33 research outputs found
Preventive effects of broccoli bioactives : role on Oxidative stress and cancer risk
No full textCruciferous vegetables (such as broccoli) seem to have an important role in cancer prevention, as suggested by the results of several epidemiological studies showing an inverse association between their consumption and cancer risk at several sites. This class of vegetables contains several antioxidants and provides glucosinolates, which are converted to isothiocyanates and indoles, the bioactives believed to be responsible for most of the protection against cancer development. Numerous mechanisms of action have been studied; they involve interconnected signaling pathways important for cancer growth and progression including the direct and indirect effect on oxidative stress, and modulation of phase I and phase II enzymes and of epigenetic mechanisms. In particular, brassica vegetables may contribute to reducing free radical-related molecular damage in subjects, such as smokers, with high exposure to oxidative stress. In this regard, the effect of broccoli intake on biomarkers of oxidative stress and cancer risk in smokers is briefly discussed
Craft beer microflora identification before and after a cleaning process
No full textAlthough beer is a relatively safe product, growth of spoilage
microorganisms can cause economic damage. The most effective
way to prevent the spoilage of beer is to control contamination
with adequate cleaning and sanitation. The aim of this work was
to evaluate the microbial flora present both before and after a
specific hygiene process was implemented during a brewpub’s
craft beer production. Various selective and differential culture
media methods for the enumeration of beer-spoilage species are
available, but they are time consuming compared to modern
techniques. The utilisation of accurate molecular methods,
added to the routine microbiological analyses, allowed for the
fast identification of common environmental contaminants of
beer. A poor sanitation plan by the brewer resulted in microbial
contamination of the brewpub. This result demonstrates the importance
of good sanitation to avoid the presence of undesirable
microorganisms in the product. A cleaning-in-place (CIP)
method, in operation in many small breweries, could be utilised
to prevent the occurrence of such brewery and beer microbial
contaminants. In small breweries, the simplest CIP units consist
of a single tank and a portable pump. This method requires no
additional equipment besides a spraying ball, which is usually
included in the design of most tanks
Effect of short-term hazelnut consumption on DNA damage and oxidized LDL in children and adolescents with primary hyperlipidemia : a randomized controlled trial
No full textChildren with primary hyperlipidemia are prone to develop premature atherosclerosis, possibly associated with increased oxidative stress. Nutritional therapy is the primary strategy in the treatment of hyperlipidemia and associated conditions. Dietary interventions with bioactive-rich foods, such as nuts, may contribute to the modulation of both lipid profile and the oxidative/antioxidant status. Our study aimed to assess the impact of a dietary intervention with hazelnuts on selected oxidative stress markers in children and adolescents with primary hyperlipidemia. A single-blind, 8-week, randomized, controlled, three-arm, parallel-group study was performed. Children and adolescents diagnosed with primary hyperlipidemia (n=60) received dietary guidelines and were randomized into three groups: group 1 received hazelnuts with skin (HZN+S), and group 2 hazelnuts without skin (HZN-S), at equivalent doses (15-30 g/day, based on body weight); group 3 (controls) received only dietary recommendations (no nuts). At baseline and after 8 weeks, plasma oxidized low-density lipoprotein (ox-LDL) concentrations, oxidative levels of DNA damage in PBMCs and potential correlation with changes in serum lipids were examined. A reduction of endogenous DNA damage by 18.9%±51.3% (P=.002) and 23.1%±47.9% (P=.007) was observed after HZN+S and HZN-S, respectively. Oxidatively induced DNA strand breaks decreased by 16.0%±38.2% (P=.02) following HZN+S treatment. Ox-LDL levels did not change after HZN+S intervention but positively correlated with total cholesterol and LDL cholesterol. A short-term hazelnut intervention improves cell DNA protection and resistance against oxidative stress but not ox-LDL in hyperlipidemic pediatric patients. The trial was registered at ISRCTN.com, ID no. ISRCTN12261900
