In-situ thermally-reduced graphene oxide/epoxy composites: thermal and mechanical properties

Graphene has excellent mechanical, thermal, optical and electrical properties and this has made it a prime target for use as a filler material in the development of multifunctional polymeric composites. However, several challenges need to be overcome in order to take full advantage of the aforementioned properties of graphene. These include achieving good dispersion and interfacial properties between the graphene filler and the polymeric matrix. In the present work we report the thermal and mechanical properties of reduced graphene oxide/epoxy composites prepared via a facile, scalable and commercially-viable method. Electron micrographs of the composites demonstrate that the reduced graphene oxide (rGO) is well-dispersed throughout the composite. Although no improvements in glass transition temperature, tensile strength, and thermal stability in air of the composites were observed, good improvements in thermal conductivity (about 36%), tensile and storage moduli (more than 13%) were recorded with the addition of 2 wt% of rGO

Structural studies of the bacterial Type II secretion system

The type II secretion system is a multiprotein machine that extends from the inner membrane to the outer membrane in Gram-negative bacteria; it transports folded proteins from the periplasm to the extracellular space. The type II secretion system comprises 12 core proteins arranged in 4 main parts: a cytoplasmic secretion ATPase, an inner membrane platform with domains that extend into the periplasm, a periplasmic pseudopilus, and an outer membrane pore formed by the secretin complex. Different species present different sets of accessory proteins. GspB, found in the plant pathogen Dickeya dadantii, reaches from the inner membrane to the periplasm anchoring and stabilizing the secretin. GspS is a lipoprotein pilotin found in both D. dadantii and the human pathogen Escherichia coli IHE3034 and it is involved in the correct localization of the secretin in the outer membrane. The correct localization of the secretin pore is of utmost importance for a fully functional system. The first part of this study explores the architecture of the outer membrane secretin complex of D. dadantii in association with GspB, and the secretin complex of E. coli IHE3034 in association with GspS, using negative stain TEM and cryo-EM. The second part of the work characterizes the interaction between the periplasmic domains of the inner membrane proteins GspL and GspM of E. coli IHE3034. Both possess a ferredoxin-like domain in the periplasmic belt followed by an alpha-helix domain that extends through the inner membrane and then connects to an N-terminal cytoplasmic domain. These proteins are the links between the substrate sensing 6 periplasmic region and the ATPase in the cytoplasm, therefore are key in the activation of the system. I propose a binding model between the ferredoxin-like domains of GspL and GspM based on NMR studies and computational modelling

Innovations in the production of ceramic environments: where craftsman meets computer

alongside active environmental performance. Responding to light-control criteria, we work with advanced digital modelling, fabrication and performance simulation tools to craft experimental full-scale ceramic prototypes of architectural daylighting components. Our research has three main goals: to investigate alternative daylighting technology solutions made of a low-impact material such as clay; to explore design methodologies that look into how current architectural ceramics manufacturing can be enhanced by emergent design and fabrication technologies; and to engage with the materiality of the clay through collaborative working with recognised artists and ceramicists. A critical aspect of our research is to test the compatibility and interoperability of different software and design techniques, as phases of the production process (optimisation of form finding) in real time. This paper presents the development, construction and analytical data of three of the experimental production methods developed during the first three years of this project

Adaptation and Validation of the MapMe Body Image Scales in Spanish Parents of Schoolchildren

\ua9 2024 by the authors.Childhood overweight and obesity is a worldwide problem and to treat it parents’ detection has to be improved. The MapMe Body Image Scales (BIS) are a visual tool developed to improve parental perception of child weight in the United Kingdon (UK) based on British growth reference criteria. The aim of this study was to make a transcultural adaptation and validation of the MapMe BIS in Spain based on International Obesity Task Force (IOTF) cut offs A descriptive cross-sectional study was done. First, a translation and cultural adaptation was carried out. A total of 155 10–11-year-old children and their parents participated in this study. Children were measured to calculate their weight status, Body Mass Index (BMI), Body Fat Percentage (BFP) and Waist Circumference (WC), and their parents completed a purpose designed questionnaire about their perception and satisfaction of child’s body weight status using the adapted BIS. Test-retest reliability, criterion validity and concurrent validity of the adapted BIS were analyzed. This study shows that the adapted MapMe BIS has good psychometric properties and is a suitable visual scale to assess parental perception of weight status in 10 and 11-year-old children in Spain

