Utility of gas inlet pressure monitoring in extracorporeal membrane oxygenation

2020 ◽  
pp. 039139882096212
Author(s):  
Yuki Nakamura ◽  
Takafumi Nakakita ◽  
Kazuhiko Yamamoto ◽  
Aki Kamada ◽  
Shinichi Iguchi ◽  
...  

Purpose: Purpose: Condensation that clogs the hollow fibers of the oxygenation and accumulation of plasma leaks reduces oxygenated lung capacity. In this study, artificial We evaluated whether monitoring changes in lung gas inlet pressure was a way to predict these complications. Methods: Changes in gas inlet pressure and oxygenation capacity of three different prostheses (BIOCUBE6000, EXCELUNG PRIME, and Capiox-LX) Evaluated the relationship. When simulating plasma leakage using BIOCUBE6000, sodium dodecyl sulfate (SDS) (1%, 0.1%, A solution of 0.01%, and RO water) reduced surface tension. During 120 minutes of circulation, changes in gas inlet pressure and leakage from the membrane into the gas flow path The amount of fluid was measured. Results: There was a significant negative correlation between the gas inlet pressure changes and the oxygenation capacity of all three oxygenators (BIOCUBE6000: R2 = 0.957, EXCELUNG PRIME: R2 = 0.946, Capiox-LX: R2 = 0.878). After 120 min of SDS solution circulation using the BIOCUBE6000, both the gas inlet pressure and the volume of fluid leaking from the membrane into the gas flow path increased in proportion to the SDS solution concentration: RO water (0.56 ± 0.11 mmHg and 16.67 mL ± 0.94 mL), 0.01% SDS (0.98 ± 0.11 mmHg and 23.3 ± 0.47 mL,) 0.1% SDS (1.64 ± 0.21 mmHg and 29.0 ± 1.63 mL), and 1%SDS (14.3 ± 0.27 mmHg and 36.7 ± 0.47 mL) (n = 3). Conclusion: This study confirmed that monitoring the gas inlet pressure changes of an oxygenator during ECMO is clinically useful.

2019 ◽  
Vol 71 (7) ◽  
pp. 942-948
Author(s):  
Qi Sun ◽  
Fangwei Xie ◽  
Kuaidi Wan ◽  
Xinjian Guo ◽  
Jie Zhu ◽  
...  

Purpose The purpose of this paper is to study the influences of the oil film thickness between the friction pairs, the rotational speed of the active and passive friction disks and the inlet pressure of the lubricant on the transmission efficiency. Design/methodology/approach A mathematical model of transmission efficiency was established, and the efficiency of transmission was studied by means of numerical analysis. Findings The results demonstrate that the transmission efficiency decreases with the thickness of the oil film increases. When the thickness of oil film d = 0.1 mm, the relationship between transmission efficiency and transmission ratio is linear, that is, with the transmission ratio increases, the transmission efficiency also increases which does not change with the inlet pressure changes. However, when d = 0.1 mm, their relationship is non-linear; the efficiency increases first and then decreases as the transmission ratio increases, but decreases as the inlet pressure increases. Originality/value The authors obtained a rule is that increasing the rotational speed and reducing the inlet pressure of the lubricating oil can improve the transmission efficiency. This study can provide a theoretical basis for power transmission designing of hydro-viscous clutch.


SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A153-A154
Author(s):  
Huisu Jeon ◽  
Sonhye Jeoung ◽  
Goeun Kim ◽  
Hyeyoung An ◽  
Hyojin Nam ◽  
...  

