首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 319 毫秒
1.
目的:探讨民航飞行人员高血压病危险因素暴露与心率变异性(HRV)及压力反射敏感度(BRS)之间的联系。方法 在参加年度大体检的450名血压正常的民航飞行人员中,根据有无危险因素暴露将其分为年龄≥40岁组、体重超重组、血脂异常组、吸烟组、饮酒组及相应对照组。采用常规自回归谱分析方法对各组飞行人员的短时程HRV信号进行分析,同时采用序贯法计算其BRS。结果 与对照组相比,年龄≥40岁的飞行人员HRV明显降低,表现为总功率(TP)、低频功率(LF)、高频功率(HF)及归一化高频成分(HFn)显降低(P<0.01),而归一化低频成分(LFn)与LF/HF则显增加(P<0.05);其BRS亦显降低(P<0.01)。其他危险因素暴露时,HRV的TP、LF及HF均显降低(P<0.05),而LFn、HFn、HFn及LF/HF则无明显变化,BRS亦显降低(P<0.05)。结论 民航飞行人员高血压病危险因素的暴露与HRV及BRS的降低密切联系;提示在高血压病发病之前,心血管自主神经调节功能即已发生异常。在对飞行人员进行高血压病的早期危险性预报时应重视对其自主神经调节功能的评价。  相似文献   

2.
目的探讨民航飞行人员高血压病患者心血管自主神经调节功能的变化规律,为合理防治高血压病提供依据.方法利用常规AR谱分析方法对14例民航飞行人员高血压病患者和14例健康飞行人员的短时程心率变异性(HRV)信号进行分析,同时采用序贯法分析其压力反射敏感度(BRS).结果①与对照组相比,高血压病患者的HRV明显降低,差异有显著性意义(P<0.05),表现为总功率(TP)、低频功率(LF)、高频功率(HF)及归一化高频成分(HFn)降低,而归一化低频成分(LFn)与LF/HF则增加;②高血压病患者的BRS较对照组降低,差异有非常显著性意义(P<0.01).结论飞行人员高血压病患者心血管自主神经调节功能明显异常,交感神经调节活动相对增强,迷走神经调节活动受到抑制.在飞行人员高血压病的防治研究中,应加强对其自主神经调节功能的分析.  相似文献   

3.
观察头高位倾斜(HUT,+65°)持续15min对10名健康男青年心率变异性(HRV)谱、血压变异性(SBPV)谱及压力反射敏感性(BRS)的影响。被试者由卧位转为HUT时,HRV高频谱峰功率(HFHRV)、总功率(TPHRV)及归一化高频谱成份(HFHRV,n)均显著降低(P<0.01),低频谱峰功率(LFHRV)仅有升高趋势,但归一化低频谱成份(LFHRV,n)显著升高;SBPV谱高、低频谱峰功率(HFSBPV,LFSBPV)及总功率(TPSBPV)均显著升高(P<0.01);BRS显著降低(P<0.01)。在HUT持续作用的6-12min期间,HRV、SBPV港的变化与HUT0-6min期间天显著性差别。结果提示立位应激时被试者心迷走神经活动降低、心交感及外周血管交感神经活动增强。  相似文献   

4.
急性缺氧条件下的心率变异性分析   总被引:11,自引:1,他引:10  
目的 以心率变异性(HRV)为定量评价心血管自主神经调节变化的指标,观察模拟5000m急性缺氧条件下,自主神经变化特点,并探讨预测缺氧耐力不良的方法。方法 被试者为11名18-30岁的健康男性,以呼吸10.5%的低氧混合气30min模拟5000m急性缺氧,以时域和频域(粗粒化谱分析,CGSA)方法进行HRV分析。并根据是否完成实验过程将被试者分为耐力良好组(A组)和耐力不良组(B组)。结果 耐力良好组在缺氧时心率显著增快,相邻RR间期之差的均方根值(RMSSD)显著减小,LFn.u(LF的标准单位)和LF/HF显著增大,HF和HFn.u.(HF的标准化单位)显著减小。两组比较,缺氧5-10min时,LFn.u.和LF/HF在B组显著大于A组,缺氧10-15min时,RMSSD在B组显著小于A组。结论 在模拟5000m急性缺氧条件下,交感神经活动增强,迷走神经活动减弱;HRV分析对评价缺氧耐力有一定的预测性。  相似文献   

