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   123篇
  免费   4篇
耳鼻咽喉   1篇
妇产科学   5篇
基础医学   12篇
口腔科学   1篇
临床医学   10篇
内科学   32篇
皮肤病学   4篇
神经病学   16篇
特种医学   3篇
外科学   22篇
预防医学   7篇
眼科学   8篇
药学   4篇
肿瘤学   2篇
  2022年   1篇
  2021年   4篇
  2020年   2篇
  2019年   7篇
  2018年   6篇
  2017年   4篇
  2016年   7篇
  2015年   1篇
  2014年   2篇
  2013年   7篇
  2012年   11篇
  2011年   10篇
  2010年   5篇
  2009年   8篇
  2008年   8篇
  2007年   7篇
  2006年   6篇
  2005年   4篇
  2003年   3篇
  2002年   4篇
  2001年   1篇
  2000年   2篇
  1999年   4篇
  1998年   2篇
  1996年   1篇
  1995年   1篇
  1991年   2篇
  1990年   1篇
  1989年   3篇
  1988年   1篇
  1986年   1篇
  1977年   1篇
排序方式: 共有127条查询结果,搜索用时 15 毫秒
1.
2.
3.
Serum selenium levels were determined in 92 healthy subjects [40 men, 52 women; mean age 33.5 +/- 1.6 (s.e.m.) years, range 16-71 years] living in the province of Barcelona, Catalunya, Spain. Only well-nourished individuals with unremarkable clinical history, normal blood chemistry and haematological tests were selected. The subjects were divided into 6 age groups for each sex. Serum samples were analysed using a modification of the standard electrothermal graphite furnace atomic absorption spectrophotometry method to shorten the procedure while maintaining its accuracy. A significant correlation (y = -1.31 + 1.51 x; r = 0.9967, P less than 0.001) was observed between our method and the standard assay method. The mean serum selenium concentration was 60.39 micrograms/l, 95 per cent CI 53.35-67.45 micrograms/l. There were age- but no sex-group differences (P less than 0.001). This result is similar to that found in countries whose low selenium levels have been related to an increased risk of some disease states. Clinical and health implications of this suboptimal selenium status are discussed.  相似文献   
4.
5.
PurposeCrucial steps have been adopted by health and regulatory authorities around the world to respond to the COVID-19 pandemic. This review aims to highlight these steps by providing an overview of the regulatory approaches adopted during the onset of the pandemic, provide an assessment of observed trends, and offer some reflections and proposals to leverage learnings and opportunities from this current pandemic.MethodsDocuments and informational materials on regulating the development and management of medical products during the COVID-19 pandemic were collected and classified. These materials were sourced from official websites and press releases from health authorities and international bodies from selected markets across the globe, and covered the period between January and July 2020. Additional information to support this study was gathered through a literature review and analysis of related data available from the public domain, and was complemented with the authors' personal experience.FindingsCommunication has been vital in addressing the impact of COVID-19. A total of 1705 documents and informational materials related to health or regulatory response to the COVID-19 pandemic were gathered. Of these, 343 (around 20%) were identified as regulatory agilities. These agile approaches were classified into 3 categories, namely, where health and regulatory authorities had: (1) facilitated product management across the entire lifecycle, notably in expediting medical product use for COVID-19, ensuring the continuity of clinical trials, and addressing supply chain issues; (2) strengthened international cooperation; and (3) addressed regulatory burden with the adoption of electronic and digital tools.ImplicationsWhile many regulatory measures have been introduced temporarily as a response to the COVID-19 crisis, there are opportunities for leveraging an understanding from these approaches in order to collectively achieve more efficient regulatory systems and to mitigate and address the impact of COVID-19 and further future-proof the regulatory environment.  相似文献   
6.
7.
During last years, molecular markers have been increased as prognostic factors routinely screened in acute myeloid leukemia (AML). Recently, an increasing interest has been reported in introducing to clinical practice screening for mutations in the CCAAT/enhancer-binding protein ?? (CEBPA) gene in AML, as it seems to be a good prognostic factor. However, there is no reliable established method for assessing CEBPA mutations during the diagnostic work-up of AMLs. We describe here a straightforward and reliable fragment analysis method based in PCR capillary electrophoresis (PCR-CE) for screening of CEBPA mutations; moreover, we present the results obtained in 151 intermediate-risk karyotype AML patients (aged 16?C80?years). The method gave a specificity of 100% and sensitivity of 93% with a lower detection limit of 1?C5% for CEBPA mutations. The series found 19 mutations and four polymorphisms in 12 patients, seven of whom (58%) presented two mutations. The overall frequency of CEBPA mutations in AML was 8% (n?=?12). CEBPA mutations showed no coincidence with FLT3-ITD or NPM1 mutations. CEBPA mutation predicted better disease-free survival in the group of patients without FLT3-ITD, NPM, or both genes mutated (HR 3.6, IC 95%; 1.0?C13.2, p?=?0.05) and better overall survival in patients younger than 65 of this group without molecular markers (HR 4.0, IC 95%; 1.0?C17.4, p?=?0.05). In conclusion, the fragment analysis method based in PCR-CE is a rapid, specific, and sensitive method for CEBPA mutation screening and our results confirm that CEBPA mutations can identify a subgroup of patients with favorable prognosis in AML with intermediate-risk karyotype.  相似文献   
8.

