180 research outputs found

    Rhenium mixed-ligand complexes with S,N,S-tridentate thiosemicarbazone/thiosemicarbazide ligands

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    Rhenium(V) complexes containing tridentate thiosemicarbazones/thiosemicarbazides (H2L1) derived from N-[Nâ€Č,Nâ€Č-dialkylamino(thiocarbonyl)]benzimidoyl chlorides with 4,4-dialkylthiosemicarbazides have been synthesized by ligand-exchange reactions starting from [ReOCl(L1)]. The chlorido ligand of [ReOCl(L1)] (4) is readily replaced and reactions with ammonium thiocyanate or potassium cyanide give [ReO(NCS)(L1)] (6) and [ReO(CN)(L1)] (7), respectively. The reaction of (NBu4)[ReOCl4] with H2L1 and two equivalents of ammonium thiocyanate, however, gives in a one-pot reaction [ReO(NCS)2(HL1)] (8), in which the pro-ligand H2L1 is only singly deprotonated. An oxo-bridged, dimeric nitridorhenium(V) compound of the composition [{ReN(HL1)}2O] (11) is obtained from a reaction of (NBu4)[ReOCl4], H2L1 and sodium azide. The six-coordinate complexes [ReO(L1)(Ph2btu)] (12), where HPh2btu is N,N-diphenyl-Nâ€Č-benzoylthiourea, can be obtained by treatment of [ReOCl(L1)] with HPh2btu in the presence of NEt3. Studies of the antiproliferative effects of the [ReOX(L1)] system (X = Cl−, NCS− or CN−) on breast cancer cells show that the lability of a monodentate ligand seems to play a key role in the cytotoxic activity of the metal complexes, while the substitution of this ligand by the chelating ligand Ph2btu− completely terminates the cytotoxicity

    Adequate magnesium level as an associated factor of pre-diabetes and diabetes mellitus remission in patients with obesity submitted to bariatric surgery

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    Bariatric surgery (BS) can lead to remission of type 2 diabetes mellitus (T2DM), however, the evidence on the influence of preoperative serum magnesium levels on this reversal is scarce. To study the influence of preoperative serum magnesium levels on the pre-T2DM and T2DM remission one year after BS. Retrospective study carried out among 1656 patients with obesity who underwent BS in the Centro Hospitalar UniversitĂĄrio SĂŁo JoĂŁo. T2DM and pre-T2DM remission were defined as being normal glycaemic measures of at least one year's after BS and without pharmacological therapy. To assess the association between preoperative serum magnesium levels and pre- and T2DM remission, logistic regression models, crude and adjusted for sex, age and body mass index were computed. Patients with normoglycaemia presented hypomagnesaemia less often than those patients with pre-T2DM and T2DM (17.0% vs. 21.3% vs. 39.9%) (p < 0.001). One year after BS, 62.9% of patients with pre-T2DM or T2DM before BS showed remission. Adequate magnesium levels were positively associated with T2DM and pre-T2DM remission, one year after BS (OR 1.79; 95% CI 1.34-2.38), independently of sex, age, and body mass index. Adequate preoperative serum magnesium levels showed to be an important clinical parameter for pre-T2DM and T2DM remission.Isabel Maia holds a PhD Grant (ref:SFRH/BD/117371/2016/PT), which is co-funded by the Foundation for Science and Technology (FCT) and the POCH/FSE Program

    Oral glucose tolerance testing at 1 h and 2 h: relationship with glucose and cardiometabolic parameters and agreement for pre-diabetes diagnosis in patients with morbid obesity

