期刊文献+
共找到45,799篇文章
< 1 2 250 >
每页显示 20 50 100
Effects of unilateral superimposed high-frequency jet ventilation on porcine hemodynamics and gas exchange during one-lung flooding
1
作者 Thomas Lesser Frank Wolfram +1 位作者 Conny Braun Reiner Gottschall 《World Journal of Experimental Medicine》 2024年第1期88-99,共12页
BACKGROUND Superimposed high-frequency jet ventilation(SHFJV)is suitable for respiratory motion reduction and essential for effective lung tumor ablation.Fluid filling of the target lung wing one-lung flooding(OLF)is ... BACKGROUND Superimposed high-frequency jet ventilation(SHFJV)is suitable for respiratory motion reduction and essential for effective lung tumor ablation.Fluid filling of the target lung wing one-lung flooding(OLF)is necessary for therapeutic ultrasound applications.However,whether unilateral SHFJV allows adequate hemodynamics and gas exchange is unclear.AIM To compared SHFJV with pressure-controlled ventilation(PCV)during OLF by assessing hemodynamics and gas exchange in different animal positions.METHODS SHFJV or PCV was used alternatingly to ventilate the non-flooded lungs of the 12 anesthetized pigs during OLF.The animal positions were changed from left lateral position to supine position(SP)to right lateral position(RLP)every 30 min.In each position,ventilation was maintained for 15 min in both modalities.Hemodynamic variables and arterial blood gas levels were repeatedly measured.RESULTS Unilateral SHFJV led to lower carbon dioxide removal than PCV without abnormally elevated carbon dioxide levels.SHFJV slightly decreased oxygenation in SP and RLP compared with PCV;the lowest values of PaO_(2) and PaO_(2)/FiO_(2) ratio were found in SP[13.0;interquartile range(IQR):12.6-5.6 and 32.5(IQR:31.5-38.9)kPa].Conversely,during SHFJV,the shunt fraction was higher in all animal positions(highest in the RLP:0.30).CONCLUSION In porcine model,unilateral SHFJV may provide adequate ventilation in different animal positions during OLF.Lower oxygenation and CO_(2) removal rates compared to PCV did not lead to hypoxia or hypercapnia.SHFJV can be safely used for lung tumor ablation to minimize ventilation-induced lung motion. 展开更多
关键词 One-lung ventilation Unilateral superimposed high-frequency jet ventilation One-lung flooding
下载PDF
Kinematic deformation and intensity assessment of the 2021 Maduo M_(S)7.4 earthquake in Qinghai revealed by high-frequency GNSS
2
作者 Yu Li Yuebing Wang +2 位作者 Lijiang Zhao Hongbo Shi Pingping Wang 《Geodesy and Geodynamics》 EI CSCD 2024年第3期230-240,共11页
Rapid acquisition of the kinematic deformation field and seismic intensity distribution of large earthquakes is crucial for postseismic emergency rescue,disaster assessment,and future seismic risk research.The advance... Rapid acquisition of the kinematic deformation field and seismic intensity distribution of large earthquakes is crucial for postseismic emergency rescue,disaster assessment,and future seismic risk research.The advancement of GNSS observation and data processing makes it play an important role in this field,especially the high-frequency GNSS.We used the differential positioning method to calculate the 1 HZ GNSS data from 98 sites within 1000 km of the M_(S)7.4 Maduo earthquake epicenter.The kinematic deformation field and the distribution of the seismic intensity by using the peak ground velocity derived from displacement waveforms were obtained.The results show that:1)Horizontal coseismic response deformation levels ranging from 25 mm to 301 mm can be observed within a 1000 km radius from the epicenter.Coseismic response deformation on the east and west sides shows bilateral asymmetry,which markedly differs from the symmetry presented by surface rupture.2)The seismic intensity obtained through high-frequency GNSS and field investigations exhibits good consistency of the scope and orientation in the high seismic intensity area,although the former is generally slightly smaller than the latter.3)There may exist obstacles on the eastern side of the seismogenic fault.The Maduo earthquake induced a certain tectonic stress loading effect on the western Kunlun Pass-Jiangcuo fault(KPJF)and Maqin-Maqu segment,resulting in higher seismic risk in the future. 展开更多
关键词 Maduo earthquake high-frequency GNSS Kinematic deformation Seismic intensity
下载PDF
Dynamic Response of Foundations during Startup of High-Frequency Tunnel Equipment
3
作者 Dawei Ruan Mingwei Hu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第7期821-844,共24页
