高温高湿环境与常温环境运动中能量消耗的差异

目的:比较高温高湿环境和常温环境中不同运动强度下能量消耗的差异,为高温高湿环境中的训练和比赛提供参考。方法:10名成年男性分别在湿热环境(温度33±1℃,相对湿度65%±3%)和常温环境(温度23±2℃,相对湿度45%±2%)下,分别完成40%VO2max、60%VO2max、80%VO2max三个强度的跑台运动,运动时间20min。使用固定式气体代谢仪(Cortex Metalyzer 3B)测定运动过程中的能量消耗。结果:相比常温环境,机体在高温高湿环境同等强度运动中,呼吸频率显著增加,每分通气量非常显著性增高(P<0.01),但机体摄氧量,除60%VO2max强度外,增高不显著,呼吸交换率除60%VO2max强度外,显著性降低(P<0.05);机体脂肪的氧化量、供能量均显著性提高(P<0.05),供能比例除60%VO2max强度外,显著性增高(P<0.05);但机体的总能量消耗,除40%VO2max强度外,变化不显著。整个运动过程中,随运动强度的增加糖供能速率逐渐增加,但同等强度运动中,高温高湿环境中的糖供能速率较常温时低,脂肪供能速率较常温时高。结论:脂肪是高温高湿环境下安静和低强度运动中机体的主要供能物质。相比常温环境,高温高湿环境下同等强度运动中脂肪的供能比例更高。     

穿戴防毒装具时热负荷限度的研究

本研究目的在于阐明穿戴防毒装具活动时,热负荷限度的机体反应特点。29名健康战士在热气候下穿戴防毒装具,以约5km/h 的速度行进,当达到热负荷限度指征为止。共观察55人次。在干球温度/黑球温度(Td/Tg)为31.7～34.3℃/35.9～42.9℃条件下,耐受时间仅30～40min,行程2.3～4.1km 即达热负荷限度。Td、Tg 与各项生理指标增速相关最密切,可认为是评价防化作业时环境热强度的最佳指标,使用其回归方程,可以预测在上述活动条件下的耐受时间。     

环境因素对暖体假人模拟潮湿服装的蒸发散热性能分析

目的研究不同环境条件下重度体力劳动者显性出汗时的散热特性,为改善高温高湿劳动环境提供参考。方法基于暖体假人实验平台,运用SPSS软件进行回归分析,研究环境温度(10～34℃)、相对湿度(60%～96%)、风速(0～4m/s)及假人表面温度(31～37℃)对完全潮湿服装蒸发散热占模拟假人总散热比的影响。结果环境温度对完全潮湿服装蒸发散热占模拟假人总散热比有显著正向影响(P0.05);风速对其有显著负向影响(P0.05);相对湿度与假人表面温度则对其影响不大(P0.05);4个因素的影响程度排序:环境温度风速相对湿度假人表面温度。结论在环境温度、湿度不易改变的情况下,为提高重体力劳动者散热强度,保证工人健康,增加环境风速为较好方法。     

不同湿度高温环境下急性大强度运动应激前后人体血浆游离HSP72浓度变化

目的:观察不同湿度高温环境下急性大强度运动前后人体血浆游离HSP72浓度变化。方法:随机挑选10名有训练经历的大学生(平均年龄21.8岁),进行4次高温下递增负荷大强度力竭性跑台运动,运动环境相对湿度(RH)分别设定为20%、40%、60%、80%,温度均为33℃,每次运动间隔一周。分别用电子体温计和红外体温计测定运动前后口腔温度和体表温度,计算平均体表温度(mean skintemperature,MST),运动前后抽取静脉血肝素抗凝分离血浆,采用ELISA法测定血浆HSP72浓度。结果:运动后口腔温度和MST显著升高(P<0.01),20%RH条件下运动后口腔温度显著低于60%RH和80%RH(P<0.01),运动后MST变化为20%RH<40%RH<60%RH<80%RH,且不同相对湿度间两两相比有显著性差异(P<0.01),运动后MST与相对湿度存在明显线性关系(r2=0.79,P<0.01)。除40%RH条件外,其他相对湿度条件下大强度运动后血浆HSP72均明显升高(P<0.05)。结论:高温高湿环境中运动,湿度增加加剧了体表温度的升高,运动热应激促使血浆HSP72升高,可能对机体起全身性作用。     

