Design and testing of a microchannel reactor for the PROX reaction

The different steps for manufacturing a microchannel reactor for the PROX reaction are discussed. Transient Liquid Phase bonding (TLP) using a Ni-B-Si amorphous melt spun is used for joining micromilled Al-alloyed ferritic stainless steel plates followed by recrystallization at 1200°C for 5h. A CuOx-CeO2 catalyst synthesized by the coprecipitation method was washcoated on the microchannel block resulting in a homogenous 20-30μm thick layer. The catalytic activity for CO-PROX reaction is similar in both the powder catalyst and the microchannel coated reactor but the selectivity is higher in the microchannel reactor. © 2010 Elsevier B.V.Ministerio de Ciencia e Innovación MAT-2006-12386-C05, ENE-2009-14522-C05-01, BES-2007-14409, BES-2007-15297Junta de Andalucía P06-TEP-0848

The formation of small-scale umbral brightenings in sunspot atmospheres

Sunspot atmospheres have been shown to be highly inhomogeneous hosting both quasi-stable and transient features, such as small-scale umbral brightenings (previously named "umbral micro-jets") and dark fibril-like events. Aims. We seek to understand the morphological properties and formation mechanisms of small-scale umbral brightenings (analogous to umbral micro-jets). In addition, we aim to understand whether links between these events and short dynamic fibrils, umbral flashes, and umbral dots can be established. Methods. A Swedish 1 m Solar Telescope (SST) filtergram time-series sampling the Ca ii H line and a CRisp Imaging Spectro-Polarimeter (SST/CRISP) full-Stokes 15-point Ca ii 8542 Å line scan dataset were used. The spatial resolutions of these datasets are close to 0.1′′ and 0.18′′ with cadences of 1.4 s and 29 s, respectively. These data allowed us to construct light-curves, plot line profiles, and to perform a weak-field approximation in order to infer the magnetic field strength. Results. The average lifetime and lengths of the 54 small-scale brightenings identified in the sunspot umbra are found to be 44.2 s (σ = 20 s) and 0.56′′ (σ = 0.14′′), respectively. The spatial positioning and morphological evolution of these events in Ca ii H filtergrams was investigated finding no evidence of parabolic or ballistic profiles nor a preference for co-spatial formation with umbral flashes. Line scans in Ca ii 8542 Å and the presence of Stokes V profile reversals provided evidence that these events could form in a similar manner to umbral flashes in the chromosphere (i.e. through the formation of shocks either due to the steepening of localised wavefronts or due to the impact of returning material from short dynamic fibrils, a scenario we find evidence for). The application of the weak-field approximation indicated that changes in the line-of-sight magnetic field were not responsible for the modifications to the line profile and suggested that thermodynamic effects are, in fact, the actual cause of the increased emission. Finally, a sub-set of small-scale brightenings were observed to form at the foot-points of short dynamic fibrils. Conclusions. The small-scale umbral brightenings studied here do not appear to be jet-like in nature. Instead they appear to be evidence of shock formation in the lower solar atmosphere. We found no correlation between the spatial locations where these events were observed and the occurrence of umbral dots and umbral flashes. These events have lifetimes and spectral signatures comparable to umbral flashes and are located at the footpoints of short dynamic fibrils, during or at the end of the red-shifted stage. It is possible that these features form due to the shocking of fibrilar material in the lower atmosphere upon its return under gravity

Deficit irrigation and emerging fruit crops as a strategy to save water in Mediterranean semiarid agrosystems

Water scarcity in Mediterranean climate areas will be progressively aggravated by climate change, population increase and urban, tourism and industrial activities. To protect water resources and their integrity for future use and to improve biodiversity, besides following advanced deficit irrigation strategies in fruit cultivation, attention could well be directed towards what are at present underused plant materials able to withstand deficit irrigation with minimum impact on yield and fruit quality. To this end, the state of the art as regards deficit irrigation strategies and the response of some very interesting emerging fruit crops [jujube (Zizyphus jujuba Mill.), loquat (Eriobotrya japonica Lindl.), pistachio (Pistacia vera L.) and pomegranate (Punica granatum L.)] are reviewed. The strengths and weaknesses of deficit irrigation strategies and the mechanisms developed by these emerging fruit crops in the face of water stress are discussed. The response of these crops to deficit irrigation, with special attention paid to the effect on yield but also on fruit quality and health-related chemical compounds, was analysed in order to assess their suitability for saving water in Mediterranean semiarid agrosystems and to analyze their potential role as alternatives to currently cultivated fruit crops with higher water requirements. Finally, the factors involved in establishing an identity brand (hydroSOS) to protect fruits obtained under specific DI conditions are discussed

