Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.066
Filtrar
1.
Sci Rep ; 11(1): 14477, 2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34262082

RESUMO

Air quality in urban areas and megacities is dependent on emissions, physicochemical process and atmospheric conditions in a complex manner. The impact on air quality metrics of the COVID-19 lockdown measures was evaluated during two periods in Athens, Greece. The first period involved stoppage of educational and recreational activities and the second severe restrictions to all but necessary transport and workplace activities. Fresh traffic emissions and their aerosol products in terms of ultrafine nuclei particles and nitrates showed the most significant reduction especially during the 2nd period (40-50%). Carbonaceous aerosol both from fossil fuel emissions and biomass burning, as well as aging ultrafine and accumulation mode particles showed an increase of 10-20% of average before showing a decline (5 to 30%). It is found that removal of small nuclei and Aitken modes increased growth rates and migration of condensable species to larger particles maintaining aerosol volume.


Assuntos
Aerossóis/análise , Poluição do Ar/análise , Nitratos/análise , Material Particulado/análise , Emissões de Veículos/análise , Aerossóis/química , Poluentes Atmosféricos/análise , COVID-19 , Meio Ambiente , Monitoramento Ambiental , Grécia , Humanos , SARS-CoV-2 , Fatores de Tempo
2.
J Phys Chem Lett ; 12(23): 5503-5511, 2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34087076

RESUMO

The properties of aerosols are of paramount importance in atmospheric chemistry and human health. The hydrogen bond network of glycerol-water aerosols generated from an aqueous solution with different mixing ratios is probed directly with X-ray photoelectron spectroscopy. The carbon and oxygen X-ray spectra reveal contributions from gas and condensed phase components of the aerosol. It is shown that water suppresses glycerol evaporation up to a critical mixing ratio. A dielectric analysis using terahertz spectroscopy coupled with infrared spectroscopy of the bulk solutions provides a picture of the microscopic heterogeneity prevalent in the hydrogen bond network when combined with the photoelectron spectroscopy analysis. The hydrogen bond network is composed of three intertwined regions. At low concentrations, glycerol molecules are surrounded by water forming a solvated water network. Adding more glycerol leads to a confined water network, maximizing at 22 mol %, beyond which the aerosol resembles bulk glycerol. This microscopic view of hydrogen bonding networks holds promise in probing evaporation, diffusion dynamics, and reactivity in aqueous aerosols.


Assuntos
Aerossóis/química , Glicerol/química , Espectroscopia Fotoeletrônica/métodos , Água/química , Aerossóis/análise , Glicerol/análise , Ligação de Hidrogênio , Soluções/análise , Soluções/química , Água/análise
3.
Food Chem ; 362: 130238, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34098441

RESUMO

The aims of present study were to determine the impact of rutin complexation on the ability of soybean protein isolates (SPI) to form and stabilize foams and its mechanism. At pH 7.0, the foaming capacity and foaming stability of the rutin-SPI complexes (28.33% and 14.22%) was appreciably changed when compared with that of SPI alone (19.64% and 32.95%). The improvement in foaming properties was mainly attributed to decrease gas bubble size and increase interfacial thickness as suggested by light microscopy analysis. UV-visible spectroscopy showed that the absorption peak of the SPI was increased and red shifted after complexation with rutin. ITC confirmed that there was an interaction between rutin and SPI. This interaction was hydrophobic interaction and the binding process was entropy driven. This study shows that the foaming properties of plant-based proteins can be improved by forming complexes with flavonoids, which may be useful for foaming agents in foods.


Assuntos
Flavonoides/metabolismo , Rutina/farmacologia , Proteínas de Soja/efeitos dos fármacos , Aerossóis/química , Flavonoides/química , Interações Hidrofóbicas e Hidrofílicas , Proteínas de Soja/química , Proteínas de Soja/metabolismo
4.
Molecules ; 26(11)2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34071301

RESUMO

The new screening method for rapid evaluation of major phenolic compounds in apples has been developed. Suitability of coupling HPLC/UHPLC separation with the diode-array detection and universal charged aerosol detection with respect to the presence of interfering substances was tested. Characteristics of both detection techniques were compared and method linearity, limits of detection and quantitation, and selectivity of them determined. Student t-test based on slopes of calibration plots was applied for the detailed comparison. The diode-array detection provided the best results regarding sensitivity and selectivity of the developed method in terms of evaluation of phenolics profiles. The response of the charged aerosol detector was negatively affected by co-eluting substances during rapid-screening analyses. Coulometric detection was used for advanced characterization of extracts in terms of antioxidant content and strength to obtain more complex information concerning sample composition. This detection also allowed evaluation of unidentified compounds with antioxidant activity. HPLC/UHPLC separation using a combination of diode-array and coulometric detectors thus represented the best approach enabling quick, yet complex characterization of bioactive compounds in apples.


