785 research outputs found
Assessing psychache as a suicide risk variable: Data with the Portuguese version of the psychache scale
Several studies have consistently related psychological pain to suicide risk. Psychache,
according to Shneidman's perspective and measured by the Psychache Scale has been confirmed
as an important variable in risk prediction. In the present study, we evaluated psychache
as a construct related to suicide risk using data obtained with the Portuguese
version of the Psychache Scale translated from the original English version. A community
sample of 628 individuals responded to the Portuguese version of the Psychache Scale, the
Suicidal Behavior Questionnaire-Revised, the CES-D Scale, the Beck Hopelessness Scale, and
the Suicide Ideation Questionnaire. Results supported the unidimensional scoring of the
Psychache scale, its ability to differentiate between individuals at-risk for suicide from individuals
not at-risk, its relationship with different, but related, constructs and its ability to
predict suicide ideation
Response of micro- and macrovascular endothelial cells to starch-based fiber meshes for bone tissue engineering
The establishment of a functional vasculature is as yet an unrealized milestone in bone reconstruction therapy. For this study, fibermesh
scaffolds obtained from a blend of starch and poly(caprolactone) (SPCL), that have previously been shown to be an excellent
material for the proliferation and differentiation of bone marrow cells and thereby represent great potential as constructs for bone
regeneration, were examined for endothelial cell (EC) compatibility. To be successfully applied in vivo, this tissue engineered construct
should also be able to support the growth of ECs in order to facilitate vascularization and therefore assure the viability of the construct
upon implantation. The main goal of this study was to examine the interactions between ECs and SPCL fiber meshes. Primary cultures of
HUVEC cells were selected as a model of macrovascular cells and the cell line HPMEC-ST1.6R as a model for microvascular ECs.
Both macro- and microvascular ECs adhered to SPCL fiber-mesh scaffolds and grew to cover much of the available surface area of the
scaffold. In addition, ECs growing on the SPCL fibers exhibited a typical morphology, maintained important functional properties, such
as the expression of the intercellular junction proteins, PECAM-1 and VE-cadherin, the expression of the most typical endothelial
marker vWF and sensitivity to pro-inflammatory stimuli, as shown by induction of the expression of cell adhesion molecules (CAMs) by
lipopolysaccharide (LPS). These data indicate that ECs growing on SPCL fiber-mesh scaffolds maintain a normal expression of ECspecific
genes/proteins, indicating a cell compatibility and potential suitability of these scaffolds for the vascularization process in bone
tissue engineering in vivo
Surface-modified 3D starch-based scaffold for improved endothelialization for bone tissue engineering
Providing adequate vascularization is one of the main hurdles to the widespread clinical application of
bone tissue engineering approaches. Due to their unique role in blood vessel formation, endothelial
cells (EC) play a key role in the establishment of successful vascularization strategies. However,
currently available polymeric materials do not generally support EC growth without coating with
adhesive proteins. In this work we present argon plasma treatment as a suitable method to render the
surface of a 3D starch-based scaffold compatible for ECs, this way obviating the need for protein precoating.
To this end we studied the effect of plasma modification on surface properties, protein
adsorption and ultimately on several aspects regarding EC behaviour. Characterization of surface
properties revealed increased surface roughness and change in topography, while at the chemical level
a higher oxygen content was demonstrated. The increased surface roughness of the material, together
with the changed surface chemistry modulated protein adsorption as indicated by the different
adsorption profile observed for vitronectin. In vitro studies showed that human umbilical vein ECs
(HUVECs) seeded on plasma-modified scaffolds adhered, remained viable, proliferated, and
maintained the typical cobblestone morphology, as observed for positive controls (scaffold pre-coated
with adhesive proteins). Furthermore, genotypic expression of endothelial markers was maintained and
neighbouring cells expressed PECAM-1 at the single-cell-level. These results indicate that Ar plasma
modification is an effective methodology with potential to be incorporated in biomaterial strategies to
