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   735篇
  免费   49篇
  国内免费   6篇
耳鼻咽喉   1篇
儿科学   3篇
基础医学   58篇
临床医学   23篇
内科学   27篇
皮肤病学   1篇
神经病学   612篇
特种医学   3篇
外科学   1篇
综合类   11篇
预防医学   9篇
药学   36篇
中国医学   3篇
肿瘤学   2篇
  2023年   10篇
  2022年   10篇
  2021年   36篇
  2020年   35篇
  2019年   17篇
  2018年   22篇
  2017年   24篇
  2016年   24篇
  2015年   14篇
  2014年   29篇
  2013年   30篇
  2012年   18篇
  2011年   38篇
  2010年   40篇
  2009年   39篇
  2008年   36篇
  2007年   38篇
  2006年   25篇
  2005年   27篇
  2004年   39篇
  2003年   41篇
  2002年   27篇
  2001年   15篇
  2000年   14篇
  1999年   11篇
  1998年   14篇
  1997年   11篇
  1996年   7篇
  1995年   10篇
  1994年   9篇
  1993年   9篇
  1992年   4篇
  1991年   9篇
  1990年   3篇
  1989年   8篇
  1988年   7篇
  1987年   3篇
  1986年   4篇
  1985年   8篇
  1984年   5篇
  1983年   5篇
  1982年   4篇
  1981年   4篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1974年   1篇
  1971年   1篇
排序方式: 共有790条查询结果,搜索用时 15 毫秒
1.
In this case report, we discuss a patient presenting with parkinsonism followed by a non-amnestic dementia with aphasic clinical features, as well as frontal dysexecutive syndrome. There was a family history of dementia with an autopsy diagnosis of “Pick's disease” in the proband's father. Neuroimaging of the patient revealed focal and severe temporal lobe and lesser frontoparietal lobe atrophy. At autopsy, there was severe frontotemporal lobar degeneration. Histologic evaluation revealed an absence of tau or transactivation response DNA-binding protein of 43 kDa (TDP) pathology but rather severe Lewy body deposition in the affected cortices. Genetic phenotyping revealed a novel missense mutation (p.E83Q) in exon 4 of the gene encoding α-synuclein (SNCA). This case study presents a patient with a novel SNCA E83Q mutation associated with widespread Lewy body pathology with prominent severe atrophy of the frontotemporal lobes and corresponding cognitive impairment.  相似文献   
2.
ObjectiveTo investigate the molecular cause(s) underlying a severe form of infantile-onset parkinsonism and characterize functionally the identified variants.MethodsA trio-based whole exome sequencing (WES) approach was used to identify the candidate variants underlying the disorder. In silico modeling, and in vitro and in vivo studies were performed to explore the impact of these variants on protein function and relevant cellular processes.ResultsWES analysis identified biallelic variants in WARS2, encoding the mitochondrial tryptophanyl tRNA synthetase (mtTrpRS), a gene whose mutations have recently been associated with multiple neurological phenotypes, including childhood-onset, levodopa-responsive or unresponsive parkinsonism in a few patients. A substantial reduction of mtTrpRS levels in mitochondria and reduced OXPHOS function was demonstrated, supporting their pathogenicity. Based on the infantile-onset and severity of the phenotype, additional variants were considered as possible genetic modifiers. Functional assessment of a selected panel of candidates pointed to a de novo missense mutation in CHRNA6, encoding the α6 subunit of neuronal nicotinic receptors, which are involved in the cholinergic modulation of dopamine release in the striatum, as a second event likely contributing to the phenotype. In silico, in vitro (Xenopus oocytes and GH4C1 cells) and in vivo (C. elegans) analyses demonstrated the disruptive effects of the mutation on acetylcholine receptor structure and function.ConclusionOur findings consolidate the association between biallelic WARS2 mutations and movement disorders, and suggest CHRNA6 as a genetic modifier of the phenotype.  相似文献   
3.
