Antifouling Marine Coatings with a Potentially Safer and Sustainable Synthetic Polyphenolic Derivative

The development of harmless substances to replace biocide-based coatings used to prevent or manage marine biofouling and its unwanted consequences is urgent. The formation of biofilms on submerged marine surfaces is one of the first steps in the marine biofouling process, which facilitates the further settlement of macrofoulers. Anti-biofilm properties of a synthetic polyphenolic compound, with previously described anti-settlement activity against macrofoulers, were explored in this work. In solution this new compound was able to prevent biofilm formation and reduce a pre-formed biofilm produced by the marine bacterium, Pseudoalteromonas tunicata. Then, this compound was applied to a marine coating and the formation of P. tunicata biofilms was assessed under hydrodynamic conditions to mimic the marine environment. For this purpose, polyurethane (PU)-based coating formulations containing 1 and 2 wt.% of the compound were prepared based on a prior developed methodology. The most effective formulation in reducing the biofilm cell number, biovolume, and thickness was the PU-based coating containing an aziridine-based crosslinker and 2 wt.% of the compound. To assess the marine ecotoxicity impact of this compound, its potential to disrupt endocrine processes was evaluated through the modulation of two nuclear receptors (NRs), peroxisome proliferator-activated receptor gamma (PPAR gamma), and pregnane X receptor (PXR). Transcriptional activation of the selected NRs upon exposure to the polyphenolic compound (10 mu M) was not observed, thus highlighting the eco-friendliness towards the addressed NRs of this new dual-acting anti-macro- and anti-microfouling agent towards the addressed NRs

Stereology shows that damaged liver recovers after protein refeeding

Objective: The aim of the present study was to investigate the putative effects of a low-protein diet on the three-dimensional structure of hepatocytes and determine whether this scenario could be reversed by restoring the adequate levels of protein to the diet. Methods: Using design-based stereology, the total number and volume of hepatocytes were estimated in the liver of mice in healthy and altered (by protein malnutrition) conditions and after protein renutrition. Results: This study demonstrated a 65% decrease in the liver volume (3302 mm3 for the control for undernourished versus 1141 mm3 for the undernourished group) accompanied by a 46% reduction in the hepatocyte volume (8223 μm3 for the control for undernourished versus 4475 μm3 for the undernourished group) and a 90% increase in the total number of binucleate hepatocytes (1 549 393 for the control for undernourished versus 2 941 353 for the undernourished group). Reinstating a normoproteinic diet (12% casein) proved to be effective in restoring the size of hepatocytes, leading to an 85% increase in the total number of uninucleate hepatocytes (15 988 560 for the undernourished versus 29 600 520 for the renourished group), and partially reversed the liver atrophy. Conclusions: Awareness of these data will add to a better morphologic understanding of malnutrition-induced hepatopathies and will help clinicians improve the diagnosis and treatment of this condition in humans and in veterinary practice

Digital LED Pixels: Instructions for use and a characterization of their properties

This article details how to control light emitting diodes (LEDs) using an ordinary desktop computer. By combining digitally addressable LEDs with an off-the-shelf microcontroller (Arduino), multiple LEDs can be controlled independently and with a high degree of temporal, chromatic, and luminance precision. The proposed solution is safe (can be powered by a 5-V battery), tested (has been used in published research), inexpensive (∼ $60 +$2 per LED), highly interoperable (can be controlled by any type of computer/operating system via a USB or Bluetooth connection), requires no prior knowledge of electrical engineering (components simply require plugging together), and uses widely available components for which established help forums already exist. Matlab code is provided, including a ‘minimal working example’ of use suitable for use by beginners. Properties of the recommended LEDs are also characterized, including their response time, luminance profile, and color gamut. Based on these, it is shown that the LEDs are highly stable in terms of both luminance and chromaticity, and do not suffer from issues of warm-up, chromatic shift, and slow response times associated with traditional CRT and LCD monitor technology

