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   29016篇
  免费   2477篇
  国内免费   726篇
耳鼻咽喉   686篇
儿科学   508篇
妇产科学   233篇
基础医学   2153篇
口腔科学   392篇
临床医学   4455篇
内科学   3452篇
皮肤病学   363篇
神经病学   2391篇
特种医学   480篇
外国民族医学   3篇
外科学   1486篇
综合类   4791篇
现状与发展   3篇
一般理论   1篇
预防医学   3605篇
眼科学   381篇
药学   2586篇
  39篇
中国医学   3513篇
肿瘤学   698篇
  2024年   124篇
  2023年   685篇
  2022年   1166篇
  2021年   1637篇
  2020年   1506篇
  2019年   1250篇
  2018年   1293篇
  2017年   1155篇
  2016年   1232篇
  2015年   1029篇
  2014年   2287篇
  2013年   2165篇
  2012年   2039篇
  2011年   1972篇
  2010年   1538篇
  2009年   1296篇
  2008年   1222篇
  2007年   1228篇
  2006年   1011篇
  2005年   876篇
  2004年   734篇
  2003年   745篇
  2002年   477篇
  2001年   496篇
  2000年   381篇
  1999年   340篇
  1998年   223篇
  1997年   224篇
  1996年   195篇
  1995年   205篇
  1994年   183篇
  1993年   126篇
  1992年   109篇
  1991年   104篇
  1990年   91篇
  1989年   78篇
  1988年   59篇
  1987年   65篇
  1986年   45篇
  1985年   100篇
  1984年   83篇
  1983年   78篇
  1982年   75篇
  1981年   51篇
  1980年   66篇
  1979年   26篇
  1978年   40篇
  1977年   22篇
  1976年   19篇
  1974年   16篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
《Clinical neurophysiology》2021,132(7):1622-1635
ObjectiveTo assess whether ictal electric source imaging (ESI) on low-density scalp EEG can approximate the seizure onset zone (SOZ) location and predict surgical outcome in children with refractory epilepsy undergoing surgery.MethodsWe examined 35 children with refractory epilepsy. We dichotomized surgical outcome into seizure- and non-seizure-free. We identified ictal onsets recorded with scalp and intracranial EEG and localized them using equivalent current dipoles and standardized low-resolution magnetic tomography (sLORETA). We estimated the localization accuracy of scalp EEG as distance of scalp dipoles from intracranial dipoles. We also calculated the distances of scalp dipoles from resection, as well as their resection percentage and compared between seizure-free and non-seizure-free patients. We built receiver operating characteristic curves to test whether resection percentage predicted outcome.ResultsResection distance was lower in seizure-free patients for both dipoles (p = 0.006) and sLORETA (p = 0.04). Resection percentage predicted outcome with a sensitivity of 57.1% (95% CI, 34–78.2%), a specificity of 85.7% (95% CI, 57.2–98.2%) and an accuracy of 68.6% (95% CI, 50.7–83.5%) (p = 0.01).ConclusionIctal ESI performed on low-density scalp EEG can delineate the SOZ and predict outcome.SignificanceSuch an application may increase the number of children who are referred for epilepsy surgery and improve their outcome.  相似文献   
992.
《Clinical neurophysiology》2021,132(9):2222-2231
ObjectiveChildhood absence epilepsy (CAE) is a disease with distinct seizure semiology and electroencephalographic (EEG) features. Differentiating ictal and subclinical generalized spikes and waves discharges (GSWDs) in the EEG is challenging, since they appear to be identical upon visual inspection. Here, spectral and functional connectivity (FC) analyses were applied to routine EEG data of CAE patients, to differentiate ictal and subclinical GSWDs.MethodsTwelve CAE patients with both ictal and subclinical GSWDs were retrospectively selected for this study. The selected EEG epochs were subjected to frequency analysis in the range of 1–30 Hz. Further, FC analysis based on the imaginary part of coherency was used to determine sensor level networks.ResultsDelta, alpha and beta band frequencies during ictal GSWDs showed significantly higher power compared to subclinical GSWDs. FC showed significant network differences for all frequency bands, demonstrating weaker connectivity between channels during ictal GSWDs.ConclusionUsing spectral and FC analyses significant differences between ictal and subclinical GSWDs in CAE patients were detected, suggesting that these features could be used for machine learning classification purposes to improve EEG monitoring.SignificanceIdentifying differences between ictal and subclinical GSWDs using routine EEG, may improve understanding of this syndrome and the management of patients with CAE.  相似文献   
993.
《Clinical neurophysiology》2021,132(12):3104-3115
ObjectiveWe aimed to establish an objective neurophysiological test protocol that can be used to assess the somatosensory nervous system.MethodsIn order to assess most fiber subtypes of the somatosensory nervous system, repetitive stimuli of seven different modalities (touch, vibration, pinprick, cold, contact heat, laser, and warmth) were synchronized with the electroencephalogram (EEG) and applied on the cheek and dorsum of the hand and dorsum of the foot in 21 healthy subjects and three polyneuropathy (PNP) patients. Latencies and amplitudes of the modalities were assessed and compared. Patients received quantitative sensory testing (QST) as reference.ResultsWe found reproducible evoked potentials recordings for touch, vibration, pinprick, contact-heat, and laser stimuli. The recording of warm-evoked potentials was challenging in young healthy subjects and not applicable in patients. Latencies were shortest within Aβ-fiber-mediated signals and longest within C-fibers. The test protocol detected function loss within the Aβ-fiber and Aδ-fiber-range in PNP patients. This function loss corresponded with QST findings.ConclusionIn this pilot study, we developed a neurophysiological test protocol that can specifically assess most of the somatosensory modalities. Despite technical challenges, initial patient data appear promising regarding a possible future clinical application.SignificanceEstablished and custom-made stimulators were combined to assess different fiber subtypes of the somatosensory nervous system using modality-specific evoked potentials.  相似文献   
994.
Due to novel gene therapy opportunities, genetic screening is no longer restricted to familial cases of ALS (FALS) cases but also aplies to the sporadic populations (SALS). Screening of four main genes (C9orf72, SOD1, TARDBP and FUS) identified the causes in 15% of Amyotrophic Lateral Sclerosis (ALS) patients (two third of the familial cases and 8% of the sporadic ones) but their respective contribution to ALS phenotype varies according the age of disease onset. The genetic overlap between ALS and other diseases is expanding and includes frontotemporal dementia, Paget's Disease of Bone, myopathy for adult cases, HSP and CMT for young cases highlighing the importance of retrieving the exhaustive familial history for each indivdual with ALS. Incomplete disease penetrance, diversity of the possible phenotypes, as well as the lack of confidence concerning the pathogenicity of most identified variants and/or possible oligogenic inheritance are burdens of ALS genetic counseling to be delivered to patients and at risk individuals. The multitude of rare ALS genetic causes identifed seems to converge to similar cellular pathways leading to inapropriate response to stress emphacising new potential therapeutic options for the disease.  相似文献   
995.
996.
目的 探讨髓过氧化物酶抗中性粒细胞胞质抗体(MPO-ANCA)相关性肥厚性硬脑膜炎(HCP)合并肉芽肿性血管炎(GPA)的临床特点、治疗及预后.方法 回顾性分析2016-06—2020-06郑州大学第一附属医院神经内科住院治疗的MPO-ANCA相关性HCP合并GPA患者的临床资料.结果 5例患者均为亚急性或慢性起病,病...  相似文献   
997.

