RESUMO
Oil-in-water emulsions (EM) have been extensively used for the encapsulation of lipophilic bioactive compounds and posterior incorporation into food matrices to obtain functional foods. Conversely, novel excipient oil-in-water emulsions (EXC) present identical composition and structure as EM, albeit are not bioactive by themselves since no bioactive compound is encapsulated. Instead, EXC aims at improving the bioavailability of foods' natural bioactive compounds upon co-ingestion with nutrient-rich foods. In this work, EM and EXC were produced and their stability and functionality as delivery systems for α-tocopherol compared. Emulsions were formulated with corn oil and lecithin, and their composition was optimized using experimental designs. Formulations produced with 3 % lecithin and 5 % oil attained smallest particles sizes with the lowest polydispersity index of all tested formulations and remained stable up to 60 days. Encapsulation of α-tocopherol did not have a significative impact on the structural properties of the particles produced with the same composition. α-tocopherol stability during in vitro digestion was superior in EM regardless the processing methodology (EM stability < 50 %, EXC stability < 29 %), indicating that EM offered greater protection against the digestive environment. α-tocopherol's bioaccessibility was significantly increased when encapsulated or when digested with added excipient emulsions (82-92 % and 87-90 % for EM and EXC, respectively). In conclusion, EM were more efficient vehicles for the selected bioactive compound, however, the good results obtained with EXC imply that excipient emulsions have a great potential for applications on foods to improve their natural bioactive compounds' bioavailability without the need of further processing.
Assuntos
Disponibilidade Biológica , Digestão , Emulsões , Excipientes , Tamanho da Partícula , alfa-Tocoferol , Emulsões/química , alfa-Tocoferol/química , Excipientes/química , Lecitinas/química , Óleo de Milho/química , Sistemas de Liberação de MedicamentosRESUMO
Leptomeningeal gliomatosis (LG) is characterized by extensive dissemination of neoplastic glial cells in the subarachnoid space either without an intraparenchymal glioma (primary LG or PLG) or secondary to an intraparenchymal glioma (secondary LG or SLG). Given the low frequency of LG in human and veterinary medicine, specific diagnostic criteria are lacking. Here, we describe 14 cases of canine LG that were retrospectively identified from 6 academic institutions. The mean age of affected dogs was 7.3 years and over 90% of patients were brachycephalic. Clinical signs were variable and progressive. Relevant magnetic resonance image findings in 7/14 dogs included meningeal enhancement of affected areas and/or intraparenchymal masses. All affected dogs were euthanized because of the poor prognosis. Gross changes were reported in 12/14 cases and consisted mainly of gelatinous leptomeningeal thickening in the brain (6/12 cases) or spinal cord (2/12 cases) and 1 or multiple, gelatinous, gray to red intraparenchymal masses in the brain (6/12 cases). Histologically, all leptomeningeal neoplasms and intraparenchymal gliomas were morphologically consistent with oligodendrogliomas. Widespread nuclear immunolabeling for OLIG2 was observed in all neoplasms. The absence of an intraparenchymal glioma was consistent with PLG in 3 cases. The remaining 11 cases were diagnosed as SLG.
Assuntos
Doenças do Cão , Glioma , Neoplasias Meníngeas , Humanos , Cães , Animais , Estudos Retrospectivos , Glioma/diagnóstico , Glioma/veterinária , Neoplasias Meníngeas/veterinária , Neoplasias Meníngeas/diagnóstico , Medula Espinal/diagnóstico por imagem , Medula Espinal/patologia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Imageamento por Ressonância Magnética/veterinária , Doenças do Cão/diagnóstico , Doenças do Cão/patologiaRESUMO
Distinct patterns of local infiltration are a common feature of canine oligodendroglioma and astrocytoma, and typically involve the surrounding neuroparenchyma, ventricles, or leptomeninges. Infiltration of adjacent extraneural sites is rare and has not been well documented in veterinary medicine. Here we describe 6 canine gliomas with cribriform plate involvement (compression or infiltration) and caudal nasal invasion confirmed by neuroimaging, autopsy, and/or histology. All affected dogs were adults (9-12-y-old), and 3 were brachycephalic. Clinical signs were associated with the brain tumor, with no respiratory signs reported. Magnetic resonance imaging in 2 patients revealed a rostral intraparenchymal telencephalic mass with extension into the cribriform plate. All dogs were euthanized. Gross changes consisted of poorly demarcated, white or pale-yellow, soft, and, in oligodendrogliomas, gelatinous, intraparenchymal masses that expanded the rostral portions of the telencephalon and adhered firmly to the ethmoid bone and cribriform plate. Gliomas were classified as high-grade oligodendrogliomas (4 cases) and high-grade astrocytomas (2 cases) based on histology and immunohistochemistry for OLIG2 and GFAP. In all cases, there was evidence of cribriform plate invasion and, in one case, additional invasion of the caudal nasal cavity.
