短时间飞行训练飞行员脑血流动力学的研究

在生理状态下,机体本身具有主动调节脑血流动力的功能,脑血流变化受低气压缺氧、镁离子、咖啡因、热应激、激素水平等诸多因素的影响[1-5].正加速度飞行应激可削弱飞行员的脑自主调节,甚至出现意识丧失,危及飞行员的生命[6-7].研究高性能战斗机飞行员飞行时一过性生理变化机制已成为航空医学的重点课题之一[8-9].我们通过经颅多普勒(TCD)技术,对战斗机飞行员飞行训练前后大脑中动脉血流动力学参数进行检测并分析,以评价短时间飞行训练对飞行员脑血流动力学的影响.     

基于睡眠的飞行员疲劳测量方法对比研究

飞行员的工作性质使得其睡眠严重紊乱,在昼夜节律的作用下,飞行员因睡眠不足产生疲劳,从而影响其工作效率,增加事故风险,研究与睡眠有关的飞行员疲劳对于降低飞行事故／事件,保障飞行员的健康与安全具有重要意义。作为飞行员疲劳研究的基础,作者从飞行员疲劳测量方法的性质、分类、特征等方面对飞行员疲劳测量工具进行了系统的对比分析与探讨,认为对于诸多的疲劳测量工具,应从中选取适用于飞行员工作特点和实际运行环境的方法来综合测量飞行员的疲劳状态。以超长航程为例,说明测量方法的使用原则和方法,从而为疲劳的实时测量提供依据。     

疗养期间心理咨询保健体会

飞行心理健康对飞行员心身整体健康以及飞行安全有着重要意义。通过分析飞行员的心理健康现状,可以降低飞行训练过程中,造成人为差错的事故率。     

飞行人员颈椎曲度异常的DR特征及病因分析

目的：探讨飞行人员颈椎曲度异常的DR特征及病因。方法：选择120例DR表现为颈椎曲度异常的飞行人员影像及I隘床资料,侧位测量其颈椎曲度,根据DR颈椎曲度异常的程度将颈椎曲度分为变直、反曲及过曲3组,按飞行机种和飞行时间进行统计学分析。结果：120例患者中,颈椎曲度变直84例,反曲33例,过曲3例。各组间两两比较有显著性差异（P〈0．01）：歼击机飞行员的颈椎曲度异常率高于运输机和直升机飞行员,飞行时间在1000-2000h的飞行员的颈椎曲度异常率高于飞行时间小于1000h和大于2000h的飞行员。结论：飞行人员的颈椎曲度异常的发病率与机种、飞行时间有密切相关性,分析颈椎曲度的改变将有助于飞行人员退行性疾病的诊断。     

航线飞行特质人格和航线飞行工作情境人格对飞行员心理健康的影响

目的 考察航线飞行特质人格和航线飞行工作情境人格对航线飞行员心理健康的影响. 方法 采用自编量表“航线飞行员人格量表”和临床症状自评量表(SCL-90)对南方航空公司及其分公司的286名男性飞行员进行心理测量研究. 结果 心理健康的各个因子均值在1.36～1.64之间,心理健康总评分也在2分以下.另外,阳性项目数平均值为25.57,远远小于40的异常标准,并且无明显峰值出现.总体健康水平和航线飞行特质人格的相关系数(-0.75)显著高于和航线飞行工作情境人格的相关系数(-0.17);航线飞行特质人格和航线飞行工作情境人格均单独对心理健康有直接影响作用;另外,航线飞行特质人格还可通过影响航线飞行工作情境人格进而影响心理健康. 结论 航线飞行员整体心理健康状况良好;两种人格对心理健康均有预测作用,其中航线飞行特质人格显示了较强的预测作用,航线飞行工作情境人格在航线飞行特质人格对心理健康的影响中发挥着部分中介作用.     

姿势控制感觉重塑效应在飞行员脑力疲劳预警中的作用

军事飞行人机交互复杂,飞行员易产生较大的脑力负荷,影响作业能力,危害飞行安全。因此,飞行员脑力负荷的快速评估与预警意义重大。而常用的心电、脑电等客观手段理论复杂,量表等主观方法不准确,并不适合航空兵部队应用。国外研究表明,在疲劳状态影响下,人体的姿势稳定性下降显著,且与其他方法结果相关。其中,姿势控制的感觉重塑效应可以降低姿势控制能力的下降程度,限制了姿势控制测量技术在疲劳评估预警中的应用。因此,本文综述了感觉重塑效应在脑力负荷评估中的作用,为疲劳预警提供可行性的研究思路。     

