2,022 research outputs found
Activity of cefiderocol against high-risk clones of multidrug-resistant Enterobacterales, Acinetobacter baumannii, Pseudomonas aeruginosa and Stenotrophomonas maltophilia
BACKGROUND:
Cefiderocol is a novel siderophore cephalosporin, developed for activity against MDR Gram-negative bacilli (MDR-GNB).
OBJECTIVES:
To assess the in vitro antibacterial activity of cefiderocol against a collection of MDR-GNB clinical isolates from hospitals in southern Spain.
METHODS:
Two hundred and thirty-one isolates of successful clones were tested: 125 Enterobacterales (121 ESBL- and/or carbapenemase-producing Klebsiella pneumoniae and 4 carbapenemase-producing Enterobacter cloacae), 80 Acinetobacter baumannii, 6 Pseudomonas aeruginosa and 20 Stenotrophomonas maltophilia. Ceftolozane/tazobactam, ceftazidime, ceftazidime/avibactam, cefepime, aztreonam, meropenem, amikacin, ciprofloxacin, colistin and tigecycline were used as comparators against Enterobacterales, P. aeruginosa and A. baumannii. Minocycline, levofloxacin and trimethoprim/sulfamethoxazole were studied against S. maltophilia instead of aztreonam, ciprofloxacin and cefepime. MICs were determined by broth microdilution according to CLSI guidelines. MIC determination was performed in CAMHB for all antimicrobials except cefiderocol, where iron-depleted CAMHB was used.
RESULTS:
Cefiderocol showed potent in vitro activity against the isolates analysed. MIC50 and MIC90 values were in the ranges 0.125-8 mg/L and 0.5-8 mg/L, respectively, and 98% of isolates were inhibited at ≤4 mg/L. Only five isolates showed cefiderocol MICs of >4 mg/L: three ST2/OXA-24/40-producing A. baumannii, one ST114/VIM-1-producing E. cloacae and one ST114/VIM-1 + OXA-48-producing E. cloacae. All KPC-3-producing K. pneumoniae were susceptible to cefiderocol, even those resistant to ceftazidime/avibactam. P. aeruginosa isolates showed cefiderocol MICs of <4 mg/L, including those resistant to ceftolozane/tazobactam. S. maltophilia isolates displayed cefiderocol MICs of <4 mg/L, including those resistant to levofloxacin and/or trimethoprim/sulfamethoxazole.
CONCLUSIONS:
Cefiderocol showed excellent activity against MDR-GNB, including carbapenem-resistant isolates, and was the most active antimicrobial tested against this collection
A transcriptomic approach to study the effect of long-term starvation and diet composition on the expression of mitochondrial oxidative phosphorylation genes in gilthead sea bream (Sparus aurata)
© 2017 The Author(s). Background: The impact of nutritional status and diet composition on mitochondrial oxidative phosphorylation (OXPHOS) in fish remains largely unknown. To identify biomarkers of interest in nutritional studies, herein we obtained a deep-coverage transcriptome by 454 pyrosequencing of liver and skeletal muscle cDNA normalised libraries from long-term starved gilthead sea bream (Sparus aurata) and fish fed different diets. Results: After clean-up of high-throughput deep sequencing reads, 699,991 and 555,031 high-quality reads allowed de novo assembly of liver and skeletal muscle sequences, respectively (average length: 374 and 441 bp; total megabases: 262 and 245 Mbp). An additional incremental assembly was completed by integrating data from both tissues (hybrid assembly). Assembly of hybrid, liver and skeletal muscle transcriptomes yielded, respectively, 19,530, 11,545 and 10,599 isotigs (average length: 1330, 1208 and 1390 bp, respectively) that were grouped into 15,954, 10,033 and 9189 isogroups. Following annotation, hybrid transcriptomic data were used to construct an oligonucleotide microarray to analyse nutritional regulation of the expression of 129 genes involved in OXPHOS in S. aurata. Starvation upregulated cytochrome c oxidase components and other key OXPHOS genes in the liver, which exhibited higher sensitive to food deprivation than the skeletal muscle. However, diet composition affected OXPHOS in the skeletal muscle to a greater extent than in the liver: most of genes upregulated under starvation presented higher expression among fish fed a high carbohydrate/low protein diet. Conclusions: Our findings indicate that the expression of coenzyme Q-binding protein (COQ10), cytochrome c oxidase subunit 6A2 (COX6A2) and ADP/ATP translocase 3 (SLC25A6) in the liver, and cytochrome c oxidase subunit 5B isoform 1 (COX5B1) in the liver and the skeletal muscle, are sensitive markers of the nutritional condition that may be relevant to assess the effect of changes in the feeding regime and diet composition on fish farming.Peer ReviewedPostprint (published version
Interference-aware MIMO precoder design with realistic power constraints
