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   2417篇
  免费   223篇
  国内免费   39篇
耳鼻咽喉   11篇
儿科学   93篇
妇产科学   39篇
基础医学   111篇
口腔科学   43篇
临床医学   423篇
内科学   390篇
皮肤病学   8篇
神经病学   152篇
特种医学   57篇
外科学   167篇
综合类   295篇
一般理论   4篇
预防医学   481篇
眼科学   16篇
药学   187篇
  12篇
中国医学   98篇
肿瘤学   92篇
  2024年   1篇
  2023年   48篇
  2022年   57篇
  2021年   112篇
  2020年   143篇
  2019年   127篇
  2018年   141篇
  2017年   117篇
  2016年   101篇
  2015年   93篇
  2014年   196篇
  2013年   249篇
  2012年   132篇
  2011年   138篇
  2010年   130篇
  2009年   114篇
  2008年   105篇
  2007年   113篇
  2006年   90篇
  2005年   85篇
  2004年   63篇
  2003年   55篇
  2002年   33篇
  2001年   45篇
  2000年   34篇
  1999年   27篇
  1998年   29篇
  1997年   13篇
  1996年   7篇
  1995年   15篇
  1994年   9篇
  1993年   14篇
  1992年   8篇
  1991年   9篇
  1990年   4篇
  1989年   4篇
  1988年   2篇
  1987年   2篇
  1986年   3篇
  1985年   4篇
  1984年   1篇
  1983年   1篇
  1982年   2篇
  1981年   1篇
  1974年   1篇
  1972年   1篇
排序方式: 共有2679条查询结果,搜索用时 15 毫秒
1.
PurposeTo review and to compare indirectly the outcomes of minimally invasive therapies for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia.Materials and MethodsA literature search via Medline and Cochrane Central databases was completed for randomized control studies published between January 2000 to April 2020 for the following therapies: Rezum, Urolift, Aquablation, and prostatic artery embolization (PAE). Data on the following variables were included: International prostate symptom score (IPSS), maximum urinary flow rate, quality of life, and postvoid residual (PVR). Standard mean differences between treatments were compared through a meta-analysis using transurethral resection of the prostate (TURP) to assess differences in treatment effect.ResultsThere was no significant difference in outcomes between therapies for IPSS at the 3, 6, and 12-month follow ups. Although outcomes for Rezum were only available out to 3 months, there were no consistently significant differences in outcomes when comparing Aquablation versus PAE versus Rezum. TURP PVR was significantly better than Urolift at 3, 6, and 12 months. No significant differences in minor or major adverse events were noted.ConclusionAlthough significant differences in outcomes were limited, Aquablation and PAE were the most durable at 12 months. PAE has been well studied on multiple randomized control trials with minimal adverse events while Aquablation has limited high quality data and has been associated with bleeding-related complications.  相似文献   
2.
3.
In 2014, the Emergency Nutrition Network published a report on the relationship between wasting and stunting. We aim to review evidence generated since that review to better understand the implications for improving child nutrition, health and survival. We conducted a systematic review following PRISMA guidelines, registered with PROSPERO. We identified search terms that describe wasting and stunting and the relationship between the two. We included studies related to children under five from low- and middle-income countries that assessed both ponderal growth/wasting and linear growth/stunting and the association between the two. We included 45 studies. The review found the peak incidence of both wasting and stunting is between birth and 3 months. There is a strong association between the two conditions whereby episodes of wasting contribute to stunting and, to a lesser extent, stunting leads to wasting. Children with multiple anthropometric deficits, including concurrent stunting and wasting, have the highest risk of near-term mortality when compared with children with any one deficit alone. Furthermore, evidence suggests that the use of mid-upper-arm circumference combined with weight-for-age Z score might effectively identify children at most risk of near-term mortality. Wasting and stunting, driven by common factors, frequently occur in the same child, either simultaneously or at different moments through their life course. Evidence of a process of accumulation of nutritional deficits and increased risk of mortality over a child's life demonstrates the pressing need for integrated policy, financing and programmatic approaches to the prevention and treatment of child malnutrition.  相似文献   
4.
5.
PurposeThe purpose of this study was to retrospectively investigate risk factors for chest port (port) infections within 30 days of placement (early port infections) in adult oncologic patients.Materials and MethodsThis single-institution, three-center retrospective study identified 1,714 patients (868 males, 846 females; median age 60.0 years old) who underwent port placement between January 2013 and August 2017. All patients received an intravenous antibiotic prior to port placement. The median absolute neutrophil count was 5,260 cells/μL, the median white blood cell (WBC) count was 7,700 cells/μL, and the median serum albumin was 4.00 g/dL at the time of port placement. Double-lumen ports were most commonly implanted (74.85%) more frequently in an outpatient setting (72.69%). Risk factors for early port infections were elucidated using univariate and multivariate proportional subdistribution hazard regression analyses.ResultsA total of 20 patients (1.2%) had early port infections; 15 patients (0.9%) had positive blood cultures. The mean time to infection was 20 days (range, 9–30 days). The port-related 30-day mortality rate was 0.2% (4 of 1,714 patients). Most bloodstream infections were attributed to Staphylococcus spp. (n = 11). In multivariate analysis, hematologic malignancy (hazard ratio [HR], 2.61; 95% confidence interval (CI), 1.15–5.92.; P = .02), hypoalbuminemia (albumin <3.5 g/dL; HR, 3.52; 95% CI: 1.48–8.36; P = .004), leukopenia (WBC <3,500 cells/μL; HR, 3.00; 95% CI: 1.11–8.09; P = .03), and diabetes mellitus (HR, 3.71; 95% CI: 1.57–8.83) remained statistically significant risk factors for early port infection.ConclusionsHematologic malignancy, hypoalbuminemia, leukopenia, and diabetes mellitus at the time of port placement were independent risk factors for early port infections.  相似文献   
6.