Hot-electron Electroluminescence In AlGaAs/GaAs Heterojunction Bipolar-transistor
No full textWhen biased in the active region at high collector voltages, AlGaAs/GaAs single heterojunction bipolar transistors have been observed to emit light in the 1. 1-2.5 eV energy range. The spectral distribution of the emitted radiation results from the superimposition of (i) two peaks at about 1.4 and 2.1 eV, due to band-to-band recombination of cold electrons and holes, and (ii) a nearly exponential tail due to hot-electron-induced electroluminescence, whose intensity depends on reverse collector-base voltage. Moreover, a linear correlation has been found between the intensity of the bot-electron-induced electroluminescence and the current generated by impact ionization
Six-Week Consumption of a Wild Blueberry Powder Drink Increases Bifidobacteria in the Human Gut
No full textWild blueberries are a rich source of polyphenols and other compounds that are highly metabolized by the intestinal microbiota and may, at the same time, affect the intestinal environment itself. A repeated-measure, crossover dietary intervention on human volunteers was designed to study the effect of six week consumption of a wild blueberry (Vaccinium angustifolium) drink, versus a placebo drink, in modulating the intestinal microbiota. Relative to total eubacteria, Bifidobacterium spp. significantly increased following blueberry treatment (P ≥ 0.05), while Lactobacillus acidophilus increased after both treatments (P ≥ 0.05). No significant differences were observed for Bacteroides spp., Prevotella spp., Enterococcus spp., and Clostridium coccoides. Bifidobacteria, which have been largely proposed to be of benefit for the host, appeared to be selectively favored suggesting an important role for the polyphenols and fiber present in wild blueberries. Results obtained suggest that regular consumption of a wild blueberry drink can positively modulate the composition of the intestinal microbiota
Berry Fruit Consumption and Metabolic Syndrome
No full textMetabolic Syndrome is a cluster of risk factors which often includes central obesity, dyslipidemia, insulin resistance, glucose intolerance, hypertension, endothelial dysfunction, as well as a pro-inflammatory, pro-oxidant, and pro-thrombotic environment. This leads to a dramatically increased risk of developing type II diabetes mellitus and cardiovascular disease, which is the leading cause of death both in the United States and worldwide. Increasing evidence suggests that berry fruit consumption has a significant potential in the prevention and treatment of most risk factors associated with Metabolic Syndrome and its cardiovascular complications in the human population. This is likely due to the presence of polyphenols with known antioxidant and anti-inflammatory effects, such as anthocyanins and/or phenolic acids. The present review summarizes the findings of recent dietary interventions with berry fruits on human subjects with or at risk of Metabolic Syndrome. It also discusses the potential role of berries as part of a dietary strategy which could greatly reduce the need for pharmacotherapy, associated with potentially deleterious side effects and constituting a considerable financial burden
Effects of Dietary Wild Blueberry on Inflamation, Lipid Metabolism and Endothelial Function in a Model of Metabolic Syndrome: A Nutrigenomics Approach
No full textThe goal of this project was to investigate the ability of a wild blueberry-enriched diet to improve parameters related to the pathogenesis of metabolic syndrome in the obese Zucker rat (OZR), which is a valid experimental model for this condition.
Fifty-two of OZR, and 52 lean littermate controls (LZR), were placed on either an 8% freeze-dried wild-blueberry enriched diet, or an isocaloric blueberry-free control diet, for a total of eight weeks. Rats were placed on the experimental diets between 8 and 16 weeks of age, when they start developing the metabolic abnormalities that are characteristic of metabolic syndrome. The effects of wild blueberries were evaluated on plasma lipids, plasma markers of glucose metabolism; plasma markers of inflammation; expression of genes related to the inflammatory response, lipid and glucose metabolism both in the liver and the abdominal adipose tissue; and ex vivo response of the aortic vessel to vasoconstricting and vasorelaxing stimuli.