谷氨酰胺对高温下游泳大鼠LA、CPK、游泳时间及骨骼肌的影响

目的探讨高温环境下运动机体补充外源性谷氨酰胺(G ln)对抗疲劳能力的影响。方法在仿真模拟热气候舱内[环境温度(39.5±0.5)℃,相对湿度(70±3)%]大鼠采用力竭性游泳运动方式,通过补充G ln对比实验,观察力竭运动后大鼠的存活时间以及血清中乳酸(LA)含量、肌酸磷酸激酶(CPK)、游泳时间和骨骼肌组织学的变化。结果在36℃水温中游泳50 m in后补充谷氨酰胺组大鼠血清LA、CPK活力低于对照组(P<0.01),力竭性游泳时间为(85.5±10.0)m in,较对照组的(55.0±7.1)m in明显延长。结论补充谷氨酰胺可明显提高机体在高温环境下的抗疲劳能力。     

不同湿度高温环境下机体有氧运动能力相关指标比较

目的:探讨不同湿度高温环境对有氧运动能力的影响。方法:随机选取10名男性大学生为对象,设定环境温度为33℃,相对湿度分别为20%、40%、60%、80%作为模型,实验时间4周,两次测试之间间隔1周。测试时受试者进行递增负荷跑台运动,以8 km/h为起始速度,每分钟增加0.8 km/h到16 km/h为止,然后逐级加坡度,0.5%为起始坡度,每分钟递增0.5%直至受试者不能坚持,运动过程中监测心率、摄氧量、每分钟通气量(VE)以及主观用力感觉指数(RPE),测试前及结束后无名指采血测试血乳酸。结果:不同湿度高温环境下运动VE、最大心率(HRmax)、最大摄氧量(VO2max)无显著性差异,60%相对湿度下运动时VO2max(3831.7±313.16 ml/min)、VE(137.5±9.38 L/min)、HRmax(199.1±8.29 beat/min)均较其余相对湿度大。20%相对湿度组运动后3 min及5 min血乳酸较80%湿度组显著升高(P<0.05),60%相对湿度组运动后3 min血乳酸亦显著高于80%湿度组(P<0.05)。80%相对湿度组运动后1 min RPE仍显著高于40%相对湿度组(P<0.05),20%相对湿度组RPE值增加较缓慢,运动至第7和10 min时RPE值显著低于60%相对湿度组(P<0.05)。结论:与其余湿度相比,33℃高温环境下,80%相对湿度中机体有氧运动能力并未得到充分发挥。     

某部装备长时作业物理环境及军人睡眠节律调查分析

目的 明确某部装备物理环境及长时作业军人睡眠节律规律,为相关作业效能保障提升技术奠定基础。方法 采用自制问卷调查不同作业时期军人舒适性影响因素及保障需求,以噪声、温湿度、照度等参数评估装备长时作业物理环境状况,采用慕尼黑睡眠时型问卷（MCTQ）填写、体温监测的方式调查军人睡眠节律状况。结果 设备噪声、密闭空间、昼夜颠倒等因素对军人作业舒适性影响较大;某部装备长时作业各舱内环境噪声强度为50.0～72.5 dB(A),频谱范围主要为200 Hz以下的低频噪声;环境温度为22.2～36.0℃,相对湿度为42.6%～73.3%,照度为3.6～1092 lx;军人社会性时差均值为（1.56±2.39）h;军人在作业前期体温呈明显的睡眠节律性,作业中期睡眠节律性降低,作业后期睡眠节律性趋近于无。结论 军事作业中期军人睡眠节律发生紊乱,且随着作业时间延长而逐渐加重,较高强度噪声等不良物理环境可能是重要影响因素。     

