Identificación y comparación de enterobacterias en pacientes con enfermedad periimplantar en una población Bogotana

Objetivo: El objetivo de este trabajo fue identificar la presencia de enterobacterias y su tipificación en muestras de placa subgingival de implantes y dientes adyacentes a implantes de pacientes parcial y completamente edéntulos residentes en Bogotá; con diagnóstico de Mucositis y Periimplantitis para posteriormente comparar los resultados. Materiales y Métodos: Participaron 31 pacientes, con un total de 103 implantes de los cuales 91 implantes fueron diagnóstico con Mucositis y 12 diagnostico de Periimplantitis. Tres pacientes de los 31 fueron edéntulos totales y tuvieron diagnostico de Mucositis. No hubo pacientes edéntulos diagnosticados con Periimplantitis. Se tomaron muestras del fondo del surco con puntas de papel estériles, las cuales fueron sembradas en agar MacConkey e identificadas por medio de espectrometría de masas utilizando el sistema MALDI-TOF MS. Los tres microorganismos que se aislaron con mayor frecuencia en pacientes parcialmente edéntulos tanto en dientes como en implantes fueron K. oxytoca, E. cloacae y E. cloacae complex. Una paciente con Periimplantitis tuvo una muestra positiva para Mycoplasma arginini el cual no está reportado como asociado con enfermedad periodontal o periimplantar. En los pacientes edéntulos se aislaron Acinetobacter iwoffii, Stenotophomonas maltophilia y Enterobacter kobei, los cuales están reportados como asociados a enfermedad peridontal y periimplantar. Una paciente con síndrome de Sjögren, la cual presentó diagnóstico de mucositis y un aislamiento de Acinetobacter iwoffii y Stenotophomonas maltophilia. En conclusión, los microorganismos aislados están relacionados con enfermedad periimplantar y periodontal a excepción del Mycoplasma arginini. Al existir coincidencias en el aislamiento de enterobacterias en dientes e implantes se observa que los surcos periodontales pueden servir como reservorio de bacterias la cuales posteriormente pueden colonizar los tejidos periimplantares. La flora oral en pacientes edéntulos puede resultar menos patológica que la que se presenta en pacientes parcialmente edéntuos, debido a los hallazgos en esta estudio. Se recomienda realizar más investigaciones en el tema para lograr definir el papel de las enterobacterias en la enfermedad periimplantar.Abstract. Objective: The objective of this study was to identify the presence and species of enterobacteria in samples of subgingival plaque from implants and adjacent teeth of edentulous and partially edentulous patients diagnosed with Periimplantitis to be compared with patients with a diagnosis of Mucositis in a Bogotan population. Materials and Methods: 31 patients participate. A total of 103 implants were evaluated, which 91 had Mucositis diagnosis and 12 Periimplantitis diagnosis. 3 patients out of 31 were edentulous and had Mucositis diagnosis. There were edentulous patients diagnosed with Periimplantitis. Socket samples were taken with sterile paper points, which were grown on MacConkey agar and identified by mass spectrometry using the MALDI-TOF MS system. The three microorganisms were isolated most often in partially edentulous patients, in both teeth and implants were K. oxytoca, E. cloacae and E. cloacae complex. One patient with Periimplantitis diagnosis had a positive sample Mycoplasma arginini which is not reported as associated with periodontal or peri-implant disease. In edentulous patients Acinetobacter iwoffii, Enterobacter Kobei and Stenotophomonas maltophilia were isolated, which are reported to be associated with periodontal and peri-implant disease. There was a patient with Sjögren's syndrome, which presented muchositis diagnosis and isolation of Acinetobacter iwoffii and Stenotophomonas maltophilia. In conclusion, the isolated microorganisms are related to peri-implant and periodontal disease except Mycoplasma arginini. As there coincidences in isolating enterobacteria teeth and implants shows that the periodontal pockets may serve as a reservoir of the bacteria which then colonize the peri-implants tissues. The oral flora in edentulous patients may be less morbid than occurs in patients partially edentulous due to the findings in this study. it is recommended further research in the field to define the role of enterobacteria in the peri-implant disease.Otr

Parliamentary roll-call voting as a complex dynamical system:The case of Chile

A method is proposed to study the temporal variability of legislative roll-call votes in a parliament from the perspective of complex dynamical systems. We studied the Chilean Chamber of Deputies’ by analyzing the agreement ratio and the voting outcome of each vote over the last 19 years with a Recurrence Quantification Analysis and an entropy analysis (Sample Entropy). Two significant changes in the temporal variability were found: one in 2014, where the voting outcome became more recurrent and with less entropy, and another in 2018, where the agreement ratio became less recurrent and with higher entropy. These changes may be directly related to major changes in the Chilean electoral system and the composition of the Chamber of Deputies, given that these changes occurred just after the first parliamentary elections with non-compulsory voting (2013 elections) and the first elections with a proportional system in conjunction with an increase in the number of deputies (2017 elections) were held.</p

Synthesis of oligonucleotides carrying anchoring groups and their use in the preparation of oligonucleotide-gold conjugates

