Skin temperature feedback optimizes microclimate cooling

INTRODUCTION: A novel pulsed cooling paradigm (PCskin) integrating mean skin temperature (Tsk) feedback was compared with constant cooling (CC) or time-activated pulsed cooling (PC). METHODS: Eight males exercised while wearing personal protective equipment (PPE) in a warm, dry environment (dry bulb temperature: 30 degrees C; dew-point temperature: 11 degrees C) in each of the tests. Treadmill exercise was performed (approximately 225 W x m(-2)) for 80 min. A liquid cooling garment (LCG) covered 72% of the body surface area. Core temperature (Tc), local skin temperatures, heart rate, inlet and outlet LCG perfusate temperatures, flow, and electrical power to the LCG and metabolic rate were measured during exercise. RESULTS: At 75 min of exercise Tsk was higher (33.9 +/- 0.2 degrees C) in PCskin, than in PC (33.1 +/- 0.5 degrees C) or CC (32.0 +/- 0.6 degrees C) and PC > CC. The changes in Tc and heart rate during the tests were not different. Tc at 75 min was not different among the cooling paradigms (37.6 +/- 0.3 degrees C in PCskin, 37.6 +/- 0.2 degrees C in PC and 37.6 +/- 0.2 degrees C in CC). Heart rate averaged 124 +/- 10 bpm in PCskin, 120 +/- 9 bpm in PC and 117 +/- 9 bpm in CC. Total body insulation (degrees C x W(-1) x m(-2)) was significantly reduced in PCskin (0.020 +/- 0.003) and PC (0.024 +/- 0.004) from CC (0.029 +/- 0.004). Electrical power in PCskin was reduced by 46% from CC and by 28% from PC. DISCUSSION/CONCLUSION: Real-time Tsk feedback to control cooling optimized LCG efficacy and reduced electrical power for cooling without significantly changing cardiovascular strain in exercising men wearing PPE.     

Heat acclimatization by a method utilizing microclimate cooling

A new approach to heat acclimatization has been shown to be feasible during laboratory experimentation. Wearing microclimate suits containing dry ice as the coolant, three groups of men were subjected to a moderate work rate in three different environments for 4 h/d for 8 d. Physiological responses on a subsequent heat tolerance test indicate that the group subjected to an environment of 32.0 degrees C W. B. and 33.5 degrees C D.B. were fully heat acclimatized. The 33/35 degrees C group were also well-acclimatized but developed dangerously high body temperatures during the first 2 d. Only partial acclimatization was achieved by the 31/33 degrees C group. The reason why the men acquire heat acclimatization while wearing the microclimate suits in a hot environment is probably that microclimate cooling does not prevent body temperature from rising--it only prevents it from rising excessively. It should be remembered that only one-third of the body is cooled while the rest shows the normal sweating response.     

Portable, ambient air microclimate cooling in simulated desert and tropic conditions

We examined the feasibility of providing ambient air during exercise and conditioned (cooled) air during rest on reducing physiological strain and optimizing tolerance time. Six male soldiers attempted 250-min exposures in hot/dry and hot/wet environments. Subjects wore chemical protective clothing over the combat vehicle crewman uniform and an air-cooled vest. They alternated between 50 min of treadmill walking (420 W) and 50 min of rest (105 W). During the walks, a backpack mounted blower provided a total of 10 or 18 cfm of air to the vest and face; while subjects received 18 cfm of conditioned air from an umbilical during rest. A control test with conditioned air during rest, but only a ventilated facepiece during work was also conducted in the hot/dry environment. In the hot/dry environment the ambient air backpack extended (p less than 0.05) tolerance time and significantly reduced rectal temperatures, heart rates and sweating rates compared to control; no differences were found between 10 and 18 cfm. In the hot/wet environment, tolerance time was extended compared to a predicted tolerance time assuming no microclimate cooling. We conclude that the ambient air backpack reduced physiological strain and improved tolerance time of combat vehicle crewmen during exercise in the heat.     

Heat strain during at-sea helicopter operations and the effect of passive microclimate cooling.

Twelve Navy H-3 helicopter aircrew members were monitored (heart rate, skin and rectal temperatures) in both microclimate cooling (ice) vest and non-vest conditions during at-sea operations in the high heat environment of the Persian Gulf. During all flights and flight phases, ambient dry bulb temperatures ranged from 31.0 degrees C (in-flight) to 48.6 degrees C (hover). Heart rate was greatest during hover and on-deck (range: 89.9 to 145.0 beats/min) without an ice vest, yet was significantly reduced with ice (range: 79.7 to 86.0 beats/min) (p less than 0.05). Rectal temperature was not found to be different between vest and non-vest conditions; however, change across flight phases in both conditions was significant (p less than 0.05). Analysis of variance demonstrated significantly lower mean weighted skin temperatures (p less than 0.05) when wearing the ice vest. These data suggest that wearing a protective cooling vest can reduce the heat strain associated with helicopter flight in high heat environments.     

