Thermal-hydraulic assessment of Once-Through Steam Generators for EU-DEMO WCLL Breeding Blanket primary cooling system application

Once-Through Steam Generators (OTSGs) were recently selected to be installed in the Primary Heat Transfer Systems (PHTS) related to EU-DEMO WCLL Breeding Blanket (BB). Referring to the Balance of Plant Direct Coupling Design (BoP-DCD) option, these components are used to deliver the thermal power removed from the two principal blanket subsystems, i.e. First Wall (FW) and Breeder Zone (BZ), to the Power Conversion System (PCS). OTSG design foresees a vertical component with primary water moving downward inside tube bundle and secondary fluid flowing throughout shell in counter current. The latter moves firstly downwards through the annular downcomer and then goes up in the central riser, where it boils up to super-heated steam conditions. Then, it is deflected by the upper tubesheet, flows again downwards along the steam downcomer and exits through the laterally connected steam nozzles. In the last years, as part of the research activities associated to the Work Package Balance of Plant (WPBoP), a detailed analysis of the steam generator, aimed at deeply understanding the main thermal-hydraulic aspects characterizing its performances during the pulsed regime of DEMO normal operations, was performed. To fulfil this scope, a complete model of the component was prepared by using the best-estimate system code RELAP5/MOD3.3, selected to be also the reference design verification tool. During operations, OTSG experiences full-load and low-load alternative phases with rapid transitions from one another. The steam generator capability to follow such load variations avoiding the occurrence of instabilities in the component was studied. The computational activity carried out was a preliminary thermal-hydraulic characterization of the component conceptual design during both pulse and dwell phases. The feedbacks of this analysis were also fundamental for the conceptualization of the steam generator mock-up to be installed in the planned STEAM facility that will be built at the ENEA Research center of Brasimone

Production of Composite Zinc Oxide–Polylactic Acid Radiopaque Filaments for Fused Deposition Modeling: First Stage of a Feasibility Study

Three-dimensional printing technologies are becoming increasingly attractive for their versatility; the geometrical customizability and manageability of the final product properties are the key points. This work aims to assess the feasibility of producing radiopaque filaments for fused deposition modeling (FDM), a 3D printing technology, starting with zinc oxide (ZnO) and polylactic acid (PLA) as the raw materials. Indeed, ZnO and PLA are promising materials due to their non-toxic and biocompatible nature. Pellets of PLA and ZnO in the form of nanoparticles were mixed together using ethanol; this homogenous mixture was processed by a commercial extruder, optimizing the process parameters for obtaining mechanically stable samples. Scanning electron microscopy analyses were used to assess, in the extruded samples, the homogenous distribution of the ZnO in the PLA matrix. Moreover, X-ray microtomography revealed a certain homogenous radiopacity; this imaging technique also confirmed the correct distribution of the ZnO in the PLA matrix. Thus, our tests showed that mechanically stable radiopaque filaments, ready for FDM systems, were obtained by homogenously loading the PLA with a maximum ZnO content of 6.5% wt. (nominal). This study produced multiple outcomes. We demonstrated the feasibility of producing radiopaque filaments for additive manufacturing using safe materials. Moreover, each phase of the process is cost-effective and green-oriented; in fact, the homogenous mixture of PLA and ZnO requires only a small amount of ethanol, which evaporates in minutes without any temperature adjustment. Finally, both the extruding and the FDM technologies are the most accessible systems for the additive manufacturing commercial apparatuses

Conceptual Design of the Steam Generators for the EU DEMO WCLL Reactor

In the framework of the EUROfusion Horizon Europe Programme, ENEA and its linked third parties are in charge of the conceptual design of the steam generators belonging to EU DEMO WCLL Breeding Blanket Primary Heat Transfer Systems (BB PHTSs). In particular, in 2021, design activities and supporting numerical simulations were carried out in order to achieve a feasible and robust preliminary concept design of the Once Through Steam Generators (OTSGs), selected as reference technology for the DEMO Balance of Plant at the end of the Horizon 2020 Programme. The design of these components is very challenging. In fact, the steam generators have to deliver the thermal power removed from the two principal blanket subsystems, i.e., the First Wall (FW) and the Breeding Zone (BZ), to the Power Conversion System (PCS) for its conversion into electricity, operating under plasma pulsed regime and staying in dwell period at a very low power level (decay power). Consequently, the OTSG stability and control represent a key point for these systems' operability and the success of a DEMO BoP configuration with direct coupling between the BB PHTS and the PCS. In this paper, the authors reported and critically discussed the FW and BZ steam generators' thermal-hydraulic and mechanical design, the developed 3D CAD models, as well as the main results of the stability analyses and the control strategy to be adopted