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    Background: One hour plasma glucose concentration (1hPG) during an oral glucose tolerance test (OGTT) may be an alternative to 2-h plasma glucose concentration (2hPG) in the identification of individuals at increased risk of hyperglycaemia, although its role is not fully understood. Aim: We aim to investigate the relationship of these measures with other glucose parameters, as well as their relationship with cardiometabolic risk markers and the level of agreement for prediabetes mellitus diagnosis, in a sample of patients with morbid obesity. Methods: We retrospectively evaluated 656 patients with morbid obesity without diagnosed diabetes. To define prediabetes with 2hPG, 2022 American Diabetes Association guidelines criteria were used, while for 1hPG, glucose ≄ 155 mg/dL was considered. Cohen’s Kappa coefficient was used to assess the agreement between both measures of prediabetes mellitus diagnosis. Results: A Cohen’s Kappa coefficient of 0.405 (p < 0.001) was obtained. The 1hPG were positively correlated with homeostatic model assessment for insulin resistance (HOMA-IR) (ρ = 0.281, p < 0.001), fasting plasma glucose (FPG) (ρ = 0.581, p < 0.001), glycated haemoglobin (Hb1AC) (ρ = 0.347, p < 0.001) and were negatively correlated with homeostatic model assessment for cell-ÎČ function (HOMA-ÎČ) (ρ = −0.092, p = 0.018). 2hPG were also correlated with the same parameters, except for HOMA-ÎČ. Conclusion: A fair agreement between 1 and 2hPG was verified. 1hPG criteria may be a useful indicator of ÎČ-cell dysfunction and insulin resistance in patients with morbid obesity without diabetes diagnosis. © 2022, The Author(s).Funding text 1: We would like to acknowledge the support of all the endocrinologists, surgeons and nutritionists of the Multidisciplinary Group for Surgical Management of Obesity.; Funding text 2: Isabel Maia holds a PhD Grant (ref: SFRH/BD/117371/2016) co-funded by the Foundation for Science and Technology—FCT (The Portuguese Ministry of Science, Technology and Higher Education) and the POCH/FSE programme

    Palladium(II) complexes with thiosemicarbazones: syntheses, characterization and cytotoxicity against breast cancer cells and anti-mycobacterium tuberculosis activity

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    Three PdII complexes were prepared from N(4)-substituted thiosemicarbazones: [Pd(aptsc)(PPh3)](NO3)‱H2O, 1, [Pd(apmtsc)(PPh3)](NO3), 2, and [Pd(apptsc)(PPh3)](NO3)‱H2O, 3, where PPh3 = triphenylphosphine; Haptsc = 2-acetylpyridine-thiosemicarbazone; Hapmtsc = 2-acetylpyridine-N(4)-methyl-thiosemicarbazone and Happtsc = 2-acetylpyridine-N(4)-phenyl-thiosemicarbazone. All complexes were characterized by elemental analysis, IR, UV-Vis, 1H and 31P{1H} NMR spectroscopies, and had their crystalline structures determined by X-ray diffractometry from single crystals. The monoanionic thiosemicarbazonate ligands act in a tridentate mode, binding to the metal through the pyridine nitrogen, the azomethine nitrogen and the sulfur atoms. The cytotoxic activity against the breast cancer cell line MDA-MB231 and the anti-Mycobacterium tuberculosis H37Rv ATCC 27294 activity were evaluated for the compounds. All PdII complexes were highly active against the studied cell line, presenting similar values of IC50, around 5 ”mol L-1, while the clinically applied antitumor agent cisplatin was inactive. The compounds show remarkable anti-M. tuberculosis activities, presenting MIC values comparable or better than some commercial anti-M tuberculosis drugs.FAPESPCAPESCNPqFINE

    O sistema PBL, problem-based learning, no ensino de medicina no Brasil : anålise bibliogråfica sobre a sua execução

