138 research outputs found
Satisfaction with human resource management practices and turnover intention in a five-star hotel : the mediating role of perceived organizational support
Employeesâ satisfaction with human resources management (HRM) practices has been
envisaged as a solid predictor of turnover; nonetheless, how these practices may influence
employeeâs behavior is still an unclear process. There are suggestions that HRM practices may
be distal determinants of turnover, as their effects may be mediated by more proximal
variables such as perceived organizational support. This study empirically tested a model of
research arising from these theoretical suggestions in a five-star hotel. The data collected
from the survey of 152 workers were subjected to structural equation analyses. The results
showed that the theoretical model had a strong fit to the data, giving empirical support to the
prediction that satisfaction with HRM practices reduces turnover intentions, by increasing
perceived organizational support. The importance of these results is discussed and
interpreted from the point of view of strategic gains associated to the quality of HRM
practices for the management of voluntary turnover.info:eu-repo/semantics/publishedVersio
Multidrug-resistant Pseudomonas aeruginosa: an endemic problem in Brazil
Relatos mundiais tĂȘm documentado a problemĂĄtica da endemicidade de isolados clĂnicos de Pseudomonas aeruginosa multirresistente (MDR) aliada a elevados Ăndices de morbidade/mortalidade. No Brasil, surtos de infecção ocasionados por P. aeruginosa tĂȘm sido relacionados com uma disseminação clonal da espĂ©cie. Atualmente, as opçÔes terapĂȘuticas para o tratamento das infecçÔes causadas por esse microrganismo sĂŁo limitadas, muitas vezes restringindo-se ao uso de carbapenĂȘmicos (p. ex., imipenem [IPM]). Assim, a resistĂȘncia ao IPM Ă© uma questĂŁo de saĂșde pĂșblica, uma vez que esse antibiĂłtico Ă© empregado como Ășltimo recurso no tratamento de infecçÔes de origem hospitalar, causadas por bactĂ©rias Gram-negativas multirresistentes. No Brasil, os principais mecanismos relacionados com fenĂłtipos multirresistentes de P. aeruginosa sĂŁo produção de metalobetalactamase (MBL) do tipo SPM-1, presença de metilase 16S rRNA RmtD, perda de porina OprD e superexpressĂŁo de bombas de efluxo, o que pode explicar os altos Ăndices de resistĂȘncia a carbapenĂȘmicos e aminoglicosĂdeos. A emergĂȘncia de cepas com essas caracterĂsticas Ă© preocupante, tendo em vista a escassez de terapias efetivas no tratamento de infecçÔes por esse patĂłgeno. Finalmente, com base em relatos nacionais, publicados por diferentes grupos de pesquisa, podemos deduzir que a convergĂȘncia de mĂșltiplos mecanismos de resistĂȘncia em P. aeruginosa tem sido um evento favorĂĄvel para a seleção de diferentes clones endĂȘmicos multirresistentes disseminados no Brasil.Global reports have documented the endemicity of multidrug-resistant (MDR) Pseudomonas aeruginosa associated with high levels of morbidity/mortality. In Brazil, outbreaks of MDR P. aeruginosa have been related to clonal dissemination. Currently, therapeutic options for the treatment of these infections are restricted to carbapenemic antibiotics (i.e., imipenem [IPM]). Thus, carbapenem resistance is a public health issue, since carbapenems are considered the last resort to nosocomial infections caused by MDR Gram-negative bacteria. In Brazil, the main mechanisms associated with MDR P. aeruginosa phenotypes are metallo-betalactamase (MBL) production (SPM-1 enzyme), presence of 16S rRNA methylase RmtD, loss of OprD porin, and overexpression of efflux pumps, which may explain the high level of carbapenem and aminoglycoside resistance. Accordingly, the emergence and dissemination of MDR strains is worrisome. Finally, based on national reports published by different groups of investigators, it is deduced that the convergence of multiple mechanisms of P. aeruginosa resistance has played a major role in the selection of endemic MDR clones widespread in Brazil
Enseñanza de quĂmica a alumnos con discapacidad visual
