171 research outputs found
Molecular findings and approaches spotlighting Mycobacterium bovis persistence in cattle
Mycobacterium tuberculosis (Mtb) and Mycobacterium bovis (M. bovis) are the etiological agents of human and bovine tuberculosis (TB, bTB) respectively, and share genetic identity over 99% at the whole genome level. Progress has been made towards explaining how mycobacteria and their infected hosts remain in balance without producing clinical symptoms of disease, a phenomenon referred to as latency or persistence, which can be mimicked by certain in vitro conditions. Latency/persistence has mainly been studied using Mtb, where the two-component signalling system, dosRS, has been assigned an instrumental role, and even constitutes the current basis for development of new diagnostic methods and treatment addressing this particular stage of TB. M. bovis conserves homolog genes that in Mtb play a role in human latent TB infection and that, by analogy, would allow it to enter a persistent state in infected cattle; nevertheless, little attention has been paid to this stage in bovine hosts. We suggest that many of the advances acquired through the study of Mtb can and should be taken into consideration by research groups and veterinary professionals dealing with bTB. The study of the infection in bovines, paying particular attention to defining the molecular and cellular markers of a M. bovis persistent infection in cattle, presents great opportunities for the development and trial of new diagnostic tests and vaccines, tools that will surely help in promoting eradication of bTB in high-burden settings
Preferential oxidation of CO (CO-PROX) over CuOx/CeO2 coated microchannel reactor
The general aspects of the synthesis and characterization results of a CuOx/CeO2 catalyst were presented. In addition the principal steps for manufacturing a microchannel reactor and for the coating of the CuOx/CeO2 catalyst onto the microchannels walls, were also summarized. The catalytic activity of this microchannel reactor during the preferential oxidation of CO (CO-PROX) was evaluated employing a feed-stream that simulates a reformate off-gas after the WGS unit. Two activation atmospheres were studied (H2/N2 and O2/N 2). The reducing pretreatment improved the resistance to deactivation by formation of carbonaceous species over the catalyst surface at high temperatures. The presence of H2O and CO2 in the feed-stream was also analyzed indicating that the adsorption of CO2 inhibited the conversion of CO at lower temperatures because these compounds modified the active sites through the formation of carbonaceous species on the catalyst surface. Finally, the experimental results of the microreactor performance were compared with CFD simulations that were carried out using a kinetic for the CuOx/CeO2 powder catalyst. The experimental results were reasonably well described by the model, thus confirming its validity.Peer Reviewe
Experimental and DFT Study of the [AuAr(AsPh3)]-Catalyzed cis/trans Isomerization of [PdAr2(AsPh3)2] (Ar = C6F5 or C6Cl2F3): Alternative Mechanisms and Its Switch upon Pt for Pd Substitution
Producción CientíficaThe aryl transmetalation processes between cis-[PdRf2(AsPh3)2] (Rf = C6Cl2F3) and [AuPf(AsPh3)] (Pf = C6F5) has been studied experimentally and by DFT calculations. Aryl exchange with or without isomerization of the Pd geometry occurs by ligand displacement of one AsPh3 ligand by an [AuAr(AsPh3)] molecule, which coordinates using the Au–Ar bond electron density, followed or not by a second switch to the next aryl (Ar) group. The transition states are bridged Ar–Au(AsPh3)–Ar′ structures with fairly planar geometries. Alternatively, a direct switch of the Au(AsPh3) fragment to either cis or trans Ar groups on Pd can be achieved from a square-pyramidal [(AsPh3)Au-PdAr3(AsPh3)] intermediate or transition state. The later pathway is less favorable for the case studied (M = Pd), but it is preferred for the same chemical system with M = Pt. The study provides some clues on exchanges that can be relevant in organic syntheses catalyzed by bimetallic systems.Ministerio de Economía, Industria y Competitividad (projects CTQ2016-80913-P and CTQ2017-89217-P)Junta de Castilla y León (projects VA051P17 and VA062G18)Xunta de Galicia (Consolidación GRC ED431C2017/61 from DXPCTSUG; ED-431G/02-FEDER “Unha maneira de facer Europa” to CINBIO, a Galician research center 2016−2019
Mitochondrial echoes of first settlement and genetic continuity in El Salvador
Background: From Paleo-Indian times to recent historical episodes, the Mesoamerican isthmus played an important role in the distribution and patterns of variability all around the double American continent. However, the amount of genetic information currently available on Central American continental populations is very scarce. In order to shed light on the role of Mesoamerica in the peopling of the New World, the present study focuses on the analysis of the mtDNA variation in a population sample from El Salvador.
