Thiamin nutrition and catalysis-induced instability of thiamin diphosphate

Thiamin (vitamin B1) is required in animal diets because it is the precursor of the enzyme cofactor, thiamin diphosphate. Unlike other B vitamins, the dietary thiamin requirement is proportional to non-fat energy intake but there is no obvious biochemical reason for this relationship. In the present communication we show for two enzymes that the cofactor undergoes a slow destruction during catalysis, which may explain the interdependence of thiamin and energy intakes.

Picosecond soliton transmission using concatenated nonlinear optical loop mirror intensity filters

We investigate the use of nonlinear optical loop mirrors as saturable absorbers in picosecond soliton transmission systems. It is found that they allow short (1–5-ps) pulses to be propagated through chains of optical amplifiers spaced at intervals of typically 10 km. The loop mirror removes dispersive waves and stabilizes the peak amplitude of the soliton. An additional advantage is that the self-frequency shift of the soliton may be suppressed by bandwidth filtering without causing growth of dispersive waves at the center of the passband. The timing jitter and soliton interactions present in the scheme are also described.

Investigation of photorefractive subharmonics in the absence of wavemixing

Using a new optical configuration free from the influence of photorefractive optical nonlinearity, we investigate the main characteristics of the spatial subharmonic K/2 excited in a Bi12SiO20 crystal by a light-intensity pattern with wave vector K and frequency O. It is shown that in a large region of intensity and applied electric field the optimum value O of the frequency corresponds to the conditions of parametric excitation of the weakly damped eigenmodes of the medium: the space-charge waves. The threshold and above-threshold characteristics of the subharmonic regime are in good agreement with the theory.

Investigation of photorefractive subharmonics in the absence of wavemixing

Using a new optical configuration free from the influence of photorefractive optical nonlinearity, we investigate the main characteristics of the spatial subharmonic K/2 excited in a Bi12SiO20 crystal by a light-intensity pattern with wave vector K and frequency O. It is shown that in a large region of intensity and applied electric field the optimum value O of the frequency corresponds to the conditions of parametric excitation of the weakly damped eigenmodes of the medium: the space-charge waves. The threshold and above-threshold characteristics of the subharmonic regime are in good agreement with the theory.

Picosecond soliton transmission using concatenated nonlinear optical loop-mirror intensity filters

The issues involved in employing nonlinear optical loop mirrors (NOLMs) as intensity filters in picosecond soliton transmission were examined in detail. It was shown that inserting NOLMs into a periodically amplified transmission line allowed picosecond solitons to be transmitted under conditions considered infeasible until now. The loop mirrors gave dual function, removing low-power background dispersive waves through saturable absorption and applying a negative feedback mechanism to control the amplitude of the solitons. The stochastic characteristics of the pulses that were due to amplifier spontaneous-emission noise were investigated, and a number of new properties were determined. In addition, the mutual interaction between pulses was also significantly different from that observed for longer-duration solitons. The impact of Raman scattering in the computations was included and it was shown that soliton self-frequency shifts may be eliminated by appropriate bandwidth restrictions.

Trajetórias e fatores associados a qualidade de vida de mães de recém-nascidos pré-termos de muito baixo peso até três anos após o parto