The specialized equipment utilized in long-line tunnel engineering is evolving towards large-scale,multifunctional,and complex orientations.The vibration caused by the high-frequency units during regular operation is ... The specialized equipment utilized in long-line tunnel engineering is evolving towards large-scale,multifunctional,and complex orientations.The vibration caused by the high-frequency units during regular operation is supported by the foundation of the units,and the magnitude of vibration and the operating frequency fluctuate in different engineering contexts,leading to variations in the dynamic response of the foundation.The high-frequency units yield significantly diverse outcomes under different startup conditions and times,resulting in failure to meet operational requirements,influencing the normal function of the tunnel,and causing harm to the foundation structure,personnel,and property in severe cases.This article formulates a finite element numerical computation model for solid elements using three-dimensional elastic body theory and integrates field measurements to substantiate and ascertain the crucial parameter configurations of the finite element model.By proposing a comprehensive startup timing function for high-frequency dynamic machines under different startup conditions,simulating the frequency andmagnitude variations during the startup process,and suggesting functions for changes in frequency and magnitude,a simulated startup schedule function for high-frequency machines is created through coupling.Taking into account the selection of the transient dynamic analysis step length,the dynamic response results for the lower dynamic foundation during its fundamental frequency crossing process are obtained.The validation checks if the structural magnitude surpasses the safety threshold during the critical phase of unit startup traversing the structural resonance region.The design recommendations for high-frequency units’dynamic foundations are provided,taking into account the startup process of the machine and ensuring the safe operation of the tunnel. 展开更多
关键词 Tunnel equipment high-frequency units startup conditions transient dynamics dynamic response foundation design
下载PDF
Brain protective effect of dexmedetomidine vs propofol for sedation during prolonged mechanical ventilation in non-brain injured patients
4
作者 Hong-Xun Yuan Li-Na Zhang +1 位作者 Gang Li Li Qiao 《World Journal of Psychiatry》 SCIE 2024年第3期370-379,共10页
BACKGROUND Dexmedetomidine and propofol are two sedatives used for long-term sedation.It remains unclear whether dexmedetomidine provides superior cerebral protection for patients undergoing long-term mechanical venti... BACKGROUND Dexmedetomidine and propofol are two sedatives used for long-term sedation.It remains unclear whether dexmedetomidine provides superior cerebral protection for patients undergoing long-term mechanical ventilation.AIM To compare the neuroprotective effects of dexmedetomidine and propofol for sedation during prolonged mechanical ventilation in patients without brain injury.METHODS Patients who underwent mechanical ventilation for>72 h were randomly assigned to receive sedation with dexmedetomidine or propofol.The Richmond Agitation and Sedation Scale(RASS)was used to evaluate sedation effects,with a target range of-3 to 0.The primary outcomes were serum levels of S100-βand neuron-specific enolase(NSE)every 24 h.The secondary outcomes were remifentanil dosage,the proportion of patients requiring rescue sedation,and the time and frequency of RASS scores within the target range.RESULTS A total of 52 and 63 patients were allocated to the dexmedetomidine group and propofol group,respectively.Baseline data were comparable between groups.No significant differences were identified between groups within the median duration of study drug infusion[52.0(IQR:36.0-73.5)h vs 53.0(IQR:37.0-72.0)h,P=0.958],the median dose of remifentanil[4.5(IQR:4.0-5.0)μg/kg/h vs 4.6(IQR:4.0-5.0)μg/kg/h,P=0.395],the median percentage of time in the target RASS range without rescue sedation[85.6%(IQR:65.8%-96.6%)vs 86.7%(IQR:72.3%-95.3),P=0.592],and the median frequency within the target RASS range without rescue sedation[72.2%(60.8%-91.7%)vs 73.3%(60.0%-100.0%),P=0.880].The proportion of patients in the dexmedetomidine group who required rescue sedation was higher than in the propofol group with statistical significance(69.2%vs 50.8%,P=0.045).Serum S100-βand NSE levels in the propofol group were higher than in the dexmedetomidine group with statistical significance during the first six and five days of mechanical ventilation,respectively(all P<0.05).CONCLUSION Dexmedetomidine demonstrated stronger protective effects on the brain compared to propofol for long-term mechanical ventilation in patients without brain injury. 展开更多
关键词 DEXMEDETOMIDINE PROPOFOL SEDATION Prolonged mechanical ventilation Brain protective
下载PDF
Driving pressure in mechanical ventilation:A review
5
作者 Syeda Farheen Zaidi Asim Shaikh +2 位作者 Daniyal Aziz Khan Salim Surani Iqbal Ratnani 《World Journal of Critical Care Medicine》 2024年第1期15-27,共13页
Driving pressure(ΔP)is a core therapeutic component of mechanical ventilation(MV).Varying levels ofΔP have been employed during MV depending on the type of underlying pathology and severity of injury.However,ΔP lev... Driving pressure(ΔP)is a core therapeutic component of mechanical ventilation(MV).Varying levels ofΔP have been employed during MV depending on the type of underlying pathology and severity of injury.However,ΔP levels have also been shown to closely impact hard endpoints such as mortality.Considering this,conducting an in-depth review ofΔP as a unique,outcome-impacting therapeutic modality is extremely important.There is a need to understand the subtleties involved in making sureΔP levels are optimized to enhance outcomes and minimize harm.We performed this narrative review to further explore the various uses ofΔP,the different parameters that can affect its use,and how outcomes vary in different patient populations at different pressure levels.To better utilizeΔP in MV-requiring patients,additional large-scale clinical studies are needed. 展开更多
