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1.
Small ; : e2312235, 2024 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-38433104

RESUMO

Bombarding WS2 multilayered nanoparticles and nanotubes with focused ion beams of Ga+ ions at high doses, larger than 1016 cm-2 , leads to drastic structural changes and melting of the material. At lower doses, when the damage is negligible or significantly smaller, the amount of implanted Ga is very small. A substantial increase in the amount of implanted Ga, and not appreciable structural damage, are observed in nanoparticles previously hydrogenated by a radio-frequency activated hydrogen plasma. Density functional calculations reveal that the implantation of Ga in the spaces between adjacent layers of pristine WS2 nanoparticles is difficult due to the presence of activation barriers. In contrast, in hydrogenated WS2 , the hydrogen molecules are able to intercalate in between adjacent layers of the WS2 nanoparticles, giving rise to the expansion of the interlayer distances, that in practice leads to the vanishing of the activation barrier for Ga implantation. This facilitates the implantation of Ga atoms in the irradiation experiments.

2.
Phys Chem Chem Phys ; 26(5): 3941-3949, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38241018

RESUMO

Molecular self-assembled films have recently attracted increasing attention within the field of nanotechnology as they offer a route to obtain new materials. However, careful selection of the molecular precursors and substrates, as well as exhaustive control of the system evolution is required to obtain the best possible outcome. The three-fold rotational symmetry of melamine molecules and their capability to form hydrogen bonds make them suitable candidates to synthesize this type of self-assembled network. In this work, we have studied the polymorphism of melamine nanostructures on Au(111) at room temperature. We find two coverage-dependent phases: a honeycomb structure (α-phase) for submonolayer coverage and a close-packed structure (ß-phase) for full monolayer coverage. A combined scanning tunnel microscopy and density functional theory based-calculations study of the transition regime where both phases coexist allows describing the mechanism underlying this coverage driven phase transition in terms of the changes in the molecular lateral tension.

3.
Adv Sci (Weinh) ; 10(29): e2303562, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37590383

RESUMO

The development of n-type organic semiconductors has evolved significantly slower in comparison to that of p-type organic semiconductors mainly due to the lack of electron-deficient building blocks with stability and processability. However, to realize a variety of organic optoelectronic devices, high-performance n-type polymer semiconductors are essential. Herein, conjugated microporous polymers (CMPs) comprising isoindigo acceptor units linked to benzene or pyrene donor units (BI and PI) showing n-type semiconducting behavior are reported. In addition, considering the challenges of deposition of a continuous and homogeneous thin film of CMPs for accurate Hall measurements, a plasma-assisted fabrication technique is developed to yield uniform thin films. The fully conjugated 2D networks in PI- and BI-CMP films display high electron mobility of 6.6 and 3.5 cm2 V-1 s-1 , respectively. The higher carrier concentration in PI results in high conductivity (5.3 mS cm-1 ). Both experimental and computational studies are adequately combined to investigate structure-property relations for this intriguing class of materials in the context of organic electronics.

4.
Nanoscale ; 15(35): 14680, 2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37622397

RESUMO

Correction for 'In situ observation of the on-surface thermal dehydrogenation of n-octane on Pt(111)' by Daniel Arribas et al., Nanoscale, 2023, https://doi.org/10.1039/d3nr02564k.

5.
Nanoscale ; 15(35): 14458-14467, 2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37458500

RESUMO

The catalytic dehydrogenation of alkanes constitutes a key step for the industrial conversion of these inert sp3-bonded carbon chains into other valuable unsaturated chemicals. To this end, platinum-based materials are among the most widely used catalysts. In this work, we characterize the thermal dehydrogenation of n-octane (n-C8H18) on Pt(111) under ultra-high vacuum using synchrotron-radiation X-ray photoelectron spectroscopy, temperature-programmed desorption and scanning tunneling microscopy, combined with ab initio calculations. At low activation temperatures, two different dehydrogenation stages are observed. At 330 K, n-C8H18 effectively undergoes a 100% regioselective single C-H bond cleavage at one methyl end. At 600 K, the chemisorbed molecules undergo a double dehydrogenation, yielding double bonds in their carbon skeletons. Diffusion of the dehydrogenated species leads to the formation of carbon molecular clusters, which represents the first step towards poisoning of the catalyst. Our results reveal the chemical mechanisms behind the first stages of alkane dehydrogenation on a platinum model surface at the atomic scale, paving the way for designing more efficient dehydrogenation catalysts.

