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1.
Environ Monit Assess ; 193(12): 809, 2021 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-34783906

RESUMEN

The use of biodiesel blends with petroleum diesel in vehicular engines demands the evaluation of the possible impacts and effects of the gases emitted from their combustion on the environment. Among studies on these questions, biomonitoring using lichens is a viable alternative, given their interactions with the elements dispersed in the atmosphere, as well as its sensitivity and capacity to retain contaminants. In this study, we analyzed the effects of gas emissions from the combustion of biodiesel mixture with petroleum diesel on Cladonia verticillaris thalli. Samples of the lichen (10 g) were exposed to the gases emitted by the exhaust of the generator engine during the combustion process of biodiesel mixtures to petroleum diesel (7% (B7), 10% (B10), 40% (B40), 50% (B50), and 70% (B70)). At 90 days after exposure, samples were analyzed for n-alkane profiles, thallus morphology, photosynthetic pigment contents, and secondary lichen metabolites (protocetraric and fumarprotocetraric acids). Sets B7 and B10 showed better resistance of the lichen to pollutants. Set B40 showed a high stress evidenced by the chain elongation of n-alkanes structure and high chlorophyll production, presenting high morphological damages when compared to the control sets, B7 and B10. The results showed significant reductions of n-alkanes profiles for mixtures with high concentrations of biodiesel (B50 and B70), as well as decreases in the chlorophyll content. These groups showed an increase in the synthesis of secondary metabolites, corroborating the hypothesis that high concentrations of biodiesel in the mixture with petroleum diesel have greater impacts on the lichen. Schematic model for demonstration of using the lichen Cladonia verticillaris as biomonitor of effects from gas emissions from the combustion of biodiesel blends with petroleum diesel by a stationary engine.


Asunto(s)
Biocombustibles , Líquenes , Ascomicetos , Biocombustibles/análisis , Conservación de los Recursos Naturales , Monitoreo del Ambiente , Gasolina/análisis , Emisiones de Vehículos/análisis
2.
Acta Bioeng Biomech ; 22(3): 139-152, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33518727

RESUMEN

PURPOSE: Bone is a hierarchical material that can be characterized from the microscale to macroscale. Multiscale models make it possible to study bone remodeling, inducing bone adaptation by using information of bone multiple scales. This work proposes a computationally efficient homogenization methodology useful for multiscale analysis. This technique is capable to define the homogenized microscale mechanical properties of the trabecular bone highly heterogeneous medium. METHODS: In this work, a morphology- based fabric tensor and a set of anisotropic phenomenological laws for bone tissue was used, in order to define the bone micro-scale mechanical properties. To validate the developed methodology, several examples were performed in order to analyze its numerical behavior. Thus, trabecular bone and fabricated benchmarks patches (representing special cases of trabecular bone morphologies) were analyzed under compression. RESULTS: The results show that the developed technique is robust and capable to provide a consistent material homogenization, indicating that the homogeneous models were capable to accurately reproduce the micro-scale patch mechanical behavior. CONCLUSIONS: The developed method has shown to be robust, computationally less demanding and enabling the authors to obtain close results when comparing the heterogeneous models with equivalent homogenized models. Therefore, it is capable to accurately predict the micro-scale patch mechanical behavior in a fraction of the time required by classic homogenization techniques.


Asunto(s)
Hueso Esponjoso/diagnóstico por imagen , Imagenología Tridimensional , Algoritmos , Fenómenos Biomecánicos , Simulación por Computador/economía , Humanos , Reproducibilidad de los Resultados , Estrés Mecánico
3.
An Acad Bras Cienc ; 88(3): 1431-7, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27508993

RESUMEN

Mangroves represent areas of high biological productivity and it is a region rich in bioactive substances used in medicine production. Conocarpus erectus (Combretaceae) known as button mangrove is one of the species found in mangroves and it is used in folk medicine in the treatment of anemia, catarrh, conjunctivitis, diabetes, diarrhea, fever, gonorrhea, headache, hemorrhage, orchitis, rash, bumps and syphilis. The present study aimed to investigate the acute toxicity of aqueous extract of leaves of C. erectus in Swiss albino mice. The plant material was collected in Vila Velha mangroves, located in Itamaracá (PE). The material was subjected to a phytochemical screening where extractive protocols to identify majority molecules present in leaves were used. The evaluation of acute toxicity of aqueous extract of C. erectus followed the model of Acute Toxicity Class based on OECD 423 Guideline, 2001. The majority molecules were identified: flavonoids, tannins and saponins. The LD50 was estimated at 2,000 mg/kg bw. Therefore, the aqueous extract showed low acute toxicity classified in category 5.


