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   495篇
  免费   36篇
  国内免费   4篇
耳鼻咽喉   6篇
儿科学   20篇
妇产科学   11篇
基础医学   48篇
口腔科学   6篇
临床医学   36篇
内科学   115篇
皮肤病学   5篇
神经病学   44篇
特种医学   34篇
外科学   95篇
综合类   10篇
预防医学   22篇
眼科学   4篇
药学   43篇
中国医学   5篇
肿瘤学   31篇
  2023年   8篇
  2022年   6篇
  2021年   17篇
  2020年   7篇
  2019年   8篇
  2018年   22篇
  2017年   18篇
  2016年   12篇
  2015年   25篇
  2014年   18篇
  2013年   22篇
  2012年   30篇
  2011年   30篇
  2010年   20篇
  2009年   11篇
  2008年   16篇
  2007年   17篇
  2006年   23篇
  2005年   26篇
  2004年   12篇
  2003年   22篇
  2002年   19篇
  2001年   10篇
  2000年   14篇
  1999年   7篇
  1998年   4篇
  1997年   5篇
  1996年   7篇
  1995年   7篇
  1993年   4篇
  1992年   12篇
  1991年   5篇
  1990年   10篇
  1989年   9篇
  1988年   4篇
  1987年   4篇
  1986年   6篇
  1984年   4篇
  1983年   4篇
  1979年   2篇
  1976年   4篇
  1975年   2篇
  1974年   2篇
  1973年   4篇
  1972年   2篇
  1970年   3篇
  1969年   4篇
  1940年   1篇
  1935年   1篇
  1931年   1篇
排序方式: 共有535条查询结果,搜索用时 15 毫秒
11.
12.
13.

Background  

Purified water for pharmaceutical purposes must be free of microbial contamination and pyrogens. Even with the additional sanitary and disinfecting treatments applied to the system (sequential operational stages), Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were isolated and identified from a thirteen-stage purification system. To evaluate the efficacy of the chemical agents used in the disinfecting process along with those used to adjust chemical characteristics of the system, over the identified bacteria, the kinetic parameter of killing time (D-value) necessary to inactivate 90% of the initial bioburden (decimal reduction time) was experimentally determined.  相似文献   
14.
15.
BACKGROUND AND AIM OF THE STUDY: Clinical and echocardiographic results were investigated to evaluate mitral valve repair in patients undergoing coronary artery bypass grafting (CABG) for ischemic cardiomyopathy (ICM) with moderately severe mitral regurgitation (MR). METHODS: A total of 78 patients (21 women, 57 men; mean age 69.5 +/- 7.8 years) with ischemic mitral regurgitation underwent mitral valve repair and CABG. The mean left ventricular ejection fraction (LVEF) was 42.4 +/- 12.4%. Among the patients, 19 (24.4%) had preoperative congestive heart failure (CHF). This surgery constituted a second such operation in five patients (6.4%). The MR was grade 3+ in 28 patients (35.9%) and 4+ in 50 (64.1%). The mean number of grafts was 3.6 per patient. RESULTS: Hospital mortality was 11.5% (n = 9). Risk factors for early mortality were preoperative NYHA class > or = III (p = 0.014), preoperative heart failure (p <0.001) and reoperation (p = 0.002). The five-year survival was 82.6 +/- 5.9%, and freedom from grade > or =2+ MR was 93.1 +/- 4.1%. Postoperatively, 66 patients (89.6%) were in NYHA class I and seven (9.4%) in class II, demonstrating a statistically significant improvement (p = 0.03). Late echocardiography showed a significant improvement in LVEF (from 42.4 +/- 12.4% to 51.7 +/- 10.9%; p = 0.01) and a reduction in pulmonary artery pressure (from 37.6 +/- 11.9 mmHg to 29.3 +/- 7.4 mmHg; p = 0.004). CONCLUSION: It is concluded that in patients with ICM, mitral valve repair combined with CABG provides a dramatic improvement in ejection fraction and in CHF, with excellent long-term survival, even in patients with a low LVEF.  相似文献   
16.
