Charge Carrier Injection Electroluminescence with CO-Functionalized Tips on Single Molecular Emitters.

We investigate electroluminescence of single molecular emitters on NaCl on Ag(111) and Au(111) with submolecular resolution in a low-temperature scanning probe microscope with tunneling current, atomic force, and light detection capabilities. The role of the tip state is studied in the photon maps of a prototypical emitter, zinc phthalocyanine (ZnPc), using metal and CO-metal tips. CO-functionalization is found to have an impact on the resolution and contrast of the photon maps due to the localized overlap of the p-orbitals on the tip with the molecular orbitals of the emitter. The possibility of using the same CO-functionalized tip for tip-enhanced photon detection and high resolution atomic force is demonstrated. We study the electroluminescence of ZnPc, induced by charge carrier injection at sufficiently high bias voltages. We propose that the distinct level alignment of the ZnPc frontier orbitals with the Au(111) and Ag(111) Fermi levels governs the primary excitation mechanisms as the injection of electrons and holes from the tip into the molecule, respectively. These findings put forward the importance of the tip status in the photon maps and contribute to a better understanding of the photophysics of organic molecules on surfaces.

Gate-Tunable Renormalization of Spin-Correlated Flat-Band States and Bandgap in a 2D Magnetic Insulator.

Emergent quantum phenomena in two-dimensional van der Waal (vdW) magnets are largely governed by the interplay between exchange and Coulomb interactions. The ability to precisely tune the Coulomb interaction enables the control of spin-correlated flat-band states, band gap, and unconventional magnetism in such strongly correlated materials. Here, we demonstrate a gate-tunable renormalization of spin-correlated flat-band states and bandgap in magnetic chromium tribromide (CrBr3) monolayers grown on graphene. Our gate-dependent scanning tunneling spectroscopy (STS) studies reveal that the interflat-band spacing and bandgap of CrBr3 can be continuously tuned by 120 and 240 meV, respectively, via electrostatic injection of carriers into the hybrid CrBr3/graphene system. This can be attributed to the self-screening of CrBr3 arising from the gate-induced carriers injected into CrBr3, which dominates over the weakened remote screening of the graphene substrate due to the decreased carrier density in graphene. Precise tuning of the spin-correlated flat-band states and bandgap in 2D magnets via electrostatic modulation of Coulomb interactions not only provides effective strategies for optimizing the spin transport channels but also may exert a crucial influence on the exchange energy and spin-wave gap, which could raise the critical temperature for magnetic order.

Highly Durable Nanoporous Cu2-xS Films for Efficient Hydrogen Evolution Electrocatalysis under Mild pH Conditions.

Copper-based hydrogen evolution electrocatalysts are promising materials to scale-up hydrogen production due to their reported high current densities; however, electrode durability remains a challenge. Here, we report a facile, cost-effective, and scalable synthetic route to produce Cu2-xS electrocatalysts, exhibiting hydrogen evolution rates that increase for ∼1 month of operation. Our Cu2-xS electrodes reach a state-of-the-art performance of ∼400 mA cm-2 at -1 V vs RHE under mild conditions (pH 8.6), with almost 100% Faradaic efficiency for hydrogen evolution. The rise in current density was found to scale with the electrode electrochemically active surface area. The increased performance of our Cu2-xS electrodes correlates with a decrease in the Tafel slope, while analyses by X-ray photoemission spectroscopy, operando X-ray diffraction, and in situ spectroelectrochemistry cooperatively revealed the Cu-centered nature of the catalytically active species. These results allowed us to increase fundamental understanding of heterogeneous electrocatalyst transformation and consequent structure-activity relationship. This facile synthesis of highly durable and efficient Cu2-xS electrocatalysts enables the development of competitive electrodes for hydrogen evolution under mild pH conditions.

Role of the Magnetic Anisotropy in Atomic-Spin Sensing of 1D Molecular Chains.

