睡眠剥夺条件下服用咖啡因对工作绩效的影响

目的　探讨睡眠剥夺条件下服用咖啡因对工作绩效的影响。　方法　８ 名受试者用药前后自身对照,每名受试者重复５ 次实验。每次实验时在从６：００ 至次日９：００ 的２７ ｈ 的睡眠剥夺过程中于凌晨１：００ 分别服用安慰剂（食用淀粉）或咖啡因（ ２００ ｍ ｇ 和３００ ｍ ｇ）或苯丙胺（５ ｍ ｇ 和 １０ｍ ｇ）,采用随机双盲给药。并在服药前１ ｈ 及服药后１ ｈ、３ ｈ、５ ｈ、７ ｈ 各完成一组认知任务工作绩效的测试。　结果　与安慰剂组比较,咖啡因可以显著降低单、双任务反应时、双任务跟踪误差（Ｐ＜０．０５）;服用咖啡因后主观任务难度降低（Ｐ＜ ０．０５） 。咖啡因 ２００ ｍ ｇ、３００ ｍ ｇ 的作用效果与苯丙胺５ ｍ ｇ、１０ ｍ ｇ 作用基本相当。咖啡因的这些作用在服药后１ ｈ 即可出现,持续至服药后７ ｈ。２００ ｍ ｇ 与３００ ｍ ｇ 咖啡因组间无显著差异（Ｐ＜ ０．０５）。　结论　咖啡因２００ ｍ ｇ 和咖啡因３００ ｍ ｇ 对于睡眠不足和睡眠剥夺引起的工作绩效的变化具有明显的改善作用     

48h睡眠剥夺对追踪作业工效,双手协调能力的影响

目的探讨４８ｈ睡眠剥夺对情绪、追踪作业工效、视反应能力及双手协调能力的影响。方法１４名健康男性青年在睡眠剥夺条件下，每间隔４ｈ进行光标追踪、Ｏｄｄｂａｌ模式视反应双重任务测试、双手追踪测试及ＰＯＭＳ情绪情感量表测试。结果双重任务中，光标追踪距离（Ｄ）在睡眠剥夺３２ｈ、４４ｈ和４８ｈ时显著升高（Ｐ＜０．０５），视反应的平均反应时（ｍＲＴ）、靶刺激反应时（ＴｓＲＴ）、非靶刺激反应时（ＮＴｓＲＴ）及刺激的反应正确率（ＡＲ）在睡眠剥夺２０ｈ及其以后各时程均显著改变，反应时延长，正确率下降（Ｐ＜０．０５）。靶刺激的反应正确率（ＴｓＡＲ）在睡眠剥夺２０ｈ及其以后各时程均显著下降（Ｐ＜０．０５）。双手追踪测试中，光标追踪距离（Ｄ）在睡眠剥夺４８ｈ显著降低（Ｐ＜０．０１）。随睡眠剥夺时程的增加，消极情绪状态值逐步升高（Ｐ＜０．０５），积极情绪状态值逐步下降（Ｐ＜０．０５）。结论睡眠剥夺对目标追踪能力、视反应能力有较大程度的影响；轻度影响双手协调能力；情绪改变明显，不良情绪状态值增加。     

短效类催眠药三唑仑和速可眠对模拟飞行工作能力的影响

目的利用飞行模拟器评价短效类催眠药三唑仑和速可眠对模拟飞行工作能力的影响。方法４名男性受试者在３周内分别在３个实验批次中于午间１２：００交叉服用安慰剂、三唑仑（０．２５ｍｇ）和速可眠（１００ｍｇ）后，在噪声干扰下睡眠５ｈ，于用药后８ｈ、１０ｈ、１２ｈ和２１ｈ（次日上午９：００）在飞行模拟器上操纵完成双１８０°大航线飞行任务，按照空军模拟器飞行训练大纲要求，实行５分制评分标准，评定用药后的飞行成绩、实时记录受试者心电图和对完成飞行任务的主观评价。结果服用三唑仑后８ｈ、１０ｈ、１２ｈ和２１ｈ飞行成绩的正确保持率分别为０．７６２、０．７５５、０．７２２、０．７６１，服用速可眠后飞行成绩的正确保持率分别为０．７８３、０．７４７、０．７３８、０．８１０，对４名受试者服用不同药物、用药后不同时间的模拟飞行成绩进行三因素方差分析，差异显著（Ｐ＞０．０５）。服用两种催眠药８ｈ后对受试者模拟飞行中的心率无明显影响（Ｐ＞０．０５）。受试者对完成模拟飞行任务后的六项调查主观感受无明显不良影响。结论服用短效类催眠药三唑仑和速可眠睡眠，于用药后８ｈ参加模拟飞行未见明显副作用和后遗效应。     

