33 research outputs found
Improving Commercial Motor Bike Rim Disc Hardness Using a Continuous-Wave Infrared Fibre Laser
This study is focused on examining the feasibility of applying laser hardening to a commercial metallic bike rim, employing a CW IR fibre laser. The research comprises two main phases. The first phase involves an assessment of the impact of laser parameters on the metallic microstructure, while the second phase involves the actual laser hardening of the bike rim. A comprehensive evaluation encompassing hardness measurements, optical microscopy, and scanning electron microscopy was conducted on the samples. The microstructure type can be manipulated by skilfully adjusting the laser parameters, allowing for the creation of various microstructure variants within the laser-hardened zone for specific laser conditions. In this regard, multiple microstructure types were observed. The hardness of the laser-processed zones exhibited variations corresponding to the specific microstructure. Notably, the molten zone (MZ) and the second heat-affected zone (HAZ II) exhibited the highest levels of hardness. Furthermore, it was observed that a scan overlap of โฅ 75% led to an augmentation in hardness. This study sheds light on the intricate interplay between laser parameters, microstructure, and resultant hardness in the context of laser hardening of metallic materials
A Calorimetric Characterization of Cr(VI)-Reducing Arthrobacter oxydans
This is the first of a series of calorimetric studies designed to characterize and understand survival mechanisms of metal-reducing bacteria isolated from metal-polluted environments. In this paper we introduce a new concept of thermal spectrum of the endothermic melting of complex biological systems (e.g., proteins, nucleic acids, ribosomes, membrane structures) in intact cells. All thermal spectra measured are thermograms that describe the temperature dependence of heat capacity change of the complex systems of biologically active substances in bacterial cells. This new concept of thermal spectrum was applied to investigate spectral features from intact cells of Cr(VI)-reducer Arthrobacter oxydans at different points of their growth conditions and stages. Over the temperature range of 40โ105ยฐC, we observed that spectral changes are particularly significant in the 40โ90ยฐC interval. This may correspond to the orderly changes in subcellular structural elements: proteins, ribosomes and RNA, membranes, and various structural elements of the cell wall during different points of the growth cycle and growth conditions. Spectral changes in the 90โ105ยฐC region are less pronounced, implicating that the structural composition of DNA-Protein (DNP) complexes may change little
Immunoglobulin, glucocorticoid, or combination therapy for multisystem inflammatory syndrome in children: a propensity-weighted cohort study
Background: Multisystem inflammatory syndrome in children (MIS-C), a hyperinflammatory condition associated with SARS-CoV-2 infection, has emerged as a serious illness in children worldwide. Immunoglobulin or glucocorticoids, or both, are currently recommended treatments. Methods: The Best Available Treatment Study evaluated immunomodulatory treatments for MIS-C in an international observational cohort. Analysis of the first 614 patients was previously reported. In this propensity-weighted cohort study, clinical and outcome data from children with suspected or proven MIS-C were collected onto a web-based Research Electronic Data Capture database. After excluding neonates and incomplete or duplicate records, inverse probability weighting was used to compare primary treatments with intravenous immunoglobulin, intravenous immunoglobulin plus glucocorticoids, or glucocorticoids alone, using intravenous immunoglobulin as the reference treatment. Primary outcomes were a composite of inotropic or ventilator support from the second day after treatment initiation, or death, and time to improvement on an ordinal clinical severity scale. Secondary outcomes included treatment escalation, clinical deterioration, fever, and coronary artery aneurysm occurrence and resolution. This study is registered with the ISRCTN registry, ISRCTN69546370. Findings: We enrolled 2101 children (aged 0 months to 19 years) with clinically diagnosed MIS-C from 39 countries between June 14, 2020, and April 25, 2022, and, following exclusions, 2009 patients were included for analysis (median age 8ยท0 years [IQR 4ยท2โ11ยท4], 1191 [59ยท3%] male and 818 [40ยท7%] female, and 825 [41ยท1%] White). 