Evaluation of commercial DNA extraction methods for biosecurity applications

An essential starting point when using molecular methods to identify bacterial biosecurity agents is an efficient extraction procedure that can extract DNA from Gram-positive and Gram-negative bacteria, lyse bacteria and remove inhibitors. ChargeSwitch gDNA mini bacteria kit (Invitrogen), QIAamp DNA extraction kit (Qiagen) with and without bead-beating, and Isolate II Genomic DNA kit (Bioline) were assessed for DNA extraction from Gram-positive (Bacillus thuringiensis) and Gram-negative (Escherichia coli) culture and environmental wipe samples. DNA was quantified using fluorometry, spectrophotometry and real-time polymerase chain reaction (PCR), and correlation between methods examined. In general, ChargeSwitch resulted in the highest DNA yield, however it was more expensive, did not remove environmental inhibitors or lyse all bacteria. Silica-based methods were efficient at lysing bacteria, removing inhibitors and generating sufficient DNA for downstream applications. Bead-beating added additional time and costs but did not significantly increase yields. There was limited correlation between DNA quantifications determined using fluorometry, spectrophotometry and real-time PCR. Results show a range of methods should be considered when developing extraction protocols for biosecurity applications with the optimal method dependant on sample type and starting material amount. Isolate II is recommended for extraction from culture or wipe samples, particularly with small quantities commonly encountered in biosecurity scenarios.     

三种试剂盒与放射配体法检测谷氨酸脱羧酶抗体的比较

目的为合理选择谷氨酸脱羧酶抗体（GAD-Ab）检测试剂盒及准确判定结果提供依据.方法采用2种酶联免疫吸附测定（ELISA）试剂盒和1种免疫放射（IRMA）试剂盒检测88例已经放射配体（RLA）法核实抗体滴度的血清标本,对比各试剂盒检测结果与RLA法的一致性并选择一致性较好的试剂盒;与RLA法同时检测140例门诊连续就诊糖尿病患者的血清标本,确定经该试剂盒筛查后需采用RLA法复查标本的浓度范围.结果①3种试剂盒与RLA法检测结果一致性为Medizym试剂盒（75%）＞RSR试剂盒（73.9%）＞Biomerica试剂盒（62.5%）,Kappa值分别为Medizym试剂盒（0.408,中度）＞RSR试剂盒（0.405,中度）＞Biomerica试剂盒（0.185,较差）;②3种试剂盒受试者工作特征（ROC）曲线下面积：Medizym试剂盒（0.812）＞RSR试剂盒（0.727）＞Biomerica试剂盒（0.666）;③3种试剂盒检测结果与RLA法相关性为RSR试剂盒（r=0.992）＞Medizym试剂盒（r=0.791）＞Biomerica试剂盒（r=-0.055）;④RSR试剂盒检测标本浓度为0.25～0.99 U/ml者需进一步采用RLA法复查.结论RSR和Medizym试剂盒检测GAD-Ab效果较好.RSR试剂盒检测GAD-Ab浓度值为0.25～0.99 U/ml时,建议采用RLA法复查.     

Evaluation of three methods of platelet labelling

The study of the kinetics of labelled platelets makes sense only when the platelets preserve their viability after separation and labelling. The separation and labelling procedures described in the manual of two producers of 111In-oxinate (Amersham, Mallinckrodt) have been evaluated by in vitro aggregation tests. The method of Mallinckrodt diminished the aggregation capacities of the thrombocytes. The labelled platelets with normal in vitro aggregation response (Amersham) were tested in vivo in 11 patients who underwent peripheral bypass surgery. The platelet half-life and the platelet accumulation on bypass grafts were checked one week post-operatively. Because of the poor in vivo response of both methods (exponential half-life curve and bad graft visualization), a third method was optimized in our laboratory with good in vitro and in vivo results in 12 patients.     

Evaluation of a commercial red-dyed plastic film for gamma-radiation monitoring

The radiation response characteristics of the radiation-induced bleaching of a commercially available plastic film tinted with red colour are investigated, as well as pre- and post-irradiation stability. By spectrophotometry of this film, a wide range of absorbed doses may be measured (10–600 kGy). The new film monitor is flexible, rugged and stable on extended storage before and after irradiation, although there is some short-term instability in the first few days after irradiation. A computer program has been used for regression analysis of thickness and dye variations in the plastic film. The results indicate a relatively uniform distribution and homogeneity of dye and thickness in the plastic material. This thin (0.03 mm) dyed-plastic radiation monitor is widely available in large quantities and inexpensive, which makes it suitable for routine high-dose photon applications in radiation processing of materials.     