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    Introdução: Entre as estratĂ©gias de ensino e aprendizagem utilizadas nas prĂĄticas pedagĂłgicas, a Problem Based Learning (PBL) (Aprendizagem Baseada em Problemas) Ă© utilizada desde 1960, em especial nos cursos de Medicina. Mesmo sendo uma estratĂ©gia valiosa, um dos seus obstĂĄculos Ă© a pouca prĂĄtica dos alunos em atividades autodirigidas, pesquisa e construção coletiva do conhecimento. Objetivo: Rastrear elementos constitutivos da PBL atravĂ©s de dados colhidos em artigos pesquisados em sĂ­tios de divulgação cientĂ­fica; Avaliar, nos estudos selecionados, os aspectos positivos e negativos que estejam relacionados com a metodologia do Sistema PBL aplicada ao ensino mĂ©dico no Brasil. Metodologia: Estudo bibliogrĂĄfico de 13 textos utilizando um modelo de desconstrução, denominada AnĂĄlise Textual Discursiva (ATD) que consiste em: transformação dos artigos em pedaços menores; anĂĄlise textual; identificação de padrĂ”es convergentes e divergentes em relação a PBL; organização e sĂ­ntese dos dados, culminando com a elaboração de estratĂ©gia adaptativa da PBL para o curso de Medicina. Resultados: Foram encontradas 116 citaçÔes que convergiam para referĂȘncias positivos acerca da metodologia PBL e 40 citaçÔes que divergiam acerca dos pontos positivos. Os aspectos positivos como o desenvolvimento de atitudes e habilidades; desenvolvimento de competĂȘncias anteriores ao curso; efeitos positivos depois de terminada a graduação, como autonomia de estudo e a articulação entre currĂ­culo e realidade profissional, representam pontos a serem reforçados na aula. Em contraponto, foi observado que dentre os negativos a nĂŁo compreensĂŁo do papel do professor como tutor; necessidade de conteĂșdo formal tradicional pelos alunos e a expectativa que o professor retire as suas dĂșvidas sĂŁo pontos a serem evitados. ConclusĂ”es: A metodologia PBL deverĂĄ servir como metodologia ativa para aproveitar ao mĂĄximo as habilidades que os alunos jĂĄ apresentam, potencializando o aprendizado na educação mĂ©dica em sala de aula. Palavras-Chave: PBL; curso de medicina; metodologia ativa; educação mĂ©dica.ABSTRACT Introduction: Among the teaching and learning strategies used in teaching practices, the Problem Based Learning (PBL) (Problem Based Learning) has been used since 1960, especially in medical courses. Although a valuable strategy, one of its obstacles is the lack of practice of students in self-directed activities, research and collective construction of knowledge. Objective: Tracking constitutive elements of PBL through data collected on items surveyed in science communication sites and arrange them in order to develop a student's adaptation strategy to this methodological way. Evaluate the selected studies, the positive and negative aspects that are related to the methodology of PBL system applied to medical education in Brazil. Methodology: bibliographic study of 13 texts using a deconstruction model, called Discursive Textual Analysis (DTA) consisting of: transforming items into smaller pieces; textual analysis; identifying convergent and divergent patterns in relation to PBL; organization and synthesis of data, culminating with in the development of adaptive strategy of PBL to Medical Course. Results: It has been found 116 quotes that converged into positive notes about the PBL methodology and 40 quotes that differed about the positive ones. These quotations are placed in lines of analysis, based on a model of adaptation of the PBL student body. The positive aspects represent points to be reinforced in the classroom and the negative ones to be avoided. Conclusions: The PBL methodology should serve as active methodology to make the most of the skills that students already have, enhancing learning in medical education in the classroom Keywords: PBL; medical schools; active methodology; medical education

    Evidence for Color Dichotomy in the Primordial Neptunian Trojan Population

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    In the current model of early Solar System evolution, the stable members of the Jovian and Neptunian Trojan populations were captured into resonance from the leftover reservoir of planetesimals during the outward migration of the giant planets. As a result, both Jovian and Neptunian Trojans share a common origin with the primordial disk population, whose other surviving members constitute today's trans-Neptunian object (TNO) populations. The cold classical TNOs are ultra-red, while the dynamically excited "hot" population of TNOs contains a mixture of ultra-red and blue objects. In contrast, Jovian and Neptunian Trojans are observed to be blue. While the absence of ultra-red Jovian Trojans can be readily explained by the sublimation of volatile material from their surfaces due to the high flux of solar radiation at 5AU, the lack of ultra-red Neptunian Trojans presents both a puzzle and a challenge to formation models. In this work we report the discovery by the Dark Energy Survey (DES) of two new dynamically stable L4 Neptunian Trojans,2013 VX30 and 2014 UU240, both with inclinations i >30 degrees, making them the highest-inclination known stable Neptunian Trojans. We have measured the colors of these and three other dynamically stable Neptunian Trojans previously observed by DES, and find that 2013 VX30 is ultra-red, the first such Neptunian Trojan in its class. As such, 2013 VX30 may be a "missing link" between the Trojan and TNO populations. Using a simulation of the DES TNO detection efficiency, we find that there are 162 +/- 73 Trojans with Hr < 10 at the L4 Lagrange point of Neptune. Moreover, the blue-to-red Neptunian Trojan population ratio should be higher than 17:1. Based on this result, we discuss the possible origin of the ultra-red Neptunian Trojan population and its implications for the formation history of Neptunian Trojans

