9 research outputs found
Controllability of periodic linear systems, the Poincaré sphere, and quasi-affine systems
For periodic linear control systems with bounded control range, an autonomized system is introduced by adding the phase to the state of the system. Here, a unique control set (i.e., a maximal set of approximate controllability) with nonvoid interior exists. It is determined by the spectral subspaces of the homogeneous part which is a periodic linear differential equation. Using the Poincaré sphere, one obtains a compactification of the state space allowing us to describe the behavior “near infinity” of the original control system. Furthermore, an application to quasi-affine systems yields a unique control set with nonvoid interior
Controllability of periodic linear systems, the Poincare sphere, and quasi-affine systems
For periodic linear control systems with bounded control range, an
autonomized system is introduced by adding the phase to the state of the
system. Here a unique control set (i.e., a maximal set of approximate
controllability) with nonvoid interior exists. It is determined by the spectral
subspaces of the homogeneous part which is a periodic linear differential
equation. Using the Poincar\'e sphere one obtains a compactification of the
state space allowing us to describe the behavior near infinity of the original
control system. Furthermore, an application to quasi-affine systems yields a
unique control set with nonvoid interior.Comment: 26 page
Control sets for affine systems, spectral properties, and projective spaces
For affine control systems with bounded control range the control sets, i.e.,
the maximal subsets of complete approximate controllability, are studied using
spectral properties. For hyperbolic systems there is a unique control set with
nonvoid interior and it is bounded. For nonhyperbolic systems, these control
sets are unbounded. In an appropriate compactification of the state space there
is a unique chain control set and the relations to the homogenous part of the
control system are worked out.Comment: corrected version 27 page
Designing bioactive porous titanium interfaces to balance mechanical properties and in vitro cells behavior towards increased osseointegration
Titanium implant failures are mainly related to stress shielding phenomenon and the poor cell interaction with host bone tissue. The development of bioactive and biomimetic Ti scaffolds for bone regeneration remains a challenge which needs the design of Ti implants with enhanced osseointegration. In this context, 4 types of titanium samples were fabricated using conventional powder metallurgy, fully dense, dense etched, porous Ti, and porous etched Ti. Porous samples were manufactured by space holder technique, using ammonium bicarbonate particles as spacer in three different ranges of particle size (100–200 μm, 250–355 μm and 355–500 μm). Substrates were chemically etched by immersion in fluorhydric acid at different times (125 and 625 s) and subsequently, were characterized from a micro-structural, topographical and mechanical point of view. Etched surfaces showed an additional roughness preferentially located inside pores. In vitro tests showed that all substrates were biocompatible (80% of cell viability), confirming cell adhesion of premioblastic cells. Similarly, osteoblast showed similar cell proliferation rates at 4 days, however, higher cell metabolic activity was observed in fully dense and dense etched surfaces at 7 days. In contrast, a significant increase of alkaline phosphatase enzyme expression was observed in porous and porous etched samples compared to control surfaces (dense and dense etched), noticing the suitable surface modification parameters (porosity and roughness) to improve cell differentiation. Furthermore, the presence of pores and rough surfaces of porous Ti substrates remarkably decreased macrophage activation reducing the M1 phenotype polarization as well M1 cell marker expression. Thus, a successful surface modification of porous Ti scaffolds has been performed towards a reduction on stress shielding phenomenon and enhancement of bone osseointegration, achieving a biomechanical and biofunctional equilibrium.Ministry of Economy and Competitiveness of Spain grant MAT2015-71284-PJunta de Andalucía – FEDER (Spain) Project Ref. P12-TEP-140
Control sets for bilinear and affine systems
For homogeneous bilinear control systems, the control sets are characterized
using a Lie algebra rank condition for the induced systems on projective space.
