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   5723篇
  免费   354篇
  国内免费   79篇
耳鼻咽喉   52篇
儿科学   297篇
妇产科学   86篇
基础医学   744篇
口腔科学   253篇
临床医学   571篇
内科学   1145篇
皮肤病学   130篇
神经病学   388篇
特种医学   528篇
外科学   782篇
综合类   70篇
预防医学   254篇
眼科学   90篇
药学   432篇
  2篇
中国医学   4篇
肿瘤学   328篇
  2021年   54篇
  2020年   38篇
  2019年   53篇
  2018年   81篇
  2017年   45篇
  2016年   71篇
  2015年   85篇
  2014年   140篇
  2013年   177篇
  2012年   201篇
  2011年   160篇
  2010年   186篇
  2009年   154篇
  2008年   195篇
  2007年   239篇
  2006年   192篇
  2005年   221篇
  2004年   161篇
  2003年   164篇
  2002年   168篇
  2001年   161篇
  2000年   171篇
  1999年   159篇
  1998年   173篇
  1997年   179篇
  1996年   164篇
  1995年   143篇
  1994年   149篇
  1993年   138篇
  1992年   112篇
  1991年   127篇
  1990年   131篇
  1989年   127篇
  1988年   108篇
  1987年   119篇
  1986年   102篇
  1985年   104篇
  1984年   69篇
  1983年   49篇
  1982年   53篇
  1981年   44篇
  1980年   50篇
  1979年   49篇
  1978年   43篇
  1977年   62篇
  1976年   63篇
  1975年   61篇
  1974年   41篇
  1973年   34篇
  1969年   33篇
排序方式: 共有6156条查询结果,搜索用时 15 毫秒
991.
One hundred and six patients with stage Ic to IV ovarian carcinoma were treated by a protocol consisting of optimal debulking surgery followed by 9 cycles of CHAP chemotherapy. Clinical response was confirmed by a second-look procedure. Sixty-nine patients (65%) responded with 54 histological complete remissions (50.8%). Nineteen patients did not receive any complementary treatment due to a negative reaction, or prolonged neutropenia. Seven patients received maintenance chemotherapy, 10 an abdominal radiotherapy, 22 intraperitoneal chemotherapy and 11 autologous bone marrow transplantation. The 5-year survival rate was 32.5% and disease-free survival rate was 39.7%. Prognostic-factor analysis showed that age, initial staging, residual disease and cytological grading were significant. The authors propose a classification based on the risk of relapse, and different therapeutic indications for improving response rate and patient survival.  相似文献   
992.
People are the major source of bacterial contamination in the hospital environment, and to control environmental bacteria, the shedding potential of people must be controlled. In a conventional operating room, the more complete the surgical attire worn by everyone in the room, the better the control; i.e., body exhaust equipment for the anesthesiologist and the scrub nurse is essential. The laminar airflow filter system and ultraviolet light are effective environmental controls for preventing wound contamination.  相似文献   
993.
994.
995.
Intraoperative ultrasound examination of the brain   总被引:5,自引:0,他引:5  
In a preliminary demonstration of cranial intraoperative real-time ultrasound, both supratentorial and posterior fossa scans displayed the pertinent anatomy. A grade III astrocytoma was visualized on the supratentorial scan as well. Ultrasound may be valuable for surgical planning and biopsy procedures because of its reliable depiction of intracranial anatomy and ease of use.  相似文献   
996.
997.

Background  

Improving the quality of health care requires a range of evidence-based activities. Audit and feedback is commonly used as a quality improvement tool in the UK National Health Service [NHS]. We set out to assess whether current guidance and systematic review evidence can sufficiently inform practical decisions about how to use audit and feedback to improve quality of care.  相似文献   
998.
We studied two large consanguineous families from Oman with a distinct form of spondyloepiphyseal dysplasia (SED Omani type). By using a genome-wide linkage approach, we were able to map the underlying gene to a 4.5-centimorgan interval on chromosome 10q23. We sequenced candidate genes from the region and identified a missense mutation in the chondroitin 6-O-sulfotransferase (C6ST-1) gene (CHST3) changing an arginine into a glutamine (R304Q) in the well conserved 3'-phosphoadenosine 5'-phosphosulfate binding site. C6ST-1 catalyzes the modifying step of chondroitin sulfate (CS) synthesis by transferring sulfate to the C-6 position of the N-acetylgalactosamine of chondroitin. From the crystal structures of other sulfotransferases, it could be inferred that Arg-304 is essential for the structure of the cosubstrate binding site. We used recombinant C6ST-1 to show that the identified missense mutation completely abolishes C6ST-1 activity. Disaccharide composition analysis of CS chains by anion-exchange HPLC shows that both Delta HexA-GalNAc(6S) and Delta HexA(2S)-GalNAc(6S) were significantly reduced in the patient's cells and that Delta HexA-GalNAc(4S,6S), undetectable in controls, was elevated. Analysis of the patient's urine shows marked undersulfation of CS, in particular reduction in 6-O-sulfated disaccharide and an increase in the nonsulfated unit. Our results indicate that the mutation in CHST3 described here causes a specific but generalized defect of CS chain sulfation resulting in chondrodysplasia with major involvement of the spine.  相似文献   
999.
The abscopal effect is a phenomenon in which local radiotherapy is associated with the regression of metastatic cancer at a distance from the irradiated site. The abscopal effect may be mediated by activation of the immune system. Ipilimumab is a monoclonal antibody that inhibits an immunologic checkpoint on T cells, cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4). We report a case of the abscopal effect in a patient with melanoma treated with ipilimumab and radiotherapy. Temporal associations were noted: tumor shrinkage with antibody responses to the cancer-testis antigen NY-ESO-1, changes in peripheral-blood immune cells, and increases in antibody responses to other antigens after radiotherapy. (Funded by the National Institutes of Health and others.).  相似文献   
1000.

Background

Breast papillomas often are diagnosed with core needle biopsy (CNB). Most studies support excision for atypical papillomas, because as many as one half will be upgraded to malignancy on final pathology. The literature is less clear on the management of papillomas without atypia on CNB. Our goal was to determine factors associated with pathology upgrade on excision.

Methods

Our pathology database was searched for breast papillomas diagnosed by CNB during the past 10 years. We identified 277 charts and excluded lesions associated with atypia or malignancy on CNB. Two groups were identified: papillomas that were surgically excised (group 1) and those that were not (group 2). Charts were reviewed for the subsequent diagnosis of cancer or high-risk lesions. Appropriate statistical tests were used to analyze the data.

Results

A total of 193 papillomas were identified. Eighty-two lesions were excised (42%). Caucasian women were more likely to undergo excision (p = 0.03). Twelve percent of excised lesions were upgraded to malignancy. Increasing age was a predictor of upgrading, but this was not significant. Clinical presentation, lesion location, biopsy technique, and breast cancer history were not associated with pathology upgrade. Two lesions in group 2 ultimately required excision due to enlargement, and both were upgraded to malignancy.

Conclusions

Twenty-four percent of papillomas diagnosed on CNB have upgraded pathology on excision—half to malignancy. All of the cancers diagnosed were stage 0 or I. For patients in whom excision was not performed, 2 of 111 papillomas were later excised and upgraded to malignancy.  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