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1.
Meat Sci ; 197: 109053, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36493555

RESUMO

To test the hypothesis that lambs fed freeze-dried Nannochloropsis oceanica (NO) biomass will have a higher deposition of EPA in tissues than those fed other Nannochloropsis EPA-sources, we fed 28 lambs with one of four diets: i) C, control, without EPA; ii) O, with 1.2% Nannochloropsis oil; iii) SD, with 12.3% spray-dried NO biomass; iv) FD, with 9.2% freeze-dried NO biomass. Dry matter intake, growth, tissues fatty acid composition, oxidative stability and sensory traits of the resultant meat were evaluated. The EPA was highest in tissues of lambs fed SD and FD compared with O but was similar between SD and FD. Total trans-18:1 did not differ among treatments, but the t10/t11-18:1 ratio decreased with all EPA containing diets. EPA diets were also supplemented with Vitamin E preventing the lipid oxidation in EPA-enriched meat and the meat sensory traits were not affected although occasionally some off-flavours were detected in FD meat.


Assuntos
Ácidos Graxos Ômega-3 , Microalgas , Carne Vermelha , Ovinos , Animais , Suplementos Nutricionais , Dieta/veterinária , Carne Vermelha/análise , Ácidos Graxos , Carne/análise , Ração Animal/análise
2.
Clin Biomech (Bristol, Avon) ; 90: 105490, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34601326

RESUMO

BACKGROUND: Advancing age and degeneration frequently lead to low back pain, which is the most prevalent musculoskeletal disorder worldwide. Degenerative changes in intervertebral discs and musculo-ligamentous incapacity to compensate sagittal imbalance are typically amongst the sources of instability, with spinal fusion techniques being the main treatment options to relieve pain. The aims of this work were to: (i) assess the link between ligament degeneration and spinal instability by determining the role of each ligament per movement, (ii) evaluate the impact of disc height reduction in degenerative changes, and (iii) unveil the most advantageous type of posterior fixation in Oblique Lumbar Interbody Fusion to prevent adjacent disc degeneration. METHODS: Two L3-L5 finite element models were developed, being the first in healthy condition and the second having reduced L4-L5 height. Different degrees of degeneration were tested, combined with different fixation configurations for Oblique Lumbar Interbody Fusion. FINDINGS: Facet capsular ligament and anterior longitudinal ligament were the most influential ligaments for spinal stability, particularly with increasing degeneration and disc height reduction. Pre-existent degeneration had lower influence than the fusion procedure for the risk of adjacent disc degeneration, being the highest stability and minimal degeneration achieved with bilateral fixation. Right unilateral fixation was more suited to reduce disc stress than left unilateral fixation. INTERPRETATION: Bilateral fixation is the best option to stabilize the spinal segment, but unilateral right fixation may suffice. This has direct implications for clinical practice, and the extension to a population-based study will allow for more efficient fusion surgeries.


Assuntos
Degeneração do Disco Intervertebral , Disco Intervertebral , Fusão Vertebral , Simulação por Computador , Humanos , Disco Intervertebral/cirurgia , Degeneração do Disco Intervertebral/cirurgia , Vértebras Lombares/cirurgia
3.
Chemosphere ; 250: 126248, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32092573

RESUMO

Medium density fiberboard (MDF) wastes were converted into an efficient char able to uptake Food Red 17 dye (FR17) from colored effluents. The yield of the pyrolysis process, in terms of char, was 29%. The produced char presented micro and mesoporous, with surface area of 218.8 m2 g-1 and total pore volume of 0.122 cm3 g-1. Regarding to the FR17 adsorption, removal percentages of 90% were found at pH 2 and using 0.5 g L-1 of char. Pseudo-first and pseudo-second order models were adequate to represent the adsorption kinetic profile, being the equilibrium reached within 20 min. Freundlich model was selected to represent the equilibrium data. The maximum adsorption capacity was 210 mg g-1. The adsorption of FR17 on the char was endothermic and physical in nature. The char was efficient for 8 adsorption-desorption cycles, maintaining the same adsorption capacity. In brief, this work demonstrated a useful practice in terms of cleaner production. It was possible add value to MDF wastes, generating an efficient and reusable adsorbent to treat colored effluents containing FR 17 dye.


Assuntos
Compostos Azo/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Corantes , Concentração de Íons de Hidrogênio , Cinética , Pirólise , Água , Poluentes Químicos da Água/análise
4.
Soft Matter ; 13(38): 6678-6688, 2017 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-28858364

RESUMO

Nature abounds with helical filaments designed for specific tasks. For instance, some plants use tendrils to coil and attach to the surroundings, while Spiroplasma, a helical bacterium, moves by inverting the helical handedness along the filament axis. Therefore, developing methods to shape filaments on demand to exhibit a diversity of physical properties and shapes could be of interest to many fields, such as the textile industry, biomedicine or nanotechnology. Electrospinning is a simple and versatile technique that allows the production of micro and nanofibres with many different helical shapes. In this work, we review the different electrospinning procedures that can be used to obtain helical shapes similar to those found in natural materials. These techniques also demonstrate that the creation of helical shapes at the micro/nanoscale is not limited by the chirality of the building blocks at the molecular level, a finding which opens new horizons on filament shaping.