Methodology/Principal Findings: We have carried out DNA sequencing of the entire control region of the mitochondrial DNA (mtDNA) genome in 90 individuals from El Salvador. We have also compiled more than 3,985 control region profiles from the public domain and the literature in order to carry out inter-population comparisons. The results reveal a predominant Native American component in this region: by far, the most prevalent mtDNA haplogroup in this country (at ~90%) is A2, in contrast with other North, Meso- and South American populations. Haplogroup A2 shows a star-like phylogeny and is very diverse with a substantial proportion of mtDNAs (45%; sequence range 16090–16365) still unobserved in other American populations. Two different Bayesian approaches used to estimate admixture proportions in El Salvador shows that the majority of the mtDNAs observed come from North America. A preliminary founder analysis indicates that the settlement of El Salvador occurred about 13,400±5,200 Y.B.P.. The founder age of A2 in El Salvador is close to the overall age of A2 in America, which suggests that the colonization of this region occurred within a few thousand years of the initial expansion into the Americas.
Conclusions/Significance: As a whole, the results are compatible with the hypothesis that today's A2 variability in El Salvador represents to a large extent the indigenous component of the region. Concordant with this hypothesis is also the observation of a very limited contribution from European and African women (~5%). This implies that the Atlantic slave trade had a very small demographic impact in El Salvador in contrast to its transformation of the gene pool in neighbouring populations from the Caribbean facade
Study of the near-barrier scattering of 8He on 208Pb
The structure and dynamics of 8He have been studied through the collision process with a 208Pb target at energies of 22 and 16 MeV, above and below the Coulomb barrier, respectively. The energy and angular distributions of the elastically scattered 8He and the 6,4He fragments were measured. In this paper, we discuss the method used to determine the effective position of the beam spot on the reaction target and the scattering and solid angles of each pixel of the detector array.Ministerio de Economía y Competitividad FPA2010-22131-C021-01, FPA2014-59954-C3-1-PMinistry of Science and Higher Education of Poland N202 033637European Science Foundation EUI2009-0416
Gestión investigativo laboral para estudiantes de la carrera de medicina en el consultorio. Estudio preliminar / Working investigative management for medical students at the medical office: a preliminary study
Con el objetivo de identificar las tendencias existentes acerca de cómo se dirige el PDE de los estudiantes de la Carrera de Medicina de todos los años, a nivel del Consultorio Médico en su componente investigativo laboral, se realizó el presente trabajo utilizando métodos teóricos y empíricos de la investigación, donde empleando el análisis de 2 preguntas en un grupo focal organizado, al respecto, se muestran un número de limitaciones que hacen que la gestión de este proceso sea insuficiente a este nivel, no lográndose la necesaria planificación, organización, regulación y control del proceso, lo cual repercute en la adquisición de las habilidades necesarias por los educandos. Palabras clave: recursos humanos en salud, educación médica, consultorios médicos, investigación. ABSTRACT The present work is aimed at identifying the present trends about how to manage the PDE in medical students at medical office using theoretical and empirical methods for the research using the analysis of 2 questions in a group designed for this purpose . Some limitations as planning, organizations and the control of the process are shown which obstruct the management of this process with some grade of repercussion on the necessary skills for the students.Key words: health manpower, medical education, physicians' offices, research
Gestión investigativo laboral para estudiantes de la carrera de medicina en el consultorio. Estudio preliminar / Working investigative management for medical students at the medical office: a preliminary study
Con el objetivo de identificar las tendencias existentes acerca de cómo se dirige el PDE de los estudiantes de la Carrera de Medicina de todos los años, a nivel del Consultorio Médico en su componente investigativo laboral, se realizó el presente trabajo utilizando métodos teóricos y empíricos de la investigación, donde empleando el análisis de 2 preguntas en un grupo focal organizado, al respecto, se muestran un número de limitaciones que hacen que la gestión de este proceso sea insuficiente a este nivel, no lográndose la necesaria planificación, organización, regulación y control del proceso, lo cual repercute en la adquisición de las habilidades necesarias por los educandos. Palabras clave: recursos humanos en salud, educación médica, consultorios médicos, investigación. ABSTRACT The present work is aimed at identifying the present trends about how to manage the PDE in medical students at medical office using theoretical and empirical methods for the research using the analysis of 2 questions in a group designed for this purpose . Some limitations as planning, organizations and the control of the process are shown which obstruct the management of this process with some grade of repercussion on the necessary skills for the students.Key words: health manpower, medical education, physicians' offices, research
