Passivation behaviour of Alloy 31 (UNS N08031) in polluted phosphoric acid at different temperatures

The influence of temperature (20–80 °C) and chloride concentration (0.06–0.42 wt.% KCl) on the electrochemical behaviour of the UNS N08031 was studied in 40 wt.% polluted phosphoric acid solution. Passivation behaviour was investigated by using potentiostatic tests at different potentials. From the linear regions of the log i vs. log t transients, the parameter n was obtained. The results showed that the applied potential hardly affects on the passivation rate n. However, n values decreased when temperature increased. The values of n demonstrated that the passive film formed on Alloy 31 was compact and highly protective.The authors express their gratitude to the MAEC of Spain (PCI Mediterraneo C/8196/07, C/018046/08, D/023608/09 and D/030177/10), to Programa de Apoyo a la Investigacion y Desarrollo de la UPV (PAID-06-09) and to the Generalitat Valenciana (GV/2011/093) for the financial support and to Dr. Asuncion Jaime for her translation assistance.Escrivá Cerdán, C.; Blasco Tamarit, ME.; García García, DM.; García Antón, J.; Guenbour, A. (2012). Passivation behaviour of Alloy 31 (UNS N08031) in polluted phosphoric acid at different temperatures. Corrosion Science. 56:114-122. https://doi.org/10.1016/j.corsci.2011.11.014S1141225

Propofol-Induced Changes in Neurotrophic Signaling in the Developing Nervous System In Vivo

Several studies have revealed a role for neurotrophins in anesthesia-induced neurotoxicity in the developing brain. In this study we monitored the spatial and temporal expression of neurotrophic signaling molecules in the brain of 14-day-old (PND14) Wistar rats after the application of a single propofol dose (25 mg/kg i.p). The structures of interest were the cortex and thalamus as the primary areas of anesthetic actions. Changes of the protein levels of the brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), their activated receptors tropomyosin-related kinase (TrkA and TrkB) and downstream kinases Akt and the extracellular signal regulated kinase (ERK) were assessed by Western immunoblot analysis at different time points during the first 24 h after the treatment, as well as the expression of cleaved caspase-3 fragment. Fluoro-Jade B staining was used to follow the appearance of degenerating neurons. The obtained results show that the treatment caused marked alterations in levels of the examined neurotrophins, their receptors and downstream effector kinases. However, these changes were not associated with increased neurodegeneration in either the cortex or the thalamus. These results indicate that in the brain of PND14 rats, the interaction between Akt/ERK signaling might be one of important part of endogenous defense mechanisms, which the developing brain utilizes to protect itself from potential anesthesia-induced damage. Elucidation of the underlying molecular mechanisms will improve our understanding of the age-dependent component of anesthesia-induced neurotoxicity

Caloric Restriction Suppresses Microglial Activation and Prevents Neuroapoptosis Following Cortical Injury in Rats

Traumatic brain injury (TBI) is a widespread cause of death and a major source of adult disability. Subsequent pathological events occurring in the brain after TBI, referred to as secondary injury, continue to damage surrounding tissue resulting in substantial neuronal loss. One of the hallmarks of the secondary injury process is microglial activation resulting in increased cytokine production. Notwithstanding that recent studies demonstrated that caloric restriction (CR) lasting several months prior to an acute TBI exhibits neuroprotective properties, understanding how exactly CR influences secondary injury is still unclear. The goal of the present study was to examine whether CR (50% of daily food intake for 3 months) alleviates the effects of secondary injury on neuronal loss following cortical stab injury (CSI). To this end, we examined the effects of CR on the microglial activation, tumor necrosis factor-α (TNF-α) and caspase-3 expression in the ipsilateral (injured) cortex of the adult rats during the recovery period (from 2 to 28 days) after injury. Our results demonstrate that CR prior to CSI suppresses microglial activation, induction of TNF-α and caspase-3, as well as neurodegeneration following injury. These results indicate that CR strongly attenuates the effects of secondary injury, thus suggesting that CR may increase the successful outcome following TBI

Translational control of depression-like behavior via phosphorylation of eukaryotic translation initiation factor 4E