热应激小鼠脑电图表现及脑组织的电镜观察分析

目的 研究急性热应激条件下小鼠脑组织超微结构及脑电图的变化。方法 采用恒温恒湿动物箱建立不同温度（24℃、34℃、37℃、38．5℃、40℃、42℃,各60min,相对湿度60％）的热应激模型。观察成年昆明种小鼠的行为表现,监测体温及脑电图。透射电镜观察大脑海马组织的细胞形态改变。结果 34℃环境温度仅引起小鼠直肠温度升高。37℃以上的环境温度不仅使小鼠直肠温度升高,还使其发生脱水,且诱发小鼠惊跳、逃窜行为;脑电图出现明显异常,幅值增大,节律减慢,但42℃环境温度下脑电图频率增快。电镜检查结果提示只有42℃环境温度才引起海马组织病理性改变。结论 小鼠对环境高热敏感,随着核心温度升高出现行为性体温调节,其脑电图及脑组织细胞形态学变化反映了高温环境对中枢神经系统的影响。40℃以下环境高温引起的急性脑功能紊乱是可逆的,42℃的环境温度可造成脑组织结构改变,大多数小鼠会因中暑而死亡。     

穿戴防毒装具热适应锻炼提高热负荷限度的初步研究

19名健康战士按其反应分为二组,甲组9人,热锻炼后直肠温度可达38.90～39.39℃,乙组10人,热锻炼后直肠温度可达38.40～38.81℃。结果表明高湿热锻炼提高机体热负荷耐受能力和体力,甲组较乙组提高更多,能坚持至直肠温度达40°,心率170bpm,平均体温39.2℃、BHSI389kJ/m~2、PSI5.4,出汗率增加2.4ml/min 行军时速明显增加(自83.5增至91.0m/min)。而乙组热负荷耐受能力提高不多,出汗率减少1.7ml/min,行军速度未增快。但尿常规变化和不适感二组都明显改善。     

不同湿热环境下颅脑火器伤死亡因素分析

目的　研究高温高湿环境下颅脑火器伤后生命体征变化特点及死亡因素。　方法　杂种猫 3 2只随机分为 4组 ,火器伤后分别放入A (2 5℃、相对湿度 50 % )、B (3 5℃、相对湿度85% )、C(3 8℃、相对湿度 90 % )、D(40℃、相对湿度 95% )四种环境中。每隔 10min记录一次血压、脉搏、呼吸频率及体温 ,到 6h时结束实验。　结果　常温枪伤组实验过程中生命体征稳定 ,随着温度及湿度的增加 ,各组动物相同时相点的体温、呼吸及心率均明显不同 (P <0 .0 5)。A组、B组动物在伤后 6h内均无死亡。C组 1.5h开始死亡 ,至 5h动物全部死亡 ,平均生存时间为 3 .4h。D组 0 .5h开始死亡 ,至 2 .5h动物全部死亡 ,平均生存时间为 2 .0h。　结论　高温高湿环境对颅脑火器伤时的生命体征变化和死亡率影响显著     

舱温降低对人体的影响

为探讨舱温降低对人体的影响，观察了穿着不同热阻服装的５名男性青年受试者在２０℃、、１５℃、１０℃三种舱温条件下，直肠度、皮肤热液、体表红外热图等指标的变化。结果表明，随着舱温的下降，平均皮温及肢端温度降低，体表热流明显增高，皮肤红外热图 分布也有明显改变。     

Effects of menthol application on the skin during prolonged immersion in swimmers and controls

We hypothesized that menthol application on the skin would enhance vasoconstriction of subjects immersed in cool water, which would reduce heat loss and rectal temperature (Tre) cooling rate. Furthermore, it was hypothesized that this effect would be greater in individuals acclimatized to immersion in 24 °C water, such as swimmers. Seven swimmers (SW) and seven physical education students (CON) cycled at 60% VO₂ max until Tre attained 38 °C, and were then immediately immersed in stirred water maintained at 24 °C on two occasions: without (NM) and with (M; 4.6 g per 100 mL of water) whole‐body skin application of menthol cream. Heart rate, Tre, proximal–distal skin temperature gradient, oxygen uptake (VO₂), electromyographic activity (EMG), and thermal sensation were measured. Tre reduction was similar among SW and CON in NM and CON in M (?0.71±0.31 °C in average), while it was smaller for SW in M (?0.37±0.18 °C, P < 0.01). VO₂ and heart rate were greater in M compared with NM condition (P = 0.01). SW in M exhibited a shift of the threshold for shivering, as reflected in increased VO₂ and EMG activity, toward a higher Tre compared with the other trials. Menthol application on the skin before immersion reduces heat loss, but defends Tre decline more effectively in swimmers than in non‐swimmers.     

