50 research outputs found

    Boro-nitriding coating on pure iron by powder-pack boriding and nitriding processes

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    To alleviate spallation and crack difficulties exhibited by a borided metallic surface when it is subjected to a normal, heavy and sliding load under dry conditions, a boron nitride coating was produced on pure iron in two stages: boriding the iron surface at 950 °C for 6 h and then nitriding the pre-borided iron at 550 °C for 6 h. The powder-pack technique was used in both stages. XRD measurements confirmed that the grown layers were nitrides and duplex borides. The produced diffusion of the layers reached 240 µm in depth as measured by SEM images. The measured microhardness across the case favoured the interphase cohesion between the iron nitrides and iron borides layers. Consequently, the multicomponent coating exhibited superior wear resistance to an applied normal load under dry sliding contact conditions in comparison to borided iron

    Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites

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    The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that the wood in the starch composites did not prevent water loss from the samples.Peer reviewe

    Autoantibodies against type I IFNs in patients with life-threatening COVID-19

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    Interindividual clinical variability in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is vast. We report that at least 101 of 987 patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia had neutralizing immunoglobulin G (IgG) autoantibodies (auto-Abs) against interferon-w (IFN-w) (13 patients), against the 13 types of IFN-a (36), or against both (52) at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 of the 101 were men. A B cell autoimmune phenocopy of inborn errors of type I IFN immunity accounts for life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men

    Post-Operative Functional Outcomes in Early Age Onset Rectal Cancer

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    Background: Impairment of bowel, urogenital and fertility-related function in patients treated for rectal cancer is common. While the rate of rectal cancer in the young (<50 years) is rising, there is little data on functional outcomes in this group. Methods: The REACCT international collaborative database was reviewed and data on eligible patients analysed. Inclusion criteria comprised patients with a histologically confirmed rectal cancer, <50 years of age at time of diagnosis and with documented follow-up including functional outcomes. Results: A total of 1428 (n=1428) patients met the eligibility criteria and were included in the final analysis. Metastatic disease was present at diagnosis in 13%. Of these, 40% received neoadjuvant therapy and 50% adjuvant chemotherapy. The incidence of post-operative major morbidity was 10%. A defunctioning stoma was placed for 621 patients (43%); 534 of these proceeded to elective restoration of bowel continuity. The median follow-up time was 42 months. Of this cohort, a total of 415 (29%) reported persistent impairment of functional outcomes, the most frequent of which was bowel dysfunction (16%), followed by bladder dysfunction (7%), sexual dysfunction (4.5%) and infertility (1%). Conclusion: A substantial proportion of patients with early-onset rectal cancer who undergo surgery report persistent impairment of functional status. Patients should be involved in the discussion regarding their treatment options and potential impact on quality of life. Functional outcomes should be routinely recorded as part of follow up alongside oncological parameters

    Fungal Melanins and their Potential Applications: A Review

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    Melanins are complex molecules found in many organisms including bacteria, fungi, plants, and animals that have protective functions against stress. In fungi there are several biochemical routes for their synthesis, and their diversity and structural complexity have made their analysis and characterization difficult. However, the possible specific functions of melanins in organisms have been determined. Based on their physicochemical properties, their potential in the application in various areas of interest and benefit of the human being have been visualized, such as in health and medicine, in bioremediation, and in the food industry. In this review, the type of melanins produced by fungi are discussed, as well as their main biological functions, the main biochemical routes involved in their synthesis, and potential applications in various areas. An important research area is visualized to find the best melanin-producing fungi as well as the conditions in which their production is maximized, in order to continue investigating the relationship of the structure of melanin with its biological functions as well as the determination of its physicochemical properties to establish its applications

    Wild meat trade over the last 45 years in the Peruvian Amazon

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    Altres ajuts: Acord transformatiu CRUE-CSICWe thank the market vendors in Iquitos who supported and participated in the project. The present study would not have been possible without the logistical and financial support of the Center for International Forestry Research (CIFOR-CGIAR-USAID-DFID), the Wildlife Conservation Society (WCS), the Earthwatch Institute, the Gordon & Betty Moore Foundation, the Iniciativa para la Conservación de la Amazonia (ICAA), the World Wildlife Fund (WWF), and the Darwin Initiative, UK. H.R.E.B. is supported by the Brazilian National Council for Scientific and Technological Development (CNPq) (grant number 201475/2017-0). T.Q.M. is supported by the WCS Graduate Scholarship Program, a program of the Wildlife Conservation Society, and the Christensen Conservation Leaders Scholarship, by the Wildlife Conservation Network Scholarship Program through the Sidney Byers Scholarship award, and The British Federation of Women Graduates through the Funds for Women Graduates.Altres ajuts: CNPq/201475/2017-

    Gonadotropin-inhibitory hormone (GnIH) distribution in the brain of the ancient fish Atractosteus tropicus (Holostei, Lepisosteiformes)

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    The Holostei group occupies a critical phylogenetic position as the sister group of the Teleostei. However, little is known about holostean pituitary anatomy or brain distribution of important reproductive neuropeptides, such as the gonadotropin-inhibitory hormone (GnIH). Thus, the present study set out to characterize the structure of the pituitary and to localize GnIH-immunoreactive cells in the brain of Atractosteus tropicus from the viewpoint of comparative neuroanatomy. Juveniles of both sexes were processed for general histology and immunohistochemistry. Based on the differences in cell organization, morphology, and staining properties, the neurohypophysis and three regions in the adenohypophysis were identified: the rostral and proximal pars distalis (PPD) and the pars intermedia. This last region was found to be innervated by the neurohypophysis. This organization, together with the presence of a saccus vasculosus, resembles the general teleost pituitary organization. A vast number of blood vessels were also recognized between the infundibulum floor of the hypothalamus and the PPD, evidencing the characteristic presence of a median eminence and a portal system. However, this well-developed pituitary portal system resembles that of tetrapods. As regards the immunohistochemical localization of GnIH, we found four GnIH-immunoreactive (GnIH-ir) populations in three hypothalamic nuclei (suprachiasmatic, retrotuberal, and tuberal nuclei) and one in the diencephalon (prethalamic nucleus), as well as a few scattered neurons throughout the olfactory bulbs, the telencephalon, and the intersection between them. GnIH-ir fibers showed a widespread distribution over almost all brain regions, suggesting that GnIH function is not restricted to reproduction only. In conclusion, the present study describes, for the first time, the pituitary of A. tropicus and the neuroanatomical localization of GnIH in a holostean fish that exhibits a similar distribution pattern to that of teleosts and other vertebrates, suggesting a high degree of phylogenetic conservation of this system.Fil: Beriotto, Agustina Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Di Yorio, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Pérez Sirkin, Daniela Irina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Toledo Solis, Francisco J.. Universidad Juárez Autónoma de Tabasco; MéxicoFil: Peña Marín, Emyr S.. Universidad Juárez Autónoma de Tabasco; MéxicoFil: Álvarez González, Carlos A.. Universidad Juárez Autónoma de Tabasco; MéxicoFil: Tsutsui, Kazuyoshi. Waseda University; JapónFil: Vissio, Paula Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

    Echinococcus granulosus cattle strain identification in an autochthonous case of cystic echinococcosis in central Mexico

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    Echinococcosis is a frequent hepatic parasitic disease in several countries but it is practically absent in Mexico. A cattle strain of Echinococcus granulosus was identified by RAPD, PCR-RFLP and mitochondrial CO1 gene analysis in an autochthonous case. The parasite was obtained after a laparoscopic excision of a liver cyst from a patient that was symptomatic for 6 years but mis-diagnosed before hospitalization
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