Atomization Device Research Articles

Study on the influence of aerosol atomization by ultrasonic atomization on coal spontaneous combustion

ABSTRACT Influenced by the complex environment and the nature of process materials in goaf, the prevention and control of spontaneous combustion of coal (CSC) in the deep part of goaf were facing many difficulties. To investigate the performance of ultrasonic atomized aerosols, a series of atomization experiments were conducted using a self-developed ultrasonic atomization device. The main conclusions are as follows: under the same atomization conditions, the atomized particle sizes of several inhibitors (except PAS-W) are concentrated in the <8 μm range, with a content of more than 88%, indicating that the aerosol particles produced by ultrasonic atomization are small in size and uniform in distribution. Compared with water and MgCl2 inhibitors, aerosol particles produced by PAS-W are less likely to pass through the voids of the coal body, and have poorer permeability and diffusivity. As the temperature increases, the viscosity and surface tension of the inhibitor decrease, and the percentage of aerosol particles with particle size <8 μm produced by ultrasonic atomization is more than 88%, indicating that the atomization effect is improved. After increasing the temperature, the contact angle between PAS-W inhibitor and coal reduces from 54.7° to 40.8°, and the wettability is better. Compared with raw coal, the final temperature of the PAS-W aerosol treated coal sample is delayed 21.86°C, and has significant retarding property. When the wind speed is 3 m/s, the effect of PAS-W aerosol particle generation, permeability, and particle size distribution is the best. The results of the study are of great significance in improving the ultrasonic atomized aerosol fire prevention technology and realizing large-scale CSC prevention in goaf.

Supersonic coaxial aerodynamic atomization dust removal technology

The high concentration of respirable dust pollution created during coal mining has long been known to be harmful to employee health. A water absorbing atomization device has certain advantages when spray trapping particle sizes of PM2.5–10. To further improve the PM0–2.5 trapping efficiency, supersonic coaxial pneumatic atomization dust removal technology has been developed. The effects of fog droplet characteristics on the instantaneous diffusion of dust were studied by numerical simulation and macro- and microexperiments for the first time, and the coupling characteristics of fog droplets and dust fields were obtained. The results show that with increasing aerodynamic pressure, the supersonic range extends along the axis toward the nozzle outlet, and the average velocity in the tube increases. Under different pressures, the droplet particle size in the supersonic coaxial atomizing nozzle is <6 μm and decreases with increasing aerodynamic pressure. When a droplet effuses from the nozzle, the transonic distribution of the flow field causes the droplet velocity to increase first and then decrease under the drag force. The droplet field characteristic distribution of supersonic coaxial atomization is determined by droplet evaporation, condensation, and migration. Under the same pressure, with increasing spray distance, the distribution of the droplet particle size increases in a stepwise manner, and the droplet velocity decreases according to an exponential function so that the droplet field produces a high-speed fine fog area. The range of droplets with higher velocities and smaller particle sizes is mainly influenced by migration and increases with increasing pressure. The coupling effect droplet field and dust field can be characterized by the instantaneous dispersion of dust and are determined by the distribution characteristics of the fog droplet field. The large range of high-speed fine fog produced by supersonic coaxial atomization technology easily traps respirable dust, and the classification efficiency of PM0–2.5 reaches 90%. In this study, a new dynamic microfog dust trapping technique was proposed, and a new method of instantaneous sampling combined with a microscopic dispersion test was adopted to characterize the temporal and spatial distributions of dust fields affected by fog droplet fields, reveal the generation of dynamic microfog and the mechanism of dust trapping, enrich the theory of fine dust trapping, and provide technical support for the safe production and utilization of coal.

A Comparative Study of Parent and Child Perspectives on Using the Intranasal Mucosal Atomization Device for Behavior Management in Pediatric Dental Sedation.

