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1.
Artigo em Inglês | MEDLINE | ID: mdl-38842428

RESUMO

In a previous study characterizing Campylobacter strains deficient in selenium metabolism, 50 strains were found to be similar to, but distinct from, the selenonegative species Campylobacter lanienae. Initial characterization based on multilocus sequence typing and the phylogeny of a set of 20 core genes determined that these strains form three putative taxa within the selenonegative cluster. A polyphasic study was undertaken here to further clarify their taxonomic position within the genus. The 50 selenonegative strains underwent phylogenetic analyses based on the sequences of the 16S rRNA gene and an expanded set of 330 core genes. Standard phenotypic testing was also performed. All strains were microaerobic and anaerobic, Gram-negative, spiral or curved cells with some displaying coccoid morphologies. Strains were motile, oxidase, catalase, and alkaline phosphatase positive, urease negative, and reduced nitrate. Strains within each clade had unique phenotypic profiles that distinguished them from other members of the genus. Core genome phylogeny clearly placed the 50 strains into three clades. Pairwise average nucleotide identity and digital DNA-DNA hybridization values were all below the recommended cut-offs for species delineation with respect to C. lanienae and other related Campylobacter species. The data presented here clearly show that these strains represent three novel species within the genus, for which the names Campylobacter devanensis sp. nov. (type strain RM3662T=LMG 33097T=NCTC 15074T), Campylobacter porcelli sp. nov. (type strain RM6137T=LMG 33098T=CCUG 77054T=NCTC 15075T) and Campylobacter vicugnae sp. nov. (type strain RM12175T=LMG 33099T=CCUG 77055T=NCTC 15076T) are proposed.


Assuntos
Técnicas de Tipagem Bacteriana , Campylobacter , DNA Bacteriano , Tipagem de Sequências Multilocus , Hibridização de Ácido Nucleico , Filogenia , RNA Ribossômico 16S , Análise de Sequência de DNA , RNA Ribossômico 16S/genética , Campylobacter/genética , Campylobacter/classificação , Campylobacter/isolamento & purificação , Animais , DNA Bacteriano/genética , Suínos , Ruminantes/microbiologia
2.
Theor Appl Genet ; 133(11): 3119-3137, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32803378

RESUMO

KEY MESSAGE: Quantitation of leaf surface wax on a population of switchgrass identified three significant QTL present across six environments that contribute to leaf glaucousness and wax composition and that show complex genetic × environmental (G × E) interactions. The C4 perennial grass Panicum virgatum (switchgrass) is a native species of the North American tallgrass prairie. This adaptable plant can be grown on marginal lands and is useful for soil and water conservation, biomass production, and as a forage. Two major switchgrass ecotypes, lowland and upland, differ in a range of desirable traits, and the responsible underlying loci can be localized efficiently in a pseudotestcross design. An outbred four-way cross (4WCR) mapping population of 750 F2 lines was used to examine the genetic basis of differences in leaf surface wax load between two lowland (AP13 and WBC) and two upland (DAC and VS16) tetraploid cultivars. The objective of our experiments was to identify wax compositional variation among the population founders and to map underlying loci responsible for surface wax variation across environments. GCMS analyses of surface wax extracted from 4WCR F0 founders and F1 hybrids reveal higher levels of wax in lowland genotypes and show quantitative differences of ß-diketones, primary alcohols, and other wax constituents. The full mapping population was sampled over two seasons from four field sites with latitudes ranging from 30 to 42 °N, and leaf surface wax was measured. We identified three high-confidence QTL, of which two displayed significant G × E effects. Over 50 candidate genes underlying the QTL regions showed similarity to genes in either Arabidopsis or barley known to function in wax synthesis, modification, regulation, and transport.