Aims:

To assess sleep quality in patients with primary headaches before and after prophylactic treatment using a validated sleep-screening instrument.

Materials and Methods:

A total of 147 patients, including 63 tension type headache (TTH) and 84 migraine patients were included. Patients were examined in terms of frequency and severity of headaches and sleep quality before and 12 weeks after prophylactic treatment with either propranolol or amitriptyline.

Results:

Baseline Visual Analogue Score (VAS) in migraine patients was 7.99 ± 1.39 compared with 6.86 ± 1.50 in TTH group (P < 0.001). VAS score after the first month of treatment was 6.08 ± 1.88 in migraine patients and 5.40 ± 1.61 in TTH (P = 0.023). VAS scores decreased after the third month of treatment to 4.32 ± 2.29 in migraine patients and 4.11 ± 1.66 in TTH patients (P = 0.344). The decrease was significant for patients treated with amitriptyline but not for those with propranolol. Baseline Pittsburgh Sleep Quality (PSQI) scores were 5.93 ± 2.43 in migraine patients and 6.71 ± 2.39 in TTH patients. Poor quality of sleep (PSQI ≥ 6) prior to prophylactic treatment was observed in 61.4% of migraine patients and in 77.7% of TTH patients. Comparison of PSQI scores before and 3 months following treatment showed significantly improved quality of sleep in all treatment groups; the greatest significance was detected in migraine patients with initial PSQI scores of ≥6 and treated with amitriptyline (P < 0.001).

Conclusions:

Increased understanding of routine objective sleep measures in migraine patients is needed to clarify the nature of sleep disturbances associated with primary headaches. This may in turn lead to improvements in headache treatments.  相似文献   
998.
999.
1000.
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