Ultrasonic Nebulizer Research Articles

Cough Test Results during Screening for Silent Aspiration Are Affected by Risk Factors for Silent Cerebral Infarct in Older Adults with Chronic Disease.

The cough reflex does not change with age. However, older adults with chronic diseases often have a reduced cough reflex. The effects of several risk factors on reduced cough sensitivity in older adults remain unclear. This study aims to clarify the risk factors for reduced cough sensitivity in older adults with chronic diseases. This cross-sectional study included participants aged <65 years (young group; n = 21), those aged ≥65 years (older adults with chronic disease group; n = 18), and those with dysphagia (dysphagia group; n = 16). A cough test was performed on all participants using an ultrasonic nebulizer with a mist of 1% w/v citric acid physiologic saline. Cough response was observed in the young (21/21), older adult (9/18), and dysphagia (13/16) groups. The difference between the young and older adult groups was significant (p < 0.01). The older adult and dysphagia groups had decreased cough sensitivity compared to the younger group. Cough sensitivity was affected by risk factors for silent cerebral infarct and age. Our findings show that cough test results might be affected by risk factors for silent cerebral infarction in older adults with chronic diseases.

Analysis of the domestic market of compressor and ultrasonic nebulizers

The aim of the work is to organize informational files about compressors and ultrasonic nebulizers determination of actuality and availability in marketing analysis of the domestic market. Materials and methods. Data from the Apteka.UA and the official website of Tabletki.ua were used to analyze the brand and assortment structure of ultrasonic and compressor nebulizers. The search analytical, systematic, comparative, and statistical methods and methods of mathematical and logical analysis were used in the work. Results. The analysis of the market of assortment and brand structures of the compressor and ultrasonic nebulizers was carried out. The obtained results showed the presence on the market of 16 manufacturers from 10 countries in the world of compressor nebulizers and 9 manufacturers from 7 countries in the world of ultrasonic nebulizers. Among them, the largest suppliers were identified, such as Omron Healthcare (Japan) and LLC Medhouse Swiss GmbH (Ukraine). The calculated stress coefficient indicated greater competition between compressor manufacturers (Kvi = 0.94) compared to ultrasonic (Kvi = 0.88) nebulizers. The level of monopolization was determined using the Herfindahl–Hirschman index. The results indicated a moderately concentrated market for both types of nebulizers. Analysis of socio-economic affordability by indicators of price liquidity ratio and solvency adequacy noted low availability of this group of goods for consumers of pharmacies. Conclusions. The results of the company structure research indicated the vast majority of manufacturers of foreign companies and a wide range of both ultrasonic and compressor nebulizers. In the course of the work, the available commodity positions in pharmacies in Ukraine were investigated. According to the calculations of the coefficient of tension and the level of monopolization. It was possible to determine the competitiveness among manufacturing firms. The results of the assessment of the liquidity ratio and the adequacy of solvency made it possible to assess the purchasing power of the population in this group of goods.

A surfactant-free approach: Novel one-step ultrasonic nebulizer spray method to generate amphiphilic Janus particles

HypothesisA solvent evaporation-induced phase separation method, which is based on the preferential partitioning of two or more immiscible materials after solvent evaporation on providing heat, has been one of the main strategies for synthesis of Janus particles (JPs). Considering this approach, it should be possible to synthesize surfactant free-JPs in continuous flow by the ultrasonic nebulizer spray method. ExperimentsTwo polymers, polystyrene and polymethylmethacrylate, were dissolved in dichloromethane, and droplets of a precursor solution generated by an ultrasonic nebulizer were then conveyed through a borosilicate glass cylinder with two heating zones. The solvent evaporation-induced phase separation occurred in a single flow process, which resulted in the preferential partitioning of two incompatible polymers in the droplets, leading to the formation of the spherical bicompartmental JPs. FindingsThe successful fabrication of spherical JPs was observed at high polymer concentrations (1.5 and 2.0 wt%), and at elevated temperature (40–75 °C). The fluorescent compartmentalization of JPs was confirmed. Furthermore, the interfacial arrangement of JPs at oil–water interface was studied. A detailed explanation of theoretical prediction of interfacial configurations of JPs was provided. Lastly, the generated JPs were proved as Pickering stabilizers at the oil–water interface.

