346 research outputs found

    C II abundances in early-type stars: solution to a notorious non-LTE problem

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    We address a long-standing discrepancy between non-LTE analyses of the prominent C II 4267 and 6578/82 A multiplets in early-type stars. A comprehensive non-LTE model atom of C II is constructed based on critically selected atomic data. This model atom is used for an abundance study of six apparently slow-rotating main-sequence and giant early B-type stars. High-resolution and high-S/N spectra allow us to derive highly consistent abundances not only from the classical features but also from up to 18 further C II lines in the visual - including two so far unreported emission features equally well reproduced in non-LTE. These results require the stellar atmospheric parameters to be determined with care. A homogeneous (slightly) sub-solar present-day carbon abundance from young stars in the solar vicinity (in associations and in the field) of log C/H +12= 8.29+/-0.03 is indicated.Comment: 8 pages, 5 figure

    Seasonal and Temperature-Associated Increases in Gram-Negative Bacterial Bloodstream Infections among Hospitalized Patients

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    BACKGROUND: Knowledge of seasonal trends in hospital-associated infection incidence may improve surveillance and help guide the design and evaluation of infection prevention interventions. We estimated seasonal variation in the frequencies of inpatient bloodstream infections (BSIs) caused by common bacterial pathogens and examined associations of monthly BSI frequencies with ambient outdoor temperature, precipitation, and humidity levels. METHODS: A database containing blood cultures from 132 U.S. hospitals collected between January 1999 and September 2006 was assembled. The database included monthly counts of inpatient blood cultures positive for several clinically important Gram-negative bacteria (Acinetobacter spp, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa) and Gram-positive bacteria (Enterococcus spp and Staphylococcus aureus). Monthly mean temperature, total precipitation, and mean relative humidity in the postal ZIP codes of participating hospitals were obtained from national meteorological databases. RESULTS: A total of 211,697 inpatient BSIs were reported during 9,423 hospital-months. Adjusting for long-term trends, BSIs caused by each gram-negative organism examined were more frequent in summer months compared with winter months, with increases ranging from 12.2% for E. coli (95% CI 9.2-15.4) to 51.8% for Acinetobacter (95% CI 41.1-63.2). Summer season was associated with 8.7% fewer Enterococcus BSIs (95% CI 11.0-5.8) and no significant change in S. aureus BSI frequency relative to winter. Independent of season, monthly humidity, monthly precipitation, and long-term trends, each 5.6°C (10°F) rise in mean monthly temperature corresponded to increases in gram-negative bacterial BSI frequencies ranging between 3.5% for E. coli (95% CI 2.1-4.9) to 10.8% for Acinetobacter (95% CI 6.9-14.7). The same rise in mean monthly temperature corresponded to an increase of 2.2% in S. aureus BSI frequency (95% CI 1.3-3.2) but no significant change in Enterococcus BSI frequency. CONCLUSIONS: Summer season and higher mean monthly outdoor temperature are associated with substantially increased frequency of BSIs, particularly among clinically important gram-negative bacteria

    The use of pediatric flexible bronchoscopy in the COVID-19 pandemic era

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    On March 11, 2020, the World Health Organization (WHO) declared the pandemic because of a novel coronavirus, called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In January 2020, the first transmission to healthcare workers (HCWs) was described. SARS-CoV-2 is transmitted between people because of contact, droplets, and airborne. Airborne transmission is caused by aerosols that remain infectious when suspended in air over long distances and time. In the clinical setting, airborne transmission may occur during aerosol generating procedures like flexible bronchoscopy. To date, although the role of children in the transmission of SARS-CoV-2 is not clear the execution of bronchoscopy is associated with a considerably increased risk of SARS-CoV-2 transmission to HCWs. The aim of this overview is to summarize available recommendations and to apply them to pediatric bronchoscopy. We performed systematic literature searches using the MEDLINE (accessed via PubMed) and Scopus databases. We reviewed major recommendations and position statements published at the moment by the American Association for Bronchology and Interventional Pulmonology, WHO, European Center for Disease Prevention and Control and expert groups on the management of patients with COVID-19 to limit transmission among HCWs. To date there is a lack of recommendations for safe bronchoscopy during the pandemic period. The main indications concern adults and little has been said about children. We have summarized available recommendations and we have applied them to pediatric bronchoscopy

    Phase behaviors of binary mixtures composed of banana-shaped and calamitic mesogens

