Effect of the adaptive intermittent ventilation before radical operation for lung cancer under one-lung ventilation on the non-ventilated lung tissue injury and apoptosis molecule protein expression

Objective: To study the effect of the adaptive intermittent ventilation before radical operation for lung cancer under one-lung ventilation on non-ventilated lung tissue injury and apoptosis molecule protein expression. Methods: A total of 288 patients who received radical operation for lung cancer in the hospital between February 2015 and January 2017 were divided into control group and observation group by random number table method, each with 144 cases. Control group received routine one-lung ventilation, and observation group received preoperative adaptive intermittent ventilation of non-ventilated lung tissue. The differences in the levels of inflammatory factors and oxidative stress indexes in serum as well as the apoptosis molecule protein expression in affected-side normal lung tissue were compared between the two groups of patients immediately after intubation and at two-lung ventilation (T0) as well as 10 min before operation ended and at one-lung ventilation (T1). Results: At T0, the differences in the levels of inflammatory factors and oxidative stress indexes in serum as well as the apoptosis molecule protein expression in affected-side normal lung tissue were not significantly significant between the two groups of patients;at T1, IL-1β, IL-8, TNF-α, MPO and MDA levels in serum as well as Bax, caspase-2 and caspase-3 protein expression in normal lung tissue of observation group were lower than those of control group while SOD level in serum and Bcl-2 protein expression in normal lung tissue were higher than those of control group. Conclusion: Adaptive intermittent ventilation before radical operation for lung cancer under one-lung ventilation can effectively reduce the non-ventilated lung tissue injury and inhibit the apoptosis of normal lung cells.

Effectiveness of adaptive servo-ventilation

Adaptive servo-ventilation(ASV) has been developed as a specific treatment for sleep-disordered breathing, in particular Cheyne-Stokes respiration with central sleep apnea(CSA). Heart failure patients often have sleep-disordered breathing, which consists of either obstructive sleep apnea(OSA) or CSA. Other medical conditions, such as stroke, acromegaly, renal failure, and opioid use may be associated with CSA. Continuous positive airway pressure(CPAP) therapy is widely used for patients with OSA, but some of these patients develop CSA on CPAP, which is called treatmentemergent CSA. CPAP can be useful as a treatment for these various forms of CSA, but it is insufficient to eliminate respiratory events in approximately half of patients with CSA. As compared to CPAP, ASV may be a better option to treat CSA, with sufficient alleviation of respiratory events as well as improvement of cardiac function in heart failure patients. In patients without heart failure, ASV can also alleviate CSA and relieve their symptom. Recently, ASV has been widely used for patients with various forms of CSA. ASV may be also used in the setting without CSA, but it should be assessed more carefully. Clinicians should have a better understanding of the indications for ASV in each setting.

Optimization of a Solar Chimney with a Horizontal Absorber for Building Ventilation:A Case Study

A study is conducted to optimize the geometry of a solar chimney equipped with a horizontal absorber in order to improve its performances in relation to the provision of ventilation.The problem is tackled through numerical solution of the governing equations for mass,momentum and energy in their complete three-dimensional and unsteady formulation.The numerical framework also includes a turbulence model(k-ε)and a radiant heat transfer(DO)model.Moreover,a Multi-Objective Genetic Algorithm(MOGA)is employed to derive the optimal configuration of the considered solar chimney.It is shown that an air velocity of 0.2 m/s can be obtained.This value is the minimum allowed air velocity according to the ASHRAE’s(American Society of Heating,Refrigerating and Air-Conditioning Engineers)adaptive comfort approach.