Background Dental anxiety in children often necessitates sedation for effective treatment. Different methods of sedation have proved to be beneficial. However, intranasalsedation provides a needleless, rapid drug delivery method that bypasses hepatic metabolism. Intranasal sedative drugs can be delivered using a mucosal atomization device (MAD). This study aimed to find the opinions, beliefs, and existing knowledge of parents and children regarding intranasal sedation and the method of drug delivery through MAD. Materials and methods The study comprised 50 parents, aged 20 to 50, who came in with a single child, aged five to nineyears. In separate rooms, parents and kids were each shown a video about the use of the intranasal sedation technique with MAD as a pharmaceutical help during routine dental procedures. After the video presentation, each participant was required to complete a pretested self-made questionnaire with 21 questions and multiple-choice options. The chi-square test was used in the statistical analysis of the completed questionnaires (P < 0.05). Paired t-test was used for behavior assessment of the children before and after intranasal sedation. Results A significant correlation between parental socioeconomic status and acceptance of intranasal sedation was observed. Parents with higher education levels exhibited a greater level of acceptance (P = 0.000). Parents whose children had prior dental experiences were more likely to view intranasal sedation as a safe option (P = 0.038). Additionally, a significant proportion of previously sedated children expressed willingness to undergo treatment using intranasal sedation. Evaluation of children's behavior before and after treatment revealed a notable improvement, indicating the effectiveness of intranasal sedation (P = 0.000). Conclusion The study thoroughly investigated how parents and children view intranasal sedation via MAD. It revealed a positive perception of safety and trust among parents regarding this method for pediatric dental procedures.

Experimental Study on Atomization Characteristics of Swirl Nozzle under Annular Airflow Impingement

Pressure nozzles are widely used in spray drying and other industries. In order to improve the atomization characteristics of pressure cyclone nozzles, a new type of annular jet gas impingement atomization device is developed. We use high-speed imaging and digital image processing and other methods to analyze the spray characteristics of the different annular device configurations (using four, six, and eight tubes) and under different gas–liquid mass flow rates. It is shown that with an increase in the Air–Liquid mass Ratio (ALR), the liquid film breakup process changes from undulating sheet breakup to perforated sheet breakup and the breakup length decreases. The breakup length decreases the most under the condition of six-tube airflow with the range of 31–55%, while the Sauter mean diameter (SMD) basically does not change. With the increase in ALR and the Weber number of liquid (Wel), the droplet size distribution becomes more uniform. The spray characteristics of the atomizer assisted by gas jets reaches the best state when Wel = 4596.3 and m˙g = 1.97 g/s. The experimental conclusions have some guiding significance for the design and optimization of the atomization devices in spray drying towers.

Effective dose of intranasal remimazolam for preoperative sedation in preschool children: a dose-finding study using Dixon's up-and-down method.

Most preschool children are distressed during anesthesia induction. While current pharmacological methods are useful, there is a need for further optimization to an "ideal" standard. Remimazolam is an ultra-short-acting benzodiazepine, and intranasal remimazolam for pre-induction sedation may be promising. This study included 32 preschool children who underwent short and minor surgery between October 2022 and January 2023. After pretreatment with lidocaine, remimazolam was administered to both nostrils using a mucosal atomizer device. The University of Michigan Sedation Score (UMSS) was assessed for sedation 6, 9, 12, 15, and 20min after intranasal atomization. We used Dixon's up-and-down method, and probit and isotonic regressions to determine the 50% effective dose (ED50) and 95% effective dose (ED95) of intranasal remimazolam for pre-induction sedation. Results: Twenty-nine pediatric patients were included in the final analysis. The ED50 and ED95 of intranasal remimazolam for successful pre-induction sedation, when processed via probit analysis, were 0.65 (95% confidence interval [CI], 0.59-0.71) and 0.78mg/kg (95% CI, 0.72-1.07), respectively. In contrast, when processed by isotonic regression, they were 0.65 (95% CI: 0.58-0.72mg/kg) and 0.78mg/kg (95% CI: 0.69-1.08mg/kg), respectively. At 6min after intranasal remimazolam treatment, 81.2% (13/16) of "positive" participants were successfully sedated with a UMSS ≧ 1. All the "positive" participants were successfully sedated within 9min. Intranasal remimazolam is feasible for preschool children with a short onset time. For successful pre-induction sedation, the ED50 and ED95 of intranasal remimazolam were 0.65 and 0.78mg/kg, respectively.

