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   2909篇
  免费   265篇
  国内免费   197篇
耳鼻咽喉   22篇
儿科学   19篇
妇产科学   26篇
基础医学   323篇
口腔科学   18篇
临床医学   421篇
内科学   412篇
皮肤病学   24篇
神经病学   214篇
特种医学   93篇
外国民族医学   5篇
外科学   354篇
综合类   540篇
现状与发展   1篇
预防医学   142篇
眼科学   47篇
药学   286篇
  2篇
中国医学   137篇
肿瘤学   285篇
  2024年   10篇
  2023年   43篇
  2022年   123篇
  2021年   155篇
  2020年   132篇
  2019年   87篇
  2018年   83篇
  2017年   83篇
  2016年   83篇
  2015年   116篇
  2014年   161篇
  2013年   147篇
  2012年   178篇
  2011年   211篇
  2010年   136篇
  2009年   127篇
  2008年   143篇
  2007年   142篇
  2006年   152篇
  2005年   104篇
  2004年   93篇
  2003年   88篇
  2002年   59篇
  2001年   82篇
  2000年   61篇
  1999年   105篇
  1998年   48篇
  1997年   49篇
  1996年   49篇
  1995年   53篇
  1994年   28篇
  1993年   20篇
  1992年   27篇
  1991年   19篇
  1990年   28篇
  1989年   30篇
  1988年   25篇
  1987年   13篇
  1986年   16篇
  1985年   17篇
  1984年   4篇
  1983年   2篇
  1982年   5篇
  1981年   7篇
  1980年   5篇
  1979年   9篇
  1978年   2篇
  1975年   2篇
  1974年   2篇
  1966年   2篇
排序方式: 共有3371条查询结果,搜索用时 15 毫秒
71.
The Global Leadership Initiative on Malnutrition (GLIM) has achieved a consensus for the diagnosis of malnutrition in recent years. This study aims to determine the prognostic effect of the GLIM after cardiac surgery. A total of 603 patients in the training cohort and 258 patients in the validation cohort were enrolled in this study. Perioperative characteristics and follow-up data were collected. A nomogram based on independent prognostic predictors was developed for survival prediction. In total, 114 (18.9%) and 48 (18.6%) patients were defined as being malnourished according to the GLIM criteria in the two cohorts, respectively. Multivariate regression analysis showed that GLIM-defined malnutrition was an independent risk factor of total complication (OR 1.661, 95% CI: 1.063–2.594) and overall survival (HR 2.339, 95% CI: 1.504–3.637). The c-index was 0.72 (95% CI: 0.66–0.79) and AUC were 0.800, 0.798, and 0.780 for 1-, 2-, and 3-year survival prediction, respectively. The calibration curves of the nomogram fit well. In conclusion, GLIM criteria can efficiently identify malnutrition and has a prognostic effect on clinical outcomes after cardiac surgery. GLIM-based nomogram has favorable performance in survival prediction.  相似文献   
72.
Effective nutrition and exercise interventions may improve sarcopenia in the elderly. The purpose of our study was to investigate the effectiveness of Internet-based nutrition and exercise interventions in the elderly with sarcopenia. Participants were divided into 4 groups: control, nutrition, exercise, and comprehensive (nutrition plus exercise) groups; there was at least 50 participants in each group. Our trial lasted 12 weeks. We conducted dietary and exercise interventions through an app and collected feedback from the participants every three weeks. Information on the diet, skeletal muscle mass, and muscle function was collected before and after the interventions. The comprehensive group had higher high-quality protein intake than the control (p = 0.017) and exercise (p = 0.012) groups. After the interventions, we obtained differences in skeletal muscle mass, skeletal muscle mass/height2, skeletal muscle mass/weight, muscle mass/BMI, and skeletal muscle mass/body fat percentage (p < 0.05). Changes in average daily energy and total daily protein intakes were not significantly different; however, there was an overall improvement in the intervention groups relative to baseline data. There were no changes in the average daily time of moderate physical activity. The Internet was an effective tool of nutrition intervention in the elderly with sarcopenia. The Internet-based nutrition intervention improved high-quality protein intake and skeletal muscle mass in the elderly with sarcopenia.  相似文献   
73.
目的:通过对放疗疗程中不同时段CBCT图像的影像组学分析,寻找早期定量预测食管癌放疗放射性肺炎(RP)的参数,结合临床特征和肺剂量体积参数建立联合Nomogram模型并探讨这一模型对食管癌RP的预测价值。方法:回顾分析2017—2019年间临床资料、剂量学参数、CBCT图像资料完整的96例胸中段食管鳞癌调强放疗患者资料...  相似文献   
74.
建立糖尿病心肌病动物模型方法的实验研究   总被引:10,自引:0,他引:10  
目的研究建立糖尿病心肌病动物模型的科学、实用的方法。方法应用链脲佐菌素对SD大鼠进行一次性腹腔注射,通过观察大鼠的一般状况、进食量、进水量、尿量、体重的变化,监测血糖、尿糖、心肌酶含量、胰岛素水平、心肌超微结构、心脏大血管内膜情况及心电图情况来评估糖尿病心肌病的发病情况。结果腹腔注射STZ 3周后,模型组大鼠出现病态表现,进食量、饮水量、尿量增加,体重下降。血糖值、尿糖值及肌酸激酶、乳酸脱氢酶值均较对照组大鼠升高。胰岛素水平较对照组明显降低,心肌超微结构符合糖尿病心肌病表现,心脏大血管未见纤维斑块和粥样斑块。结论对SD大鼠进行一次性腹腔注射链脲佐菌素(55mg/kg),大鼠于注射后第3周可出现稳定的糖尿病心肌病状态。这是一种可靠且实用性强的糖尿病心肌病动物模型的制备方法。  相似文献   
75.
76.
臧丽丽  江瑞   《护理与康复》2021,20(6):27-30
目的 调查血液透析患者动静脉内瘘自我护理行为现状并分析其影响因素,为临床护理干预提供理论依据.方法 采用便利抽样法,选取湖州市某三级甲等医院血液透析行动静脉内瘘患者118例为调查对象,采用一般资料调查表及血液透析患者动静脉内痿自我护理行为量表进行调查,运用单因素分析及多元线性回归分析其自我护理行为影响因素.结果 血液透...  相似文献   
77.
Zhang Z  Liu S  Lin X  Teng G  Yu T  Fang F  Zang F 《Neuroradiology》2011,53(3):177-184