Assuntos
Astrocitoma , Neoplasias Encefálicas , Glioma , Oligodendroglioma , Humanos , Cães , Animais , Oligodendroglioma/patologia , Oligodendroglioma/veterinária , Osso Etmoide/patologia , Glioma/diagnóstico por imagem , Glioma/veterinária , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/veterinária , Astrocitoma/patologia , Astrocitoma/veterináriaRESUMO
Increased doublecortin (DCX) immunolabeling at the tumor margins has been associated with tumor infiltration in human glioma and canine anaplastic meningioma. No association between DCX immunolabeling and glioma infiltration has been reported in dogs, to our knowledge. Here we compare the DCX immunolabeling in 14 diffusely infiltrating gliomas (gliomatosis cerebri) and 14 nodular gliomas with distinct degrees of tumor infiltration. Cytoplasmic DCX immunolabeling was classified according to intensity (weak, moderate, strong), distribution (1 = <30% immunolabeling, 2 = 30-70% immunolabeling, 3 = >70% immunolabeling), and location within the neoplasm (random or at tumor margins). Immunolabeling was detected in 6 of 14 (43%) diffusely infiltrating gliomas and 8 of 14 (57%) nodular gliomas. Diffusely infiltrating gliomas had moderate and random immunolabeling, with distribution scores of 1 (4 cases) or 2 (2 cases). Nodular gliomas had strong (6 cases) or moderate (2 cases) immunolabeling, with distribution scores of 1 (3 cases), 2 (3 cases), and 3 (2 cases), and random (6 cases) and/or marginal (3 cases) immunolabeling. Increased DCX immunolabeling within neoplastic cells palisading around necrosis occurred in 4 nodular gliomas. DCX immunolabeling was not increased at the margins of diffusely infiltrating gliomas, indicating that DCX should not be used as an immunomarker for glioma infiltration in dogs.
Assuntos
Neoplasias Encefálicas , Doenças do Cão , Glioma , Neoplasias Meníngeas , Meningioma , Humanos , Animais , Cães , Neoplasias Encefálicas/veterinária , Neoplasias Encefálicas/patologia , Glioma/veterinária , Glioma/patologia , Meningioma/veterinária , Neoplasias Meníngeas/veterinária , Proteínas do Domínio DuplacortinaRESUMO
Electrohydrodynamic processing (EHDP) allows the use of a wide range of biopolymers and solvents, including food-grade biopolymers and green solvents, for the development of micro- and nanostructures. These structures present a high surface-area-to-volume ratio and different shapes and morphologies. The aim of this work was to design and produce hydroxypropyl methylcellulose (HPMC)-based micro- and nanostructures through EHD processing using green solvents, while exploring the influence of process and solution parameters, and incorporating a bioactive extracted from a food by-product. Low (LMW) and high (HMW) molecular weight HPMC have been used as polymers. The design-of-experiments methodology was used to determine the effects of process parameters (polymer concentration, flow rate, tip-to-collector distance, and voltage) of EHDP on the particle and fibre diameter, aspect ratio, diameter distribution, aspect ratio distribution, and percentage of fibre breakage. Additionally, melanoidins extracted from spent coffee grounds were encapsulated into the HPCM-based structures at a concentration of 2.5 mg melanoidins/mL of the polymer solution. Polymer solutions were characterised regarding their viscosity, surface tension and conductivity, and showed that the incorporation of melanoidins increased the viscosity and conductivity values of the polymer solutions. The developed structures were characterised regarding their thermal properties, crystallinity and morphology before and after melanoidin incorporation and it was observed that melanoidin incorporation did not significantly influence the characteristics of the produced micro- and nanostructures. Based on the results, it is possible to envision the use of the produced micro- and nanostructures in a wide range of applications, both in food and biomedical fields.
