A theoretical study on the mechanism of the base-promoted decomposition of N-chloro,N-methylethanolamine

The first step of the base-promoted decomposition of N-chloro,N-methylethanolamine in aqueous solution (CH3N(Cl)CH2CH2OH + HO- →imine + Cl- + H2O (+ CH2O)→amine + aldehyde) is investigated at the MP2/6-31++G(d,p) computing level. Solvation is included by using both a microsolvated model, in which two explicit water molecules simulate the specific solvent effects, and a hybrid cluster-continuum model, by applying a polarized continuum on the previous results, to account for the bulk effect of the solvent. Four alternative pathways (bimolecular fragmentation, Hofmann, Zaitsev and intramolecular eliminations) are possible for the rate-limiting step of this base-promoted decomposition. These reactive processes are bimolecular asynchronous concerted reactions. The common feature of the four pathways is the proton transfer to HO- being more advanced than all other molecular events, whereas imine formation is delayed. Non-reactive cyclic arrangements involving one of the explicit water molecules are found at transition structures of Hofmann and Zaitsev eliminations, such water molecule acting both as H+ donor and acceptor. Although MP2 calculations misjudge the absolute activation Gibbs free energy values, this computational level adequately predicts the enhancement in the decomposition rate due to the presence of the -OH grou

Effect of Ionizing Radiation on Human Myeloperoxidase: Reaction With Hydrated Electrons

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] Myeloperoxidase (MPO) is a myeloid-lineage restricted enzyme largely expressed in the azurophilic granules of neutrophils. It catalyses the formation of reactive oxygen species, mainly hypochlorous acid, contributing to anti-pathogenic defense. Disorders in the production or regulation of MPO may lead to a variety of health conditions, mainly of inflammatory origin, including autoimmune inflammation. We have studied the effect of ionizing radiation on the activity of MPO, as measured by the capacity retained by the enzyme to produce hypochlorous acid as reactive oxygen species after exposure to successive doses of solvated electrons, the strongest possible one-e− reducing agent in water. Chlorination activity was still present after a very high irradiation dose, indicating that radiation damage does not take place at the active site, hindered in the core of MPO structure. Decay kinetics show a dependence on the wavelength, supporting that the process must occur at peripheral functional groups situated on external and readily accessible locations of the enzyme. These results are relevant to understand the mechanism of resistance of our innate anti-pathogenic defense system and also to get insight into potential strategies to regulate MPO levels as a therapeutic target in autoimmune diseases.This work was supported by: the Spanish Ministerio de Ciencia y Tecnología (CTQ2004-00534/BQU), the European Commission through the Access to Large-Scale Scientific Facilities Program (ref 41365), and the regional government of the Xunta de Galicia (Project GPC ED431B 2020/52)Xunta de Galicia; ED431B 2020/5

HDL cholesterol efflux capacity in rheumatoid arthritis patients: contributing factors and relationship with subclinical atherosclerosis

Background: Lipid profiles appear to be altered in rheumatoid arthritis (RA) patients because of disease activity and inflammation. Cholesterol efflux capacity (CEC), which is the ability of high-density lipoprotein cholesterol to accept cholesterol from macrophages, has been linked not only to cardiovascular events in the general population but also to being impaired in patients with RA. The aim of this study was to establish whether CEC is related to subclinical carotid atherosclerosis in patients with RA. Methods: We conducted a cross-sectional study that encompassed 401 individuals, including 178 patients with RA and 223 sex-matched control subjects. CEC, using an in vitro assay, lipoprotein serum concentrations, and standard lipid profile, was assessed in patients and control subjects. Carotid intima-media thickness (CIMT) and carotid plaques were assessed in patients with RA. A multivariable analysis was performed to evaluate the relationship of CEC with RA-related data, lipid profile, and subclinical carotid atherosclerosis. Results: Mean (SD) CEC was not significantly different between patients with RA (18.9 ± 9.0%) and control subjects (16.9 ± 10.4%) (p = 0.11). Patients with RA with low (? coefficient ?5.2 [?10.0 to 0.3]%, p = 0.039) and moderate disease activity (? coefficient ?4.6 [?8.5 to 0.7]%, p = 0.020) were associated with lower levels of CEC than patients in remission. Although no association with CIMT was found, higher CEC was independently associated with a lower risk for the presence of carotid plaque in patients with RA (odds ratio 0.94 [95% CI 0.89?0.98], p = 0.015). Conclusions: CEC is independently associated with carotid plaque in patients with RA

Neonatal and adult recent thymic emigrants produce IL-8 and express complement receptors CR1 and CR2