Assuntos
Interação Gene-Ambiente , Panicum/genética , Folhas de Planta/química , Locos de Características Quantitativas , Ceras , Mapeamento Cromossômico , Cruzamentos Genéticos , Ecótipo , Ligação Genética , Genótipo , Panicum/química , Fenótipo , Tetraploidia
3.
Med Humanit ; 45(3): 294-303, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31371484

RESUMO

Health research is often bounded by disciplinary expertise. While cross-disciplinary collaborations are often forged, the analysis of data which draws on more than one discipline at the same time is underexplored. Life of Breath, a 5-year project funded by the Wellcome Trust to understand the clinical, historical and cultural phenomenology of the breath and breathlessness, brings together an interdisciplinary team, including medical humanities scholars, respiratory clinicians, medical anthropologists, medical historians, cultural theorists, artists and philosophers. While individual members of the Life of Breath team come together to share ongoing work, collaborate and learn from each other's approach, we also had the ambition to explore the feasibility of integrating our approaches in a shared response to the same piece of textual data. In this article, we present our pluralistic, interdisciplinary analysis of an excerpt from a single cognitive interview transcript with a patient with chronic obstructive pulmonary disease. We discuss the variation in the responses and interpretations of the data, why research into breathlessness may particularly benefit from an interdisciplinary approach, and the wider implications of the findings for interdisciplinary research within health and medicine.


Assuntos
Pesquisa Biomédica/métodos , Dispneia , Relações Interprofissionais , Comportamento Cooperativo , Interpretação Estatística de Dados , Humanos , Comunicação Interdisciplinar
4.
Plant J ; 91(3): 361-370, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28432803

RESUMO

Due to a large and growing collection of genomic and experimental resources, Brachypodium distachyon has emerged as a powerful experimental model for the grasses. To add to these resources we sequenced 21 165 T-DNA lines, 15 569 of which were produced in this study. This increased the number of unique insertion sites in the T-DNA collection by 21 078, bringing the overall total to 26 112. Thirty-seven per cent (9754) of these insertion sites are within genes (including untranslated regions and introns) and 28% (7217) are within 500 bp of a gene. Approximately 31% of the genes in the v.2.1 annotation have been tagged in this population. To demonstrate the utility of this collection, we phenotypically characterized six T-DNA lines with insertions in genes previously shown in other systems to be involved in cellulose biosynthesis, hemicellulose biosynthesis, secondary cell wall development, DNA damage repair, wax biosynthesis and chloroplast synthesis. In all cases, the phenotypes observed supported previous studies, demonstrating the utility of this collection for plant functional genomics. The Brachypodium T-DNA collection can be accessed at http://jgi.doe.gov/our-science/science-programs/plant-genomics/brachypodium/brachypodium-t-dna-collection/.


Assuntos
Brachypodium/genética , DNA Bacteriano/genética , Plantas Geneticamente Modificadas/genética , Dano ao DNA/genética , Genoma de Planta/genética , Genômica , Íntrons/genética , Mutagênese Insercional
5.
J Nanosci Nanotechnol ; 15(1): 616-27, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26328414

RESUMO

The present study reports on the development of hybrid poly(lactic acid) (PLA) fibres loaded with highly crystalline bacterial cellulose nanowhiskers (BCNW) by the novel solution blow spinning method. Furthermore, fibres with antimicrobial properties were generated by incorporating carvacrol and THC as antimicrobial agents and the biocide effect against Listeria monocytogenes was studied. Initially, PLA blow spun fibres containing BCNW were optimized in terms of morphology and thermal properties. The addition of BCNW was seen to significantly increase the viscosity and surface tension of solutions, restricting the capacity to form fibres for concentrations greater than 30 wt.-% BCNW. 15 wt.-% BCNW was selected as the optimum nanofiller loading as it led to the most uniform fibres morphology, with BCNW homogeneously distributed along the fibres' axis. Subsequently, carvacrol and THC were incorporated into the fibres to confer them with antimicrobial properties, although the hydrophobic PLA matrix did not provide an efficient release of the antimicrobials. Thus, hydrophilic substances were added in order to trigger the antimicrobials release through water sorption mechanisms. The addition of the BCNW filler was not seen to significantly increase the antimicrobial capacity of the fibres by itself and, hence, gelatin was added to help promoting further the hydrophylicity and biocide performance of the fibres. Nevertheless, for the more hydrophilic THC, the biocide capacity of the fibres with gelatin was accentuated further by the presence of the BCNW.


