387 research outputs found

    Simulation and optimization of evacuation routes in case of fire in underground mines

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    Risks of fire occurrence in underground mines are known for a long time. Evacuation and rescue plans allow to each underground mine to respond and establish control in case of emergency. The primary goal of this paper is to determine the optimal system for evacuation in case of fire in underground mines and through a process of computer simulation to be presented to all workers that are affected by this issue. In this study is developed a system that allows by using available software to work out the complete evacuation plans that include analysis of fire scenarios and optimal routes for evacuation. With development of database of fire scenarios, it is possible to plan routes for evacuation in all situations. This presented methodology can serve to make effective system for evacuation and rescue in case of fire and to help save lives and protect the financial investment in the mine. This methodology represents the most economical option of making an effective system for evacuation and also can serve as an idea of making a software package that includes all the steps of making a system for evacuation and rescue in case of fire in underground mines. This presented model will have increased accuracy compared to other models presented so far, because of the prepared 3D model of the underground mine which includes the actual dimensions of the mine along with its associated elements from which the fire dynamics and system for evacuation depends

    Dissemination of methicillin-resistant Staphylococcus aureus USA300 sequence type 8 lineage in Latin America.

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    BACKGROUND: Methicillin-resistant Staphylococus aureus (MRSA) is an important nosocomial and community-associated (CA) pathogen. Recently, a variant of the MRSA USA300 clone emerged and disseminated in South America, causing important clinical problems. METHODS: S. aureus isolates were prospectively collected (2006-2008) from 32 tertiary hospitals in Colombia, Ecuador, Peru, and Venezuela. MRSA isolates were subjected to antimicrobial susceptibility testing and pulsed-field gel electrophoresis and were categorized as health care-associated (HA)-like or CA-like clones on the basis of genotypic characteristics and detection of genes encoding Panton-Valentine leukocidin and staphylococcal cassette chromosome (SCC) mec IV. In addition, multilocus sequence typing of representative isolates of each major CA-MRSA pulsotype was performed, and the presence of USA300-associated toxins and the arcA gene was investigated for all isolates categorized as CA-MRSA. RESULTS: A total of 1570 S. aureus were included; 651 were MRSA (41%)--with the highest rate of MRSA isolation in Peru (62%) and the lowest in Venezuela (26%)--and 71%, 27%, and 2% were classified as HA-like, CA-like, and non-CA/HA-like clones, respectively. Only 9 MRSA isolates were confirmed to have reduced susceptibility to glycopeptides (glycopeptide-intermediate S. aureus phenotype). The most common pulsotype (designated ComA) among the CA-like MRSA strains was found in 96% of isolates, with the majority (81%) having a \u3c or =6-band difference with the USA300-0114 strain. Representative isolates of this clone were sequence type 8; however, unlike the USA300-0114 strain, they harbored a different SCCmec IV subtype and lacked arcA (an indicator of the arginine catabolic mobile element). CONCLUSION: A variant CA-MRSA USA300 clone has become established in South America and, in some countries, is endemic in hospital settings

    Update on Fever of Unknown Origin in Children: Focus on Etiologies and Clinical Approach

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    Fever of unknown origin (FUO) can be caused by four etiological categories of diseases. The most common cause of FUO in children is represented by infections, followed by inflammatory conditions and neoplastic causes; a decreasing quote remains still without diagnosis. Despite the fact that several diagnostic and therapeutic approaches have been proposed since the first definition of FUO, none of them has been fully validated in pediatric populations. A focused review of the patient’s history and a thorough physical examination may offer helpful hints in suggesting a likely diagnosis. The diagnostic algorithm should proceed sequentially, and invasive testing should be performed only in select cases, possibly targeted by a diagnostic suspect. Pioneering serum biomarkers have been developed and validated; however, they are still far from becoming part of routine clinical practice. Novel noninvasive imaging techniques have shown promising diagnostic accuracy; however, their positioning in the diagnostic algorithm of pediatric FUO is still not clear. This narrative review aims to provide a synopsis of the existent literature on FUO in children, with its major causes and possible diagnostic workup, to help the clinician tackle the complex spectrum of pediatric FUO in everyday clinical practice

    Intra- and Juxta-Articular Osteoid Osteoma Mimicking Arthritis: Case Series and Literature Review

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    Background: Intra- and juxta-articular osteoid osteomas are rare, representing less than 10% of all osteomas. Compared to the classic diaphyseal or metaphyseal site of long bones, they often have an atypical onset, a longest diagnostic delay, and frequent initial misdiagnoses, with pictures that can mimic inflammatory monoarthritis. We aimed to describe a case series, and to provide a literature review of this uncommon and misleading tumor location. Methods: We performed a retrospective analysis of patients referred to three pediatric rheumatology centers, with a final diagnosis of articular osteoid osteoma. A review of the literature was additionally conducted. Results: We included 10 patients with a mean age of 14 years. All patients with unusual sites (olecranon fossa, lumbar vertebra, distal phalanx of the toe, fibula) had a misdiagnosis, and cases with initial suspicion of monoarthritis had the longest diagnostic delay, up to 24 months. The literature review confirms the significant risk of misdiagnosis, and an average time from symptom onset to diagnosis ranging from 0.4 to 1.8 years. Conclusions: Articular osteoid osteoma may mimic arthritis, especially in adolescence. Knowledge of the atypical forms of presentation, and of the clinical and radiological pitfalls, reduces the risk of diagnostic error