Abstract Introduction Bedtime Procrastination (BP) is defined as the behavior of going to bed later than intended, despite the absence of external factors. Bedtime procrastination is also prevalent among insomnia patients, and is associated with various sleep problems. Recent studies suggest emotional regulation as a mechanism of the procrastination behavior that is the conceptual foundation of bedtime procrastination. Emotional regulation difficulties are also associated with insomnia, but there is still a lack of research on the relationship between insomnia, emotional regulation strategies and bedtime procrastination. Thus, the study assumed that severity of insomnia would affect bedtime procrastination, and examined the moderating effect of the emotional regulation strategies in this relationship. Methods This study was conducted in 376 adults (mean age 23.73 ±2.14 years, 84.6% females). Participants were asked to answer Bedtime procrastination scale (BPS), an emotional regulation strategy checklist, and the Insomnia severity scale (ISI). Results As a result, a significant positive correlation was found between insomnia severity and bedtime procrastination (r=.286, p<.01), and avoidant/distractive regulation style (r=.101, p<.05). active regulation style (r=-.172, p<.01) and support seeking regulation style (r=-.102, p<.01) showed a significant negative correlation with the severity of insomnia. Bedtime procrastination behavior showed significant negative correlation only with active regulation style (r=-.151, p<.01). Support seeking regulation style moderated the relationship between insomnia and bedtime procrastination behavior (B=.0165, 95%, CI=.0014, .0316). The interaction effect between insomnia and support seeking regulation style was also significant (∆R^2=.0112, p<.05), indicating that the effect of insomnia on bedtime procrastination depends on the level of use of the support seeking regulation style. Conclusion These findings suggest that the level of support seeking regulation style is meaningful in terms of how insomnia affects bedtime procrastination. Support (if any) This work was supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea(NRF-2018S1A5A8026807)


Author(s):  
Kenneth J. Kelly ◽  
Gregory C. Pacifico ◽  
Michael Penev ◽  
Andreas Vlahinos

The National Renewable Energy Laboratory (NREL) and Plug Power Inc. have been working together to develop fuel cell modeling processes to rapidly assess critical design parameters and evaluate the effects of variation on performance. This paper describes a methodology for investigating key design parameters affecting the thermal performance of a high temperature, polybenzimidazole (PBI)-based fuel cell stack. Nonuniform temperature distributions within the fuel cell stack may cause degraded performance, induce thermo-mechanical stresses, and be a source of reduced stack durability. The three-dimensional (3-D) model developed for this project includes coupled thermal/flow finite element analysis (FEA) of a multi-cell stack integrated with an electrochemical model to determine internal heat generation rates. Sensitivity and optimization algorithms were used to examine the design and derive the best choice of the design parameters. Initial results showed how classic design-of-experiment (DOE) techniques integrated with the model were used to define a response surface and perform sensitivity studies on heat generation rates, fluid flow, bipolar plate channel geometry, fluid properties, and plate thermal material properties. Probabilistic design methods were used to assess the robustness of the design in response to variations in load conditions. The thermal model was also used to develop an alternative coolant flow-path design that yields improved thermal performance. Results from this analysis were recently incorporated into the latest Plug Power coolant flow-path design. This paper presents an evaluation of the effect of variation on key design parameters such as coolant and gas flow rates and addresses uncertainty in material thermal properties.


1992 ◽  
Vol 70 (11) ◽  
pp. 1457-1467 ◽  
Author(s):  
John W. Downie ◽  
J. Andrew Armour

The relationship between vesical mechanoreceptor field dimensions and afferent nerve activity recorded in pelvic plexus nerve filaments was examined in chloralose-anesthetized cats. Orthogonal receptor field dimensions were monitored with piezoelectric ultrasonic crystals. Reflexly generated bladder contractile activity made measurements difficult, therefore data were collected from cats subjected to actual sacral rhizotomy. Afferent activity was episodic and was initiated at different pressure and receptor field dimension thresholds. Maximum afferent activity did not correlate with maximum volume or pressure. Furthermore, activity was not linearly related to intravesical pressure, receptor field dimensions, or calculated wall tension. Pressure–length hysteresis of the receptor fields occurred. The responses of identified afferent units and their associated receptor field dimensions to brief contractions elicited by the ganglion stimulant 1,1-dimethyl-4-phenylpiperazinium iodide (2.5–20 μg i.a.), studied under constant volume or constant pressure conditions, are compatible with bladder mechanoreceptors behaving as tension receptors. Because activity generated by bladder mechanoreceptors did not correlate in a simple fashion with intravesical pressure or receptor field dimensions, it is concluded that such receptors are influenced by the viscoelastic properties of the bladder wall. Furthermore, as a result of the heterogeneity of the bladder wall, receptor field tension appears to offer a more precise relationship with the activity of bladder wall mechanoreceptors than does intravesical pressure.Key words: bladder distension, intravesical pressure, sacral rhizotomy, viscoelasticity.


