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   35519篇
  免费   1828篇
  国内免费   162篇
耳鼻咽喉   386篇
儿科学   856篇
妇产科学   473篇
基础医学   4693篇
口腔科学   938篇
临床医学   2348篇
内科学   9389篇
皮肤病学   783篇
神经病学   2608篇
特种医学   1178篇
外科学   5711篇
综合类   182篇
一般理论   4篇
预防医学   1333篇
眼科学   494篇
药学   2566篇
中国医学   138篇
肿瘤学   3429篇
  2023年   204篇
  2022年   375篇
  2021年   655篇
  2020年   352篇
  2019年   499篇
  2018年   620篇
  2017年   568篇
  2016年   607篇
  2015年   587篇
  2014年   853篇
  2013年   1044篇
  2012年   1582篇
  2011年   1710篇
  2010年   1038篇
  2009年   950篇
  2008年   1578篇
  2007年   1777篇
  2006年   1718篇
  2005年   1854篇
  2004年   1764篇
  2003年   1683篇
  2002年   1571篇
  2001年   1206篇
  2000年   1275篇
  1999年   1118篇
  1998年   452篇
  1997年   319篇
  1996年   324篇
  1995年   290篇
  1994年   245篇
  1993年   259篇
  1992年   768篇
  1991年   705篇
  1990年   675篇
  1989年   735篇
  1988年   645篇
  1987年   608篇
  1986年   549篇
  1985年   523篇
  1984年   342篇
  1983年   288篇
  1979年   262篇
  1978年   187篇
  1977年   164篇
  1974年   161篇
  1973年   167篇
  1972年   170篇
  1971年   157篇
  1970年   156篇
  1969年   145篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
International Journal of Clinical Oncology - The practice of cancer diagnosis disclosure to children has been changed with the times. The regulations of clinical trials in the 2000s might change...  相似文献   
2.

Background

Photosensitizers used for photodynamic therapy (PDT) to treat dermatologic disease are metabolized into mainly protoporphyrin IX (PpIX), which has five absorption wavelength peaks: 410?nm, 510?nm, 545?nm, 580?nm, and 630?nm. Although only red light around 635?nm and blue light around 400?nm are used as light sources for PDT, the efficiency of PDT might be improved by using multiple wavelengths, including those that correspond to the other absorption peaks of PpIX. Furthermore, because the target disease often occurs on the face, a flexible-type light-source unit that can be fitted to the lesion without unnecessarily exposing the mucous membranes, e.g., the eyes, nostrils, and mouth, is preferred.

Objective

We investigated the efficacy of a flexible light-emitting diode (LED) unit that emits multiple wavelengths to improve PDT effects.

Methods

HaCaT cells were incubated with 5-ALA and subsequently irradiated with either a single wavelength or sequentially with two wavelengths. Cell viability and reactive oxygen species were analyzed. Nude mice were implanted with COLO679 cells by subcutaneous injection into the flank. 5-ALA was subcutaneously injected into the tumor. The tumor was irradiated with 50?J/cm2 (day 0) and assessed daily until day 21.

Results

The synergistic PDT effects of dual-wavelength irradiation and reactive oxygen species production were highest with the 405-nm and 505-nm wavelength combination. This dual wavelength combination was also the most effective in vivo.

Conclusion

We could therefore conclude that dual-wavelength PDT is an efficient strategy for improving the therapeutic effects of PDT. Using a flexible LED unit is expected to achieve more uniform irradiation of uneven areas.  相似文献   
3.
4.
5.
6.
7.
8.
Burning mouth syndrome (BMS) is a chronic oro‐facial pain disorder of unknown cause. It is more common in peri‐ and post‐menopausal women, and sex hormone dysregulation is believed to be an important causative factor. Psychosocial events often trigger or exacerbate symptoms, and persons with BMS appear to be predisposed towards anxiety and depression. Atrophy of small nerve fibres in the tongue epithelium has been reported, and potential neuropathic mechanisms for BMS are now widely investigated. Historically, BMS was thought to comprise endocrinological, psychosocial and neuropathic components. Neuroprotective steroids and glial cell line–derived neurotrophic factor family ligands may have pivotal roles in the peripheral mechanisms associated with atrophy of small nerve fibres. Denervation of chorda tympani nerve fibres that innervate fungiform buds leads to alternative trigeminal innervation, which results in dysgeusia and burning pain when eating hot foods. With regard to the central mechanism of BMS, depletion of neuroprotective steroids alters the brain network–related mood and pain modulation. Peripheral mechanistic studies support the use of topical clonazepam and capsaicin for the management of BMS, and some evidence supports the use of cognitive behavioural therapy. Hormone replacement therapy may address the causes of BMS, although adverse effects prevent its use as a first‐line treatment. Selective serotonin reuptake inhibitors (SSRIs) and serotonin and noradrenaline reuptake inhibitors (SNRIs) may have important benefits, and well‐designed controlled studies are expected. Other treatment options to be investigated include brain stimulation and TSPO (translocator protein 18 kDa) ligands.  相似文献   
9.
Objective: Induction chemoradiotherapy followed by anatomical resection is a current therapeutic strategy for non-small-cell lung cancer with mediastinal node involvement. Dense peritracheal fibrosis and sclerosis after chemoradiotherapy cause difficult mediastinal node dissection. We evaluated a novel technique to make the mediastinal node dissection easier after induction therapy. Methods: At the end of mediastinoscopic node biopsy for staging of lung cancer, cotton-type collagen was inserted anterior and lateral to the trachea in patients with pathologically confirmed mediastinal node involve-ment (n=45). The induction therapy consisted of concurrent use of platinum-based chemotherapy and hyperfractionated radiotherapy. After the chemoradiotherapy all patients underwent a pulmonary resection with complete mediastinal node dissection 7–12 weeks after the collagen insertion. Surgical findings of the mediastinum and the time for node dissection were compared with those without collagen insertion at mediastinoscopy after chemoradiotherapy (n=5). Results: All five patients without collagen insertion showed sclerotic and fibrotic change of mediastinal nodes with severe adhesion to the trachea. In 42 of 45 patients with collagen insertion (93.3%) the collagen remained unabsorbed and separated the mediastinal nodes from the trachea. Mediastinal node dissection was easily accomplished by removing mediastinal tissues lateral and anterior to the collagen. The rate of mediastinal node separation was significantly higher with collagen insertion than without (p< 0.0001). The times for node dissection in patients with and without collagen insertion showed no significant difference. Conclusion: Cotton-type collagen insertion at staging mediastinoscopy for lung cancer separates the mediastinal nodes from the trachea and makes the node dissection easier after induction chemoradiotherapy.  相似文献   
10.
Aim: Older residents in Japan requiring rehabilitation often reside in health‐care facilities for the elderly (HCFE) prior to being discharged to home. The return home can be very stressful for both the elder and family caregiver. The purpose of this study was to clarify the differences in plans for home life between the residents of a HCFE who were scheduled for discharge home and their family caregivers. Method: Semistructured interviews were conducted with eight pairs of elders and caregivers. Results: Differences were seen in several areas, including dietary preferences, recognition of the elder’s independence, preconceptions or not knowing about the elder’s pleasurable activities, and the way of care. Conclusions: Differences with regard to enjoyable activities for the elderly arose from a lack of understanding of the lives of the elderly on the part of their families.  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