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   1070篇
  免费   65篇
  国内免费   11篇
耳鼻咽喉   17篇
儿科学   51篇
妇产科学   28篇
基础医学   120篇
口腔科学   12篇
临床医学   75篇
内科学   224篇
皮肤病学   14篇
神经病学   72篇
特种医学   17篇
外国民族医学   1篇
外科学   175篇
综合类   9篇
预防医学   94篇
眼科学   30篇
药学   104篇
中国医学   10篇
肿瘤学   93篇
  2023年   10篇
  2022年   27篇
  2021年   53篇
  2020年   21篇
  2019年   39篇
  2018年   44篇
  2017年   20篇
  2016年   33篇
  2015年   54篇
  2014年   68篇
  2013年   57篇
  2012年   84篇
  2011年   78篇
  2010年   43篇
  2009年   45篇
  2008年   73篇
  2007年   70篇
  2006年   65篇
  2005年   51篇
  2004年   39篇
  2003年   35篇
  2002年   18篇
  2001年   5篇
  2000年   12篇
  1999年   4篇
  1998年   6篇
  1997年   6篇
  1995年   6篇
  1994年   3篇
  1993年   3篇
  1992年   5篇
  1991年   5篇
  1990年   5篇
  1989年   9篇
  1988年   4篇
  1987年   8篇
  1986年   6篇
  1985年   2篇
  1984年   5篇
  1982年   2篇
  1980年   6篇
  1977年   2篇
  1974年   3篇
  1971年   2篇
  1969年   1篇
  1966年   1篇
  1965年   1篇
  1964年   1篇
  1963年   1篇
  1959年   1篇
排序方式: 共有1146条查询结果,搜索用时 15 毫秒
61.
62.

OBJECTIVES:

Atrial fibrillation is the most common sustained arrhythmia and is associated with poor outcomes, including stroke. The ability of anticoagulation therapy to reduce the risk of stroke has been well established; however, the prevalence of anticoagulation therapy use in the Public Health System is unknown. The aim of this study is to evaluate both the prevalence of anticoagulation therapy among patients with atrial fibrillation and the indications for the treatment.

METHODS:

In this cross-sectional study, we included consecutive patients who had atrial fibrillation documented by an electrocardiogram performed between September 2011 and March 2012 at a university hospital of the Public Health System. The variables analyzed included the risk of a thromboembolic event and/or bleeding, the use of antiplatelet or anticoagulation therapy, the location where the electrocardiogram report was initially reviewed and the specialty of the physician who initially reviewed it.

RESULTS:

We included 162 patients (mean age 68.9 years, 56% men). Hypertension (90.1%), heart failure (53.4%) and stroke (38.9%) were the most prevalent diseases found. Only 50.6% of the patients knew that they had atrial fibrillation. Regarding the use of therapy, only 37.6% of patients classified as high risk according to the CHADS2 scores and 35.5% according to the CHA2DS2VASc used oral anticoagulation. A presumptive diagnosis of heart failure and the fact that the electrocardiogram was evaluated by a cardiologist were the only independent predictors of the use of anticoagulants.

CONCLUSIONS:

Our study found a low prevalence of oral anticoagulation therapy among patients with atrial fibrillation and an indication for stroke prophylaxis for the use of this therapy, including among those with high CHADS2 and CHA2DS2VASc scores.  相似文献   
63.
Nutrient reference values (NRVs) for zinc set by several expert groups differ widely and may affect the predicted prevalence of inadequate zinc intake. We examined this possibility using NRVs published by four different authorities and nationally representative dietary intake data collected among children aged 12–59 months and women in Cameroon. Usual zinc intake was estimated from 24 h recall data using the National Cancer Institute method. Prevalences of total zinc intake below the dietary requirement and of “absorbable zinc intake” below the physiological requirement were estimated using NRVs published by the World Health Organization (WHO), US Institute of Medicine (IOM), International Zinc Nutrition Consultative Group (IZiNCG), and European Food Safety Authority (EFSA). The prevalence of inadequate zinc intake ranged from 10% (IZiNCG—physiological requirement, 95% CI 7–13%) to 81% (EFSA—physiological requirement, 95% CI 78–84%) among children and 9% (WHO—physiological requirement, 95% CI 8–11.0%) to 94% (IOM—physiological requirement, 95% CI 92–95%) among women These differences in the prevalence of inadequate intake translated into sizeable differences in the predicted benefit and cost-effectiveness of zinc fortification programs. Depending on the NRVs applied, assessments differ regarding the need for and design of zinc fortification programs. Efforts are needed to harmonize NRVs for zinc.  相似文献   
64.
Population studies have demonstrated an association between sodium and potassium intake and blood pressure levels and lipids. The aim of this study was to describe the dietary intake and contribution of sodium and potassium to the Mexican diet, and to describe its association with nutrition status and clinical characteristics. We analyzed a national survey with 4219 participants. Dietary information was obtained with a 24-h recall. Foods and beverages were classified according to level of processing. The mean intake (mg/d) of Na was 1512 in preschool children, 2844 in school-age children, 3743 in adolescents, and 3132 in adults. The mean intake (mg/d) of K was 1616 in preschool children, 2256 in school-age children, 2967 in adolescents, and 3401 in adults. Processed and ultra-processed foods (UPF) contribute 49% of Na intake in preschool children, 50% in school-age children, 47% in adolescents, and 39% in adults. Adults with high Na intake had lower serum concentrations of cholesterol, HDL-c, and LDL-c. A significant proportion of the Mexican population has a high intake of Na (64–82%) and low K (58–73%). Strategies to reduce Na and increase K intake need to reduce the possibility of having high BP and serum lipid disturbances.  相似文献   
65.
Extracorporeal membrane oxygenation (ECMO) is considered as a supportive treatment that provides circulatory and ventilatory support and can be thought off as a bridge to organ recovery. Since 2009, it has been applied as a rescue treatment for patients with severe adult respiratory distress syndrome (ARDS) mainly due to viral causes. In December 2019, several patients presented with a constellation of symptoms of viral pneumonia in China. A new strain of the corona virus family, called COVID-19, has been discovered to be the cause of this severe mysterious illness that was named severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2). This new virus continued to spread across the globe leading to the World Health Organization announcing it as a pandemic in the early 2020. By the end of March 2021, the number of COVID-19 cases worldwide exceeded 126 million cases. In Saudi Arabia, the first confirmed case of COVID-19 was reported in the 2nd March 2020. By the end of March 2021, the total number of confirmed COVID-19 cases in Saudi Arabia is just above 360,000. In anticipation of the need of ECMO for the treatment of patients with SARS‑CoV‑2 based on the previous Middle East respiratory syndrome coronavirus pandemic experience, the Saudi Extra-Corporeal Life Support (ECLS) chapter that is under the umbrella of the Saudi Critical Care Society (SCCS) convened a working group of ECMO experts. The mission of this group was to formulate a guidance for the use of ECMO as a last resort for patients with severe ARDS, especially with COVID-19 based on available evidence. The ECLS-SCCS chapter wanted to generate a document that can be used to simple guide, with a focus on safety, to provide ECMO service for patients with severe ARDS with a special focus on SARS‑CoV‑2.  相似文献   
66.
67.

Objective

Several studies have suggested a defective automatic nervous system (ANS) in idiopathic vesical hyperactivity syndrome. The study of heart rate variability (HRV) is a non-invasive and validated method for measuring ANS activity. We therefore used this method for vesical filling in a control population (women with stress urinary incontinence: SUI) and in female patients with idiopathic vesical hyperactivity syndrome.

Materials and methods

We included 7 women with pure SUI and 3 with idiopathic vesical hyperactivity syndrome. Continuous ECG recording was performed over 10 minutes with an empty bladder and during artificial bladder filling. Heart rate variations were measured by frequential indices: low frequency, which mainly reflected sympathetic modulation, and high frequency, which is related to the parasympathetic system.

