流固耦合作用下真实人体上呼吸道呼吸流涡结构演化的数值仿真

通过构建真实人体上呼吸道三维规范模型,运用大涡模拟数值方法,对考虑流固耦合作用的低强度循环呼吸模式下人体上呼吸道内的呼吸流进行了数值仿真,研究分析了人体口喉模型及气管支气管内的气流涡结构及其演化过程。结果表明,循环吸气过程中,气流在口腔中部以及舌苔上部形成多个涡管,在声门部位形成强烈的射流,在气管前壁出现马蹄涡,到气管中部大尺度涡结构逐步消失,支气管中只剩下一系列小尺度涡结构;循环呼气过程中,气流在气管底部产生较为复杂的涡结构,随着气流在气管内的融合,涡强度逐步减弱,在咽喉后壁形成拱状涡,气流进入口腔后,涡结构破裂,涡量扩散,没有较大的涡结构产生。

HLY-92型呼吸流率仪及信号的校正方法

目的 :检验 HL Y- 92型呼吸流率仪校正方法的可行性 .方法 :1根据氧气和氮气的流率测量值对呼吸气体进行粘性校正 ;2应用定径孔输出的流率值 ,实时校定 HL Y-92型呼吸流率仪 .结果 :1比较氧气和氮气粘性校正前后的测量结果 ,粘性校正前 ,其相对误差是 9% ,粘性校正后 ,其相对误差是 1% ;2 HL Y- 92型呼吸流率仪与定径孔校定装置的测量结果基本一致 ,其误差平均值为 0 .6 4% .结论 :呼吸气体的粘性校正可提高 HL Y- 92型呼吸流率仪测量精度 ;定径孔实时校定装置为 HL Y- 92型呼吸流率仪准确测量空中飞行人员的呼吸流率提供了可能 .

流程式呼吸训练结合科勒效应在钆塞酸二钠磁共振增强扫描患者中的应用

目的探讨流程式呼吸训练结合科勒效应在钆塞酸二钠(gadoxetate disodium,Gd-EOB-DTPA)磁共振增强扫描患者中的应用效果。方法纳入郑州大学第一附属医院磁共振科的进行MR Gd-EOB-DTPA上腹部增强检查的影像资料共82例,其中随机选取2022年1月-2022年2月期间常规训练的患者41例作为对照组,进行回顾性分析;再随机选取2022年5月-2022年6月流程式呼吸训练结合科勒效应的患者41例作为实验组,比较两组患者动脉期图像质量、检查时长、T2扫描时长、增强前T1扫描次数、动脉期扫描时长、增强扫描一次性成功率。结果实验组图像质量优于对照组,差异具有统计学意义(Z=6.600,P=0.037);实验组T2扫描时长、动脉期扫描时长、检查总时长明显短于对照组,增强前T1扫描次数明显少于对照组,差异具有统计学意义(t=2.197,P=0.031;t=4.118,P=0.000;t=3.484,P=0.001;χ^(2)=6.474,P=0.011),增强扫描一次性成功率由87.80%提高到95.12%。结论流程式呼吸训练结合科勒效应应用于Gd-EOB-DTPA磁共振增强扫描检查患者中,可有效提高Gd-EOB-DTPA磁共振增强成像动脉期图像质量,提高扫描一次性成功率,缩短扫描总时长。

人体上呼吸道口喉呼吸流涡结构演化对病毒气溶胶扩散的影响研究

揭示涡结构演化对病毒气溶胶扩散的影响作用,对于有效防治呼吸道疾病具有非常重要的意义.本文运用大涡模拟的方法,对人体在循环呼吸模式下口喉模型内的涡结构演化及气溶胶扩散进行了数值仿真研究,分析了口喉模型内涡结构演化过程以及气溶胶扩散状态.结果表明:受呼吸流涡结构演化的影响,颗粒轨迹主要分布在上气道内涡量集中的区域;受横向涡结构和纵向涡结构的共同影响,部分病毒气溶胶颗粒具备了混合有环状轨迹和波状轨迹的螺旋状轨迹.本研究从微观角度揭示了涡结构演化与气溶胶扩散行为的关系,为深入认识病毒气溶胶上呼吸道传播特点提供了新的途径.

