403 research outputs found
Optimization of the determination of tocopherols in Agaricus sp. edible mushrooms by a normal phase liquid chromatographic method
Individual tocopherol profile of five Agaricus mushroom species, widely consumed in Portugal, was obtained by a normal-phase high-performance liquid chromatography (NP-HPLC). It was used a simple
solid–liquid extraction procedure without saponification step and the chromatographic separation was
achieved using a YMC-Pack Polyamine II column using an isocratic elution with hexane/ethyl acetate
(70:30, v/v) at a flow rate of 1.0 mL/min. The effluent was monitored by a fluorescence detector. All
the compounds were separated in a period of time of 30 min. The method proved to be sensitive, reproducible
and accurate, allowing the determination of tocopherols
Composição química e valor nutricional de cogumelos silvestres comestíveis do nordeste de Portugal
Neste trabalho, determinou-se a composição química e o valor nutricional de cinco espécies
de cogumelos silvestres comestíveis (Agaricus arvensis, Lactarius deliciosus, Leucopaxillus
giganteus, Sarcodon imbricatus, Tricholoma portentosum) vulgarmente consumidos na região de
Trás-os-Montes, Nordeste de Portugal. A avaliação da composição química incluíu determinação de
humidade, gordura total, proteína total, cinzas, hidratos de carbono e do valor nutricional. O perfil de
macronutrientes revelou genericamente que os cogumelos silvestres são fontes ricas em proteínas e
hidratos de carbono, e que contêm quantidades reduzidas de gordura. A análise da composição em
ácidos gordos, realizada por cromatografia gás-líquido acoplada a um detector de ionização de chama
(GC/FID), permitiu a quantificação de quinze ácidos gordos. Os ácidos gordos insaturados e, em
particular, os ácidos oleico e linoleico, são os mais abundantes. Determinou-se também a composição
em açucares individuais por cromatografia líquida de alta resolução acoplada a um detector de índice
de refracção (HPLC/RI), sendo o manitol e a trealose os açucares mais abundantes
Contribution of the Epstein-Barr virus to the oncogenesis of mature T-cell lymphoproliferative neoplasms
EBV is a lymphotropic virus, member of the Herpesviridae family that asymptomatically infects more than 90% of the human population, establishing a latent infection in memory B cells. EBV exhibits complex survival and persistence dynamics, replicating its genome through the proliferation of infected B cells or production of the lytic virions. Many studies have documented the infection of T/NK cells by EBV in healthy individuals during and after primary infection. This feature has been confirmed in humanized mouse models. Together these results have challenged the hypothesis that the infection of T/NK cells per se by EBV could be a triggering event for lymphomagenesis. Extranodal NK/T-cell lymphoma (ENKTCL) and Epstein-Barr virus (EBV)-positive nodal T- and NK-cell lymphoma (NKTCL) are two EBV-associated lymphomas of T/NK cells. These two lymphomas display different clinical, histological and molecular features. However, they share two intriguing characteristics: the association with EBV and a geographical prevalence in East Asia and Latin America. In this review we will discuss the genetic characteristics of EBV in order to understand the possible role of this virus in the oncogenesis of ENKTCL and NKTCL. In addition, the main immunohistological, molecular, cytogenetic and epigenetic differences between ENKTCL and NKTCL will be discussed, as well as EBV differences in latency patterns and other viral molecular characteristics
Polymer electrolytes for electrochromic devices through solvent casting and sol-gel routes
Ionically conductive membranes of gelatin and d-PCL(530)/siloxane doped with cyano-based ionic
liquids (ILs) were prepared through solvent casting and sol-gel methods, respectively. The
membranes were characterized in terms of ionic conductivity, thermal behavior, morphology, and
structure. All samples, except the d-PCL(530)/siloxane matrix, exhibited a predominantly
amorphous morphology. The samples prepared through solvent casting and sol-gel displayed a
minimum thermal stability of 170 and 230 ºC, respectively. The ionic conductivity varied
accordingly with the type, quantity, and length of the alkyl chain of the cation of the ILs. The
sample with the highest ionic conductivity was gelatin0.5[C2mim][N(CN)2] with 2.40 x 10-3 S.
cm-1 at 25 ºC and 1.68 x 10-2 S. cm-1 at 95 ºC. The good results of ionic conductivity encouraged the
assembly and characterization of prototypes of electrochromic devices (ECDs). The best results
were obtained with glass/ITO/WO3/gelatin1[C2mim][SCN]/CeO2-TiO2/ITO/glass configuration that
showed a fast color switching time (~ 15 s) and a good open circuit memory (~ 4 hours). The ECD
changed its color from pale blue to transparent, and its charge density decreased from -17.53 to -
2.71 mC. cm-2 during 640 color/bleaching cycles.This work was supported by Fundação para a Ciência e a Tecnologia (FCT) in the
framework of the Research unit GREEN-it "Bioresources for Sustainability"
(UID/Multi/04551/2013), Laboratório Associado para a Química Verde – Tecnologias e Processos
Limpos-LAQV (UID/QUI/50006/2013), grant SRFH/BD/90366/2012 (R.L.) and a contract under
Investigador FCT 2012 program (J.M.S.S.E.). It was also co-financed by FEDER through the
COMPETE Program and PT2020 Partnership Agreement (POCI-01-0145-FEDER – 007265). M.M.
