Mechanical behaviour of bamboo at elevated temperatures – Experimental studies

The growing demand for sustainable load-bearing materials drives the need for understanding the various design considerations these pose within the modern built environment. Engineered bamboo is a material with outstanding physical and mechanical properties, in addition to producing a minimum carbon footprint. However, extensive research is needed before engineered bamboo can be used with the confidence conferred to other more conventional building construction materials. When aiming for higher and larger bamboo-based structures, load-bearing behaviour during and after fire becomes a key consideration. This paper describes the outcomes of a comprehensive study conducted to understand the mechanical behaviour of bamboo (Phyllostachys pubescens species) at elevated temperatures; more specifically investigating the reduction of compressive and tensile strength, as well as the Modulus of Elasticity (MoE) up to 250 °C. Findings from this work show that at 200 °C, bamboo retains 20%, 42% and 70% of the compressive strength, tensile strength and modulus of elasticity at ambient, respectively. The results presented herein, which provide thorough understanding of strength and elasticity reduction at elevated temperatures, enable the development of stress-strain constitutive models that will constitute the basis for designing fire-safe bamboo structures

Pharmacological considerations for the treatment of COVID-19 in people living with HIV (PLWH)

Altres ajuts: Gilead Sciences (GLD14/293, GLD17/00299, GLD19/00008)Altres ajuts: European Regional Development Fund (FEDER)Introduction: When coronavirus infectious disease-2019 (COVID-19) blew up, ill-fated auguries on the collision between COVID-19 and the human immunodeficiency virus (HIV) epidemics loomed. Areas covered: Data from observational studies suggest similar incidence attacks of SARS-CoV-2 infection in people living with HIV (PLWH) and HIV-uninfected populations. The mortality rate of COVID-19 is similar in both populations too. The authors discuss the role of combination antiretroviral therapy (cART) in preventing infection or reducing COVID-19 severity. They also discuss the pharmacological interventions for COVID-19 in PLWH. Expert opinion: Management of COVID-19 in PLWH is no different from the general population. It should be based on careful supportive care, emphasizing lung-protective ventilation, and wise pharmacological interventions. The antiviral drug remdesivir and dexamethasone are the only pharmacological interventions with clinical benefit for COVID-19, whereas anticoagulation may prevent thrombotic complications. The experience with using these drugs in PLWH is limited, which prevents from rendering well-founded conclusions. Until more data on COVID-19 in PLWH become available, the best weapons within our reach are sound supportive care and sensible use of RDV and dexamethasone, bearing in mind the potential for drug-drug interactions of most corticosteroids and antiretroviral drugs

Efecto del contenido de humedad en la resistencia a tensión paralela a la fibra del bambú Guadua Angustifolia Kunth

El bambú guadua, se ve afectado por diferentes factores que pueden modificar su resistencia mecánica, entre los que se encuentra el factor de modificación por contenido de humedad. Diferentes estudios han mostrado que la resistencia mecánica del material ante diferentes solicitaciones de carga disminuye a medida que el contenido de humedad aumenta. Para realizar la investigación se tomaron muestras de 10 culmos obtenidos de 3 regiones de Colombia. Se seleccionaron tramos de las diferentes partes de la guadua en altura: cepa, basa y sobrebasa. De cada tramo se extrajeron como mínimo siete probetas, las cuales conservaban características muy similares ya que provenían de la misma sección de bambú y se ensayaron con diferente contenido de humedad. La determinación de la resistencia a tensión paralela a la fibra y el contenido de humedad del material, se hizo siguiendo los procedimientos de la Norma Técnica Colombiana NTC 5525. Se encontró que la resistencia a tensión paralela a la fibra no se ve afectada en el rango de contenido de humedad en el que el material es usado como elemento estructural en construcciones