Results

In the control group, no significant changes in heart rate variations during filling were noted. However, in the idiopathic vesical hyperactivity group, cardiac neurovegetative control was different from the control group, and varied during filling, going from empty bladder parasympathetic hypertonia to sympathetic hypertonia at the end of filling. At the end of filling, when vesical continence is ensured by the sympathetic system, we noted a significant increase in sympathetic tone (P = 0.001), associated with a reduction in cardiac parasympathetic tone (P < 0.0001). These results demonstrate vegetative balance dysfunction in idiopathic vesical hyperactivity syndrome.

Conclusion

This preliminary study demonstrates a predominance of parasympathetic activity with an empty bladder and a predominance of sympathetic activity at the end of bladder filling in OAB. The results suggest a defective autonomic nervous system with idiopathic OAB. Further studies in a larger OAB population compared with normal urinary-symptom free patients are necessary to confirm this hypothesis.  相似文献   
68.
Many neurodegenerative disorders are caused by abnormal accumulation of misfolded proteins. In spinocerebellar ataxia type 1 (SCA1), accumulation of polyglutamine-expanded (polyQ-expanded) ataxin-1 (ATXN1) causes neuronal toxicity. Lowering total ATXN1, especially the polyQ-expanded form, alleviates disease phenotypes in mice, but the molecular mechanism by which the mutant ATXN1 is specifically modulated is not understood. Here, we identified 22 mutant ATXN1 regulators by performing a cross-species screen of 7787 and 2144 genes in human cells and Drosophila eyes, respectively. Among them, transglutaminase 5 (TG5) preferentially regulated mutant ATXN1 over the WT protein. TG enzymes catalyzed cross-linking of ATXN1 in a polyQ-length–dependent manner, thereby preferentially modulating mutant ATXN1 stability and oligomerization. Perturbing Tg in Drosophila SCA1 models modulated mutant ATXN1 toxicity. Moreover, TG5 was enriched in the nuclei of SCA1-affected neurons and colocalized with nuclear ATXN1 inclusions in brain tissue from patients with SCA1. Our work provides a molecular insight into SCA1 pathogenesis and an opportunity for allele-specific targeting for neurodegenerative disorders.  相似文献   
69.
Haemophilus influenzae was isolated from patients with respiratory tract infections in five centers in Saudi Arabia. All of the 129 isolates tested by MIC agar dilution were fully susceptible to ceftazidime and ciprofloxacin but 13.2% were resistant to ampicillin, 7% to tetracycline, 5.4% to chloramphenicol, 3.9% to roxithromycin, and 1.6% to amoxicillin/clavulanic acid. Seventeen (13.2%) of all isolates produced TEM-1 type beta-lactamase, the majority (82%) characterized as biotype I or II with 4 (23.5%) encapsulated and belonging to serotype b. There was a clear distinction between the prevalence of beta-lactamase production in hospital patients (26.3% of 19 isolates) compared with community based patients (10.9% of 110 isolates). In addition, we report an increase in the prevalence of beta-lactamase negative, ampicillin intermediate strains (BLNAI) compared to previous studies in this defined geographical region. Changes in the frequency and nature of antimicrobial resistance in common respiratory pathogens confirms the need to maintain surveillance.  相似文献   
70.
A case of Rett syndrome in a-3 1/2 year-old girl is presented. The patient had normal pre and perinatal period and normal psychomotor development till the age of 14 months, followed by behavioural, social and psychomotor regression. Physical examination revealed a below normal head circumference, loss of eye and psychic contact, stereotypic hand movements and gait disturbance. No laboratory test can confirm the diagnosis of Rett syndrome, therefore the diagnosis was established by virtue of history of illness and clinical manifestations. This is the first case of Rett syndrome found and reported in Indonesia.  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