3,396 research outputs found

    Utilization of big data to improve management of the emergency departments. Results of a systematic review

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    Background. The emphasis on using big data is growing exponentially in several sectors including biomedicine, life sciences and scientific research, mainly due to advances in information technologies and data analysis techniques. Actually, medical sciences can rely on a large amount of biomedical information and Big Data can aggregate information around multiple scales, from the DNA to the ecosystems. Given these premises, we wondered if big data could be useful to analyze complex systems such as the Emergency Departments (EDs) to improve their management and eventually patient outcomes. Methods. We performed a systematic review of the literature to identify the studies that implemented the application of big data in EDs and to describe what have already been done and what are the expectations, issues and challenges in this field. Results. Globally, eight studies met our inclusion criteria concerning three main activities: the management of ED visits, the ED process and activities and, finally, the prediction of the outcome of ED patients. Although the results of the studies show good perspectives regarding the use of big data in the management of emergency departments, there are still some issues that make their use still difficult. Most of the predictive models and algorithms have been applied only in retrospective studies, not considering the challenge and the costs of a real-time use of big data. Only few studies highlight the possible usefulness of the large volume of clinical data stored into electronic health records to generate evidence in real time. Conclusion. The proper use of big data in this field still requires a better management information flow to allow real-time application

    Berry Curvature Spectroscopy from Bloch Oscillations

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    Artificial crystals such as moir\'e superlattices can have a real-space periodicity much larger than the underlying atomic scale. This facilitates the presence of Bloch oscillations in the presence of a static electric field. We demonstrate that the optical response of such a system, when dressed with a static field, becomes resonant at the frequencies of Bloch oscillations, which are in the terahertz regime when the lattice constant is of the order of 10 nm. In particular, we show within a semiclassical band-projected theory that resonances in the dressed Hall conductivity are proportional to the lattice Fourier components of the Berry curvature. We illustrate our results with a low-energy model on an effective honeycomb lattice.Comment: 6 + 4 pages, 3 figures. Published versio

    Pictures of a crisis. Destination marketing organizations’ Instagram communication before and during a global health crisis

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    The COVID-19 pandemic enhanced social media communications at a time individuals were unable to leave their homes due to the lockdown measures. A lack of research has been identified on how destination marketing organizations use social media during global health crises. Addressing this gap, the present research uses a mixed-method approach to examine the use of Instagram by Milan and Paris’ Destination Marketing Organi- zations before and during COVID-19 and user engagement with it. Via a quantitative content analysis, Study 1 reveals communication differences between destinations and a change in promotion focus during the pandemic. Both DMOs focus on posts portraying “Culture, History and Art”, which signifies stability and eternity as opposed to uncertain times. Using a thematic analysis, Study 2 reveals that both organizations promoted pro-social behavior also by employing influencers. Overall, research results document tourism organizations’ pro-social use of social media during a global health crisis

    Preliminary Characterization of Thin Biofilms by Optical Microscopy

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    A simple non-invasive technique has been used that employs conventional optical microscopy and a glass flow cell to observe biofilms formed on opaque thin substrata. The technique allows the roughness of the biofilm and the substratum to be evaluated, and the biofilm thickness to be easily measured. The biofilm density may be quantified through colour gradients. In addition, sorne details of biofilm growth processes like the formation of water channels and pores, and interactions between planktonic and sessile cells can be visualized. Results related to the development of thin biofilms and their response to the environment under different conditions are reported. Pure and mixed microbial cultures and different solid substrata were assessed.Facultad de Odontologí

    Cytotoxicity of Copper Ions Released from Metal : Variation with the Exposure Period and Concentration Gradients

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    The aim of this work is to contribute to the elucidation of the cytotoxic process caused by the copper ions released from the biomaterials. Clonal cell lines UMR106 were used in the experiments. Copper ions were obtained from two different sources: copper salts and metal dissolution. Experiments carried out with constant ion concentrations (copper salts) were compared with those with concentrations that vary with time and location (dissolution of the metal). Present results and others previously reported could be interpreted through mathematical models that describe: (1) the variation of concentration of copper ions with time and location within a biofilm and (2) the variation of the killing rate with the concentration of the toxic ion and time. The large number of dead cells found near the copper sample with an average ion concentration below the toxic limit could be interpreted bearing in mind that these cells should be exposed to a local concentration higher than this limit. A logarithmic dependence between the number of cells and exposure time was found for nearly constant ion concentrations. Apparent discrepancies, observed when these results and those of different researchers were contrasted, could be explained considering the dissimilar experimental conditions such as the source of the ions and their local concentration at real time.Facultad de Odontologí

