1,445 research outputs found

    Thermomechanical Modeling of Welding and Galvanizing a Steel Beam Connection Detail to Examine Susceptibility to Cracking

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    Hot-dip galvanizing is the process of submerging steel elements into molten zinc to form a metallurgically bonded zinc coating that serves as corrosion protection for the steel substrate. Used with great success on an industrial scale for many decades, hot-dip galvanizing is a ubiquitous process. On occasion, cracks in steel members develop during galvanizing. While such cracking remains a poorly understood phenomenon, previous research has attributed the formation of cracks to the combined effects of residual strains introduced by welding and temperature-induced deformations caused by the hot-dip galvanizing process. This article presents thermomechanical analyses of a structural steel beam with a welded double-angle connection detail where cracking occurred during hot-dip galvanizing. Three-dimensional finite element models of the beam and connection detail were analyzed using the finite element analysis software Abaqus (Dassault Systèmes, Vélizy-Villacoublay, France). The welding process was simulated using the Abaqus Welding Interface, maintaining the welding sequence of the connection. After welding, the entire beam was subjected to a temperature field that was specified through a user subroutine in Abaqus, simulating the hot-dip galvanizing process. The temperature field had a bath temperature of 450°C and a thermal cycle that included dipping, dwell time, and removal from the bath. Material properties used in the simulation were nonlinear and temperature dependent. The parameters of the study were the welding sequences, heat input during welding, and the depth of the double-angle connection. It was observed that strain demands due to welding and hot-dip galvanizing were high magnitude at the cracked location in the beam. The relative significance of strain demands due to welding and of hot-dip galvanizing on the propensity for the beam to develop cracks are discussed

    Perceived status threat and the health of white Americans: Scoping review protocol

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    Pre-COVID-19 pandemic rising white mortality in the United States is not explained by traditional social and economic population health indicators, suggesting that white Americans’ perceived decline in relative status is a determinant of increases in white mortality. Not only does the mechanism of status threat explain white Americans’ widespread support for many of the racist views and policies propagated by the Trump Administration, social scientists have found that status threat is also related to declines in whites’ health at the population level. Because white Americans’ social and political beliefs can affect health at the population level, it is critically important to capture emerging literature concerning whites’ perceived status threat. The goal of this project is to document what is currently known about status threat in the social and medical sciences, and to synthesize how status threat influences white Americans’ health and health behaviors. This protocol details the methods we will use to explore how status threat has been measured across disciplines so that we can summarize current literature, identify gaps in the existing knowledge base, and inform directions for future research on the topic

    Osteoprotegerin reduces the development of pain behaviour and joint pathology in a model of osteoarthritis

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    Acknowledgements: OPG-Fc was a kind gift from Amgen Ltd. Funding: This work was supported by Arthritis Research UK, grant number 18769Peer reviewedPublisher PD

    Photochemistry of Furyl- and Thienyldiazomethanes: Spectroscopic Characterization of Triplet 3-Thienylcarbene

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    Photolysis (λ \u3e 543 nm) of 3-thienyldiazomethane (1), matrix isolated in Ar or N2 at 10 K, yields triplet 3-thienylcarbene (13) and α-thial-methylenecyclopropene (9). Carbene 13 was characterized by IR, UV/vis, and EPR spectroscopy. The conformational isomers of 3-thienylcarbene (s-E and s-Z) exhibit an unusually large difference in zero-field splitting parameters in the triplet EPR spectrum (|D/hc| = 0.508 cm–1, |E/hc| = 0.0554 cm–1; |D/hc| = 0.579 cm–1, |E/hc| = 0.0315 cm–1). Natural Bond Orbital (NBO) calculations reveal substantially differing spin densities in the 3-thienyl ring at the positions adjacent to the carbene center, which is one factor contributing to the large difference in D values. NBO calculations also reveal a stabilizing interaction between the sp orbital of the carbene carbon in the s-Z rotamer of 13 and the antibonding σ orbital between sulfur and the neighboring carbon—an interaction that is not observed in the s-E rotamer of 13. In contrast to the EPR spectra, the electronic absorption spectra of the rotamers of triplet 3-thienylcarbene (13) are indistinguishable under our experimental conditions. The carbene exhibits a weak electronic absorption in the visible spectrum (λmax = 467 nm) that is characteristic of triplet arylcarbenes. Although studies of 2-thienyldiazomethane (2), 3-furyldiazomethane (3), or 2-furyldiazomethane (4) provided further insight into the photochemical interconversions among C5H4S or C5H4O isomers, these studies did not lead to the spectroscopic detection of the corresponding triplet carbenes (2-thienylcarbene (11), 3-furylcarbene (23), or 2-furylcarbene (22), respectively)

