Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Food Res Int ; 190: 114566, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38945597

RESUMO

This study assessed water relaxometry of beef exposed to different ageing techniques by examining the inner and surface regions using time-domain nuclear magnetic resonance (TD-NMR) relaxometry. Beef strip loins were aged under vacuum (Wet), under vacuum using moisture absorbers (Abs), under vacuum using moisture absorbers and with mechanical tenderisation (AbsTend), or without any packaging (Dry). The ageing technique significantly influenced various meat parameters, including dehydration, total loss, and the moisture content of the meat surface. The transverse (T2) relaxation times provided a more sensitive indicator of the changes in meat water relaxometry than the longitudinal (T1) relaxation times. The Dry samples exhibited distinct differences in the T2 signals between the surface and inner regions of the meat. In particular, for the inner region, there were significant differences in signal areas between the Wet and Dry samples, and the Abs and AbsTend samples were positioned closely together between the Dry and Wet samples. The principal component analysis supported these findings: it indicated some differentiation among the ageing techniques in the score plot, but the differentiation was more pronounced when analysing the surface region. Additionally, there was a strong correlation between dehydration and the T2 values, leading to a clustering of the samples based on the ageing technique. The overlap between the Abs and AbsTend samples, situated between the Dry and Wet samples, suggests the potential of these treatments to produce meat with properties that are intermediate to Wet and Dry meat. Furthermore, tenderisation did not lead to greater dehydration.


Assuntos
Manipulação de Alimentos , Espectroscopia de Ressonância Magnética , Água , Água/química , Animais , Bovinos , Espectroscopia de Ressonância Magnética/métodos , Manipulação de Alimentos/métodos , Vácuo , Carne Vermelha/análise , Fatores de Tempo , Carne/análise , Análise de Componente Principal
2.
Polymers (Basel) ; 15(21)2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37959983

RESUMO

A detailed structural investigation of a promising bio-based polymer, polyglycerol citrate polyester, obtained by the bulk polycondensation of glycerol (Gly) against citric acid (Cit) under mild reaction was performed. The reaction in conditions with and without catalyst use (sulfuric acid, H2SO4) was investigated, showing evidence that it is possible to modify the polymer solubility according to the ratio and catalyst utilization. 13C and 1H NMR indicated that synthesis catalyzed with Cit excess leads to higher esterification degrees of citrate groups. In contrast, the Gly moieties are more prominent in catalyzed polymers regardless of the excess monomers. Overall, a successful conversion of Gly and Cit into polyesters was attained even without catalysis, enabling a simple route for the large-scale production of this green material to be used as a coating material. This polymer has been shown to be well-suited for coating seeds and might be a promising material for similar agricultural applications. Tests on soybean seed coating with a PGCit solution of 75% indicated that the seed quality and germination rate were not affected by the PGCit coating, concluding that this polymer is suitable for this application.

3.
Molecules ; 28(13)2023 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-37446742

RESUMO

With sensitivity being the Achilles' heel of nuclear magnetic resonance (NMR), the superior mass sensitivity offered by micro-coils can be an excellent choice for tiny, mass limited samples such as eggs and small organisms. Recently, complementary metal oxide semiconductor (CMOS)-based micro-coil transceivers have been reported and demonstrate excellent mass sensitivity. However, the ability of broadband CMOS micro-coils to study heteronuclei has yet to be investigated, and here their potential is explored within the lens of environmental research. Eleven nuclei including 7Li, 19F, 31P and, 205Tl were studied and detection limits in the low to mid picomole range were found for an extended experiment. Further, two environmentally relevant samples (a sprouting broccoli seed and a D. magna egg) were successfully studied using the CMOS micro-coil system. 13C NMR was used to help resolve broad signals in the 1H spectrum of the 13C enriched broccoli seed, and steady state free precession was used to improve the signal-to-noise ratio by a factor of six. 19F NMR was used to track fluorinated contaminants in a single D. magna egg, showing potential for studying egg-pollutant interactions. Overall, CMOS micro-coil NMR demonstrates significant promise in environmental research, especially when the future potential to scale to multiple coil arrays (greatly improving throughput) is considered.