Preterm birth is a public health problem worldwide. It holds growing global incidence rates, high mortality rates and a risk of the long-term sequelae in the newborn. It is also poses burden on the family and society. Mothers of very low birth weight (VLBW) preterm infants may develop psychological disorders, and impaired quality of life (QoL). Factors related to mothers and children in the postpartum period may be negatively associated with the QoL of these mothers. The aim of this study was to assess factors possibly associated with the QoL of mothers of VLBW preterm newborns during the first three years after birth. Mothers of VLBW preterm answered the World Health Organization Quality of Life (WHOQOL)-bref and the Beck Depression Inventory (BDI) in five time points up to 36 months postpartum, totalizing 260 observations. The WHOQOL–bref scores were compared and correlated with sociodemographic and clinical variables of mothers and children at discharge (T0) and at six (T1), twelve (T2), 24 (T3) and 36 (T4) months after the delivery. We used the Kruskal Wallis test to compared scores across different time points and correlated WHOQOL-bref scores with the sociodemographic and clinical variables of mothers and preterm infants. Multiple linear regression models were used to evaluate the contribution of these variables for the QoL of mothers. The WHOQOL–bref scores at T1 and T2 were higher when compared to scores in T0 in the physical health dimension (p = 0.013). BDI scores were also higher at T1 and T2 than those at T0 (p = 0.027). Among the maternal variables that contributed most to the QoL of mothers, there were: at T0, stable marital union (b= 13.60; p= 0.000) on the social relationships dimension, gestational age (b= 2.38; p= 0.010) in the physical health dimension; post-hemorrhagic hydrocephalus (b= -10.05; p= 0.010; b= -12.18; p= 0.013, respectively) in the psychological dimension; at T1 and T2, Bronchopulmonary dysplasia (b= -7.41; p= 0.005) and female sex (b= 8,094; p= 0.011) in the physical health dimension and environment, respectively. At T3, family income (b= -12.75’ p= 0.001) in the environment dimension, the SNAPPE neonatal severity score (b= -0.23; p= 0.027) on the social relationships dimension; at the T4, evangelical religion (b= 8.11; p= 0.019) and post-hemorrhagic hydrocephalus (b: -18.84 p: 0.001) on the social relationships dimension. The BDI scores were negatively associated with WHOQOL scores in all dimensions and at all times points: (-1.42 ≤ b ≤ -0.36; T0, T1, T2, T3 and T4). We conclude that mothers of preterm infants VLBW tend to have a transient improvement in the physical well-being during the first postpartum year. Their quality of life seems to return to levels at discharge between two and three years after delivery. The presence of maternal depressive symptoms and diagnosis of post-hemorrhagic hydrocephalus or BDP are factors negatively associated with the QoL of mothers. Social, religious and economic variables are positively associated with the QoL of mothers of VLBW preterm.

De Invloed van Altruïsme op de Samenhang tussen Leeftijd en Mentale Veerkracht

Het primaire doel van deze studie was meer helderheid te krijgen over de invloed van altruïsme op de positieve associatie tussen leeftijd en mentale veerkracht. Het secundaire doel was een factor te kunnen aanwijzen die de positieve relatie tussen leeftijd en mentale veerkracht zou mediëren of anderszins verklaren. Meer begrip over factoren die samenhangen met mentale veerkracht, zou kunnen leiden tot de ontwikkeling en verfijning van trainingen ter bevordering van mentale veerkracht. De studie kende een cross-sectionele opzet met één meetmoment. Van de 92 oudere deelnemers werden er 66 met hulp van sleuteldeelnemers in het netwerk van de onderzoeker gevonden. De overige 26 zijn oudere deelnemers uit de database van de OU. Alle jongvolwassenen zijn afkomstig uit de database van de OU. In totaal zijn er 160 deelnemers geïncludeerd in deze studie, waarvan 68 jongvolwassenen tussen de 18 en 45 en 92 oudere volwassenen van 60 jaar of ouder. De uitgevoerde regressie analyses waren gericht op de veronderstelde mediërende verklaring door altruïsme van de relatie tussen leeftijd en mentale veerkracht. Mentale veerkracht werd gemeten met de Resilience Scale (RS-nl; Portzky, 2010). De Nederlandse vertaling van de NEO Five Factor Inventory (NEO-FFI; Hoekstra, Ormel & Fruyt, 1996) werd gebruikt om altruïsme te meten. Van de RS-nl is de totaalscore geanalyseerd, van de NEO zijn alleen de vragen met betrekking tot altruïsme geanalyseerd. De mediatie-analyse is uitgevoerd middels de 4 stappen methode van Baron en Kenny (beschreven in Verboon, 2010). De hypothese betreffende de positieve samenhang tussen leeftijd en mentale veerkracht werd bevestigd (b = .12, t(153) = 3.91, p < .001). Er werd geen samenhang tussen leeftijd en altruïsme of tussen altruïsme en mentale veerkracht gevonden. Hierdoor kon er geen sprake zijn van mediatie door altruïsme op de relatie tussen leeftijd en mentale veerkracht.

La supplémentation nutritionnelle dans la prévention et le traitement des troubles cognitifs associés à la maladie d’Alzheimer

