Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Intervalo de ano de publicação
2.
Animals (Basel) ; 13(23)2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-38067060

RESUMO

A study was conducted to evaluate the effects of different sources and levels of supplemental amino acid-complexed minerals (AACM), with and without enzyme phytase (EZ). A total of 512 Dekalb White laying hens at 67 weeks of age were used in a 2 × 3 + 2 factorial arrangement of 8 treatments and 8 replications each. The main effects included EZ supplementation (10,000 FTU kg-1) and AACM inclusion level (100, 70, and 40% of inorganic mineral recommendations), plus 2 control treatments. The group of hens fed AACM-100 showed lower feed intake than the inorganic mineral (IM) group. The diet containing AACM-EZ-70 provided a higher (p < 0.05) laying percentage and a lower (p < 0.05) feed conversion ratio than both the IM and IM-EZ diets. The groups fed AACM-EZ-40, AACM-EZ-100, and AACM-70 produced heavier yolks (p < 0.05). Hens fed IM laid eggs with the lowest yolk and albumen weights (p < 0.05). Layers fed with AACM-100 and AACM-70 produced the most resistant eggshells to breakage (p < 0.05). In diets containing phytase, the optimal AACM recommendations for better performance and egg quality in older laying hens are: 42, 49, 5.6, 28, 0.175, and 0.70 mg kg-1 for Zn, Mn, Cu, Fe, Se, and I, respectively.

3.
Av. odontoestomatol ; 39(6): 251-259, Oct-Dic, 2023. graf, tab
Artigo em Espanhol | IBECS | ID: ibc-232033

RESUMO

Introducción: El quiste óseo simple (QOS) es un pseudoquiste intraóseo, de etiología desconocida que representa el 1% de los quistes maxilares. Radiográficamente se observa una imagen radiolúcida de bordes bien definidos, irregulares o festoneados. Su tratamiento consiste en la exploración quirúrgica y curetaje de paredes óseas. En pocas ocasiones se ha descrito resolución espontánea. El propósito de este documento es presentar un caso de QOS de resolución espontánea y realizar una revisión de literatura.Reporte de caso:Mujer de 12 años consulta para evaluación odontológica de rutina. En radiografía panorámica se observa lesión radiolúcida entre raíces de dientes 4.4 y 4.5, de límites bien definidos corticalizados. Se complementó con tomografía computarizada de haz cónico, donde se observó adelgazamiento de tablas óseas. Se realizó un diagnóstico presuntivo de QOS. Se controló a los 3 y 3,5 años observándose hueso de leve mayor densidad que el hueso circundante.Materiales y métodos:Se realizó una revisión de literatura sobre QOS de resolución espontánea en PubMed, Scopus y Web of Science, relacionando los términos libres “simple bone cyst” “spontaneous resolution” “jaws” y sus variantes.Resultados:Se encontraron 13 casos de QOS de resolución espontánea. Las características clínicas y radiográficas de los casos coinciden con la literatura. El 54% de los casos tuvo resolución espontánea en un periodo menor o igual a 5 años.Conclusión:En el presente caso se realizó el seguimiento radiográfico del paciente, demostrando que controlar en el tiempo puede considerarse como tratamiento, ya que la lesión podría resolverse espontáneamente.(AU)


Introduction: Simple bone cyst (SBC) is an intraosseous pseudocyst, of unknown etiology, which represents 1% of maxillary cysts. Radiographically, a radiolucent image with well-defined, irregular or scalloped edges is observed. Treatment consists of surgical exploration and curettage of bone walls. Spontaneous resolution has rarely been described. The purpose of this paper is to present a case of spontaneous resolution of SBC and perform a literature review.Case Report:A 12-year-old woman attends to a routine dental evaluation. Panoramic radiography shows a radiolucent image between roots of teeth 4.4 and 4.5, of well-defined corticated borders. It was complemented with cone-beam computed tomography examination, where thinning of cortical bone was observed. A presumptive diagnosis of SBC was performed. Controls at 3 and 3,5 years were performed and bone of slightly higher density than the surrounding bone was observed.Materials and methods:A literature review on SBC of spontaneous resolution was performed in PubMed, Scopus and Web of Science, relating the free terms “simple bone cyst” “spontaneous resolution” “jaws” and their variants.Results:13 cases of spontaneous resolution of SBC were found. The clinical and radiographic characteristics of the cases coincide with the literature. 54% of cases had spontaneous resolution in a period of 5 years or less.Conclusion:In the case presented, radiographic follow-up of the patient was performed, demonstrating that following-up can be considered as treatment, since the lesion could resolve spontaneously.(AU)


