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1.
Microb Pathog ; 195: 106895, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39208965

RESUMO

Deadly outbreaks among poultry, wild birds, and carnivorous mammals by the highly pathogenic H5N1 virus of the clade 2.3.4.4b have been reported in South America. The increasing virus incidence in various mammal species poses a severe zoonotic and pandemic threat. In Uruguay, the clade 2.3.4.4b viruses were first detected in February 2023, affecting wild birds and backyard poultry. Three months after the first reported case in Uruguay, the disease affected a population of 23 coatis (Nasua) in an ecological park. Most animals became infected, likely directly or indirectly from wild birds in the park, and experienced sudden death. Five animals from the colony survived, and four of them developed antibodies. The genomes of the H5N1 strains infecting coatis belonged to the B3.2 genotype of the clade 2.3.4.4b. Genomes from coatis were closely associated with those infecting backyard poultry, but transmission likely occurred through wild birds. Notable, two genomes have a 627K substitution in the RNA polymerase PB2 subunit, a hallmark amino acid linked to mammalian adaptation. Our findings support the ability of the avian influenza virus of the 2.3.4.4b clade to infect and transmit among terrestrial mammals with high pathogenicity and undergo rapid adaptive changes. It also highlights the coatis' ability to develop immunity and naturally clear the infection.


Assuntos
Animais Selvagens , Genoma Viral , Virus da Influenza A Subtipo H5N1 , Influenza Aviária , Mutação , Filogenia , Procyonidae , Animais , Procyonidae/virologia , Influenza Aviária/virologia , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/patogenicidade , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Genoma Viral/genética , Uruguai , Animais Selvagens/virologia , Aves/virologia , Infecções por Orthomyxoviridae/virologia , Infecções por Orthomyxoviridae/veterinária , Aves Domésticas/virologia , Genótipo , Mamíferos/virologia , América do Sul , Surtos de Doenças/veterinária
2.
Virus Evol ; 10(1): veae031, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38756986

RESUMO

The highly pathogenic avian influenza viruses of clade 2.3.4.4b have caused unprecedented deaths in South American wild birds, poultry, and marine mammals. In September 2023, pinnipeds and seabirds appeared dead on the Uruguayan Atlantic coast. Sixteen influenza virus strains were characterized by real-time reverse transcription PCR and genome sequencing in samples from sea lions (Otaria flavescens), fur seals (Arctocephalus australis), and terns (Sterna hirundinacea). Phylogenetic and ancestral reconstruction analysis showed that these strains have pinnipeds most likely as the ancestral host, representing a recent introduction of clade 2.3.4.4b in Uruguay. The Uruguayan and closely related strains from Peru (sea lions) and Chile (sea lions and a human case) carry mammalian adaptative residues 591K and 701N in the viral polymerase basic protein 2 (PB2). Our findings suggest that clade 2.3.4.4b strains in South America may have spread from mammals to mammals and seabirds, revealing a new transmission route.

3.
Dalton Trans ; 53(22): 9301-9305, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38768304

RESUMO

The electronic structure of [OsF6]2- and PtF6 complexes was studied by means of CASSCF/NEVPT2 multiconfigurational calculations, including spin-orbital coupling, which is very relevant in the case of these metals. From these calculations, it is possible to establish that in the octahedral symmetry (Oh), the ground state is non-magnetic (Jeff = 0) because of the strong ligand field, and the interaction with paramagnetic excited states is almost negligible, resulting in a non-magnetic behavior, which is in agreement with the experimental evidence.

