呼吸分子筛富氧气体排氮的效果

由中华医学会航空航天医学分会主办的全国第六次航空航天医学学术会议将于 2 0 0 2年 6月 2 6～2 9日在浙江宁波市召开。本次会议共收到应征论文 2 1 9篇 ,经专家评审组采用双向多重盲法 (作者与审者间双盲、审者间互盲 )审稿方式初选后 ,再集中会审 ,充分保证了公平、优质地录选稿件。最终录用 1 2 9篇 ,其中英语专题会交流 9篇 ,大会交流 1 7篇 ,专题会交流 1 0 3篇。现将这次会议入选论文以摘要形式在本刊预先发表。为了方便检索与学术交流 ,我们在每篇摘要前加了顺序编号 ,并标注了关键词 ;英语专题会交流论文摘要以中英文对照形式刊发 ;中文摘要加注了中国图书馆分类法分类号。     

结合运动的氧气预呼吸对减压病的预防作用

目的 综述国外氧气预呼吸过程中进行体育运动以提高对减压病预防作用的科研工作进展。资料来源与选择 主要资料选自公开发表的氧气预呼吸过程中进行体育运动以提高对减压病预防作用的文献。资料引用 参考文献16篇。资料综合 氧气预呼吸过程中进行体育活动可以减少减压病发生率，这已为低压减压实验及数学模型初步证实，这种作用可能是因为体育运动能使肺通气量、心输出量及组织灌流增加引起排氮效率提高的结果。结论 结合运动的氧气预呼吸可以缩短氧气预呼吸时间而保持预防效果，符合高空飞行及航天员出舱活动的需要，故此方法值得深入研究。     

富氧联合运动训练治疗急性高原反应效果观察

目的:观察富氧联合运动训练治疗急性高原反应(AMS)的效果。方法:将AMS 28例随机分成富氧联合运动训练组(观察组)和对照组各14例。对照组处于自然低氧环境中,不进行运动训练;观察组分别在26.0%、24.5%、23.0%和21.5%的富氧条件下,进行运动训练各1天;观察比较两组训练期间和训练结束后第1天的收缩压(SBP)、舒张压(DBP)、心率(HR)、血氧饱和度(SO2)水平和AMS评分。结果:训练第1天,观察组HR非常显著低于对照组(P<0.01);训练期间及训练结束后第1天SBP和DBP两组间差异不显著(P>0.05);观察组SO2水平非常显著高于对照组(P<0.01);观察组训练期间和训练后第1天AMS评分非常显著低于对照组(P<0.01)。结论:富氧联合运动训练可有效减轻AMS症状,缩短习服时间。     

氧气对减压病(DCS)的作用原理

在高空减压时,组织氮过饱和,产生气泡,导致DCS症状。预先氧合(通过在高空暴露前预先呼吸100％的氧气从组织排除氮气)能够在组织和血液之间建立一个分压梯度。在预先氧合时排氮的潜力是基于组织的灌注率和扩散率。通过锻炼在预先氧合时增加     

飞行环境的生理学挑战:21世纪的航空中氧气的应用

在近10年间似乎是极端的飞行环境中,航空航天技术的进展已使得民用和军事航空更为广泛地执行其任务。然而,人对氧气的生理学需求始终未改变。为了满足在面临更需要的环境条件和飞行操纵中生理学要求,本专题将讨论影响氧气系统的要求。与生理学防护有关的问题和用于军事、民用及医疗运输方案的氧气系统的性能要求将被论及。特定的热点问题将包括氧     

模拟微重力状态下减压的气相形成

前言 在飞船舱外零重力下活动的宇航员的减压病与在地面同R值的测试比有明显的减少。为了研究这一点,采用椅形支架模型在低压舱模拟微重力状态下,对受试者进行了减压。方法 志愿者歇于椅中共6h,后4h为预吸O_2期。受试者在预吸O_2期间既可轻微活动(25W)也可保持安静。接着在低压舱中于歇于座椅位置,减压到30000英尺(9144m)3h。这些歇在座椅中预吸氧的受试者,和他们自身在高空的另一处     

富氧室对高原移居者运动前后肺通气功能的影响

目的：探讨在高原建立富氧室对移居者肺通气功能的影响;方法：对移居海拔3700m一年的10名受试者在进入富氧室前后分别进行功率自行车递增负荷运动,用ES800肺功量仪检测肺通气功能,并与安静时比较;结果：与安静时对照,富氧前运动后FEV1／FVC％降低,MVV增加,均有非常显著性差异（P＜0．01）,FVC、FEF25％－75％、FEV1、PEF都有降低趋势,但无统计学意义（P＞0．05）;富氧次日运动后FVC、FEV1、PEF和MVV增加非常显著（P＜0．01）;与富氧前运动后比较,富氧次日运动后FVC、FEF25％－75％、FEV1、PEF、FEV1／FVC％及MVV均显著增加（P＜0．05或P＜0．01）;结论：富氧室能改善高原移居者运动后的肺通气功能,是一种较为理想的供氧途径。     

