152 research outputs found

    Effects of external global noise on the catalytic CO oxidation on Pt(110)

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    Oxidation reaction of CO on a single platinum crystal is a reaction-diffusion system that may exhibit bistable, excitable, and oscillatory behavior. We studied the effect of a stochastic signal artificially introduced into the system through the partial pressure of CO. First, the external signal is employed as a turbulence suppression tool, and second, it modifies the boundaries in the bistable transition between the CO and oxygen covered phases. Experiments using photoemission electron microscopy (PEEM) together with numerical simulations performed with the Krischer-Eiswirth-Ertl (KEE) model are presented.Comment: 15 pages, 7 figures, accepted in J. Chem. Phy

    Body image and dietary habits in adolescents: a systematic review

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    Context: Adolescence is a critical developmental stage in which increasing concerns about body image (BI) coincide with the consolidation of dietary habits (DHs). Multiple studies have sought robust associations between BI and DHs to prevent unhealthy behaviors. Objective: The aim of this systematic review was to examine the available literature on the association between BI perception (BIP) and/or satisfaction (BIS) and DHs in adolescents. Data Sources: A search was carried out of 5 electronic databases (PubMed, SciELO, Cochrane, Embase, and PsycInfo) using a combination of keywords (and synonyms) related to adolescence, BI, and diet. Data Extraction: Data screening, extraction, and quality assessment were performed independently by 2 investigators using the PRISMA and AXIS guidelines. Data Analysis: Of 2496 articles screened, 30 articles, published in English or Spanish, that evaluated the relationship between BI and DHs in adolescents aged between 10 years and 18 years, were included. A relationship between accurate BI perception in adolescents and healthy DHs was reported in 5 articles (16.2%). A relationship between overestimation of body weight in adolescents and healthy DHs was reported in 4 articles (13.3%). A relationship between underestimation of body weight and unhealthy DHs was reported in 8 articles (26.7%). In addition, 4 articles (13.3%) reported a relationship between BIS and healthy DHs. The desire to gain weight was associated with unhealthy DHs in 3 (10%) of the articles, while the desire to lose weight was related to healthy DHs in 3 (10%) of the articles and to unhealthy DHs in 3 (10%) other articles. There were also gender differences in the relationship between BIP or BIS and DHs. Conclusion: Adolescents who underestimate their body weight tend to report less healthy DHs than body weight overestimators. Adolescents unsatisfied with their BI and with a drive for thinness frequently engage in DHs linked to losing weight. Systematic Review Registration: PROSPERO registration no. CRD42020184625

    Alpiste : variaciones en el rendimiento de grano y otras características de interés agronómico ante cambios en la densidad de siembra

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    43-55El efecto de un amplio rango de densidades de siembra sobre el rendimiento de grano en alpiste (Phalaris canariensis L.), sus componentes y otras características de interés agronómico fueron estudiadas en ensayos a campo en Balcarce (Bs. As.) Argentina, durante los años 2004 y 2007. Se utilizó la población argentina de alpiste que fue sembrada teniendo como objetivo el logro de: 100, 300, 600, 900, 1200, 1500, 1800, 2100 y 2400 plantas m-2. El diseño experimental fue en bloques completos aleatorizados con cuatro repeticiones. Los resultados muestran que la densidad de siembra no afectó la fenología del cultivo, ni el peso de las semillas, pero sí se observó una disminución, lineal, de la altura de plantas en la medida que se incrementó el número de plantas. El aumento de la densidad se relacionó negativamente con el número de panojas planta-1 y con el número de semillas panoja-1. Con más de 600 plantas m-2 logradas, el número de panojas planta-1 fue inferior a 1. Por ello, las siembras que aseguren el logro de 300 a 400 plantas m-2 permitirían llegar a antesis con una cobertura foliar de 90 por ciento, 600 a 800 panojas m-2 (dadas por el logro de, por lo menos dos macollos fértiles planta-1) y altos rendimientos de grano (1931 kg ha-1 en el año 2004 y 1312 kg ha-1 en el año 2007)

    Development and validation of a questionnaire to evaluate lifestyle-related behaviors in elementary school children

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    Background: The SI! Program promotes cardiovascular health through a multilevel school-based intervention on four lifestyle-related components: diet, physical activity, understanding the body and heart, and management of emotions. We report here the development and validation of the KAH (knowledge, attitudes and habits)-questionnaire adapted for elementary school children (6-7 years old) as a tool for the forthcoming evaluation of the SI! Program, where the KAH scoring will be the primary outcome. The efficacy of such an intervention will be based on the improvements in children's KAH towards a healthy lifestyle. Methods: The questionnaire validation process started with a pool of items proposed by the pedagogical team who developed the SI! Program for elementary school. The questionnaire was finalized by decreasing the number of items from 155 to 48 using expert panels and statistical tests on the responses from 384 children (ages 6-7). A team of specialized psychologists administered the questionnaire at schools providing standard directions for the final administration. The internal consistency was assessed using Cronbach's a coefficients. Reliability was measured through the split-half method, and problematic items were detected applying the item response theory. Analysis of variance and Tukey's test of additivity were used for multiple comparisons. Results: The final KAH-questionnaire for elementary school children should be administered to children individually by trained staff. The 48 items-questionnaire is divided evenly between the 4 components of the intervention, with an overall Cronbach's a = 0.791 (a = 0.526 for diet, a = 0.537 for physical activity, a = 0.523 for human body and heart, and a = 0.537 for management of emotions). Conclusions: The KAH-questionnaire is a reliable instrument to assess the efficacy of the SI! Program on instilling healthy lifestyle-related behaviors in elementary school children.This work is supported by the SHE Foundation (Foundation for Science, Health and Education) and the Daniel and Nina Carasso Foundation.S

