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   910篇
  免费   54篇
  国内免费   12篇
耳鼻咽喉   3篇
儿科学   30篇
妇产科学   11篇
基础医学   93篇
口腔科学   34篇
临床医学   78篇
内科学   173篇
皮肤病学   8篇
神经病学   106篇
特种医学   97篇
外科学   157篇
综合类   51篇
预防医学   18篇
眼科学   3篇
药学   87篇
中国医学   3篇
肿瘤学   24篇
  2022年   5篇
  2021年   9篇
  2020年   5篇
  2019年   13篇
  2018年   8篇
  2017年   6篇
  2016年   13篇
  2015年   15篇
  2014年   24篇
  2013年   17篇
  2012年   34篇
  2011年   38篇
  2010年   27篇
  2009年   23篇
  2008年   41篇
  2007年   39篇
  2006年   35篇
  2005年   23篇
  2004年   28篇
  2003年   29篇
  2002年   22篇
  2001年   29篇
  2000年   30篇
  1999年   25篇
  1998年   39篇
  1997年   27篇
  1996年   27篇
  1995年   14篇
  1994年   22篇
  1993年   19篇
  1992年   27篇
  1991年   21篇
  1990年   29篇
  1989年   28篇
  1988年   30篇
  1987年   17篇
  1986年   22篇
  1985年   16篇
  1984年   8篇
  1983年   5篇
  1982年   6篇
  1981年   7篇
  1980年   7篇
  1978年   6篇
  1977年   7篇
  1976年   4篇
  1975年   6篇
  1974年   4篇
  1968年   4篇
  1937年   4篇
排序方式: 共有976条查询结果,搜索用时 0 毫秒
1.
2.
Erratum     
The online version of the original article can be found at  相似文献   
3.
Effects of intravenously administered dyes on pulse oximetry readings   总被引:6,自引:0,他引:6  
  相似文献   
4.
STUDY OBJECTIVE: To determine the increase in flow of a hydratable enlarging intravenous (IV) catheter in anesthetized patients. DESIGN: A randomized, nonblinded study, with standard Teflon IV catheters used as controls. SETTING: Operating room at a university medical center. PATIENTS: Thiry adult patients receiving general anesthesia for lower extremity surgery. INTERVENTIONS: An IV catheter was placed in the upper extremity, and flow measurements were made by measuring the time for infusion of 250 ml of normal saline within 1 minute after placement and at 1 hour after placement. MEASUREMENTS AND MAIN RESULTS: The enlarging catheters had a statistically significant average flow increase of 26% after 1 hour indwelling time. The standard Teflon catheters had no statistically significant change in flow after 1 hour. The percentage increase in flow for the enlarging catheters was not as great as previously seen in vitro. CONCLUSIONS: Flow through enlarging IV catheters placed in anesthetized patients increases after 1 hour. The percentage increase in flow is not as great as previously seen in vitro and may be due to skin, vein, and subcutaneous tissues preventing complete expansion.  相似文献   
5.
6.
The incidence (%) of hyperbilirubinemia (serum bilirubin ≥257 μmol/l) was similar in neonates with a combination of ABO incompatibility and glucose-6-phosphate dehydrogenase (G-6-PD) deficiency (45%), with ABO incompatibility (54%) or G-6-PD deficiency (37%), alone (ns). Carboxyhemoglobin values, corrected for inspired CO, were similarly elevated in all three groups (0.87 ± 0.32%, 0.82 ± 0.29%, 0.76 ± 0.18%, respectively, ns), but correlated with bilirubin only in those with ABO incompatibility alone. ABO-incompatible/G-6-PD-deficient neonates, compared with those with either condition alone, are not at increased risk for hemolysis or hyperbilirubinemia.  相似文献   
7.
8.
9.
10.
CXC chemokines modulate host immunity, neovascularization, growth and invasive behaviour of tumours. Despite their relevance in tumour biology, chemokine expression in intestinal- and diffuse-type gastric carcinoma, which exhibit a completely different growth pattern, has not been investigated in detail. In this study, expression of the CXC chemokines CXCL8 [interleukin (IL)-8], CXCL1 [growth-related oncogene alpha (Gro alpha)], CXCL9 [monokine induced by interferon (IFN)-gamma] and CXCL10 [IFN-gamma-inducible protein-10 (IP-10)] and the corresponding chemokine receptors CXCR1-3 was investigated by immunohistochemistry in intestinal- and diffuse-type gastric carcinoma. Tumour cells of all patients expressed CXCL8. CXCL8 expression was significantly stronger in tumour cells of diffuse- rather than intestinal-type gastric carcinoma (P < 0.01) as determined by a semiquantitative score. CXCL1 was expressed almost exclusively by diffuse- but not intestinal-type carcinoma cells. The corresponding chemokine receptors, CXCR1 and CXCR2, were found on carcinoma cells. Furthermore, CXCL8 expression correlated with number of tumour vessels (P < 0.01), suggesting an angiogenetic function in gastric carcinoma not only in vitro but also in vivo. CXCL10 and CXCL9, attractants for T cells, were expressed by peritumorous macrophages in close proximity to IFN-gamma-producing CXCR3-positive T cells in both tumour types. These chemokines may attract gastric carcinoma-infiltrating T cells via an IFN-gamma-mediated pathway and enhance host immunity against the tumour. In gastric carcinoma a complex interplay between CXC-chemokine signals derived from both tumour cells and tumour-infiltrating immune cells may exhibit pleiotropic effects in tumour biology that go far beyond their originally described functions as leucocyte chemoattractants. Because CXCL8 and CXCL1, which are known to increase growth and invasive behaviour of malignant tumours, are significantly stronger expressed in diffuse- than intestinal-type gastric carcinoma, one may speculate that these chemokines influence the different growth pattern of gastric carcinoma types.  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