Nonharmonic oscillations of nanosized cantilevers due to quantum-size effects

Using a one-dimensional jellium model and standard beam theory we calculate the spring constant of a vibrating nanowire cantilever. By using the asymptotic energy eigenvalues of the standing electron waves over the nanometer-sized cross-section area, the change in the grand canonical potential is calculated and hence the force and the spring constant. As the wire is bent more electron states fits in its cross section. This has an impact on the spring"constant" which oscillates slightly with the bending of the wire. In this way we obtain an amplitude-dependent resonance frequency of the oscillations that should be detectable.Comment: 6 pages, 5 figure

Social Avoidance in Depression:A Study Using a Social Decision-Making Task

Depression significantly affects interpersonal functioning. Social avoidance may play an important role in depression, limiting opportunities and social skills acquisition, contributing to the maintenance of social difficulties. In the last few years, the need for studying social interactions using interactive tasks has been highlighted. This study investigated social avoidance in unmedicated depressed (n = 26) and matched healthy control (n = 26) participants, using a novel computerized social decision-making task (the TEAM task). In this task, participants choose between a social option (playing in a team with a coplayer) and an individual option (playing alone). Although the social option is more profitable from a material point of view, it can also be challenging because of social comparison and guilt feelings for failing the team. It was found that the higher the rank of the coplayer, the stronger the negative emotions (shame, guilt) reported by participants and the more they opted for the individual option. Depressed participants reported significantly less positive (happiness) and more negative (shame, guilt, disappointment) feelings regarding the task. Importantly, depressed participants chose the individual option significantly more often than controls, which led to lower gains in this group. Furthermore, as the task progressed, controls selected the individual option less often, whereas depressed participants selected the individual option more often. Our findings illustrate the importance of social avoidance in depression and how this behavior can lead to negative consequences. They also highlight the role of social comparison and guilt-related processes in underlying social avoidance in depression. (PsycINFO Database Record (c) 2019 APA, all rights reserved

How effective is tetracaine 4% gel, before a venipuncture, in reducing procedural pain in infants: a randomized double-blind placebo controlled trial

BACKGROUND: Procedural pain relief is sub-optimal in neonates. Topical tetracaine provides pain relief in children. Evidence of its efficacy and safety in neonates is limited. The objective of this study was to assess the efficacy and safety of topical tetracaine on the pain response of neonates during a venipuncture. METHODS: Medically stable infants greater than or equal to 24 weeks gestation, requiring a venipuncture, were included. Following randomization and double blinding, 1.1 g of tetracaine or placebo was applied to the skin for 30 minutes. Participants received oral sucrose if they met local eligibility criteria. The venipuncture was performed according to a standard protocol. A medium effect size in the pain score (corresponding to about 2 point difference in the PIPP score) was considered clinically significant, leading to a sample size of 142 infants, with 80% statistical power. Local skin reactions and immediate adverse cardiorespiratory events were noted. The primary outcome, PIPP score at 1 minute, was analysed using an independent Student's t-test. RESULTS: One hundred and forty two infants were included, 33 +/- 4 weeks gestation, 2100 +/- 900 grams and 6 +/- 3 days of age. There was almost no difference in PIPP scores at 1 minute between groups (mean difference -0.09; 95% confidence interval [CI]: -1.68 to 1.50; P = . 91). Similarly, there were no differences in PIPP scores during the 2(nd), 3(rd )and 4th minute. Duration of cry did not differ between the groups (median difference, 0; 95% CI, -3 to 0; P = . 84). The majority of infants in both groups received sucrose 24%. Sucrose had a significant effect on the PIPP score, as assessed by an ANOVA model (p = 0.0026). Local skin erythema was observed transiently in 11 infants (7 in the tetracaine and 4 in the placebo group). No serious side effect was observed. CONCLUSION: Tetracaine did not significantly decrease procedural pain in infants undergoing a venipuncture, when used in combination with routine sucrose administration