Medio de comunicación La Comarca como emprendimiento digital

Visibilizar al medio de comunicación La Comarca como un emprendimiento digitalLos medios de comunicación digitales en el mundo han logrado operar gracias al funcionamiento de plataformas que congregan a usuarios para que estos consuman los contenidos de cibermedios o de otros cibernautas, ello ha permitido crear y consolidar empresas periodísticas que ofrecen valor a la comunidad en Internet; por lo tanto, la visibilización de La Comarca como un emprendimiento digital es una oportunidad para llevar a la práctica la teoría sobre periodismo, redes sociales, identidad corporativa y emprendimiento. La presente investigación se desarrolla con una metodología mixta, la cual emplea elementos cuantitativos y cualitativos examinados mediante los tipos de estudio descriptivo y longitudinal que permiten analizar los resultados de un cuestionario, una entrevista estructurada y la recopilación de datos secundarios el cambio que ha tenido el cibermedio La Comarca luego de aplicarse la identidad corporativa, ello con el fin de que los lectores comprendan de qué manera el desempeño de este concepto puede contribuir a la visibilización de un proyecto periodístico regional como un emprendimiento digital.Digital media in the world have managed to operate thanks to the operation of platforms that bring together users to consume the contents of cybermedia or other cybernauts, this has allowed the creation and consolidation of journalistic companies that offer value to the Internet community; therefore, the visibility of La Comarca as a digital enterprise is an opportunity to put into practice the theory on journalism, social networks, corporate identity and entrepreneurship. This research is developed with a mixed methodology, which employs quantitative and qualitative elements examined through descriptive and longitudinal types of study that allow analyzing the results of a questionnaire, a structured interview and the collection of secondary data the change that the cybermedia La Comarca has had after the corporate identity, so that readers understand how the performance of this concept can contribute to the visibility of a regional journalistic project as a digital venture

Medio de comunicación La Comarca como emprendimiento digital

Visibilizar al medio de comunicación La Comarca como un emprendimiento digitalLos medios de comunicación digitales en el mundo han logrado operar gracias al funcionamiento de plataformas que congregan a usuarios para que estos consuman los contenidos de cibermedios o de otros cibernautas, ello ha permitido crear y consolidar empresas periodísticas que ofrecen valor a la comunidad en Internet; por lo tanto, la visibilización de La Comarca como un emprendimiento digital es una oportunidad para llevar a la práctica la teoría sobre periodismo, redes sociales, identidad corporativa y emprendimiento. La presente investigación se desarrolla con una metodología mixta, la cual emplea elementos cuantitativos y cualitativos examinados mediante los tipos de estudio descriptivo y longitudinal que permiten analizar los resultados de un cuestionario, una entrevista estructurada y la recopilación de datos secundarios el cambio que ha tenido el cibermedio La Comarca luego de aplicarse la identidad corporativa, ello con el fin de que los lectores comprendan de qué manera el desempeño de este concepto puede contribuir a la visibilización de un proyecto periodístico regional como un emprendimiento digital.Digital media in the world have managed to operate thanks to the operation of platforms that bring together users to consume the contents of cybermedia or other cybernauts, this has allowed the creation and consolidation of journalistic companies that offer value to the Internet community; therefore, the visibility of La Comarca as a digital enterprise is an opportunity to put into practice the theory on journalism, social networks, corporate identity and entrepreneurship. This research is developed with a mixed methodology, which employs quantitative and qualitative elements examined through descriptive and longitudinal types of study that allow analyzing the results of a questionnaire, a structured interview and the collection of secondary data the change that the cybermedia La Comarca has had after the corporate identity, so that readers understand how the performance of this concept can contribute to the visibility of a regional journalistic project as a digital venture

Description of small and large-scale cross laminated timber fire tests

A large-scale fire test was conducted on a compartment constructed from cross laminated timber (CLT). The internal faces of the compartment were lined with non-combustible board, with the exception of one wall and the ceiling where the CLT was exposed directly to the fire inside the compartment. Extinction of the fire occurred without intervention. During the fire test, measurements were made of incident radiant heat flux, gas phase temperature, and in-depth temperature in the CLT. In addition, gas flow velocities and gas phase temperatures at the opening were measured, as well as incident heat fluxes at the facade due to flames and the plume leaving the opening. The fuel load was chosen to be sufficient to attain flashover, to achieve steady-state burning conditions of the exposed CLT, but to minimize the probability of uncertain behaviors induced by the specific characteristics of the CLT. Ventilation conditions were chosen to approximate maximum temperatures within a compartment. Wood cribs were used as fuel and, following decay of the cribs, self-extinction of the exposed CLT rapidly occurred. In parallel with the large-scale test, a small scale study focusing on CLT self-extinction was conducted. This study was used to establish: the range of incident heat fluxes for which self-extinction of the CLT can occur; the duration of exposure after which steady-state burning occurred; and the duration of exposure at which debonding of the CLT could occur. The large-scale test is described, and the results from both the small and large-scale tests are compared. It is found that self-extinction occurred in the large-scale compartment within the range of critical heat fluxes obtained from the small scale tests

Differential effects of dolutegravir, bictegravir and raltegravir in adipokines and inflammation markers on human adipocytes

