26 research outputs found

    Packet Reservation Multiple Access (PRMA) with Random Contention

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    Packet reservation multiple access (PRMA) can be considered as a merge of slotted ALOHA protocol and time division multiple access (TDMA) protocol. Independent terminals transmit packets to base station by contending to access an available time slots. A terminal that succeeds in reserving a certain time slot keeps on this reservation for transmitting its subsequent packets. Speech activity detection is used in PRMA to improve system capacity. In this work we propose a simpler contention mechanism that does not depend on a predetermined permission probability as in the original PRMA. In the new method, terminals select the contention slot uniformly from the pool of remaining free slots in the current frame. We evaluate the performance of the new contention mechanism in terms of various metrics including maximum number of carried voice calls and packet delays for a given acceptable drop rate of voice packets. We show that the new mechanism is superior to that of the original PRMA for loaded systems and is expected to be insensitive for traffic source burstiness

    Anti-inflammatory and anti-oxidant properties of Ipomoea nil (Linn.) Roth significantly alleviates cigarette smoke (CS)-induced acute lung injury via possibly inhibiting the NF-κB pathway

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    Acute respiratory distress syndrome (ARDS), a serious manifestation of acute lung injury (ALI), is a debilitating inflammatory lung disease that is caused by multiple risk factors. One of the primary causes that can lead to ALI/ARDS is cigarette smoke (CS) and its primary mode of action is via oxidative stress. Despite extensive research, no appropriate therapy is currently available to treat ALI/ARDS, which means there is a dire need for new potential approaches. In our study we explored the protective effects of 70 % methanolic-aqueous extract of Ipomoea nil (Linn.) Roth, named as In.Mcx against CS-induced ALI mice models and RAW 264.7 macrophages because Ipomoea nil has traditionally been used to treat breathing irregularities. Male Swiss albino mice (20–25 ± 2 g) were subjected to CS for 10 uninterrupted days in order to establish CS-induced ALI murine models. Dexamethasone (1 mg/kg), In.Mcx (100 200, and 300 mg/kg) and normal saline (10 mL/kg) were given to respective animal groups, 1 h before CS-exposure. 24 h after the last CS exposure, the lungs and bronchoalveolar lavage fluid (BALF) of all euthanized mice were harvested. Altered alveolar integrity and elevated lung weight-coefficient, total inflammatory cells, oxidative stress, expression of pro-inflammatory cytokines (IL-1β and IL-6) and chemokines (KC) were significantly decreased by In.Mcx in CS-exposed mice. In.Mcx also revealed significant lowering IL-1β, IL-6 and KC expression in CSE (4 %)-activated RAW 264.7 macrophage. Additionally, In.Mcx showed marked enzyme inhibition activity against Acetylcholinesterase, Butyrylcholinesterase and Lipoxygenase. Importantly, In.Mcx dose-dependently and remarkably suppressed the CS-induced oxidative stress via not only reducing the MPO, TOS and MDA content but also improving TAC production in the lungs. Accordingly, HPLC analysis revealed the presence of many important antioxidant components. Finally, In.Mcx showed a marked decrease in the NF-κB expression both in in vivo and in vitro models. Our findings suggest that In.Mcx has positive therapeutic effects against CS-induced ALI via suppressing uncontrolled inflammatory response, oxidative stress, lipoxygenase and NF-κB p65 pathway

    A global action agenda for turning the tide on fatty liver disease

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    Background and Aims: Fatty liver disease is a major public health threat due to its very high prevalence and related morbidity and mortality. Focused and dedicated interventions are urgently needed to target disease prevention, treatment, and care. Approach and Results: We developed an aligned, prioritized action agenda for the global fatty liver disease community of practice. Following a Delphi methodology over 2 rounds, a large panel (R1 n = 344, R2 n = 288) reviewed the action priorities using Qualtrics XM, indicating agreement using a 4-point Likert-scale and providing written feedback. Priorities were revised between rounds, and in R2, panelists also ranked the priorities within 6 domains: epidemiology, treatment and care, models of care, education and awareness, patient and community perspectives, and leadership and public health policy. The consensus fatty liver disease action agenda encompasses 29 priorities. In R2, the mean percentage of “agree” responses was 82.4%, with all individual priorities having at least a super-majority of agreement (> 66.7% “agree”). The highest-ranked action priorities included collaboration between liver specialists and primary care doctors on early diagnosis, action to address the needs of people living with multiple morbidities, and the incorporation of fatty liver disease into relevant non-communicable disease strategies and guidance. Conclusions: This consensus-driven multidisciplinary fatty liver disease action agenda developed by care providers, clinical researchers, and public health and policy experts provides a path to reduce the prevalence of fatty liver disease and improve health outcomes. To implement this agenda, concerted efforts will be needed at the global, regional, and national levels

    A global research priority agenda to advance public health responses to fatty liver disease

