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   37153篇
  免费   3671篇
  国内免费   1385篇
耳鼻咽喉   176篇
儿科学   372篇
妇产科学   339篇
基础医学   1888篇
口腔科学   203篇
临床医学   7859篇
内科学   4590篇
皮肤病学   110篇
神经病学   7884篇
特种医学   1159篇
外科学   2950篇
综合类   5543篇
现状与发展   5篇
预防医学   2552篇
眼科学   189篇
药学   3315篇
  76篇
中国医学   2524篇
肿瘤学   475篇
  2024年   160篇
  2023年   880篇
  2022年   1550篇
  2021年   2397篇
  2020年   2253篇
  2019年   1816篇
  2018年   1823篇
  2017年   1840篇
  2016年   1794篇
  2015年   1558篇
  2014年   2981篇
  2013年   3388篇
  2012年   2474篇
  2011年   2312篇
  2010年   1921篇
  2009年   1562篇
  2008年   1494篇
  2007年   1504篇
  2006年   1334篇
  2005年   1036篇
  2004年   824篇
  2003年   742篇
  2002年   702篇
  2001年   546篇
  2000年   417篇
  1999年   374篇
  1998年   285篇
  1997年   227篇
  1996年   196篇
  1995年   184篇
  1994年   195篇
  1993年   147篇
  1992年   123篇
  1991年   114篇
  1990年   111篇
  1989年   99篇
  1988年   96篇
  1987年   85篇
  1986年   94篇
  1985年   87篇
  1984年   83篇
  1983年   60篇
  1982年   63篇
  1981年   65篇
  1980年   36篇
  1979年   39篇
  1978年   30篇
  1977年   23篇
  1976年   30篇
  1975年   16篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
BackgroundPeriodontitis is associated with the pathogenesis of atherosclerotic plaque, and hypersensitive C reactive protein (hs-CRP) and lipoprotein-associated phospholipase A2 (Lp-PLA2) are the serum biomarkers of the stability of atherosclerotic plaque. Whether periodontitis is associated with the serum level of hs-CRP and Lp-PLA2 of acute ischemic stroke remains unclear.Material and MethodsWe recruited 103 cases with acute ischemic stroke within 7 days after stroke onset. Pocket depth and clinical attachment loss were assessed by oral examination to define the severe periodontitis. Demographic information including gender, age and body weight index, income level, education level, past medical history include smoking history, drinking history, ischemic stroke history, coronary heart disease, hypertension, diabetes and hyperlipidemia were collected, and serum biomarkers including white blood cell (WBC), fibrinogen, total cholesterol (TC), triglyceride (TG), lower density lipoprotein (LDL-C), high density lipoprotein (HDL-C), hs-CRP, HemoglobinA1c (HbAlc), Homocysteine (HCY) and Lp-PLA2 were tested.Results65 (63.1%) cases were diagnosed as severe periodontitis. Severe periodontitis group showed more male, age, drinking history, higher levels of hs-CRP and Lp-PLA2. Multivariate logistic regression showed that severe periodontitis was were significantly associated with hs-CRP (OR = 2.367, 95%CI: 1.182–4.738; P = .015) and Lp-PLA2 (OR = 2.577, 95% CI: 1.010–6.574; P = .048).ConclusionsSevere periodontitis is independently associated with the serum Level of hs-CRP and Lp-PLA2 in patients with acute ischemic stroke. Whether the improvement of periodontitis could decrease the occurrence and re-occurrence of ischemic stroke by stablizating atherosclerotic plaque need be further studied in future.  相似文献   
22.
