RESUMEN

Combined allergic rhinitis and asthma syndrome (CARAS) is an airway-type 2 immune response with a profuse inflammatory process widely affecting the world population. Due to the compromise of quality of life and the lack of specific pharmacotherapy, the search for new molecules becomes relevant. This study aimed to evaluate the effectiveness of the Morita-Bailys-Hillman adduct (CISACN) treatment in the CARAS experimental model. Female BALB/c mice were ovalbumin (OVA) -sensitized and -challenged and treated with CISACN. The treatment decreased the eosinophil migration to the nasal and lung cavities and tissues and the goblet cell hyperplasia/hypertrophy, attenuated airway hyperactivity by reducing the hyperplasia/hypertrophy of the smooth muscle and the extracellular matrix's thickness. Also, the treatment reduced the clinical signs of rhinitis as nasal rubbing and sneezing in a histamine-induced nasal hyperreactivity assay. The immunomodulatory effect of CISACN was by reducing OVA-specific IgE serum level, and IL-33, IL-4, IL-13, and TGF-ß production, dependent on IFN-γ increase. Furthermore, the effect of CISACN on lung granulocytes was by decreasing the p-p38MAPK/p65NF-κB signaling pathway. Indeed, CISACN reduced the p38MAPK and p65NF-κB activation. These data demonstrated the anti-inflammatory and immunomodulatory effects of the CISACN with scientific support to become a pharmacological tool to treat airway inflammatory diseases.

Asunto(s)

Acrilonitrilo , Asma , Rinitis Alérgica , Animales , Femenino , Ratones , Acrilonitrilo/administración & dosificación , Asma/tratamiento farmacológico , Asma/metabolismo , Citocinas/metabolismo , Modelos Animales de Enfermedad , Hiperplasia , Hipertrofia , Inmunidad , Inflamación/tratamiento farmacológico , Interleucina-4/farmacología , Pulmón , Ratones Endogámicos BALB C , Ovalbúmina , Calidad de Vida , Rinitis Alérgica/tratamiento farmacológico , Células Th2

RESUMEN

This study validated an analytical technique using headspace gas chromatography with flame ionization detection to quantify acrylonitrile monomer with a quantification limit of 0.10 ± 0.04 µg kg-1 . Subsequently, the acrylonitrile migration from polypropylene granules was evaluated in food simulants water and ethanol (50% v/v) and at two temperatures (20 ± 1°C and 44 ± 2°C) for up to 6 weeks, representing the service time of a bottle. From the experimental data obtained, pseudo-second-order kinetics were adjusted to represent the acrylonitrile migration into the simulants. For water, equilibrium concentrations of 13.58 and 16.58 µg kg-1 at 20 and 44°C, respectively, were obtained, while for 50% ethanol, 15.07 and 16.40 µg kg-1 were obtained for the same temperatures. The experimental results and the values estimated from the migration kinetics indicate that the maximum acrylonitrile concentration will not exceed the tolerable specific limit established in regulations. PRACTICAL APPLICATION: The migration of compounds such as acrylonitrile can be a drawback resulting in an undesirable reduction in the shelf life of liquid foods packaged in bottles made of materials such as polypropylene. In this paper, acrylonitrile migration kinetics and a methodology are proposed to determine whether the tolerable migration limits are ever reached, which can serve as a tool for producers of this type of packaging of food to predict shelf life.

Asunto(s)

Acrilonitrilo , Embalaje de Alimentos , Polipropilenos , Acrilonitrilo/análisis , Etanol/química , Agua/química , Contaminación de Alimentos/análisis

RESUMEN

BACKGROUND: Despite its homeostatic role, inflammation is involved in several pathologies, such as acute lung injury. Morita-Ballys-Hilman adducts (MBHA) are a group of synthetic molecules and present a wide range of biological activities, including anti-inflammatory action. Thus, this study aimed to assess whether ISACN, an MBHA, modulates inflammation during acute lung injury induced by lipopolysaccharide (LPS). METHODS: BALB/c mice were intraperitoneally treated with 24 mg/kg ISACN and challenged with LPS (2.5 mg/kg). On bronchoalveolar lavage fluid (BALF), we assessed the total and differential leukocyte count and measurement of protein leakage, cytokines (IL-1ß, IL-6, and TNF-α), and chemokine (CXCL-1). Additionally, lung histopathology was also performed (H&E staining). In vitro studies were conducted with peritoneal macrophages to assess the possible mechanism of action. They were cultured in the presence of ISACN (5 and 10 µM) and stimulated by LPS (1 µg/mL). RESULTS: ISACN reduced neutrophil migration, protein leakage, and inflammatory cytokines (IL-1ß, IL-6, and TNF-α) without interfering with the production of CXCL1. In addition, ISACN caused a decrease in LPS-induced lung injury as evident from histopathological changes. In peritoneal macrophages, ISACN diminishes the nitric oxide and cytokine levels (IL-1ß, IL-6, and TNF-α). The treatment with ISACN (10 µM) also reduced LPS-induced TLR4, CD69, iNOS overexpression, and the LPS-induced ERK, JNK, and p38 phosphorylation. CONCLUSION: Thus, this work showed for the first time the immunomodulatory action of MBHA in LPS-induced acute lung injury and provided new evidence for the mechanisms related to the anti-inflammatory effect of ISACN.