La educaciĂłn formal en Brasil tiene como primer principio la âigualdad de condiciones de acceso y permanencia en la escuelaâ (Brasil, 1996). En este contexto, el proyecto âEnseñanza de QuĂmica a Alumnos con Discapacidad Visualâ busca desarrollar recursos y metodologĂas para una enseñanza de QuĂmica que atienda alumnos con ceguera o baja visiĂłn. En este proyecto, con el objetivo de atender alumnos y profesores de la enseñanza secundaria, iniciamos la adaptaciĂłn del libro âQuĂmica e Sociedadeâ (Santos, Mol y colaboradores, 2005). El trabajo consiste de varias etapas: transcripciĂłn de los textos del libro; descripciĂłn de imĂĄgenes; construcciĂłn de modelos didĂĄcticos; adaptaciĂłn de actividades experimentales
Multidrug-resistant Pseudomonas aeruginosa: an endemic problem in Brazil
Relatos mundiais tĂȘm documentado a problemĂĄtica da endemicidade de isolados clĂnicos de Pseudomonas aeruginosa multirresistente (MDR) aliada a elevados Ăndices de morbidade/mortalidade. No Brasil, surtos de infecção ocasionados por P. aeruginosa tĂȘm sido relacionados com uma disseminação clonal da espĂ©cie. Atualmente, as opçÔes terapĂȘuticas para o tratamento das infecçÔes causadas por esse microrganismo sĂŁo limitadas, muitas vezes restringindo-se ao uso de carbapenĂȘmicos (p. ex., imipenem [IPM]). Assim, a resistĂȘncia ao IPM Ă© uma questĂŁo de saĂșde pĂșblica, uma vez que esse antibiĂłtico Ă© empregado como Ășltimo recurso no tratamento de infecçÔes de origem hospitalar, causadas por bactĂ©rias Gram-negativas multirresistentes. No Brasil, os principais mecanismos relacionados com fenĂłtipos multirresistentes de P. aeruginosa sĂŁo produção de metalobetalactamase (MBL) do tipo SPM-1, presença de metilase 16S rRNA RmtD, perda de porina OprD e superexpressĂŁo de bombas de efluxo, o que pode explicar os altos Ăndices de resistĂȘncia a carbapenĂȘmicos e aminoglicosĂdeos. A emergĂȘncia de cepas com essas caracterĂsticas Ă© preocupante, tendo em vista a escassez de terapias efetivas no tratamento de infecçÔes por esse patĂłgeno. Finalmente, com base em relatos nacionais, publicados por diferentes grupos de pesquisa, podemos deduzir que a convergĂȘncia de mĂșltiplos mecanismos de resistĂȘncia em P. aeruginosa tem sido um evento favorĂĄvel para a seleção de diferentes clones endĂȘmicos multirresistentes disseminados no Brasil474Global reports have documented the endemicity of multidrug-resistant (MDR) Pseudomonas aeruginosa associated with high levels of morbidity/mortality. In Brazil, outbreaks of MDR P. aeruginosa have been related to clonal dissemination. Currently, therapeutic options for the treatment of these infections are restricted to carbapenemic antibiotics (i.e., imipenem [IPM]). Thus, carbapenem resistance is a public health issue, since carbapenems are considered the last resort to nosocomial infections caused by MDR Gram-negative bacteria. In Brazil, the main mechanisms associated with MDR P. aeruginosa phenotypes are metallo-betalactamase (MBL) production (SPM-1 enzyme), presence of 16S rRNA methylase RmtD, loss of OprD porin, and overexpression of efflux pumps, which may explain the high level of carbapenem and aminoglycoside resistance. Accordingly, the emergence and dissemination of MDR strains is worrisome. Finally, based on national reports published by different groups of investigators, it is deduced that the convergence of multiple mechanisms of P. aeruginosa resistance has played a major role in the selection of endemic MDR clones widespread in Brazi
Preliminary evaluation of zeolite-based platforms as potential dual drug delivery systems against microbial infections in the tumor microenvironment
Several zeolite-based delivery systems (ZDS) built with faujasite structure were prepared containing silver (Ag+) and 5-Fluorouracil (5-FU) as antimicrobial and antineoplastic agents, respectively. The idea behind this drug combination is an answer to the increasing evidence of colonization of tumor microenvironments by pathogenic microorganisms and their active role in tumor growth. Two ZDS with a fixed load of 5-FU and different silver loads, Ag7(5-FU).info:eu-repo/semantics/publishedVersio
Characterisation of Films Based on Exopolysaccharides from Alteromonas Strains Isolated from French Polynesia Marine Environments
LA/P/0140/202019
UID/AGR/04129/2020
