99 research outputs found

    Effect of Partial Replacement of Slag and Nano Silica Infused Slag on Properties of Concrete

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    Investigations were carried out on the changes in properties of concrete when steel slag is used in concrete in its normal form and after modifying its properties by infusing it with nano-silica. The sand is replaced by steel slag and modified steel slag by 10%, 20% and 30% in M30 grade concrete. Tests results on compressive strength and workability of concrete revealed that compressive strength of concrete cubes after 28 days increased by 25.4%, 26.4% and 45.2% for 10%, 20% and 30% respectively after replacing sand by steel slag. After modification of steel slag properties by infusing it with nano silica, the 28 days compressive strength was observed to be increased by 38.19%, 35.80% and 27.89% for 10%, 20% and 30% as compared to traditional concrete mix respectively after replacement. Infusing steel slag with nano silica increased the compressive strength of concrete mix by 20.17%, 25.74% and 49.64% for 10%, 20% and 30% respectively when compared to normal steel slag concrete mix. It was also observed that using steel slag in concrete mix also influences on water consumption in concrete mix. Workability tests conducted using 0.45 and 0.5 w/c ratio and the inference was that the workability increased with the increase in percentage of steel slag but workability decreases with the increase in percentage of modified steel slag

    MoS2-graphene-CuNi2S4 nanocomposite an efficient electrocatalyst for the hydrogen evolution reaction

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    We present a facile methodology for the synthesis of a novel 2D-MoS2, graphene and CuNi2S4 (MoS2-g-CuNi2S4) nanocomposite that displays highly efficient electrocatalytic activity towards the production of hydrogen. The intrinsic hydrogen evolution reaction (HER) activity of MoS2 nanosheets was significantly enhanced by increasing the affinity of the active edge sites towards HĂľ adsorption using transition metal (Cu and Ni2) dopants, whilst also increasing the edge sites exposure by anchoring them to a graphene frame- work. Detailed XPS analysis reveals a higher percentage of surface exposed S at 17.04%, of which 48.83% is metal bonded S (sulfide). The resultant MoS2-g-CuNi2S4 nanocomposites are immobilized upon screen-printed electrodes (SPEs) and exhibit a HER onset potential and Tafel slope value of -0.05 V (vs. RHE) and 29.3 mV dec-1, respectively. These values are close to that of the polycrystalline Pt electrode (near zero potential (vs. RHE) and 21.0 mV dec-1, respectively) and enhanced over a bare/unmodified SPE (-0.43 V (vs. RHE) and 149.1 mV dec-1, respectively). Given the efficient, HER activity displayed by the novel MoS2-g-CuNi2S4/SPE electrochemical platform and the comparatively low associated cost of production for this nanocomposite, it has potential to be a cost-effective alternative to Pt within electrolyser technologies

    Bowel ischaemia in COVID-19 infection: a scoping review protocol

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    Introduction: COVID-19 disease was declared as a pandemic by WHO since March 2020 and can have a myriad of clinical presentations affecting various organ systems. Patients with COVID-19 are known to have an increased risk of thromboembolism, including cardiovascular, pulmonary and cerebral ischaemic events. However, an increasing number of case studies have reported that COVID-19 infection is also associated with gastrointestinal ischaemia. This scoping review aims to collate the current evidence of COVID-19-related gastrointestinal ischaemia and raise awareness among healthcare professionals of this lesser known, but serious, non-pulmonary complication of COVID-19 infection. Methods: The proposed scoping review will be conducted as per the Arksey and O’Malley methodological framework (2005) the Joanna Briggs Institute methodology for scoping reviews. A systematic search will be undertaken on different databases including EMBASE, PubMed and MEDLINE. Two independent reviewers will screen titles, abstracts and full-text articles according to the inclusion criteria and extract relevant data from the included articles. Results will be presented in a tabular form with a narrative discussion. Ethics and dissemination: Ethical approval will not be required for this scoping review. This scoping review will provide an extensive overview of the association between COVID-19 infection and bowel ischaemia. Further ethical and methodological challenges will also be discussed in our findings to define a new research agenda. Findings will be disseminated through peer-reviewed publications and presentations at both national and international conferences