5.
目的探讨电动三维滚轮在飞行人员前庭功能选拔中的作用。方法对20名飞行人员分别进行转椅90 s和三维滚轮5 min的测试,观察在此过程中被试者的血压、心率、心率变异性(heart rate variability,HRV)和呼吸等各项生理指标,并依据症状和主诉对其前庭功能进行评级并对比两者通过率。结果相较于转椅测试,飞行人员在三维滚轮测试过程中的心率显著升高,LFn显著降低,HFn显著升高,LF/HF明显降低(P0.05)。二者前庭自主神经稳定性分级结果一致,合格率均为95%。结论电动三维滚轮可以用于飞行人员前庭功能稳定性的选拔。  相似文献   

6.
跨时区飞行对飞行员心率变异性的影响   总被引:4,自引:3,他引:1  
目的 探讨跨时区飞行对飞行员心率变异性的影响 ,以评价其对飞行员自主神经系统的作用。 方法 采用 2 4h动态心电图方法检测 16名跨时区国际长途飞行的飞行员动态心电图及心率变异性 (HRV) ;另外检测 10名国内昼间飞行的飞行员动态心电图及HRV作为对照。检查指标 :①HRV的低频功率 (0 .0 4~ 0 .15Hz ,LF) ;②HRV的高频功率 (0 .15~ 0 .4 0Hz,HF) ;③HRV的总频功率 (0 .0 4~ 0 .4 0Hz,TF)。计算飞行员HRV谱成份的夜间调节指数。用两组飞行员调节指数的差值作为自主神经负荷程度的定量估计。 结果 对照组飞行员的HF反映迷走神经活性在 2 4h中显示明显的昼夜节律 ,即夜间HF增高 ,LF降低 ;白天HF降低 ,LF增高。交感神经活性在跨时区飞行组上述谱成份的昼夜节律性明显降低。②对照组飞行员的HF夜间调节指数为 0 .32± 0 .11,而跨时区飞行组HF夜间调节指数为 0 .0 6± 0 .0 2 (P <0 .0 5 )。对照组LF夜间调节指数为 - 0 .0 2± 0 .0 8,而跨时区飞行组LF夜间调节指数为 - 0 .0 9± 0 .0 4 (P <0 .0 5 )。 结论 跨时区飞行使飞行员HRV谱成份的昼夜周期节律显著降低  相似文献   

7.
有晕厥史飞行员立位应激下自主神经功能评价   总被引:5,自引:0,他引:5  
目的:评价加速度引起的意识丧失(G-LOC)或血管迷走性晕厥(VVS)飞行员在立位耐力试验(OTT)条件下自主遥作用。方法:对30例晕厥并阳 性OTT病例组(I组),20例晕厥并阴性OTT病例组(Ⅱ组)和15例年龄,性别,飞行机种,飞行时间相匹配的健康飞行员(对照组)的心率变异(HRV)和OTT的关系进行研究,对所测量OTT前后心率(HR),收缩压(SBP),舒张压(DBP)和HRV指标进行对比分析。结果:3组被试者OTT前平均HR,SBP,DBP比较无显著性差异(P>0.05),OTT后I组HR明显高于其他两组(P<0.01),SBP和DBP明显低于其他两组(P<0.01),HRV指标中I组24h连续RR间期标准差(SDNN),HRV三角指数(HRVI),RR间期平均值(RR)明显小于其他两组(P<0.01),平均1h 功率谱分析I组低频成分/高频成份比值(LF/HF)明显高于其他两组(P<0.05),结论:晕厥并阳性OTT飞行员立位应激下交感神经张力增强,副交感神经张力减弱,使自主神经功能失调。  相似文献   