Asunto(s)
Myrtaceae/toxicidad , Extractos Vegetales/toxicidad , Hojas de la Planta/toxicidad , Humedales , Animales , Flavonoides/análisis , Flavonoides/toxicidad , Masculino , Ratones , Myrtaceae/química , Fitoquímicos , Hojas de la Planta/química , Saponinas/análisis , Saponinas/toxicidad , Taninos/análisis , Taninos/toxicidad , Pruebas de Toxicidad
4.
J Arthroplasty ; 31(1): 234-9, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26362785

RESUMEN

To study the prevalence of Staphylococcus aureus carriage and the impact of preoperatively treating carriers in prosthetic joint infection (PJI), a prospective randomized trial was organized. From January 2010 to December 2012, 1028 of 1305 total joint arthroplasties performed were screened, and selected carriers underwent preoperative decolonization. We observed a 22.2% (228/1028) S aureus colonization rate and only 0.8% methicillin-resistant S aureus. Prosthetic joint infection rate was higher, albeit not significantly, in S aureus carriers than among noncarriers-3.9% (9/228) vs 2.0% (16/800). Treated and untreated carriers showed no significant differences-3.4% (3/89) vs 4.3% (6/139). Most of the 14 S aureus PJI occurred in noncarriers suggesting a lack of causal relation between nasal and PJI S aureus. No clear benefit in screening/decolonizing carriers before total joint arthroplasty could be demonstrated.


Asunto(s)
Artroplastia de Reemplazo de Cadera/métodos , Artroplastia de Reemplazo de Rodilla/métodos , Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/prevención & control , Staphylococcus aureus , Infección de la Herida Quirúrgica/prevención & control , Adulto , Anciano , Anciano de 80 o más Años , Artroplastia/efectos adversos , Femenino , Humanos , Masculino , Resistencia a la Meticilina , Persona de Mediana Edad , Prevalencia , Estudios Prospectivos , Factores de Riesgo , Adulto Joven
5.
An Acad Bras Cienc ; 87(3): 1701-9, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26221983

RESUMEN

In this study, pulp and kernel of fruits from six Arecaceae species were subjected to proximate analysis, fatty acid composition and total carotenoid content analysis. The species with the highest carbohydrate, lipid and protein values were Ptychosperma macarthurii(70.1 g/100 g in the kernel), Syagrus cearensis(40.6 g/100 g in the kernel), andS. coronata(20.6 g/100 g in the pulp). The ash content ranged from 0.61 to 7.51 g/100 g. Lauric, palmitic, and oleic acids were the major fatty acids identified. The total carotenoid contents and retinol activity equivalents were highest in the Pinanga kuhlii (180.3 µg/g) and Acrocomia intumescens (138.0 µg/g) pulp oils. Retinol activity equivalents varied between the investigated species (456 to 1515 µg RAE/100 g). Native species such as A. intumescens, S. coronata, and S. cearensis are good sources of fresh food for the underserved populations that inhabit poorly developed areas such as the semi-arid region of Brazil. P. macarthurii, an exotic species, is an excellent source of ash and carotenoids, demonstrating its potential both as a food source and as bioactive compounds. Pulp and kernel ofA. intumescens,could be a good alternative feedstock for soap and biodiesel production, respectively.


Asunto(s)
Arecaceae/química , Frutas/química , Valor Nutritivo , Arecaceae/clasificación , Brasil , Carbohidratos/análisis , Carotenoides/análisis , Ácidos Grasos/análisis , Lípidos/análisis , Proteínas de Plantas/análisis
6.
Rev. bras. farmacogn ; 23(6): 913-919, Nov-Dec/2013. tab, graf
Artículo en Inglés | LILACS | ID: lil-704261

