272 research outputs found
Enhanced fluid dynamics in 3D monolithic reactors to improve the chemical performance: experimental and numerical investigation
Three-dimensional (3D) Fe/SiC monoliths with parallel interconnected channels and different cell geometries (square, troncoconical, and triangular) were manufactured by robocasting and used as catalytic reactors in hydroxylation of phenol using hydrogen peroxide to produce dihydroxybenzenes; the reaction was performed at Cphenol,0 = 0.33 M, Cphenol,0:CH2O2,0 = 1:1 M, WR = 3.7 g, T = 80-90 °C, and τ = 0-254 gcat·h·L-1 with water as a solvent. The values of the apparent kinetic rate constants demonstrated the superior performance of the triangular cell monoliths for hydrogen peroxide decomposition, phenol hydroxylation, and dihydroxybenzene production reactions. A computational fluid dynamic model was validated with the experimental results. It demonstrated that the triangular cell monoliths, with a lower channel hydraulic diameter and not-facing interconnections, provided a higher internal macrotortuosity that induced an oscillating flow of the liquid phase inside the channels, leading to an additional transverse flow between adjacent parallel channels. This behavior, not observed in the other two geometries, resulted in a better overall performanceThe authors thank the financial support by the Community of Madrid through the project S2018/EMT-4341 and the Government of Spain through the projects: PGC2018- 095642-B-I00 and RTI2018-095052-B-I00 (MCIU/AEI/ FEDER, UE). Also, G. Vega acknowledges the Universidad Autónoma de Madrid for the predoctoral contrac
Differential modulation of IL-8 and TNF-α expression in human keratinocytes by buflomedil chlorhydrate and pentoxifylline
Pentoxifylline (PTX) is a methylxanthine derivative used in a wide range of
dermatoses. As well as its hemorrheologic activity, PTX has anti-inflammatory
properties. Buflomedil chlorhydrate (BC) is another hemorrheological drug with
peripheral vasodilatory action, whose clinical uses are similar to those of PTX.
Both drugs increase intracellular levels of cAMP, either secondary to
phosphodiesterase inhibition (PTX) or adenyl-cyclase stimulation (BC). Long-term
cultures of normal human keratinocytes were prepared in a free-serum medium, and
stimulated with 1 mg/ml of phorbol 12-myristate 13-acetate (TPA) and PTX or BC
(100-1000 micrograms/ml). Levels of TNF-alpha, IL-1 alpha, IL-1 beta, IL-8 and
TGF-beta 1 using ELISA and Northern blot or RT-PCR techniques were measured.
TPA-induced TNF-alpha and IL-8 release from keratinocytes. TPA did not induce
IL-1 alpha or IL-1 beta release of keratinocytes. TPA increased RNA expression of
the TNF-alpha, IL-1 alpha, IL-1 beta, IL-8 and TGF-beta 1. BC diminished
TPA-induced TNF-alpha and IL-8 release from keratinocytes; in the case of IL-8 it
is possible that this inhibition occur to transcriptional level. Moreover PTX was
unable to inhibit TNF-alpha and IL-8 synthesis and expression. PTX and BC reduced
TPA-induced IL-1 alpha and beta expression. It is possible that BC action is
specifically exerted on keratinocytes, because we did not find similar results
with TNF-alpha and IL-8 synthesis in mononuclear peripheral blood cells
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Effect of Printing Parameters on the Internal Geometry of Products Manufactured by Fused Filament Fabrication (FFF)
The internal geometry of a 3D-printed product determines its mechanical properties. In Fused
Filament Fabrication (FFF) the filaments that build up the internal geometry suffer from variations
that have not been sufficiently studied. This research focused on identifying the parameters that
most affect the filaments and finding the optimum values to reduce their variations. A fractional
factorial design of experiments was used to detect the printing parameters of FFF that most affect
the width of extruded filaments, these results were also statistically analyzed. A response
optimization was done to obtain the values of the printing parameters that will give the closest
width of extruded filaments to the nozzle of the 3D printer used. Results showed layer height has
the largest impact on filament width variation.Mechanical Engineerin
Multianalyte analysis of volatile compounds in virgin olive oils using SPME-GC with FID or MS detection: results of an international interlaboratory validation
The organoleptic assessment (Panel test) is the only procedure within the official methods for determining the quality of virgin olive oils that involves an expert panel. There is an urgent need for analytical methodology that can reliably measure volatile compounds in virgin olive oils that is capable of supporting and anticipating the official Panel test. For this reason, a new method based on solid-phase microextraction–gas chromatography with the choice of two possible detectors (FID or MS) was subjected to a large international interlaboratory validation study. The study involved a two-stage process: first, a pretrial phase in which 7 participants were exposed to the method for the first time to identify any initial problems with the methodology; then, a formal validation stage (trial proper), which involved 20 laboratories from Europe, USA, Japan and China. The performance of the different detectors was investigated. While both methods have advantages, the method using FID provided better results for 11 compounds, in terms of reproducibility, compared to MS. This information will allow to implement the method with accurate information of the method performance depending on the detector used. Practical applications: This study provides information from an interlaboratory validation of a method for measuring volatile compounds in virgin olive oils conducted with laboratories (from industry and academia) working in the olive oil sector. The information on the expected analytical errors in the determination of each volatile compound is necessary to apply this method for supporting the official Panel test (sensory analysis). The SPME-GC-MS/FID methods proposed in this work can be used for the internal quality control of a company/distributor/quality control laboratory and could also be used in cases of difficult/contradictory organoleptic assessment, or to confirm results from sensory panels in cases of disputes/disagreement (Reg. EU 2022/2105)