Assuntos
Aerossóis/química , Cromatografia Líquida de Alta Pressão/métodos , Eletroquímica/métodos , Malus/metabolismo , Antioxidantes/química , Calibragem , Cromatografia/métodos , Tecnologia de Alimentos , Limite de Detecção , Fenol/química , Fenóis/análise , Reprodutibilidade dos Testes
5.
AAPS PharmSciTech ; 22(5): 185, 2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34143327

RESUMO

Respiratory diseases are among the leading causes of morbidity and mortality worldwide. Innovations in biochemical engineering and understanding of the pathophysiology of respiratory diseases resulted in the development of many therapeutic proteins and peptide drugs with high specificity and potency. Currently, protein and peptide drugs are mostly administered by injections due to their large molecular size, poor oral absorption, and labile physicochemical properties. However, parenteral administration has several limitations such as frequent dosing due to the short half-life of protein and peptide in blood, pain on administration, sterility requirement, and poor patient compliance. Among various noninvasive routes of administrations, the pulmonary route has received a great deal of attention and is a better alternative to deliver protein and peptide drugs for treating respiratory diseases and systemic diseases. Among the various aerosol dosage forms, dry powder inhaler (DPI) systems appear to be promising for inhalation delivery of proteins and peptides due to their improved stability in solid state. This review focuses on the development of DPI formulations of protein and peptide drugs using advanced spray drying. An overview of the challenges in maintaining protein stability during the drying process and stabilizing excipients used in spray drying of proteins and peptide drugs is discussed. Finally, a summary of spray-dried DPI formulations of protein and peptide drugs, their characterization, various DPI devices used to deliver protein and peptide drugs, and current clinical status are discussed.


Assuntos
Peptídeos Catiônicos Antimicrobianos/síntese química , Composição de Medicamentos/métodos , Inaladores de Pó Seco/métodos , Proteínas Recombinantes/síntese química , Secagem por Atomização , Administração por Inalação , Aerossóis/química , Animais , Peptídeos Catiônicos Antimicrobianos/administração & dosagem , Dessecação/métodos , Excipientes/química , Humanos , Isoleucina/administração & dosagem , Isoleucina/síntese química , Manitol/administração & dosagem , Manitol/síntese química , Tamanho da Partícula , Peptídeos , Pós/química , Proteínas Recombinantes/administração & dosagem
6.
J Phys Chem Lett ; 12(20): 5023-5029, 2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34024101

RESUMO

Lipopolysaccharides (LPS) in sea spray aerosol (SSA) particles have recently been shown to undergo heterogeneous reactions with HNO3 in the atmosphere. Here, we integrate theory and experiment to further investigate how the most abundant sea salt cations, Na+, Mg2+, and Ca2+, impact HNO3 reactions with LPS-containing SSA particles. Aerosol reaction flow tube studies show that heterogeneous reactions of SSA particles with divalent cation (Mg2+ and Ca2+) and LPS signatures were less reactive with HNO3 than those dominated by monovalent cations (Na+). All-atom molecular dynamics simulations of model LPS aggregates suggest that divalent cations cross-link the oligosaccharide chains to increase molecular aggregation and rigidity, which changes the particle phase and morphology, decreases water diffusion, and consequently decreases the reactive uptake of HNO3. This study provides new insight into how complex chemical interactions between ocean-derived salts and biogenic organic species can impact the heterogeneous reactivity of SSA particles.