Silva acknowledges CNPq (PVE grant 406617/2013-9) for the mobility grant provided by this
institution. A. Pawlicka and R.C. Sabadini acknowledge CNPq (grant 305029/2013-4 and
152252/2016-9), and F.C. Sentanin acknowledges CAPES (grant PNPD20131739- 33002045017P6).info:eu-repo/semantics/publishedVersio
Electrochemical applications of electrolytes based on ionic liquids
The potential utility of room temperature ionic liquids as
electrolytes in current electrochemical applications has been
explored. Hence, the electrochemical behavior of [Ni(tmc)]Br2
complex at a glassy carbon electrode in the absence or in the
presence of unsaturated halides in the ionic liquids, 1-ethyl-3-
methylimidazolium ethylsulfate, [C2mim][C2SO4] and N,N,Ntrimethyl-
N-(2-hydroxyethyl) ammonium
bis(trifluoromethylsulfonyl)imide, [N1 1 1 2(OH)][NTf2], has been
examined by cyclic voltammetry. It was observed that
[Ni(tmc)]2+ complex is reduced in a reversible one-electron step
and the electrogenerated [Ni(tmc)]+ complex catalytically reduces
the carbon-halogen bond of unsaturated halides.
The potencial use of natural ionic conducting polymer
matrixes was also investigated. Samples of natural
macromolecules-based electrolytes with the ionic liquid 1-ethyl-
3-methylimidazolium ethylsulfate, [C2mim][C2SO4], were
prepared and characterized. The preliminary studies carried out
with electrochromic devices (ECDs) incorporating optimized
compositions have confirmed that these materials may perform as
satisfactory multifunctional component layers in the field of
ECD-based devices.Fundação para a Ciência e a Tecnologia (FCT
Effect of biofunctionalized implant surface on osseointegration: a histomorphometric study in dogs
Among the different properties that influence bone apposition around implants, the chemical or biochemical composition of implant surface may interfere on its acceptance by the surrounding bone. The aim of this study was to investigate if a biofunctionalization of implant surface influences the bone apposition in a dog model and to compare it with other surfaces, such as a microstructured created by the grit-blasting/acid-etching process. Eight young adult male mongrel dogs had the bilateral mandibular premolars extracted and each one received 6 implants after 12 weeks, totaling 48 implants in the experiment. Four groups of implants were formed with the same microrough topography with or without some kind of biofunctionalization treatment. After histomorphometric analysis, it was observed that the modified microstructured surface with a "low concentration of the bioactive peptide" provided a higher adjacent bone density (54.6%) when compared to the other groups (microstructured + HA coating = 46.0%, microstructured only = 45.3% and microstructured + "high concentration of the bioactive peptide" = 40.7%), but this difference was not statistically significant. In conclusion, biofunctionalization of the implant surface might interfere in the bone apposition around implants, especially in terms of bone density. Different concentrations of bioactive peptide lead to different results.Entre as diferentes propriedades de uma superfície capazes de influenciar a deposição óssea ao redor de implantes, a composição química e bioquímica pode atuar no reconhecimento do tecido ósseo circundante. O presente trabalho investigou a influência da biofuncionalização de superfícies de implante na deposição óssea ao redor dos mesmos em um modelo animal, comparando-as com outras superfícies, como a microtexturizada obtida pelo processo de jateamento e ataque ácido. Metodologicamente, os pré-molares mandibulares bilaterais de 8 cães foram extraídos e após 12 semanas foram instalados 6 implantes em cada cão, constituindo uma amostra de 48 implantes. Dos 4 grupos experimentais de diferentes superfícies, todos continham a mesma microtopografia rugosa, porém possuindo ou não alguma biofuncionalização. A análise histomorfométrica revelou que a superfície microtexturizada modificada pela adição de baixa concentração peptídica obteve uma maior densidade óssea adjacente (54,6%) quando comparada aos outros grupos (microtexturizada + HA = 46%, somente microtexturizada = 45,3% e microtexturizada com adição de alta concentração peptídica = 40,7%), no entanto estas diferenças numéricas não foram estatisticamente significantes. Dentro deste contexto, conclui-se que a biofuncionalização da superfície de implantes pode interferir na aposição óssea, em particular na densidade óssea, e que diferentes concentrações peptídicas podem conduzir a diferentes resultados.FAPES
Author Correction: Escherichia coli and Salmonella Enteritidis dual-species biofilms: interspecies interactions and antibiofilm efficacy of phages
Correction to: Scientifc Reports https://doi.org/10.1038/s41598-019-54847-y, published online 03 December 2019(undefined)info:eu-repo/semantics/publishedVersio
Arterial oxygenation and acid-base status before and during oxygen supplementation in captive European bison (Bison bonasus) immobilized with etorphine-acepromazine-xylazine
