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   2232篇
  免费   151篇
  国内免费   111篇
耳鼻咽喉   37篇
儿科学   66篇
妇产科学   22篇
基础医学   673篇
口腔科学   38篇
临床医学   132篇
内科学   229篇
皮肤病学   62篇
神经病学   291篇
特种医学   62篇
外国民族医学   1篇
外科学   237篇
综合类   230篇
一般理论   1篇
预防医学   99篇
眼科学   139篇
药学   87篇
  3篇
中国医学   47篇
肿瘤学   38篇
  2023年   34篇
  2022年   48篇
  2021年   96篇
  2020年   72篇
  2019年   84篇
  2018年   80篇
  2017年   60篇
  2016年   88篇
  2015年   63篇
  2014年   119篇
  2013年   124篇
  2012年   81篇
  2011年   109篇
  2010年   81篇
  2009年   114篇
  2008年   113篇
  2007年   92篇
  2006年   97篇
  2005年   90篇
  2004年   55篇
  2003年   82篇
  2002年   53篇
  2001年   47篇
  2000年   46篇
  1999年   35篇
  1998年   28篇
  1997年   28篇
  1996年   20篇
  1995年   37篇
  1994年   41篇
  1993年   37篇
  1992年   50篇
  1991年   21篇
  1990年   28篇
  1989年   17篇
  1988年   25篇
  1987年   21篇
  1986年   21篇
  1985年   28篇
  1984年   21篇
  1983年   19篇
  1982年   23篇
  1981年   15篇
  1980年   23篇
  1979年   11篇
  1978年   6篇
  1977年   2篇
  1973年   4篇
  1969年   1篇
  1968年   1篇
排序方式: 共有2494条查询结果,搜索用时 31 毫秒
1.
BackgroundDentatorubral-pallidoluysian atrophy (DRPLA) is a rare autosomal dominant spinocerebellar ataxia caused by pathological expansion of CAG trinucleotide repeats in the ATN1 gene. Most cases were described in patients from Japanese ancestry who presented with adult-onset progressive cerebellar ataxia associated with cognitive impairment, choreoathetosis and other movement disorders. DRPLA has been rarely described in Brazilian patients.MethodsWe performed a retrospective observational multicentric study including six different Neurology Centers in Brazil. All patients with genetically confirmed diagnosis of DRPLA had their medical records evaluated and clinical, genetic and neuroimaging features were analyzed.ResultsWe describe of eight Brazilian patients (5 male, 3 female) from four nuclear families with genetically confirmed DRPLA. The most common neurological features included cerebellar ataxia (n = 7), dementia (n = 3), chorea (n = 2), psychiatric disturbances (n = 2), progressive myoclonic epilepsy (n = 2) and severe bulbar signs (n = 1). Progressive myoclonic epilepsy was observed in two juvenile-onset cases before 20-year. A large CAG trinucleotide length was observed in the two juvenile-onset cases and genetic anticipation was observed in all cases. Neuroimaging studies disclosed cerebellar atrophy (n = 6), as well as brainstem and cerebellar atrophy (n = 2) and leukoencephalopathy (n = 1).ConclusionThe patients described herein reinforce that clinical features of DRPLA are highly influenced by age of onset, genetic anticipation and CAG repetition lengths. There is a large complex spectrum of neurological features associated with DRPLA, varying from pure cerebellar ataxia to dementia associated with other movement disorders (myoclonus, choreoathetosis). DRPLA is an unusual cause of cerebellar ataxia and neurodegeneration in Brazilian patients.  相似文献   
2.
3.
《Clinical neurophysiology》2020,131(11):2651-2656
ObjectiveAs concerns regarding neurological manifestations in COVID-19 (coronavirus disease 2019) patients increase, limited data exists on continuous electroencephalography (cEEG) findings in these patients. We present a retrospective cohort study of cEEG monitoring in COVID-19 patients to better explore this knowledge gap.MethodsAmong 22 COVID-19 patients, 19 underwent cEEGs, and 3 underwent routine EEGs (<1 h). Demographic and clinical variables, including comorbid conditions, discharge disposition, survival and cEEG findings, were collected.ResultscEEG was performed for evaluation of altered mental status (n = 17) or seizure-like events (n = 5). Five patients, including 2 with epilepsy, had epileptiform abnormalities on cEEG. Two patients had electrographic seizures without a prior epilepsy history. There were no acute neuroimaging findings. Periodic discharges were noted in one-third of patients and encephalopathic EEG findings were not associated with IV anesthetic use.ConclusionsInterictal epileptiform abnormalities in the absence of prior epilepsy history were rare. However, the discovery of asymptomatic seizures in two of twenty-two patients was higher than previously reported and is therefore of concern.SignificancecEEG monitoring in COVID-19 patients may aid in better understanding an epileptogenic potential of SARS-CoV2 infection. Nevertheless, larger studies utilizing cEEG are required to better examine acute epileptic risk in COVID-19 patients.  相似文献   
4.
Ataxia     
《Neurologic Clinics》2015,33(1):225-248
  相似文献   
5.

