模拟高湿热行军锻炼对心电图影响的观察

12名战士穿戴防毒装具于热室内(Td33.8℃)行军锻炼,时速5.4km,每次50.4～58.3min,连续10天,最后直肠温度和心率显著降低。热应激标准试验(Td34.7℃)耐热时间显著延长。心电图可见,锻炼前QRS时间显著缩短、P_1幅度显著增加,P/P—R段比值超过1.6正常标准、R(_V5)+S_(V1)减,R_(V1)+S_(V5)略增,Q—Tr显著延长;锻炼后P_1幅度较前略增、QRS时间缩短稍减、P/P—R段比值减至正常、R_(V5)+S_(V1)和R_(V1)+S_(V5)略增、Q—Tr缩短接近安静水平,显示心脏特别是左房和右室功能得到加强,冠脉供血有较大提高。     

高湿热环境习服锻炼对全身汗液中营养成分含量的影响

本实验观察了高湿热环境热习服锻炼对人体汗液中矿物盐、氨基酸和维生素流失的影响。受试者为12名健康战士,锻炼方式为穿全身式防毒装具,于热气候室内以时速5.4km速度步行至自觉疲乏为止,连续10天,每天锻炼时间平均56.2min,平均直肠温度达38.5℃。标准试验对比证明,高湿热锻炼明显提高了人体热负荷的耐受能力。汗液中电解质浓度仅zn增高13.6%,K、Ca、Mg、Cu、Fe、Na有不同程度的降低,血清K、Na、Zn也降低。汗液中氨基酸除苯丙胺酸、蛋氨酸和胱氨酸下降较少外,其它14种氨基酸都明显降低。维生素B_1、B_2减少一半以上,维生素C减少35.5%。综上所述,热习服后可以大大减少汗液中营养成分的流失。     

体力负荷对高温耐力的影响

本文研究了环境温度为27～50℃,相对湿度50～75%,中等强度以下体力负荷时机体生理反应特点。探讨了高温耐力与体力负荷、环境温、湿度的关系。结果表明在环境温湿度、体力负荷综合作用下,直肠温度和皮肤温度升高的幅度存在着差异,此差异决定丁机体与环境热交换的数量和性质。机体高温耐受时间随环境温湿度、体力负荷应激的增加而缩短。并将该种关系拟合了数学模型,此模型可预测环境温度40～50℃,相对湿度50～75%、中等强度以下体力负荷时机体高温耐受时间。     

湿热环境重强度劳动时的湿黑球温度界限

本文依据战士在湿热条件下进行时速6km负重行军时的生理反应,提出适于我军重强度作业使用的湿黑球温度(WGT)的界限值标准.实验在热区野外进行,观察行军过程受试者的肛温、心率、出汗率、皮肤温度等项生理指标以及自觉症状.结果提示:(1)在热环境下重强度劳动者的生理反应与WGT密切相关,p皆小于0.01;(2)WGT能够很好地反映与人体热紧张程度相应的环境热强度;(3)重强度劳动4h的WGT安全上限值为26.5～27.0℃;(4)当WGT为28.2±1.0、29.4±1.0、30.5±0.6℃时,重强度劳动的耐受时间分别为3、2和1h左右.     

直升机飞行人员防毒面具呼吸性能评价

目的评价直升机飞行人员防毒面具的呼吸性能。方法在低压舱内用人头模型和由3名受试者佩戴防毒面具,测试在不同高度(地面、2km、4km)和不同鼓风量(0L/min、40L/min、80L/min)条件下,防毒面具的呼吸阻力、二氧化碳浓度、氧气浓度和受试者血氧饱和度、心率。结果防毒面具配备鼓风机可在一定程度上减轻吸气负荷和改善装具腔内气体质量。结论鼓风机的鼓风量为40L/min时,防毒面具适应人体呼吸性能最佳。     