Effect of particle size distribution on the transmission efficiency of atomized water to the tracheal tube

Ultrasonic atomization is a widely used technology. As the atomization device, lead zirconate titanate (PZT) and lithium niobate (LN) are comparatively investigated through experimental and numerical schemes. However, knowledge on a profitable scheme by which to efficiently deliver the atomized particles into the tracheal tube remains unclear. In this study, the physical difference of the transmission efficiency of water particles atomized by PZT and LN devices was measured. The water particles atomized by PZT and LN were injected into a human airway model including a nasal cavity and bronchial tube. The distribution of the amount of transmitted particles deposited at each of the monitoring positions was then estimated using the results of image analysis of color intensity. As a result, the atomized particles of the PZT device, which produced larger particles than the LN device, were more strongly affected by inertia and tended to be deposited at the area closer to the entrance of the nasal cavity. In contrast, the particles produced by the LN device tended to be transmitted deeper into the trachea. The experimental results indicated that the particle size distribution of PZT and LN, which have quite different maximum sizes of particles, largely influences the spatial distribution characteristics of particle deposition along the airway from the nasal cavity to the trachea.

Sensory Quality and Shelf-life Enhancement of Vegetables Irradiated with Mid- infrared

Vegetables play a highly significant role in our daily dietary intake. The inherent perishability of vegetables restricts their exportation and necessitates early consumption. Consequently, ongoing research endeavors aim to develop technologies that can extend the shelf life of vegetables. In this study, we subjected vegetables to irradiation using a mid-infrared ray with a wavelength of 2-6 μm. To achieve this, we utilized a recently invented atomizer device termed MIRGA (Mid-infrared generating atomizer). During spraying of MIRGA, the contained chemical solution is expelled at a determined plunger pressure, leading to the oscillation of ions in the sprayed mist, thereby generating 2-6 μm mid-infrared. This mid-infrared energy exerts its influence on the chemical bonds within the vegetable molecules, resulting in improvements in taste, aroma, overall sensory satisfaction, and shelf life. Notably, the shelf life of vegetables increased by a range of 16-900% and 9-314% (duration) when stored at room temperature and refrigerated, respectively. These beneficial alterations, which are mediated by the 2-6 μm mid-infrared ray, are substantiated through a variety of instrumentation and sensory expert panel results that elucidate the physicochemical characteristics of the vegetables. Employing MIRGA in various domains of food technology represents a plausible and viable option.

Intranasal Lidocaine Administration via Mucosal Atomization Device: A Simple and Successful Treatment for Postdural Puncture Headache in Obstetric Patients.

(1) Background: Postdural puncture headache (PDPH) remains a serious complication in obstetric patients. While the epidural blood patch represents the current gold standard in therapy, a growing number of alternative measures are thought to be beneficial for clinical management. The purpose of this study was to retrospectively analyze the efficacy of intranasal lidocaine administration to treat PDPH in obstetrics at our university hospital; (2) Methods: A retrospective analysis of the medical records of patients with PDPH has been performed focusing on the techniques of administration, dosing, treatment duration, impact on pain intensity as well as side effects of intranasal lidocaine; (3) Results: During the study period, 5610 obstetric patients received neuraxial anesthesia, of whom 43 (0.77%) developed PDPH. About one third of the patients with PDPH after spinal anesthesia (n = 8), epidural anesthesia (n = 5) or both (n = 2) were treated with intranasal lidocaine. Lidocaine was administered either via gauze compresses (GC, n = 4), a mucosal atomization device (MAD, n = 8) or with a second-line mucosal atomization device due to low gauze compress efficacy (n = 3). All patients treated with lidocaine refused the epidural blood patch. Nebulization of lidocaine resulted in a significant reduction in pain intensity after the first dose (p = 0.008). No relevant side effects developed except sporadic temporal pharyngeal numbness. The utilization of the mucosal atomization device averted the necessity for an epidural blood patch, whether employed as the primary or secondary approach; (4) Conclusions: Our data imply that the mucosal atomization device enhances the efficacy of intranasal lidocaine administration in obstetric patients suffering from PDPH.