8.
目的:以心率变异性(HRV)为定量评价心血管自主神经调节变化的指标,观察模拟5000m急性缺氧条件下,自主神经变化特点,并探讨预测缺氧耐力不良的方法。方法:被试为11名18-30岁的健康男性,以呼吸10.5%的低氧混合气30min模拟5000m急性缺氧,以时域和频域(粗粒化谱分析,CGSA)方法进行HRV分析,并根据是否完成实验过程将被试分为耐力良好组(A组)和耐力不良组(B组),结果:耐力良好组在缺氧时心率显增快,相邻RR间期之差的均方根值(RMSSD)显减小,LFn.u.(LF的标准化单位)和LF/HF显增大,HF和HFn.u.(HF的标准化单位)显减小,两组比较,缺氧5-10min时,LFn.u.和LF/HF 在B组显大于A组,缺氧10-15min时,RMSSD在B组显小于A组,结论:在模拟5000m急性缺氧条件下,交感神经活动增强,迷走神经活动减弱;HRV分析对评价缺氧耐力有一定的预测性。  相似文献   

9.
地面模拟长航时飞行时飞行学员心率和心率变异性的变化   总被引:1,自引:1,他引:0  
目的探讨飞行人员长航时飞行中生理变化特点,观察心理疲劳对抗措施对长航时飞行心理疲劳的缓解作用。方法20名健康男性教-8飞行学员随机分为对照组和试验组,在教-8飞行模拟器上进行8h的长航时模拟飞行。试验组在飞行中的休息阶段采取放松措施,对照组休息阶段不采取任何措施。记录飞行学员模拟飞行过程中的心电信号,分析心率、心率变异性(heart rate variability,HRV)以及体动强度。结果模拟长航时飞行中,试验组的平均心率显著低于对照组(F-184.241,P-0.000),试验组休息时平均心率低于飞行时(F-17.564,P-0.000);而对照组在飞行和休息时心率变化规律不明显(F-2.014,P-0.156)。对照组休息时较飞行时校正低频功率(low frequency normalized unit,LFnu)、低频高频比值(LF/HF)显著增加,校正高频功率(highfre-quency normalized unit,HFnu)显著降低。而试验组在休息时LFnu、HFnu、LF/HF指标与飞行时比较,仅第1次第有明显变化(P〈O.05)。对照组的体动强度在休息时显著高于飞行阶段,而试验组没有明显改变。结论地面模拟长航时飞行试验中,受试者的自主神经兴奋性因试验因素的变化存在明显的变化规律。从心率变化分析,地面模拟长航时飞行属于单位时问内低负荷持续作业的试验模型。在飞行中的休息阶段实施放松措施能有效缓解受试者的焦虑、烦躁情绪。HRV频域指标中,LFnu、HFnu、LF/HF可作为评价情绪负荷较为敏感的指标。  相似文献   

10.
运动对健康中老年人心率变异性的影响及其意义   总被引:4,自引:0,他引:4  
用时域和频域两种方法,对44名经常参加健身运动的健康中老年人和76名缺乏运动的健康中老年人安静状态下记录的24小时动态心电图进行心率变异(HRV)分析,旨在了解健身运动对健康中老年人心脏自主神经功能的影响。结果显示:经常参加健身运动者心率明显低于对照组(P<0.001),HRV的指标中,24h内全部正常RR问期的标准差(SDNN),24h连续的每5分钟节段RR同期标准差(SDANNI),24h相邻正常RR间期的均方根值(RMSSD),24h内相邻两个正常RR间期差值大于50ms占总心搏的百分比(PNN50)、总功率(TP)、超低频功率(ULW)、极低频功率(VLF)以及高频功率(HF)均明显高于对照组(P<0.05),但低频功率(LF)和24h连续的每5分钟节没RR间期标准差的平均值(SDNNI)两组之间无显著性差异(P>0.05)。结果提示:长期参加健身运动能提高健康中老年人迷走神经的张力,而对交感神经张力无明显的影响。  相似文献   

11.
The aim was to give a systematic presentation of physiologic and pathologic calcifications and ossifications in the face and neck with a special emphasis on clinical relevance. In a sometimes subacute setting one should recognize specific calcifications which often lead to important diagnoses such as fungal sinusitis or sclerosing labyrinthitis. In a more chronic situation intraocular calcifications in small children are pathognomonic for retinoblastoma. Juxtatumoral sclerosis of the laryngeal cartilage in laryngopharyngeal carcinoma is usually caused by tumor infiltration of the cartilage resulting in a higher tumor stage and, this way, has a major impact on the therapeutical strategy. Calcified lymph nodes are mainly unspecific but can be the result of tuberculosis or metastases of thyroid cancer. Cross-sectional imaging methods, most of all computed tomography, are ideally suited to reveal head and neck calcifications and ossifications, especially those which are clinically relevant.  相似文献   