One-dimensional metal-organic chains often possess a complex magnetic structure susceptible to modification by alteration of their chemical composition. The possibility to tune their magnetic properties provides an interesting playground to explore quasi-particle interactions in low-dimensional systems. Despite the great effort invested so far, a detailed understanding of the interactions governing the electronic and magnetic properties of the low-dimensional systems is still incomplete. One of the reasons is the limited ability to characterize their magnetic properties at the atomic scale. Here, we provide a comprehensive study of the magnetic properties of metal-organic one-dimensional (1D) coordination polymers consisting of 2,5-diamino-1,4-benzoquinonediimine ligands coordinated with Co or Cr atoms synthesized under ultrahigh-vacuum conditions on a Au(111) surface. A combination of integral X-ray spectroscopy with local-probe inelastic electron tunneling spectroscopy corroborated by multiplet analysis, density functional theory, and inelastic electron tunneling simulations enables us to obtain essential information about their magnetic structures, including the spin magnitude and orientation at the magnetic atoms, as well as the magnetic anisotropy.

Non-covalent control of spin-state in metal-organic complex by positioning on N-doped graphene.

Nitrogen doping of graphene significantly affects its chemical properties, which is particularly important in molecular sensing and electrocatalysis applications. However, detailed insight into interaction between N-dopant and molecules at the atomic scale is currently lacking. Here we demonstrate control over the spin state of a single iron(II) phthalocyanine molecule by its positioning on N-doped graphene. The spin transition was driven by weak intermixing between orbitals with z-component of N-dopant (pz of N-dopant) and molecule (dxz, dyz, dz2) with subsequent reordering of the Fe d-orbitals. The transition was accompanied by an electron density redistribution within the molecule, sensed by atomic force microscopy with CO-functionalized tip. This demonstrates the unique capability of the high-resolution imaging technique to discriminate between different spin states of single molecules. Moreover, we present a method for triggering spin state transitions and tuning the electronic properties of molecules through weak non-covalent interaction with suitably functionalized graphene.

Stable Au-C bonds to the substrate for fullerene-based nanostructures.

We report on the formation of fullerene-derived nanostructures on Au(111) at room temperature and under UHV conditions. After low-energy ion sputtering of fullerene films deposited on Au(111), bright spots appear at the herringbone corner sites when measured using a scanning tunneling microscope. These features are stable at room temperature against diffusion on the surface. We carry out DFT calculations of fullerene molecules having one missing carbon atom to simulate the vacancies in the molecules resulting from the sputtering process. These modified fullerenes have an adsorption energy on the Au(111) surface that is 1.6 eV higher than that of C60 molecules. This increased binding energy arises from the saturation by the Au surface of the bonds around the molecular vacancy defect. We therefore interpret the observed features as adsorbed fullerene-derived molecules with C vacancies. This provides a pathway for the formation of fullerene-based nanostructures on Au at room temperature.

Estilos atribucionales en estudiantes españoles de Educación Secundaria Obligatoria con alta ansiedad social autoinformada / Attributional styles in Spanish students of Compulsory Secondary Education with high social anxiety self-reported

Resumen El objetivo de este estudio fue analizar la relación entre la ansiedad social y las autoatribuciones causales académicas en una muestra de 2022 (51.1% varones) adolescentes españoles de 12 a 16 años. La ansiedad social se evaluó utilizando el cuestionario Social Phobia and Anxiety Inventory (SPAI) y para el análisis de las autoatribuciones académicas se administró el Sydney Attribution Scale (SAS). Los resultados indican que los estudiantes con alta ansiedad social atribuyen sus fracasos en lectura y matemáticas más internamente (baja capacidad y bajo esfuerzo) y menos externamente que los alumnos sin alta ansiedad social. Además, los estudiantes con alta ansiedad social suelen atribuir sus éxitos en lectura menos externamente y sus éxitos en matemáticas menos internamente (capacidad) que los estudiantes sin alta ansiedad social. Asimismo, los resultados obtenidos de la regresión logística señalan que la alta ansiedad social actúa como predictor positivo respecto a la realización de autoatribuciones causales de los fracasos a la baja capacidad y a la falta de esfuerzo y como predictor negativo de la realización de autoatribuciones de los éxitos a la capacidad y la suerte y de atribuciones de los fracasos a causas externas.