Asunto(s)

Acrilonitrilo , Lesión Pulmonar Aguda , Ratones , Animales , Lipopolisacáridos/toxicidad , Acrilonitrilo/efectos adversos , Acrilonitrilo/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Interleucina-6/metabolismo , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/tratamiento farmacológico , Lesión Pulmonar Aguda/metabolismo , Pulmón , Citocinas/metabolismo , Antiinflamatorios/uso terapéutico , Inflamación/inducido químicamente , Inflamación/tratamiento farmacológico , Inflamación/metabolismo

RESUMEN

Nylon 6/acrylonitrile-butadiene-styrene nanocomposites were prepared by mixing in a molten state and injection molded for application in electromagnetic interference shielding and antistatic packaging. Multi-wall carbon nanotubes (MWCNT) and maleic anhydride-grafted ABS compatibilizer were incorporated to improve the electrical conductivity and mechanical performance. The nanocomposites were characterized by oscillatory rheology, Izod impact strength, tensile strength, thermogravimetry, current-voltage measurements, shielding against electromagnetic interference, and scanning electron microscopy. The rheological behavior evidenced a severe increase in complex viscosity and storage modulus, which suggests an electrical percolation phenomenon. Adding 1 to 5 phr MWCNT into the nanocomposites produced electrical conductivities between 1.22 × 10-6 S/cm and 6.61 × 10-5 S/cm. The results make them suitable for antistatic purposes. The nanocomposite with 5 phr MWCNT showed the highest electromagnetic shielding efficiency, with a peak of -10.5 dB at 9 GHz and a value around -8.2 dB between 11 and 12 GHz. This was possibly due to the higher electrical conductivity of the 5 phr MWCNT composition. In addition, the developed nanocomposites, regardless of MWCNT content, showed tenacious behavior at room temperature. The results reveal the possibility for tailoring the properties of insulating materials for application in electrical and electromagnetic shielding. Additionally, the good mechanical and thermal properties further widen the application range.

Asunto(s)

Acrilonitrilo , Nanocompuestos , Nanotubos de Carbono , Butadienos , Caprolactama/análogos & derivados , Conductividad Eléctrica , Polímeros , Estireno

RESUMEN

Morita-Baylis-Hillman adducts (MBHA) are synthetic molecules with several biological actions already described in the literature. It has been previously described that adduct 2-(3-hydroxy-2-oxoindolin-3-yl)acrylonitrile (ISACN) has anticancer potential in leukemic cells. Inflammation is often associated with the development and progression of cancer. Therefore, to better understand the effect of ISACN, this study aimed to evaluate the anti-inflammatory potential of ISACN both in vitro and in vivo. Results demonstrated that ISACN negatively modulated the production of inflammatory cytokines IL-1ß, TNF-α, and IL-6 by cultured macrophages. In vivo, ISACN 6 and 24 mg/kg treatment promoted reduced leukocyte migration, especially neutrophils, to the peritoneal cavity of zymosan-challenged animals. ISACN displays no anti-edematogenic activity, but it was able to promote a significant reduction in the production of inflammatory cytokines in the peritoneal cavity. These data show, for the first time, that MBHA ISACN negatively modulates several aspects of the inflammatory response, such as cell migration and cytokine production in vivo and in vitro, thus having an anti-inflammatory potential.

Asunto(s)

Acrilonitrilo/farmacología , Antiinflamatorios/farmacología , Citocinas/metabolismo , Mediadores de Inflamación/metabolismo , Macrófagos Peritoneales/efectos de los fármacos , Peritonitis/prevención & control , Acrilonitrilo/análogos & derivados , Animales , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/metabolismo , Ratones , Infiltración Neutrófila/efectos de los fármacos , Neutrófilos/efectos de los fármacos , Neutrófilos/inmunología , Neutrófilos/metabolismo , Peritonitis/inducido químicamente , Peritonitis/inmunología , Peritonitis/metabolismo , Zimosan

RESUMEN

The aim of this work is to develop compatibilization strategies for High Impact Polystyrene (HIPS)/ Acrylonitrile-Butadiene-Styrene (ABS) blends from WEEE in order to add value to these recycled plastics by improving their mechanical performance. Results from a screening study of HIPS/ABS blends compatibilization by the addition of Styrene-Butadiene Rubber (SBR) are presented. Two different weight proportion of HIPS/ABS physical blends were analyzed, 80/20 and 20/80, with three different concentration of SBR: 2, 10 and 20 wt%. Compatibilization efficiency was analyzed from an accurate thermal and mechanical analysis, by comparing each physical blend and corresponding compatibilized blends with SBR. Results were discussed relating glass transition changes with mechanical performance, both aspects were interpreted in terms of blend morphology. Phase and fillers dispersion and distribution as well as SBR amount and its interaction with each phase were accurate analyzed. Compatibilization of HIPS/ABS blends from WEEE with the addition of SBR is effective in blends with HIPS as main component. With the addition of 2 wt% of SBR, strength and toughness have notably increased respect to the corresponding physical blend, 244% and 186% respectively. From this screening study is possible to infer that SBR is a sustainable and efficient compatibilizer of HIPS rich blends allowing to obtain a final blend that can be used as a replacement material of separated resins from WEEE.