6.
Biosens Bioelectron ; 222: 115006, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36538869

RESUMO

Biosensors based on graphene field-effect transistors have become a promising tool for detecting a broad range of analytes. However, their performance is substantially affected by the functionalization protocol. In this work, we use a controlled in-vacuum physical method for the covalent functionalization of graphene to construct ultrasensitive aptamer-based biosensors (aptasensors) able to detect hepatitis C virus core protein. These devices are highly specific and robust, achieving attomolar detection of the viral protein in human blood plasma. Such an improved sensitivity is rationalized by theoretical calculations showing that induced polarization at the graphene interface, caused by the proximity of covalently bound molecular probe, modulates the charge balance at the graphene/aptamer interface. This charge balance causes a net shift of the Dirac cone providing enhanced sensitivity for the attomolar detection of the target proteins. Such an unexpected effect paves the way for using this kind of graphene-based functionalized platforms for ultrasensitive and real-time diagnostics of different diseases.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Grafite , Hepatite C , Humanos , Proteínas do Core Viral , Hepatite C/diagnóstico
7.
J. Health NPEPS ; 7(2): 1-18, jul - dez, 2022.
Artigo em Espanhol | LILACS, BDENF - enfermagem (Brasil), Coleciona SUS (Brasil) | ID: biblio-1425070

RESUMO

RESUMENObjetivo: determinar la relación entre la inteligencia emocional y la prevalencia del consumo de alcohol en jóvenes universitarios. Método: diseñodescriptivo, transversal y correlacional, muestreo no probabilístico por conveniencia con una muestra de 365 estudiantes de una institución pública de educación superior en el periodo 2021-2022, en H. Matamoros, Tamaulipas, México, se utilizó estadística descriptiva y correlacional. Resultados: el género femenino fue mayor (76.7%), con un rango de edad de 18 a 24 años, donde la prevalencia de consumo de alcohol en la vida fue de 77% y la edad de primer consumo se ubicó entre 15 y 18 años (56.4%). El consumo lapsico fue en el último año 38.8%. Las dimensiones inteligencia emocional de atención de los sentimientos y reparación de emociones presentaron en ambos géneros valores similares, en su mayoría un nivel adecuado y excelente. La correlación en mujeres entre edad de consumo de alcohol y las dimensiones la inteligencia emocional, fue significativa e inversa. Conclusión:los estudiantes presentan altas prevalencias de consumo y inteligencia emocional, se encontró que para el género masculino la claridad emocional requiere estrategias que permitan mejorarla.


Objective:to determine the relationship between emotional intelligence and the prevalence of alcohol consumption in university students. Method: descriptive, cross-sectional and correlational design, non-probabilistic convenience sampling with a sample of 365 students from a public institution of higher education in the period 2021-2022, in H. Matamoros, Tamaulipas, Mexico, descriptive and correlational statistics were used. Results: the female gender was higher (76.7%), with an age range of 18 to 24 years, where the prevalence of alcohol consumption in life was 77% and the age of first consumption was between 15 and 18 years. (56.4%). The lapsique consumption was in the last year 38.8%. The emotional intelligence dimensions of attention to feelings and repair of emotions presented similar values in both genders, mostly an adequate and excellent level. The correlation in women between the age of alcohol consumption and the emotional intelligence dimensions was significant and inverse. Conclusion: the students present high prevalences of consumption and emotional intelligence, it was found that for the male gender, emotional clarity requires strategies that allow it to be improved.


