602 research outputs found
A Systematic Stress Management Program for the Business Setting
Stress is a factor that is dysfunctional to an organization. In people related businesses, it is an important element that must be controlled
Effects of cold-rolling deformation on texture evolution and mechanical properties of Ti-29Nb-9Ta-10Zr alloy
International audienceThe crystallographic texture of Ti-29Nb-9Ta-10Zr alloy is studied after cold-rolling with different amounts of thickness reduction, up to 60%. The major texture components developed during cold-rolling were: γ-fibre components: {111}〈View the MathML source〉, {111}〈View the MathML source〉, {111}〈View the MathML source〉 and {111}〈View the MathML source〉; texture component: {112}〈View the MathML source〉 and texture components: {001}〈View the MathML source〉 and {010}〈001〉. Besides crystallographic texture the resulted mechanical properties were studied by nanoindentation. It was showed that the decrease in Young's modulus after different cold-rolling stages is mainly attributed to the stress-induced α″-Ti phase formation. At 60% cold-rolling thickness reduction obtained an elastic modulus close to 45.29±3.81 GPa, coupled with an average Vickers microhardness close to 279.83±4.28 HV
Urinary clusterin and cystatin B as biomarkers of tubular injury in dogs following envenomation by the European adder
Diagnosing acute kidney injury remains a challenge since the established renal biomarkers, serum creatinine (sCr) and symmetric dimethylarginine (SDMA) reflect glomerular function and not tubular injury. Sensitive tubular markers such as urinary clusterin (uClust) and cystatin B (uCysB) have been proposed to detect AKI at an earlier stage. Since envenomation by the European adder (Vipera berus berus) could serve as a spontaneous disease model of AKI we investigated these new biomarkers in affected dogs. Concentrations of uClust and uCysB as well as sCr and SDMA were analyzed retrospectively in stored samples from 26 dogs with snake envenomation and 13 healthy controls. Higher concentrations of uClust (P <0.012) and uCysB (P <0.001) were observed in the snake-envenomed group. Normalization of uClust and uCysB to urinary creatinine did not alter the results. No differences were observed in sCr and SDMA between the snake-envenomed group and the healthy control group. Spearman rank correlation analysis revealed a strong association of uClust with uCysB in the snake-envenomed dogs (r = 0.75 P <0.001) but not in the healthy controls. The high percentage of snake-envenomed dogs with increased uClust and uCysB concentrations in the absence of increased sCr and SDMA suggests renal tubular injury in the affected dogs. Larger prospective case-controlled studies are warranted to evaluate the clinical utility and prognostic value of these biomarkers.Peer reviewe
When to start antiretroviral therapy: The need for an evidence base during early HIV infection
Background
Strategies for use of antiretroviral therapy (ART) have traditionally focused on providing treatment to persons who stand to benefit immediately from initiating the therapy. There is global consensus that any HIV+ person with CD4 counts less than 350 cells/μl should initiate ART. However, it remains controversial whether ART is indicated in asymptomatic HIV-infected persons with CD4 counts above 350 cells/μl, or whether it is more advisable to defer initiation until the CD4 count has dropped to 350 cells/μl. The question of when the best time is to initiate ART during early HIV infection has always been vigorously debated. The lack of an evidence base from randomized trials, in conjunction with varying degrees of therapeutic aggressiveness and optimism tempered by the risks of drug resistance and side effects, has resulted in divided expert opinion and inconsistencies among treatment guidelines. Discussion
On the basis of recent data showing that early ART initiation reduces heterosexual HIV transmission, some countries are considering adopting a strategy of universal treatment of all HIV+ persons irrespective of their CD4 count and whether ART is of benefit to the individual or not, in order to reduce onward HIV transmission. Since ART has been found to be associated with both short-term and long-term toxicity, defining the benefit:risk ratio is the critical missing link in the discussion on earlier use of ART. For early ART initiation to be justified, this ratio must favor benefit over risk. An unfavorable ratio would argue against using early ART. Summary
There is currently no evidence from randomized controlled trials to suggest that a strategy of initiating ART when the CD4 count is above 350 cells/μl (versus deferring initiation to around 350 cells/μl) results in benefit to the HIV+ person and data from observational studies are inconsistent. Large, clinical endpoint-driven randomized studies to determine the individual health benefits versus risks of earlier ART initiation are sorely needed.
