Extraction of silymarin compounds from milk thistle (Silybum marianum) seed using hot, liquid water as the solvent

High-value specialty chemicals are usually obtained from natural products by extracting with generally regarded as safe (GRAS) solvents. Because organic solvents are quite often used, high operating and disposal costs occur. When compared to traditional solvents, water is an interesting alternative because of its low operating and disposal costs. Milk thistle contains compounds (taxifolin, silychristin, silydianin, silybinin A, and silybinin B) that display hepatoxic protection properties. This paper examines the batch extraction of silymarin compounds from milk thistle seed meal in 50°C, 70°C, 85°C and 100°C water as a function of time. For taxifolin, silychristin, silybinin A, and silybinin B, extraction with 100°C water resulted in the highest yields. After 210 min of extraction at 100°C, the yield of taxifolin was 1.2 mg/g of seed while the yields of silychristin, silybinin A, and silybinin B were 5.0, 1.8 and 3.3 mg/g of seed, respectively. The ratios of the extracted compounds, and particularly the ratios at long extraction times, showed that the more polar compounds (taxifolin and silychristin) were preferentially extracted at 85°C, while the less polar silybinin was preferentially extracted at 100°C

Switchgrass storage effects on the recovery of carbohydrates after liquid hot water pretreatment and enzymatic hydrolysis

Perennial grasses that would be used for bioenergy and bioproducts production will need to be stored for various periods of time to ensure a continual feedstock supply to a bioprocessing facility. The effects of storage practices on grass composition and the response of grasses to subsequent bioprocesses such as pretreatment and enzymatic hydrolysis needs to be understood to develop the most efficient storage protocols. This study examined the effect of outdoor storage of round switchgrass bales on composition before and after liquid hot water pretreatment (LHW) and enzymatic hydrolysis. This study also examined the effect of washing LHW pretreated biomass prior to enzymatic hydrolysis. It was determined that switchgrass composition after baling was stable. As expected, glucan and lignin contents increased after LHW due to decreases in xylan and galactan. Washing biomass prior to enzymatic hydrolysis reduced saccharification, especially in samples from the interior of the bale, by at least 5%

Soutien à domicile ou relogement d'un aîné en perte d'autonomie, n'ayant pas été déclaré inapte et vivant seul : prise de décision de la triade aîné, enfants et travailleur social

S’il est bien connu que la grande majorité des personnes vieillissantes souhaitent pouvoir vivre dans leur domicile aussi longtemps que possible, pour diverses raisons, il semble que le choix de rester à la maison n’en devienne plus un à un moment ou à un autre dans le processus de perte d’autonomie fonctionnelle pouvant subvenir avec le vieillissement. Ce changement de milieu de vie, lorsqu’il n’est pas le premier choix d’une personne apte à consentir à ce « soin », a suscité notre intérêt, plus particulièrement dans une situation où la personne aînée vit seule à domicile. Comment une personne n’ayant pas été déclarée inapte qui aspire à rester chez elle en vient-elle à la décision de se reloger vers une ressource d’habitation? L’expérience du processus décisionnel résultant du soutien à domicile ou du relogement d’un aîné en perte d’autonomie, n’ayant pas été déclaré inapte et vivant seul, n’a jusqu’à présent, à notre connaissance, pas fait le sujet d’étude au Québec. Par le biais de cette recherche, nous voulons comprendre ce processus décisionnel important en explorant les perspectives de l’aîné, des enfants impliqués dans la décision et du travailleur social. Les facteurs susceptibles d’influencer le soutien à domicile ou le relogement d’un aîné, les rôles adoptés par chacun des acteurs, le pouvoir décisionnel de chacune des personnes impliquées de même que les perspectives de tout un chacun sur la situation de l’aîné et les limites du soutien à domicile forment le centre de nos questionnements. Beaucoup d’enjeux concernent les décisions prises à l’égard des aînés au nom de leur bien et de leur intérêt et les tensions entre la sécurité et la liberté se rejoignent dans cette recherche pour questionner le rapport au risque de chacune des parties prenantes à la décision de soutien à domicile ou de relogement d’un aîné en perte d’autonomie, n’ayant pas été déclaré inapte et vivant seul. Cette recherche conduite selon une méthode qualitative procède à trois études de cas pour mieux comprendre le processus décisionnel de relogement d’aînés n’ayant pas été déclarés inaptes et vivant seuls. Chaque cas est formé d’une triade composée d’un aîné, le(s) enfant(s) impliqué(s) dans le processus décisionnel et un travailleur social. L’échantillonnage de type non-probabiliste s’est effectué selon la méthode boule de neige. La collecte de données a été réalisée par des entrevues individuelles semi-dirigées à l’aide de grilles d’entrevues. Cette recherche se distingue par sa méthodologie d’analyse intra-triades et inter-triades, mais aussi dans l’angle du rapport au risque qui apporte une toute nouvelle analyse à un processus décisionnel déjà très peu étudié. Les résultats démontrent l’implication non-négligeable des enfants dans le processus décisionnel de relogement de leur parent en perte d’autonomie par l’influence que leurs inquiétudes pour la sécurité de leur parent à domicile exercent sur l’analyse de la situation du travailleur social. Dans une sincère intention de faire au mieux pour la personne aînée, les enfants et les travailleurs sociaux tendent vers des interventions de protection en recherchant pour cette dernière une sécurité et une surveillance qu’ils veulent omniprésentes, au détriment de la valorisation de sa capacité à s’autodéterminer et à gérer les risques comme elle l’entend. Selon les résultats obtenus, il apparaît que de la part des parties prenantes à un tel processus décisionnel, les risques et le fardeau qu’ils représentent chez ceux qui les identifient influencent à la fois leur implication auprès de la personne à domicile et leur rôle dans le processus décisionnel. Plus les risques inquiètent les enfants, plus leur implication au domicile de leur parent augmente, de même que leur risque d’épuisement. Lorsque les enfants atteignent leur limite dans l’accompagnement à domicile de leur parent en perte d’autonomie, leur épuisement s’ajoute comme un élément favorisant le relogement de la personne aînée vivant seule dans l’évaluation du travailleur social. De plus, nous avons observé qu’une différence dans la tolérance aux risques des enfants et de leur parent aîné se manifeste chez le travailleur social comme un besoin d’apaiser les insécurités des enfants. Une négociation s’engage alors entre les travailleurs sociaux, la personne aînée et ses enfants vers une option qui semble pouvoir profiter à toutes les parties : le relogement