富氧室对高原5 380m移居者记忆与肢体运动能力的影响

(马勇 ,等 .中国行为医学科学 ,2 0 0 4 ,13(2 ) :2 0 4～ 2 0 5 )　　高原低氧、低气压等综合因素导致移居者机体各项生理功能降低 ,海拔越高 ,缺氧程度就越重 ,低氧暴露时间越久 ,人体生理功能的衰退就越甚。高原慢性缺氧不但会导致人体发生脏器功能性低下 ,甚至会发生器质性损害。本文在海拔 5 380m低氧环境下 ,应用心理生理功能检测的途径对建立高原富氧室提高和改善久居高海拔地区移居人群记忆、心理运动功能研究进行可行性试验。作者选择驻守海拔 5 380m 4个月的高原某边防部队士兵 2 0人 ,于进入富氧室前采用DDX2 0 0型电脑多项心…     

海拔3700m富氧室对高原人体运动血气及心率的影响

目的：探讨在3700m高原建立富氧室对机体运动后血气及心率的影响。方法：对海拔3700m高原的10例健康青年在进入富氧室前、后分别进行功率自行车递增负荷运动，检测pH值、二氧化碳分压（PCO2）、氧分压（PO2）、肺泡、动脉氧分压（AaDO2)、血氧饱和度（SaO2)、心率及5min恢复心率；结果：富氧后较富氧前pH增高显著（P＜0．05）；PCO2、PO2、SaO2增高，即刻心率、AaDO2降低，差别有非常显著性（P＜0．01）；恢复心率无统计学差异（P＞0．05）；结论：富氧室能改善高原低氧人体气体交换和心脏工作效能，是一种较为理想的高原供氧途径。     

复杂压力暴露条件下从失事潜艇快速上浮脱险后余氮张力的初步探讨

目的 探讨失事潜艇艇员在高压下暴露并从失事潜艇快速上浮脱险后体内余氮张力的计算方法.方法 对失事潜艇脱险过程进行分解,采用微积分等方法,建立脱险艇员出水时体内氮张力值的理论计算公式,并将此氮张力值换算成相对饱和深度.结果 建立的理论计算公式可以计算在7、12 m饱和后,在不同深度脱险时体内余氮张力值对应的相对饱和深度.结论 本研究建立的理论计算公式可为减压病的预测提供参考,为分析复杂压力暴露后快速上浮脱险方法的安全性提供理论依据.     

微重力与减压病低发病率

目的综述国外有关微重力下减压病发病率减少机制的研究工作进展。资料来源与选择主要资料选自公开发表的研究模拟微重力影响减压病发病率的实验工作报道。资料引用参考文献19篇。资料综合模拟微重力下减压病发病率减少的原因：①体液的氮清除率增加。②下肢缺乏动力。结论微重力下氮清除率增加已被证实，而下肢缺乏动力的效应尚有争议。     

快速减压对兔血气、电解质和肺病理的影响

目的 探讨快速减压对兔动脉血气、电解质和肺病理改变的影响。方法 将14只实验兔放入加压舱中，于5min内用压缩空气加压至0．6MPa，停留60min，然后于3～5min内减至常压。分别于进舱前、出舱后3h和3d，进行动脉血气、电解质和肺病理检查。结果 （1）快速减压可造成兔动脉血氧分压（PaO2）、氧饱和度（SaO2）和二氧化碳分压（PaCO2）下降；红细胞压积（Hct）升高。（2）快速减压可造成兔肺泡壁充血、肺泡腔内渗出，肺毛细血管内气泡形成。结论（1）快速减压可造成家兔动脉血气改变和血液浓缩。（2）肺毛细血管内气泡可能是引起动脉血气改变和血液浓缩的原因。     