IntroductionThere is little information on the late stages of parkinsonism.MethodsWe conducted a multicentre study in 692 patients with late stage parkinsonism in six European countries. Inclusion criteria were disease duration of ≥7 years and either Hoehn and Yahr stage ≥4 or Schwab and England score of 50 or less.ResultsAverage disease duration was 15.4 (SD 7.7) years and mean total UPDRS score was 82.7 (SD 22.4). Dementia according to MDS-criteria was present in 37% of patients. Mean levodopa equivalence dose was 874.1 (SD 591.1) mg/d. Eighty two percent of patients reported falls, related to freezing (16%) or unrelated to freezing (21% of patients) or occurring both related and unrelated to freezing (45%), and were frequent in 26%. Moderate-severe difficulties were reported for turning in bed by 51%, speech by 43%, swallowing by 16% and tremor by 11%. Off-periods occurred in 68% and were present at least 50% of the day in 13%, with morning dystonia occurring in 35%. Dyskinesias were reported by 45% but were moderate or severe only in 7%. Moderate-severe fatigue, constipation, urinary symptoms and nocturia, concentration and memory problems were encountered by more than half of participants. Hallucinations (44%) or delusions (25%) were present in 63% and were moderate-severe in 15%. The association with overall disability was strongest for severity of falls/postural instability, bradykinesia, cognitive score and speech impairment.ConclusionThese data suggest that current treatment of late stage parkinsonism in the community remains insufficiently effective to alleviate disabling symptoms in many patients.  相似文献   
4.
IntroductionMild parkinsonian signs (MPS) are associated with morbidity. Identification of MPS progression markers may be vital for preventive management, yet has not been pursued. This study aimed to ascertain clinical/neuroimaging features predictive of MPS progression.Methods205 participants in the Health ABC Study were included. MPS was defined using published guidelines. MPS progression was evaluated by determining UPDRS-III change between baseline and follow-up ≥2 years later. Standard brain MRI and DTI were obtained at baseline. Correlation coefficients between demographics, vascular risk factors, imaging markers, and UPDRS-III change were adjusted for follow-up time. Linear regression was used to adjust for possible confounders in the relationship between imaging markers and MPS progression.Results30% of participants had baseline MPS. Demographics and risk factors did not differ significantly between participants with MPS (MPS+) and without MPS (MPS-). Mean follow-up time was 3.8±0.8 years. Older age, male gender, diabetes were associated with faster rate of UPDRS-III change in MPS- but not MPS+ participants. Among MPS- participants, the only imaging marker associated with faster UPDRS-III progression was higher gray matter mean diffusivity (MD), widespread in various cortico-subcortical bihemispheric regions, independent of age, gender, diabetes. No imaging features were associated with UPDRS-III change among MPS+ participants.ConclusionsLower gray matter integrity predicted MPS progression in those who did not have baseline MPS. Microstructural imaging may capture early changes related to MPS development, prior to macrostructural change. Any future management promoting gray matter preservation may inhibit MPS development.  相似文献   
5.
6.
ObjectivesDespite its use in determining nigrostriatal degeneration, the lack of a consistent interpretation of nigrosome 1 susceptibility map-weighted imaging (SMwI) limits its generalized applicability. To implement and evaluate a diagnostic algorithm based on convolutional neural networks for interpreting nigrosome 1 SMwI for determining nigrostriatal degeneration in idiopathic Parkinson's disease (IPD).MethodsIn this retrospective study, we enrolled 267 IPD patients and 160 control subjects (125 patients with drug-induced parkinsonism and 35 healthy subjects) at our institute, and 24 IPD patients and 27 control subjects at three other institutes on approval of the local institutional review boards. Dopamine transporter imaging served as the reference standard for the presence or absence of abnormalities of nigrosome 1 on SMwI. Diagnostic performance was compared between visual assessment by an experienced neuroradiologist and the developed deep learning-based diagnostic algorithm in both internal and external datasets using a bootstrapping method with 10000 re-samples by the “pROC” package of R (version 1.16.2).ResultsThe area under the receiver operating characteristics curve (AUC) (95% confidence interval [CI]) per participant by the bootstrap method was not significantly different between visual assessment and the deep learning-based algorithm (internal validation, .9622 [0.8912–1.0000] versus 0.9534 [0.8779-0.9956], P = .1511; external validation, 0.9367 [0.8843-0.9802] versus 0.9208 [0.8634-0.9693], P = .6267), indicative of a comparable performance to visual assessment.ConclusionsOur deep learning-based algorithm for assessing abnormalities of nigrosome 1 on SMwI was found to have a comparable performance to that of an experienced neuroradiologist.  相似文献   
7.