Previous studies have reported converging lung cancer rates between sexes. We examine lung cancer incidence rates in young women vs. young men in 40 countries across five continents. Lung and bronchial cancer cases by 5-year age group (ages 30–64) and 5-year calendar period (1993–2012) were extracted from Cancer Incidence in Five Continents. Female-to-male incidence rate ratios (IRRs) and 95% confidence intervals (95%CIs) were calculated by age group and birth cohort. Among men, age-specific lung cancer incidence rates generally decreased in all countries, while in women the rates varied across countries with the trends in most countries stable or declining, albeit at a slower pace compared to those in men. As a result, the female-to-male IRRs increased among recent birth cohorts, with IRRs significantly greater than unity in Canada, Denmark, Germany, New Zealand, the Netherlands and the United States. For example, the IRRs in ages 45–49 year in the Netherlands increased from 0.7 (95% CI: 0.6–0.8) to 1.5 (95% CI: 1.4–1.7) in those born circa 1948 and 1963, respectively. Similar patterns, though nonsignificant, were found in 23 additional countries. These crossovers were largely driven by increasing adenocarcinoma incidence rates in women. For those countries with historical smoking data, smoking prevalence in women approached, but rarely exceeded, those of men. In conclusion, the emerging higher lung cancer incidence rates in young women compared to young men is widespread and not fully explained by sex differences in smoking patterns. Future studies are needed to identify reasons for the elevated incidence of lung cancer among young women.  相似文献   
7.
ABSTRACT

This article analyses how the HIV care cascade, an analytical tool, has become a policy practice that determines the direction and content of international AIDS policy. It traces the development of the cascade through from its emergence around 2011 to its position framing global AIDS policy by 2018. The article distinguishes between the cascade model as a mapping tool and the care cascade as a policy that aims to end the AIDS epidemic. It then argues that the move from an analytical to a policy tool has important implications, both for the scope of policies and for policy-relevant research. It concludes by considering its implications in determining policy direction. The qualitative research that informs the article is based on published care cascade research and policy documents, and observations of the presentations and discussions at the 2012 and 2018 International AIDS Conferences (IAS). The article uses textual analysis to develop its argument.  相似文献   
8.
目的探讨PBL与CBL教学法在留学生实验诊断教学的应用效果。方法将PBL联合案例教学法(CBL)应用于临床医学本科留学生实验诊断教学,与大班传统讲授教学方法(对照组)相比较,通过问卷调查和成绩分析学习效果。结果试验组在激发学习兴趣和培养临床思维能力方面均高于对照组,理论知识的成绩和实习的成绩也是试验组优于对照组,P<0.05。结论PBL与CBL教学联合应用于实验诊断教学中能够有效提高教学质量,并受到学生的认可和喜爱。  相似文献   
9.
《The Journal of arthroplasty》2020,35(8):2200-2203
BackgroundRecently, a revised definition of the minor criteria scoring system for diagnosing periprosthetic joint infection (PJI) was developed by the second International Consensus Meeting on musculoskeletal infection. The new system combines preoperative and intraoperative findings, reportedly achieving high sensitivity and specificity. We aimed to validate the modified scoring system at a high-volume center.MethodsWe retrospectively reviewed patients who underwent a revision total hip or knee arthroplasty at our institution from May 2015 to August 2018. Serum C-reactive protein, synovial white blood cell count and polymorphonuclear percentage, leukocyte esterase test, alpha-defensin, microbiological and histologic results, and documented existence of sinus tract and intraoperative purulence were available for all patients. Cases with at least 1 major criterion were considered as infected. Using the new minor criteria, a score of ≥6 reflects PJI, while a score <3 can be considered as noninfected. Sensitivity, specificity, mean accuracy (ACC), positive predictive value (PPV), and negative predictive value (NPV) were analyzed.ResultsA total of 345 cases were included. A cutoff score of ≥6 points had the following diagnostic performance: area under the curve (AUC) = 0.90; ACC = 0.88; sensitivity = 0.96; specificity = 0.84; PPV = 0.70; NPV = 0.98. Diagnostic performance was better for the hip (AUC = 0.92; ACC = 0.90; sensitivity = 0.96; specificity = 0.86; PPV = 0.81; NPV = 0.98) than the knee (AUC = 0.89; ACC = 0.85; sensitivity = 0.95; specificity = 0.83; PPV = 0.59; NPV = 0.98).ConclusionThe modified scoring system proposed by the 2018 International Consensus Meeting in diagnosing PJI showed high sensitivity and a good performance, especially as rule-out diagnostic criteria. The cutoff level seems to be different between the hip and knee. Further validation studies considering the acknowledged limitations are recommended.  相似文献   
10.
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