4.
Nanomaterials (Basel) ; 14(3)2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38334529

RESUMO

This study explores cutting-edge and sustainable green methodologies and technologies for the synthesis of functional nanomaterials, with a specific focus on the removal of water contaminants and the application of kinetic adsorption models. Our research adopts a conscientious approach to environmental stewardship by synergistically employing eco-friendly silver nanoparticles, synthesized using Justicia spicigera extract as a biogenic reducing agent, in conjunction with Mexican zeolite to enhance contaminant remediation, particularly targeting Cu2+ ions. Structural analysis, utilizing X-ray diffraction (XRD) and high-resolution scanning and transmission electron microscopy (TEM and SEM), yields crucial insights into nanocomposite structure and morphology. Rigorous linear and non-linear kinetic models, encompassing pseudo-first order, pseudo-second order, Freundlich, and Langmuir, are employed to elucidate the kinetics and equilibrium behaviors of adsorption. The results underscore the remarkable efficiency of the Zeolite-Ag composite in Cu2+ ion removal, surpassing traditional materials and achieving an impressive adsorption rate of 98% for Cu. Furthermore, the Zeolite-Ag composite exhibits maximum adsorption times of 480 min. In the computational analysis, an initial mechanism for Cu2+ adsorption on zeolites is identified. The process involves rapid adsorption onto the surface of the Zeolite-Ag NP composite, followed by a gradual diffusion of ions into the cavities within the zeolite structure. Upon reaching equilibrium, a substantial reduction in copper ion concentration in the solution signifies successful removal. This research represents a noteworthy stride in sustainable contaminant removal, aligning with eco-friendly practices and supporting the potential integration of this technology into environmental applications. Consequently, it presents a promising solution for eco-conscious contaminant remediation, emphasizing the utilization of green methodologies and sustainable technologies in the development of functional nanomaterials.

5.
Viruses ; 15(9)2023 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-37766312

RESUMO

BACKGROUND: Avian influenza viruses (genus Alphainfluenzavirus, family Orthomyxoviridae) infect avian and mammal hosts. In 2022, the high pathogenicity avian influenza virus (H5N1) spread to South America, resulting in the loss of thousands of wild birds, including endangered species, and severely impacting the global poultry industry. OBJECTIVES: We analyzed the complete genomes of influenza viruses obtained from wild birds and backyard poultry in Uruguay between February and May 2023. METHODS: Twelve complete genomes were obtained in 2023 from cloacal swabs using Illumina sequencing. Genomes were phylogenetically analyzed with regional and global strains. FINDINGS: The identified strains have multiple basic amino acids at the hemagglutinin cleavage sites, which is typical for highly pathogenic strains. The Uruguayan viruses belonged to hemagglutinin clade 2.3.4.4b of the H5N1 subtype. A reassortment in North America has resulted in some segments of South American strains being of Eurasian or North American origins. The Uruguayan viruses shared a common ancestor with South American strains from Argentina and Chile. The influenza viruses displayed a spatiotemporal divergence pattern rather than being host-specific. MAIN CONCLUSIONS: The arrival of the 2.3.4.4b clade in Uruguay may have been mediated by birds that acquired the virus from Argentine and Chilean waterfowl migrating in the Pacific Flyway.


Assuntos
Virus da Influenza A Subtipo H5N1 , Vírus da Influenza A , Influenza Aviária , Animais , Uruguai/epidemiologia , Virus da Influenza A Subtipo H5N1/genética , Hemaglutininas , Influenza Aviária/epidemiologia , Virulência , Chile , Mamíferos
6.
Pharmaceutics ; 15(3)2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36986757

RESUMO

Medicinal plants have been used since prehistoric times and continue to treat several diseases as a fundamental part of the healing process. Inflammation is a condition characterized by redness, pain, and swelling. This process is a hard response by living tissue to any injury. Furthermore, inflammation is produced by various diseases such as rheumatic and immune-mediated conditions, cancer, cardiovascular diseases, obesity, and diabetes. Hence, anti-inflammatory-based treatments could emerge as a novel and exciting approach to treating these diseases. Medicinal plants and their secondary metabolites are known for their anti-inflammatory properties, and this review introduces various native Chilean plants whose anti-inflammatory effects have been evaluated in experimental studies. Fragaria chiloensis, Ugni molinae, Buddleja globosa, Aristotelia chilensis, Berberis microphylla, and Quillaja saponaria are some native species analyzed in this review. Since inflammation treatment is not a one-dimensional solution, this review seeks a multidimensional therapeutic approach to inflammation with plant extracts based on scientific and ancestral knowledge.