680 (33ยท8%) patients received primary treatment with intravenous immunoglobulin, 698 (34ยท7%) with intravenous immunoglobulin plus glucocorticoids, 487 (24ยท2%) with glucocorticoids alone; 59 (2ยท9%) patients received other combinations, including biologicals, and 85 (4ยท2%) patients received no immunomodulators. There were no significant differences between treatments for primary outcomes for the 1586 patients with complete baseline and outcome data that were considered for primary analysis. Adjusted odds ratios for ventilation, inotropic support, or death were 1ยท09 (95% CI 0ยท75โ1ยท58; corrected p value=1ยท00) for intravenous immunoglobulin plus glucocorticoids and 0ยท93 (0ยท58โ1ยท47; corrected p value=1ยท00) for glucocorticoids alone, versus intravenous immunoglobulin alone. Adjusted average hazard ratios for time to improvement were 1ยท04 (95% CI 0ยท91โ1ยท20; corrected p value=1ยท00) for intravenous immunoglobulin plus glucocorticoids, and 0ยท84 (0ยท70โ1ยท00; corrected p value=0ยท22) for glucocorticoids alone, versus intravenous immunoglobulin alone. Treatment escalation was less frequent for intravenous immunoglobulin plus glucocorticoids (OR 0ยท15 [95% CI 0ยท11โ0ยท20]; p<0ยท0001) and glucocorticoids alone (0ยท68 [0ยท50โ0ยท93]; p=0ยท014) versus intravenous immunoglobulin alone. Persistent fever (from day 2 onward) was less common with intravenous immunoglobulin plus glucocorticoids compared with either intravenous immunoglobulin alone (OR 0ยท50 [95% CI 0ยท38โ0ยท67]; p<0ยท0001) or glucocorticoids alone (0ยท63 [0ยท45โ0ยท88]; p=0ยท0058). Coronary artery aneurysm occurrence and resolution did not differ significantly between treatment groups. Interpretation: Recovery rates, including occurrence and resolution of coronary artery aneurysms, were similar for primary treatment with intravenous immunoglobulin when compared to glucocorticoids or intravenous immunoglobulin plus glucocorticoids. Initial treatment with glucocorticoids appears to be a safe alternative to immunoglobulin or combined therapy, and might be advantageous in view of the cost and limited availability of intravenous immunoglobulin in many countries. Funding: Imperial College London, the European Union's Horizon 2020, Wellcome Trust, the Medical Research Foundation, UK National Institute for Health and Care Research, and National Institutes of Health
Immunoglobulin, glucocorticoid, or combination therapy for multisystem inflammatory syndrome in children: a propensity-weighted cohort study
Background Multisystem inflammatory syndrome in children (MIS-C), a hyperinflammatory condition associated with SARS-CoV-2 infection, has emerged as a serious illness in children worldwide. Immunoglobulin or glucocorticoids, or both, are currently recommended treatments. Methods The Best Available Treatment Study evaluated immunomodulatory treatments for MIS-C in an international observational cohort. Analysis of the first 614 patients was previously reported. In this propensity-weighted cohort study, clinical and outcome data from children with suspected or proven MIS-C were collected onto a web-based Research Electronic Data Capture database. After excluding neonates and incomplete or duplicate records, inverse probability weighting was used to compare primary treatments with intravenous immunoglobulin, intravenous immunoglobulin plus glucocorticoids, or glucocorticoids alone, using intravenous immunoglobulin as the reference treatment. Primary outcomes were a composite of inotropic or ventilator support from the second day after treatment initiation, or death, and time to improvement on an ordinal clinical severity scale. Secondary outcomes included treatment escalation, clinical deterioration, fever, and coronary artery aneurysm occurrence and resolution. This study is registered with the ISRCTN registry, ISRCTN69546370. Findings We enrolled 2101 children (aged 0 months to 19 years) with clinically diagnosed MIS-C from 39 countries between June 14, 2020, and April 25, 2022, and, following exclusions, 2009 patients were included for analysis (median age 8ยท0 years [IQR 4ยท2โ11ยท4], 1191 [59ยท3%] male and 818 [40ยท7%] female, and 825 [41ยท1%] White). 