228 research outputs found

    A FIXED POINT APPROACH TO STABILITY OF A CUBIC FUNCTIONAL EQUATION IN 2-BANACH SPACES

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    In this paper, we prove a new type of stability and hyperstability results forthe following cubic functional equationf (2x + y) + f (2x - y) = 2f (x + y) + 2f (x - y) + 12f(x)in 2-Banach spaces using fixed point approach

    Synthesis, characterization and antibacterial investigation of silver-copper nanoalloys

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    Cataloged from PDF version of article.Ag-Cu nanoalloys were synthesized by chemical co-reduction of their metal salts in aqueous solution with hydrazine hydrate, in the presence of complexing agent and stabilizer, preventing the oxidation of copper, as revealed by XPS. Their antibacterial behavior was tested against Escherichia coli strains, attesting far better ability of the Ag-Cu compared to Ag-only nanoparticles. © 2011 The Royal Society of Chemistry

    Towards taxane analogues synthesis by dienyne ring closing metathesis

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    Herein we report the facile construction of taxadiene analogues by ring closing metathesis of dienynes built on a cyclohexenone with a natural configuration at C1 and its further transformation to incorporate most of the key functional groups of taxolThis work was supported by the Spanish Ministry of Economy and Competitivity (Mineco) and the ERDF (CTQ2010‐15725, CTQ2013‐43264‐R and CTQ2014‐51912‐REDC), and by the Xunta de Galicia and the ERDF (GPC2013‐039, EM2012/117 and EM2014/011). N. S. thanks Mineco for his FPU contract and S. P.‐E. to the CONACYT for his fellowship (No. 162219). We also thank ORFEO‐CINCA networkNO

    Relative expression of rRNA transcripts and 45S rDNA promoter methylation status are dysregulated in tumors in comparison with matched-normal tissues in breast cancer

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    Ribosomal RNA (rRNA) expression, one of the most important factors regulating ribosome production, is primarily controlled by a CG-rich 45S rDNA promoter. However, the DNA methylation state of the 45S rDNA promoter, as well as its effect on rRNA gene expression in types of human cancers is controversial. In the present study we analyzed the methylation status of the rDNA promoter (-380 to +53 bp) as well as associated rRNA expression levels in breast cancer cell lines and breast tumor-normal tissue pairs. We found that the aforementioned regulatory region was extensively methylated (74-96%) in all cell lines and in 68% (13/19 tumor-normal pairs) of the tumors. Expression levels of rRNA transcripts 18S, 28S, 5.8S and 45S external transcribed spacer (45S ETS) greatly varied in the breast cancer cell lines regardless of their methylation status. Analyses of rRNA transcript expression levels in the breast tumor and normal matched tissues showed no significant difference when normalized with TBP. On the other hand, using the geometric mean of the rRNA expression values (GM-rRNA) as reference enabled us to identify significant changes in the relative expression of rRNAs in the tissue samples. We propose GM-rRNA normalization as a novel strategy to analyze expression differences between rRNA transcripts. Accordingly, the 18S rRNA/GM-rRNA ratio was significantly higher whereas the 5.8S rRNA/GM-rRNA ratio was significantly lower in breast tumor samples than this ratio in the matched normal samples. Moreover, the 18S rRNA/GM-rRNA ratio was negatively correlated with the 45S rDNA promoter methylation level in the normal breast tissue samples, yet not in the breast tumors. Significant correlations observed between the expression levels of rRNA transcripts in the normal samples were lost in the tumor samples. We showed that the expression of rRNA transcripts may not be based solely on promoter methylation. Carcinogenesis may cause dysregulation of the correlation between spliced rRNA expression levels, possibly due to changes in rRNA processing, which requires further investigation

