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   1117篇
  免费   71篇
  国内免费   14篇
耳鼻咽喉   26篇
儿科学   24篇
妇产科学   34篇
基础医学   108篇
口腔科学   29篇
临床医学   85篇
内科学   306篇
皮肤病学   14篇
神经病学   63篇
特种医学   50篇
外科学   196篇
综合类   51篇
预防医学   38篇
眼科学   28篇
药学   81篇
中国医学   2篇
肿瘤学   67篇
  2023年   16篇
  2022年   63篇
  2021年   74篇
  2020年   54篇
  2019年   57篇
  2018年   73篇
  2017年   61篇
  2016年   45篇
  2015年   48篇
  2014年   60篇
  2013年   83篇
  2012年   102篇
  2011年   71篇
  2010年   55篇
  2009年   41篇
  2008年   42篇
  2007年   37篇
  2006年   37篇
  2005年   51篇
  2004年   52篇
  2003年   27篇
  2002年   23篇
  2001年   1篇
  2000年   4篇
  1999年   2篇
  1998年   3篇
  1997年   5篇
  1996年   2篇
  1994年   4篇
  1993年   1篇
  1992年   1篇
  1990年   2篇
  1984年   2篇
  1980年   1篇
  1979年   1篇
  1977年   1篇
排序方式: 共有1202条查询结果,搜索用时 15 毫秒
51.
52.

Introduction

The myocardial performance index (MPI) has been described as a non-invasive Doppler measurement of ventricular function. The aim of this study was to assess MPI following surgical correction of ventricular septal defect (VSD) and to evaluate its impact on postoperative recovery.

Material and methods

This is a prospective study involving 30 children (16 girls and 14 boys) operated on for VSD (group I). The control group (group II) consisted of 30 healthy children (age and sex matched).

Results

We found that both the right and left ventricular (RV and LV) MPI correlated significantly with the ejection fraction (EF) (r = –0.49, p = 0.006, r = –0.51, p = 0.004, respectively). The LV EF and the LV FS were negatively correlated, while the left and right ventricular MPI was positively correlated with the: LVEDD (p = 0.000), the VSD size (p = 0.000), and the postoperative course of the patients in terms of the duration of ventilation (p = 0.000), the duration of use of inotropics (p = 0.000) and the duration of staying in the ICU (p = 0.000). By linear regression, the factors that correlated with the postoperative course of VSD surgery were the RV MPI pre-surgery, MPI 2 days after surgery and the ejection fraction (p = 0.000).

Conclusions

Myocardial performance index is a useful index for measurement of the left and right ventricular function. It correlates significantly with the ejection fraction, fractional shortening, VSD size, and the left ventricular size. It also significantly predicts the outcome of VSD surgery.  相似文献   
53.
54.

Purpose

To identify and compare predictors of local tumor progression (LTP)-free survival (LTPFS) after radiofrequency (RF) ablation and microwave (MW) ablation of colorectal liver metastases (CLMs).

Materials and Methods

This is a retrospective review of CLMs ablated from November 2009 to April 2015 (110 patients). Margins were measured on contrast-enhanced computed tomography (CT) 6 weeks after ablation. Clinical and technical predictors of LTPFS were assessed using a competing risk model adjusted for clustering.

Results

Technique effectiveness (complete ablation) was 93% (79/85) for RF ablation and 97% (58/60) for MW ablation (P = .47). The median follow-up period was significantly longer for RF ablation than for MW ablation (56 months vs. 29 months) (P < .001). There was no difference in the local tumor progression (LTP) rates between RF ablation and MW ablation (P = 0.84). Significant predictors of shorter LTPFS for RF ablation on univariate analysis were ablation margins 5 mm or smaller (P < .001) (hazard ratio [HR]: 14.6; 95% confidence interval [CI]: 5.2–40.9) and perivascular tumors (P = .021) (HR: 2.2; 95% CI: 1.1–4.3); both retained significance on multivariate analysis. Significant predictors of shorter LTPFS on univariate analysis for MW ablation were ablation margins 5 mm or smaller (P < .001) (subhazard ratio: 11.6; 95% CI: 3.1–42.7) and no history of prior liver resection (P < .013) (HR: 3.2; 95%: 1.3–7.8); both retained significance on multivariate analysis. There was no LTP for tumors ablated with margins over 10 mm (median LTPFS: not reached). Perivascular tumors were not predictive for MW ablation (P = .43).