7.
Horiz. sanitario (en linea) ; 19(1): 27-36, ene.-abr. 2020. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1143045

RESUMO

Abstract Objective To determine the effect of resistance exercise routine and dancing in the lower limbs of no institutionalized elderly, cognitively intact, functional for basic activities of daily living without falling risks. Material and Methods A quasi-experimental study, the effect of an intervention on a single group, consisting of 26 persons aged 60 AM considering criteria of inclusion and non-inclusion was determined. The Short Portable Mental Status Questionnaire was used; Katz Scale and the Scale of Tinetti. The information obtained was analyzed in two stages, descriptive and inferential. In the first phase, frequency distribution tables and measures of central tendency and dispersion for all variables were obtained, as discussed in qualitative or quantitative variables, respectively. In the second phase, the effect of the intervention trophism comparing averages, muscle strength and arcs of movement group and individual pre- and post-intervention was evaluated. Results There was a trend for improvement in the flexibility of the hip, knee and ankle mostly knee extension remained the same, 84.61% and 80.76% right left. Left hip extension remains the same at 50% and 53.84%, the right side. Muscle strength increased overall in all muscle groups of both lower extremities. Trophism increased in diameter thighs, calves by 46% and over 50% were similar diameters, some of the older adults lost weight so their diameter decreased. Conclusions This program showed significant changes in muscle strength and range of motion in the study participants could see the significant association between dancing Zumba Gold and resistance exercises to increase muscle strength, flexibility lower extremities and increased level of activity in older adults. Exercise and physical activity are important for the positive effects that cause health and improvements in the diameter of the thighs and increased functionality of the elderly.


Resumen Objetivo Determinar el efecto de una rutina de ejercicios de resistencia y baile en miembros inferiores de adultos mayores no institucionalizados, cognitivamente íntegros, funcionales para actividades básicas de la vida diaria, sin riesgo de caídas. Material y métodos Estudio cuasi-experimental, se determinó el efecto de una intervención sobre un grupo único, constituido por 26 personas AM de 60 años considerando criterios de inclusión y de no inclusión. Se utilizó el Short Portable Mental Status Questionnaire; la Escala de Katz y la Escala de Tinetti. La información obtenida fue analizada en dos fases, descriptiva e inferencial. En la primera fase, se obtuvieron tablas de distribución de frecuencias así como medidas de tendencia central y de dispersión para todas las variables, según se trató de variables cualitativas o cuantitativas, respectivamente. En la segunda fase, se evaluó el efecto de la intervención comparando los promedios de trofismo, fuerza muscular y de arcos de movimientos, individuales y grupales pre- y post intervención. Resultados Hubo tendencia a la mejoría en la flexibilidad en cadera, rodilla y tobillo en su mayoría, la extensión de rodilla se mantuvo igual, 84.61% derecha y 80.76% izquierda. La extensión de cadera izquierda permanece igual en un 50% y 53.84%, del lado derecho. La fuerza muscular incrementó en general en todos los grupos musculares de ambas extremidades inferiores. El trofismo de muslos aumentó en su diámetro, las pantorrillas en un 46% y más del 50% mantuvieron diámetros similares Algunos de los AM bajaron de peso, por lo tanto sus diámetros disminuyeron. Conclusiones Este programa mostró modificaciones significativas en la fuerza muscular y rangos de movimientos en los participantes del estudio, se pudo ver la asociación importante que existe entre el baile de Zumba Gold y Ejercicios de Resistencia con el incremento de la fuerza muscular, flexibilidad de las extremidades inferiores y el incremento en el nivel de la actividad en los adultos mayores. El ejercicio y la actividad física son importantes, por los efectos positivos que causan sobre la salud y la mejoría en el diámetro de los muslos y el aumento en la funcionalidad del adulto mayor.