5.
Eur Phys J E Soft Matter ; 39(9): 89, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27677987

RESUMO

The hygroscopic method developed previously for studies of lyotropic liquid crystals is used for the first time in experiments with millimetric capillary bridges made of a hydroxypropylcellulose/water mixture. Composition of such very small samples is controlled via humidity of the surrounding air. By a slow and well-controlled drying of initially isotropic samples, the isotropic/anisotropic phase transition is crossed and polydomain pseudo-isotropic capillary bridges are prepared. Kept in an atmosphere of constant humidity, these bridges are stretched and the strain-induced birefringence [Formula: see text] n is measured as a function of the draw ratio [Formula: see text] . The variation of [Formula: see text] n with [Formula: see text] is interpreted in terms of an affine uniaxial deformation of the initial pseudo-isotropic texture.

6.
Bioresour Technol ; 218: 153-60, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27367811

RESUMO

The influence of process conditions (rotary speed/temperature) on the performance of a rotary kiln reactor for non-catalytic pyrolysis of a perennial grass (elephant grass) was investigated. The product yields, the production of non-condensable gases as well as the biochar properties were evaluated. The maximum H2 yield was close to that observed for catalytic pyrolysis processes, while the bio-oil yield was higher than reported for pyrolysis of other biomass in rotary kiln reactors. A H2/CO ratio suitable for Fischer-Tropsch synthesis (FTS) was obtained. The biochars presented an alkaline pH (above 10) and interesting contents of nutrients, as well as low electrical conductivity, indicating a high potential as soil amendment.


Assuntos
Biomassa , Carvão Vegetal , Pennisetum , Solo/química , Catálise , Cátions , Cromatografia Gasosa , Condutividade Elétrica , Gases , Temperatura Alta , Hidrogênio/química , Concentração de Íons de Hidrogênio , Lignina/química , Temperatura , Termogravimetria
7.
Rev. bras. plantas med ; 17(4,supl.3): 1169-1176, 2015. tab, graf
Artigo em Português | LILACS | ID: lil-776616

RESUMO

RESUMO As plantas medicinais representam um dos principais recursos terapêuticos utilizado pelo homem para a cura e prevenção de doenças, no entanto, para que o tratamento seja seguro e eficaz é necessário conhecer seus componentes químicos. Dessa forma, o intuito deste trabalho foi determinar os parâmetros farmacognosticos para o estabelecimento do controle de qualidade da droga vegetal composta pelas folhas de Erythroxylum suberosum A. St.-Hil., pertencentes à família Erythroxylaceae ocorrente no Cerrado. Para tanto, foram coletadas folhas adultas nas proximidades da Universidade Federal de Goiás, Goiânia-GO. Foram determinados o teor de umidade por meio de balança com irradiação de raios infravermelho e o teor de cinzas totais. Na prospecção fitoquímica foram pesquisadas as classes de metabólitos secundários e realizou-se o doseamento de fenóis totais, flavonoides e taninos totais. Os resultados dos testes de pureza realizados, teor de umidade e teor de cinzas totais, estão de acordo com os limites estabelecidos pelas especificações farmacopeicas. As análises fitoquímicas evidenciaram a presença de flavonoides, taninos, cumarinas, saponinas e resinas. No doseamento de fenóis totais, taninos e flavonoides presentes nas folhas de E. suberosum A. St.-Hil. obteve-se respectivamente 17,97%, 6,31%, 3,87%. Estes resultados confirmam os dados da literatura quanto à presença destes compostos em Erythroxylaceae, pois de acordo com nas folhas de E. tortuosum obteve-se valores de 10%, 8,4% e 0,064% de Fenóis, Taninos e flavonoides, respectivamente e nas folhas de E. deciduum foram encontrados 12,04% de fenóis totais, 0,87% de taninos e 1,37% de flavonoides. Os resultados encontrados no presente trabalho também se tornam relevantes quando comparadas as quantidades desses metabólitos com espécies clássicas na biossíntese de compostos fenólicos como o teor de taninos de Stryphnodendron adstringens (Mart.) Coville e em Eugenia uniflora L. foi de 29,9% e 2,96%, respectivamente. Teores de flavonóides que variaram entre 0,65% a 0,79% na Calendula officinalis L. e Ginkgo bilobaL. 0,59%, 0,75% e 0,79%. Sendo assim, a quantidade considerável de compostos fenólicos obtida em E. suberosum A. St.-Hil. sugere que a espécie possua um importante potencial terapêutico e quem sabe potencial antioxidante, a ser explorado em estudos posteriores.