Optimising multi-vent module-based adaptive ventilation using a novel parameter for improved indoor air quality and health protection

As infectious respiratory diseases are highly transmissible through the air,researchers have improved traditional total volume air distribution systems to reduce infection risk.Multi-vent module-based adaptive ventilation(MAV)is a novel ventilation type that facilitates the switching of inlets and outlets to suit different indoor scenarios without changing ductwork layout.However,little research has evaluated MAV module sizing and air velocity selection,both related to MAV system efficiency in removing contaminants and the corresponding level of protection for occupants in the ventilated room.Therefore,the module-source offset ratio(MSOR)is proposed,based on the MAV module size and its distance from an infected occupant,to inform selection of optimal MAV module parameters.Computational fluid dynamics simulations illustrated contaminant distribution in a two-person MAV equipped office.Discrete phase particles modelled respiratory contaminants from the infected occupant,and contaminant concentration distributions were compared under four MAV air distribution layouts,three air velocities,and three module sizes considered using the MsOR.Results indicate that lower air velocities favour rising contaminant levels,provided the ventilation rate is met.Optimal contaminant discharge can be achieved when the line of outlets is located directly above the infected occupant.Using this parameter to guide MAV system design,85.7% of contaminants may be rendered harmless to the human body within 120 s using the default air vent layout.A more appropriate supply air velocity and air vent layout increases this value to 91.4%.These results are expected to inform the deployment of MAV systems to reduce airborne infection risk.

Effective improvement of a local thermal environment using multi-vent module-based adaptive ventilation

Indoor thermal comfort is essential as it improves living standards.Activity scenarios of personnel are in the process of a dynamic change.In most interior spaces with fixed working stations,people directly blown by cold air have a poor thermal experience.Therefore,to meet the differentiated environmental demands,one challenge is to explore novel ventilation strategies to satisfy the changing environmental needs.An adaptive strategy,multi-vent module-based adaptive ventilation(MAV),was designed to increase the adjustability of air distribution and better adapt to variable demands.A classroom was chosen as a representative model with multiple scenarios during its use.Simulations were conducted to verify the three-level control effect of MAV on improving the thermal environment.The results revealed that different vent solutions create different airflow patterns and thermal environments,which can be matched to the scenarios.The scale for ventilation efficiency No.4,which measured the influence scope of supply air,was used to evaluate the zoning division control in MAV.The space under the charge of a concerned MAV module showed a higher SVE4 than that at other zones.This implied that the zoning division can be effectively implemented.Thermal comfort measured using the air diffusion performance index,predicted mean vote,and draught rate showed that the application of MAV is better than that of the fixed MV mode,and the discomfort experienced when exposed to cold air can be avoided.It is believed that these results will help extend the research of adaptive ventilation strategies.

严寒地区混合垂直通风猪舍环境质量评价

为探究垂直通风系统(屋顶与粪坑混合排风)在寒区猪舍中的适应性,该研究在秋冬季节对内蒙古某规模化猪舍的热湿与空气质量环境进行了实时连续监测,并根据测试结果对猪舍环境质量进行评价。结果表明:1)测试期间,舍内平均温度、相对湿度以及氨气(NH_(3))、二氧化碳(CO_(2))、总悬浮颗粒物(total suspended particulate, TSP)浓度分别为22.7℃、59.6%、6.5 mg/m^(3)、2 200 mg/m^(3)、2 915μg/m^(3),舍内通风量为0.34~0.39 m^(3)/(h·kg),各环境指标基本满足生产环境阈值要求;保育期间舍内有效环境温度范围为27.1~30.7℃,存在轻度热应激情况,占总监测时间的12.9%;2)舍内温度、相对湿度与NH_(3)、CO_(2)、TSP浓度空间分布不均匀系数分别为0.01、0.15、0.45、0.03、0.15,各环境参数空间分布均较为均匀;3)试验单元(U1、U3)猪的平均日增质量、料重比与死淘率分别842和818 g/d、2.68和2.79、1.68%和1.31%,生产性能良好。综上,不设吊顶的侧墙进风,屋顶与粪坑混合排风的垂直通风系统,总体上能够满足严寒地区猪舍秋冬季热湿环境与空气质量调节需求,保证良好的生产性能。

