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   18593篇
  免费   1950篇
  国内免费   901篇
耳鼻咽喉   94篇
儿科学   826篇
妇产科学   104篇
基础医学   2175篇
口腔科学   317篇
临床医学   1285篇
内科学   6505篇
皮肤病学   143篇
神经病学   98篇
特种医学   610篇
外科学   1724篇
综合类   2923篇
现状与发展   3篇
预防医学   726篇
眼科学   145篇
药学   1921篇
  4篇
中国医学   1531篇
肿瘤学   310篇
  2024年   94篇
  2023年   412篇
  2022年   671篇
  2021年   828篇
  2020年   898篇
  2019年   839篇
  2018年   863篇
  2017年   896篇
  2016年   763篇
  2015年   837篇
  2014年   1137篇
  2013年   1369篇
  2012年   1124篇
  2011年   1194篇
  2010年   1022篇
  2009年   976篇
  2008年   1019篇
  2007年   988篇
  2006年   878篇
  2005年   747篇
  2004年   573篇
  2003年   446篇
  2002年   409篇
  2001年   348篇
  2000年   244篇
  1999年   232篇
  1998年   222篇
  1997年   170篇
  1996年   163篇
  1995年   122篇
  1994年   131篇
  1993年   93篇
  1992年   81篇
  1991年   65篇
  1990年   73篇
  1989年   42篇
  1988年   50篇
  1987年   58篇
  1986年   52篇
  1985年   53篇
  1984年   49篇
  1983年   20篇
  1982年   48篇
  1981年   34篇
  1980年   25篇
  1979年   16篇
  1978年   16篇
  1977年   15篇
  1976年   13篇
  1974年   9篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Iron overload and liver fibrosis   总被引:1,自引:0,他引:1  
  相似文献   
32.
To clarify the histological status of the pancreas tail after pancreatoduodenectomy (PD), fibrosis, islets of Langerhans, and A, B, and D cells were examined histometrically in surgical cases of pancreatic cancer. The same investigations were also performed during an autopsy examination of the pancreas tail of survivors of surgery who had received either PD or total pancreatectomy with segmental autotransplantation (SAT). In the surgical cases, fibrosis and the islet percentage compared with nonpancreatic cancer cases were significantly higher while the B cell ratio was significantly lower. In addition, in pancreatic cancer patients, the fibrosis and islet ratio in the group with a blocked pancreatic duct were higher while the B cell ratio was lower than in the group with an open pancreatic duct. A direct relationship between the islet ratio and the degree of fibrosis, and an inverse relationship between the B cell ratio and the degree of fibrosis, were thus found. From the autopsy cases, the fibrosis progressed and the islet ratio increased following PD, but after SAT only the islet ratio increased compared to the time of surgery. The progression of fibrosis after PD thus suggests the presence of some problems in both the surgical method and postoperative management.  相似文献   
33.
Fourteen adult patients (mean age 22.5 years, range 18–35) with cystic fibrosis undertook nocturnal nasogastric feeding for a mean period of 14.7 (range 6–18) months consuming an average of 1042 ml of a high energy feed on five nights of each week. Following this protocol all patients gained weight (mean weight gain 5.4 kg, range 2–17). For the group as a whole, lung function remained stable during the period of feeding; however a significant correlation between improvement in lung function and weight gain was demonstrated. Hyperglycaemia during feeding in this adult population was common (9/14, 64%) but was easily controlled with insulin therapy.  相似文献   
34.
目的 :探讨各种肝病患者血清肝纤维化标志的改变 ,甘草酸二胺注射液对肝脏炎症、纤维化指标的作用。方法 :用放免法检测透明质酸 (HA)、层粘蛋白 (LN)、Ⅲ型前胶原多肽 (PCⅢ )。结果 :急性肝炎的三种肝纤指标均升高 (P <0 0 5 )。急黄肝高于急无黄肝 (P <0 0 5 )。慢性肝炎 1 1 2例 ,三项肝纤指标显著高于正常对照 (P <0 0 5 )。慢肝重度显著高于慢肝轻度 (P<0 0 0 1 )。肝硬化的三项肝纤指标又显著高于慢肝 (P <0 0 0 1 ) ,其它肝病的肝纤指标也升高。 2 5例慢肝用甘草酸二胺注射液治疗 2月 ,ALT、AST、GGT显著降低 (P <0 0 1 )。三项肝纤指标中HA降低较显著 (P =0 0 5 ) ,LN和PCⅢ虽有降低 ,但差异不明显 (P =0 4 5 9,P =0 1 92 )。结论 :各种肝病的三项肝纤维化指标均升高 ,以慢肝重度 ,肝硬化升高明显。甘草酸二胺注射液治疗有抗炎及改善肝纤维化的作用  相似文献   
35.
36.