急性轻中度缺氧致情绪情感状态的改变

在低压舱缺氧模拟实验中以３００ｍ作对照,取２８００ｍ、３６００ｍ、４４００ｍ高度暴露１小时,采用情绪状态问卷和状态－焦虑问题１８名健康男性青年试的情绪变化,结果随高度的增加,情绪状态问卷中紧张－焦虑困惑－迷茫和疲备－惰性消极情绪状态值及伏状焦虑得分逐渐增加,而其中的积极情绪状态有力－好动得分则依次下降（Ｐ〈０．０５或Ｐ〈０．０１）,但情绪状态中愤怒－敌意和抑郁－沮丧的得分无显性变化（Ｐ〉０．０５）,２８００ｍｍ急性暴露的即刻,紧张－焦虑得分显高于对照水平（Ｐ〈０．０５）,暴露１小时后又下降至对照组水平,提示急性轻、中度度氧暴露对人的情绪及情感产生负影响,随高度的增加而影响加重。     

红景天与乙酰唑胺改善高原脑—体工作前后的光觉对比研究

目的：探讨在高原低氧条件下药物对人脑－体工作前后光觉的改善作用,为高原抗低氧药物的筛选、改善和提高脑－体功效能力积累借鉴资料;方法：采用暗房夜光表检测法对服用三普红景天组、乙酰唑胺组和安慰剂组,每组８人,于服药前进行运动前、运动后和睡眠剥夺前、睡眠剥夺２４ｈ后和运动前、运动后的间适应检测。服药２０天后,重复检测上述运动和睡眠剥夺２４ｈ前后的暗适应时间,进行组间及服药前后的对比;结果：红景天组、乙酰唑胺组服药后均较服药前暗应用时间显著缩短（Ｐ〈０．０１或Ｐ〈０．０５）,对照组服药前后无显著差异（Ｐ〉０．０５）;红景天组与对照组（服安慰剂）服药后暗适应时间显著缩短（Ｐ〈０．０５）;红景天组与乙酰唑胺组服药后比较无较显著性差异（Ｐ〉０．０５）;乙酰唑胺组与对照组比较服药后,暗适应时间虽缩短,但无统计学意义（Ｐ〈０．０     

红景天中药复方对海拔3600m高原移居者PWC170的影响

我们在海拔３６００ｍ高原地区，就红景天中药复方对从平原移居到该地区１～２年的受试者劳动能力的影响进行了观察。试验分为药物组（服红景天中药复方）和对照组（服安慰剂），连服９天药。然后用踏阶法测定停药后第１、４和７天时两组受试者的ＰＷＣ１７０。结果为药物组的ＰＷＣ１７０比对照组分别高１２．１％（Ｐ＜０．０１）、９．８％（Ｐ＜０．０５）和３．５％；药物组受试者的ＰＷＣ１７０比服药前分别高１３．３％（Ｐ＜０．０１）、１０．３％（Ｐ＜０．０１）和７．５％（Ｐ＜０．０５）。提示：该药在提高高原人体劳动能力方面具有明显的作用。     