Assuntos
Humanos , Feminino , Criança , Cistos Ósseos/classificação , Cistos Ósseos/diagnóstico , Cistos Maxilomandibulares , Radiografia Panorâmica , Odontologia , Medicina Bucal , Pacientes Internados , Exame Físico , Odontopediatria
4.
Av. odontoestomatol ; 37(4): 160-168, oct.-dic. 2021. ilus
Artigo em Espanhol | IBECS | ID: ibc-217509

RESUMO

Introducción: Los equipos radiográficos dentales portátiles (ERDP) son dispositivos transportables e inalámbricos cuyo uso se ha masificado. No se encontró revisiones de la literatura recientes que analicen comprehensivamente los ERPD. El propósito del presente artículo es analizar la información actual sobre componentes, características técnicas, forma de uso y recomendaciones de protección radiológica de los ERDP. Materiales y métodos: Se realizó una revisión de la literatura sobre ERDP de la última década en Scopus, PubMed y Web of Science, relacionando el término libre “handheld dental X-ray” y sus variantes a través del término booleano OR. Revisión: Los ERDP se diferencian de los equipos radiográficos fijos en que tienen una batería recargable y un blindaje externo de retrodispersión. Además, el miliamperaje es menor en ERDP, por lo que los tiempos de exposición son mayores. La forma de uso del ERDP para disminuir el riesgo de exposición a radiaciones ionizantes del operador es sostenerlo a la distancia de un antebrazo del cuerpo manteniendo la emisión del rayo central paralela al piso. Se describen recomendaciones asociadas a protección radiológica para el uso de los ERDP para proteger al paciente, operador y población general de los potenciales riesgos de las radiaciones ionizantes. Conclusión: La amplia variedad de ERPD y su distinta forma de uso, implica un potencial mayor riesgo de exposición a radiación al operador. Los ERDP no debieran considerarse un reemplazo de los equipos radiográficos fijos y su uso debería restringirse a situaciones en que sea imposible el uso equipos radiográficos fijos. (AU)


Introduction: Handheld dental X-ray equipment (HDXE) are portable and wireless devices whose use has become massive. No recent reviews of literature that comprehensively analyze HDXE were found. The aim of the present article was to analyze the current information available on components, technical features, way of use and recommendations on radiological protection of HDXE. Materials and methods: A review of published literature on HDXE in the last decade was made in Scopus, PubMed and Web of Science relating the free term “handheld dental X-ray” and its variants through the Boolean term OR. Review: HDXE differ from wall-mounted X-ray equipment in that they have a rechargeable battery and external backscatter shielding. Furthermore, milliamperage is lower in HDXE and because of this, exposure times are longer. The way to use HDXE to reduce risk of exposure to ionizing radiation to the operator is to hold it at a forearm distance of the body, keeping the central beam emission parallel to the floor. There are radiological protection recommendations for the use of HDXE that seek to protect the patient, operator and general population from the potential risks of ionizing radiation. Conclusions: The wide variety of HDXE and its different form of use implies a potential greater risk of exposure to radiation to the operator. HDXE should not be considered as a replacement for wall-mounted equipment and their use should be restricted to situations where wall-mounted equipment is impossible to use. (AU)


Assuntos
Humanos , Raios X , Radiografia Dentária/instrumentação , Proteção Radiológica , Equipamentos e Provisões
5.
PLoS One ; 15(11): e0239229, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33147220

RESUMO

In the intestinal lumen, excess of oxides and sulfates interfere with the absorption of minerals due to competition from the same absorption site. Amino acids-mineral complexed (AACM) is intended to minimize these problems, which might be absorbed by different absorption sites. Then, a study including Zinc (Zn), Manganese (Mn) and Copper (Cu) from different sources was carried out to evaluate the performance, blood parameters and reproductive organs development of Brown Laying Hens. A total of 800 Lohmann Brown Lite were fed, from one-day-old to 182-days-old, Zn, Mn and Cu from different sources. Measurements were made from 105 to 182-days-old. The laying hens were distributed according to a completely randomized design with 20 replicates and 20 birds per experimental unit. The treatments consisted of a diet supplemented with 70, 70 and 8 mg/kg of Zn, Mn and Cu; respectively, from inorganic sources (IM). The second treatment contained 40, 40 and 2.75 mg/kg of Zn, Mn and Cu, respectively from IM plus 30, 30 and 5.25 mg/kg of Zn, Mn and Cu; respectively, from AACM sources. Performance and reproductive organs development (oviduct and ovary weight), tibia weight, liver weight, egg output and body weight, and blood variables were evaluated. Data were compared by Student's t-test (P < 0.05). Laying hens fed AACM reached 35% of egg output two days earlier and presented heavier tibia bone than the IM group. Those hens also presented greater oviduct weight, greater hematocrit and greater serum concentration of total leukocytes, erythrocytes, eosinophils, monocytes and the hormones T4 and FSH, than the hens fed IM. The supplementation of AACM in laying hens' diets since one-day-old improves the productive performance from the beginning of egg output to peak production, which is justified by better development of bones and oviduct, hormone production and immune system support.