This proceedins at: 2013 IEEE International Conference on Communications Workshops (ICC) took place 2013 June 9-13 in Budapest, Hungary.In this work an interference-aware precoder design is proposed for a downlink wireless cellular system. Each base-station designs a precoder with a joint MMSE-ZF criteria for the user information and the interference to other cells. In a realistic power constraint scenario, where each base-station has a limitation on the maximum power available power to be transmitted, the precoder filter can be analytically solved and this solution is provided. The simulated performance of the interference-aware filter in terms of achievable rates and MSE shows some advantages compared to other solutions in the literature designed with the aim of full interference cancellation such as block diagonalization schemes.This work has been partly funded by projects GRE3N (TEC2011-29006-C03-01/02/03) and COMONSENS (CSD 2008-00010).Publicad
Direct radiation estimates from horizontal global irradiance values
One of the main factors determining the economic feasibility of a solar thermal power plant is the
availability of direct radiation at the plant site. During last years, two Central Receiver Power Plants (Solgas and
Colon Solar) have been proposed in the South West of Spain (Huelva). For this area only global solar radiation data
are available in a historical representative database. Based on an 11 years radiation database gathered at a nearby
location, distance less than 100 km, 12 correlations, (one per month), between Mt and Md have been obtained. Solar
global radiation data from the power plant site and generated correlations have allowed the "construction" of a Direct
Radiation Design year that has been used both to design the solar plant heliostat field and receiver and to estimate
annual energy produced by the solar plant
A educação estatística à luz da educação matemática crítica
In a review of statistical education research from recent dissertations, one finds extensive inquiry into literacy, culture, reasoning, and statistical thinking, as well as evidence of the international community's tendency to incorporate critical theory into education. In this article, an exploration of possible relationships and convergences between principles of technical mathematics education and guidelines of statistical education is presented, which encourages the search for joint proposals and offers promising ideas both for teaching-learning and for education research in statistics. In addition, it seeks to search for joint proposals to integrate the social, cultural, and political dimensions in the educational practices of statistics to contribute to the formation of participatory citizens of society.En una revisión de la investigación en educación estadística desde disertaciones recientes, se encuentra extensa indagación en torno a la alfabetización, cultura, razonamiento y pensamiento estadístico, así como evidencias de la tendencia de la comunidad internacional a incorporar la teoría crítica en la educación. En este artículo, se presenta una exploración acerca de posibles relaciones y convergencias entre principios de la educación matemática crítica y lineamientos de la educación estadística, que propicia la búsqueda de propuestas en conjunto y ofrece ideas promisorias tanto para la enseñanza-aprendizaje como para la investigación en estadística. Además, pretende la búsqueda de propuestas en conjunto para integrar las dimensiones sociales, culturales y políticas en las prácticas educativas de la estadística, y así contribuir a la formación de ciudadanos participativos de la sociedad.Em uma revisão da pesquisa em educação estatística, a partir de dissertações recentes, encontra-se uma extensa indagação sobre a alfabetização, cultura, razonamento e pensamento estatístico, bem como evidências da tendência da comunidade internacional de incorporar a teoria crítica na educação. Neste artigo, apresenta-se então uma exploração sobre possíveis relações e convergências entre princípios da educação matemática crítica e diretrizes da educação estatística, que propicia a busca das propostas em conjunto e oferece ideias promissoras tanto para o ensino-aprendizagem, quanto para a investigação estatística. Além disso, considera a busca de propostas em conjunto para integrar as dimensões sociais, culturais e políticas nas práticas educacionais da estatística, e assim, contribuir para a formação de cidadãos participativos da sociedade
Reporting antimicrobial susceptibilities and resistance phenotypes in Staphylococcus spp.: a nationwide proficiency study
Objectives
To evaluate the proficiency of microbiology laboratories in Spain in antimicrobial susceptibility testing (AST) of Staphylococcus spp.
Materials and methods
Eight Staphylococcus spp. with different resistance mechanisms were selected: six Staphylococcus aureus (CC-01/mecA, CC-02/mecC, CC-03/BORSA, CC-04/MLSBi, CC-06/blaZ and CC-07/linezolid resistant, cfr); one Staphylococcus epidermidis (CC-05/linezolid resistant, 23S rRNA mutation); and one Staphylococcus capitis (CC-08/daptomycin non-susceptible). Fifty-one laboratories were asked to report: (i) AST system used; (ii) antimicrobial MICs; (iii) breakpoints used (CLSI or EUCAST); and (iv) clinical category. Minor, major and very major errors (mEs, MEs and VMEs, respectively) were determined.
