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   1305篇
  免费   71篇
  国内免费   5篇
耳鼻咽喉   26篇
儿科学   71篇
妇产科学   33篇
基础医学   183篇
口腔科学   92篇
临床医学   83篇
内科学   351篇
皮肤病学   30篇
神经病学   72篇
特种医学   46篇
外科学   128篇
综合类   7篇
一般理论   1篇
预防医学   134篇
眼科学   13篇
药学   72篇
中国医学   4篇
肿瘤学   35篇
  2023年   13篇
  2022年   18篇
  2021年   37篇
  2020年   23篇
  2019年   28篇
  2018年   28篇
  2017年   28篇
  2016年   24篇
  2015年   29篇
  2014年   48篇
  2013年   54篇
  2012年   89篇
  2011年   123篇
  2010年   59篇
  2009年   46篇
  2008年   69篇
  2007年   71篇
  2006年   51篇
  2005年   62篇
  2004年   58篇
  2003年   45篇
  2002年   40篇
  2001年   32篇
  2000年   28篇
  1999年   23篇
  1998年   18篇
  1997年   13篇
  1996年   17篇
  1995年   10篇
  1994年   18篇
  1993年   16篇
  1992年   16篇
  1991年   11篇
  1990年   19篇
  1989年   16篇
  1988年   14篇
  1987年   12篇
  1986年   8篇
  1985年   12篇
  1984年   4篇
  1983年   3篇
  1982年   3篇
  1981年   4篇
  1979年   5篇
  1976年   5篇
  1975年   5篇
  1972年   5篇
  1969年   7篇
  1966年   2篇
  1939年   2篇
排序方式: 共有1381条查询结果,搜索用时 15 毫秒
21.
The surgical technique of anterior vertebral arthrodesis has been modified by the introduction of cages in spinal surgery. The classical technique recommends removal of the vertebral endplate and exposure of bleeding cancellous bone. However, after the observation of cage subsidence during postoperative follow-up, the vertebral endplate is no longer removed, due to its greater mechanical resistance which can prevent cage subsidence. The mechanical characteristics of the vertebral endplate are well known, in contrast to its osteogenic potential, which was investigated in the present experimental study. The study was conducted on mongrel dogs of both sexes, which were submitted to anterior corpectomy at the cervical spine level. A cortico-cancellous bone graft removed from the tibia was used for the reconstruction of the vertebral segment, which was used with osteosynthesis plates. At the site of contact between the surface of the vertebral body and the bone graft, the vertebral endplate was completely removed and cancellous bone was exposed in the inferior vertebra, whereas in the superior vertebra of the arthrodesed vertebral segment only curettage was performed, and the vertebral endplate was preserved, as recommended for cage implantation. Twenty adult dogs of both sexes were divided into four experimental groups according to time of sacrifice (15, 30, 90, and 180 days). The consolidation of the bone graft with the vertebral body was evaluated by histology using hematoxilin-eosin and Gomori trichrome staining. In the interface between the bone graft and the vertebral body surface in which the vertebral endplate was not removed, graft consolidation was not observed in any of the group I animals (sacrificed after 15 days), and was observed in 1/5 animals of group II (30 days), in 2/5 animals of group III (90 days), and in 4/5 animals of group IV (180 days). In the interface between the graft and the vertebral body in which the vertebral endplate was removed, bone-graft consolidation was observed in all animals of all experimental groups (15, 30, 90, and 180 days). Bone-graft consolidation with the surface of the vertebral body was influenced by the removal or maintenance of the vertebral endplate. Due to the importance of this structure in current surgical procedures, this phenomenon deserves to be studied in more detail in order to understand the basic events involved in this process.Research carried out in the Department of Biomechanics, Medicine and Rehabilitation of the Locomotor Apparatus, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, 14048-900 Ribeirão Preto, SP, Brazil.  相似文献   
22.

