Effect of nanostructured WO3 layers in the sensitivity to nitrogen oxide in YSZ-based electrochemical sensors for automotive applications

AbstractThe sensitivity to nitrogen monoxide (NO) is studied and compared when using several YSZ-based electrochemical gas sensors with identical characteristics but covered by different porous layers over one of their catalytic Pt electrodes. Sensors are exposed to several exhaust gas mixtures containing nitrogen monoxide. The gases are composed by a low concentration of NO dissolved in N2 atmosphere or by a low concentration of NO dissolved in a multi-component mixture similar to exhaust gases from internal combustion engines. The optimum layer thickness and preparation temperture to enhance NO sensitivity are studied. Regarding the composition of the layers, layers made of nanostructured WO3 mixed with porous YSZ seem to maximize the NO sensitivity and decrease crossed sensitivities

A Family of Hybrid Space-Time Codes for MIMO Wireless Communications

Hybrid MIMO space-time codes combine the benefits of spatial multiplexing with diversity gain to achieve both high spectral efficiency and link reliability. In this paper, we present a family of hybrid codes, known as LD STBC-VBLAST codes, along with a receiver architecture suitable for low-complexity hardware implementation. We show that, under Rayleigh fading, the performance of LD STBC-VBLAST codes is superior to other recently proposed hybrid codes. We also present a technique to derive, from a given propagation scenario, spatially correlated MIMO channel models adequate for space-time coding performance analysis. Using this technique, we evaluate the performance of LD STBC-VBLAST codes under several correlated channels.ITESO, A.C.ITSONCINVESTAV-IPNPROME

Quantitative Model of the Behavior of the Limiting Current Oxygen Sensors

AbstractA physicochemical model of the I(V) response of amperometric oxygen sensors based in ion conduction is proposed. Although the qualitative behavior of these devices is well known, there is a lack of a quantitative description of the response of the sensors in their normal operation conditions. The model focuses on diffusion across a porous layer and minimization of the oxygen-ion electrochemical potential in steady state. It provides an analytical expression describing the current-voltage dependence in terms of oxygen diffusivity, ionic conductivity, temperature and geometrical parameters. Experimental measurements of our owndesigned amperometric ceramic sensors are in agreement with the proposed model

Estimación de la resistencia a compresión simple del jabre estabilizado “in situ” con cemento como material en la formación de explanadas de carreteras

Granite rock has powerful alterations at several meters of depth. The clayed sand resulting is commonly known as jabre. This “in situ” mixture of cement-stabilized soil requires a laboratory formula. Even when the test section is correctly verified, the mechanical properties of the homogeneous mixture of jabre exhibit high degrees of dispersion. The laboratory work undertaken included particle-size analysis and screening, defini­tion of liquid and plastic limits, compressive strength, dry density and moisture content over stabilized samples, modified Proctor, California Bearing Ratio (CBR) and the determination of the workability of the hydrauli­cally bound mixtures. The stress resistance curve was analyzed by means of a multilinear model of unconfined compressive strength (UCS). Since practical engineering only requires UCS for 7 days, in order to gain greater knowledge of the material, other UCS transformations were used at other curing times such as 7, 14 and 28 days.La roca granítica presenta habitualmente un horizonte de alteración con varios metros de potencia. La arena arcillosa resultante como producto de alteración se deno­mina comúnmente jabre. Aunque la fórmula de trabajo de la estabilización de jabre con cemento se verifique correctamente en tramos de prueba, la estabilización “in situ” del jabre con cemento presenta habitualmente elevadas dispersiones. Entre los ensayos de laboratorio efectuados se encuentran los ensayos de análisis granulo­métrico, límites de Atterberg, resistencia a compresión simple (RCS), la densidad y humedad sobre probetas de suelo estabilizado, Proctor modificado, índice CBR (California Bearing Ratio) y el plazo de trabajabilidad de la mezcla con cemento. La curva de endurecimiento del suelo estabilizado fue ajustada mediante un modelo multi­lineal. Aunque tradicionalmente se especifique la RCS a 7 días, buscando definir un mejor comportamiento del material, los autores calcularon otros modelos de jabre estabilizado para roturas a 7, 14 y 28 días

