2,064 research outputs found

    An intersection-movement-based stochastic dynamic user optimal route choice model for assessing network performance

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    Different from traditional methods, this paper formulates the logit-based stochastic dynamic user optimal (SDUO) route choice problem as a fixed point (FP) problem in terms of intersection movement choice probabilities, which contain travelers’ route information so that the realistic effects of physical queues can be captured in the formulation when a physical-queue traffic flow model is adopted, and that route enumeration and column generation heuristics can be avoided in the solution procedure when efficient path sets are used. The choice probability can be either destination specific or origin–destination specific, resulting into two formulations. To capture the effect of physical queues in these FP formulations, the link transmission model is modified for the network loading and travel time determination. The self-regulated averaging method (SRAM) was adopted to solve the FP formulations. Numerical examples were developed to illustrate the properties of the problem and the effectiveness of the solution method. The proposed models were further used to evaluate the effect of information quality and road network improvement on the network performance in terms of total system travel time (TSTT) and the cost of total vehicle emissions (CTVE). Numerical results show that providing better information quality, enhancing link outflow capacity, or constructing a new road can lead to poor network performance.postprin

    Extract of Zanthoxylum bungeanum maxim seed oil reduces hyperlipidemia in hamsters fed high-fat diet via activation of peroxisome proliferator-activated receptor γ

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    Purpose: To investigate the anti-hyperlipidaemic effect of extract of Zanthoxylum bungeanum Maxim. seed oil (EZSO) on high-fat diet (HFD)-induced hyperlipidemic hamsters.Methods: Following feeding with HFD for 30 days, hyperlipidemic hamsters were intragastrically treated with EZSO for 60 days. Serum levels of triglyceride (TG), total cholesterol (TC), low-density-lipoproteincholesterol (LDL-C), nitric oxide (NO) and malondialdehyde (MDA) were analyzed. Protein expression and location of peroxisome proliferator-activated receptor γ (PPARγ) in liver were determined by Western blot and immunohistochemical assays, respectively.Results: EZSO at 5 and 10 g/kg significantly reduced levels of TG by 26 and 23 % (p < 0.05), TC by 19 % (p < 0.01) and 13 % (p < 0.01), LDL-C by 18 % (p < 0.05) and 21 % (p < 0.01), NO by 15 % (p < 0.01) and 31 % (p < 0.01), and MDA by 16 % (p < 0.05) and 30 % (p < 0.01), respectively, in serum of hyperlipidemic hamsters. However, EZSO did not show significant effect on HDL-C level in serum. Furthermore, EZSO at 5 and 10 g/kg markedly promoted protein expression of PPARγ by 71 % (p < 0.05) and 102 % (p < 0.01) in liver tissue of hyperlipidemic hamsters. EZSO also notably increased the content of PPARγ protein in the nucleus of liver cells of hyperlipidemic hamsters.Conclusion: These findings suggest that EZSO can reduce hyperlipidemia and improve oxidative stress in hyperlipidemic hamsters through activation of PPARγ, and that EZSO is a promising novel hypolipidemic health product.Keywords: Zanthoxylum bungeanum, Peroxisome proliferator activated receptor γ, Hyperlipidemia, Hamster, High-fat die

    Ischaemic post-conditioning protects lung from ischaemia-reperfusion injury by up-regulation of haeme oxygenase-1