短效类催眠药三唑仑和速可眠对模拟飞行工作能力的影响

目的　利用飞行模拟器评价短效类催眠药三唑仑和速可眠对模拟飞行工作能力的影响。　方法　４ 名健康青年男性志愿者,连续３ 周模拟飞行试验,每周一次。受试者于中午１２：００ 分别交叉服用三唑仑（０．２５ ｍ ｇ）,速可眠（１００ ｍ ｇ）和安慰剂后,在噪声干扰下睡眠５ ｈ,分别于用药后８ ｈ、１０ ｈ、１２ ｈ 和２１ ｈ 在飞行模拟器上检测模拟飞行能力,并记录模拟飞行中心率和受试者对完成飞行任务的主观评价。　结果　用药前和用药后８ ｈ、１０ ｈ、１２ ｈ、２１ ｈ 的模拟飞行工作能力变化和两种催眠药三唑仑和速可眠对模拟飞行中的心率变化及完成模拟飞行任务的主观评价均无明显差异。　结论　服用短效类催眠药三唑仑和速可眠诱导睡眠,用药后８ ｈ 对模拟飞行工作能力未见明显副作用     

急性低压缺氧对人的感知觉能力的影响

目的　研究急性低压缺氧对人的感知觉能力的影响。　方法　用低压舱模拟２ ８００ ｍ 、３ ６００ ｍ 、４ ４００ ｍ 三个高度的急性缺氧暴露１ ｈ,考察１８ 名健康男性青年对长度判断、图案比较、数字检索等测验绩效的变化。　结果　以３００ ｍ 高度所测参数作为正常对照值,２ ８００ ｍ 缺氧暴露１ ｈ,长度判断的综合绩效已低于对照值（Ｐ＜ ０．０５）,３ ６００ ｍ 暴露１ ｈ 各项测验的反应时间明显延长（Ｐ＜ ０．０１）,综合绩效显著降低。但图案比较和数字检索测验的错误率无显著改变（Ｐ＞ ０．０５）,４ ４００ ｍ 暴露１ ｈ 各项测试的综合绩效进一步降低。错误率也显著增加（Ｐ＜ ０．０５）。　结论　２ ８００ ｍ高度的低压缺氧即对感知觉能力产生一定负面影响,且随着高度的增加进一步加重。不同测验项目受缺氧影响的特性和阈值不同     

Effects of Acute Moderate Hypoxia on Human Performance of Arithmetic

为观察急性中度缺氧对人计算能力的影响，利用低压舱模拟３００ｍ（对照）、３６００ｍ、４４００ｍ、５０００ｍ高度的缺氧暴露，考察１６名健康男性青年的连续计算、系列加减及心算测验综合绩效的变化。结果显示，３６００ｍ缺氧暴露１ｈ，连续计算测验的错误率增加、系列加减运算的反应时延长、综合绩效下降，均达到显著水平（Ｐ＜０．０５）。４４００ｍ缺氧暴露各项测验的绩效均显著下降（Ｐ＜０．０５）。５０００ｍ暴露时各项测验的绩效进一步降低（Ｐ＜０．０１）。提示：急性中度缺氧１ｈ对人的计算能力有一定影响，且随高度的增加而加重     

十全大补丸防护环孢菌素A肾毒性的实验研究

目的：以急性环孢菌素Ａ（ＣｓＡ） 肾毒性大鼠为模型,观察气血双补药十全大补丸防护ＣｓＡ 肾毒性的作用。方法：大鼠分为４ 组：ⅠＣｓＡ组（０．０５ｇ·ｋｇ－１） ,ⅡＣｓＡ加十全大补丸高剂量组（０．０５ｇ·ｋｇ－１ ＋ ０．６ｇ·ｋｇ－１） ,ⅢＣｓＡ加十全大补丸低剂量组（０．０５ｇ·ｋｇ－１ ＋ ０．３ｇ·ｋｇ－ １） ,Ⅳ空白对照组（ 等量２％ 羧甲基纤维素ＣＭＣ） ｑｄ,ｉｇ,连续７ｄ。末次给药后,单个收集大鼠２４ｈ 尿液;末次给药２４ｈ 后,眼眶取血,测定超氧化物歧化酶（ＳＯＤ）、丙二醛（ＭＤＡ） 、谷胱甘肽ｓ－ 转移酶（ＧＳＴ） 、肌酐（Ｃｒ） 、尿素氮（ＢＵＮ） 。取肾脏作病理检查。结果：用药７ｄ 后,ＣｓＡ组２４ｈ 尿量明显减少,十全大补丸组明显增加（ Ｐ＜ ０．０１）;ＣｓＡ组Ｃｒ、ＢＵＮ上升,十全大补丸两组降低（ Ｐ＜０ ．０５） ;各组ＳＯＤ、ＧＳＴ活力无显著性差异,十全大补丸高低剂量组ＭＤＡ 较ＣｓＡ 组明显升高（ Ｐ＜ ０．０１） 。结论：十全大补丸对ＣｓＡ 所致大鼠肾毒性有保护作用,抗氧化清除自由基作用不明显     