Asunto(s)

Butadienos , Elastómeros , Residuos Electrónicos , Estirenos , Acrilonitrilo , Poliestirenos

RESUMEN

Due to the continual increase in waste generated from electronic devices, the management of plastics, which represents between 10 and 30% by weight of waste electrical and electronic equipment (WEEE or e-waste), becomes indispensable in terms of environmental and economic impacts. Considering the importance of acrylonitrile-butadiene-styrene (ABS), polycarbonate (PC), and their blends in the electronics and other industries, this study presents a new application of laser-induced breakdown spectroscopy (LIBS) for the fast and direct determination of PC and ABS concentrations in blends of these plastics obtained from samples of e-waste. From the LIBS spectra acquired for the PC/ABS blend, multivariate calibration models were built using partial least squares (PLS) regression. In general, it was possible to infer that the relative errors between the theoretical or reference and predicted values for the spiked samples were lower than 10%.

Asunto(s)

Acrilonitrilo/análisis , Butadienos/análisis , Residuos Electrónicos/análisis , Plásticos/química , Cemento de Policarboxilato/análisis , Poliestirenos/análisis , Administración de Residuos/métodos , Rayos Láser , Análisis Espectral

RESUMEN

The purpose of this study was to evaluate acrylonitrile butadiene styrene (ABS) and polyamide implants in rabbits submitted to evisceration at the macroscopic and microstructure level and to assess clinical response and histopathological changes as well. For the experimental study implants of 12mm diameter were prepared by rapid prototyping, weighed and the outer and inner surfaces evaluated macroscopically and by electron microscopy. In addition, a compression test was performed and ultrastructural damage was then determined. After evisceration of the left eyeball, nine New Zealand rabbits received ABS implants and nine others received polyamide implants. The animals were assessed daily for 15 days after surgery and every seven days until the end of the study (90 days). Histopathological evaluation was performed at 15, 45 and 90 days after surgery. The ABS implants weighed approximately 0.44g, while the polyamide ones weighed 0.61g. Scanning electron microscopy demonstrated that the ABS implants had regular-sized, equidistant micropores, while the polyamide ones showed micropores of various sizes. The force required to fracture the ABS implant was 14.39 ±0.60 Mpa, while for the polyamide one, it was 16.80 ±1.05 Mpa. Fifteen days after surgery, we observed centripetal tissue infiltration and scarce inflammatory infiltrate. Implants may be used in the filling of anophthalmic cavities, because they are inert, biocompatible and allow tissue integration.(AU)

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Avaliou-se a macroscopia, a microestrutura, a resposta clínica e histopatológica de implantes de acrilonitrila butadieno estireno (ABS) e poliamida em coelhos submetidos à evisceração. Para o estudo experimental, os implantes foram elaborados por meio de prototipagem rápida, com 12mm de diâmetro, pesados e tiveram suas superfícies avaliadas macroscopicamente e por microscopia eletrônica de varredura. Adicionalmente, foi realizado ensaio de compressão para determinar a força necessária para fraturar os implantes. Após a evisceração do olho esquerdo, nove coelhos da raça Nova Zelândia receberam implantes de poliamida e nove outros receberam implantes de ABS. Os animais foram avaliados diariamente nos primeiros 15 dias após a cirurgia e a cada sete dias até o fim do período experimental (90 dias). Avaliação histopatológica foi realizada aos 15, 45 e 90 dias após a cirurgia. Os implantes de ABS pesaram 0,44g, e os de poliamida 0,61g. A microscopia eletrônica de varredura demonstrou que os implantes de ABS eram formados por microporos equidistantes, enquanto os de poliamida apresentavam microporos de vários tamanhos. A força necessária para fraturar os implantes de ABS foi de 14.39±0.60 Mpa, enquanto para os de poliamida foi de 16.80±1.05Mpa. Quinze dias após a cirurgia, foi observada infiltração fibrovascular centrípeta. Os implantes podem ser utilizados para correção de cavidades anoftálmicas por se mostrarem inertes, biocompatíveis e permitirem a infiltração tecidual.(AU)

Asunto(s)

Animales , Conejos , Materiales Biocompatibles/análisis , Evisceración del Ojo/veterinaria , Ojo Artificial/veterinaria , Polímeros , Acrilonitrilo/análisis , Butadienos/análisis , Microscopía Electrónica de Rastreo/veterinaria , Nylons