12.
This article discusses the imaging manifestations of infectious and inflammatory conditions of the head and neck. Special attention is paid to the sites, routes of spread, and complications of neck infections. Because the clinical signs and symptoms and the complications of these conditions are often determined by the precise anatomic site involved, anatomic considerations are stressed. Familiarity with the fascial layers, spaces of the neck, and the contents of each space is helpful for this discussion. The fascial layers of the neck are important barriers to infection, and once infection is established, the fascial layers play a part in directing its spread.  相似文献   

13.
目的:分离纯化幽门螺杆菌分泌和重组表达的细胞空泡毒素抗原( VacA)蛋白,并评价其致细胞空泡效应及致细胞凋亡效应。方法分别从幽门螺杆菌ATCC26695菌株培养上清和重组表达VacA蛋白的pQE30-VacA-E.coliM15基因工程菌中分离纯化VacA蛋白,经酸化后,以不同终浓度(5,10 ng/ml)分别与人胃腺癌AGS细胞共孵24 h,观察致空泡效应,并通过流式细胞术检测细胞凋亡。结果成功分离纯化出幽门螺杆菌分泌和重组表达的VacA蛋白;幽门螺杆菌分泌的VacA蛋白能显著引起AGS细胞的空泡样改变及凋亡(P<0.01),而重组表达的VacA蛋白致细胞空泡样改变及凋亡不显著( P>0.05)。结论幽门螺杆菌分泌的VacA蛋白有良好的空泡毒性及致凋亡效应,而重组表达的VacA蛋白无致空泡及凋亡效应,幽门螺杆菌分泌的VacA蛋白可用于VacA作用机制的研究。  相似文献   

14.
化学武器公约( CWC)和生物武器公约( BWC)是为禁止生产、发展、储存和使用化学武器和生物武器而制定的国际公约。近年来,科学技术快速发展,知识交叉渗透,学科之间出现整合和融合,促进了科技进步和经济发展。其中化学和生物学融合在有力促进制药、健康卫生、绿色化学和环境保护等产业进步的同时,也对化学和生物武器公约的履约产生了重要的影响。该文综述了与化学武器和生物武器公约相关的化学和生物学融合进展,并分析其对公约履约的影响。  相似文献   

15.
This study evaluated if the ventilatory response to exercise is impaired by the cramp position of rowing. Maximal oxygen uptake (VO2max), maximal expiratory volume (VEmax), and maximal heart rate (HRmax) during rowing and running were compared in 55 males (age, mean +/- SD, 21 +/- 3 years; height 176 +/- 5 cm; body mass 72 +/- 6 kg) and 18 females (age 20 +/- 2 years; height 164 +/- 5 cm; body mass 61 +/- 4 kg). VEmax was larger during rowing than during running (males, 157 +/- 16 vs. 147 +/- 13 L min(-1); 114 +/- 9 vs. 105 +/- 11 L min(-1), P<0.01). Also VO2max was larger during rowing than during running (males, 4.5 +/- 0.5 vs. 4.3 +/- 0.4 L min(-1); females, 3.3 +/- 0.4 vs. 3.2 +/- 0.4 L min(-1), P<0.01). However, HRmax was lower during rowing than during running (males, 194 +/- 8 vs. 198 +/- 11 beats min(-1); females, 192 +/- 6 vs. 196 +/- 8 beats min(-1), P<0.05). VEmax was correlated to body mass and fat-free mass, as was VO2max. Thus, the oxygen pulse (VO2max/HRmax) was larger during rowing than during running, while the ventilatory equivalent for oxygen (VEmax/VO2max) was similar. We showed that bending the body during rowing does not seem to impair ventilation either in males or in females. The results indicate that VEmax and VO2max relate to body size and fat-free mass for both females and males. The findings indicate that the involvement of more muscles, the entrainment, and the body position during rowing facilitates ventilation and venous return and lowers maximal heart rate.  相似文献   