Conclusions

Regardless of the thermal ablation modality used, margins larger than 5 mm are critical for local tumor control, with no LTP noted for margins over 10 mm. Unlike RF ablation, the efficiency of MW ablation was not affected for perivascular tumors.  相似文献   
55.

Introduction

Living donor liver transplantation (LDLT) is a complex surgery with high risk for massive bleeding and blood component transfusion. This retrospective study investigated the effect of adopting ROTEM based transfusion algorithm on blood products transfusion practice among LDLT recipients and the effect of this change on patient outcome.

Material and methods

Data of 216 patients with predicted intraoperative massive bleeding (blood loss ≥70?ml blood/kg, or blood loss >150?ml/min with hemodynamic affection with continuing need for transfusion) were collected from our database. Patients were divided into two groups according to transfusion protocol applied; Pre-ROTEM group (n?=?95), ROTEM group (n?=?121). Basal characteristics, blood component transfusion, graft outcome and patient outcome (28-day mortality and one-year mortality) were compared between the two groups.

Results

Transfused packed red blood cells (PRBCs) units, fresh frozen plasma (FFP) units, and application of massive transfusion protocol (MTP) were significantly lower in the ROTEM group compared to pre-ROTEM group [8(7) vs 4.5(5), p?<?0.01, 12.5(4) vs 5.6(3), p?<?0.001, 29% vs 20%, p?<?0.005 respectively]. The survival distributions for the two studied groups showed no statistically significant difference, p?<?0.46.

Conclusions

ROTEM based transfusion algorithms applied in LDLT decreased blood component transfusion and enhanced early graft function.  相似文献   
56.

Background

The use of synthetic mesh for ventral hernia repair under contaminated conditions is a controversial issue due to the considerable risk of surgical site infection (SSI). This study aimed to review the outcomes of repair of incarcerated and strangulated ventral hernias with or without synthetic mesh in compliance with established clinical guidelines regarding the incidence of SSI and hernia recurrence.

Methods

The records of patients with complicated ventral hernias who were treated with or without synthetic mesh repair were reviewed. Variables collected included the characteristics of patients and of ventral hernias, type of repair, and incidence of SSI and recurrence.

Results

One hundred twenty-two patients (56 males) of a mean age of 56 years were included. Fifty-two (42.6%) and 70 (57.4%) patients presented with incarcerated and strangulated ventral hernias, respectively. Sixty-six (54%) patients were treated with on-lay mesh repair, and 56 (46%) were managed with suture repair. Twenty-one patients required bowel resection. SSI was detected in eight (6.5%) patients. There was no significant difference between both groups regarding the incidence of SSI (7.5% for mesh group vs 5.3% for suture group). Recurrence occurred in seven patients. Median follow-up period was 24 months. The suture repair group had a significantly higher incidence of recurrence than the mesh group. Diabetes mellitus, previous recurrence, and intestinal resection were significant predictors for SSI.

Conclusion

Following established guidelines, synthetic mesh repair of incarcerated and strangulated ventral hernias attained lower recurrence rate, comparable incidence of SSI, and higher rate of seroma formation than suture repair.

Trial registration

Research Registry, researchregistry1891
  相似文献   
57.
58.

Background

Contrast-induced encephalopathy (CIE) is a syndrome that may be clinically unrecognized and misdiagnosed as cerebral edema.

Methods

Case report and review.