适应性支持通气对COPD并发呼吸衰竭患者肺损伤及撤机成功率的影响

目的:观察适应性支持通气对慢性阻塞性肺疾病(COPD)并发呼吸衰竭患者肺损伤及撤机成功率的影响。方法:选取南昌市洪都中医院2020年8月—2023年8月收治的80例行机械通气治疗的COPD并发呼吸衰竭患者为对象,按随机数字表法分为A组(适应性支持通气模式)、B组(同步间歇指令+压力支持通气模式),各40例。比较两组血气指标、呼吸功能、急性生理与慢性健康状况评价Ⅱ(APACHEⅡ)评分、不良事件及撤机情况。结果:治疗后,两组动脉氧分压(PaO_(2))、动脉二氧化碳分压(PaCO_(2))、酸碱度(pH值)、APACHEⅡ评分比较,差异均无统计学意义(P>0.05)。A组一次性撤机成功率、达峰时间比(TPTEF/TE)、达峰容积比(VPEF/VE)均高于B组,吸呼比(TI/TE)、呼吸频率(RR)均低于B组,差异均有统计学意义(P<0.05)。两组治疗期间不良事件发生率比较,差异无统计学意义(P>0.05)。结论:适应性支持通气用于COPD并发呼吸衰竭患者能更好地改善呼吸功能,提高一次性撤机成功率。

早期分阶段肺康复锻炼联合适应性支持通气对急性呼吸窘迫综合征患者肺功能及血气指标的影响

目的探讨早期分阶段肺康复锻炼联合适应性支持通气(ASV)对急性呼吸窘迫综合征(ARDS)患者肺功能及血气指标的影响。方法选取2021年1月至2023年2月我院收治的ARDS患者78例,按照随机数字表法分为对照组与观察组各39例,比较两组患者治疗前后的肺功能指标、血气指标、生活质量变化情况和呼吸机通气时间、住院时间、并发症发生情况。结果与治疗前相比,治疗后两组的深吸气量(IC)、第一秒用力呼气容积(FEV_(1))的值、FEV_(1)与用力肺活量的比值(FEV_(1)/FCV)、动脉血氧分压(PaO_(2))、血氧饱和度(SaO_(2))、PaO_(2)/FiO_(2)水平、生活质量评分显著升高,二氧化碳分压(PaCO_(2))水平显著降低(P<0.05),且观察组的IC、FVC、FEV_(1)/FVC、PaO_(2)、SaO_(2)、PaO_(2)/FiO_(2)水平、生活质量评分高于对照组,PaCO_(2)水平低于对照组(P<0.05);观察组呼吸机通气时间、住院时间显著低于对照组(P<0.05),患者并发症总发生率低于对照组(P<0.05)。结论早期分阶段肺康复锻炼联合ASV模式可以改善ARDS患者的肺功能和血气指标,降低并发症的发生率,缩短恢复时间,提高患者的生活质量。

结合疫情环境滨海高校绿色建筑概念设计——探索风能的利用

随着经济高速发展,环境问题成为我们面临的巨大挑战。研究绿色能源利用,发展绿色建筑技术,是目前建筑行业的发展趋势。滨海城市拥有丰富的风能、潮汐能等绿色清洁能源,使得绿色建筑的建造有更广阔的发挥空间。根据大连市区具体校园环境,利用计算机模拟软件设计一套能够利用这些清洁能源的模式。经过理论推演、建筑形体推敲的方法,营造一个适合利用风能的建筑概念(环境风6 m/s,风道内最大可达12 m/s)。此外,通过其他节能手法,如辅助日照,将幕墙设计成可活动式,以改变阳光入射方向,补充建筑采光;降低风噪,实现无能耗无尘通风;通过形体设计以提高建筑的通风效率,改良“方盒子”形式的建筑的不利因素;利用环境水体制冷,利用水体底部的低于空气温度的环境来调节室内温度等,从多个方面满足建筑的使用要求,降低建筑的能量消耗。为了适应疫情爆发的突发状况,建筑设计概念还加入了“适疫情化”设计逻辑。通过研究探索滨海地区绿色建筑形式与运行模式,在为绿色建筑发展提供新的设计概念的同时,实现了疫情模式下的管理方法改变。

