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   1900篇
  免费   105篇
  国内免费   7篇
耳鼻咽喉   19篇
儿科学   62篇
妇产科学   48篇
基础医学   286篇
口腔科学   26篇
临床医学   203篇
内科学   368篇
皮肤病学   145篇
神经病学   120篇
特种医学   32篇
外科学   225篇
综合类   18篇
一般理论   1篇
预防医学   170篇
眼科学   59篇
药学   99篇
肿瘤学   131篇
  2023年   14篇
  2022年   53篇
  2021年   70篇
  2020年   60篇
  2019年   63篇
  2018年   77篇
  2017年   53篇
  2016年   50篇
  2015年   51篇
  2014年   78篇
  2013年   84篇
  2012年   138篇
  2011年   160篇
  2010年   111篇
  2009年   83篇
  2008年   117篇
  2007年   116篇
  2006年   89篇
  2005年   113篇
  2004年   81篇
  2003年   55篇
  2002年   64篇
  2001年   18篇
  2000年   13篇
  1999年   21篇
  1998年   14篇
  1997年   13篇
  1996年   15篇
  1995年   3篇
  1994年   5篇
  1993年   6篇
  1992年   5篇
  1991年   4篇
  1990年   5篇
  1989年   4篇
  1987年   5篇
  1984年   8篇
  1983年   3篇
  1982年   3篇
  1980年   4篇
  1979年   4篇
  1978年   5篇
  1977年   12篇
  1976年   5篇
  1975年   9篇
  1974年   15篇
  1972年   2篇
  1971年   3篇
  1970年   13篇
  1967年   3篇
排序方式: 共有2012条查询结果,搜索用时 15 毫秒
11.
Cerebral injury leading to brain death (BD) causes major physiologic derangements in potential organ donors, which may result in vascular-endothelial activation and affect posttransplant graft function. We investigated the kinetic of pro-coagulatory and pro-inflammatory endothelial activation and the subsequent oxidative stress and renal tubular injury, early after BD declaration. BD was induced by slowly inflating a balloon-catheter inserted in the extradural space over a period of 30 min. Rats (n = 30) were sacrificed 0.5, 1, 2 or 4 h after BD-induction and compared with sham-controls. This study demonstrates immediate pro-coagulatory and pro-inflammatory activation of vascular endothelium after BD in kidney donor rats, proportional with the duration of BD. E- and P-Selectins, Aα/Bβ-fibrinogen mRNA were abruptly and progressively up-regulated from 0.5 h BD onwards; P-Selectin membrane protein expression was increased; fibrinogen was primarily visualized in the peritubular capillaries. Plasma von Willebrand factor was significantly higher after 2 h and 4 h BD. Urine heart-fatty-acid-binding-protein and N-acetyl-glucosaminidase, used as new specific and sensitive markers of proximal and distal tubular damage, were found significantly increased after 0.5 h, with a maximum at 4 h. Unexpectedly, oxidative stress was detectable only late, after the installation of tubular injury, suggesting only a secondary role for hypoxia in triggering these injuries.  相似文献   
12.
We performed a systematic review of the literature on the diagnosis and treatment of secondary aortoenteric fistulas (AEF). A MEDLINE search was performed of articles published in English or Spanish between January 1991 and August 2006. Diagnostic methods, treatment modalities and the results of surgical treatment were analyzed. The most frequent first aortic surgery associated with AEF was repair of abdominal aortic aneurysm (54.31%). The most common form of presentation was gastrointestinal bleeding. Repair through in situ prosthetic replacement had the lowest early mortality rates (8-13.3%) compared with graft excision and extraanatomic revascularization (18.2-44%). AEF is a serious entity and diagnosis requires a high index of suspicion based on clinical findings and indirect data from imaging techniques (computed tomography). The most appropriate therapeutic option continues to be controversial.  相似文献   
13.
14.

Background

Complete encasement of the inferior vena cava by retroperitoneal tumors is rare. Although replacement of the vena cava has been considered for various conditions in adults, it is rarely used in children except for challenging resections and as a last chance approach – often aiming more at debulking than cure.

Materials and methods

From January 2009 to February 2017, 4 patients (2 adrenal neuroblastomas, 1 renal cell carcinoma, 1 infantile fibrosarcoma) underwent elective en-bloc resection of tumor and of the infrahepatic portion of the inferior vena cava (IVC), with planned IVC prosthetic replacement. In three cases a portion of the left renal vein had to be resected as well, with the vein reanastomosed onto the prosthesis, and a concomitant auto-transplantation of the right kidney was associated in one neuroblastoma patient.