promote the formation of vascularized engineered bone
Endothelial cell colonization and angiogenic potential of combined nano- and micro-fibrous scaffolds for bone tissue engineering
Presently the majority of tissue engineering approaches aimed at regenerating bone relies only on postimplantation
vascularization. Strategies that include seeding endothelial cells (ECs) on biomaterials
and promoting their adhesion, migration and functionality might be a solution for the formation of
vascularized bone. Nano/micro-fiber-combined scaffolds have an innovative structure, inspired by
extracellular matrix (ECM) that combines a nano-network, aimed to promote cell adhesion, with
a micro-fiber mesh that provides the mechanical support. In this work we addressed the influence of
this nano-network on growth pattern, morphology, inflammatory expression profile, expression of
structural proteins, homotypic interactions and angiogenic potential of human EC cultured on a scaffold
made of a blend of starch and poly(caprolactone). The nano-network allowed cells to span between
individual micro-fibers and influenced cell morphology. Furthermore, on nano-fibers as well as on
micro-fibers ECs maintained the physiological expression pattern of the structural protein vimentin and
PECAM-1 between adjacent cells. In addition, ECs growing on the nano/micro-fiber-combined scaffold
were sensitive to pro-inflammatory stimulus. Under pro-angiogenic conditions in vitro, the ECM-like
nano-network provided the structural and organizational stability for ECs’ migration and organization
into capillary-like structures. The architecture of nano/micro-fiber-combined scaffolds elicited and
guided the 3D distribution of ECs without compromising the structural requirements for bone
regeneration.M.I. Santos would like to acknowledge the Portuguese Foundation for Science and Technology (FCT) for her PhD scholarship (SFRH/BD/13428/2003). This work was partially supported by FCT through funds from POCTI and/or FEDER programs and by the European Union funded STREP Project HIPPOCRATES (NMP3-CT-2003-505758). This work was carried out under the scope of the European NoE EXPERTISSUES (NMP3-CT-2004-500283)
Does psychache mediate the relationship between general distress and suicide ideation?
This study evaluated whether psychache (i.e., mental pain) mediates the association between general distress, assessed as the frequency and the intensity of psychological symptoms in the previous week, and suicide ideation in community adults. For a sample of 202 adults, psychache fully mediated the relationship between suicide ideation and the frequency of psychological symptoms, and partially mediated the relationship between suicide ideation and the intensity of psychological symptoms. As such, mental pain fully or partially explains the process linking the frequency and the intensity of general distress to suicide ideation and, thus, mental pain is a target for potential intervention
Stress ocupacional e alteração do Estatuto da Carreira Docente português
Este estudo foi realizado com 1162 professores, tendo como objetivo analisar a experiência de stress e a síndrome de “burnout”, antes a após a alteração do Estatuto da Carreira Docente em Portugal. Assim, foram efetuadas duas avaliações em momentos temporais distintos, assumindo-se um plano transversal de recolha de dados (2004/2005, n=689 e 2008/2009, n=473). O protocolo de avaliação incluiu medidas de fontes de stress (Questionário de Stress nos Professores, Gomes, Silva, Mourisco, Mota, & Montenegro, 2006) e de “burnout” (Inventário de “Burnout” de Maslach – Versão para Professores, Maslach, Jackson, & Leiter, 1996; Maslach, Jackson, & Schwab, 1996, Adaptação de Gomes et al., 2006). Os resultados indicaram que a experiência de stress e de “burnout” aumentou entre as duas avaliações, verificando-se em 2008/2009 aumentos em áreas relacionadas com as pressões de tempo/excesso de trabalho e com o trabalho burocrático/administrativo e, inversamente, diminuições em áreas relacionadas com as diferentes capacidades e motivações dos alunos. Quanto à predição da síndrome de “burnout”, não se verificaram alterações substanciais nas variáveis preditoras nos dois momentos. Em síntese, os resultados indicaram aumentos nas exigências profissionais dos professores, mas não se pode afirmar que tal se deva às alterações do Estatuto da Carreira Docente uma vez que não observámos alterações no stress associado à carreira docente.(undefined
Twenty-Four-Hour Central (Aortic) Systolic Blood Pressure: Reference Values and Dipping Patterns in Untreated Individuals.
