Environmental Hazards of Giant Reed (Arundo donax L.) in the Macaronesia Region and Its Characterisation as a Potential Source for the Production of Natural Fibre Composites.

This paper summarises the results obtained from the characterisation of giant reed (Arundo donax L.) plant and fibres. The research is part of a project developed in the Macaronesia region, of which the aim is to demonstrate the feasibility of using biomass from invasive plant species in the composites sector as a way of financing control campaigns and habitats conservation labours. An experimental procedure for the extraction of fibre bundles from this plant was developed, and the material obtained was characterised in terms of chemical composition, thermogravimetry and infrared spectra to evaluate its potential application in the production of polymeric composite materials as a strategy for the valorisation of residual biomass from this invasive species in Macaronesia. Thermoplastic matrix composites with fibre content up to 40 wt.% were produced and their mechanical properties under tensile, flexural and impact loading were determined. No references on the preparation of composite materials with polyolefin matrices and giant reed fibres have been found. Results obtained from mechanical tests show a good performance of the manufactured composites, with a significant increase in both flexural and tensile stiffness; the flexural modulus is almost tripled for PE-based composites and rises to 88% with respect to PP matrix. The ultimate flexural strength and the tensile and flexural yield strength are kept at acceptable values compared to neat polymer materials, although ultimate tensile strength and impact resistance are significantly affected when natural fibres are added.

Opuntia spp. Fibre Characterisation to Obtain Sustainable Materials in the Composites Field.

Some studies have evaluated the use of Opuntia as reinforcement for polymeric matrices, obtaining good results in energy absorption tests and increasing the tensile elastic modulus. However, no studies focusing on the previous characterisation of the fibres and their treatment to improve compatibility with polymeric matrices have been found. This work analyses the chemical composition of Opuntia maxima (OM) and Opuntia dillenii (OD) cladodes and fibre, studying how different treatments influence it. AOAC 2000 methods were used to determine non-structural components and the Van Soest method was used to estimate structural components. Surface characteristics of the samples were also evaluated by Fourier Transform Infrared Spectroscopy (FTIR). Opuntia fibre presented higher cellulose (50-66%) and lignin (6-14%) content and lower hemicellulose (8-13%) content than Opuntia cladodes (9-14% cellulose, 20-50% hemicellulose, 1-4% lignin). Despite the variability of lignocellulosic materials, OD cladodes treated with water and acetic acid achieved an increase in the structural components. Alkaline fibre treatment removed pectin and hemicellulose from the fibre surface, slightly increasing the cellulose content. Future research should evaluate whether the treated Opuntia fibre can improve the mechanical properties of reinforced polymer.

Are Natural-Based Composites Sustainable?

This paper assesses the aspects related to sustainability of polymer composites, focusing on the two main components of a composite, the matrix and the reinforcement/filler. Most studies analyzed deals with the assessment of the composite performance, but not much attention has been paid to the life cycle assessment (LCA), biodegradation or recyclability of these materials, even in those papers containing the terms "sustainable" (or its derivate words), "green" or "eco". Many papers claim about the sustainable or renewable character of natural fiber composites, although, again, analysis about recyclability, biodegradation or carbon footprint determination of these materials have not been studied in detail. More studies focusing on the assessment of these composites are needed in order to clarify their potential environmental benefits when compared to other types of composites, which include compounds not obtained from biological resources. LCA methodology has only been applied to some case studies, finding enhanced environmental behavior for natural fiber composites when compared to synthetic ones, also showing the potential benefits of using recycled carbon or glass fibers. Biodegradable composites are considered of lesser interest to recyclable ones, as they allow for a higher profitability of the resources. Finally, it is interesting to highlight the enormous potential of waste as raw material for composite production, both for the matrix and the filler/reinforcement; these have two main benefits: no resources are used for their growth (in the case of biological materials), and fewer residues need to be disposed.

Factores que influyen en el destete precoz de lactantes pertenecientes al Centro de Salud Augusto Egas, Ecuador / Fatores que influenciam o desmame precoce em bebês pertencentes ao Centro de Saúde Augusto Egas, Equador / Factors that influence the early weaning on infants belonging to the Augusto Egas Health Center, Ecuador