Evaluation of the use of intranasal atipamezole to reverse the sedative effects of xylazine in dogs.

To assess the ability of intranasal atipamezole to reverse sedative effects of xylazine in dogs. Prospective proof-of-concept study. University research laboratory. Six healthy, staff-owned dogs. Dogs were sedated with 1.1mg/kg of xylazine intravenously. The sedation score of each dog was recorded every 5minutes until they achieved a sedation score of >13/21 for 3 readings. Once achieved, 0.3mg/kg of atipamezole was administered intranasally using a mucosal atomization device. Sedation scores continued to be recorded every 5minutes until successful reversal was achieved (<4/21). Average times to standing and normal wakefulness after administration of intranasal atipamezole were 6minutes, 30seconds and 7minutes, 20seconds, respectively. Intranasal atipamezole successfully reversed the sedation effects of xylazine. The findings of this study provide justification for future controlled prospective studies into the potential use of intranasal atipamezole in a variety of settings including exposure to xylazine in operational canines as well as bioavailability studies for optimal dosing.

169 Effects of Intranasal Prebiotics, Probiotics and Synbiotics on the Nasopharyngeal Microbiota of Feedlot Cattle

Abstract The emergence of antibiotic-resistant pathogens associated with bovine respiratory disease (BRD) presents a significant challenge to the beef industry, as antibiotic administration is commonly used to prevent and control BRD in feedlot cattle. Alternatives to antibiotics are therefore needed as part of new management strategies to reduce antibiotic use and BRD. We recently developed probiotics comprised of six Lactobacillus strains that inhibited the BRD pathogen Mannheimia haemolytica, and conferred longitudinal modulation of the nasopharyngeal microbiota in calves when a single dose was administered intranasally. In the present study, we evaluated the effects of a prebiotic (lactulose) alone and in combination with probiotic bacteria on the nasopharyngeal microbiota of feedlot calves. The probiotic bacteria consisted of 6 strains of Lactobacillus originated from the nasopharyngeal microbiota of healthy feedlot cattle. The calves were assigned to one of five treatments (n = 8 calves per treatment) and house individually: 1) Syringe-Probiotic group received intra-nasal probiotic cocktail via syringe that was attached to a 25-cm long catheter; 2) MAD-Probiotic group received an intra-nasal probiotic cocktail with a mucosal atomization device; 3) MAD-Synbiotic group received an intra-nasal probiotic cocktail containing prebiotic lactulose (0.5%, suspended in PBS) with a mucosal atomization device; 4) MAD-Prebiotic group received intra-nasal prebiotic lactulose (0.5%, suspended in PBS) with a mucosal atomization device; and 5) MAD-PBS (Control) group received only PBS with a mucosal atomization device. Utilization of a syringe versus mucosal atomization device was tested to determine if mode of probiotic bacteria delivery had an impact on the respiratory microbiota. Deep nasopharyngeal swab samples were collected on day 0 (24 h prior to treatment administration), 2 (24h post intranasal treatment), 3, 6, 9 and 14 days. Genomic DNA was extracted from the swabs and processed for nasopharyngeal microbiota characterization by sequencing 16S rRNA gene amplicon sequencing. When administered to calves intranasally, lactulose had no effect on the diversity or community structure of bacteria (PERMANOVA, P &amp;gt; 0.05) and had limited prolonged effect on specific genera. In addition, when administered as a synbiotic with a multi-strain cocktail of Lactobacillus probiotic bacteria, colonization was not enhanced. However, probiotic bacteria did affect the bacterial structure of NP bacteria (P &amp;lt; 0.05) and increased microbial network interactions. The strongest effect was observed when probiotic bacteria were administered alone, using an atomization device. Overall, this study showed that the bovine respiratory microbiota can be altered by administration of probiotics and may therefore provide new opportunities to enhance microbiome-mediated respiratory resistance against BRD pathogens. While colonization and growth of probiotic bacteria in the respiratory tract are unlikely to be modified by prebiotics delivered in PBS solution, the delivery method and time of application are important factors that need to be evaluated to have optimal efficacy of biologicals.