Resumo Objetivo Para determinar o efeito de uma rotina de exercícios de resistência e dança nos membros inferiores de idosos não institucionalizados, cognitivamente íntegros e funcionais para atividades básicas da vida diária, sem risco de queda. Material e métodos Estudo quase experimental, determinou-se o efeito de uma intervenção sobre um único grupo, constituído por 26 pessoas AM de 60 anos considerando critérios de inclusão e não-inclusão. Utilizou-se o Short Portable Mental Status Questionnaire; a escala Katz e a escala de Tinetti. A informação obtida foi analisada em duas fases, descritiva e inferencial. Na primeira fase, foram obtidos tabelas de distribuição de frequência assim como medidas de tendência central e de dispersão para todas as variáveis, segundo se tratou de variáveis qualitativas ou quantitativas, respectivamente. Na segunda fase, avaliou-se o efeito da intervenção através da comparação da média de trofismo, força muscular e arcos de movimentos, individual, em grupo pré- e pós-intervenção. Resultados Houve uma tendência de melhora na flexibilidade do quadril, joelho e tornozelo principalmente, a extensão do joelho permaneceu a mesma, 84,61% direita e 80,76% para a esquerda. A extensão do quadril esquerdo permanece igual em um 50% e 53,84%, no lado direito. A força muscular aumentou geralmente em todos os grupos musculares de ambas as extremidades inferiores. O trofismo de coxas aumentou em diâmetro, pantorilha em um 46% e mais do 50% mantiveram diâmetros semelhantes. Alguns dos AM perderam peso, pelo que os seus diâmetros diminuíram. Conclusões Este programa mostrou mudanças significativas na força muscular e amplitude de movimento nas participantes do estudo, pôde-se ver a associação significativa que existe entre a dança Zumba Ouro e Exercícios de Resistência com o aumento da força muscular, flexibilidade das extremidades inferiores e o aumento no nível da atividade em adultos mais velhos. O exercício e a atividade física são importantes, pelos efeitos positivos que causam sobre a saúde e a melhoria do diâmetro das coxas e do aumento da funcionalidade do idoso.


résumé est disponible dans le document

8.
Nanomaterials (Basel) ; 9(11)2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31752428

RESUMO

Bimetallic Au@Pt nanoparticles (NPs) with Pt monolayer shell are of much interest for applications in heterogeneous catalysts because of enhanced catalytic activity and very low Pt-utilization. However, precisely controlled synthesis with uniform Pt-monolayers and stability on the AuNPs seeds remain elusive. Herein, we report the controlled deposition of Pt-monolayer onto uniform AuNPs seeds to obtain Au@Pt core-shell NPs and their Pt-coverage dependent electrocatalytic activity for methanol electro-oxidation. The atomic ratio between Au/Pt was effectively tuned by varying the precursor solution ratio in the reaction solution. The morphology and atomic structure of the Au@Pt NPs were analyzed by high-resolution scanning transmission electron microcopy (HR-STEM) and X-ray diffraction (XRD) techniques. The results demonstrated that the Au@Pt core-shell NPs with Pt-shell thickness (atomic ratio 1:2) exhibit higher electrocatalytic activity for methanol electro-oxidation reaction, whereas higher and lower Pt ratios showed less overall catalytic performance. Such higher catalytic performance of Au@Pt NPs (1:2) can be attributed to the weakened CO binding on the Pt/monolayers surface. Our present synthesis strategy and optimization of the catalytic activity of Au@Pt core-shell NPs catalysts provide promising approach to rationally design highly active catalysts with less Pt-usage for high performance electrocatalysts for applications in fuel cells.

9.
Materials (Basel) ; 12(19)2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31581421

RESUMO

The demand for hydrophobic polymer-based protective coatings to impart high corrosion resistance has increased recently. The increase of the hydrophobicity in a hybrid coating is a new challenge, for that reason and in order to protect a metallic surface of oxidant agents, a poly (methyl methacrylate) (PMMA) coating with the addition of a different amount of silicon dioxide (SiO2) was developed. The hybrid coating was applied on a sample of stainless steel AISI 304 by the dip-coating method. The characterization of the coatings was determined by electrochemical impedance spectroscopy and with a scanning electrochemical microscopy. The best coatings were PMMA and PMMA + SiO2 0.01% that exhibits a real impedance in the Nyquist diagram of 760 and 427,800 MΩ⋅cm2, respectively, and the modulus of the real impedance in the Bode diagram present values of 2.2 × 108 and 3.3 × 108 Ω⋅cm2. Moreover, the phase angle presents constant values around 75° to 85° and 85° for the PMMA and PMMA + SiO2 0.01%, respectively. Moreover, the values of the real resistance for the PMMA + SiO2 0.01% coating present values in the order of Mega-ohms despite the coating exhibits an artificial defect in their surface. The contact angle test showed that the hydrophobicity of the hybrid PMMA + SiO2 0.01% coating is higher than that of the pure PMMA coatings. The hybrid PMMA + SiO2 coatings developed in this work are a very interesting and promising area of study in order to develop efficient products to protect metallic surfaces from corrosion phenomenon.