热脱水对高温及常温环境中渐增负荷运动时血乳酸浓度的影响

本研究旨在探讨在热脱水之后，高温、常温及非脱水条件下运动时血乳酸（ＨＬａ）的变化。１２名身体健康男大学生（非热环境适应者），在以下３种不同环境条件下，进行功率自行车渐增负荷运动，测定吸氧量（ＶＯ２）、通气量（ＶＥ）、心率（ＨＲ）及直肠温度（Ｔｒ）：（１）在常温条件下，不进行桑拿浴（Ｎ２５℃）：（２）进行桑拿浴后，在常温条件下（ｍ５℃）；（３）进行桑拿浴后，在高温条件下（Ｄ４Ｏ℃）。结果如下：（ｕＤ４Ｏ℃渐增负荷运动时，ＨＬａ显著性高于Ｄ２５℃和Ｎ２５℃，并且渐增负荷运动ｍ５℃时Ｍａ也高于Ｎ２５℃。但是３种条件下ＶＯ２却未出现显著性差异；（２）不但Ｎ２５℃时最大吸氧量（Ｖｑｎｔａｘ）要比ｏ２５℃和Ｄ４０℃高，而且Ｄ２５℃时ＶＯ２ｍａｘ也比Ｄ４０℃高。Ｎ２５℃时力竭时间明显长于Ｄ２５℃和ＭＯ℃。结果表明，热脱水之后，高温渐增负荷运动时ＨＩａ上升由于活动肌肉的糖元分解增强，而非局部缺氧所致。肝脏清除ＨＬａ能力下降也可导致ＨＬａ上升。     

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。     

飞行人员坚持体能锻炼应对热应激的初步探讨

目的 通过在35℃,相对湿度70%的高温舱中进行热应激测试的方法对受试者进行热耐受能力的评估。方法 选择17名空军特色医学中心的工作人员,锻炼员8名为试验组,另外9名为对照组,在高温舱中进行热负荷运动（以75 W功率蹬自行车120 min,转速维持在60～70 r/min）,监测并记录其核心温度、皮肤温度、心率、出汗量等数据。结果 2组平均皮肤温度增长率、心率增长率、达到最大心率时间、出汗率和热应激时间比较差异有统计学意义（P<0.05）,肛温增长率比较差异无统计学意义（P>0.05）。结论 坚持体能锻炼可有效应对热应激,提高热耐受能力。     

+G_z负荷下动物心率变化特点及指标选取方法的探讨

用大白鼠和家兔对+Gz负荷下心率的变化规律进行了实验研究。指出,同心率可作为运动负荷的指标一样,在一定的G值范围内,可作为+Gz负荷强度的指标。用负荷心率曲线时间积分的增量(△St)作指标,能更灵敏地反映负荷及心脏代偿情况。对用心率作为动物G耐力耐受终点指标进行了探讨,以心功能衰竭期心率曲线的拐点处心率为依据,提出大白鼠宜取心率降至负荷前的68％(或2/3);家兔可取3/4为指标。并指出,由于耐受终点心率呈右偏态分布,不能求均值。     

夏季10公里急行军训练战士的肛温的预测和控制

15名战士负重12kg在夏季进行10km急行军,测定了行军战士的Tr、HR、SW等指标,结果表明,战士行军至10km终点时的Tr(℃)与行军开始时环境的WBGT℃和完成10km急行军的时间(min)显著相关,行军战士的Tr(℃)可用下列公式预测和控制:Tr(℃)=37.4885+0.0542WBGT(℃)×100/t(min)     

Physiological cost and thermal envelope: A novel approach to cycle garment evaluation during a representative protocol

This study aimed to examine thermoregulation in different clothing assemblies during a representative cycling exercise protocol. Six men undertook cycling exercise simulating representative thermal exchange challenges while wearing low (LOW), intermediate (INT1 and INT2), or high (HI) amounts of clothing. Exercise was conducted at 14.5 °C, 46.8% relative humidity and included a “flat” [45 min at 35% peak power output (PPO), wind speed 8.3 m/s], “uphill” (30 min at 55% PPO, wind speed 3.6 m/s), and “downhill” (20 min at 50 W, wind speed 16.7 m/s) stage. Rectal temperature changed with the exercise stage and was independent of clothing assembly. In contrast, an “envelope” was evident for mean body temperature, resulting from differences in mean skin temperature between the LOW and HI conditions. The elevated mean body temperature in HI was associated with increased physiological “cost,” in the form of increased sweat production and heart rate. Physiological cost provides a better index of clothing performance than deep body temperature in the “thermoregulatory zone,” as a consequence sports clothing should attempt to optimize the balance between comfort and reduced physiological cost.     