    Polyelectrolyte Bundles

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    Using extensive Molecular Dynamics simulations we study the behavior of polyelectrolytes with hydrophobic side chains, which are known to form cylindrical micelles in aqueous solution. We investigate the stability of such bundles with respect to hydrophobicity, the strength of the electrostatic interaction, and the bundle size. We show that for the parameter range relevant for sulfonated poly-para-phenylenes (PPP) one finds a stable finite bundle size. In a more generic model we also show the influence of the length of the precursor oligomer on the stability of the bundles. We also point out that our model has close similarities to DNA solutions with added condensing agents, hinting to the possibility that the size of DNA aggregates is under certain circumstances thermodynamically limited.Comment: 10 pages, 8 figure

    Synthesis, characterization and antibacterial investigation of silver-copper nanoalloys

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    Ag-Cu nanoalloys were synthesized by chemical co-reduction of their metal salts in aqueous solution with hydrazine hydrate, in the presence of complexing agent and stabilizer, preventing the oxidation of copper, as revealed by XPS. Their antibacterial behavior was tested against Escherichia coli strains, attesting far better ability of the Ag-Cu compared to Ag-only nanoparticles. © 2011 The Royal Society of Chemistry

    Modern Techniques for Memorizing Foreign Words

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    The article describes a comparative experiment studying the efficiency of five popular techniques which improve people's ability to memorize foreign words. The best results were achieved using two techniques: watching English movies with subtitles and writing letters in English

    Diet and Anxiety: A Scoping Review.

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    Anxiety disorders are the most common group of mental disorders. There is mounting evidence demonstrating the importance of nutrition in the development and progression of mental disorders such as depression; however, less is known about the role of nutrition in anxiety disorders. This scoping review sought to systematically map the existing literature on anxiety disorders and nutrition in order to identify associations between dietary factors and anxiety symptoms or disorder prevalence as well as identify gaps and opportunities for further research. The review followed established methodological approaches for scoping reviews. Due to the large volume of results, an online program (Abstrackr) with artificial intelligence features was used. Studies reporting an association between a dietary constituent and anxiety symptoms or disorders were counted and presented in figures. A total of 55,914 unique results were identified. After a full-text review, 1541 articles met criteria for inclusion. Analysis revealed an association between less anxiety and more fruits and vegetables, omega-3 fatty acids, "healthy" dietary patterns, caloric restriction, breakfast consumption, ketogenic diet, broad-spectrum micronutrient supplementation, zinc, magnesium and selenium, probiotics, and a range of phytochemicals. Analysis revealed an association between higher levels of anxiety and high-fat diet, inadequate tryptophan and dietary protein, high intake of sugar and refined carbohydrates, and "unhealthy" dietary patterns. Results are limited by a large percentage of animal and observational studies. Only 10% of intervention studies involved participants with anxiety disorders, limiting the applicability of the findings. High quality intervention studies involving participants with anxiety disorders are warranted

    Does Race Play a Role in Complications and Outcomes of Philadelphia Chromosome-Negative Myeloproliferative Neoplasms?

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    BACKGROUND: Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) are a group of hematologic malignancies with known vascular complications. The role race and ethnicity play in these complications is less defined. We aimed to further evaluate the role of race in patients without a history of previous thrombotic or hemorrhagic events. METHODS: In this retrospective study, 300 adult patients with MPN were included; 270 (90.0%) were White and 30 (10.0%) were non-White. The non-White group primarily consisted of African American or Black (26 patients), followed by others. Median age at diagnosis was 58 years for White patients and 61.5 years for non-White patients. The interaction between outcomes and vascular events with race was evaluated using multivariate logistical regression models. RESULTS: The incidence of thrombotic events was inversely correlated with age at diagnosis, with younger patients demonstrating a higher rate of thrombotic events over time (p < .001). The incidence of thrombotic or hemorrhagic events did not differ between White and non-White patients. A statistically significant difference in median survival was observed between White and non-White patients: 29 years (95% confidence interval [CI]: 21.8-not reached) versus 13 years (95% CI: 5.7-22.7), respectively (p = .016). CONCLUSION: This study did not find a significant difference in the rate of thrombotic or hemorrhagic events between White and non-White patients with MPN but suggested that non-White patients had significantly shorter median survival than White patients. Such observations may inform future studies to further characterize racial disparities in outcomes
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