    Palladium(II) complexes with thiosemicarbazones: syntheses, characterization and cytotoxicity against breast cancer cells and Anti-Mycobacterium tuberculosis activity

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    TrĂȘs complexos de PdII com tiossemicarbazonas N(4)-substituĂ­das foram preparados: [Pd(aptsc)(PPh3)](NO3) H2O, 1, [Pd(apmtsc)(PPh3)](NO3), 2, e [Pd(apptsc)(PPh3)](NO3) H2O, 3, sendo PPh3 = trifenilfosfina; Haptsc = 2-acetilpyridina-tiossemicarbazona; Hapmtsc = 2-acetilpiridina-N(4)-metil-tiossemicarbazona e Happtsc = 2-acetilpiridina-N(4)-fenil-tiossemicarbazona. Os complexos foram caracterizados por anĂĄlise elementar, IR, UV-Vis, ÂčH e 31P{ÂčH} NMR e tiveram suas estruturas cristalinas determinadas por difratometria de raios X em monocristal. Os ligantes tiossemicarbazonatos monoaniĂŽnicos atuam de modo tridentado, ligando-se ao metal pelos ĂĄtomos de nitrogĂȘnio piridĂ­nico, nitrogĂȘnio azometĂ­nico e enxofre. A atividade citotĂłxica frente Ă  linhagem de cĂ©lulas tumorais MDA-MB231 (tumor de mama) e a atividade anti-Mycobacterium tuberculosis H37Rv ATCC 27294 dos compostos foram investigadas. Os complexos de PdII mostraram-se altamente ativos contra as cĂ©lulas tumorais, com valores de IC50 em torno de 5 ”mol L-1, enquanto o agente antitumoral em uso clĂ­nico cisplatina mostrou-se inativo. Os compostos apresentaram atividade anti-M. tuberculosis significante, com valores de CIM comparĂĄveis ou melhores que aqueles referentes a alguns fĂĄrmacos usados clinicamente contra tuberculose.Three PdII complexes were prepared from N(4)-substituted thiosemicarbazones: [Pd(aptsc)(PPh3)](NO3) H2O, 1, [Pd(apmtsc)(PPh3)](NO3), 2, and [Pd(apptsc)(PPh3)](NO3) H2O, 3, where PPh3 = triphenylphosphine; Haptsc = 2-acetylpyridine-thiosemicarbazone; Hapmtsc = 2-acetylpyridine-N(4)-methyl-thiosemicarbazone and Happtsc = 2-acetylpyridine-N(4)-phenyl-thiosemicarbazone. All complexes were characterized by elemental analysis, IR, UV-Vis, ÂčH and 31P{ÂčH} NMR spectroscopies, and had their crystalline structures determined by X-ray diffractometry from single crystals. The monoanionic thiosemicarbazonate ligands act in a tridentate mode, binding to the metal through the pyridine nitrogen, the azomethine nitrogen and the sulfur atoms. The cytotoxic activity against the breast cancer cell line MDA-MB231 and the anti-Mycobacterium tuberculosis H37Rv ATCC 27294 activity were evaluated for the compounds. All PdII complexes were highly active against the studied cell line, presenting similar values of IC50, around 5 ”mol L-1, while the clinically applied antitumor agent cisplatin was inactive. The compounds show remarkable anti-M. tuberculosis activities, presenting MIC values comparable or better than some commercial anti-M tuberculosis drugs