10.
Front Chem ; 7: 454, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31297366

RESUMO

Re(I) complexes have exposed highly suitable properties for cellular imaging (especially for fluorescent microscopy) such as low cytotoxicity, good cellular uptake, and differential staining. These features can be modulated or tuned by modifying the ligands surrounding the metal core. However, most of Re(I)-based complexes have been tested for non-walled cells, such as epithelial cells. In this context, it has been proposed that Re(I) complexes are inefficient to stain walled cells (i.e., cells protected by a rigid cell wall, such as bacteria and fungi), presumably due to this physical barrier hampering cellular uptake. More recently, a series of studies have been published showing that a suitable combination of ligands is useful for obtaining Re(I)-based complexes able to stain walled cells. This review summarizes the main characteristics of different fluorophores used in bioimage, remarking the advantages of d6-based complexes, and focusing on Re(I) complexes. In addition, we explored different structural features of these complexes that allow for obtaining fluorophores especially designed for walled cells (bacteria and fungi), with especial emphasis on the ligand choice. Since many pathogens correspond to bacteria and fungi (yeasts and molds), and considering that these organisms have been increasingly used in several biotechnological applications, development of new tools for their study, such as the design of new fluorophores, is fundamental and attractive.

11.
Phys Chem Chem Phys ; 21(16): 8428-8433, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30945710

RESUMO

DFT calculations were carried out on a series of tetrahedral 16-atom superatomic clusters having 20 or 18 jellium electrons (je) and structurally related to Au20, namely, [M16]4-/2- (M = Cu, Ag, and Au) and [M4'M12'']0/2+ (M' = Zn, Cd, Hg; M'' = Cu, Ag, Au). While the bare homonuclear 20-je species required further stabilization to be isolated, their 18-je counterparts exhibited better stability. Lowering the electron count led to structural modification from a compact structure (20-je) to a hollow sphere (18-je). Such a change could be potentially controlled by tuning redox properties. Among the 20-je heteronuclear [M4'M12''] neutral series, [Zn4Au12] appeared to meet the best stability criteria, but their 18-je relatives [M4'M12'']+, in particular [Zn4Cu12]2+ and [Cd4Au12]2+, offered better opportunities for obtaining stable species. Such species exhibit the smallest models for the M(111) surface of fcc metals, which expose designing rules towards novel high-dopant-ratio clusters as building blocks of nanostructured materials.

12.
J Phys Chem B ; 123(15): 3219-3231, 2019 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-30925049

RESUMO

The design of organometallic complexes used as selective intercalators to bind and react at DNA mismatch sites has concentrated efforts in the last few years. In this context, lanthanides have received attention to be employed as active optical centers due to their spectroscopic properties. Despite the fact that there are several experimental data about synthesis and DNA binding of these compounds, theoretical analyses describing their interaction with DNA are scarce. To understand the binding to regular and mismatched DNA sequences as well as to determine the effect of the intercalation on the spectroscopic properties of the complexes, a complete theoretical study going from classical to relativistic quantum mechanics calculations has been performed on some lanthanide complexes with phenanthroline derivatives synthesized and characterized herein, viz. [Nd(NO3)3(H2O)(dppz-R)] with R = H, NO2-, CN- and their [Nd(NO3)3(H2O)(dpq)] analogue, which was computationally modeled. The results were in correct agreement with the available experimental data showing that dppz complexes have higher binding affinities to DNA than dpq one and supporting the idea that these complexes are not selective to mismatch sites in the sampled time scale. Finally, the spectroscopic analysis evidence an intercalative binding mode and made possible the elucidation of the emission mechanism of these systems. This approach is proposed as a benchmark study to extend this methodology on similar systems and constitutes the first theoretical insight in the interaction between DNA and lanthanide complexes.


