Atresia of inferior vena cava (IVC) is a rare congenital malformation associated with high risk of venous thrombosis that still has unknown etiology, although intrauterine IVC thrombosis has been ...suggested to be involved. The identification of IVC atresia in a case with early idiopathic venous thrombosis and antithrombin deficiency caused by the homozygous SERPINC1 c.391C > T variant (p.Leu131Phe; antithrombin Budapest 3) encouraged us to evaluate the role of this severe thrombophilia in this vascular abnormality. We have done a cross‐sectional study in previously identified cohorts of patients homozygous for the Budapest 3 variant (N = 61) selected from 1118 patients with congenital antithrombin deficiency identified in two different populations: Spain (N = 692) and Hungary (N = 426). Image analysis included computed tomography and phlebography. Atresia of the IVC system was observed in 17/24 cases (70.8%, 95% confidence interval CI: 48.9%–87.3%) homozygous for antithrombin Budapest 3 with available computed tomography (5/8 and 12/16 in the Spanish and Hungarian cohorts, respectively), 16 had an absence of infrarenal IVC and one had atresia of the left common iliac vein. All cases with vascular defects had compensatory mechanisms, azygos‐hemiazygos continuation or double IVC, and seven also had other congenital anomalies. Short tandem repeat analysis supported the specific association of the IVC system atresia with SERPINC1. We show the first evidence of the association of a severe thrombophilia with IVC system atresia, supporting the possibility that a thrombosis in the developing fetal vessels is the reason for this anomaly. Our hypothesis‐generating results encourage further studies to investigate severe thrombophilic states in patients with atresia of IVC.
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•A computational framework applied to consider the natural convection problem in a cavity with micropolar fluid.•The material parameter decreases with Rayleigh number and particle ...volume fraction.•The values of Ψmax and Nuave decrease 17.1% and 10.8%, respectively while Nmax increases 19.8% when K increases from 1 to 2.
Micropolar fluids are the media in which their behavior is affected by the microrotation of the substructure particles. In the present work, the natural-convection flow of a micropolar-nanofluid (Al2O3/water) in the presence of an inclined magnetic field in a semi-annulus enclosure is investigated. The influence of active parameters on magneto-natural convection is investigated. The governing equations (mass, momentum, microrotation, and energy) are numerically solved by CVFEM. Moreover, for some conservative comparisons, the equations are solved by Ansys Fluent CFD code which is conjugated by an innovative nondimensionlization scheme. The effects of important parameters are investigated on the streamlines, isotherms, microrotation contours, the maximum absolute value of stream function (Ψmax), the average Nusselt number (Nuave) and the maximum absolute value of microrotation Nmax∗. The results discovered that the values of Nuave descend with ascending the Hartmann number (Ha) and material parameter (K) while it ascends with ascending Rayleigh number (Ra) and particle volume fraction (ϕ). The value of Nuave descends 10.8% while Nmax∗ increases 19.8% when K increases from 1 to 2. The value of Nuave descends 44.83% when Ha increases from 25 to 75 at λ=45°. The minimum value of Nuave occurs at λ=45° for Ha=25 and at λ=30° for Ha=50 and Ha=75.
Selection of dairy sheep based on production levels has caused a loss of rusticity, which might compromise their future resilience to nutritional challenges. Although refocusing breeding programs ...toward improved feed efficiency (FE) is expected, more-efficient ewes also seem to be more productive. As a first step to examine the relationship between FE and resilience in dairy sheep, in this study we explored the variation in the response to and the recovery from an acute nutritional challenge in high-yielding Assaf ewes phenotypically divergent for FE. First, feed intake, milk yield and composition, and body weight changes were recorded individually over a 3-wk period in a total of 40 sheep fed a total mixed ration (TMR) ad libitum. Data were used to calculate their FE index (FEI, defined as the difference between the actual and predicted intake estimated through net energy requirements for maintenance, production, and weight change). The highest and lowest FE ewes (H-FE and L-FE groups, respectively; 10 animals/group) were selected and then subjected to the nutritional challenge (i.e., withdrawing the TMR and limiting their diet only to the consumption of straw for 3 d). Afterward, sheep were fed again the TMR ad libitum. Temporal patterns of variation in performance traits, and ruminal fermentation and blood parameters were examined. A good consistency between FEI, residual feed intake, and feed conversion ratio was observed. Results supported that H-FE were more productive than L-FE sheep at similar intake level. Average time trends of milk yield generated by a piecewise model suggest that temporal patterns of variation in this trait would be related to prechallenge production level (i.e., H-FE presented quicker response and recovery than L-FE). Considering all studied traits, the overall response to and recovery from underfeeding was apparently similar or even better in H-FE than in L-FE. This would refute the initial hypothesis of a poorer resilience of more-efficient sheep to an acute underfeeding. However, the question remains whether a longer term feed restriction might impair the ability of H-FE ewes to maintain or revert to a high-production status, which would require further research.