    Aberrant epithelial GREM1 expression initiates colonic tumorigenesis from cells outside the stem cell niche

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    Hereditary mixed polyposis syndrome (HMPS) is characterized by the development of mixed-morphology colorectal tumors and is caused by a 40-kb genetic duplication that results in aberrant epithelial expression of the gene encoding mesenchymal bone morphogenetic protein antagonist, GREM1. Here we use HMPS tissue and a mouse model of the disease to show that epithelial GREM1 disrupts homeostatic intestinal morphogen gradients, altering cell fate that is normally determined by position along the vertical epithelial axis. This promotes the persistence and/or reacquisition of stem cell properties in Lgr5-negative progenitor cells that have exited the stem cell niche. These cells form ectopic crypts, proliferate, accumulate somatic mutations and can initiate intestinal neoplasia, indicating that the crypt base stem cell is not the sole cell of origin of colorectal cancer. Furthermore, we show that epithelial expression of GREM1 also occurs in traditional serrated adenomas, sporadic premalignant lesions with a hitherto unknown pathogenesis, and these lesions can be considered the sporadic equivalents of HMPS polyps

    Is There a Place for Dietary Fiber Supplements in Weight Management?

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    Inadequate dietary fiber intake is common in modern diets, especially in children. Epidemiological and experimental evidence point to a significant association between a lack of fiber intake and ischemic heart disease, stroke atherosclerosis, type 2 diabetes, overweight and obesity, insulin resistance, hypertension, dyslipidemia, as well as gastrointestinal disorders such as diverticulosis, irritable bowel disease, colon cancer, and cholelithiasis. The physiological effects of fiber relate to the physical properties of volume, viscosity, and water-holding capacity that the fiber imparts to food leading to important influences over the energy density of food. Beyond these physical properties, fiber directly impacts a complex array of microbiological, biochemical, and neurohormonal effects directly through modification of the kinetics of digestion and through its metabolism into constituents such as short chain fatty acids, which are both energy substrates and important enteroendocrine ligands. Of particular interest to clinicians is the important role dietary fiber plays in glucoregulation, appetite, and satiety. Supplementation of the diet with highly functional fibers may prove to play an important role in long-term obesity management

    Effects of the WHO Labour Care Guide on cesarean section in India: a pragmatic, stepped-wedge, cluster-randomized pilot trial

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    Cesarean section rates worldwide are rising, driven by medically unnecessary cesarean use. The new World Health Organization Labour Care Guide (LCG) aims to improve the quality of care for women during labor and childbirth. Using the LCG might reduce overuse of cesarean; however, its effects have not been evaluated in randomized trials. We conducted a stepped-wedge, cluster-randomized pilot trial in four hospitals in India to evaluate the implementation of an LCG strategy intervention, compared with routine care. We performed this trial to pilot the intervention and obtain preliminary effectiveness data, informing future research. Eligible clusters were four hospitals with >4,000 births annually and cesarean rates ≥30%. Eligible women were those giving birth at ≥20 weeks' gestation. One hospital transitioned to intervention every 2 months, according to a random sequence. The primary outcome was the cesarean rate among women in Robson Group 1 (that is, those who were nulliparous and gave birth to a singleton, term pregnancy in cephalic presentation and in spontaneous labor). A total of 26,331 participants gave birth. A 5.5% crude absolute reduction in the primary outcome was observed (45.2% versus 39.7%; relative risk 0.85, 95% confidence interval 0.54-1.33). Maternal process-of-care outcomes were not significantly different, though labor augmentation with oxytocin was 18.0% lower with the LCG strategy. No differences were observed for other health outcomes or women's birth experiences. These findings can guide future definitive effectiveness trials, particularly in settings where urgent reversal of rising cesarean section rates is needed. Clinical Trials Registry India number: CTRI/2021/01/03069
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