Microdeterminación espectrofotométrica de Cu (II) por extracción de su complejo con 5,7-d¡bromo-8-hidrox¡qu¡noleína

The charasterictics of the Cu(II)-dibromoxine complex and its extraction into organic solvents are studied. In alkaline médium the formation of the complex and its extraction into chloroform is very selective. As result a new extractive spectrophotometric method for determination of copper (molar absorptivity 6,3·104 l.mol-1·cm-1) between 0,3-0,7 {xg/ml, is proposed. The new method showing a standard desviation of 0,24 %, has been succesfuUy applied to the Cu(II) analysis 0,04-0,06 %) in metallic lead.Se estudian las características del complejo de Cu(II) con 5,7-dibromo- -8-hidroxiquinoleína (dibromoxina) y su extracción en disolventes orgánicos. En medio alcalino la formación y extracción en cloroformo es muy selectiva. De las investigaciones realizadas se propone un nuevo método para la determinación espectrofotométrica de cobre entre 0,3- 0,7 ug/ml, la absortividad molar del complejo es 6,3·104 l.mol-1cm-1. La desviación estándar es 0,24 %. El método se ha aplicado con excelentes resultados para la determinación de cobre en muy pequeña cantidad, en plomo metálico

La complejidad terapéutica tras el implante de una válvula aórtica transcatéter (TAVI): un caso infrecuente de trombosis y endocarditis

La implantación de una válvula aórtica transcatéter (TAVI, transcatheter aortic valve implantation) es una práctica extendida en pacientes con estenosis aórtica de riesgo quirúrgico intermedio y alto. Se han descrito complicaciones como endocarditis e incluso trombosis valvular clínica, aunque con una incidencia de esta última de tan sólo 0.6% a 2.8% y es más frecuente luego los procedimientos valve-in-valve y válvulas expandibles con balón. La trombosis debe sospecharse en cualquier paciente con síntomas recientes de insuficiencia cardíaca, un episodio embólico o aumento manifiesto de los gradientes. La antivitamina K o la heparina no fraccionada son la primera línea de tratamiento. En la actualidad existe controversia acerca del tratamiento y la necesidad de la doble antiagregación tras el implante, ya que ésta parece aumentar los episodios hemorrágicos sin reducir las complicaciones isquémicas..

Reduction of ureteral stent encrustation by modulating the urine pH and inhibiting the crystal film with a new oral composition: a multicenter, placebo controlled, double blind, randomized clinical trial

Background: Encrustation of ureteral double J stents is a common complication that may affect its removal. The aim of the proposed study is to evaluate the efficacy and safety of a new oral composition to prevent double J stent encrustation in indwelling times up to 8 weeks. Methods: A double-blinded, multicenter, placebo-controlled trial was conducted with 105 patients with indwelling double J stents enrolled across 9 public hospitals in Spain. The patients were randomly assigned (1:1) into intervention (53 patients) or placebo (52 patients) groups for 3 to 8 weeks and both groups self-monitored daily their morning urine pH levels. The primary outcome of analysis was the degree of stent ends encrustation, defined by a 4-point score (0 - none; 3 - global encrustation) using macroscopic and electron microscopy analysis of crystals, after 3 to 8-w indwelling period. Score was exponentially transformed according to calcium levels. Secondary endpoints included urine pH decrease, stent removal, and incidence of adverse events. Results: The intervention group benefits from a lower global encrustation rate of stent ends than placebo group (1% vs 8.2%; p < 0.018). Mean encrustation score was 85.12 (274.5) in the placebo group and 18.91 (102.27) in the intervention group (p < 0.025). Considering the secondary end points, treated patients reported greater urine pH decreases (p = 0.002). No differences in the incidence of adverse events were identified between the groups. Conclusions: Our data suggest that the use of this new oral composition is beneficial in the context of ureteral double J indwelling by decreasing mean, as well as global encrustation

Effects of the lava flows associated with the eruption of the volcano ot Cumbre vieja (2021) on the insular shelf and slope of La Palma island (Canary Islands)

Peer reviewe

Sobrevivencia de pacientes con Enfermedad Renal Crónica Tradicional y no Tradicional en clínicas de hemodiálisis del Instituto Guatemalteco de Seguridad Social de Escuintla, Suchitepéquez y Retalhuleu, Guatemala