飞行员低高度迅速减压训练方法的效果和安全性研究

目的 研究低高度迅速减压训练方法 的训练效果和安全性. 方法 以187名男性高性能战斗机飞行员为对象,采用序贯试验设计,随机分为减压供氧组(A组,93人)和减压不供氧组(B组,94人).每批次试验A组和B组各1人参加,首先低压舱以30～40 m/s速度上升至起爆高度2500 m,并停留1～3 min,待心率稳定后,进行减压准备.各项准备就绪后,开始减压,低压舱在0.48 s内迅速减压至5500 m高度.在此高度停留1～2 min后,低压舱以10～20 m/s速度下降至地面.下降过程中高度低于4000 m后停止供氧.试验过程中记录飞行员不同时期的血氧饱和度、ECG(标准肢体Ⅱ导联)和减压瞬间的肺内减压峰值.低压舱试验完成后进行胸部X线透视检查并填写调查问卷,问卷内容包括试验过程中的主观体验和对迅速减压训练效果的评价. 结果 A组血氧饱和度在供氧期间始终维持在99%左右,停止供氧后出现明显下降,然后,随着高度降低逐渐回升;B组血氧饱和度则与高度呈现明显负相关的变化.ECG分析显示:两组飞行员心率在减压前均持续上升,在减压即刻达到最大值,A组(87.87士15.97)次/min,B组(91.29±2.78)次/min,减压后则明显降低;肢体Ⅱ导联T波振幅在减压即刻,即心率最大时显著降低,A组(0.19±0.11)mV,B组(0.20士0.12)mV.肺内减压峰值为(139士11)mm H2O(1 mm H2O=9.8 Pa).全部飞行员减压试验后胸部X线透视检查未见异常.调查问卷结果 显示100%被调查人员认为该方法 能较真实模拟飞机增压座舱发生迅速减压的情景,并有效提高飞行员迅速判断是否发生迅速减压的能力. 结论 飞行员低高度迅速减压训练方法 具有明确的训练效果和肯定的安全性. Abstract： Objective To study the effectiveness and safety of pilot's rapid decompression (RD)training at low altitude. Methods According to sequential design methods, 187 male high performance fighter pilots were selected for RD and divided as Group A (93 pilots) and B (94 pilots),that with and without oxygen supply respectively. Each traning was for 2 pilots who were respectively from Group A and B. Training started from the climb to 2500 m with the rate of 30-40 m/s and stayed there 1-3 minutes for stabilizing heart rate (HR). RD was executed to 5500 m within 0. 48 s and returned to ground level by the rate of 10-20 m/s after plateau maintained for 1-2 min. Oxygen had no longer supplied while the altitude was lower than 4000 m in descend. The saturation of blood oxygen (SaO2), electrocardiogram (ECG) and peak value of pressure in lung were recorded during training.Pilots were examined by thoracic roentgenoscopy when training finished and completed a questionnaire that concerned about subjective experience and the evaluation of the effect of rapid decompression training. Results Observed SaO2 in Group A was about 99% when oxygen applied but significantly dropped as the supply stopped and finally gradually recovered. In Group B, SaO2 was decreased with the altitude. ECG analysis showed that pilots in both groups appeared growing HR before RD applied and respectively reached peak value at RD started (87. 87 ±15. 97) beats/min in Group A and (91. 29±2.78) beats/min in Group B. Then HR was significantly dropped in descend. The amplitude of lead Ⅱ T wave was significantly reduced as maximum HR appeared (0.19±0.11) mV in Group A and (0. 20±0.12) mV in Group B. During decompression the peak value of the pressure in lung was (139±11) mm H2O (1 mm H2O=9.8 Pa). No abnormity was observed by thoracic roentgenoscopy for both groups. Questionnaire analysis showed that all pilots admitted the reality of simulated RD and the effectiveness of judging the happening of RD in time. Conclusions The RD training program for pilots at low altitude is categorically safe and effective.     

高压氧对实验性减压病兔脊髓bFGF表达的影响

目的探讨实验性减压病兔脊髓bFGF的改变及高压氧对其影响。方法实验家兔随机分为7组：正常组、减压病3h组、减压病3d组、高压氧3h组、高压氧3d组、常氧高压氮3h组、常氧高压氮3d组。采用快速减压方法制备减压病模型，用免疫组织化学方法检测胸髓及腰髓中bFGF表达。结果（1）快速减压后各组bFGF表达均较正常组增加（P〈0．01），3h组之间无差异（P〉0．05）；（2）减压病3d组较3h组bFGF表达显著增高（P〈0．01），高压氧3d组较3h组显著降低（P〈0．01），常氧高压氮3d组较3h组有所降低（P〈0．05）；（3）高压氧3d组与常氧高压氮3d组均较减压病3d组显著降低（P〈0．01），高压氧3d组较常氧高压氮3d组降低（P〈0．05）。结论减压病脊髓损伤后bFGF表达增加；高压氧和常氧高压氮对减压病脊髓损伤起保护作用，高压氧效果优于常氧高压氮。     