RESUMEN

Calotropis procera (Aiton) W.T.Aiton,Apocynaceae, popularly known as "algodão-de-seda", is a wild African bush, rich in bioactive substances that determine the medicinal potential of this species. Diabetes mellitus is a disease that affects about 10% of the population. This study aimed to evaluate the antihyperglycaemic activity of the hydroalcoholic extract of the leaves of C. procera of occurrence in coast of Pernambuco, Brazil. The hydroalcholic extract of the leaves of C. procera (300 and 600 mg/kg/day), vehicle, insulin (6U, s.c.) or metformin (500 mg/ kg/day) were administered orally to streptozotocin-induced diabetic rats (n = 7/group) for four weeks. Changes in body weight, food and water intake, biochemical markers, fasting glucose levels and oral glucose tolerance test were evaluated. The results showed that the C. procera dried extract (300 and 600 mg/kg) reduced significantly the level of blood glucose throughout the evaluation period and improved metabolic status of the animals and ameliorate the oral tolerance glucose test. The phytochemical screening revealed and quantified the presence of phenolic compounds and flavonoids in a percentage of 29.1 and 2.9%, respectively. Thus, we conclude that the extract of the leaves of C. procera has antihyperglycemic activity.

7.
An. acad. bras. ciênc ; 75(4): 431-439, Dec. 2003. tab, graf
Artículo en Inglés | LILACS | ID: lil-348796

RESUMEN

The effects of the contents and chemical composition of the foliar epicuticular waxes of species from the caatinga (Aspidosperma pyrifolium, Capparis yco, Maytenus rigida and Ziziphus joazeiro) and cerrado (Aristolochia esperanzae, Didymopanax vinosum, Strychnos pseudoquina and Tocoyena formosa) were evaluated as to the resistance to water loss by means of an experimental device constructed for this purpose. In general, the waxes of the caatinga species investigated were more efficient against water loss than cerrado species. Increase of the thickness of the waxy deposits from 40 to 90m g.cm-2 had no significant effect on the resistance to water loss. The chemistry of the wax constituents was shown to be an important factor to determine the degree of resistance to evaporation. n-Alkanes and alcoholic triterpenes were the most efficient barriers, while hentriacontan-16-one (a ketone) and ursolic acid (an acid triterpene) revealed lowefficiency. The higher efficiency of the waxes of the leaves from caatinga species (mainly those of C. yco and Z. joazeiro) is probably accounted for the predominance of n-alkanes in their composition. The lower efficiency of the waxes of A. pyrifolium (caatinga), T. formosa and A. esperanzae (both species from the cerrado) is probably a consequence of the predominance of triterpenoids in the waxes of the two former species and hentriacontan-16-one in the latter


Asunto(s)
Plantas , Agua , Ceras , Brasil , Clima Desértico , Permeabilidad , Hojas de la Planta , Plantas , Triterpenos
8.
An Acad Bras Cienc ; 75(4): 431-9, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14605678

RESUMEN

The effects of the contents and chemical composition of the foliar epicuticular waxes of species from the caatinga (Aspidosperma pyrifolium, Capparis yco, Maytenus rigida and Ziziphus joazeiro) and cerrado (Aristolochia esperanzae, Didymopanax vinosum, Strychnos pseudoquina and Tocoyena formosa) were evaluated as to the resistance to water loss by means of an experimental device constructed for this purpose. In general, the waxes of the caatinga species investigated were more efficient against water loss than cerrado species. Increase of the thickness of the waxy deposits from 40 to 90 microg.cm-2 had no significant effect on the resistance to water loss. The chemistry of the wax constituents was shown to be an important factor to determine the degree of resistance to evaporation. n-Alkanes and alcoholic triterpenes were the most efficient barriers, while hentriacontan-16-one (a ketone) and ursolic acid (an acid triterpene) revealed low efficiency. The higher efficiency of the waxes of the leaves from caatinga species (mainly those of C. yco and Z. joazeiro) is probably accounted for the predominance of n-alkanes in their composition. The lower efficiency of the waxes of A. pyrifolium (caatinga), T. formosa and A. esperanzae (both species from the cerrado) is probably a consequence of the predominance of triterpenoids in the waxes of the two former species and hentriacontan-16-one in the latter.


Asunto(s)
Plantas/química , Agua/metabolismo , Ceras/química , Brasil , Clima Desértico , Hidrocarburos/análisis , Permeabilidad , Hojas de la Planta/química , Hojas de la Planta/metabolismo , Plantas/metabolismo , Triterpenos/análisis , Ácido Ursólico
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