Assuntos
Poluentes Ambientais , Flúor , Espectroscopia de Ressonância Magnética , Óxidos , Semicondutores , Espectroscopia de Ressonância Magnética/métodos , Brassica/química , Sementes/química , Daphnia magna , Animais , Poluentes Ambientais/análise
4.
Int J Mol Sci ; 23(20)2022 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-36293386

RESUMO

Multidrug-resistant bacteria represent a global health and economic burden that urgently calls for new technologies to combat bacterial antimicrobial resistance. Here, we developed novel nanocomposites (NCPs) based on chitosan that display different degrees of acetylation (DAs), and conjugated polymer cyano-substituted poly(p-phenylene vinylene) (CNPPV) as an alternative approach to inactivate Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria. Chitosan's structure was confirmed through FT-Raman spectroscopy. Bactericidal and photobactericidal activities of NCPs were tested under dark and blue-light irradiation conditions, respectively. Hydrodynamic size and aqueous stability were determined by DLS, zeta potential (ZP) and time-domain NMR. TEM micrographs of NCPs were obtained, and their capacity of generating reactive oxygen species (ROS) under blue illumination was also characterized. Meaningful variations on ZP and relaxation time T2 confirmed successful physical attachment of chitosan/CNPPV. All NCPs exhibited a similar and shrunken spherical shape according to TEM. A lower DA is responsible for driving higher bactericidal performance alongside the synergistic effect from CNPPV, lower nanosized distribution profile and higher positive charged surface. ROS production was proportionally found in NCPs with and without CNPPV by decreasing the DA, leading to a remarkable photobactericidal effect under blue-light irradiation. Overall, our findings indicate that chitosan/CNPPV NCPs may constitute a valuable asset for the development of innovative strategies for inactivation and/or photoinactivation of bacteria.


Assuntos
Quitosana , Nanocompostos , Humanos , Quitosana/farmacologia , Quitosana/química , Espécies Reativas de Oxigênio/farmacologia , Staphylococcus aureus , Escherichia coli , Nanocompostos/química , Antibacterianos/farmacologia , Antibacterianos/química , Bactérias
5.
Meat Sci ; 194: 108978, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36116280

RESUMO

The aim of this work was to compare the lipidome and metabolome profiling in the Longissimus thoracis muscle early and late postmortem from high and normal ultimate pH (pHu) beef. Lipid profiling discriminated between high and normal pHu beef based on fatty acid metabolism and mitochondrial beta-oxidation of long chain saturated fatty acids at 30 min postmortem, and phospholipid biosynthesis at 44 h postmortem. Metabolite profiling also discriminated between high and normal pHu beef, mainly through glutathione, purine, arginine and proline, and glycine, serine and threonine metabolisms at 30 min postmortem, and glycolysis, TCA cycle, glutathione, tyrosine, and pyruvate metabolisms at 44 h postmortem. Lipid and metabolite profiles showed reduced glycolysis and increased use of alternative energy metabolic processes that were central to differentiating high and normal pHu beef. Phospholipid biosynthesis modification suggested high pHu beef experienced greater oxidative stress.


Assuntos
Lipidômica , Metaboloma , Animais , Bovinos , Concentração de Íons de Hidrogênio , Glutationa/metabolismo , Fosfolipídeos , Músculo Esquelético/metabolismo
6.
Prog Biomater ; 11(3): 263-271, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35739413

RESUMO

We evaluated the influence of the open porosity of alumina (Al2O3) substrates on the phase formation of calcium phosphates deposited onto it surface. The Al2O3 substrates were prepared with different porosities by the foam-gelcasting method associated with different amounts of polyethylene beads. The substrates were coated biomimetically for 14 and 21 days of incubation in a simulated body fluid (SBF). Scanning electron microscopy characterisation and X-ray computed microtomography showed that the increase in the number of beads provided an increase in the open porosity. The X-ray diffraction and infrared spectroscopy showed that the biomimetic method was able to form different phases of calcium phosphates. It was observed that the increase in the porosity favoured the formation of ß-tricalcium phosphate for both incubation periods. The incubation period and the porosity of the substrates can influence the phases and the amount of calcium phosphates formed. Thus, it is possible to target the best application for the biomaterial produced.

