42 research outputs found

    Silicon carbide particulates incorporated into microalloyed steel surface using TIG: microstructure and properties

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    Surface metal matrix composites have been developed to enhance properties such as erosion, wear and corrosion of alloys. In this study, ~5 ”m or ~75 ”m SiC particulates were preplaced on a microalloyed steel. Single track surface zones were melted by a tungsten inert gas torch, and the effect of two heat inputs, 420Jmm-1 and 840 Jmm-1,compared. The results showed that the samples melted using 420Jmm-1 were crack-free. Pin-on-disk wear testing under dry sliding conditions were conducted. The effects of load and sliding velocity were used to characterise the performance of the crack-free samples. Microstructural and X-ray diffraction studies of the surface showed that the SiC had dissolved, and that martensite, was the main phase influencing the hardness

    International lower limb collaborative (INTELLECT) study: a multicentre, international retrospective audit of lower extremity open fractures

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    Trauma remains a major cause of mortality and disability across the world1, with a higher burden in developing nations2. Open lower extremity injuries are devastating events from a physical3, mental health4, and socioeconomic5 standpoint. The potential sequelae, including risk of chronic infection and amputation, can lead to delayed recovery and major disability6. This international study aimed to describe global disparities, timely intervention, guideline-directed care, and economic aspects of open lower limb injuries

    KrĂŒppel-like factor 6 is a transcriptional activator of autophagy in acute liver injury

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    Kruppel-like factor 6 (KLF6) is a transcription factor and tumor suppressor. We previously identified KLF6 as mediator of hepatocyte glucose and lipid homeostasis. The loss or reduction of KLF6 is linked to the progression of hepatocellular carcinoma, but its contribution to liver regeneration and repair in acute liver injury are lacking so far. Here we explore the role of KLF6 in acute liver injury models in mice, and in patients with acute liver failure (ALF). KLF6 was induced in hepatocytes in ALF, and in both acetaminophen (APAP)- and carbon tetrachloride (CCl4)- treated mice. In mice with hepatocytespecific Klf6 knockout (DeltaKlf6), cell proliferation following partial hepatectomy (PHx) was increased compared to controls. Interestingly, key autophagic markers and mediators LC3-II, Atg7 and Beclin1 were reduced in DeltaKlf6 mice livers. Using luciferase assay and ChIP, KLF6 was established as a direct transcriptional activator of ATG7 and BECLIN1, but was dependent on the presence of p53. Here we show, that KLF6 expression is induced in ALF and in the regenerating liver, where it activates autophagy by transcriptional induction of ATG7 and BECLIN1 in a p53-dependent manner. These findings couple the activity of an important growth inhibitor in liver to the induction of autophagy in hepatocytes

    Influence of cutting environments on surface integrity and power consumption of austenitic stainless steel

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    Surface roughness is a result of the cutting parameters such as: cutting speed, feed per tooth and the axial depth of cut, also the tool’s geometry, tool’s wear vibrations, etc. Moreover, the surface finish influences mechanical properties such as fatigue behaviour, wear, corrosion, lubrication and electrical conductivity and the combination of cutting parameters influence the power consumption during the machining process affecting the environment. The research reported herein is focused mainly on searching for an optimum combination of cutting parameters to obtain a low value of surface roughness and minimize energy consumption when milling an austenitic stainless steel in different cutting environments. The experiments were conducted on a Siemens 840D Bridgeport Vertical Machining Centre 610XP2. The selection of this workpiece material was based on it’s widely applications in cutlery, surgical instruments, industrial equipment and in the automotive and aerospace industry due to its high corrosion resistance and high strength characteristics. The results show that the dry cutting environment is the best option in terms of power consumption and surface roughness values to conduct the milling of an austenitic stainless steel under the selected cutting parameters
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