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Pervaporation (PV) of membrane separation technology has become an efficient approach to separate alcohols from aqueous solution. In this study, focusing on increasing the total flux and breaking the trade-off in PV, an ultra-thin and high flux poly-dimethyldiethoxysilane (PDMDES)/poly(vinylidene fluoride) (PVDF) composite membrane was prepared. By employing various means, the characterizations of PDMDES/PVDF composite membrane were extensively investigated and the promising results indicated the high hydrophobicity and good affinity to alcohols. To be specific, PDMDES selective layer with different thicknesses, the thinnest of which was approximately 265 nm, were fabricated, and better PV performance can be achieved in a thickness range of 1.10 ~ 1.69 [micro]m, The optimal PV performance of PDMDES/PVDF composite membrane was obtained in separating methanol from 5 wt% methanol/water solution at 40[degrees]C, resulting in a total high permeation flux of 5.38 kg [m.sup.-2] [h.sup.-1] and a higher pervaporation separation index (PSI) of 18.63 kg [m.sup.-2] [h.sup.-1]. Highlights * The ultra-thin and high flux composite membranes for alcohols recovery via pervaporation (PV) are prepared by using monomer in membrane preparation through a simple fabrication method. * The trade-off is broken in the ultra-thin composite membrane compared with traditional composite membrane. * The influence between membrane thickness and PV performance is investigated through experimental tests, and the results show that the ultra-thin composite membrane has a total high permeation flux of 5.38 kg [m.sup.2] [h.sup.-1]. KEYWORDS alcohols recovery, high flux, PDMDES, pervaporation performance, thin thickness, 1 | INTRODUCTION With the development of society, there has been an increasing demand for clean, non-polluting, efficient, and renewable energy which will gradually replace the traditional energy. (1) As [...]

The exchange of water vapor between high-concentration droplets and air significantly influences droplet deposition in the upper airway model during nebulizer use. This study employed a two-way coupled Eulerian–Lagrange method to quantify nebulized droplet evaporation and relative humidity (RH) variations within an idealized mouth–throat (MT) airway model, utilizing validated numerical models. The water vapor interaction between high-concentration droplets and inhaled air was computed using a multiplier based on the particle parcel method. Simulations of normal saline droplet flow inhalation in the MT airway were conducted under two environmental conditions: indoor (26.5 °C, RH = 50%) and warm and wet (30 °C, RH = 75%), with various inhalation flow rates mirroring previous experiments. Droplet deposition fractions (DFs) and deposition patterns were recorded. The results indicated that DF initially decreased and then increased with rising inhalation flow rates. The largest discrepancy between predicted and measured DFs was 10.86%. These findings support the theory that the balance between droplet evaporation and elevated air RH dictates the deposition of nebulized droplets in the airway. Additionally, simulations revealed that environmental conditions significantly affect droplet DF, with variations up to 20.78%. The deposition hotspot shifted from the anterior to the posterior pharynx. [ABSTRACT FROM AUTHOR]

Respiratory infections are currently understood to be caused by pathogens released through the nose or mouth of an infected individual, and subsequently transmitted to susceptible hosts. These pathogens are enclosed in liquid particles that are aerosolized from the respiratory tract during activities such as breathing, speaking, sneezing, and coughing. These particles vary widely in size, ranging from submicron to several microns. While past research has largely overlooked the human respiratory system, recent analysis has revealed that the actual structure of the nasal cavity significantly influences the prediction of aerosol transmission during exhalation. In this study, computational fluid dynamics (CFD) simulations were conducted to analyze the aerosol transmission generated during exhalation from the nasal and oral cavities. Realistic nasal and oral cavity structures were taken into account, and authentic temperature distributions were applied to the surfaces. Additionally, inhalation conditions for susceptible individuals were established to evaluate the risk of inhalation-generated exposure. Through various simulation scenarios, we separately discussed the impact of environmental wind speed, separation distance, and exhalation flow rate. The simulation results indicate that environmental wind amplifies the complexity of the flow field and the transmission and deposition of particles between two individuals. Under ambient wind velocities of 0.5 m/s and 1 m/s, it was observed that over 80% of the particles with a diameter of 1 µm inhaled through the nasal cavity accounted for the total deposition on the infected individual. Furthermore, high exhalation flow rates exhibited higher deposition ratios at close distances, in line with our expectations. Therefore, it is advisable to minimize close contact as much as possible during periods of frequent respiratory infections, and to wear masks in order to reduce the risk of inhalation exposure. Implications: During the activities such as breathing, speaking, sneezing, and coughing, liquid particles containing pathogens are aerosolized from the respiratory tract and are released from nose or mouth through the nebulization. In this study, we investigated the transmission of aerosols from human exhalation in the outdoor environment, innovatively taking the real oral-nasal structure and the active inhalation of vulnerable people into consideration, and explored the human-to-human transmission of respiratory viruses. The results are beneficial for public health assessment and policy development. [ABSTRACT FROM AUTHOR]

This study presents the first known successful in vitro measurement of both deposition fractions (DFs) and spatial deposition patterns of nebulized droplets in a realistic human upper respiratory tract model. The model, based on computed tomography scan data of a healthy adult male, accurately replicates the complex geometries of the oral and pharyngeal regions. Experiments were conducted using three different vibrating mesh nebulizer (VMN) systems at varying inhalation flow rates (15–60 l/min). Fluorescein-tagged saline solutions were nebulized, with deposition patterns—representing the spatial distribution of deposited droplets—visualized through ultraviolet fluorescence and DFs quantified based on the absorbance of the rinsate solution. Results show that the DFs and patterns are significantly influenced by flow rate, with deposition shifting from the oral cavity to the oropharyngeal region as flow rate increases. This study provides new insight into aerosol transport and deposition in realistic human airways and offers valuable data for optimizing nebulizer design and improving aerosol drug delivery efficiency in clinical applications. [ABSTRACT FROM AUTHOR]