Influence of aerodynamic pressure on dust removal by supersonic siphon atomization

At present, there are many problems in coal mine operation, such as formation of large amounts of dust, complex dust migration behavior, severe respiratory harm, poor on-site performance of spray dust removal technology under windy conditions, and low collection efficiency of respirable dust. To solve the above problems, the finite element method of computational fluid dynamics (CFD) was used. The Spalart-Allmaras turbulence model of COMSOL software and the tracking module for atomized particles broken by droplets were used. They were combined with the Fraunhofer diffraction principle to study the distributions of the velocity of the airflow field, droplet size, droplet velocity and wind resistance for a supersonic water siphonic atomization device. The influence of the above factors on dust removal at different aerodynamic pressures was studied experimentally. The relationships between spray characteristics, flow field velocity distribution, dust removal effect and spray characteristics were revealed. The research showed that with increasing pressure, the supersonic component accounted for an increased proportion of the flow field inside the nozzle, average velocity of the flow field increased, atomization efficiency increased, droplet particle size decreased, and droplet velocity increased. The particle size of the droplets first increased, then decreased and then increased with increasing spraying distance. Additionally, the range of high-speed fine droplet size fog increased with increasing pressure. At the same transverse wind speed, with increasing pressure, the deflection point of the fog field moved backward, and the wind resistance of the spray was enhanced. With the increase in aerodynamic pressure, the dust isolation and negative pressure effect of spray and the dust collection efficiency increased, and there was an optimal value for dust removal in a limited space. The reason was that when the pressure increased to a certain extent, the air flow reversed in the coil at the bottom of the limited space, which blew the dust that was not aggregated at the bottom away from the area where dust was falling. Thus, the dust was entrained in fog droplets but could not be removed from the air flow. The dust dispersion in the air flow after purification differed greatly at different pressures because the removal efficiency of dust in the 2.5–10 μm particle size range was mainly affected by the pressure. In a field study of a fully mechanized mining face, the fog curtain formed by the device covered the whole section under the condition of airflow disturbance with large transverse velocity, and the comprehensive respirable dust removal efficiency of the working area reached 92.3%. Thus, this method showed good wind resistance and dust removal performance. The study of this technology can provide a clean working environment and theoretical guidance for the safe production of coal in the future, especially for fully mechanized mining faces.

Composition design of high Bs Fe-based amorphous powders with good sphericity

Fe83SixByC(17-x-y) has good glass forming ability (GFA), and high saturation magnetic induction (Bs), and spherical amorphous powder can be prepared using a gas–water coupling atomization (GWC) device. Herein, the effects of metalloid elements (B, C, Si and P) on the thermal parameters and magnetic properties of the Fe83SixByC(17-x-y) powder are discussed. The research conclusion shows that the Fe83Si2.5B11.5C3 amorphous powder exhibits the best comprehensive performance. Through the Lorentz microscope pattern of Fe83Si2.5B11.5C3 amorphous powder, magnetic domains walls are observed to gather and interlace in the outer region of the particle. The Fe83Si2.5B11.5C3 amorphous powder exhibits a high initial crystallization temperature (Tx1), followed by a ΔTx of 27 ℃, and then crystallization completion at 561.1 ℃. Some clusters or primary crystals are produced in the amorphous matrix after annealing at 520 ℃ (below Tx1 534 ℃) for 1 h. A further increase in the annealing temperature to 570 ℃ (beyond Te1 561.1 ℃) causes the precipitation of a large amount of crystalline phase α- Fe (Si) and hard magnetic phase Fe2B, thereby resulting in the rapid deterioration of the magnetic properties of the amorphous powder.