    Microvesicles: ROS scavengers and ROS producers

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    This review analyzes the relationship between microvesicles and reactive oxygen species (ROS). This relationship is bidirectional; on the one hand, the number and content of microvesicles produced by the cells are affected by oxidative stress conditions; on the other hand, microvesicles can directly and/or indirectly modify the ROS content in the extra- as well as the intracellular compartments. In this regard, microvesicles contain a pro-oxidant or antioxidant machinery that may produce or scavenge ROS: direct effect. This mechanism is especially suitable for eliminating ROS in the extracellular compartment. Endothelial microvesicles, in particular, contain a specific and well-developed antioxidant machinery. On the other hand, the molecules included in microvesicles can modify (activate or inhibit) ROS metabolism in their target cells: indirect effect. This can be achieved by the incorporation into the cells of ROS metabolic enzymes included in the microvesicles, or by the regulation of signaling pathways involved in ROS metabolism. Proteins, as well as miRNAs, are involved in this last effect

    Remodeling of the chromatin structure of the facioscapulohumeral muscular dystrophy (FSHD) locus and upregulation of FSHD-related gene 1 (FRG1) expression during human myogenic differentiation

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    <p>Abstract</p> <p>Background</p> <p>Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant neuromuscular disorder associated with the partial deletion of integral numbers of 3.3 kb D4Z4 DNA repeats within the subtelomere of chromosome 4q. A number of candidate FSHD genes, adenine nucleotide translocator 1 gene (<it>ANT1</it>), FSHD-related gene 1 (<it>FRG1</it>), <it>FRG2 </it>and <it>DUX4c</it>, upstream of the D4Z4 array (FSHD locus), and double homeobox chromosome 4 (<it>DUX4</it>) within the repeat itself, are upregulated in some patients, thus suggesting an underlying perturbation of the chromatin structure. Furthermore, a mouse model overexpressing <it>FRG1 </it>has been generated, displaying skeletal muscle defects.</p> <p>Results</p> <p>In the context of myogenic differentiation, we compared the chromatin structure and tridimensional interaction of the D4Z4 array and <it>FRG1 </it>gene promoter, and <it>FRG1 </it>expression, in control and FSHD cells. The <it>FRG1 </it>gene was prematurely expressed during FSHD myoblast differentiation, thus suggesting that the number of D4Z4 repeats in the array may affect the correct timing of <it>FRG1 </it>expression. Using chromosome conformation capture (3C) technology, we revealed that the <it>FRG1 </it>promoter and D4Z4 array physically interacted. Furthermore, this chromatin structure underwent dynamic changes during myogenic differentiation that led to the loosening of the <it>FRG1</it>/4q-D4Z4 array loop in myotubes. The <it>FRG1 </it>promoter in both normal and FSHD myoblasts was characterized by H3K27 trimethylation and Polycomb repressor complex binding, but these repression signs were replaced by H3K4 trimethylation during differentiation. The D4Z4 sequences behaved similarly, with H3K27 trimethylation and Polycomb binding being lost upon myogenic differentiation.</p> <p>Conclusion</p> <p>We propose a model in which the D4Z4 array may play a critical chromatin function as an orchestrator of <it>in cis </it>chromatin loops, thus suggesting that this repeat may play a role in coordinating gene expression.</p

    Performance of Prognostic Scoring Systems in MINOCA: A Comparison among GRACE, TIMI, HEART, and ACEF Scores

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    Background: the prognosis of patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) is not benign; thus, prompting the need to validate prognostic scoring systems for this population. Aim: to evaluate and compare the prognostic performance of GRACE, TIMI, HEART, and ACEF scores in MINOCA patients. Methods: A total of 250 MINOCA patients from January 2017 to September 2021 were included. For each patient, the four scores at admission were retrospectively calculated. The primary outcome was a composite of all-cause death and acute myocardial infarction (AMI) at 1-year follow-up. The ability to predict 1-year all-cause death was also tested. Results: Overall, the tested scores presented a sub-optimal performance in predicting the composite major adverse event in MINOCA patients, showing an AUC ranging between 0.7 and 0.8. Among them, the GRACE score appeared to be the best in predicting all-cause death, reaching high specificity with low sensitivity. The best cut-off identified for the GRACE score was 171, higher compared to the cut-off of 140 generally applied to identify high-risk patients with obstructive AMI. When the scores were tested for prediction of 1-year all-cause death, the GRACE and the ACEF score showed very good accuracy (AUC = 0.932 and 0.828, respectively). Conclusion: the prognostic scoring tools, validated in AMI cohorts, could be useful even in MINOCA patients, although their performance appeared sub-optimal, prompting the need for risk assessment tools specific to MINOCA patients