Bicalutamide, an androgen receptor antagonist, effectively alleviate allergic rhinitis via suppression of PI3K–PKB activity

ObjectivesTo investigate the therapeutic effect of Bicalutamide, an androgen receptor antagonist on the onset and development of allergic rhinitis in an animal model.Methods40 male BALB/c mice were randomly divided into five groups (eight mice per group). Aluminum hydroxide powder was used as an adjuvant, combined with Ovalbumin (OVA) to establish the mouse model of allergic rhinitis via ultrasonic nebulization of OVA to stimulate the nasal cavity. Mice in Bica#1 group were intraperitoneally injected with 0.02 mg Bicalutamide/0.5 ml of normal saline daily for 7 consecutive days; mice in Bica#2 group were administered 0.02 mg Bicalutamide/0.5 ml of normal saline via intraperitoneal injection for 5 consecutive days, and then the same amount of normal saline was injected intraperitoneally for 2 consecutive days. Enzyme-linked immunosorbent assay was adopted to detect the serological levels of IgE, IL-4, and IL-6 production. Eosinophil infiltration was observed under microscope after hematoxylin and eosin staining of nasal mucosa. Quantitative PCR and Western blot were employed for determination of histamine receptors mRNA expression and PI3K/PKB associated protein levels, respectively.ResultsHistological analysis shown that allergic lesion was induced after OVA sensitization. Intraperitoneal injection with 0.02 mg Bicalutamide daily for 7 consecutive days significantly reduced the allergic lesion; however, mice injected with the same amount of normal saline at the same time demonstrated no allergic rhinitis symptoms. In addition, there was a significant reduction in eosinophils number in Bicalutamide treated mice (n = 8) compared to the OVA group (n = 8) (OVA: 19.6 ± 5.3 vs. Bica#1: 7.7 ± 0.8 vs. Bica#2: 9.4 ± 1.2, both p < 0.01). Furthermore, ELISA results revealed that the serological levels of IgE (OVA: 17.3 ± 1.7 µg/ml vs. Bica#1: 9.2 ± 0.6 vs. Bica#2: 10.4 ± 2.3, both p < 0.05), IL-4 (OVA: 164.3 ± 5.1 pg/ml vs. Bica#1: 110.2 ± 3.1 vs. Bica#2: 115.3 ± 4.1, both p < 0.05) and IL-6 (OVA: 167.3 ± 3.7 pg/ml vs. Bica#1: 117.5 ± 6.5 vs. Bica#2: 114.8 ± 2.4, both p < 0.05) were significantly decreased after two different dosage of Bicalutamide treatment. Similarly, histamine receptors in mast cells were significantly reduced after two different dosage of Bicalutamide treatment. More importantly, p-PKB protein was notably reduced after two different dosage of Bicalutamide treatment compared to the OVA group, mTOR protein levels were also down regulated after two different dosage of Bicalutamide treatment.ConclusionsOur data demonstrated that androgen receptor antagonist Bicalutamide can significantly alleviate allergic rhinitis lesion in the animal model. PI3K/PKB activity in mast cells was suppressed after Bicalutamide injection. Our results provide important implication in allergic rhinitis prevention and treatment.

Sensitivity enhancement in inductively coupled plasma mass spectrometry using nebulization methods via nitrogen mixed gas effect.

We demonstrate the sensitivity enhancement in inductively coupled plasma mass spectrometry (ICP-MS) by combining ultrasonic nebulization via the nitrogen mixed gas effect. We showed the effect of nitrogen gas concentration (0-5%) in the nebulizer gas on the signal sensitivity for 63 elements using commercially available (concentric and ultrasonic) nebulizers. In addition, the limit of detection (ng L-1) was calculated in each case. Finally, we compared the sensitivity (i.e., the slope of the calibration curve), background noise intensity, and three-dimensional intensity distribution in the plasma to elucidate the effects of the concurrent use of mixed gas plasmas and nebulization methods.