RESUMEN

The purpose of this study was to evaluate acrylonitrile butadiene styrene (ABS) and polyamide implants in rabbits submitted to evisceration at the macroscopic and microstructure level and to assess clinical response and histopathological changes as well. For the experimental study implants of 12mm diameter were prepared by rapid prototyping, weighed and the outer and inner surfaces evaluated macroscopically and by electron microscopy. In addition, a compression test was performed and ultrastructural damage was then determined. After evisceration of the left eyeball, nine New Zealand rabbits received ABS implants and nine others received polyamide implants. The animals were assessed daily for 15 days after surgery and every seven days until the end of the study (90 days). Histopathological evaluation was performed at 15, 45 and 90 days after surgery. The ABS implants weighed approximately 0.44g, while the polyamide ones weighed 0.61g. Scanning electron microscopy demonstrated that the ABS implants had regular-sized, equidistant micropores, while the polyamide ones showed micropores of various sizes. The force required to fracture the ABS implant was 14.39 ±0.60 Mpa, while for the polyamide one, it was 16.80 ±1.05 Mpa. Fifteen days after surgery, we observed centripetal tissue infiltration and scarce inflammatory infiltrate. Implants may be used in the filling of anophthalmic cavities, because they are inert, biocompatible and allow tissue integration.(AU)

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Avaliou-se a macroscopia, a microestrutura, a resposta clínica e histopatológica de implantes de acrilonitrila butadieno estireno (ABS) e poliamida em coelhos submetidos à evisceração. Para o estudo experimental, os implantes foram elaborados por meio de prototipagem rápida, com 12mm de diâmetro, pesados e tiveram suas superfícies avaliadas macroscopicamente e por microscopia eletrônica de varredura. Adicionalmente, foi realizado ensaio de compressão para determinar a força necessária para fraturar os implantes. Após a evisceração do olho esquerdo, nove coelhos da raça Nova Zelândia receberam implantes de poliamida e nove outros receberam implantes de ABS. Os animais foram avaliados diariamente nos primeiros 15 dias após a cirurgia e a cada sete dias até o fim do período experimental (90 dias). Avaliação histopatológica foi realizada aos 15, 45 e 90 dias após a cirurgia. Os implantes de ABS pesaram 0,44g, e os de poliamida 0,61g. A microscopia eletrônica de varredura demonstrou que os implantes de ABS eram formados por microporos equidistantes, enquanto os de poliamida apresentavam microporos de vários tamanhos. A força necessária para fraturar os implantes de ABS foi de 14.39±0.60 Mpa, enquanto para os de poliamida foi de 16.80±1.05Mpa. Quinze dias após a cirurgia, foi observada infiltração fibrovascular centrípeta. Os implantes podem ser utilizados para correção de cavidades anoftálmicas por se mostrarem inertes, biocompatíveis e permitirem a infiltração tecidual.(AU)

Asunto(s)

Animales , Conejos , Evisceración del Ojo/veterinaria , Ojo Artificial/veterinaria , Polímeros , Materiales Biocompatibles/análisis , Acrilonitrilo/análisis , Butadienos/análisis , Microscopía Electrónica de Rastreo/veterinaria , Nylons

RESUMEN

We report single crystal X-ray diffraction (hereafter, SCXRD) analyses of derivatives featuring the electron-donor N-ethylcarbazole or the (4-diphenylamino)phenyl moieties associated with a -CN group attached to a double bond. The compounds are (2Z)-3-(4-(diphenylamino)-phenyl)-2-(pyridin-3-yl)prop-2-enenitrile (I), (2Z)-3-(4-(diphenylamino)phenyl)-2-(pyridin-4-yl)-prop-2-enenitrile (II) and (2Z)-3-(9-ethyl-9H-carbazol-3-yl)-2-(pyridin-2-yl)enenitrile (III). SCXRD analyses reveal that I and III crystallize in the monoclinic space groups P2/c with Z' = 2 and C2/c with Z' = 1, respectively. Compound II crystallized in the orthorhombic space group Pbcn with Z' = 1. The molecular packing analysis was conducted to examine the pyridine core effect, depending on the ortho, meta- and para-positions of the nitrogen atom, with respect to the optical properties and number of independent molecules (Z'). It is found that the double bond bearing a diphenylamino moiety introduced properties to exhibit a strong π-π-interaction in the solid state. The compounds were examined to evaluate the effects of solvent polarity, the role of the molecular structure, and the molecular interactions on their self-assembly behaviors. Compound I crystallized with a cell with two conformers, anti and syn, due to interaction with solvent. DFT calculations indicated the anti and syn structures of I are energetically stable (less than 1 eV). Also electrochemical and photophysical properties of the compounds were investigated, as well as the determination of optimization calculations in gas and different solvent (chloroform, cyclohexane, methanol, ethanol, tetrahydrofuran, dichloromethane and dimethyl sulfoxide) in the Gaussian09 program. The effect of solvent by PCM method was also investigated. The frontier HOMO and LUMO energies and gap energies are reported.