Assuntos
Ração Animal/análise , Galinhas/crescimento & desenvolvimento , Cobre/administração & dosagem , Manganês/administração & dosagem , Zinco/administração & dosagem , Animais , Peso Corporal , Galinhas/sangue , Galinhas/fisiologia , Suplementos Nutricionais , Feminino , Tamanho do Órgão , Oviposição
6.
Int J Biol Macromol ; 122: 866-872, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30391588

RESUMO

Grewia polysaccharides were isolated using sodium metabisulphite and phosphate buffers and the influence of the different extraction techniques on the chemical composition and structural characteristics of the extracts were determined. Structure and chemical composition of the resulting polysaccharide extracts were determined using FT-IR and NMR spectroscopy, neutral sugar analysis, size exclusion chromatography coupled to multi-angle light scattering (SEC-MALS), dilute solution viscometry and steady shear rheology. Chemical composition was similar irrespectively of the extraction solvent used and ranged between 11.1 and 16.5% for protein, 53.4 and 66.9% for total carbohydrate, 18.5 and 35.1% for total uronic acid and 23.5 and 28.6% for rhamnose. Predominate sugars in the extracts were rhamnose and uronic acids with spectroscopy showing the presence of esterified groups. Intrinsic viscosity varied between 6.5 and 9.1 dL g-1 and related with molar mass (754-2778 × 103 g mol-1). Grewia polysaccharide dispersions at 1 g dL-1 exhibited a shear thinning flow behaviour with crude and sodium metabisulphite extracts having higher viscosities. Overall, differences in extraction techniques produced grewia samples with tailored bulk properties for use in the food and pharmaceutical industries.


Assuntos
Fenômenos Químicos , Grewia/química , Gomas Vegetais/química , Peso Molecular , Gomas Vegetais/isolamento & purificação , Viscosidade
7.
J Phys Chem B ; 122(29): 7286-7294, 2018 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-29965758

RESUMO

The interplay of degree of methylesterification (DM), pH, temperature, and concentration on the macromolecular interactions of pectin in solution has been explored. Small-angle X-ray scattering complemented by atomic force microscopy and molecular dynamics was employed to probe chain dimensions and solution structure. Two length scales have been observed with the first level of structure characterising chain clusters with sizes ranging between 100-200 nm. The second level of structure arises from single biopolymer chains with a radius of gyration between ∼6 and 42 nm. The development of a range of macromolecular dimensions in vitro and in silico shows that the chain flexibility increases with DM and at acidic pH, whereas hydrogen bonding is the responsible thermodynamic driving force for cluster formation. High methyl pectins create structures of lower fractal dimension with less efficient packing. This work unveils pectin conformations covering most of its industrially and biologically relevant environments, enabling rational design of advanced biomaterials based on pectin.


Assuntos
Pectinas/química , Soluções/química , Esterificação , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Microscopia de Força Atômica , Simulação de Dinâmica Molecular , Espalhamento a Baixo Ângulo , Temperatura , Termodinâmica , Difração de Raios X
8.
Food Biophys ; 13(1): 71-79, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29503599

RESUMO

The emulsifying characteristics of pectins isolated from six different okra genotypes were investigated and their structure-function relationships have been evaluated. Emulsion formation and stabilization of acidic oil-in-water emulsions (pH 2.0, φ = 0.1) were studied by means of droplet size distribution, ζ-potential measurements, viscometry, interfacial composition analysis and fluorescence microscopy. Fresh and aged emulsions differed in terms of droplet size distribution, interfacial protein and pectin concentrations (Γ) depending on the molecular properties of pectin that was used. Specifically, pectins with intermediate length of RG-I branching with molar ratio of (Ara + Gal)/Rha between 2 and 3 exhibit the optimum emulsification capacity whereas samples with the molar ratio outside this range do not favour emulsification. Additionally, low amounts of RG-I segments (HG/RG-I > 2) improve long term stability of emulsions as opposed to the samples that contain high amounts of RG-I (HG/RG-I < 2) which lead to long term instability. Protein was not found to be the controlling factor for the stability of the dispersions. The present results show that rational design of pectin should be sought before application as functional ingredient in food and/or pharmaceutical systems.