Wild blueberry consumption resulted in a significant reduction in circulating levels of markers of inflammatory status, as well as a down-regulation of their expression both in the abdominal adipose tissue and the liver. Wild blueberry diet had a positive impact on lipid profile, with significant reductions in serum triglyceride and total cholesterol concentrations. It also positively affected the expression of key enzymes and transcription factors involved in lipid and cholesterol metabolism, including sterol regulatory element binding proteins and peroxisome proliferator-activated receptors. Consumption of wild blueberries improved several markers of glucose and insulin metabolism, including plasma glycated hemoglobin, resistin and retinol binding protein 4 concentrations. Finally, the wild blueberry diet modulated the aortic biomechanical function of the OZR by partially restoring the impaired phenylephrine-induced constrictor responses, and attenuating the exaggerated response to acetylcholine-induced vasorelaxation.
In conclusion, regular consumption of dietary achievable amounts of wild blueberries was able to decrease markers of inflammation, improve blood lipid profile, modulate vasoreactivity, and affect the expression of genes involved in the inflammatory response, lipid and glucose metabolism, and endothelial function in the OZR model of metabolic syndrome
Synthesis and characterization of polymeric nanoreactors for applications in catalytic aqueous biphasic reactions
No full textLAUREA MAGISTRALECon il presente lavoro abbiamo sviluppato nuove micelle reticolate al centro (CCMs) per l’applicazione come nano-reattori in reazioni di catalisi micellare omogenea bifasica, con lo scopo di riciclare il catalizzatore e ridurre i rifiuti. Per esempio riducendo o eliminando il solvente organico.
Basandoci sulle ricerche realizzate in precedenza dal LCAC team, si è ipotizzato che le CCMs con un guscio polielettrolitico rispetto al caso di micelle con guscio neutro, dovrebbero ridurre la quantità di catalizzatore perso durante il processo catalitico. Le CCMs con guscio policationico (PVPMe+I-) e polianionico (PSS-Na+) sono state sintetizzate e caratterizzate attraverso DLS, TEM e spettroscopia NMR. Entrambi i tipi di CCMs sono state realizzate in due forme: con leganti del tipo trifenilfosfina (TPP) all’interno del cuore delle micelle, per ancorare il precatalizzatore metallico, e senza siti di coordinazione, per ancorare il precatalizzatore sulla superficie delle CCMs tramite interazione elettrostatica, o per altre applicazioni catalitiche. Se la sintesi del primo tipo di CCMs con il guscio policationico richiede cinque passaggi nel caso di guscio polianonico, la stessa morfologia finale è ottenuta con tre passaggi di sintesi nel caso del guscio polianionico.
Un’attenzione speciale è stata dedicata allo studio dell’influenza del rapporto idrofilico/idrofobico (PVPMe+I- /PS) delle catene polimeriche sulla morfologia delle micelle risultanti. Due tendenze sono state scoperte. In primo luogo è stato messo in evidenza come questo rapporto influenzi l’organizzazione delle macromolecole prima della reticolazione con DEGDMA, permettendo a seconda del rapporto PVPMe+I- /PS la formazione di sfere o una miscela di sfere, fibre e vescicole. In secondo luogo è stato mostrato che il passaggio finale di reticolazione permette di ristabilire più o meno una morfologia sferica nel campione, sebbene questo sia caratterizzato da una maggiore polidispersità.
Le nuove CCMs con un guscio policationico (PVPMe+I- ) e leganti del tipo TPP nel cuore, sono state caricate con successo con due complessi metallici del tipo Rh(I) e spettri 31P NMR di entrambe le specie (con rapporto 1:1 Rh/TPP ) sono stati registrati.
