Evaluation of mineral content of enamel prepared by erbium, chromium:yttrium–scandium–gallium–garnet laser

The aim of this study was to evaluate the mineral content of enamel etched at two different power settings with an erbium, chromium:yttrium–scandium–gallium–garnet (Er,Cr:YSGG) laser. Buccal, lingual and mesial or distal surfaces of five premolar teeth were cut, and three enamel slabs were obtained from each tooth. Fifteen enamel specimens were divided into three groups (1 W, 2 W and control) of five specimens each and subjected to Er,Cr:YSGG laser. The mean percentage weights of the five elements [calcium (Ca), potassium (K), magnesium (Mg), sodium (Na) and phosphorus (P)] in each slab were measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). One way analysis of variance (ANOVA) was used to analyze differences among the groups (1 W, 2 W and control). There were no significant differences among the groups (1 W, 2 W and control) for Ca, K, Mg, Na, or P, or for the Ca/P ratio (P > 0.05). Scanning electron microscopy (SEM) photographs indicated that the surface irregularities increased with increased power setting. Laser treatment did not affect the mean percentage weights of Ca, K, Mg, Na, and P, or the Ca/P ratio, in any group.     

Neuronal SIRT1 regulates endocrine and behavioral responses to calorie restriction

Mammalian life span can be extended by both calorie restriction (CR) and mutations that diminish somatotropic signaling. Sirt1 is a mediator of many effects of CR in mammals, but any role in controlling somatotropic signaling has not been shown. Since the somatotropic axis is controlled by the brain, we created mice lacking Sirt1 specifically in the brain and examined the impacts of this manipulation on somatotropic signaling and the CR response. These mutant mice displayed defects in somatotropic signaling when fed ad libitum, and defects in the endocrine and behavioral responses to CR. We conclude that Sirt1 in the brain is a link between somatotropic signaling and CR in mammals.     

Anatomical and histological morphometry of the sural nerve in human fetuses

Introduction

In our study, the aim was to anatomically and histologically investigate the morphometric structures of the branches involved in the sural nerve and sural nerve formation.

Attachment and coping as facilitators of posttraumatic growth in Turkish university students experiencing traumatic events

This study was designed to explore the role of attachment and coping as facilitators of posttraumatic growth (PTG) in a sample of Turkish university students who experienced traumatic life events. Participants who reported a traumatic event from a list were asked to choose the most distressing one; to answer questions related to the impact of the trauma; and to fill out measures of attachment styles, ways of coping, and PTG. PTG was regressed on gender, trauma-related factors, attachment styles, and coping styles in order to examine the associations with PTG. Felt helplessness and horror, fatalistic coping, and optimistic coping were significant predictors of PTG. Fatalistic coping partially mediated the relationship between attachment anxiety and PTG.     

Resorufin Enters the Photodynamic Therapy Arena: A Monoamine Oxidase Activatable Agent for Selective Cytotoxicity

A red-absorbing, water-soluble, and iodinated resorufin derivative (R1) that can be selectively activated with a monoamine oxidase (MAO) enzyme was synthesized, and its potential as a photodynamic therapy (PDT) agent was evaluated. R1 showed high ¹O₂ generation yields in aqueous solutions upon addition of MAO isoforms, and it was further tested in cell culture studies. R1 induced photocytotoxicity after being triggered by endogenous MAO enzyme in cancer cells with a much higher efficiency in SH-SY5Y neuroblastoma cells with high MAO-A expression. Additionally, R1 displayed differential cytotoxicity between cancer and normal cells, without any considerable dark toxicity. To the best of our knowledge, R1 marks the first example of a resorufin-based photosensitizer (PS) as well as the first anticancer drug that is activated by a MAO enzyme. Remarkably, the target PDT agent was obtained only in three steps as a result of versatile resorufin chemistry.     

SiO2 Nanoparticule-induced size-dependent genotoxicity – an in vitro study using sister chromatid exchange,micronucleus and comet assay

Fine particles with a characteristic size smaller than 100?nm (i.e. nanoparticlesspread out in nowadays life. Silicon or Si, is one of the most abundant chemical elements found on the Earth. Its oxide forms, such as silicate (SiO₄) and silicon dioxide, also known as silica (SiO₂), are the main constituents of sand and quartz contributing to 90% of the Earth's crust. In this work, three genotoxicity systems “sister chromatid exchange, cytokinesis block micronucleus test and single cell gel electrophoresis (comet) assay” were employed to provide further insight into the cytotoxic and mutagenic/genotoxic potential of SiO₂ nanoparticules (particle size 6?nm, 20?nm, 50?nm) in cultured peripheral blood lymphocytes as in vitro. It was observed that there is a significant decrease in Mitotic index (MI), Cytokinesis block proliferation index (CBPI), proliferation index (PRI) values expressed as Cell Kinetic parameters compared with negative control (p?2 (6?nm, 20?nm, 50?nm) (p?p?p?2 nanoparticles at different size (6, 20, 50?nm) progressively increased the SCE frequency and DNA damage on the basis the AU values compared with negative control (p?2 nanoparticules is dependent to particule size.