Sighs are physiological phenomena and may occasionally occur during sleep in healthy young adults. Although inspiratory sighs are considered a diagnostic red flag for the parkinsonian form of multiple system atrophy (MSA), its frequency and characteristics are unclear. We aimed to define sigh frequency during sleep recordings in patients with MSA compared to Parkinson's disease (PD) patients, as well as evaluate possible associated breathing disorders or autonomic changes. We analyzed 9 polysomnography's from patients with MSA and 9 from matched PD patients. The proportion of MSA patients (both MSA-P and MSA-C) with sleep-related sighs was significantly higher than that of PD patients, and these occurred predominantly in stages N1 and N2. The median sigh index in sleep and wakefulness were also significantly higher in MSA, although with a significant inter-subject variability. Higher sigh indexes were not associated to other breathing disturbances or with longer disease duration. In MSA, 12% of sighs were associated with oxygen desaturation, while none of the events in PD patients presented with significant changes in oxygen saturation. Respiratory events followed 45% of sighs in MSA, predominantly central sleep apneas, and 29% of sighs in PD, predominantly hypopneas. Our data suggests that high sigh frequencies during sleep should also be considered a red flag for MSA, and future studies should aim to determine whether increased sighing frequency during sleep is specific for this disorder.  相似文献   
8.
目的 探讨普拉克索对老年血管性帕金森综合征(vascular parkinsonism,VP)患者非运动症状及氧化应激的影响。方法 纳入2015年1月—2016年6月于宁波市奉化区人民医院接受治疗的96例老年VP患者,按照随机化原则分为2组,各48例。2组均接受抗凝、改善循环、神经营养治疗,观察组在此基础上应用普拉克索,对照组应用美多芭片。分别于治疗前、治疗12月时测评患者统一帕金森病评定量表(UPDRS)、汉密尔顿抑郁量表(HAMD)、社会功能活动问卷(FAQ)、匹兹堡睡眠质量指数量表(PSQI)评分变化情况,并统计肢体感觉异常、自主神经症状发生情况,同时采集患者空腹静脉血,检测血清丙二醛、同型半胱氨酸、血钙、对氧磷酶-1水平。结果 2组治疗前UPDRS、HAMD、FAQ、PSQI量表评分,血清丙二醛、同型半胱氨酸、血钙、对氧磷酶-1水平均接近,组间差异无统计学意义。治疗后上述指标均有所改善,且观察组UPDRS各部分得分、HAMD和FAQ得分、PSQI各维度得分均显著低于对照组(P<0.05),丙二醛、同型半胱氨酸水平显著低于对照组(P<0.05),对氧磷酶-1水平显著高于对照组(P<0.05)。观察组治疗期间肢体感觉异常、自主神经症状发生率显著低于对照组(P<0.05)。结论 普拉克索能够有效改善老年VP患者非运动症状,抑制氧化应激损伤,对老年VP患者疗效更优。  相似文献   
9.
10.
Rapid‐onset dystonia‐parkinsonism (RDP) is caused by mutations in the ATP1A3 gene. This observational study sought to determine if cognitive performance is decreased in patients with RDP compared with mutation‐negative controls. We studied 22 familial RDP patients, 3 non‐motor‐manifesting mutation‐positive family members, 29 mutation‐negative family member controls in 9 families, and 4 unrelated RDP patients, totaling 58 individuals. We administered a movement disorder assessment, including the Burke‐Fahn‐Marsden Dystonia Rating Scale (BFMDRS) and the Unified Parkinson's Disease Rating Scale (UPDRS) and a cognitive battery of memory and learning, psychomotor speed, attention, and executive function. The cognitive battery was designed to evaluate a wide range of functions; recognition memory instruments were selected to be relatively pure measures of delayed memory, devoid of significant motor or vocal production limitations. Comparisons of standardized cognitive scores were assessed both with and without controlling for psychomotor speed and similarly for severity of depressive symptoms. A majority of RDP patients had onset of motor symptoms by age 25 and had initial symptom presentation in the upper body (face, mouth, or arm). Among patients, the BFMDRS (mean ± SD, 52.1 ± 29.5) and UPDRS motor subscore (29.8 ± 12.7) confirmed dystonia‐parkinsonism. The affected RDP patients performed more poorly, on average, than mutation‐negative controls for all memory and learning, psychomotor speed, attention, and executive function scores (all P ≤ 0.01). These differences persisted after controlling for psychomotor speed and severity of depressive symptoms. Impaired cognitive function may be a manifestation of ATP1A3 mutation and RDP. © 2014 International Parkinson and Movement Disorder Society  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