890 research outputs found
Relationship of sleep quality and health-related quality of life in adolescents according to self- and proxy ratings: a questionnaire survey
Roeser K, Eichholz R, Schwerdtle B, Schlarb A, Kübler A. Relationship of sleep quality and health-related quality of life in adolescents according to self- and proxy ratings: a questionnaire survey. Front Psychiatry. 2012;3:76:76.Introduction: Sleep disturbances are common in adolescents and adversely affect performance, social contact, and susceptibility to stress. We investigated the hypothesis of a relationship between sleep and health-related quality of life (HRQoL), and applied self- and proxy ratings. Materials and Methods: The sample comprised 92 adolescents aged 11–17 years. All participants and their parents completed a HRQoL measure and the Sleep Disturbance Scale for Children (SDSC). Children with SDSC T-scores above the normal range (above 60) were classified as poor sleepers. Results: According to self- and proxy ratings, good sleepers reported significantly higher HRQoL than poor sleepers. Sleep disturbances were significantly higher and HRQoL significantly lower in self- as compared to parental ratings. Parent-child agreement was higher for subscales measuring observable aspects. Girls experienced significantly stronger sleep disturbances and lower self-rated HRQoL than boys. Discussion: Our findings support the positive relationship of sleep and HRQoL. Furthermore, parents significantly underestimate sleep disturbances and overestimate HRQoL in their children
Rapid Prototyping of 3D Biochips for Cell Motility Studies Using Two-Photon Polymerization
The study of cellular migration dynamics and strategies plays a relevant role in the
understanding of both physiological and pathological processes. An important example
could be the link between cancer cell motility and tumor evolution into metastatic
stage. These strategies can be strongly influenced by the extracellular environment
and the consequent mechanical constrains. In this framework, the possibility to study
the behavior of single cells when subject to specific topological constraints could
be an important tool in the hands of biologists. Two-photon polymerization is a
sub-micrometric additive manufacturing technique that allows the fabrication of 3D
structures in biocompatible resins, enabling the realization of ad hoc biochips for cell
motility analyses, providing different types of mechanical stimuli. In our work, we present
a new strategy for the realization of multilayer microfluidic lab-on-a-chip constructs
for the study of cell motility which guarantees complete optical accessibility and the
possibility to freely shape the migration area, to tailor it to the requirements of the
specific cell type or experiment. The device includes a series of micro-constrictions
that induce different types of mechanical stress on the cells during their migration. We
show the realization of different possible geometries, in order to prove the versatility of
the technique. As a proof of concept, we present the use of one of these devices for the
study of the motility of murine neuronal cancer cells under high physical confinement,
highlighting their peculiar migration mechanisms
Intermediate filaments ensure resiliency of single carcinoma cells, while active contractility of the actin cortex determines their invasive potential
During the epithelial-to-mesenchymal transition, the intracellular cytoskeleton undergoes severe
reorganization which allows epithelial cells to transition into a motile mesenchymal phenotype.
Among the different cytoskeletal elements, the intermediate filaments keratin (in epithelial cells)
and vimentin (in mesenchymal cells) have been demonstrated to be useful and reliable histological
markers. In this study, we assess the potential invasiveness of six human breast carcinoma cell lines
and two mouse fibroblasts cells lines through single cell migration assays in confinement. We find
that the keratin and vimentin networks behave mechanically the same when cells crawl through
narrow channels and that vimentin protein expression does not strongly correlate to single cells
invasiveness. Instead, we find that what determines successful migration through confining spaces
is the ability of cells to mechanically switch from a substrate-dependent stress fibers based
contractility to a substrate-independent cortical contractility, which is not linked to their tumor
phenotype
The Technological Development of Minimally Invasive Spine Surgery
Minimally invasive spine surgery has its roots in the mid-twentieth century with a few surgeons and a few techniques, but it has now developed into a large field of progressive spinal surgery. A wide range of techniques are now called \ minimally invasive,\ and case reports are submitted constantly with new \ minimally invasive\ approaches to spinal pathology. As minimally invasive spine surgery has become more mainstream over the past ten years, in this paper we discuss its history and development. © 2014 Laura A. Snyder et al
O conhecimento tradicional em sementes crioulas: uma experiência vivenciada na terra indígena Guarita.
Resumos do VIII Congresso Brasileiro de Agroecologia - Porto Alegre/RS - 25 a 28/11/2013
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