关键词 Driving pressure Acute respiratory distress syndrome MORTALITY Positive end-expiratory pressure ventilator induced lung injury Mechanical ventilation
下载PDF
Therapeutic efficacy of methylprednisolone sodium succinate via diverse administration routes for mid-to high-frequency sudden sensorineural hearing loss
6
作者 Xiang-Da Meng Ting-Ting Li Li-Min Deng 《World Journal of Clinical Cases》 SCIE 2024年第18期3321-3331,共11页
BACKGROUND Sudden sensorineural hearing loss(SSNHL),characterized by a rapid and unexplained loss of hearing,particularly at moderate to high frequencies,presents a significant clinical challenge.The therapeutic use o... BACKGROUND Sudden sensorineural hearing loss(SSNHL),characterized by a rapid and unexplained loss of hearing,particularly at moderate to high frequencies,presents a significant clinical challenge.The therapeutic use of methylprednisolone sodium succinate(MPSS)via different administration routes,in combination with conventional medications,remains a topic of interest.AIM To compare the therapeutic efficacy of MPSS administered via different routes in combination with conventional drugs for the treatment of mid-to high-frequency SSNHL.METHODS The medical records of 109 patients with mid-to high-frequency SSNHL were analyzed.The patients were divided into three groups based on the route of administration:Group A[intratympanic(IT)injection of MPSS combined with mecobalamin and Ginkgo biloba leaf extract injection],Group B(intravenous injection of MPSS combined with mecobalamin and Ginkgo biloba leaf extract injection),and Group C(single IT injection of MPSS).The intervention effects were compared and analyzed.RESULTS The posttreatment auditory thresholds in Group A(21.23±3.34)were significantly lower than those in Groups B(28.52±3.36)and C(30.23±4.21;P<0.05).Group A also exhibited a significantly greater speech recognition rate(92.23±5.34)than Groups B and C.The disappearance time of tinnitus,time to hearing recovery,and disappearance time of vertigo in Group A were significantly shorter than those in Groups B and C(P<0.05).The total effective rate in Group A(97.56%)was significantly greater than that in Groups B and C(77.14%and 78.79%,χ^(2)=7.898,P=0.019).Moreover,the incidence of adverse reactions in Groups A and C was significantly lower than that in Group B(4.88%,3.03%vs 2.57%,χ^(2)=11.443,P=0.003),and the recurrence rate in Group A was significantly lower than that in Groups B and C(2.44%vs 20.00%vs 21.21%,χ^(2)=7.120,P=0.028).CONCLUSION IT injection of MPSS combined with conventional treatment demonstrates superior efficacy and safety compared to systemic administration via intravenous infusion and a single IT injection of MPSS.This approach effectively improves patients'hearing and reduces the risk of disease recurrence. 展开更多
关键词 Sudden loss of hearing at middle-and high-frequency of the descending type Methylprednisolone sodium succinate Intratympanic injection Intravenous injection
下载PDF
Effects of acetylcysteine on micro-inflammation and pulmonary ventilation in chronic obstructive pulmonary disease exacerbation
7
作者 Li-Yuan Huang Bin Huang +1 位作者 Zheng Lv Xiao-Dan Lu 《World Journal of Clinical Cases》 SCIE 2024年第18期3482-3490,共9页
BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease(AECOPD)is a serious complication of chronic obstructive pulmonary disease,often characterized by increased morbidity and mortality.In traditional ... BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease(AECOPD)is a serious complication of chronic obstructive pulmonary disease,often characterized by increased morbidity and mortality.In traditional Chinese medicine,AECOPD is linked to phlegm-heat and blood-stasis,presenting symptoms like thick sputum,fever,and chest pain.It has been shown that acetylcysteine inhalation in conjunction with conventional therapy significantly reduced inflammatory markers and improved lung function parameters in patients with AECOPD,suggesting that acetylcysteine may be an important adjunctive therapy for patients with phlegm-heat-blood stasis type AECOPD.AIM To investigate the effect of acetylcysteine on microinflammation and lung ventilation in patients with phlegm-heat and blood-stasis-type AECOPD.METHODS One hundred patients with phlegm-heat and blood-stasis-type AECOPD were randomly assigned to two groups.The treatment group received acetylcysteine inhalation(10%solution,5 mL,twice daily)along with conventional therapy,whereas the control group received only conventional therapy.The treatment duration was 14 d.Inflammatory markers(C-reactive protein,interleukin-6,and tumor necrosis factor-alpha)in the serum and sputum as well as lung function parameters(forced expiratory volume in one second,forced vital capacity,and peak expiratory flow)were assessed pre-and post-treatment.Acetylcysteine inhalation led to significant reductions in inflammatory markers and improvements in lung function parameters compared to those in the control group(P<0.05).This suggests that