Objetivo:determinar a relação entre a inteligência emocional e a prevalência do consumo de álcool em estudantes universitários. Método: desenho descritivo, transversal e correlacional, amostragem não probabilística de conveniência com 365 estudantes de uma instituição pública de ensino superior no período de 2021 a 2022, em H. Matamoros, Tamaulipas, México. Aplicou estatística descritiva e correlacional. Resultados: o sexofeminino foi maior (76,7%), com faixa etária de 18 a 24 anos, onde a prevalência de consumo de álcool na vida foi de 77% e a idade do primeiro consumo foi entre 15 e 18 anos (56,4%). O consumo lapsico foi no ano passado 38,8%. As dimensões da inteligênciaemocional de atenção aos sentimentos e reparação de emoções apresentaram valores semelhantes em ambos os sexos, na sua maioria um nível adequado e excelente. A correlação das mulheres entre a idade de consumo de álcool e as dimensões da inteligência emocional foi significativa e inversa. Conclusão: os alunos apresentam altas prevalências de consumo e inteligência emocional, e verificou-se que para o gênero masculino, a clareza emocional requer estratégias que permitam melhorá-la.


Assuntos
Estudantes , Consumo de Bebidas Alcoólicas , Inteligência Emocional
8.
Nanomaterials (Basel) ; 12(4)2022 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-35215003

RESUMO

This work contributes to enlightening the opportunities of the anisotropic scheme of non-covalent interactions present in supramolecular materials. It provides a top-down approach based on their selective disruption that herein has been employed to process a conventional microcrystalline material to a nanofibrillar porous material. The developed bulk microcrystalline material contains uracil-1-propionic acid (UPrOH) nucleobase as a molecular recognition capable building block. Its crystal structure consists of discrete [Cu(UPrO)2 (4,4'-bipy)2 (H2 O)] (4,4'-bipy=4,4'-bipyridine) entities held together through a highly anisotropic scheme of non-covalent interactions in which strong hydrogen bonds involving coordinated water molecules provide 1D supramolecular chains interacting between them by weaker interactions. The sonication of this microcrystalline material and heating at 45 °C in acetic acid-methanol allows partial reversible solubilization/recrystallization processes that promote the cross-linking of particles into an interlocked platelet-like micro-particles metal-organic gel, but during CO2 supercritical drying, the microcrystalline particles undergo a complete morphological change towards highly anisotropic nanofibers. This unprecedented top-down microstructural conversion provides a nanofibrillar material bearing the same crystal structure but with a highly increased surface area. Its usefulness has been tested for HPLC separation purposes observing the expected nucleobase complementarity-based separation.

9.
ACS Appl Mater Interfaces ; 14(1): 2015-2022, 2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-34931799

RESUMO

Photocatalytic CO2 reduction into formate (HCOO-) has been widely studied with semiconductor and molecule-based systems, but it is rarely investigated with covalent organic frameworks (COFs). Herein, we report a novel donor-acceptor COF named Co-PI-COF composed of isoindigo and metallated porphyrin subunits that exhibits high catalytic efficiency (∼50 µmol formate g-1 h-1) at low-power visible-light irradiation and in the absence of rare metal cocatalysts. Density functional theory calculations and experimental diffuse-reflectance measurements are used to explain the origin of catalytic efficiency and the particularly low band gap (0.56 eV) in this material. The mechanism of photocatalysis is also studied experimentally and is found to involve electron transfer from the sacrificial agent to the excited Co-PI-COF. The observed high-efficiency conversion could be ascribed to the enhanced CO2 adsorption on the coordinatively unsaturated cobalt centers, the narrow band gap, and the efficient transfer of the charge originating from the postsynthetic metallation. It is anticipated that this study will pave the way toward the design of new simple and efficient catalysts for photocatalytic CO2 reduction into useful products.