Polypteridae (Actinopterygii: Cladistia) and DANA-SINEs insertions

SINE sequences are interspersed throughout virtually all eukaryotic genomes and greatly outnumber the other repetitive elements. These sequences are of increasing interest for phylogenetic studies because of their diagnostic power for establishing common ancestry among taxa, once properly characterized. We identified and characterized a peculiar family of composite tRNA-derived short interspersed SINEs, DANA-SINEs, associated with mutational activities in Danio rerio, in a group of species belonging to one of the most basal bony fish families, the Polypteridae, in order to investigate their own inner specific phylogenetic relationships. DANA sequences were identified, sequenced and then localized, by means of fluorescent in situ hybridization (FISH), in six Polypteridae species (Polypterus delhezi, P. ornatipinnis, P. palmas, P. buettikoferi P. senegalus and Erpetoichthys calabaricus) After cloning, the sequences obtained were aligned for phylogenetic analysis, comparing them with three Dipnoan lungfish species (Protopterus annectens, P. aethiopicus, Lepidosiren paradoxa), and Lethenteron reissneri (Petromyzontidae)was used as outgroup. The obtained overlapping MP, ML and NJ tree clustered together the species belonging to the two taxonomically different Osteichthyans groups: the Polypteridae, by one side, and the Protopteridae by the other, with the monotypic genus Erpetoichthys more distantly related to the Polypterus genus comprising three distinct groups: P. palmas and P. buettikoferi, P. delhezi and P. ornatipinnis and P. senegalus. In situ hybridization with DANA probes marked along the whole chromosome arms in the metaphases of all the Polypteridae species examined

Dyslipidemia and Cardiovascular Prevention in the Elderly: A Balance between Benefits and Risks of Statin Treatment in a Specific Population

Introduction: Atherosclerotic Cardiovascular Diseases (CVD) are among the most relevant causes of morbidity and mortality worldwide, especially in aged people. Statins are one of the leading pharmacological interventions against atherosclerosis and are widely used to reduce the risk of occurring coronary artery diseases and related outcomes in both primary and secondary prevention. The management of chronic diseases is improved considerably over time, leading to an increase in life expectancy despite heavier comorbidity-related burdens in the elderly. Aims: The paper focused on the role of statins in the management of atherosclerosis and related burdens in elderly patients. Results: Statins are essential in reducing the risk of CVD in secondary and primary prevention, particularly in high-risk individuals. Guidelines encourage using specific algorithms with age-specific cutoffs to assess individual cardiovascular risk irrespective of baseline age, as the expansion of life expectancy produces favorable effects of statin treatment in those over 70. Discussion: Besides the estimation of baseline CV risk, a specific age-related assessment is also necessary before prescribing statin treatment in aged people focusing on frailty, potential pharmacological interactions due to polypharmacotherapy, cognitive impairment, and background chronic comorbidities, such as diabetes mellitus. Before starting statin therapy, an accurate choice of type and dose of statins is needed as potential adverse events are more prevalent with high-dose than low-to-moderatedose regimens and with lipophile than hydrophile statins (e.g., potential implication on intra-cerebral cholesterol metabolism). Conclusion: Despite possible adverse events, elderly patients should receive statins, when appropriate, to avoid the first occurrence of recurrent cardiovascular events and related burdens

Dyslipidemia and cardiovascular prevention in the elderly: a balance between benefits and risks of statin treatment in a specific population

Introduction: Atherosclerotic Cardiovascular Diseases (CVD) are among the most relevant causes of morbidity and mortality worldwide, especially in aged people. Statins are one of the leading pharmacological interventions against atherosclerosis and are widely used to reduce the risk of occurring coronary artery diseases and related outcomes in both primary and secondary prevention. The management of chronic diseases is improved considerably over time, leading to an increase in life expectancy despite heavier comorbidity-related burdens in the elderly. Aims: The paper focused on the role of statins in the management of atherosclerosis and related burdens in elderly patients. Results: Statins are essential in reducing the risk of CVD in secondary and primary prevention, particularly in high-risk individuals. Guidelines encourage using specific algorithms with age-specific cut-offs to assess individual cardiovascular risk irrespective of baseline age, as the expansion of life expectancy produces favorable effects of statin treatment in those over 70. Discussion: Besides the estimation of baseline CV risk, a specific age-related assessment is also necessary before prescribing statin treatment in aged people focusing on frailty, potential pharmacological interactions due to polypharmacotherapy, cognitive impairment, and background chronic comorbidities, such as diabetes mellitus. Before starting statin therapy, an accurate choice of type and dose of statins is needed as potential adverse events are more prevalent with high-dose than low-to-moderate-dose regimens and with lipophile than hydrophile statins (e.g., potential implication on intra-cerebral cholesterol metabolism). Conclusion: Despite possible adverse events, elderly patients should receive statins, when appropriate, to avoid the first occurrence of recurrent cardiovascular events and related burdens

