污水处理厂恶臭气体健康风险评估

2011年和2012年夏季在天津市纪庄子污水处理厂进行恶臭气体监测,通过GC-MS分析恶臭气体的浓度及恶臭指数,同时选取24名（男11名,女13名）被试者佩戴HOLTER进行急性暴露实验,评估其健康风险。实验共检测出67种恶臭物质,格栅处恶臭气体浓度最高,以硫化物和含氧化合物为主;格栅处的急性暴露实验结果显示被试者血压反应正常,最快心率明显偏高,且多出现于现场测试时段,HRV参数值均偏离正常范围,表明受恶臭气体刺激被试者交感神经活动增强;对污泥脱水间恶臭气体进行致癌和非致癌风险评估可知,二氯甲烷和苯存在潜在致癌风险,恶臭非致癌危害指数HI小于1,其非致癌健康风险在可接受范围内。     

基于希尔伯特振动分解的心音身份识别算法

心音信号是典型的非平稳信号,该文提出了基于希尔伯特振动分解的心音信号分析方法.将心音信号分解为一组自适应谐波分量作为特征参数进行身份识别.对码本大小为60的心音数据库进行实验,结果识别率到达93.3％,证明了这个方法的有效性.     

Evaluation of upper-limb body postures based on the effects of back and shoulder flexion angles on subjective discomfort ratings,heart rates and muscle activities

A possible limitation of many ergonomics checklists that evaluate postures is an independent evaluation of each body segment without considering the coordination between body segments and resulting in the under-/over-estimation of body postures. A total of 20 men were selected to evaluate the effects of shoulder and back flexion angles on the upper-limb muscle activities, subjective discomforts and heart rates. Interesting findings were obtained from the coordination between back flexion angles and shoulder flexion angles. At a back flexion angle of 45°, the discomfort and heart rates were the least at a shoulder flexion angle of 45°. The %MVC also showed a similar trend. It could be inferred that the 0° shoulder flexion angle would be a natural posture, when the back flexion angle is 0°, whereas 45° shoulder flexion might be a more natural posture when the back flexion angle is 45°.

Statement of Relevance: This study evaluated the effects of back and shoulder flexion angles on subjective as well as objective measures. The findings of this study considered the coordination between two body flexion angles and could be used to improve the accuracy of existing ergonomics evaluation methods for body postures.     

Physical and thermal strain of firefighters according to the firefighting tactics used to suppress wildfires

The aim of this study was to analyse the physiological strain of firefighters, using heart rate (HR) and core temperature, during real wildfire suppression according to the type of attack performed (direct, indirect or mixed). Threeintensity zones were established according to the HR corresponding to the ventilatory threshold (VT) and respiratory compensation threshold (RCT): zone 1, <VT; zone 2 (Z2), between VT and RCT; zone 3 (Z3), >RCT. The exercise workload (training impulse (TRIMP)), the physiological strain index (PSI) and the cumulative heat strain index(CHSI) were calculated using the time spent in each zone, and the HR and core temperature, respectively. Significantly higher mean HR, time spent in Z2 and Z3 and TRIMP h^?1 were found in direct and mixed versus indirect attacks. The highest PSI and CHSI were observed in the direct attack. In conclusion, exercise strain and combined thermal strain, but not core temperature during wildfire suppression, are related to the type of attack performed.

Statement of relevance: Our findings demonstrated that wildfire firefighting is associated with high physiological demands, which vary significantly depending on the tactics chosen for performing the task. These results should be kept in mind when planning programmes to improve wildland firefighters' physical fitness, which will allow improvement in their performance.     

Cardiac frequency throughout a working shift in coal miners

Despite the ever-increasing mechanization of industrial activities, coal mining still remains a physically demanding occupation as it is not always possible to extensively mechanize the extraction process. To estimate the physical effort necessary to sustain coal mining activities in a poorly-mechanized mine, cardiac frequency (?/_c) was measured throughout the working shift with a Sport-Tester PE3000 (Polar Electro OY. Finland) in a representative sample of 73 Asturian miners engaged in a full spectrum of underground work. The mean ± SD of the overall?/_c values measured in miners working at the coal face (Group 1, 33 subjects, mean age 32·7 years, age range 21–48 years R was 106·5 ± 18·2 beats min^?1. In other miners (Group 2, 40 subjects, mean age 34·6 years, age range 23–48 years) corresponding figures were 1031 ±177 beats-min_?1 (p<0·05). Subjects' average working shift?_c Lbeats. Min^?1) was not related to age, measured (treadmill) VO₂ max nor VO₂ max.kg body weight^?1, while average working-shift? _c (%? _c max) was weakly related to age (r = 0·396, p<0·05), VO₂ max (r equals; 0·295, p < 0·05) and VO₂max.kg body weight^?1 (r= 0·352, p<0·05). Working-shift peak? _c (beats · min^?1) was negatively related to age (r = 0·334, p < 0·05). Our study has provided the distribution of the overall ? _c values likely to be found in subjects working in these poorly-mechanized mines. However, average working-shift ? _c differs considerably from subject to subject and is largely unpredictable.     

