Effect of CMV and Aging on the Differential Expression of CD300a, CD161, T-bet, and Eomes on NK Cell Subsets

Natural killer cells are innate lymphoid cells involved in the defence against virus-infected cells and tumour cells. NK cell phenotype and function is affected with age and CMV latent infection. Aging affects the frequency and phenotype of NK cells and CMV infection also contributes to these alterations. Thus, a reduction of CD56bright NK cell subpopulation associated with age and an expansion of memory-like NK cells CD56dimCD57+NKG2C+ probably related to CMV-seropositivity have been described. NK cells express T-bet and Eomes transcription factors that are necessary for the development of NK cells. Here we analyse the effect of age and CMV-seropositivity on the expression of CD300a and CD161 inhibitory receptors and T-bet and Eomes transcription factors in NK cell subsets defined by the expression of CD56 and CD57. CD300a is expressed by the majority of NK cells. CD56bright NK cells express higher levels of CD300a than CD56dim NK cells. An increase in the expression of CD300a was associated with age whereas a decreased expression of CD161 in CD56dim NK cells was associated with CMV-seropositivity. In CD56dim NK cells an increased percentage of CD57+CD300a+ and a reduction in the percentage of CD161+CD300a+ cells were found to be associated with CMV-seropositivity. Regarding T-bet and Eomes transcription factors, CMV-seropositivity was associated with a decrease of T-bethi in CD56dimCD57+ NK cells from young individuals whereas Eomes expression was increased with CMV-seropositivity in both CD56bright and CD56dimCD57+/− (from middle-age and young individuals, respectively) and was decreased with ageing in all NK subsets from the three group of age. In conclusion, CMV infection and age induce significant changes in the expression of CD300a and CD161 in NK cell subsets defined by the expression of CD56 and CD57. T-bet and Eomes are differentially expressed on NK cell subsets and their expression is affected by CMV latent infection and ageing

Nutrition, diet and immunosenescence

Ageing is characterized by immunosenescence and the progressive decline in immunity in association with an increased frequency of infections and chronic disease. This complex process affects both the innate and adaptive immune systems with a progressive decline in most immune cell populations and defects in activation resulting in loss of function. Although host genetics and environmental factors, such as stress, exercise and diet can impact on the onset or course of immunosenescence, the mechanisms involved are largely unknown. This review focusses on identifying the most significant aspects of immunosenescence and on the evidence that nutritional intervention might delay this process, and consequently improve the quality of life of the elderly

Fundamentals of methanol synthesis on metal carbide based catalysts: activation of CO2 and H2

CO2 hydrogenation to methanol and other alcohols constitutes an appealing route to recycle the large amount accumulated in the atmosphere through fossil-derived fuels burning. However, CO2 high chemical stability makes the overall process difficult and appropriate catalysts are needed. Transition metal carbides, either as active phase or as a support for noble metal clusters, have been shown to be able to activate CO2. Here, the mechanism involved in the decomposition of H2 and CO2 on many early transition metal carbides (TMC) surfaces is analyzed with the help of density functional theory (DFT) based calculations complemented by key experiments. Results show that H2 dissociation on VC and δ-MoC is unlikely, that TiC and ZrC are more reactive leading to an exothermic but activated process and that the C:Mo ratio is determinant factor since H2 dissociation on β-Mo2C(001) surface is even more exothermic. The DFT based calculations also show that CO2 adsorption on TMC results in an activated species with TMC→CO2 charge transfer, C-O bond elongations and OCO bending. Supporting Cu4 and Au4 clusters on TMC(001) surfaces leads to more active catalysts due to the induced charge polarization. For H2 dissociation, TiC appears to be the best support, enhancing H2 both thermodynamics and kinetics. CO2 is strongly adsorbed on supported Cu4 and Au4 clusters, and the adsorption energy strength correlates with the methanol formation rate: Cu4/TiC(001) > Au4/TiC(001) > Cu/ZnO(001) >> Cu(111), thus providing potential alternative catalysts for methanol synthesis, in principle dozens of times better than commercial Cu/ZnO based catalysts