Using surfactants to improve the particle size of Arctium lappa L. polysaccharides, and the optimal process conditions were obtained by single factor and response surface method. The structure of Arctium lappa L. polysaccharides before and after improvement was characterized by UV, Fourier transform infrared spectroscopy (FT-IR), particle size, and scanning electron microscopy. The results showed that the optimal process conditions for improving the particle size of Arctium lappa L. polysaccharides were as follows: The surfactant was Tween-80, the concentration was 0.5%, the vortex time was 16 s, and the pH was 5.67, under these conditions, the particle size of Arctium lappa L. polysaccharides was 6.19±0.14 nm. FT-IR analysis showed that the modification with surfactants did not change the structure of Arctium lappa L. polysaccharides. The UV spectrum showed a slight fluctuation at 280 nm, which might be attributed to the UV absorption of surfactants in this wave band. The particle size analysis showed that the grain size of improved Arctium lappa L. polysaccharides decreased significantly compared with unimprovement. The scanning electron microscopy results showed that the improved Arctium lappa L. polysaccharides exhibited a more ordered spherical structure and more uniform sizes. This study can provide a theoretical basis for the preparation of a polysaccharide system with controlled particle size. [ABSTRACT FROM AUTHOR]

This study aimed to investigate factors influencing fetal growth restriction (FGR) occurrence and assess the clinical significance of fetal cardiac parameters in FGR prediction. Methods: Pregnant women with clinically suspected FGR (n=179) and uncomplicated pregnancies (n=53) were included. All had undergone routine obstetric ultrasonography and fetal echocardiography. Umbilical artery flow (UAF) and fetal cardiac parameters (left atrial transverse diameter (LAd), right atrial transverse diameter (RAd), left ventricular transverse diameter (LVd), right ventricular transverse diameter (RVd), foramen ovale width, atrial septum diameter, interventricular septal thickness, left ventricular posterior wall thickness, right ventricular free wall thickness, aortic diameter, pulmonary artery diameter, mitral E velocity, mitral A velocity, tricuspid E velocity, tricuspid A velocity, aortic valve peak flow velocity, and pulmonary valve peak flow velocity) were detected. Follow up was conducted until birth, various fetal clinical parameters were collected: maternal body mass index (BMI), hypertensive disorders complicating pregnancy (HDCP), abnormal umbilical artery flow, placental or umbilical cord anomalies, low amniotic fluid volume, preterm birth, emergency cesarean delivery, maternal height, maternal age, gestational diabetes mellitus (GDM), hypothyroidism, assisted reproductive technology (ART), parity, and neonatal gender. Participants were categorized into confirmed FGR (n=119) and control (n=113) groups based on neonatal birth weight. Results: Significant differences were observed between groups in maternal BMI, HDCP, abnormal UAF, placental or umbilical cord anomalies, low amniotic fluid volume, preterm birth, and emergency cesarean delivery. FGR was positively related to abnormal UAF, placental or umbilical cord anomalies, preterm birth and emergency cesarean delivery and negatively to maternal BMI (r=− 0.276). Compared to the control group, the FGR group exhibited significantly larger RAd, RVd, RA/LA, and RV/LV. Conclusion: Fetal growth-restricted fetuses have enlarged right heart structures. Fetal cardiac examinations are valuable for early FGR diagnosis, potentially improving neonatal body weight and reducing adverse pregnancy outcomes. [ABSTRACT FROM AUTHOR]

The efficient delivery of nicotine in e-cigarette aerosols depends on the deposition efficiency of these aerosols within the respiratory tract. Accurate prediction of the hygroscopic growth of e-cigarette aerosols is pivotal to understanding their deposition. This study introduces a novel experimental approach to quantify the water activity coefficient, which is a crucial parameter governing the extent of hygroscopic growth in e-cigarette aerosols. Propylene glycol (PG) and vegetable glycerin (VG) are the primary components of e-liquid so that are used as the experimental subjects. Our findings reveal intriguing trends in the behavior of PG and VG mixtures. As relative humidity (RH) increases, these mixtures exhibit elevated equilibrium mass fractions of water accompanied by a decrease in water activity coefficients. Moreover, higher initial PG/VG mass ratios lead to decreased mass fractions of water and increased water activity coefficients. Notably, solution pH also impacts water activity coefficients, with higher pH levels corresponding to increased coefficients. The results reveal the factors which can affect the hygroscopic growth of e-cigarette aerosols, thus contributing to the understanding of the deposition of such aerosols within the respiratory tract. Moreover, the experimental apparatus proposed in this study provides a straightforward and reliable method to obtain hygroscopic parameters of multicomponent solutions. Copyright © 2024 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

The coronavirus disease 2019 (COVID-19) pandemic, which caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), lead to a crisis with devastating disasters to global public economy and health. Several studies suggest that the SARS-CoV-2 nucleocapsid protein (N protein) is one of uppermost structural constituents of SARS-CoV-2 and is relatively conserved which could become a specific diagnostic marker. In this study, eight single domain antibodies recognized the N protein specifically which were named pN01–pN08 were screened using human phage display library. According to multiple sequence alignment and molecular docking analyses, the interaction mechanism between antibody and N protein was predicted. ELISA results indicated pN01–pN08 with high affinity to protein N. To improve their efficacy, two fusion proteins were prepared and their affinity was tested. These finding showed that fusion proteins had higher affinity than single domain antibodies and will be used as diagnosis for the pandemic of SARS-CoV-2. [ABSTRACT FROM AUTHOR]