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    In this work, five mixtures with different concentrations of banana-shaped and calamitic compounds have been prepared and subsequently studied by polarizing optical microscopy, differential scanning calorimetry, and X-ray diffraction on non-oriented samples. The phase sequences and molecular parameters of the binary systems are presented

    Update of the European paediatric respiratory medicine syllabus

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    The 10-year-old European syllabus for paediatric respiratory medicine (PRM; also known as paediatric pulmonology) was updated by a consensus-based method using an expert task force for redrafting, and a subsequent Delphi process to achieve consensus. There was a high degree of consensus for the final syllabus, which has been streamlined and made more relevant to current practice. All modules are now mandatory apart from the undertaking of research projects, which is optional. Although there are still a number of countries in Europe which do not recognise PRM as a separate subspecialty, there are paediatric respiratory physicians practising in every country in Europe, and a current and harmonised European syllabus in the subspecialty remains important for defining the training and areas of practice of PRM practitioners

    Evaluation of a Bioactive Glass Alloplast in Treating Periodontal Intrabony Defects

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141993/1/jper1346.pd

    O Gerador automático de programas - FAST CASE

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    This paper presents an automatic code generator for the Delphi Development Environment. This module which is an extension of FAST CASE, obtains the program specifications from the requirements and design models stored in the project database. The structure of the generated code follows a standard architecture and can be compiled to an executable program.Este artigo apresenta um gerador automático de programas para o ambiente Delphi. Este módulo, que é uma extensão do FAST CASE, obtém as especificações do programa a ser gerado a partir dos dados contidos nos modelos de requisitos e de análise e projeto. A estrutura do programa gerado segue a arquitetura padrão da Metodologia Rápida. O código fonte, ao ser compilado no ambiente Delphi gera um programa executável

    Modulated structures in electroconvection in nematic liquid crystals

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    Motivated by experiments in electroconvection in nematic liquid crystals with homeotropic alignment we study the coupled amplitude equations describing the formation of a stationary roll pattern in the presence of a weakly-damped mode that breaks isotropy. The equations can be generalized to describe the planarly aligned case if the orienting effect of the boundaries is small, which can be achieved by a destabilizing magnetic field. The slow mode represents the in-plane director at the center of the cell. The simplest uniform states are normal rolls which may undergo a pitchfork bifurcation to abnormal rolls with a misaligned in-plane director.We present a new class of defect-free solutions with spatial modulations perpendicular to the rolls. In a parameter range where the zig-zag instability is not relevant these solutions are stable attractors, as observed in experiments. We also present two-dimensionally modulated states with and without defects which result from the destabilization of the one-dimensionally modulated structures. Finally, for no (or very small) damping, and away from the rotationally symmetric case, we find static chevrons made up of a periodic arrangement of defect chains (or bands of defects) separating homogeneous regions of oblique rolls with very small amplitude. These states may provide a model for a class of poorly understood stationary structures observed in various highly-conducting materials ("prechevrons" or "broad domains").Comment: 13 pages, 13 figure

    Archaeological memory and urban morphology: the republican model in the imperial E42

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    The idea that the modern city should rise on a tabula rasa of the ancient city has been promoted since the Plan Voisin (Lecorbusier, 1925), and was essentially conceived on the ideology of the destruction of the ancienne regime, or to better say the destruction of its space, as a base to build a new world. Nowadays we recognize that demolitions of urban fabric inside historical cities are not conceivable, they were accomplished mostly by absolutist regimes or war bombings, upholding in substance the very same effect. Therefore we should reconsider critically the foundation of the E42 in Rome (1941), shown by fascist propaganda as a modern foundation, but planned outside the city centre. Even though meaningful demolitions were accomplished inside the monumental area of the Roman forums in the ‘30, in a very subtle manner, the archaeological topography of the ancient republican Rome became part of the new E42. The foundation was based on analogous orientations, in relationship with the foundation day of ancient Rome. Form and meaning of architectures, recalling the memory urban parts of ancient Rome, were used as archetypes to symbolize the past glory of Rome. This study presents the comparative analysis of the Palace of Receptions and Congresses (Adalberto Libera, 1938) and of the Temple of Venus and Rome (Hadrian, 121 ad), analyzing the city through models, proposing a new interpretation of the E42 as an analogous city. This comparative analysis recognizes in the plan elements of non-immediate perception, tracing a key to understand the meaning of the spaces of the city.Publisher versio
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