9.
Biopolymers ; 107(6)2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28142189

RESUMO

Mesoscopic structure of pectin with different molecular characteristics was investigated by means of small angle X-ray scattering (SAXS), electrokinetic measurements and data modelling. The influence of a broad range of pH (2-7) on chain conformation in the dilute and semi-diluted regime was investigated. Scattering data and concomitant analysis revealed two length scales at all environmental conditions studied. pH showed greater influence at acidic values (pH 2.0) enhancing the globular component of the structure due to association of galacturonic acid residues. Double logarithmic scattering intensity plots revealed fractal dimensions of 1.9 ± 0.2 in the low-q regime and 1.5 ± 0.2 in the high q-region, irrespectively of the specific environment. Increase in branching of RG-I regions of the polysaccharide chains enhanced the compact conformation irrespectively of the pH or concentration. The present work shows that radical changes in pectin conformation can be induced only under strongly acidic conditions a finding that has important consequences in tailoring the technological performance of these biopolymers.


Assuntos
Pectinas/química , Configuração de Carboidratos , Concentração de Íons de Hidrogênio , Espalhamento a Baixo Ângulo , Soluções , Difração de Raios X
10.
Colloids Surf B Biointerfaces ; 145: 301-308, 2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-27209382

RESUMO

Pectins with distinct molecular design were isolated by aqueous extraction at pH 2.0 or 6.0 and were examined in terms of their formation and stabilisation capacity of model n-alkane-in-water emulsions at acidic pH (pH 2.0). The properties and stability of the resulting emulsions were examined by means of droplet size distribution analysis, Lifshitz-Slyozov-Wagner modelling, bulk rheology, interfacial composition analysis, large-amplitude oscillatory surface dilatational rheology, electrokinetic analysis and fluorescence microscopy. Both pectin preparations were able to emulsify alkanes in water but exhibited distinct ageing characteristics. Emulsions prepared using pectin isolated at pH 6.0 were remarkably stable with respect to droplet growth after thirty days of ageing, while those prepared with pectin isolated at pH 2.0 destabilised rapidly. Examination of chemical composition of interfacial layers indicated multi-layered adsorption of pectins at the oil-water interface. The higher long-term stability of emulsions prepared with pectin isolated at high pH is attributed to mechanically stronger interfaces, the highly branched nature and the low hydrodynamic volume of the chains that result in effective steric stabilisation whereas acetyl and methyl contents do not contribute to the long-term stability. The present work shows that it is possible by tailoring the fine structure of pectin to engineer emulsions that operate in acidic environments.


Assuntos
Emulsões/química , Óleos/química , Pectinas/química , Água/química , Adsorção , Alcanos/química , Fluorescência , Tamanho da Partícula , Reologia
11.
Carbohydr Polym ; 127: 182-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25965472

RESUMO

The influence of pH on the mechanical relaxation of LM-pectin in the presence of co-solute has been investigated by means of differential scanning calorimetry, ζ-potential measurements and small deformation dynamic oscillation in shear. pH was found to affect the conformational properties of the polyelectrolyte altering its structural behavior. Cooling scans in the vicinity of the glass transition region revealed a remarkable change in the viscoelastic functions as the polyelectrolyte rearranges from extended (neutral pH) to compact conformations (acidic pH). This conformational rearrangement was experimentally observed to result in early vitrification at neutral pH values where dissociation of galacturonic acid residues takes place. Time-temperature superposition of the mechanical shift factors and theoretical modeling utilizing WLF kinetics confirmed the accelerated kinetics of glass transition in the extended pectin conformation at neutral pH. Determination of the relaxation spectra of the samples using spectral analysis of the master curves revealed that the relaxation of macromolecules occurs within ∼ 0.1s regardless of the solvent pH.


Assuntos
Pectinas/química , Vitrificação , Abelmoschus/química , Concentração de Íons de Hidrogênio
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...