Caffeine effects on marksmanship during high-stress military training with 72 hour sleep deprivation

PURPOSE: Navy SEALs (sea, air, land) are elite special warfare units that conduct unconventional warfare primarily in marine environments. Marksmanship accuracy and sighting time were quantified with 62 male trainees during Navy SEAL Hell Week, which involves the combined stress of sleep loss, operational combat scenarios, and cold-wet environmental conditions. Caffeine was administered to minimize deficits due to sleep deprivation. METHODS: Volunteers dry-fired a disabled rifle equipped with a laser-based marksmanship simulator system to measure shooting speed and accuracy. The target was a 2.3-cm diameter circle at a distance of 5 m, simulating a 46 cm target at a distance of 50 m. Marksmanship was assessed prior to training, and at 73 and 80 h into Hell Week. Volunteers were randomly assigned to 1 of 4 treatments: 100, 200, or 300 mg of caffeine or a placebo. Dosing occurred 72 h after training commenced. RESULTS: The combined effects of almost 73 h of total sleep deprivation and operational and environmental stress degraded all marksmanship accuracy measures (p < 0.05) as shown by the 37.5% increase in percent of targets missed, 38% increase in distance from center of mass of the target, and the 235% increase in shot group tightness. Sighting time increased by 53% or 3.1 s after 73 h of sleep deprivation (p < 0.05). Sighting time was significantly faster in sleep deprived individuals after taking 200 or 300 mg of caffeine compared with placebo or 100 mg of caffeine. No differences in accuracy measures between caffeine treatment groups were evident at any test period. CONCLUSION: During periods of sleep deprivation combined with other stressors, the use of 200 or 300 mg of caffeine enabled SEAL trainees to sight the target and pull the trigger faster without compromising shooting accuracy.     

Modafinil vs. caffeine: effects on fatigue during sleep deprivation

INTRODUCTION: The extent to which modafinil and caffeine reverse fatigue effects (defined as performance decrements with time on task) during total sleep deprivation was investigated. METHODS: There were 50 healthy young adults who remained awake for 54.5 h (06:30 day 1 to 13:00 day 3). A 10-min vigilance test was administered bi-hourly from 08:00 day 1 until 22:00 day 2. At 23:55 day 2 (after 41.5 h awake), double-blind administration of one of five drug doses (placebo; modafinil 100, 200, or 400 mg; or caffeine 600 mg; n = 10 per group) was followed by hourly testing from 00:00 through 12:00 day 3. Response speed (reciprocal of reaction time) across the 10-min task (by 1-min block) was analyzed prior to and after drug administration. RESULTS: A fatigue effect (response speed degradation across the 10-min task) was exacerbated by sleep deprivation and circadian rhythmicity. Prior to the drug, this effect was maximal between 08:00 and 12:00 day 3 (24-28 h sleep deprivation). Modafinil 400 mg attenuated fatigue in a manner comparable to that seen with caffeine 600 mg; these effects were especially salient during the circadian nadir of performance (06:00 through 10:00); modafinil 200 mg also reversed fatigue, but for a shorter duration (3 min) than modafinil 400 mg (8 min) or caffeine 600 mg (6 min). DISCUSSION AND CONCLUSIONS: Time-on-task effects contributed to the performance degradation seen during sleep deprivation; effects which were reversed by caffeine and, at appropriate doses, by modafinil. Because the duration of efficacy for reversing time-on-task effects was shorter at lower drug dosages, the latter must be considered when determining the appropriate dose to use during sustained operations.     