胃食管反流病相关性呼吸系病及咽喉病研究

近年来发现与胃食管反流病相关的消化道外症状日益增多,国内文献对胃食管反流病的中医辨证分型中,多有报道痰气交阻或痰气郁结胸膈的类型,表明胃食管反流病,常伴有呼吸病及咽喉病症状,由于相当数量的胃食管反流病患者,其临床胃食管反流表现不明显,没有典型的烧心、反酸等反流症状,且胃食管反流病有食管黏膜上皮结构改变(反流性食管炎、Barrette上皮化生)者为34%,常易漏诊胃食管反流病,影响及时诊断与正确治疗。中医对哮喘、咳嗽、咽喉痛的治疗,经验丰富,疗效颇佳,对这类患者,尤其是常规治疗疗效不明显的,一定要考虑同时存在胃食管反流病的可能,选用抑酸剂及促动力药治疗胃食管反流病,同时加用对哮喘、咳嗽、咽喉痛有效的中西药,以提高疗效。本文介绍胃食管反流病相关性呼吸系病及咽喉病的现状及中医对它们的认识,旨在提高对这类疾病的认识,及时诊断和治疗不典型的胃食管反流病,避免漏诊或误诊。

人体呼吸系统力学属性下呼吸动力过程的仿真研究

人体呼吸动力过程的呼吸参数和动态变化影响和决定了与人体呼吸领域相关设备的研制和参数设定。根据人体呼吸的运动规律,构建呼吸动力方程;进而利用仿真手段模拟人体呼吸动力过程,获得呼吸过程中的肺容积、呼吸流率和呼吸时间等动态呼吸参数。与以往的研究和实测数据验证比较,仿真过程和获得的数据贴近人体的实际呼吸运动过程;并且设置了更为详尽且独立的影响呼吸动力过程的参数,给出了易于理解的仿真框架。呼吸肌作用力方程和仿真获得的动态呼吸参数可用于人体模拟肺、供氧系统和辅助呼吸装置等设备的设计和参数设定。

换流站内换流变压器呼吸系统在线监测系统

本文利用西门子1200 PLC和MCGS组态软件,结合温度传感器、湿度传感器、串行通信技术、以太网技术实现了换流站内换流变压器呼吸系统的在线监测。系统能够实时监测换流变压器呼吸器的内部湿度、管路压力、管路气体温度、环境温度等参数,并根据湿度变化、对比等情况进行分析,给出合理检修建议。

Correlations Between Plant Biomass and Soil Respiration in a Leymus chinensis Community in the Xilin River Basin of Inner Mongolia

This paper reports on two years of measurement of soil respiration and canopy-root biomass in a Leymus chinensis community in the Xilin River basin of Inner Mongolia. Correlations between components of plant biomass and soil respiration rates were examined. From respiration data based on CO2 uptake by NaOH and corresponding root biomass values for each run of 10 plots, a linear regression of CO2 evolution rates on root dry weights has been achieved for every ten days. By applying the approach of extrapolating the regressive line to zero root biomass, the proportion of the total soil respiration flux that is attributable to live root respiration was estimated to be about 27% on average, ranging from 14% to 39% in the growing season in 1998. There were no evident relations between the total canopy biomass or root biomass and CO2 evolution rates, but a significant exponential relation did exist between tire live-canopy biomass and CO2 evolution rates.

Creation method for bi-level positive airway pressure based on pressure and flow feedback

An airway pressure and flow data acquisition system is developed to investigate the approach to building the bi-level positive airway pressure BiPAP in a ventilator.A number of experiments under different breathing situations and states are conducted and the experimental data are recorded.According to the data from these experiments the variation characteristics of the pressure and flow are analyzed using Matlab. The data analysis results show that the pressure increases while the flow decreases in the expiratory phase contrarily the pressure decreases while the flow increases in the inspiratory phase during the apnea state both the pressure and the flow remain unchanged. According to the above variation characteristics of breath a feedback-based method for creating bi-level positive airway pressure is proposed. Experiments are implemented to verify the BiPAP model. Results demonstrate that the proposed method works effectively in following respiration and caters well to most polypnea and apnea events.