7.
Anim Biotechnol ; 33(4): 710-722, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33021130

RESUMO

The aim of this study was to investigate the effects of probiotics on pre-weaning performance, muscle, and fat deposition and serum metabolite profiles in male and female Senepol calves. Thirty new-born Senepol calves, 15 males and 15 females, were randomly allocated to the following treatments: CON a control group that received the basal creep feeding diet and PRO animals that received the basal diet with addition of 2 g/100 kg of body weight (BW) of probiotic. PRO supplementation did not change the DMI but increased average BW, final BW, ADG relative to animals fed CON. Additionally, PRO improved LMA and marbling. Regardless of the serum metabolite profile, the important metabolites for discriminating PRO and CON were glutamine, leucine, creatine, acetate, creatinine, arginine, glutamate, hippurate, glycerol, carnitine, lactate, carnosine, myo-inositol and histidine. According to gender, males had an overabundance of glutamine, glycerol, isoleucine, creatinine and glucose, whereas females had an overabundance of acetyl carnitine, glutamate and carnitine. In conclusion, the addition of PRO in the pre-weaning diet of calves increases performance, weight at weaning and muscle and fat deposition on the carcass, improving proteins and fatty acid metabolism, the immune system response and rumen development.


Assuntos
Ração Animal , Antibacterianos , Ração Animal/análise , Animais , Carnitina , Bovinos , Creatinina , Dieta/veterinária , Suplementos Nutricionais , Feminino , Glutamatos , Glutamina , Glicerol , Masculino , Metaboloma , Desmame , Aumento de Peso
8.
Anim Biotechnol ; 33(6): 1308-1317, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34057399

RESUMO

The aim of this study was to investigate the serum and meat metabolomic changes according to the genetic potential for muscularity of non-castrated Nellore males and its association with phenotypic traits. Forty-eight non-castrated Nellore males were separated into two groups based on their genetic potential for post-weaning muscularity: high (HM) and low (LM). Selection for muscularity did not cause noticeable differences in the traits evaluated during the finishing phase and after slaughter. However, several metabolites in meat and serum, have changed according to the muscularity group. HM animals presented an over-abundance of glycerol, glutamine, choline, methylhistidine, betaine, creatinine and methionine in serum, compared with their LM counterparts. Similarly, the meat samples of HM animals were rich in glucose-6-phosphate, lactate, pyruvate, creatinine, betaine, choline, glycerol and arginine relative to LM bulls. Inosine monophosphate was the only metabolite over-abundant in LM animals. In conclusion, the genetic potential for post-weaning muscularity did not affect performance during the finishing phase, carcass traits and meat quality. However, multivariate analysis shows that the genetic potential of muscularity can be correlated with serum lipid and protein metabolites, and with energy metabolism in meat, providing a footprint of cattle muscularity metabolism.


Assuntos
Betaína , Glicerol , Bovinos/genética , Animais , Masculino , Creatinina , Carne , Colina , Composição Corporal/genética
9.
J Anim Sci ; 99(9)2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34402901

RESUMO

This study aimed to evaluate the effect of dietary yerba mate (Ilex paraguariensis) extract (YME) on muscle metabolomics and physicochemical properties of lamb meat. Thirty-six uncastrated male lambs (90 d old) were fed experimental diets, which treatments consisted of 0%, 1%, 2%, and 4% inclusion of YME. Animals were fed for 50 d before slaughter. Muscle and meat samples were collected for metabolomics and meat quality analysis, respectively. The experiment was carried out in a randomized block design and analyzed using orthogonal contrasts. There was a quadratic effect of YME inclusion in tenderness (P < 0.05) and a positive linear effect on meat lightness (P < 0.05). No qualitative changes (P > 0.05) on individual metabolites were observed; however, changes in the quantitative metabolic profile were observed, showing that animals fed 1% and 2% of YME have a greater concentration of desirable endogenous muscle antioxidants, with direct impact on metabolic pathways related to beta-alanine metabolism and glutathione metabolism. Therefore, YME dietary supplementation up to 2% of the diet to lambs had little to no effects on the majority of meat quality traits evaluated; moreover, 4% of YME inclusion negatively affected feed intake and meat quality traits.


Assuntos
Ilex paraguariensis , Carne Vermelha , Animais , Dieta/veterinária , Carne , Metabolômica , Músculos , Extratos Vegetais , Carne Vermelha/análise , Ovinos , Carneiro Doméstico
10.
Meat Sci ; 181: 108606, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34146920

RESUMO

The aim of this study was to explore the use of TD-NMR relaxometry and 1H NMR spectroscopy-based for detecting differences in meat quality attributes. There was limited association between various TD-NMR signals and any physicochemical parameters of fresh and aged meat differing in tenderness ratings. Samples were then divided into three groups based on statistical changes in metabolite concentration. Group A samples possessed near linear increases in metabolite concentration over aging time; whereas samples assigned to Groups B and C were characterized by increases in metabolites that peaked between 7 and 14 days, and up to 14 days aging, respectively. 1H NMR spectroscopy discriminated meat quality using changes in metabolites reflective of glycolysis, the citric acid cycle, protein degradation, amino acid generation and purine metabolisms. These data suggest segregation of meat quality is possible using both NMR technologies but additional work is necessary to understand fully their utility in a commercial industry setting.


