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   192091篇
  免费   32633篇
  国内免费   2724篇
耳鼻咽喉   5578篇
儿科学   6264篇
妇产科学   2850篇
基础医学   8633篇
口腔科学   2186篇
临床医学   29054篇
内科学   57871篇
皮肤病学   8378篇
神经病学   17772篇
特种医学   8016篇
外科学   47873篇
综合类   403篇
现状与发展   72篇
一般理论   6篇
预防医学   8022篇
眼科学   4294篇
药学   3557篇
中国医学   176篇
肿瘤学   16443篇
  2024年   706篇
  2023年   4992篇
  2022年   1660篇
  2021年   3897篇
  2020年   6436篇
  2019年   2755篇
  2018年   8194篇
  2017年   7940篇
  2016年   9204篇
  2015年   9267篇
  2014年   16572篇
  2013年   17033篇
  2012年   7847篇
  2011年   8142篇
  2010年   11815篇
  2009年   15552篇
  2008年   8306篇
  2007年   6759篇
  2006年   9253篇
  2005年   6557篇
  2004年   5952篇
  2003年   4980篇
  2002年   5043篇
  2001年   4194篇
  2000年   3354篇
  1999年   3696篇
  1998年   4359篇
  1997年   4060篇
  1996年   3932篇
  1995年   3678篇
  1994年   2372篇
  1993年   2031篇
  1992年   1653篇
  1991年   1671篇
  1990年   1254篇
  1989年   1375篇
  1988年   1209篇
  1987年   1004篇
  1986年   1008篇
  1985年   847篇
  1984年   697篇
  1983年   637篇
  1982年   631篇
  1981年   548篇
  1980年   483篇
  1979年   387篇
  1978年   429篇
  1977年   472篇
  1975年   325篇
  1972年   333篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Two Janus-associated kinase inhibitors (JAKi) (initially ruxolitinib and, more recently, fedratinib) have been approved as treatment options for patients who have intermediate-risk and high-risk myelofibrosis (MF), with pivotal trials demonstrating improvements in spleen volume, disease symptoms, and quality of life. At the same time, however, clinical trial experiences with JAKi agents in MF have demonstrated a high frequency of discontinuations because of adverse events or progressive disease. In addition, overall survival benefits and clinical and molecular predictors of response have not been established in this population, for which the disease burden is high and treatment options are limited. Consistently poor outcomes have been documented after JAKi discontinuation, with survival durations after ruxolitinib ranging from 11 to 16 months across several studies. To address such a high unmet therapeutic need, various non-JAKi agents are being actively explored (in combination with ruxolitinib in first-line or salvage settings and/or as monotherapy in JAKi-pretreated patients) in phase 3 clinical trials, including pelabresib (a bromodomain and extraterminal domain inhibitor), navitoclax (a B-cell lymphoma 2/B-cell lymphoma 2-xL inhibitor), parsaclisib (a phosphoinositide 3-kinase inhibitor), navtemadlin (formerly KRT-232; a murine double-minute chromosome 2 inhibitor), and imetelstat (a telomerase inhibitor). The breadth of data expected from these trials will provide insight into the ability of non-JAKi treatments to modify the natural history of MF.  相似文献   
6.
7.
8.
9.

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   
10.
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