10.
Work ; 69(3): 957-967, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34219690

RESUMO

BACKGROUND: The constant changes in the global economy generate instability in the markets, favoring the closing of companies, dismissals of personnel, job losses. Unemployment has been associated with adverse psychological effects, serving as a predictor of poor mental health. OBJECTIVE: The main goal was to analyze the relation between work status and mental health. METHODS: A cross-sectional, quantitative study was carried out with a sample of community population, inhabitants of the urban area of a Mexican city. The sample consisted of 1351 participants, being 577 men (43%) and 774 women (57%) with an average age of 41.46 (SD = 17.00). The participants were selected by a quota sampling, in 13 representative points of Matamoros' city urban area. Home surveys were applied; the Spanish version of the Symptom Checklist 90 (SCL-90) was used for mental health assessment. RESULTS: The model explaining the relation between work status and mental health (GFI) was significant (p < 0.01). Unemployment was related to higher scores in all sub-scales of psychopathologies evaluated by the SCL-90, in comparison with the rest of work status categories. CONCLUSIONS: The unemployed, followed by housewives, presented indicators of poorer mental health, while the retired and those in strikes or lockouts showed the best mental health indexes.


Assuntos
Saúde Mental , Desemprego , Adulto , Cidades , Estudos Transversais , Feminino , Humanos , Masculino , México
11.
Front Psychol ; 12: 657428, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34108913

RESUMO

Aim: The presence of noise in urban environments is rarely considered a factor that causes damage to the environment. The primary generating source is transportation means, with vehicles being the ones that affect cities the most. Traffic noise has a particular influence on the quality of life of those who are exposed to it and can cause health alterations ranging from annoyance to cardiovascular diseases. This study aims to describe the relationship between the traffic noise level and the perceived annoyance in the inhabitants of a city on the Northern Border of Mexico. The work carried out in a city represents the vulnerability characteristics: economic, social, and migratory of its sizable portion of the inhabitants. Due to that, it is impossible to identify precisely the number of residents as the number of vehicles in circulation. Methods: The streets and avenues with an annual average daily traffic of more than 1,000 vehicles were considered for the measurement of traffic noise. The equipment used was a vehicle gauge with non-invasive speed radar; type I integrating sound level meters, with their respective gauges and tripods. A questionnaire was applied to people living within 250 m of the streets and avenues in which the noise was measured. Results: The noise measurement found a parameter of LAeq estimated for 12 h during the day, exceeding 70 dBA. The data received from the questionnaire were statistically tested by using Pearson's correlation tests. A total number of 2,350 people were participated, of whom 1,378 were women (58.6%) and 972 were men (41.4%). The age of participants is ranged from 18 to 75 years. The overall perception of traffic noise annoyance identified that 1,131 participants (48.1%) responded "Yes" as they considered the noise annoying. Participants who responded "No" as well as those who responded "Do not know" resulted in a total of 1,219 people (51.9%). Conclusion: The results show that the population is desensitized to traffic noise and does not perceive it as an annoyance. The flow of vehicles and the type of vehicles are the significant factors for the propagation and increase in the traffic noise levels. Women present a considerable appreciation of traffic noise perception instead of younger people who demonstrate a higher tolerance to high-level exposure. This reflects the lack of information of the population around the noise problem and its effects.

12.
RSC Adv ; 11(5): 2701-2705, 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35424226

RESUMO

A conjugated poly(azomethine) network based on ambipolar terthiophene-naphthalimide assemblies has been synthesized and its electrochemical and UV-vis absorption properties have been investigated. The network has been found to be a promising candidate for the photocatalytic degradation of organic pollutants in aqueous media.