Os desafios enfrentados pelos iniciantes na prática de enfermagem

O estudo teve o objetivo de investigar os desafios enfrentados pelas enfermeiras no início da profissão. As informações foram obtidas por entrevistas semiestruturadas de 31 profissionais de enfermagem formados entre 2000 a 2004. A análise foi feita pelo software Atlas Ti para análise qualitativa. Os recém-graduados enfrentaram desafios referentes às atividades: a) Relacionamento com a equipe de trabalho; b) Competência e habilidade técnica. Conclui-se que os recém-graduados estão pouco preparados para desempenhar a função de liderar uma equipe de enfermagem, bem como para o cuidado em unidades de alta complexidade. Para enfrentar esses desafios, novas estratégias de ensino e de prática devem ser traçadas de comum acordo entre docentes e enfermeira e enfermeiros atuantes na prática.Este estudio tuvo como objetivo investigar los desafíos enfrentados por las enfermeras en el inicio del ejercicio de su profesión. La recolección de datos fue efectuada a través de encuestas semiestructuradas, realizadas a 31 profesionales de enfermería que obtuvieron su graduación en el periodo de 2000 a 2004. El análisis fue efectuado con el software Atlas Ti para análisis cuantitativo. Los recién graduados enfrentaron desafíos en relación a: a) relación con el resto del equipo de trabajo; b) competencia y habilidad técnica. Se concluye en que los novatos están poco preparados para ejercer la función de liderar un equipo de enfermería y también para la atención en unidades de alta complejidad. Para enfrentar tales desafíos es necesario desarrollar nuevas estrategias de enseñanza y de práctica, en total acuerdo entre los docentes y profesionales con actuación efectiva.The purpose of the study was to investigate the challenges faced by the nurses during the first years of their nursing work. A total of 31 novice nurses were included in the sample that answered a questionnaire with open and closed questions. The data analysis was conducted by using the qualitative software called Atlas Ti. The novice nurses deal with some challenges related to: a) leadership team; b) the competence and technique ability. The findings suggested that the nursing novice is not well prepared for assuming a leadership role as well as for caring in the settings of high-complexity. In order to cope those challenges new strategies of education and nursing practice has to be developed together with nurses educators and nurses practitioners

Human bone marrow mesenchymal stem cells : a systematic reappraisal via the genostem experience

Genostem (acronym for “Adult mesenchymal stem cells engineering for connective tissue disorders. From the bench to the bed side”) has been an European consortium of 30 teams working together on human bone marrow Mesenchymal Stem Cell (MSC) biological properties and repair capacity. Part of Genostem activity has been dedicated to the study of basic issues on undifferentiated MSCs properties and on signalling pathways leading to the differentiation into 3 of the connective tissue lineages, osteoblastic, chondrocytic and tenocytic. We have evidenced that native bone marrow MSCs and stromal cells, forming the niche of hematopoietic stem cells, were the same cellular entity located abluminally from marrow sinus endothelial cells. We have also shown that culture-amplified, clonogenic and highly-proliferative MSCs were bona fide stem cells, sharing with other stem cell types the major attributes of self-renewal and of multipotential priming to the lineages to which they can differentiate (osteoblasts, chondrocytes, adipocytes and vascular smooth muscle cells/pericytes). Extensive transcription profiling and in vitro and in vivo assays were applied to identify genes involved in differentiation. Thus we have described novel factors implicated in osteogenesis (FHL2, ITGA5, Fgf18), chondrogenesis (FOXO1A) and tenogenesis (Smad8). Another part of Genostem activity has been devoted to studies of the repair capacity of MSCs in animal models, a prerequisite for future clinical trials. We have developed novel scaffolds (chitosan, pharmacologically active microcarriers) useful for the repair of both bone and cartilage. Finally and most importantly, we have shown that locally implanted MSCs effectively repair bone, cartilage and tendonWork supported by the European Community (Key action 1.2.4-3 Integrated Project Genostem, contract No 503161)

Single-neuron dynamics in human focal epilepsy

Epileptic seizures are traditionally characterized as the ultimate expression of monolithic, hypersynchronous neuronal activity arising from unbalanced runaway excitation. Here we report the first examination of spike train patterns in large ensembles of single neurons during seizures in persons with epilepsy. Contrary to the traditional view, neuronal spiking activity during seizure initiation and spread was highly heterogeneous, not hypersynchronous, suggesting complex interactions among different neuronal groups even at the spatial scale of small cortical patches. In contrast to earlier stages, seizure termination is a nearly homogenous phenomenon followed by an almost complete cessation of spiking across recorded neuronal ensembles. Notably, even neurons outside the region of seizure onset showed significant changes in activity minutes before the seizure. These findings suggest a revision of current thinking about seizure mechanisms and point to the possibility of seizure prevention based on spiking activity in neocortical neurons