Новый взгляд на кросслинкинг роговицы и его применение в офтальмологии

The accumulated experimental and clinical data on corneal crosslinking made it possible to take a different look at the possibilities of its use for therapeutic and prophylactic purposes in various ophthalmic pathologies. Purpose. To consider new approaches to corneal crosslinking, criteria for its evaluation and expansion of the range of its applications in ophthalmology. Material and methods. Eight-year experimental (20 porcine eyes, 90 rabbit eyes) and clinical studies (610 surgeries) on photorefractive and phototherapeutic surgeries with saturation of the corneal stroma with riboflavin during laser correction of ametropias and the treatment of various diseases of the cornea were analyzed. A comprehensive examination was carried out using modern diagnostic devices. Particular emphasis was placed on the technique of two-wavelength optical scanning of the cornea. Results. Experimental and clinical studies have shown the benefits of corneal photoablation with riboflavin. The use of an ultrasonic nebulizer and isotonic 0.25% riboflavin solution cooled to +5–7°С provided the effect of local aeration and hypothermia. Such technology did not affect the accuracy of refractive ablation and blocked the negative effect of induced secondary radiation on keratocytes, nerves, and the underlying layers of the cornea. This reduced the aseptic in flammatory response and the risk of developing an irreversible form of fibroplasia. Ablation with riboflavin initiated a fading effect of crosslinking. Such prophylactic crosslinking in excimer laser surgery of the cornea proved to be sufficient to compensate for the weakening of its strength and photoprotective properties. These studies predetermined the development of a new technology of therapeutic crosslinking with riboflavin activation by subablative radiation of an argon-fluorine excimer laser for keratoectasias and other pathologies of the cornea. According to OCT and densitometry, all the classic signs of traditional crosslinking were noted. Two-wavelength optical scanning of the cornea revealed the effect of dehydration and an increase in the refractive index of the cornea, which can be considered as one of the objective criteria for assessing crosslinking. Conclusion. Crosslinking of the cornea with argon-fluorine excimer laser radiation in ablative and subablative modes expands the range of its application for the prevention of fibroplasia, keratoectasia during photorefractive, phototherapeutic ablation, treatment of keratoconus, secondary keratoectasias and other diseases of the cornea. Key words: crosslinking, cornea, photorefractive and phototherapeutic keratoablation, keratoconus, secondary kertoectasias, corneal pathology

Development and technical validation of an ultrasound nebulizer to deliver intraperitoneal pressurized aerosols in a rat colon cancer peritoneal metastases model

Background/aimTo develop and validate a nebulizer device for anti-cancer research on pressurized intraperitoneal aerosol supply in a preclinical peritoneal metastases (PM) rat model.Material and methodsFor aerosol generation, an ultrasonic nebulizer (USN) was modified. Aerosol analyses were performed ex-vivo by laser diffraction spectrometry (LDS). Intraperitoneal (IP) 99mtechnetium sodium pertechnetate (99mTc) aerosol distribution and deposition were quantified by in-vivo single photon emission computed tomography (SPECT/CT) and compared to liquid IP instillation of equivalent volume/doses of 99mTc with and without capnoperitoneum. PM was induced by IP injection of HCT116-Luc2 human colon cancer cells in immunosuppressed RNU rats. Tumor growth was monitored by bioluminescence imaging (BLI), 18F-FDG positron emission tomography (PET) and tissues examination at necropsy.ResultsThe USN was able to establish a stable and reproducible capnoperitoneum at a pressure of 8 to 10 mmHg. LDS showed that the USN provides a polydisperse and monomodal aerosol with a volume-weighted diameter of 2.6 μm. At a CO2 flow rate of 2 L/min with an IP residence time of 3.9 s, the highest drug deposition efficiency was found to be 15 wt.-%. In comparison to liquid instillation, nebulization showed the most homogeneous IP spatial drug deposition. Compared to BLI, 18F-FDG-PET was more sensitive to detect smaller PM nodules measuring only 1–2 mm in diameter. BLI, 18F-FDG PET and necropsy analyses showed relevant PM in all animals.ConclusionsThe USN together with the PM rat model are suitable for robust and species-specific preclinical pharmacological studies regarding intraperitoneal delivery of pressurized aerosolized drugs and cancer research.

Photoelectron Spectroscopy of OH--Anion-Water Clusters Generated by Ultrasonic Nebulizer.

Investigating molecules in the gas phase is the only way to discover their intrinsic molecular properties; however, it is challenging to produce the gaseous phase of large-molecule chemicals. Thermal evaporation is typically used to convert molecules into gases, but it is still challenging to study ionic molecules in solutions in the gas phase. Electrospray ionization is one of the best methods to generate molecules in the gas phase, and it is uniquely capable of studying large biomolecules, including proteins. However, the molecular temperature required to study the spectroscopic properties of the molecules is very high. In this study, we developed a new, simple evaporation method using an ultrasonic nebulizer to obtain gas-phase molecules. Using this new equipment, we observed OH− anions and their water clusters in the gas phase and obtained their photoelectron spectra. We observed that the vertical electron-detachment energy (VDE) of OH− was 1.90 ± 0.05 eV and the VDEs of its water clusters and OH− (H2O)n (n = 1–2) decreased to 1.50 ± 0.05 eV (n = 1) and 1.30 ± 0.05 eV (n = 2), respectively.