Cette recension systématique analyse 19 essais cliniques randomisés contre placebo qui mesurent l’effet de suppléments d’oméga-3, de vitamines B (B6, B9 et B12), ou de vitamines antioxydantes (C et E), sur le fonctionnement cognitif d’aînés avec ou sans trouble cognitif. Les bases de données consultées pour la recherche des articles sont Cochrane Library, Current Contents, EBSCO, EMBASE, MEDLINE et PsycNet. Les mots clés utilisés sont «alzheimer’s disease», or «mild cognitive impairment», or «cognitive decline»; and «dietary supplements» or «vitamin C», or «vitamin E», or «alpha-tocopherol», or «vitamin B», or «cobalamin», or «folic acid», or «omega 3», or «fatty acids»; and «prevention», or «treatment». La recherche inclut les articles publiés en anglais et en français, de 1999 à juin 2014. Les différents suppléments à l’étude sont bien tolérés et sécuritaires. Des résultats significatifs sont enregistrés sur des mesures cognitives suite à la supplémentation en oméga-3, et en vitamines B, chez des participants sans trouble cognitif ou avec un diagnostic de trouble cognitif léger. Chez les participants atteints de la maladie d’Alzheimer, des résultats significatifs sont surtout enregistrés sur des mesures fonctionnelles, de symptômes psychologiques et comportementaux, ou de qualité de vie, suite à l’administration d’un supplément nutritionnel. La présence d’une hétérogénéité importante dans la méthodologie des essais cliniques limite toutefois les conclusions quant à la pertinence clinique de ces traitements. L’établissement de lignes directrices suite à un consensus d’experts s’avère nécessaire afin d’uniformiser la recherche sur cette nouvelle piste d’intervention dans la prévention et le traitement de la maladie d’Alzheimer.

Influência da tecnologia no desenvolvimento do pensamento algébrico : um estudo no 1º CEB

Relatório de Estágio apresentado à Escola Superior de Educação do Instituto Politécnico de Castelo Branco para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Educação Pré-Escolar e Ensino do 1º Ciclo do Ensino Básico.

Estudo comparativo entre eletrodo fixo e eletrodo móvel (caneta) no fortalecimento perineal

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências Médicas, Programa de Pós-Graduação em Ciências Médicas, 2011.

Deflazacort Versus Prednisolone: Randomized Controlled Trial in Treatment of Children With Idiopathic Nephrotic Syndrome

Background: Corticosteroids are the main therapy of nephrotic syndrome and goal of corticosteroid therapy is to obtain maximum clinical benefit with minimum adverse effects. Children are more vulnerable to side effects of corticosteroids related to growth and adrenal suppression, so a search for an alternative steroid with fewer side-effects is underway. Deflazacort is an oxazoline derivative and preliminary data suggest reduced osteoporosis, lesser growth retardation and weight gain with deflazacort. Objectives: This study was done to compare the effectiveness and safety of deflazacort in idiopathic nephrotic syndrome. Patients and Methods: Twenty five children with age between 2 to 12 years, with idiopathic nephrotic syndrome were enrolled. They were randomly assigned to receive deflazacort (Group A, n = 12) or prednisolone (Group B, n = 13) and were followed up for six months. Results: All children of group A and 11 of group B had remission. Two children from group B were steroid resistant. Mean time taken to induce remission was significantly (P = 0.012) less in group A (10.25 ± 2.41 days) than group B (12.55 ± 1.44 days). One patient in group A had relapse on follow up as compared to 3 in group B (P = 0.58). Statistically significant difference (P = 0.03) in change in mean height was found between group A (2.13 ± 0.50cm) and B (1.44 ± 0.45 cm), with group B gaining less height. Conclusions: Remission rate in both groups was comparable although time taken to induce remission was shorter in deflazacort group and there was a significant difference in change of mean height on follow up with prednisolone group gaining lesser height.

Effects of vitamin E deficiency on fatigue and muscle contractile properties

Radical-mediated oxidative damage of skeletal muscle membranes has been implicated in the fatigue process. Vitamin E (VE) is a major chain breaking antioxidant that has been shown to reduce contraction-mediated oxidative damage. We hypothesized that VE deficiency would adversely affect Muscle contractile function, resulting in a more rapid development of muscular fatigue during exercise. To test this postulate, rats were fed either a VE-deficient (EDEF) diet or a control (CON) diet containing VE. Following a 12-week feeding period, animals were anesthetized and mechanically ventilated. Muscle endurance (fatigue) and contractile properties were evaluated using an in situ preparation of the tibialis anterior (TA) muscle. Contractile properties of the TA muscle were determined before and after a fatigue protocol. The muscle fatigue protocol consisted of 60 min of repetitive contractions (250 ms trains at 15 Hz; duty cycle = I I %) of the TA muscle. Prior to the fatigue protocol, no significant differences existed in the force-frequency curves between EDEF and CON animals. At the completion of the fatigue protocol, muscular force production was significantly (P

A single high dose of oral vitamin D3 is insufficient to correct a deficiency in a rheumatologic population