Kinetics determination of soybean oil transesterification in the design of a continuous biodiesel production process

One-step batch transesterification consisting of three stepwise reversible reactions of pure soybean oil with methanol was conducted at two different mixing speeds (600 and 300 rpm) to produce soybean oil fatty acid methyl esters (biodiesel). In both batch reactions, sodium methoxide (1.09 wt% based on soybean oil) was used as the catalyst, the reaction temperature was 60oC, and the methanol-to-oil molar ratio was 6:1. The objectives were to determine and/or investigate: 1) the mechanism and order of the reaction, 2) the reaction rate constants, 3) the effect of changes in mixing intensity on the reaction rate, 4) the comparison of the reaction mechanism and kinetic rate constants calculated with established literature references (for validation), and 5) how to interpret and utilize the kinetics analysis in the design of a continuous pilot-scale biodiesel production process. The kinetics analysis from the experiment showed that a second-order kinetic mechanism provided a good fit for the reaction. Kinetic rate constants at both mixing speeds were calculated and ranged from -3.10 x 10-3 - 0.028 (wt% min)-1 for the triglyceride, monoglyceride, and diglyceride forward reactions. The rate constants were slightly higher at the 600 rpm mixing speed. Higher mixing intensity also resulted in an increased purity of methyl esters (95.2 wt %). At both mixing speeds, monoglycerides showed the smallest percent elimination of all reaction intermediates at approximately 30%. The rate constants calculated for monoglycerides were the lowest as well. The monoglyceride rate constant of 0.0149 (wt% min)-1 was used in the design of a continuous process in a 100 gallon vessel, which is a scale of operation that could be easily adopted by a cooperative of oil seed producers or geographically isolated plant-oil producing villages. This Honors thesis was a component of a Biological and Agricultural Engineering team Senior Design project which consisted of designing a continuous biodiesel process from production to purification

The Effect of Water Extracted Silibinin on Reactive Oxygen Species (ROS) Production of Macrophages

The world is actively looking for technology to produce sustainable liquid fuels to replace our reliance on petroleum-based fuels. Biomass can be converted either through the thermochemical or saccharification platforms into fuels such as ethanol or butanol. In addition to converting the biomass into liquid fuels, valuable phytochemicals can be extracted prior, during, or after the conversion. Extracting useful phytochemicals, as a part of the overall conversion of biomass to fuels, is included in the concept of the biobased biorefinery. However, the key to effectively and economically extract phytochemicals from biomass is the ability to couple the extraction to the energy conversion steps; that is, extraction with either dilute acid or water. Phytochemical extraction with organic solvents cannot be easily coupled with an energy conversion process because the solvents must be removed before proceeding to energy conversion, thereby complicating and increasing the cost of the process. By extracting the phytochemicals with water or dilute acid, a simple unit operation can be added to the existing biomass conversion technology, ultimately adding value to the biomass

