20 research outputs found
Análise comparativa de revestimento de fachada: estudo de caso de substituição do revestimento cerâmico aderido por revestimento de acm em fachada ventilada em um edifício / Comparative analysis of facade coating: case study of replacement of ceramic coating adhered by acm coating on ventilated facade in a building
De modo geral, estamos vendo no Brasil uma evolução e busca por inovação nas técnicas construtivas. Buscando-se por materiais mais sustentáveis, eficientes e com maior durabilidade. Dada a importância da fachada de uma edificação, é fundamental que se dê bastante atenção a ela na hora de projetar uma construção nova, ou realizar uma reforma. O revestimento cerâmico aderido de fachada pode apresentar problemas muito precocemente, e com isso surge a necessidade da implementação de novas tecnologias construtivas que melhorem o desempenho e eleve a vida útil dos revestimentos de fachadas. A fachada ventilada é uma dessas novas tecnologias no Brasil. O princípio fundamental das fachadas ventiladas é seu sistema de juntas abertas, que permite que o espaço entre as placas não receba vedação completa nas aberturas inferiores e superiores, possibilitando, assim, a criação da lâmina de ar na cavidade entre as duas paredes. Dentre os materiais que podem ser aplicados em fachada ventilada, destaca-se o ACM, além de versátil e bonito, é um produto muito seguro. Nesse artigo objetivou-se comparar os custos da substituição de todo o revestimento cerâmico aderido mantendo-se o mesmo sistema, e comparando-o com a possibilidade de ter-se optado por fachada ventilada em ACM, em um edifício.
KCTD12 Auxiliary Proteins Modulate Kinetics of GABAB Receptor-Mediated Inhibition in Cholecystokinin-Containing Interneurons
Cholecystokinin-expressing interneurons (CCK-INs) mediate behavior state-dependent inhibition in cortical circuits and themselves receive strong GABAergic input. However, it remains unclear to what extent GABAB receptors (GABABRs) contribute to their inhibitory control. Using immunoelectron microscopy, we found that CCK-INs in the rat hippocampus possessed high levels of dendritic GABABRs and KCTD12 auxiliary proteins, whereas postsynaptic effector Kir3 channels were present at lower levels. Consistently, whole-cell recordings revealed slow GABABR-mediated inhibitory postsynaptic currents (IPSCs) in most CCK-INs. In spite of the higher surface density of GABABRs in CCK-INs than in CA1 principal cells, the amplitudes of IPSCs were comparable, suggesting that the expression of Kir3 channels is the limiting factor for the GABABR currents in these INs. Morphological analysis showed that CCK-INs were diverse, comprising perisomatic-targeting basket cells (BCs), as well as dendrite-targeting (DT) interneurons, including a previously undescribed DT type. GABABR-mediated IPSCs in CCK-INs were large in BCs, but small in DT subtypes. In response to prolonged activation, GABABR-mediated currents displayed strong desensitization, which was absent in KCTD12-deficient mice. This study highlights that GABABRs differentially control CCK-IN subtypes, and the kinetics and desensitization of GABABR-mediated currents are modulated by KCTD12 proteins
Differential surface density and modulatory effects of presynaptic GABAB receptors in hippocampal cholecystokinin and parvalbumin basket cells
Irritability in youth: A critical integrative review
Irritability, defined as proneness to anger that may reach an impairing extent, is common in youth. There has been a recent upsurge in relevant research. We combine systematic and narrative review approaches to integrate the latest clinical and translational findings and provide suggestions to address research gaps.
Clinicians and researchers should assess irritability routinely; specific assessment tools are now available. Informant effects are prominent, stable, and vary by age and gender. The prevalence of irritability is particularly high in attention deficit hyperactivity disorder, autism spectrum disorder, and mood and anxiety disorders. Irritability is associated with impairment and suicidality risk independent of co-occurring diagnoses.
Irritability trajectories have been identified that are differentially associated with clinical outcomes; some begin early in life. Youth irritability is associated with increased risk later in life for anxiety, depression, behavioral problems, and suicidality. Irritability is moderately heritable and genetic associations differ based on age and comorbid illnesses. Parent management training is effective for constructs related to irritability, but its efficacy in irritability should be tested rigorously, as should novel mechanism-informed interventions (e.g., those targeted to frustration exposure).