Introducción: La lactancia materna exclusiva aporta macro y micronutrientes que son suficientes para un correcto desarrollo y crecimiento del lactante. La promoción de la lactancia materna exclusiva debe ser óptima, puesto que en la actualidad el destete precoz ha aumentado en gran magnitud. Objetivo: Determinar qué factores influyen en el destete precoz en madres con lactantes de 0 a 11 meses en el Centro de Salud Augusto Egas, de la ciudad de Santo Domingo, Ecuador. Método: Se utilizó un estudio correlacional, descriptivo, con enfoque cuantitativo, durante el periodo de julio hasta inicios de agosto de 2021, en una población de 252 madres que asistieron dicha unidad de salud. Se realizó un muestreo por conveniencia donde se obtuvo una muestra de 153 madres. Las variables medidas, fueron: dificultades a inicio de la lactancia materna, alimentos con los que complementaron la lactancia materna exclusiva, abandono precoz, mitos que influyeron en el abandono parcial o completo de la lactancia materna exclusiva y madres que recibieron información después del parto. Resultados: El 85 por ciento de las madres refirió dificultades en la cantidad suficiente de leche. Las madres no abandonaron la lactancia por decisión propia, el 64,7 por ciento expresó no creer en los mitos. Hubo mayoría de acuerdo en haber recibido una correcta información después del parto por parte del personal de salud (64,7 por ciento). Conclusión: La insuficiente cantidad de leche en las madres es el factor que más influye en esta unidad de salud, por lo que optan por una alimentación mixta(AU).

Introduction: Exclusive breastfeeding provides macro and micronutrients that are sufficient for the correct development and growth of the infant. The promotion of exclusive breastfeeding should be optimal, since early weaning has greatly increased nowadays. Objective: To determine what factors influence early weaning in mothers with infants from 0 to 11 months at the Augusto Egas Health Center, in the city of Santo Domingo, Ecuador. Method: A descriptive correlational study was undertaken, with a quantitative approach, during the period from July to the beginning of August 2021, in a population of 252 mothers who attended this health unit. A convenience sampling was carried out, and a sample of 153 mothers was obtained. The variables measured were: difficulties at the beginning of breastfeeding, foods that supplemented exclusive breastfeeding, early abandonment, myths that influenced the partial or complete abandonment of exclusive breastfeeding, and mothers who received information after delivery. Results: 85 percent of the mothers reported difficulties in the sufficient quantity of milk. Mothers did not abandon breastfeeding by their own decision, 64.7 percent expressed not believing in the myths. There was a majority of agreement in having received correct information after delivery from health personnel (64.7 percent). Conclusion: The insufficient amount of milk in mothers is the factor that influences the most in this health unit, so they opted for a mixed diet(AU).

Introdução: O aleitamento materno exclusivo fornece macro e micronutrientes suficientes para o correto desenvolvimento e crescimento da criança. A promoção do aleitamento materno exclusivo deve ser ótima, pois hoje o desmame precoce aumentou muito. Objetivo: determinar quais fatores influenciam o desmame precoce de mães com bebês de 0 a 11 meses no Centro de Saúde Augusto Egas, na cidade de Santo Domingo, Equador. Método: Foi utilizado um estudo descritivo correlacional, com abordagem quantitativa, no período de julho a início de agosto de 2021, em uma população de 252 mães atendidas nesta unidade de saúde. Realizou-se uma amostragem por conveniência, obtendo-se uma amostra de 153 mães. As variáveis mensuradas foram: dificuldades no início da amamentação, alimentos que complementavam a amamentação exclusiva, abandono precoce, mitos que influenciaram no abandono parcial ou total do aleitamento materno exclusivo e mães que receberam informações após o parto. Resultados: 85 porcento das mães relataram dificuldade na quantidade suficiente de leite. As mães não abandonaram a amamentação por decisão própria, 64,7 porcento expressaram não acreditar nos mitos. Houve maior concordância em ter recebido informações corretas do pessoal de saúde após o parto (64,7 porcento). Conclusão: A quantidade insuficiente de leite das mães é o fator que mais influencia esta unidade de saúde, por isso optam por uma alimentação mista(AU).

Cell-free protein synthesis and purification of human dopamine D2 receptor long isoform.

The human dopamine D2 receptor long isoform (D2L) has significant implications in neurological and neuropsychiatric disorders such as Parkinson's disease and schizophrenia. Detailed structural knowledge of this receptor is limited owing to its highly hydrophobic nature, which leads to protein aggregation and host toxicity when expressed in cellular systems. The newly emerging field of cell-free protein expression presents numerous advantages to overcome these challenges. This system utilizes protein synthesis machinery and exogenous DNA to synthesize functional proteins outside of intact cells. This study utilizes two different cell-free systems for the synthesis of human dopamine D2L receptor. These include the Escherichia coli lysate-based system and the wheat-germ lysate-based system. The bacterial cell-free method used pET 100/D-TOPO vector to synthesize hexa-histidine-tagged D2L receptor using a dialysis bag system; the resulting protein was purified using nickel-nitrilotriacetic acid affinity resin. The wheat germ system used pEU-glutathione-S-transferase (GST) vector to synthesize GST-tagged D2L receptor using a bilayer translation method; the resulting protein was purified using a GST affinity resin. The presence and binding capacity of the synthesized D2L receptor was confirmed by immunoblotting and radioligand competition assays, respectively. Additionally, in-gel protein sequencing via Nano LC-MS/MS was used to confirm protein synthesis via the wheat germ system. The results showed both systems to synthesize microgram quantities of the receptor. Improved expression of this highly challenging protein can improve research and understanding of the human dopamine D2L receptor.