The maintenance of peripheral naive T lymphocytes in humans is dependent on their homeostatic division, not continuing emigration from the thymus, which undergoes involution with age. However, postthymic maintenance of naive T cells is still poorly understood. Previously we reported that recent thymic emigrants (RTEs) are contained in CD31+CD25- naive T cells as defined by their levels of signal joint T cell receptor rearrangement excision circles (sjTRECs). Here, by differential gene expression analysis followed by protein expression and functional studies, we define that the naive T cells having divided the least since thymic emigration express complement receptors (CR1 and CR2) known to bind complement C3b- and C3d-decorated microbial products and, following activation, produce IL-8 (CXCL8), a major chemoattractant for neutrophils in bacterial defense. We also observed an IL-8-producing memory T cell subpopulation coexpressing CR1 and CR2 and with a gene expression signature resembling that of RTEs. The functions of CR1 and CR2 on T cells remain to be determined, but we note that CR2 is the receptor for Epstein-Barr virus, which is a cause of T cell lymphomas and a candidate environmental factor in autoimmune disease

Boosting adults\u27 scientific literacy with experiential learning practices

Working as an interdisciplinary team, from the departments of Education and Biology we organized a short experiential learning seminar followed by a hands-on workshop for the promotion of citizen scientific literacy. Participants were adult lifelong learners enrolled in University programs, and others were adults interested in scientific activities without a motivation towards continuous learning. Through a teaching dynamic based on learning science by doing science, they could make close contact with the research procedures in scientific laboratories and learn about the use of DNA to identify unknown fish species. The data collected about their learning gains in this science literacy experience showed that elder lifelong learners found the basic scientific concepts more difficult to understand than the non-lifelong learners, but were more motivated to engage in science education activities than the latter, which makes them a very interesting potential group to recruit for citizen science initiatives. (DIPF/Orig.

Sustainable Management Plans in Fisheries and Genetic Tools: An Overview of the Challenge in Invertebrates’ Fisheries at the Central Area of the Southern Bay of Biscay, Spain

The fishing and aquaculture sectors are an important source of development around the globe. In Asturias (Spain), the diversity and richness of the fishing grounds of the Cantabrian Sea favored the historical settlement of a large number of communities closely linked to the marine environment and fishing resources, forming an integral part of the region’s cultural and natural heritage. However, aquatic ecosystems are facing, nowadays, important threats from anthropogenic activities. To address these problems and avoid their impact on fishing activities, it is essential to know the ecological and genetic status of the species. Despite this, the application of genetic tools is still incipient in many species of commercial interest; however, its use can help to generate data that allow better regulation and fisheries planning. Here, the use of genetic markers and educational strategies in the management of some shellfish species of great commercial and cultural value in Asturias are reviewed. Moving toward sustainable fisheries management is a priority that can only be achieved through R + D + i, educational strategies, and the development and implementation of a regional strategy oriented toward the sustainable management and exploitation

La incidencia de programas de actividad física en la población de adultos mayores

Different institutions affirm that it could show down the declivity of the functional capacities, as result of the old age, by the practice of physical activity make suitable for elderly. The Taiji-Quan, a slow Chinese physical activity, smooth and low physiological work, seems to be a suitable practice for elderly. The main target was to prove if three months of Taiji-Quan practice improve the functional and healthy physical condition of persons above 60 years old. We realized a study with a group of 66 persons, with a mean age of 69,73 years old. We made a control of two hours of Taiji-Quan per week along three months and we made an initial test before the control, and intermediate test and a final postest. The results display statistically significant improvements in the diastolic and systolic blood pressure, in the repose cardiac frequency, in the static and dynamic balance, in the flexibility and in the strength of arms and legs and in the endurance. The Taiji-Quan can be a physical activity suitable for improving the functional and healthy physical condition for elderly.Diferentes organismos afirman que se puede ralentizar el declive de las capacidades funcionales que se produce con la vejez, mediante la práctica de actividad física adaptada a las personas mayores. El Tai- Chi-Chuan, una gimnasia china lenta, suave y de bajas demandas fisiológicas, parece cumplir con los prerrequisitos necesarios para ser practicada por este colectivo. Nos planteamos un objetivo principal: comprobar si tres meses de práctica de Tai-Chi-Chuan mejoraban la condición física funcional y saludable de las personas mayores de 60 años. Se realizó un estudio con un grupo de 66 personas, con una edad media de 69,73 años. Se llevó a cabo una intervención de dos horas de Tai-Chi a la semana durante tres meses y se realizó un test inicial antes del tratamiento, un test intermedio y un postest final. Los resultados obtenidos muestran mejoras estadísticamente significativas en la presión sanguínea diastólica y sistólica, en la frecuencia cardíaca en reposo, en el equilibrio estático y dinámico, en la flexibilidad y en la fuerza de los miembros inferiores y superiores además de mejoras en la resistencia cardiovascular. El Tai-Chi-Chuan, por lo tanto, puede ser una actividad física adecuada para mejorar la condición física funcional y saludable de las personas mayores