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   1149篇
  免费   63篇
  国内免费   8篇
耳鼻咽喉   44篇
儿科学   66篇
妇产科学   69篇
基础医学   65篇
口腔科学   67篇
临床医学   87篇
内科学   228篇
皮肤病学   31篇
神经病学   64篇
特种医学   54篇
外科学   299篇
综合类   15篇
预防医学   32篇
眼科学   24篇
药学   37篇
中国医学   2篇
肿瘤学   36篇
  2023年   11篇
  2022年   10篇
  2021年   28篇
  2020年   19篇
  2019年   21篇
  2018年   34篇
  2017年   22篇
  2016年   47篇
  2015年   45篇
  2014年   48篇
  2013年   61篇
  2012年   81篇
  2011年   74篇
  2010年   48篇
  2009年   40篇
  2008年   88篇
  2007年   104篇
  2006年   112篇
  2005年   69篇
  2004年   85篇
  2003年   55篇
  2002年   47篇
  2001年   19篇
  2000年   9篇
  1999年   12篇
  1998年   4篇
  1997年   4篇
  1996年   2篇
  1995年   4篇
  1994年   3篇
  1993年   2篇
  1992年   3篇
  1991年   2篇
  1990年   1篇
  1988年   1篇
  1986年   1篇
  1982年   1篇
  1979年   1篇
  1978年   1篇
  1960年   1篇
排序方式: 共有1220条查询结果,搜索用时 46 毫秒
991.
992.
We report a case of a subperiosteal osteoid osteoma on the talar neck that was removed arthroscopically. Intralesional excision, en bloc resection, and percutaneous ablation techniques have all been used for the treatment of osteoid osteoma. For intra-articular osteoid osteomas, arthroscopy-assisted removal of the tumor has been described in a few case reports. Obtaining a nidus fragment for pathologic evaluation is important during arthroscopic removal of intra-articular osteoid osteomas. Sometimes it is not possible to obtain a specimen for pathologic examination. In the present case, the osteoid osteoma on the talar neck was easily located, the nidus was completely removed, and the tumor was extirpated.  相似文献   
993.
Malignant fibrous histiocytoma of bone is the osseous counterpart of the tumor in soft tissue. It is a rare primary bone tumor, and there have been conflicting reports on its grades of malignancy. The appendicular skeleton, especially the femur, is the most common site of involvement, whereas the calcaneus is rarely involved. We describe a primary malignant fibrous histiocytoma of the calcaneal bone in a 21-year-old man. The patient underwent neoadjuvant and adjuvant chemotherapy and below-the-knee amputation, and no local recurrence or metastasis was noted after 2 years of follow-up.  相似文献   
994.
Primary omental pregnancy on the gastrocolic ligament   总被引:1,自引:0,他引:1  
Omental pregnancy is an extremely rare form of abdominal pregnancy. Only 16 cases had been reported in the literature, and most were secondary omental pregnancies. We presented a case of primary omental pregnancy located on "gastrocolic ligament" diagnosed at surgical operation. The aim of this presentation is to remember that pregnancy can exist in unusual localizations, so abdominal observation and examination is very important during operations.  相似文献   
995.

Perioperative myocardial injury is an important reason of mortality and morbidity after neurosurgery. It usually is missed due to its asymptomatic character. In the present study, we investigated myocardial injury after noncardiac surgery (MINS) incidence, the risk factor for MINS, and association of MINS with 30-day mortality in neurosurgery patients. Patients with cardiac risk who underwent elective neurosurgery were enrolled to present prospective cohort study. The patients’ demographics, comorbidities, medications used, medical history, and type of operation were recorded. The high-sensitivity cardiac troponin (hs-cTn) levels of the patients were measured 12, 24, and 48 h after surgery. The patients were considered MINS-positive if at least one of their postoperative hs-cTn measurement values was?≥?14 ng/l. All the patients were followed up for 30 days after surgery for evaluation of their outcomes, including total mortality, mortality due to cardiovascular cause, and major cardiac events. A total of 312 patients completed the study and 64 (20.5%) of them was MINS-positive. Long antiplatelet or anticoagulant drug cessation time (OR: 4.9, 95% CI: 2.1–9.4) was found the most prominent risk factor for MINS occurrence. The total mortality rate was 2.4% and 6.2% in patients MINS-negative and MINS-positive, respectively (p?=?0.112). The mortality rate due to cardiovascular reasons (0.8% for without MINS, 4.7 for with MINS, and p?=?0.026) and incidence of the major cardiac events (4% for without MINS, 10.9 for with MINS, and p?=?0.026) were significantly higher in patients with MINS. MINS is a common problem after neurosurgery, and high postoperative hs-cTn level is associated with mortality and morbidity.

