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   4353篇
  免费   397篇
  国内免费   86篇
耳鼻咽喉   51篇
儿科学   143篇
妇产科学   186篇
基础医学   605篇
口腔科学   56篇
临床医学   473篇
内科学   1011篇
皮肤病学   41篇
神经病学   253篇
特种医学   338篇
外科学   593篇
综合类   123篇
一般理论   3篇
预防医学   203篇
眼科学   165篇
药学   258篇
中国医学   20篇
肿瘤学   314篇
  2023年   23篇
  2022年   49篇
  2021年   80篇
  2020年   69篇
  2019年   76篇
  2018年   119篇
  2017年   85篇
  2016年   67篇
  2015年   109篇
  2014年   125篇
  2013年   177篇
  2012年   225篇
  2011年   233篇
  2010年   164篇
  2009年   136篇
  2008年   201篇
  2007年   229篇
  2006年   242篇
  2005年   222篇
  2004年   233篇
  2003年   202篇
  2002年   198篇
  2001年   196篇
  2000年   118篇
  1999年   121篇
  1998年   98篇
  1997年   71篇
  1996年   85篇
  1995年   78篇
  1994年   69篇
  1993年   68篇
  1992年   53篇
  1991年   58篇
  1990年   48篇
  1989年   59篇
  1988年   61篇
  1987年   62篇
  1986年   48篇
  1985年   42篇
  1984年   28篇
  1983年   23篇
  1982年   17篇
  1981年   27篇
  1980年   27篇
  1979年   19篇
  1978年   13篇
  1977年   24篇
  1976年   13篇
  1975年   17篇
  1974年   6篇
排序方式: 共有4836条查询结果,搜索用时 0 毫秒
1.
2.

Background

Persistent iatrogenic atrial septal defect (iASD) is a common but poorly characterized complication after cryoballoon (CB) pulmonary vein isolation (PVI) procedures. We therefore investigate its prevalence, evolution, risk factors, and clinical outcomes in a prospective longitudinal study.

Methods

A total of 108 patients (41 women, mean age 57 ± 11.3) underwent CB PVI for AF. Serial transesophageal echocardiography (TEE) was performed 9 months and then annually until 6 years after the procedure to study the characteristics of persistent iASD.

Results

Persistent iASD occurred in 33 (30.6%) patients 9 months after CB PVI. Spontaneous closure of iASD was found in 6 (22.2%) and 3 (15.8%) patients 2 and 3 years after the procedures, respectively. No spontaneous closure was observed on 4, 5, and 6-year TEE follow-up. The projected long-term persistence rate of iASD after CB PVI was therefore 20% (30.6% × 0.778 × 0.842). Using multivariate logistic regression, a higher number of cryoapplications (≥ 2 minutes) was the only independent predictor of persistent iASD 9 months after CB PVI (odds ratio [OR] 1.207; 95% confidence interval [CI], 1.033-1.411, P = 0.018). Two (1.9%) patients with significantly larger iASD size than the others (long diameter 12.6 ± 0.8 vs 3.7 ± 1.5 mm, P < 0.001; short diameter 10.9 ± 0.2 vs 3 ± 1.1 mm, P < 0.001) required percutaneous closure because of exertional dyspnea and right ventricular enlargement. Over 129.7 patient-years follow-up, during which iASD persisted, there was no occurrence of neurologic events.

Conclusions

Approximately one fifth of patients undergoing CB PVI will have permanently persistent iASD. Patients with defect sizes of greater than 10 mm may need percutaneous closure due to significant left-to-right shunting.  相似文献   
3.
The ease of measurement and the quantitative nature of bone mineral densitometry (BMD) is clinically appealing. Despite BMD's proven capability to stratify fracture risk, data indicate that clinical risk factors provide complementary information on fracture susceptibility that is independent of BMD. Methods to quantify fracture risk using both clinical and BMD variables would have great appeal for clinical decision-making. We describe a procedure for quantifying hip fracture risk (5-yr and remaining lifetime) based on (1) the individual's age alone (base model, assuming average clinical risk factors and bone density), (2) incorporation of multiple patient-specific clinical risk factor data in the base model, and (3) incorporation of both patient-specific clinical risk factor data and BMD results.  相似文献   
4.
5.
Objective: Two major changes have occurred in inguinal hernia repair during the last two decades: (i) the use of tension‐free mesh repair; and (ii) the application of laparoscopic technique for repair. The aims of the present study were to study: (i) how inguinal hernia repair was carried out; and (ii) the outcome of inguinal hernia repair in Hospital Authority (HA) hospitals. Methodology: This was a retrospective analysis on 8311 elective inguinal hernia repairs performed in 16 HA hospitals from January 2001 to December 2003. The mean age was 63.9 ± 14.2 years, and the male to female ratio was 22.0 : 1.0. Among these, 869 (10.5%) repairs were performed with the laparoscopic approach and 7442 (89.5%) repairs with the open approach. The proportion of laparoscopic hernia repair increased from 8.7% to 12.6%. Results: For open repair, 39% of cases were carried out with regional anaesthesia, 32% with general anaesthesia and 29% with local anaesthesia (LA). Furthermore, mesh repair was used in 88% of the patients. For laparosocpic repair, 98.4% of cases were carried out under general anaesthesia, and all patients had mesh repair using the totally extraperitoneal approach. A significantly higher proportion of bilateral repair and recurrent hernia repair was performed with the laparoscopic approach (P = 0.000). For primary unilateral repair, there was no significant difference in the postoperative length of stay (LOS) and the total LOS between the laparoscopic and the open surgery groups. No difference in LOS was found in recurrent hernia repair between the two groups. With respect to bilateral repair, both the preoperative LOS (P = 0.036) and total LOS (P = 0.039) were shorter in the laparoscopic group. Furthermore, a significantly higher proportion of day‐surgery patients was observed in the laparoscopic group than the open surgery group (21.3%vs 16.9%, P = 0.001). Nevertheless, when only the results of 2003 were analyzed, the postoperative LOS (P = 0.000) and total LOS (P = 0.000) were significantly shorter in the laparoscopic group than the open surgery group. The LOS parameters were significantly shorter in the open surgery LA subgroup compared with the non‐LA subgroup (P = 0.000), and they were not different from those in the laparoscopic group. Conclusions: The open mesh repair is the predominant approach for inguinal hernia repair in HA hospitals. The originally described local anaesthetic approach was under utilized, although it resulted in good outcome. The use of laparoscopic hernia repair is increasing and a learning curve was recently observed with improved outcome.  相似文献   
6.
We describe a 15-y-old girl with Fechtner-like syndrome, who is the first Chinese reported to have this rare syndrome. She presented with left homonymous hemianopia and neuroimaging revealed haemorrhage in both parietal and occipital lobes. Peripheral blood smear showed macrothrombocytopenia and intracytoplasmic inclusion bodies inside leucocytes. Thrombocytopenia and proteinuria responded to intravenous immunoglobulin and pulsed methylprednisolone. This case illustrates that life-threatening haemorrhage can occur in patients with Fechtner syndrome. Although there was no effective treatment reported in the literature, high dose steroid and immunoglobulin seemed to be useful in our patient. Our patient also had nephritic-nephrotic syndrome with renal insufficiency, which is unusual in adolescent female patients.  相似文献   
7.
8.
9.
10.
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