    The role of the genetic counsellor: a systematic review of research evidence

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    In Europe, genetic counsellors are employed in specialist genetic centres or other specialist units. According to the European Board of Medical Genetics, the genetic counsellor must fulfil a range of roles, including provision of information and facilitation of psychosocial adjustment of the client to their genetic status and situation. To evaluate the extent to which genetic counsellors fulfil their prescribed roles, we conducted a systematic review of the published relevant scientific evidence. We searched five relevant electronic databases (Medline, CINAHL, SocIndex, AMED and PsychInfo) using relevant search terms and handsearched four subject-specific journals for research-based papers published in English between 1 January 2000 and 30 June 2013. Of 419 potential papers identified initially, seven satisfied the inclusion criteria for the review. Themes derived from the thematic analysis of the data were: (i) rationale for genetic counsellors to provide care, (ii) appropriate roles and responsibilities and (iii) the types of conditions included in the genetic counsellor caseload. The findings of this systematic review indicate that where genetic counsellors are utilised in specialist genetic settings, they undertake a significant workload associated with direct patient care and this appears to be acceptable to patients. With the burden on genetic services, there is an argument for the increased use of genetic counsellors in countries where they are under-utilised. In addition, roles undertaken by genetic counsellors in specialist genetic settings could be adapted to integrate genetic counsellors into multi-disciplinary teams in other specialisms

    A prospective cohort study assessing clinical referral management & workforce allocation within a UK regional medical genetics service

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    Abstract Ensuring patient access to genomic information in the face of increasing demand requires clinicians to develop innovative ways of working. This paper presents the first empirical prospective observational cohort study of UK multi-disciplinary genetic service delivery. It describes and explores collaborative working practices including the utilisation and role of clinical geneticists and non-medical genetic counsellors. Six hundred and fifty new patients referred to a regional genetics service were tracked through 850 clinical contacts until discharge. Referral decisions regarding allocation of lead health professional assigned to the case were monitored, including the use of initial clinical contact guidelines. Significant differences were found in the cases led by genetic counsellors and those led by clinical geneticists. Around a sixth, 16.8% (109/650) of referrals were dealt with by a letter back to the referrer or re-directed to another service provider and 14.8% (80/541) of the remaining patients chose not to schedule an appointment. Of the remaining 461 patients, genetic counsellors were allocated as lead health professional for 46.2% (213/461). A further 61 patients did not attend. Of those who did, 86% (345/400) were discharged after one or two appointments. Genetic counsellors contributed to 95% (784/825) of total patient contacts. They provided 93.7% (395/432) of initial contacts and 26.8% (106/395) of patients were discharged at that point. The information from this study informed a planned service re-design. More research is needed to assess the effectiveness and efficiency of different models of collaborative multi-disciplinary working within genetics services. Keywords (MeSH terms) Genetic Services, Genetic Counseling, Interdisciplinary Communication, Cohort Studies, Delivery of Healthcare, Referral and Consultation

    Biomolecular Detection employing the Interferometric Reflectance Imaging Sensor (IRIS)

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    The sensitive measurement of biomolecular interactions has use in many fields and industries such as basic biology and microbiology, environmental/agricultural/biodefense monitoring, nanobiotechnology, and more. For diagnostic applications, monitoring (detecting) the presence, absence, or abnormal expression of targeted proteomic or genomic biomarkers found in patient samples can be used to determine treatment approaches or therapy efficacy. In the research arena, information on molecular affinities and specificities are useful for fully characterizing the systems under investigation

    Pharyngeal carriage of Neisseria species in the African meningitis belt.