Assuntos
Nanoestruturas , Polímeros , Condutividade Elétrica , Derivados da Hipromelose , Polímeros/químicaRESUMO
Dysphagia is a swallowing disorder that mainly affects elderly but can be minimized by thickening of liquid foods. Flaxseed gum (FG) was studied as a potential alternative thickener for dysphagia patients in comparison to commercial thickeners based on xanthan gum (XG) and modified starch (MS). Rheological and tribological responses of biopolymer-based thickening solutions (0.75-3% w/w) incorporated in different food matrices (water, orange-flavoured soy juice and skim milk) were recorded and correlated. In general, the increase in gums concentration led to increases in viscosity, viscoelastic properties and lubricating capacity. An opposite behavior was observed for the MS-based products, since an increase in concentration led to a lower increase in viscosity and viscoelastic properties but caused a decrease in the lubricating capacity. These results indicated that associating tribology to rheology is crucial to further define formulations with pleasant swallowing characteristics.
RESUMO
There is an increasing demand for alternative and sustainable protein sources, such as vegetables, insects and microorganisms, that can meet the nutritional and sensory pleasantness needs of consumers. This emergent interest for novel protein sources, allied with "green" and cost-effective processing technologies, such as high hydrostatic pressure, ohmic heating and pulsed electric fields, can be used as strategies to improve the consumption of proteins from sustainable sources without compromising food security. In addition to their nutritional value, these novel proteins present several technological-functional properties that can be used to create various protein systems in different scales (i.e., macro, micro and nano scale), which can be tailored for a specific application in innovative food products. However, in order for these novel protein sources to be broadly used in future food products, their fate in the human gastrointestinal tract (e.g., digestion and bioavailability) must be assessed, as well as their safety for consumers must be clearly demonstrated. In particular, these proteins may become novel allergens triggering adverse reactions and, therefore, a comprehensive allergenicity risk assessment is needed. This review presents an overview of the most promising alternative protein sources, their application in the production of innovative food systems, as well as their potential effects on human health. In addition, new insights on sustainable processing strategies are given.
Assuntos
Proteínas Alimentares , Proteínas de Bactérias , Qualidade de Produtos para o Consumidor , Manipulação de Alimentos , Hipersensibilidade Alimentar , Inocuidade dos Alimentos , Tecnologia de Alimentos , Proteínas Fúngicas , Proteínas de Insetos , Valor Nutritivo , Proteínas de Vegetais Comestíveis , Medição de RiscoRESUMO
Hydrophobic bioactives can be more easily incorporated into food and have their bioavailability enhanced if nanostructured lipid carriers (NLC) are used as carriers. In the present study, beta-carotene-loaded NLC were produced by low emulsification using murumuru butter and a mixture of Span 80 and Cremophor RH40 as surfactants. Their average diameter was 35 nm and alpha-tocopherol was required to protect the encapsulated ß-carotene. Besides the evaluation of their physicochemical stability, NLC were submitted to dynamic in vitro digestion and cell viability assays with Caco-2 and HEPG cells. The bioaccessibility of beta-carotene in the dynamic system was about 42%. Regarding cell viability, results indicated NLC were toxic to the cell cultures tested. Such high toxicity is probably related to the type of surfactant used and to the extremely reduced particle size, which may have led to an intense and fast permeation of the NLC through the cells.
