194 research outputs found

    Mathematical Modelling of Different Types of Body Support Surface for Pressure Ulcer Prevention

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    Pressure ulcer is a common problem for today’s healthcare industry. It occurs due to external load applied to the skin. Also when the subject is immobile for a longer period of time and there is continuous load applied to a particular area of human body, blood flow gets reduced and as a result pressure ulcer develops. Body support surface has a significant role in preventing ulceration so it is important to know the characteristics of support surface under loading conditions. In this paper we have presented mathematical models of different types of viscoelastic materials and also we have shown the validation of our simulation results with experiments

    A Review on Pressure Ulcer: Aetiology, Cost, Detection and Prevention Systems

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    Pressure ulcer (also known as pressure sore, bedsore, ischemia, decubitus ulcer) is a global challenge for today’s healthcare society. Found in several locations in the human body such as the sacrum, heel, back of the head, shoulder, knee caps, it occurs when soft tissues are under continuous loading and a subject’s mobility is restricted (bedbound/chair bound). Blood flow in soft tissues becomes insufficient leading to tissue necrosis (cell death) and pressure ulcer. The subject’s physiological parameters (age, body mass index) and types of body support surface materials (mattress) are also factors in the formation of pressure ulcer. The economic impacts of these are huge, and the subject’s quality of life is reduced in many ways. There are several methods of detecting and preventing ulceration in human body. Detection depends on assessing local pressure on tissue and prevention on scales of risk used to assess a subject prior to admission. There are also various types of mattresses (air cushioned/liquid filled/foam) available to prevent ulceration. But, despite this work, pressure ulcers remain common.This article reviews the aetiology, cost, detection and prevention of these ulcers

    Restrained Shrinkage of Fly Ash Based Geopolymer Concrete and Analysis of Long Term Shrinkage Prediction Models

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    The research presented in this manuscript describes the procedure to quantify the restrained shrinkage of geopolymer concrete (GPC) using ring specimen. Massive concrete structures are susceptible to shrinkage and thermal cracking. This cracking can increase the concrete permeability and decrease the strength and design life. This test is comprised of evaluating geopolymer concrete of six different mix designs including different activator solution to fly ash ratio and subjected to both restrained and free shrinkage. Test results obtained from this experimental setup was plotted along with the available empirical equation to observe the shrinkage strain of GPC and a model was suggested to predict the shrinkage strain of GPC. It was found from this study that along with activator solution to fly ash ratio the final compressive strength of GPC plays an important role on shrinkage strai

    Maximising the number of participants in a ride-sharing scheme: MIP versus CP formulations

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    Ride sharing schemes aim to reduce the number of cars in congested cities, while providing the participants with a cheaper alternative to solo driving. To ensure a ride-sharing scheme thrives, it is important to maintain a high participation rate. This requires an adequate balance between drivers and riders. And thus ride matches should be proposed which maximize the number of participants. Different variants of the ride sharing problem have been solved using mixed integer programming. In this paper, we introduce a constraint programming formulation for the problem that uses cumulative constraints with dependencies between trip times. In experiments based on collected trip schedules from four different regions, the constraint model outperforms the MIP model. However, when we change the problem by assuming all drivers have flexible roles, the MIP model allows faster solution times than the CP model

    Chemical Modification Effect on the Mechanical Properties of Coir Fiber

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    Natural fiber has a vital role as a reinforcing agent due to its renewable, low cost, biodegradable, less abrasive and eco-friendly nature. Whereas synthetic fibers like glass, boron, carbon, metallic, ceramic and inorganic fibers are expensive and not eco-friendly. Coir is one of the natural fibers easily available in Bangladesh and cheap. It is derived from the husk of the coconut (Cocos nucifera). Coir has one of the highest concentrations of lignin, which makes it stronger. In recent years, wide range of research has been carried out on fiber reinforced polymer composites [4-13].The aim of the present research is to characterize brown single coir fiber for manufacturing polymer composites reinforced with characterized fibers. Adhesion between the fiber and polymer is one of factors affecting the strength of manufactured composites. In order to increase the adhesion, the coir fiber was chemically treated separately in single stage (with Cr2(SO4)3•12(H2O)) and double stages (with CrSO4 and NaHCO3). Both the raw and treated fibers were characterized by tensile testing, Fourier transform infrared (FTIR) spectroscopic analysis, scanning electron microscopic analysis. The result showed that the Young's modulus increased, while tensile strength and strain to failure decreased with increase in span length. Tensile properties of chemically treated coir fiber was found higher than raw coir fiber, while the double stage treated coir fiber had better mechanical properties compared to the single stage treated coir fiber. Scanning electron micrographs showed rougher surface in case of the raw coir fiber. The surface was found clean and smooth in case of the treated coir fiber. Thus the performance of coir fiber composites in industrial application can be improved by chemical treatment

    Differential effects of polyphenols on proliferation and apoptosis in human myeloid and lymphoid leukemia cell lines.