Oligodeoxynucleotide conjugates 1-15 carrying anchoring groups such as amino, thiol, pyrrole, and carboxy groups were prepared. A post-synthetic modification protocol was developed. In this method 2′-deoxy-O4-(p-nitrophenyl)uridine-3-phosphoramidite was prepared and incorporated in oligonucleotides. After assembly, the modified nucleoside was made to react with different amines carrying the anchoring groups. At the same time, protecting groups were removed to yield the desired oligonucleotide conjugates. In a second approach, amino, thiol, and carboxylic groups were introduced into the 3′-end of the oligonucleotides by preparing solid supports loaded with the appropriate amino acids. Oligonucleotide-gold conjugates were prepared and their binding properties were examined.Peer reviewe

Arrested dynamics of the dipolar hard-sphere model

We report the combined results of molecular dynamics simulations and theoretical calculations concerning various dynamical arrest transitions in a model system representing a dipolar fluid, namely, N (softcore) rigid spheres interacting through a truncated dipole-dipole potential. By exploring different regimes of concentration and temperature, we find three distinct scenarios for the slowing down of the dynamics of the translational and orientational degrees of freedom: At low ({$\eta$} = 0.2) and intermediate (${\eta}$ = 0.4) volume fractions, both dynamics are strongly coupled and become simultaneously arrested upon cooling. At high concentrations ({$\eta$} $\lt$ 0.6), the translational dynamics shows the features of an ordinary glass transition, either by compressing or cooling down the system, but with the orientations remaining ergodic, thus indicating the existence of partially arrested states. In this density regime, but at lower temperatures, the relaxation of the orientational dynamics also freezes. The physical scenario provided by the simulations is discussed and compared against results obtained with the self-consistent generalized Langevin equation theory, and both provide a consistent description of the dynamical arrest transitions in the system. Our results are summarized in an arrested states diagram which qualitatively organizes the simulation data and provides a generic picture of the glass transitions of a dipolar fluid

Structural Characterization of Linear Three-Dimensional Random Chains: Energetic Behaviour and Anisotropy

In this work, we will make an energetic and structural characterization of three-dimensional linear chains generated from a simple self-avoiding random walk process in a finite time, without boundary conditions, without the need to explore all possible configurations. From the analysis of the energy balance between the terms of interaction and bending (or correlation), it is shown that the chains, during their growth process, initially tend to form clusters, leading to an increase in their interaction and bending energies. Larger chains tend to “escape” from the cluster when they reach a number of “steps” N>∼1040 , resulting in a decrease in their interaction energy, however, maintaining the same behavior as flexion energy or correlation. This behavior of the bending term in the energy allows distinguishing chains with the same interaction energy that present different structures. As a complement to the energy analysis, we carry out a study based on the moments of inertia of the chains and their radius of gyration. The results show that the formation of clusters separated by “tails” leads to a final “prolate” structure for this type of chain, the same structure evident in real polymeric linear chains in a good solvent

Apolar carbohydrates as DNA capping agents

Mono- and disaccharides have been shown to stack on top of DNA duplexes stabilizing sequences with terminal C–G base pairs. Here we present an apolar version of glucose and cellobiose as new capping agents that stack on DNA increasing considerably its stability with respect to their natural polyhydroxylated mono- and disaccharide DNA conjugates.Ministerio de Ciencia, Innovación y Universidades CTQ2006-01123, CTQ2007-68014- C02-02, CTQ2009-13705, BFU2007-63287Generalitat de Catalunya 2009/SGR/208Instituto de Salud Carlos III CB06_01_001

Medição e análise dos resultados da prova básica de matemática aplicada a estudantes que ingressam à Fundação Universidade Autónoma de Colômbia

The research project “Quality indicators of academic services offered by Dept. of Natural and Exact Sciences based on Statistical Process Control” was used to evaluate, measure and analyze a number of variables that allowed quality indicators of academics service offered by the Dept. of Natural and Exact Sciences at Fundación Universidad Autónoma de Colombia. One of these variables is an “Introductory Mathematics Course.” This short paper shows some general results of a basic mathematics test, applied to students who entered at the University during the first half of 2014. The test is intended to assess the level of the acquired mathematical knowledge by the students to begin their career. The results showed that most of the students have not passed the test, and based on data analysis we build indicators to look for strategies in order to improve the academic level of the students.Dentro del proyecto de investigación "Indicadores de calidad en los servicios académicos ofrecidos por el Departamento de Ciencias Naturales y Exactas, basado en Control Estadístico de Procesos" se evaluaron, midieron y analizaron una serie de variables las cuales permitieron construir indicadores de calidad en los servicios académicos que ofrece dicho departamento en la Fundación Universidad Autónoma de Colombia. Una de estas variables es la "Realización curso de Matemática Introductoria". En este breve artículo se muestran algunos resultados generales de una prueba básica de matemáticas, aplicada a estudiantes que ingresaron a la Universidad, durante el primer semestre de 2014, la cual pretende evaluar el nivel de conocimientos matemáticos con los que llegan los estudiantes a iniciar su carrera profesional.Los resultados obtenidos mostraron que la mayoría de estudiantes no la aprobaron. Con base en el análisis de la información obtenida se construyeron indicadores que permitirán buscar estrategias de mejoramiento del nivel académico de los estudiantes.Dentro do projeto de pesquisa “Indicadores de qualidade nos serviços académicos oferecidos pelo Departamento de Ciências Naturais e Exatas, baseado no Controle Estadístico de Processos” se avaliaram, mediram e analisaram um conjunto de variáveis, as quais permitiram a construção de indicadores de qualidade nos serviços académicos oferecidos pelo Departamento de Ciências Naturais e Exatas da Fundacional Universidade Autónoma de Colômbia. Uma dessas variáveis é a “Realização do curso de Matemática Introdutória”. Neste breve artigo mostram-se alguns resultados gerais de uma prova básica de matemática, aplicada a estudantes que ingressaram à Universidade, durante o primeiro semestre de 2014, a qual pretende avaliar o nível de conhecimentos matemáticos com que chegam os estudantes a começar a sua carreira profissional. Os resultados obtidos mostraram que na maioria os estudantes não aprovaram-na. Baseados na análise da informação obtida construíram-se indicadores que permitirão procurar estratégias de melhoramento do nível académico dos estudantes