Results
The greatest MIC discrepancies found were: (i) by AST method: 19.4% (gradient diffusion); (ii) by antimicrobial agent: daptomycin (21.3%) and oxacillin (20.6%); and (iii) by isolate: CC-07/cfr (48.0%). The greatest error rates were: (i) by AST method: gradient diffusion (4.3% and 5.1% VMEs, using EUCAST and CLSI, respectively); (ii) by breakpoint: 3.8% EUCAST and 2.3% CLSI; (iii) by error type: mEs (0.8% EUCAST and 1.0% CLSI), MEs (1.8% EUCAST and 0.7% CLSI) and VMEs (1.2% EUCAST and 0.6% CLSI); (iii) by antimicrobial agent: VMEs (4.7% linezolid and 4.3% oxacillin using EUCAST); MEs (14.3% fosfomycin, 9.1% tobramycin and 5.7% gentamicin using EUCAST); and mEs (22.6% amikacin using EUCAST).
Conclusions
Clinical microbiology laboratories should improve their ability to determine the susceptibility of Staphylococcus spp. to some antimicrobial agents to avoid reporting false-susceptible or false-resistant results. The greatest discrepancies and errors were associated with gradient diffusion, EUCAST breakpoints and some antimicrobials (mEs for aminoglycosides; MEs for fosfomycin, aminoglycosides and oxacillin; and VMEs for linezolid and oxacillin)
Perspectiva Ciencia, Tecnología y Sociedad en el aprendizaje de las ciencias
En este trabajo, hemos querido profundizar en el proceso de enseñanza-aprendizaje de las ciencias desde el enfoque Ciencia, Tecnología y Sociedad, que pretende formar a ciudadanos alfabetizados científica y tecnológicamente, que sean capaces de tomar decisiones y de participar de forma responsable en la sociedad actual. A partir de la puesta en práctica en el aula de la unidad didáctica Ciencia, Tecnología y Sociedad, Clones, ¿Gemelos de distinta edad?, hemos querido explorar qué y cómo aprenden un grupo de alumnos de 1º de Bachillerato de la asignatura Ciencias para el Mundo Contemporáneo
Panorama da pesquisa em educação estatística desde teses doutorais 2000-2014
The article presents the formulation of categories aimed to review and classify doctoral theses according to their theoretical approaches, relevant topics in educational action, subjects or focus of interest, characterization of methodological principles and ideas about the teaching-learning of stochastics. The methodology mixes the hermeneutic qualitative paradigm with quantitative methods based on statistical counts. Results show the systematization of 129 theses with advisors from universities in 18 countries, their main theoretical approach being Literacy, reasoning and statistical thinking. The qualitative paradigm is prioritized over the quantitative paradigm. The relevant focuses of interest are students from introductory courses in statistics and the disciplinary subject under study is descriptive statistics. Finally, the paper highlights the teaching of stochastics focused on real contexts in search of a critical education.En búsqueda de estrategias que posicionen de manera crítica la labor de grupos de investigación que trabajan en el campo de la educación estocástica4 (en especial la labor de la línea de Educación Estadística del grupo Didáctica de la Matemática de la UPN), se considera la elaboración de un panorama acerca de la investigación en dicho ámbito, como tarea que posibilita iniciar la reformulación de una agenda de trabajo investigativo afín con las tendencias actuales.La investigación inicia con la formulación de categorías que orientan la revisión y clasificación de tesis doctorales a la luz de enfoques teóricos, temas objeto de atención en la acción educativa, sujetos o focos de interés, caracterización de principios metodológicos que respaldan la indagación, e ideas acerca de la enseñanza-aprendizaje de la estocástica. La metodología de investigación del proyecto mezcla el paradigma cualitativo hermenéutico con métodos cuantitativos basados en recuentos estadísticos. El primero posibilita la acción interpretativa de las tesis, propicia la generación de categorías de análisis para su caracterización. Lo cuantitativo facilita la descripción de tendencias así como el afinamiento y la selección de una muestra de juicio de trece tesis.Entre los resultados se señala el acopio y la sistematización de 129 tesis asesoradas en universidades de 18 países. Se constata que el enfoque teórico “Alfabetización, razonamiento y pensamiento estadístico” es predominante y propio del campo. Respecto a las metodologías, la investigación cualitativa prima sobre la cuantitativa, y se reconoce el uso frecuente del “diseño de instrucción”. Los sujetos foco de interés investigativo más comunes son estudiantes de cursos introductorios de estadística, sin dejar de lado estudiantes de colegio y profesores de matemáticas (en formación inicial o continuada). En los temas disciplinares objeto de estudio, sobresale la estadística descriptiva sobre temas como la probabilidad, la inferencia y la variabilidad. Por último, se resalta la enseñanza de la estocástica centrada en contextos reales donde el aprendiz es