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   774篇
  免费   54篇
  国内免费   2篇
耳鼻咽喉   17篇
儿科学   22篇
妇产科学   19篇
基础医学   64篇
口腔科学   74篇
临床医学   62篇
内科学   169篇
皮肤病学   3篇
神经病学   33篇
特种医学   43篇
外科学   159篇
综合类   7篇
一般理论   2篇
预防医学   21篇
眼科学   38篇
药学   20篇
肿瘤学   77篇
  2023年   12篇
  2022年   15篇
  2021年   42篇
  2020年   26篇
  2019年   38篇
  2018年   35篇
  2017年   33篇
  2016年   39篇
  2015年   38篇
  2014年   49篇
  2013年   56篇
  2012年   68篇
  2011年   66篇
  2010年   37篇
  2009年   31篇
  2008年   43篇
  2007年   62篇
  2006年   55篇
  2005年   37篇
  2004年   21篇
  2003年   17篇
  2002年   4篇
  2001年   1篇
  2000年   2篇
  1999年   1篇
  1992年   2篇
排序方式: 共有830条查询结果,搜索用时 31 毫秒
1.
OBJECTIVE: The purpose of this study was to evaluate the effect of immediate and delayed post space preparation on the sealing ability of a new root canal filling material. STUDY DESIGN: Seventy-two extracted teeth were prepared and obturated with gutta-percha/AH-Plus and Resilon/Epiphany sealer by the lateral compaction technique. The teeth were divided randomly into 4 groups, and the post space was prepared either immediately after filling or after the obturated teeth had been stored in saline at 37 degrees C for a week. Leakage was determined by a fluid-transport device. RESULTS: The results showed that immediate post space preparation of the Resilon/Epiphany-filled group had a mean leakage value of 0.81 microL/h, whereas the delayed preparation had a mean leakage value of 0.75 microL/h. No difference (P > .05) in microleakage was found between gutta-percha/AH-Plus and Resilon/Epiphany-filled groups after immediate preparation. There was significant difference between gutta-percha/AH-Plus and Resilon/Epiphany groups in the delayed post space preparation (P < .05). CONCLUSION: Epiphany/Resilon obturation achieved better sealing than gutta-percha/AH-Plus at the apical end, especially in delayed post space preparation when mechanical techniques were used.  相似文献   
2.
3.
4.
Background/Objective: Ischemia is a leading cause of morbidity in Mechanical Intestinal Obstruction (MIO) in which the timing of decisions of whether to proceed to surgical or conservative treatment is critical in emergency departments (ED). While advanced technological options are available, patients may be negatively affected by the application of contrast agents or radiation. The use of ultrasound is limited because of the air in the intestines does not allow a good field of vision. While biomarkers can be considered as a good alternative option at this point. In the present study we examine the effect of hemogram and blood gas parameters on early surgical decision-making in MIO patients.MethodInvolved in this observational prospective study were 264 patients diagnosed with MIO who presented to the Department of Emergency Medicine, Ataturk Research and Training Hospital, Katip Celebi University between February 2018 and February 2019. Contrast-enhanced tomography (CECT) and laboratory results of the patients were recorded. Pathology reports of the patients who underwent surgery were collected. Laboratory data were analyzed by comparing CECT and pathology reports.ResultsIn a ROC analysis of the laboratory values of the patients who were diagnosed with ileus, the sensitivity was calculated as 80% and the specificity was 57.7 in values above WBC>10.75 (109/L), 96.6%, and the specificity was 31.1% in N/L > 2.9. For intestinal ischemia, the cut-off values were WBC> 12.6 and N/L > 3.2, Lactate >2.8 mmol/L and B.E < -3.6 mmol/L.ConclusionDiagnoses of ileus are based on the results examinations and imaging methods. More data are needed to support decisions on the timing of surgery in ED. WBC, N/L, Lactate and Base Excess indicate an ischemic segment. When the parameters are evaluated together, they strongly support early surgical decision-making regarding the treatment of intestinal ischemia.  相似文献   
5.
6.
Retroperitoneal fibrosis (RF) is a clinical entity characterized by the progressive proliferation of connective tissue that rarely forms a mass involving the periaortic area of the abdomen, which may be idiopathic as well as a result of an inflammatory process after aneurysmal dilatation of the aorta. This fibrotic tissue may cover both aorta and iliac arteries, reach the retroperitoneum and surrounding ureters, and cause serious obstructions and renal insufficiency in three-quarters of patients. Most of the patients are known to have atherosclerosis and local inflammation against the antigens of the plaques. A systemic autoimmune disease presenting with retroperitoneal fibrosis seems to be pronounced more frequently nowadays because of the elevated acute-phase reactant levels, positive autoantibodies, and concurrent autoimmune diseases affecting other organs in majority of the diagnosed patients. Ultrasonography, computed tomography, magnetic resonance imaging, positron emission tomography, and retroperitoneal biopsy are useful in diagnosing and assessing the full extent of the disease. Surgical interventions such as ureterolysis and aneurysm repair are frequently performed, but medical therapy including steroids and immunosuppressants is often needed because of the inflammatory and chronic-relapsing nature of the disease.

In this paper, we described two cases diagnosed with RF secondary to hemilaminectomy and hypothyroidism, and we summarized the literature related to RF.  相似文献   
7.
8.
9.
Abstract

Objective: Gastric distention and perforation are possible results in a preterm newborn with esophageal atresia and distal tracheoesophageal fistula, especially when there is a need for mechanical ventilatory support. The results of the reported cases treated with emergency thoracotomy and fistula ligation after gastrostomy are not very satisfactory. Sometimes simple temporary solutions can be useful for stabilization and allow safety for required surgical treatment for later.

Patient and methods: Two preterm newborns with esophageal atresia and distal tracheoesophageal fistula complicated by gastric perforation were reported.

Results: Both of the patients were initially treated with a simple peritoneal drainage and, then the definitive operations were performed without any problem in stabilized patients.

Conclusion: Performing fistula ligation or occlusion as an initial treatment in patients with impaired cardiac and respiratory functions may worsen the status of the patient. In such cases, it could be better to perform simple interventions first to facilitate subsequent treatments.  相似文献   
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