Consideration of physiological response in numerical models of temperature during MRI of the human head

Purpose

To examine the thermal effects of the physiological response to heating during exposure to radiofrequency (RF) electromagnetic fields in magnetic resonance imaging (MRI) with a head‐specific volume coil.

Materials and Methods

Numerical methods were used to calculate the temperature elevation in MRI of the human head within volume coils from 64–400 MHz at different power levels both with and without consideration of temperature‐induced changes in rates of metabolism, perspiration, radiation, and perfusion.

Results

At the highest power levels currently allowed in MRI for head volume coils, there is little effect from the physiological response as predicted with existing methods. This study does not rule out the possibility that at higher power levels or in different types of coils (such as extremity or whole‐body coils) the physiological response may have more significant effects.

Conclusion

In modeling temperature increase during MRI of the human head in a head‐sized volume coil at up to 3.0 W/kg head‐average specific energy absorption rates, it may not be necessary to consider thermally induced changes in rates of metabolism, perfusion, perspiration, and radiation. J. Magn. Reson. Imaging 2008;28:1303–1308. © 2008 Wiley‐Liss, Inc.     

现场坦克车内高温条件下人体热状态理论预测的验证

本文描述了把体温调节数学模型的实验室研究推广到坦克现场的应用情况,结果表明,模型在高温环境中预测人体热状态的生理指标Tr,Ts 等的变化与实测基本一致。     

The determinants of thermal comfort in cool water

Water‐based activities may result in the loss of thermal comfort (TC). We hypothesized that in cooling water, the hands and feet would be responsible. Supine immersions were conducted in up to five clothing conditions (exposing various regions), as well as investigations to determine if a “reference” skin temperature (T_sk) distribution in thermoneutral air would help interpret our findings. After 10 min in 34.5 °C water, the temperature was decreased to 19.5 °C over 20 min; eight resting or exercising volunteers reported when they no longer felt comfortable and which region was responsible. TC, rectal temperature, and T_sk were measured. Rather than the extremities, the lower back and chest caused the loss of overall TC. At this point, mean (SD) chest T_sk was 3.3 (1.7) °C lower than the reference temperature (P = 0.005), and 3.8 (1.5) °C lower for the back (P = 0.002). Finger T_sk was 3.1 (2.7) °C higher than the reference temperature (P = 0.037). In cool and cooling water, hands and feet, already adapted to colder air temperatures, will not cause discomfort. Contrarily, more discomfort may arise from the chest and lower back, as these regions cool by more than normal. Thus, T_sk distribution in thermoneutral air may help understand variations in TC responses across the body.     

飞行员配穿囊式抗荷服在不同代谢水平时的温度舒适性评定

目的　评价飞行员配穿囊式抗荷服在不同代谢水平、不同环境温度条件下的温度舒适性。　方法　 6名受试者分别以不同的代谢水平暴露于 2 0℃、2 5℃和 35℃环境 ,配穿装备为KH 3抗荷服和KH 7抗荷服。每次试验 70min。采用微小气候评定装置测量衣下温度和衣下潮湿率 ,并以 3种主观感觉评定温度舒适性。　结果　试验期间 ,Ⅲ组 (或Ⅳ组 )的衣下温度增值和衣下潮湿率增值均无显著性意义。Ⅰ组 (或Ⅱ组 )、Ⅴ组 (或Ⅵ组 )、Ⅶ组 (或Ⅷ组 )分别与Ⅲ组 (或Ⅳ组 )比较 ,衣下温度增值、衣下潮湿率增值均有显著或非常显著性意义 (P <0 .0 5或P <0 .0 1)。Ⅰ组 (或Ⅱ组 )与Ⅴ组 (或Ⅵ组 )的衣下温度增值、衣下潮湿率增值均有显著性意义 (P <0 .0 5 )。Ⅰ组～Ⅷ组的衣下温度、衣下潮湿率作比较 ,Ⅶ组 (或Ⅷ组 )与其它各组的增值均有非常显著性意义 (P <0 .0 1)。　结论　在一定的环境温度范围内 ,代谢水平可以比环境温度更能影响人体的温度舒适性。 2 0℃环境中 ,飞行员配穿KH 3抗荷服和KH 7抗荷服飞行时 ,衣下微小气候是不适宜的。在 2 5℃环境下从事低代谢率活动时 ,对温度舒适无显著性影响。 35℃环境中 ,即使从事低代谢水平活动 ,也将严重影响飞行员温度舒适。     