Associations between irritability and suicidality and the impact of cultural context are important, under-researched topics. Large, diverse, longitudinal samples that extend into adulthood are needed. Data from both animal and human research indicate that aberrant responses to frustration and threat are central to the pathophysiology of irritability, thus affording important translational opportunities
Stem- and progenitor cell proliferation in the dentate gyrus of the reeler mouse.
Adult hippocampal neurogenesis has been implicated in hippocampus-dependent learning and memory. Furthermore, the decline of neurogenesis accompanying aging could be involved in age-related cognitive deficits. It is believed that the neural stem cell niche comprises a specialized microenvironment regulating stem cell activation and maintenance. However, little is known about the significance of the extracellular matrix in controlling adult stem cells. Reelin is a large glycoprotein of the extracelluar matrix known to be of crucial importance for neuronal migration. Here, we examined the local interrelation between Reelin expressing interneurons and putative hippocampal stem cells and investigated the effects of Reelin deficiency on stem cell and progenitor cell proliferation. Reelin-positive cells are found in close vicinity to putative stem cell processes, which would allow for stem cell regulation by Reelin. We investigated the proliferation of stem cells in the Reelin-deficient reeler hippocampus by Ki67 labeling and found a strong reduction of mitotic cells. A detailed analysis of dividing Type 1, type 2 and type 3 cells indicated that once a stem cell is recruited for proliferation, the progression to the next progenitor stage as well as the number of mitotic cycles is not altered in reeler. Our data point to a role for Reelin in either regulating stem cell quiescence or maintenance
A Close proximity between a Reelin+ interneuron (red) and a GFAP+ putative stem cell (green) in the SGZ of a wild-type mice.
<p><b>B</b> Example of close apposition of GFAP+ glial processes and a Reelin+ dendrite as revealed by electron microscopic double immunolabeling. Reelin labeling is visualized by DAB precipitate (yellow overlay), GFAP by gold particles (arrows). Scale bar in A: 10 μm, in B: 0.2 μm. GCL: granule cell layer, SGZ: subgranular zone.</p
Reduced proliferation in reeler hippocampus.
<p><b>A, B</b> show an example of Ki67+ mitotic cells (red, arrows) of the hippocampal dentate gyrus in a wild-type mouse (A) and a reeler mouse (B). Additional labeling of young DCX+ (green) neurons reveals the structural disorganization in <i>reeler</i>. <b>C</b> Quantification of Ki67+ cells. There are significantly reduced numbers of mitotic cells in the <i>reeler</i> dentate gyrus. Mean values + SEM are given, *** p < 0.001. Scale bar: 50 μm. wt: wild-type, GCL: granule cell layer, SGZ: subgranular zone, H: hilus.</p
Type 1, type 2 and type 3 cells undergoing mitosis.
<p><b>A-C</b> show an example of a Nestin+/GFAP+/Ki67+ type 1 cell in the control dentate gyrus (arrow: Ki67, blue), <b>D-F</b> in the <i>reeler</i> dentate gyrus (arrow: Ki67). In D-F additionally a Nestin+/GFAP−/Ki67+ is labelled (short arrow). <b>G-I</b> display a DCX+/Nestin−/Ki67+ type 3 cell (arrow) in a wild-type animal, <b>J-L</b> in <i>reeler</i>. In <b>G-I</b> an additional DCX-/Nestin+/Ki67+, presumptive type 1 cell is present (short arrow). <b>M, N</b> Quantified cell fractions among all mitotic cells in the dentate gyrus for the two triple-staining experiments performed. <b>O</b> Incidence of Ki67+ cluster size in control and <i>reeler</i> dentate gyrus. In control animals cell clusters often consisted of only three cells, whereas clusters in <i>reeler</i> contained significantly more, often five cells. Data are represented by mean values; * p < 0.05, *** p < 0.0001. Scale bars: 10 μm.</p