Introduction Vitamin D plays a major role in bone metabolismand neuromuscular function. Supplementation with vitamin D iseffective to reduce the risk of fall and of fracture. However adherenceto oral daily vitamin D is low. Screening and correcting vitamin Dinsufficiency in a rheumatologic population could improve bothmorbidity and quality of life. After determining the prevalence ofvitamin D deficiency in this population, we evaluated if supplementationwith a single high dose of oral 25-OH vitamin D3 wassufficient to correct this abnormality.Methods During one month (November 2009), levels of 25-OHvitamin D were systematically determined in our rheumatology outpatientclinic and classified in: vitamin D deficiency (< 10 μg/l),vitamin D insufficiency (10 to 30 μg/l) or normal vitamin D (> 30 μg/l).Patients with insufficiency or deficiency received respectively a singlehigh dose of 300'000 IU or 600'000 IU oral vitamin D3. In addition,all patients with osteoporosis were prescribed daily supplement ofcalcium (1 g) and vitamin D (800 IU). 25-OH vitamin D levels werereevaluated after 3 months.Results Vitamin D levels were initially determined in 292 patients(mean age 53, 211 women, 87 % Caucasian). 77 % had inflammatoryrheumatologic disease (IRD), 20 % osteoporosis (OP) and 12 %degenerative disease (DD). Vitamin D deficiency was present in 20(6.8 %), while 225 (77.1 %) had insufficiency. Of the 245 patientswith levels < 30μg/l, a new determination of vitamin D level wasavailable in 173 (71 %) at 3 months.Conclusion Vitamin D insufficiency is highly prevalent in ourrheumatologic population (84 %), and is not adequately correctedby a single high dose of oral vitamin D3 in > 50 % of the patientswith IRD and DD. In patients with OP, despite association of asingle high dose with daily oral vitamin D supplementation, 40 %of patients are still deficient when reevaluated at 3 months.

Symptômes dépressifs et douleurs diffuses chez un détenu : penser au déficit en vitamine D [Depressive symptoms and widespread pains in a prisoner. Think on vitamin D deficiency].

The confinement can lead to an important limitation of sun exposure of the prisoners. This limitation can lead to a deficit in vitamin D, source of diverse disorders. Diffuse pains of members and of joints are the most classics troubles. The association of vitamin D deficiency and psychiatric disorders is frequent but badly known. Even if there is still no evidence indicating a cause and effect relationship between vitamin D deficiency and depressive episodes, the contribution of vitamin D deficiency in the arisen of a depression has to be considered. The treatment of vitamin D deficiency cannot, in itself, constitute a treatment of the depressive disorder but contributes to the improvement of the whole status The psychiatric follow-up remains indispensable, in particular because of the suicidal risk, particularly present in prison.

A Single High Dose of Oral Vitamin D3 Is Not Enough to Correct Insufficiency and Deficiency in a Rheumatologic Population

Introduction: Vitamin D plays a major role in bone metabolism and neuromuscular function. Supplementation with vitamin D is effective to reduce the risk of fall and of fracture. However adherence to oral daily vitamin D supplementation is low. Screening and correcting vitamin D insufficiency in a general rheumatologic population could improve both morbidity and quality of life in these patients with chronic painful disorders and at high risk of osteoporosis. After determining the prevalence of vitamin D deficiency in this population, we evaluated if supplementation with a single high dose of oral 25-OH vitamin D3 was sufficient to correct this abnormality. Methods: During one month (November 2009), levels of 25-OH vitamin D were systematically determined in our rheumatology outpatient clinic and classified into three groups: vitamin D deficiency (<10 μg/l), vitamin D insufficiency (10 to 30 μg/l) or normal vitamin D (>30 μg/l). Patients with insufficiency or deficiency received respectively a single high dose of 300000 IU or 600000 IU oral vitamin D3. In addition, all patients with osteoporosis were prescribed daily supplement of calcium (1 g) and vitamin D (800 IU). 25-OH vitamin D levels were reevaluated after 3 months. Results: Vitamin D levels were initially determined in 292 patients (mean age 53, 211 women, 87% Caucasian). 77% had inflammatory rheumatologic disease (IRD), 20% osteoporosis (OP) and 12% degenerative disease (DD). Vitamin D deficiency was present in 20 (6.8%), while 225 (77.1%) had insufficiency. Of the 245 patients with levels <30 μg/l, a new determination of vitamin D level was available in 173 (71%) at 3 months. Conclusion: Vitamin D insufficiency is highly prevalent in our rheumatologic population (84%), and is not adequately corrected by a single high dose of oral vitamin D3 in more than half of the patients with IRD and DD. In patients with OP, despite association of a single high dose with daily oral vitamin D supplementation, 40% of patients are still deficient when reevaluated at 3 months.