Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Environ Res ; 216(Pt 1): 114501, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36220443

RESUMO

A number of flavored capsule heat-not-burn (FC-HNB) tobacco products such as IQOS, Lil, and Glo have been introduced as a new generation of cigarettes. As they can release various types of volatile organic compounds (VOCs), it is important to assess the harmfulness associated with their use. Thus, the composition of VOCs in HNB cigarette vapor was evaluated to investigate the interactive roles of key variables controlling the relationships between VOC composition and capsule breaking, particularly the compositional changes induced by capsule breaking and release of flavor from FC-HNB cigarettes relative to regular products. As the capsules of FC-HNB cigarettes were broken, the total VOC concentrations increased by as high as eight times from 60.3 ± 0.48 to 488 ± 21.8 µg cig-1. The key VOC components released after breaking the flavored capsules were identified as ethyl butyrate (157 ± 13.6 µg cig-1; Lil), isoamyl acetate (76.9 ± 1.98 µg cig-1; Lil), and limonene (52.3 ± 3.29 µg cig-1; Glo). If the primary health risks of FC-HNB cigarette vapor are assessed using National Institute for Occupational Safety & Health (NIOSH) guidelines, 2,3-butanedinone exceeds the maximum daily intake limit (i.e., 0.05 mg day-1). Our study is expected to offer valuable insights into the harmful effects of direct and indirect exposure to various VOCs in FC-HNB products.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Produtos do Tabaco , Compostos Orgânicos Voláteis , Temperatura Alta , Fumar
2.
Environ Res ; 209: 112866, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35134376

RESUMO

In this study, the composition of mainstream smoke was investigated with an emphasis on a list of volatile organic compounds (VOCs: e.g., isoprene, acrylonitrile, methyl ethyl ketone, benzene, toluene, m-xylene and styrene) using the two types of flavor capsule cigarettes (FCCs, here coded as F1 and F2) in reference to one commercial, non-flavored (NF) and 3R4F cigarette. The concentrations of all the target compounds from FCCs were quantified under two contrasting conditions (i.e., with and without breaking the capsules). The effect of breaking the capsule was apparent in the FCC products with the enhancement of VOC levels, specifically between after and before breaking the capsules (e.g., 1.10-1.58 folds (benzene) and 1.30-1.53 folds (acetonitrile)). Such increases were apparent in both FCC samples if assessed in terms of the total amount of VOCs (TVOC): (1) F1 (from 2159 to 2530 µg cig-1 (p = 9.42 × 10-6)) and (2) F2 (from 1470 to 2014 µg cig-1 (p = 0.05)). In addition, these TVOC levels determined from the FCCs were 1.62- to 1.83- and 1.29- to 1.46-fold higher than those of the NF cigarette and the 3R4F cigarette, respectively. Thus, these FCC products are suspected to play a role as stronger sources of VOCs than the general cigarette products.


Assuntos
Produtos do Tabaco , Compostos Orgânicos Voláteis , Benzeno/análise , Fumaça , Nicotiana , Compostos Orgânicos Voláteis/análise
3.
Sci Total Environ ; 743: 140761, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32659563

RESUMO

In an effort to develop a cost-effective mitigation tool for volatile organic compounds, particularly formaldehyde (FA), microporous activated carbon (AC) was modified into three different forms of AC-1, AC-2, and AC-3 using a raw commercial AC product (AC-0). First, AC-1 and AC-2 were produced by the modification of AC-0 with N/S heteroatoms using identical mixture of dicyandiamide and thiourea precursors through either solvothermal (AC-1) or microwave-assisted calcination (AC-2) synthesis. Second, aminosilane-functionalized AC (AC-3) was prepared solvothermally using N-[3-(Trimethoxysilyl)propyl]ethylenediamine reagent. The relative adsorption performances for gaseous FA (1 ppm) in terms of 10% breakthrough volume (BTV10: L atm g-1) at near-ambient conditions (25 °C and 1 atm) were AC-3 (132) > AC-2 (66.5) > AC-1 (14.2) > AC-0 (10.4). In a comparison based on partition coefficients (mole kg-1 Pa-1) at BTV10, AC-3 outperformed AC-0 by a factor of 214, while the adsorption performance of AC-2 was 36-times higher than AC-1. The enhanced performance of AC-2 over AC-1 reflected the effect of the microwave synthesis protocol on the improvement of surface chemistry (e.g., N/S doping) and texture (e.g., surface area and pore volume) of AC-based adsorbents as compared to conventional solvothermal method. Further, the prominent role of surface chemistry (e.g., relative to textural properties), as observed with the increases in the amount of doped functional elements (including N:C and silicon:C ratios), is supported by the apparent dependence of performance on the selected modification procedures. Based on kinetic and X-ray photoelectron spectroscopy analyses, the superiority of aminosilylated AC-3 can be attributed to a synergistic effect between physisorption (e.g., pore diffusion) and chemical interactions of the FA carbonyl (C=O) group with amine and silica functionalities (via Mannich coupling [Schiff base] and cycloaddition reaction mechanisms, respectively). This confirms the significance of surface chemistry, relative to pore diffusion, in achieving maximum adsorption of gaseous FA molecules.