Development of dust collection and removal technology of comprehensive mechanized excavation face

To solve the problem of excavation face dust control,the theory of dust removal after collection was put forward.Through a large number of theoretical and experimental researches,a new wind screen dust-collection system which was applied to comprehen- sive excavation face was developed.To set a wind dam in jet stream box,achieve the function of multi-stage and multiple-level regulation,lots of experimentation was carried out to obtain higher jet stream velocity with the minimum loss of energy.Experiments show that the slit width in the exports of wind screen dust-collection system should be 10 to 15 mm.For the general excavation roadway,after wind attenuation,the velocity can be greater than 3 m/s at the roof which meets the requirements of respirable dust control.

Respiratory Distress Resulting from Gastroesophageal Reflux Is not Asthma,but Laryngotracheal Irritation,Spasm,even Suffocation

ESPITE the strong association between gastroesophageal reflux disease （GERD） and asthma has been undisputedly established and widely recognized by experts in advanced countries. Yet few topics in medicine are as controversial as the causal relationship between GERD and asthma： some argue that GERD causes asthma, while others think the other way around is true, still quite a few believe that bronchodilator medications are to blame. This controversy continues to be a conundrum or more piece of the puzzle.1 We would like to share two thoughts which might be a belated revelation with scholars and experts and invite them for further cooperative studies： the GERD-derived respiratory distress is not asthma, but GERD pure and simple; and the pathogenesis of respiratory distress is not asthma, but laryngotracheal irritation/spasm/suffocation.

H5N1 influenza viruses： outbreaks and biological properties

All known subtypes of influenza A viruses are maintained in wild waterfowl, the natural reservoir of these viruses. Influenza A viruses are isolated from a variety of animal species with varying morbidity and mortality rates. More importantly, influenza A viruses cause respiratory disease in humans with potentially fatal outcome. Local or global outbreaks in humans are typically characterized by excess hospitalizations and deaths. In 1997, highly pathogenic avian influenza viruses of the H5N1 subtype emerged in Hong Kong that transmitted to humans, resulting in the first documented cases of human death by avian influenza virus infection. A new outbreak started in July 2003 in poultry in Vietnam, Indonesia, and Thailand, and highly pathogenic avian H5N1 influenza viruses have since spread throughout Asia and into Europe and Africa. These viruses continue to infect humans with a high mortality rate and cause worldwide concern of a looming pandemic. Moreover, H5N1 virus outbreaks have had devastating effects on the poultry industries throughout Asia. Since H5N1 virus outbreaks appear to originate from Southern China, we here examine H5N1 influenza viruses in China, with an emphasis on their biological properties.

Correlation between severity of endoscopic findings and apnea-hypopnea index in patients with gastroesophageal reflux disease and obstructive sleep apnea

AIM: To assess the relationship between severity of gastroesophageal reflux disease and apnea-hypopnea index (AHI) as an indicator of the severity of obstructive sleep apnea. METHODS: Data of 57 patients with proven obstructive sleep apnea and gastroesophageal reflux disease were analyzed. Patients were divided into two groups according to severity of the sleep apnea: 'mild-moderate' (A)-AHI 5≥5-30, n=27, 'severe' (B)-AHI >30, n=30. All patients underwent apnea monitoring during the night, upper panendoscopy and were asked about typical reflux symptoms. RESULTS: All examined patients in both groups showed a significant overweight and there was a positive correlation between body mass index and the degree of sleep apnea (P = 0.0002). The occurence of erosive reflux disease was significantly higher in 'severe' group (P = 0.0001). Using a logistic regression analysis a positive correlation was found between the endoscopic severity of reflux disease and the AHI (P = 0.016). Forty-nine point five percent of the patients experienced the typical symptoms of reflux disease at least three times a week and there was no significant difference between the two groups. CONCLUSION: A positive correlation can be found between the severity of gastroesophageal reflux disease and obstructive sleep apnea.