Central (aortic) systolic blood pressure (cSBP) is the pressure seen by the heart, the brain, and the kidneys. If properly measured, cSBP is closer associated with hypertension-mediated organ damage and prognosis, as compared with brachial SBP (bSBP). We investigated 24-hour profiles of bSBP and cSBP, measured simultaneously using Mobilograph devices, in 2423 untreated adults (1275 women; age, 18-94 years), free from overt cardiovascular disease, aiming to develop reference values and to analyze daytime-nighttime variability. Central SBP was assessed, using brachial waveforms, calibrated with mean arterial pressure (MAP)/diastolic BP (cSBPMAP/DBPcal), or bSBP/diastolic blood pressure (cSBPSBP/DBPcal), and a validated transfer function, resulting in 144 509 valid brachial and 130 804 valid central measurements. Averaged 24-hour, daytime, and nighttime brachial BP across all individuals was 124/79, 126/81, and 116/72 mm Hg, respectively. Averaged 24-hour, daytime, and nighttime values for cSBPMAP/DBPcal were 128, 128, and 125 mm Hg and 115, 117, and 107 mm Hg for cSBPSBP/DBPcal, respectively. We pragmatically propose as upper normal limit for 24-hour cSBPMAP/DBPcal 135 mm Hg and for 24-hour cSBPSBP/DBPcal 120 mm Hg. bSBP dipping (nighttime-daytime/daytime SBP) was -10.6 % in young participants and decreased with increasing age. Central SBPSBP/DBPcal dipping was less pronounced (-8.7% in young participants). In contrast, cSBPMAP/DBPcal dipping was completely absent in the youngest age group and less pronounced in all other participants. These data may serve for comparison in various diseases and have potential implications for refining hypertension diagnosis and management. The different dipping behavior of bSBP versus cSBP requires further investigation
Soluble perlecan domain i enhances vascular endothelial growth factor-165 activity and receptor phosphorylation in human bone marrow endothelial cells
<p>Abstract</p> <p>Background</p> <p>Immobilized recombinant perlecan domain I (PlnDI) binds and modulates the activity of heparin-binding growth factors, <it>in vitro</it>. However, activities for PlnDI, in solution, have not been reported. In this study, we assessed the ability of soluble forms to modulate vascular endothelial growth factor-165 (VEGF<sub>165</sub>) enhanced capillary tube-like formation, and VEGF receptor-2 phosphorylation of human bone marrow endothelial cells, <it>in vitro</it>.</p> <p>Results</p> <p>In solution, PlnDI binds VEGF<sub>165 </sub>in a heparan sulfate and pH dependent manner. Capillary tube-like formation is enhanced by exogenous PlnDI; however, PlnDI/VEGF<sub>165 </sub>mixtures combine to enhance formation beyond that stimulated by either PlnDI or VEGF<sub>165 </sub>alone. PlnDI also stimulates VEGF receptor-2 phosphorylation, and mixtures of PlnDI/VEGF<sub>165 </sub>reduce the time required for peak VEGF receptor-2 phosphorylation (Tyr-951), and increase Akt phosphorylation. PlnDI binds both immobilized neuropilin-1 and VEGF receptor-2, but has a greater affinity for neuropilin-1. PlnDI binding to neuropilin-1, but not to VEGF receptor-2 is dependent upon the heparan sulfate chains adorning PlnDI. Interestingly, the presence of VEGF<sub>165 </sub>but not VEGF<sub>121 </sub>significantly enhances PlnDI binding to Neuropilin-1 and VEGF receptor-2.</p> <p>Conclusions</p> <p>Our observations suggest soluble forms of PlnDI are biologically active. Moreover, PlnDI heparan sulfate chains alone or together with VEGF<sub>165 </sub>can enhance VEGFR-2 signaling and angiogenic events, <it>in vitro</it>. We propose PlnDI liberated during basement membrane or extracellular matrix turnover may have similar activities, <it>in vivo</it>.</p
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.Comment: Major update of previous version. This is the reference document for
LBNE science program and current status. Chapters 1, 3, and 9 provide a
comprehensive overview of LBNE's scientific objectives, its place in the
landscape of neutrino physics worldwide, the technologies it will incorporate
and the capabilities it will possess. 288 pages, 116 figure
Períodos de condicionamento alimentar de juvenis de pirarucu na transição da alimentação de ração úmida para seca
Resumo: O objetivo deste trabalho foi avaliar o efeito de períodos de condicionamento alimentar sobre o desempenho produtivo e a sobrevivência de juvenis de pirarucu (Arapaima gigas), durante a transição da alimentação com massa de peixe moída para dieta formulada seca. Animais com 15,8±1,2 g foram avaliados com substituições graduais da dieta a cada 2, 3, 4 e 5 dias. Após 12 dias de condicionamento alimentar, as substituições a cada dois e três dias proporcionaram as maiores taxas de crescimento específico. Recomenda-se a substituição da dieta à base de peixe moído por dieta formulada seca a cada dois ou três dias
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