This is based on a classical Diophantine approximation result. For affine
control systems, the control sets around the equilibria for constant controls
are characterized with particular attention to the question when the control
sets are unbounded.Comment: 28 page
Características microbiológicas do suco de laranja in natura Microbiological characteristics of orange juices
Sucos de laranja frescos são amplamente consumidos, devido ao seu sabor agradável e por representar uma importante fonte de vitamina C, minerais e carboidratos. Essas características tornam o suco um meio propício ao desenvolvimento de microrganismos, incluindo patógenos capazes de sobreviver em ambientes ácidos, como E. coli, Salmonella e Listeria monocytogenes. A qualidade microbiológica do suco de laranja pode ser avaliada pela contagem de bactérias mesófilas heterotróficas totais, bactérias ácido-láticas (BAL), bolores e leveduras, coliformes totais e fecais, além da detecção direta de patógenos. Neste trabalho foi realizado o acompanhamento dessas características para 50 amostras de suco fresco de marcas comercializadas no Rio de Janeiro. As amostras foram adquiridas e mantidas sob refrigeração a 4ºC, até o momento das análises. Além das contagens mencionadas, foi realizada a pesquisa de E. coli e Salmonella sp. As contagens de microorganismos mesófilos heterotróficos e BAL, para a maioria das amostras, mostraram-se em níveis elevados. O nível de coliformes fecais em 15% das amostras foi acima do permitido pela legislação. Os perfis de susceptibilidade a antimicrobianos de coliformes isolados estavam dentro do previsto para amostras ambientais ou fecais não submetidas a grande pressão seletiva.<br>Fresh orange juices are very popular as a source of vitamin C, minerals and carbohydrates. However, for the same reasons, they are a suitable environment for the microorganism growth, including pathogens that are able to survive in such conditions, as E. coli, Salmonella and Listeria monocytogenes. To assure the quality of these products, microbiological safety monitoring is needed, through measuring lactic acid bacteria (LAB), moulds and yeasts, total and fecal coliforms and total plate counts. These parameters were monitored for 50 fresh juice samples commercialized in Rio de Janeiro, Brazil. The samples were acquired and maintained under refrigerated conditions. Tests were also made for the detection of E. coli and Salmonella sp. The LAB and total plate counts were, for the most of the samples, higher than the expected. The fecal coliforms levels of 15% of the samples were above those permitted by law. The susceptibility patterns for fecal coliforms isolates were as the expected to environmental or fecal samples that were not under selective pressure
Assistência multiprofissional em unidade de terapia intensiva ao paciente portador de síndrome de Prader-Willi: um enfoque odontológico
A síndrome de Prader-Willi (SPW) é uma doença neurocomportamental genética que afeta o desenvolvimento da criança, resultando em obesidade, estatura reduzida, hipotonia, distúrbios endócrinos e déficit cognitivo que podem comprometer a integridade da cavidade oral. O presente estudo tem como finalidade apresentar um caso de paciente branco, masculino, 15 anos de idade portador da referida síndrome cujo exame clínico intra-oral evidenciou presença de placa bacteriana, gengivite, má-oclusão, salivação viscosa e múltiplas lesões ulceradas em lábio, mucosa jugal, gengiva inserida, dorso e ventre lingual e lesões papulares ulceradas em borda lateral da língua. Após realização de biópsia excisional, foi constatada a presença de lesão herpética em cavidade oral e lesões cutâneas típicas do herpes que foram associadas a possível causa de encefalite herpética. Assim, observou-se que grande parcela dos efeitos deletérios da SPW podem ser amenizados com o diagnóstico correto e intervenções terapêuticas e educacionais precoces, sendo importante a atuação de uma equipe multiprofissional integrada e o desenvolvimento de protocolos assistenciais para melhor manejo dos pacientes portadores da síndrome de Prader-Willi
Assistência multiprofissional em unidade de terapia intensiva ao paciente portador de síndrome de Prader-Willi: um enfoque odontológico
Mosaic human preimplantation embryos and their developmental potential in a prospective, non-selection clinical trial
Chromosome imbalance (aneuploidy) is the major cause of pregnancy loss and congenital disorders in humans. Analyses of small biopsies from human embryos suggest that aneuploidy commonly originates during early divisions, resulting in mosaicism. However, the developmental potential of mosaic embryos remains unclear. We followed the distribution of aneuploid chromosomes across 73 unselected preimplantation embryos and 365 biopsies, sampled from four multifocal trophectoderm (TE) samples and the inner cell mass (ICM). When mosaicism impacted fewer than 50% of cells in one TE biopsy (low-medium mosaicism), only 1% of aneuploidies affected other portions of the embryo. A double-blinded prospective non-selection trial (NCT03673592) showed equivalent live-birth rates and miscarriage rates across 484 euploid, 282 low-grade mosaic, and 131 medium-grade mosaic embryos. No instances of mosaicism or uniparental disomy were detected in the ensuing pregnancies or newborns, and obstetrical and neonatal outcomes were similar between the study groups. Thus, low-medium mosaicism in the trophectoderm mostly arises after TE and ICM differentiation, and such embryos have equivalent developmental potential as fully euploid ones