When reconstruction comes around: Ni, Cu, and Au adatoms on d-MoC(001)

The interaction of Au, Cu, and Ni metal atoms with the δ-MoC(001) surface was studied using periodic Density Functional (DF) calculations to analyse adsorption energies and equilibrium geometries, work functions, atomic charges, Projected Density Of States (PDOS), and shifts of the transition metal d-band center. The atomic adsorption is found to cause an in-plane distortion of the surface, and, besides, the interaction strength turns to be coverage dependent. A lower coverage allows for a better accommodation of the adsorbate, alongside causing a d-band centre shift to more negative energies, as shown by plots of the PDOS. Regardless of the coverage, interaction strength diminishes following the order Ni > Cu > Au. Adatom chemical activity can be inferred based on the calculated d-band centre; Ni being the most active metal, followed by Cu, and Au later on for every coverage studied. This result correlates well with experiments on other transition metal carbides. Atomic adsorption also notably diminishes surface work function, with the concomitant repercussions on the electrocatalysis field

Evaluation of Biogenic Amine and Free Fatty Acid Profiles During the Manufacturing Process of Traditional Dry-Cured Tuna

The aim of this study was to investigate the changes in the formation of biogenic amines and free fatty acids occurring during the manufacturing process of a traditional dry-cured product based on yellowfin tuna, Thunnus albacares (protected geographical indication-Mojama) and how the different processing stages could affect food safety aspects. The biogenic amines profile was determined by HPLC-DAD, following the official methodology, and free fatty acids were quantified by GC-MS. Histamine levels found in all stages of the manufacturing process did not exceed the maximum limits established in the European Commission (100-200 mg/kg) and US Food and Drug Administration (50 mg/kg) regulations. Other biogenic amines, such as cadaverine and putrescine, were detected at low level or below the limit of detection. Yellowfin tuna filets could be classified as lean fish flesh, presenting 1.18% fat on average. An increment in the free fatty acid fraction was evidenced along the manufacturing process, ranging from 10.37% of the total lipids in fresh loins to 16.88% in the dry-cured filet product. The results indicated that the traditional manufacturing process of mojama, consisting of salting and drying tuna loins kept at a controlled temperature, promoted a moderate lipolysis phenomenon, and the formation of free fatty acids with high proportions of unsaturated fatty acids, likely arising from the lipolysis of muscle phospholipids

Device for negative pressure wound therapy in low-resource regions: open-source description and bench test evaluation

Background: Negative (vacuum) pressure therapy promotes wound healing. However, commercially available devices are unaffordable to most potential users in low- and middle-income countries (LMICs), limiting access to many patients who could benefit from this treatment. This study aimed to design and test a cheap and easy-to-build negative pressure device and provide its detailed open-source description, thereby enabling free replication. Methods: the negative pressure device was built using off-the-shelf materials available via e-commerce and was based on a small pump, a pressure transducer, and the simplest Arduino controller with a digital display (total retail cost ≤ 75 US$). The device allows the user to set any therapeutic range of intermittent negative pressure and has two independent safety mechanisms. The performance of the low-cost device was carefully tested on the bench using a phantom wound, producing a realistic exudate flow rate. Results: the device generates the pressure patterns set by the user (25-175 mmHg of vacuum pressure, 0-60 min periods) and can drain exudate flows within the clinical range (up to 1 L/h). Conclusions: a novel, low-cost, easy-to-build negative pressure device for wound healing displays excellent technical performance. The open-source hardware description provided here, which allows for free replication and use in LMICs, will facilitate the application and wider utilization of this therapy to patients

Boosting the activity of transition metal carbides towards methane activation by nanostructuring