High-yield sample introduction using nebulized film dielectric barrier discharge assisted chelate vapor generation for trace rare earth elements determination by inductively coupled plasma mass spectrometry

A new sample introduction method of nebulized film dielectric barrier discharge (NFDBD) assisted chelate vapor generation coupled with inductively coupled plasma mass spectrometry (ICP-MS) for trace rare earth elements (REEs) determination in environmental water was developed in this work. Using 2,2,6,6-tetramethyl-3,5-heptanedione (DPM) as chelating reagent, the volatile and stable chelates of REE-DPM were effectively vaporized in NFDBD sampling system, leading to 8–9 folds enhancement of REEs sensitivity compared with solution nebulization sampling system, with the sample introduction efficiencies between 51.9% and 66.0%. The enhancement mechanism and the experimental parameters for REEs determination including the DPM concentration, the carrier solution concentration, the input discharge voltage and the argon flow rate were evaluated in detail. The interferences from sample matrix at 10 mg L−1 level and the degradation product of DPM at 0.5 mmol L−1 were also found negligible for trace REEs determination in NFDBD sampling system. Under optimized conditions, the relative standard deviations for 15 REEs were between 0.3% and 2.5% at the concentration of 0.5 μg L−1 and the detection limits for 15 REEs were between 0.0009 and 0.11 ng L−1, which were 1–2 orders of magnitude lower than other sampling systems such as solution nebulization, membrane desolvation, ultrasonic nebulization and electrothermal vaporization and 2–4 folds lower than NFDBD vapor generation system without chelate. This proposed method not only can be used for trace REEs determination directly in freshwater samples, but also is promising for seawater determination without column separation.

In situ quantitative analysis by ultrasonic extraction and nebulization combined with hydrogen flame ionization mass spectrometry: Diisopropylnaphthalene (DIPN), a marker of recycled paper in packing materials

Ambient mass spectrometry is used for direct analysis and high-throughput screening in many fields. However, most researches are about qualitative analysis. Quantitative detection based on AMS only performs on standard compounds and the relative standard deviation is so large that the accuracy of the result is low. In this study, a hydrogen flame ion source with ultrasonic nebulizer as sampling unit was established to enable solid samples to extract, nebulize and quantitatively detect in situ, with high sensitivity. This device was used to quantificationally determine the content of diisopropylnaphthalene (DIPN) in food packaging paper to identify recycled paper. Rapid analysis was performed in situ without complex pretreatment and the whole analysis time was less than 10 min. It's environmentally friendly that only 100 mg (or less) of sample and no more than 1 mL of solvent are required for one test. The external standard method was used for quantitative determination. The limit of detection was measured to be as low as 0.01 ng mL−1 and the linear dynamic range was 0.03–0.60 μg mL−1 in positive multiple reactions monitoring mode. It has been successfully applied to detect actual samples and the content of DIPN was 0.020–0.095 mg kg−1.

Place of nebulizer therapy in the treatment of bronchial asthma in children

The review article presents an analysis of the data of foreign and domestic researchers characterizing the effectiveness of nebulizer therapy for bronchial asthma in children. The paper considers new data comparing the effectiveness of aerosol delivery devices. The advantage of inhalation therapy, which determines its widespread use in childhood, is its rapid delivery to the respiratory tract, high local and low systemic concentrations of the drug in target organs. Difficulties in observing the correct inhalation technique due to the difficulty of synchronizing inhalation and drug delivery, especially in young children, remain an urgent problem in the practice of treating chronic bronchopulmonary diseases, which leads to a severe and uncontrolled course, disability and adverse outcomes. The main disadvantage of ultrasonic nebulizers is the inactivation of suspensions, antibiotics and other drugs. Widely used jet nebulizers create noise during inhalation, have a large residual volume in the nebulizer chamber. In this regard, the improvement of delivery forms continues, taking into account the anatomical and physiological characteristics of the respiratory organs, the age of patients and comorbid conditions. The characteristics of the optimal inhaler include simplicity and ease of use, reliability, the possibility of effective inhalation of various drugs in combination with economical consumption. From this point of view, one of the universal means of transporting aerosols is membrane or electronic mesh (mesh) nebulizers, which provide excellent regional drug deposition in all age groups of children. The rapid achievement of clinical effect, compactness, mobility expand the possibilities of using mesh nebulizers at all levels of medical care.