ObjectivesThe aim of this study was to report 1-year clinical outcomes following commercial transcatheter left atrial appendage occlusion (LAAO) in the United States.BackgroundThe National Cardiovascular Data Registry LAAO Registry was initiated to meet a condition of Medicare coverage and allow the assessment of clinical outcomes. The 1-year rates of thromboembolic events after transcatheter LAAO in such a large cohort of “real-world” patients have not been previously reported.MethodsPatients entered into the National Cardiovascular Data Registry LAAO Registry for a Watchman procedure between January 1, 2016, and December 31, 2018, were included. The primary endpoint was ischemic stroke. Key secondary endpoints included the rate of ischemic stroke or systemic embolism, mortality, and major bleeding. Major bleeding was defined as any bleeding requiring hospitalization, and/or causing a decrease in hemoglobin level > 2g/dL, and/or requiring blood transfusion that was not hemorrhagic stroke. The Kaplan-Meier method was used for 1-year estimates of cumulative event rates.ResultsThe study population consisted of 36,681 patients. The mean age was 76.0 ± 8.1 years, the mean CHA2DS2-VASc score was 4.8 ± 1.5, and the mean HAS-BLED score was 3.0 ± 1.1. Prior stroke was present in 25.5%, clinically relevant bleeding in 69.5%, and intracranial bleeding in 11.9%. Median follow-up was 374 days (IQR: 212-425 days). The Kaplan-Meier–estimated 1-year rate of ischemic stroke was 1.53% (95% CI: 1.39%-1.69%), the rate of ischemic stroke or systemic embolism was 2.19% (95% CI: 2.01%-2.38%), and the rate of mortality was 8.52% (95% CI: 8.19%-8.87%). The 1-year estimated rate of major bleeding was 6.93% (95% CI: 6.65%-7.21%). Most bleeding events occurred between discharge and 45 days following the procedure.ConclusionsThis study characterizes important outcomes in a national cohort of patients undergoing transcatheter LAAO in the United States. Clinicians and patients can integrate these data in shared decision making when considering this therapy.  相似文献   
23.
目的 分析乌司他丁与连续性血液净化联用对热射病患者所产生的影响。方法 选取2017年5月—2019年2月在海南医学院第二附属医院进行治疗的88例热射病患者作为研究对象,将其分为研究组和常规组,常规组患者接受常规治疗,研究组患者在常规治疗基础上,将乌司他丁与连续性血液净化联用。分析两种治疗措施的效果。结果 治疗前两组患者的IL-17、TNF-α、cTnⅠ、β2-MG、PT、D-D、ET和TM水平,差异无统计学意义(P>0.05)。经治疗两组患者的上述指标水平都表现出下降的趋势,相对于常规组,研究组患者下降水平更明显,差异具有统计学意义(P<0.05)。研究组治疗的总有效率为95.5%,高于常规组的72.7%,差异具有统计学意义(P<0.05)。结论 运用乌司他丁与连续性血液净化联用的疗法对热射病患者进行治疗,可获得十分理想的治疗效果,可在临床工作中推广。  相似文献   
24.
基于调控肠道菌群探讨中药防治脑卒中   总被引:3,自引:3,他引:0  
肠道菌群是一个独特的生态系统,被称为人体"被遗忘的器官",被誉为人类的"第二基因组"。肠道菌群失调与许多中枢神经系统疾病相关,例如帕金森病、阿尔茨海默症、精神分裂症及多发性硬化等。脑卒中具有高的发病率、复发率、死亡率和致残率的特点。肠道菌群在脑卒中的发生、发展中起着关键的作用,可通过影响机体的吸收、代谢、血压、血糖、血脂及动脉粥样斑块等因素,进一步影响脑卒中的发病。中医认为脾胃气血流注失度、阴阳盛衰失衡,机体生理功能失调,化生"风、火、痰、虚、瘀"等病理产物,可致中风的发生。脾胃主腐熟运化水谷,肠道菌群影响饮食的消化吸收,现代研究的肠道菌群功能与中医之脾胃功能失调相关。因此,调整肠道菌群的稳态,可作为一个潜在的干预靶点预防和治疗缺血性脑卒中。中药干预脑卒中已经取得了很好的疗效,是否与调节肠道菌群有关,值得未来做进一步的研究。同时对中药有效成分(小檗碱、黄芩苷、白藜芦醇等),中药单方(丹参、红景天等)和中药组方(补阳还五汤、脑心通胶囊、补中益气汤等)防治脑缺血的研究进展进行综述,为缺血性脑卒中的预防和开发提供新的途径和思路。  相似文献   
25.