Performance, feed utilization and hepatic molecular metabolic response of weaned juvenile Atlantic bluefin tuna (Thunnus thynnus, L): effect of lipid level and source

The development of formulated diets and feeds is essential to increase production of farmed tuna species. There is limited knowledge of this topic, mainly on Pacific Bluefin tuna (Thunnus orientalis) in Japan, whereas no major attempts have been made with Atlantic Bluefin tuna (Thunnus thynnus; ABT). In the present study, two trials were performed using inert formulated diets as on-growing feeds for weaned ABT juvenile in order to establish adequate dietary levels of both lipid and omega-3 long-chain polyunsaturated fatty acids (LC-PUFA). In a first trial, ABT (initial weight = 2.9±0.9g) were fed for 10 days with either a commercial (Magokoro®, MGK) or two experimental feeds with two different lipid levels (15 or 20%) using krill oil (KO) as the single lipid source in order to estimate the suitable lipid content. Fish fed MGK displayed the highest growth, followed by 15KO, with no differences in fish survival. Thus, a lipid content of 15% was considered better than 20% for ABT juveniles. In the second trial, fish (initial weight = 3.3 ± 0.6g) were fed either MGK, 15KO or a feed containing 15% lipid with a combination (1:1, v/v) KO and rapeseed oil (RO) (15KORO). Fish fed 15KO and 15KORO showed the highest growth in terms of weight and fork length (including weight gain and SGR). Increasing dietary lipid level or adding RO to the feeds did not increase liver lipid content. The liver fatty acid profile largely reflected dietary intake confirming very limited LC-PUFA biosynthetic activity for this teleost species. In this respect, liver of fish fed 15KO and 20KO displayed the highest contents of docosahexaenoic acid (DHA). The hepatic expression of genes of lipid and fatty acid metabolism, transcription factors, and antioxidant enzymes was investigated with many of the genes showing regulation by both dietary lipid and LC-PUFA contents. The present study showed promising results that suggested ABT juveniles can be on grown on inert dry feeds that supported good fish growth and the accumulation of the health-promoting fatty acid DHA. Further studies are required in order to fully elucidate lipid and fatty acid requirements of this iconic species regarding dietary sources and production costs

Evaluation of Moringa oleifera and corn starch as feed for seed production of the pearl oyster Pteria sterna (Gould,1851)

In the search for complementary diets to improve performance in bivalve farming, the use of terrestrial plants with nutritional and nutraceutical properties has been proposed as an alternative. The effectiveness of moringa leaf meal Moringa oleifera (Mo) was evaluated under controlled laboratory conditions (30 days), as a dietary supplement during the pre-growth stage of Pteria sterna seeds (7.2 ± 0.59 mm), as well as its combinations with microalgae and corn starch (Co), on growth and survival in the laboratory and its subsequent initial suspended culture in the sea. Diets were formulated with a mixture of the microalgae Tetraselmis suecica and Chaetoceros gracilis (M), diet M; M and 5% Mo (M + Mo); diet M and 5% corn starch (M + Co); 100% moringa leaf meal (Mo); 100% corn starch (Co), and diet M with 2.5% Mo and 2,5% Co (M + Mo + Co). The Mo diet did not provide preseed sustainability, resulting in 100% mortality at 30 days. From the rest of the diets, M obtained the lowest oyster survival, while M + Mo and M + Mo + Co showed the highest growth rates. At the end of the laboratory bioassay, the seeds were sown in a culture system in the open sea (50 days), where the highest growth occurred in the juveniles previously fed with M + Mo + Co. The results suggest that, in the nursery, P. sterna pre-seeds can be maintained with a diet of 100% corn starch, but not with 100% moringa flour, probably due to its poor digestibility. However, moringa used as an additive to the microalgae diet provided a higher yield in the oyster, which is reflected in a higher yield in the initial culture outdoors.Universidade de Vigo/CISUGCYTEDUniversidad Técnica de Manabí, Ecuador | Ref. PYTBEC408-2018-FCV001