Purpose

The aim of this investigation was to suggest practices to improve the delivery of work-integrated learning (WIL) in radiography training in South Africa (SA).

Methods

An extensive survey was conducted among all universities in SA involved in the training of radiography students, to investigate the current delivery of WIL. Data were collected by means of quantitative questionnaires with open-ended qualitative components. The questionnaire was distributed to lecturers (n = 32), clinical supervisors (n = 44) and final-year students in Radiography (n = 146).

Results

The quantitative (closed questions) and qualitative (open-ended comments) findings from the stakeholders with regard to the improvement of practice in the delivery of WIL in radiography training are presented in this article. The main themes discussed relate to curriculum design for WIL, teaching/learning of WIL, assessment of WIL and management and coordination of WIL.

Conclusion

WIL is a powerful pedagogy if implemented and managed correctly. The results from this study may enable lecturers in radiography programmes in SA to improve the delivery of WIL in the training of high quality, employable graduates.  相似文献   
6.
This article focuses on the functional features of positive-pressure ventilators, the modes of invasive and non-invasive mechanical ventilation, and the main ventilator settings. It also highlights the potential complications of mechanical ventilation, the basic principles of weaning, and the pathophysiological basis of patient-ventilator dyssynchrony.  相似文献   
7.
Background: Mutations in BEST1 account for autosomal dominant vitreoretinochoroidopathy (ADVIRC), a rare inherited retinal dystrophy with presenile cataracts and incomplete anterior segment development. The long-term clinical findings and visual prognosis of these patients continues to evolve over time.

Materials and Methods: The retina was assessed by fundus photography, fluorescein angiography, and spectral domain optical coherence tomography. Sanger dideoxy chain-termination sequencing identified mutations in BEST1. Bioinformatic tools were used to predict changes in splicing. An in vitro splicing assay was applied to evaluate for altered pre-mRNA splicing.

Results: Long-term follow up of the first ever reported ADVIRC proband revealed progressive foveal atrophy in both eyes 3 decades after his initial presentation. Progressive retinal ischemia, bilateral iris atrophy, and pseudophakodnesis were observed on follow up. The patient was heterozygous for a c.248G?>?A missense mutation in exon 4 of BEST1, affecting a highly conserved transmembrane domain. Although computational prediction models suggest a change in the binding probability of splicing-associated SR proteins, in vitro splicing assays failed to demonstrate an effect of the c.248G?>?A mutation on splicing of BEST1 exon 3 or exon 4.

Conclusions: Progressive posterior chorioretinal changes occurred over time in the initial ADVIRC proband, leading to visual loss. The causative mutation in this patient falls in the transmembrane domain of the BEST1 protein, with unclear functional consequences. Although previous studies showed alteration in pre-mRNA splicing, in vitro splicing assays failed to demonstrate this in our patient.  相似文献   
8.
9.
BACKGROUND Axenfeld-Rieger syndrome(ARS)is an autosomal dominant genetic disease characterized by ocular developmental disorders and its association with torsion of wandering spleen(WS)has not been reported to date to the best of our knowledge.This study aimed to describe a rare case of ARS observed at our emergency department.CASE SUMMARY A 25-year-old female presented with a constant lower abdominal pain of increasing severity.Diagnostic computed tomography with intravenous contrast material showed a non-homogenously enhanced splenic parenchyma with a twisted vascular pedicle.Further,an emergent laparoscopic exploration was performed,and an ischemic spleen without its normal ligamentous attachments was noted.Notably,the spleen did not regain its normal vascularity after detorsion;thus,we performed the laparoscopic total splenectomy.The postoperative course was uneventful,and the patient was discharged on the 5th postoperative day.This case demonstrates a rare association of WS and ARS.CONCLUSION Early diagnosis of WS in the emergency department is important to prevent pedicle torsion or splenic necrosis and to avoid splenectomy.  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