1,770 research outputs found
Inflammatory Bowel Disease in Latin America: A Systematic Review
BACKGROUND: Inflammatory bowel disease (IBD) is the name given to two inflammatory diseases of the colon and/or small intestine: Crohn disease (CD) and ulcerative colitis (UC). There is no information summarizing the complete body of evidence about IBD in developing regions, including Latin America. OBJECTIVES: To estimate the burden of IBD in Latin America. METHODS: We conducted a systematic review searching published and unpublished studies on major international and regional databases from January 2000 to September 2015. Outcomes considered were incidence, prevalence, mortality, hospitalization attributable, treatment patterns, comparative effectiveness, patient-reported outcomes, and adherence to treatment. Pairs of reviewers independently selected, extracted, and assessed the risk of bias of the studies. Discrepancies were solved by consensus. RESULTS: We retrieved 3445 references, finally including 25 studies. Only 19% of the observational studies had a low risk of bias for participant selection and 60% were based on registries. The incidence ranged from 0.74 to 6.76/100,000 person-years for UC and from 0.24 to 3.5/100,000 person-years for CD. The prevalence rate ranged from 0.99 to 44.3/100,000 inhabitants for UC and 0.24 to 16.7/100,000 inhabitants for CD. Mortality rates ranged from 0.60 to 1.02 for UC and from 0.23 to 0.40 for CD. Patient-reported outcomes showed a decrease in quality of life associated with depression and anxiety and correlated with the time of diagnosis. The most frequently used medication in the studies was mesalazine. CONCLUSIONS: The burden of IBD in Latin America seems to be important, but there is a considerable gap of high-quality evidence in the region
La Ingeniería Divertida: Gravity Challenge.
La competición se utiliza en muchos entornos educativos, especialmente en el ámbito anglosajón, como medio para contribuir al desarrollo de las habilidades de los alumnos, aspecto este que se encuentra íntimamente ligado a la adquisición de determinadas competencias profesionales. En el sector de la ingeniería y arquitectura resulta de gran importancia y por ello, la Universidad Politécnica de Madrid ha organizado durante el curso 2006‐07 un conjunto de competiciones de estudiantes muy diversas. Una de estas competiciones es la denominada GRAVITY CHALLENGE, en la que los equipos participantes se enfrentaban al reto de lanzar un huevo desde una altura de 15 metros y conseguir que aterrice en el suelo sin romperse. Los equipos ganadores serían aquellos que lograsen este objetivo de la forma más creativa. En este trabajo se describe el procedimiento seguido para la organización de esta competición en la que participaron 27 equipos de distintas universidades. También se presentan los resultados y se hace una reflexión sobre los objetivos formativos que consideramos alcanzados
Heavy metals, PAHs and POPs in recycled polyethylene samples of agricultural, post-commercial, post-industrial and post-consumer origin
In the present work, recycled polyethylene (LDPE) samples of agricultural, post-commercial, post-industrial and post-consumer origin were selected and analysed. The analysis comprised the determination of different contaminants such as metals, polycyclic aromatic hydrocarbons (PAHs), dioxin-like biphenyl polychlorides (PCBs), and polychlorinated-dibenzo-p-dioxins and furans (PCDD/Fs). A comparison with one sample of virgin plastic (unrecycled) was performed. The study aimed at stressing the importance of this type of analysis in recycled plastics. Indeed, such an examination will determine the material’s final destination, and the possible origin of the pollutants analysed is investigated. Black post-industrial and post-consumer samples presented the highest concentration of PCBs and PCDD/Fs, attaining a maximum value of 2.40 pg WHO-TEQ/g, while the least toxic sample (post-commercial) presented a toxicity of 0.38 pg WHO-TEQ/g. PAHs content was also much higher in black samples, reaching 514.41 ng/g, while the lowest concentrations were obtained for the post-commercial plastic sample, which did not exceed 38.98 ng/g. The higher PAHs concentrations in the black samples were related to the carbon black content of the black samples, which was 2.00% for black post-industrial sample and 1.51% for post-consumer sample. The PCDD/Fs congener profile observed in almost all samples was very similar to the profile found in the literature on urban air samples, indicating that the plastic is mainly influenced by the environment. The presence of some metals (mainly copper) showed a slight correlation with PCDD/Fs content. The pollutants analysed were found to be significantly reduced during the cleaning processes that are generally carried out in recycling companies.This work was supported by the Ministry of Science and Innovation (Spain) [grant number PID2019-105359RB-I00], and by the University of Alicante [grant number UAUSTI21-03]