Assuntos
Cálcio/química , Lipopolissacarídeos/química , Magnésio/química , Ácido Nítrico/química , Água do Mar/química , Sódio/química , Aerossóis/química , Cátions/química , Tamanho da Partícula , Sais/química , Propriedades de Superfície
7.
Int J Biol Macromol ; 182: 413-424, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33798572

RESUMO

Most of the spray products in the market for wound healing applications are loaded with antibiotics that exert their antibacterial effect within the inflammatory stage of wound healing without demonstrating any effect in the subsequent proliferation stage. This study introduces a new aerosolized nanopowder (ANP) formula that not only exhibits antibacterial effect but also antioxidant and enhanced cell proliferation effects. Within the introduced ANP formula, Avicenna marina (Am) extract and neomycin (NM) antibiotic have been loaded within silk-fibroin nanoparticles (FB NPs). The Am has been extracted via different solvent systems, and investigated for its antioxidant and antibacterial activity as well as its ability to enhance cell proliferation. The physicochemical properties, size, zeta-potential and morphology of the prepared Am/FB NPs, NM/FB NPs and ANP formula were investigated. Besides, the ANP formula exhibited good antibacterial activities against Staphylococcus aureus, Methicillin resistant S. aureus, Pseudomonas aeruginosa and Resistant P. aeruginosa. Scratch wound healing assay on human fibroblast monolayers demonstrated 100% wound closure after 24 h upon using the ANP formula as compared to 70% wound closure for positive control (NM). The wound healing ability of the ANP formula has been further confirmed by histopathological evaluation of the wound site and depicted a marked increase in fibroblast proliferation and reduction of inflammatory cells after 15 days with a complete wound closure as compared to controls. The obtained results prove the beneficial effects of the Am extract on wound healing and introduce the developed multitask nanopowder formula as a potential wound healing spray.


Assuntos
Aerossóis/química , Fibroínas/química , Nanopartículas/química , Cicatrização , Animais , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Linhagem Celular , Proliferação de Células , Liberação Controlada de Fármacos , Epiderme/efeitos dos fármacos , Epiderme/fisiologia , Fibroblastos/efeitos dos fármacos , Humanos , Neomicina/administração & dosagem , Neomicina/farmacologia , Ratos
8.
Phys Chem Chem Phys ; 23(14): 8847-8853, 2021 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-33876044

RESUMO

The local electronic structure of aqueous histidine, an amino acid important in nature and biology, is revealed by aerosol X-ray photoemission spectroscopy. A detailed picture of the photoionization dynamics emerges by tuning the pH of the aqueous solution from which the aerosols are generated, allowing us to report the X-ray photoelectron spectroscopy (XPS) of histidine. Assignment of the experimental photoelectron spectra of the C1s and N1s levels allows the determination of the protonation state of histidine in these aqueous aerosols and is confirmed by density functional calculations. XPS spectra show that at pH = 1, both imidazole and amine group nitrogens are protonated, at pH = 7, the amine group nitrogen is protonated and the carboxyl group carbon is deprotonated resulting in a zwitterionic structure, and at pH = 13, only the carboxyl group remains deprotonated. Comparison of these results with previous experimental and theoretical results suggests that X-ray spectroscopy on aqueous aerosols can provide a convenient and simple way of probing their electronic structure in aqueous solutions.


Assuntos
Histidina/química , Aerossóis/química , Teoria da Densidade Funcional , Concentração de Íons de Hidrogênio , Modelos Químicos , Espectroscopia Fotoeletrônica , Prótons , Água/química
9.
PLoS One ; 16(4): e0249586, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33819294

