Search

Background: Circuit clotting remains a major problem during continuous kidney replacement therapy (CKRT), particularly in patients with contraindications to anticoagulant use. We hypothesized that the different options of alternative replacement fluid infusion sites might affect circuit lifespan. However, research‐based evidence supporting an optimal replacement fluid infusion strategy is limited. Therefore, we aimed to evaluate the effect of three dilution modes (pre‐dilution, post‐dilution, and pre‐ to post‐dilution) on circuit lifespan during continuous veno‐venous hemodiafiltration (CVVHDF). Methods: This prospective cohort study was conducted between December 2019 and December 2020. Patients requiring CKRT were enrolled to receive pre‐dilution, post‐dilution, or pre‐ to post‐dilution fluid infusion with CVVHDF. The primary endpoint was circuit lifespan, and the secondary outcomes included the clinical parameters of patients, such as changes in serum creatinine (Scr) and blood urea nitrogen (BUN) levels, 28‐day all‐cause mortality, and length of stay. For all patients included in this study, only the first circuit used was recorded. Results: Among the 132 patients enrolled in this study, 40 were in the pre‐dilution mode, 42 were in the post‐dilution mode, and 50 were in the pre‐ to post‐dilution mode. The mean circuit lifespan was significantly longer in the pre‐ to post‐dilution group (45.72 h, 95% CI, 39.75–51.69 h) than in the pre‐dilution group (31.58 h, 95% CI, 26.33–36.82 h) and the post‐dilution group (35.20 h, 95% CI, 29.62–40.78 h). There was no significant difference between the pre‐ and post‐dilution group circuit lifespan (p > 0.05). Kaplan–Meier survival analysis revealed a significant difference between the three dilution modes (p = 0.001). No significant differences were observed in terms of changes in the Scr and BUN levels, admission day, and 28‐day all‐cause mortality among the three dilution groups (p > 0.05). Conclusion: The pre‐ to post‐dilution mode significantly prolonged circuit lifespan but did not reduce Scr and BUN levels, compared with the pre‐dilution and post‐dilution modes during CVVHDF when no anticoagulants were used. [ABSTRACT FROM AUTHOR]

This study proposes a novel variable air pressure supply structure based on the electromagnetic effect. This structure can be implemented in various soft robots driven by air pressure, including pneumatic artificial muscles, pneumatic soft grippers, and other soft robots. The structure's main body comprises a hollow circular tube, a magnetic piston arranged in the tube, and an electromagnetic solenoid nested outside the tube. The electromagnetic solenoid is designed with special winding and power supply access modes, generating either an attractive force or a repulsive force on the magnetic piston. This solenoid conforms with the magnetic piston expectation in the tube by changing the polarity direction. The interior of the whole structure is a closed space. The gas is conveyed to the soft robot by the gas guide hoses at the two ends of the structure, and the expansion energy of the compressed gas is fully utilized. Then, the gas supply pressure is controlled to drive the robot. The mathematical model of the structure is established based on the analysis of the electromagnetic force and gas pressure on the piston. The simulation results show that the structure's inherent vibration characteristics under various parameters align with expectations. The real-time automatic optimization of the controller parameters is realized by optimizing the incremental proportional-integral-derivative (PID) controller based on a neural network. The simulation results show that the structure can meet the application requirements. The experimental results show that the proposed gas supply structure can provide a continuous pressure supply curve with any frequency in a specific amplitude range and has an excellent tracking effect on the sinusoidal-like pressure curve. [ABSTRACT FROM AUTHOR]

In order to investigate the effects of thermally conductive fillers on the pyrolysis and smoke release characteristics of tobacco granules under heating and non-combustion conditions, a thermal conductivity tester, a thermogravimetric analyzer (TGA) and a cone calorimeter (CONE) were used to study the influences of thermally conductive fillers of different contents and types on the thermal conductivity, pyrolysis and smoke release of the prepared tobacco granules. The results showed that: 1) With the increase of CaCO3 powder content, the thermal conductivity of tobacco granules increased. The thermal conductivity decreased slightly due to self-aggregation of the filler when the CaCO3 addition reached 20%. Whiskers could effectively restrain the self-aggregation of the fillers in the substrate. The effects of SiC on thermal conductivity were more significant than CaCO3. 2) Compared with the control, the differential thermal gravity(DTG)curve of the tobacco granules shifted towards the low temperature region after adding thermally conductive filler. The higher the thermal conductivity of the filler, the larger the curve shifting range and the higher the maximum weight loss rate were. Under different heating conditions, the DTG curve of the sample with the largest thermal conductivity was always on the low temperature side of the control. With the increase of heating rate, the difference of the pyrolysis characteristic parameters between the sample and the control reduced gradually, and the effects of thermal conductivity difference on the pyrolysis process of tobacco granules lessened. 3) Compared with the control, the initial smoke release rate of the tobacco granules increased after adding thermally conductive filler; the maximum smoke release rate increased with the increase of thermal conductivity, and the smoke release was aggregated. The release rates of CO and CO2 increased significantly with the increase of the thermal conductivity of the filler, indicating that the pyrolysis degree of tobacco granules was enhanced. However, the promotion of the thermal conductivity could easily cause heat accumulation and tobacco granule combustion. [ABSTRACT FROM AUTHOR]