    Roses in the Nonperturbative Current Response of Artificial Crystals

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    In two-dimensional artificial crystals with large real-space periodicity, the nonlinear current response to a large applied electric field can feature a strong angular dependence, which encodes information about the band dispersion and Berry curvature of isolated electronic Bloch minibands. Within the relaxation-time approximation, we obtain analytic expressions up to infinite order in the driving field for the current in a band-projected theory with time-reversal and trigonal symmetry. For a fixed field strength, the dependence of the current on the direction of the applied field is given by rose curves whose petal structure is symmetry constrained and is obtained from an expansion in real-space translation vectors. We illustrate our theory with calculations on periodically-buckled graphene and twisted double bilayer graphene, wherein the discussed physics can be accessed at experimentally-relevant field strengths.Comment: 8 + 22 pages, 4 + 12 figures. Published versio

    Towards a Comparative Index Assessing Mechanical Performance, Material Consumption and Energy Requirements for Additive Manufactured Parts

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    The increasing use of Additive Manufacturing technologies and systems in several industrial sectors and their numerous applications turn the attention of scientists and investigators to studying and evaluating the environmental impacts of these processes. Additive Manufacturing generally allows for a reduction of raw material consumption and waste generation. On the other hand, the need for long processing times and the necessary thermal conditioning of the manufacturing chamber to avoid product defects, lead to a considerable amount of consumed energy per produced item. Energy consumption has been a primary concern of the research on the sustainability of Additive Manufacturing indeed. More recent studies extended the analysis through more complete evaluation methods such as the Life Cycle Assessment. This approach allows a detailed description of environmental impacts but is affected by some concerns about the need for an interpretation of the final results, which can be non-univocal. This fact is particularly critical when the assessment is intended to be used for comparison between alternative solutions. In this study, a novel index is introduced including three main aspects: material consumption, energy requirements and mechanical performance. The proposed formulation makes the index immediately usable for comparing alternative solutions. Within the scope of this study, the index has been applied to one of the most widespread Additive Manufacturing processes, namely Fused Filament Fabrication. The presented case study demonstrates the suitability of the proposed method to compare and identify the optimal choice among alternative manufacturing scenarios

    Preliminary Characterization of Thin Biofilms by Optical Microscopy

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    A simple non-invasive technique has been used that employs conventional optical microscopy and a glass flow cell to observe biofilms formed on opaque thin substrata. The technique allows the roughness of the biofilm and the substratum to be evaluated, and the biofilm thickness to be easily measured. The biofilm density may be quantified through colour gradients. In addition, sorne details of biofilm growth processes like the formation of water channels and pores, and interactions between planktonic and sessile cells can be visualized. Results related to the development of thin biofilms and their response to the environment under different conditions are reported. Pure and mixed microbial cultures and different solid substrata were assessed.Facultad de Odontologí

    Microstructural characteristics of thin biofilms through optical and scanning electron microscopy

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    The combination of a conventional optical microscope with a specially designed glass flow cell was used to visualize ‘in situ’ biofilms formed on opaque thin biomaterials through a simple non-invasive way (optical microscopy of thin biofilms, OMTB). Comparisons of OMTB with scanning electron microscopy (SEM) images were made. Thin metallic dental biomaterials were used as substrata. They were immersed in a synthetic saliva and in a modified Mitis–Salivarius medium inoculated with a consortium of oral microorganisms. To study the effect of bacterial motility, Pseudomonas fluorescens cultures were also used. The processes which give rise to the formation of the biofilm were monitored through OMTB. Biofilm microstructures like pores, water channels, streamers and chains of Streptococci, attached to the surface or floating in the viscous interfacial environment, could be distinguished. Thickness and roughness of the biofilms formed on thin substrata could also be evaluated. Distortions introduced by pretreatments carried out to prepare biological materials for SEM observations could be detected by comparing OMTB and SEM images. SEM images (obtained at high magnification but ex situ, not in real time and with pretreatment of the samples) and OMTB images (obtained in situ, without pretreatments, in real time but at low magnification) in combination provided complementary information to study biofilm processes on thin substrata.Facultad de Odontologí
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