Assuntos
Anti-Infecciosos/química , Ácido Láctico/química , Nanofibras/química , Nanotecnologia/métodos , Polímeros/química , Anti-Infecciosos/farmacologia , Varredura Diferencial de Calorimetria , Celulose/química , Celulose/metabolismo , Cimenos , Gluconacetobacter xylinus/química , Gluconacetobacter xylinus/metabolismo , Listeria monocytogenes/efeitos dos fármacos , Monoterpenos/química , Monoterpenos/farmacologia , Poliésteres , Viscosidade
6.
AANA J ; 82(3): 198-202, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25109157

RESUMO

This prospective, experimental, mixed study determined whether there were differences in intraosseous (IO) and intravenous (IV) whole blood transfusion relative to hemolysis and transfusion time. Swine were assigned to the IV group (n = 6) with an 18-gauge catheter in the auricular vein or the IO group (n = 7) with a 15-gauge 10 needle in the proximal humerus. Following baseline specimen collection, 900 mL of blood was collected from each animal. The collected blood was autologously transfused by the IV or IO route using a pressure infusion bag inflated to 300 mm Hg, with immediate posttransfusion specimen collection. Hemolysis was defined by the amount of plasma free hemoglobin. Multivariate analysis of variance revealed no significant differences between groups relative to posttransfusion free hemoglobin or transfusion time (P = .065). The IV group's mean free hemoglobin level was 10.23 +/- 10.52 micromol/L; the IO group, 7.2 +/- 5.82 micromol/L. The IV group's mean transfusion time was 13.48 +/- 4.1 minutes; the IO group, 28.70 +/- 19.51 minutes. Intraosseous transfusion does not significantly increase hemolysis or transfusion time compared with IV transfusion. Clinically, it can take up to twice as long to transfuse 900 mL of blood IO compared with IV.


Assuntos
Transfusão de Sangue/métodos , Hemólise , Choque Hemorrágico/terapia , Administração Intravenosa , Animais , Infusões Intraósseas , Modelos Animais , Projetos Piloto , Suínos , Fatores de Tempo
7.
Carbohydr Polym ; 329: 121802, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38286526

RESUMO

Multivariate models were developed to classify cellulose nanofibril (CNF) fibrillation by a quality index from near infrared (NIR) spectra. Commercial pulps of Eucalyptus spp. were used to produce cellulose nanofibrils by means of a fibrillator mill. After each of the five passes through the mill, samples were collected and analyzed for energy consumption and fiber classification. As a standard, pulps were oxidized with TEMPO reagent followed by a single pass through the mill to compare the resulting quality of CNFs produced by each method. NIR spectra of CNFs were associated with quality indices determined by conventional laboratory analyses that included morphology, turbidity, mechanical properties, X-ray diffraction and quality index measurements. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were applied to the spectral and experimental data. Fibrillator milling to obtain CNFs was efficient and resulted in gel formation following the third pass through the mill. NIR spectroscopy combined with PLS-DA was used successfully to create a model to classify quality of CNFs with 96 % certainty in 3 wt% solutions. These findings suggest that NIR spectroscopy holds promise for estimating CNF quality in suspension, particularly in real-time industrial applications where reliable estimates are crucial.