民用救捞船上加改装医疗救护模块的研究

目的 研究执行航天员海上救援任务的民用救捞船上加改装医疗救护模块的技术与方法.方法 根据任务的需要,对2型6艘民用救捞船船型,采用3种不同的加改装设计方案.依据快速救护性、布局合理性和经济实用性3个主要性能指标,对3种方案作出评估.结果 实践证明,3种加改装方案都明显提高救捞船的海上医疗救护能力,其中方案2最佳.结论 根据载人航天任务海上应急医疗救护的需要,经加改装实践和海上3次载人航天任务的检验,此加改装技术与方法科学合理,能满足性能要求,对完成航天员海上救援任务具有重要意义.     

创伤评分法应用评价

目的：探讨创伤评分法的有效应用,减少评分性误差,方法：对随机选取的1855例创伤患者分为3组：门诊治疗组583例,住院治疗组907例及强化治疗组365例,应用创伤记分（TS）,院前指数（PHI）,格拉斯哥昏迷评分（GCS）,损伤严重度评分（ISS）,创伤与损伤严重度评分（TRISSRT）,ASCOT法以及国际分类损伤严重度评分（ICISS）等常用的几种创伤评分法分别计量其损伤严重程度,并将各评分法实施结果加以比较分析,结果：各创伤评分的接受顺工作特性曲线下面积（AUC0均在0．81－0．91,特异性,敏感性及准确性达78％以上,误分性和类选性指标显示,生理履指标多发生伤情判别过量,类选不足,解剖性指是多出现伤情判别不足,类选过量;伤员预后仅靠生理,解剖或年龄等参数评估笔存概率（Ps)有可能存在较大的预测性误差,结论：创伤评分法应结合实际情况,具体伤性以及评分参数加以选择运用或完善评定。     

Validity and repeatability of three in-shoe pressure measurement systems

In-shoe pressure measurement devices are used in research and clinic to quantify plantar foot pressures. Various devices are available, differing in size, sensor number and type; therefore accuracy and repeatability. Three devices (Medilogic, Tekscan and Pedar) were examined in a 2 day × 3 trial design, quantifying insole response to regional and whole insole loading. The whole insole protocol applied an even pressure (50–600 kPa) to the insole surface for 0–30 s in the Novel TruBlue™ device. The regional protocol utilised cylinders with contact surfaces of 3.14 and 15.9 cm² to apply pressures of 50 and 200 kPa. The validity (% difference and Root Mean Square Error: RMSE) and repeatability (Intra-Class Correlation Coefficient: ICC) of the applied pressures (whole insole) and contact area (regional) were outcome variables. Validity of the Pedar system was highest (RMSE 2.6 kPa; difference 3.9%), with the Medilogic (RMSE 27.0 kPa; difference 13.4%) and Tekscan (RMSE 27.0 kPa; difference 5.9%) systems displaying reduced validity. The average and peak pressures demonstrated high between-day repeatability for all three systems and each insole size (ICC ≥ 0.859). The regional contact area % difference ranged from −97 to +249%, but the ICC demonstrated medium to high between-day repeatability (ICC ≥ 0.797). Due to the varying responses of the systems, the choice of an appropriate pressure measurement device must be based on the loading characteristics and the outcome variables sought. Medilogic and Tekscan were most effective between 200 and 300 kPa; Pedar performed well across all pressures. Contact area was less precise, but relatively repeatable for all systems.     

Evaluation of three embolic agents in pig rete

In ongoing research into potential embolic agents, three substances were evaluated for their effectiveness in occluding the pig rete. Selective injection of these agents produced varying degrees of occlusion, with the most effective a microfibrillar collagen hemostat in a 33% ethanol solution. Angiostat, a collagen particulate, did not produce rete occlusion, and all pigs injected with it developed adverse effects, including coma and apnea. Tisseel, a tissue sealant, produced partial rete occlusion, but was uniformly difficult to manage through long catheters, and its use was discontinued. Microfibrillar collagen hemostat with ethanol appears to have the greatest potential as an embolic agent in low-flow structures.     

A comparison of three commercially available PET imaging systems.

Three commercial positron emission tomography (PET) imagers were assessed using the same test protocol (Positron Corporation 'Posicam', Siemens Ecat 951/31 and the Scanditronix PC 4096-15WB). A cylindrical phantom and a 'Jaszczak' phantom both filled with 18F were employed to measure sensitivity, slice uniformity, transaxial and axial resolution and cold rod contrast. The spread of results were as follows: sensitivity varied from 2.08 to 3.73 kcps kBq-1 ml-1 (77-138 kcps microCi-1 ml-1); radial resolution on axis (at 17.5 cm) varied from 5.0 to 5.9 mm (6.7-8.1 mm); tangential resolution ranged from 5.4 to 5.8 mm (6.7-8.6 mm); axial resolution ranged from 4.6 to 11.5 mm (6.6-13.6 mm); contrast in the middle of a 30 mm diameter rod varied from 98 to 93% and for a 5 mm rod from 37 to 22%. The performance of all three systems approximated reasonably well to the manufacturers' published specifications. The most significant differences were found to be in sensitivity, axial resolution and deadtime correction and can be explained by the choice of crystal size and crystal/photomultiplier configuration.