19 research outputs found

    Method for machining holes in composite materials

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    A method for boring well defined holes in a composite material such as graphite/epoxy is discussed. A slurry of silicon carbide powder and water is projected onto a work area of the composite material in which a hole is to be bored with a conventional drill bit. The silicon carbide powder and water slurry allow the drill bit, while experiencing only normal wear, to bore smooth, cylindrical holes in the composite material

    Modelling esophageal adenocarcinoma and Barrett’s esophagus with patient-derived organoids

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    Currently, esophageal adenocarcinoma (EAC) research is hindered by a dearth of adequate models to study this disease. Traditional cell line and genetically engineered mouse models are lacking in biological and physiological significance, whilst the inefficiency of patient-derived xenografts limit their potential applications. This review describes the landscape of EAC research using patient-derived organoids (PDOs). Here, we detail the methods of establishment and optimization of EAC PDO cultures, as well as current and prospective applications of these models. We further highlight a crucial knowledge gap in the mechanisms of EAC transformation from its precursor lesion, Barrett’s esophagus (BE). As such, we also describe the culture requirements of BE PDOs and attempts to model tumorigenesis using PDO models

    Ribosome Binding of a Single Copy of the SecY Complex: Implications for Protein Translocation

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    The SecY complex associates with the ribosome to form a protein translocation channel in the bacterial plasma membrane. We have used cryo-electron microscopy and quantitative mass spectrometry to show that a nontranslating E. coli ribosome binds to a single SecY complex. The crystal structure of an archaeal SecY complex was then docked into the electron density maps. In the resulting model, two cytoplasmic loops of SecY extend into the exit tunnel near proteins L23, L29, and L24. The loop between transmembrane helices 8 and 9 interacts with helices H59 and H50 in the large subunit RNA, while the 6/7 loop interacts with H7. We also show that point mutations of basic residues within either loop abolish ribosome binding. We suggest that SecY binds to this primary site on the ribosome and subsequently captures and translocates the nascent chain

    Ribosome Binding of a Single Copy of the SecY Complex: Implications for Protein Translocation

    Get PDF
    The SecY complex associates with the ribosome to form a protein translocation channel in the bacterial plasma membrane. We have used cryo-electron microscopy and quantitative mass spectrometry to show that a nontranslating E. coli ribosome binds to a single SecY complex. The crystal structure of an archaeal SecY complex was then docked into the electron density maps. In the resulting model, two cytoplasmic loops of SecY extend into the exit tunnel near proteins L23, L29, and L24. The loop between transmembrane helices 8 and 9 interacts with helices H59 and H50 in the large subunit RNA, while the 6/7 loop interacts with H7. We also show that point mutations of basic residues within either loop abolish ribosome binding. We suggest that SecY binds to this primary site on the ribosome and subsequently captures and translocates the nascent chain

    Molecular identification of clinical and environmental avian Aspergillus isolates

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    Aspergillosis causes high morbidity and mortality in avian species. The main goal of this study was to use molecular techniques to identify Aspergillus species collected from different avian species with aspergillosis. A subsample of those isolates was also screened for resistance to itraconazole. Over a 2-year period, clinical samples were recovered from 44 birds with clinical signs of the disease, clinical pathology results suspicious of aspergillosis, or from birds that died from Aspergillus spp. infection. Environmental sampling was also performed in seabird rehabilitation centers and natural seabird environments. Seventy-seven isolates (43 clinical and 34 environmental) were identified as Aspergillus fumigatus sensu stricto. No cryptic species from the Fumigati section were detected. Two environmental isolates were identified as Aspergillus nidulans var. dentatus and Aspergillus spinulosporus. None of the Aspergillus isolates tested were resistant to itraconazole. Our study emphasizes the dominant association of Aspergillus fumigatus sensu stricto in avian mycoses and shows the lack of itraconazole resistance in the studied isolates.info:eu-repo/semantics/publishedVersio

    Coping strategies to prevent or reduce stress and burnout among oncology physicians: a systematic review

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    The purpose of this systematic review (SR) was to identify interventions that are effective to prevent or reduce stress and burnout among oncologists. Search was conducted in eight electronic databases and grey literature databases, with no language or time restrictions. Included studies involved medical oncologists and contained interventions to prevent or deal with stress or burnout with outcomes assessment. In two selection phases process, 19 out of 3,020 studies were included. Risk of bias was low for nine studies, moderate for six studies and high for four ones. Certainty of evidence was considered low and very low for the analyzed outcomes. Interventions varied a lot and those which had a significant effect in stress and burnout reduction among oncologists were experience sharing between female doctors in virtual groups, integrative meetings outside the work environment, and team sessions supervised by counselors. Although interventions had variable effects on reducing or preventing burnout and stress, mores studies are needed due to outcomes low evidence

    Using age compositions derived from spatio-temporal models and acoustic data collected by uncrewed surface vessels to estimate Pacific hake (Merluccius productus) biomass-at-age

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    Generating biomass-at-age indices for fisheries stock assessments with acoustic data collected by uncrewed surface vessels (USVs) has been hampered by the need to resolve acoustic backscatter with contemporaneous biological (e.g., age) composition data. To address this limitation, Pacific hake (Merluccius productus; “hake”) acoustic data were gathered from a USV survey (in 2019) and acoustic-trawl survey (ATS; 2019 and eight previous years), and biological data were gathered from fishery-dependent and non-target (i.e., not specifically targeting hake) fishery-independent sources (2019 and eight previous years). To overcome the lack of contemporaneous biological sampling in the USV survey, age class compositions were estimated from a generalized linear mixed spatio-temporal model (STM) fit to the fishery-dependent and non-target fishery-independent data. The validity of the STM age composition estimation procedure was assessed by comparing estimates to age compositions from the ATS in each year. Hake biomass-at-age was estimated from all combinations of acoustics (USV or ATS in 2019, ATS only in other years) and age composition information (STM or ATS in all years). Across the survey area, proportional age class compositions derived from the best STM differed from ATS observations by 0.09 on average in 2019 (median relative error (MRE): 19.45%) and 0.14 across all years (MRE: 79.03%). In data-rich areas (i.e., areas with regular fishery operations), proportional age class compositions from the STM differed from ATS observations by 0.03 on average in 2019 (MRE: 11.46%) and 0.09 across years (MRE: 54.96%). On average, total biomass estimates derived using STM age compositions differed from ATS age composition-based estimates by approximately 7% across the study period (~ 3% in 2019) given the same source of acoustic data. When biomass estimates from different sources of acoustic data (USV or ATS) were compared given the same source of age composition data, differences were nearly ten-fold greater (22% or 27%, depending on if ATS or STM age compositions were used). STMs fit to non-contemporaneous data may provide suitable information for assigning population structure to acoustic backscatter in data-rich areas, but advancements in acoustic data processing (e.g., automated echo classification) may be needed to generate viable USV-based estimates of biomass-at-age
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