猴对宇宙舱内环境的适应过程中体温昼夜节律和乳酸脱氢酶谱变化

本文从代谢方面以体温昼夜节律和乳酸脱氢酶(LDHI-5)研究猴对宇宙舱内环境适应的可能性及所需的训练次数。使用公猴(Macaca Nemeslrina)9只。设计了体温昼夜节律的拟合方程。结果表明经4次训练后的猴对宇宙舱内环境产生了基本适应。表现为体温由升高转为正常;体温昼夜节律由失同步转为再同步化;LDH5由显著升高(P<0.001)在两天内恢复到实验前水平。结果提示此种基线训练,需要较多的次数。为达到对宇宙舱内环境的完全适应,训练得少于4次。如果能结合选拔择优则可望缩短训练程序。     

服装对人体与环境换热的影响

本文根据能量平衡、质量平行原理,将服装简化成圆筒,推导了服装内存在蒸发时,体表与环境换热的综合方程得出了干换热阻力因子和蒸发换热阻力因子。用这两个因子对裸体体温调节数学模型进行修正,可使裸体模型适用于着装情况。将修正后模型的预测结果与实验值进行了比较,结果表明本文所做的假设和推导是合理的。     

应用非致冷镜头的红外热成像仪对76例正常人阳虚质的评价研究

目的:探讨非致冷镜头的红外热成像仪扫描下阳虚体质的评价部位。方法:募集22~71岁健康人共80例,根据中医体质调查表筛选出平和体质及阳虚体质的健康人76例纳入本研究,分为健康平和质组(30例)和健康阳虚质组(46例)。运用HIR-2000型红外热像诊断系统,对每位受试者行全身扫描并采集图像,完成每例受试者全身共计47个区位热值的测量,所有数据在SPSS 19.0软件下进行分析。结果:2组受试者年龄分布差异无统计学意义;健康平和质组与健康阳虚质组红外热成像热值表现特点如下:47个区位中,前额和面部为热值最高的2个区位,头后位上部和头后位中部为热值最低的2个区位。健康平和质组较健康阳虚质组在示指、中指、无名指、股前区、膝部、小腿前区、股后区、小腿后区等8个区位热值更高(P0.05);其中,股后区、小腿后区热值偏高更明显(P0.01)。结论:①示指、中指、无名指和下肢是应用非致冷镜头的红外热像诊断系统判定阳虚的敏感区位。②无论何种致冷方式的红外热成像仪对膝部、股后区与小腿后区热值差异的研究具有可重复性。③冬季仅行下肢部扫描即可进行阳虚评价。     

Influence of Scandinavian scientists in exercise physiology

The cradle of Scandinavian exercise physiology was in Copenhagen. Peter Ludwig Panum (1820-1885) was head of a new physiological laboratory and his research included respiration, digestion and metabolism. Christian Bohr (1855-1911) was his most prominent co-worker and became his successor in 1885. Part of Bohr's training was in Leipzig, Germany, with Carl Ludwig, which led to his lifelong interest in problems of pulmonary exchange and blood transport of oxygen and carbon dioxide. He discovered the effect of carbon dioxide on the dissociation curve of hemoglobin (the Bohr effect). He attracted eminent young co-workers, among them A. Krogh, V. Henriques and K. A. Hasselbalch (known for the Henderson-Hasselbalch formula). One of his children, Niels Bohr, became one of the greatest modem nuclear physicists. We could name August Krogh as the father of exercise physiology in Scandinavia. This review will concentrate on some of his and his co-workers' and students' scientific achievements up to the 1940s.