Composites carbon foams based on sucrose-based char matrix and graphite filler were prepared and characterised with the aim of hosting sugar alcohols as phase-change materials (PCMs) in the context ...of thermal energy storage (TES). Seasonal solar TES demands an excellent undercooling of the molten PCM infiltrated in the foam, so that the heat can be stored as long as possible. The present paper demonstrates how the surface of such composite foams, i.e., comprising two carbon phases of different reactivities, can be modified for promoting undercooling. For that purpose, 8 different hydrophobisation treatments were applied, and the results were compared with those of the non-treated foam, in which heterogeneous nucleation could not be avoided. We show that one kind of functionalisation was successful, i.e., it fully preserved the melting point and the enthalpy of melting of the hosted phase-change material and completely avoided the heterogeneous nucleation of the PCM, while maintaining the thermal conductivity in the range required for this kind of application.
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•Seasonal heat thermal storage (STES) is addressed, based on composite carbon foams.•The latter were hydrophobised by 8 different methods and fully characterised.•Infiltration with sugar alcohols (SA) as phase-change materials was carried out.•Some hydrophobised materials fully prevented the heterogeneous nucleation of SA.•Excellent undercooling was thus evidenced, therefore promoting long-term STES.
Carbon foams specifically designed for seasonal solar thermal energy storage (SSTES) were prepared and characterised. For working efficiently as hosts for sugar alcohols used as phase-change ...materials and allowing the achievement of compact and affordable systems for SSTES, drastic conditions were required: thermal conductivity higher than 3 W m−1 K−1, porosity higher than 86% and cost not much higher than 6 € kg−1. For designing such materials, carbon foams combining a partly graphitised matrix derived from sucrose char, filled by natural graphite flakes of typical size 6 μm were suggested. Nickel nitrate was used as both graphitisation catalyst and blowing agent. Both nitrate and graphite were selected out of other materials of the same kind, shown to present lower performances. As thermal conductivity and porosity vary in opposite ways, finding a formulation optimising both parameters was only possible through an experimental design associated with statistical analysis of results. The results were modelled, and the model allowed finding formulations matching all initial requirements. Such good results were explained by the excellent dispersion of graphite filler and partial graphitisation of the matrix evidenced by polarised-light optical microscopy, X-ray diffraction and Raman mapping studies.
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Essentials We investigated the molecular base of antithrombin deficiency in cases without SERPINC1 defects. 27% of cases presented hypoglycosylation, transient in 62% and not restricted to ...antithrombin. Variations in genes involved in N-glycosylation underline this phenotype. These results support a new form of thrombophilia. Click here to listen to Dr Huntington's perspective on thrombin inhibition by the serpins
Background Since the discovery of antithrombin deficiency, 50 years ago, few new thrombophilic defects have been identified, all with weaker risk of thrombosis than antithrombin deficiency. Objective To identify new thrombophilic mechanisms. Patients/methods We studied 30 patients with antithrombin deficiency but no defects in the gene encoding this key anticoagulant (SERPINC1). Results A high proportion of these patients (8/30: 27%) had increased hypoglycosylated forms of antithrombin. All N-glycoproteins tested in these patients (α1-antitrypsin, FXI and transferrin) had electrophoretic, HPLC and Q-TOF patterns indistinguishable from those of the congenital disorders of glycosylation (rare recessive multisystem disorders). However, all except one had no mental disability. Moreover, intermittent antithrombin deficiency and hypoglycosylation was recorded in five out of these eight patients, all associated with moderate alcohol intake. Genetic analysis, including whole exome sequencing, revealed mutations in different genes involved in the N-glycosylation pathway. Conclusions Our study provides substantial and novel mechanistic insights into two disease processes, with potential implications for diagnosis and clinical care. An aberrant N-glycosylation causing a recessive or transient antithrombin deficiency is a new form of thrombophilia. Our data suggest that congenital disorders of glycosylation are probably underestimated, especially in cases with thrombosis as the main or only clinical manifestation.
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