acetylcysteine could serve as an effective adjunct therapy for patients with phlegm-heat and blood-stasis-type AECOPD.RESULTS Acetylcysteine inhalation significantly reduced inflammatory markers in the serum and sputum and improved lung ventilation function parameters in patients with phlegm-heat and blood-stasis type AECOPD compared with the control group.These differences were statistically significant(P<0.05).The study concluded that acetylcysteine inhalation had a positive effect on microinflammation and lung ventilation function in patients with this type of AECOPD,suggesting its potential as an adjuvant therapy for such cases.CONCLUSION Acetylcysteine inhalation demonstrated significant improvements in reducing inflammatory markers in the serum and sputum,as well as enhancing lung ventilation function parameters in patients with phlegm-heat and bloodstasis type AECOPD.These findings suggest that acetylcysteine could serve as a valuable adjuvant therapy for individuals with this specific type of AECOPD,offering benefits for managing microinflammation and optimizing lung function. 展开更多
关键词 Acute exacerbation Chronic obstructive pulmonary disease Traditional Chinese medicine ACETYLCYSTEINE Phlegm-heat and blood-stasis Lung ventilation function
下载PDF
Respiratory Mechanics, Respiratory Muscle Strength, Control of Ventilation and Gas Exchange in Patients with Autoimmune Liver Disease
8
作者 Ahmet Baydur Jacob Korula 《Open Journal of Respiratory Diseases》 2024年第2期25-38,共14页
Objectives: To assess respiratory elastance and resistive properties in patients with autoimmune liver disorders using the passive relaxation expiration technique and compare findings to a group of patients with non-a... Objectives: To assess respiratory elastance and resistive properties in patients with autoimmune liver disorders using the passive relaxation expiration technique and compare findings to a group of patients with non-autoimmune liver disease and control subjects. These findings were then related to control of ventilation and gas exchange. A secondary objective was to assess respiratory muscle strength and gas exchange and their relation to respiratory mechanics. Methods: Measurements included respiratory elastance and resistance using the passive relaxation method. Pulmonary function, gas exchange and control of ventilation were assessed using standard methods. Results: a) Compared to control subjects, Ers in patients with liver disease was on average 50% greater than in controls;b) mean respiratory resistance, expressed as the respiratory constants, K<sub>1</sub> and K<sub>2</sub> in the Rohrer relationship, Pao/V’ = K<sub>1</sub> + K<sub>2</sub>V’, was not different from control resistance;c) mean maximal inspiratory and maximal expiratory pressures averaged 36% and 55% of their respective control values;d) inspiratory occlusion pressure in 0.1 sec (P<sub>0.1</sub>) was increased and negatively associated with FVC;and e) increases in P<sub>0.1</sub>, mean inspiratory flow (Vt/Ti) and presence of respiratory alkalosis confirmed the increase in ventilatory drive. Despite inspiratory muscle weakness in patients, P<sub>0.1</sub>/Pimax averaged 5-fold higher than in control subjects. Conclusions: Despite inspiratory muscle weakness and a V’<sub>E</sub> similar to that in normal subjects, central drive is increased in patients with chronic liver disease. The increase in ventilatory drive is related to smaller lung volumes and weakly associated with increase in respiratory elastance. Findings confirm that P<sub>0.1</sub> is a reliable measure of central drive and is an approach that can be used in the evaluation of control of ventilation in patients with chronic liver disease. 展开更多
关键词 Autoimmune Liver Disease Control of ventilation Occlusion Pressure Passive Relaxation Method Primary Biliary Cirrhosis Respiratory Elastance Respiratory Resistance
下载PDF
Impact of Sedation Protocols on Elderly Patients Undergoing Mechanical Ventilation and Off-Line Weaning
9
作者 Yihui Li Yamin Yuan +1 位作者 Jinquan Zhou Li Ma 《Journal of Clinical and Nursing Research》 2024年第4期322-333,共12页
The proportion of elderly patients in intensive care is increasing, and a significant proportion of them require mechanical ventilation. How to implement safe and effective mechanical ventilation for elderly patients,... The proportion of elderly patients in intensive care is increasing, and a significant proportion of them require mechanical ventilation. How to implement safe and effective mechanical ventilation for elderly patients, and when appropriate off-line is an important issue in the field of critical care medicine. Appropriate sedation can improve patient outcomes, but excessive sedation may lead to prolonged mechanical ventilation and increase the risk of complications. Elderly patients should be closely monitored and evaluated on an individual basis while offline, and the sedation regimen should be dynamically adjusted. This requires the healthcare team to consider the patient’s sedation needs, disease status, and pharmacodynamics and pharmacokinetics of the drug to arrive at the best strategy. Although the current research has provided valuable insights and strategies for sedation and off-line management, there are still many problems to be further explored and solved. 展开更多
关键词 Elderly patients Mechanical ventilation Off-line strategy Sedation treatment
下载PDF
Comparison of High-Frequency Oscillation Ventilation with Conventional Mandatory Ventilation in Animal ARDS Model
10
作者 SHI Guo-chao HUANG Shao-guang LI Min DENG Wei-wa WAN Huan-ying 《上海第二医科大学学报》 CSCD 北大核心 2005年第10期1091-1091,共1页
关键词 振动频率 通风技术 动物实验 爱滋病
下载PDF
COMPARISON OF HIGH-FREQUENCY OSCILLATION VEN-TILATION WITH CONVENTIONAL MANDATORY VENTILATION IN ANIMAL ARDS MODEL
11
作者 时国朝 黄绍光 +2 位作者 李敏 邓伟吾 万欢英 《Journal of Shanghai Second Medical University(Foreign Language Edition)》 2005年第2期96-100,共5页
Objective To compare effect of high-frequency oscillation ventilation (HFOV) and conventional mandatory ventilation (CMV) on lung injury development in rabbit with acute respiratory distress syndrome (ARDS). Methods A... Objective To compare effect of high-frequency oscillation ventilation (HFOV) and conventional mandatory ventilation (CMV) on lung injury development in rabbit with acute respiratory distress syndrome (ARDS). Methods Animals that underwent saline lung lavage to produce lung injury were randomized to one of the two treatment groups (HFOV or CMV, n=6). PaCO_ 2 was maintained between 35-45mmHg and arterial oxygen saturation (SaO_ 2) was maintain >88% by adjusting corresponding ventilator parameters. Ventilation period was 6h. Lung fluids were aspirated before and at the end of ventilation for cell analysis. Then the animals were euthanized, lung tissue was removed for wet/dry weight measurement, light and electron microscopic examination. Results The difference of artery blood gas analyses(pH, PaO_ 2, PaCO_ 2) between HFOV and CMV was insignificant. The difference between HFOV and CMV in cytological examination of lung fluids, wet/dry weight measurement was also insignificant. But compared with CMV,HFOV not only reduced the area of lung injury, but also reduced lung injury score in light and electron microscopic examination. Conclusion When same artery blood gas analysis was obtained, HFOV significantly reduced lung injury development in ARDS animal than CMV. As a lung protection strategy, HFOV can be used in the treatment of ARDS. 展开更多
关键词 振动频率 空气流通 导管通气 严重呼吸综合征 肺疾病 动物实验
下载PDF
Effect of different ventilation methods combined with pulmonary surfactant on neonatal acute respiratory distress syndrome 被引量:2
12
作者 Qing Qing Ping Zha +1 位作者 Li-Ying Dai Yang Wang 《World Journal of Clinical Cases》 SCIE 2023年第25期5878-5886,共9页
BACKGROUND Acute respiratory distress syndrome precipitates is widespread pulmonary injury in impacted individuals,the neonatal respiratory distress syndrome(NRDS),primarily observed in preterm infants,represents a pr... BACKGROUND Acute respiratory distress syndrome precipitates is widespread pulmonary injury in impacted individuals,the neonatal respiratory distress syndrome(NRDS),primarily observed in preterm infants,represents a prevalent critical condition in neonatal clinical settings.AIM To investigate the clinical efficacy of various ventilation strategies combined with pulmonary surfactant(PS)therapy in the treatment of NRDS.METHODS A total of 20 neonates diagnosed with respiratory distress syndrome,admitted between May 2021 and June 2022,were randomly assigned to either a research group or a control group.Neonates in the research group received treatment involving high-frequency oscillatory ventilation(HFOV)in conjunction with PS.In contrast,neonates in the control group were administered either controlled mechanical ventilation or synchronous intermittent mandatory ventilation,combined with PS.Arterial blood samples from the neonates in both groups were collected before treatment,as well as 6 h,12 h,24 h,and 48 h post-treatment.These samples underwent blood gas analysis,with measurements taken for pH value,partial pressures of oxygen(O_(2))and carbon dioxide.Concurrently,data was collected on the duration of ventilator use,length of hospitalization time,O_(2) treatment time,treatment outcomes,and complications of the ventilator.RESULTS From 6-48 h post-treatment,both groups demonstrated significant improvements in arterial blood pH and oxygen partial pressure,along with a significant decrease in carbon dioxide partial pressure compared to pre-treatment values(P<0.05).Although these changes progressed over time,there were no significant differences between the two groups(P>0.05).However,the research group had significantly lower X-ray scores,shorter hospitalization time,and less time on O_(2) therapy compared to the control group(P<0.05).Mortality rates were similar between the two groups(P>0.05),but the research group had a significantly lower incidence of complications(P<0.05).CONCLUSION The integration of HFOV combine with PS has proven to effectively expedite the treatment duration,decrease the occurrence of complications,and secure the therapeutic efficacy in managing NRDS. 展开更多
关键词 Neonatal respiratory distress syndrome Pulmonary surfactant Mechanical ventilation Respiratory distress syndrome Acute respiratory distress syndrome
下载PDF
Radio-frequency measurements of energetic-electron-driven emissions using high-frequency magnetic probe on XuanLong-50 spherical torus
13
作者 王明远 伦秀春 +3 位作者 薄晓坤 刘兵 刘阿娣 石跃江 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第4期33-38,共6页
A high-frequency magnetic probe is designed and developed on the XuanL ong-50(EXL-50)spherical torus to measure high-frequency magnetic field fluctuation.The magnetic loop,radio filters,radio-frequency limiter,and dat... A high-frequency magnetic probe is designed and developed on the XuanL ong-50(EXL-50)spherical torus to measure high-frequency magnetic field fluctuation.The magnetic loop,radio filters,radio-frequency limiter,and data acquisition system of the probe are comprehensively examined.The fluctuation data from the EXL-50 plasma are analyzed in the time–frequency domain using fast Fourier transforms.Moreover,distinct high-frequency instabilities are detected using this diagnostic system.In particular,significant frequency chirping is observed,which is consistent with the bumpon-tail drive instability predicted using the Berk–Breizman model. 展开更多
关键词 high-frequency magnetic probe high-frequency instabilities XuanLong-50
下载PDF
Clinical evaluation of ventilation mode on acute exacerbation of chronic obstructive pulmonary disease with respiratory failure
14
作者 Jun-Jun Wang Zhong Zhou Li-Ying Zhang 《World Journal of Clinical Cases》 SCIE 2023年第26期6040-6050,共11页
BACKGROUND At present,understanding of the most effective ventilation methods for treating chronic obstructive pulmonary disease(COPD)patients experiencing acute worsening symptoms and respiratory failure remains rela... BACKGROUND At present,understanding of the most effective ventilation methods for treating chronic obstructive pulmonary disease(COPD)patients experiencing acute worsening symptoms and respiratory failure remains relatively limited.This report analyzed the efficiency and side effects of various ventilation techniques used for individuals experiencing an acute COPD exacerbation.AIM To determine whether pressure-controlled ventilation(PCV)can lower peak airway pressures(PAPs)and reduce the incidence of barotrauma compared to volume-controlled ventilation(VCV),without compromising clinical outcomes and oxygenation parameters.METHODS We have evaluated 600 patients who were hospitalized due to a severe COPD exacerbation,with 400 receiving mechanical ventilation for the respiratory failure.The participants were divided into two different groups,who were administered either VCV or PCV,along with appropriate management.We thereafter observed patients'attributes,clinical factors,and laboratory,radiographic,and arterial blood gas evaluations at the start and during their stay in the intensive care unit(ICU).We have also employed appropriate statistical methods for the data analysis.RESULTS Both the VCV and PCV groups experienced significant enhancements in the respiratory rate,tidal volume,and arterial blood gas values during their time in the ICU.However,no significant distinctions were detected between the groups in terms of oxygenation indices(partial pressures of oxygen/raction of inspired oxygen ratio)and partial pressures of carbon dioxide improvements.There was no considerable disparity observed between the VCV and PCV groups in the hospital mortality(32%vs 28%,P=0.53),the number of days of ICU stay[median interquartile range(IQR):9(6-14)d vs 8(5-13)d,P=0.41],or the duration of the mechanical ventilation[median(IQR):6(4-10)d vs 5(3-9)d,P=0.47].The PCV group displayed lower PAPs compared to the VCV group(P<0.05)from the beginning of mechanical ventilation until extubation or ICU departure.The occurrence of barotrauma was considerably lower in the PCV group in comparison to the VCV group(6%vs 16%,P=0.03).CONCLUSION Both VCV and PCV were found to be effective in treating patients with acute COPD exacerbation.However,PCV was associated with lower PAPs and a significant decrease in barotrauma,thus indicating that it might be a safer ventilation method for this group of patients.However,further large-scale study is necessary to confirm these findings and to identify the best ventilation approach for patients experiencing an acute COPD exacerbation. 展开更多
关键词 Chronic obstructive pulmonary disease Mechanical ventilation Volume-controlled ventilation Pressurecontrolled ventilation BAROTRAUMA Respiratory failure
下载PDF
Mechanical ventilation and outcomes in COVID-19 patients admitted to intensive care unit in a low-resources setting: A retrospective study
15
作者 Sarakawabalo Assenouwe Tabana Essohanam Mouzou +7 位作者 Ernest Ahounou Lidaw Déassoua Bawe Awèréou Kotosso Koffi Atsu Aziagbe Eyram Makafui Yoan Amekoudi Mamoudou Omourou Chimene Etonga Anoudem Komi Séraphin Adjoh 《Journal of Acute Disease》 2023年第5期186-191,共6页
Objective:To describe the strategies and outcomes of mechanical ventilation in a poorly equipped facility.Methods:This retrospective descriptive study included patients with COVID-19 who were admitted to the intensive... Objective:To describe the strategies and outcomes of mechanical ventilation in a poorly equipped facility.Methods:This retrospective descriptive study included patients with COVID-19 who were admitted to the intensive care unit(ICU)and mechanically ventilated between September 1,2020,and May 31,2021.Data were collected from medical records and databases.Results:54 Patients aged(62.9±13.3)years were included.Among these cases,79.6%had at least one comorbidity.On admission,all patients had hypoxia.The median peripheral oxygen saturation in room air was 76%(61%,83%).Non-invasive ventilation(NIV)was performed in 75.9%of the patients,and invasive mechanical ventilation(IMV)in 68.5%.IMV was performed on patients due to severe coma(8.1%),failure of standard oxygen therapy(27.0%),and failure of NIV(64.9%).An arterial blood gas test was performed in 14.8%of the patients.NIV failed in 90.2%of cases and succeeded in 9.8%.IMV was successful in 5.4%of cases,vs.94.6%of mortality.The overall mortality rate of patients on ventilation in the ICU was 88.9%.The causes of death included severe respiratory distress syndrome(85.2%),multiple organ failure(14.8%),and pulmonary embolism(13.0%).Conclusions:The ventilation management of COVID-19 patients in the ICU with NIV and IMV in a scarce resource setting is associated with a high mortality rate.Shortcomings are identified in ventilation strategies,protocols,and monitoring.Required improvements were also proposed. 展开更多
关键词 Coronavirus disease 2019 Intensive care unit Hy-poxia Invasive ventilation Non-invasive ventilation Arterial blood gas
下载PDF
Invasive versus non-invasive ventilation in patients with COVID-19 pneumonia:A retrospective study
16
作者 Abhijit Nair Jacob Paul +1 位作者 Ajay Yadav Khalid Al Sawafi 《Journal of Acute Disease》 2023年第2期61-66,共6页
Objective:To compare the survival and length of stay of invasive ventilation(IV)with those of non-invasive ventilation(NIV)in patients with COVID-19 acute respiratory distress syndrome in a single hospital from May 20... Objective:To compare the survival and length of stay of invasive ventilation(IV)with those of non-invasive ventilation(NIV)in patients with COVID-19 acute respiratory distress syndrome in a single hospital from May 2020 to March 2021.Methods:After obtaining approval from the Hospital Director,the data of COVID-19 patients including demographics,type of respiratory support(non-invasive ventilation or invasive ventilation),duration of ventilation,length of stay,discharge,and death were collected and analyzed.Results:Out of the 152 patients identified,134 patients were analyzed.The median intubation days were 10.0(Q1:3.5,Q3:13.5)in the IV group and 0.0(Q1:0.0,Q3:0.0)days in the NIV-only group.Out of the 101 patients who received NIV,43 patients were subsequently intubated due to failure of NIV.Of the 63 patients(47.01%)who died,22(66.66%)were from the IV group and 40(92.02%)were from the NIV-followed-by-intubation group,and 1(1.72%)were from the NIV-only group.Multivariate analysis showed that the presence of a respiratory comorbidity(OR=16.56,95%CI=1.56-175.48,P=0.02)was an independent predictor of survival.Conclusions:Respiratory co-morbidity is a significant adverse predictor of survival outcome.The decision on the type of respiratory support should be made on a patient-to-patient basis. 展开更多
关键词 Acute respiratory distress syndrome COVID-19 Intensive care unit Invasive ventilation MORBIDITY MORTALITY Non-invasive ventilation
下载PDF
Ultra-broadband acoustic ventilation barrier based on multi-cavity resonators
17
作者 许雨薇 管义钧 +4 位作者 吴成昊 葛勇 司乔瑞 袁寿其 孙宏祥 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第12期397-403,共7页
The numerical simulations and experimental results of an ultra-broadband acoustic ventilation barrier composed of periodic unit cells are reported in this paper.Based on multiple mechanisms,including sound absorption ... The numerical simulations and experimental results of an ultra-broadband acoustic ventilation barrier composed of periodic unit cells are reported in this paper.Based on multiple mechanisms,including sound absorption by eigenmodes of the unit cell and sound reflection by a plate structure on upper surface of the unit cell,a single-layer ventilation barrier with broadband sound reduction is designed,and its working bandwidth can reach about 1560 Hz.The experimental results accord well with the simulation results.Furthermore,two types of three-layer ventilation barriers are designed and demonstrated by using the unit cells with different values of a(the length of the hollow square region)and w(the width of the channel between the adjacent cavities),and the bandwidths of both ventilation barriers can increase to 3160 Hz and 3230 Hz,respectively.The designed barrier structures have the advantages of ultra-broadband sound reduction and ventilation,which paves the way to designing high-performance ventilation barriers for the applications in environmental protection and architectural acoustics. 展开更多
关键词 acoustic metamaterials ultra-broadband sound reduction acoustic barrier ventilation
下载PDF
Treatment of a large area perioral viral herpes infection following noninvasive ventilation:A case report
18
作者 A-Mao Tang Jia-Ying Xu +1 位作者 Rong Wang Yi-Min Li 《World Journal of Clinical Cases》 SCIE 2023年第8期1857-1861,共5页