Whole-genome sequencing of European autochthonous and commercial pig breeds allows the detection of signatures of selection for adaptation of genetic resources to different breeding and production systems
Background: Natural and artificial directional selection in cosmopolitan and autochthonous pig breeds and wild boars have shaped their genomes and resulted in a reservoir of animal genetic diversity. Signatures of selection are the result of these selection events that have contributed to the adaptation of breeds to different environments and production systems. In this study, we analysed the genome variability of 19 European autochthonous pig breeds (Alentejana, BÃsara, Majorcan Black, Basque, Gascon, Apulo-Calabrese, Casertana, Cinta Senese, Mora Romagnola, Nero Siciliano, Sarda, KrÅ¡kopolje pig, Black Slavonian, Turopolje, Moravka, Swallow-Bellied Mangalitsa, Schwäbisch-Hällisches Schwein, Lithuanian indigenous wattle and Lithuanian White old type) from nine countries, three European commercial breeds (Italian Large White, Italian Landrace and Italian Duroc), and European wild boars, by mining wholegenome sequencing data obtained by using a DNA-pool sequencing approach. Signatures of selection were identified by using a single-breed approach with two statistics [within-breed pooled heterozygosity (HP) and fixation index (FST)] and group-based FST approaches, which compare groups of breeds defined according to external traits and use/specialization/type.
Results: We detected more than 22 million single nucleotide polymorphisms (SNPs) across the 23 compared populations and identified 359 chromosome regions showing signatures of selection. These regions harbour genes that are already known or new genes that are under selection and relevant for the domestication process in this species, and that affect several morphological and physiological traits (e.g. coat colours and patterns, body size, number of vertebrae and teats, ear size and conformation, reproductive traits, growth and fat deposition traits). Wild boar related signatures of selection were detected across all the genome of several autochthonous breeds, which suggests that crossbreeding (accidental or deliberate) occurred with wild boars.
Conclusions: Our findings provide a catalogue of genetic variants of many European pig populations and identify genome regions that can explain, at least in part, the phenotypic diversity of these genetic resources
Genomic diversity, linkage disequilibrium and selection signatures in European local pig breeds assessed with a high density SNP chip
Genetic characterization of local breeds is essential to preserve their genomic variability, to advance conservation policies and to contribute to their promotion and sustainability. Genomic diversity of twenty European local pig breeds and a small sample of Spanish wild pigs was assessed using high density SNP chips. A total of 992 DNA samples were analyzed with the GeneSeek Genomic Profiler (GGP) 70 K HD porcine genotyping chip. Genotype data was employed to compute genetic diversity, population differentiation and structure, genetic distances, linkage disequilibrium and effective population size. Our results point out several breeds, such as Turopolje, Apulo Calabrese, Casertana, Mora Romagnola and Lithuanian indigenous wattle, having the lowest genetic diversity, supported by low heterozygosity and very small effective population size, demonstrating the need of enhanced conservation strategies. Principal components analysis showed the clustering of the individuals of the same breed, with few breeds being clearly isolated from the rest. Several breeds were partially overlapped, suggesting genetic closeness, which was particularly marked in the case of Iberian and Alentejana breeds. Spanish wild boar was also narrowly related to other western populations, in agreement with recurrent admixture between wild and domestic animals. We also searched across the genome for loci under diversifying selection based on FST outlier tests. Candidate genes that may underlie differences in adaptation to specific environments and productive systems and phenotypic traits were detected in potentially selected genomic regions
Comparison of the GPVI inhibitors losartan and honokiol