Comparison of Soil Respiration in Two Grass-Dominated Communitiesin the Xil in River Basin: Correlations and Controls

A comparative study of soil respiration was conducted between in a semi-arid steppe community and in a wet meadow community in the Xilin River Basin of Nei Mongol. The seasonal pattern, the climatic controls, and the correlations of soil respiration with plant biomass components, were examined for each community. The main results are reported as follows: (1) The seasonal changes in soil respiration in the two communities had similar dynamic patterns (both being of two peaks), ranging from 312.8 to 1738.9 mg C(.)m(-2).s(-1) and from 354.6 to 2235.6 Mg C.m(-2).s(-1) in the growing season for the steppe plot and the meadow plot respectively. The soil respiration rate of the meadow plot was distinctly higher than that of the steppe plot, with the daily averages being 1349.6 mg C-m(-2).s(-1) and 785.9 mg C-m(-2).s(-1) respectively. (2) The correlation between soil respiration rate and soil moisture was much more significant than with temperature for the steppe community, and being on the contrary for the meadow community, reflecting the different effects of the two climatic factors in different habitats. Based on these regressive relations, the total CO2 efflux rate in the growing season in 2001 was estimated as 142.4 g C/m(2) in the steppe plot, and 236.1 g C/m(2) in the meadow plot. (3) There was no evident relation between the total canopy biomass and CO2 evolution rate, but a significant power function relation between the live canopy biomass and CO2 evolution rate in the meadow plot was detected. In the steppe plot, there existed only a weak relation between soil respiration and either live or total canopy biomass.

The effect of slow deep breathing relaxation exercise on pain levels during and post chest tube removal after coronary artery bypass graft surgery

Objectives:This study aimed to evaluate the effectiveness of slow deep breathing relaxation exercise(SDBRE)in reducing patients’pain levels during chest tube removal(CTR)post coronary artery bypass grafting(CABG)surgery.Methods:In 2019,fifty post-CABG patients were conveniently selected from a cardiac intensive care unit in Jordan’s major referral heart institute.The patients were randomly assigned to either an intervention group or a control group.A total of 25 patients were assigned into the experimental group who received slow deep breathing relaxation Exercise(SDBRE)alongside the conventional care before CTR.The remaining 25 patients constituted the control group(50%)that had CTR following conventional care.The Visual Analogue Scale(VAS)was used to measure the participants’pain levels during three phases:before CTR(Time 1),5-min post CTR(Time 2),and 15-min post CTR(Time 2)to compare the intervention effect between the two groups.Results:The data analysis findings for the control and intervention group of patients showed that there was a statistically significant decline in their pain level across time for both groups(H¼32.71,P<0.01;H=47.23,P<0.01)respectively.The intervention group had significantly lower pain levels than the control group at Time 2(3.50[1.20,5.30]vs.7.90[7.00,9.00],P<0.01)and Time 3(0.00[0.00,1.30]vs.3.60[2.40,4.10]P<0.01).Conclusions:Using SDBRE during CTR is an effective technique for reducing pain which can minimize the need for analgesics and their associated adverse effects.

Is the severity of obstructive sleep apnea or the magnitude of respiratory effort associated with gastroesophageal reflux?

In a recent issue ot World Journal of Gastroenterology, Demeter et al., reported that in patients having both gastro-esophageal reflux disease （GERD） and obstructive sleep apnea （OSA）, there was a positive correlation between endoscopic findings of GERD and the number of apneas and hypopneas per hour, namely apnea hypopnea index. They proposed that the severity of OSA and GERD are parallel to each other. The study of Demeter and colleagues is very important, not only for assessing reflux-induced esophageal damage in OSA,

A new design of foam spray nozzle used for precise dust control in underground coal mines

In order to improve the utilization rate of foam,an arc jet nozzle was designed for precise dust control.Through theoretical analysis,the different demands of foam were compared amongst arc jets,flat jets and full cone jets when the dust source was covered identically by foam.It is proved that foam consumption was least when an arc jet was used.Foam production capability of an arc jet nozzle under different conditions was investigated through experiments.The results show that with the gas liquid ratio(GLR)increasing,the spray state of an arc jet nozzle presents successively water jet,foam jet and mist.Under a reasonable working condition range of foam production and a fixed GLR,foam production quantity increases at first,and then decreases with the increase of liquid supply quantity.When the inner diameter of the nozzle is 14 mm,the best GLR is 30 and the optimum liquid supply quantity is0.375 m^3/h.The results of field experiments show that the total dust and respirable dust suppression efficiency of arc jet nozzles is 85.8%and 82.6%respectively,which are 1.39 and 1.37 times higher than the full cone nozzles and 1.20 and 1.19 times higher than the fiat nozzles.