A nivel mundial, la enfermedad renal crónica (ERC), representa un problema de salud ingente, con un incremento de 82.3 % de muertes en las últimas dos décadas, ya sea por la ERC secundaria a diabetes o hipertensión arterial entre otras, o la enfermedadrenal crónica de causa no tradicional (ERCnT), relacionada con las condiciones extremas de trabajo agrícola en Mesoamérica, la inadecuada rehidratación y al estrés por calor. Debido a la falta de datos sobre las características epidemiológicas de estasenfermedades, se realizó un estudio sobre la sobrevivencia de 55 pacientes con ERC y ERCnT, en tres departamentos de la costa sur de Guatemala, por medio de un estudio transversal retrospectivo en pacientes en estadio V con tratamiento de hemodiálisisen el Instituto Guatemalteco de Seguridad Social (IGSS). Se aplicó el análisis estadístico de Kaplan-Meier para calcular las tasas de sobrevivencia a 5 años. Se determinó que la ERCnT tiene una mayor sobrevivencia (69.6 %) con respecto a ERC (38.9 %) yuna mayor tasa de sobrevivencia en mujeres (58.8 %) que en hombres (47.4 %). Al comparar las vías de acceso vascular en la hemodiálisis, los pacientes con fístula tienen menor tasa de mortalidad (22.9) que los que utilizaban catéter (39.0). La tasa de incidencia de mortalidad general en pacientes con ERC y ERCnT durante el período de enero de 2013 a agosto 2019 fue de 29.1 por 100 años/personas. La mayor tasa de mortalidad en estos pacientes estuvo asociada a eventos cardiovasculares (36.4 %)

Sobrevivencia de pacientes con Enfermedad Renal Crónica Tradicional y no Tradicional en clínicas de hemodiálisis del Instituto Guatemalteco de Seguridad Social de Escuintla, Suchitepéquez y Retalhuleu, Guatemala

A nivel mundial, la enfermedad renal crónica (ERC), representa un problema de salud ingente, con un incremento de 82.3 % de muertes en las últimas dos décadas, ya sea por la ERC secundaria a diabetes o hipertensión arterial entre otras, o la enfermedadrenal crónica de causa no tradicional (ERCnT), relacionada con las condiciones extremas de trabajo agrícola en Mesoamérica, la inadecuada rehidratación y al estrés por calor. Debido a la falta de datos sobre las características epidemiológicas de estasenfermedades, se realizó un estudio sobre la sobrevivencia de 55 pacientes con ERC y ERCnT, en tres departamentos de la costa sur de Guatemala, por medio de un estudio transversal retrospectivo en pacientes en estadio V con tratamiento de hemodiálisisen el Instituto Guatemalteco de Seguridad Social (IGSS). Se aplicó el análisis estadístico de Kaplan-Meier para calcular las tasas de sobrevivencia a 5 años. Se determinó que la ERCnT tiene una mayor sobrevivencia (69.6 %) con respecto a ERC (38.9 %) yuna mayor tasa de sobrevivencia en mujeres (58.8 %) que en hombres (47.4 %). Al comparar las vías de acceso vascular en la hemodiálisis, los pacientes con fístula tienen menor tasa de mortalidad (22.9) que los que utilizaban catéter (39.0). La tasa de incidencia de mortalidad general en pacientes con ERC y ERCnT durante el período de enero de 2013 a agosto 2019 fue de 29.1 por 100 años/personas. La mayor tasa de mortalidad en estos pacientes estuvo asociada a eventos cardiovasculares (36.4 %)

Effects of the lava flows associated to the Tajogaite volcano eruption (2021) on the insular shelf and slope of La Palma island

The eruption of the Cumbre Vieja volcano started on September 19, 2021, on the island of La Palma, following a seismic swarm that affected the southern half of the island. The lava flowed westward and reached the coastline 8 days later in the area between Punta de la Bombilla and Tazacorte harbour. Four oceanographic cruises on board the research vessels Ramón Margalef and Ángeles Alvariño (Spanish Institute of Oceanography, IEO-CSIC) aimed to (i) characterizing the petrologic features prior to the arrival of the lava flows into the coastline, (ii) assessing the variations of the water-magma system when the lava flowed into the sea, and (iii) evaluating the main changes in the system after the end of the eruption. High-resolution bathymetric maps obtained with the multibeam echosounder EM710, combined with submarine high- definition ROV LIROPUS images and rocks samples collected from the sea bottom, showed that lava flowed down the shelf and upper slope as block (aa) and pillow lava flows, being conditioned by small gullies on the upper slope. Significant morphological changes have been defined in the subaerial northern and southern lava deltas (areas of 5,4 and 43 ha, respectively), and on a submarine area of ~30 ha. Volcanic material has been identified as far as 1.2 km from the original coastline at ~305 m seawater depth. Preliminary petrographic studies determine that the began as tephrites and later evolved intro basanites with olivine, pyroxene, amphibole and plagioclase phenocrysts within a glassy matrix with variable number of vesicles. The total volume of lava reaching the submarine environment is estimated of around 3 Mm3 with maximum thickness ca. 40 m along previous submarine slope gullies. Integrated with multidisciplinary analyses of the water column and ecosystem changes, this study will improve the knowledge of the magmatic evolution from depth up to eruption and will be useful for the risk management of future eruptive events.Peer reviewe

Perivascular spaces are associated with tau pathophysiology and synaptic dysfunction in early Alzheimer’s continuum