Assuntos
Eucalyptus , Nanofibras , Celulose/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Eucalyptus/química , Carboidratos , Difração de Raios X , Nanofibras/química
8.
Polymers (Basel) ; 14(18)2022 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-36146029

RESUMO

Raw and torrefied rice hulls (RRH and TRH) were incorporated into polyhydroxybutyrate (PHB) as fillers using extrusion and injection molding to produce biomass-polymer composites. Filler and composite materials were characterized by particle size analysis, thermomechanical analysis, thermogravimetric analysis, differential scanning calorimetry, FTIR analysis, CHNSO analysis, and mechanical testing. Heat distortion temperature of the RRH composites were 16-22 °C higher than TRH composites. The RRH composite samples showed a 50-60% increase in flexural modulus and 5% increase in stress at yield compared to PHB, while TRH composite samples showed nearly equal flexural modulus and a 24% decrease in stress at yield. The improved mechanical properties of the RRH composites in comparison to TRH composites were due to better particle-matrix adhesion. FTIR analysis showed RRH particles contained more surface functional groups containing oxygen than TRH particles, indicating that RRHs should be more compatible with the polar PHB plastic. SEM images showed space between filler and plastic in TRH composites and better wetted filler particles in the RRH composites.

9.
J Food Sci ; 87(11): 4796-4807, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36181485

RESUMO

Isochoric impregnation was explored as a novel pressure-assisted infusion technique to fortify plant materials with bioactive compounds. Apple and potato cylinders were impregnated with a sucrose solution containing 4% ascorbic acid (AA) while freezing under isochoric conditions. Isochoric impregnation resulted in greater infusion of AA compared to infusion at atmospheric pressure, which demonstrated the feasibility of this impregnation technology. Processing temperatures (-3°C and -5°C) and processing times (1, 3, and 5 h) significantly affected the AA infusion. The AA content values ranged from 446 to 516 mg/100 g for apples and 322 to 831 mg/100 g for sweet potatoes under isochoric conditions. For both plant materials, isochoric impregnation at -3°C did not cause major changes in texture and microstructure of the biological tissues. These results indicated that isochoric impregnation of solid foods could be a feasible technology for infusion of bioactive compounds without significantly altering their matrix. PRACTICAL APPLICATION: The findings of this study showed that the use of isochoric impregnation as a fortification technique is a promising way to develop fresh-like and value-added products with improved nutrition during preservation at subfreezing temperatures.


Assuntos
Malus , Solanum tuberosum , Isocoros , Congelamento , Ácido Ascórbico
10.
Foods ; 10(2)2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33670567

RESUMO

The cracking of sweet cherries causes significant crop losses. Sweet cherries (cv. Bing) were coated by electro-spraying with an edible nanoemulsion (NE) of alginate and soybean oil with or without a CaCl2 cross-linker to reduce cracking. Coated sweet cherries were stored at 4 °C for 28 d. The barrier and fruit quality properties and nutritional values of the coated cherries were evaluated and compared with those of uncoated sweet cherries. Sweet cherries coated with NE + CaCl2 increased cracking tolerance by 53% and increased firmness. However, coated sweet cherries exhibited a 10% increase in water loss after 28 d due to decreased resistance to water vapor transfer. Coated sweet cherries showed a higher soluble solid content, titratable acidity, antioxidant capacity, and total soluble phenolic content compared with uncoated sweet cherries. Therefore, the use of the NE + CaCl2 coating on sweet cherries can help reduce cracking and maintain their postharvest quality.

11.
Food Res Int ; 143: 110228, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33992342

RESUMO

This study investigated the potential of isochoric freezing to preserve tomatoes. Isochoric freezing is an emerging technology that preserves biological matter at subfreezing temperatures without any ice damage. Isochoric freezing was compared with freezing under isobaric conditions and with preservation techniques used in the food industry: cold storage at 10 °C and individual quick freezing (IQF). Physicochemical and nutritional properties were evaluated weekly for four weeks. Preservation under isochoric conditions maintained the mass, color, nutrient content (ascorbic acid, lycopene and phenolics) and antioxidant activity of the fresh tomatoes. Also, isochoric preservation led to minimal texture damage. In comparison, mass loss of tomatoes stored at 10 °C for 3 weeks contributed to changes in overall visual quality and firmness as well as significant losses in nutrient content. The greatest mass, texture, and nutrients losses were obtained for tomatoes subjected to IQF and isobaric freezing. The results show that isochoric freezing has the potential to preserve tomatoes while maintaining physicochemical and nutritional properties similar to those of fresh tomatoes which might find application in the commercial preservation of tomatoes.