Asunto(s)

Acrilonitrilo/química , Carbazoles/química , Estructura Molecular , Acrilonitrilo/síntesis química , Carbazoles/síntesis química , Cristalografía por Rayos X , Electrones , Modelos Moleculares , Piridinas/química

RESUMEN

BACKGROUND: The search for new active compounds from the Brazilian flora has intensified in recent years, especially for new drugs with antibiotic potential. Accordingly, the aim of this study was to determine whether riachin has antibiotic activity in itself or is able to modulate the activity of conventional antibiotics. METHODS: A non-cyanogenic cyanoglycoside known as riachin was isolated from Bauhinia pentandra, and was tested alone and in combination with three antibiotics (clindamycin, amikacin, and gentamicin) against multiresistant bacterial strains (Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus). RESULTS: Riachin did not show significant antibiotic activity when tested alone against any strain (P>0.05). However, when combined with conventional antibiotics, it showed drug-modifying activity against strains of S. aureus exposed to clindamycin (P<0.001) as well as against P. aeruginosa exposed to amikacin (P<0.001). Although riachin did not show direct antibiotic activity, it had synergistic activity when combined with amikacin or clindamycin. The mechanism of action of this synergism is under investigation. CONCLUSION: The results of this work demonstrate that some substances of natural origin can enhance the effectiveness of certain antibiotics, which means a substantial reduction in the drug dose required and possibly in consequent adverse events for patients.

Asunto(s)

Acrilonitrilo/análogos & derivados , Antibacterianos/farmacología , Bauhinia/química , Glucósidos/farmacología , Extractos Vegetales/farmacología , Acrilonitrilo/farmacología , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Sinergismo Farmacológico , Escherichia coli/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos

RESUMEN

Polymeric materials constitute a considerable fraction of waste computer equipment and polymers acrylonitrile-butadiene-styrene and high-impact polystyrene are the main thermoplastic polymeric components found in waste computer equipment. Identification, separation and characterisation of additives present in acrylonitrile-butadiene-styrene and high-impact polystyrene are fundamental procedures to mechanical recycling of these polymers. The aim of this study was to evaluate the methods for identification of acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment in Brazil, as well as their potential for mechanical recycling. The imprecise utilisation of symbols for identification of the polymers and the presence of additives containing toxic elements in determinate computer devices are some of the difficulties found for recycling of acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment. However, the considerable performance of mechanical properties of the recycled acrylonitrile-butadiene-styrene and high-impact polystyrene when compared with the virgin materials confirms the potential for mechanical recycling of these polymers.

Asunto(s)

Acrilonitrilo/análisis , Butadienos/análisis , Residuos Electrónicos/análisis , Estireno/análisis , Brasil , Computadores , Fenómenos Mecánicos , Poliestirenos/análisis , Reciclaje , Reología

RESUMEN

OBJECTIVES: To update a cohort study of chemical workers and reevaluate lung cancer mortality in relation to acrylonitrile (AN) exposure. METHODS: Subjects were 2096 workers employed during 1955 to 2011. We identified 474 deaths through 2011, and quantitatively estimated worker exposures to AN. Analyses included national and county-based standardized mortality ratios and relative risk regression of internal cohort rates. RESULTS: We found no statistically significant excess mortality risks associated with Lima employment for any cause of death category, including lung cancer and other cancer sites implicated in previous studies. CONCLUSIONS: This update provides no evidence that exposure to AN at levels experienced by Lima workers is associated with an increased risk of lung cancer mortality, as suggested in original study. Earlier reported bladder cancer risks decreased to a much lower, not statistically significant level.

Asunto(s)

Acrilonitrilo/análisis , Carcinógenos/análisis , Industria Química/estadística & datos numéricos , Neoplasias/mortalidad , Enfermedades Profesionales/mortalidad , Exposición Profesional/análisis , Acrilonitrilo/toxicidad , Adulto , Anciano , Contaminantes Ocupacionales del Aire/análisis , Contaminantes Ocupacionales del Aire/toxicidad , Carcinógenos/toxicidad , Causas de Muerte , Neoplasias del Sistema Nervioso Central/mortalidad , Estudios de Cohortes , Femenino , Humanos , Neoplasias Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , Ohio/epidemiología , Neoplasias de la Próstata/mortalidad , Medición de Riesgo , Estados Unidos/epidemiología , Neoplasias de la Vejiga Urinaria/mortalidad

RESUMEN

OBJECTIVES: To evaluate the extent to which lung cancer mortality risk estimates in relation to acrylonitrile (AN) exposure may have been confounded by smoking in the presence of misclassified smoking data. METHODS: Subjects were 992 white men employed for three or more months between 1960 and 1996 at a chemical plant in Lima, Ohio. We used Monte Carlo-based sensitivity analysis to address possible confounding by smoking. RESULTS: In Monte Carlo simulations that accounted for the relationship between smoking and AN exposure, mean relative risks for lung cancer mortality in relation to AN exposure decreased and we observed somewhat less evidence of an exposure-response relationship. CONCLUSIONS: Our simulations suggest that the relationship between AN exposure and lung cancer mortality was positively confounded by smoking in the original Lima cohort study.

