
  1993年   11篇
  1992年   35篇
  1991年   20篇
  1990年   22篇
  1989年   14篇
  1988年   21篇
  1987年   25篇
  1986年   17篇
  1985年   15篇
  1984年   10篇
  1983年   6篇
  1981年   3篇
  1980年   5篇
  1978年   6篇
  1977年   3篇
  1976年   3篇
  1974年   5篇
  1973年   5篇
  1972年   5篇
  1967年   4篇
排序方式: 共有1881条查询结果,搜索用时 15 毫秒
21.
22.
23.
ObjectiveTo document our observation of “close-loop” obstruction among patients with dual urethral obstruction from BPH and urethral stricture disease.Materials and MethodsThe hospital records of all patients that presented to our centres with evidences of urethral stricture co-existing with BPH were retrospectively reviewed from January 2007 to December 2011. Among other things, the salient features in the contrast radiograph of those with “close-loop” obstruction and their treatment were documented and analysed.ResultsForty three patients were managed for radiological evidence of urethral stricture and elevated bladder base (dual obstruction). Thirty (69.7%) of these patients had open prostatectomy with easy dilatation of the urethral stricture. Twelve (27.9%) of the patients had urethroplasty for urethral stricture diseases; of these twelve, five patients presented with persistent LUTS (“close loop” obstruction). These five (11.6%) patients were aged between 50 to 80 years; they all had suprapubic cystostomy. In addition to delineating the anatomy of the urethral stricture and elevated bladder base, other salient features on the contrast radiographies included dilated prostatic urethral, visualization of the seminal vesicles and closed bladder neck on voiding cystogram. The initial treatment was urethroplasty but two each had combination therapy (with alpha adrenergic blocker and 5-alpha reductase inhibitor) and open prostatectomy respectively as further treatment while the last patient had perineal urethrostomy as first-stage redo-urethroplasty.Conclusion“Close-loop” urethral obstruction appears to be an entity that needs further evaluation.  相似文献   
24.
25.
Journal of Clinical Immunology - A Correction to this paper has been published: https://doi.org/10.1007/s10875-021-01030-6  相似文献   
26.
27.
OBJECTIVE:: To determine predictors of fistula repair outcomes 3 months postsurgery. METHODS:: We conducted a multicountry prospective cohort study between 2007 and 2010. Outcomes, measured 3 months postsurgery, included fistula closure and residual incontinence in women with a closed fistula. Potential predictors included patient and fistula characteristics and context of repair. Multivariable generalized estimating equation models were used to generate adjusted risk ratios (RRs) and 95% confidence intervals (CIs). RESULTS:: Women who returned for follow-up 3-month postsurgery were included in predictors of closure analyses (n=1,274). Small bladder size (adjusted RR 1.57, 95% CI 1.39-1.79), prior repair (adjusted RR 1.40, 95% CI 1.11-1.76), severe vaginal scarring (adjusted RR 1.56, 95% CI 1.20-2.04), partial urethral involvement (adjusted RR 1.36, 95% CI 1.11-1.66), and complete urethral destruction or circumferential defect (adjusted RR 1.72, 95% CI 1.33-2.23) predicted failed fistula closure. Women with a closed fistula at 3-month follow-up were included in predictors of residual incontinence analyses (n=1,041). Prior repair (adjusted RR 1.37, 95% CI 1.13-1.65), severe vaginal scarring (adjusted RR 1.35, 95% CI 1.10-1.67), partial urethral involvement (adjusted RR 1.78, 95% CI 1.27-2.48), and complete urethral destruction or circumferential defect (adjusted RR 2.06, 95% CI 1.51-2.81) were significantly associated with residual incontinence. CONCLUSION:: The prognosis for genital fistula closure is related to preoperative bladder size, previous repair, vaginal scarring, and urethral involvement. LEVEL OF EVIDENCE:: II.  相似文献   
28.
29.