Intranasal Atomization of Ketamine, Medetomidine and Butorphanol in Pet Rabbits Using a Mucosal Atomization Device

A non-invasive method of drug delivery, intranasal atomization, has shown positive results in human medicine and in some animal species. The objective of this study was to evaluate the effects of intranasal atomization, compared to intramuscular administration, of a mix of anesthetic drugs in pet rabbits. In total, 104 mixed-breed pet rabbits, undergoing various types of surgery, received a combination of ketamine, medetomidine, and butorphanol (20, 0.4, and 0.2 mg/kg) by intranasal atomization using a Mucosal Atomization Device (Group MAD) or intramuscular administration (Group IM). When required, isoflurane was dispensed through a face mask. At the end of the procedures, atipamezole was administered using the same routes in the respective Groups. There were no differences in time to loss of righting reflex between the groups, while differences were found for the need for isoflurane (higher in Group MAD) and recovery time, occurring earlier in Group MAD. The results suggest that intranasal atomization of a combination of ketamine, medetomidine, and butorphanol produces a lighter depth of anesthesia in pet rabbits, compared to intramuscular administration. Intranasal atomization can be performed to administer sedative and anesthetic drugs, avoiding the algic stimulus related to the intramuscular inoculation of drugs.

Adenoviral vector vaccines are effective mucosal booster modalities to elevate systemic and establish mucosal immunity against SARS-CoV-2

Abstract Licensed SARS-CoV-2 vaccines induce robust systemic immune responses, but mucosal immunity in the respiratory tract in form of secretory immunoglobulin A (IgA) or tissue-resident memory T cells (TRM) is not established. Inducing such front-line immunity by mucosal boosting might reduce the individual risk of breakthrough infections and thereby likely mitigate infection dynamics on population level as well. The following project evaluates preclinical and licensed adenoviral vector (Ad) platforms as mucosal SARS-CoV-2 boosters. We show that nasal instillation of Ad5- and Ad19a-Spike following a systemic DNA or mRNA priming results in strong systemic and mucosal immunity in mice. In contrast to two intramuscular injections with a licensed mRNA vaccine, the mucosal boost with Ad vectors induced CD103 +CD69 +tissue-resident memory CD8 +T cells and high levels of Spike-specific IgA in the respiratory tract as well as an enhanced mucosal neutralization of variants of concern. Moreover, the protective efficacy of the mRNA prime/intranasal Ad5 boost strategy was not inferior to two intramuscular mRNA immunizations. In a more translational approach, we employed Janssen’s Ad26.COV2.S as a mucosal booster delivered by a medical mucosal atomization device after a systemic mRNA prime of mice. Concerning systemic responses, the mucosal boost was similarly immunogenic compared to an intramuscular boost with the same vaccine. However, only a mucosal delivery provoked TRM and IgA in the respiratory tract as well as a robust mucosal neutralization of Omicron variants. In conclusion, a mucosal booster immunization is a promising approach to establish mucosal immunity in addition to systemic responses in an mRNA vaccine-primed population.

Effect of Age and Head Position on Total and Regional Aerosol Deposition in Three-Dimensional Models of Human Intranasal Airways Using a Mucosal Atomization Device.