Il latex contenente micelle con il precursore metallico coordinato alle TPP ([RhCl(COD)]@CCM) è stato testato in idrogenazione catalitica di stirene e 1-octene esibendo risultati incoraggianti. In particolare, un test d’idrogenazione catalitica dello stirene può essere condotto in stirene puro, senza solventi aggiuntivi, con una percentuale di Rh molto bassa (0.0046%) e raggiungere una conversione del 41% che rappresenta un turnover number (TON, moli di prodotto/moli di catalizzatore di rodio) di 27000. È stato possibile riciclare il catalizzatore conducendo quindi un secondo test d’idrogenazione catalitica dello stirene, tuttavia è stata ottenuta una conversione molto più bassa.In the context of Green Chemistry, in terms of recyclability of catalysts, and reduction of waste, by e.g. using less or no organic solvents, we developed in the present work new core-cross-linked micelles (CCMs) as reusable nano-reactors for applications in homogeneous micellar-biphasic catalytic reactions.
Based on previous investigations realized in the LCAC team, it appears that CCMs with a polyelectrolyte shell, vs. neutral shell, may lead to a reduce amount of leaching during the catalytic processes. Therefore, two types of CCMs, with a polycationic (PVPMe+I-) or polyanionic (PSS-Na+) shell were successfully synthesized and characterized by multinuclear NMR spectroscopy, DLS and TEM. Each class of CCMs were produced in two forms: with triphenylphosphine (TPP) ligands inside the core of the micelles, for further metalation with a catalytically active metal center, or without confined coordination site, for anchoring catalytically active species on the periphery of the CCM by electrostatic interactions for other catalytic applications. While the first family of CCMs, with a polyvinylpyridinium (PVPMe+I-) required five steps to be obtained, its polyvinylsulfonate (PSS-Na+) analog was accessible in only three steps.
A special attention was dedicated to analyze the influence of the hydrophilic/hydrophobic ratio (PVP/PS) of the polymer chains on the morphology of the resulting micellar species. This study led to two mains trends. First, this ratio clearly influences the arrangement of the macromolecular entities before cross-linking with DEGDMA, affording, depending of the (PVP/PS) ratios, only spheres or mixtures of spherical entities, fibers and/or vesicles. Secondly, it has been shown that the final cross-linking step allows to (re-)establish a more or less uniform morphology of the samples, however with broader polydispersities of the resulting CCMs.
The new CCMs with a PVPMe+I- shell and TPP ligands in the core were successfully metalated with two Rh(I) metal complexes and 31P NMR spectra of both species (with 1:1 Rh/TPP ratios) could be recorded.
Finally, the [RhCl(COD)]@CCM species was evaluated in the catalytic hydrogenation of styrene and 1-octene and exhibited encouraging results. Especially, one run could be performed in pure styrene, without additional solvent and at very low loading of Rh (0.0046%) and afforded 41% conversion, which represents a turnover number (TON, mole of product/mole of Rh cat.) of 27 000. We were able to recycle the catalyst and a second run of catalysis was performed affording, however, much lower conversion
Improvement of lymphocyte resistance against H2O2-induced DNA damage in Sprague–Dawley rats after eight weeks of a wild blueberry (Vaccinium angustifolium)-enriched diet
No full textThe effect of wild-blueberry consumption on the resistance of H2O2-induced DNA damage was evaluated in the Sprague–Dawley (SD) rat. Thirty-two, four week-old SD rats were randomly assigned to two groups of sixteen rats each and fed a control diet (C) or a wild-blueberry (WB) diet for four or eight weeks. Following the dietary treatment, plasma antioxidant capacity was assessed by the TRAP assay. Ex vivo protection from H2O2-induced DNA damage was evaluated in lymphocytes by means of the comet assay. No significant effect was detected in plasma antioxidant capacity at four and eight weeks in both dietary groups. In contrast, the level of DNA damage was significantly lower in rats fed the WB diet compared with those on the C diet after eight weeks (11.2 ± 1.0% vs 17.2 ± 2.4% DNA in tail, p ≤ 0.05) but not after four weeks. In conclusion, while WB consumption did not affect plasma antioxidant activity, it improved lymphocyte protection against oxidative damage, but only after eight weeks