RESUMO

Medical procedures that produce aerosolized particles are under great scrutiny due to the recent concerns surrounding the COVID-19 virus and increased risk for nosocomial infections. For example, thoracostomies, tracheotomies and intubations/extubations produce aerosols that can linger in the air. The lingering time is dependent on particle size where, e.g., 500 µm (0.5 mm) particles may quickly fall to the floor, while 1 µm particles may float for extended lengths of time. Here, a method is presented to characterize the size of <40 µm to >600 µm particles resulting from surgery in an operating room (OR). The particles are measured in-situ (next to a patient on an operating table) through a 75mm aperture in a ∼400 mm rectangular enclosure with minimal flow restriction. The particles and gasses exiting a patient are vented through an enclosed laser sheet while a camera captures images of the side-scattered light from the entrained particles. A similar optical configuration was described by Anfinrud et al.; however, we present here an extended method which provides a calibration method for determining particle size. The use of a laser sheet with side-scattered light provides a large FOV and bright image of the particles; however, the particle image dilation caused by scattering does not allow direct measurement of particle size. The calibration routine presented here is accomplished by measuring fixed particle distribution ranges with a calibrated shadow imaging system and mapping these measurements to the in-situ imaging system. The technique used for generating and measuring these particles is described. The result is a three-part process where 1) particles of varying sizes are produced and measured using a calibrated, high-resolution shadow imaging method, 2) the same particle generators are measured with the in-situ imaging system, and 3) a correlation mapping is made between the (dilated) laser image size and the measured particle size. Additionally, experimental and operational details of the imaging system are described such as requirements for the enclosure volume, light management, air filtration and control of various laser reflections. Details related to the OR environment and requirements for achieving close proximity to a patient are discussed as well.


Assuntos
Aerossóis/química , Salas Cirúrgicas/organização & administração , Tamanho da Partícula , COVID-19/prevenção & controle , COVID-19/virologia , Humanos
10.
Phys Rev Lett ; 126(3): 034502, 2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33543958

RESUMO

To quantify the fate of respiratory droplets under different ambient relative humidities, direct numerical simulations of a typical respiratory event are performed. We found that, because small droplets (with initial diameter of 10 µm) are swept by turbulent eddies in the expelled humid puff, their lifetime gets extended by a factor of more than 30 times as compared to what is suggested by the classical picture by Wells, for 50% relative humidity. With increasing ambient relative humidity the extension of the lifetimes of the small droplets further increases and goes up to around 150 times for 90% relative humidity, implying more than 2 m advection range of the respiratory droplets within 1 sec. Employing Lagrangian statistics, we demonstrate that the turbulent humid respiratory puff engulfs the small droplets, leading to many orders of magnitude increase in their lifetimes, implying that they can be transported much further during the respiratory events than the large ones. Our findings provide the starting points for larger parameter studies and may be instructive for developing strategies on optimizing ventilation and indoor humidity control. Such strategies are key in mitigating the COVID-19 pandemic in the present autumn and upcoming winter.


Assuntos
Líquidos Corporais/química , Líquidos Corporais/virologia , COVID-19/transmissão , Modelos Biológicos , Aerossóis/química , Microbiologia do Ar , Movimentos do Ar , COVID-19/virologia , Simulação por Computador , Transmissão de Doença Infecciosa , Expiração , Humanos , Pandemias , SARS-CoV-2/química , SARS-CoV-2/isolamento & purificação
11.
Sci Rep ; 11(1): 3953, 2021 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-33597564

RESUMO

Contact and inhalation of virions-carrying human aerosols represent the primary transmission pathway for airborne diseases including the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Relative to sneezing and coughing, non-symptomatic aerosol-producing activities such as speaking are highly understudied. The dispersions of aerosols from vocalization by a human subject are hereby quantified using high-speed particle image velocimetry. Syllables of different aerosol production rates were tested and compared to coughing. Results indicate aerosol productions and penetrations are not correlated. E.g. 'ti' and 'ma' have similar production rates but only 'ti' penetrated as far as coughs. All cases exhibited a rapidly penetrating "jet phase" followed by a slow "puff phase." Immediate dilution of aerosols was prevented by vortex ring flow structures that concentrated particles toward the plume-front. A high-fidelity assessment of risks to exposure must account for aerosol production rate, penetration, plume direction and the prevailing air current.


Assuntos
Aerossóis/análise , COVID-19/transmissão , SARS-CoV-2/química , Fala/fisiologia , Adulto , Aerossóis/química , COVID-19/virologia , Tosse , Humanos , Masculino , Tamanho da Partícula , Reologia/métodos , SARS-CoV-2/patogenicidade , Espirro , Comportamento Verbal/fisiologia
12.
J Chromatogr A ; 1639: 461927, 2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33540181