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    Background: Mortality rates for leukemia are high despite considerable improvements in treatment. Since polyphenols exert pro-apoptotic effects in solid tumors, our study investigated the effects of polyphenols in haematological malignancies. The effect of eight polyphenols (quercetin, chrysin, apigenin, emodin, aloe-emodin, rhein, cis-stilbene and trans-stilbene) were studied on cell proliferation, cell cycle and apoptosis in four lymphoid and four myeloid leukemic cells lines, together with normal haematopoietic control cells. Methods: Cellular proliferation was measured by CellTiter-Glo® luminescent assay; and cell cycle arrest was assessed using flow cytometry of propidium iodide stained cells. Apoptosis was investigated by caspase-3 activity assay using flow cytometry and apoptotic morphology was confirmed by Hoescht 33342 staining. Results: Emodin, quercetin, and cis-stilbene were the most effective polyphenols at decreasing cell viability (IC50 values of 5-22 µM, 8-33 µM, and 25-85 µM respectively) and inducing apoptosis (AP50 values (the concentration which 50% of cells undergo apoptosis) of 2-27 µM, 19-50 µM, and 8-50 µM respectively). Generally, lymphoid cell lines were more sensitive to polyphenol treatment compared to myeloid cell lines, however the most resistant myeloid (KG-1a and K562) cell lines were still found to respond to emodin and quercetin treatment at low micromolar levels. Non-tumor cells were less sensitive to all polyphenols compared to the leukemia cells. Conclusions: These findings suggest that polyphenols have anti-tumor activity against leukemia cells with differential effects. Importantly, the differential sensitivity of emodin, quercetin, and cis-stilbene between leukemia and normal cells suggests that polyphenols are potential therapeutic agents for leukemia

    Regional and oyster microenvironmental scale heterogeneity in the Pacific oyster bacterial community.

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    Different organs of a host represent distinct microenvironments resulting in the establishment of multiple discrete bacterial communities within a host. These discrete bacterial communities can also vary according to geographical location. For the Pacific oyster, Crassostrea gigas, the factors governing bacterial diversity and abundance of different oyster microenvironments are poorly understood. In this study, the factors shaping bacterial abundance, diversity and composition associated with the C. gigas mantle, gill, adductor muscle, and digestive gland were characterised using 16S (V3-V4) rRNA amplicon sequencing across six discrete estuaries. Both location and tissue-type, with tissue-type being the stronger determinant, were factors driving bacterial community composition. Bacterial communities from wave-dominated estuaries had similar compositions and higher bacterial abundance despite being geographically distant from one another, possibly indicating that functional estuarine morphology characteristics are a factor shaping the oyster bacterial community. Despite the bacterial community heterogeneity, examinations of the core bacterial community identified Spirochaetaceae bacteria as conserved across all sites and samples. Whereas members of the Vulcaniibacterium, Spirochaetaceae and Margulisbacteria, and Polynucleobacter were regionally conserved members of the digestive gland, gill, and mantle bacterial communities respectively. This indicates that baseline bacterial community profiles for specific locations are necessary when investigating bacterial communities in oyster health

    KARAKTERISTIK ATC Kappaphycus alvarezii PADA PERLAKUAN UMUR PANEN DAN SUHU EKSTRAKSI BERBEDA

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    One of the ATC quality is influenced by the length time of harvesting and temperature of extraction.The aimof the research was to determine the influenced of different time of harvesting K.alvarezii and the degree temperatureextraction process to the quality of the ATC product (yield, gel strength and viscosity). The material used wastaken from the Bandengan coastal area, Jepara. The treatments used was the difference temperature of extractionprocess which are 70oC and 80oC and the difference of harvesting time 35, 40, and 45 days. K.alvarezii extracted using6% KOH solution for 4 hours, dried and then is milled. The yield test showed that the used extraction temperatureof 80oC produces a higher yield than the temperature of 70oC, the percentage yield of ATC powder was increasein along with harvesting time of K.alvarezii. The gel strength test showed that the use of extraction temperature of70oC produces a higher gel strength and viscosity than the temperature of 80oC, the highest gel strength obtainedat 40 days harvesting time of seaweed.One of the ATC quality is infl uenced by the length time of harvesting and temperature of extraction.The aimof the research was to determine the infl uenced of different time of harvesting K.alvarezii and the degree temperatureextraction process to the quality of the ATC product (rendemen, gel strength and viscosity). The material used wastaken from the Bandengan coastal area, Jepara. The treatments used was the difference temperature of extractionprocess which are 70oC and 80oC and the difference of harvesting time 35, 40, and 45 days. K.alvarezii extracted using6% KOH solution for 4 hours, dried and then is milled. The yield test showed that the used extraction temperatureof 80oC produces a higher yield than the temperature of 70oC, the percentage yield of ATC powder was increasein along with harvesting time of K.alvarezii. The gel strength test showed that the use of extraction temperature of70oC produces a higher gel strength and viscosity than the temperature of 80oC, the highest gel strength obtainedat 40 days harvesting time of seaweed

    Glutathione is key to the synergistic enhancement of doxorubicin and etoposide by polyphenols in leukaemia cell lines

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    Recently published in Nature: Cell Death and Discovery, Mahbub et al.1 have demonstrated that polyphenols can synergistically enhance the action of the topoisomerase II inhibitors: doxorubicin and etoposide in leukaemia cells. A reduction of glutathione (GSH) was strongly associated with sensitising cells to the pro-apoptotic effects of polyphenols when used in combination with doxorubicin or etoposide. Importantly, when polyphenols and topoisomerase II inhibitors were combined, it was possible to induce a synergistic decrease in cell proliferation (measured as ATP levels), cell-cycle arrest and induction of apoptosis in leukaemia cell lines

    Morphine-induced hallucinations - resolution with switching to oxycodone: a case report and review of the literature

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    Palliation of pain with morphine in cancer patients can be complicated by adverse effects. Tolerance to these effects such as nausea and drowsiness usually occurs within a few days allowing continuation of morphine therapy. However, some patients may develop intolerable adverse effects even after several months on morphine when the dose is increased. A case of morphine-induced hallucinations in a cancer patient who had been on a subcutaneous infusion of diamorphine for several months is discussed. A switch to oxycodone resolved his hallucinations and gave him a new lease of life. The theories behind and evidence for opioid-switching is discussed along with strategies for dealing with intolerable opioid-induced adverse effects
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