Who do I want in my team: social avoidance of high qualified partners in depression and social anxiety

Background: Social difficulties are inherent to social anxiety and are critical in depression. A key feature in both disorders is social avoidance, which leads to the loss of opportunities and precludes from improving social abilities. The need for studying social functioning using interactive tasks that immerse the subject in a social context has been highlighted. Methods: We developed an interactive task that allows measuring social avoidance. In each round, participants choose between two categories of co-players, with which kind of partner they would like to make a team. In material terms, it is always better to choose the high-category option. However, this maximizes chances for being the worst player in the team, which relates to upward social comparison and guilt. Participants with varied levels of depression and social anxiety symptoms performed this task. Results: The higher the depression and social anxiety symptoms, the more that participants avoided the highcategory partners, the lower the number of points earned and the higher the negative emotions (guilt, nervousness, shame) reported about having to play with a co-player, with this effect becoming more accentuated as the rank of the co-player increased. Limitations: The study sample was restricted to university students and included mostly women. Conclusions: This work provides a tool for studying social avoidance through an interactive set-up and contributes to the understanding of this behavior in mental health

Nonlinear complexity analysis of brain fMRI signals in schizophrenia

Peer reviewedPublisher PD

Analgesia e sedação durante a instalação do cateter central de inserção periférica em neonatos

Objetivou-se caracterizar as estratégias de analgesia e sedação em neonatos submetidos à instalação do cateter central de inserção periférica (CCIP) e relacioná-las ao número de punções venosas, duração do procedimento e posicionamento da ponta do cateter. Estudo transversal com coleta prospectiva de dados, realizado em uma unidade de cuidados intensivos neonatais de um hospital privado na cidade de São Paulo, no período de 31 de agosto de 2010 a 01 de julho de 2011, em que foram avaliadas 254 inserções do CCIP. A adoção de estratégias analgésicas ou sedativas ocorreu em 88 (34,6%) instalações do cateter e não esteve relacionada ao número de punções venosas, duração do procedimento ou posicionamento da ponta do cateter. As estratégias mais frequentes foram a administração endovenosa de midazolam em 47 (18,5%) e fentanil em 19 (7,3%) inserções do cateter. Recomenda-se maior adoção de estratégias analgésicas antes, durante e após o procedimento

Phosphorylation controls autoinhibition of cytoplasmic linker protein-170

Author Posting. © American Society for Cell Biology, 2010. This article is posted here by permission of American Society for Cell Biology for personal use, not for redistribution. The definitive version was published in Molecular Biology of the Cell 21 (2010): 2661-2673, doi:10.1091/mbc.E09-12-1036.Cytoplasmic linker protein (CLIP)-170 is a microtubule (MT) plus-end-tracking protein that regulates MT dynamics and links MT plus ends to different intracellular structures. We have shown previously that intramolecular association between the N and C termini results in autoinhibition of CLIP-170, thus altering its binding to MTs and the dynactin subunit p150Glued (J. Cell Biol. 2004: 166, 1003–1014). In this study, we demonstrate that conformational changes in CLIP-170 are regulated by phosphorylation that enhances the affinity between the N- and C-terminal domains. By using site-directed mutagenesis and phosphoproteomic analysis, we mapped the phosphorylation sites in the third serine-rich region of CLIP-170. A phosphorylation-deficient mutant of CLIP-170 displays an "open" conformation and a higher binding affinity for growing MT ends and p150Glued as compared with nonmutated protein, whereas a phosphomimetic mutant confined to the "folded back" conformation shows decreased MT association and does not interact with p150Glued. We conclude that phosphorylation regulates CLIP-170 conformational changes resulting in its autoinhibition.This work was supported by National Institutes of Health grant GM-25062 (to G.G.B.); Netherlands Organization for Scientific Research grants (to A. A. and N. G.); a Cancer Genomics Centre grant (to J.v.H.); and Presidential Program of Russian Academy of Sciences and RFBP grant 05-04-4915 (to E.S.N.)