LA/P/0037/2020This work assessed the film-forming capacity of exopolysaccharides (EPS) produced by six Alteromonas strains recently isolated from different marine environments in French Polynesia atolls. The films were transparent and resulted in small colour alterations when applied over a coloured surface (ÎEab below 12.6 in the five different colours tested). Moreover, scanning electron microscopy showed that the EPS films were dense and compact, with a smooth surface. High water vapour permeabilities were observed (2.7â6.1 Ă 10â11 mol mâ1 sâ1 Paâ1), which are characteristic of hydrophilic polysaccharide films. The films were also characterised in terms of barrier properties to oxygen and carbon dioxide. Interestingly, different behaviours in terms of their mechanical properties under tensile tests were observed: three of the EPS films were ductile with high elongation at break (Δ) (35.6â47.0%), low tensile strength at break (ê) (4.55â11.7 MPa) and low Youngâs modulus (Δm) (10â93 MPa), whereas the other three were stiffer and more resistant with a higher ê (16.6â23.6 MPa), lower Δ (2.80â5.58%), and higher Δm (597â1100 MPa). These properties demonstrate the potential of Alteromonas sp. EPS films to be applied in different areas such as biomedicine, pharmaceuticals, or food packaging.publishersversionpublishe
A protocol to evaluate retinal vascular response using optical coherence tomography angiography
Copyright © 2019 Sousa, Leal, Moreira, do Vale, Silva-Herdade, Aguiar, DionĂsio, AbegĂŁo Pinto, Castanho and Marques-Neves. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these termsIntroduction: Optical coherence tomography angiography (OCT-A) is a novel diagnostic tool with increasing applications in ophthalmology clinics that provides non-invasive high-resolution imaging of the retinal microvasculature. Our aim is to report in detail an experimental protocol for analyzing both vasodilatory and vasoconstriction retinal vascular responses with the available OCT-A technology.
Methods: A commercial OCT-A device was used (AngioVueÂź, Optovue, CA, United States), and all examinations were performed by an experienced technician using the standard protocol for macular examination. Two standardized tests were applied: (i) the hypoxia challenge test (HCT) and (ii) the handgrip test, in order to induce a vasodilatory and vasoconstriction response, respectively. OCT-A was performed at baseline conditions and during the stress test. Macular parafoveal vessel density of the superficial and deep plexuses was assessed from the en face angiograms. Statistical analysis was performed using STATA v14.1 and p < 0.05 was considered for statistical significance.
Results: Twenty-four eyes of 24 healthy subjects (10 male) were studied. Mean age was 31.8 ± 8.2 years (range, 18â57 years). Mean parafoveal vessel density in the superficial plexus increased from 54.7 ± 2.6 in baseline conditions to 56.0 ± 2.0 in hypoxia (p < 0.01). Mean parafoveal vessel density in the deep plexuses also increased, from 60.4 ± 2.2 at baseline to 61.5 ± 2.1 during hypoxia (p < 0.01). The OCT-A during the handgrip test revealed a decrease in vessel density in both superficial (55.5 ± 2.6 to 53.7 ± 2.9, p < 0.001) and deep (60.2 ± 1.8 to 56.7 ± 2.8, p < 0.001) parafoveal plexuses.
Discussion: In this work, we detail a simple, non-invasive, safe, and non-costly protocol to assess a central nervous system vascular response (i.e., the retinal circulation) using OCT-A technology. A vasodilatory response and a vasoconstriction response were observed in two physiologic conditionsâmild hypoxia and isometric exercise, respectively. This protocol constitutes a new way of studying retinal vascular changes that may be applied in health and disease of multiple medical fields.This study was supported by the Faculty of Medicine of the University of Lisbon, AstraZeneca Foundation â 14th Grant.info:eu-repo/semantics/publishedVersio
Retinal vascular reactivity in type 1 diabetes patients without retinopathy using optical coherence tomography angiography
Copyright © 2020 The Authors. This work is licensed under a Creative Commons Attribution-Non-Commercial-No-Derivatives 4.0 International License.Purpose: We hypothesize that patients with type 1 diabetes (T1D) may have abnormal retinal vascular responses before diabetic retinopathy (DR) is clinically evident. Optical coherence tomography angiography (OCTA) was used to dynamically assess the retinal microvasculature of diabetic patients with no clinically visible retinopathy.