Behavioral abnormalities in synapsin II knockout mice implicate a causal factor in schizophrenia.

Recent studies on the phosphoprotein synapsin II have revealed reduced expression in postmortem medial prefrontal cortex tissues from subjects with schizophrenia, and chronic antipsychotic drug treatment has resulted in concurrent increases in synapsin II mRNA and protein levels. Collectively, this research suggests a role of synapsin II in the pathophysiology of schizophrenia; however, whether synapsin II plays a causal role in this disease process still remains unclear. Therefore, the goal of this investigation was to examine whether synapsin II knockout mice display behavioral abnormalities commonly expressed in preclinical animal models of schizophrenia, namely deficits in prepulse inhibition (PPI), decreased social behavior, and locomotor hyperactivity. Results indicate that mice with knockout of the synapsin II gene demonstrate deficits in PPI at three prepulse intensities (67, 70, and 73 dB), along with deficits in habituation to startle to a 110 dB acoustic pulse. Knockout animals also expressed decreased social behavior and increased locomotor activity when compared to wildtype and heterozygous populations. Complete knockout of the synapsin II gene was confirmed in postmortem brain tissues via immunoblotting. In conclusion, these results confirm that synapsin II knockout mice display behavioral endophenotypes similar to established preclinical animal models of schizophrenia, and lend support to the notion that abnormalities in synapsin II expression may play a causal role in the underlying pathophysiological mechanisms of schizophrenia.

MIF-1 and its peptidomimetic analogs attenuate haloperidol-induced vacuous chewing movements and modulate apomorphine-induced rotational behavior in 6-hydroxydopamine-lesioned rats.

Two melanocyte-stimulating hormone release inhibiting factor-1 (MIF-1) also known as L-prolyl-L-leucyl-glycinamide (PLG) peptidomimetic analogs, 3(R)-[[[2(S)-pyrrolidinyl]carbonyl]-amino]-3-(butyl)-2-oxo-1-pyrrolidineacetamide trifluoroacetate (A) and 3(R)-[[[2(S)-pyrrolidinyl]carbonyl]amino]-3-(benzyl)-2-oxo-1-pyrrolidineacetamide trifluoroacetate (B), were evaluated for their ability to modulate dopaminergic activity by measuring apomorphine-induced rotations in 6-hydroxydopamine (6-OHDA)-lesioned rats, and haloperidol (HP)-induced vacuous chewing movements (VCMs) in rats; animal models of Parkinson's disease (PD) and human tardive dyskinesia (TD), respectively. In the 6-OHDA model, both analogs were found to potentiate the contralateral rotational behavior induced by apomorphine dose-dependently and with approximately the same potency. Furthermore, each analog was able to significantly attenuate HP-induced VCMs with almost equal efficacy. The potency and efficacy of these analogs were significantly greater than their parent compound, PLG. These results suggest that both analogs can modulate dopaminergic activity in vivo, likely by the same mechanisms recruited by PLG previously reported.

Modulation of agonist binding to human dopamine receptor subtypes by L-prolyl-L-leucyl-glycinamide and a peptidomimetic analog.

The present study was undertaken to investigate the role of the hypothalamic tripeptide L-prolyl-L-leucyl-glycinamide (PLG) and its conformationally constrained analog 3(R)-[(2(S)-pyrrolidinylcarbonyl)amino]-2-oxo-1-pyrrolidineacetamide (PAOPA) in modulating agonist binding to human dopamine (DA) receptor subtypes using human neuroblastoma SH-SY5Y cells stably transfected with respective cDNAs. Both PLG and PAOPA enhanced agonist [3H]N-propylnorapomorphine (NPA) and [3H]quinpirole binding in a dose-dependent manner to the DA D2L,D2S, and D4 receptors. However, agonist binding to the D1 and D3 receptors and antagonist binding to the D2L receptors by PLG were not significantly affected. Scatchard analysis of [3H]NPA binding to membranes in the presence of PLG revealed a significant increase in affinity of the agonist binding sites for the D2L, D2S, and D4 receptors. Analysis of agonist/antagonist competition curves revealed that PLG and PAOPA increased the population and affinity of the high-affinity form of the D2L receptor and attenuated guanosine 5'-(beta,gamma-imido)-triphosphate-induced inhibition of high-affinity agonist binding sites for the DA D2L receptor. Furthermore, direct NPA binding with D2L cell membranes pretreated with suramin, a compound that can uncouple receptor/G protein complexes, and incubated with and without DA showed that both PLG and PAOPA had only increased agonist binding in membranes pretreated with both suramin and DA, suggesting that PLG requires the D2L receptor/G protein complex to increase agonist binding. These results suggest that PLG possibly modulates DA D2S, D2L, and D4 receptors in an allosteric manner and that the coupling of D2 receptors to the G protein is essential for this modulation to occur.