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1.
Phys Chem Chem Phys ; 17(24): 15746-55, 2015 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-26013735

RESUMO

We use a combination of tandem ion mobility spectrometry (IMS-IMS, with differential mobility analyzers), molecular dynamics (MD) simulations, and analytical models to examine both neutral solvent (H2O) and ion (solvated Na(+)) evaporation from aqueous sodium chloride nanodrops. For experiments, nanodrops were produced via electrospray ionization (ESI) of an aqueous sodium chloride solution. Two nanodrops were examined in MD simulations: a 2500 water molecule nanodrop with 68 Na(+) and 60 Cl(-) ions (an initial net charge of z = +8), and (2) a 1000 water molecule nanodrop with 65 Na(+) and 60 Cl(-) ions (an initial net charge of z = +5). Specifically, we used MD simulations to examine the validity of a model for the neutral evaporation rate incorporating both the Kelvin (surface curvature) and Thomson (electrostatic) influences, while both MD simulations and experimental measurements were compared to predictions of the ion evaporation rate equation of Labowsky et al. [Anal. Chim. Acta, 2000, 406, 105-118]. Within a single fit parameter, we find excellent agreement between simulated and modeled neutral evaporation rates for nanodrops with solute volume fractions below 0.30. Similarly, MD simulation inferred ion evaporation rates are in excellent agreement with predictions based on the Labowsky et al. equation. Measurements of the sizes and charge states of ESI generated NaCl clusters suggest that the charge states of these clusters are governed by ion evaporation, however, ion evaporation appears to have occurred with lower activation energies in experiments than was anticipated based on analytical calculations as well as MD simulations. Several possible reasons for this discrepancy are discussed.

2.
J Environ Sci (China) ; 26(9): 1913-20, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-25193842

RESUMO

The characteristics of the particles of the smoke that is emitted from the burning of biomass fuels were experimentally investigated using a laboratory-scale tube furnace and different types of biomass fuels: rubber wood, whole wood pellets and rice husks. Emitted amounts of particles, particle-bound polycyclic aromatic hydrocarbons (PAHs) and water-soluble organic carbon (WSOC) are discussed relative to the size of the emitted particles, ranging to as small as nano-size (<70nm), and to the rate of heating rate during combustion. differential thermal analysis (DTA) and thermogravimetric analysis (TG) techniques were used to examine the effect of heating rate and biomass type on combustion behaviors relative to the characteristics of particle emissions. In the present study, more than 30% of the smoke particles from the burning of biomass fuel had a mass that fell within a range of <100nm. Particles smaller than 0.43µm contributed greatly to the total levels of toxic PAHs and WSOC. The properties of these particles were influenced by the fuel component, the combustion conditions, and the particle size. Although TG-DTA results indicated that the heating rate in a range of 10-20°C did not show a significant effect on the combustion properties, there was a slight increase in the decomposition temperature as heating rate was increased. The nano-size particles had the smallest fraction of particle mass and particle-bound PAHs, but nonetheless these particles registered the largest fraction of particle-bound WSOC.


Assuntos
Biomassa , Nanopartículas/química , Fumaça/análise , Gases/análise , Compostos Orgânicos/análise , Tamanho da Partícula , Hidrocarbonetos Policíclicos Aromáticos/análise
3.
Sci Rep ; 13(1): 21608, 2023 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-38062060

RESUMO

No official clinical reference values have been established for MostGraph, which measures total respiratory resistance and reactance using the forced oscillation technique, complicating result interpretation. This study aimed to establish a reference range for MostGraph measurements and examine its usefulness in discriminating participants with asthma from controls (participants without any respiratory diseases). The study also aimed to investigate the effectiveness of deep learning in discriminating between the two aforementioned groups. To establish reference ranges, the MostGraph measurements of healthy controls (n = 215) were power-transformed to distribute the data more normally. After inverse transformation, the mean ± standard deviation × 2 of the transformed values were used to establish the reference ranges. The number of measured items outside the reference ranges was evaluated to discriminate patients with asthma (n = 941) from controls. Additionally, MostGraph measurements were evaluated using deep learning. Although reference ranges were established, patients with asthma could not be discriminated from controls. However, with deep learning, we could discriminate between the two groups with 78% accuracy. Therefore, deep learning, which considers multiple measurements as a whole, was more effective in interpreting MostGraph measurement results than use of reference ranges, which considers each result individually.