4.
Water Res ; 132: 200-210, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29331908

RESUMO

This research was based on the investigation of a major principle, regarding the effects of NaCl and KH2PO4 concentrations on struvite recovery, with electricity production using magnesium-air fuel cell electrocoagulation, in accordance with the concentration of phosphorous and chloride. The weight ratio of N:P in the synthetic wastewater was in the range of 1.2-21. The concentration of NH4Cl was fixed at 0.277 M (approximately 3888 ppm as NH3-N and 5000 ppm as NH4), while PO4-P was in the range of 0.006-0.1 M. In addition, the concentrations of NaCl as electrolyte were 0, 0.01, and 0.1 M. Phosphate removal increased linearly with the Mg:P ratio, up to approximately 1.1 mol mol-1, irrespective of the initial concentrations of phosphate and NaCl. The one-to-one reaction as mole ratio between phosphate and the dissolved Mg ions resulted in phosphate removal, with the production of a one-to-one magnesium/phosphate mineral, such as struvite. The average removal rate of phosphorous in experiments without a dose of NaCl was 4.19 mg P cm-2 h-1, which was lower than the relative values of 5.35 and 4.77 mg P cm-2 h-1, in experiments with 0.01 and 0.1 M NaCl. The dissolution rate of Mg with electro-oxidation determined the rate of phosphorous removal with struvite recovery. The average removal rates of phosphorous with dose concentrations of 0.006, 0.01 and 0.02 M KH2PO4 were 4.02, 5.54, 6.9 mg P cm-2 h-1, respectively, which increased with the increase in KH2PO4 dose. However, in experiments with a dose of 0.05 and 0.1 M KH2PO4, the average removal rates of phosphorous decreased to 4.84 and 2.51, respectively. The maximum power densities in the electrolyte mixture of 0.05 M KH2PO4/0.277 M NH4Cl, 0.01 M NaCl/0.05 M KH2PO4/0.277 M NH4Cl, and 0.1 NaCl/0.05 KH2PO4/0.277 M NH4Cl were 25.1, 26.4, and 33.2 W/m2, respectively. The increase in the NaCl dose concentration resulted in an increase in the maximum power density and current density. A dose above 0.05 M KH2PO4 resulted in the decrease of the maximum power densities. However, when the dose was below 0.05 M KH2PO4, the maximum power density increased with the increase in KH2PO4 dose.


Assuntos
Técnicas Eletroquímicas , Fósforo/isolamento & purificação , Estruvita/química , Eliminação de Resíduos Líquidos/métodos , Eletricidade , Magnésio/química , Fosfatos/química , Fósforo/química , Compostos de Potássio/química , Cloreto de Sódio/química , Águas Residuárias/química
5.
Toxins (Basel) ; 8(2): 51, 2016 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-26907344

RESUMO

Celiac plexus block (CPB) is one of the main treatment options for patients resistant to conventional antihypertensive drugs. We present a case of resistant hypertension (RHTN) that was treated with CPB using botulinum toxin. An 18-year-old male patient with RHTN, who suffered from persistent hypertension even after combination therapy and a renal denervation procedure, was referred to our pain center for CPB. CPB using botulinum toxin following the use of only local anesthetics resulted in control of systolic blood pressure (BP) at ~150 mmHg for at least three months.


Assuntos
Anti-Hipertensivos/uso terapêutico , Toxinas Botulínicas/uso terapêutico , Plexo Celíaco/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Adolescente , Pressão Sanguínea/efeitos dos fármacos , Plexo Celíaco/fisiologia , Resistência a Medicamentos , Humanos , Masculino
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...