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   20527篇
  免费   2114篇
  国内免费   972篇
耳鼻咽喉   24篇
儿科学   147篇
妇产科学   48篇
基础医学   706篇
口腔科学   58篇
临床医学   5124篇
内科学   3095篇
皮肤病学   21篇
神经病学   6426篇
特种医学   559篇
外科学   648篇
综合类   2715篇
现状与发展   5篇
预防医学   1017篇
眼科学   51篇
药学   1298篇
  21篇
中国医学   1612篇
肿瘤学   38篇
  2024年   143篇
  2023年   558篇
  2022年   1071篇
  2021年   1445篇
  2020年   1264篇
  2019年   1149篇
  2018年   1194篇
  2017年   1126篇
  2016年   1110篇
  2015年   932篇
  2014年   1769篇
  2013年   2091篇
  2012年   1260篇
  2011年   1172篇
  2010年   962篇
  2009年   850篇
  2008年   790篇
  2007年   802篇
  2006年   725篇
  2005年   510篇
  2004年   437篇
  2003年   351篇
  2002年   373篇
  2001年   279篇
  2000年   210篇
  1999年   178篇
  1998年   145篇
  1997年   99篇
  1996年   74篇
  1995年   66篇
  1994年   84篇
  1993年   68篇
  1992年   48篇
  1991年   34篇
  1990年   32篇
  1989年   25篇
  1988年   24篇
  1987年   27篇
  1986年   25篇
  1985年   18篇
  1984年   18篇
  1983年   22篇
  1982年   20篇
  1981年   9篇
  1980年   8篇
  1979年   8篇
  1978年   3篇
  1977年   3篇
  1975年   2篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Lesion evolution during focal cerebral ischemia may depend on flow restrictions or on accumulation of toxic mediators within the infarct and expansion of these factors to the periinfarct region. So far, the precise contribution of flow dependent versus spreading-mediated impairment of viable periinfarct tissue has not been determined. Therefore, we measured lesion expansion, flow restrictions and glutamate distribution on serial brain sections at different time points after experimental focal ischemia.Permanent focal ischemia was induced by occlusion of the right middle cerebral artery in male rats and the flow reduction was subsequently measured at 1, 12 and 24 h using iodo[14C]antipyrine autoradiography. Additionally, the necrotic volume was determined on serial brain sections and the glutamate content was measured in tissue samples from adjacent microdissections.Twelve hours after focal ischemia no noteworthy viable areas with blood flow restrictions of 20-40 ml 100 g− 1 min− 1 existed but at 24 h the necrotic tissue exceeded the hemodynamically compromised region by 40 ± 21 mm3 (24%). Furthermore, at 12 and 24 h the glutamate content was elevated in areas surrounding the infarct.Relevant flow restrictions are detectable only during early stages of infarct maturation, whereas the propagation of secondary factors may be the predominant mechanism for delayed infarct evolution.  相似文献   
2.
眼底动脉硬化与血压、血糖、血脂的多元分析与评估   总被引:1,自引:0,他引:1  
目的探讨眼底动脉硬化与血压、血脂、血糖的相关性,评估中风危险度。方法对2004年5月至2008年10月就诊的患者335例,作为观察组,并与无症状的健康体检者180例作对照,动态检测眼底动脉硬化、血压、血糖、血脂的异常变化,并做综合量化评估。结果脑血管疾病与眼底动脉硬化、血压、血糖、血脂等因素密切相关。结论眼底动脉硬化、血糖、血脂、血压异常的量化评分,能够预估中风,以便采取预防性治疗。  相似文献   
3.
中风毒邪论是一种与传统中医中风病理有所不同的理论 ,在中风毒邪论指导下形成解毒通络方是较为理想的神经保护剂 ,可解决目前神经保护治疗的主要障碍 ,有望成为提高中医治疗中风急性期疗效的关键  相似文献   
4.
目的 观察急性大血管闭塞性轻型卒中患者血管内治疗的疗效及安全性。
方法 回顾性分析2018年1月-2019年5月行血管内治疗的急性大血管闭塞性轻型卒中(NIHSS评分
≤5分)患者的临床资料。观察术后血管成功再通率(mTICI≥2b级)、围手术期并发症、90 d良好预后率
(mRS评分≤2分)等。
结果 共纳入13例患者,平均年龄58.7±14.5岁,男性11例(84.6%)。术后血管成功再通率100%;围
手术期并发症2例,假性动脉瘤1例、无症状性颅内出血1例;90 d良好预后率100%。
结论 急性大血管闭塞性轻型卒中行血管内治疗可能是安全、有效的。  相似文献   
5.