Recombinant DNA Technology for Melanoma Immunotherapy: Anti-Id DNA Vaccines Targeting High Molecular Weight Melanoma-Associated Antigen

Anti-idiotypic MK2-23 monoclonal antibody (anti-Id MK2-23 mAb), which mimics the high molecular weight melanoma-associated antigen (HMW-MAA), has been used to implement active immunotherapy against melanoma. However, due to safety and standardization issues, this approach never entered extensive clinical trials. In the present study, we investigated the usage of DNA vaccines as an alternative to MK2-23 mAb immunization. MK2-23 DNA plasmids coding for single chain (scFv) MK2-23 antibody were constructed via the insertion of variable heavy (VH) and light (VL) chains of MK2-23 into the pVAC-1mcs plasmids. Two alternative MK2-23 plasmids format VH/VL, and VL/VH were assembled. We demonstrate that both polypeptides expressed by scFv plasmids in vitro retained the ability to mimic HMW-MAA antigen, and to elicit specific anti-HMW-MAA humoral and cellular immunoresponses in immunized mice. Notably, MK2-23 scFv DNA vaccines impaired the onset and growth of transplantable B16 melanoma cells not engineered to express HMW-MAA. This pilot study suggests that optimized MK2-23 scFv DNA vaccines could potentially provide a safer and cost-effective alternative to anti-Id antibody immunization, for melanoma immunotherapy

Hypothyroidism in older adults: A narrative review

Introduction: The prevalence of hypothyroidism increases along with aging, resulting in one of the most common comorbidities among patients over 75 years. The leading causes of hypothyroidism in older adults are iatrogenic, Hashimoto's thyroiditis, and medications. Aims: The narrative review aimed to discuss the clinical characteristics of hypothyroidism in older adults and the impact of hormonal replacement therapy on survival rates. Results: Thyroid function declines over time due to physiological changes in the thyroid stimulating hormone signaling, iodine absorption and metabolism, thyroid hormone metabolism, and activity at peripheral sites. A serum TSH value over the upper limit of the normal reference range is not necessarily attributable to hypothyroidism. However, an appropriate diagnostic work-up is required to rule out true hypothyroidism and discriminate the etiology (i.e., thyroid autoimmune diseases, iodine deficiency, drug-induced hypothyroidism). Levothyroxine treatment should be considered in cases of overt hypothyroidism. A complete risk-to-benefit assessment, particularly considering the overall health status, life expectancy, cognitive function, mood, and cardiovascular and neurological background, should be considered before treating subclinical hypothyroidism with more potential benefits in patients under 75 years old. Levothyroxine formulations facilitating hormone absorption and increasing compliance to long-term treatment should be preferred. TSH target should usually be set over 3 mIU/ml. Conclusion: Defining optimal diagnostic approaches and targeted therapeutic strategies should be considered in the personalized management of aged patients with hypothyroidism

Tumor endothelial marker 8 enhances tumor immunity in conjunction with immunization against differentiation Ag

BACKGROUND: We have previously shown that xenogenic DNA vaccines encoding rat neu and melanosomal differentiation Ag induce tumor immunity. Others have developed vaccines targeting tumor neovasculature. Tumor endothelial marker 8 (TEM8) is expressed in the neovasculature of human tumors, and in the mouse melanoma B16, but its expression is limited in normal adult tissues. We describe a DNA vaccine combining xenogeneic tumor Ag and TEM8. METHODS: In-situ hybridization was used to detect TEM8 RNA in mouse tumors. Mice transgenic for the rat neu proto-oncogene were immunized with DNA vaccines encoding TEM8 and the extracellular domain of rat neu and challenged with the 233-VSGA1 breast cancer cell line. In parallel experiments, C57BL/6 mice were immunized with TEM8 and human tyrosinase-related protein 1 (hTYRP1/hgp75) and challenged with B16F10 melanoma. RESULTS: TEM8 was expressed in the stroma of transplantable mouse breast and melanoma tumors. In both model systems, TEM8 DNA had no activity as a single agent but significantly enhanced the anit-tumor immunity of neu and hTYRP1/hgp75 DNA vaccines when given in concert. The observed synergy was dependent upon CD8+ T cells, as depletion of this cell population just prior to tumor challenge obviated the effect of the TEM8 vaccine in both tumor models. DISCUSSION: A local immune responses to TEM8 may increase inflammation or tumor necrosis within the tumor, resulting in improved Ag presentation of HER2/neu and hTYRP1/hgp75. Alternatively, TEM8 expression in host APC may act more as an adjuvant than an immunologic target