目的 建立一种快速、灵敏的高效液相色谱-串联质谱(HPLC-MS/MS)方法以测定人血浆中对乙酰氨基酚浓度,并应用于两种对乙酰氨基酚制剂的人体药代动力学和生物等效性研究。方法 以替硝唑为内标,200μL血浆样品经5倍于其体积的乙酸乙酯液液萃取,再经Waters XBridge? C18柱等度洗脱分离后导入串联质谱,以正离子多反应监测模式进行定量分析,对乙酰氨基酚和内标的选择性反应离子对分别是m/z 152→110和248→121。方法经验证后应用于19名健康受试者单剂量空腹口服两种对乙酰氨基酚制剂500mg后药代动力学和生物等效性的研究。结果 血浆中对乙酰氨基酚在0.1~8.0 μg·mL-1范围内线性良好(r2 > 0.99),最低检测限为 0.1 μg·mL-1,提取回收率为91.0%~98.7%,日内和日间准确度分别为98.8%~111.3% (精密度:CV ? 9.03%)和94.9%~102.6% (精密度:CV ? 10.68%)。生物等效性试验中,受试制剂与参比制剂的主要药代动力学参数Cmax、AUC0-t和AUC0-∞ 几何均值比的90%置信区间分别为83.50%~105.79%,94.25%~101.54%和93.24%~101.02%,均落在生物等效可接受标准80.00%~125.00%范围内。结论 所建立测定人血浆中对乙酰氨基酚浓度的HPLC-MS/MS法具有快速灵敏、回收率高、选择性好的特点,适用于对乙酰氨基酚片人体药代动力学和生物等效性研究。受试制剂与参比制剂在人体内吸收速度和程度相似,两种制剂生物等效。  相似文献   
17.
18.
19.
Retinol-binding protein 4 (RBP4) is an adipocytokine associated with insulin resistance (IR). We tested serum levels of RBP4 to assess its link with steatosis in patients with genotype 1 chronic hepatitis C (CHC) or nonalcoholic fatty liver disease (NAFLD). Nondiabetic patients with CHC (n = 143) or NAFLD (n = 37) were evaluated by liver biopsy and anthropometric and metabolic measurements, including IR by the homeostasis model assessment. Biopsies were scored by Scheuer classification for CHC, and Kleiner for NAFLD. Steatosis was tested as a continuous variable and graded as absent-mild <30%, or moderate-severe > or =30%. Thirty nondiabetic, nonobese blood donors served as controls. RBP4 levels were measured by a human competitive enzyme-linked immunosorbent assay kit (AdipoGen). Mean values of RBP4 were similar in NAFLD and CHC (35.3 +/- 9.3 microg/L versus 36.8 +/- 17.6; P = 0.47, respectively), and both were significantly higher than in controls (28.9 +/- 12.1; P = 0.02 and P = 0.01, respectively). RBP4 was higher in CHC patients with steatosis than in NAFLD (42.1 +/- 19.7 versus 35.2 +/- 9.3; P = 0.04). By linear regression, RBP4 was independently linked to steatosis only (P = 0.008) in CHC, and to elevated body mass index (P = 0.01) and low grading (P = 0.04) in NAFLD. By linear regression, steatosis was independently linked to homeostasis model assessment score (P = 0.03) and high RBP4 (P = 0.003) in CHC. By logistic regression, RBP4 was the only variable independently associated with moderate-severe steatosis in CHC (odds ratio, 1.045; 95% confidence interval, 1.020 to 1.070; P = 0.0004), whereas waist circumference was associated with moderate-severe steatosis in NAFLD (odds ratio, 1.095; 95% confidence interval, 1.007 to 1.192; P = 0.03). CONCLUSION: In nondiabetic, nonobese patients with genotype 1 CHC, serum RBP4 levels might be the expression of a virus-linked pathway to steatosis, largely unrelated to IR.  相似文献   
20.
BACKGROUNDCoronavirus disease (COVID) is a new and highly contagious infectious disease caused by the coronavirus (COVID-19 or severe acute respiratory syndrome coronavirus 2). There is limited data regarding the incidence and management of COVID-19 in immunocompromised patients’ post-transplantation. In the pre-COVID-19 era, these patients were already at an increased risk of developing opportunistic infections. These often manifested with atypical symptoms.CASE SUMMARYWe report another case of uneventful COVID-19 pneumonia in a 58-year old male who was 18 mo’ post liver transplantation. He received tacrolimus monotherapy since July 2019. The clinical manifestations included only epigastric pain radiating to the right hypochondrium, nausea and vomiting. He had no fevers, cough, shortness of breath, anosmia or dysgeusia even if the chest computed tomography scan revealed an extension of the multiple patchy ground-glass density shadows to the upper lobe of the left lung too. He was hospitalised and received a course of oral chloroquine (200 mg × 3 per day) for a period of 10 d. Interestingly, the COVID 19 infection was uneventful though there were no modifications to his tacrolimus dosing. He was successfully discharged. We performed subsequent follow-up via telemedicine.CONCLUSIONIn light of the current pandemic, it is even more important to identify how the liver recipient’s patients present and are managed, especially for immunosuppression treatment.  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