Towards surface diffusion potential mapping on atomic length scale

The surface diffusion potential landscape plays an essential role in a number of physical and chemical processes such as self-assembly and catalysis. Diffusion energy barriers can be calculated theoretically for simple systems, but there is currently no experimental technique to systematically measure them on the relevant atomic length scale. Here, we introduce an atomic force microscopy based method to semiquantitatively map the surface diffusion potential on an atomic length scale. In this proof of concept experiment, we show that the atomic force microscope damping signal at constant frequency-shift can be linked to nonconservative processes associated with the lowering of energy barriers and compared with calculated single-atom diffusion energy barriers.Comment: 8 pages and 3 figure

Statics and dynamics of Mn-chains on Si(001)

Manganese self-assembles into atomic chains on the Si(001) reconstructed surface. Our combined scanning tunneling microscopy, atomic force microscopy (AFM) and density functional theory (DFT) study revealed a simple necklace-like structure of the Mn chains. The DFT calculated adsorption energies support a single Mn atom adsorption H' site, however no gain in energy promoting the formation of chains was found. We use atom manipulation techniques to deconstruct the chains and confirm the H' site model. Moreover, we show that the manipulated atoms dissipate energies, in the damping channel of AFM, that can be compared to the diffusion energies from DFT calculations

The playful activities for the learning of mathematics in learning by competences

32 Reunión Latinoamericana de Matemática Educativa (Relme), evento desarrollado en la Universidad de Medellín, Colombia, del 2 al 6 de Junio de 2018.En este Taller, se expone el proyecto “Actividades lúdicas para el aprendizaje de la Matemática en el aprendizaje por competencias” que se aplicó en un primer curso de matemática durante el ciclo 2018-1. Las actividades realizadas fueron trabajadas semanalmente y sirven de apoyo para las sesiones online, en ellas se consideran no sólo los temas de la sesión online si no también los temas vistos en la semana. En dichas actividades el estudiante desarrolla habilidades matemáticas de la competencia Razonamiento Cuantitativo como interpretación, representación y cálculo. El objetivo fue conocer las actitudes de los estudiantes frente a las actividades lúdicas, evaluar conocimientos previos y logrados durante la actividad. Como metodología se realizaron 14 actividades lúdicas y se observó y registró valoración a través de preguntas abiertas. Las actividades lúdicas fueron bien recibidas por los estudiantes como forma de integración, autoevaluación y motivación, forma de trabajo dinámica y creativa

Towards surface diffusion potential mapping on atomic length scale

© 2019 Author(s). The surface diffusion potential landscape plays an essential role in a number of physical and chemical processes such as self-assembly and catalysis. Diffusion energy barriers can be calculated theoretically for simple systems, but there is currently no experimental technique to systematically measure them on the relevant atomic length scale. Here, we introduce an atomic force microscopy based method to semiquantitatively map the surface diffusion potential on an atomic length scale. In this proof of concept experiment, we show that the atomic force microscope damping signal at constant frequency-shift can be linked to nonconservative processes associated with the lowering of energy barriers and compared with calculated single-atom diffusion energy barriers.status: publishe

Opioid-based micro and nanoparticulate formulations: alternative approach on pain management