睡眠剥夺对飞行员的影响及预防

1睡眠剥夺对飞行能力的影响 1．1睡眠剥夺对脑力工作及飞行能力的影响 睡眠剥夺对大脑功能的影响最早,最明显,会使飞行员警戒性降低,持续注意力、注意转移能力和注意分配能力下降,记忆能力下降,反应速度下降,思维能力下降。睡眠剥夺过程中困倦程度升高的直接后果是微睡眠的不断出现,这些会导致飞行操作以及仪表判读出现差错或无法及时发现和处理突发事件,甚至常规操作也可能发生错、忘、漏动作。睡眠剥夺还能影响飞行员的视觉功能和前庭功能,而相应影响到飞行员对外界环境的感知和飞行状态的判断,导致飞行错觉,从而威胁到飞行安全。     

缺氧对高原驻训飞行员夜间飞行暗适应功能的影响

了解高原环境特点及其对人体的影响,掌握其对健康影响的规律,对飞行人员适应高原环境,保持飞行能力,保障飞行安全具有重要意义.为此,我们对某部进驻高原开展夜间飞行训练的飞行员进行了夜间暗适应功能调查,以期为圆满完成高原夜航训练任务提供参考依据.     

歼击机座舱噪声与飞行员的听力

随着航空事业的发展,飞机噪声越来越大,不少文章报道了飞行员的听力损伤情况,但是我军现有各主要机种座舱内噪声有多大?它与飞行员的听力损伤关系如何?这是飞行劳动卫生保障面临的一个实际问题,也是为了保障飞行安全,制订军用飞机座舱噪声标准所必须解决的问题。本文拟就歼击机为例进行实验研究,为此,我们测定了歼—6,歼—7,歼—8飞机座舱内的噪声强度,检查了不同年限的飞行员的听力,现报告如下。     

飞行员工作倦怠及其与职业应激的相关性

目的探讨飞行员工作倦怠及其与职业应激的关系,为防控飞行员工作倦怠提供依据。方法采取整群抽样的方法,从福建、浙江两省中按不同机型抽取4个飞行部队中的500名飞行员(均为男性)作为调查对象。应用Maslach工作倦怠量表通用版(MBI-GS)测量飞行员的工作倦怠,应用职业应激量表测量飞行员的职业应激;采用多元线性回归对飞行员工作倦怠的影响因素进行分析。结果飞行员工作倦怠各个维度总得分为:衰竭7.427±5.924,消极怠慢5.720±5.720,专业低效能感20.809±9.460,工作倦怠总分与职业应激总分呈正相关(P0.05);影响飞行员工作倦怠的因素依次为:物理条件应激、人际关系应激、受教育程度、家庭人均月收入。结论飞行员的职业应激对产生工作倦怠有显著影响,应制定降低职业应激的合理措施,减缓工作倦怠。     

Incremental Doses of Nitrate-Rich Beetroot Juice Do Not Modify Cognitive Function and Cerebral Blood Flow in Overweight and Obese Older Adults: A 13-Week Pilot Randomised Clinical Trial

Nitrate-rich food increases nitric oxide (NO) production and may have beneficial effects on vascular, metabolic, and brain function. This pilot study tested the effects of prolonged consumption of a range of doses of dietary nitrate (NO₃⁻), provided as beetroot juice, on cognitive function and cerebral blood flow (CBF) in overweight and obese older participants. The study had a 13-week single-blind, randomised, parallel design, and 62 overweight and obese older participants (aged 60 to 75 years) received the following interventions: (1) high NO₃⁻ (2 × 70 mL beetroot juice/day) (2) medium NO₃⁻ (70 mL beetroot juice/day), (3) low NO₃⁻ (70 mL beetroot juice on alternate days), or (4) placebo (70 mL of NO₃⁻-depleted beetroot juice on alternate days). Cognitive functions were assessed using the Computerised Mental Performance Assessment System (COMPASS) assessment battery. CBF, monitored by concentration changes in oxygenated and deoxygenated haemoglobin, was assessed in the frontal cortex using near-infrared spectroscopy. The findings of this pilot study showed that cognitive function and CBF were not affected by supplementation with NO₃⁻-rich beetroot juice for 13 weeks, irrespective of the NO₃⁻ dose administered. These findings require confirmation in larger studies using more sophisticated imaging methods (i.e., MRI) to determine whether prolonged dietary NO₃⁻ supplementation influences brain function in older overweight people.     

DHA-rich oil modulates the cerebral haemodynamic response to cognitive tasks in healthy young adults: a near IR spectroscopy pilot study

The impact of dietary n-3 PUFA on behavioural outcomes has been widely researched; however, very little attention has been given to their impact on brain functioning in physiological terms. A total of twenty-two healthy adults took part in this double-blind, placebo-controlled study, wherein the cerebral haemodynamic effects of 12 weeks of daily dietary supplementation with either 1 g DHA-rich or 1 g EPA-rich fish oil (FO) or placebo (1 g olive oil) were assessed. Relative changes in the concentration of oxygenated Hb (oxy-Hb) and deoxygenated Hb were assessed in the prefrontal cortex using near IR spectroscopy (NIRS) during the performance of four computerised cognitive tasks. Supplementation with DHA-rich FO, in comparison with placebo, resulted in a significant increase in the concentrations of oxy-Hb and total levels of Hb, indicative of increased cerebral blood flow (CBF), during the cognitive tasks. In comparison, no effect on CBF was observed following supplementation with EPA-rich FO, where concentration changes in the chromophores followed the same pattern as placebo. These encouraging pilot data warrant further application of NIRS in this area.     

