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   1370篇
  免费   72篇
  国内免费   23篇
耳鼻咽喉   6篇
儿科学   15篇
妇产科学   93篇
基础医学   157篇
口腔科学   2篇
临床医学   220篇
内科学   233篇
皮肤病学   6篇
神经病学   123篇
特种医学   32篇
外科学   177篇
综合类   44篇
一般理论   1篇
预防医学   78篇
眼科学   17篇
药学   108篇
中国医学   28篇
肿瘤学   125篇
  2024年   1篇
  2023年   8篇
  2022年   26篇
  2021年   37篇
  2020年   20篇
  2019年   23篇
  2018年   51篇
  2017年   30篇
  2016年   24篇
  2015年   47篇
  2014年   60篇
  2013年   83篇
  2012年   124篇
  2011年   111篇
  2010年   57篇
  2009年   68篇
  2008年   105篇
  2007年   86篇
  2006年   79篇
  2005年   76篇
  2004年   54篇
  2003年   44篇
  2002年   35篇
  2001年   30篇
  2000年   37篇
  1999年   19篇
  1998年   10篇
  1997年   11篇
  1996年   8篇
  1995年   9篇
  1993年   5篇
  1992年   19篇
  1991年   10篇
  1990年   9篇
  1989年   9篇
  1988年   6篇
  1987年   8篇
  1986年   4篇
  1985年   4篇
  1984年   3篇
  1983年   8篇
  1982年   1篇
  1978年   3篇
  1977年   1篇
  1976年   1篇
  1974年   1篇
排序方式: 共有1465条查询结果,搜索用时 0 毫秒
991.
992.
Synthesis and antibacterial evaluation of certain quinolone derivatives.   总被引:12,自引:0,他引:12  
A number of 7-substituted quinolone derivatives were synthesized and evaluated for antibacterial and cytotoxic activities. Preliminary results indicated that most compounds tested in this study demonstrated better activity against methicillin-resistant Staphylococcus aureus than norfloxacin. Among them, 1-(4-amino-2-fluorophenyl)-6-fluoro-1,4-dihydro-7-[4-[2-(4-methoxyphenyl)-2-hydroxyiminoethyl]-1-piperazinyl]-4-oxo-3-quinolinecarboxylic acid (11d) and its ketone precursor 10d exhibited significant activities against Klebsiella pneumoniae, methicillin-resistant S. aureus, erythromycin- and ampicillin-resistant Streptococcus pneumoniae, and vancomycin-resistant Enterococcus faecalis. Due to strong cytotoxicities of 11d (a mean log GI(50) of -5.40), compound 10d, with good antibacterial activities and low cytotoxicities (a mean log GI(50) of -4.67), is a more potential drug candidate.  相似文献   
993.
994.
995.
996.
Recurrence of pressure ulcers following reconstructive surgery occurs frequently, causing a significant burden on the patient and the public health care system. We assessed risk factors for the recurrence of pressure ulcers based on the experience of a single surgeon at our medical centre. We retrospectively analysed patients admitted to our medical centre with stage III and IV pressure ulcers who underwent reconstructive surgery. The hospital database was searched for patients diagnosed with pressure ulcers who underwent reconstructive surgery. Patient characteristics analysed included age, sex, cause and location of defect, comorbidities, lesion size, wound reconstruction methods, operation time, debridement times, duration of hospital stay, and wound complications. Recurrence and mortality rates were retrospectively examined. One hundred and eighty-nine patients were enrolled, and 166 patients with 176 pressure ulcers met our inclusion criteria. All 14 recurrences (7.95%) were followed for at least 1 year. Logistic regression analysis indicated that recurrence was associated with albumin levels (P = 0.001) and wound size (P = 0.043); however, no association was found for body mass index, bacterial profile, comorbidities, localisation, previous surgery, operation time, or time to admission for reconstruction. In conclusion, higher albumin levels were associated with lower recurrence rates in patients who underwent reconstructive surgery.  相似文献   
997.
998.
The goal of this study was to determine the utility of submental ultrasound parameters in distinguishing difficult airway management from easy airway management. Forty-one adult patients who underwent elective surgery under general anesthesia with endotracheal intubation from March to December 2018 were included. We used submental ultrasound to measure tongue base thickness (TBT) in the midsagittal plane and the distance between lingual arteries (DLA) in the transverse dimension. The primary outcome was difficult laryngoscopy, and the secondary outcome was difficult mask ventilation. Receiver operating characteristic curve analysis and logistic regression revealed no correlation between difficult laryngoscopy and SMUS measurements. Nevertheless, patients with difficult mask ventilation had significantly higher TBT (p = 0.009) and longer DLA (p = 0.010). After adjustment of confounding factors, increased TBT (>69.6 mm) was the sole independent predictor of difficult mask ventilation. The results indicated that SMUS is effective in predicting difficult mask ventilation but not difficult laryngoscopy.  相似文献   
999.
Genital warts are a common sexually transmitted disease caused by human papillomavirus (HPV) infections. The prevalence of dementia is 4–8% in those aged 65 years or older in Taiwanese community studies, with a high social and economic burden for patients, family caregivers, the community and society. Previous studies have shown that viral infections such as herpes simplex and herpes zoster were associated with dementia. This study aimed to investigate the association between dementia and HPV infections. A population-based cohort study using data from Taiwan’s National Health Insurance Research Database was conducted. Fine and Grays’s survival analysis was employed to estimate the hazard ratios (HR) and 95% confidence intervals (CI) for the association between genital warts and dementia. From all of the potential participants aged 50 years or more, a total of 16 116 patients were enrolled, including 4029 genital warts-infected patients, with 12 087 sex-, age- and indexed date-matched controls (1:3). The cumulative incidences of dementia were 10.72 per 103 person-years and 6.43 per 103 person-years in the genital warts and control group, respectively. There were 475 dementia cases from the genital warts cohort during the follow-up period of 15 years. The adjusted HR for dementia was 1.485 (95% CI, 1.321–1.668; P < 0.001) for genital warts patients after adjusting for all of the covariates. Our study indicates that genital warts infection may increase the risk of dementia.  相似文献   
1000.
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