多模块适应性通风的污染物扩散控制性能研究——以应对教室使用情景变化为例

提出了一种多模块适应性通风(multi-module adaptive ventilation, MAV)方法,同时研究其在多场景类型建筑中面对室内场景变化和污染源位置变化时,控制污染物扩散和排除污染物的性能。以一教室为模型,利用计算流体动力学(computational fluid dynamics, CFD)技术模拟教室正常上课和集体讨论场景下的污染物分布情况,并在正常上课场景下进行污染源位置变化的讨论。其中示踪气体CO_(2)用于模拟感染者咳嗽产生的污染物。选用了5种不同的MAV模式和传统混合通风(mixing ventilation, MV)模式,比较了它们在面对教室内不同污染源位置和不同场景时,人员呼吸区的污染物浓度和去除率。结果表明合适的MAV模式下污染物在呼吸区的相对浓度更低、排除率更高,其中MAV平行模式在集体讨论场景下、污染源位置为P3时的呼吸区污染物去除率(contaminant removal efficiency, CRE)是MV模式的7.52倍,呼吸区相对污染物质量浓度C_r为MV模式的52.4%,说明合适的MAV模式能更好地适应场景和污染源位置的变化。

Adaptive thermal comfort in naturally ventilated hostels of warm and humid climatic region,Tiruchirappalli,India

Thermal comfort is an important factor in hostel buildings when the aim is to maximize the productivity of the students.Due to the extreme weather conditions,achieving thermal comfort in a hostel building in a hot and humid climate is even more difficult.Studies conducted in naturally ventilated hostel buildings in warm-humid climates involved the influence of outdoor air temperature only up to 34.4℃ and have been conducted in a specific season.In contrast,the Tiruchirappalli climate is characterized by a higher range of environmental variables.Therefore,to understand the thermal comfort conditions and usage of the environmental controls in naturally ventilated hostel buildings at the higher range of the environmental variables,a thermal comfort field study spread over one year was carried out at the National Institute of Technology,Tiruchirappalli,India,in twenty-seven hostel buildings.This study relies on field observation and thermal comfort responses from 2028 questionnaires collected from the students between September 2019 to August 2020.The analysis revealed a neutral temperature of 29.5℃ and a comfort range from 26.1℃ to 32.8℃,indicating a wide range of ther-mal adaptation than suggested by the National Building Code of India and ASHRAE standard 55.The preferred temperature was 27.8℃,indicating that students preferred a cooler environment.Acceptability with sweating conditions extended the upper limit of thermal acceptability from 31.8℃ to 32.4℃.The use of a mosquito net can increase the probability of opening a window.Results indicated that overall behavioral adjustment could extend the comfort limits.The study results would be helpful to develop guidelines and designs for naturally ventilated hostel buildings in warm and humid climates that will contribute to reducing energy demand.

Assessment of Adaptive Rate Response Provided by Accelerometer, Minute Ventilation and Dual Sensor Compared with Normal Sinus Rhythm During Exercise： A Self-controlled Study in Chronotropically Competent Subjects

Background：Dual sensor （DS） for rate adaption was supposed to be more physiological.To evaluate its superiority,the DS （accelerometer [ACC] and minute ventilation [MV]） and normal sinus rate response were compared in a self-controlled way during exercise treadmill testing.Methods：This self-controlled study was performed in atrioventricular block patients with normal sinus function who met the indications of pacemaker implant.Twenty-one patients came to the 1-month follow-up visit.Patients performed a treadmill test 1-month post implant while programmed in DDDR and sensor passive mode.For these patients,sensor response factors were left at default settings （ACC =8,MV =3） and sensor indicated rates （SIRs） for DS,ACC and MV sensor were retrieved from the pacemaker memories,along with measured sinus node （SN） rates from the beginning to 1-minute after the end of the treadmill test,and compared among study groups.Repeated measures analysis of variance and profile analysis,as well as variance analysis of randomized block designs,were used for statistical analysis.Results：Fifteen patients （15/2 l） were determined to be chronotropically competent.The mean differences between DS SIRs and intrinsic sinus rates during treadmill testing were smaller than those for ACC and MV sensor （mean difference between SIR and SN rate：ACC vs.SN,MV vs.SN,DS vs.SN,respectively,34.84,17.60,16.15 beats/min）,though no sensors could mimic sinus rates under the default settings for sensor response factor （ACC vs.SN P-adjusted 〈 0.001; MV vs.SN P-adjusted =0.002; DS vs.SN P-adjusted =0.005）.However,both in the range of 1st minute and first 3 minutes of exercise,only the DS SIR profile did not differ from sinus rates （P-adjusted =0.09,0.90,respectively）.Conclusions：The DS under default settings provides more physiological rate response during physical activity than the corresponding single sensors （ACC or MV sensor）.Further study is needed to determine if individual optimization would further improve adaptive performance of the DS.