Asunto(s)

Acrilonitrilo/toxicidad , Carcinógenos/toxicidad , Industria Química , Neoplasias Pulmonares/mortalidad , Enfermedades Profesionales/mortalidad , Exposición Profesional , Fumar/epidemiología , Contaminantes Ocupacionales del Aire/toxicidad , Estudios de Casos y Controles , Estudios de Cohortes , Simulación por Computador , Factores de Confusión Epidemiológicos , Recolección de Datos/normas , Humanos , Neoplasias Pulmonares/etiología , Masculino , Método de Montecarlo , Enfermedades Profesionales/etiología , Exposición Profesional/efectos adversos , Ohio/epidemiología , Prevalencia

RESUMEN

O objetivo do presente estudo foi de avaliar a influência de soluções de resina com diferentes proporções de monômeros e diferentes concentrações em massa de nanofibras nas propriedades flexurais de compósitos resinosos experimentais reforçados com nanofibras de poliacrilonitrila (PAN). Materiais e métodos: Nanofibras de PAN foram produzidas pelo processo de eletrofiação e caraterizadas por teste de tração e microscopia eletrônica de varredura (MEV). Os compósitos experimentais foram produzidos pela infiltração das mantas de nanofibras com diferentes misturas de BisGMA-TEGDMA (BisGMA/TEGDMA: proporções em % massa de 30/70, 50/50, e 70/30). Foram incorporadas diferentes concentrações em massa de nanofibras (de 0% a 8%). Espécimes em forma de barra foram seccionados a partir de blocos do compósito experimental e armazenados em água na temperatura de 37oC por 24h anteriormente à realização dos testes de flexão de três pontos. Foram avaliados a resistência flexural (RF), o módulo flexural (MF) e o trabalho de fratura (TF). Resultados: Os testes de tração das nanofibras de PAN demonstraram um comportamento anisotrópico das mantas de nanofibras. As propriedades mecânicas exibiram maiores valores na direção perpendicular ao eixo de rotação do coletor metálico utilizado na produção das fibras por eletrofiação. Maiores proporções de BisGMA nas misturas de resina resultaram em maiores valores de RF e MF, o que não ocorreu para os valores de TF. A adição de diferentes concentrações de nanofibras não afetou as propriedades de RF e MF em comparação com o grupo controle (resina pura) (p>0.05). No entanto, a adição das nanofibras promoveu um aumento significante do TF, principalmente para as misturas de resina com maior proporção de TEGDMA (p<0,05). Significância: A inclusão de nanofibras de PAN em resinas de modo a formar compósitos resinosos reforçados por nanofibras não afetou negativamente as propriedades flexurais do material e resultou em um aumento significativo da...

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The present study had the objectives to evaluate the influence of different resin blends concentrations and nanofibers mass ratio on flexural properties of experimental Poliacrylonitrile (PAN) nanofibers reinforced composite. Materials and Methods: Poliacrylonitrile (PAN) nanofibers mats were produced by electrospinning and characterized by tensile testing and scanning electron microscopy (SEM). Experimental resin-fiber composite beams were manufactured by infiltrating PAN nanofiber meshs with varied concentrations of BisGMA-TEGDMA resin blends (BisGMA/TEGDMA: 30/70, 50/50 and 70/30 weight %). The mass ratio of fiber to resin varied from 0% to 8%. Beams were cured and stored in water at 37oC. Flexural strength (FS), flexural modulus (FM) and work of fracture (WF) were evaluated by three-point bending test after 24 hs storage. Results: The tensile properties of the PAN nanofibers indicated an anisotropic behavior being always higher when tested in a direction perpendicular to the rotation of the collector drum. Except for WF, the other flexural properties (FS and FM) were always higher as the ratio of BisGMA to TEGDMA increased in the neat resin beams. The addition of different ratios of PAN fibers did not affect FS and FM of the composite beams as compared to neat resin beams (p>0.05). However, the addition of fibers significantly increased the WF of the composite beams, and this was more evident for the blends with higher TEGDMA ratios (p<0.05). Significance: The inclusion of PAN nanofibers into resin blends did not negatively affect the properties of the composite and resulted in an increase in toughness that is a desirable property for a candidate material for restorative application.