Assuntos
Manipulação de Alimentos , Carne Vermelha/análise , Animais , Bovinos , Qualidade dos Alimentos , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Masculino
11.
Metabolomics ; 17(3): 27, 2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33594460

RESUMO

INTRODUCTION: The study of metabolic profile can be an important tool to better understand, at a systemic level, metabolic alterations caused by different pathological conditions, such as obesity. Furthermore, it allows the discovery of metabolic biomarkers, which may help to diagnose alterations caused by obesity. OBJECTIVE: To investigate the metabolic profile of blood serum of obese dogs, control dogs, and dogs that were subjected to a weight loss program. METHODS: Ten obese adult spayed female dogs were included, and their body composition was determined by the deuterium isotope dilution method. The dogs were subjected to a weight loss program and formed a new experimental group after losing 20% of the initial body weight. A third experimental group was composed of ten lean adult spayed female dogs. The metabolic profile of blood serum was evaluated through nuclear magnetic resonance (NMR). Principal Component Analyses (PCA) and Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) models were constructed using Pareto scaling pre-processing. Pathway analysis was also performed using the MetaboAnalist online tool. RESULTS: The PCA shows that the control and after weight loss groups presented a trend to negative PC1, indicating similarities between these two groups. In contrast, obese animals presented a tendency to appear on negative PC2 indicating a different metabolic profile. The OPLS-DA analysis of the serum indicated that healthy groups presented higher content of glucose, while animals that lost weight had higher levels of cholesterol and lactate than the control group. On the other hand, the analysis showed that lipid content, cholesterol, and branched-chain amino acids were highest in obese animals. Variable Influence on Projection (VIP) analysis demonstrated that Lactate is the most important metabolite for the OPLS-DA model and Hierarchical Cluster Analysis (HCA) corroborated the similarity between the control group and the obese after weight loss groups. Moreover, the pathway analysis indicated the most important metabolic pathways related to this dataset. CONCLUSIONS: The metabolomic assessment based on NMR of blood serum differed between obese dogs and animals in optimal body condition. Moreover, the weight loss resulted in metabolic profiles similar to those observed in lean animals.


Assuntos
Metaboloma , Metabolômica/métodos , Obesidade/sangue , Soro/metabolismo , Redução de Peso , Animais , Análise Discriminante , Cães , Feminino , Espectroscopia de Ressonância Magnética , Redes e Vias Metabólicas , Análise de Componente Principal
12.
Poult Sci ; 99(11): 6247-6257, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33142543

RESUMO

Metabolite profiles of chicken breast extracts and water mobility in breasts were studied using proton nuclear magnetic resonance (1H-NMR) spectroscopy and time-domain NMR (TD-NMR) relaxometry, respectively, using normal breast (NB), and wooden breast (WB) and white striping (WS) myopathies in broilers. One thousand eight hundred sixty broilers were raised to commercial standards, receiving the same diets that were formulated as per the different growth stages. At 49 D of age, 200 animals were slaughtered following routine commercial procedures, and at 4 h postmortem, the whole breast (pectoralis major muscle) was removed and visually inspected by an experienced meat inspector who selected NB (without myopathies) and samples with the presence of WS and WB myopathies. Fifteen breasts (5 each of NB, WS, and WB) were analyzed through TD-NMR relaxometry, and samples of approximately 20 g were taken from each breast and frozen at -80°C for metabolite profiling through 1H-NMR spectroscopy. Multivariate statistical analysis was used to evaluate the effect on water relaxometry and metabolite profile in accordance with the presence and type of myopathy in the breast. 1H-NMR data showed that the metabolite profiles in WS and WB breasts were different from each other and from NB. This pilot study shows that myopathies appear to be related to hypoxia, connective tissue deposition, lower mitochondrial function, and greater oxidative stress compared with NB. The longitudinal and transverse relaxation time of the breasts determined by TD-NMR relaxometry was shorter for NB than that for WS and WB, indicating greater water mobility in breasts affected by myopathies. 1H-NMR spectroscopy can be used to differentiate the metabolism of WS, WB, and NB, and TD-NMR has the potential to be a fast, simple, and noninvasive method to distinguish NB from WB and WS. As a practical application, the metabolomic profile as per the occurrence of breast myopathies may be used for a better understanding of these issues, which opens a gap to mitigate the incidence and severity of WS and WB. In addition, the present study brings an opportunity for the development of a new and objective tool to classify the incidence of breast myopathies through TD-NMR relaxometry.