Field study on thermal comfort of naturally ventilated residences in southwest China

Kunming,a city in southwest China,has a climate that is different from most of the other places in the world because of its unique geographical characteristics.Due to its temperate climate,most of the residential buildings in this region are naturally ventilated.Accordingly,a winter thermal comfort study was conducted in Kunming to reveal the thermal response of residents.Indoor and outdoor environmental parameters were measured,and participants were investigated about their clothing,thermal sensations,thermal preferences,and thermal acceptance using online questionnaires.Data from 162 valid questionnaires were collected in the survey.Although the climate is referred to as“mild”,the survey showed that the indoor temperature during winter was lower than the typical comfort range.Nevertheless,the participants responded that most of them felt neutral and comfortable.The neutral temperature of participants living in Kunming was determined to be 16.96℃.The acceptable thermal sensation vote(TSV)range of the residents is-0.72 to 1.52.The acceptable indoor air temperature range is 15.03℃ to 19.55℃,and the optimum indoor air temperature is 17.2℃.According to this study,the existing thermal comfort evaluation models can hardly predict residents’thermal responses in Kunming well.

Model-based adaptive controller for personalized ventilation and thermal comfort in naturally ventilated spaces

This work develops a standalone autonomously controlled personalized ventilation(PV)unit in a naturally ventilated(NV)office space to maintain acceptable thermal comfort{TQ under steady and transient indoor conditions and activity levels.The NV-PV proportional integral derivative(PID)controller adjusts the PV supply temperature(7spv)at the occupant set flow rate(Qspv)based on predicted TC using a regression model.The target TC level that the controller attains at all times is between 0(neutral)and 1(slightly comfortable).Process transfer functions were developed and then used to find the adaptive PID tuning coefficients using the Internal Model Control(IMC)method.The controller was tested in a case study at indoor temperature range of 25 to 33℃ with relative humidity range of 55%and 80%.It was shown that the NV-PV controller adjusted Tspv to maintain acceptable TC under transients of indoor conditions and metabolic rates.

Intelligent predictive model of ventilating capacity of imperial smelt furnace

In order to know the ventilating capacity of imperial smelt furnace(ISF), and increase the output of plumbum, an intelligent modeling method based on gray theory and artificial neural networks(ANN) is proposed, in which the weight values in the integrated model can be adjusted automatically. An intelligent predictive model of the ventilating capacity of the ISF is established and analyzed by the method. The simulation results and industrial applications demonstrate that the predictive model is close to the real plant, the relative predictive error is 0.72%, which is 50% less than the single model, leading to a notable increase of the output of plumbum.

重庆自然通风食堂的室内热环境评价研究

为了研究当前功能逐渐复合,但热环境普遍不容乐观的高校自然通风食堂建筑的热舒适水平,在夏季和过渡季分别通过现场环境参数实测和主观问卷结合的形式调查重庆地区高校餐饮建筑室内热舒适水平,将食堂建筑的热环境数据与主观投票结果进行回归分析。并通过平均投票数TSV对PMV进行修正得出人群热舒适范围。研究表明:食堂内用餐与非用餐者对室内热环境评价有明显差别,中性温度前者低于后者,差值在2.1~2.8℃之间;前者热舒适范围上下限值也都低于后者,差值在1.7~3.4℃之间。实际热感觉投票结果同预测投票值之间有明显差别。由此得出室内热环境的研究数据及评价,以期指导将来的建筑设计和实践。

负压通风环境下自适应补风系统设计

该项目为上海市检测中心生物与安全检测实验楼,因实验工艺排风造成风压失衡导致了一系列问题,经过对现场实勘和了解业主需求,提出了3个相对简单易行的改造方案,并对比了3个方案各自的优缺点,选定了最终实施方案。该项目整个大楼新增了负压自适应补风系统,介绍了系统的构成原理、控制逻辑和控制方法。针对系统中的新风机组需要大幅度变风量、变制冷量的运行特点,分析了传统直接蒸发式新风机组的构造特点,指出了其应用于该系统的不适应性,并提出了机组的改进措施。最后,分享了此类型改造项目的设计体会,可供类似工程设计参考。