Actigraphy data in pediatric research : the role of sleep diaries

Background. When assessing children's sleep using actigraphy, researchers usually rely on a sleep diary completed by a parent as an aid in scoring actigraphic data. However, parental nonadherence in completing the sleep diary may significantly reduce the amount of available data. The current study examined the agreement between actigraphic data scored with and without a sleep diary to evaluate the impact of not using a sleep diary when studying children's sleep with actigraphy. Methods. Sixty children (aged 6–10 years; 36 girls) wore an actigraph for three to seven consecutive nights, and mothers were asked to complete a diary of their child's sleep during the same period. Actigraphy data were scored under two conditions (with and without diary) rated independently for each child by two different research assistants, who each scored 50% of the files in each condition. Results. Group-level analyses and intraclass correlations revealed very strong convergence between the two scoring conditions: on all sleep variables (sleep duration, wake duration, and sleep efficiency), average mean differences were very small and intraclass correlations very high. Bland and Altman’s (1999) approach allowed for a child-by-child examination of agreement between the two conditions and revealed that, although they cannot be considered interchangeable, the two conditions produce quite minimal differences in the estimation of sleep variables. Conclusions. The findings suggest that it is possible to use some actigraphy data for which no corresponding diary data are available, although this approach should be used sparingly

Normative developmental trajectories of actigraphic sleep variables during the preschool period : a three-wave longitudinal study

Important changes in sleep are believed to occur in the preschool years, but studies that have documented these changes were generally cross‐sectional or based on subjective sleep measures. The current longitudinal study modeled the developmental trajectories followed by five sleep variables objectively assessed during the preschool period. Children (N = 128) wore an actigraph over 3 days at 2, 3, and 4 years of age and change in sleep variables was assessed with growth curves. The results showed a linear decrease of daytime, total, and nighttime sleep duration, and a linear increase of sleep efficiency and proportion of nighttime to total sleep. For all sleep variables, the rhythm of change was relatively uniform across children, but there was significant inter‐individual variation around the initial status for most variables. To our knowledge, this study is the first to model the developmental trajectories followed by several sleep variables during the preschool period

Sleeping Toward Behavioral Regulation: Relations Between Sleep and Externalizing Symptoms in Toddlers and Preschoolers

Objective: The aim of this study was to investigate the concurrent and longitudinal relations between sleep and externalizing symptoms among young children. Method: Sixty-four families (mostly Caucasian; 36 boys) were met twice, when children were 2 (T1) and 4 years of age (T2). At T1, children wore an actigraph monitor for a 72-hour period, and both mothers and fathers completed the Child Behavior Checklist (CBCL). At T2, both parents as well as the daycare educator filled the CBCL. Results: At T1, longer sleep duration and higher sleep efficiency was associated with fewer externalizing symptoms as assessed by mothers. Results also indicated that higher sleep efficiency at T1 was related to fewer parent-reported externalizing symptoms at T2 (while controlling for prior externalizing symptoms). Relations between sleep efficiency at T1 and externalizing symptoms as assessed by mothers at T1 and by fathers at T2 were moderated by child sex, such that links were significant among boys only. Results pertaining to educators’ reports were inconclusive. Conclusions: The current study highlights the importance of rapidly treating sleep difficulties, which are associated with persistent behavioral maladjustment, perhaps especially for boys

G-quadruplex located in the 5’UTR of the BAG-1 mRNA affects both its cap-dependent and cap-independent translation through global secondary structure maintenance

Abstract: The anti-apoptotic BAG-1 protein isoforms are known to be overexpressed in colorectal tumors and are considered to be potential therapeutic targets. The isoforms are derived fromalternative translation initiations occuring at four in-frame start codons of a single mRNA transcript. Its 5'UTR also contains an internal ribosome entry site (IRES) regulating the capindependent translation of the transcript. An RNA Gquadruplex (rG4) is located at the 5'end of the BAG- 1 5'UTR, upstream of the known cis-regulatory elements. Herein, we observed that the expression of BAG-1 isoforms is post-transcriptionally regulated in colorectal cancer cells and tumors, and that stabilisation of the rG4 by small molecules ligands reduces the expression of endogenous BAG-1 isoforms. We demonstrated a critical role for the rG4 in the control of both cap-dependent and independent translation of the BAG-1 mRNA in colorectal cancer cells. Additionally, we found an upstream ORF that also represses BAG-1 mRNA translation. The structural probing of the complete 5'UTR showed that the rG4 acts as a steric block which controls the initiation of translation at each start codon of the transcript and also maintains the global 5'UTR secondary structure required for IRES-dependent translation