Methods: Controlled nonrandomized interventional study. The studied population included 48 eyes of 24 T1D patients and 24 demographically similar healthy volunteers. A commercial OCTA device (AngioVue) was used, and two tests were applied: (1) the hypoxia challenge test (HCT) and (2) the handgrip test to induce a vasodilatory or vasoconstrictive response, respectively. The HCT is a standardized test that creates a mild hypoxic environment equivalent to a flight cabin. The handgrip test (i.e., isometric exercise) induces a sympathetic autonomic response. Changes in the parafoveal superficial and deep capillary plexuses in both tests were compared in each group. Systemic cardiovascular responses were also comparatively evaluated.
Results: In the control cohort, the vessel density of the median parafoveal superficial and deep plexuses increased during hypoxia (F1,23 = 15.69, P < 0.001 and F1,23 = 16.26, P < 0.001, respectively). In the T1D group, this physiological response was not observed in either the superficial or the deep retinal plexuses. Isometric exercise elicited a significant decrease in vessel density in both superficial and deep plexuses in the control group (F1,23 = 27.37, P < 0.0001 and F1,23 = 27.90, P < 0.0001, respectively). In the T1D group, this response was noted only in the deep plexus (F1,23 = 11.04, P < 0.01).
Conclusions: Our work suggests there is an early impairment of the physiological retinal vascular response in patients with T1D without clinical diabetic retinopathy.info:eu-repo/semantics/publishedVersio
Assessment of the suitability of chitosan/polybutylene succinate scaffolds seeded with mouse mesenchymal progenitor cells for a cartilage tissue engineering approach
In this work, scaffolds derived from a new biomaterial originated from the combination of a natural
material and a synthetic material were tested for assessing their suitability for cartilage tissue engineering
applications. In order to obtain a better outcome result in terms of scaffoldsâ overall properties,
different blends of natural and synthetic materials were created. Chitosan and polybutylene succinate (CPBS)
50/50 (wt%) were melt blended using a twin-screw extruder and processed into 5 5 5mm scaffolds
by compression moulding with salt leaching. Micro-computed tomography analysis calculated an
average of 66.29% porosity and 92.78% interconnectivity degree for the presented scaffolds. The salt
particles used ranged in size between 63 and 125 lm, retrieving an average pore size of 251.28 lm.
Regarding the mechanical properties, the compressive modulus was of 1.73 ± 0.4MPa (Esec 1%). Cytotoxicity
evaluation revealed that the leachables released by the developed porous structures were not
harmful to the cells and hence were noncytotoxic. Direct contact assays were carried out using a mouse
bone marrowâderived mesenchymal progenitor cell line (BMC9). Cells were seeded at a density of 5 105
cells/scaffold and allowed to grow for periods up to 3 weeks under chondrogenic differentiating conditions.
Scanning electron microscopy analysis revealed that the cells were able to proliferate and colonize
the scaffold structure, and MTS test demonstrated cell viability during the time of the experiment.
Finally, Western blot performed for collagen type II, a natural cartilage extracellular matrix component,
showed that this protein was being expressed by the end of 3 weeks, which seems to indicate that the
BMC9 cells were being differentiated toward the chondrogenic pathway. These results indicate the
adequacy of these newly developed C-PBS scaffolds for supporting cell growth and differentiation toward
the chondrogenic pathway, suggesting that they should be considered for further studies in the cartilage
tissue engineering field.J. T. Oliveira would like to acknowledge the grant (SFRH/ BD17135/2004) from Portuguese Foundation for Science and Technology (FCT). The authors would like to thank Fernanda Marques, at the Institute for Health and Life Sciences (ICVS), University of Minho, Braga, Portugal, for her help with the Western blot analysis, as well as the staff at ICVS for allowing to use their facilities. The monoclonal antibody for collagen type II was obtained from the Developmental Studies Hybridoma Bank developed under the auspices of the NICHD and maintained by the Department of Biological Sciences, University of Iowa (Iowa City, IA). This work was carried out under the scope of the European NoE EXPERTISSUES (NMP3-CT-2004-500283), and partially supported by the European Project GENOSTEM (LSHB-CT-2003-503161) and the FCT Project CartiScaff (POCTI/SAU-BMA/58991/2004)
- âŠ