Breast cancer PAM50 signature: correlation and concordance between RNA-Seq and digital multiplexed gene expression technologies in a triple negative breast cancer series
[Background]: Full RNA-Seq is a fundamental research tool for whole transcriptome analysis. However, it is too costly and time consuming to be used in routine clinical practice. We evaluated the transcript quantification agreement between RNA-Seq and a digital multiplexed gene expression platform, and the subtype call after running the PAM50 assay in a series of breast cancer patients classified as triple negative by IHC/FISH. The goal of this study is to analyze the concordance between both expression platforms overall, and for calling PAM50 triple negative breast cancer intrinsic subtypes in particular.[Results]: The analyses were performed in paraffin-embedded tissues from 96 patients recruited in a multicenter, prospective, non-randomized neoadjuvant triple negative breast cancer trial (NCT01560663). Pre-treatment core biopsies were obtained following clinical practice guidelines and conserved as FFPE for further RNA extraction. PAM50 was performed on both digital multiplexed gene expression and RNA-Seq platforms. Subtype assignment was based on the nearest centroid classification following this procedure for both platforms and it was concordant on 96% of the cases (N = 96). In four cases, digital multiplexed gene expression analysis and RNA-Seq were discordant. The Spearman correlation to each of the centroids and the risk of recurrence were above 0.89 in both platforms while the agreement on Proliferation Score reached up to 0.97. In addition, 82% of the individual PAM50 genes showed a correlation coefficient > 0.80.[Conclusions]: In our analysis, the subtype calling in most of the samples was concordant in both platforms and the potential discordances had reduced clinical implications in terms of prognosis. If speed and cost are the main driving forces then the preferred technique is the digital multiplexed platform, while if whole genome patterns and subtype are the driving forces, then RNA-Seq is the preferred method.M.M was supported by two research grants from Ministry of Economy and Competitiveness ISCIII-FIS grants (PI 12/02684): “Predictores genómicos de respuesta a la quimioterapia neoadyuvante con docetaxel-carboplatino en pacientes con cáncer de mama triple negativo”/“Genomic predictors of response to neoadjuvant chemotherapy with docetaxel-carboplatin in patients with triple negative breast cancer”; and (PI 15/00117): “Cáncer de mama triple negative: Predicción de respuesta a docetaxel-carboplatino neoadyuvante mediante caracterización de TILs y firmas inmunes basadas en secuenciación masiva de RNA”/” Triple negative breast cancer: Prediction of response to neoadjuvant docetaxel-carboplatin by characterization of TILs and immune signatures based on massive RNA sequencing”. C.M.P was supported by funds from the NCI Breast SPORE program (P50-CA58223).Peer reviewe
Nuclear astrophysics with radioactive ions at FAIR
R. Reifarth et al: ; 12 págs.; 9 figs.; Open Access funded by Creative Commons Atribution Licence 3.0 ; Nuclear Physics in Astrophysics VI (NPA6)The nucleosynthesis of elements beyond iron is dominated by neutron captures
in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during
those processes, because they are shielded from the s-process
ow and r-process -decay chains.
These nuclei are attributed to the p and rp process.
For all those processes, current research in nuclear astrophysics addresses the need for more
precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct
or inverse kinematics, forward or time-reversed direction are investigated to determine or at least
to constrain the desired reaction cross sections.
The Facility for Antiproton and Ion Research (FAIR) will oer unique, unprecedented
opportunities to investigate many of the important reactions. The high yield of radioactive
isotopes, even far away from the valley of stability, allows the investigation of isotopes involved
in processes as exotic as the r or rp processes.This project was supported by the HGF Young Investigators Project VH-NG-327, EMMI, H4F,
HGS-HIRe, JINA, NAVI, DFG and ATHENA.Peer Reviewe
Guerra y conflictos contemporáneos : reflexiones generales para el caso colombiano.
El presente trabajo brinda herramientas académicas para entender la evolución a nivel global de las formas de guerra y conflicto en la historia reciente, mirando las transformaciones que atraviesa Colombia en lo relativo a la violencia interna. Desde la historia, la ciencia política y las relaciones internacionales, los autores reflexionan y proponen puntos de vista para académicos, tomadores de decisiones y en general para la sociedad con el fin de aportar nuevas maneras de entender los escenarios a los cuales el país se enfrenta. Esta investigación plantea cuestionamientos y sugiere perspectivas para una Colombia contemporánea en su relación con las dinámicas globale
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