128 research outputs found

    Influence of the processing route on the mechanical properties at high temperatures of Mg-Ni-Y-RE alloys containing LPSO-phases

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    The mechanical properties at high temperatures of two Mg-Ni-Y-RE alloys prepared by conventional or powder metallurgy routes have been evaluated. All alloys exhibit high-strength up to 250°C but their strength depends more on the composition of the alloy rather than on the processing route. High strength of the alloys arises from their fine grain size but there is an additional contribution of load transfer from the magnesium matrix towards the second phases in the alloys processed by the conventional route while additional hardening in the alloys prepared by powder metallurgy is due to Orowan mechanism. Above 250°C, the strength drops to very low values but all alloys exhibit high elongations and grain boundary sliding is the controlling mechanism. Grain boundary sliding also induces cracking of the coarse second phases into smaller pieces during the initial stages of plastic deformation of conventionally processed alloys

    Bucomaxillofacial cancer and major considerations and treatments: a concise systematic review

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    Introduction: According to National Cancer Institute, a total of 16,290 new cases of oral cancer are estimated in Brazil in 2017, with 12,370 new cases of oral cavity cancer in men and 4,010 in women corresponding to an estimated risk of 11.54 cases new for every 100 thousand men and 3.92 for each 100 thousand women. In this sense, oral cancer therapy is associated with a multitude of head and neck sequelae including hyposalivation, increased risk of tooth decay, osteoradionecrosis of the jaw, radiation fibrosis syndrome, mucositis, chemotherapy-induced neuropathy, dysgeusia, dysphagia, mucosal lesions, trismus, and infections. Objective: The present study addressed the main considerations about maxillofacial cancer and possible treatments based on the literary findings through a narrative and integrative review. Methods: Clinical studies with qualitative and/or quantitative analysis were included, following the rules of the systematic review-PRISMA. Results and Conclusion: A total of 86 articles were found involving "Bucomaxillofacial Treatment in Cancer Patients". A total of 29 articles were evaluated in full, and 24 were included and discussed in this study. Oral cancer or oral carcinoma is a chronic, complex, multifactorial pathology resulting from the interaction of intrinsic and extrinsic factors that leads to an imbalance in the process of cell proliferation and growth control. There is an association between periodontal disease, nutritional status parameters, and antimicrobial protein levels, in the case of erythroplakia, 70.0 % to 95.0 % of these lesions are cancerous at the time of initial biopsy or will progress to cancer. In invasive squamous cell carcinoma, cancer cells have penetrated deeper layers of the oral cavity and oropharynx. Therefore, preparing a comprehensive treatment plan for cancer patients is essential to help minimize the risks of developing these oral and dental complications. In addition, dentists should consider a patient's ongoing cancer therapy for those patients who come to the dentist while receiving cancer treatment

    Taxonomic reassessment of the genus Dichotomius (Coleoptera: Scarabaeinae) through integrative taxonomy

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    Dung beetles of the subfamily Scarabaeinae are widely recognised as important providers of multiple ecosystem services and are currently experiencing revisions that have improved our understanding of higher-level relationships in the subfamily. However, the study of phylogenetic relationships at the level of genus or species is still lagging behind. In this study we investigated the New World beetle genus Dichotomius, one of the richest within the New World Scarabaeinae, using the most comprehensive molecular and morphological dataset for the genus to date (in terms of number of species and individuals). Besides evaluating phylogenetic relationships, we also assessed species delimitation through a novel Bayesian approach (iBPP) that enables morphological and molecular data to be combined. Our findings support the monophyly of the genus Dichotomius but not that of the subgenera Selenocopris and Dichotomius sensu stricto (s.s). Also, our results do not support the recent synonymy of Selenocopris with Luederwaldtinia. Some species-groups within the genus were recovered, and seem associated with elevational distribution. Our species delimitation analyses were largely congruent irrespective of the set of parameters applied, but the most robust results were obtained when molecular and morphological data were combined. Although our current sampling and analyses were not powerful enough to make definite interpretations on the validity of all species evaluated, we can confidently recognise D. nisus, D. belus and D. mamillatus as valid and well differentiated species. Overall, our study provides new insights into the phylogenetic relationships and classification of dung beetles and has broad implications for their systematics and evolutionary analyses. Copyright © 2019 Pardo-Diaz et al

    Effects of dietary free fatty-acid content and saturation degree on lipid-class composition and fatty-acid digestibility along the gastrointestinal tract in broiler starter chickens

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    The aim of the present study is to assess the effect of the dietary free fatty acid (FFA) content and dietary fat saturation degree on the fatty-acid (FA) digestibility and lipid-class content along the gastrointestinal tract and excreta in broiler chickens. The 8 experimental diets resulted from replacing crude soybean oil with soybean acid oil from chemical refining, or crude palm oil with palm FA distillate from physical refining. Thus, there were 4 soybean and 4 palm diets with 6% added fat varying in their FFA% (5, 15, 35, and 50%). Samples of digestive content (gizzard, duodenum, jejunum, and ileum) and excreta were collected at 14 D for the determination of the FA digestibility and lipid-class content. The total FA digestibility coefficients reported for the chickens fed S diets in the jejunum, ileum, and excreta were higher than for those fed P diets (P ≤ 0.02). The general greater digestibility of the unsaturated diets was mainly explained by a higher contribution of the ileum to the absorption of saturated FA. The dietary FFA content mainly affected the FA absorption process. The diets with 50% FFA presented lower saturated FA digestibility coefficients in the jejunum and ileum (P ≤ 0.03), and higher content of FFA in the ileum and excreta (P ≤ 0.014), in comparison to the diets with 5% FFA. The 15% FFA diets were not different from the 5% FFA diets, regarding the saturated FA digestibility in the jejunum and excreta, and the FFA content in the ileum and excreta. It was concluded that unsaturated diets with moderate content of dietary FFA (up to 15%) could be used in broiler-chicken starter diets, as they led to similar FA absorption and performance results to the diets with the lowest dietary FFA content. From the present study, it has also been concluded that dietary saturated FA content has a greater impact on FA absorption than the dietary FFA content has