Background: This study examined the effect of age and head position on total and regional deposition of aerosol delivered by a mucosal atomization device (MAD™) in three-dimensional (3D) models of the intranasal airways of an 18-, 5-, and 2-year-old human. Models consisted of four pieces: anterior nose and nasal cavity that was divided horizontally into upper, middle, and lower thirds. Methods: Models were tested six times at supine, supine with head backward at 45° (supine45), and sitting with head backward at 45° (sitting45). The MAD delivered saline/fluorescein aerosol into model nostrils, during static airflow. Model pieces were tested for fluorescence using a fluorometer, and deposition calculated as percent fluorescence per piece relative to its reference. Total deposition (four pieces combined) and regional deposition (four pieces separately) were calculated. Results: Age and head position had little effect on total deposition. In contrast, deposition in the upper and middle third supine45 and in the lower third sitting45 was significantly different in the 2-year-old model, compared with the two older models. In addition, some head positions significantly increased deposition in the upper, middle, and lower thirds within each model, compared with other positions. Upper deposition was significantly greater at supine45, compared with sitting45 (18-year-old) and supine45, compared with supine and sitting45 (5-year-old). Middle deposition was significantly greater at supine and supine45, compared with sitting45 (2-year-old). Lower deposition was significantly greater at sitting45, compared with supine45 (18-year-old); supine and sitting45, compared with supine45 (5-year-old); and sitting45, compared with supine45 and supine (2-year-old). Conclusions: Age and head position significantly affected regional deposition of aerosol delivered by the MAD in these 3D models. Such models might be used to study other methods for targeting intranasal regions with aerosolized medications in children and adults.

Development of air-assisted atomization device for the delivery of cells in viscous biological ink prepared with sodium alginate

Skin wounds, especially large-area skin trauma, would bring great pain and even fatal risk to patients. In recent years, local autologous cell transplantation has shown great potential for wound healing and re-epithelialization. However, when the cell suspension prepared with normal saline is delivered to the wound, due to its low viscosity, it is easy to form big drops in the deposition and lose them from the wound bed, resulting in cell loss and uneven coverage. Here, we developed a novel air-assisted atomization device (AAAD). Under proper atomization parameters, 1% (w/v) sodium alginate (SA) solution carrier could be sprayed uniformly. Compared with normal saline, the run-off of the SA on the surface of porcine skin was greatly reduced. In theory, the spray height of AAAD could be set to achieve the adjustment of a large spray area of 1–12 cm2. In the measurement of droplet velocity and HaCaT cell viability, the spray height of AAAD would affect the droplet settling velocity and then the cell delivery survival rate (CSR). Compared with the spray height of 50 mm, the CSR of 100 mm was significantly higher and could reach 91.09% ± 1.82% (92.82% ± 2.15% in control). For bio-ink prepared with 1% (w/v) SA, the viability remained the same during the 72-h incubation. Overall, the novel AAAD uniformly atomized bio-ink with high viscosity and maintained the viability and proliferation rate during the delivery of living cells. Therefore, AAAD has great potential in cell transplantation therapy, especially for large-area or irregular skin wounds.

Fe(81-x-y)Si9B10CxCry amorphous magnetic powder fabricated by gas-water coupled rapid-setting sedimentation atomization

In this study, Fe(81-x-y)Si9B10CxCry (x = 0, 2, and y = 0, 2, at.%) amorphous powders with high sphericity were prepared using a gas-water coupled rapid-setting sedimentation atomization (GWC) device. The morphology and internal structure of the Fe(81-x-y)Si9B10CxCry amorphous powder are analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results show that the alloy composition and particle size have a significant effect on the sphericity and glass forming ability (GFA) of amorphous powders. The Fe79Si9B10C2 and Fe77Si9B10Cr2C2 amorphous powders under 45 μm have formed a completely amorphous structure. However, the Fe81Si9B10 amorphous powders above 30 μm were partially crystallized. Among the three groups of amorphous powder samples, the Fe81Si9B10 amorphous powder with the highest saturation magnetization, the Fe77Si9B10Cr2C2 amorphous powder had the lowest core losses and the Fe79Si9B10C2 amorphous powder exhibited the best comprehensive performance.