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    Background & aims An estimated 38% of adults worldwide have non-alcoholic fatty liver disease (NAFLD). From individual impacts to widespread public health and economic consequences, the implications of this disease are profound. This study aimed to develop an aligned, prioritised fatty liver disease research agenda for the global health community. Methods Nine co-chairs drafted initial research priorities, subsequently reviewed by 40 core authors and debated during a three-day in-person meeting. Following a Delphi methodology, over two rounds, a large panel (R1 n = 344, R2 n = 288) reviewed the priorities, via Qualtrics XM, indicating agreement using a four-point Likert-scale and providing written feedback. The core group revised the draft priorities between rounds. In R2, panellists also ranked the priorities within six domains: epidemiology, models of care, treatment and care, education and awareness, patient and community perspectives, and leadership and public health policy. Results The consensus-built fatty liver disease research agenda encompasses 28 priorities. The mean percentage of ‘agree’ responses increased from 78.3 in R1 to 81.1 in R2. Five priorities received unanimous combined agreement (‘agree’ + ‘somewhat agree’); the remaining 23 priorities had >90% combined agreement. While all but one of the priorities exhibited at least a super-majority of agreement (>66.7% ‘agree’), 13 priorities had 90% combined agreement. Conclusions Adopting this multidisciplinary consensus-built research priorities agenda can deliver a step-change in addressing fatty liver disease, mitigating against its individual and societal harms and proactively altering its natural history through prevention, identification, treatment, and care. This agenda should catalyse the global health community’s efforts to advance and accelerate responses to this widespread and fast-growing public health threat. Impact and implications An estimated 38% of adults and 13% of children and adolescents worldwide have fatty liver disease, making it the most prevalent liver disease in history. Despite substantial scientific progress in the past three decades, the burden continues to grow, with an urgent need to advance understanding of how to prevent, manage, and treat the disease. Through a global consensus process, a multidisciplinary group agreed on 28 research priorities covering a broad range of themes, from disease burden, treatment, and health system responses to awareness and policy. The findings have relevance for clinical and non-clinical researchers as well as funders working on fatty liver disease and non-communicable diseases more broadly, setting out a prioritised, ranked research agenda for turning the tide on this fast-growing public health threat

    Vitamin C as a potential ameliorating agent against hepatotoxicity among alcoholic abusers

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    OBJECTIVE: Drug and substance abuse remains a major medical problem globally. Alcohol consumption, particularly heavy drinking, is an important risk factor for many health problems and is a major contributor to the global burden of disease. Vitamin C has proven to be defensive against toxic substances and provides antioxidant and cytoprotective activity to hepatocytes. The aim of this study was to investigate vitamin C as a potential ameliorating agent against hepatotoxicity among alcohol abusers. PATIENTS AND METHODS: This study was a cross-sectional study that included eighty male hospitalized alcohol abusers and twenty healthy people as a control group. Alcohol abusers received standard treatment plus vitamin C. Total protein, albumin, total Bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and 8-hydroxhguanosine (8-OHdG) were investigated. RESULTS: This study reported that, in the alcohol abuser group, there was a significant increase in the total protein, bilirubin, AST, ALT, ALP, TBARS, SOD and 8-OHdG; on the other hand, there was a significant decrease in albumin, GSH and CAT compared with the control group. The alcohol abuser group treated with vitamin C showed a significant decrease in total protein, bilirubin, AST, ALT, ALP, TBARS, SOD and 8-OHdG; on the other hand, there was a significant increase in albumin, GSH and CAT compared with the control group. CONCLUSIONS: This study’s findings suggest that alcohol abuse induces significant alterations in various hepatic biochemical parameters and oxidative stress and that vitamin C has a partial protective role in countering alcohol abuse-induced hepatotoxicity. Using vitamin C as an adjunctive supplement to standard treatment may be helpful in minimizing the toxic side effects of alcohol abuse

    Low cost, high sensitivity detection of waterborne Al3+ cations and F− anions via the fluorescence response of a morin derivative dye

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    Morin dye is known as a cheap and readily available selective ‘off → on’ fluorescent sensitiser when immobilised in a phase transfer membrane for the detection of Al3+ ions. Here, a morin derivative, NaMSA, which readily dissolves in water with good long-term stability is used in conjunction with a fibre optic transducer with lock-in detection to detect Al3+ in drinking water below the potability limit. The combination of a water soluble dye and the fibre optic transducer require neither membrane preparation nor a fluorescence spectrometer yet still display a high figure-of- merit. The known ability to recover morin-based Al3+ cation sensors selectively by exposure to fluoride (F−) anions is further developed enabling a complementary sensing of either fluoride anions, or aluminium cations, using the same dye with a sub-micromolar limit-of-detection for both ions. The sensor performance parameters compare favourably to prior reports on both aqueous aluminium and fluoride ion sensing

    Experimental study of the impact of CO2 injection on the pore structure of coal: A case study from the Bowen Basin, Australia

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    This study investigates the impact of carbon dioxide (CO2) on the pore structure of coal during CO2 injection to understand the technical challenges associated with CO2 sequestration in depleted coal seam gas reservoirs. In an integrated approach, Micro-Computed Tomography (micro-CT) scanning, helium porosity and air permeability tests are performed on a coal sample prior to and after CO2 flooding experiments to identify both reversible and irreversible changes in cleat and fracture networks. The results indicate that irreversible changes contribute to a 43% reduction in effective porosity, which can be readily observed in the 3D model of the cleat and fracture networks constructed after CO2 flooding. At lower effective stresses, pore compressibility offsets the matrix swelling effect, resulting in improved permeability, which is beneficial for CO2 injection. Additionally, the analysis of borehole image logs of the study well reveals that most fractures and cleats terminate within coal intervals, with very few fractures extending into adjacent strata that are siltstone and fine sandstone with very low permeability.Alireza Salmachi, Abbas Zeinijahromi, Mohammed Said Algarni, Nawaf Abdullah Abahussain, Saad Abdullah Alqahtani, Alexander Badalyan, Mohammad Rezaee, Mojtaba Rajab
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