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    OBJECTIVES: Neisseria meningitidis, together with the non-pathogenic Neisseria species (NPNs), are members of the complex microbiota of the human pharynx. This paper investigates the influence of NPNs on the epidemiology of meningococcal infection. METHODS: Neisseria isolates were collected during 18 surveys conducted in six countries in the African meningitis belt between 2010 and 2012 and characterized at the rplF locus to determine species and at the variable region of the fetA antigen gene. Prevalence and risk factors for carriage were analyzed. RESULTS: A total of 4694 isolates of Neisseria were obtained from 46,034 pharyngeal swabs, a carriage prevalence of 10.2% (95% CI, 9.8-10.5). Five Neisseria species were identified, the most prevalent NPN being Neisseria lactamica. Six hundred and thirty-six combinations of rplF/fetA_VR alleles were identified, each defined as a Neisseria strain type. There was an inverse relationship between carriage of N. meningitidis and of NPNs by age group, gender and season, whereas carriage of both N. meningitidis and NPNs was negatively associated with a recent history of meningococcal vaccination. CONCLUSION: Variations in the prevalence of NPNs by time, place and genetic type may contribute to the particular epidemiology of meningococcal disease in the African meningitis belt.MenAfriCar was funded by the Wellcome Trust (086546/Z/08/Z) and the Bill and Melinda Gates Foundation (51251). Kanny Diallo holds a Wellcome Trust Training Fellowship in Public Health and Tropical Medicine.This is the final version of the article. It first appeared from Elsevier via https://doi.org/10.1016/j.jinf.2016.03.01

    “How Long Have I Got?”—A Prospective Cohort Study Comparing Validated Prognostic Factors for Use in Patients with Advanced Cancer

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    © AlphaMed Press 2019 Background: The optimal prognostic factors in patients with advanced cancer are not known, as a comparison of these is lacking. The aim of the present study was to determine the optimal prognostic factors by comparing validated factors. Materials and Methods: A multicenter, prospective observational cohort study recruited patients over 18 years with advanced cancer. The following were assessed: clinician-predicted survival (CPS), Eastern Cooperative Oncology Group performance status (ECOG-PS), patient reported outcome measures (anorexia, cognitive impairment, dyspnea, global health), metastatic disease, weight loss, modified Glasgow Prognostic Score (mGPS) based on C-reactive protein and albumin, lactate dehydrogenase (LDH), and white (WCC), neutrophil (NC), and lymphocyte cell counts. Survival at 1 and 3 months was assessed using area under the receiver operating curve and logistic regression analysis. Results: Data were available on 478 patients, and the median survival was 4.27 (1.86–7.03) months. On univariate analysis, the following factors predicted death at 1 and 3 months: CPS, ECOG-PS, mGPS, WCC, NC (all

    Novel sampling method for assessing human-pathogen interactions in the natural environment using boot socks and citizen scientists, with application to Campylobacter seasonality

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    This paper introduces a novel method for sampling pathogens in natural environments. It uses fabric boot socks worn over walkers' shoes to allow the collection of composite samples over large areas. Wide-area sampling is better suited to studies focusing on human exposure to pathogens (e.g., recreational walking). This sampling method is implemented using a citizen science approach: groups of three walkers wearing boot socks undertook one of six routes, 40 times over 16 months in the North West (NW) and East Anglian (EA) regions of England. To validate this methodology, we report the successful implementation of this citizen science approach, the observation that Campylobacter bacteria were detected on 47% of boot socks, and the observation that multiple boot socks from individual walks produced consistent results. The findings indicate higher Campylobacter levels in the livestock-dominated NW than in EA (55.8% versus 38.6%). Seasonal differences in the presence of Campylobacter bacteria were found between the regions, with indications of winter peaks in both regions but a spring peak in the NW. The presence of Campylobacter bacteria on boot socks was negatively associated with ambient temperature (P = 0.011) and positively associated with precipitation (P < 0.001), results consistent with our understanding of Campylobacter survival and the probability of material adhering to boot socks. Campylobacter jejuni was the predominant species found; Campylobacter coli was largely restricted to the livestock-dominated NW. Source attribution analysis indicated that the potential source of C. jejuni was predominantly sheep in the NW and wild birds in EA but did not differ between peak and nonpeak periods of human incidence
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