ABSTRACT Medicinal plants represent a major therapeutic resources used by man for the cure and prevention of diseases, however, that the treatment be safe and effective it is necessary to know their chemical components. Thus, the aim of this work was to determine the pharmacognostic parameters for the establishment of the plant drug quality control made by the leaves of Erythroxylum suberosum A. St.-Hil., belonging to the family Erythroxylaceae occurring in the Cerrado. To this end, adult leaves were collected near the Federal University of Goiás, Goiânia-GO. It was determined the moisture content through scale radiating infrared rays and the content of total ash. The phytochemical screening of secondary metabolites classes were surveyed and performed the determination of total phenols, flavonoids and total tannins. The results of the purity tests, moisture content and total ash content, are in accordance with the limits established by the pharmacopeic specifications. The phytochemical analysis revealed the presence of flavonoids, tannins, coumarins, saponins and resins. The determination of total phenols, tannins and flavonoids quantities present in the leaves of E. suberosum A. St.-Hil. were obtained respectively as 17.97%, 6.31%, 3.87%. These results confirm the literature data for the presence of these compounds in Erythroxylaceae, since according to the leaves of E. tortuosum yielded values of 10%, 8.4% and 0.064% of phenols, tannins and flavonoids, respectively. On the E. deciduum leaves were found 12.04% of total phenols, tannins 0.87% and 1.37% of flavonoids. The results of this work also become relevant when comparing the amounts of these metabolites with classic species in the biosynthesis of phenolic compounds such as tannins content in barbatimão and pitanga was 29.9% and 2.96%, respectively. Flavonoid contents ranging from 0.65% to 0.79% in calendula and ginkgo 0.59%, 0.75% and 0.79%. Thus, considerable amount of phenolic compounds obtained in E. suberosum. A. St. Hil. It suggests that the species has an important therapeutic potential and who knows antioxidant potential to be explored in further studies.


Assuntos
Plantas Medicinais/classificação , Erythroxylaceae/química , /classificação , Fenóis/farmacologia , Controle de Qualidade
8.
J Phys Chem B ; 118(20): 5600-7, 2014 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-24784500

RESUMO

A detailed study of the cross-relaxation effects between the ¹H and ²H spins systems is presented in the nematic phase of a 5-cyanobiphenyl (5CB) liquid crystal, partially deuterated at α position (5CB-αd2). The proton spin-lattice relaxation time was measured at a frequency range from 5 kHz to 100 MHz at a temperature 5 K below the nematic-isotropic phase transition. In the low frequency domain, the spin-lattice relaxation rate (T1⁻¹) dispersion clearly differs from that of the fully protonated 5CB homologue. At two distinct frequencies, T1⁻¹ presents two distinct local maxima and for low frequencies T1⁻¹ presents a stronger frequency dependence when compared with what is observed for 5CB. The T1⁻¹ dispersion obtained for 5CB-αd2 for frequencies above 60 kHz was interpreted in terms of the relaxation mechanisms usually accepted to interpret the spin-lattice relaxation in nematic phases in general and 5CB in particular. For lower frequencies it was necessary to consider cross-relaxation contributions between the proton and deuterium reservoirs. A detailed model interpretation of the deuterium quadrupolar dips with respect to the proton-spin relaxation is presented. The analysis of the quadrupolar relaxation independently confirms that the order director fluctuations is the dominant mechanism of proton relaxation in the low frequency domain.

9.
Artigo em Inglês | MEDLINE | ID: mdl-24580233

RESUMO

We consider a fiber made of a soft elastic material, encased in a stiff elastic shell (core-shell geometry). If the core and shell dimensions are mismatched, e.g., because the core shrinks while the shell does not, but the two remain attached, then an elastic instability is triggered whereby wrinkles may appear on the shell. The wrinkle orientation may be longitudinal (along the fiber axis), polar (along the fiber perimeter), or a mixture of both, depending on the fiber's geometrical and material parameters. Here we investigate under what conditions longitudinal or polar wrinkling will occur.


Assuntos
Cristalização/métodos , Modelos Químicos , Modelos Moleculares , Nanopartículas/química , Nanopartículas/ultraestrutura , Nanoporos/ultraestrutura , Anisotropia , Simulação por Computador , Tamanho da Partícula
10.
Artigo em Inglês | MEDLINE | ID: mdl-24580246

RESUMO

This work demonstrates the feasibility of using polymeric micro- and nanofiber-composed films and liquid crystals as electrically switchable scattering light shutters. We present a concept of electro-optic device based on an innovative combination of two mature technologies: optics of nematic liquid crystals and electrospinning of nanofibers. These devices have electric and optical characteristics far superior to other comparable methods. The simulation presented shows results that are highly consistent with those of experiments and that explain the working mechanism of the devices.


Assuntos
Cristais Líquidos/química , Cristais Líquidos/efeitos da radiação , Sistemas Microeletromecânicos/instrumentação , Nanofibras/química , Nanofibras/ultraestrutura , Nanotecnologia/instrumentação , Refratometria/instrumentação , Campos Eletromagnéticos , Desenho de Equipamento , Análise de Falha de Equipamento , Estudos de Viabilidade , Nanotecnologia/métodos , Refratometria/métodos , Processamento de Sinais Assistido por Computador/instrumentação
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