547 research outputs found

    Distributed QoS Guarantees for Realtime Traffic in Ad Hoc Networks

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    In this paper, we propose a new cross-layer framework, named QPART ( QoS br>rotocol for Adhoc Realtime Traffic), which provides QoS guarantees to real-time multimedia applications for wireless ad hoc networks. By adapting the contention window sizes at the MAC layer, QPART schedules packets of flows according to their unique QoS requirements. QPART implements priority-based admission control and conflict resolution to ensure that the requirements of admitted realtime flows is smaller than the network capacity. The novelty of QPART is that it is robust to mobility and variances in channel capacity and imposes no control message overhead on the network

    Associations between psychopathic traits and brain activity during instructed false responding

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    Lying is one of the characteristic features of psychopathy, and has been recognized in clinical and diagnostic descriptions of the disorder, yet individuals with psychopathic traits have been found to have reduced neural activity in many of the brain regions that are important for lying. In this study, we examine brain activity in sixteen individuals with varying degrees of psychopathic traits during a task in which they are instructed to falsify information or tell the truth about autobiographical and non-autobiographical facts, some of which was related to criminal behavior. We found that psychopathic traits were primarily associated with increased activity in the anterior cingulate, various regions of the prefrontal cortex, insula, angular gyrus, and the inferior parietal lobe when participants falsified information of any type. Associations tended to be stronger when participants falsified information about criminal behaviors. Although this study was conducted in a small sample of individuals and the task used has limited ecological validity, these findings support a growing body of literature suggesting that in some contexts, individuals with higher levels of psychopathic traits may demonstrate heightened levels of brain activity

    A comparative study of HPLC-DAD and UPLC-UV methods for simultaneous determination of 11 polyphenols in Moringa oleifera leaves

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    Purpose: To develop, validate and compare two chromatographic methods - high performance liquid chromatography with diode array detector ((HPLC-DAD) and high performance liquid chromatography with ultraviolet detection (UPLC-UV) for the effective analysis of polyphenols in Moringa oleifera leaves.Methods: HPLC-DAD and UPLC-UV methods were applied for the accurate determination of eleven major polyphenols in Moringa oleifera leaves. The chromatographic conditions of the eleven polyphenols was determined on two C18 column by gradient elution with 0.5 % phosphoric acid solution -acetonitrile as the eluate, and at a flow rate of 1.0 and 0.5 mL/min for HPLC-DAD and UPLC-UV methods, respectively. Detector parameter of UPLC-UV was fixed at 203 nm. The assay methods were validated systematically.Results: The instrumental methods (HPLC-DAD and UPLC-UV) had good linearity, precision,repeatability and recovery. For both methods, quantification limits of UPLC-UV (0.057 - 0.363 μg/mL) were lower than those of UPLC-UV (0.094 - 1.532 μg/mL). The UPLC method with a shorter running time and more sensitive detection was applied in comparing to the HPLC method. After optimization and evaluation, the baseline of 11 compounds was separated effectively within 68 and 34 min, respectively.Conclusion: The developed HPLC-DAD and UPLC-UV assays were successfully utilized for thesimultaneous analysis of eleven major polyphenols and can readily be utilized as quality control tools for Moringa oleifera leaves in China, with UPLC-UV method showing better separation, lower organic solvent usage and shorter analytical period

    Q-Switched 2 Micron Solid-State Lasers and Their Applications

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    In this chapter, we overview the Q-switched 2 μm solid-state laser development achieved in recent years, including flash- and diode-pumped solid-state lasers based on active and passive modulators. In summary, active Q-switching is still the first choice for obtaining large pulse energy at 2 μm currently, while passive Q-switching based on saturable absorbers (SAs), especially the newly emerging broadband low-dimension nanomaterial, is becoming promising approach in generating Q-switched 2 μm lasers specially with high repetition rate, although the output power, pulse duration, and pulse energy needs further enhancement. Besides, some important applications of 2 μm lasers, such as medicine, laser radar, and infrared directional interference, have also been introduced in brief

    One-step hydrothermal synthesis of fluorescence carbon quantum dots with high product yield and quantum yield

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    A one-step hydrothermal synthesis of nitrogen and silicon co-doped fluorescence carbon quantum dots (N,Si-CQDs), from citric acid monohydrate and silane coupling agent KH-792 with a high product yield (PY) of 52.56% and high quantum yield (QY) of 97.32%, was developed. This greatly improves both the PY and QY of CQDs and provides a new approach for a large-scale production of high-quality CQDs. Furthermore, N,Si-CQDs were employed as phosphors without dispersants to fabricate white light-emitting diodes (WLEDs) with the color coordinates at (0.29, 0.32). It is suggested that N,Si-CQDs have great potential as promising fluorescent materials to be applied in WLEDs.Peer reviewe

    Echinacoside attenuates lipopolysaccharide-induced acute lung injury in newborn mice via inactivation of NF- κB/NLRP3 signaling pathway

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    Purpose: To investigate the effect of echinacoside (ECH) on acute lung injury (ALI) and the underlying mechanism of action.Methods: The ALI model was established through intranasal instillation of lipopolysaccharide (LPS). Lung tissue damage was determined using hematoxylin and eosin (H&E) staining and lung wet-to-dry–weight ratio. Bronchoalveolar lavage fluid (BALF) protein concentration, cell count, and cytokine level were evaluated. Western blotting was used to determine protein expression level.Results: ECH attenuated lung tissue injury and lung wet-to-dry–weight ratio in the ALI model (p < 0.01). The total protein content and number of total cells, neutrophils, and macrophages increased in BALF of mice treated with LPS, but these increases were reversed by ECH treatment (p < 0.01). The levels of TNF-α and IL-1β increased in BALF and lung tissue of LPS-treated mice; however, ECH treatment decreased these changes (p < 0.01). In addition, ECH inhibited the activation of the nuclear factor-κB (NF-κB)/NLR family pyrin domain containing 3 (NLRP3) pathway in LPS-treated mice (p < 0.01).Conclusion: Echinacoside attenuates LPS-induced ALI via inactivation of the NF-κB/NLRP3 pathway, making echinacoside a potential drug for the treatment of ALI. Keywords: Echinacoside, Acute lung injury, Lipopolysaccharide, Nuclear factor-κB, NLR family pyrin domain containing

    Effects of Some Common Food Constituents on Cardiovascular Disease

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    Cardiovascular diseases are the major cause of morbidity and mortality worldwide, and there is considerable interest in the role of dietary constituents and supplements in the prevention and treatment of these disorders. We reviewed the major publications related to potential effects on cardiovascular risk factors and outcomes of some common dietary constituents: carotenoids, flavonoid-rich cocoa, tea, red wine and grapes, coffee, omega-3 fatty acids, and garlic. Increased intake of some of these has been associated with reduced all-cause mortality or reduced incidence of myocardial infraction, stroke, and hypertension. However, although the evidence from observational studies is supportive of beneficial effects for most of these foodstuffs taken as part of the diet, potential benefits from the use of supplements derived from these natural products remain largely inconclusive

    EXOGEN Ultrasound Bone Healing System for Long Bone Fractures with Non-Union or Delayed Healing: A NICE Medical Technology Guidance

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    A routine part of the process for developing National Institute for Health and Care Excellence (NICE) medical technologies guidance is a submission of clinical and economic evidence by the technology manufacturer. The Birmingham and Brunel Consortium External Assessment Centre (EAC; a consortium of the University of Birmingham and Brunel University) independently appraised the submission on the EXOGEN bone healing system for long bone fractures with non-union or delayed healing. This article is an overview of the original evidence submitted, the EAC’s findings, and the final NICE guidance issued
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