Aversive stimulation during the stress-hyporesponsive period does not affect the number of corticotroph cells in neonatal male rats

Immunohistochemistry was used to evaluate the effects of neonatal handling and aversive stimulation during the first 10 days of life on the number of corticotrophs in the anterior lobe of the pituitary of 11-day-old male Wistar rats. Since adult rats handled during infancy respond with reduced corticosterone secretion in response to stressors and with less behavior inhibition in novel environments, we assumed that neonatal stimulation could affect pituitary morphology during this critical period of cell differentiation. Three groups of animals were studied: intact (no manipulation, N = 5), handled (N = 5) and stimulated (submitted to 3 different aversive stimuli, N = 5). The percentage of ACTH-immunoreactive cells in the anterior lobe of the pituitary (number of ACTH-stained cells divided by total number of cells) was determined by examining three slices per pituitary in which a minimum of 200 cells were counted by two independent researchers. Although animals during the neonatal period are less reactive to stress-like stimulation in terms of ACTH and corticosterone secretion, results showed that the relative number of ACTH-stained cells of neonatal handled (0.25 +/- 0.01) and aversive stimulated (0.29 +/- 0.03) rats was not significantly different from intact (0.30 +/- 0.03) animals. Neonatal stimulation may have a differential effect on the various subpopulations of corticotroph cells in the anterior pituitary.     

Topology optimization of piezoelectric macro-fiber composite patches on laminated plates for vibration suppression

Structural and Multidisciplinary Optimization - This work presents a new methodology for the topology optimization of piezoelectric actuators in laminated composite structures with the objective of...     

Intensification of photocatalytic pollutant abatement in microchannel reactor using TiO2 and TiO2‐graphene

A microfluidic device was applied to the photocatalytic degradation of methylene blue as a model pollutant. Titanium dioxide nanoparticles (TiO₂–P25) and a synthesized composite TiO₂‐graphene catalyst were immobilized on the inner walls of a borosilicate glass microfluidic chip. The deposition evolution of the nanoparticles was evaluated by monitoring the optical profile of the system. It was found that a higher initial reaction rate was obtained in the microreactor containing composite catalyst (TiO₂‐GR) on the inner walls, but both systems (TiO₂ and TiO₂‐GR) achieved similar reaction rates when the steady‐state was reached. Decolorization rate of methylene blue in our microfluidic chips was found to be approximately one order of magnitude higher than equivalent macroscopic systems reported in the literature at similar experimental conditions. Additionally, computational simulations were performed to investigate the physics involved in these processes. The model was experimentally validated for further scale‐out studies. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2794–2802, 2016     

Propranolol hydrochloride degradation using La@TiO2 functionalized with CMCD

Propranolol hydrochloride can be considered a persistent and bioaccumulative pharmaceutical in the environment. This drug and its by-products are potentially toxic and have adverse effects, since these compounds have been associated with endocrine-disrupting effects, reproductive deficiencies, embryo abnormalities and pericardial oedema. TiO₂–La 0.05%–carboxymethyl-β-cyclodextrin (CMCD) nanoparticles were successfully prepared by a simple two-step method, which consists of sonification and functionalization. The characterization analyses reveal that lanthanum is dispersed on the semiconductor surface, probably forming Ti–O–La bonds, which can induce oxygen vacancies and surface defects that effectively restrain the recombination of photogenerated electron/holes pairs. The efficiency of TiO₂–La 0.05%–CMCD samples in degradation of propranolol under UV-light irradiation is higher than that of pristine TiO₂ within 20 min reaction, probably due to complex formation between the β-blocker and the oligosaccharide, which allows us to propose a photocatalytic mechanism based on the formation of intermediates and competition of these compounds to the radicals and CMCD cavities.     

Long-lasting effects of neonatal stimulation on the behavior of rats.

The present study aimed to analyze the effects of neonatal stimulation on species-specific behaviors (defensive reactions to a predator and social interactions) in adult male and female rats. Handling and an unpredictable sequence of aversive stimuli were applied to male and female pups from the 1st to the 10th day after delivery; behavioral inhibition, aggression, and sexual behavior were evaluated in adulthood. Results showed that either neonatal handling or aversive stimulation decreased behavioral inhibition in a novel and potentially harmful situation (open field with a predator) in both male and female rats and increased maternal aggressive behavior. Sexual behavior in both males and females decreased, which could affect reproductive capability. The results could cast doubts on the generalization of beneficial effects of neonatal stimulation on the behavior of adult rats. (PsycINFO Database Record (c) 2010 APA, all rights reserved)