Background: Perivascular spaces (PVS) have an important role in the elimination of metabolic waste from the brain. It has been hypothesized that the enlargement of PVS (ePVS) could be affected by pathophysiological mechanisms involved in Alzheimer’s disease (AD), such as abnormal levels of CSF biomarkers. However, the relationship between ePVS and these pathophysiological mechanisms remains unknown. Objective: We aimed to investigate the association between ePVS and CSF biomarkers of several pathophysiological mechanisms for AD. We hypothesized that ePVS will be associated to CSF biomarkers early in the AD continuum (i.e., amyloid positive cognitively unimpaired individuals). Besides, we explored associations between ePVS and demographic and cardiovascular risk factors. Methods: The study included 322 middle-aged cognitively unimpaired participants from the ALFA + study, many within the Alzheimer’s continuum. NeuroToolKit and Elecsys® immunoassays were used to measure CSF Aβ42, Aβ40, p-tau and t-tau, NfL, neurogranin, TREM2, YKL40, GFAP, IL6, S100, and α-synuclein. PVS in the basal ganglia (BG) and centrum semiovale (CS) were assessed based on a validated 4-point visual rating scale. Odds ratios were calculated for associations of cardiovascular and AD risk factors with ePVS using logistic and multinomial models adjusted for relevant confounders. Models were stratified by Aβ status (positivity defined as Aβ42/40 < 0.071). Results: The degree of PVS significantly increased with age in both, BG and CS regions independently of cardiovascular risk factors. Higher levels of p-tau, t-tau, and neurogranin were significantly associated with ePVS in the CS of Aβ positive individuals, after accounting for relevant confounders. No associations were detected in the BG neither in Aβ negative participants. Conclusions: Our results support that ePVS in the CS are specifically associated with tau pathophysiology, neurodegeneration, and synaptic dysfunction in asymptomatic stages of the Alzheimer’s continuum

Radial evolution of the April 2020 stealth coronal mass ejection between 0.8 and 1 AU - Comparison of Forbush decreases at Solar Orbiter and near the Earth

Aims. We present observations of the first coronal mass ejection (CME) observed at the Solar Orbiter spacecraft on April 19, 2020, and the associated Forbush decrease (FD) measured by its High Energy Telescope (HET). This CME is a multispacecraft event also seen near Earth the next day. Methods. We highlight the capabilities of HET for observing small short-term variations of the galactic cosmic ray count rate using its single detector counters. The analytical ForbMod model is applied to the FD measurements to reproduce the Forbush decrease at both locations. Input parameters for the model are derived from both in situ and remote-sensing observations of the CME. Results. The very slow (~350 km/s) stealth CME caused a FD with an amplitude of 3 % in the low-energy cosmic ray measurements at HET and 2 % in a comparable channel of the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on the Lunar Reconnaissance Orbiter, as well as a 1 % decrease in neutron monitor measurements. Significant differences are observed in the expansion behavior of the CME at different locations, which may be related to influence of the following high speed solar wind stream. Under certain assumptions, ForbMod is able to reproduce the observed FDs in low-energy cosmic ray measurements from HET as well as CRaTER, but with the same input parameters, the results do not agree with the FD amplitudes at higher energies measured by neutron monitors on Earth. We study these discrepancies and provide possible explanations. Conclusions. This study highlights that the novel measurements of the Solar Orbiter can be coordinated with other spacecraft to improve our understanding of space weather in the inner heliosphere. Multi-spacecraft observations combined with data-based modeling are also essential to understand the propagation and evolution of CMEs as well as their space weather impacts

Lucro líquido do franqueado: um sinal para a escolha de franquia em época de crise

Este artículo aborda desde la perspectiva de la Teoría de Señales la elección de una franquicia por un potencial franquiciado que elige este canal de distribución por primera vez. El objetivo es analizar la relación entre algunas señales enviadas por el franquiciador y la elección de una franquicia por el potencial franquiciado. Concluimos que los efectos de las variables macroeconómicas de España en el periodo 2006-2013 influyeron en los ingresos netos de los franquiciados para que se convirtiera en una señal empleada por éstos a la hora de elegir la franquicia donde abrir un establecimiento.This paper adopts the perspective of Theory of Signals to discuss how someone starting a business as a franchisee for the first time can choose a suitable franchise brand. The aim was to analyze the relationship between certain signals sent by the franchisor and the choice of a franchise brand by the prospective franchisee. Using panel data, we found that the effects of macroeconomic variables in Spain for the 2006-2013 crisis period influenced franchisees' net income, which thus became a relevant signal in their process of choosing a franchise brand to start a business.Sob a perspectiva da Teoria de Sinais, este artigo aborda a seleção de uma franquia por um franqueado que elege esse potencial canal de distribuição pela primeira vez. O objetivo é analisar a relação entre alguns sinais enviados pelo franqueador e a escolha de uma franquia pelo potencial franqueado. Usando a metodologia de dados em painel, os resultados obtidos nos permitiram concluir que os efeitos das variáveis macroeconômicas da Espanha no período de crise econômica (2006-2013) influenciaram as receitas líquidas dos franqueados, tornando-se um sinal para eles elegerem onde abrir um estabelecimento franqueado