Ethanol increases phosphodiesterase 4 activity in bovine bronchial epithelial cells.

Ethanol exposure in airway epithelium increases cyclic AMP (cAMP)-dependent protein kinase (PKA) activity. Activation of PKA and cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG) has been shown to increase ciliary beat frequency (CBF) in bovine bronchial epithelial cells (BBECs). We have shown that biologically relevant concentrations of ethanol stimulate increases in CBF in a nitric oxide-dependent manner, mediated through elevated cAMP levels and subsequent PKA activation. This ethanol-driven rapid and transient increase in CBF occurs 15 to 30 min after exposure to 100 mM ethanol. However, after prolonged exposure to 100 mM ethanol (>/=6 h), CBF and the catalytic activity of PKA return to baseline levels. We hypothesize that cyclic nucleotide-dependent phosphodiesterase (PDE) activity attenuates the duration of ethanol-stimulated ciliary motility. The effect of ethanol on the PDE activity in BBECs was determined through direct assay of catalytic activity. When BBECs were incubated with 100 mM ethanol, significant increases in cAMP levels occurred within 1 h, with corresponding increases in PKA activity. Treatment of BBECs with 100 mM ethanol increased cAMP-PDE activity significantly by 4 h. 3-Isobutyl-1-methylxanthine, Ro 20-1724, and rolipram inhibited ethanol-stimulated cAMP-PDE activity. These agents inhibited ethanol-stimulated cAMP-PDE activity and increased the magnitude of ethanol-stimulated PKA activity observed under the same conditions. These findings support the idea that acute exposure (<6 h) to ethanol increases cAMP levels, and the associated increase in PKA activation is regulated by cAMP-dependent PDE, specifically PDE4. Other compensatory mechanisms however, may be responsible for the down-regulation of PKA, which occurs after chronic epithelial exposure (>/=6 h) to ethanol.     

Effect of sulfur dioxide on mucociliary activity and ciliary beat frequency in guinea pig trachea

Summary The effects of 30 min exposure to sulfur dioxide on mucociliary activity (MCA) and ciliary beat frequency (CBF) were studied in 31 guinea pig tracheas. MCA was measured by recording the light reflected from ciliated mucous membranes using an infrared bar code reader. CBF of single ciliated cells obtained by brushing was measured with phase-contrast microscopy. Each tracheal sample was exposed to SO₂ at concentrations ranging from 2.5 to 12.5 ppm, or to air for control purposes. MCA and CBF were measured before and immediately after gas exposure. A reduction in mean MCA of 63% (P = 0.0007) and statistically insignificant changes in CBF (P > 0.05) were recorded at concentrations of 2.5 PPM SO₂. Higher SO₂ concentrations caused a further impairment of MCA as well as a dose-dependent decrease in CBF (P = 0.002). A concentration of 12.5 PPM SO₂ induced a decrease from baseline values of approximately 80% in mean MCA and of roughly 70% in mean CBE This study demonstrates a dose-dependent SO₂-induced decrease in MCA of guinea pig tracheas. The decrease in MCA was associated with an impairment of CBF only at SO₂ concentrations higher than 5.0 ppm.     

Alcohol consumption and cerebral blood flow among older adults

A substantial epidemiological literature now supports the existence of a J or U-shaped association between alcohol consumption and a broad range cardiovascular health outcomes including stroke. Although it is well documented that alcoholics exhibit both global and regional cerebral hypoperfusion in the sober state, little is known regarding the effects of a broader range of alcohol consumption on cerebral blood flow (CBF). The present study employed positron emission tomography with H(2)(15)O to assess quantitative global and regional CBF in 86 participants (51 men and 35 women; mean age 60.1) as a function of self-reported weekly alcohol consumption (none, <1, 1 to <7, 7 to <15, and >15 drinks per week). Analyses controlling for age, gender, and vascular health (carotid intima-media thickness) revealed that, relative to the weighted population mean, global CBF was greater in the lightest alcohol consumption group (<1 per week) and lower in the heaviest (>15 per week). Effects did not vary across regions of interest. This report is the first to describe an inverted J-shaped relationship between alcohol consumption and CBF in the absence of stroke.     