    Minding the gap: The importance of active facilitation in moving boundary objects from in-theory to in-use as a tool for knowledge mobilisation

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    The Health Inequalities Assessment Toolkit (HIAT) was developed to support those involved in health research to integrate a focus on health inequalities. Our study focuses on bringing together the concepts of boundary objects (BO) and brokers-as-bricoleurs to explain the implementation of the HIAT within a research capacity building programme. Exploring the extent to which (i) the HIAT operated as a BO and (ii) the ideal conditions to nurture and enhance its effectiveness during knowledge mobilisation. We employed a qualitative approach to analyse: semi-structured focus groups and telephone interviews; secondary data from an evaluation of the wider research programme within which the capacity building was situated. Data was thematically analysed incorporating the properties of a BO: meaningfulness, convergence, resonance and authenticity. Four main themes identified: (1) Generating convergence through creating a focus (2) Reconciling differences to create a common language (3) Workshop facilitators: boundary brokers-as-bricoleurs, (4) Thoughts into action. The HIAT operated as a BO, enabling individuals across the different project teams to galvanise around the issue of health inequalities, explore collaboratively and incorporate equity within service evaluations. Highlighting the importance of involving brokers with an ability to improvise and mobilise around the HIAT, using their expertise to translate and interpret across boundaries and emphasise shared goals. Reflecting on this, a modified tool with additional resources beyond socio-economic causes has been launched as a forum to consider health inequalities from diverse perspectives for use beyond UK health and social care research

    Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC

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    This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing

    Performance Assessment in Fingerprinting and Multi Component Quantitative NMR Analyses

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    An interlaboratory comparison (ILC) was organized with the aim to set up quality control indicators suitable for multicomponent quantitative analysis by nuclear magnetic resonance (NMR) spectroscopy. A total of 36 NMR data sets (corresponding to 1260 NMR spectra) were produced by 30 participants using 34 NMR spectrometers. The calibration line method was chosen for the quantification of a five-component model mixture. Results show that quantitative NMR is a robust quantification tool and that 26 out of 36 data sets resulted in statistically equivalent calibration lines for all considered NMR signals. The performance of each laboratory was assessed by means of a new performance index (named Qp-score) which is related to the difference between the experimental and the consensus values of the slope of the calibration lines. Laboratories endowed with a Qp-score falling within the suitable acceptability range are qualified to produce NMR spectra that can be considered statistically equivalent in terms of relative intensities of the signals. In addition, the specific response of nuclei to the experimental excitation/relaxation conditions was addressed by means of the parameter named NR. NR is related to the difference between the theoretical and the consensus slopes of the calibration lines and is specific for each signal produced by a well-defined set of acquisition parameters

    Photocrosslinkable starch cinnamyl ethers as bioinspired bio-based polymers

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    A novel starch-based ether bearing cinnamyl functionalities, conferring photo-crosslinking properties, is synthesised by reaction with cinnamyl chloride in the presence of sodium hydroxide. Natural yuca was selected as a sustainable source of starch. Three different molar equivalents of reagents are used, affording starch-cinnamyl ethers with different degrees of substitution, ranging from 0.09 to 1.24, as determined by liquid phase nuclear magnetic resonance (NMR). The double bonds in the cinnamyl moieties show reactivity towards photodimerization upon irradiation at 254 nm, affording a novel cross-linked bio-inspired polymer. The formation of the covalent ether linkage and the [2+2] cycloaddition of the cinnamyl units are confirmed by a combination of spectroscopic techniques, including solid state NMR. The materials are further characterized by gel permeation chromatography (GPC), thermogravimetric analysis (TGA), and X-ray diffraction analysis (XRD). Starch-cinnamyl ethers with a DS of 0.09 are water soluble, and suitable for the preparation of transparent films potentially exploitable for biodegradable packaging materials

    Factors associated with self-reported discrimination against men who have sex with men in Brazil

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    OBJECTIVE: To estimate self-reported discrimination due to sexual orientation among men who have sex with men (MSM) in Brazil and to analyze associated factors. METHODS: A cross-sectional study of 3,859 MSM recruited in 2008–2009 with respondent driven sampling. Data collection conducted in health centers in 10 Brazilian cities. A face-to-face questionnaire was used and rapid HIV and syphilis tests conducted. Aggregated data were weighted and adjusted odds ratio estimated to measure the association between selected factors and self-reported discrimination due to sexual orientation. RESULTS: The sample was predominantly young, eight plus years of schooling, pardo (brown), single, low-income, and identified themselves as gay or homosexual. The prevalence of self-reported discrimination due to sexual orientation was 27.7% (95%CI 26.2–29.1). Discrimination was independently associated with: age < 30 years, more years of schooling,community involvement and support, history of sexual and physical violence, suicidal thoughts, and unprotected receptive anal intercourse. CONCLUSIONS: The prevalence of self-reported discrimination among MSM in Brazil is high. These results challenge the assumptions that MSM-specific prevention and support programs are not required or that health professionals do not need special training to address MSM needs
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