Mechanical Response of He- Implanted Amorphous SiOC/ Crystalline Fe Nanolaminates

This study investigates the microstructural evolution and mechanical response of sputter-deposited amorphous silicon oxycarbide (SiOC)/crystalline Fe nanolaminates, a single layer SiOC film, and a single layer Fe film subjected to ion implantation at room temperature to obtain a maximum He concentration of 5 at. %. X-ray diffraction and transmission electron microscopy indicated no evidence of implantation-induced phase transformation or layer breakdown in the nanolaminates. Implantation resulted in the formation of He bubbles and an increase in the average size of the Fe grains in the individual Fe layers of the nanolaminates and the single layer Fe film, but the bubble density and grain size were found to be smaller in the former. By reducing the thicknesses of individual layers in the nanolaminates, bubble density and grain size were further decreased. No He bubbles were observed in the SiOC layers of the nanolaminates and the single layer SiOC film. Nanoindentation and scanning probe microscopy revealed an increase in the hardness of both single layer SiOC and Fe films after implantation. For the nanolaminates, changes in hardness were found to depend on the thicknesses of the individual layers, where reducing the layer thickness to 14 nm resulted in mitigation of implantation-induced hardening

Redox signaling, Nox5 and vascular remodeling in hypertension

Purpose of review: Extensive data indicate a role for reactive oxygen species (ROS) and redox signaling in vascular damage in hypertension. However, molecular mechanisms underlying these processes remain unclear, but oxidative post-translational modification of vascular proteins is critical. This review discusses how proteins are oxidatively modified and how redox signaling influences vascular smooth muscle cell growth and vascular remodeling in hypertension. We also highlight Nox5 as a novel vascular ROS-generating oxidase. Recent findings: Oxidative stress in hypertension leads to oxidative imbalance that affects vascular cell function through redox signaling. Many Nox isoforms produce ROS in the vascular wall, and recent findings show that Nox5 may be important in humans. ROS regulate signaling by numerous processes including cysteine oxidative post-translational modification such as S-nitrosylation, S-glutathionylation and sulfydration. In vascular smooth muscle cells, this influences cellular responses to oxidative stimuli promoting changes from a contractile to a proliferative phenotype. Summary: In hypertension, Nox-induced ROS production is increased, leading to perturbed redox signaling through oxidative modifications of vascular proteins. This influences mitogenic signaling and cell cycle regulation, leading to altered cell growth and vascular remodeling in hypertension

Microglia, the missing link in the brain-gut-hypertension axis

No abstract available

Vascular smooth muscle contraction in hypertension

Hypertension is a major risk factor for many common chronic diseases, such as heart failure, myocardial infarction, stroke, vascular dementia and chronic kidney disease. Pathophysiological mechanisms contributing to the development of hypertension include increased vascular resistance, determined in large part by reduced vascular diameter due to increased vascular contraction and arterial remodelling. These processes are regulated by complex interacting systems such as the renin angiotensin aldosterone system (RAAS), sympathetic nervous system, immune activation and oxidative stress, which influence vascular smooth muscle function. Vascular smooth muscle cells are highly plastic and in pathological conditions undergo phenotypic changes from a contractile to a proliferative state. Vascular smooth muscle contraction is triggered by an increase in intracellular free calcium concentration ([Ca2+]i), promoting actin-myosin cross-bridge formation. Growing evidence indicates that contraction is also regulated by calcium-independent mechanisms involving RhoA-Rho kinase (ROCK), protein kinase C (PKC) and mitogen-activated protein kinase (MAPK) signaling, reactive oxygen species and reorganization of the actin cytoskeleton. Activation of immune/inflammatory pathways and noncoding RNAs are also emerging as important regulators of vascular function. Vascular smooth muscle cell [Ca2+]i, not only determines the contractile state but also influences activity of many calcium-dependent transcription factors and proteins thereby impacting the cellular phenotype and function. Perturbations in vascular smooth muscle cell signaling and altered function influence vascular reactivity and tone, important determinants of vascular resistance and blood pressure. Here we discuss mechanisms regulating vascular reactivity and contraction in physiological and pathophysiological conditions and highlight some new advances in the field, focusing specifically on hypertension