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2017-05-31T19:35:35Z No. of bitstreams: 1 São Pedro A Opioid-based micro....pdf: 1317810 bytes, checksum: 2be9c3779af52bfd7d7a1620e85edb8b (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2017-05-31T19:49:48Z (GMT) No. of bitstreams: 1 São Pedro A Opioid-based micro....pdf: 1317810 bytes, checksum: 2be9c3779af52bfd7d7a1620e85edb8b (MD5)Made available in DSpace on 2017-05-31T19:49:48Z (GMT). No. of bitstreams: 1 São Pedro A Opioid-based micro....pdf: 1317810 bytes, checksum: 2be9c3779af52bfd7d7a1620e85edb8b (MD5) Previous issue date: 2016Universidade Federal da Bahia. Escola Politécnica. Programa de Pós Graduação em Engenharia Industrial. Salvador, BA, BrasilUniversidade Federal da Bahia. Faculdade de Farmácia. Programa de Pós-Graduação em Farmácia. Salvador, BA, BrasilUniversidade Federal da Bahia. Faculdade de Farmácia. Programa de Pós-Graduação em Farmácia. Salvador, BA, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Laboratório de Imunofarmacologia e Engenharia Tecidual. Salvador, BA, BrasilUniversidade Federal da Bahia. Escola Politécnica. Programa de Pós Graduação em Engenharia Industrial. Salvador, BA, BrasilUniversidade Federal da Bahia. Escola Politécnica. Programa de Pós Graduação em Engenharia Industrial. Salvador, BA, BrasilOpioids have been used as the reference treatment on chronic pain. However, they are related to serious adverse effects which affect the patient compliance to treatment, as well as, his quality of life. Particulate formulations have been investigated as an alternative to improve opioid efficacy and safety

Pharmacological Properties of Riparin IV in Models of Pain and Inflammation

Riparins, natural alkaloids of the alkamide group, can be synthesized by simple methods, enhancing their potential application in pharmaceutical development. Here, the pharmacological properties of riparins were investigated in in vitro and in vivo assays of pain and inflammation in Swiss mice. Inflammatory mediators were measured by radioimmunoassay and Real-Time PCR. Riparins I, II, III and IV (1.56–100 mg/kg; ip) produced dose-related antinociceptive effects in the formalin test, exhibiting ED50 values of 22.93, 114.2, 31.05 and 6.63 mg/kg, respectively. Taking the greater potency as steering parameter, riparin IV was further investigated. Riparin IV did not produce antinociceptive effect on the tail flick, suggesting that its antinociception is not a centrally-mediated action. In fact, riparin IV (1.56–25 mg/kg) produced dose-related antinociceptive and antiedematogenic effects on the complete Freund’s adjuvant (CFA)-induced paw inflammation in mice. During CFA-induced inflammation, riparin IV did not modulate either the production of cytokines, TNF-α and IL-10, or COX-2 mRNA expression. On the other hand, riparin IV decreased the PGE2 levels in the inflamed paw. In in vitro assays, riparin IV did not exhibit suppressive activities in activated macrophages. These results indicate, for the first time, that riparin IV induces antinociceptive and anti-inflammatory effects, possibly through the inhibition of prostanoid production

(E)-2-Cyano-3-(1H-Indol-3-yl)-N-Phenylacrylamide, a Hybrid Compound Derived from Indomethacin and Paracetamol: Design, Synthesis and Evaluation of the Anti-Inflammatory Potential

The compound (E)-2-cyano-3-(1H-indol-3-yl)-N-phenylacrylamide (ICMD-01) was designed and developed based on the structures of clinically relevant drugs indomethacin and paracetamol through the molecular hybridization strategy. This derivative was obtained by an amidation reaction between substituted anilines and ethyl 2-cyanoacetate followed by a Knoevenagel-type condensation reaction with indole aldehyde that resulted in both a viable synthesis and satisfactory yield. In order to assess the immunomodulatory and anti-inflammatory activity, in vitro assays were performed in J774 macrophages, and significant inhibitions (p < 0.05) of the production of nitrite and the production of cytokines (IL-1β and TNFα) in noncytotoxic concentrations were observed. The anti-inflammatory effect was also studied via CFA-induced paw edema in vivo tests and zymosan-induced peritonitis. In the paw edema assay, ICMD01 (50 mg kg−1) showed satisfactory activity, as did the group treated with dexamethasone, reducing edema in 2–6 h. In addition, there was no significant inhibition of PGE2, IL-1β or TNFα in vivo. Moreover, in the peritonitis assay that assesses leukocyte migration, ICMD-01 exhibited promising results. Therefore, these preliminary studies demonstrate this compound to be a strong candidate for an anti-inflammatory drug together with an improved gastrointestinal safety profile when compared to the conventional anti-inflammatory drugs

