91 research outputs found

    From the search for diagnosis to treatment uncertainties: challenges of care for rare genetic diseases in Brazil = Da busca pelo diagnóstico às incertezas do tratamento: desafios do cuidado para as doenças genéticas raras no Brasil

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    Rare genetic diseases are an important public health problem, but they are still little studied in Collective Health. This article aims to analyze the 'therapeutic itineraries' of patients in search of a diagnosis and treatment for rare genetic diseases in the cities of Rio de Janeiro, Salvador and Porto Alegre. It focuses on the material challenges, emotional and structural problems faced in these trajectories. Semi-structured interviews were conducted with patients/caregivers and health professionals in the context of public health medical genetics. Our findings suggest that the experience of the rare genetic disease is aggravated by practical, inter-relational and bureaucratic/institutional problems. The reality of long and circuitous journeys to obtain a diagnosis, non-geneticists' lack of knowledge about rare diseases, difficulties in transportation and access to specialists, diagnostic and complementary examinations, and access to high-cost medicines and food supplies were common challenges in all the narratives examined in the three Brazilian cities. In addition, adherence to care provided by medical genetics requires action and strategies that depend on arrangements involving family members, physicians, patient associations, and the state. / As doenças genéticas raras constituem um importante problema de saúde pública, mas ainda são pouco estudadas na perspectiva da Saúde Coletiva. Este artigo tem por objetivo analisar os itinerários terapêuticos de pacientes com doenças genéticas raras nas cidades do Rio de Janeiro, Salvador e Porto Alegre, tendo por foco os desafios materiais, emocionais e estruturais enfrentados na busca por diagnóstico e tratamento. Foram realizadas entrevistas semiestruturadas com pacientes/cuidadores e profissionais de saúde em serviços públicos de genética médica. Observou-se que a experiência da doença genética rara, além de ser um desafio em si pelo caráter debilitante e incapacitante, é agravada por problemas de ordem prático-relacionais e burocrático-institucionais que não se resolvem com a chegada a um serviço especializado. A existência de longos itinerários terapêuticos até o diagnóstico, o desconhecimento dos médicos não geneticistas sobre as doenças raras, as dificuldades de transporte e de acesso a especialistas, a exames diagnósticos e complementares e o acesso a medicamentos e insumos alimentares de alto custo foram comuns às narrativas nas três cidades. A adesão aos cuidados oferecidos exigem estratégias de ação que dependem de arranjos envolvendo familiares, médicos, associações de pacientes e o Estado

    Mechanical properties of cotton fabric reinforced geopolymer composites at 200-1000 °C

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    Geopolymer composites containing woven cotton fabric (0–8.3 wt%) were fabricated using the hand lay-up technique, and were exposed to elevated temperatures of 200 °C, 400 °C, 600 °C, 800 °C and 1000 °C. With an increase in temperature, the geopolymer composites exhibited a reduction in compressive strength, flexural strength and fracture toughness. When heated above 600 °C, the composites exhibited a significant reduction in mechanical properties. They also exhibited brittle behavior due to severe degradation of cotton fibres and the creation of additional porosity in the composites. Microstructural images verified the existence of voids and small channels in the composites due to fibre degradation

    Effects of slag content on the residual mechanical properties of ambient air-cured geopolymers exposed to elevated temperatures

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    This paper presents the effects of various slag contents on the residual compressive strength and physical properties of ambient air-cured fly ash-slag blended geopolymers after exposure to various elevated temperatures up to 800°C. The results showed an increasing trend in the compressive strength of ambient air-cured geopolymers with increase in the slag contents after exposure to 400 and 600°C temperatures. This trend deviated, however, at 800°C. Nevertheless, all the geopolymers showed reductions in control compressive strength at ambient temperature after exposure to elevated temperatures. The reductions were much higher at 600 and 800°C compared to 400°C. All the geopolymers exhibited significant damage in terms of cracking after exposure to a temperature of 800°C compared to 400 and 600°C and significant damage occurred at slag contents of 15–30%. Scanning electron microscopic (SEM) images of the above geopolymers also showed higher porosity at 800°C compared to 400 and 600°C. Traces of calcite/calcium silicate hydrate (CSH) peaks are observed in the X-ray diffraction (XRD) analysis of fly ash-slag geopolymers, and the intensity of those peaks increased with increases in slag contents. After exposure to elevated temperatures, the calcite/CSH peaks disappeared and new phases of nepheline and gehlenite were formed at 800°C in all the fly ash-slag geopolymers

    Generation of amorphous carbon and crystallographic texture during low-temperature subseismic slip in calcite fault gouge

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    Identification of the nano-scale to micro-scale mechanochemical processes occurring during fault slip is of fundamental importance to understand earthquake nucleation and propagation. Here we explore the micromechanical processes occurring during fault nucleation and slip at subseismic rates (∼3 × 10−6 m s–1) in carbonate rocks. We experimentally sheared calcite-rich travertine blocks at simulated upper crustal conditions, producing a nano-grained fault gouge. Strain in the gouge is accommodated by cataclastic comminution of calcite grains and concurrent crystal-plastic deformation through twinning and dislocation glide, producing a crystallographic preferred orientation (CPO). Continued wear of fine-grained gouge particles results in the mechanical decomposition of calcite and production of amorphous carbon. We show that CPO and the production of amorphous carbon, previously attributed to frictional heating and weakening during seismic slip, can be produced at low temperature during stable slip at subseismic rates without slip weakening

    Combining Nitrous Oxide with Carbon Dioxide Decreases the Time to Loss of Consciousness during Euthanasia in Mice — Refinement of Animal Welfare?