13.
Inorg Chem ; 60(2): 1208-1219, 2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33378202

RESUMO

Two coordination polymers with formulas [CuI(dapym)]n and [Cu2I2(dapym)]n (dapym = 2,4-diaminopyrimidine) have been synthesized in water at room temperature. According to the stoichiometry used, mono (1D) and the two-dimensional (2D) structures can be obtained. Both are made up of Cu2I2 double chains. Their high insolubility in the reaction medium also makes it possible to obtain them on a nanometric scale. Their structural flexibility and short Cu-Cu distances provoke interesting optoelectronic properties and respond to physical stimuli such as pressure and temperature, making them interesting for sensor applications. The experimental and theoretical studies allow us to propose different emission mechanisms with different behaviors despite containing the same organic ligand. These behaviors are attributed to their structural differences. The emission spectra versus pressure and temperature suggest competencies between different transitions, founding critical Cu2I2 environments, i.e., symmetric in the 1D compound and asymmetric for the 2D one. The intensity in the 2D compound's emission increases with decreasing temperature, and this behavior can be rationalized with a structural constriction that decreases the Cu-Cu and Cu-I distances. However, compound 1D exhibits a contrary behavior that may be related to a change of the organic ligand's molecular configuration. These changes imply that a more significant Π-Π interaction counteracts the contraction in distances and angles when the temperature decreased. Also, the experimental conductivity measurements and theoretical calculations show a semiconductor behavior. The absorption of the 1D compound in UV, its intense emission at room temperature, and the reduction to nanometric size have allowed us to combine it homogeneously with ethyl vinyl acetate (EVA), creating a new composite material. The external quantum efficiency of this material in a Si photovoltaic mini-module has shown that this compound is an active species with application in solar cells since it can move the photons of the incident radiation (UV region) to longer wavelengths.

14.
Radiat Oncol ; 15(1): 246, 2020 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-33109238

RESUMO

BACKGROUND AND OBJECTIVE: Radiation pneumonitis (RP) could be a lethal complication of lung cancer treatment. No reliable predictors of RP severity have been recognized. This prospective pilot study was performed to identify early predictors of high grade lung toxicity and to evaluate clinical, biological or dosimetric features associated with different grades of toxicity. METHOD: Sixteen patients with non-small cell lung cancer with indication of concurrent chemoradiotherapy using 60 Gy/2 Gy/fraction starting at cycle one of platinum based chemotherapy were included. Bronchoalveolar lavage (BAL), pulmonary function testing (PFT), and 18F-2-fluoro-2-deoxy-D-glucose positron-emission tomography was performed before radiotherapy (RT), after three weeks of treatment, and two months post-RT. For analysis, patients were grouped by grade (low [G1-G2] vs. high [G3-G5]). The two groups were compared to identify predictors of RP. Protein expression BAL and lung tissue metabolism was evaluated in two patients (RP-G1 vs. RP-G3). Categorical variables such as comorbidities, stages and locations were summarized as percentages. Radiation doses, pulmonary function values and time to RP were summarized by medians with ranges or as means with standard deviation. Longitudinal analysis PFT was performed by a T-test. RESULTS: All 16 patients developed RP, as follows: G1 (5 pts; 31.3%); G2 (5 pts; 31.3%); G3 (5 pts; 31.3%); and G5 (1 pts; 6.1%). Patients with high grade RP presented significant decrease (p = 0.02) in diffusing lung capacity for carbon monoxide (DLCO) after three weeks of RT. No correlation between dosimetric values and RP grades was observed. BAL analysis of the selected patients showed that CXCL-1, CD154, IL-1ra, IL-23, MIF, PAI-1 and IFN-γ were overexpressed in the lungs of the RP-G3 patient, even before treatment. The pre-RT SUVmax value in the RP-G3 patient was non-significantly higher than in the patient with RP-G1. CONCLUSIONS: RT induces some degree of RP. Our data suggest that decrease in DLCO% is the most sensitive parameter for the early detection of RP. Moreover, we detect biological differences between the two grades of pneumonitis, highlighting the potential value of some cytokines as a prognostic marker for developing high grade lung toxicity. Further multicenter studies with larger sample size are essential to validate these findings.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/radioterapia , Pneumonite por Radiação/etiologia , Idoso , Carcinoma Pulmonar de Células não Pequenas/fisiopatologia , Citocinas/análise , Feminino , Volume Expiratório Forçado , Humanos , Neoplasias Pulmonares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos , Pneumonite por Radiação/diagnóstico , Dosagem Radioterapêutica , Índice de Gravidade de Doença
15.
ACS Sustain Chem Eng ; 8(7): 2973-2980, 2020 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-32953286