Multiwavelength studies of MHD waves in the solar chromosphere: An overview of recent results

The chromosphere is a thin layer of the solar atmosphere that bridges the relatively cool photosphere and the intensely heated transition region and corona. Compressible and incompressible waves propagating through the chromosphere can supply significant amounts of energy to the interface region and corona. In recent years an abundance of high-resolution observations from state-of-the-art facilities have provided new and exciting ways of disentangling the characteristics of oscillatory phenomena propagating through the dynamic chromosphere. Coupled with rapid advancements in magnetohydrodynamic wave theory, we are now in an ideal position to thoroughly investigate the role waves play in supplying energy to sustain chromospheric and coronal heating. Here, we review the recent progress made in characterising, categorising and interpreting oscillations manifesting in the solar chromosphere, with an impetus placed on their intrinsic energetics.Comment: 48 pages, 25 figures, accepted into Space Science Review

Bronchoscopist's perception of the quality of the single-use bronchoscope (Ambu aScope4™) in selected bronchoscopies: a multicenter study in 21 Spanish pulmonology services

Background: The disposable bronchoscope is an excellent alternative to face the problem of SARS-CoV-2 and other cross infections, but the bronchoscopist's perception of its quality has not been evaluated. Methods: To evaluate the quality of the Ambu-aScope4 disposable bronchoscope, we carried out a cross-sectional study in 21 Spanish pulmonology services. We use a standardized questionnaire completed by the bronchoscopists at the end of each bronchoscopy. The variables were described with absolute and relative frequencies, measures of central tendency and dispersion depending on their nature. The existence of learning curves was evaluated by CUSUM analysis. Results: The most frequent indications in 300 included bronchoscopies was bronchial aspiration in 69.3% and the median duration of these was 9.1 min. The route of entry was nasal in 47.2% and oral in 34.1%. The average score for ease of use, image, and aspiration quality was 80/100. All the planned techniques were performed in 94.9% and the bronchoscopist was satisfied in 96.6% of the bronchoscopies. They highlighted the portability and immediacy of the aScope4TM to start the procedure in 99.3%, the possibility of taking and storing images in 99.3%. The CUSUM analysis showed average scores > 70/100 from the first procedure and from the 9th procedure more than 80% of the scores exceeded the 80/100 score. Conclusions: The aScope4™ scored well for ease of use, imaging, and aspiration. We found a learning curve with excellent scores from the 9th procedure. Bronchoscopists highlighted its portability, immediacy of use and the possibility of taking and storing images

Type 2 Diabetes Variants Disrupt Function of SLC16A11 through Two Distinct Mechanisms

Type 2 diabetes (T2D) affects Latinos at twice the rate seen in populations of European descent. We recently identified a risk haplotype spanning SLC16A11 that explains ∼20% of the increased T2D prevalence in Mexico. Here, through genetic fine-mapping, we define a set of tightly linked variants likely to contain the causal allele(s). We show that variants on the T2D-associated haplotype have two distinct effects: (1) decreasing SLC16A11 expression in liver and (2) disrupting a key interaction with basigin, thereby reducing cell-surface localization. Both independent mechanisms reduce SLC16A11 function and suggest SLC16A11 is the causal gene at this locus. To gain insight into how SLC16A11 disruption impacts T2D risk, we demonstrate that SLC16A11 is a proton-coupled monocarboxylate transporter and that genetic perturbation of SLC16A11 induces changes in fatty acid and lipid metabolism that are associated with increased T2D risk. Our findings suggest that increasing SLC16A11 function could be therapeutically beneficial for T2D. Video Abstract [Figure presented] Keywords: type 2 diabetes (T2D); genetics; disease mechanism; SLC16A11; MCT11; solute carrier (SLC); monocarboxylates; fatty acid metabolism; lipid metabolism; precision medicin