BACKGROUND: Assessment of nutritional status in children with cystic fibrosis (CF) is clinically relevant. Methods to measure nutritional status should be reliable and non-invasive, and reference values should be available. AIM: To compare weight and height measurements and measurements of specific body compartments in children with CF. METHODS: In a cross-sectional survey of 58 children with CF (28 females), we compared height and weight (expressed as: weight-for-height, body mass index (BMI), height-for-age and weight-for-age) with fat mass (skinfold sum (SFS)), muscle mass (upper arm circumference (UAC)) and bioelectrical impedance analysis (BIA). Results were expressed as Z-scores, using Dutch reference values. RESULTS: BMI and weight-for-height were within the normal range (mean Z-score (range): -0.13 (-1.5, 2.7) and -0.02 (-1.7, 2.8)). Weight and height corrected for age were below normal (mean Z-score (range): -0.79 (-2.4, -0.05) and -1.2 (-2.8, 1.4) (P<0.01)). Lean body mass by skinfold sum (LBM(sfs)), UAC and BIA were also significantly below reference values (mean Z-score (range): -0.9 (-2.2, 1.8), -0.95 (-2.4, 1.8) and -1.1 (-3.6, 1.0) (P<0.01)). Lean body mass (LBM) by BIA correlated with LBM(sfs). BIA systematically underestimated LBM in both CF patients and in control subjects. CONCLUSION: Nutritional status of children with CF must be evaluated, using age-corrected weight and height expressed in Z-score. LBM estimated by SFS, UAC and by BIA appear to be useful, although longitudinal studies in CF children should be performed to evaluate their clinical significance in detecting changes in nutritional status.  相似文献   
37.
Fifty mothers and 44 well siblings of children and adolescents with cystic fibrosis (CF) participated in this study to identify correlates of maternal well-being. Participants completed postal questionnaires which assessed maternal well-being, problems experienced surrounding the illness and treatment and the nature of the sibling relationship. Due to the demanding nature of treatment and the fact that CF is both genetic and incurable at present we anticipate mothers of these children will experience higher levels of stress and consequently poorer well-being than the normal population. In addition, illness severity, problems with adherence to treatment, child communication, maternal support and the sibling relationship are expected to relate to maternal well-being. Mothers in this sample did not rate their well-being as any different to the normal population. Results suggest that mothers are likely to rate their own well-being as poor when they report more frequent problems surrounding the illness and treatment and well children rate their sibling relationship as having frequent disagreements and aggression. This study highlights factors that are related to maternal well-being in families where one child has CF. These mothers as a group do not appear to be experiencing more stress in their daily lives than the normal population but certain illness and family variables are related to their well-being when examining the mothers on certain dimensions.  相似文献   
38.
(Received for publication on Nov. 14, 1996; accepted on May 12, 1997)  相似文献   
39.
Summary Four hundred and seventy villagers of Ndombo, a village with recently established intensive transmission of Schistosoma mansoni in the Senegal River Basin, were enrolled in a study with the intention to assess hepatosplenic morbidity. All patients were examined parasitologically and by ultrasound. Hepatic fibrosis serum markers were determined in 153 adult patients (aminoterminal propeptide of procollagen type III, hyaluronan and laminin). By ultrasound, about 60% of the patients showed early stages of hepatic involvement, 3% of the patients unequivocally showed severe hepatosplenic pathology (grade 3 according to the Managil classification), whereas in another study performed in the same village 3 years earlier, no patients with severe hepatosplenic pathology had been found. No correlation between the aminoterminal propeptide of procollagen type III, hyaluronan or laminin and the ultrasound findings could be established. These hepatic fibrosis serum markers do not seem to be a sensitive method to detect early hepatic fibrosis in schistosomiasis.  相似文献   
40.
目的探讨SNHG6对急性心肌梗死(AMI)小鼠左心室心肌的影响。 方法将30只雄性C57/BL6小鼠构建成AMI小鼠后随机均分为AMI组、AMI+SNHG6组、AMI+miR-101-3p组、AMI+SNHG6+miR-101-3p组、AMI+miR-101-3p+TGFBR1组,另设正常小鼠6只为假手术组。qRT-PCR检测AMI小鼠SNHG6、miR-101-3p表达水平。心脏彩超检测各组小鼠左室射血分数(LVEF);马松和天狼星红染色法以及免疫组化分析各组小鼠左心室心肌纤维化变化。将H9C2细胞株分为阴性对照组(转染空质粒)、SNHG6组(转染质粒SNHG6)、miR-101-3p组(转染质粒miR-101-3p)。Western blotting检测各组TGFBR1蛋白表达;采用双荧光素酶报告基因法预测并验证SNHG6/miR-101-3p/TGFBR1荧光素酶活性及调控机制。 结果AMI小鼠较假手术组SNHG6表达显著增加,miR-101-3p降低(P<0.05)。与AMI组比较,AMI+SNHG6组小鼠LVEF降低,心肌纤维化程度加重(P<0.05);AMI+miR-101-3p组LVEF升高,心肌纤维化程度减轻(P<0.05)。AMI+SNHG6+miR-101-3p组较AMI+SNHG6组LVEF升高、心肌纤维化程度减轻(P<0.05),而AMI+miR-101-3p+TGFBR1组较AMI+miR-101-3p组LVEF降低、心肌纤维化程度加重(P<0.05)。双荧光素酶报告基因法验证显示,miR-101-3p组SNHG6、TGFBR1野生型质粒的荧光素酶活性较阴性对照组明显降低(P<0.05)。 结论SNHG6抑制miR-101-3p上调TGFBR1加重AMI小鼠左心室心肌纤维化。  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