Assuntos
Solanum lycopersicum , Vitis , Criopreservação , Congelamento , Isocoros
12.
Carbohydr Polym ; 252: 117165, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33183616

RESUMO

Commercializing dried microfibrillated cellulose (MFC) has always been a challenge mainly due to the tendency of MFC to aggregate. In this study MFC samples were submitted to drying/redispersion cycles at different temperatures. Morphology, crystallinity and mechanical performance of films were analyzed throughout the cycles. Microscopy images, particle size and stability in water showed that aggregation happens more severely with 5 drying/redispersion cycles and at drying temperatures of 75 and 100 °C. Particles once-dried at 20 °C formed the same size and web-like structure as the MFC-control. Crystallinity and crystallite sizes increased with drying/redispersion cycles especially when dried at 75 and 100 °C, however drying/redispersion cycles also led to a reduction in mechanical performance due to aggregation. While oven-drying is not the most suitable method, milder action at room temperature once-drying led to suspension stability in water, morphology and mechanical properties close to never-dried MFC, which makes this treatment a feasible option to maintain cellulose quality.

13.
J Food Sci ; 85(9): 2656-2664, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32860220

RESUMO

The enhanced interest in greater convenience foods has recently led to the expansion of minimally processed potato products. This study investigated the effects of isochoric freezing on pre-peeled potato cubes, including quality attributes (microstructure, texture, and color), nutritional value (ascorbic acid (AA) content, total phenolic content, and antioxidant capacity), and polyphenol oxidase activity. Isochoric freezing (-3 °C/30 MPa) was compared with isobaric freezing (-3 °C/0.1 MPa) and individual quick freezing followed by frozen storage at -20 °C for 4 weeks. The isochoric sample had lower drip loss and volume shrinkage as well as better preserved texture and microstructure than the other samples. All freezing methods caused an increase in total phenolic content and antioxidant capacity, but a decrease in AA content. Also, all freezing methods caused browning of the thawed potatoes, but isochoric freezing delayed its onset for more than 1 week. PRACTICAL APPLICATION: Results showed that isochoric freezing of pre-peeled and cut potatoes caused less freeze damage than isobaric and individual quick freezing, which might find application in the commercial preservation of minimally processed food products.


Assuntos
Conservação de Alimentos/métodos , Tubérculos/química , Solanum tuberosum/química , Antioxidantes/análise , Ácido Ascórbico/análise , Congelamento , Valor Nutritivo , Oxirredução , Fenóis/análise
14.
Carbohydr Polym ; 207: 100-107, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30599989

RESUMO

The objective of this work was to prepare bio-based thin films and evaluate the additions of magnetite and glycerol on the physico-chemical (flexibility, wettability and barrier properties) and dielectric properties of cellulose/chitosan-based films. The films were prepared by solution casting and presented a suitable dispersion of the constituents observed by SEM and FTIR. The films were thermally stable up to 150 °C and had a higher flexibility, wettability and lower barrier properties upon addition of glycerol. The calculated dielectric constant (εr) for the composite films was based on measurements of capacitance, at 100 and 1000 Hz, with the additions of magnetite and glycerol more than doubling the εr increasing the charge storage capacity. The bio-based thin films have potential to be used as insulators in capacitors on the production of green electronics thus, reducing toxic and nonrenewable e-waste generation.