A probabilistic fatigue crack growth life approach to the definition of inspection intervals for railway axles
Different options that rely on fracture mechanics are currently used in engineering during the design and assessment of components. One of the most important aspects is the time taken for a crack to extend to its critical size. If this time is long enough, a design concept based on inspection intervals can be applied, as is it the case of a railway axle component. To define inspection intervals that ensure the continuous and safe operation of a damage-tolerant railway axle, a reliable estimation of its fatigue crack growth life is required. Due to the uncertainties involved in the fatigue process, inspections must be devised not only considering the uncertainties in the performance of the inspection technique, but also based on a probabilistic lifespan prediction. From this premise, this paper presents a procedure for determination of inspection intervals that uses a conservative fatigue crack growth life estimation based on the lifespan probability distribution. A practical example to illustrate the reliability-based inspection planning methodology in a railway axle under random bending loading is given. The inspection intervals are further assessed in terms of overall probability of detecting cracks in successive inspections and in terms of probability of failure, considering the probability of detection curve of the non-destructive testing technique. The procedure developed provides recommendation for the definition of inspection intervals and associated inspection techniques
Simulador de Técnicas de Depuração Extra-Renal/Hemofiltração: Uso da Simulação para Treino no Manuseamento deste Dispositivo
Introdução: A simulação possibilita o ensino e treino de técnicas de suporte de vida complexas sem riscos para o doente. Até ao momento, as únicas opções de treino no manuseamento de terapêuticas de depuração extra-renal contínua (TDEC) eram a aprendizagem directa em doentes submetidos a esta técnica ou mediante observação dos efeitos da manipulação do circuito não conectado ao doente. Por este motivo foi elaborado um simulador de TDEC, usado em cursos de simulação realizados para treino de equipas de cuidados intensivos pediátricos (UCIP).
Objectivos: Analisar a performance e utilidade de um novo simulador que possibilita o controlo externo do dispositivo de TDEC, simulando "in situ" cenários que mimetizam condições de doentes tratados com TDEC.
Métodos: Foi criado um dispositivo que, uma vez conectado ao aparelho de TDEC, permite o controlo em tempo real de todas as pressões de hemofiltração, de acordo com as condições clínicas e acções dos participantes. Foram simulados diversos cenários e complicações possíveis em doentes submetidos a estas técnicas e avaliada a performance deste dispositivo "in vitro". A satisfação dos participantes foi avaliada mediante a aplicação de um inquérito.
Resultados: Foram realizados 4 cursos de TDEC de Maio de 2009 a Março de 2012. Incluídos 60 participantes, todos com experiência clínica prévia em UCIP. Realizados 32 cenários, abrangendo complicações relacionados com o cateter, coagulação dos filtros e ajuste inadequado dos parâmetros de hemofiltração. Nos cenários simulados, o dispositivo simulador permitiu, em tempo real, mudanças simples e rápidas nas pressões do monitor de TDEC e em resposta às atitudes tomadas pelos participantes para a sua resolução. Não foram registadas intercorrências relacionadas com disfunção do dispositivo.
Os participantes consideraram-no muito útil como ferramenta de aprendizagem activa, permitindo uma gestão realista das condições clínicas simuladas, com potencial impacto sobre a sua futura prática diária. Os instrutores consideraram-no fácil de manusear e realista.
Conclusões: Este simulador permite uma simulação mais fidedigna dos cenários de TDEC, resolvendo o problema da interferência do instrutor no cenário simulado. Este poderia melhorar as capacidades dos simuladores de alta fidelidade disponíveis e utilizar-se como uma ferramenta docente na formação de profissionais de saúde
Ricci Collineations of the Bianchi Type II, VIII, and IX Space-times
Ricci and contracted Ricci collineations of the Bianchi type II, VIII, and IX
space-times, associated with the vector fields of the form (i) one component of
is different from zero and (ii) two components of are
different from zero, for , are presented. In subcase (i.b), which
is , some known solutions are found, and in subcase
(i.d), which is , choosing ,
the Bianchi type II, VIII, and IX space-times is reduced to the
Robertson-Walker metric.Comment: 12 Pages, LaTeX, 1 Table, no figure
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