Translation of mRNA into protein has a fundamental role in neurodevelopment, plasticity, and memory formation; however, its contribution in the pathophysiology of depressive disorders is not fully understood. We investigated the involvement of MNK1/2 (MAPK-interacting serine/threonine-protein kinase 1 and 2) and their target, eIF4E (eukaryotic initiation factor 4E), in depression-like behavior in mice. Mice carrying a mutation in eIF4E for the MNK1/2 phosphorylation site (Ser209Ala, Eif4e ki/ki), the Mnk1/2 double knockout mice (Mnk1/2 -/-), or mice treated with the MNK1/2 inhibitor, cercosporamide, displayed anxiety-and depression-like behaviors, impaired serotonin-induced excitatory synaptic activity in the prefrontal cortex, and diminished firing of the dorsal raphe neurons. In Eif4e ki/ki mice, brain IκBα, was decreased, while the NF-κB target, TNFα was elevated. TNFα inhibition in Eif4e ki/ki mice rescued, whereas TNFα administration to wild-type mice mimicked the depression-like behaviors and 5-HT synaptic deficits. We conclude that eIF4E phosphorylation modulates depression-like behavior through regulation of inflammatory responses

Dissolution of chromium in sulfuric acid

By combining electrochemical corrosion rate measurements and spectrophotometric analysis of the electrolyte it was shown that at room temperature chromium dissolves in deaerated 0.1 M Na2SO4 + H2SO4 (pH 1) solution as Cr(II) and Cr(III) ions in he ratio Cr(II) : Cr(III) @ 7 : 1. This process was stable over 4 h without any detectable change. The total corrosion rate of chromium calculated from the analytical data is about 12 times higher, than that determined electrochemically by cathodic Tafel line extrapolation to the corrosion potential. This finding was confirmed by applying the weight-loss method for the determination of the corrosion rate. This enormous difference between these experimentally determined corrosion rates can be explained by the rather fast, anomalous dissolution process proposed by Kolotyrkin and coworkers (chemical reaction of Cr with H2O molecules) occurring simultaneously with the electrochemical corrosion process

Phosphorus fertilizers as a source of uranium in Serbian soils

Around 1500 t of mineral fertilizers based on phosphorus are applied per annum in Serbia. It is estimated that around 210 kg of uranium (30 g/ha) are in this way introduced into the environment. Due to this fact there is a risk of exposing local population to ionizing radiation. The purpose of this article was to determine whether long-term application of phosphorus fertilizers causes increase of uranium content in arable soils. These investigations were made using field experiments that were set up on three types of soil, chernozem, smonitza and pseudogley, more than 30 years ago. Same variants of mineral nutrition were used in these experiments and all fields had parcels without application of fertilizers (controls). Soil samples were taken from two soil layers (0–30 cm and 30–60 cm) continuously in a period of five years. Statistical analysis of the results obtained indicates that significant differences exist between the control and application of phosphorus fertilizers in the layer from 0–30 cm, while no such differences were found for the layer from 30–60 cm. Physicochemical soil properties change the process of uranium migration and mobilization. Indeed the fixation of uranium by investigated soil types decreases in the following order: chernozem>smonitza>>pseudogley. Since the natural content of uranium in Serbian soils is in the interval from 0.08 to 5.9 ppm, it can be concluded that the results obtained in this investigation are within natural limits. Indeed, the values obtained for total uranium content in the investigated experimental variants were in the range from 0.65 to 1.94 ppm. This finding is of great value from the aspect of environmental protection and prevention of uranium of anthropogenic origin to be incorporated in food chain

Summary of pros and cons for invertebrate pollinator pan trap and net sampling techniques based on this study.

<p>✓✓ - Ideal;</p><p>✓- suitable;</p><p>X - not suitable</p>1<p>– net sampling usually required and ideal but not sufficient to determine visitor function.</p>2<p>– This can be effectively managed to make it suitable.</p

Species richness per transect of each method for the three sampling trips (average ±SE, n = 24).

<p>The method by trip interaction effect was significant (F_(2,6)  = 33.35, P<0.01) as nets sampled more species in June and November 2010, but not in July 2011 where there was no difference. ***  = <i>P</i><0.001, **  = <i>P</i><0.01, ns  = <i>P</i>>0.05, significance determined with Tukey HSD test.</p

Invertebrate abundance per transect of each method at each site and trip (average ±SE, n = 8).

<p>An interaction effect between method, trip and site was found (F_(4,6)  = 5.66, P<0.05). **  = <i>P</i><0.01, *  = <i>P</i><0.05, ns = <i>P</i>>0.05, significance determined with Tukey HSD test.</p