Assuntos
Metabolômica , Doenças Musculares , Músculos Peitorais , Doenças das Aves Domésticas , Animais , Galinhas , Carne/análise , Doenças Musculares/patologia , Doenças Musculares/veterinária , Ressonância Magnética Nuclear Biomolecular , Músculos Peitorais/química , Projetos Piloto , Doenças das Aves Domésticas/patologia , Água/química
13.
Food Res Int ; 132: 109056, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32331638

RESUMO

Thirty each Nellore (NEL) and crossbred Angus × Nellore (AxN) were used to evaluate the effect of feeding soybean oil (SBO) and breed on meat sensory acceptability and its relation to muscle metabolite profiles. Cattle were fed for 133 d on two different diets: 1) basal feedlot diet (CON) and 2) CON diet with 3.5% added SBO. No interactions between diet and genetic group were detected for any traits measured. Meat from animals fed SBO diet had lower overall liking, flavor, tenderness and juiciness scores compared to meat from animals fed CON diet. The four most important compounds differing between animals fed CON and SBO diets were betaine, glycerol, fumarate, and carnosine, suggesting that metabolic pathways such as glycerolipid metabolism; glycine, serine and threonine metabolism; glutamine and glutamate metabolism; valine, leucine and isoleucine biosynthesis; and alanine, aspartate and glutamate metabolism were affected by diets. Nellore beef had a higher overall liking and meat flavor scores than AxN beef. The four most important compounds differing between breeds were glycine, glucose, alanine, and carnosine, which may indicate that metabolic pathways such as glutathione metabolism; primary bile acid biosynthesis; alanine, aspartate and glutamate metabolism; and valine, leucine and isoleucine biosynthesis were affected by genetic groups. Meat carnosine, inosine monophosphate, glutamate, betaine, glycerol and creatinine levels were correlated with sensory acceptability scores. Meat metabolite profiles and sensory acceptability were differentially impacted by diet and breed.


Assuntos
Ração Animal , Comportamento do Consumidor , Dieta/veterinária , Carne/análise , Óleo de Soja , Paladar , Animais , Brasil , Bovinos , Metabolismo dos Lipídeos , Metabolômica
14.
Int J Biol Macromol ; 144: 143-150, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31843606

RESUMO

Herein we describe the interaction of starch, urea, and melamine (C3N6H6) in composite materials for use as controlled-release plant fertilizer. Slow-release fertilizers are important in minimizing nutrient losses due to run-off, leaching, and other factors. Urea is an effective plasticizer for starch and is an important nitrogen fertilizer throughout the world. Melamine also has high nitrogen content and could be combined with urea-starch composites to provide enhanced controlled-release fertilizer. This study reports the structural interaction and the performance gain of melamine addition to starch-urea composites. Composites were characterized by spectroscopic techniques (FT-Raman and 13C NMR) detailing the interaction between melamine, urea, and starch. These interactions helped facilitate extrusion processing by lowering viscosity and processing temperatures suggesting an enhanced starch plasticizing effect of starch-urea-melamine composites. Further research into the co-plasticization of starch by urea and melamine could be exploited for improved controlled-release fertilizer products. Further research into the co-plasticization of starch by urea and melamine could be exploited for improved controlled-release fertilizer products.