Direct Structural Identification and Quantification of the Split-Vacancy Configuration for Implanted Sn in Diamond

We demonstrate formation of the ideal split-vacancy configuration of the Sn-vacancy center upon implantation into natural diamond. Using beta-emission channeling following low fluence 121Sn implantation (2E12 atoms/cm2, 60 keV) at the ISOLDE facility at CERN, we directly identified and quantified the atomic configurations of the Sn-related centers. Our data show that the split-vacancy configuration is formed immediately upon implantation with a surprisingly high efficiency of ~40%. Upon thermal annealing at 920°C ~30% of Sn is found in the ideal bond-center position. Photoluminescence revealed the characteristic SnV- line at 621 nm, with an extraordinarily narrow ensemble linewidth (2.3 nm) of near-perfect Lorentzian shape. These findings further establish the SnV- center as a promising candidate for single photon emission applications, since, in addition to exceptional optical properties, it also shows a remarkably simple structural formation mechanism

Synthesis of Few-Layered Transition-Metal Dichalcogenides by Ion Implantation of Chalcogen and Metal Species into Sapphire

International audienc

Pharmacological Properties of Riparin IV in Models of Pain and Inflammation

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2017-03-16T17:04:18Z No. of bitstreams: 1 Nascimento OA Pharmacological ....pdf: 1543204 bytes, checksum: 62ff0f3c4a1831446c9052206ab3c303 (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2017-03-16T17:14:05Z (GMT) No. of bitstreams: 1 Nascimento OA Pharmacological ....pdf: 1543204 bytes, checksum: 62ff0f3c4a1831446c9052206ab3c303 (MD5)Made available in DSpace on 2017-03-16T17:14:05Z (GMT). No. of bitstreams: 1 Nascimento OA Pharmacological ....pdf: 1543204 bytes, checksum: 62ff0f3c4a1831446c9052206ab3c303 (MD5) Previous issue date: 2016Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Fundação Oswaldo Cruz (FIOCRUZ).Universidade Federal da Bahia. Faculdade de Farmácia. Salvador, BA, BrasilFundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, BrasilUniversidade Federal da Bahia. Faculdade de Farmácia. Salvador, BA, BrasilUniversidade Federal da Paraíba. Laboratório de Tecnologia Farmacêutica. João Pessoa, PB, BrasilUniversidade Federal do Piauí. Departamento de Bioquímica e Farmacologia. Teresina, PI, BrasilUniversidade Federal da Bahia. Faculdade de Farmácia. Salvador, BA, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, BrasilFundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil / Hospital São Rafael. Centro de Biotecnologia e Terapia Celular. Salvador, BA, BrasilRiparins, natural alkaloids of the alkamide group, can be synthesized by simple methods, enhancing their potential application in pharmaceutical development. Here, the pharmacological properties of riparins were investigated in in vitro and in vivo assays of pain and inflammation in Swiss mice. Inflammatory mediators were measured by radioimmunoassay and Real-Time PCR. Riparins I, II, III and IV (1.56-100 mg/kg; ip) produced dose-related antinociceptive effects in the formalin test, exhibiting ED50 values of 22.93, 114.2, 31.05 and 6.63 mg/kg, respectively. Taking the greater potency as steering parameter, riparin IV was further investigated. Riparin IV did not produce antinociceptive effect on the tail flick, suggesting that its antinociception is not a centrally-mediated action. In fact, riparin IV (1.56-25 mg/kg) produced dose-related antinociceptive and antiedematogenic effects on the complete Freund's adjuvant (CFA)-induced paw inflammation in mice. During CFA-induced inflammation, riparin IV did not modulate either the production of cytokines, TNF-α and IL-10, or COX-2 mRNA expression. On the other hand, riparin IV decreased the PGE₂ levels in the inflamed paw. In in vitro assays, riparin IV did not exhibit suppressive activities in activated macrophages. These results indicate, for the first time, that riparin IV induces antinociceptive and anti-inflammatory effects, possibly through the inhibition of prostanoid production