Results

A 72-year-old woman was admitted for elective endovascular embolization of a 10-mm left anterior communicating artery aneurysm. One hour post-procedure, she acutely developed global aphasia. Emergent head computed tomography (CT) and computed tomography-angiography (CTA) showed high attenuation of the left hemispheric subarachnoid spaces interpreted as hemispheric edema; emergent magnetic resonance imaging revealed left hemispheric punctate infarcts. At 12 h, she developed right hemiparesis and encephalopathy. Repeat CTA and CT perfusion revealed decreased left hemisphere cerebral blood flow and diminutive caliber of distal left middle cerebral artery territory vasculature. Repeated angiography with intra-arterial verapamil and systemic blood pressure augmentation were performed for presumed vasospasm. At 20 h, head CT was concerning for worsening left hemispheric edema, but dual-energy, iodine-subtracting sequences revealed significant contrast extravasation contributing to the appearance of sulcal effacement but without actual edema. Out of concern for blood–brain barrier breakdown from CIE, pressor augmentation was discontinued and the patient gradually improved to full neurological recovery within 72 h of symptom onset.

Conclusions

Our case is the first known to report the use of dual-energy, iodine-subtracting CT as a diagnostic tool in differentiating between cerebral edema and pseudoedema in CIE.
  相似文献   
59.
Even in the hands of highly experienced bariatric surgeons, perioperative complications are inevitable. Of these, leaks and fistulas are amongst the scariest complications. Intrathoracic gastric fistulas (ITGF) can be associated with serious morbidity, mostly when cases are misdiagnosed or detected with delay. This is a systematic review of the literature to investigate the clinical and surgical outcomes of morbidly obese adult patients with a confirmed diagnosis of ITGF following bariatric surgery. A pooled analysis of 25 articles, encompassing 76 patients with post-bariatric ITGF, showed that the clinical outcome depends on the initial presentation, timing of the diagnosis in relation to symptom onset, and prompt and effective treatment. Any septic or unstable patient must undergo urgent surgical intervention, while stable patients might tolerate a step-up approach and watchful waiting for nonsurgical treatment. Among those who undergo surgery, treatment failure and the mortality rate are substantially high. Contingent upon a prompt management strategy, patients with postbariatric ITGF can generally have a favorable outcome in the long term.  相似文献   
60.

Background

To compare selected outcomes (30-day reoperation and total length of hospital stay) following emergency appendectomy between populations from New York State and England.

Methods

This retrospective cohort study used demographic and in-hospital outcome data from Hospital Episode Statistics (HES) and the New York Statewide Planning and Research Cooperative System (SPARCS) administrative databases for all patients aged 18+ years undergoing appendectomy between April 2009 and March 2014. Univariate and adjusted multivariable logistic regression were used to test significant factors. A one-to-one propensity score matched dataset was created to compare odd ratios (OR) of reoperations between the two populations.

Results

A total of 188,418 patient records, 121,428 (64.4%) from England and 66,990 (35.6%) from NYS, were extracted. Appendectomy was completed laparoscopically in 77.7% of patients in New York State compared to 53.6% in England (P < 0.001). The median lengths of hospital stay for patients undergoing appendectomy were 3 (interquartile range, IQR 2–4) days versus 2 (IQR 1–3) days (P < 0.001) in England and New York State, respectively. All 30-day reoperation rates were higher in England compared to New York State (1.2 vs. 0.6%, P < 0.001), representing nearly a twofold higher risk of 30-day reoperation (OR 1.88, 95% CI 1.64–2.14, P < 0.001). As the proportion of appendectomy completed laparoscopically increased, there was a reduction in the reoperation rate in England (correlation coefficient ?0.170, P = 0.036).

Conclusions

Reoperations and total length of hospital stay is significantly higher following appendectomy in England compared to New York State. Increasing the numbers of appendectomy completed laparoscopically may decrease length of stay and reoperations.
  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