148 patients with various forms of cerebrovascular disease (CVD) were studied by means of a multiparametric analysis ofin vitro platelet aggregation, based on the following six parameters: ADP and epinephrine primary and secondary aggregation thresholds and percent maximum aggregation induced by optimal concentrations of ADP and epinephrine. These patients were assigned to four study groups, according to clinical diagnosis supported by CT scan, of transient ischemic attack and reversible neurological deficit (TIA-RIND), or completed stroke, in the presence or absence respectively of antiplatelet medical treatment at the time of the study. A statistically significant increase of thein vitro platelet aggregation was found in 44.4% of the untreated TIA-RIND patients and in 33.9% of the untreated stroke patients. However this last group showed a higher percentage of very marked hyperaggregation. Differences between the two treated study groups and controls were not signicant. No difference was found in collagen-and ristocetin-induced aggregation between the patient groups and the controls.
Sommario 148 pazienti con varie forme di malattia cerebrovascolare, sono stati studiati con analisi multiparametriche dell'aggregazione piastrinica in vitro sulla base dei seguenti sei parametri: le soglie di aggregazione primaria e secondaria e l'aggregazione massima percentuale indotta da ADP ed Epinefrina. Questi pazienti sono stati suddivisi in 4 gruppi di studio in accordo con la diagnosi clinica confortata dai dati della TAC e cioè: TIA, RIND, o rammollimento in presenza o in assenza rispettivamente di un trattamento antiaggregante nel momento dello studio. è stato trovato un aumento statisticamente significativo dell'aggregazione in vitro delle piastrine nel 44.4% dei casi TIA, RIND non trattati e nel 33,9% dei casi di rammollimento non trattati. Quest'ultimo gruppo, però, ha dimostrato una più alta percentuale di iperaggregazione molto marcata. Le differenze tra i 2 gruppi di studio trattati con antiaggreganti e i controlli non erano significative. Inoltre nessuna differenza è stata riscontrata tra i gruppi e i controlli nell'aggregazione indotta da collageno e ristocetina.
  相似文献   
6.
Valid classification of stroke is essential to initiate effective acute management and early secondary prevention strategies. To accurately evaluate stroke subtype a number of diagnostic procedures have to be performed. This study sought to investigate variations in use of diagnostic procedures across selected European hospitals. First-ever stroke patients were sampled over a 1-year period through 11 hospital-based registers across 10 European countries. We defined a diagnostic standard for valid aetiological classification of ischemic stroke including brain imaging, vascular imaging and echocardiography. The impact of socio-demographic, clinical and structural characteristics on performance of the diagnostic standard was assessed using multivariate logistic regression analyses. A total of 1721 patients were included in the study. 83.1% received brain imaging, ranging from 32.8% to 100%. The diagnostic standard was performed in 40.4% of stroke patients, ranging from 0% to 77.2%. Patients with increasing age ( P  < 0.001) and with more severe strokes ( P  = 0.001) were less probably to receive the diagnostic standard. Patients treated in stroke units and neurological departments were more frequently investigated with the diagnostic standard ( P  < 0.001). Less than half of hospitalized stroke patients across Europe underwent diagnostic procedures to allow for aetiological classification of stroke, which may hamper the initiation of effective early management and secondary prevention.  相似文献   
7.
Intracranial Angioplasty and Stenting in the Awake Patient   总被引:1,自引:0,他引:1  
BACKGROUND AND PURPOSE: Endovascular treatment for intracranial atherosclerosis is evolving, but complications remain an issue. Most interventions are performed under general anesthesia, preventing intraprocedural clinical evaluations. We describe our approach to intracranial angioplasty and stenting, using local rather than general anesthesia, and intraprocedural neurological assessment. METHODS: We prospectively collected procedural and outcome information on all patients undergoing intracranial angioplasty and stenting. Patients underwent interventions under local anesthesia with mild intravenous sedation or analgesia only if needed. Intraoperative neurological evaluations were performed, and symptomatology was used to guide the interventional technique. RESULTS: Forty-eight arteries in 40 patients with a mean age of 65.2 years were treated. Thirty-two anterior and 16 posterior circulation segments were treated. Technical success was achieved in 100% of patients with reduction of the mean pretreatment stenosis from 85 +/- 8.6% to 7 +/- 10.1%. Stents were deployed in 40 segments; five patients were treated with drug-eluting stents. The cobalt-chromium coronary stents were the easiest to deliver. Thirty-seven patients were treated under local anesthesia and, of those, 61.4% experienced intraprocedural symptoms that led to some alteration of the interventional technique. Headache was the most common symptom, and, when persistent, it heralded the occurrence of subarachnoid hemorrhage. There were seven total neurological complications, but only five (10.5%) led to permanent morbidity (4 strokes) or mortality (1 death). CONCLUSIONS: Intracranial angioplasty and stenting can be successfully performed using coronary techniques and equipment including drug-eluting stents. Local anesthesia permits neurological evaluations and often leads to the adjustment of the interventional technique, potentially making the procedure safer.  相似文献   
8.
Stroke-induced hemiballismus (HB) has been reported to improve motor function in people with Parkinson's disease (PD). We report on a patient who developed HB from a parietal infarct. The HB was improved by very low-dose clozapine but the HB did not improve the parkinsonism. This suggests that HB itself, whether from a lesion in the subthalamic nucleus or elsewhere, is not what improves motor function in PD; instead, the physiological function of the damaged structure is the determining factor.  相似文献   
9.
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