In order to develop key flavors for heated tobacco products, tobacco leaves from domestic and overseas were selected to prepare dry distilled flavor samples. The molecular distillation technology was applied to further refine flavor samples to obtain targeted light and heavy fractions. GC-MS and thermogravimetric analyses were used to investigate the differences in components and pyrolysis behaviors of the dry distilled flavor samples before and after molecular distillation. The results showed that: 1)Mass fractions of nicotine, pyridines, furfurals and ketones in the dry distilled flavor from Brazil leaf were higher, while those of furans and pyrones were lower. The dry distilled flavor samples prepared from Hunan, Henan and Yunnan tobacco leaves all presented higher mass fractions of characteristic components. 2)The light fractions obtained from the dry distilled flavor samples from Brazil and Yunnan tobacco leaves by molecular distillation contained greater mass fractions of nicotine and volatile aroma components, and could be thermal decomposed and released below 220 °C completely. The heavy fractions contained higher mass fractions of non-volatile components, and their corresponding thermal decomposition process was distributed in the temperature range of 110~350 °C. 3)The applications of tobacco dry distilled flavor samples and their molecular distillation products promoted the sensory quality of heated tobacco products to a certain degree, mainly in the strength, aroma quality, aroma quantity and taste. The promotion effects of the light fractions were more significant, while the heavy fractions effectively improved the consistency of aroma during smoking. [ABSTRACT FROM AUTHOR]

To study the influences of types and contents of aerosol carriers on pyrolysis and smoke release of tobacco granules, wet granulation of tobacco was prepared with different glycerin/propylene glycol ratios. The granule samples were studied with thermogravimetric-Fourier transform infrared (TG-FTIR), cone calorimeter(CONE), and steady-state pyrolysis. The aerosol particle size formed was analyzed using an impact particle analyzer. The results showed that: 1) With the increase of propylene glycol, the initial weight loss rate and total weight loss of tobacco granules increased significantly. The main weight loss temperature region shifted towards lower temperature regions. The main thermal weight loss temperature range prepared with single aerosol carrier was narrower than that with the mixed aerosol carrier. Moreover, the weight loss rates at the oxidative pyrolysis stage were inversely proportional to the glycerin content. 2) The infrared spectra indicated that tobacco granules began releasing aerosol carrier from 100 °C when propylene glycol was added. With the increase of propylene glycol content, the releases of carbohydrates, phenols, organic acids, amines (eg. nicotine), alkanes, olefins and other compounds changed in a complex manner. At the oxidative pyrolysis stage, the main gaseous products from tobacco granules containing glycerin were CO2, H2O, CO and carbonyl compounds. With the increase of propylene glycol content, the characteristic peaks of hydrocarbons and carbonyl compounds were strengthened, and the intensities of characteristic CO and CO2 peaks increased at 350 and 400 °C respectively, suggesting a more severe pyrolysis of tobacco. 3) With the increase of propylene glycol, the range of smoke release time decreased, the total amount of smoke release reduced. The tobacco granules prepared with 30% (mass fraction) propylene glycol had the slowest initial smoke release rate. With the increase of glycerin content, the release rates of CO and CO2 from tobacco granule decreased. 4) With the increase of glycerin content, the total mass of aerosol increased, while the mean particle size of aerosol decreased first and then increased. [ABSTRACT FROM AUTHOR]

In order to reveal the effects of cigarette burning rate on its ash integrity, ash color value, ash crack rate, ash shrink rate, burn line width, burn line uniformity, burning rates of 46 cigarette samples were measured using machine vision technology under the ISO smoking regime. Statistical analyses were employed to investigate the correlation between the ash integrity and burning rate of the cigarettes. The results showed that: 1) Puffing was an important factor affecting the ash integrity of the test cigarettes, and the shrink rate and crack rate of ash column also increased. The burn line became wider and more irregular and the ash color was whiter during puffing. The seam of cigarette paper improved the ash integrity of the ash column, and effectively reduced the large increase of the ash crack rate of the section with single layer cigarette paper caused by puffing. 2) The variations of ash color value and the burn line uniformity were small, the variations of the burn line width, burning rate and ash shrink rate were medium, and the variation of ash crack rate was large. 3) The burning rate significantly positively correlated with ash color value and significantly negatively correlated with ash crack rate, ash shrink rate and burn line width. However, its correlation with the burn line uniformity was not significant. 4) With the increase of cigarette burning rate, the value of ash color increased first and then tended to be stable, the ash crack rate decreased first and then increased, and the ash shrink rate and burn line width decreased gradually. [ABSTRACT FROM AUTHOR]

Objective: Acute kidney injury (AKI) is one of common complications of wasp/bee stings. Phospholipase A 2 (PLA 2 ) is a vital pathogenic composition of wasp/bee venom. We aimed to investigate the role of complement mediated mitochondrial apoptosis in PLA 2 induced AKI., Materials and Methods: PLA 2 induced AKI model was established by injecting PLA 2 into via tail vein on mice. The pathological changes and the microstructural changes of kidney, complement activation, inflammation and apoptosis were detected in vitro and in vivo respectively., Results: The results showed that PLA 2 induced AKI models were successfully established in vivo and vitro. Compared with control, serum creatinine and urea nitrogen levels were elevated. Complement system activation and mitochondrial damage were observed. Expressions of IL-6, TNF-α, cleaved caspase-3 and cleaved caspase-9, and Bax/Bcl-2 increased in PLA 2 induced AKI models. TNF-α/NF-κB signaling pathway activation in AKI models., Conclusion: In the present study, PLA 2 induced AKI model was first successfully established to our knowledge. The role of complement mediated mitochondrial apoptosis pathway in renal tubular epithelial cells in PLA 2 induced AKI were verified in vitro and vivo., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Ltd.)