Results

All patients had an uncomplicated postoperative course. In one patient, the prosthetic conduit is patent at long-term (43?months), while the middle portion of the prosthesis did eventually thrombose at mid-term after surgery in the three others – with no related symptoms. Interestingly, all renal venous reconstructions remain patent. Three patients (2 neuroblastomas and 1 infantile fibrosarcoma) are alive and disease-free at 43, 74 and 108?months after surgery, respectively. One patient with renal cell carcinoma died of recurrence of the disease 21?months after surgery.

Conclusion

Resection and reconstruction of the vena cava, including the renal vein portion, can be considered and planned electively in case of tumoral encasement. This strategy is associated with good tolerance of the operation, low morbidity and satisfactory long-term function, even in cases with progressive and/or secondary partial thrombosis.

Level of Evidence

IV  相似文献   
15.

Objective

To determine and compare specific factors that could be associated and predictive with successful prosthetic rehabilitation in major lower-limb amputations.

Methods

A 15-year long (2000–2014) retrospective observational cohort study was conducted. Two different criteria were used to define successful prosthetic rehabilitation: (1) the ability to walk at least 45 m, regardless of assistive devices; and (2) walking >45 m without other ambulatory aids than one cane (if required). Age, gender, comorbidities, cause and level of amputation, stump characteristics, ulcers in the preserved limb, and time between surgery and physical therapy were examined as predictors of successful prosthetic rehabilitation.

Results

A total of 169 patients (61.60 ± 15.9 years) were included. Regarding walking ability with or without walking aids, the presence of ulcers in the preserved limb was individually associated with failed prosthetic rehabilitation (p < 0.001), while being male (OR = 0.21; 95%CI = 0.06–0.80) and transtibial level of amputation (OR = 6.73; 95%CI = 1.92–23.64) were identified as independent predictors of failure and success, respectively. Regarding the criterion of successful rehabilitation, a shorter time until rehabilitation was individually associated with improved walking ability (p < 0.013), while failure could be predicted by comorbidities (OR = 0.48; 95%CI = 0.29–0.78) and age groups of 65–75 years old (OR = 0.19; 95%CI = 0.05–0.78) and over 75 years old (OR = 0.19; 95%CI = 0.04–0.91).

Conclusions

Regarding walking ability with or without walking aids, male gender and transtibial level of amputation are independently associated with failure and success respectively, whereas older age and comorbidities can predict failed prosthetic rehabilitation when assistive walking devices are considered. Future prospective cohort studies are needed to confirm these findings.  相似文献   
16.

Background

As the number of obese patients in the United States continues to grow, there is a parallel increase in the number of bariatric surgery patients. A quarter of these patients will return to the Emergency Department (ED) within the first two years of the index procedure.

Objective

An understanding of the most common bariatric procedures and their related complications will greatly aide the Emergency Medicine physician in the care of these patients.

Discussion

Abdominal pain is the most common reason for bariatric patients to present to the ED and can represent a diagnostic challenge to EM physicians. It is important that EM physicians have a good understanding of bariatric procedures. We describe the three most common bariatric procedures: 1) the Laparoscopic Adjustable Gastric Banding (LAGB); 2) the Laparoscopic Sleeve Gastrectomy (LSG); 3) and the Roux-en-Y Gastric Bypass (RYGB). Due to the unique altered anatomy following the procedures there are specific complications related to each individual procedure. We will describe the most common presentations of abdominal pain in the post bariatric surgery patient. Finally, we will review new endoscopic procedures and the associated complications that may cause patients to present to the ED.

Conclusion

Certain complications in bariatric surgery patients can have a high rate of morbidity and mortality. An improved understanding of bariatric procedures and their complications will allow for improved vigilance and management.  相似文献   
17.
Clinical Rheumatology - Systemic lupus erythematosus (SLE) is the prototypic autoimmune disease that disrupts numerous immunity mechanisms with the potential to exert damage to any organ or tissue....  相似文献   
18.
19.
20.
Gangliogliomas are well-differentiated, slow-growing tumors. The majority are grade I of WHO. It appears predominantly in children and young adults. Most are located at the temporal lobe, and as symptomatology more frequent epileptic seizures of difficult pharmacological control. In general, they have a good prognosis after surgical resection. The anaplasic variant, considered to be grade III of the WHO, presents greater clinical and radiological aggressiveness. Leptomeningeal dissemination is exceptional in these types of tumors, but when diagnosed it presents a rapidly progressive and fatal course for the patient.  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