Spray pyrolysis deposited aluminium-indium zinc oxide thin films and study of their electrical and photoluminescence properties

The structural, optical, photoluminescence and electrical behaviour of aluminium and indium doped ZnO (AIZO) thin films are investigated for different dopant compositions. AIZO thin films were grown on glass substrates using an ultrasonic nebuliser spray pyrolysis process at 400 °C substrate temperature. Ammonium acetate is used as a stabiliser as well as a binding agent in the precursor solution. It was found that a shift in crystalline nature as the deposition time increases. Further, these thin films show hexagonal nanostructures, according to XRD investigations. Optical studies show that AIZO films have transmittance of more than 70%. Electrical study reveals that resistivity of AIZO thin films range from 2.35 to 4.591 × 10−3 Ωcm.

A Matrix Sublimation Device with an Integrated Solvent Nebulizer for MALDI-MSI.

The current matrix deposition methods in MALDI-mass spectrometry imaging (MALDI-MSI) face technical problems related to the inhomogeneous distribution of crystals and the low analyte extraction and cocrystallization efficiency. In this work, an integrated matrix sublimation device with synchronous solvent nebulization was developed for MALDI-MSI. Droplets of solvents were directly introduced into the chamber of the sublimator by using a miniaturized ultrasonic nebulizer unit. The synchronous and asynchronous working modes of solvent nebulization and matrix sublimation were systematically investigated. Imaging of both protein and small metabolite distributions in mouse brain tissue sections was successfully performed using the developed matrix deposition device. The sensitivity and quality of the images were clearly improved in synchronous mode compared with those of the conventional spray and sublimation methods. These results demonstrate that the integrated device with both solvent nebulization and matrix sublimation is a useful tool in MALDI-MSI applications.

H2O2 generation enhancement by ultrasonic nebulisation with a zinc layer for spray disinfection

With the outbreak of COVID-19, microbial pollution has gained increasing attention as a threat to human health. Consequently, many research efforts are being devoted to the development of efficient disinfection methods. In this context, hydrogen peroxide (H2O2) stands out as a green and broad-spectrum disinfectant, which can be produced and sprayed in the air directly by cavitation in ultrasonic nebulisation. However, the yield of H2O2 obtained by ultrasonic nebulisation is too low to satisfy the requirements for disinfection by spraying and needs to be improved to achieve efficient disinfection of the air and objects. Herein, we report the introduction of a zinc layer into an ultrasonic nebuliser to improve the production of H2O2 and generate additional Zn2+ by self-corrosion, achieving good disinfecting performance. Specifically, a zinc layer was assembled on the oscillator plate of a commercial ultrasonic nebuliser, resulting in a 21-fold increase in the yield of H2O2 and the production of 4.75 μg/mL Zn2+ in the spraying droplets. When the generated water mist was used to treat a bottle polluted with Escherichia coli for 30 min, the sterilisation rate reached 93.53%. This ultrasonic nebulisation using a functional zinc layer successfully enhanced the production of H2O2 while generating Zn2+, providing a platform for the development of new methodologies of spray disinfection.

The diagnostic yield and safety of sputum induction in suspected pulmonary tuberculosis: The experience of a single tertiary care center in Saudi Arabia.

Sputum smear microscopy examination and culture for tuberculosis (TB) remain a fundamental tool of diagnosis but may be negative up to 50% case of active pulmonary TB. Bronchoscopy to obtain sputum is invasive and not readily available. Alternative methods of obtaining sputum specimens are crucial in suspected pulmonary TB cases who are unable to expectorate. In this context, it may be beneficial to stimulate sputum production by administering a mist of hypertonic saline produced by ultrasonic nebulization. The aims of the study are to describe the experience of a tertiary center in Saudi Arabia with sputum induction (SI) for the investigation of patients suspected to have sputum scare TB. A retrospective cohort study was performed. All patients suspected of sputum scare TB and investigated with SI were included. Standard descriptive statistics were used. Categorical data presented as frequency were compared using the Chi square test. Continuous data presented as mean ± standard deviation were compared using Student's t test. Sensitivity, specificity, and predictive values were calculated. Of 252 patients with suspected TB who underwent SI, 78 (31%) were ultimately diagnosed to have TB. Culture of induced sputum confirmed the diagnosis of TB in 44 (56.4%) of these patients. However, the diagnosis of TB would have been missed in 13.5% of the cohort if no further investigations were done. The incidence of complications was low. No patients required hospitalization or specialist intervention. SI is safe well tolerated and inexpensive. It may reduce the need for bronchoscopy in patients with suspected sputum scare TB. However, around 20% of TB can be missed by SI unless further investigations are performed. Hence, patients suspected to have sputum scare TB in whom the risk of bronchoscopy is high, a clinical decision on the appropriateness of empirical therapy is often required.