<p>Losartan and honokiol are small molecules which have been described to inhibit aggregation of platelets by collagen. Losartan has been proposed to block clustering of GPVI but not to affect binding of collagen. Honokiol has been reported to bind directly to GPVI but only at a concentration that is three orders of magnitude higher than that needed for inhibition of aggregation. The mechanism of action of both inhibitors is so far unclear. In the present study, we confirm the inhibitory effects of both agents on platelet aggregation by collagen and show that both also block the aggregation induced by the activation of CLEC-2 or the low affinity immune receptor FcγRIIa at similar concentrations. For GPVI and CLEC-2, this inhibition is associated with a reduction in protein tyrosine phosphorylation of multiple proteins including Syk. In contrast, on a collagen surface, spreading of platelets and clustering of GPVI (measured by single molecule localisation microscopy) was not altered by losartan or honokiol. Furthermore, in flow whole-blood, both inhibitors suppressed the formation of multi-layered platelet thrombi at arteriolar shear rates at concentrations that hardly affect collagen-induced platelet aggregation in platelet rich plasma. Together, these results demonstrate that losartan and honokiol have multiple effects on platelets which should be considered in the use of these compounds as anti-platelet agents.</p
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Low dose Btk inhibitors selectively block platelet activation by CLEC-2
Inhibitors of the tyrosine kinase Btk have been proposed as novel antiplatelet agents. In this study we show that low concentrations of the Btk inhibitor ibrutinib block CLEC-2-mediated activation and tyrosine phosphorylation including Syk and PLCγ2 in human platelets. Activation is also blocked in patients with X-linked agammaglobulinaemia (XLA) caused by a deficiency or absence of Btk. In contrast, the response to GPVI is delayed in the presence of low concentrations of ibrutinib or in patients with XLA, and tyrosine
phosphorylation of Syk is preserved. A similar set of results is seen with the second-generation inhibitor, acalabrutinib. The differential effect of Btk inhibition in CLEC-2 relative to GPVI signalling is explained by the positive feedback role involving Btk itself, as well as ADP and thromboxane A2 mediated activation of P2Y12 and TP receptors, respectively. This feedback role is not seen in mouse platelets and, consistent with this, CLEC-2-mediated activation is blocked by high but not by low concentrations of ibrutinib. Nevertheless, thrombosis was absent in 8 out of 13 mice treated with ibrutinib. These results show that Btk
inhibitors selectively block activation of human platelets by CLEC-2 relative to GPVI suggesting that they can be used at ‘low dose’ in patients to target CLEC-2 in thrombo-inflammatory disease
Cómo y cuándo derivar un paciente con cefalea secundaria y otros tipos de dolores craneofaciales desde Urgencias y Atención Primaria: recomendaciones del Grupo de Estudio de Cefaleas de la Sociedad Española de NeurologÃa
Introducción: Cuando se sospecha que estamos ante una cefalea secundaria y se deriva un paciente a Urgencias o a la consulta de NeurologÃa es importante saber qué exploraciones complementarias son oportunas hacer en cada caso, además de saber posteriormente cuál es el circuito adecuado que ha de seguir el paciente. Por este motivo, el Grupo de Estudio de Cefaleas de la Sociedad Española de NeurologÃa (GECSEN) ha decidido crear unas recomendaciones consensuadas que establezcan un protocolo de derivación de pacientes con cefalea y/o neuralgias craneofaciales.
Desarrollo: Se ha contactado con neurólogos jóvenes con interés y experiencia en cefalea y con la Junta Directiva del GECSEN han desarrollado este documento que, por razones prácticas, se ha dividido en 2 artÃculos. El primero centrado en las cefaleas primarias y neuralgias craneofaciales, y este centrado en las cefaleas secundarias y otros dolores craneofaciales. El enfoque es práctico, con tablas que resumen los criterios de derivación con exploraciones complementarias y otros especialistas a los que derivar, para que sea útil y facilite su uso en nuestra práctica asistencial diaria.
Conclusiones: Esperamos ofrecer una guÃa y herramientas para mejorar la toma de decisiones ante un paciente con cefalea valorando exploraciones a priorizar y que circuitos seguir para asà evitarla duplicación de consultas y retrasos en el diagnóstico y en el tratamiento
Genomic diversity, linkage disequilibrium and selection signatures in European local pig breeds assessed with a high density SNP chip
Genetic characterization of local breeds is essential to preserve their genomic variability, to advance conservation policies and to contribute to their promotion and sustainability. Genomic diversity of twenty European local pig breeds and a small sample of Spanish wild pigs was assessed using high density SNP chips. A total of 992 DNA samples were analyzed with the GeneSeek Genomic Profiler (GGP) 70 K HD porcine genotyping chip. Genotype data was employed to compute genetic diversity, population differentiation and structure, genetic distances, linkage disequilibrium and effective population size. Our results point out several breeds, such as Turopolje, Apulo Calabrese, Casertana, Mora Romagnola and Lithuanian indigenous wattle, having the lowest genetic diversity, supported by low heterozygosity and very small effective population size, demonstrating the need of enhanced conservation strategies. Principal components analysis showed the clustering of the individuals of the same breed, with few breeds being clearly isolated from the rest. Several breeds were partially overlapped, suggesting genetic closeness, which was particularly marked in the case of Iberian and Alentejana breeds. Spanish wild boar was also narrowly related to other western populations, in agreement with recurrent admixture between wild and domestic animals. We also searched across the genome for loci under diversifying selection based on F-S(T) outlier tests. Candidate genes that may underlie differences in adaptation to specific environments and productive systems and phenotypic traits were detected in potentially selected genomic regions
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