Assuntos
DNA/química , DNA/genética , Teoria da Densidade Funcional , Neodímio/química , Sequência de Bases , Modelos Moleculares , Conformação de Ácido Nucleico
13.
Rev Med Inst Mex Seguro Soc ; 56(4): 341, 2018 11 30.
Artigo em Espanhol | MEDLINE | ID: mdl-30521177

RESUMO

In relation to the letter to the editor on the article "Professionalism in physicians in a second-level hospital" this reply is issued.


En relación a la carta al editor sobre el artículo "Profesionalismo en médicos de segundo nivel" se emite esta réplica.

14.
Nanomaterials (Basel) ; 8(11)2018 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-30453604

RESUMO

ß-Cyclodextrin (ßCD), the less water soluble of the cyclodextrins, has been used as a capping agent in the preparation of semiconductor nanocrystals or quantum dots (QDs). Nevertheless, no reports have been found in the use of the highly water-soluble polymer of this, prepared by the crosslinking of the ßCD units with epichlorohydrin in basic medium (ßCDP). This polymer, besides to overcome the low solubility of the ßCD, increases the inclusion constant of the guest; two parameters that deserve its use as capping agent, instead of the native cyclodextrin. In the present manuscript, we afforded the in-situ aqueous preparation of cadmium telluride (CdTe) QDs capped with ßCDP. The polymer influence on the photoluminescent properties of the nanocrystals was analyzed. The ßCDP controls the nanocrystals growth during the Oswald ripening stage. Consequently, the CdTe capped ßCDP QDs showed lower Stokes-shift values, higher photoluminescent efficiency, and narrower size distribution than for nanocrystals obtained in the absence of polymer. Transmission electron microscopy (TEM) micrographs and energy dispersive X-ray spectroscopy (EDS) analysis revealed the composition and crystallinity of the CdTe QDs. This ßCDP capped CdTe QDs is a potential scaffold for the supramolecular modification of QDs surface.

15.
Front Chem ; 6: 345, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30211148

RESUMO

In this study, we explored new properties of the bioinspired pyridine benzimidazole compound B2 (2,4-di-tert-butyl-6-(3H-imidazo[4,5-c]pyridine-2-yl)phenol) regarding its potential use as a differential biomarker. For that, we performed 1D 1HNMR (TOCSY), UV-Vis absorption spectra in different organic solvents, voltammetry profile (including a scan-rate study), and TD-DFT calculations that including NBO analyses, to provide valuable information about B2 structure and luminescence. In our study, we found that the B2 structure is highly stable, where the presence of an intramolecular hydrogen bond (IHB) seems to have a crucial role in the stability of luminescence, and its emission can be assigned as fluorescence. In fact, we found that the relatively large Stokes Shift observed for B2 (around 175 nm) may be attributed to the stability of the B2 geometry and the strength of its IHB. On the other hand, we determined that B2 is biocompatible by cytotoxicity experiments in HeLa cells, an epithelial cell line. Furthermore, in cellular assays we found that B2 could be internalized by passive diffusion in absence of artificial permeabilization at short incubation times (15 min to 30 min). Fluorescence microscopy studies confirmed that B2 accumulates in the endoplasmic reticulum (ER) and Golgi apparatus, two organelles involved in the secretory pathway. Finally, we determined that B2 exhibited no noticeable blinking or bleaching after 1 h of continuous exposure. Thus, B2 provides a biocompatible, rapid, simple, and efficient way to fluorescently label particular organelles, producing similar results to that obtained with other well-established but more complex methods.