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    Objective: The emergence of ischaemic post-conditioning (IPO) provides a potential method for experimentally and clinically attenuating various types of organ injuries. There has been little work, however, examining its effects in the setting of lung ischaemia reperfusion (IR). The stress protein, haeme oxygenase-1 (HO-1), has been found to exert a potent, protective role in a variety of lung injury models. In this study, we hypothesised that the induction of HO-1 by IPO plays a protective role against the deleterious effects of IR in the lung. Methods: Anaesthetised and mechanically ventilated adult Sprague-Dawley rats were randomly assigned to one of the following groups (n = 8 each): the sham-operated control group, the IR group (40 min of left-lung ischaemia and 105 min of reperfusion), the IPO group (three successive cycles of 30-s reperfusion per 30-s occlusion before restoring full perfusion) and the ZnPPIX + IPO group (ZnPPIX, an inhibitor of HO-1, was injected intra-peritoneally at 20 mg kg -1 24 h prior to the experiment and the rest of the procedures were similar to that of the IPO group). Lung injury was assessed by arterial blood gas analysis, wet-to-dry lung weight ratio and tissue histological changes. The extent of lipid peroxidation was determined by measuring plasma levels of malondialdehyde (MDA) production. Expression of HO-1 was determined by immunohistochemistry. Results: Lung IR resulted in a significant reduction of PaO 2 (data in IR, P < 0.05 vs. data in sham) and increase of lung wet-to-dry weight ratio, accompanied with increased MDA production and severe lung pathological morphological changes as well as a compensatory increase in HO-1 protein expression, as compared with sham (All P < 0.05). IPO markedly attenuated all the above pathological changes seen in the IR group and further increased HO-1 expression. Treatment with ZnPPIX abolished all the protective effects of post-conditioning. Conclusion: It may be concluded that IPO protects IR-induced lung injury via induction of HO-1. © 2009 Elsevier Ltd. All rights reserved.postprin

    A time-dependent transit equilibrium assignment model for congested transit network

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    2002-2003 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Magnetic field effects on the electroluminescence of organic light emitting devices: A tool to indicate the carrier mobility

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    The magnetoelectroluminescence (MEL) of organic light emitting devices with a N, N′ -bis(l-naphthyl)- N, N′ -diphenyl- 1, l′ -biphentl- 4, 4′ -diamine:tris-(8-hydroxyquinoline) aluminum (NPB: Alq 3) mixed emission layer (EML) has been investigated. We find that MEL is maximized when the volume ratio of NPB of the mixed EML reaches 30% and the EML thickness is 40 nm. The features of MEL under various magnetic field strengths are insensitive to the change in EML thickness and mixing ratio. Meanwhile, MEL has a close relationship with the carrier mobility. We have conducted a theoretical study to further verify the relationship. Our experimental and theoretical results confirm that MEL can function as a tool to indicate the mobility. © 2010 American Institute of Physics.published_or_final_versio

    Stepwise photoassisted decomposition of carbohydrates to H2

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    Biomass reforming by harvesting solar energy can provide green hydrogen. Current biomass photoreforming provides H2 erratically and in limited yield although efficiently, owing to intermittent features of solar light and incomplete degradation of biomass C-C bonds. Here, we detour the flaws by prioritizing conversion of carbohydrates to liquid hydrogen carriers (LHCs, consisting of HCOOH and HCHO), appropriate for transportation. Subsequently, the LHCs are fully decomposed, releasing only H-2 and CO2. This stepwise process enables complete scission of carbohydrate C-C bonds, affording 44 g of H-2 per kg of glucose thereof. Intermittent solar light provides the photoenergy and heat to split glucose car-bons to produce LHCs (2.5 mmol h(-1)) in a flow apparatus. This work demonstrates hydrogen production and storage by empha-sizing the complete scission of biomass C-C bonds

    Down-regulated CK8 expression in human intervertebral disc degeneration

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    As an intermediate filament protein, cytokeratin 8 (CK8) exerts multiple cellular functions. Moreover, it has been identified as a marker of notochord cells, which play essential roles in human nucleus pulposus (NP). However, the distribution of CK8 positive cells in human NP and their relationship with intervertebral disc degeneration (IDD) have not been clarified until now. Here, we found the percentage of CK8 positive cells in IDD (25.7+/-4.14%) was significantly lower than that in normal and scoliosis NP (51.9+/-9.73% and 47.8+/-5.51%, respectively, p<0.05). Western blotting and qRT-PCR results confirmed the down-regulation of CK8 expression in IDD on both of protein and mRNA levels. Furthermore, approximately 37.4% of cell clusters were CK8 positive in IDD. Taken together, this is the first study to show a down-regulated CK8 expression and the percentage of CK8 positive cell clusters in IDD based upon multiple lines of evidence. Consequently, CK8 positive cells might be considered as a potential option in the development of cellular treatment strategies for NP repair.published_or_final_versio

    Strain distribution in epitaxial SrTiO₃thin films

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    2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
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