Assuntos
Antioxidantes/administração & dosagem , Portadores de Fármacos/química , Lipídeos/química , Provitaminas/administração & dosagem , alfa-Tocoferol/administração & dosagem , beta Caroteno/administração & dosagem , Antioxidantes/química , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/toxicidade , Combinação de Medicamentos , Humanos , Lipídeos/toxicidade , Magnoliopsida/química , Nanoestruturas/química , Nanoestruturas/toxicidade , Transição de Fase , Provitaminas/química , Temperatura de Transição , alfa-Tocoferol/química , beta Caroteno/químicaRESUMO
Soluble flaxseed gum (SFG) extracted at different temperatures (25, 40, and 60 °C) was analyzed in relation to the yield, polysaccharides and phenolics composition, surface charge, color, and rheological properties. The yield of SFG extract increased as the extraction temperature increased. The SFG xylan was the main component regardless the extraction temperature, but a reduction of substituents on the xylose chain was observed when increasing the extraction temperature. The phenolic compounds were also affected by the extraction temperature, influencing the antioxidant capacity of the gum. For all the extraction temperatures, SFG aqueous solutions showed a shear time-independent and shear-thinning behavior. Furthermore, oscillatory measurements showed a prevailing viscous character, but the decrease of the extraction temperature resulted in an increase of both G' and G". Therefore, SFG extracted at low extraction temperatures showed higher viscous and elastic properties, while high extraction temperatures increased the antioxidant activity.
Assuntos
Antioxidantes/farmacologia , Compostos de Bifenilo/antagonistas & inibidores , Fenóis/farmacologia , Picratos/antagonistas & inibidores , Gomas Vegetais/química , Temperatura , Xilanos/farmacologia , Antioxidantes/química , Antioxidantes/isolamento & purificação , Fenóis/química , Fenóis/isolamento & purificação , Gomas Vegetais/isolamento & purificação , Reologia , Xilanos/química , Xilanos/isolamento & purificaçãoRESUMO
The potential use of cellulose nanofibers (CNFs) as a reinforcing agent in banana starch-based nanocomposite films was investigated. CNFs were isolated from banana peel (Musa paradisiaca) by enzymatic hydrolysis. Banana starch-based nanocomposite films were prepared with CNFs using the casting method. CNFs effect on cell viability and on nanocomposite films properties' was investigated. The cytotoxicity of CNFs was assessed on Caco-2 cell line. CNFs were not cytotoxic at 50-2000 µg/mL. However, CNFs above 2000 µg/mL significantly decreased cell viability. Topography analysis showed that the incorporation of CNFs modified the film structure. The nanocomposites exhibited a complex structure due to strong interactions between CNFs and starch matrix, promoting a remarkable improvement on mechanical and water barrier properties, opacity and UV light barrier compared to the control film. CNFs can offer a great potential as reinforcing material for starch-based nanocomposite films, producing a value-added food packaging from a waste material.
Assuntos
Celulose/toxicidade , Frutas/química , Musa/química , Nanocompostos/toxicidade , Nanofibras/toxicidade , Amido/toxicidade , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Celulose/química , Módulo de Elasticidade , Embalagem de Alimentos/instrumentação , Humanos , Hidrólise , Nanocompostos/química , Nanofibras/química , Permeabilidade , Amido/química , Resistência à Tração , Água/químicaRESUMO
Most gluten-free bakery formulations have starch sources of low nutritional value. The objective of this work was to use fava beans (Phaseolus lunatus) for the production of gluten-free sponge cakes, in addition to evaluating the effects of the partial substitution of fava bean flour by galactomannan and xanthan gum, isolated or mixed at 0.5 and 1.0% proportions, compared with a commercial reference. The properties such as viscosity, specific gravity and microscopy of the air bubbles were evaluated in the raw cakes, while the cooked cakes were analyzed according to physicochemical (chemical composition, specific volume, texture and color) and sensorial properties. Hydrocolloids increased the viscosity, specific gravity, and incorporation of air into the batters. Xanthan gum increased the cakes' firmness after cooking; in what concerns color parameters, hydrocolloids did not interfere. Cakes based on fava beans had better sensory acceptance with or without the presence of hydrocolloids and presented higher levels of moisture, proteins, lipids and ashes when compared to the commercial reference, proving to be an excellent food option without gluten and high nutritional value.
