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   182篇
  免费   8篇
  国内免费   7篇
儿科学   6篇
基础医学   17篇
口腔科学   4篇
临床医学   23篇
内科学   54篇
皮肤病学   1篇
神经病学   4篇
特种医学   6篇
外科学   7篇
综合类   10篇
预防医学   10篇
药学   34篇
中国医学   6篇
肿瘤学   15篇
  2023年   2篇
  2021年   16篇
  2020年   6篇
  2019年   5篇
  2018年   7篇
  2017年   5篇
  2016年   1篇
  2015年   1篇
  2014年   8篇
  2013年   5篇
  2012年   19篇
  2011年   11篇
  2010年   7篇
  2009年   12篇
  2008年   12篇
  2007年   14篇
  2006年   15篇
  2005年   3篇
  2004年   10篇
  2003年   6篇
  2002年   1篇
  2001年   2篇
  1999年   2篇
  1997年   1篇
  1996年   1篇
  1992年   1篇
  1990年   3篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1985年   1篇
  1983年   1篇
  1980年   1篇
  1979年   1篇
  1978年   2篇
  1977年   2篇
  1976年   1篇
  1975年   1篇
  1974年   3篇
  1969年   1篇
  1967年   1篇
  1965年   2篇
排序方式: 共有197条查询结果,搜索用时 234 毫秒
1.
2.
3.
4.
BACKGROUNDRecurrent acute pancreatitis (RAP) may be a presenting feature of and an indication for resection of pancreatic cysts, including intra-ductal papillary mucinous neoplasm (IPMN). Few data are available regarding the prevalence of malignancy and post-operative RAP in this population.AIMTo study the role of resection to help prevent RAP and analyze if presentation as RAP would be a predictor for malignancy.METHODSThis retrospective study assessed 172 patients who underwent surgical resection of pancreatic cystic neoplasms at a university hospital between 2002 and 2016. The prevalence of preoperative high-risk cyst features, and of neoplasia was compared between patients with and without RAP. To identify the cause of pancreatitis, all the patients had a detailed history of alcohol, smoking, medications obtained, and had cross-sectional imaging (contrast-enhanced computed tomography/magnetic resonance imaging) and endoscopic ultrasound to look for gallstone etiology and other structural causes for pancreatitis. The incidence of RAP post-resection was the primary outcome.RESULTSIPMN accounted for 101 cases (58.7%) {[branch duct (BD) 59 (34.3%), main duct (MD) 42] (24.4%)}. Twenty-nine (16.9%) presented with RAP (mean 2.2 episodes): 15 had BD-IPMN, 8 MD-IPMN, 5 mucinous cystic neoplasm and 1 serous cystic neoplasm. Malignancy was similar among those with vs without RAP for all patients [6/29 (20.7%) vs 24/143 (16.8%)] and IPMN patients [6/23 (26.1%) vs 23/78 (29.5%)], although tended to be higher with RAP in BD-IPMN, [5/15 (33.3%) vs 3/44 (6.8%), P = 0.04]. At mean follow-up of 7.2 years, 1 (3.4%) RAP patient had post-resection RAP. The mean episodes of acute pancreatitis before vs after surgery were 3.4 vs 0.02 (P < 0.0001). CONCLUSIONMalignancy was not increased in patients with pancreatic cystic neoplasms who have RAP compared to those without RAP. In addition, specific cyst charac-teristics were not clearly associated with RAP. The incidence of RAP was markedly decreased in almost all patients following cyst resection.  相似文献   
5.
The correlation between 2 predictors of vascular events, plasma fibrinogen and serum lipoprotein (a), was evaluated in patients referred to a specialist clinic because of primary hyperlipidemia. A significant correlation existed between fibrinogen and lipoprotein (a) in nonsmokers but not in smokers. Plasma fibrinogen concentration correlated positively and significantly with serum lipoprotein (a) levels in men nonsmokers without cardiovascular disease and in women nonsmokers with cardiovascular disease. Nonsmoker women without cardiovascular disease had significantly higher plasma fibrinogen (3.63 g/L versus 3.07 g/L, P < .0001) than the corresponding men. Nonsmoker women with and without cardiovascular disease had significantly higher lipoprotein (a) levels than the corresponding groups of men (0.36 versus 0.18 g/L; P = .0015 and 0.40 versus 0.26 g/L; P = .008), respectively. The relationship between fibrinogen and lipoprotein (a) levels alters markedly depending on the population selected. This relationship is influenced by gender, the presence of cardiovascular disease and smoking status.  相似文献   
6.
Glutathione-S-transferases (GSTs) not only show cytoprotective role and their involvement in the development of anticancer drug resistance, but also transmit signals that control cell proliferation and apoptosis. However, the role of GST isoforms in chemotherapy resistance remains elusive in pancreatic cancer. Here, we demonstrated that gemcitabine treatment increased the GSTM2 expression in pancreatic cancer cell lines. Knockdown of GSTM2 by siRNA elevated apoptosis and decreased viability of pancreatic cancer cells treated with gemcitabine. Moreover, in vivo experiments further showed that shRNA induced GSTM2 downregulation enhanced drug sensitivity of gemcitabine in orthotopic pancreatic tumor mice. We also found that GSTM2 levels were lower in tumor tissues than in non-tumor tissues and higher GSTM2 expression was significantly associated with longer overall survival. In conclusion, our findings indicate that GSTM2 expression is essential for the survival of pancreatic cancer cells undergoing gemcitabine treatment and leads to chemo resistance. Downregulation of GSTM2 in pancreatic cancer may benefit gemcitabine treatment. GSTM2 expression in patients also shows significant correlation with overall survival. Thus, our study suggests that GSTM2 is a potential target for chemotherapy optimization and prognostic biomarker of pancreatic cancer.  相似文献   
7.
8.
The antioxidant activity and the membrane effects of linear furanocoumarin marmesinin isolated from Aegle marmelose was evaluated during experimental myocardial injury. Isoproterenol (150 mg kg(-1) intraperitonially twice at an interval of 24 h) caused increase in the levels of serum marker enzymes via creatinekinase (CK), creatinekinase-MB (CK-MB) isoenzyme, lactatedehydrogenase (LDH) and lactatedehydrogenase isoenzyme (LDH1). It also produced electrocardiographic changes such as increased heart rate, reduced R amplitude and ST elevation. Marmesinin at a dose of 200 mg kg(-1), when administered orally, demonstrated a decrease in serum enzyme levels and restored the electrocardiographic changes towards normalcy. Myocardial injury was accompanied by the disintegration of lipidperoxides and the impairment of natural scavengers. Marmesinin oral treatment for 2 days before and during isoproterenol administration decreased the effect of lipidperoxidation. It was also shown to have a membrane stabilizing action by inhibiting the release of beta-glucuronidase from the subcellular fractions. Thus, linear furanocoumarin marmesinin could have the protective effect against the damage caused by experimental myocardial injury.  相似文献   
9.
Context: Ulva lactuca Linnaeus (Chlorophyceae), a commonly distributed seaweed, is rich in polysaccharide but has not been studied extensively.