Assuntos
Celulose/química , Óxido Ferroso-Férrico/química , Nanofibras/química , Quitosana/química , Módulo de Elasticidade , Capacitância Elétrica , Glicerol/química , Química Verde/instrumentação , Fenômenos Magnéticos , Resistência à Tração , Molhabilidade
15.
Polymers (Basel) ; 11(8)2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31370362

RESUMO

This paper provides proof of concept that activated carbon (AC) may be readily produced using limited conversion methods and resources from sawdust of massaranduba (Manilkara huberi) wood, thereby obtaining value-added products. Sawdust was sieved and heat-treated in an oxygen-free muffle furnace at 500 °C to produce charcoal. The charcoal was activated in a tubular electric furnace at 850 °C while being purged with CO2 gas. Microstructural, thermal and physical properties of the three components: sawdust, charcoal and AC were compared by means of field emission scanning electron microscopy (FESEM), X-ray diffractometry (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), density and water adsorption/desorption measurements. The resulting AC had a large surface area as measured by Brunauer-Emmett-Teller (BET) comparable to other such values found in the literature. The large surface area was due to pore development at the microstructural level as shown by FESEM. XRD illustrated that sawdust had a semi-crystalline structure whereas charcoal and AC evidenced mostly amorphous structures. TGA and DSC showed that AC had high reactivity to moisture compared to sawdust and charcoal.

16.
Jt Comm J Qual Patient Saf ; 34(4): 196-200, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18468356

RESUMO

BACKGROUND: The conventional standard of care for many patients at Saint Joseph HealthCare, a three-hospital system in Kentucky, includes the use of anticoagulant therapy. In view of the morbidity and mortality associated with anticoagulation-related complications, the prevention of bleeding and thrombotic adverse drug events was identified as a primary process improvement initiative. METHODS: Following establishment of an interdisciplinary team, formal evaluations of anticoagulant-use practices and associated patient outcomes occurred via several mechanisms. A variety of process improvement activities were conducted, including the creation of a pharmacist-managed hospital anticoagulant therapy service. A pharmacist consult service for the medical staff provided initiation, management, and monitoring of anticoagulation, including bridge therapy and reversal if necessary. RESULTS: The rate of thrombotic events decreased from 4.6% in 2004 to 3.9% in 2006 and further decreased to 0.0% for patients managed by collaborative physician and pharmacist practice. Hospitalwide bleeding and thrombotic reactions decreased from a monthly average of 11.52 events per 1,000 anticoagulant doses dispensed in 2004 to 0.07 in 2006. A cost-benefit evaluation indicated an annual savings of up to $9.8 million in avoidable costs. DISCUSSION: In this interdisciplinary project, anticoagulant safety was integrated throughout the institution, and a variety of medication safety systems were successfully employed.


Assuntos
Sistemas de Notificação de Reações Adversas a Medicamentos/organização & administração , Anticoagulantes/efeitos adversos , Erros de Medicação/prevenção & controle , Gestão da Segurança/métodos , Anticoagulantes/administração & dosagem , Distinções e Prêmios , Hemorragia/induzido quimicamente , Hemorragia/prevenção & controle , Humanos , Kentucky , Sistemas Multi-Institucionais , Estudos de Casos Organizacionais , Equipe de Assistência ao Paciente/organização & administração , Trombose/induzido quimicamente , Trombose/prevenção & controle
17.
J Food Sci ; 83(7): 1880-1887, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29846934

RESUMO

Food waste is currently being generated at an increasing rate. One proposed solution would be to convert it to biopolymers for industrial applications. We recovered chitin from mushroom waste and converted it to chitosan to produce edible coatings. We then used layer-by-layer (LbL) electrostatic deposition of the polycation chitosan and the polyanion alginate to coat fruit bars enriched with ascorbic acid. The performance of the LbL coatings was compared with those containing single layers of fungal chitosan, animal origin chitosan and alginate. Bars containing alginate-chitosan LbL coatings showed increased ascorbic acid content, antioxidant capacity, firmness and fungal growth prevention during storage. Also, the origin of the chitosan did not affect the properties of the coatings. PRACTICAL APPLICATION: Mushroom stalk bases could be an alternative source for isolating chitosan with similar properties to animal-based chitosan. Also, layer-by-layer assembly is a cheap, simple method that can improve the quality and safety of fruit bars.