Altres ajuts: European Regional Development Fund (FEDER); Gilead. European Union NextGeneration EU/PRTR.Aims: To assess the potential direct effects of the integrase strand-transfer inhibitors (INsTIs) dolutegravir, bictegravir, and raltegravir, drugs used as treatment for people living with human immunodeficiency virus (PLWH), on human adipose cells. Main methods: Drugs were added to the differentiation medium of human Simpson-Golabi-Behmel syndrome (SGBS) adipose cells and morphological adipogenesis was monitored for 10 days. Also, adipocytes were exposed to drugs following differentiation (day 14). The gene expression levels of selected adipogenesis markers, adipocyte metabolism markers, adipokines, and cytokines were determined by quantitative-reverse transcription polymerase-chain reaction. The release of adiponectin and leptin into the culture medium was measured using specific enzyme-linked immunosorbent assay, and release of interleukin-6 and chemokine (C[sbnd]C motif) ligand-2 using Multiplex assays. Key findings: Overall morphological adipogenesis was unaltered by INsTIs. The expression of adipogenesis marker genes (peroxisome proliferator-activated receptor-Ɣ and lipoprotein lipase) was slightly reduced in dolutegravir-treated differentiating adipocytes. Bictegravir repressed gene expression and the release of pro-inflammatory cytokines in differentiating adipocytes. Dolutegravir and raltegravir increased interleukin-6 gene expression, but only dolutegravir increased interleukin-6 release. Dolutegravir repressed adiponectin expression and release in differentiating adipocytes and had a similar but milder effect on leptin. Drug treatment of mature adipocytes reduced adiponectin gene expression in response to dolutegravir. Significance: The INsTIs studied do not have a significant effect on human adipose cell differentiation but exert distinct effects on gene expression and secretion of adipokines and cytokines. These findings will help understand and manage the effects of INsTI-containing treatments on body weight and metabolic dysregulation in PLWH

Errors in chromosome segregation during oogenesis and early embryogenesis

Errors in chromosome segregation occurring during human oogenesis and early embryogenesis are very common. Meiotic chromosome development during oogenesis is subdivided into three distinct phases. The crucial events, including meiotic chromosome pairing and recombination, take place from around 11 weeks until birth. Oogenesis is then arrested until ovulation, when the first meiotic division takes place, with the second meiotic division not completed until after fertilization. It is generally accepted that most aneuploid fetal conditions, such as trisomy 21 Down syndrome, are due to maternal chromosome segregation errors. The underlying reasons are not yet fully understood. It is also clear that superimposed on the maternal meiotic chromosome segregation errors, there are a large number of mitotic errors taking place post-zygotically during the first few cell divisions in the embryo. In this chapter, we summarise current knowledge of errors in chromosome segregation during oogenesis and early embryogenesis, with special reference to the clinical implications for successful assisted reproduction

Expansión lineal y punto de saturación de las fibras de la Guadua angustifolia Kunth

Guadua angustifolia Kunth is a bamboo species, which has been widely used in construction. G. angustifolia is considered a hygroscopic material due to its capacity of absorb water, leading to changes in dimensions, strength, and stiffness due to variation of moisture content. The fibre saturation point (FSP) is reached when at certain moisture content, the material does not present dimensional changes and does not undergo variations in the mechanical strength. Specimens from the upper, middle and upper part of the bamboo were analysed in order to determine the FSP. Two methods were used to determine the FSP; the first method used the dimensional variation of the material at different moisture contents. The results showed that FSP is around 34.05%. The second method allowed verifying the FSP of Guadua angustifolia Kunth from the analysis of the parallel compression strength at different moisture contents. This method found that FSP was around 34%. Finally, a modification factor due to moisture content for compression strength was presented, as well as the equation for linear expansion of the material.La Guadua angustifolia Kunth es una especie de bambú que ha sido ampliamente utilizado en la construcción. Gracias a su capacidad de absorber agua, la G. angustifolia experimenta cambios en sus dimensiones, resistencia y rigidez debido a la variación del contenido de humedad. El punto de saturación de las fibras (PSF) se alcanza cuando a un determinado contenido de humedad el material no presenta cambios dimensionales ni variaciones en la resistencia mecánica. Para determinar el PSF de G. angustifolia se analizaron probetas de la parte inferior, intermedia y superior de la guadua. Se utilizaron dos metodologías: el primer método midió la variación dimensional, encontrando que el PSF está alrededor de 34.05 %; el segundo determinó la variación de la resistencia a la compresión paralela, encontrando que el PSF está alrededor de 34 %. Por último, se presentaron los factores de modificación de la resistencia a compresión para diferentes contenidos de humedad, así como la ecuación de expansión lineal del material