    Expression Profiling of FSHD-1 and FSHD-2 Cells during Myogenic Differentiation Evidences Common and Distinctive Gene Dysregulation Patterns

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    BACKGROUND: Determine global gene dysregulation affecting 4q-linked (FSHD-1) and non 4q-linked (FSHD-2) cells during early stages of myogenic differentiation. This approach has been never applied to FSHD pathogenesis. METHODOLOGY/PRINCIPAL FINDINGS: By in vitro differentiation of FSHD-1 and FSHD-2 myoblasts and gene chip analysis we derived that gene expression profile is altered only in FSHD-1 myoblasts and FSHD-2 myotubes. The changes seen in FSHD-1 regarded a general defect in cell cycle progression, probably due to the upregulation of myogenic markers PAX3 and MYOD1, and a deficit of factors (SUV39H1 and HMGB2) involved in D4Z4 chromatin conformation. On the other hand, FSHD-2 mytubes were characterized by a general defect in RNA metabolism, protein synthesis and degradation and, to a lesser extent, in cell cycle. Common dysregulations regarded genes involved in response to oxidative stress and in sterol biosynthetic process. Interestingly, our results also suggest that miRNAs might be implied in both FSHD-1 and FSHD-2 gene dysregulation. Finally, in both cell differentiation systems, we did not observe a gradient of altered gene expression throughout the 4q35 chromosome. CONCLUSIONS/SIGNIFICANCE: FSHD-1 and FSHD-2 cells showed, in different steps of myogenic differentiation, a global deregulation of gene expression rather than an alteration of expression of 4q35 specific genes. In general, FSHD-1 and FSHD-2 global gene deregulation interested common and distinctive biological processes. In this regard, defects of cell cycle progression (FSHD-1 and to a lesser extent FSHD-2), protein synthesis and degradation (FSHD-2), response to oxidative stress (FSHD-1 and FSHD-2), and cholesterol homeostasis (FSHD-1 and FSHD-2) may in general impair a correct myogenesis. Taken together our results recapitulate previously reported defects of FSHD-1, and add new insights into the gene deregulation characterizing both FSHD-1 and FSHD-2, in which miRNAs may play a role

    NIPBL: a new player in myeloid cells differentiation

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    NUCLEOPHOSMIN1 (NPM1) is the most frequently mutated gene in acute myeloid leukemia. Notably, NPM1 mutations are always accompanied by additional mutations such as those in cohesin genes RAD21, SMC1A, SMC3, STAG2 but not in the cohesin regulator NIPBL. In this work, we analyze a cohort of adult patients with acute myeloid leukemia and NPM1 mutation and we observe specific reduction in the expression of NIPBL but not in other cohesin genes. In our zebrafish model, the overexpression of the mutated form of NPM1 also induced the down-regulation of nipblb, the zebrafish orthologue of the human NIPBL. To investigate the hematopoietic phenotype and the interaction between mutated NPM1 and nipblb, we generate a zebrafish model with nipblb down-regulation that shows an increased number of myeloid progenitors. This phenotype is due to a hyper activation of the canonical Wnt pathway: the rescue of myeloid cells blocked in an undifferentiated state is possible when the Wnt pathway is inhibited by ddk1b mRNA injection or indomethacin administration. Our results reveal for the first time a role for NIPBL during zebrafish hematopoiesis and suggest that NIPBL/NPM1 interplay may regulate myeloid differentiation in zebrafish and humans through the canonical Wnt pathway and that dysregulation of these interactions may drive to leukemic transformations

    Ovarian dysfunction and FMR1 alleles in a large Italian family with POF and FRAXA disorders: case report

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    BACKGROUND: The association between premature ovarian failure (POF) and the FMR1 repeat number (41> CGG(n)< 200) has been widely investigated. Current findings suggest that the risk estimation for POF can be calculated in the offspring of women with pre-mutated FMR1 alleles. CASE PRESENTATION: We describe the coexistence in a large Italian kindred of Fragile X syndrome and familial POF in females with ovarian dysfunctions who carried normal or expanded FMR1 alleles. Genetic analysis of the FMR1 gene in over three generations of females revealed that six carried pre-mutated alleles (61–200), of which two were also affected by POF. However a young woman, who presented a severe ovarian failure with early onset, carried normal FMR1 alleles (<40). The coexistence within the same family of two dysfunctional ovarian conditions, one FMR1-related and one not FMR1-related, suggests that the complexity of familial POF conditions is larger than expected. CONCLUSION: Our case study represents a helpful observation and will provide familial cases with heterogeneous etiology that could be further studied when candidate genes in addition to the FMR1 premutation will be available
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