Assuntos
Agaricales/química , Alginatos/análise , Quitosana/química , Aditivos Alimentares/química , Frutas/química , Quitosana/isolamento & purificação , Aditivos Alimentares/isolamento & purificação , Manipulação de Alimentos , Ácido Glucurônico/análise , Ácidos Hexurônicos/análise , Lanches
18.
J Food Sci ; 82(6): 1402-1411, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28471491

RESUMO

The primary advantage of nanofibers over larger diameter fibers is the larger surface area to volume ratio. This study evaluated solution blow spinning (SBS) processing conditions for obtaining food-grade gelatin nanofibers from mammalian and fishery byproducts, such as pork skin gelatins (PGs) and high molecular weight fish skin gelatin (HMWFG). HMWFG had a highest intact collagen structure compared to PGs. PGs with different Bloom values, solution viscosities, and surface tensions were compared with HMWFG for their ability to produce nanofibers through SBS. Only HMWFG fibers were obtained irrespective of processing conditions, which looked like fluffy cotton candy. HMWFG nanofibers had round morphologies with a narrower diameter distribution and lower average fiber diameter (AFD) under medium gelatin concentrations, medium air pressures, and medium feed rates. The highest glass transition temperature (Tg ) values were obtained at medium concentrations, medium air pressure, and either high or low feed rate. The thinnest HMWFG nanofibers with an AFD of 80.1 nm and the highest Tg value of 59.0 °C could be formed by combining a concentration of 17.6% (w/v), an air pressure of 0.379 MPa, and a feed rate of 0.06 mL/min from the response surface analysis. HMWFG Brunauer, Emmett, and Teller surface area increased from 221 to 237 m2 /g, indicating their potential applicability for active compound carrier.


Assuntos
Manipulação de Alimentos , Gelatina/química , Nanofibras/química , Animais , Peixes , Fenômenos Mecânicos , Reologia , Pele , Soluções , Suínos , Viscosidade
19.
Carbohydr Polym ; 167: 97-104, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28433182

RESUMO

Brown mushroom (Agaricus bisporus) stalk bases from mushroom waste were treated with UV-B light to rapidly increase vitamin D2 content. Chitin was also recovered from this waste and converted into chitosan by N-deacetylation. FTIR spectra showed that the mushroom chitosan were similar to chitosan from animal sources. Chitosan films were prepared using high molecular weight (HW), low molecular weight (LW) and fungal chitosan. UV-B treated mushroom particles were also incorporated into fungal chitosan films. The fungal chitosan films showed similar density, porosity and water vapor barrier properties to the LW and HW chitosan films. However, fungal chitosan films were more hydrophobic and less flexible than the LW and HW chitosan films. Addition of mushroom particles did not significantly affect mechanical or water barrier properties of the fungal chitosan films.

20.
Carbohydr Polym ; 163: 101-107, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28267486

RESUMO

A hybrid catalyst was prepared using cellulose nanofibrils and magnetite to degrade organic compounds. Cellulose nanofibrils were isolated by mechanical defibrillation producing a suspension used as a matrix for magnetite particles. The solution of nanofibrils and magnetite was dried and milled resulting in a catalyst with a 1:1 ratio of cellulose and magnetite that was chemically and physically characterized using light, scanning electron and transmission electron microscopies, specific surface area analysis, vibrating sample magnetometry, thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction, catalytic potential and degradation kinetics. Results showed good dispersion of the active phase, magnetite, in the mat of cellulosic nanofibrils. Leaching and re-use tests showed that catalytic activity was not lost over several cycles. The hybrid material produced was tested for degradation of methylene blue dye in Fenton-like reactions resulting in a potential catalyst for use in degradation of organic compounds.


Assuntos
Celulose/química , Óxido Ferroso-Férrico/química , Resíduos Industriais , Têxteis , Purificação da Água , Catálise , Nanopartículas , Difração de Raios X
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