Assuntos
Asma , Aprendizado Profundo , Humanos , Valores de Referência , Espirometria/métodos , Testes de Função Respiratória/métodos , Asma/diagnóstico , Resistência das Vias Respiratórias
4.
Nihon Kokyuki Gakkai Zasshi ; 47(10): 947-52, 2009 Oct.
Artigo em Japonês | MEDLINE | ID: mdl-19882921

RESUMO

A 74-year-old-man (case 1) was admitted to our hospital because of dry cough, fever, and dyspnea on effort. His daughter-in-law, a 53-year-old-woman (case 2), was also admitted to our hospital on suspicion of hypersensitivity pneumonitis (HP). Their diagnoses of HP were established by radiological, serological, and histological examinations. It was necessary to differentiate between summer-type hypersensitivity pneumonitis (SHP) and bird breeder's lung due to their special environment. Several examinations, including immunological findings of BALF, returning-home provocation test, and antigen inhalation challenge test, enabled us to establish their diagnoses of SHP.


Assuntos
Alveolite Alérgica Extrínseca/diagnóstico , Pulmão do Criador de Aves/diagnóstico , Idoso , Diagnóstico Diferencial , Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
5.
Ind Health ; 53(2): 124-31, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25382381

RESUMO

Breathing machines are widely used to evaluate respirator performance but they are capable of generating only limited air flow patterns, such as, sine, triangular and square waves. In order to evaluate the respirator performance in practical use, it is desirable to test the respirator using the actual breathing patterns of wearers. However, it has been a difficult task for a breathing machine to generate such complicated flow patterns, since the human respiratory volume changes depending on the human activities and workload. In this study, we have developed an electromechanical breathing simulator and a respiration sampling device to record and reproduce worker's respiration. It is capable of generating various flow patterns by inputting breathing pattern signals recorded by a computer, as well as the fixed air flow patterns. The device is equipped with a self-control program to compensate the difference in inhalation and exhalation volume and the measurement errors on the breathing flow rate. The system was successfully applied to record the breathing patterns of workers engaging in welding and reproduced the breathing patterns.


Assuntos
Teste de Materiais/instrumentação , Respiração , Dispositivos de Proteção Respiratória/normas , Adulto , Desenho de Equipamento , Humanos , Masculino , Teste de Materiais/métodos , Saúde Ocupacional , Ventilação Pulmonar , Soldagem
6.
J Hazard Mater ; 246-247: 26-33, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23280051

RESUMO

The destruction of naphthalene, as representative polycyclic aromatic hydrocarbons, by surface dielectric barrier discharge is investigated in air as well as dry and humidified nitrogen at ambient temperature. Naphthalene destruction efficiency is evaluated in terms of chemical change vis-a-vis energy utilization. The detected byproducts are qualitatively evaluated in order to understand the role of the active species in the destruction process. The results show that the destruction efficiency and the energy efficiency are higher in the dry nitrogen than in the humidified nitrogen, and these decrease with the increase of the humidity. Measured concentration of ozone as a byproduct qualitatively indicates the roles of oxygen and ozone in the destruction process in air. The analysis of the aerosol particles formed during the destruction process, both in the dry and humidified nitrogen, confirmed the adverse effects of the humidity on the byproducts formation and subsequently on the destruction process.