Laboratory testing of a shuttle car canopy air curtain for respirable coal mine dust control

Canopy air curtain （CAC） technology has been developed by the National Institute for Occupational Safety and Health （NIOSH） for use on continuous miners and subsequently roof bolting machines in underground coal mines to protect operators of these machines from overexposure to respirable coal mine dust. The next logical progression is to develop a CAC for shuttle cars to protect operators from the same overexposures. NIOSH awarded a contract to Marshall University and J.H. Fletcher to develop the shuttle car CAC. NIOSH conducted laboratory testing to determine the dust control efficiency of the shuttle car CAC. Testing was conducted on two different cab configurations： a center drive similar to that on a Joy 10SC32AA cab model and an end drive similar to that on a Joy 10SC32AB cab model. Three different ventilation velocities were tested-0.61, 2.0, 4.3 rrds （120, 400, and 850 fpm）. The lowest, 0.61 m/s （120 fpm）, represented the ventilation velocity encountered during loading by the continuous miner, while the 4.3 m/s （850 fpm） velocity represented ventilation velocity airflow over the shuttle car while tramming against ventilation airflow. Test results showed an average of the dust control efficiencies ranging from 74 to 83% for 0.61 m/s （120 fpm）, 39%-43% for 2.0 m/s （400 fpm）, and 6%-16% for 4.3 m/s （850 fpm）. Incorporating an airflow spoiler to the shuttle car CAC design and placing the CAC so that it is located 22.86 cm （9 in.） forward of the operator improved the dust control efficiency to 51%-55% for 4.3 m/s （850 fpm） with minimal impact on dust control efficiencies for lower ventilation velocities. These laboratory tests demonstrate that the newly developed shuttle car CAC has the potential to successfully protect shuttle car operators from coal mine respirable dust overexposures.

Respiratory Virus Multiplex RT-PCR Assay Sensitivities and Influence Factors in Hospitalized Children with Lower Respiratory Tract Infections

Multiplex RT-PCR assays have been widely used tools for detection and differentiation of a panel of respiratory viral pathogens. In this study, we evaluated the Qiagen ResPlex lI V2.0 kit and explored factors influencing its sensitivity. Nasopharyngeal swab （NPS） specimens were prospectively collected from pediatric inpatients with lower respiratory tract infections at the time of admission in the Shenzhen Children＇s Hospital from May 2009 to April 2010. Total nucleic acids were extracted using the EZ1 system （Qiagen, Germany） and 17 respiratory viruses and genotypes including influenza A virus （FluA）, FluB, parainfluenza virus 1 （PIV1）, PIV2, PIV3, PIV4, respiratory syncytial virus （RSV）, human metapneumovirus （hMPV）, rhinoviruses （RhV）, enteroviruses （EnV）, human bocaviruses （hBoV）, adenoviruses （AdV）, four coronaviruses （229E, OC43, NL63 and HKU1）, and FluA 2009 pandemic H1NI（H1NI-p） were detected and identified by the ResPlex II kit. In parallel, 16 real-time TaqMan quantitative RT-PCR assays were used to quantitatively detect each virus except for RhV. Influenza and parainfluenza viral cultures were also performed. Among the total 438 NPS specimens collected during the study period, one or more viral pathogens were detected in 274 （62.6%） and 201（45.9%） specimens by monoplex TaqMan RT-PCR and multiplex ResPlex, respectively. When results from monoplex PCR or cell culture were used as the reference standard, the multiplex PCR possessed specificities of 92.9-100.0%. The sensitivity of multiplex PCR for PIV3, hMPV, PIV1 and BoV were 73.1%, 70%, 66.7% and 55.6%, respectively, while low sensitivities （11.1%-40.0%） were observed for FluA, EnV, OC43, RSV and H1N1. Among the seven viruses/genotypes detected with higher frequencies, multiplex PCR sensitivities were correlated significantly with viral loads determined by the TaqMan RT-PCR in FluA, H 1N 1-p and RSV （p=0.011-0.000） The Qiagen ResPlex II multiplex RT-PCR kit possesses excellent specificity for simultaneous detection of 17 viral pathogens in NPS specimens in pediatric inpatients at the time of admission. The sensitivity of multiplex RT-PCR was influenced by viral loads, specimen process methods, primer and probe design and amplification condition.