Caffeine effects on recovery sleep following 27 h total sleep deprivation

INTRODUCTION: Caffeine is widely used to reverse alertness and performance decrements. However, caffeine's effects on subsequent recovery sleep and post-recovery performance are not well documented and, therefore, were evaluated. METHODS: Six habitually low (LC: < or = 100 mg x d(-1)) and three habitually high (HC: > or = 400 mg x d(-1)) caffeine users completed a randomized crossover design. After 20 h of wakefulness, repeated doses of caffeine gum [0 (placebo) mg, 100 (low dose) mg, or 300 (high dose) mg] were administered at 03:00, 05:00, and 07:00. At 10:00 (27 h sleep deprivation) subjects slept for 8 h, followed by Psychomotor Vigilance Task (PVT) administration at 33 and 65 min post-awakening. RESULTS: Low dose caffeine increased stage 1 minutes only. However, high dose caffeine impaired sleep maintenance (reduced total sleep time/increased wake) and reduced sleep depth (increased stage 1 minutes/percentage and slow-wave sleep (SWS) latency, and reduced SWS minutes during the first third of the sleep period). With high dose caffeine, LC users had less SWS percentage as compared with HC users. The HC users had reduced stage 2 percentage with high dose caffeine as compared with placebo and low dose caffeine. Caffeine dose and habitual caffeine use did not influence post-recovery sleep PVT performance. DISCUSSION: Caffeine exerts mild deleterious dose-response effects on recovery sleep following total sleep deprivation, primarily early in the sleep period, with potential recovery from these effects after sufficient sleep as suggested by lack of post-recovery sleep performance deficits. Habitual caffeine use appears to minimally reduce caffeine effects.     

Multiple caffeine doses maintain vigilance during early morning operations

INTRODUCTION: When used to counteract the effects of sleep deprivation, multiple doses of caffeine are typically ingested across an extended period of time. The goal of this study was to determine the optimal dose of caffeine for sustaining performance during sleep loss with administration of multiple doses. METHODS: There were 48 subjects (28 men, 20 women) who were randomly assigned to 1 of 4 groups (placebo, 50, 100, or 200 mg caffeine). After an overnight 8-h sleep period, subjects were required to remain awake for the ensuing 29 h. Control data were collected until 03:00 (Day 3), followed by three 2-h test blocks. At 03:00, 05:00, and 07:00 subjects chewed two sticks of gum (Stay Alerts chewing gum) containing caffeine or placebo. Six 10-min sessions on a version of the Psychomotor Vigilance Test (PVT) were completed during each 2-h test block. The Stanford Sleepiness Scale (SSS) was administered after each PVT. RESULTS: Lapses on the PVT were categorized as response times greater than 1, 3, or 5 s. Lapses in all categories significantly increased in the placebo group. Caffeine significantly reduced the number of lapses in a dose-related manner; and performance was maintained at baseline levels for the entire sleep loss period with multiple doses of 200 mg caffeine. There was a significant main effect for session on the SSS, the score increasing over time, but no significant differences between groups. DISCUSSION: These results indicate that a bi-hourly administration of 200 mg of caffeine maintains vigilance performance across a single night without sleep.     

Caffeine improves physical performance during 24 h of active wakefulness

BACKGROUND: Reductions in both cognitive and physical performance occur during periods of sleep loss with sustained operations. It was the purpose of this study to examine the effects of caffeine on activities chosen to simulate the physical challenges that might occur during a military scenario involving a period of sleep loss. METHODS: There were 16 subjects (26.7 +/- 7.8 yr, 83.8 +/- 11.0 kg) who completed a double-blind caffeine and placebo trial involving a control day and sleep period followed by 28 h of sleep deprivation. A 400-mg dose of caffeine was administered at 21:30 followed by subsequent 100-mg doses at 03:00 and 05:00. At 22:00, subjects began a 2-h forced march followed by a sandbag piling task. A treadmill run to exhaustion at 85% of maximal aerobic power was performed at 07:00 of the second day of sleep deprivation. RESULTS: Caffeine had no effect on the heart rate or oxygen consumption, but rating of perceived exertion (RPE) was reduced with caffeine during the forced march. Time to complete the sandbag piling task during set 1 was significantly reduced with caffeine (12.9 +/- 1.0 min) compared with placebo (13.8 +/- 1.0 min) but there was no difference during set 2 and RPE was increased. Time to exhaustion was significantly increased 25% during the run with caffeine (17.0 +/- 4.4 min) compared with placebo (13.5 +/- 3.3 min), and caffeine maintained performance at control levels (16.9 +/- 4.6 min). CONCLUSIONS: It was concluded that caffeine is an effective strategy to maintain physical performance during an overnight period of sleep loss at levels comparable to the rested state.     