Assuntos
Poluentes Atmosféricos/química , Naftalenos/química , Nitrogênio/química , Espécies Reativas de Nitrogênio/química
12.
Basic Clin Pharmacol Toxicol ; 104(5): 352-9, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19175362

RESUMO

TAS-108 is a novel steroidal anti-oestrogen, expected to be useful for the treatment of breast cancer. The present study was conducted to investigate the safety, tolerability and pharmacokinetics of TAS-108 following the administration at a single oral dose of 40 mg to up to 120 mg in 12 post-menopausal women and the effect of food on the pharmacokinetics of the drug. All adverse events were mild and involved transient symptoms that resolved without therapeutic intervention. TAS-108 was readily absorbed and plasma levels of TAS-108 steadily declined, apparently in a multi-exponential manner. C(max) and AUC(0-12) were proportionally increased with increasing dose of TAS-108. The C(max) and AUC(0-t) of TAS-108 and its metabolite, deEt-TAS-108, were significantly increased to approximately 150% when TAS-108 was administered after a meal. Food did not affect the elimination half-life of TAS-108 or its metabolites. In this escalating dose-study of TAS-108, the drug was well tolerated by healthy post-menopausal Japanese women. The pharmacokinetics of TAS-108 indicated dose proportionality, and its bioavailability was significantly increased by food intake.


Assuntos
Estradiol/análogos & derivados , Antagonistas de Estrogênios/uso terapêutico , Estrogênios/metabolismo , Pós-Menopausa/metabolismo , Administração Oral , Disponibilidade Biológica , Neoplasias da Mama/metabolismo , Neoplasias da Mama/prevenção & controle , Relação Dose-Resposta a Droga , Esquema de Medicação , Estradiol/administração & dosagem , Estradiol/efeitos adversos , Estradiol/farmacocinética , Estradiol/uso terapêutico , Antagonistas de Estrogênios/administração & dosagem , Antagonistas de Estrogênios/efeitos adversos , Antagonistas de Estrogênios/farmacocinética , Feminino , Humanos , Japão , Pessoa de Meia-Idade
13.
Environ Sci Technol ; 39(14): 5436-41, 2005 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-16082977

RESUMO

The acetaldehyde adsorption capacities of activated carbons impregnated with various amines were experimentally studied by using fixed beds. It was found that the adsorption capacity of impregnated activated carbons is influenced by the steric structure of impregnants as well as their acidity. For activated carbons impregnated with aromatic amines, ortho and meta substituents on the benzene ring hindered the condensation reaction with acetaldehyde. The activated carbon impregnated with aminobenzenesulfonic acids differed from that impregnated with the other amines in the acetaldehyde adsorption mechanism in that a Doebner-Miller reaction was involved. Also, aminobenzenesulfonic acids were not only the reactant but also the acid catalyst in the removal of acetaldehyde. Since p-aminobenzenesulfonic acid reacts with acetaldehyde without steric hindrance in the Doebner-Miller reaction, it is the most suitable impregnant for the chemisorption of acetaldehyde.


Assuntos
Acetaldeído/isolamento & purificação , Poluentes Atmosféricos/isolamento & purificação , Carbono/química , Adsorção , Aminas/química , Teste de Materiais , Volatilização
14.
Environ Sci Technol ; 36(19): 4170-4, 2002 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-12380091

RESUMO

Removal technique of trace volatile organic compounds (VOCs) from air or other gases is of great concern in order to obtain contamination-free indoor air and various process gases for semiconductor manufacturing process. We propose a new technique for separating trace gas components. This technique utilizes preferential ionization and electrical migration of ions. Nitrogen and oxygen gas flow containing toluene vapor is divided into two flows, while the flow is irradiated with alpha-ray from 241Am under a DC electric field. The ionized toluene vapor in one flow electrically migrates into the other flow causing toluene rich and free flows. The separation efficiency of toluene is 50% when 0.5 L/min of inlet nitrogen stream contains 0.15 ppm of toluene at the applied voltage of 250 V. The separation efficiency of toluene increases with the mole fraction of oxygen in the carrier gas. The cation concentration flowing out from the separator is lower than the number of separated toluene molecules by 6 orders of magnitude, but the dependency of toluene separation efficiency on the applied voltage is the same as that of cation separation efficiency. The dependency of separation efficiency on the applied voltage and the gas flow velocity is qualitatively explained by the separation model which accounts for the generation and neutralization of VOC ions in the separator.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Compostos Orgânicos/isolamento & purificação , Eletricidade Estática , Volatilização
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