16.
Thirty-six patients with calcification or ossification at or around the coracoclavicular and coracoacromial regions were analyzed with regard to type, location, and configuration of the deposits and related clinical history. Calcification or ossification in the coracoclavicular region resulted largely from trauma (36%) or renal failure (28%). Trauma patients may develop punctate calcification or ossification but do not develop the tumoral type of calcification. About 5% of the renal failure patients had coracoclavicular ligament calcifications, one-half of which were of the tumoral type. Renal failure patients may have punctate or tumoral calcifications but do not develop ossification.  相似文献   

17.
18.
在真核生物基因表达的转录后调节中,RNA结合蛋白( RBP)起着关键作用,很多RBP的异常与人类疾病的发生密切相关。自2000年的RNA免疫沉淀和芯片分析方法( RNA immunoprecipitation with differential display or microarray analysis , RIP-ChIP)出现以来,人们开始就RBP与RNA相互作用进行了系统而广泛的研究。经过改良和发展,基于体内实时紫外交联免疫沉淀法( ultraviolet crosslinking and immunoprecipitation , CLIP )、交联免疫沉淀cDNA文库高通量测序法( high-throughput sequencing of CLIP cDNA library , HITS-CLIP)、光催化核糖核苷增强交联和免疫沉淀法( photoactivatable-ribonucleoside-enhanced crosslinking and immunprecipitation , PAR-CLIP)以及提高个别核苷酸分辨率交联和免疫共沉淀法( individual nucleotide resolution CLIP , iCLIP)等RIP-ChIP衍生方法相继产生,使用这些方法,可以解析RBP的RNA识别特异性,而且通过与高通量测序技术结合,可以实现转录组尺度的RBP的靶序列的鉴定,分辨率也得到极大提高。该文就RNA与蛋白的相互作用的基本原理及其研究进展、相关技术存在的问题以及发展趋势进行简要综述。  相似文献   

19.
Older prisoners are the fastest growing group of prisoners in many countries. The purpose of this study is to explore the phenomenon of detention of persons suffering from dementia. Medline searches were conducted for relevant articles, chapters and books published until August 2016. Search terms included dementia, elderly, prison and criminal. Publications found through this indexed search were reviewed for further relevant references. As results, there is a lack of data about elderly with dementia in prisons. Given the rise in the average age, it is reasonable to hypothesize that the number of older prisoners is growing. Moreover, some elderly are imprisoned with a concomitant cognitive impairment or psychiatric disorder while others will develop such diseases once incarcerated. At the present time, legal and social systems seem unprepared to handle the phenomenon of dementia in prison. As proposal, health assessments for older first time offenders should become a practice inside the correctional facilities and include an evaluation for specific health issues, such as psychiatric comorbidity and cognitive impairment.  相似文献   

20.
In patients with renal failure, iodinated contrast agents may cause acute deterioration of the renal function and gadolinium-based contrast agents (GBCAs) may cause nephrogenic systemic fibrosis (NSF). The administration of a contrast agent must thus be reviewed for each patient and evaluation of renal function is paramount even though its estimation using formulas derived from the creatinine level may fluctuate. For iodinated contrast agents, contrast induced nephropathy is reduced by hydratation, preferably intravenous, when the GFR is less than 60 ml/min. The risk for intravenous injections is less than the risk for arterial injections, and the GFR threshold may be reduced to 45 ml/min. For gadolinium-based contrast agents, patients at risk for NSF are those with end-stage renal disease and patients undergoing dialysis. In such cases, the injection of a gadolinium-based contrast agent is only considered after a risk-benefit analysis has been completed, an alternate linear or macrocyclic agent issued and the dose limited to 0,1 mmol Gd/kg. Recently, recommendations from US and European agencies have converged. Learning objectives: to be familiar with the risk factors of CIN with iodinated contrast agents; to be familiar with hydration procedures for patients at risk of CIN; to be familiar with the diagnostic criteria of NSF; to be familiar with the classification of GBCA with regards to the risk of NSF; to be familiar with the contraindications of the different groups of GBCA.  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