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    Carbon dioxide (CO2) is the most commonly used euthanasia agent for rodents despite potentially causing pain and distress. Nitrous oxide is used in man to speed induction of anaesthesia with volatile anaesthetics, via a mechanism referred to as the “second gas” effect. We therefore evaluated the addition of Nitrous Oxide (N2O) to a rising CO2 concentration could be used as a welfare refinement of the euthanasia process in mice, by shortening the duration of conscious exposure to CO2. Firstly, to assess the effect of N2O on the induction of anaesthesia in mice, 12 female C57Bl/6 mice were anaesthetized in a crossover protocol with the following combinations: Isoflurane (5%)+O2 (95%); Isoflurane (5%)+N2O (75%)+O2 (25%) and N2O (75%)+O2 (25%) with a total flow rate of 3l/min (into a 7l induction chamber). The addition of N2O to isoflurane reduced the time to loss of the righting reflex by 17.6%. Secondly, 18 C57Bl/6 and 18 CD1 mice were individually euthanized by gradually filling the induction chamber with either: CO2 (20% of the chamber volume.min−1); CO2+N2O (20 and 60% of the chamber volume.min−1 respectively); or CO2+Nitrogen (N2) (20 and 60% of the chamber volume.min−1). Arterial partial pressure (Pa) of O2 and CO2 were measured as well as blood pH and lactate. When compared to the gradually rising CO2 euthanasia, addition of a high concentration of N2O to CO2 lowered the time to loss of righting reflex by 10.3% (P<0.001), lead to a lower PaO2 (12.55±3.67 mmHg, P<0.001), a higher lactataemia (4.64±1.04 mmol.l−1, P = 0.026), without any behaviour indicative of distress. Nitrous oxide reduces the time of conscious exposure to gradually rising CO2 during euthanasia and hence may reduce the duration of any stress or distress to which mice are exposed during euthanasia

    Academic mobility, transnational identity capital, and stratification under conditions of academic capitalism

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    Academic mobility has existed since ancient times. Recently, however, academic mobility—the crossing of international borders by academics who then work ‘overseas’—has increased. Academics and the careers of academics have been affected by governments and institutions that have an interest in coordinating and accelerating knowledge production. This article reflects on the relations between academic mobility and knowledge and identity capital and their mutual entanglement as academics move, internationally. It argues that the contemporary movement of academics takes place within old hierarchies among nation states, but such old hierarchies intersect with new academic stratifications which will be described and analysed. These analytical themes in the article are supplemented by excerpts from interviews of mobile academics in the UK, USA, New Zealand, Korea and Hong Kong as selected examples of different locales of academic capitalism

    Characterization of supplementary cementitious materials by thermal analysis

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    Working Group 1 of RILEM TC 238-SCM ‘Hydration and microstructure of concrete with supplementary cementitious materials (SCMs)’ is defining best practices for the physical and chemical characterization of SCMs, and this paper focusses on their thermal analysis. Thermogravimetric analysis (TGA) can provide valuable data on the chemical and mineralogical composition of SCMs. Loss-on-ignition (LOI) testing is a commonly used, standardized, but less sophisticated version of TGA that measures mass at endpoints only, with heating generally in air. In this paper we describe the use of TGA and LOI to characterize Portland cement with limestone additions, coal combustion fly ashes, ground-granulated blast furnace slag, calcined clays, and natural pozzolans. This paper outlines the value and limitations of TGA and LOI (in the formats defined in different standards regimes) for material characterization, and describes testing methods and analysis. TGA testing parameters affect the mass loss recorded at temperatures relevant for LOI measurements (700–1000 °C) of slags and fly ashes, mainly associated with oxidation reactions taking place upon heating. TGA of clays and natural pozzolans is utilized to identify optimal calcination conditions leading to dehydroxylation and consequent structural amorphization, particularly for kaolinite. However, dehydroxylation and amorphization do not occur at similar temperatures for all clays, limiting the applicability of TGA for this purpose. Although TGA is widely utilized for characterization of SCMs, the testing parameters significantly affect the results obtained, and TGA results require careful interpretation. Therefore, standardization of TGA testing conditions, particularly for LOI determination of slags and fly ashes, is required

    Causes and effects of delays in construction of medium scale drinking water supply projects in Sri Lanka

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    Most of the infrastructure developments are carried out on project basis. Construction projects frequently suffer from delay, though there are many sophisticated tools and techniques available for construction project management. This paper presents the results of a questionnaire survey conducted to identify and rank the causes and effects of delays in construction of medium scale drinking water supply projects in Sri Lanka. Both Severity Index (SI) and Frequency Index (FI) were used to rank the importance of the factors and the findings of the study indicate that inclement weather conditions, contractors' financial difficulties, shortage of labour, rules and regulations of road authorities, delays in sub contractors' work, material import delays and ineffective planning and scheduling of projects by contractors are among the most important factors causing delay in construction of medium scale drinking water supply projects. Moreover, time overruns, cost overruns, funding difficulties, development of unfair relationships among the parties and disputes are the most important effects due to delay. Delays are costly for both clients and contractors and often result in disputes and claims. Therefore in order to improve the situation and avoid / mitigate delays in construction of medium scale water supply projects, several prescriptions are recommended for clients and contractors

    Medical aspects of fitness to drive

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