脊髓型减压病大鼠脊髓组织内NGF和Trk A的蛋白表达

目的 观察大鼠脊髓减压病后脊髓组织内神经生长因子（NGF）及其受体酪氨酸激酶A（Trk A）蛋白表达随疾病进程的变化过程，探讨减压病脊髓损伤后自身的神经保护机制。方法 采用1.0MPa暴露5.5min后极快速减压的方法制备SD大鼠脊髓减压病模型，在出舱0，6，24，48，72h应用免疫组织化学染色和半定量图象分析方法检测脊髓组织NGF及其受体Trk A的蛋白表达。结果 极快速减压后6h开始有少量NGF和Trk A蛋白表达，在24h表达明显增强并达到高峰，此后Trk A表达逐渐减弱，NGF表达直到72h仍比基础值明显增加。结论减压病脊髓损伤诱导了脊髓神经元和胶质细胞的NGF及其受体的合成，提示脊髓型减压病在损伤神经组织的同时也激活了自身的神经保护机制，通过Trk A受体途径NGF可能在保护受损神经细胞中起作用。     

Effects of controlled frequency breathing during exercise on blood gases and acid-base balance

The purpose of this study was to determine the effect of a reduced ventilatory frequency (Vf) on blood gases and acid-base changes during three intensities of cycling exercise. VO2max and lactate threshold workload (LaT) of six subjects were assessed on a Monark ergometer. Experimental rides were performed 1) with no restriction on Vf (NB) and 2) with a prescribed Vf of 10/min (CFB). Each exercise period consisted of 8 min at 10% of VO2max below the LaT (WI), followed immediately by 8 min at LaT (WII), followed immediately by 8 min at 10% of VO2max above LaT (WIII). Blood was taken from a heated fingertip at the end of each load and analyzed for lactate concentration, pH, PO2, and PCO2. Respiratory exchange was monitored continuously using open circuit indirect calorimetry. Minute ventilation (VE) was significantly reduced by CFB at all three workloads. The reduced VE resulted in lower (p less than 0.05) blood PO2 at each workload (p less than 0.05), however, neither blood lactate nor VO2 were significantly different between CFB and NB for the three loads. Blood [H+] was significantly higher in CFB than NB at all three loads with the greatest difference between trials at WIII (NB: 37.93 +/- 0.68 nM: CFB: 44.77 +/- 1.02 nM). This was accounted for by a significantly higher PCO2 during CFB in WII and WIII (WII, NB: 33.0 +/- 1.4 mmHg, CFB: 35.7 +/- 2.7 mmHg; WIII, NB: 31.2 +/- 1.7 mmHg, CFB: 38.9 +/- 2.4 mmHg).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effectiveness of exercise intervention on improving fundamental movement skills and motor coordination in overweight/obese children and adolescents: A systematic review

Objectives

Childhood obesity is negatively associated with fundamental movement skill and motor coordination, which in turn constrains physical activity participation and adherence thereby forming a ‘vicious cycle’. However, developing motor skill and coordination in childhood could help to break the vicious cycle to reduce childhood obesity.The objective of this systematic review was to determine the effectiveness of exercise and physical activity interventions on improving fundamental movement skill and motor coordination in overweight/obese children and adolescents.

Effects of caffeine and exercise on body fat levels of the rat

Caffeine stimulates a release of free fatty acids from adipose tissue and has been shown to enhance fat utilization during an acute bout of prolonged aerobic exercise. A previous study indicated that chronically ingesting caffeine prior to exercise in an aerobic training program may enhance the fat-reducing effects of exercise. In the present study, mature male rats were divided into four groups: two groups swam 90 min/day, 5 days/week for 10 weeks (caf-ex, no caf-ex), while two groups served as sedentary controls (caf-sed, no caf-sed). The groups that received caffeine were administered, by gavage, 5 mg caffeine/kg body weight, dissolved in saline, 45 min prior to the start of exercise. The no caf groups received saline only. After the training period, body fat weight was determined by petroleum ether extraction of the fat from a dried, homogenized sample in a soxhlet apparatus. Body weight, percent body fat, epididymal fat pad weight, and food intake were all significantly lower in the exercised groups than the sedentary groups (P less than 0.05). The exercised groups weighed approximately 50-70 g less, % BF was 3.4% lower, EFP were approximately 2.5 g lighter, and food intake was 49-66 g less. There was no statistically significant difference between the caffeine and no caffeine groups on any of the variables tested (P greater than 0.05). This study did not find that caffeine enhanced the fat-reducing potential of the aerobic exercise.