Molecular aspects of lipid metabolism, digestibility and antioxidant status of Atlantic bluefin tuna (T. thynnus L.) larvae during first feeding

Atlantic bluefin tuna (Thunnus thynnus L.; ABT) larvae were fed on enriched rotifers Brachionus rotundiformis and copepod nauplii Acartia tonsa from first feeding to 15 days post hatching. Rotifers were enriched with five different commercial products: OG, MG, AG and RA plus selenium and vitamin E. Copepods (COP) were cultured with the algae Rhodomonas baltica. Metabolic processes were studied by determining the expression of 30 genes related to lipid metabolism (transcription factors, fatty acid metabolism and lipid homeostasis), antioxidant enzymes, myogenesis and digestive enzymes. Growth and development parameters and high expression of myogenesis genes myhc2 and tropo indicated that COP were better than enriched rotifers as live prey for first feeding ABT. COP and AG-fed larvae showed the lowest values for the transcription factors pparã and srebp2. The expression of fas showed differences among treatments, with highest relative expression in COP-fed larvae and those fed with RA rotifers. In relation to fatty acid catabolism, larvae fed RA had the highest aco expression levels, with the lowest observed in those fed COP. The expression profiles of lipid homeostasis genes showed that larvae fed COP had higher fabp2 and 4 expressions. Larvae fed AG showed the lowest lpl expression levels, with highest values observed in larvae fed OG. Regarding antioxidant enzyme gene expression, sod showed highest values in larvae fed COP and RA, with larvae fed MG rotifers showing lowest expression levels. A similar pattern was observed for the expression of cat and gpx1 and 4. The expression of genes for digestive enzymes showed that tryp expression levels were highest in COP-fed larvae but, in contrast, COP-fed larvae showed the lowest anpep and alp levels. ABT larvae fed AG displayed the lowest expression level of pla2. bal1 and bal2 presented similar expression patterns, with highest values in COP-fed ABT and lowest expression in larvae fed AG rotifers. Copepods were a superior live prey for first feeding ABT larvae compared to enriched rotifers, as indicated by the higher growth and flexion index achieved by COP-fed larvae, possibly reflecting the higher protein content of the copepods.This work was supported by the Consejería de Innovación, Ciencia y Empresa de la Junta de Andalucía, Proyecto de Excelencia de Promoción General del Conocimiento [Ref. RNM 733, 2012], and Programa Estatal de Investigación del Ministerio de Economía y Competitividad [Ref. AGL2014-52003-C2-1-R, 2014].Versión del edito

Root extracts of Saussurea costus as prospective detoxifying food additive against sodium nitrite toxicity in male rats

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGThe goal of this study was to investigate the effects of three different extracts of Saussurea costus roots (ethanol, methanol, and water) as a food additive in alleviating the harmful effect of sodium nitrite in rat meals. Thirty-five adult male rats were divided into five groups as follows: control, sodium nitrite (NaNO2; 75 mg/kg BW, single oral dose), S. costus 70% ethanol, 70% methanol, and aqueous extracts (300 mg/kg BW), respectively for four weeks followed by a single dose of NaNO2 24h before decapitation. Results showed that the 70% ethanol extract of S. costus has a higher concentration of total phenolic content, total flavonoids, and antioxidant effect than the 70% methanol and water extracts. Rats pretreated with S. costus extracts reduced the harmful effects induced by NaNO2 and improved the hematological parameters, liver, and kidney function biomarkers as well as lipid profile as compared to the NaNO2 group. Furthermore, S. costus improved the histopathological alterations in the liver and kidney induced by NaNO2 and improved meat sensory evaluation. Conclusively, the 70% ethanol extract of S. costus roots is the most effective extract as an antioxidant against the toxicity of sodium nitrite in male rats and might be used safely as a natural additive in the food industry