The interaction of methane with pristine surfaces of bulk MoC and Mo2C is known to be weak. In contrast, a series of X-ray photoelectron spectroscopy (XPS) experiments, combined with thermal desorption mass spectroscopy (TDS), for MoCy (y = 0.5-1.3) nanoparticles supported on Au(111)¿which is completely inert towards CH4¿show that these systems adsorb and dissociate CH4 at room temperature and low CH4 partial pressure. This industrially-relevant finding has been further investigated with accurate density functional theory (DFT) based calculations on a variety of MoCy supported model systems. The DFT calculations reveal that the MoCy/Au(111) systems can feature low C-H bond scission energy barriers, smaller than the CH4 adsorption energy. Our theoretical results for bulk surfaces of Mo2C and MoC show that a simple Brønsted-Evans-Polanyi (BEP) relationship holds for C-H bond scission on these systems. However, this is not the case for methane activation on the MoCy nanoparticles as a consequence of their unique electronic and chemical properties. The discovery that supported molybdenum carbide nanoparticles are able to activate methane at room temperature paves the road towards the design of a new family of active carbide catalysts for methane activation and valorisation, with important implications in climate change mitigation and carbon cycle closure

The conversion of CO2 to methanol on orthorhombic β-Mo2C and Cu/β-Mo2C catalysts: mechanism for admetal induced change in the selectivity and activity

The conversion of CO2 into methanol catalyzed by β-Mo2C and Cu/β-Mo2C surfaces has been investigated by means of a combined experimental and theoretical study. Experiments have shown the direct activation and dissociation of the CO2 molecule on bare β-Mo2C, whereas on Cu/β-Mo2C, CO2 must be assisted by hydrogen for its conversion. Methane and CO are the main products on the clean surface and methanol production is lower. However, the deposition of Cu clusters avoids methane formation and increases methanol production even above that corresponding to a model of the technical catalyst. DFT calculations on surface models of both possible C- and Mo-terminations, corroborate the experimental observations. Calculations for the clean Mo-terminated surface reveal the existence of two possible routes for methane production (C + 4H → CH4; CH3O + 3H → CH4 + H2O) which are competitive with methanol synthesis, displaying slightly lower energy barriers. On the other hand, a model for Cu deposited clusters on the Mo- terminated surface points towards a new route for methanol and CO production avoiding methane formation. The new route is a direct consequence of the generation of a Mo2C-Cu interface. The present experimental and theoretical results entail the interesting catalytic properties of Mo2C as an active support of metallic nanoparticles, and also illustrate how the deposition of a metal can drastically change the activity and selectivity of a carbide substrate for CO2 hydrogenation

Guía: Cómo desarrollar un Plan de Acción Climática en México

El Pacto Global de los Alcaldes por el Clima y la Energía (GCoM) apoya a las autoridades locales en el combate al cambio climático. El México, el GCoM invita a los gobiernos municipales a asumir un compromiso político voluntario para implementar acciones bajo tres pilares: la mitigación climática, la adaptación climática y el acceso a la energía. Con el fin de traducir el compromiso político en medidas prácticas, los signatarios de GCoM se comprometen a elaborar e implementar un Plan de Acción Climática (PAC). La integración de un PAC a nivel local es coherente con la legislación mexicana. La Ley General de Cambio Climático establece en su artículo 9.º que corresponde a los Municipios “formular, conducir y evaluar la política municipal en materia de cambio climático en concordancia con la política nacional y estatal”. Por lo tanto, resulta pertinente generar recomendaciones específicas para apoyar a los gobiernos locales en la definición y ejecución de su política climática. La presente Guía ha sido adaptada con base en experiencias anteriores del Joint Research Centre (JRC) en Europa y otras regiones del mundo. Asimismo, se utilizaron como insumos las experiencias y buenas prácticas recabadas durante un proyecto piloto (GCoM México: Showcase Cities) en donde se apoyó a Municipios mexicanos en la integración de su PAC, a través del Programa de Cooperación Urbana Internacional - Norte América (IUC-NA) de la Unión Europea.JRC.C.2 - Energy Efficiency and Renewable