Establishment of gene-vaccinated skin grafting against Toxoplasma gondii infection in mice

Vaccine effects of in vivo gene-vaccinated skin graft were evaluated against Toxoplasma gondii (T. gondii) infection. By using a gene gun, cDNA coding T. gondii SAG1 molecule was intracutaneously vaccinated into C57BL/6 (B6; a susceptible strain), BALB/c (a resistant strain) and (C57BL/6 x BALB/c) F1 (CBF1) mice, and the gene-vaccinated skin of these strains was transplanted to CBF1 mice. Regarding the antibody production against SAG1, CBF1-recipient mice transplanted with the SAG1 gene-vaccinated B6 skin were high responders, whereas CBF1 mice skin grafted with vaccinated skin of both BALB/c and CBF1 mice were low responders. The donor-derived LC/DC migrated to the draining lymph nodes of the recipients from the skin graft within 3 days. The vaccine effect against T. gondii challenge infection was obtained in CBF1 mice which received the skin graft of the SAG1 gene-vaccinated BALB/c mice.     

Impact of a daily 10-minute strength and flexibility program in a manufacturing plant

In summary, employees' flexibility and mood showed modest improvements following the implementation of a plant-wide, 10-minute, daily flexibility and strength program. The initial six-week pilot study, administered prior to the plant-wide program implementation, successfully assessed program feasibility, assessed the efficiency of program implementation, identified administrative and logistical concerns, and generated pilot data needed to secure managerial support. Despite the noted significant increases in grip strength in the pilot study, no increases were observed following the six months of plant-wide implementation. This may be related to the differences in low average pretest grip strength for the pilot study compared to the higher scores for the main study population. The pilot study subjects may have received a sufficient exercise stimulus to increase grip strength over the course of six weeks. In contrast, this may not have been the case for the main study subjects due to their higher initial mean grip strength. An increased number of exercises designed to directly impact grip strength may be needed to improve this parameter.     

TCD联合APACHEⅡ评分在腹部心肺复苏脑功能预后中的价值

目的探讨早期经颅多普勒超声(TCD)和APACHEⅡ评分对腹部心肺复苏术后患者脑功能复苏预后的评估价值。 方法选取郑州人民医院医疗集团及三门峡中心医院所属急救站急诊经腹部心肺复苏救治成功后66例心搏骤停(CA)患者为研究对象进行回顾性病例对照研究,其中男性34例,女性32例;年龄19～80岁,平均(50.91±14.50)岁。患者根据复苏后3个月内的格拉斯哥-匹兹堡脑功能分级(CPC)分为预后良好组(CPC 1～CPC 2,29例)和预后不良组(CPC 3～CPC 5,37例)。比较两组患者腹部心肺复苏成功后24h经TCD测得的脑血流和APACHEⅡ评分结果,分析两指标的相关性并分别绘制对CA患者脑复苏预后预测的受试者工作特征(ROC)曲线,计算ROC曲线下面积以评估该指标对CA患者脑复苏预后预测的准确性。 结果预后良好组CA患者腹部提压心肺复苏后24 h的脑血流明显高于预后不良组[(6.23±1.88) vs (4.88±1.15),P<0.05],APACHEⅡ评分明显低于预后不良组[(15.31±5.37)分vs (25.05±7.94)分,P<0.05],两者呈负相关性。脑血流对脑功能预后预测的曲线下面积为0.722,APACHEⅡ评分曲线下面积为0.844。 结论心肺复苏早期脑血流越大、APACHEⅡ评分越低,患者脑功能预后越好。两者对腹部提压心肺复苏术后CA患者的脑功能预后评价具有指导意义。     

Long term effects of military jet aircraft noise exposure during childhood on hearing threshold levels

Some research suggests that young children may be relatively more susceptible to noise-induced hearing loss (NIHL) than adults, and that the unique noise footprint associated with military jet aircraft is particularly damaging to hearing. This pilot study looked for evidence of NIHL in adults who have been exposed to military jet noise in early childhood, while living in Married Quarters on active RAF fast jet stations. Many Married Quarters lie within 70 dB(A) Leq contours, fewer in 83 dB(A) Leq contours. A cross-sectional pilot study was undertaken to examine the hypothesis that military jet noise exposure early in life is associated with raised hearing thresholds.     

超声多普勒测定正常早产儿脑血流速度的研究

目的:探讨正常早产儿脑血流参数值以及胎龄(gestational age,GA)、出生体重(b irth we ight,BW)、日龄、血压对早产儿脑血流的影响。方法:应用超声多普勒测定正常早产儿的脑血流参数。结果:生后第2天各组正常早产儿的颈内动脉(ICA)、大脑前动脉(ACA)的收缩期峰值血流速度(Vs)、平均血流速度(mV)与第1天比较差异显著(P<0.01);正常早产儿脑血流速度与胎龄(GA)、体重(BW)呈正相关。结论:在评价早产儿脑血流灌注状态时,应注意GA、BW、日龄对其的影响。