920 resultados para Selective grinding
Resumo:
Introduction: The knowledge of dental occlusion should be considered the basic foundation to an excellent orthodontic practice. The patient's diagnose without the centric relation assessment can take the orthodontist to an unpleasant surprises. The use of rectangular archwires requires occlusal contacts been checked to decide what kind of the dental movement will be necessary to achieve the dental equilibrium and mainly to investigate if the movement will be possible. Considering the occlusal surfaces complexity, the occlusal adjustment by selective grinding should be performed during the orthodontic treatment to allow vertical dental movements reducing treatment's time. Occlusal interferences are responsible not only for biomechanics adverse effects, producing undesirable dental movements, but also for potential side effects such as excessive forces (occlusal trauma), leading to roots reabsorption. The occlusal adjustment is a determinant point on dental balance after the end of orthodontics treatments, where each posterior occlusal tooth contacts A and B, or B and C on buccolingual aspect, as well as the stoppers and equalizers contacts on mesiodistal direction must be achieved and well established. The appropriate role of anterior teeth in mandibular movements must be determined, allowing immediate disclusion of posterior teeth, known as anterior guide, and promoting protecting muscle forces to the stomatognathic system. Selective grinding should not be used. in place of well planned and executed orthodontic movement. Aim: The aim of this article is to present the rationale use of occlusal adjustment in Orthodontics.
Resumo:
We examine the nature and extent of statutory executive stock option (ESO) disclosures by Australian listed companies over the 2001 to 2004 period, and the influence of corporate governance mechanisms on these disclosures. Our results show a progressive increase in overall compliance from 2001 to 2004. However, despite the improved compliance, the results reveal managements’ continued reluctance to disclose more sensitive ESO information. Factors associated with good internal governance, including board independence, audit committee independence and effectiveness, and compensation committee independence and effectiveness are found to contribute to improved compliance. Similarly, certain external governance factors are associated with improved disclosure, including external auditor quality, shareholder activism (as proxied by companies identified as poor performers by the Australian Shareholders’ Association), and regulatory intervention.
Resumo:
Carbon nanotubes (CNTs) are expected to become the ideal constituent of many technologes, in particular for future generation electronics. This considerable interest is due to their unique electrical and mechanical properties. They show indeed super-high current-carrying capacity, ballistic electron transport and good field-emission properties. Then, these superior features make CNTs the most promising building blocks for electronic devices, as organic solar cells and organic light emitting devices (OLED). By using Focused Ion Beam (FIB) patterning it is possible to a obtain a high control on position, relative distances and diameter of CNTs. The present work shows how to grow three-dimensional architecture made of vertical-aligned CNTs directly on silicon. Thanks to the higher activity of a pre-patterned surface the synthesis process results very quick, cheap and simple. Such large area growths of CNTs could be used in preliminary test for application as electrodes for organic solar cells.
Resumo:
The effects of exercise and breakfast manipulations on mood and motivation to eat were assessed in 11 healthy females who were regular exercisers and habitual breakfast eaters. The study involved a two by two repeated-measures design, with exercise (or no exercise) and a high-energy breakfast (or low-energy breakfast) as the repeated measures. The exercise or no-exercise session (0800 h) was followed by consumption of the low- or high-energy breakfast (0900 h). An ad libitum lunch test meal was provided 4 hours after the beginning of the exercise session (1200 h). Mood and motivation to eat were continuously tracked from 0800 until 1700 h by an electronic appetite ratings system (EARS). In general, morning subjective mood states (e.g., contentment) were significantly lower in the low-energy breakfast condition, but exercise reversed this effect. Exercise also significantly decreased feelings of lethargy, independent of the breakfast condition. Desire-to-eat and fullness ratings were significantly increased in the low-energy breakfast and high-energy breakfast conditions, respectively. Impairments of mood disappeared in the afternoon after consumption of an ad libitum lunch. In these healthy young adults, the condition inducing the largest energy deficit (exercise and low-energy breakfast) was not associated with the lowest mental states.
Resumo:
The absence of cellular immunity is central to the pathogenesis of herpesvirus-mediated diseases after allogeneic hemopoietic stem cell transplantation (HSCT). For both bone marrow (BM)– and granulocyte-colony stimulating factor–mobilized peripheral blood stem cells (PBSCs) HSCT, donor-derived Epstein-Barr virus (EBV) and cytomegalovirus (CMV) peptide–specific CD8+ T cells clones undergo early expansion and persist long-term, with additional diversification arising from novel antigen-specific clones from donor-derived progenitors. Whether BM or PBSC is the superior source of antiviral CD8+ T cells is unclear. Given that PBSC has largely replaced BM as a source of stem cells for HSCT, it is unlikely that herpesvirus effector T-cell reconstitution will ever be compared prospectively. PBSC grafts contain 10 to 30 times more T cells than BM and a randomized study found proven viral infections were more frequent in BM than PBSC recipients, suggesting viral-specific T-cell immunity is enhanced in PBSC. Recently Moss showed in lung cancer patients that herpesvirus-specific BM-derived CD8+ T cells have unique homing properties relative to herpesvirus-specific CD8+ T cells present in unmobilized peripheral blood (PB). Immunodominant EBV-lytic peptide–specific CD8+ T cells were enriched in BM but were reduced for CMV peptide–specific CD8+ T cells relative to PB. EBV-latent peptide–specific CD8+ T cells were equivalent, which has relevance in the context of posttransplantation lymphoproliferative disorder for which impaired EBV-latent CD8+ T-cell immunity is a risk-factor. A comparison of herpesvirus-specific cellular immunity in PBSC versus PB has yet to be performed.
Resumo:
The effective removal of pollutants using a thermally and chemically stable substrate that has controllable absorption properties is a goal of water treatment. In this study, the surfaces of thin alumina (γ-Al2O3) nanofibres were modified by the grafting either of two organosilane agents, 3-chloro-propyl-triethoxysilane (CPTES) and octyl-triethoxysilane (OTES). These modified materials were then trialed as absorbents for the removal of two herbicides, alachlor and imazaquin from water. The formation of organic groups during the functionalisation process established super hydrophobic sites on the surfaces of the nanofibres. This super hydrophobic group is a kind of protruding adsorption site which facilitates the intimate contact with the pollutants. OTES grafted substrate were shown to be more selective for alachlor while imazaquin selectivity is shown by the CPTES grafted substrate. Kinetics studies revealed that imazaquin was rapidly adsorbed on CPTES-modified surfaces. However, the adsorption of alachlor by OTES grafted surface was achieved more slowly.