Background  

Some studies have found that lower parity and higher or lower social class (depending on the study) are associated with increased risks of childhood acute lymphoblastic leukaemia (ALL). Such findings have led to suggestions that infection could play a role in the causation of this disease. An earlier New Zealand study found a protective effect of parental marriage on the risk of childhood ALL, and studies elsewhere have reported increased risks in relation to older parental ages. This study aimed to assess whether lower parity, lower social class, unmarried status and older parental ages increase the risk of childhood ALL (primarily). These variables were also assessed in relation to the risks of childhood acute non-lymphoblastic leukaemia, non-Hodgkin's lymphomas and Hodgkin's disease.  相似文献   
23.
Patients undergoing elective PCI are traditionally admitted overnight, however day case PCI cuts costs and has been proposed as a safe method for selected patients. We evaluated the success and long term clinical outcomes of day case percutaneous coronary intervention (PCI) for outpatients with stable angina.In total, 484 consecutive patients treated over a five year period with planned day case PCI were studied and followed up for 12 months. Successful PCI with same day discharge was performed in 463 patients (95.7%). There were 21 patients (4.3%) who required hospital admission. Reasons for failed discharge were hematoma formation (n = 7, 1.4%), coronary dissection (n = 4, 0.8%), post-procedural chest pain (n = 3, 0.6%), prolonged procedure (n = 2, 0.4%), and 1 each of acute stent thrombosis, coronary perforation, anaphylaxis, minor drug reaction and a functional study for untreated disease. One year follow up was complete for 439/484 (90.7%). At 12 months there were 6 hospitalizations for angina (1.2%, 95% CI 0.6–3.0%), 20 repeat revascularisations (4.1%, 95% CI 2.7–6.3%), 3 myocardial infarctions (0.6%, 95% CI 0.2–2.1%) and 2 deaths (0.4%, 95% CI 0.1–1.6%). Event free survival at 1 year follow up was 93.6% (95% CI 90.7–95.6%).Selecting patients for day case PCI is safe, and can achieve a high rate of success with excellent long term outcomes.  相似文献   
24.
25.
Clinical Oral Investigations - To evaluate therapeutic effects of laser therapy on patients with recurrent aphthous stomatitis assessing evidences from previously published systematic reviews. An...  相似文献   
26.
Objectives

To compare the efficacy and safety of diode laser and electrocautery techniques for inflammatory fibrous hyperplasia (IFH) removal.

Materials and methods

In this randomized double-blind clinical trial, 40 individuals were randomly allocated to two groups: group 1 (G1) consisted of 20 individuals assigned to treatment with diode laser and group 2 (G2) consisted of 20 individuals assigned to treatment with electrocautery. The following transoperative parameters were evaluated: bleeding, temperature, and surgical technique parameters (energy deposited on tissue, flow rate, and time of incision). The postoperative parameters evaluated were as follows: pain, functional alterations (chewing, speaking), analgesic medication intake, swelling, healing of the wound area, and patient satisfaction.

Results

Among the 40 individuals included in the study, four (two in G1 and two in G2) did not complete the entire follow-up. Therefore, 36 individuals (18 in G1 and 18 in G2) participated. Participants in G1 and in G2 had similar demographic characteristics. No difference regarding the trans- or postoperative parameters evaluated was observed between G1 and G2 (p > 0.05). Also, no difference regarding the time for healing was observed between groups.

Conclusions

Diode laser seems to be as effective and safe as electrocautery when applied under similar conditions for IFH removal.

Clinical relevance

IFH corresponds to 65% of the lesions observed in denture wearers. This study shows that under similar conditions diode laser is as effective and safe as electrocautery for removal of IFH.

  相似文献   
27.
28.
Meckel's diverticulum (MD) is a persistent embryonic remnant occurring in 2% of the general population. This entity is usually clinically silent and is only discovered when complications occur. Diagnosis is rarely made preoperatively. Surgical resection of symptomatic MD is widely accepted but the most appropriate management of asymptomatic MD remains unclear. We present a case of MD that summarizes some of the complications that may occur. The peculiarity of this case was that the complications were caused by a leiomyoma. The presence of tumoral disease in MD accounts for 3.2% of complications. The most common neoplasm is carcinoid tumor. Few publications have reported benign neoplasms in MD, probably due to their low incidence.  相似文献   
29.
Purpose : This study involved an extensive search for randomized controlled clinical trials comparing bilateral balanced and canine‐guided dentures, and questioned whether a bilateral balanced occlusion is imperative for successful denture treatment. Materials and Methods : Studies were identified by searching electronic databases (PubMed/MEDLINE, ISI Web of Science, LILACS, and BBD). The keywords “denture” and “occlusion” were used. The minimum inclusion requirements were (1) randomized controlled trials with patients of any age wearing both maxillary and mandibular conventional complete dentures (CDs), (2) comparison between bilateral balanced and canine‐guided dentures, and (3) assessment of masticatory function and/or patients’ satisfaction. Results : The search resulted in the identification of 5166 articles. Subsequently, 5156 articles were excluded on the basis of title and abstract. By the end of the search phase, seven randomized controlled trials were considered eligible. Conclusions : Current scientific evidence suggests that bilateral balanced occlusion is not imperative for successful treatment with conventional CDs in average patients. More studies are necessary to identify if specific clinical conditions may benefit from a balanced occlusion.  相似文献   
30.
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