103 research outputs found

    Antiferromagnetic single-chain magnet slow relaxation in the {Tb(α-fur)3}n polymer with non-Kramers ions

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    We report the synthesis, crystal structure and magnetic properties of a new molecular complex based on a Tb(iii) ion supported by 2-furancarboxylic molecules: {Tb(α-fur)(HO)} (α-fur = CHOCOO). Two slightly different Tb sites (A and B) exist depending on the position of one of the dangling ligands. Ab initio calculations predict that, for both sites, the magnetic ground state is highly anisotropic (g∗ = 17.8) and consists of a quasi-doublet with a small gap, well isolated from the next excited state. The α-fur ligand forms 1D polymeric chains of Tb ions of the same type (either A or B) running along the c-axis. The crystal structure is formed by the supramolecular stacking along the a-axis of 2D layers containing parallel chains of the same type. Static magnetization and heat capacity measurements show that, magnetically, the system can be modeled as an ensemble of Ising chains of non-Kramers Tb ions with effective spin S∗ = 1/2, antiferromagnetically (AF) coupled by a weak intrachain interaction (J∗/k = -0.135 K). At very low temperatures, the static susceptibility reflects the presence of a 2-4% concentration of defects in the chains. Ac susceptibility measurements at H = 0 performed down to mK temperatures have enabled us to observe the slow relaxation of magnetization through two different pathways. They are assigned to Single-Chain-Magnet (SCM) behavior in two different types of AF chains (A and B), triggered by the existence of defects breaking the chains into segments with short-range order. At temperatures below 0.1 K this mechanism is replaced by individual relaxation of the ions through direct processes. Under the application of a magnetic field the system slowly relaxes by two distinct direct processes, strongly affected by a phonon bottleneck effect.This work has been financed by MECOM Projects MAT11/23791 and MAT11/27233-C02-02, MAT2015-68204-R, MAT2014-53921-R, DGA IMANA E34 and MOLCHIP E98 Projects. Consolider Nanoselect (CSD2007-00041) and by a grant of the Ministry of National Education, CNCS – UEFISCDI, project number PN-II-ID-PCE-2012-4-0261. D. P. thanks the Alexander von Humboldt (AvH) Foundation for financial support.Peer Reviewe

    Lanthanide luminescence to mimic molecular logic and computing through physical inputs

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    The remarkable advances in molecular logic reported in the last decadedemonstrate the potential of luminescent molecules for logical operations, aparadigm-changing concerning silicon-based electronics. Trivalent lanthanide(Ln3+) ions, with their characteristic narrow line emissions, long-lived excitedstates, and photostability under illumination, may improve the state-ofthe-art molecular logical devices. Here, the use of monolithic silicon-basedstructures incorporating Ln3+ complexes for performing logical functions isreported. Elementary logic gates (AND, INH, and DEMUX), sequential logic(KEYPAD LOCK), and arithmetic operations (HALF ADDER and HALF SUBTRACTOR)exhibiting a switching ratio >60% are demonstrated for the firsttime using nonwet conditions. Additionally, this is the first report showingsequential logic and arithmetic operations combining molecular Ln3+ complexesand physical inputs. Contrary to chemical inputs, physical inputs mayenable the future concatenation of distinct logical functions and reuse of thelogical devices, a clear step forward toward input–output homogeneity that isprecluding the integration of nowadays molecular logic devices.</p

    Exploiting the Redox Activity of MIL-100(Fe) Carrier Enables Prolonged Carvacrol Antimicrobial Activity

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    The design of efficient food contact materials that maintain optimal levels of food safety is of paramount relevance to reduce the increasing number of foodborne illnesses. In this work, we develop a smart composite metal-organic framework (MOF)-based material that fosters a unique prolonged antibacterial activity. The composite is obtained by entrapping a natural food preserving molecule, carvacrol, into a mesoporous MIL-100(Fe) material following a direct and biocompatible impregnation method, and obtaining particularly high payloads. By exploiting the intrinsic redox nature of the MIL-100(Fe) material, it is possible to achieve a prolonged activity against Escherichia coli and Listeria innocua due to a triggered two-step carvacrol release from films containing the carvacrol@MOF composite. Essentially, it was discovered that based on the underlying chemical interaction between MIL-100(Fe) and carvacrol, it is possible to undergo a reversible charge-transfer process between the metallic MOF counterpart and carvacrol upon certain chemical stimuli. During this process, the preferred carvacrol binding site was monitored by infrared, Mössbauer, and electron paramagnetic resonance spectroscopies, and the results are supported by theoretical calculations

    Diabetic retinopathy as a predictor of cardiovascular morbidity and mortality in subjects with type 2 diabetes