RESUMO

The present work describes a simultaneous mixed-mode high performance liquid chromatography (HPLC) method combined with a universal and non-selective-response detector for the complete ethoxymer profiling of alcohol ethoxy sulphate mixtures. The optimized HPLC methodology combines the dual hydrophilic (HILIC) and reversed-phase selectivity of a surfactant-type column in order to render a comprehensive and simultaneous separation of more than 50 endogenous ethoxymers in a single analysis. Furthermore, an accurate quantitation of every single analyte was achieved using a final universal charged aerosol detector (CAD) including specific mathematical processing tools. Results obtained helped describing a complete alkyl chain and ethoxymer distribution of the investigated AES samples. Method validation evidences provided reliability of the individual ethoxymer contributions determined with the proposed HPLC-CAD methodology. Regarding accuracy including independent nuclear magnetic resonance (NMR) experiments, an excellent correlation was found between the structural information provided by a COSY NMR spectrum and the CAD results regarding the mono/polyethoxylated and the non-ethoxylated/ethoxylated distribution. Additional calculations including the average molecular weight and the degree of ethoxylation for the reference AES sample showed minimum differences (relative error < 1 %) between the two considered techniques. An outstanding precision and linearity along the working concentration range (r2>0.999) was also observed. The individual limit of detection for the target sulphate ethoxymers was determined to be in the low ppm range. Further validated distribution profiles for a large number of AES samples demonstrated the applicability of the optimized HPLC-CAD methodology to routine surfactant screenings. Therefore, the hereby developed methodology provided extensive information regarding the detailed individual ethoxymer profile of AES formulations, which can be extremely useful for the surfactant industry in order to gain information on specific synthesis routes and/or detergency properties.


Assuntos
Aerossóis/análise , Álcoois/química , Cromatografia Líquida de Alta Pressão/métodos , Etil-Éteres/química , Sulfatos/química , Aerossóis/química , Interações Hidrofóbicas e Hidrofílicas , Espectroscopia de Ressonância Magnética , Peso Molecular , Reprodutibilidade dos Testes
13.
Int J Mol Sci ; 22(2)2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33429876

RESUMO

Iron is typically the dominant metal in the ultrafine fraction of airborne particulate matter. Various studies have investigated the toxicity of inhaled nano-sized iron oxide particles (FeOxNPs) but their results have been contradictory, with some indicating no or minor effects and others finding effects including oxidative stress and inflammation. Most studies, however, did not use materials reflecting the characteristics of FeOxNPs present in the environment. We, therefore, analysed the potential toxicity of FeOxNPs of different forms (Fe3O4, α-Fe2O3 and γ-Fe2O3) reflecting the characteristics of high iron content nano-sized particles sampled from the environment, both individually and in a mixture (FeOx-mix). A preliminary in vitro study indicated Fe3O4 and FeOx-mix were more cytotoxic than either form of Fe2O3 in human bronchial epithelial cells (BEAS-2B). Follow-up in vitro (0.003, 0.03, 0.3 µg/mL, 24 h) and in vivo (Sprague-Dawley rats, nose-only exposure, 50 µg/m3 and 500 µg/m3, 3 h/d × 3 d) studies therefore focused on these materials. Experiments in vitro explored responses at the molecular level via multi-omics analyses at concentrations below those at which significant cytotoxicity was evident to avoid detection of responses secondary to toxicity. Inhalation experiments used aerosol concentrations chosen to produce similar levels of particle deposition on the airway surface as were delivered in vitro. These were markedly higher than environmental concentrations. No clinical signs of toxicity were seen nor effects on BALF cell counts or LDH levels. There were also no significant changes in transcriptomic or metabolomic responses in lung or BEAS-2B cells to suggest adverse effects.


Assuntos
Lesão Pulmonar Aguda/fisiopatologia , Inflamação/fisiopatologia , Pulmão/efeitos dos fármacos , Nanopartículas Magnéticas de Óxido de Ferro/toxicidade , Lesão Pulmonar Aguda/induzido quimicamente , Aerossóis/química , Aerossóis/toxicidade , Poluentes Atmosféricos/toxicidade , Animais , Linhagem Celular , Humanos , Inflamação/induzido quimicamente , Exposição por Inalação , Pulmão/patologia , Material Particulado/toxicidade , Ratos , Ratos Sprague-Dawley
14.
AAPS PharmSciTech ; 22(1): 20, 2021 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-33389225

