Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic

Interactions of magnesia castables used in steelmaking with calcium aluminate slag

Slag penetration into a magnesia refractory castable was investigated by the crucible test method. A synthetic calcium aluminate slag system has been used to corrode a commercial magnesia mix refractory for 1, 2, 3, 4, 5 and 6 h at 1450°C and 1600°C. It has been shown that the penetration rate was controlled by a diffusion mechanism at 1450°C, capillaries being the main channels of initial slag penetration into the refractory. In the penetration process, calcium silicate was formed on the surfaces of MgO grains, and around them by reaction between the grain boundary and mayenite, as a main phase of slag with a low melting point. Dissolution of the refractory components in the slag supported the penetration process at 1600°C. In this case, dissolution of the refractory components in the slag not only makes new open channels, but also changes the local slag composition, resulting in a decrease of viscosity and an increase of surface tension of the sla

Design and development of an ingenious cricket ball decorative stitching machine

231-234This paper presents an ingenious cricket ball decorative stitching machine, developed by CMERI, Durgapur, which provides simultaneous stitching of two parallel rows on each hemispherical leather cup of cricket ball. A unique dual needlelooper arrangement of chain stitching is developed for decorative stitching on curved surface of hemispherical leather cup. Salient design features and working principle of ball holding and indexing mechanism are discussed. Operation of motor drives, optical interrupter type sensor, and encoder are synchronized and automated by micro-controller with programmable and erasable memory. Machine tested successfully and will produce better quality cricket balls in less time than manual stitching

Recycling end-of-life waste materials as resources in EAF steelmaking - fundamentals of high temperature reactions and industrial implementations

The steel industry consumes a large amount of energy GHG emissions. Rubber tires and agricultural wastes have the potential to be used in industries seeking alternative fuel and sustainable raw materials sources. Previous studies focused on recycling these materials as fuel resources, i.e. rubber in cement industry and agricultural materials for power production. The present paper focuses on investigations of carbon /slag reactions, namely slag foaming using rubber and palm shell wastes as sustainable carbon sources through quantitative estimation of the slag volume. An improved volume ratio for the rubber blend compared to coke was seen. Foaming was also improved when palm shell char was used as carbon material. Industrial implementations at OneSteel showed reductions in electrical energy and carbon consumption. These results indicate that partial replacement of coke with rubber and palm shell is efficient due to improved interactions with EAF slag

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The power of steelmaking-harnessing high-temperature reactions to transform waste into raw material resources

Iron- and steelmaking processes present a largely untapped opportunity to transform some of the world's most problematic waste streams into raw materials for production. This opportunity lies in their high-temperature environments, which offer sustainable pathways for utilizing chemical reactions to repurpose waste materials as resources, such as reducing iron oxide to iron and dissolving the carbon in waste materials into metal. High- Temperature environments can be leveraged to revolutionize the role steelmakers play in globally significant, large-scale recycling, without making fundamental changes to manufacturing processes. This presentation describes the broad opportunities available to iron- and steelmakers to utilize waste streams - ranging from polymeric materials to agricultural wastes - as raw materials. The potential to implement such novel recycling solutions are not generally available to many other materials industries because they operate at relatively lower temperatures, which may not be suitable for triggering useful chemical transformations. Recycling waste polymeric materials in steelmaking is one solution for end-of-life products, which currently impose a serious burden on overstretched landfills, as is the case with some plastics. Specifically, this lecture presents fundamental understanding of different plastic wastes - melamine, high-density polyethylene, polycarbonate and Bakelite, as well as agricultural waste and tires - and their transformations and chemical reactions at high temperatures. Plant results from EAF steelmaking in Sydney, Australia, where recycling waste is now standard practice, will also be included