Some 70–80% of subjects with psychotic risk syndrome (PRS) have lifetime comorbidity, with depressive disorders being the most common. A high proportion of patients with PRS present nonspecific symptoms which can be confounding factors for diagnosis. Depressive and negative symptoms may be difficult to distinguish and it is important to differentiate them. The aim of this study is to assess the presence of depressive disorder in a child and adolescent sample of PRS and to examine the presence of negative symptoms and detect possible confounding characteristics between them and depressive symptoms. This is a naturalistic multi-site study with subjects who met PRS criteria. A sample of 89 PRS adolescent patients was included. Major depressive disorder (MDD) is the most prevalent comorbid disorder (34.83%). The sample was divided into patients who met criteria for MDD (PRS-MDD, n = 31) and those who did not have this disorder (PRS-ND, n = 44). We obtained significant differences in the attenuated negative symptoms (ANS) between PRS-MDD and PRS-ND (68.18 vs. 90.32%, respectively, p = 0.021). Subjects with MDD presented a higher score in ANS and Hamilton Depression Rating Scale (HDRS). Moreover, we obtained a correlation between negative symptomatology and HDRS score with a higher score on HDRS in subjects with higher negative symptom scores (r = 0.533, p < 0.001). More research is needed to fine tune differentiation between depressive and negative symptoms and learn more about the possible impact of MDD on PRS children and adolescents.

  相似文献   
9.

Introduction and objectives

Current therapeutic options for severe aortic stenosis (AS) include transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR). Our aim was to describe the prognosis of patients with severe AS after the decision to perform an intervention, to study the variables influencing their prognosis, and to describe the determinants of waiting time > 2 months.

Methods

Subanalysis of the IDEAS (Influence of the Severe Aortic Stenosis Diagnosis) registry in patients indicated for TAVI or SAVR.

Results

Of 726 patients with severe AS diagnosed in January 2014, the decision to perform an intervention was made in 300, who were included in the present study. The mean age was 74.0 ± 9.7 years. A total of 258 (86.0%) underwent an intervention: 59 TAVI and 199 SAVR. At the end of the year, 42 patients (14.0%) with an indication for an intervention did not receive it, either because they remained on the waiting list (34 patients) or died while waiting for the procedure (8 patients). Of the patients who died while on the waiting list, half did so in the first 100 days. The mean waiting time was 2.9 ± 1.6 for TAVI and 3.5 ± 0.2 months for SAVR (P = .03). The independent predictors of mortality were male sex (HR, 2.6; 95%CI, 1.1-6.0), moderate-severe mitral regurgitation (HR, 2.6; 95%CI, 1.5-4.5), reduced mobility (HR, 4.6; 95%CI, 1.7-12.6), and nonintervention (HR, 2.3; 95%CI, 1.02-5.03).

Conclusions

Patients with severe aortic stenosis awaiting therapeutic procedures have a high mortality risk. Some clinical indicators predict a worse prognosis and suggest the need for early intervention.  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