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   171篇
  免费   17篇
  国内免费   2篇
儿科学   7篇
妇产科学   12篇
基础医学   28篇
临床医学   16篇
内科学   53篇
神经病学   9篇
外科学   13篇
综合类   8篇
预防医学   4篇
眼科学   1篇
药学   8篇
肿瘤学   31篇
  2023年   3篇
  2022年   2篇
  2021年   6篇
  2020年   3篇
  2019年   10篇
  2018年   6篇
  2017年   1篇
  2016年   6篇
  2015年   9篇
  2014年   9篇
  2013年   15篇
  2012年   12篇
  2011年   18篇
  2010年   10篇
  2009年   9篇
  2008年   8篇
  2007年   7篇
  2006年   9篇
  2005年   4篇
  2004年   4篇
  2003年   2篇
  2001年   3篇
  2000年   3篇
  1999年   4篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1990年   2篇
  1989年   3篇
  1988年   2篇
  1987年   2篇
  1983年   1篇
  1980年   1篇
  1969年   1篇
  1968年   1篇
  1967年   1篇
  1966年   1篇
  1960年   1篇
  1954年   1篇
  1945年   1篇
  1933年   1篇
  1929年   1篇
  1927年   1篇
  1925年   1篇
  1924年   1篇
排序方式: 共有190条查询结果,搜索用时 15 毫秒
11.
As health care continues to change and evolve in a digital society, there is an escalating need for physicians who are skilled and enabled to deliver care using digital health technologies, while remaining able to successfully broker the triadic relationship among patients, computers and themselves. The focus needs to remain firmly on how technology can be leveraged and used to support good medical practice and quality health care, particularly around resolution of longstanding challenges in health care delivery, including equitable access in rural and remote areas, closing the gap on health outcomes and experiences for First Nations peoples and better support in aged care and those living with chronic disease and disability. We propose a set of requisite digital health competencies and recommend that the acquisition and evaluation of these competencies become embedded in physician training curricula and continuing professional development programmes.  相似文献   
12.
Mouse zygotes were cultured in medium containing follicular fluid from patients who had follicles containing oocytes which fertilized, did not fertilize, or were atretic and who did or did not become pregnant after in vitro fertilization and embryo replacement. The inhibitory effect was least with the follicular fluid from follicies in which the oocytes subsequently fertilized, greater when the oocytes did not fertilize, and most inhibitory when the follicle contained an atretic oocyte. More mouse zygotes developed to blastocysts when culture medium was supplemented with follicular fluid from patients who became pregnant compared to those who did not become pregnant. There was no difference in pregnancy outcome when an oocyte which subsequently fertilized was obtained from the follicle. These results indicate that follicles contain a substance(s) which inhibits mouse zygote development in vitro and that the inhibitory activity is related to the developmental potential of the oocyte in the follicle.  相似文献   
13.
14.
Ionizing and nonionizing radiation affect not only directly targeted cells but also surrounding “bystander” cells. The underlying mechanisms and therapeutic role of bystander responses remain incompletely defined. Here we show that photosentizer activation in a single cell triggers apoptosis in bystander cancer cells, which are electrically coupled by gap junction channels and support the propagation of a Ca2+ wave initiated in the irradiated cell. The latter also acts as source of nitric oxide (NO) that diffuses to bystander cells, in which NO levels are further increased by a mechanism compatible with Ca2+-dependent enzymatic production. We detected similar signals in tumors grown in dorsal skinfold chambers applied to live mice. Pharmacological blockade of connexin channels significantly reduced the extent of apoptosis in bystander cells, consistent with a critical role played by intercellular communication, Ca2+ and NO in the bystander effects triggered by photodynamic therapy.  相似文献   
15.
16.
17.
Endoscopic ultrasound-guided fine needle aspiration is a multistep procedure that involves proper clinical indication, correct selection of needles, adapting evidence-based techniques such as the fanning maneuver and not routinely using suction or the stylet for tissue sampling, and establishing reliable cytopathology support. Integrating cytopathology in the training curriculum and developing a more flexible platform of needles and echoendoscopes are likely to further advance the field of endosonography. This review aims to summarize the technical issues that are key to performing high-quality endoscopic ultrasound-guided fine needle aspiration.  相似文献   
18.
19.
Growing tumors acquire the ability to resist immune recognition and immune-mediated injury. Among several mechanisms, mouse and human tumors share the ability to alter the normal hematopoiesis, leading to accumulation of cells of the myelo-monoctytic lineage at the tumor site and in different primary and secondary lymphoid organs. These cells aid tumor development by providing molecules and factors essential for tumor growth and neovascularization but also exert a profound inhibitory activity on both tumor-specific and nonspecific T lymphocytes. The present article summarizes recent findings on the interaction between developing cancers and these recently described "myeloid suppressor cells".  相似文献   
20.
OBJECTIVE(S): To determine how the type of embryo fragmentation on day 3 affects progression of human embryos to blastocyst and pregnancy rates following embryo transfer. STUDY DESIGN: Retrospective analysis of all in vitro fertilization cycles in patients < or =40 years of age or younger from January 2002 through December 2003, during which time surplus day 3 embryos were transferred to blastocyst medium for extended culture. All embryos (4 cells or more) not suitable for transfer or freezing 72 hours following in vitro fertilization were placed into microdroplets (60 microL) of blastocyst medium and cultured for an additional 48 hours to assess blastocyst formation. Normal blastocyst development required blastulation, a visible inner-cell mass, trophectoderm cells covering 60% of the inner zona surface and thinning of the zona. The rate of blastocyst formation was then analyzed (chi 2 and analysis of variance) against the type of fragmentation 72 hours after insemination. Pregnancy outcomes were analyzed with respect to the pattern of fragmentation in cleaving embryos transferred after 3 days of culture. RESULTS: A total of 1566 embryos were cultured beyond day 3 of development of which 229 (14.6%) reached the blastocyst stage and were frozen. Embryos exhibiting no fragmentation or type I fragmentation had significantly higher blastocyst development rates (27.9% and 19.9%) than embryos with type 2 or 3 fragmentation (13.9 and 8.8, respectively; P < .001). No embryos with type 4 or 5 fragmentation progressed to blastocyst. The average type of fragmentation in transferred embryos correlated with pregnancy outcome and embryo age. CONCLUSION(S): More pervasive embryo fragmentation was associated with a decreasing rate of blastocyst development with day 3 embryos. To the extent that blastocyst development rates of day 3 embryos is an index of embryo viability, our findings establish that careful classification of the type of embryo fragmentation is important in selection of day 3 embryos for transfer. Recent reports of associations among embryo fragmentation, aneuploidy, apoptosis, and patient age support these conclusions.  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