el foco de atención en búsqueda de su formación crítica.O artigo apresenta a formulação de categorias orientadas à revisão e classificação de teses doutorais segundo suas abordagens teóricas, temas objeto de atenção na ação educativa, sujeitos ou focos de interesse, caracterização de princípios metodológicos e ideias acerca do ensino e a aprendizagem da estocástica. A metodologia mistura o paradigma qualitativo hermenêutico com métodos quantitativos baseados nas contagens estatísticas. Os resultados mostram a sistematização de 129 teses assessoradas em universidades de 18 países. Sua abordagem teórica predominante é a Alfabetização, Razoamento e Pensamento Estatístico. Existe uma priorização do paradigma qualitativo sobre o quantitativo. Os sujeitos alvo são estudantes de classes introdutórias de estatística e o tema disciplinar objeto de estudo sobressaliente é a estatística descritiva. Finalmente, ressalta-se o ensino da estocástica centrada em contextos reais, procurando uma formação de tipo crítico
Exploração da noção de distribuição da variabilidade
This article presents the results of a study aimed at verifying whether the work of variability contributes to developing the notion of statistical distribution. The authors carried out a teaching experiment in which they proposed a sequence of instruction whose purpose was that prospective mathematics teachers reach a wider idea of such concept. From the intuitive exploration of the data collections and the transit through several representation registers with the help of technology, the authors found that students actually note and take into consideration aspects related to the variability which, in turn, are linked to the notion of distribution. In other words, it is clear that, when students informally inquire about variability of data collections, in fact they are developing characteristics of distribution.Este artículo presenta los resultados de una investigación dirigida a comprobar si el trabajo desde la variabilidad contribuye al desarrollo de la noción de distribución estadística. Para ello, se optó por ejecutar un experimento de enseñanza en el que se propuso una secuencia de instrucción orientada a que los candidatos a profesores de matemáticas lleguen a una idea más amplia de este concepto. A partir de la exploración intuitiva de colecciones de datos y del tránsito por varios registros de representación con la ayuda de la tecnología, se encontró que los estudiantes en formación efectivamente notan y consideran diversos aspectos relacionados con la variabilidad que a su vez están ligados a la noción de distribución. En otras palabras, al indagar de manera informal sobre la variabilidad de colecciones de datos, en realidad los estudiantes están develando características de la distribución.Este artigo apresenta os resultados de uma investigação que procurou verificar se o trabalho de variabilidade contribui para raciocinar sobre a noção de distribuição estatística. Assim propomos uma sequência de instrução com estudantes candidatos para professores de matemática que visa alcançar uma ideia de distribuição mais ampla. A partir da exploração intuitiva das coleções de dados e do trânsito através de diversos registros de representação com a ajuda da tecnologia, constata-se que os alunos efetivamente percebem e consideram vários aspectos relacionados à variabilidade que por sua vez estão ligados à noção de distribuição. Em outras palavras, é claro que, quando os estudantes examinam informalmente a variabilidade das coletas de dados, na realidade, estão desenvolvendo características da distribuição
Effectiveness and Efficiency of Drug Eluting Stents
Coronary artery disease (CAD), also known as ischemic heart disease (IHD) and coronary
heart disease (CHD), is caused by the narrowing (stenosis) of one or more coronary arteries,
due to atherosclerosis, restricting blood flow and reducing the supply of oxygen to the heart
muscle. Transient shortages in blood flow and oxygen lead to angina pectoris and chest
pain, which may radiate to the left shoulder, arms, neck, back or jaw. Stable angina
symptoms do not tend to progress in intensity over time. More seriously, the rupturing of
an atherosclerotic plaque (causing a thrombotic occlusion) and stenosis of the vessel can
result in acute myocardial infarction (AMI) due to a critical reduction in the blood supply to
the heart muscle (myocardial ischemia). High levels of morbidity and mortality associated
with this infarction are a consequence of ischemia. It is vital to promptly re-establish
coronary blood flow after an infarction, because sustained ischemic damages and injuries to
the heart muscle may lead to sudden death or heart failure. In addition to infarction, acute
symptomatic manifestations of ischemic heart disease include unstable angina, and less
common conditions such as cardiogenic shock and sudden death (Thygesen, 2007)..
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