气道压力释放通气在急性呼吸窘迫综合征中的应用

在小潮气量肺保护性通气时代,急性呼吸窘迫综合征(acute respiratory distress syndrome, ARDS)患者的病死率仍高,机械通气参数设置不当会进一步增加呼吸机相关性肺损伤风险。由于ARDS患者肺泡的黏弹性,气道压力释放通气(airway pressure release ventilation, APRV)长时间的吸气、较高的压力以及短暂的释放可能更适合ARDS肺泡病理生理学变化。APRV有肺复张、稳定肺泡结构等优势,已经显示出作为一种肺保护通气策略的巨大潜力,本文将对APRV相关研究进展进行综述。

不同通气模式治疗慢性阻塞性肺疾病合并呼吸衰竭临床疗效及患者呼吸动力学、肺功能水平比较

目的:探究采用不同通气模式对呼吸系统疾病患者进行治疗的临床疗效,并分析其对患者呼吸动力学以及肺功能指标的影响,为临床治疗提供理论依据。方法:收集收治的116例慢性阻塞性肺疾病(COPD)合并呼吸衰竭患者作为研究对象,并根据通气模式将其分为同步间歇指令通气(SIMV)+压力支持通气(PSV)组和适应性压力支持通气(ASV)组各58例。①记录并比较两组患者治疗前后血气指标变化情况;②比较两组患者治疗后呼吸动力学指标(Ppeak、Pplat、Pmean)变化情况;③比较两组患者治疗前后肺功能相关指标变化情况;④记录两组患者不良反应的发生情况。结果:①治疗前ASV组与SIMV+PSV组患者pH值、血氧分压(PaO_(2))、血二氧化碳分压(PaCO_(2))以及动脉血氧分压与吸入气氧浓度的比值(PaO_(2)/FiO_(2))比较无统计学差异(均P>0.05);治疗后两组患者pH值无显著变化(均P>0.05),PaO_(2)、PaO_(2)/FiO_(2)明显升高(均P<0.05),PaCO_(2)明显降低(P<0.05),但治疗后组间比较无统计学差异(均P>0.05);②治疗后,ASV组患者Ppeak、Pplat、Pmean等各项呼吸动力学指标均明显低于SIMV+PSV组患者,组间比较差异有统计学意义(均P<0.05);③治疗前ASV组与SIMV+PSV组患者1s用力呼气末容积(FEV1)、用力肺活量(FVC)以及呼气高峰流量(PEFR)比较无统计学差异(均P>0.05);治疗后两组患者FEV1、FVC以及PEFR均明显升高(均P<0.05),且治疗后组间比较差异有统计学意义(均P<0.05);④与SIMV+PSV组患者相比,ASV组患者不良反应以及呼吸机相关性肺炎的发生例数均有减少,总发生率明显降低(均P<0.05)。结论:对COPD合并呼吸衰竭患者进行治疗时,与SIMV+PSV通气模式相比,采用ASV通气模式具有更好的临床疗效,能够显著改善患者肺功能状况,明显提高患者呼吸动力学稳定性,也能显著降低患者不良反应的发生风险。

基于蚁群优化ANFIS模型的建筑室温状态和能耗预测

建筑采暖、通风和空调(HVAC)系统占据了超过一半的建筑能耗,系统的运行状态和能耗预测是节约建筑能耗、确保热舒适性的关键。提出一种基于蚁群优化算法(ACO)优化的自适应神经网络模糊推理系统(ANFIS),对暖通空调中空气处理单元(AHU)的状态和能耗进行建模和预测。通过蚁群优化算法和最小二乘法对ANFIS网络训练过程中前提参数和结论参数的寻优,进一步提高ANFIS方法对于HVAC等非线性系统建模的速度和精度。与随机森林(RF)、支持向量机(SVM)、BP神经网络和一般ANFIS等模型进行比较,验证了该方法具有更好的预测效果。