2021 ◽  
Vol 49 (4) ◽  
pp. 1-10
Author(s):  
Min Li ◽  
Ziyu Zhao ◽  
Lijuan Cui

We examined the relationships among psychological empowerment, emotional labor strategies, and job burnout of frontline hotel employees with reference to conservation of resources theory and the job demands–resources model. A sample of 414 employees from a Chinese chain hotel was recruited to take part in this study. There was a significant negative correlation between psychological empowerment and job burnout for these frontline hotel employees. Furthermore, the emotional labor strategies of deep acting and automatic regulation played partial mediating roles in the relationship between psychological empowerment and job burnout, which has implications for the development of intervention mechanisms and work practices for addressing burnout.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yuan-yan Hu ◽  
Peng Wang ◽  
Xin-qiang Wang ◽  
Tian-qiang Hu

Purpose Despite concerns about the effect of internet addiction, little is known about how psychological suzhi impacts the internet addiction of college students. This paper aims to investigate the relationship between psychological suzhi and internet addiction among college students. Design/methodology/approach Using the college student psychological suzhi scale and internet addiction test, 2,070 college students from 11 universities in North China, East China, South China and Southwest China were tested. Findings The detection rate of internet addiction in this college sample of students was 18.8%. There was a significant negative correlation between students’ psychological suzhi and internet addiction (r = −0.408, p < 0.01). Hierarchical regression analysis showed that adaptability and individuality in psychological suzhi significantly negatively predicted college students’ internet addiction tendency (p < 0.001). Originality/value This study is the first to show a relationship between psychological suzhi and internet addiction in college students. In detail, the adaptability and individuality of college students’ psychological suzhi are protective factors related to internet addiction. The results also suggested that the authors can prevent and intervene in internet addiction by modifying college students’ adaptability and individuality.


2013 ◽  
Vol 8 (1) ◽  
pp. 155892501300800 ◽  
Author(s):  
Xupin Zhuang ◽  
Kaifei Jia ◽  
Bowen Cheng ◽  
Ketian Guan ◽  
Weimin Kang ◽  
...  

Solution blowing is an innovative process for spinning nanofibers from polymer solutions using high-velocity gas flow as fiber-forming driving force. Polyacrylonitrile (PAN) nanofibers were prepared using PAN solutions in N, N-Dimethylformamide and the morphologies of the fibers were examined using a scanning electron microscope. The process parameters including solution concentration, gas pressure supplied to the gas cavity, and solution-feeding rate were varied to investigate their effects on the morphologies of the fibers. PAN fibers were successfully prepared in the form of a nonwoven web. The fiber diameters mostly ranged in hundreds of nanometers and were affected by the process parameters. Results indicated that solution blowing is an alternative technique for manufacturing nonwoven webs that consist of micro- and nanofibers.


2020 ◽  
Vol 20 (1) ◽  
pp. 49-55
Author(s):  
Nareerut Jariyapunya ◽  
Blažena Musilová

AbstractBased on the mechanical properties of stretch fabrics and Laplace’s law, the mathematical models have been developed enabling one to determine the values of the relationship between the fabric strain and the circumferential stress depending on pressure and diameter of the body. The results obtained refer to the values of the parameters assessed for the initial phase of their exploitation, which allow us to preliminarily predict the values of these parameters.


2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Linhong Wang ◽  
Yan Ruan ◽  
Jianping Chen ◽  
Yunxiao Luo ◽  
Fan Yang

AbstractThis study aimed to noninvasively assess the relationship between the labial gingival thickness (GT) and the underlying bone thickness (BT) of maxillary anterior teeth by two digital techniques. A total of 30 periodontally healthy participants with 172 maxillary anterior teeth were enrolled. GT and BT were measured at 2, 4 and 6 mm apical to the cemento-enamel junction (CEJ) by two digital techniques: M1—cone-beam computed tomography (CBCT) and M2—digital intraoral scanning (DIS) combined with CBCT. The Pearson's correlation coefficient was calculated to determine the correlation between GT and BT. A significant negative correlation was identified between GT and BT at 2 mm apical to the CEJ for central incisors (CI), lateral incisors (LI), and canines (CA) both by M1 and M2, while a weak negative correlation at 4 mm apical to the CEJ was observed by M1 for CA. No significant correlation was found at other sites by both M1 and M2. The labial BT was < 1 mm in most cases (85% of CI; 97% of LI; and 90% of CA). Within the limitation of this study, it was concluded that GT and BT seemed to be negatively correlated at 2 mm apical to the CEJ. Therefore, caution is warranted when implant restoration at the esthetic area of the anterior teeth.


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