32h睡眠剥夺对健康男性心理旋转速度的影响

目的 通过32 h完全睡眠剥夺(sleep deprivation,SD)模式,诱发个体认知能力下降,探讨32 h完全SD对心理旋转加工速度的影响.方法 8名健康男性青年志愿者在32 h完全SD条件下(凌晨6:00至次日14:00),采用自身前后对照设计,分别在8个时间点(SD 2 h、SD 14 h、SD 18 h、SD 20 h、SD 22 h、SD 24 h、SD 28 h和SD 32 h)进行字母R心理旋转测验,分析比较心理旋转加工过程中非旋转加工速度与旋转加工速度的变化.结果 随着SD时间的延长,代表非旋转阶段加工速度的截距逐渐增大,同时反映旋转阶段加下速度的斜率也逐渐变大,且差异具有统计学意义(截距F(7.56)=4.602,P＜0.01;斜率F(7.56)3.863,P＜0.05).在剥夺后22～24 h阶段,即凌晨4:00至6:00这种变化达到顶点,与其他时间点比较差异有统计学意义(P＜0.05);6:00后逐渐下降.结论 凌晨6:00开始的32 h完全SD,在SD后22～24 h可明显降低图形表象心理旋转加工速度,提示由于受试者警觉水平下降,降低了对图形表象的知觉编码、辨别、判断、选择和执行过程的速度,同时亦降低了对图形表象的旋转速度. Abstract： Objective To explore the effect of sleep deprivation(SD) on human performance by investigating the change of processing speed of mental rotation on male subjects whose sleep was deprived for 32 hour. Methods During 32 h SD (from 6:00 am to 2:00 pm next day) 8 healthy male college students were tested by letter R mental rotation task to get processing speed of rotation at different measuring time after SD start (SD 2 h, SD 14 h, SD 18 h, SD 20 h, SD 22 h, SD 24 h, SD28 h and SD 32 h). The processing speeds of rotation (slope) and non-rotation (intercept) were compared and analyzed. Results The intercept and slope that respectively indicated the processing speed of non-rotation and rotation were gradually increased with SD time (for intercept F(7.56)=4.602,P＜0.01, for slope F(7.56)=3.863,P＜0.05). The peak values of intercept and slope were appeared in the period of 22-24 h after SD start, that was from 4:00 am to 6:00 am, which were significantly higher than those in other measuring time (P＜0.05) and then followed gradual decrease.Conclusions In 32h test, 22-24 h SD that started from 6:00 am has already significantly slowed down the processing speed of mental rotation and this indicates that subject's alert has declined by the retrogression of achieving coding, identification, judgment, choice and execution tasks.     

咖啡因和三唑仑对人体科里奥利加速度耐力的影响

目的 探讨服用中枢兴奋药咖啡因及短效类催眠药三唑仑对人体科里奥利加速度耐力的影响。方法 8名健康青年男性志愿者,采用两阶段交叉设计方法,受试者随机分为两组,在5周内完成4次测试,每周1次,第3周受试者休息。受试者前两周于每周二8：00分别交叉服用咖啡因（200mg）和安慰剂各1次,每组服用咖啡因和安慰剂的先后顺序不同,在用药后1h进行科里奥利加速度耐力的检测;后两周于每周一24：00分别交叉服用三唑仑（0．25mg）和安慰剂各1次,每组受试者服用三唑仑和安慰剂的先后顺序不同,在用药8h后进行科里奥利加速度耐力的检测。结果 服用咖啡因（200mg)1h后及服用三唑仑（0．25mg)8h后受试者的科晨奥利加速度耐力值与安慰剂相比,差异无显著性意义。结论 服用中枢兴奋药咖啡因（200mg)1h后或服用短效类催眠药三唑仑（0．＝25mg)8h后人体抗晕机病能力未见明显变化。