Core temperature and heart rate response to repeated bouts of firefighting activities

During live-fire firefighting operations and training evolutions, firefighters often consume multiple cylinders of air and continue to wear their personal protective equipment even after fire suppression activities have ceased. However, most studies have only reported core temperature changes during short-term firefighting activities and have shown a very modest increase in core temperature. Therefore, the purpose of this study is to evaluate core temperature and heart rate (HR) during repeated bouts of firefighting activity over ～3 h. The results of this study show that core temperatures increase by an average of 1.9°C – to a larger magnitude than previously reported – and continue to increase during subsequent work cycles (38.4 vs. 38.7) even after long breaks of more than 30 min. The rate of core temperature increase during work continues to increase later in the training exercise (from 0.036 to 0.048°C/min), increasing the risk for exertional heat stress particularly if long-duration firefighting activity is required at these later times.

Practitioner Summary: To date, core temperature and HR changes during firefighting have been reported for short-term studies, which may significantly underestimate the physiological burden of typical firefighting activities. Firefighter core temperatures are shown to increase to a larger magnitude than previously observed and the rate of rise in core temperature increases during subsequent firefighting activities.     

A hybrid recurrent neural network‐logistic chaos‐based whale optimization framework for heart disease prediction with electronic health records

Heart disease, known interchangeably as “Cardio Vascular Disease,” blocks the blood vessels in the heart and causes heart attack, chest pain, and stroke. Heart disease is one of the leading causes of morbidity and mortality worldwide and it is one of the major causes of morbidity and mortality globally and a trending topic in clinical data analysis. Assessing risk factors related to heart disease is considered as an important step in diagnosing the disease at an early stage. Clinical data present in the form of electronic health records (EHR) can be extracted with the aid of machine learning (ML) algorithms to provide valuable decisions and predictions. ML approaches also play a vital role in early diagnosis and therapeutic monitoring of heart disease. Several research works have been carried out recently to predict heart disease. To this end, we propose a novel hybrid recurrent neural network (RNN)‐logistic chaos‐based whale optimization (LCBWO) structured hybrid framework for predicting heart disease within 5 years using EHR data. Meanwhile, in the hybrid model established multilayer bidirectional LSTM is used for feature selection, LCBWO algorithm for structural improvement and fast convergence, and LSTM for disease prediction. This research used 10 cross‐validations to obtain generalized accuracy and error values. The findings and observations provided here are focused on the knowledge obtained from the EHR report. The results show that the proposed novel hybrid RNN‐LCBWO framework achieves a higher accuracy of 98%, a specificity of 99%, precision of 96%, Mathews correlation coefficient of 91%, F‐measure of 0.9892, an area under the curve value of 98%, and a prediction time of 9.23 seconds. The accurate predictions obtained from the comparative analysis shows the significant performance of our proposed framework.     

心率影响梗死后心绞痛发生率的国内Meta分析

采用Meta分析（ Meta analysis ）的方法确定我国人群心率对急性心肌梗死（ Acute myo-cardia infarction ,AMI）患者梗死后心绞痛发生的影响。全面收集国内发表的有关AMI患者静息心率与梗死后心绞痛关系的文献,对符合条件的所有研究结果利用RevMan软件进行固定效应模型的Meta分析。计算AMI患者心率慢组相对心率快组发生梗死后心绞痛的危险（ rel-ative risk,RR）,评价心率快慢对AMI患者梗死后心绞痛发生的影响,并用漏斗图分析发表性偏倚。符合纳入标准的共7篇文献,总样本量1888例。其中心率慢组1030例,发生梗死后心绞痛128例;心率快组858例,发生梗死后心绞痛247例;合并RR＝0．46,95％可信区间是0．38-0．55。漏斗图分析提示不存在发表性偏倚。 AMI后心率增快者发生梗死后心绞痛危险增加,减慢心率可预防梗死后心绞痛的发生。     

Study on Multi-effect Time Parameters of Ergonomic Validity Index in Low-carbon Residential Kitchen

In the study on functional low-carbon ergonomic validity in buildings, ergonomic validity is different from resource validity which is easy for quantitative analysis. To eliminate the complexity and uncertainty impacts of human factors on quantitative study, it proposes a method of building a parameter of ergonomic validity --multi-effect time by using cardiotachometer to record heart rate change, being used to evaluate the functional low-carbon ergonomic validity targeting at the ontological characteristics of kitchen. This method is used to determine the physical consumption intensity （multi-effect） through heart rate incremental relation based on the principles of physiology and ergonomics, and to confirm the ergonomic validity of environmental factors by the time to complete standard work as well as multi-effect quantitative analysis. The test results show that, under the kitchen operating conditions, the multi-effect（ME） can properly reflect the real-time status of the operator and is easily operated ; the parameters obtained are not significantly related to the physiological status of the operator, and multi-effect time（MT） is sensitive to the physical consumption brought about to the operator due to kitchen environmental factors; thus, it can be taken as an objective index ,which is simple and easy to operate in residential kitchen functional low-carbon evaluation.     

家兔急性心力衰竭实验的教学体会

家兔心衰实验是医学机能实验学教学中的重要实验内容之一。通过学导式和理论联系实际的教学方法,加强学生的思考问题能力,在实验教师的指导下,使学生对学习的主动性和积极性得到充分提高,加深学生对理论知识的掌握,同时提高学生的自学和动手能力、激发学生的科研兴趣,对心衰的诊断和治疗原则的理解具有重要意义。