Assuntos
Pão/análise , Mananas/química , Polissacarídeos Bacterianos/química , Vicia faba/química , Adulto , Coloides/química , Coloides/metabolismo , Culinária , Feminino , Farinha/análise , Galactose/análogos & derivados , Glutens/análise , Humanos , Masculino , Mananas/metabolismo , Pessoa de Meia-Idade , Valor Nutritivo , Polissacarídeos Bacterianos/metabolismo , Paladar , Vicia faba/metabolismo , Viscosidade , Adulto JovemRESUMO
In this work five sources of galactomannans, Adenanthera pavonina, Cyamopsis tetragonolobus, Caesalpinia pulcherrima, Ceratonia siliqua and Sophora japonica, presenting mannose/galactose ratios of 1.3, 1.7, 2.9, 3.4 and 5.6, respectively, were used to produce galactomannan-based films. These films were characterized in terms of: water vapour, oxygen and carbon dioxide permeabilities (WVP, O 2 P and CO 2 P); moisture content, water solubility, contact angle, elongation-at-break (EB), tensile strength (TS) and glass transition temperature (T g ). Results showed that films properties vary according to the galactomannan source (different galactose distribution) and their mannose/galactose ratio. Water affinity of mannan and galactose chains and the intermolecular interactions of mannose backbone should also be considered being factors that affect films' properties. This work has shown that knowing mannose/galactose ratio of galactomannans is possible to foresee galactomannan-based edible films properties.
RESUMO
Thoracic splenosis is rare and consists of ectopic implantation of splenic tissue into the chest after concomitant thoracic and abdominal trauma with diaphragm injury. It occurs in about 18% of cases of splenic ruptures. In almost all cases, diagnosis is given incidentally once patients are usually asymptomatic. Thoracic splenosis should be considered as a differential diagnosis in all patients with history of trauma presenting with juxtapleural nodules in chest computed tomography. However, malignant conditions should be ruled out firstly. Biopsy is not essential for the diagnosis once nuclear medicine can confirm splenosis in patients with pertinent history of trauma and suggestive tomographic image. We present a typical case of thoracic splenosis whose diagnosis was made by nuclear medicine and no invasive procedures were required.
RESUMO
An essential requirement for any practical fully integrated lab-on-a-chip device is the ability to mix two or more fluids thoroughly and efficiently, i.e., in a reasonable amount of time. This paper presents a way to improve mixing in microfluidic systems combining alternate flows with obstacles using passive mixers. Numerical simulations show that the layers of high and low solute concentration, created by the alternate flow, are split into smaller chunks of fluid, due to the obstacles inserted in the mixing channel, increasing the contact area between high and low concentration regions and decreasing the critical mixing length. This improvement can lead to shorter mixing channels and to low-cost mixers fabricated by planar lithographic technology.
Assuntos
Dispositivos Lab-On-A-Chip , Engenharia Biomédica , Dispositivos Lab-On-A-Chip/estatística & dados numéricos , Técnicas Analíticas Microfluídicas , Reologia/estatística & dados numéricosRESUMO
The disruption of the milk fat globule membrane can lead to an excessive accumulation of free fatty acids in milk, which is frequently associated with the appearance of rancid flavors. Solid-phase microextraction and gas chromatography techniques have been shown to be useful tools in the quantification of individual free fatty acids in dairy products providing enough sensitivity to detect levels of rancidity in milk. Therefore, the aim of this study was to characterize the short-chain and medium-chain free fatty acid profile in i) raw untreated goat milk; ii) raw goat milk passing through pumps and heating units (plate-and-frame heat exchanger and ohmic heater); and iii) processed goat milk by conventional and ohmic pasteurization to determine the influence of each treatment in the final quality of the milk. Multivariate statistical analysis has shown that the treatments studied were not responsible for the variability found on free fatty acid contents. In particular, it was possible to conclude that ohmic pasteurization at 72 degrees C for 15 s did not promote an extended modification of free fatty acid contents in goat milk when compared with that of conventional pasteurization. Furthermore, principal component analysis showed that the capric acid can be used to discriminate goat's milk with different free fatty acid concentrations. Hierarchical cluster analysis showed evidence of the existence of correlations between contents of short and medium chain free fatty acids in goat milk.