RESUMO

The aim of present study was to evaluate the feasibility of a naringenin-hydroxypropyl-ß-cyclodextrin (naringenin-HPßCD) inhalation solution for pulmonary delivery. Naringenin, a flavanone derived from citrus fruits, has been proven to exhibit excellent peripheral antitussive effect. To address the limitation of its poor oral bioavailability and low local concentration in the lung, a naringenin-HPßCD inhalation solution was prepared for pulmonary delivery. The aerosolization performance of formulation was evaluated by next generation impactor (NGI). Both dose-dependent and time-dependent antitussive effects of naringenin-HPßCD inhalation solution on acute cough induced by citric acid in guinea pigs were investigated. In vitro toxicity of naringenin-HPßCD inhalation solution in pulmonary Calu-3 cells was evaluated by MTS assay, and in vivo local toxicity investigation was achieved by assessing bronchoalveolar lavage (BALF) and lung histology after a 7-day inhalation treatment in guinea pigs. Fine particle fraction (FPF) of the formulation was determined as 53.09%. After inhalation treatment of 15 min, naringenin-HPßCD inhalation solution within the studied range of 0.2-3.6 mg/kg could dose-dependently reduce the cough frequency with the antitussive rate of 29.42-39.42%. Naringenin-HPßCD inhalation solution in concentration range of 100-400 µM did not decrease cell viability of Calu-3 cells, and the maximum effective dose (3.6 mg/kg) was non-toxic during the short-term inhalation treatment for guinea pigs. In conclusion, naringenin-HPßCD inhalation solution was capable for nebulization and could provide rapid response with reduced dose for the treatment of cough.


Assuntos
2-Hidroxipropil-beta-Ciclodextrina/administração & dosagem , Aerossóis/química , Antitussígenos/administração & dosagem , Flavanonas/administração & dosagem , 2-Hidroxipropil-beta-Ciclodextrina/química , Administração por Inalação , Animais , Disponibilidade Biológica , Flavanonas/química , Cobaias , Pulmão , beta-Ciclodextrinas/administração & dosagem
15.
Sci Rep ; 11(1): 2508, 2021 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-33510270

RESUMO

The rapid spread of the SARS-CoV-2 in the COVID-19 pandemic had raised questions on the route of transmission of this disease. Initial understanding was that transmission originated from respiratory droplets from an infected host to a susceptible host. However, indirect contact transmission of viable virus by fomites and through aerosols has also been suggested. Herein, we report the involvement of fine indoor air particulates with a diameter of ≤ 2.5 µm (PM2.5) as the virus's transport agent. PM2.5 was collected over four weeks during 48-h measurement intervals in four separate hospital wards containing different infected clusters in a teaching hospital in Kuala Lumpur, Malaysia. Our results indicated the highest SARS-CoV-2 RNA on PM2.5 in the ward with number of occupants. We suggest a link between the virus-laden PM2.5 and the ward's design. Patients' symptoms and numbers influence the number of airborne SARS-CoV-2 RNA with PM2.5 in an enclosed environment.


Assuntos
COVID-19/transmissão , Monitoramento Ambiental/métodos , SARS-CoV-2/química , Aerossóis/análise , Aerossóis/química , Microbiologia do Ar , Poluição do Ar em Ambientes Fechados , COVID-19/epidemiologia , COVID-19/metabolismo , COVID-19/virologia , Fômites/microbiologia , Fômites/estatística & dados numéricos , Hospitais , Humanos , Malásia/epidemiologia , Pandemias , Material Particulado/análise , RNA Viral
16.
Int J Pharm ; 595: 120241, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33484917

RESUMO

Inhaled ciclesonide (CIC), a corticosteroid used to treat asthma that is also being investigated for the treatment of corona virus disease 2019, hydrolyzes to desisobutyryl-ciclesonide (des-CIC) followed by reversible esterification when exposed to fatty acids in lungs. While previous studies have described the distribution and metabolism of the compounds after inhalation, spatial localization in the lungs remains unclear. We visualized two-dimensional spatial localization of CIC and its metabolites in rat lungs after administration of a single dose of a CIC aerosol (with the mass median aerodynamic diameter of 0.918-1.168 µm) using desorption electrospray ionization-time of flight mass spectrometry imaging (DESI-MSI). In the analysis, CIC, des-CIC, and des-CIC-oleate were imaged in frozen lung sections at high spatial and mass resolutions in negative-ion mode. MSI revealed the coexistence of CIC, des-CIC, and des-CIC-oleate on the airway epithelium, and the distribution of des-CIC and des-CIC-oleate in peripheral lung regions. In addition, a part of CIC independently localized on the airway epithelium. These results suggest that distribution of CIC and its metabolites in lungs is related to both the intended delivery of aerosols to pulmonary alveoli and peripheral regions, and the potential deposition of CIC particles on the airway epithelium.