  相似文献   
996.
The purpose of this study was to assess the availability of mental health (MH) and chemical dependency (CD) services at US transplant centers, because appropriate psychosocial assessment and care is associated with better transplant outcomes. We used the 2017‐2018 American Hospital Association survey, Area Health Resource File, and Centers for Medicare & Medicaid Services Hospital Compare databases to quantify availability of services and examined associations of hospital‐ and health services area‐level characteristics with odds of offering services with generalized linear mixed models. We found that 15% of transplant centers did not offer MH services and 62% did not offer CD services. Hospitals were more likely to offer MH services if they were larger (OR [95% CI]: 1.03 [1.01, 1.06]) and had a lower rate of uninsured patients in the health services area (OR [95% CI]: 0.89 [0.80, 0.99]) and were more likely to offer CD services if they were larger (OR [95% CI]: 1.02 [1.01, 1.03]) or were members of a system (OR [95% CI]: 2.31 [1.26, 4.24]). Additional research is needed to understand whether lack of MH or CD services at transplant centers affects patients’ ability to access comprehensive psychosocial care and whether this affects patient outcomes.  相似文献   
997.

Introduction

Advances in culture-independent molecular biotechnologies have driven a greater appreciation for the function of mutualistic microorganisms in the maintenance of states of health in humans. The purpose of this study was to test the long-held hypothesis that healthy pulp lack bacteria.

Methods

Strict inclusion criteria were used to identify 10 pristine teeth from 10 healthy patients that were scheduled to be electively extracted in compliance with an orthodontic treatment plan. Using a rigorous disinfection protocol to isolate the operating field, the pulp space was accessed, and pulp tissue was collected in vivo from each tooth using a barbed broach. Genomic DNA was extracted from each pulp sample and analyzed for the presence of bacterial DNA using universal 16S ribosomal RNA polymerase chain reaction primers and MiSeq sequencing (Illumina, San Diego, CA) of community amplicons.

Results

One hundred percent (10/10) of the tested pulp tissues demonstrated the presence of bacterial DNA, with a mean of 343 operational taxonomic units per sample (range, 191–479). These were derived from 12 genera in which Ralstonia, Actinetobacter, and Staphylococcus were predominant (43%–78% of total community). None of the negative-field controls and none of the instruments used in the study tested positive for the presence of contaminating DNA.

Conclusions

This study presents evidence to support the conclusion that the pulp spaces of pristine healthy teeth contain detectable bacterial DNA.  相似文献   
998.
The administration of antineoplastic agents are associated with various vascular events. A case of acute bilateral renal infarction in a patient with non-small cell lung carcinoma during chemotherapy with cisplatin and gemcitabine is reported. The patient was misdiagnosed as having renal colic. To our knowledge, bilateral renal infarction following cisplatin and gemcitabine has not been reported previously. Renal infarction should be considered in the differential diagnosis of flank pain in a patient treated with gemcitabine and cisplatin.  相似文献   
999.
1000.
Resveratrol, a natural phenolic compound, has been shown to prevent cardiovascular diseases and cancer and exhibit neuroprotective effects. In this study, we examined the neuroprotective and antioxidant effects of resveratrol against hydrogen peroxide in embryonic neural stem cells. Hydrogen peroxide treatment alone increased catalase and glutathione peroxidase activities but did not change superoxide dismutase levels compared with hydrogen peroxide + resveratrol treatment. Nitric oxide synthase activity and concomitant nitric oxide levels increased in response to hydrogen peroxide treatment. Conversely, resveratrol treatment decreased nitric oxide synthase activity and nitric oxide levels. Resveratrol also attenuated hydrogen peroxide-induced nuclear or mitochondrial DNA damage. We propose that resveratrol may be a promising agent for protecting embryonic neural stem cells because of its potential to decrease oxidative stress by inducing higher activity of antioxidant enzymes, decreasing nitric oxide production and nitric oxide synthase activity, and alleviating both nuclear and mitochondrial DNA damage.  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