Assuntos
Ácidos Graxos não Esterificados/química , Temperatura Alta , Leite/química , Animais , Calibragem , Análise por Conglomerados , Impedância Elétrica , Ácidos Graxos não Esterificados/análise , Manipulação de Alimentos/métodos , Cabras , Modelos Lineares , Análise de Componente Principal , Padrões de ReferênciaRESUMO
Population structure and genetic diversity in the Portuguese native breeds of pigs Alentejano (AL), Bísaro (BI), and Malhado de Alcobaça (MA) and the exotic breeds Duroc (DU), Landrace (LR), Large White (LW), and Pietrain were analyzed by typing 22 microsatellite markers in 249 individuals. In general, the markers used were greatly polymorphic, with mean total and effective number of alleles per locus of 10.68 and 4.33, respectively, and an expected heterozygosity of 0.667 across loci. The effective number of alleles per locus and expected heterozygosity were greatest in BI, LR, and AL, and least in DU. Private alleles were found in 9 of the 22 markers analyzed, mostly in AL, but also in the other breeds, with the exception of LW. The proportion of loci not in Hardy-Weinberg equilibrium in each breed analyzed ranged between 0.23 (AL) and 0.41 (BI, LW, and Pietrain), mostly because of a less than expected number of heterozygotes in those loci. With the exception of MA, all breeds showed a significant deficit in heterozygosity (F(IS); P < 0.05), which was more pronounced in BI (F(IS) = 0.175) and AL (F(IS) = 0.139), suggesting that inbreeding is a major concern, especially in these breeds that have gone through a genetic bottleneck in the recent past. The analysis of relationships among breeds, assessed by different methods, indicates that DU and AL are the more distanced breeds relative to the others, with the closest relationship being observed between LR and MA. The degree of differentiation between subpopulations (F(ST)) indicates that 0.184 of the total genetic variability can be attributed to differences among breeds. The analysis of individual distances based on allele sharing indicates that animals of the same breed generally cluster together, but subdivision is observed in the BI and LR breeds. Furthermore, the analysis of population structure indicates there is very little admixture among breeds, with each one being identified with a single ancestral population. The results of this study confirm that native breeds of pigs represent a very interesting reservoir of allelic diversity, even though the current levels of inbreeding raise concerns. Therefore, appropriate conservation efforts should be undertaken, such as adopting strategies aimed at minimizing inbreeding, to avoid further losses of genetic diversity.
Assuntos
Variação Genética , Repetições de Microssatélites/genética , Suínos/genética , Animais , Cruzamento , Análise por Conglomerados , Filogenia , PortugalRESUMO
The experimental performance of a novel micro-bioreactor envisaged for parallel screening and development of industrial bioprocesses has been tested in this work. The micro-bioreactor with an internal volume of 4.5 mL is operated under oscillatory flow mixing (OFM), where a controllable mixing and mass transfer rates are achieved under batch or continuous laminar flow conditions. Several batch fermentations with a flocculent Saccharomyces cerevisiae strain were carried out at initial glucose concentrations (S(0)) range of approximately 5-20 g/L and compared to yeast growth kinetics in a stirred tank (ST) bioreactor. Aerobic fermentations were monitored ex situ in terms of pH, DO, glucose consumption, and biomass and ethanol production (wherever applicable). An average biomass production increase of 83% was obtained in the micro-bioreactor when compared with the ST, with less 93.6% air requirements. It also corresponded to a 214% increase on biomass production when compared with growth in a shaken flask (SF) at S(0) = 20 g/L. Further anaerobic fermentations at the same initial glucose concentration ranges gave the opportunity to use state-of-the-art fiber optics technology for on-line and real-time monitoring of this bioprocess. Time profiles of biomass concentration (measured as optical density (OD)) were very similar in the ST bioreactor and in the micro-bioreactor, with a highly reproducible yeast growth in these two scale-down platforms.