Reasonable Non-conventional Generator of Random Linear Chains Based on a Simple Self-avoiding Walking Process: A Statistical and Fractal Analysis

Models based on self-excluded walks have been widely used to generate random linear chains. In this work, we present an algorithm capable of generating linear strings in two and three dimensions, in a simple and efficient way. The discrete growth process of the chains takes place in a finite time, in a network without pre-established boundary conditions and without the need to explore the entire configurational space. The computational processing time and the length of the strings depending on the number of trials N′ . This number is always less than the real number of steps in the chain, N. From the statistical analysis of the characteristic distances, the radius of gyration ( Rg ), and the end-to-end distance ( Ree ), we make a morphological description of the chains and we study the dependence of this quantities on the number of steps, N. The universal critical exponent obtained are in very good agreement with previous values reported in literature. We also study fractal characteristics of the chains using two different methods, Box-Counting Dimension or Capacity Dimension and Correlation Dimension. The studies revealed essential differences between chains of different dimensions, for the two methods used, showing that three-dimensional chains are more correlated than two-dimensional chains

Carbohydrate-DNA interactions at G-quadruplexes: Folding and stability changes by attaching sugars at the 5′-End

Quadruplex DNA structures are attracting an enormous interest in many areas of chemistry, ranging from chemical biology, supramolecular chemistry to nanoscience. We have prepared carbohydrate-DNA conjugates containing the oligonucleotide sequences of G-quadruplexes (thrombin binding aptamer (TBA) and human telomere (TEL)), measured their thermal stability and studied their structure in solution by using NMR and molecular dynamics. The solution structure of a fucose-TBA conjugate shows stacking interactions between the carbohydrate and the DNA G-tetrad in addition to hydrogen bonding and hydrophobic contacts. We have also shown that attaching carbohydrates at the 5′-end of a quadruplex telomeric sequence can alter its folding topology. These results suggest the possibility of modulating the folding of the G-quadruplex by linking carbohydrates and have clear implications in molecular recognition and the design of new G-quadruplex ligands. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.We thank the MICINN (grants CTQ2009–13705, CTQ2010–20451, CTQ2010–21567-C02–02), EU COST project MP0802, Generalitat de Catalunya (2009/SGR/208), and Instituto de Salud Carlos III (CIBERBNN, CB06 01 0019) for financial support. IGP and RL thank CSIC for a JAE contract. EVC thanks the Ministry of Education for an FPU doctoral fellowship.Peer reviewe

A botanical survey of Joseph Quer’s flora española

We examine various aspects of Joseph Quer’s Flora española (1762–1764, 1784), taking into consideration the contributions made by Casimiro Gómez Ortega and proposing that he be credited as a co-author on the last two volumes of the work. Flora española comprises 2602 species, 2493 of which are vascular plants, including both wild and cultivated species. When assigned to the currently accepted species of Flora iberica, we obtain 1690 native or naturalized plant species (28 % of the total Spanish species). Most of the reported species correspond to common plants, only 3 % are considered narrowly distributed species and no more than 5 % are endemic species. In Flora española only two species are proposed as new. The limited number of new taxa may be due to Quer’s self-taught background, strongly influenced by Tournefort’s work, and the unfavourable scientific environment, characterized by the lack of resources and supporting institutions. By far the weakest points of Flora española are the names listed in alphabetical order and the use of old polynomials instead of Linnaean binomials. In contrast, the study of dried plants then kept at herbaria constituted a suitable working methodology, which made this Flora a solid base for subsequent works in the Iberian Peninsula. We also address the extensive field work carried out by Quer: he visited 632 different localities spread over most of the Iberian Peninsula. The information provided in Flora española, together with a thorough review of Quer’s herbarium vouchers, the labels of which do not include information on localities, allows us to gain valuable insights into some rare and potentially extinct species