The counter-argument to this debate topic can be freely accessed here:
http://www.biomedcentral.com/1741-7015/11/147 webcite
In vitro bio-functional performances of the novel superelastic beta-type Ti-23Nb-0.7Ta-2Zr-0.5N alloy
International audienceThe materials used for internal fracture fixations and joint replacements are mainly made of metals which still face problems ranging from higher rigidity than that of natural bone to leaching cytotoxic metallic ions. Beta (β)-type titanium alloys with low elastic modulus made from non-toxic and non-allergenic elements are desirable to reduce stress shielding effect and enhance bone remodeling. In this work, a new β-type Ti-23Nb-0.7Ta-2Zr-0.5N alloy with a Young's modulus of approximately 50 GPa was designed and characterized. The behavior of MC3T3-E1 pre-osteoblasts on the new alloy, including adhesion, proliferation and differentiation, was evaluated by examining the cytoskeleton, focal adhesion formation, metabolic activity and extracellular matrix mineralization. Results indicated that the pre-osteoblast cells exhibited a similar degree of attachment and growth on Ti-23Nb-0.7Ta-2Zr-0.5N and Ti-6Al-4V. However, the novel alloy proved to be significantly more efficient in sustaining mineralized matrix deposition upon osteogenic induction of the cells than Ti-6Al-4V control. Further, analysis of RAW 264.7 macrophages cytokine gene and protein expression indicated no significant inflammatory response. Collectively, these findings suggest that the Ti-23Nb-0.7Ta-2Zr-0.5N alloy, which has an increased mechanical biocompatibility with bone, allows a better osteogenic differentiation of osteoblast precursor cells than Ti-6Al-4V and holds great potential for future clinical prosthetic applications
Efeito do ácido giberélico e da nutrição mineral no crescimento de mudas florestais nativas.
A demanda florestal do estado, compreende a uma área anual de colheita de 15 mil ha/ano, e uma área de plantio de cerca de 100 mil ha/ano. Crescente desde 2005, impulsionada pela criação de um pólo florestal mantido por empresas consumidoras de celulose, necessita de alta produção de mudas de qualidade em tempo hábil, havendo contudo, interesse em espécies nativas do cerrado. Gastos com mudas representam 30% do custo de implantação de um reflorestamento, isso se deve ao longo tempo que estas permanecem em viveiro, recebendo tratos culturais especÃficos e onerosos. As árvores nativas têm sido exploradas recentemente, porém um dos desafios é a produção de mudas de qualidade em menor tempo. O uso de uma fertilização adequada à cada espécie, bem como fitormônios que aceleram seu crescimento podem reduzir o tempo de produção e, consequentemente, seu custo, permitindo assim que o plantio de florestas torne-se cada vez mais acessÃvel. Neste experimento objetivou-se avaliar o efeito da aplicação de diferentes soluções nutritivas e giberelina (GA3) no crescimento e desenvolvimento de mudas de cumbarú (Dipterix alata) e canafÃstula (Peltophorum dubium), visando acelerar o crescimento e agregar valor à s mudas de forma que apresentassem melhor adaptação as condições de campo. As sementes foram germinadas em câmara de germinação tipo B.O.D. a 20°C. Posteriormente, as plântulas foram transplantadas para tubetes com substrato PLANTMAX. As mudas serão avaliadas nas caracterÃsticas de altura e diâmetro de colo, peso fresco e peso seco da parte aérea e da raiz. Adotou-se delineamento em blocos ao acaso, com parcelas subdivididas, com 10 tratamentos e 8 repetições, para cada espécie. Os resultados serão submetidos à análise de variância por meio do programa computacional Estat
Holmium Laser for Endoscopic Treatment of Benign Tracheal Stenosis
Introduction Laryngotracheal stenosis is a difficult problem with varied etiology and various treatment options. The holmium laser represents another tool for the treatment of benign tracheal stenosis.
Objectives To determine the utility of holmium laser treatment for benign tracheal stenosis with regards to safety and efficacy.
Methods This was a retrospective case study examining patients with benign tracheal stenosis from 1998–2016 who underwent holmium laser treatment. Determining the safety of this procedure was the primary goal, and complications were monitored as a surrogate of safety.
Results A total of 123 patients who underwent holmium laser treatment for benign tracheal stenosis were identified. In total, 123 patients underwent 476 procedures, with follow-up ranging from 1 month to 14 years. No intraoperative or post-operative complications were identified as a direct result of the use of this particular laser.
Conclusions The holmium laser is an effective and safe laser to use for tracheal stenosis treatment. It is a contact laser with a short acting distance, which reduces the risk of injury to distal airway structures. Given the favorable experience reported here, the holmium laser should be considered when tracheal surgery is attempted
Quasi-Two-Dimensional Dynamics of Plasmas and Fluids
In the lowest order of approximation quasi-twa-dimensional dynamics of planetary atmospheres and of plasmas in a magnetic field can be described by a common convective vortex equation, the Charney and Hasegawa-Mirna (CHM) equation. In contrast to the two-dimensional Navier-Stokes equation, the CHM equation admits "shielded vortex solutions" in a homogeneous limit and linear waves ("Rossby waves" in the planetary atmosphere and "drift waves" in plasmas) in the presence of inhomogeneity. Because of these properties, the nonlinear dynamics described by the CHM equation provide rich solutions which involve turbulent, coherent and wave behaviors. Bringing in non ideal effects such as resistivity makes the plasma equation significantly different from the atmospheric equation with such new effects as instability of the drift wave driven by the resistivity and density gradient. The model equation deviates from the CHM equation and becomes coupled with Maxwell equations. This article reviews the linear and nonlinear dynamics of the quasi-two-dimensional aspect of plasmas and planetary atmosphere starting from the introduction of the ideal model equation (CHM equation) and extending into the most recent progress in plasma turbulence.U. S. Department of Energy DE-FG05-80ET-53088Ministry of Education, Science and Culture of JapanFusion Research Cente
- …