RESUMO

The effect of different deprotonators as well as washing steps and drying procedure on the synthesis of ZIF-8 from the mother liquor was investigated. The morphology, thermal stability, crystallinity, and surface area of the synthesized MOF were investigated. In addition, life-cycle assessment (LCA) or, in other words, eco-balance, was implemented as well. LCA compares the full range of environmental effects associated with the product by evaluating all inputs and outputs of material flows and predicting how such flow will affect the environment. ZIF-8 nanocrystals were synthesized from the recycled mother liquors using NaOH or NH4OH thus preserving the main characteristics of the ZIF-8 nanoparticles derived from the initial synthesis. The rest of the characterization methods confirmed the suitability of the synthesis methodology considering the phase purity of the obtained ZIF-8 and nanometer size particles. This procedure enabled us not only to obtain phase pure ZIF-8 but also to substantially decrease the amount of solvent used for washing making it a sustainable process.

16.
Educ. med. super ; 34(1): e1780, ene.-mar. 2020.
Artigo em Espanhol | LILACS, CUMED | ID: biblio-1124668

RESUMO

Introducción: El aprendizaje basado en equipos es una estrategia de enseñanza y de aprendizaje centrada en el alumno, en la cual el profesor tiene un rol facilitador. Este constituye un método pedagógico de aprendizaje activo que mejora la motivación hacia el aprendizaje y lleva a los alumnos a aplicar sus conocimientos para resolver problemas y combinar la teoría con la práctica. Los avances en educación médica a nivel mundial han llevado a las escuelas de medicina a optar por este tipo de estrategias. Objetivo: Identificar los retos de la implementación del aprendizaje basado en equipos en los programas de medicina. Resultados: Mediante la aplicación del aprendizaje basado en equipos en los programas de medicina, se identificaron los factores de sobrecarga laboral y de estudio con incidencia en los participantes en la estrategia, la necesidad de garantizar entrenamiento previo a los actores del proceso, la importancia de la realización de una adecuada distribución de los grupos de trabajo, y los recursos adicionales que deben garantizarse. Conclusiones: Para obtener beneficios pedagógicos de forma plena, la implementación del aprendizaje basado en equipos debe ser sistemática, lo que requiere procesos de formación y preparación, tanto de los estudiantes como de los profesores. Como cualquier cambio, demandará convicción, tiempo y ajustes a lo largo del proceso(AU)


Introduction: Team-based learning is a student-centered teaching and learning strategy, in which the teacher has the role of a facilitator. It constitutes an active learning pedagogical method that improves motivation towards learning and leads students to apply their knowledge to solve problems and combine theory with practice. Advances in medical education worldwide have led medical schools to opt for such strategies. Objective: To identify the challenges of implementing team-based learning in the medical major programs. Results: Through the application of team-based learning to the medical major programs, such factors as work and study overloads were identified as having an impact on the strategy participants, together with the need to guarantee prior training to the process stakeholders, the importance of adequate distribution of the working groups, and the additional resources that must be guaranteed. Conclusions: In order to obtain full pedagogical benefits, the implementation of team-based learning must be systematic, a process requiring training and preparation processes for both students and teachers. Like any change, it will demand conviction, time and adjustments throughout the process(AU)


