Blood viscoelasticity : experimental characterization and 2D-numerical simulation of the blood flow

Circulatory system diseases are the main cause of death in Europe and United States of America. This fact has promoted increasing research related to human body biomechanics. In this context, huge increase of computational capacity has become in a valuable tool for cardiovascular disease studies. Blood viscoelastic flow through healthy carotid artery was here studied. Both experimental and computational techniques were carried out in order to simulate a realistic human situation. On the one hand, regarding the experimental study, relaxation tests were performed on blood by using a rheometer. After that, the Generalized Maxwell model was used to fit experimental data time dependence of relaxation modulus. On the other hand, several numerical simulations were carried out by using finite volume methods implemented in open source software (Foam Extend 3.1). The effect of blood viscoelastic behaviour in a common human carotid artery was tested. Results from Viscoelastic and Newtonian models for blood were compared. The main conclusion of the work is that assuming blood as a Newtonian fluid can give rise to wrong predictions, especially at the near wall region.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016

Factors associated with compliance with physical activity recommendations among adolescents in Huesca.

BACKGROUND: Schools have been identified as environments of choice for physical activity promotion. This study examines factors associated with compliance with objectively assessed physical activity recommendations for early adolescents taking part in “Sigue la Huella”, a school-based intervention guided by a social ecological framework and Self-Determination Theory (Deci & Ryan, 2002). METHODS: A total of 200 students (108 boys) aged 12-13 years (M = 12.16; SD = ± 0.51), wore accelerometers during a 7-day period and completed a questionnaire. Participants were considered compliant to the recommendations if their moderate to vigorous physical activity, averaged over 7 days, was =60 minutes a day. RESULTS: 57.4% of boys and 9.9% of girls met recommendations. In a mixed logistic regression model, compliance was higher among boys and students attending private schools, and lower for obese students. Compliance was also associated with higher perceptions of physical competence, higher perceptions of autonomy in physical education, greater importance attached to physical education and less sedentary behavior. CONCLUSIONS: Assessed objectively, gender differences in compliance with physical activity recommendations were greater than expected. Self-Determination Theory emerged as a useful framework to identify motivational factors that can be addressed in school-based physical activity interventions and programs for early adolescents

Comparison between capillary electrophoresis and high performance liquid chromatography for the study of the occurrence of patulin in apple juice intended for infants

Apple juice samples intended for infants purchased in Navarra (Spain) have been analyzed for PAT occurrence. Two capillary electrophoresis methods, based on a MEKC and a CEC system, and an HPLC method were evaluated for the aforementioned study. The CEC system gave less satisfying separations and several practical problems, so samples have been analyzed by MEKC and HPLC. Both methods have been comparable in terms of recovery, precision, limits of detection, volume of organic solvents used and adequate selectivity with regard to PAT and HMF. The analysis time in HPLC has been slightly lower than in the MEKC methodology. The PAT levels obtained in apple juice by both validated methods showed a strong correlation (p<0.001). Therefore, both methodologies are useful for the accurate quantification of patulin in this matrix. The PAT levels obtained in the 20 infant apple juices samples were in a range between <LOD and 29.6 microg L(-1), with a mean concentration of 8.0 microg L(-1) which implies a dietary intake estimation of 104 ng kg(-1)b.w.day(-1) considering a body weight of 10 kg and an apple juice consumption of 130 mL day(-1), 26% of the PMTDI recommended by JECFA

A novel PKC activating molecule promotes neuroblast differentiation and delivery of newborn neurons in brain injuries

Neural stem cells are activated within neurogenic niches in response to brain injuries. This results in the production of neuroblasts, which unsuccessfully attempt to migrate toward the damaged tissue. Injuries constitute a gliogenic/non-neurogenic niche generated by the presence of anti-neurogenic signals, which impair neuronal differentiation and migration. Kinases of the protein kinase C (PKC) family mediate the release of growth factors that participate in different steps of the neurogenic process, particularly, novel PKC isozymes facilitate the release of the neurogenic growth factor neuregulin. We have demonstrated herein that a plant derived diterpene, (EOF2; CAS number 2230806-06-9), with the capacity to activate PKC facilitates the release of neuregulin 1, and promotes neuroblasts differentiation and survival in cultures of subventricular zone (SVZ) isolated cells in a novel PKC dependent manner. Local infusion of this compound in mechanical cortical injuries induces neuroblast enrichment within the perilesional area, and noninvasive intranasal administration of EOF2 promotes migration of neuroblasts from the SVZ towards the injury, allowing their survival and differentiation into mature neurons, being some of them cholinergic and GABAergic. Our results elucidate the mechanism of EOF2 promoting neurogenesis in injuries and highlight the role of novel PKC isozymes as targets in brain injury regeneration

Hyperbranched polyester polyol plasticized tapioca starch/low density polyethylene blends

ABSTRACT: In this work, low density polyethylene (LDPE)/plasticized starch (TPS) blends were prepared. The TPS employed in this study was obtained by plasticization of tapioca starch with a hyperbranched polyester polyol. Differential scanning calorimetry analysis showed that the melting temperature increased with the TPS content. The opposite effect was exhibited in the crystallization temperature and additional changes were not observed during the heating. X-ray diffraction analysis showed a reduction in intensity of the peak at Bragg’s angle 17.5°, proving a diminution on A type crystallinity with the increasing amount of LDPE. Micrographs obtained by scanning electron microscopy exhibited starch granules without destructure. TPS acted as a filler to LDPE, since the mechanical properties (Young’s modulus and tensile strength) improved ostensibly. The Young’ modulus and tensile strength decreased with the amount of LDPE, however, the elongation at break exhibited an opposite behavior

Genome-wide association studies for methane production in dairy cattle

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Genomic selection has been proposed for the mitigation of methane (CH4) emissions by cattle because there is considerable variability in CH4 emissions between individuals fed on the same diet. The genome-wide association study (GWAS) represents an important tool for the detection of candidate genes, haplotypes or single nucleotide polymorphisms (SNP) markers related to characteristics of economic interest. The present study included information for 280 cows in three dairy production systems in Mexico: 1) Dual Purpose (n = 100), 2) Specialized Tropical Dairy (n = 76), 3) Familiar Production System (n = 104). Concentrations of CH4 in a breath of individual cows at the time of milking (MEIm) were estimated through a system of infrared sensors. After quality control analyses, 21,958 SNPs were included. Associations of markers were made using a linear regression model, corrected with principal component analyses. In total, 46 SNPs were identified as significant for CH4 production. Several SNPs associated with CH4 production were found at regions previously described for quantitative trait loci of composition characteristics of meat, milk fatty acids and characteristics related to feed intake. It was concluded that the SNPs identified could be used in genomic selection programs in developing countries and combined with other datasets for global selection

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum