A preliminary epistemological ″human ecology″ framework for understanding the limits of bioethics.

This article tries to set up the epistemological bases of the science of ″human ecology″. This term has started to be used as a synonymous of morality, especially in the Catholic moral social doctrine that used for the first time to justify its marriage prospectives. We look at both terms together (human plus ecology) and we propose that human ecology should be a discipline that in the first time study human behavior and population (objective) using the postulates of the science of ecology (method) and then, once a conceptual framework for social sciences disciplines such as bioethics can be settle, could be used as a way to support or not moral postulates in the name of ecology. We conclude by defining which should be the methods of knowledge acquisition, the limits and the validity of what should be considered ″Human ecology″, that is to say, the ecology of the humans.

MOCHAs: An Emerging Class of Materials for Photocatalytic H2 Production.

Production of green hydrogen (H2) is a sustainable process able to address the current energy crisis without contributing to long-term greenhouse gas emissions. Many Ag-based catalysts have shown promise for light-driven H2 generation, however, pure Ag-in its bulk or nanostructured forms-suffers from slow electron transfer kinetics and unfavorable Ag─H bond strength. It is demonstrated that the complexation of Ag with various chalcogenides can be used as a tool to optimize these parameters and reach improved photocatalytic performance. In this work, metal-organic-chalcogenolate assemblies (MOCHAs) are introduced as effective catalysts for light-driven hydrogen evolution reaction (HER) and investigate their performance and structural stability by examining a series of AgXPh (X = S, Se, and Te) compounds. Two catalyst-support sensitization strategies are explored: by designing MOCHA/TiO2 composites and by employing a common Ru-based photosensitizer. It is demonstrated that the heterogeneous approach yields stable HER performance but involves a catalyst transformation at the initial stage of the photocatalytic process. In contrast to this, the visible-light-driven MOCHA-dye dyad shows similar HER activity while also ensuring the structural integrity of the MOCHAs. The work shows the potential of MOCHAs in constructing photosystems for catalytic H2 production and provides a direct comparison between known AgXPh compounds.

Surface Engineering of Escherichia coli to Display Its Phytase (AppA) and Functional Analysis of Enzyme Activities.

Escherichia coli phytase (AppA) is widely used as an exogenous enzyme in monogastric animal feed mainly because of its ability to degrade phytic acid or its salt (phytate), a natural source of phosphorus. Currently, successful recombinant production of soluble AppA has been achieved by gene overexpression using both bacterial and yeast systems. However, some methods for the biomembrane immobilization of phytases (including AppA), such as surface display on yeast cells and bacterial spores, have been investigated to avoid expensive enzyme purification processes. This study explored a homologous protein production approach for displaying AppA on the cell surface of E. coli by engineering its outer membrane (OM) for extracellular expression. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of total bacterial lysates and immunofluorescence microscopy of non-permeabilized cells revealed protein expression, whereas activity assays using whole cells or OM fractions indicated functional enzyme display, as evidenced by consistent hydrolytic rates on typical substrates (i.e., p-nitrophenyl phosphate and phytic acid). Furthermore, the in vitro results obtained using a simple method to simulate the gastrointestinal tract of poultry suggest that the whole-cell biocatalyst has potential as a feed additive. Overall, our findings support the notion that biomembrane-immobilized enzymes are reliable for the hydrolysis of poorly digestible substrates relevant to animal nutrition.

A thiomolybdate cluster for visible-light-driven hydrogen evolution: comparison of homogeneous and heterogeneous approaches.

This study investigates the hydrogen evolution reaction (HER) efficiency of two photosystems incorporating an all-inorganic molecular thiomolybdate [Mo3S13]2- cluster as a HER catalyst. First, we delve into the performance of a homogeneous [Mo3S13]2-/[Ru(bpy)3]2+ (Mo3/Ru) dyad which demonstrates high turnover frequencies (TOFs) and apparent quantum yields (AQYs) at 445 nm approaching the level of 0.5%, yet its performance is marked by pronounced deactivation. In contrast, a heterogeneous approach involves anchoring [Mo3S13]2- onto graphitic carbon nitride (GCN) nanosheets through weak electrostatic association with its triazine/heptazine scaffold. [Mo3S13]2-/GCN (Mo3/GCN) displays effective H2 generation under visible light, with TOF metrics on par with those of its homogeneous analog. Although substantial leaching of [Mo3S13]2- species from the Mo3/GCN surface occurs, the remaining {Mo3}-based centers demonstrate impressive stability, leading to enduring HER performance, starkly distinguishing it from the homogeneous Mo3/Ru photosystem. Photoluminescence (PL) quenching experiments confirm that the performance of Mo3/GCN is not limited by the quality of the inorganic interface, but could be optimized by using higher surface area supports or a higher concentration of [Mo3S13]2- sites. Our findings showcase complexities underlying the evaluation and comparison of photosystems comprising well-defined catalytic centers and pave the way for developing analogous surface-supported (photo)catalysts with broad use in energy applications.

In Silico Structural Analysis of Serine Carboxypeptidase Nf314, a Potential Drug Target in Naegleria fowleri Infections.

Naegleria fowleri, also known as the "brain-eating" amoeba, is a free-living protozoan that resides in freshwater bodies. This pathogenic amoeba infects humans as a casual event when swimming in contaminated water. Upon inhalation, N. fowleri invades the central nervous system and causes primary amoebic meningoencephalitis (PAM), a rapidly progressive and often fatal disease. Although PAM is considered rare, reducing its case fatality rate compels the search for pathogen-specific proteins with a structure-function relationship that favors their application as targets for discovering new or improved drugs against N. fowleri infections. Herein, we report a computational approach to study the structural features of Nf314 (a serine carboxypeptidase that is a virulence-related protein in N. fowleri infections) and assess its potential as a drug target, using bioinformatics tools and in silico molecular docking experiments. Our findings suggest that Nf314 has a ligand binding site suitable for the structure-based design of specific inhibitors. This study represents a further step toward postulating a reliable therapeutic target to treat PAM with drugs specifically aimed at blocking the pathogen proliferation by inhibiting protein function.

Surface Anchoring and Active Sites of [Mo3S13]2- Clusters as Co-Catalysts for Photocatalytic Hydrogen Evolution.

Achieving light-driven splitting of water with high efficiency remains a challenging task on the way to solar fuel exploration. In this work, to combine the advantages of heterogeneous and homogeneous photosystems, we covalently anchor noble-metal- and carbon-free thiomolybdate [Mo3S13]2- clusters onto photoactive metal oxide supports to act as molecular co-catalysts for photocatalytic water splitting. We demonstrate that strong and surface-limited binding of the [Mo3S13]2- to the oxide surfaces takes place. The attachment involves the loss of the majority of the terminal S2 2- groups, upon which Mo-O-Ti bonds with the hydroxylated TiO2 surface are established. The heterogenized [Mo3S13]2- clusters are active and stable co-catalysts for the light-driven hydrogen evolution reaction (HER) with performance close to the level of the benchmark Pt. Optimal HER rates are achieved for 2 wt % cluster loadings, which we relate to the accessibility of the TiO2 surface required for efficient hole scavenging. We further elucidate the active HER sites by applying thermal post-treatments in air and N2. Our data demonstrate the importance of the trinuclear core of the [Mo3S13]2- cluster and suggest bridging S2 2- and vacant coordination sites at the Mo centers as likely HER active sites. This work provides a prime example for the successful heterogenization of an inorganic molecular cluster as a co-catalyst for light-driven HER and gives the incentive to explore other thio(oxo)metalates.

A molecular dynamics approach on the Y393C variant of protein disulfide isomerase A1.

Human protein disulfide isomerase A1 (PDIA1) shows both catalytic (i.e., oxidoreductase) and non-catalytic (i.e., chaperone) activities and plays a crucial role in the oxidative folding of proteins within the endoplasmic reticulum. PDIA1 dysregulation is a common trait in numerous pathophysiological conditions, including neurodegenerative disorders and cancerous diseases. The 1178A>G mutation of the human PDIA1-encoding gene is a non-synonymous single nucleotide polymorphism detected in patients with Cole-Carpenter syndrome type 1 (CSS1), a particularly rare bone disease. In vitro studies showed that the encoded variant (PDIA1 Y393C) exhibits limited oxidoreductase activity. To gain knowledge on the structure-function relationship, we undertook a molecular dynamics (MD) approach to examine the structural stability of PDIA1 Y393C. Results showed that significant conformational changes are the structural consequence of the amino acid substitution Tyr>Cys at position 393 of the PDIA1 protein. This structure-based study provides further knowledge about the molecular origin of CCS1.

Índice Ventricular De Levene Y Mensuración Del Tercer Ventrículo En Neonatos Ecuatorianos Mediante Ecografía Cerebral / Levene Ventricular Index And Measurement Of The Third Ventricle In Ecuadorian Neonates By Means Of Cerebral Ultrasound

Resumen Introducción: La aplicación del ultrasonido en la evaluación cerebral del neonato posibilita la mensuración de estructuras cerebrales. Objetivo: El objetivo de este trabajo es obtener las medidas del III ventrículo y del índice de Levene en un grupo de recién nacidos ecuatorianos, con la finalidad de determinar valores de normalidad que puedan ser utilizados en el trabajo diario del servicio de neonatología. Métodos: Se seleccionó un grupo de neonatos sin alteraciones neurológicas. A través de la fontanela anterior se determinó el índice de Levene. La mensuración del diámetro del III ventrículo se realizó a través de la ventana craneal temporal. Resultados: Se incluyeron en el estudio 66 pacientes con edad post menstrual de 37 semanas (rango 27-42 semanas), predominó el sexo masculino. El peso promedio al nacer fue de 2554 gramos. El valor medio del diámetro del III ventrículo es de 1,5 mm, rango entre 0,5 mm - 3,8 mm. El índice de Lindergaard promedio fue de 12,7 mm (8,2-27 mm). Tanto el diámetro del tercer ventrículo como el índice ventricular se vieron afectados por el peso al nacer. En relación con el momento del parto no existió diferencia significativa en el tamaño ventricular. Conclusiones: Comparado con los resultados de otras series nuestro estudio ofrece parámetros diferentes.

Abstract Introduction: The application of ultrasound in the brain evaluation of the neonate allows the measurement of brain structures. Objective: To obtain the sizes of the third ventricle and the ventricular index of Levene in a group of Ecuadorian neonates without neurological alterations. To establish normal ranges that can be used in the daily work of the neonatology service. Methods: A group of neonates without neurological alterations was studied. Through the anterior fontanelle, the Levene index was determined. The third ventricle's diameter was seized through the temporal cranial window. Results: Sixty-six patients of 37 weeks' gestational age at birth (range 27-42 weeks), predominantly male and an average weight at birth of 2554 grams, were included. The third ventricle's mean diameter was 1.5 mm (range: 0.5 mm - 3.8 mm). The average Lindergaard index was 12.7 mm (8.2-27 mm). Both, the diameter of the third ventricle and the ventricular index were affected by the birth weight of newborns. Regarding the moment of delivery, there was no significant difference in ventricular size. Conclusions: Compared with the results of other series, our study offers different parameters.

Anti-inflammatory effect of Capuli cherry against LPS-induced cytotoxic damage in RAW 264.7 macrophages.

Capuli cherry (Prunus serotina Ehr. subsp. capuli (Cav.) McVaugh) fruits from the inter-Andean region of Ecuador were analysed to determine their bioactive compounds content, total antioxidant capacity, radical scavenging activity and their anti-inflammatory and protective effects against the cytotoxic damage mediated by lipopolysaccharide (LPS) in RAW 264.7 macrophages. Capuli fruits proved to be a natural source of bioactive compounds such as anthocyanins, vitamin C and ß-carotene as well as to present an important total antioxidant capacity and radical scavenging activities. RAW 264.7 macrophages were incubated with different concentration of Capuli crude extract and subsequently activated by LPS to determine the markers related to oxidative damage and the proinflammatory cytokine production. The markers of oxidative damage, nitrite levels, the interleukin 1ß messenger RNA levels and the tumor necrosis factor α mRNA levels and secretion were significantly decreased after the pre-incubated with Capuli extract and subsequently stimulated with LPS. In summary, Capuli extract attenuated the LPS-induced damage in RAW 264.7 macrophages due to its antioxidant and anti-inflammatory properties, showing that Capuli fruits may represent a relevant source of bioactive compounds with promising benefits for human health.

Influence of Botanical Origin and Chemical Composition on the Protective Effect against Oxidative Damage and the Capacity to Reduce In Vitro Bacterial Biofilms of Monofloral Honeys from the Andean Region of Ecuador.

Three types of monofloral honey from the Andean regions of Ecuador (Avocado, Eucalyptus, and Rapeseed honey) were analyzed to determine their floral origin, physicochemical parameters, chemical composition, antioxidant capacity, and their capacity to reduce in vitro bacterial biofilms. The chemical composition varied considerably depending on floral origin. The highest values of bioactive compounds were found in Avocado honey, classified as dark amber in color, while the lowest values were found in Eucalyptus honey followed by Rapeseed honey, both classified as extra light amber. When compared to Eucalyptus and Rapeseed honey, Avocado honey showed a more effective superoxide scavenging activity, chelating metal ions capacity, and a higher ability to protect human erythrocyte membranes against lipid peroxidation. For antimicrobial activity, the hydrogen peroxide content and the capacity to inhibit the biofilm formation, and to remove preformed biofilm from Staphylococcus aureus and Klebsiella pneumoniae was determined. Avocado honey showed the highest values of hydrogen peroxide content, as well as the highest capacity to reduce in vitro bacterial biofilms. A correlation between color vs. phenolics content vs. superoxide scavenging activity vs. chelating metal ions capacity, and the capacity to protect human erythrocyte membranes against lipid peroxidation was found.