Laser spectroscopy for breath analysis : towards clinical implementation

Detection and analysis of volatile compounds in exhaled breath represents an attractive tool for monitoring the metabolic status of a patient and disease diagnosis, since it is non-invasive and fast. Numerous studies have already demonstrated the benefit of breath analysis in clinical settings/applications and encouraged multidisciplinary research to reveal new insights regarding the origins, pathways, and pathophysiological roles of breath components. Many breath analysis methods are currently available to help explore these directions, ranging from mass spectrometry to laser-based spectroscopy and sensor arrays. This review presents an update of the current status of optical methods, using near and mid-infrared sources, for clinical breath gas analysis over the last decade and describes recent technological developments and their applications. The review includes: tunable diode laser absorption spectroscopy, cavity ring-down spectroscopy, integrated cavity output spectroscopy, cavity-enhanced absorption spectroscopy, photoacoustic spectroscopy, quartz-enhanced photoacoustic spectroscopy, and optical frequency comb spectroscopy. A SWOT analysis (strengths, weaknesses, opportunities, and threats) is presented that describes the laser-based techniques within the clinical framework of breath research and their appealing features for clinical use.Peer reviewe

Relatório Diagnóstico sobre o ensino superior e a ciência pós-covid-19 na Ibero-América : perspectivas e desafios 2022

O principal impacto no ensino a partir da declaração da pandemia foi a transição urgente e não planejada para modalidades de ensino remoto de emergência. A pandemia chegou e surpreendeu os países e instituições de ensino superior com capacidades diferentes para o desenvolvimento do ensino remoto de emergência e isso se refletiu nos resultados desiguais e nos desafios que tiveram que superar. Inicialmente apresentada como breve, a suspensão da presencialidade em muitos países da região ultrapassou 40 semanas e é o período sem aulas presenciais mais longo do mundo. A primeira reação das instituições foi criar comitês de crise para lidar com a emergência e garantir a continuidade do ensino de forma remota. A pandemia da covid-19 obrigou asinstituições universitárias a empreenderem esforços institucionais, acadêmicos,tecnológicos, etc., que não estavam em suas agendas e para os quais, em muitos casos,não houve preparação prévia. Esses esforços não foram apresentados de forma equilibrada no panorama regional. Embora as universidades da região já utilizassem plataformas virtuais de apoio ao ensino e à aprendizagem antes da pandemia, a maioria não eram propostas institucionais, mas sim iniciativas individuais. Esta foi a base para a continuidade da aprendizagem durante a emergência, e como a suspensão da presencialidade durou mais tempo, as instituições foram fortalecendo as propostas pedagógicas remotas de emergência no nível institucional, incorporando ferramentas e capacitação de professores. No nível institucional, para favorecer a continuidade da aprendizagem, as universidades não propuseram uma metodologia única, deixando para o pessoal docente a decisão sobre o uso das salas de aulas virtuais. Nelas, foram ministradas a maioria das aulas on-line sincronizadas, pelo menos em um primeiro momento. Embora os esforços das IES para oferecer apoio à comunidade universitária para garantir a continuidade da aprendizagem nas melhores condições possíveis sejam evidentes, havia limitações tecnológicas, tanto em termos de conectividade quanto de equipamentos, que nem sempre puderam ser cobertas. Também foram evidenciadas limitações pedagógicas, apesar do empenho para desenvolver competências básicas nos professores, visando facilitar o uso das possibilidades da educação a distância; e, por último, limitações socioemocionais, com esforços institucionais para reduzir a ansiedade e o stress gerados pelo isolamento e a desconexão social. A função de P&D universitária produziu um duplo movimento: por um lado, parou o planejamento e as ações em desenvolvimento até o surgimento da pandemia e, por outro, teve que disponibilizar e redirecionar recursos para produzir conhecimento sobre o SARS-CoV-2 e a covid-19, bem como para produzir recursos tecnológicos e auxiliar o sistema de saúde na prevenção do contágio, e no atendimento aos doentes e aos efeitos psicossociais da pandemia. As ações dos atores universitários para a contenção epidemiológica quanto à produção tecnológica e de conhecimento, são muito relevantes. Em alguns casos, surgiram de iniciativas institucionais nas IES com um histórico de capacidade de intervenção sociocomunitária e de articulação com o setor produtivo. Nesse sentido, as decisões políticas implementadas e os resultados obtidos foram, em maior ou menor grau, produto da articulação dos setores científicos e governamentais. No campo das IES, foram realizados muitos estudos e pesquisas sobre a SARS-CoV-2, a covid-19, a pandemia e seus efeitos em diferentes campos disciplinares. Em muitos casos, os esforços institucionais foram orientados para a produção e disponibilidade de recursos tecnológicos ou dispositivos de apoio social, especialmente para lidar com os efeitos dos processos do confinamento e luto pessoal. As pesquisas que não estão ligadas à covid-19 ou que não puderam ser mantidas foram adiadas em muitos países e podem enfrentar severas restrições para sua continuidade. Este risco é maior nas universidades dos países mais pobres que dependem de agências doadoras para o financiamento