Objective: The present study investigated the effects of crude fraction of Ulva lactuca polysaccharide (ULP) on d-galactosamine (d-Gal)-induced DNA damage, hepatic oxidative stress, and necrosis in rats.

Materials and methods: The rats were treated with ULP (100?mg/kg, orally) for 4 weeks before a single intraperitoneal injection of d-Gal (500?mg/kg). In addition to liver cell necrosis and DNA damage, antioxidant parameters, such as lipid peroxide (LPO), superoxide dismutase, and catalase, and histopathology of liver tissue were evaluated.

Results: ULP pre-treatment significantly attenuated a d-Gal-induced decrease in DNA and RNA levels (3.67?±?0.38) and (5.42?±?0.46), respectively. Comet tail length and acridine staining confirmed the number of cells undergoing necrosis were relatively lower in ULP treated rats (30?µm and 8–10% of counted cells) compared to rats treated with d-Gal (60?µm and 16% of counted cells). Biochemical (LPO, SOD and CAT) and histological evaluation (p?d-Gal-induced elevation of LPO and infiltration of inflammatory cells into liver tissue.

Discussion and conclusion: Although our previous studies have reported on the protective role of ULP against liver toxicity, our present findings show that ULP improved the hepatic antioxidant defense system against d-Gal-induced DNA damage and necrosis in rats.  相似文献   
10.
Obtaining growth and physiologic data in the postnatal laboratory animal is common. However, monitoring growth in utero is far more difficult, with little data available except upon termination of pregnancy. High-resolution ultrasound was used to monitor growth, morphology, and fetal well-being in normotensive and hypertensive rabbits (21 fetuses) at day 16, 20, and 26 of the 32 day gestational period. Set protocols, comparable to those routinely assessed in humans, were devised and followed for each examination. Birth weight was greater in offspring of hypertensive as compared to normotensive mothers (p < 0.001); however, litter size was reduced. The greater birth weight was reflected in growth parameters measured throughout gestation indicating the predictive value of ultrasound. High-resolution ultrasound was a reliable and sensitive method for biometric and morphologic assessment of the fetal rabbit, demonstrating that growth trajectory of offspring of hypertensive mothers may be altered early in gestation.  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