42 research outputs found
ON THE WAVE-U-OWC INTERACTION IN A NUMERICAL 2D WAVE FLUME
Several wave energy conversion techniques have been patented all over the world. Despite this large variation in design, the Wave Energy Converters (WECs) are generally categorized by location, type and modes of operation. An Oscillating Water Column consists of a chamber with an opening to the sea below the water line. An OWC consists of a box with a big vertical opening in the front wall. Waves enter through this opening with only some small diffraction effects from the front wall (and they propagate on the water surface in the box. On the roof of the box there is a tube connecting the atmosphere with the air pocket enclosed between the water surface and the roof. This tube contains one or more self-rectifying turbine (like the Wells). The air pocket inside the box, is compressed and expanded alternately. As a consequence, an air flow is produced which drives the turbine in the tube.
In the conventional OWC waves enter the plant undergoing some diffraction effects produced by the lower end of the front wall. U-OWC plants are breakwaters in reinforced concrete embodying an OWC with an additional vertical duct on the front wall.
In this work, we carried out a numerical experiment aiming to analyze the interaction between waves and a U-OWC breakwater. The numerical method adopted is the numerical integration of Reynolds averaged Navier-Stokes equation (RANS). The water-air interaction is taken into account by means of the Volume Of Fluid (VOF) model implemented in the commercial CFD code Ansys Fluent.
To validate the numerical flume, we carried out some preliminary tests finalized to compare numerical results of a vertical reflecting wall with the analytical solution of linear standing waves. The results have shown that there is a suitable correspondence between analytical and numerical simulation and this confirms that the wave field expanding along the wave flume has the characteristics of a progressive wave. The progressive wave train propagating in the wave flume impacts on a vertical wall and is reflected backwards. The reflected wave train superimposed with the incident waves generates a standing wave field propagating from the breakwater towards the wavemaker.
The numerical experiment has been carried out by substituting the vertical wall with the U-OWC. The geometry and size of the U-OWC breakwater utilized in this work is the same as the 1:6 scale physical model of breakwater tested directly, at sea, off the coast of Reggio Calabria (in the eastern coast of the Messina Straits).
The performance of the plant depends on whether it is working in resonance or not. To check the plant working conditions, we choose waves with characteristics (height and period) similar to those which interacted with the plant at sea. Therefore, we made several simulations, varying the wave period in the range [2.5, s 9 s] and maintaining the wave height fixed at 0.2m
Individual HLA heterogeneity and its implications for cellular immune evasion in cancer and beyond
Structural and functional variability of human leukocyte antigen (HLA) is the foundation for competent adaptive immune responses against pathogen and tumor antigens as it assures the breadth of the presented immune-peptidome, theoretically sustaining an efficient and diverse T cell response. This variability is presumably the result of the continuous selection by pathogens, which over the course of evolution shaped the adaptive immune system favoring the assortment of a hyper-polymorphic HLA system able to elaborate efficient immune responses. Any genetic alteration affecting this diversity may lead to pathological processes, perturbing antigen presentation capabilities, T-cell reactivity and, to some extent, natural killer cell functionality. A highly variable germline HLA genotype can convey immunogenetic protection against infections, be associated with tumor surveillance or influence response to anti-neoplastic treatments. In contrast, somatic aberrations of HLA loci, rearranging the original germline configuration, theoretically decreasing its variability, can facilitate mechanisms of immune escape that promote tumor growth and immune resistance.The purpose of the present review is to provide a unified and up-to-date overview of the pathophysiological consequences related to the perturbations of the genomic heterogeneity of HLA complexes and their impact on human diseases, with a special focus on cancer
A New Cross-Flow Type Turbine for Ultra-Low Head in Streams and Channels