This study: (i) investigated the in vitro cytotoxicity and mode of action of lurbinectedin (PM01183) and Zalypsis® (PM00104) compared with trabectedin in cell lines deficient in specific mechanisms of repair, (ii) evaluated their in vivo antitumor activity against a series of murine tumors and human xenografts. The antiproliferative activity, the DNA damage and the cell cycle perturbations induced by the three compounds on tumor lines were very similar. Nucleotide Excision Repair (NER) deficient cells were approximately fourfold more resistant to trabectedin, lurbinectedin and Zalypsis®. Cells deficient in non‐homologous end joining (NHEJ), MRN complex and translesion synthesis (TLS) were slightly more sensitive to the three compounds (approximately fivefold) while cells deficient in homologous recombination (HR) were markedly more sensitive (150–200‐fold). All three compounds showed a good antitumor activity in several in vivo models. Lurbinectedin and trabectedin had a similar pattern of antitumor activity in murine tumors and in xenografts, whereas Zalypsis® appeared to have a distinct spectrum of activity. The fact that no relationship whatsoever was found between the in vitro cytotoxic potency and the in vivo antitumor activity, suggests that in addition to direct cytotoxic mechanisms other host‐mediated effects are involved in the in vivo pharmacological effects.  相似文献   
30.
BACKGROUND. Ultrasonic integrated backscatter of myocardial walls is directly related to the morphometrically evaluated collagen content. The integrated backscatter is also increased in hypertrophic cardiomyopathy, probably because of fiber disarray. The purpose of this study was to investigate myocardial tissue reflectivity in subjects with physiological hypertrophy caused by intense physical training and to assess the relation between the acoustic properties of myocardial tissue and left ventricular wall thickness assessed by conventional two-dimensional echocardiography. METHODS AND RESULTS. Twenty-four young male athletes (14 professional cyclists and 10 weight lifters, all in full agonistic activity) were studied together with 10 normal age-matched controls with sedentary life. By means of a commercially available two-dimensional echocardiograph, standard measurements were obtained according to the recommendations of the American Society of Echocardiography. With a prototype implemented in our Institute, an on-line radiofrequency analysis of ultrasound signals was also performed to obtain quantitative operator-independent measurements of the integrated backscatter of the myocardial walls. The integrated values of the radiofrequency signal were normalized for the pericardial interface and expressed in percent integrated backscatter (%IB). Compared with control subjects, athletes showed greater thickness values of septum (controls, 9 +/- 1; cyclists, 14 +/- 2; weight lifters, 15 +/- 1 mm, mean +/- SD; p less than 0.01) and posterior wall (9 +/- 1, 12 +/- 2, and 12 +/- 1 mm, respectively; p less than 0.01) but similar values of %IB for both septum (23 +/- 4%, 21 +/- 7%, and 23 +/- 8%, p = NS) and posterior wall (10 +/- 2%, 9 +/- 2%, and 11 +/- 2%, p = NS). In athletes, no correlation was found between septal and posterior wall thickness and the corresponding regional myocardial reflectivity (r = 0.23, p = NS and r = 0.01, p = NS, respectively). Furthermore, we compared the quantitative ultrasonic data between two subsets of 10 athletes and 10 patients with hypertrophic cardiomyopathy and similar degrees of septal thickness (16 +/- 1 versus 17 +/- 1 mm, respectively, p = NS). Septal and posterior wall %IB results were significantly higher in patients with hypertrophic cardiomyopathy (53 +/- 13% and 36 +/- 9%, respectively) than in athletes (21 +/- 7% and 10 +/- 3%, respectively; p less than 0.01 for both). CONCLUSIONS. We conclude that 1) endurance athletes show a normal pattern of quantitatively assessed ultrasonic backscatter despite of a marked left ventricular hypertrophy and 2) athletes and patients with hypertrophic cardiomyopathy and similar degrees of myocardial wall thickness can be differentiated on the basis of quantitative analysis of backscattered signal.  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