Asunto(s)

Ácidos Polimetacrílicos/química , Bisfenol A Glicidil Metacrilato/química , Nanofibras/química , Polietilenglicoles/química , Resinas Compuestas/química , Análisis de Varianza , Acrilonitrilo/química , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Docilidad , Reproducibilidad de los Resultados , Propiedades de Superficie , Resistencia a la Tracción

RESUMEN

O objetivo do presente estudo foi de avaliar a influência de soluções de resina com diferentes proporções de monômeros e diferentes concentrações em massa de nanofibras nas propriedades flexurais de compósitos resinosos experimentais reforçados com nanofibras de poliacrilonitrila (PAN). Materiais e métodos: Nanofibras de PAN foram produzidas pelo processo de eletrofiação e caraterizadas por teste de tração e microscopia eletrônica de varredura (MEV). Os compósitos experimentais foram produzidos pela infiltração das mantas de nanofibras com diferentes misturas de BisGMA-TEGDMA (BisGMA/TEGDMA: proporções em % massa de 30/70, 50/50, e 70/30). Foram incorporadas diferentes concentrações em massa de nanofibras (de 0% a 8%). Espécimes em forma de barra foram seccionados a partir de blocos do compósito experimental e armazenados em água na temperatura de 37oC por 24h anteriormente à realização dos testes de flexão de três pontos. Foram avaliados a resistência flexural (RF), o módulo flexural (MF) e o trabalho de fratura (TF). Resultados: Os testes de tração das nanofibras de PAN demonstraram um comportamento anisotrópico das mantas de nanofibras. As propriedades mecânicas exibiram maiores valores na direção perpendicular ao eixo de rotação do coletor metálico utilizado na produção das fibras por eletrofiação. Maiores proporções de BisGMA nas misturas de resina resultaram em maiores valores de RF e MF, o que não ocorreu para os valores de TF. A adição de diferentes concentrações de nanofibras não afetou as propriedades de RF e MF em comparação com o grupo controle (resina pura) (p>0.05). No entanto, a adição das nanofibras promoveu um aumento significante do TF, principalmente para as misturas de resina com maior proporção de TEGDMA (p<0,05). Significância: A inclusão de nanofibras de PAN em resinas de modo a formar compósitos resinosos reforçados por nanofibras não afetou negativamente as propriedades flexurais do material e resultou em um aumento significativo da...

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The present study had the objectives to evaluate the influence of different resin blends concentrations and nanofibers mass ratio on flexural properties of experimental Poliacrylonitrile (PAN) nanofibers reinforced composite. Materials and Methods: Poliacrylonitrile (PAN) nanofibers mats were produced by electrospinning and characterized by tensile testing and scanning electron microscopy (SEM). Experimental resin-fiber composite beams were manufactured by infiltrating PAN nanofiber meshs with varied concentrations of BisGMA-TEGDMA resin blends (BisGMA/TEGDMA: 30/70, 50/50 and 70/30 weight %). The mass ratio of fiber to resin varied from 0% to 8%. Beams were cured and stored in water at 37oC. Flexural strength (FS), flexural modulus (FM) and work of fracture (WF) were evaluated by three-point bending test after 24 hs storage. Results: The tensile properties of the PAN nanofibers indicated an anisotropic behavior being always higher when tested in a direction perpendicular to the rotation of the collector drum. Except for WF, the other flexural properties (FS and FM) were always higher as the ratio of BisGMA to TEGDMA increased in the neat resin beams. The addition of different ratios of PAN fibers did not affect FS and FM of the composite beams as compared to neat resin beams (p>0.05). However, the addition of fibers significantly increased the WF of the composite beams, and this was more evident for the blends with higher TEGDMA ratios (p<0.05). Significance: The inclusion of PAN nanofibers into resin blends did not negatively affect the properties of the composite and resulted in an increase in toughness that is a desirable property for a candidate material for restorative application.

Asunto(s)

Ácidos Polimetacrílicos/química , Bisfenol A Glicidil Metacrilato/química , Nanofibras/química , Polietilenglicoles/química , Resinas Compuestas/química , Análisis de Varianza , Acrilonitrilo/química , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Docilidad , Reproducibilidad de los Resultados , Propiedades de Superficie , Resistencia a la Tracción

RESUMEN

Acrylonitrile (ACN) is a widely used chemical in the production of plastics, resins, nitriles, acrylic fibers, and synthetic rubber. Previous epidemiological investigations and animal studies have confirmed that ACN affects the lymphocytes and spleen. However, the immune toxicity mechanism is unknown. Lipid rafts are cell membrane structures that are rich in cholesterol and involved in cell signal transduction. The B cell lymophoma-10 (Bcl10) protein is a joint protein that is important in lymphocyte development and signal pathways. This study was conducted to examine the in vitro effects of ACN. We separated lipid rafts, and analyzed Bcl10 protein and caveolin. Western blotting was used to detect mitogen-activated protein kinase (MAPK) and phosphorylated MAPK levels. The results indicated that with increasing ACN concentration, the total amount of Bcl10 remained stable, but was concentrated mainly in part 4 to part 11 in electrophoretic band district which is high density in gradient centrifugation. Caveolin-1 was evaluated as a lipid raft marker protein; caveolin-1 content and position were relatively unchanged. Western blotting showed that in a certain range, MAPK protein was secreted at a higher level. At some ACN exposure levels, MAPK protein secretion was significantly decreased compared to the control group (P < 0.05). These results indicate that ACN can cause immune toxicity by damaging lipid raft structures, causing Bcl10 protein and lipid raft separation and restraining Ras-Raf-MAPK-extracellular signal-regulated kinase signaling pathways.