    OptFlux: an open-source software platform for in silico metabolic engineering

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    <p>Abstract</p> <p>Background</p> <p>Over the last few years a number of methods have been proposed for the phenotype simulation of microorganisms under different environmental and genetic conditions. These have been used as the basis to support the discovery of successful genetic modifications of the microbial metabolism to address industrial goals. However, the use of these methods has been restricted to bioinformaticians or other expert researchers. The main aim of this work is, therefore, to provide a user-friendly computational tool for Metabolic Engineering applications.</p> <p>Results</p> <p><it>OptFlux </it>is an open-source and modular software aimed at being the reference computational application in the field. It is the first tool to incorporate strain optimization tasks, i.e., the identification of Metabolic Engineering targets, using Evolutionary Algorithms/Simulated Annealing metaheuristics or the previously proposed OptKnock algorithm. It also allows the use of stoichiometric metabolic models for (i) phenotype simulation of both wild-type and mutant organisms, using the methods of Flux Balance Analysis, Minimization of Metabolic Adjustment or Regulatory on/off Minimization of Metabolic flux changes, (ii) Metabolic Flux Analysis, computing the admissible flux space given a set of measured fluxes, and (iii) pathway analysis through the calculation of Elementary Flux Modes.</p> <p><it>OptFlux </it>also contemplates several methods for model simplification and other pre-processing operations aimed at reducing the search space for optimization algorithms.</p> <p>The software supports importing/exporting to several flat file formats and it is compatible with the SBML standard. <it>OptFlux </it>has a visualization module that allows the analysis of the model structure that is compatible with the layout information of <it>Cell Designer</it>, allowing the superimposition of simulation results with the model graph.</p> <p>Conclusions</p> <p>The <it>OptFlux </it>software is freely available, together with documentation and other resources, thus bridging the gap from research in strain optimization algorithms and the final users. It is a valuable platform for researchers in the field that have available a number of useful tools. Its open-source nature invites contributions by all those interested in making their methods available for the community.</p> <p>Given its plug-in based architecture it can be extended with new functionalities. Currently, several plug-ins are being developed, including network topology analysis tools and the integration with Boolean network based regulatory models.</p

    Genetic Structure of the Tiger Mosquito, Aedes albopictus, in Cameroon (Central Africa)

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    Background: Aedes albopictus (Skuse, 1884) (Diptera: Culicidae), a mosquito native to Asia, has recently invaded all five continents. In Central Africa it was first reported in the early 2000s, and has since been implicated in the emergence of arboviruses such as dengue and chikungunya in this region. Recent genetic studies of invasive species have shown that multiple introductions are a key factor for successful expansion in new areas. As a result, phenotypic characters such as vector competence and insecticide susceptibility may vary within invasive pest species, potentially affecting vector efficiency and pest management. Here we assessed the genetic variability and population genetics of Ae. albopictus isolates in Cameroon (Central Africa), thereby deducing their likely geographic origin. Methods and Results: Mosquitoes were sampled in 2007 in 12 localities in southern Cameroon and analyzed for polymorphism at six microsatellite loci and in two mitochondrial DNA regions (ND5 and COI). All the microsatellite markers were successfully amplified and were polymorphic, showing moderate genetic structureamong geographic populations (F-ST = 0.068, P<0.0001). Analysis of mtDNA sequences revealed four haplotypes each for the COI and ND5 genes, with a dominant haplotype shared by all Cameroonian samples. The weak genetic variation estimated from the mtDNA genes is consistent with the recent arrival of Ae. albopictus in Cameroon. Phylogeographic analysis based on COI polymorphism indicated that Ae. albopictus populations from Cameroon are related to tropical rather than temperate or subtropical outgroups. Conclusion: The moderate genetic diversity observed among Cameroonian Ae. albopictus isolates is in keeping with recent introduction and spread in this country. The genetic structure of natural populations points to multiple introductions from tropical regions

    The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

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    The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected
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