    Water Splitting Electrocatalysis within Layered Inorganic Nanomaterials

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    The conversion of solar energy into chemical fuel is one of the “Holy Grails” of twenty-first century chemistry. Solar energy can be used to split water into oxygen and protons, which are then used to make hydrogen fuel. Nature is able to catalyze both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) required for the conversion of solar energy into chemical fuel through the employment of enzymes that are composed of inexpensive transition metals. Instead of using expensive catalysts such as platinum, cheaper alternatives (such as cobalt, iron, or nickel) would provide the opportunity to make solar energy competitive with fossil fuels. However, obtaining efficient catalysts based on earth-abundant materials is still a daunting task. In this chapter, we review the advancements made with zirconium phosphate (ZrP) as a support for earth-abundant transition metals for the OER. Our studies have found that ZrP is a suitable support for transition metals as it provides an accessible surface where the OER can occur. Further findings have also shown that exfoliation of ZrP increases the availability of sites where active species can be adsorbed and performance is improved with this strategy

    Phosphate, microbiota and ckd

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    Phosphate is a key uremic toxin associated with adverse outcomes. As chronic kidney disease (CKD) progresses, the kidney capacity to excrete excess dietary phosphate decreases, triggering compensatory endocrine responses that drive CKD-mineral and bone disorder (CKD-MBD). Eventu-ally, hyperphosphatemia develops, and low phosphate diet and phosphate binders are prescribed. Recent data have identified a potential role of the gut microbiota in mineral bone disorders. Thus, parathyroid hormone (PTH) only caused bone loss in mice whose microbiota was enriched in the Th17 cell-inducing taxa segmented filamentous bacteria. Furthermore, the microbiota was required for PTH to stimulate bone formation and increase bone mass, and this was dependent on bacterial production of the short-chain fatty acid butyrate. We review current knowledge on the relationship between phosphate, microbiota and CKD-MBD. Topics include microbial bioactive compounds of special interest in CKD, the impact of dietary phosphate and phosphate binders on the gut microbiota, the modulation of CKD-MBD by the microbiota and the potential therapeutic use of microbiota to treat CKD-MBD through the clinical translation of concepts from other fields of science such as the optimization of phosphorus utilization and the use of phosphate-accumulating organisms.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 860329, FIS/Fondos FEDER (PI18/01366, PI20/00744, PI19/00815, DTS18/00032, ERA-PerMed-JTC2018 (KIDNEY ATTACK AC18/00064 and PERSTIGAN AC18/00071, ISCIII-RETIC REDinREN RD016/0009), Sociedad Española de Nefrología, FRIAT, Comunidad de Madrid en Biomedicina B2017/BMD-3686 CIFRA2-C

    Roman water management impacted the hydrological functioning of wetlands during drought periods

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    During the Roman domain of the Iberian Peninsula (from 201 BCE to 460 CE) water management infrastructures were built to satisfy high water demand. However, whether the Roman activities affected the hydrological balance of Iberian wetlands remains unclear. Here, we investigate the paleo-hydrology of Lake Zóñar (southern Iberia) by using the stable isotopes (16O, 17O, 18O, 1H and 2H) of its gypsum (CaSO4·2H2O) sediments and reconstruct the isotopic composition of the lake water during Roman times. A period of recurrent lake low stand occurred between 2120 and 1890 cal. yr BP (ca. 170 BCE to 60 CE), coinciding with a relatively dry climate stage recorded by most regional paleoclimate archives. The stable isotopes and hydrochemistry of the lake water during gypsum precipitation are consistent with a shallow saline lake that evaporated under relative humidity ~ 10% lower than the present annual mean and at least 20% less rainfall amount. Our analytical and archeological findings support lake level lowering during the Roman period was probably caused by combined arid climate conditions and diversion of the inlets feeding the lake. Spring capturing was likely necessary to satisfy the high water demand of nearby Roman settlements, in the framework of a period of persistent droughts

    Configuración de servicios DHCP, DNS, controlador de dominio, proxy no transparente, cortafuegos, file server, Print server y VPN en Zentyal Server

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    En el siguiente documento se presenta de una forma detallada el proceso de instalación y configuración de Zentyal Server en una máquina virtual. Los servicios instalados corresponden a los que se consideran más importantes en un servidor de una red de computadores. La configuración lograda permitió que el equipo cliente, también basado en una distribución Linux, pudiera obtener los beneficios de estos servicios y en cada apartado el lector podrá observar el resultado final. Queda demostrado entonces la potencia de Zentyal como alternativa a servicios privativos, así como la sencillez de la interfaz y la facilidad para realizar cada operación dentro de un ambiente gráfico, lo cual lo hace más asequible a los administradores de red que usan software libre menos puristas o incluso para quienes no han tenido un primer contacto con máquinas basadas en Linux.The following document presents a detailed way of installing and configuring Zentyal Server in a virtual machine. The installed services correspond to those that are considered most important in a server of a computer network. The configuration achieved allowed the client computer, also based on a Linux distribution, to obtain the benefits of these services and in each section the reader will be able to observe the final result. So the power of Zentyal as an alternative to proprietary services is demonstrated, as well as the simplicity of the interface and the ease of performing each operation within a graphical environment ; which makes it more affordable for network administrators who use free software less purists or even for those who have not had a first contact with Linux-based machines
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