In the last few decades, hydropower production has been moving toward a new paradigm of low and diffused power density production of energy with small and mini-hydro plants, which usually do not require significant water storage. In the case of nominal power lower than 20 kW and ultra-low head H (H < 5 m), Archimedes screw or Kaplan type turbines are usually chosen due to their efficiency, which is higher than 0.85. A new cross-flow type turbine called Ultra-low Power Recovery System (UL-PRS) is proposed and its geometry and design criteria are validated in a wide range of operating conditions through 2D numerical analysis computed using the ANSYS Fluent solver. The new proposed solution is much simpler than the previously mentioned competitors; its outlet flow has a horizontal direction and attains similar efficiency. The costs of the UL-PRS turbine are compared with the costs of one Kaplan and one cross-flow turbine (CFT) in the case study of the main water treatment plant of the city of Palermo in Italy. In this case, the UL-PRS efficiency is estimated using a URANS 3D numerical analysis computed with the CFX solver
Arsenic trioxide and all-trans retinoic acid treatment for childhood acute promyelocytic leukaemia
Recruitment of MLL1 complex is essential for SETBP1 to induce myeloid transformation
Abnormal activation of SETBP1 due to overexpression or missense mutations occurs frequently in various myeloid neoplasms and associates with poor prognosis. Direct activation of Hoxa9/Hoxa10/Myb transcription by SETBP1 and its missense mutants is essential for their transforming capability; however, the underlying epigenetic mechanisms remain elusive. We found that both SETBP1 and its missense mutant SETBP1(D/N) directly interact with histone methyltransferase MLL1. Using a combination of ChIP-seq and RNA-seq analysis in primary hematopoietic stem and progenitor cells, we uncovered extensive overlap in their genomic occupancy and their cooperation in activating many oncogenic transcription factor genes including Hoxa9/Hoxa10/Myb and a large group of ribosomal protein genes. Genetic ablation of Mll1 as well as treatment with an inhibitor of the MLL1 complex OICR-9429 abrogated Setbp1/Setbp1(D/N)- induced transcriptional activation and transformation. Thus, the MLL1 complex plays a critical role in Setbp1-induced transcriptional activation and transformation and represents a promising target for treating myeloid neoplasms with SETBP1 activation
The similarity of class II HLA genotypes defines patterns of autoreactivity in idiopathic bone marrow failure disorders
Abstract Idiopathic aplastic anemia (IAA) is a rare autoimmune bone marrow failure (BMF) disorder initiated by a human leukocyte antigen (HLA)-restricted T-cell response to unknown antigens. As in other autoimmune disorders, the predilection for certain HLA profiles seems to represent an etiologic factor; however, the structure-function patterns involved in the self-presentation in this disease remain unclear. Herein, we analyzed the molecular landscape of HLA complexes of a cohort of 300 IAA patients and almost 3000 healthy and disease controls by deeply dissecting their genotypic configurations, functional divergence, self-antigen binding capabilities, and T-cell receptor (TCR) repertoire specificities. Specifically, analysis of the evolutionary divergence of HLA genotypes (HED) showed that IAA patients carried class II HLA molecules whose antigen-binding sites were characterized by a high level of structural homology, only partially explained by specific risk allele profiles. This pattern implies reduced HLA binding capabilities, confirmed by binding analysis of hematopoietic stem cell (HSC)-derived self-peptides. IAA phenotype was associated with the enrichment in a few amino acids at specific positions within the peptide-binding groove of DRB1 molecules, affecting the interface HLA-antigen-TCR β and potentially constituting the basis of T-cell dysfunction and autoreactivity. When analyzing associations with clinical outcomes, low HED was associated with risk of malignant progression and worse survival, underlying reduced tumor surveillance in clearing potential neoantigens derived from mechanisms of clonal hematopoiesis. Our data shed light on the immunogenetic risk associated with IAA etiology and clonal evolution and on general pathophysiological mechanisms potentially involved in other autoimmune disorders.Peer reviewe
Mathematics in Medical Diagnostics - 2022 Proceedings of the 4th International Conference on Trauma Surgery Technology
The 4th event of the Giessen International Conference Series on Trauma Surgery Technology took place on April, the 23rd 2022 in Warsaw, Poland. It aims to bring together practical application research, with a focus on medical imaging, and the TDA experts from Warsaw. This publication contains details of our presentations and discussions
Clinical and genomic-based decision support system to define the optimal timing of allogeneic hematopoietic stem-cell transplantation in patients with myelodysplastic syndromes
Statistical Scienc