680 (33ยท8%) patients received primary treatment with intravenous immunoglobulin, 698 (34ยท7%) with intravenous immunoglobulin plus glucocorticoids, 487 (24ยท2%) with glucocorticoids alone; 59 (2ยท9%) patients received other combinations, including biologicals, and 85 (4ยท2%) patients received no immunomodulators. There were no significant differences between treatments for primary outcomes for the 1586 patients with complete baseline and outcome data that were considered for primary analysis. Adjusted odds ratios for ventilation, inotropic support, or death were 1ยท09 (95% CI 0ยท75โ1ยท58; corrected p value=1ยท00) for intravenous immunoglobulin plus glucocorticoids and 0ยท93 (0ยท58โ1ยท47; corrected p value=1ยท00) for glucocorticoids alone, versus intravenous immunoglobulin alone. Adjusted average hazard ratios for time to improvement were 1ยท04 (95% CI 0ยท91โ1ยท20; corrected p value=1ยท00) for intravenous immunoglobulin plus glucocorticoids, and 0ยท84 (0ยท70โ1ยท00; corrected p value=0ยท22) for glucocorticoids alone, versus intravenous immunoglobulin alone. Treatment escalation was less frequent for intravenous immunoglobulin plus glucocorticoids (OR 0ยท15 [95% CI 0ยท11โ0ยท20]; p<0ยท0001) and glucocorticoids alone (0ยท68 [0ยท50โ0ยท93]; p=0ยท014) versus intravenous immunoglobulin alone. Persistent fever (from day 2 onward) was less common with intravenous immunoglobulin plus glucocorticoids compared with either intravenous immunoglobulin alone (OR 0ยท50 [95% CI 0ยท38โ0ยท67]; p<0ยท0001) or glucocorticoids alone (0ยท63 [0ยท45โ0ยท88]; p=0ยท0058). Coronary artery aneurysm occurrence and resolution did not differ significantly between treatment groups. Interpretation Recovery rates, including occurrence and resolution of coronary artery aneurysms, were similar for primary treatment with intravenous immunoglobulin when compared to glucocorticoids or intravenous immunoglobulin plus glucocorticoids. Initial treatment with glucocorticoids appears to be a safe alternative to immunoglobulin or combined therapy, and might be advantageous in view of the cost and limited availability of intravenous immunoglobulin in many countries. Funding Imperial College London, the European Union's Horizon 2020, Wellcome Trust, the Medical Research Foundation, UK National Institute for Health and Care Research, and National Institutes of Health
A Brief Overview of Operation of the Cosmophysics Laboratory of M. Nodia Institute of Geophysics, TSU at the Last Period
แฌแแ แแแแแแแแแแ แแกแฃ, แ. แแแแแแก แกแแฎ. แแแแคแแแแแแก แแแกแขแแขแฃแขแแก แแแกแแแคแแแแแฃแ แ แแแแแ แแขแแ แแแก แคแฃแแฅแชแแแแแ แแแแก แแแแ แแแ แแแแแก แแแแแ แแแแแฎแแแแ. แแแแกแแแแแแ, แแแกแแแกแฃแ แ แกแฎแแแแแแก แแแ แแแชแแแแกแ แแ แกแฎแแแแแกแฎแแ แแแแแแขแฃแ แแแ แแแแขแ แแแก แจแแ แแก แแแแจแแ แแก แแแแแแแแ. แแ แแแแแแแแแก แแคแแฅแขแฃแ แแแแก แแแกแแแ แแแแแ แแแแแ แแขแแ แแแจแ แแแแแแแแ แแแแก แแแกแแแกแฃแ แ แกแฎแแแแแแก แแแ แแแแกแขแ แแ แแแแแ แแแแ แแขแฃแ แแก แแแแแฎแแแแ.A brief overview of the latest work of the Cosmophysical Laboratory of M. Nodia Institute of Geophysics, TSU is presented. In addition, studies are being conducted on the relationship between cosmic ray variations and various climatic parameters. In order to increase the efficiency of these studies, the laboratory is upgrading equipment for recording cosmic rays
Change of Heavy Metal Concentration in Surface Waters and Soils of East Georgia Considering the Anthropogenic Impact
แจแแกแฌแแแแแแแ แแฆแแแกแแแแแ แกแแฅแแ แแแแแแก แแแแแแแ แฃแ แฌแงแแแแกแ แแ แแแแแแแแแจแ แแซแแแ แแแแแแแแแก แจแแแชแแแแแแแก แชแแแแแแแแแแ แแแ แแแแแ แแแแ แแแแแแแฃแแ แแแขแแแ แแแแก แแแแแแแแกแฌแแแแแแ 2017-2019 แฌแฌ. แงแฃแ แแแฆแแแ แแแแแฎแแแแแแฃแแแ แแกแแ แแแแแแแแแ, แ แแแแ แแชแแ แกแแแแแแซแ, แขแงแแแ แแ แแแ แชแฎแแ. แแแฉแแแแแแแ, แ แแ แแฆแแแกแแแแแ แกแแฅแแ แแแแแแก แแแแแแแแแจแ แแซแแแ แแแแแแแแแแแ แแ แแแ แแขแแขแฃแแ แแแแแแแแซแฃแ แแแแแ แแแแแแแขแแ แกแแแแแแซแ, แจแแแแแ แขแงแแแ, แฎแแแ แแแ แชแฎแแแก แแแแชแแแขแ แแชแแแแ แฃแแแแจแแแแแแ. แ แแช แจแแแฎแแแ แแซแแแ แแแแแแแแแก แจแแแชแแแแแแแก แฌแงแแแกแแชแแแแแแก แฌแงแแแแจแ, แแกแแแ แแแ แแแก แคแแ แแแแแจแแ แแ แแแแแแซแฃแ แแแแก แแแแแแ แแ แแฅแแก.The concentrations of heavy metals (copper, lead and silver) in the surface waters and soils of eastern Georgia were studied taking into account anthropogenic impact for the period 2017-2019. It is shown, that the priority soil contaminant in eastern Georgia is copper, followed by lead, and silver concentrations are not significant. As for the content of heavy metals in the waters of water bodies, it is within the normal range and does not cause pollution