Introduction  

The purpose of this study is to show the condition of laminar organization on 3.0T and 7.0T postmortem magnetic resonance imaging (MRI) and analyze developmental changes.  相似文献   
78.
目的 探讨山羊颈椎次全切除减压非融合后生物力学特性.方法 选取成年雄性山羊6只造模(模型组),术前行颈椎X线检查,排除骨性结构异常,并测量节段性Cobb角(SCA)和颈椎Cobb角(CCA)于C4行颈椎次全切除术,并植入可动人工颈椎(ACV).术后行颈椎正侧位X线检查,再次测量SCA和CCA.术后6个月处死山羊,并以6...  相似文献   
79.
复方二氯苯醚菊脂灭蚊剂由二氯苯醚菊脂、巴沙等组成.复方二氯苯醚菊脂剂对蚊、蝇的杀灭效果较好,对人畜毒性较小,是值得推广的一种杀虫剂.  相似文献   
80.

Objective

To evaluate the effect of decoction prepared with Yang-activating and stasis-eliminating medicinals from Traditional Chinese Medicine (TCM) on the intestinal mucosal permeability in rats with ulcerative colitis induced by dextran sulfate sodium (DSS).

Methods

Totally 55 male Wistar rats (body weight of 170–190 g) were randomly divided into the blank group (n = 10) and the model duplication group (n = 45). The blank group was not intervened, while the other was modeled with 5% dextran sulfate sodium by gavaging in a dosage of 4 mL per day to induce ulcerative colitis, a total of 7 days. Then, the model rats were divided into model blank group, mesalazine group and TCM group, and each group was consisted of 15 rats. They were given retention enema 10 min with normal saline, mesalazine enema (0.036 g/mL), and Yang-activating and stasis-eliminating decoction [0.54 g/mL of a decoction boiled by Puhuang (Pollen Typhae), Xiebai (Bulbus Allii Macrostemonis) and Wulingzhi (Faeces Trogopteri)] for 10 days respectively. Afterwards, all of the rats were evaluated by disease activity index (DAI), histological changes of distal colon, expression of occludin protein and ultrastructure of intestinal epithelial cells. Furthermore, ratio of lactulose to mannitol (L/M) discharged in urine was evaluated.

Results

Comparing the results between TCM and model control groups, scores of DAI and histological lesions decreased significantly (P = 0.000 < 0.01), ultrastructures of intestinal epithelial cells and tight junctions were more complete. The expression of occludin protein (P = 0.001 < 0.01) increased while the L/M value decreased significantly (P = 0.000 < 0.01) in TCM group. There was no statistical difference between the TCM and mesalazine groups in results of each item (P > 0.05).

Conclusion

The decoction prepared with Yang-activating and stasis-eliminating TCM medicianls can restore intestinal mucosal epithelial cells and tight junctions the model rats with ulcerative colitis; it can reduce histological lesions and protect the permeability of intestinal mucosa barrier in the rats as well.  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