Assuntos
Humanos , Papel (figurativo) , Conhecimento , Preparação em Desastres , Aprendizagem , Medicina
17.
Chem Sci ; 12(6): 2257-2267, 2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-34163992

RESUMO

Catechols are ubiquitous substances often acting as antioxidants, thus of importance in a variety of biological processes. The Fenton and Haber-Weiss processes are thought to transform these molecules into aggressive reactive oxygen species (ROS), a source of oxidative stress and possibly inducing degenerative diseases. Here, using model conditions (ultrahigh vacuum and single crystals), we unveil another process capable of converting catechols into ROSs, namely an intramolecular redox reaction catalysed by a Cu surface. We focus on a tri-catechol, the hexahydroxytriphenylene molecule, and show that this antioxidant is thereby transformed into a semiquinone, as an intermediate product, and then into an even stronger oxidant, a quinone, as final product. We argue that the transformations occur via two intramolecular redox reactions: since the Cu surface cannot oxidise the molecules, the starting catechol and the semiquinone forms each are, at the same time, self-oxidised and self-reduced. Thanks to these reactions, the quinone and semiquinone are able to interact with the substrate by readily accepting electrons donated by the substrate. Our combined experimental surface science and ab initio analysis highlights the key role played by metal nanoparticles in the development of degenerative diseases.

19.
Nanoscale ; 11(36): 16767-16772, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31322636

RESUMO

The ageing of graphene is an important issue that limits its technological applications. Capping layers are a good option for circumventing this problem. In this work, we propose the use of ultra-thin NaCl films as easily-removable protective layers. We have carried out a detailed characterization of the NaCl/graphene interface on metal substrates, namely Cu(111) and Ir(111), by means of complementary microscopy, electron diffraction and spectroscopic techniques. Interestingly, we show that NaCl neither interacts in a chemical way with graphene nor intercalates through it. We demonstrate that the NaCl film is stable under ambient conditions, protecting the graphene surface from oxidation. In addition, after removing the protective layer, graphene remains intact.

20.
Traffic Inj Prev ; 20(3): 303-307, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30971147

RESUMO

Objective: The objective of this study was to identify pedestrian risk behaviors that result in traffic accidents and characterization of the accidents experienced by participants in this study to provide information for the generation of integral preventive strategies. Methods: The study was correlational, descriptive, and transversal and followed a quantitative approach divided into 2 stages. In the first stage, an observational study was performed to identify the manifested risk behaviors of pedestrians, which served as a basis for the construction and design of a questionnaire. In the second stage, the questionnaire was applied to a group of 1,536 participants. Pearson's correlation coefficient was applied to establish associations between gender and age with respect to risk behaviors. Results: The 3 behaviors that participants reported performing always or very often include using electronic gadgets (except mobile phones), not using a pedestrian crosswalk, and using a mobile phone. In addition, 18.5% were involved in at least one road accident as a pedestrian in the last 5 years. Of the total number of registered accidents, 21% resulted in pedestrian injuries, 48.3% of which were serious. These were due to external causes not related to human factors or unidentified (58.5%) and behavior factors as a whole (41.4%, 31.5% of which were caused by pedestrians). Pearson's correlation coefficient showed evidence of a correlation between age and risk behaviors. Conclusions: All subjects in this study performed several risky actions as pedestrians, at least occasionally, and at least one fifth had been involved in a road accident as a pedestrian. It is known that the surroundings can positively or negatively influence individuals' behaviors; therefore, once prevention measures are identified, it is possible to influence risk behaviors. Therefore, road safety education and the physical environment must be considered together, and efforts focused on optimum infrastructure also need to consider road safety education.


Assuntos
Acidentes de Trânsito/estatística & dados numéricos , Pedestres/psicologia , Assunção de Riscos , Adolescente , Adulto , Telefone Celular/estatística & dados numéricos , Feminino , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Pedestres/estatística & dados numéricos , Inquéritos e Questionários , Ferimentos e Lesões/epidemiologia
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