Renal tissue gas tensions during hemorrhagic shock

To evaluate the development of renal hypoxia during hemorrhagic shock, fourteen dogs were induced in this study. The animals were divided equally into a group in which mean arterial pressure (MAP) was kept at 50mmHg (group 1), and into another where MAP was kept at 40mmHg for 180mim (group 2). Renal tissue gas tensions were determined by a mass spectrometer. In the 50-mmHg group, renal tissue oxygen tension (Pr_{O 2}) dropped for 15min following hemorrhage, remained constant for 90min, then fell further for 150min before a plateau was established. In the 40-mmHg group, the Pr_{O 2} dropped for 90min before reaching a plateau. The second Pr_{O 2} decline occurred at the same level in both the 50-mmHg group and the 40-mmHg group. The point at which the same Pr_{O 2} level occurred for each group suggests the cessation of oxygen consumption and the conditions of renal hypoxia. It is assumed that renal hypoxia occurs in 120min at a MAP of 50-mmHg and in 60min at a MAP of 40mmHg.(Murakawa K, Izumi R, Kobayashi A: Renal tissue gas tentions during hemorrhagic shock. J Anesth 3: 10–15, 1989)     

Changes in blood lactate and respiratory gas exchange measures in sports with discontinuous load profiles

This study compares two different sport events (orienteering = OTC; tennis = TEC) with discontinuous load profiles and different activity/recovery patterns by means of blood lactate (LA), heart rate (HR), and respiratory gas exchange measures (RGME) determined via a portable respiratory system. During the TEC, 20 tennis-ranked male subjects [age: 26.0 (3.7) years; height: 181.0 (5.7) cm; weight: 73.2 (6.8) kg; maximal oxygen consumption (V˙O₂max): 57.3 (5.1) ml·kg⁻¹·min⁻¹] played ten matches of 50 min. During the OTC, 11 male members of the Austrian National Team [age: 23.5 (3.9) years; height: 183.6 (6.8) cm; weight: 72.4 (3.9) kg; V˙O₂max: 67.9 (3.8) ml·kg⁻¹·min⁻¹] performed a simulated OTC (six sections; average length: 10.090 m). In both studies data from the maximal treadmill tests (TT) were used as reference values for the comparison of energy expenditure of OTC and TEC. During TEC, the average V˙O₂ was considerably lower [29.1 (5.6) ml^·kg^−1·min⁻¹] or 51.1 (10.9)% of VO₂max and 64.8.0 (13.3)% of V˙O₂ determined at the individual anaerobic threshold (IAT) on the TT. The short high-intensity periods (activity/recovery = 1/6) did not result in higher LA levels [average LA of games: 2.07 (0.9) mmol·l⁻¹]. The highest average V˙O₂ value for a whole game was 47.8 ml·kg^−1·min⁻¹ and may provide a reference for energy demands required to sustain high-intensity periods of tennis predominately via aerobic mechanism of energy delivery. During OTC, we found an average V˙O₂ of 56.4 (4.5) ml·kg⁻¹·min⁻¹ or 83.0 (3.8)% of V˙O₂max and 94.6 (5.2)% of V˙O₂ at IAT. In contrast to TEC, LA were relatively high [5.16 (1.5) mmol·l⁻¹) although the average V˙O₂ was significantly lower than V˙O₂ at IAT. Our data suggest that portable RGEM provides valuable information concerning the energy expenditure in sports that cannot be interpreted from LA or HR measures alone. Portable RGEM systems provide valuable assessment of under- or over-estimation of requirements of sports and assist in the optimization and interpretation of training in athletes. Electronic Publication     

便携式长时间胃电记录系统的研制

体表胃电图(electrogastrogram,ECG)具有幅值小,频率低和窄带宽的特点,并且极易受到心电、呼吸以及运动等干扰.我们研究了一种基于单片机的胃电检测方法,可以有效地从体表记录到胃电信号,采用低功耗设计,可长时间进行胃电测量.将MMC卡作为胃电的存储器,通过在MMC卡上创建FAT文件系统,可使记录的胃电数据以标准文件的格式存储在MMC卡上,保证了后续的Windows环境下数据的处理.     