16.
Front Chem ; 6: 312, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30109223

RESUMO

It has been reported that the structure of the Schiff bases is fundamental for their function in biomedical applications. Pyridine Schiff bases are characterized by the presence of a pyridine and a phenolic ring, connected by an azomethine group. In this case, the nitrogen present in the pyridine is responsible for antifungal effects, where the phenolic ring may be also participating in this bioactivity. In this study, we synthesized two new pyridine Schiff Bases: (E)-2-[(3-Amino-pyridin-4-ylimino)-methyl]-4,6-difluoro-phenol (F1) and (E)- 2-[(3-Amino-pyridin-4-ylimino)-methyl]-6-fluoro-phenol (F2), which only differ in the fluorine substitutions in the phenolic ring. We fully characterized both F1 and F2 by FTIR, UV-vis, 1H; 13C; 19F-NMR, DEPT, HHCOSY, TOCSY, and cyclic voltammetry, as well as by computational studies (DFT), and NBO analysis. In addition, we assessed the antifungal activity of both F1 (two fluorine substitution at positions 4 and 6 in the phenolic ring) and F2 (one fluorine substitution at position 6 in the phenolic ring) against yeasts. We found that only F1 exerted a clear antifungal activity, showing that, for these kind of Schiff bases, the phenolic ring substitutions can modulate biological properties. In addition, we included F1 and F2 into in epichlorohydrin-ß-cyclodextrin polymer (ßCD), where the Schiff bases remained inside the ßCD as determined by the ki , TGA, DSC, and SBET. We found that the inclusion in ßCD improved the solubility in aqueous media and the antifungal activity of both F1 and F2, revealing antimicrobial effects normally hidden by the presence of common solvents (e.g., DMSO) with some cellular inhibitory activity. The study of structural prerequisites for antimicrobial activity, and the inclusion in polymers to improve solubility, is important for the design of new drugs.

17.
Inorg Chem ; 57(9): 5120-5132, 2018 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-29693385

RESUMO

This work presents a theoretical protocol to analyze the symmetry effect on the allowed character of the transitions and to estimate the probability of energy transfer in lanthanide(III) complexes. For this purpose, a complete study was performed based on the multireference CASSCF/PT2 technique along with TDDFT, to build the energy level diagrams and determine the spectral overlap integrals, respectively. This approach was applied on a series of LnIII complexes, viz. [LnCl3(DMF)2(Dpq)]/[Ln(NO3)3(DMF)2(Dpq)], where Ln = SmIII, TbIII, ErIII/EuIII, NdIII and dpq = dipyridoquinoxaline, synthesized and characterized by Patra et al. ( Dalton Trans. 2015 , 44 ( 46 ), 19844 - 19855 ; CrystEngComm 2016 , 18 ( 23 ), 4313 - 4322 ; Inorg. Chim. Acta 2016 , 451 , 73 - 81 ). A fragmentation scheme was applied where both the ligand and the lanthanide fragments were treated separately but at the same level of theory. The symmetry analysis only partially reproduced the expected results, and a more detailed analysis of the crystal field became necessary. On the other hand, the most probable energy transfer pathways that take place in the complexes were elucidated from the energy gaps between the ligand-localized triplet state and the emitting levels of the lanthanide fragments. These gaps, which are related to the energy transfer rate, properly reproduced the trend reported experimentally for the best and worst yields. Finally, the spectral overlap integral was calculated from the emission spectra of the dpq ligand and the absorption spectra of the lanthanide fragment. The obtained values are in good agreement with the quantum yields calculated for the systems. The most remarkable aspect of this protocol was its ability to explain the emission and nonemission of the studied compounds.

18.
Inorg Chem ; 56(15): 9200-9208, 2017 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-28692259

RESUMO

A theoretical protocol to study the sensitization and emission mechanism in lanthanide compounds on the basis of multireference CASSCF/PT2 calculations is proposed and applied to [Eu(NO3)3(dppz-CN)] and [Eu(NO3)3(dppz-NO2)] compounds synthesized and characterized herein. The method consists of a fragmentation scheme where both the ligand and the lanthanide fragments were calculated separately but at the same level of theory, using ab initio wave-function-based methods which are adequate for the treatment of quasi-degenerate states. This is based on the fact that the absorption is ligand-localized and the emission is europium-centered. This characteristic allowed us to describe the most probable energy transfer pathways that take place in the complexes, which involved an ISC between the S1 to T1 ligand states, energy transfer to 5D2 in the lanthanide fragment, and further 5D0 → 7FJ emission. For both compounds, the triplet and 5D2 states were determined at the CASPT2 level to be around ∼26000 and ∼22400 cm-1, respectively. This difference is in the optimal range for the energy transfer process. Finally, the emissive state 5D0 was found at ∼18000 cm-1 and the emission bands in the range 550-700 nm, in quite good agreement with the experimental results.