Assuntos
Glucocorticoides/administração & dosagem , Glucocorticoides/farmacocinética , Pulmão/diagnóstico por imagem , Pulmão/metabolismo , Pregnenodionas/administração & dosagem , Pregnenodionas/farmacocinética , Espectrometria de Massas por Ionização por Electrospray/métodos , Administração por Inalação , Aerossóis/química , Animais , COVID-19/tratamento farmacológico , Células Epiteliais/metabolismo , Glucocorticoides/sangue , Pregnenodionas/sangue , Pregnenodionas/metabolismo , Alvéolos Pulmonares/metabolismo , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
17.
Eye (Lond) ; 35(4): 1187-1190, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32587387

RESUMO

OBJECTIVE: To assess visible aerosol generation during simulated vitrectomy surgery. METHODS: A model comprising a human cadaveric corneoscleral rim mounted on an artificial anterior chamber was used. Three-port 25 gauge vitrectomy simulated surgery was performed with any visible aerosol production recorded using high-speed 4K camera. The following were assessed: (1) vitrector at maximum cut rate in static and dynamic conditions inside the model, (2) vitrector at air-fluid interface in a physical model, (3) passive fluid-air exchange with a backflush hand piece, (4) valved cannulas under air, and (5) a defective valved cannula under air. RESULTS: No visible aerosol or droplets were identified when the vitrector was used within the model. In the physical model, no visible aerosol or droplets were seen when the vitrector was engaged at the air-fluid interface. Droplets were produced from the opening of backflush hand piece during passive fluid-air exchange. No visible aerosol was produced from the intact valved cannulas under air pressure, but droplets were seen at the beginning of fluid-air exchange when the valved cannula was defective. CONCLUSIONS: We found no evidence of visible aerosol generation during simulated vitrectomy surgery with competent valved cannulas. In the physical model, no visible aerosol was generated by the high-speed vitrector despite cutting at the air-fluid interface.


Assuntos
Aerossóis/química , COVID-19/epidemiologia , Microbolhas , SARS-CoV-2 , Vitrectomia , COVID-19/transmissão , Controle de Doenças Transmissíveis , Transmissão de Doença Infecciosa , Humanos , Simulação de Paciente
18.
Chemosphere ; 262: 127771, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32799139

RESUMO

The review initiates with current state of information on the atmospheric reaction mechanism of biogenic volatile organic compounds (BVOCs) and its fate in the atmosphere. The plants release BVOCs, i.e., isoprene, monoterpenes, and sesquiterpenes, which form secondary organic aerosols (SOA) upon oxidation. These oxidation reactions are primarily influenced by solar radiations along with other meteorological parameters viz.; temperature and relative humidity, therefore, the chemistry behind SOA formation is different during day than the night time. The review throws light upon the day and nighttime formation mechanism of SOA, recent advancements in the analytical techniques available for the measurements, and its impact on the environment. Studies have revealed that day time SOA formation is dominated by OH and O3, however, NOx initiated SOA production is dominated during night. The formation mechanism addresses that the gaseous products of VOCs are firstly formed and then partitioned over the pre-existing particles. New particle formation and biomass-derived aerosols are found to be responsible for enhanced SOA formation. 2-Dimensional gas chromatography-mass spectrometer (2D-GC/MS) is observed to be best for the analysis of organic aerosols. Radiative forcing (RF) SOA is observed to be a useful parameter to evaluate the environmental impacts of SOA and reviewed studies have shown mean RF in the ranges of -0.27 to +0.20 W m-2.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Atmosfera/química , Butadienos/análise , Hemiterpenos/análise , Monoterpenos/análise , Compostos Orgânicos Voláteis/análise , Aerossóis/química , Poluentes Atmosféricos/química , Butadienos/química , Hemiterpenos/química , Monoterpenos/química , Oxirredução , Temperatura , Compostos Orgânicos Voláteis/química
19.
Proc Natl Acad Sci U S A ; 118(2)2021 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-33376210