Effects of menthol application on the skin during prolonged immersion in cool and cold water

The aim of the study was to compare the effect of skin surface menthol application on rectal temperature (Tre) during prolonged immersion in cool and cold water. We hypothesized that menthol application would lead to a slower Tre decline due to the reduced heat loss as a consequence of the menthol‐induced vasoconstriction and that this effect would be attenuated during cold‐water immersion. Six male subjects were immersed for 55 minutes in stirred cool (24°C) or cold (14°C) water immediately after attaining a Tre of 38°C by cycling at 60% of maximum heart rate on two occasions: without (ΝM) and with (M) whole‐body skin application of menthol cream. Tre, the proximal‐distal skin temperature gradient, and oxygen uptake were continuously measured. ANOVA with repeated measures was employed to detect differences among variables. Significance level was set at 0.05. The area under the curve for Tre was calculated and was greater in 24°C M (−1.81 ± 8.22 a.u) compared to 24°C NM (−27.09 ± 19.09 a.u., P  = .03, r  = .90), 14°C NM (−18.08 ± 10.85 a.u., P  = .03, r  = .90), and 14°C M (−11.71 ± 12.58 a.u, P  = .05, r  = .81). In cool water, oxygen uptake and local vasoconstriction were increased (P  ≤ .05) by 39 ± 25% and 56 ± 37%, respectively, with menthol compared to ΝM, while no differences were observed in cold water. Menthol application on the skin before prolonged immersion reduces heat loss resulting in a blunted Tre decline. However, such a response is less obvious at 14°C water immersion, possibly because high‐threshold cold‐sensitive fibers are already maximally recruited and the majority of cold receptors saturated.     

Validity and reliability of the myTemp ingestible temperature capsule

Objectives

An accurate and non-invasive measurement of core body temperature (Tc) is of great importance to quantify exercise-induced increases in Tc in athletes or to assess changes in Tc in patient populations. The use of ingestible gastrointestinal telemetric temperature capsules is widely accepted as a surrogate marker for Tc, but widespread implementation is lacking due to the high costs of these disposable capsules. A new and cheaper temperature capsule system (i.e. myTemp) was recently introduced. The aim of present study is to determine the validity and test–retest reliability of the myTemp system.

定功率变流量气冷射频消融方式效果研究

目的验证一种定功率变流量以维持T0.2(距射频针0.2 cm处的温度)于设定值的气冷射频消融方式的可行性及有效性。方法以土豆为实验对象,设计了针对不同T0.2预设值、氮气压力、射频功率的3组实验,通过考察射频针周围组织升温幅度及升温速度确定上述3个参数对消融效果的影响。结果T0.2预设值越高,周围组织升温幅度越大;如能维持T0.2于预设值,则升温效果与氮气压力无关;同样时间内,升温幅度随功率增大而增大,但超过一定功率值后,由于消融时间缩短,升温幅度反而逐渐减小。结论定功率变流量的气冷射频消融方式优于同工况下的传统气冷射频消融方式,实验结果可为气冷射频技术的优化提供参考。     

模拟失重条件下体温调节的特点

为观察模拟失重条件下体温调节的特点，５名健康男性－６°头低卧床７ｄ、对照３ｄ、恢复２ｄ。结果表明：卧床中体温保持了觉醒－睡眠的昼变化规律，但节律发生了一定改变，直肠温度昼夜节律的改变主要出现在卧床初期。头颈部皮肤温度明显升高，温度分布改变。     