Abstract This paper sought to analyze the relationship between social anxiety and academic causal self-attributions in a sample of 2022 Spanish adolescents (51.1% male) aged 12 to 16. Social anxiety was assessed using the questionnaire Social Phobia and Anxiety Inventory (SPAI). In addition, the Sydney Attribution Scale (SAS) was administered in order to analyze academic self-attributions. The results indicate that students with high social anxiety attribute their failures in reading and math more internally (low capacity and low effort) and less externally than do students without high social anxiety. Also, students with high social anxiety often attribute their success in reading less externally and their success in math less internally (capacity) than do students without high social anxiety. Thus, the results of logistic regression indicate that high social anxiety acts as a positive predictor vis-à-vis causal self-attributions of failures to low capacity and lack of effort whereas high social anxiety acts as a negative predictor self-attributions of success to the ability and chance and attributions of failures to external causes.

Development and validation of a computer application to aid the physician's decision-making process at the start of and during treatment with insulin in type 2 diabetes: a randomized and controlled trial.

BACKGROUND: Achieving optimum blood glucose control in patients with type 2 diabetes mellitus (T2DM) is difficult. Some primary care physicians (PCPs) delay the start of insulin use because of the uncertainty in intensifying insulin therapy. The objective was to develop and validate a computer application (CA) that helps PCPs to make decisions about insulin therapy in order to achieve a significant improvement in glycated hemoglobin (HbA1c). METHODS: This was a cluster-randomized clinical trial. Fourteen primary care centers (PCCs) in Madrid with 66 PCPs and 697 T2DM patients on insulin therapy were randomly divided into two groups of seven PCCs each. In the intervention group, seven PCCs included 39 PCPs and 365 T2DM patients on insulin therapy. These PCPs were free to use the CA. A further seven PCCs were assigned to the control group with 27 PCPs and 332 T2DM patients on insulin therapy. The control group did not use the CA. The duration of the trial was 18 months to validate the CA. The outcome was a change in HbA1c from baseline. RESULTS: In the intervention group, the final HbA1c was 7.19% (standard deviation [SD] ± 0.93), with a difference from the start of -0.69% (p = .001). In the control group, it was 7.71% (SD ± 1.37), with a difference from the start of -0.09% (p not significant). CONCLUSIONS: This CA helps to improve HbA1c figures of T2DM patients with insulin when it is used by PCPs to make decisions when starting, continuing, or changing insulin and its dosage.

Impacto psicológico del ciberbullying en estudiantes universitarios: un estudio exploratorio / Cyberbullying psychological impact on university students: An exploratory study

Los objetivos de este trabajo fueron determinar la prevalencia del ciberbullying entre los participantes del es tudio, así como conocer el impacto psicológico tanto en cibervíctimas como en ciberagresores, analizando además las diferencias de género de dicho impacto. La muestra estuvo constituida por 639 estudiantes de la Universidad Pontificia Bolivariana, seccional Bucaramanga, con una media de edad de 17,6 años (chicos N = 303, chicas N = 334). Para ello se emplearon los siguientes instrumentos: (a) Escala de ciberagresiones; (b) Escala de cibervictimización; y (c) Symptom Assessment-45 Questionnaire (SA-45). Los resultados evidencian que un 27,5% de la muestra ha sido agredida en alguna ocasión, así como que 26,7% ha sido acosador durante el último año. Por otro lado, los resultados demostraron que existe un impacto psicológico (escalas del SA-45) tanto en las cibervíctimas, como en los ciberagresores. Respecto a las diferencias de género en ciberbullying se evidenciaron solo en algunas escalas (primordialmente depresión, ansiedad, sensibilidad interpersonal y somatización), aunque no fueron significativas entre los síntomas psicológicos reportados en este estudio (salvo en las escalas relacionadas con Somatización y Ansiedad fóbica)

The objectives of this study were to determine the prevalence of cyberbullying among study participants and examine the psychological impact on both cyber victims and cyber attackers, also analyzing gender differences in the impact. The sample consisted of 639 students from the Universidad Pontificia Bolivariana, Bucaramanga branch, with an average age of 17.66 years (N = 303 boys, girls N = 334). For developing this analysis, the following instruments were used: (a) Scale cyber aggressions; (B) Scale cyber victimization; and (c) Symptom Assessment Questionnaire-45 (SA-45). The results show that 27.5% of the sample has been attacked on occasion, and that the stalker was 26.7% over the past year. On the other hand, the results showed that there is a psychological impact (SA45 scales) in both cyber victims and cyber aggressors. Gender differences in cyberbullying were evident only at some scales (primarily depression, anxiety, interpersonal sensitivity and somatization), although they were not significant among the psychological symptoms reported in this study (except for scales related to Somatization and Phobic Anxiety).