Chemical immobilization of captive European bison (Bison bonasus) is often required for veterinary care, transportation, or husbandry practices playing an important role in conservation breeding and reintroduction of the species. We evaluated the efficiency and physiological effects of an etorphine-acepromazine-xylazine combination with supplemental oxygen in 39 captive European bison. Animals were darted with a combination of 1.4 mg of etorphine, 4.5 mg of acepromazine, and 20 mg of xylazine per 100 kg based on estimated body mass. Arterial blood was sampled on average 20 min after recumbency and again 19 min later and analyzed immediately with a portable i-STAT analyzer. Simultaneously, heart rate, respiratory rate, and rectal temperature were recorded. Intranasal oxygen was started after the first sampling at a flow rate of 10 mL.kg(-1).min(-1) of estimated body mass until the end of the procedure. The initial mean partial pressure of oxygen (PaO2) was 49.7 mmHg with 32 out of 35 sampled bison presenting with hypoxemia. We observed decreased respiratory rates and pH and mild hypercapnia consistent with a mild respiratory acidosis. After oxygen supplementation hypoxemia was resolved in 21 out of 32 bison, but respiratory acidosis was accentuated. Bison immobilized with a lower initial drug dose required supplementary injections during the procedure. We observed that lower mean rectal temperatures during the immobilization event were significantly associated with longer recovery times. For three bison, minor regurgitation was documented. No mortality or morbidity related to the immobilizations were reported for at least 2 months following the procedure. Based on our findings, we recommend a dose of 0.015 mg.kg(-1) etorphine, 0.049 mg.kg(-1) acepromazine, and 0.22 mg.kg(-1) xylazine. This dose reduced the need for supplemental injections to obtain a sufficient level of immobilization for routine management and husbandry procedures in captive European bison. Nevertheless, this drug combination is associated with development of marked hypoxemia, mild respiratory acidosis, and a small risk of regurgitation. Oxygen supplementation is strongly recommended when using this protocol
Newborn Urinary Metabolic Signatures of Prematurity and Other Disorders: A Case Control Study
This work assesses the urinary metabolite signature of prematurity in newborns by nuclear magnetic resonance (NMR) spectroscopy, while establishing the role of possible confounders and signature specificity, through comparison to other disorders. Gender and delivery mode are shown to impact importantly on newborn urine composition, their analysis pointing out at specific metabolite variations requiring consideration in unmatched subject groups. Premature newborns are, however, characterized by a stronger signature of varying metabolites, suggestive of disturbances in nucleotide metabolism, lung surfactants biosynthesis and renal function, along with enhancement of tricarboxylic acid (TCA) cycle activity, fatty acids oxidation, and oxidative stress. Comparison with other abnormal conditions (respiratory depression episode, large for gestational age, malformations, jaundice and premature rupture of membranes) reveals that such signature seems to be largely specific of preterm newborns, showing that NMR metabolomics can retrieve particular disorder effects, as well as general stress effects. These results provide valuable novel information on the metabolic impact of prematurity, contributing to the better understanding of its effects on the newborn's state of health.info:eu-repo/semantics/publishedVersio
Newborn Urinary Metabolic Signatures of Prematurity and Other Disorders: A Case Control Study
This work assesses the urinary metabolite signature of prematurity in newborns by nuclear magnetic resonance (NMR) spectroscopy, while establishing the role of possible confounders and signature specificity, through comparison to other disorders. Gender and delivery mode are shown to impact importantly on newborn urine composition, their analysis pointing out at specific metabolite variations requiring consideration in unmatched subject groups. Premature newborns are, however, characterized by a stronger signature of varying metabolites, suggestive of disturbances in nucleotide metabolism, lung surfactants biosynthesis and renal function, along with enhancement of tricarboxylic acid (TCA) cycle activity, fatty acids oxidation, and oxidative stress. Comparison with other abnormal conditions (respiratory depression episode, large for gestational age, malformations, jaundice and premature rupture of membranes) reveals that such signature seems to be largely specific of preterm newborns, showing that NMR metabolomics can retrieve particular disorder effects, as well as general stress effects. These results provide valuable novel information on the metabolic impact of prematurity, contributing to the better understanding of its effects on the newborn's state of health.info:eu-repo/semantics/publishedVersio
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