Assuntos
Fertilizantes/análise , Plastificantes/química , Amido/química , Triazinas/química , Ureia/química , Varredura Diferencial de Calorimetria , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Análise Espectral Raman , Amido/ultraestrutura , Difração de Raios X
15.
Carbohydr Polym ; 177: 178-186, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28962756

RESUMO

The aim of this work was to investigate the potential of a new 3,6-O,O'-dimyristoyl derivative amphiphilic chitosan (DMCh), in improving the solubility of camptothecin (CPT), a hydrophobic anticancer drug, and its potential oral delivery. FTIR, 1H NMR and solid-state 13C NMR spectroscopy were used to characterize DMCh and to determine its average degree of substitution (DS¯=6.8%). DMCh/CPT micelles size ranged from (281-357nm), zeta potential (+32-50mV) of encapsulation efficiency of 42-100%. The in vitro cell viability showed that DMCh/CPT micelles were able to reduce the toxicity of CPT. The in vitro permeability of CPT through Caco-2 and Caco-2/HT29-MTX intestinal models was increased up to ten fold when formulated into DMCh micelles, underlining the mucoadhesive properties of the nanocarrier. DMCh/CPT micelles are able to enhance CPT solubility and bioavailability while reduce its cytotoxicity, showing the great potential for intestinal delivery of hydrophobic drugs.


Assuntos
Camptotecina/metabolismo , Quitosana/química , Portadores de Fármacos/farmacologia , Células CACO-2 , Camptotecina/administração & dosagem , Camptotecina/química , Portadores de Fármacos/química , Humanos , Micelas , Tamanho da Partícula , Permeabilidade/efeitos dos fármacos , Solubilidade
16.
J Pharm Biomed Anal ; 146: 324-328, 2017 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-28915495

RESUMO

Doxorubicin, cisplatin, and tamoxifen are part of many chemotherapeutic regimens. However, studies investigating the effect of chemotherapy on the metabolism of breast cancer cells are still limited. We used 1H high-resolution magic angle spinning (HR-MAS) NMR spectroscopy to study the metabolic profile of human breast cancer MDA-MB-231 cells either untreated (control) or treated with tamoxifen, cisplatin, and doxorubicin. 1H HR-MAS NMR single pulse spectra evidenced signals from all mobile cell compounds, including fatty acids (membranes), water-soluble proteins, and metabolites. NMR spectra showed that phosphocholine (i.e., a biomarker of breast cancer malignant transformation) signals were stronger in control than in treated cells, but significantly decreased upon treatment with tamoxifen/cisplatin. NMR spectra acquired with Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence were interpreted only qualitatively because signal areas were attenuated according to their transverse relaxation times (T2). The CPMG method was used to identify soluble metabolites such as organic acids, amino acids, choline and derivatives, taurine, guanidine acetate, tyrosine, and phenylalanine. The fatty acid variations observed by single pulse as well as the lactate, acetate, glycine, and phosphocholine variations observed through CPMG 1H HR-MAS NMR have potential to characterize both responder and non-responder tumors in a molecular level. Additionally, we emphasized that comparable tumors (i.e., with the same origin, in this case breast cancer) may respond totally differently to chemotherapy. Our observations reinforce the theory that alterations in cellular metabolism may contribute to the development of a malignant phenotype and cell resistance.


Assuntos
Neoplasias da Mama/metabolismo , Aminoácidos/metabolismo , Biomarcadores/metabolismo , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Colina/metabolismo , Cisplatino/farmacologia , Doxorrubicina/farmacologia , Feminino , Humanos , Ácido Láctico/metabolismo , Metaboloma , Fosforilcolina/metabolismo , Espectroscopia de Prótons por Ressonância Magnética/métodos , Tamoxifeno/farmacologia
17.
J Magn Reson ; 283: 79-88, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28888726

RESUMO

In this article, several studies based on analytical expressions and computational simulations on Hollow Cylindrical Magnets with an external soft ferromagnetic material (HCM magnets) are presented. Electromagnetic configurations, as well as permanent-magnet-based structures, are studied in terms of magnetic field strength and homogeneity. Permanent-magnet-based structures are further analyzed in terms of the anisotropy of the magnetic permeability. It was found that the HCM magnets produce a highly homogeneous magnetic field as long as the magnetic material is isotropic. The dependency of the magnetic field strength and homogeneity in terms of the anisotropy of the magnetic permeability is also explored here. These magnets can potentially be used in medium-resolution NMR spectrometers and high-field NMR spectrometers.