YG-1 Extract Improves Acute Pulmonary Inflammation by Inducing Bronchodilation and Inhibiting Inflammatory Cytokines.

YG-1 extract used in this study is a mixture of Lonicera japonica, Arctic Fructus, and Scutellariae Radix. The present study was designed to investigate the effect of YG-1 extract on bronchodilatation (ex vivo) and acute bronchial and pulmonary inflammation relief (in vivo). Ex vivo: The bronchodilation reaction was confirmed by treatment with YG-1 concentration-accumulation (0.01, 0.03, 0.1, 0.3, and 1 mg/mL) in the bronchial tissue ring pre-contracted by acetylcholine (10 μM). As a result, YG-1 extract is considered to affect bronchodilation by increased cyclic adenosine monophosphate, cAMP) levels through the β2-adrenergic receptor. In vivo: experiments were performed in C57BL/6 mice were divided into the following groups: control group; PM2.5 (fine particulate matter)-exposed group (PM2.5, 200 μg/kg/mL saline); and PM2.5-exposed + YG-1 extract (200 mg/kg/day) group. The PM2.5 (200 μg/kg/mL saline) was exposed for 1 h for 5 days using an ultrasonic nebulizer aerosol chamber to instill fine dust in the bronchi and lungs, thereby inducing acute lung and bronchial inflammation. From two days before PM2.5 exposure, YG-1 extract (200 mg/kg/day) was administered orally for 7 days. The PM2.5 exposure was involved in airway remodeling and inflammation, suggesting that YG-1 treatment improves acute bronchial and pulmonary inflammation by inhibiting the inflammatory cytokines (NLRP3/caspase-1 pathway). The application of YG-1 extract with broncho-dilating effect to acute bronchial and pulmonary inflammation animal models has great significance in developing therapeutic agents for respiratory diseases. Therefore, these results can provide essential data for the development of novel respiratory symptom relievers. Our study provides strong evidence that YG-1 extracts reduce the prevalence of respiratory symptoms and the incidence of non-specific lung diseases and improve bronchial and lung function.

Development of a Portable Method for Serum Lithium Measurement Based on Low-Cost Miniaturized Ultrasonic Nebulization Coupled with Atmospheric-Pressure Air-Sustained Discharge.

An accurate, rapid but cheap, and portable method for monitoring of serum lithium (Li) is highly desirable for mental patients who take Li medicine for treatment. Conventional techniques are usually bulky, costly, and cannot provide on-site real-time measurements. Herein, a miniaturized, reliable, cost-effective, and portable optical emission method for rapid and sensitive determination of serum Li was developed based on a combination of miniaturized ultrasonic nebulization (MUN) and a low-power (≈22 W) atmospheric-pressure air-sustained discharge (APAD) excitation source. The proposed method eliminates the use of any compressed gas or pump and can achieve serum Li detection within 40 s with low sample consumption (less than 20 μL serum). Except for dilution with water, no extra treatment is needed for serum Li analysis by MUN-APAD-OES. In addition, it offers a significant advantage of good tolerance to the coexisting high concentration of Na, K, Ca, and Mg, which is in contrast with the obvious matrix effect encountered in conventional inductively coupled plasma optical emission spectrometry (ICP-OES). Different operating parameters affecting the performance of MUN-APAD-OES were evaluated. Under optimized conditions, the detection limit of Li (670.8 nm) was calculated to be 0.6 μg L-1 (6 μg L-1 in serum). Finally, the accuracy of the proposed method was validated by the analysis of two certified reference materials (Seronorm serum L-1 and L-2 RUO), six real human serum samples, and eight real animal serum samples. All of the results indicate that the low-cost and low-power MUN-APAD-OES provides a promising reliable method for on-site serum Li measurement and may also be extended to other elements.