Costs of production and willingness to pay for potato produced with a lower amount of agrochemicals. A case study in Argentina

In Argentina, potato growing is carried out at different times of the year and regions. The Southeastern Buenos Aires Province (SEBA) is one of the most important areas. The main destination of the product for fresh consumption is the domestic market, and Spunta is the most commercialized variety. Conventional production is characterized by high cost and intensive use of agrochemicals. Several sectors of the population, concerned about the use of agrochemicals and their effects on health and the environment, are willing to pay a Premium for food produced with a lower environmental impact. This work is focused on analyzing if it is feasible to reduce the costs of production when a lower quantity of agrochemicals is employed, and to evaluate if consumers would be willing to pay a differential price for such product.Fil: Rodríguez, Julieta A. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Lupín, Beatriz. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Lucca, Ana M. F. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina

Assessment of AC Corrosion Probability in Buried Pipelines with a FEM-Assisted Stochastic Approach

In this paper, a stochastic approach is combined with field theory and circuit methods to study how the geometrical and electrical properties of holidays (defects or pores in the insulating coating) in a metallic pipeline influence the probability of exceeding the current density limit for corrosion. Three-dimensional FEM simulations are conducted to assess the influence of the shape and electrical resistivity of the pore on the computed spread resistance value. The obtained results are then used to evaluate the probability of exceeding a given current density value for different sizes of pore and soil resistivities. Finally, a case of 50 Hz interference along a pipeline-transmission line routing is examined. The probabilistic approach presented in this paper allows the pipeline sections more subjected to the induced AC corrosion risk to be identified to be used as an auxiliary tool for adopting preventive protection countermeasures. Lastly, unlike most papers devoted to assessing electromagnetic interference on pipelines, the present work uses a probabilistic rather than a deterministic approach, representing its main novelty aspect

Fault self-defection of automatic testing systems by means of aspect-oriented programming

An Aspect Oriented approach to implement fault detection in automatic measurement systems is proposed. Faults are handled by means of "aspects", a specific software unit to better modularize issues transversal to many modules ("crosscutting concerns"). In this way, maintainability and reusability of a measurement software are improved: indeed, once a modification of the fault detection policy occurs, only the related aspects have to be modified. As an experimental case study, this technique has been applied to the fault self-detection of a flexible framework for magnetic measurements, developed at the European Organization for Nuclear Research (CERN)

Assessment of hygienic conditions of ground pepper (Piper nigrum L.) on the market in São Paulo city, by means of two methodologies for detecting the light filth

Pepper should to be collected, processed, and packed under optimum conditions to avoid the presence of foreign matter. The hygienic conditions of ground pepper marketted in São Paulo city were assessed in determining the presence of foreign matter by means of two extraction methodologies. This study was carried out during a six-month time period from May to September 2006. The occurrence of light impurities was determined either by the flotation technique following the methodology recommended by AOAC or by enzyme – linked immunosorbent assay (ELISA). It was observed that 100% of the examined samples contained insect fragments, and many samples were housing more than one type of foreign matter. Twentytwo percent of samples were unqualified for consumption owing to the occurrence of rodent hairs. For the calibration of ELISA test for quantification of insect contamination level in pepper samples, a range of standard-infested samples was prepared in adding 1, 2, 4, 8 and 10 insects in a control sample to estimate the number of insects in the analyzed samples by measuring optical densities (OD) values with a spectrophotometer. Among the 22 samples, 36.4% of samples presented OD values close to that corresponding to the standard infested with eight insects, 40.9% of samples were comparable to OD of the standard infested with four insects, 18.2% comparable to standard with 10 insects, and 4.5% to the standard with two insects. According to the results observed in the present study, the technique described in AOAC official methods manual was found more suitable for detecting not only the insects but also the additional impurities in analyzed samples, while ELISA is specific to detect myosin from the insect muscle, which undergoes serious degradation with time. Keywords: Pepper, ELISA test , Light filth, AOAC official method