Gamete biology: Perspectives for Bluefin Tuna Aquaculture

Taking care of fish reproductive physiology and gamete biology allowed significant progresses in fry production control for many commercially interesting fish. Can it be a similar situation for bluefin tuna? Fish gamete production results from long processes controlled mainly by climatic conditions, mediated by neuroendocrine and endocrine factors. The possibility to monitor the development of germinal cells by successive sampling in individual fish which easily breed in captivity, has allowed learning about the sequences of gametogenesis and their control, as well as important characteristics of fish gamete biology. The female ovarian cycle involves a progressive accumulation of yolk in the oocytes (i.e., vitellogenesis), followed by cytoplasmic and nuclear events related to maturation and ovulation. The phases of vitellogenesis and maturation are of different duration in different species. In captive fish the endocrine regulation of reproduction may be disrupted by stress, thus preventing spontaneous spawning, while the application of exogenous hormones at the conclusion of gametogenesis allowed production of good quality gametes. In males, gamete production is not continuous as in mammals. Spermatozoa are produced after a cycle that includes a resting period, followed by continuous or discontinuous sequences of spermatogenesis (spermatogenesis sensu stricto, spermiogenesis and spermiation). The discontinuity of fish sperm production may induce a phenomenon of ageing along the period of spermiation, which decreases the quality of semen with time. Wild bluefin tuna breed in specific areas during a short summer spawning season. When kept in cages in the area of Cartagena (Spain), they present developed gamete stages at the same time as wild fish, but, until now, neither mating behavior nor eggs have been observed as was the case in Japan. It has not been possible to monitor individual gonad recrudescence by successive sampling, due to inability to handle the fish without causing mortality, so that the reproduction failure remains unexplained. Hormonal stimulation may be an interesting alternative but its use requires an assessment of gonadal stage to be performed properly. The high post-handling mortality of bluefin tuna in captivity is a real bottleneck for reproduction control. The improvement of handling and the use of less stress-susceptible individuals may be a major progress for bluefin tuna reproduction control. The occurrence of a second generation of juveniles in Japan, subjected to first domestication selection may provide very interesting experimental fish.EU 5FP REPRODOTT (Q5RS-2002-01355

Pirfenidone and post-Covid-19 pulmonary fibrosis: invoked again for realistic goals

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGPirfenidone (PFN) is an anti-fbrotic drug with signifcant anti-infammatory property used for treatment of fbrotic conditions such as idiopathic pulmonary fbrosis (IPF). In the coronavirus disease 2019 (Covid-19) era, severe acute respiratory syndrome 2 (SARS-CoV-2) could initially lead to acute lung injury (ALI) and in severe cases may cause acute respiratory distress syndrome (ARDS) which is usually resolved with normal lung function. However, some cases of ALI and ARDS are progressed to the more severe critical stage of pulmonary fbrosis commonly named post-Covid-19 pulmonary fbrosis which needs an urgent address and proper management. Therefore, the objective of the present study was to highlight the potential role of PFN in the management of post-Covid-19 pulmonary fbrosis. The precise mechanism of post-Covid-19 pulmonary fbrosis is related to the activation of transforming growth factor beta (TGF-β1), which activates the release of extracellular proteins, fbroblast proliferation, fbroblast migration and myofbroblast conversion. PFN inhibits accumulation and recruitment of infammatory cells, fbroblast proliferation, deposition of extracellular matrix in response to TGFβ1 and other pro-infammatory cytokines. In addition, PFN suppresses furin (TGFβ1 convertase activator) a protein efector involved in the entry of SARS-CoV-2 and activation of TGFβ1, and thus PFN reduces the pathogenesis of SARS-CoV-2. Besides, PFN modulates signaling pathways such as Wingless/Int (Wnt/β-catenin), Yes-Associated Protein (YAP)/Transcription CoActivator PDZ Binding Motif (TAZ) and Hippo Signaling Pathways that are involved in the pathogenesis of post-Covid-19 pulmonary fbrosis. In conclusion, the anti-infammatory and anti-fbrotic properties of PFN may attenuate post-Covid-19 pulmonary fbrosis