便携式头颅CT导航下微创手术治疗高血压脑出血的疗效观察

目的 探讨便携式头颅CT导航下锁孔微创手术治疗幕上高血压脑出血的疗效及安全性. 方法 在北京军区总医院附属八一脑科医院自2010年1月至2012年12月连续收治的高血压脑出血致昏迷患者中,选择出血量有手术指征(出血量24～90 mL)的35例患者行便携式头颅CT导航下锁孔微创手术.采用格拉斯哥昏迷评分(GCS)和改良的Rankin评分(mRS)评估患者术前术后的神经系统状态.随访6个月后采用格拉斯哥预后评分(GOS)评价患者的转归. 结果 35例患者急诊入院到手术的平均时间为(11.22±6.37)h,CT扫描平均时间为(19.00±13.11) min,手术平均时间为(108.49±26.61) min.血肿全部或近全部清除(清除率＞90％)者32例(91.43％),血肿平均清除率为96.9％(77.9％～99.4％).术后GCS评分[0～15分(中位数14分)]和mRS评分[0～6分(中位数3分)]均较术前[GCS评分为3～15分(中位数9分)；mRS评分为2～5分(中位数4分)]有明显的改善.随访6个月后57.1％(20/35)的患者预后良好(GOS评分4～5分),2例患者死亡. 结论 便携式头颅CT导航下锁孔微创血肿清除术不仅可减少手术损伤,而且可提高手术效率及血肿清除率,从而有效改善患者的预后.便携式头颅CT能快速给予术前导航,对高血压脑出血患者的手术治疗可提供很大的帮助.     

Clinical gait evaluation of patients with knee osteoarthritis

Knee osteoarthritis (KOA) is the most common osteoarthritis in lower limbs, and gait measurement is important to evaluate walking function of KOA patients before and after treatment. The third generation Intelligent Device for Energy Expenditure and Activity (IDEEA3) is a portable gait analysis system to evaluate gaits. This study is to evaluate the accuracy and reliability of IDEEA3 for gait measurement of KOA patients. Meanwhile, gait differences between KOA patients and healthy subjects are examined. Twelve healthy volunteers were recruited for measurement comparison of gait cycle (GC), cadence, step length, velocity and step counts between a motion analysis system and a high-speed camera (GoPro Hero3). Twenty-three KOA patients were recruited for measurement comparison of former five parameters between GoPro Hero3 and IDEEA3. Paired t-test, Concordance Correlation Coefficient (CCC) and Intraclass Correlation Coefficient (ICC) were used for data analysis. All p-values of paired t-tests for GC, cadence, step length and velocity were greater than 0.05 while all CCC and ICC results were above 0.95. The measurements of GC, cadence, step length, velocity and step counts by motion analysis system are highly consistent with the measurements by GoPro Hero3. The measurements of former parameters by GoPro Hero3 are not statistically different from the measurements by IDEEA3. IDEEA3 can be effectively used for the measurement of GC, cadence, step length, velocity and step counts in KOA patients. The KOA patients walk with longer GC, lower cadence, shorter step length and slower speed compared with healthy subjects in natural speed with flat shoes.     

Portable XRF and principal component analysis for bill characterization in forensic science

Several modern techniques have been applied to prevent counterfeiting of money bills. The objective of this study was to demonstrate the potential of Portable X-ray Fluorescence (PXRF) technique and the multivariate analysis method of Principal Component Analysis (PCA) for classification of bills in order to use it in forensic science. Bills of Dollar, Euro and Real (Brazilian currency) were measured directly at different colored regions, without any previous preparation. Spectra interpretation allowed the identification of Ca, Ti, Fe, Cu, Sr, Y, Zr and Pb. PCA analysis separated the bills in three groups and subgroups among Brazilian currency. In conclusion, the samples were classified according to its origin identifying the elements responsible for differentiation and basic pigment composition. PXRF allied to multivariate discriminate methods is a promising technique for rapid and no destructive identification of false bills in forensic science.     

基于ADuC848便携式多参数检测仪的研制

目的:研制开发基于ADuC848的便携式多参数检测仪,并对整个系统进行详细的分析。方法:该测试仪采用ADuC848单片机作为处理芯片,通过240×128点阵图形LCD显示屏进行显示和功能设置。结果:该测试仪可以对压力、真空度、温度、湿度、气体流量等多种参数进行检测,满足了医疗设备测试与计量的实际需要。结论:多参数测试仪测量精度高、操作简便,完全可替代国外同类仪器。     

The characteristics of a low background germanium gamma ray spectrometer at China JinPing underground laboratory

A low background germanium gamma ray spectrometer, GeTHU, has been installed at China JinPing Underground Laboratory (CJPL). The integral background count rate of the spectrometer was 0.629 cpm between 40 and 2700 keV, the origins of which were studied by Monte Carlo simulation. Detection limits and efficiencies were calculated for selected gamma peaks. Some samples of rare event experiments were measured and ¹³⁷Cs contamination was found in boric acid. GeTHU will be mainly used to measure environmental samples and screen materials in dark matter and double beta decay experiments.