19.
Chemistry ; 23(47): 11330-11337, 2017 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-28628726

RESUMO

Coinage-metal atomically precise nanoclusters are made of a well-defined metallic core embedded in a ligand-protecting outer shell. Whereas gold derivatives are particularly well documented, examples of silver nanoclusters are somewhat limited and copper species remain particularly scare. Our DFT relativistic calculations on superatomic metallic cores indicate that copper species are almost as stable as gold clusters and more stable than their silver counterparts. Thus, for silver superatomic cores, the role of the stabilizing ligands is more crucial in the stabilization of the overall structure, in comparison to copper and gold. Hence, the chemistry of the earlier counterparts of gold, especially copper, should grow quickly with at least characterizations of species related to that found in the heavier elements in the triad, which requires tackling synthetic challenges. Time-dependent (TD)-DFT calculations show that with an increase of the cluster core nuclearity, the absorption bands are redshifted, allowing us to differentiate between the clusters types. Moreover, the optical properties of the silver cores are fairly different from that of their Cu and Au relatives.

20.
Rev Med Inst Mex Seguro Soc ; 55(2): 269-272, 2017.
Artigo em Espanhol | MEDLINE | ID: mdl-28296379

RESUMO

BACKGROUND: It takes many years to acquire abilities and technical skills necessary to do a good work as a doctor and even more years, for being "good professionals". Much of this training is based on old teaching schemes, but medicine has changed. So far no studies in our medium addressing the problem are known. The aim of this paper was to determine the level of professionalism in physicians that work in a second-level hospital. METHODS: Descriptive cross-sectional study. We apply a survey to physicians, residents and medical interns in a second-level hospital. We developed and implemented a questionnaire on professionalism, which contained 18 items, 3 demographic questions and 15 questions with a Likert scale, which identified four dimensions: specialized knowledge, autonomy in decision-making, self-regulation and social commitment. Descriptive and inferential statistics were used, considering significant a p-value <0.05. RESULTS: We surveyed 228 physicians, 57.5% demonstrated competence in professionalism. 93.3% of the participants were competent in specialized knowledge and 60.5% in social commitment. The physicians and residents got the higher scores, and these differences were significant between autonomy in decision-making and specialized knowledge (p < 0.001). The medical interns obtained lower scores in all dimensions compared with residents and physicians. CONCLUSIONS: More than a half of physicians surveyed had a competent level of professionalism but only in some dimensions. We observed higher scores with a higher academic grade.


Introducción: se requieren años para adquirir las habilidades y destrezas necesarias para un buen desempeño médico y varios más para ser "buen profesionista". Gran parte de este entrenamiento se fundamenta en esquemas de enseñanza antiguos, siendo que la práctica de la medicina ha cambiado notablemente. No se conocen estudios en nuestro medio que aborden el profesionalismo en médicos. El objetivo de este trabajo fue determinar el nivel de profesionalismo en médicos de un hospital de segundo nivel de atención. Métodos: estudio descriptivo-transversal. Se encuestaron médicos adscritos, residentes e internos en un hospital de segundo nivel. Se elaboró y aplicó un cuestionario sobre profesionalismo, con 18 ítems (3 preguntas demográficas y 15 tipo Likert), que incluyó 4 dimensiones: conocimiento especializado, autonomía en la toma de decisiones, autorregulación y servicio de compromiso social. Se utilizó estadística descriptiva e inferencial. Resultados: se incluyeron 228 médicos, el 57.5% fueron competentes en profesionalismo de manera global. El 93.3% en conocimiento especializado y 60.5% en compromiso social. Los médicos adscritos y residentes obtuvieron las calificaciones más altas, siendo significativas estas diferencias en conocimiento especializado y autonomía (p < 0.001). Los internos obtuvieron puntajes más bajos en todas las categorías. Conclusiones: poco más de la mitad de los médicos presentó un nivel de profesionalismo competente en algunas dimensiones. Se obtuvieron puntajes más altos a mayor grado académico.


Assuntos
Competência Clínica/estatística & dados numéricos , Ética Médica , Médicos/ética , Autonomia Profissional , Profissionalismo , Centros de Cuidados de Saúde Secundários , Estudos Transversais , Feminino , Humanos , Masculino , México , Médicos/estatística & dados numéricos , Responsabilidade Social , Inquéritos e Questionários
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