Asunto(s)

Acrilonitrilo/farmacología , Linfocitos/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Microdominios de Membrana/efectos de los fármacos , Quinasas raf/metabolismo , Proteínas ras/metabolismo , Western Blotting , Humanos , Células Jurkat , Linfocitos/metabolismo

RESUMEN

This study aimed to evaluate the effects of acrylonitrile (ACN) on neuronal morphology and apoptosis in rats. An ACN solution was administered to Wistar rats by gavage at doses of 0, 5, 10, or 20 mg/kg, 5 days a week for 13 weeks. The morphology of neurons and the presence of apoptosis was examined by light and electron microscope, DNA electrophoresis, immunohistochemistry, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling. Significant vacuolation and the widening of the interspaces around blood vessels were observed in the groups that received the highest dose. Disordered myelin sheaths, malformed neuronal nuclei, and chromatin condensation at the periphery of the nucleus that formed crescents were also observed in the treated rats. The number of apoptotic neurons was significantly decreased (P < 0.05) in the treated groups (5 mg/kg group: 1.5 ± 1.22 apoptotic neurons/slide; 10 mg/kg group: 2.5 ± 1.05 apoptotic neurons/slide; 20 mg/kg group: 2.34 ± 1.21 apoptotic neurons/slide) compared to the control group (4.5 ± 1.52 apoptotic neurons/slide). The number of Bcl-2-positive neurons and the levels of staining were increased in the treated rats compared to those of the control group. These results suggested that ACN may induce serious morphological changes in rat neurons and inhibit neuronal apoptosis in rats.

Asunto(s)

Acrilonitrilo/farmacología , Apoptosis/efectos de los fármacos , Neuronas/efectos de los fármacos , Neuronas/patología , Animales , Carcinógenos/farmacología , Femenino , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Hipocampo/patología , Masculino , Neuronas/metabolismo , Neuronas/ultraestructura , Antígeno Nuclear de Célula en Proliferación/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Células Piramidales/efectos de los fármacos , Células Piramidales/metabolismo , Células Piramidales/patología , Células Piramidales/ultraestructura , Ratas , Proteína p53 Supresora de Tumor/metabolismo

RESUMEN

Chagas disease, caused by the protozoan Trypanosoma cruzi, remains a serious health concern due to the lack of effective vaccines or satisfactory treatment. In the search for new compounds against this neglected disease, we have previously demonstrated that the compound 3-Hydroxy-2-methylene-3-(4-nitrophenylpropanenitrile) (MBHA3), derived from the Morita-Baylis-Hillman reaction, effectively caused a loss of viability in both the epimastigote and trypomastigote forms. However, the mechanisms of parasite death elicited by MBHA3 remain unknown. The aim of this study was to better understand the morphophysiological changes and the mechanism of cell death induced by MBHA3 treatment on T. cruzi. To perform this analysis, we used confocal microscopy and flow cytometry to monitor the fluorescent probes such as annexin-V/propidium iodide (AV/PI), calcein-AM/ethidium homodimer (CA/EH), acridine orange (AO) and rhodamine 123 (Rho 123). Lower concentrations of MBHA3 led to alterations in the mitochondrial membrane potential and AO labeling, but did not decrease the viability of the epimastiogote forms, as determined by the CA/EH and AV/PI assays. Conversely, treatment with higher concentrations of MBHA3 led to extensive plasma membrane damage, loss of mitochondrion membrane potential, DNA fragmentation and acidification of the cytoplasm. Our findings suggest that at higher concentrations, MBHA3 induces T. cruzi epimastigote death by necrosis in a mitochondrion-dependent manner.

Asunto(s)

Acrilonitrilo/análogos & derivados , Alcoholes Bencílicos/farmacología , Muerte Celular/efectos de los fármacos , Enfermedad de Chagas/tratamiento farmacológico , Trypanosoma cruzi/efectos de los fármacos , Acrilonitrilo/farmacología , Acrilonitrilo/uso terapéutico , Alcoholes Bencílicos/uso terapéutico , Membrana Celular/efectos de los fármacos , Enfermedad de Chagas/parasitología , Citoplasma/efectos de los fármacos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Microscopía Confocal , Nitrilos

RESUMEN

The title compound, C16H9FN2S, crystallizes as a nonmerohedral twin with twin rotation about the reciprocal-lattice vector [101]*. The molecules are nearly planar and the dihedral angle between the planes of the two aryl rings is only 4.4 (2)°. The molecules are linked by pairs of C-H···N hydrogen bonds to form cyclic centrosymmetric R2(2)(18) dimers, which are linked into chains by an aromatic π-π stacking interaction. Comparisons are made with some related 3-aryl-2-thienylacrylonitriles.

Asunto(s)

Acrilonitrilo/análogos & derivados , Benzotiazoles/química , Modelos Moleculares , Acrilonitrilo/química , Cristalografía por Rayos X , Enlace de Hidrógeno , Estructura Molecular