Assuntos
Reatores Biológicos/microbiologia , Fermentação , Microbiologia Industrial/instrumentação , Saccharomyces cerevisiae/metabolismo , Biomassa , Desenho de Equipamento/instrumentação , Saccharomyces cerevisiae/crescimento & desenvolvimentoRESUMO
A novel micro-bioreactor based on the oscillatory flow technology was applied to the scale-down of the biotechnological production of gamma-decalactone. A decrease up to 50% of the time required to obtain the maximum concentration of the compound was observed, when compared with other scaled-down platforms (stirred tank bioreactor or shake flask). A three-fold increase in gamma-decalactone productivity was obtained by increasing oscillatory mixing intensity from Re(o) approximately 482 to Re(o) approximately 1447. This was presumably related to the effective contribution of the reactor geometry to enhanced mass transfer rates between the two immiscible liquid phases involved in the process by increasing the interfacial area.
Assuntos
Reatores Biológicos/microbiologia , Técnicas de Cultura de Células/instrumentação , Lactonas/metabolismo , Mecanotransdução Celular/fisiologia , Técnicas Analíticas Microfluídicas/instrumentação , Yarrowia/metabolismo , Técnicas de Cultura de Células/métodos , Meios de Cultura/química , Emulsões/química , Desenho de Equipamento , Análise de Falha de Equipamento , Estudos de Viabilidade , Técnicas Analíticas Microfluídicas/métodos , Oscilometria/instrumentação , Oscilometria/métodos , Transição de Fase , SoluçõesRESUMO
Invertase was immobilized on aminopropyl silica (APTS-SiO2) activated with humic substances (APTS-SiO2-HS) and on aminopropyl silica activated with glutaraldehyde (APTS-SiO2-GA). The resulting activity of both systems was compared. Humic substances (HS) used for the activation of the silica were extracted from soil of Cananéia, São Paulo State, Brazil, according to the procedure recommended by the International Humic Substances Society. Activity was determined by measuring the rate of formation of reduced sugars using the reaction with dinitrosalicylic acid (DNS). The amount of HS bound on the APTS-SiO2 was equal to 50 mg. The maximum amount of invertase immobilized on APTS-SiO2-HS was 15,200 U/g while in the system APTS-SiO2-GA it was 13,400 U/g. The experimental enzymatic activity was 3,700 and 3,300 U/g, for the systems APTS-SiO2-HS and APTS-SiO2-GA, respectively. Considering the increased amount and activity of immobilized enzyme compared with the glutaraldehyde method, it was concluded that this technique opens a new perspective in the preparation of supports for enzyme immobilization employing humic substances.
Assuntos
Quelantes/análise , Glicosídeo Hidrolases/química , Substâncias Húmicas/análise , Quelantes/isolamento & purificação , Enzimas Imobilizadas , Glutaral/química , Substâncias Húmicas/isolamento & purificação , Indicadores e Reagentes , Dióxido de Silício , Espectroscopia de Infravermelho com Transformada de Fourier , beta-FrutofuranosidaseRESUMO
PIP: A survey of efforts led or sponsored by the Catholic church in response to the population problem in the Philippines. These efforts stem from the Church's belief that population growth is related to the overall picture of development, and that priority must go to social and economic justice. The Catholic Church of the Philippines (to which 85% of the population belong) views it as a problem basically involving care of people, and directs its efforts primarily at internal human sexual control rather than external contraceptive control. Family Life Education began as a program in the church in the 1960s. Efforts by priests, nuns, and lay leaders in Mindanao eventually resulted in counseling in husband-wife relations, marriage commitment, human sexuality, parent-child relations, and responsible parenthood, and to the creation of college courses to prepare teachers in tackling sex education. A program offering natural family planning was also started, initially for employees of a packing firm and later expanding throughout the province. In 1975, the program was launched in Manila, and a year later had 3 family life centers. The ovulation (or Billings) method is offered -- an advantage to low income people because it does not require purchase of a thermometer. Success of this method requires a sense of responsibility on the part of both husband and wife. Widespread international interest in the ovulation method has led to formation of an International Federation for Family Life Promotion, to which the Philippine Federation for Natural Family Planning has applied for membership. The IFFLP is working with the WHO Human Reproduction Unit on 2 projects, part of one of them (a field trial for evaluation) being conducted in Iligan City, Iloilo City, and Manila. Among the concerns of the IFFLP-WHO collaboration is developing a standardized Natural Family Planning curriculum or educational package.^ieng