Search results for " stabilization"
showing 10 items of 84 documents
Effect of two distinct implant macro-designs on the osseointegration of bicortically installed implants in two topographic sites. A histomorphometric…
2019
Antecedentes científicos y objetivos de estudio: El uso de implantes dentales como alternativa para la rehabilitación oral ha demostrado su eficacia y mostrando altas tasas de supervivencia. Un aspecto clave de la osteointegración del implante dental está relacionado con la obtención de una estabilidad primaria adecuada, asegurada por el enclavamiento mecánico entre el tejido óseo y la interfaz del implante, la cual depende en parte de la geometría del implante, la rugosidad de la superficie y la técnica quirúrgica para la preparación del lecho implantario. Varios factores están involucrados en la interacción entre la superficie del implante y el hueso nativo circundante durante la osteoint…
Specific and global regulation of mRNA stability during osmotic stress in Saccharomyces cerevisiae.
2009
Hyperosmotic stress yields reprogramming of gene expression in Saccharomyces cerevisiae cells. Most of this response is orchestrated by Hog1, a stress-activated, mitogen-activated protein kinase (MAPK) homologous to human p38. We investigated, on a genomic scale, the contribution of changes in transcription rates and mRNA stabilities to the modulation of mRNA amounts during the response to osmotic stress in wild-type and hog1 mutant cells. Mild osmotic shock induces a broad mRNA destabilization; however, osmo-mRNAs are up-regulated by increasing both transcription rates and mRNA half-lives. In contrast, mild or severe osmotic stress in hog1 mutants, or severe osmotic stress in wild-type cel…
Delay-dependent exponential stabilization of positive 2D switched state-delayed systems in the Roesser model
2014
This paper deals with the controller synthesis for a class of positive two-dimensional (2D) switched delay systems described by the Roesser model. This kind of systems has the property that the states take nonnegative values whenever the initial boundaries are nonnegative, some delay-dependent sufficient conditions for the exponential stability of positive 2D switched systems with state delays are given. Furthermore, the design of positive state feedback controller under which the resulting closed-loop system meets the requirements of positivity and exponential stability is presented in terms of linear matrix inequalities (LMIs). An example is included to illustrate the effectiveness of the…
Criteria for Laboratory Studies on Fine Soils Treated with Lime
2011
When selecting the appropriate materials for constructing road infrastructures, an important way for minimizing both the economical and environmental impact is to make use of lime for treating those natural soils that, involved in the earthwork for opening road fences, are not suitable, as they are in nature, to fulfill the specific requirements for being used as part of road construction, such as road embankments (including the capping layer) or the improved subgrade or, again, the sub-formation. From this point of view, the treatment of fine soils with lime (if needed, with lime and cement) can be considered as one of the main measures for preserving the natural environment since it fulfi…
On the relations between aromaticity and substituent effect
2019
Aromaticity/aromatic and substituent/substituent effects belong to the most commonly used terms in organic chemistry and related fields. The quantitative description of aromaticity is based on energetic, geometric (e.g., HOMA), magnetic (e.g., NICS) and reactivity criteria, as well as the properties of the electronic structure (e.g., FLU). The substituent effect can be described using either traditional Hammett-type substituent constants or characteristics based on quantum-chemistry. For this purpose, the energies of properly designed homodesmotic reactions and electron density distribution are used. In the first case, a descriptor named SESE (energy stabilizing the substituent effect) is o…
Autonomous frequency stabilization of two extended cavity diode lasers at the potassium wavelength on a sounding rocket
2016
We have developed, assembled, and flight-proven a stable, compact, and autonomous extended cavity diode laser (ECDL) system designed for atomic physics experiments in space. To that end, two micro-integrated ECDLs at 766.7 nm were frequency stabilized during a sounding rocket flight by means of frequency modulation spectroscopy (FMS) of 39^K and offset locking techniques based on the beat note of the two ECDLs. The frequency stabilization as well as additional hard- and software to test hot redundancy mechanisms were implemented as part of a state-machine, which controlled the experiment completely autonomously throughout the entire flight mission.
Wastewater modification processes assessment in a stabilization reservoir.
2008
A semi-empirical mechanistic model able to simulate the dynamics of a stabilization reservoir was developed incorporating both settling of particulate components and chemical/biological processes. Several factors affecting the reservoir effluent quality were taken into account: hydraulics and hydrology, solar radiation, atmospheric reaeration, algae, zooplankton, organic matter, pathogen bacteria, and sediment-water interaction. The model quantifies the specific influence of each factor on effluent quality, evaluating the correlation between the different considered factors. State variables included in the model were: algae, dissolved oxygen, organic matter, zooplankton and indicator bacter…
HSF1-controlled and age-associated chaperone capacity in neurons and muscle cells of C. elegans.
2010
Protein stability under changing conditions is of vital importance for the cell and under the control of a fine-tuned network of molecular chaperones. Aging and age-related neurodegenerative diseases are directly associated with enhanced protein instability. Employing C. elegans expressing GFP-tagged luciferase as a reporter for evaluation of protein stability we show that the chaperoning strategy of body wall muscle cells and neurons is significantly different and that both are differently affected by aging. Muscle cells of young worms are largely resistant to heat stress, which is directly mediated by the stress response controlled through Heat Shock Transcription Factor 1. During recover…
Bone-Healing Pattern on the Surface of Titanium Implants at Cortical and Marrow Compartments in Two Topographic Sites: an Experimental Study in Rabbi…
2018
This study evaluates the bone-healing patterns on the surface of titanium implants at the cortical and marrow compartments of bicortically-installed implants in the diaphysis and metaphysis of rabbit tibiae. In 27 New Zealand rabbits, two implants, one for each macro-design and with equal resorbable blasted media (RBM) implant surfaces, were randomly implanted in the diaphysis or metaphysis of each tibia. The flaps were sutured to allow submerged healing. The animals were sacrificed after two, four, or eight weeks, with nine weeks used for the period of healing. Ground sections were prepared and analyzed. No statistically significant differences were found between the two groups for newly f…
Photo- and thermo- oxidative stabilization of polymer-based nanocomposites through the incorporation of CNTs with in-built antioxidant activity
2017
Antioxidant molecules are physically immobilized onto multi-walled carbon nanotubes (CNTs) surface and the resulting hybrid-nanoparticles are used to prepare Ultra High Molecular Weight PolyEthylene-based nanocomposite with enhanced photo- and thermo- oxidation resistance. Natural phenols derivatives, such as quercetin and α-tocopherol, are known to be an excellent antioxidant for polyethylene, but when they are physically immobilized on CNTs the stabilizing activity strongly increase. This is due to a synergic effect stemming from the physical interaction between the antioxidants and CNTs, which cannot provide a similar stabilizing action if used separately. In particular, it is proposed t…