The Questionnaire about Interpersonal Difficulties for Adolescents: Reliability and Validity Evidence in Colombian Adolescent / El Cuestionario de Dificultades Interpersonales para adolescentes: evidencia de fiabilidad y validez en una muestra colombiana

The aim of this study was to analyze reliability and validity evidence of scores on the Colombian version of the Questionnaire about Interpersonal Difficulties for Adolescents (QIDA) in a sample of 1,628 adolescents (65.7% boys), ranging in age from 12 to 18 years. Confirmatory factor analyses replicated the correlated five-factor structure of the QIDA: Assertiveness, Heterosexual Relationships, Public Speaking, Family Relationships, and Close Friendships. Internal consistency for the QIDA and subscales scores was excellent. Girls reported higher level of perceived anxiety in heterosexual relationships, whereas boys showed more anxiety in close friendships and decreased interpersonal anxiety during adolescence. Results support the reliability and validity of the scores on the Colombian version of the QIDA.

Este objetivo de este estudio fue analizar la evidencia de fiabilidad y validez de las puntuaciones de la versión colombiana del Cuestionario de Dificultades Interpersonales para Adolescentes (QIDA) en una muestra de 1.628 adolescentes (65.7% chicos) de 12 a 18 años. Los análisis factoriales confirmatorios replicaron la estructura factorial de cinco factores relacionados: Asertividad, Relaciones Heterosexuales, Hablar en Público, Relaciones Familiares y Amigos Íntimos. La consistencia interna del QIDA y sus sub-escalas fue excelente. Las chicas informaron mayores niveles de ansiedad percibida en relaciones heterosexuales, mientras los chicos mostraron más ansiedad en relaciones con amigos íntimos. La ansiedad interpersonal disminuyó durante la adolescencia. Los resultados apoyan la fiabilidad y validez de las puntuaciones de la versión colombiana del QIDA.

[Clinical significance of Streptococcus agalactiae isolation from urine samples of outpatients from health care centers]. / Significado clínico del aislamiento de Streptococcus agalactiae de orina de pacientes de centros de salud.

INTRODUCTION: Streptococcus agalactiae is a well-recognized pathogen in the obstetric population and is a cause of invasive infection in adults with underlying diseases. Nevertheless, the role of S. agalactiae in urinary tract infections in the adult non-pregnant population treated in outpatient health care centers has been less extensively studied. METHODS: The clinical significance of S. agalactiae isolation in urine samples from health care center patients was studied in five areas of Spain over a period of six months. The study protocol included the collection of personal, epidemiological and clinical data. A total of 85 patients were studied; 79 were women (17 pregnant) and 6 men. RESULTS: Pyuria was found in 72.9% of the cases. A total of 26.4% (n = 18) of non-pregnant women and all the men had some type of chronic underlying disease and 35.3% (n = 24) had urinary disease. Among the pregnant women, 53% had asymptomatic bacteriuria and 35.3% had vaginal and/or urethral colonization. Among the group of men and non-pregnant women, the most frequent entity was non-complicated cystitis, seen in 66.1% (45 of 68) of cases, followed by complicated infection in 19.1% and asymptomatic bacteriuria in 11.8%. Of the 45 patients with non-complicated cystitis, 35 (77.7%) were over 40 years old and 19 (42.2%) were over 60 years old. CONCLUSIONS: Among the population of non-pregnant adults treated in outpatient health care centers, S. agalactiae isolation from urine was found mainly in women over 40 years old and was the cause of non-complicated urinary tract infection in more than half of cases.