Repurposing mucosal delivery devices for live attenuated tuberculosis vaccines.

Tuberculosis (TB) remains one of the most lethal infectious diseases globally. The only TB vaccine approved by the World Health Organization, Bacille Calmette-Guérin (BCG), protects children against severe and disseminated TB but provides limited protection against pulmonary TB in adults. Although several vaccine candidates have been developed to prevent TB and are undergoing preclinical and clinical testing, BCG remains the gold standard. Currently, BCG is administered as an intradermal injection, particularly in TB endemic countries. However, mounting evidence from experimental animal and human studies indicates that delivering BCG directly into the lungs provides enhanced immune responses and greater protection against TB. Inhalation therapy using handheld delivery devices is used for some diseases and allows the delivery of drugs or vaccines directly into the human respiratory tract. Whether this mode of delivery could also be applicable for live attenuated bacterial vaccines such as BCG or other TB vaccine candidates remains unknown. Here we discuss how two existing inhalation devices, the mucosal atomization device (MAD) syringe, used for influenza vaccines, and the Respimat® Soft Mist™ inhaler, used for chronic obstructive pulmonary disease (COPD) therapy, could be repurposed for mucosal delivery of live attenuated TB vaccines. We also outline the challenges and outstanding research questions that will require further investigations to ensure usefulness of respiratory delivery devices that are cost-effective and accessible to lower- and middle-income TB endemic countries.

Efficacy of Intranasal Atomized Dexmedetomidine for Sedation in Surgical Removal of Impacted Mandibular Third Molars: A Prospective Study.

To assess the efficacy of dexmedetomidine atomized intranasally for sedation during surgical removal of impacted mandibular third molars. A prospective randomized trial was conducted on 25 anxious patients between the ages of 18 and 40 who had impacted the lower third molars. An intranasal atomization device was used to give the medication 30 minutes prior to the surgical procedure. The Ramsay sedation score and Observer's assessment of alertness/sedation score were used to assess intranasal sedation. The results of our study state that the sedative effect began to take effect between 30 and 45 minutes later and was nearly back to baseline by 105 minutes after the administration of intranasal dexmedetomidine. Intranasal delivery of 1.5mg/kg atomized dexmedetomidine for patients undergoing surgical removal of impacted mandibular third teeth is safe, feasible, and clinically efficient in daycare settings based on the sedation scores, and secondary variables which were assessed.

Air-Coupled Photoacoustic Detection of Airborne Particulates.

In this study, we present a novel method to detect airborne particulates using air-coupled photoacoustics, with a goal toward detecting viral content in respiratory droplets. The peak photoacoustic frequency emitted from micrometer-sized particulates is over 1000MHz, but at this frequency, the signals are highly attenuated in air. Measurements were taken using a thin planar absorber and ultrasound transducers with peak sensitivity between 50kHz and 2000kHz and a 532nm pulsed laser to determine the optimum detection frequency. 350kHz to 500kHz provided the highest amplitude signal while minimizing attenuation in air. To simulate the expulsion of respiratory droplets, an atomizer device was used to spray droplets into open air through a pulsed laser. Droplets were composed of water, water with acridine orange dye, and water with gold nanoparticles. The dye and nanoparticles were chosen due to their similarity in the UV absorption peaks when compared to RNA. Using a 260nm laser, the average photoacoustic signal from water was the highest, and then the signal decreased with dye or nanoparticles. Increasing absorber concentrations within their respective solutions resulted in a decreasing photoacoustic signal, which is opposite to our expectations. Monte Carlo simulations demonstrated that depending on the droplet dimensions, water droplets focus photons to create a localized fluence elevation. Absorbers within the droplet can inhibit photon travel through the droplet, decreasing the fluence. Photoacoustic signals are created through optical absorption within the droplet, potentially amplified with the localized fluence increase through the droplet focusing effect, with a trade-off in signal amplitude depending on the absorber concentration.