7 research outputs found

    pH-Induced transformation of ligated Au 25 to brighter Au 23 nanoclusters

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    Thiolate-protected gold nanoclusters have recently attracted considerable attention due to their size-dependent luminescence characterized by a long lifetime and large Stokes shift. However, the optimization of nanocluster properties such as the luminescence quantum yield is still a challenge. We report here the transformation of Au25Capt18 (Capt labels captopril) nanoclusters occurring at low pH and yielding a product with a much increased luminescence quantum yield which we have identified as Au23Capt17. We applied a simple method of treatment with HCl to accomplish this transformation and we characterized the absorption and emission of the newly created ligated nanoclusters as well as their morphology. Based on DFT calculations we show which Au nanocluster size transformations can lead to highly luminescent species such as Au23Capt17

    Measurement of psychological entitlement in 28 countries

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    This article presents the cross-cultural validation of the Entitlement Attitudes Questionnaire, a tool designed to measure three facets of psychological entitlement: active, passive, and revenge entitlement. Active entitlement was defined as the tendency to protect individual rights based on self-worthiness. Passive entitlement was defined as the belief in obligations to and expectations toward other people and institutions for the fulfillment of the individual’s needs. Revenge entitlement was defined as the tendency to protect one’s individual rights when violated by others and the tendency to reciprocate insults. The 15-item EAQ was validated in a series of three studies: the first one on a general Polish sample (N = 1,900), the second one on a sample of Polish students (N = 199), and the third one on student samples from 28 countries (N = 5,979). A three-factor solution was confirmed across all samples. Examination of measurement equivalence indicated partial metric invariance of EAQ for all national samples. Discriminant and convergent validity of the EAQ was also confirmed

    Vitamin D status and its relation to exercise performance and iron status in young ice hockey players

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    <div><p>Objectives</p><p>The aim was to examine the association between serum vitamin D concentration and isometric strength of various muscle groups, vertical jump performance, and repeated sprint ability in young ice hockey players. The secondary aim was to determine the association between vitamin D deficiency and indices of iron status.</p><p>Methods</p><p>Fifty male ice hockey players (17.2±0.9 years) participated in this cross-sectional study. Exercise performance was evaluated using isometric strength measures of upper and lower extremities, vertical jump performance and repeated sprint ability (RSA). Blood samples were collected for the determination of serum 25-hydroxyvitamin D (25(OH)D) and multiple indicies of iron status.</p><p>Results</p><p>The mean serum 25(OH)D concentration was 30.4 ng·ml<sup>-1</sup> and ranged from 12.5 to 91.4 ng·ml<sup>-1</sup>. Eleven participants (22%) had vitamin D deficiency and 20 athletes (40%) had vitamin D insufficiency. Serum 25(OH)D concentration was not positively correlated with isometric muscle strength, vertical jump performance, or RSA after adjusting for age, training experience, fat mass, fat free mass and height. Serum 25(OH)D concentration was not associated with indices of iron status.</p><p>Conclusion</p><p>Vitamin D insufficiency is highly prevalent in ice hockey players, but 25(OH)D concentration but it is not associated with exercise performance or indices of iron status.</p></div

    Identification and Characterization of Dual Inhibitors of the USP25/ 28 Deubiquitinating Enzyme Subfamily

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    The ubiquitin proteasome system is widely postulated to be a new and important field of drug discovery for the future, with the ubiquitin specific proteases (USPs) representing one of the more attractive target classes within the area. Many USPs have been linked to critical axes for therapeutic intervention, and the finding that USP28 is required for c-Myc stability suggests that USP28 inhibition may represent a novel approach to targeting this so far undruggable oncogene. Here, we describe the discovery of the first reported inhibitors of USP28, which we demonstrate are able to bind to and inhibit USP28, and while displaying a dual activity against the closest homologue USP25, these inhibitors show a high degree of selectivity over other deubiquitinases (DUBs). The utility of these compounds as valuable probes to investigate and further explore cellular DUB biology is highlighted by the demonstration of target engagement against both USP25 and USP28 in cells. Furthermore, we demonstrate that these inhibitors are able to elicit modulation of both the total levels and the half-life of the c-Myc oncoprotein in cells and also induce apoptosis and loss of cell viability in a range of cancer cell lines. We however observed a narrow therapeutic index compared to a panel of tissue-matched normal cell lines. Thus, it is hoped that these probes and data presented herein will further advance our understanding of the biology and tractability of DUBs as potential future therapeutic targets
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