Circuit dissection of the role of somatostatin in itch and pain

Stimuli that elicit itch are detected by sensory neurons that innervate the skin. This information is processed by the spinal cord; however, the way in which this occurs is still poorly understood. Here we investigated the neuronal pathways for itch neurotransmission, particularly the contribution of the neuropeptide somatostatin. We find that in the periphery, somatostatin is exclusively expressed in Nppb+ neurons, and we demonstrate that Nppb+somatostatin+ cells function as pruriceptors. Employing chemogenetics, pharmacology and cell-specific ablation methods, we demonstrate that somatostatin potentiates itch by inhibiting inhibitory dynorphin neurons, which results in disinhibition of GRPR+ neurons. Furthermore, elimination of somatostatin from primary afferents and/or from spinal interneurons demonstrates differential involvement of the peptide released from these sources in itch and pain. Our results define the neural circuit underlying somatostatin-induced itch and characterize a contrasting antinociceptive role for the peptide

Increased levels of RNA oxidation enhance the reversion frequency in aging pro-apoptotic yeast mutants

Despite recent advances in understanding the complexity of RNA processes, regulation of the metabolism of oxidized cellular RNAs and the mechanisms through which oxidized ribonucleotides affect mRNA translation, and consequently cell viability, are not well characterized. We show here that the level of oxidized RNAs is markedly increased in a yeast decapping Kllsm4Δ1 mutant, which accumulates mRNAs, ages much faster that the wild type strain and undergoes regulated-cell-death. We also found that in Kllsm4Δ1 cells the mutation rate increases during chronological life span indicating that the capacity to han- dle oxidized RNAs in yeast declines with aging. Lowering intracellular ROS levels by antioxidants recovers the wild- type phenotype of mutant cells, including reduced amount of oxidized RNAs and lower mutation rate. Since mRNA oxidation was reported to occur in different neurodegen- erative diseases, decapping-deficient cells may represent a useful tool for deciphering molecular mechanisms of cell response to such conditions, providing new insights into RNA modification-based pathogenesis

The Long Life of Birds: The Rat-Pigeon Comparison Revisited

The most studied comparison of aging and maximum lifespan potential (MLSP) among endotherms involves the 7-fold longevity difference between rats (MLSP 5y) and pigeons (MLSP 35y). A widely accepted theory explaining MLSP differences between species is the oxidative stress theory, which purports that reactive oxygen species (ROS) produced during mitochondrial respiration damage bio-molecules and eventually lead to the breakdown of regulatory systems and consequent death. Previous rat-pigeon studies compared only aspects of the oxidative stress theory and most concluded that the lower mitochondrial superoxide production of pigeons compared to rats was responsible for their much greater longevity. This conclusion is based mainly on data from one tissue (the heart) using one mitochondrial substrate (succinate). Studies on heart mitochondria using pyruvate as a mitochondrial substrate gave contradictory results. We believe the conclusion that birds produce less mitochondrial superoxide than mammals is unwarranted

Expression of a barley cystatin gene in maize enhances resistance against phytophagous mites by altering their cysteine-proteases

Phytocystatins are inhibitors of cysteine-proteases from plants putatively involved in plant defence based on their capability of inhibit heterologous enzymes. We have previously characterised the whole cystatin gene family members from barley (HvCPI-1 to HvCPI-13). The aim of this study was to assess the effects of barley cystatins on two phytophagous spider mites, Tetranychus urticae and Brevipalpus chilensis. The determination of proteolytic activity profile in both mite species showed the presence of the cysteine-proteases, putative targets of cystatins, among other enzymatic activities. All barley cystatins, except HvCPI-1 and HvCPI-7, inhibited in vitro mite cathepsin L- and/or cathepsin B-like activities, HvCPI-6 being the strongest inhibitor for both mite species. Transgenic maize plants expressing HvCPI-6 protein were generated and the functional integrity of the cystatin transgene was confirmed by in vitro inhibitory effect observed against T. urticae and B. chilensis protein extracts. Feeding experiments impaired on transgenic lines performed with T. urticae impaired mite development and reproductive performance. Besides, a significant reduction of cathepsin L-like and/or cathepsin B-like activities was observed when the spider mite fed on maize plants expressing HvCPI-6 cystatin. These findings reveal the potential of barley cystatins as acaricide proteins to protect plants against two important mite pests