RESUMO

Aerosols impact climate, human health, and the chemistry of the atmosphere, and aerosol pH plays a major role in the physicochemical properties of the aerosol. However, there remains uncertainty as to whether aerosols are acidic, neutral, or basic. In this research, we show that the pH of freshly emitted (nascent) sea spray aerosols is significantly lower than that of sea water (approximately four pH units, with pH being a log scale value) and that smaller aerosol particles below 1 µm in diameter have pH values that are even lower. These measurements of nascent sea spray aerosol pH, performed in a unique ocean-atmosphere facility, provide convincing data to show that acidification occurs "across the interface" within minutes, when aerosols formed from ocean surface waters become airborne. We also show there is a correlation between aerosol acidity and dissolved carbon dioxide but no correlation with marine biology within the seawater. We discuss the mechanisms and contributing factors to this acidity and its implications on atmospheric chemistry.


Assuntos
Aerossóis/química , Água do Mar/química , Ar , Atmosfera/química , Meio Ambiente , Humanos , Concentração de Íons de Hidrogênio , Oceanos e Mares , Fitoplâncton , Água do Mar/análise
20.
J Ethnopharmacol ; 269: 113757, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33359915

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Kuanxiong aerosol (KXA) is a common clinical drug based on Fangxiang Wentong (FXWT) therapy in the treatment of angina pectoris. However, the pharmacological mechanism of KXA in the prevention and treatment of myocardial injury (MI) is not clear. AIM OF THE STUDY: The purpose of this study was to explore the protective effect of KXA on isoproterenol (ISO)-induced MI in rats. MATERIALS AND METHODS: The study included male Wistar Kyoto rats (age: 6 weeks). The rats were randomly divided into the following 5 groups (n = 6 per group): control group, ISO group, isosorbide mononitrate (ISMN) group (5 mg/kg), KXA-L group (0.1 mL/kg), and KXA-H group (0.3 mL/kg). The rats in the last three groups were given intragastric administration for 14 days, and rats in control group and ISO group were given the same amount of normal saline daily. ISO (120 mg/kg) was used to induce MI on the 13th and 14th days. We assessed electrocardiograms (ECGs), myocardial specific enzymes, histopathological changes, and apoptosis. RESULTS: We found that KXA reduced the increase in the ST-segment amplitude (elevation or depression) and the levels of myocardial marker enzymes induced by ISO in MI rats, improved the pathological changes in myocardial tissue, and reduced cardiomyocyte apoptosis. At the same time, KXA significantly inhibited the up-regulation of caspase-3 and Bax expression and down-regulation of Bcl-2 expression induced by ISO. RNA sequencing showed that 90 up-regulated genes induced by ISO were down-regulated after KXA treatment, whereas 27 down-regulated genes induced by ISO were up-regulated after KXA treatment. In addition, KEGG pathway enrichment analysis showed that the mitogen-activated protein kinase (MAPK) signaling pathway may be an important target of KXA in the treatment of ISO-induced MI in rats. The results of RNA sequencing verified by Western blot analysis showed that KXA significantly inhibited the activation of the ISO-induced MAPK pathway. CONCLUSIONS: KXA improves cardiac function in MI rats by inhibiting apoptosis mediated by the MAPK signaling pathway.


Assuntos
Aerossóis/farmacologia , Apoptose/efeitos dos fármacos , Cardiotônicos/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Infarto do Miocárdio/tratamento farmacológico , Aerossóis/química , Aerossóis/uso terapêutico , Animais , Cardiotônicos/química , Cardiotônicos/uso terapêutico , Caspase 3/genética , Regulação para Baixo/efeitos dos fármacos , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/uso terapêutico , Eletrocardiografia/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Isoproterenol/toxicidade , Masculino , Infarto do Miocárdio/induzido quimicamente , Miocárdio/metabolismo , Miocárdio/patologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Ratos Endogâmicos WKY , Transcriptoma/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Proteína X Associada a bcl-2/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...