18.
Food Res Int ; 99(Pt 1): 336-347, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28784491

RESUMO

Mate (Ilex paraguariensis A.St.-Hil.) is generally recognized as safe (GRAS status) and has a high content of alkaloids, saponins, and phenolic acids. Addition of mate extract to broilers feed has been shown to increase the oxidative stability of chicken meat, however, its effect on beef quality from animals supplemented with mate extract has not been investigated so far. Addition of extract of mate to a standard maize/soy feed at a level of 0.5, 1.0 or 1.5% w/w to the diet of feedlot for cattle resulted in increased levels of inosine monophosphate, creatine and carnosine in the fresh meat. The content of total conjugated linoleic acid increased in the meat as mate extract concentration was increased in the feed. The tendency to radical formation in meat slurries as quantified by EPR spin-trapping decreased as increasing mate extract addition to feed, especially after storage of the meat, indicating higher oxidative stability. Mate supplementation in the diet did not affect animal performance and carcass characteristics, but meat from these animals was more tender and consequently more accepted by consumers. Mate extract is shown to be a promising additive to feedlot diets for cattle to improve the oxidative stability, nutritive value and sensory quality of beef.


Assuntos
Ração Animal , Comportamento do Consumidor , Suplementos Nutricionais , Manipulação de Alimentos/métodos , Qualidade dos Alimentos , Ilex paraguariensis , Extratos Vegetais/administração & dosagem , Carne Vermelha/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos , Humanos , Julgamento , Metabolômica/métodos , Estado Nutricional , Valor Nutritivo , Odorantes , Percepção Olfatória , Oxirredução , Extratos Vegetais/metabolismo , Carne Vermelha/normas , Paladar , Percepção Gustatória
19.
Biochemistry ; 56(16): 2219-2224, 2017 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-28379688

RESUMO

Doxorubicin (Doxo), cisplatin (Cis), and tamoxifen (Tamo) are part of many chemotherapeutic regimens. However, there have been limited studies of the way metabolism in breast cancer is affected by chemotherapy. We studied, through 1H high-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy, the metabolic profile of human breast cancer MCF-7 control (Con) cells as well as MCF-7 cells treated with Tamo, Cis, and Doxo. 1H HR-MAS NMR single-pulse spectra evidenced signals from the cell compounds, including fatty acids (membranes), water-soluble proteins, and metabolites. The spectra showed that phosphocholine (i.e., biomarker of breast cancer malignant transformation) signals were stronger in Con than in treated cells. Betaine (i.e., the major osmolyte in cells) was observed at similar concentrations in MCF-7 control and treated cells but was absent in nontumor MCF-10A cells. The NMR spectra acquired with the Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence were used only in qualitative analyses because the signal areas were attenuated according to their transverse relaxation time (T2). The CPMG method was used to identify soluble metabolites such as organic acids, amino acids, choline and its derivatives, taurine, and guanidino acetate. 1H HR-MAS NMR spectroscopy efficiently demonstrated the effects of Tamo, Cis, and Doxo on the metabolic profile of MCF-7 cells. The fatty acid, phosphocholine, and choline variations observed by single-pulse HR-MAS NMR have the potential to characterize both responder and nonresponder tumors at a molecular level.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/metabolismo , Cisplatino/farmacologia , Doxorrubicina/farmacologia , Espectroscopia de Prótons por Ressonância Magnética/métodos , Tamoxifeno/farmacologia , Neoplasias da Mama/patologia , Feminino , Humanos , Células MCF-7
20.
Sci Rep ; 7: 41193, 2017 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-28117455

RESUMO

Acidobacteria have been described as one of the most abundant and ubiquitous bacterial phyla in soil. However, factors contributing to this ecological success are not well elucidated mainly due to difficulties in bacterial isolation. Acidobacteria may be able to survive for long periods in soil due to protection provided by secreted extracellular polymeric substances that include exopolysaccharides (EPSs). Here we present the first study to characterize EPSs derived from two strains of Acidobacteria from subdivision 1 belonging to Granulicella sp. EPS are unique heteropolysaccharides containing mannose, glucose, galactose and xylose as major components, and are modified with carboxyl and methoxyl functional groups that we characterized by Fourier transform infrared (FTIR) spectroscopy. Both EPS compounds we identified can efficiently emulsify various oils (sunflower seed, diesel, and liquid paraffin) and hydrocarbons (toluene and hexane). Moreover, the emulsions are more thermostable over time than those of commercialized xanthan. Acidobacterial EPS can now be explored as a source of biopolymers that may be attractive and valuable for industrial applications due to their natural origin, sustainability, biodegradability and low toxicity.


Assuntos
Acidobacteria/química , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/isolamento & purificação , Biopolímeros , Emulsificantes/química , Emulsificantes/isolamento & purificação , Emulsões/química , Monossacarídeos/química , Reologia , Microbiologia do Solo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...