BACKGROUND Alphaherpesvirus belongs to the Herpesviridae family and has large,monopartite double-stranded linear DNA.It mainly infects the skin,mucosa,and nerves,and can affect various hosts,including humans and other... BACKGROUND Alphaherpesvirus belongs to the Herpesviridae family and has large,monopartite double-stranded linear DNA.It mainly infects the skin,mucosa,and nerves,and can affect various hosts,including humans and other animals.Here,we present a case of a patient seen by the gastroenterology department at our hospital who experienced an oral and perioral herpes infection following treatment with a ven-tilator.The patient was treated with oral and topical antiviral drugs,furacilin,oral and topical antibiotics,local epinephrine injection,topical thrombin powder,and nutritional and supportive care.A wet wound healing approach was also implemented with good response.CASE SUMMARY A 73-year-old woman presented to the hospital with a chief complaint of"abdominal pain for 3 d with dizziness for 2 d."She was admitted to the intensive care unit for septic shock and spontaneous peritonitis secondary to cirrhosis and was given antiinflammatory and symptomatic supportive treatment.A ventilator was used to assist breathing for acute respiratory distress syndrome,which developed during her admission.A large area of herpes infection appeared in the perioral region 2 d following noninvasive ventilation.The patient was transferred to the gastroenterology department,at which time she had a body temperature of 37.8 C and a respiratory rate of 18/min.The patient's con-sciousness was intact,and she no longer had abdominal pain or distension,chest tightness,or asthma.At this point,the infected perioral region changed in appearance and was now accompanied by local bleeding with crusting of blood at the wounds.The surface area of the wounds measured approximately 10 cm×10 cm.A cluster blisters appeared on the patient’s right neck,and ulcers developed in her mouth.On a subjective numerical pain scale,the patient reported a pain level of 2.Overall,her diagnoses other than the oral and perioral herpes infection included:(1)Septic shock;(2)spontaneous peritonitis;(3)abdominal infection;(4)decompensated cirrhosis;and(5)hypoproteinemia.Dermatology was consulted regarding the treatment of the patient’s wounds;they suggested treatment with oral antiviral drugs,an intramuscular injection of nutritious nerve drugs,and the application of topical penciclovir and mupirocin around the lips.Stomatology was also consulted and suggested the use of nitrocilin in a local wet application around the lips.CONCLUSION Through multidisciplinary consultation,the patient’s oral and perioral herpes infection was successfully treated with the following combined approach:(1)Application of topical antviral and antibiotic treatments;(2)keeping the wound moist with a wet wound healing strategy;(3)systemic use of oral antiviral drugs;and(4)symptomatic and nutritional supportive care.The patient was discharged from the hospital after successful wound healing. 展开更多
关键词 ventilATOR Viral herpes Nursing care Case report
下载PDF
Optimization of a Solar Chimney with a Horizontal Absorber for Building Ventilation:A Case Study
19
作者 El Hadji I Cisse Baye Alioune Ndiogou +2 位作者 Soumaïla Tigampo Ababacar Thiam DorothéAzilinon 《Fluid Dynamics & Materials Processing》 EI 2023年第4期901-910,共10页
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 nume... 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. 展开更多
关键词 Natural ventilation adaptative comfort solar chimney FLUENT MOGA
下载PDF
Tuning magneto-dielectric properties of Co_(2)Z ferrites via Gd doping for high-frequency applications
20
作者 武剑 卢冰 +6 位作者 张颖 陈一鑫 孙凯 陈大明 李强 刘颖力 李颉 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期468-473,共6页
Magneto-dielectric properties of Co_(2)Z ferrite materials are tuned via Gd doping for applications in high-frequency antennas and filters in the present work.Ba_(3)Co_(2)Fe_(24-x)Gd_(x)O_(41)(x=0.00,0.05,0.10,0.15,an... Magneto-dielectric properties of Co_(2)Z ferrite materials are tuned via Gd doping for applications in high-frequency antennas and filters in the present work.Ba_(3)Co_(2)Fe_(24-x)Gd_(x)O_(41)(x=0.00,0.05,0.10,0.15,and 0.20)materials are successfully prepared by using solid-state method at 925℃for 4 h with 2.5-wt%Bi_(2)O_(3)sintering aids.The content of Gd^(3+)ion can affect micromorphology,grain size,bulk density,and magneto-dielectric properties of the ferrite.With Gd^(3+)ion content increasing,saturation magnetization(Ms)first increases and then decreases.The maximum value of Ms is 44.86 emu/g at x=0.15.Additionally,sites occupied by Gd^(3+)ions can change magnetic anisotropy constant of the ferrite.Magnetocrystalline anisotropy constant(K_1)is derived from initial magnetization curve,and found to be related to spin-orbit coupling and intersublattice interactions between metal ions.The real part of magnetic permeability(μ′)and real part of dielectric permittivity(ε′)are measured in a frequency range of 10 MHz-1 GHz.When x=0.15,material has excellent magneto-dielectric properties(μ′≈12.2 andε′≈17.61),low magnetic loss(tanδμ≈0.03 at 500 MHz),and dielectric loss(tanδε≈0.04 at 500 MHz).The results show that Gd-doped Co_(2)Z ferrite has broad application prospects in multilayer filters and high-frequency antennas. 展开更多
关键词 Co_(2)Z ferrite magneto-dielectric properties Gd doping high-frequency applications
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部