Accumulation in the blood of a deuterium tracer added to hot and cold beverages

Deterium (²H) accumulation in the circulation was determined in 10 subjects after they ingested 7 ml · kg⁻¹ of a dilute glucose-electrolyte solution that contained 10 g of ²H₂O and was hot (50°C) on one occasion and cold (4°C) on another. In addition, 7 subjects repeated their first trial on a third occasion. Subjects fasted overnight and remained seated at rest during the experiment Blood ²H concentration was significantly greater at 5 min after ingestion of the hot as compared with the cold treatment and at 60 min for the cold as compared with the hot treatment The rate of blood ²H accumulation was not different when the same solution was ingested on different days. The results indicate that the rate of ²H accumulation is: 1) similar for hot and cold solutions and 2) reproducible when the same solution is ingested on different days. This implies that the rate at which dilute glucose-electrolyte solutions are made available to the body is not much influenced by the temperature at which they are ingested.     

不同气温和体力负荷下身体各部位体表温度的变化

研究了几种气温、同一活动水平以及相同气温、不同体力负荷下的各部位体表温度变化。实验结果表明:(1)进一步确认在同一气温下头颈部皮肤温度分布的不均匀性,并表明各部位受气温的影响程度也不尽相同。(2)在同一气温下头颈部及身体其它部位的皮肤温度变化并不与体力负荷程度呈特定关系,并分析了产生这一现象的原因。(3)根据下肢为主的体力负荷对全身体表温度的影响情况,认为个体调温装备的区域性流量分配比例随身体活动形式改变而改变的必要性并不很大。由此,可以减少服装设计的复杂性。     

Effects of capsaicin application on the skin during resting exposure to temperate and warm conditions

We investigated thermoregulatory and cardiovascular responses at rest in a temperate (20°C) and in a warm (30°C) environment (40% RH) without and with the application of capsaicin on the skin. We hypothesized that regardless of environmental temperature, capsaicin application would stimulate heat loss and concomitantly deactivate heat conservation mechanisms, thus resulting in rectal temperature (Tre) and mean blood pressure decline due to excitation of heat‐sensitive TRPV1. Ten male subjects were exposed, while seated, for 30 minutes to 20.8 ± 1.0°C or to 30.6 ± 1.1°C: without (NCA) and with (CA) application of capsaicin patches on the skin. Thermoregulatory (Tre, proximal‐distal skin temperature gradient) and cardiovascular variables (modelflow technique) as well as oxygen uptake were continuously measured. The area under the curve for Tre decline at 20°C was smaller in CA (?2.1 ± 1.3 a.u.) than in NCA (?0.6 ± 1.1 a.u., P < 0.01, r = 0.8). Likewise, at 30°C it was smaller in CA (?2.2 ± 2.1 a.u.) compared to NCA (?0.8 ± 2.0 a.u., P = 0.02, r = 0.7). Local vasomotor tone and oxygen uptake, were significantly lower by 36.7% ± 94.2% and 12.3% ± 12.3%, respectively, with capsaicin compared to NCA (P = 0.05 and P < 0.01, respectively). Additionally, in 30°C CA mean arterial pressure was lower by 10.7% ± 5.9%, 8.9% ± 5.9%, and 10.6% ± 7.0% compared to 30°C NCA, 20°C NCA, and 20°C CA, respectively (P < 0.01, P = 0.02, and P < 0.01, respectively, d = 1.4‐1.8). In conclusion, capsaicin application on the skin induced vasodilation and Tre decline. At 30°C CA, thermal responses were accompanied by arterial hypotension most likely due to the interactive effects of both stressors (warm environment and capsaicin) on cutaneous vascular regulation.     

无损重构生物体温度场和内热源场的简化边界元途径

生物体温度场的无损重构是生物医学传热学研究中的一个构其重要而困难的课题。本文针对生物体内部血液灌注率场和代谢率场未知但要无损重构温度场的问题，尝试给出一种只需利用体表温度就可确定内部温度场和热源场的简化边界元技术，并以人体上臂为例进行了相应的生构。方法对编制可供实用的二、三维动态无损温软件有一定的参考价值。