Simulation of Onset of the Capillary Surface Wave in the Ultrasonic Atomizer.

The novel drug delivery system refers to the formulations and technologies for transporting a pharmaceutical compound in the body as it is needed to safely achieve its desired therapeutic effects. In this study, the onset vibrational amplitude of capillary surface waves for ultrasonic atomization spray is explained based on Faraday instability. Using ultrasonic frequency, the vibrational amplitude approached a critical point, and the liquid surface broke up into tiny drops. The micro-droplets were are steadily and continuously formed after the liquid feeding rate was optimized. The simulation study reported a minimum vibrational amplitude or onset value of 0.38 μm at 500 kHz frequency. The required minimum energy to atomize the drops was simulated by COMSOL Multiphysics simulation software. The simulation result agreed well with the numerical results of a subharmonic vibrational model that ocurred at 250 kHz frequency on the liquid surface. This newly designed single frequency ultrasonic atomizer showed its true physical characteristic of resonance on the fluid surface plane. Hence, this research will contribute to the future development of a single-frequency ultrasonic nebulizer and mechatronics for the generation of uniform atomized droplets.

Impact of phospholipids, surfactants and cholesterol selection on the performance of transfersomes vesicles using medical nebulizers for pulmonary drug delivery

The aim of this study is to formulate and optimize novel transfersome formulations for pulmonary drug delivery. Transfersome formulations (F1 – F18) were prepared by a thin-film method using three phospholipids (Soya phosphatidylcholine (SPC), Dimyristoly phosphatidylcholine (DMPC) and Hydrogenated soya phosphatidylcholine (HSPC)), in combination with three different surfactants (Tween 80, Span 80 and Span 20) with or without cholesterol, employing Beclomethasone dipropionate (BDP) as the model drug. Nano-transfersome formulations post-extrusion were delivered to a Two-stage Impinger (TSI) via three medical nebulizers (i.e. Air-jet, Ultrasonic and Vibrating mesh nebulizer). Based on the physicochemical properties, formulations F1 (SPC and Tween 80), F7 (DMPC and Tween 80) and F13 (HSPC and Tween 80) demonstrated significantly smaller VMD (162.34 ± 6.48, 198.66 ± 6.64, and 183.52 ± 7.34 nm), and significantly higher entrapment efficiency (97.56 ± 2.45, 95.67 ± 4.26 and 95.06 ± 3.38%). Based on nebulization performance, the Ultrasonic nebulizer exhibited the shortest nebulization time for formulations F1, F7 and F13 (i.e. 17.88 ± 2.45, 19.26 ± 2.04 and 19.59 ± 2.12 min), and higher output rate (212.04 ± 11.54, 194.61 ± 10.27 and 192.43 ± 9.84 mg/min), when compared to Air-jet and Vibrating mesh nebulizers. Irrespective of nebulizer type, significantly higher BDP deposition was observed in the lower stage of TSI for the F1 formulation (on average of 61%), whereas a higher amount of BDP was deposited in the upper stage of TSI using the F7 formulations (49%). Moreover, Formulation F1 in combination with Air-jet nebulizer demonstrated higher emitted dose (ED) and fine particle fraction (FPF) (82% and 83%), when compared to the counterpart formulations and nebulizer types investigated. This study has demonstrated that based on nebulizer performance, BDP deposition and formulation type; the F1 formulation in combination with an Air-jet nebulizer is most optimal for lower respiratory tract deposition, whereas the F7 formulation in combination with an Ultrasonic nebulizer is ideal for upper respiratory tract deposition.

Distribution of Rare Earth Elements and Their Applications as Tracers for Groundwater Geochemistry - A Review

Several studies investigating the behavior and environmental distribution of rare earth elements (REEs) have been reviewed to determine the geochemical processes that may affect their concentrations and fractionation patterns in groundwater and whether these elements can be used as tracers for groundwater-rock interactions and groundwater flow paths in small catchments. Inductively coupled plasma-mass spectrometry (ICP-MS), equipped with an ultrasonic nebulizer and active-film multiplier detector, is routinely used as an analytical technique to measure REEs in groundwater, facilitating the analysis of dissolved REE geochemistry. This review focuses on the distribution of REEs in groundwater and their application as tracers for groundwater geochemistry. Our review of existing literature suggests that REEs in ice cores can be used as effective tracers for atmospheric particles, aiding the identification of source regions.