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    This study aimed to evaluate the predictive value of diabetic retinopathy (DR) and its stages with the incidence of major cardiovascular events and all-cause mortality in type 2 diabetes mellitus (T2DM) persons in our large primary healthcare database from Catalonia (Spain). A retrospective cohort study with pseudo-anonymized routinely collected health data from SIDIAP was conducted from 2008 to 2016. We calculated incidence rates of major cardiovascular events [coronary heart disease (CHD), stroke, or both-macrovascular events] and all-cause mortality for subjects with and without DR and for different stages of DR. The proportional hazards regression analysis was done to assess the probability of occurrence between DR and the study events. About 22,402 T2DM subjects with DR were identified in the database and 196,983 subjects without DR. During the follow-up period among the subjects with DR, we observed the highest incidence of all-cause mortally. In the second place were the macrovascular events among the subjects with DR. In the multivariable analysis, fully adjusted for DR, sex, age, body mass index (BMI), tobacco, duration of T2DM, an antiplatelet or antihypertensive drug, and HbA1c, we observed that subjects with any stage of DR had higher risks for all of the study events, except for stroke. We observed the highest probability of all-cause death events (adjusted hazard ratios, AHRs: 1.34, 95% CI: 1.28; 1.41). In conclusion, our results show that DR is related to CHD, macrovascular events, and all-cause mortality among persons with T2DM

    Project of the academic performance improvement

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    The transition of students from high school to university is a changing and complicated stage. It is during the initial phase when most drop-outs from engineering degrees occur. There are several reasons for this, however, the most highlighted ones are: i) the mismatch between the students knowledge level after finishing high school and the initial level required by the university degrees; and ii) the lack of a habit and constancy of study on the part of the students. The proposed project aims to design specific tools to improve academic performance in the initial phase of the Degree in Industrial Technologies imparted at ESEIAAT by addressing the two problems mentioned before. In light of this, the measures adopted to solve these points will be tackled separately and properly explained in the following two blocks: block I) Initial level acces, block II) Monitoring of self-learning. Finally, an assessment of the strategies followed will be carried out in a final phase, block III) Integration project

    Diferencias en el perfil de derivación recibido en los centros de rehabilitación psicosocial en función del género.

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    Introducción: La percepción de los profesionales que trabajan en recursos de atención social a personas con trastorno mental grave apunta a la existencia de diferencias en las características de los hombres y mujeres que llegan a estos dispositivos. Material y Método: Este trabajo pretende ser una aproximación al análisis de dichas diferencias, para lo cual se ha comparado el perfil sociodemográfico y clínico-psiquiátrico de los hombres y mujeres derivados a los Centros de Rehabilitación Psicosocial de San Fernando de Henares, Alcalá de Henares y La Elipa, pertenecientes a la Red de recursos de atención social a personas con enfermedad mental grave y duradera de la Comunidad de Madrid, durante un período de cinco años. Durante esos años u total de 302 personas fueron derivadas a estos recursos, 188 varones y 114 mujeres. La muestra total se dividió en dos grupos: hombres-mujeres y se realizaron las tablas de contingencia y los análisis estadísticos pertinentes de las variables referidas. Resultados: Los análisis realizados indican que las mujeres que son derivadas a estos recursos son más mayores que los hombres, tienen en mayor medida certificado de minusvalía, cobran más a menudo pensiones no contributivas, no tienen una profesión definida y llegan tras un periodo de evolución mayor del trastorno

    Trends in Mortality Due to Myocardial Infarction, Stroke, and Pulmonary Embolism in Patients Receiving Dialysis

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    IMPORTANCE During the past decades, improvements in the prevention and management of myocardial infarction, stroke, and pulmonary embolism have led to a decline in cardiovascular mortality in the general population. However, it is unknown whether patients receiving dialysis have also benefited from these improvements. OBJECTIVE To assess the mortality rates for myocardial infarction, stroke, and pulmonary embolism in a large cohort of European patients receiving dialysis compared with the general population. DESIGN, SETTING, AND PARTICIPANTS In this cohort study, adult patients who started dialysis between 1998 and 2015 from 11 European countries providing data to the European Renal Association Registry were and followed up for 3 years. Data were analyzed from September 2020 to February 2022. EXPOSURES Start of dialysis. MAIN OUTCOMES AND MEASURES The age- and sex-standardized mortality rate ratios (SMRs) with 95% CIs were calculated by dividing the mortality rates in patients receiving dialysis by the mortality rates in the general population for 3 equal periods (1998-2003, 2004-2009, and 2010-2015). RESULTS In total, 220 467 patients receiving dialysis were included in the study. Their median (IQR) age was 68.2 (56.5-76.4) years, and 82 068 patients (37.2%) were female. During follow-up, 83 912 patients died, of whom 7662 (9.1%) died because of myocardial infarction, 5030 (6.0%) died because of stroke, and 435 (0.5%) died because of pulmonary embolism. Between the periods 1998 to 2003 and 2010 to 2015, the SMR of myocardial infarction decreased from 8.1 (95% CI, 7.8-8.3) to 6.8 (95% CI, 6.5-7.1), the SMR of stroke decreased from 7.3 (95% CI, 7.0-7.6) to 5.8 (95% CI, 5.5-6.2), and the SMR of pulmonary embolism decreased from 8.7 (95% CI, 7.6-10.1) to 5.5 (95% CI, 4.5-6.6). CONCLUSIONS AND RELEVANCE In this cohort study of patients receiving dialysis, mortality rates for myocardial infarction, stroke, and pulmonary embolism decreased more over time than in the general population.Peer reviewe
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