Background

Acute stroke codes may be activated for anisocoria, but how often these codes lead to a final stroke diagnosis or alteplase treatment is unknown. The purpose of this study was to assess the frequency of anisocoria in stroke codes that ultimately resulted in alteplase administration.

Methods

We retrospectively assessed consecutive alteplase-treated patients from a prospectively-collected stroke registry between February 2015 and July 2018. Based on the stroke code exam, patients were categorized as having isolated anisocoria [A+(only)], anisocoria with other findings [A+(other)], or no anisocoria [A?]. Baseline demographics, stroke severity, alteplase time metrics, and outcomes were also collected.

Results

Ninety-six patients received alteplase during the study period. Of the 94 who met inclusion criteria, there were 0 cases of A+(only). There were 9 cases of A+(other) (9.6%). A+(other) exhibited higher baseline National Institutes of Health (NIH) Stroke Scale scores compared to A? (17 versus 7; P?=?.0003), and no additional differences in demographics or alteplase time metrics. Final stroke diagnosis and other outcome measures were no different between A+(other) and A?. Of the A+ patients without pre-existing anisocoria, 5 of 6 (83%) had posterior circulation events or diffuse subarachnoid hemorrhage.

Conclusions

In this exploratory analysis, zero patients with isolated anisocoria received alteplase treatment. Anisocoria as a part of the neurologic presentation occurred in 10% of alteplase patients, and was strongly associated with a posterior circulation event. Therefore, we conclude that anisocoria has a higher likelihood of leading to alteplase treatment when identified in the presence of other neurologic deficits.  相似文献   
26.
Introduction: Current research suggests that pediatric stroke is associated with a reduction in intellectual functioning. However, less is known about academic achievement and the contribution of specific executive functions to math and literacy in this population. The current study investigates behavioral ratings of executive functioning and their relationship to math and spelling performance in children with a history of unilateral arterial ischemic stroke.

Method: Thirty-two pediatric patients with stroke (Mage = 9.5 ± 2.7 years) and 32 demographically equivalent, healthy controls were tested on standardized measures of arithmetic, spelling, and intelligence. Executive functioning data were collected via standardized parent questionnaire.

Results: Relative to controls, stroke participants demonstrated significantly poorer functioning in math, spelling, metacognition, and behavioral-regulation. Pencil and paper arithmetic was particularly challenging for the stroke group, with 40% of patients reaching levels of clinical impairment. Hierarchical regression in stroke participants further revealed that metacognition was a robust predictor of academic deficits. Stroke occurring in later childhood and affecting cortical and subcortical brain regions also presented as potential clinical risk factors.

Conclusions: Children with stroke were especially vulnerable to math achievement deficits. Metacognition made a substantial contribution to academic achievement abilities among stroke patients, and results underscore the importance of early metacognitive skills in the completion of schoolwork. Results also emphasize that pediatric stroke patients are a heterogeneous group with regard to functioning and that there is value in examining standard score distributions of clinical participant samples.  相似文献   

27.
Objectives: Suicide is best studied by deconstructing the psychological experiences preceding suicidal death. We assessed the characteristics of tedium vitae (feeling tired of life) after first ever stroke in Nigerian survivors.

Methods: Using the Schedule for Clinical Assessment in Neuropsychiatry, tedium vitae was assessed in 130 stroke survivors attending rehabilitation in a large Nigerian university hospital. Global cognitive and executive dysfunctions were evaluated, respectively, using the Mini Mental State Examination and the modi?ed Indiana University Token test. All participants had their index stroke 3 to 24 months before recruitment into the study. We also examined a comparative group of 130 age, gender, and education matched apparently normal persons who were unrelated to the stroke survivors. Associations were explored using univariate and multivariate logistic regression analyses.

Results: Tedium vitae was experienced by 16 (12.3%) stroke survivors compared with 5 (3.9%) in the comparative group (O. R = 3.5, 95% C. I = 1.3–9.9, p = 0.018). Among stroke survivors, those who were retired were more likely to experience tedium vitae (56.2%, p = 0.045). In analyses adjusting for the effect of systemic hypertension, cognitive dysfunction, retirement and marital separation, there was a 3.5-fold increase in the odds of experiencing tedium vitae after surviving a stroke (O. R = 3.5, 95% C. I = 1.1–11.6, p = 0.042).

Conclusions: Tedium vitae is a common suicidal experience after stroke and may be among the earliest perceptible pointer to impending poststroke suicide. It is easy to assess and may be less costly to obtain an adequate sample size in studies aiming to understand the phenomenon of suicide in the stroke population.  相似文献   

28.
29.
30.
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