3,291 research outputs found

    Switchable polarization manipulation, optical logical gates and conveyor belt based on U-shaped \ce{VO2} nanoholes

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    Based on U-shaped plasmonic nanoholes in an \ce{Au-VO2-Au} film, we propose to achieve several switchable functions at the telecom wavelength by transition from the \ce{VO2} semiconductive state to the metallic state. The first is the polarization manipulation of four different polarization states (x&yx\&y-polarization, LCP, and RCP). An array of U-shaped holes constitutes of the high efficiency SPP splitter, and thus the spin-encoded optical logical gates can be achieved. Furthurmore, we prove that a nano-optical conveyor belt can be build up with such U-shaped holes, making the transport of nanoparticles over the film efficiency by transforming between two spin states periodically, and the transport direction switchably along with the \ce{VO2} phase

    Complex phase diagram and supercritical matter

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    Supercritical region is often described as uniform with no definite transitions. The distinct behaviors of the matter therein, e.g., as liquid-like and gas-like, however, indicate their should-be different belongings. Here, we provide a mathematical description of these phenomena by revisiting the Lee-Yang (LY) theory and using a complex phase diagram, e.g. a 4-D one with complex TT and pp. Beyond the critical point, the 2-D phase diagram with real TT and pp, i.e. the physical plane, is free of LY zeros and hence no criticality emerges. But off-plane zeros in this 4-D scenario still come into play by inducing critical anomalies for different physical properties. This is evidenced by the correlation between the Widom lines and LY edges in van der Waals model and water. The present distinct criteria to distinguish the supercritical matter manifest the high-dimensional feature of the phase diagram: e.g. when the LY zeros of complex TT or pp are projected onto the physical plane, a boundary defined by isobaric heat capacity CpC_p or adiabatic compression coefficient KTK_T emanates. These results demonstrate the incipient phase transition nature of the supercritical matter

    2-(4-Bromo­phen­yl)-N-(2-methoxy­phen­yl)acetamide

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    In the title compound, C15H14BrNO2, the 4-bromo­phenyl fragment makes a dihedral angle of 76.55 (17)° with the acetamide unit and the dihedral angle between the two benzene rings is 50.88 (14)°. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds and C—H⋯π contacts connect the mol­ecules, forming chains propagating in [100]

    Chinese Herbal Medicine Liu Jun Zi Tang and Xiang Sha Liu Jun Zi Tang for Functional Dyspepsia: Meta-Analysis of Randomized Controlled Trials

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    Objectives. To assess the efficacy and safety of Liu Jun Zi Tang (LJZT) and Xiang Sha Liu Jun Zi Tang (XSLJZT) for treating functional dyspepsia. Methods. Literature searches were carried out on Medline database, Cochrane Library, CNKI database, Chinese Biomedical Literature database, Wanfang database, and VIP database up to July 2012. Hand search for further references was conducted. Study selection, data extraction, quality assessment, and data analyses were performed according to the Cochrane standards. Results. Fifteen publications in total were suitable for inclusion. There was evidence that LJZT compared with prokinetic drugs increased symptom improvement (odds ratio 1.96, 95% CI 1.15 to 3.36). There was also evidence that XSLJZT compared with prokinetic drugs increased symptom improvement (odds ratio 2.63, 95% CI 1.72 to 4.03). No adverse events were reported in LJZT or XSLJZT group in any of these randomized controlled trials. Conclusion. LJZT and XSLJZT might be more effective compared with prokinetic drugs in the treatment of functional dyspepsia, and no side effects are identified in the included trials. However, due to poor methodological quality in the majority of included studies, the potential benefit from LJZT and XSLJZT need to be confirmed in rigorously designed, multicentre, and large-scale trials

    Engineering cofactor metabolism for improved protein and glucoamylase production in Aspergillus niger

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    Background: Nicotinamide adenine dinucleotide phosphate (NADPH) is an important cofactor ensuring intracellular redox balance, anabolism and cell growth in all living systems. Our recent multi-omics analyses of glucoamylase (GlaA) biosynthesis in the filamentous fungal cell factory Aspergillus niger indicated that low availability of NADPH might be a limiting factor for GlaA overproduction. Results: We thus employed the Design-Build-Test-Learn cycle for metabolic engineering to identify and prioritize effective cofactor engineering strategies for GlaA overproduction. Based on available metabolomics and 13C metabolic flux analysis data, we individually overexpressed seven predicted genes encoding NADPH generation enzymes under the control of the\ua0Tet-on gene switch in two A. niger recipient strains, one carrying a single and one carrying seven glaA gene copies, respectively, to test their individual effects on GlaA and total protein overproduction. Both strains were selected to understand if a strong pull towards glaA biosynthesis (seven gene copies) mandates a higher NADPH supply compared to the native condition (one gene copy). Detailed analysis of all 14 strains cultivated in shake flask cultures uncovered that overexpression of the gsdA gene (glucose 6-phosphate dehydrogenase), gndA gene (6-phosphogluconate dehydrogenase) and maeA gene (NADP-dependent malic enzyme) supported GlaA production on a subtle (10%) but significant level in the background strain carrying seven glaA gene copies. We thus performed maltose-limited chemostat cultures combining metabolome analysis for these three isolates to characterize metabolic-level fluctuations caused by cofactor engineering. In these cultures, overexpression of either the gndA or maeA gene increased the intracellular NADPH pool by 45% and 66%, and the yield of GlaA by 65% and 30%, respectively. In contrast, overexpression of the gsdA gene had a negative effect on both total protein and glucoamylase production. Conclusions: This data suggests for the first time that increased NADPH availability can indeed underpin protein and especially GlaA production in strains where a strong pull towards GlaA biosynthesis exists. This data also indicates that the highest impact on GlaA production can be engineered on a genetic level by increasing the flux through the pentose phosphate pathway (gndA gene) followed by engineering the flux through the reverse TCA cycle (maeA gene). We thus propose that NADPH cofactor engineering is indeed a valid strategy for metabolic engineering of A. niger to improve GlaA production, a strategy which is certainly also applicable to the rational design of other microbial cell factories.[Figure not available: see fulltext.]

    Exosomes from embryonic mesenchymal stem cells alleviate osteoarthritis through balancing synthesis and degradation of cartilage extracellular matrix

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    Abstract Background Mesenchymal stem cell therapy for osteoarthritis (OA) has been widely investigated, but the mechanisms are still unclear. Exosomes that serve as carriers of genetic information have been implicated in many diseases and are known to participate in many physiological processes. Here, we investigate the therapeutic potential of exosomes from human embryonic stem cell-induced mesenchymal stem cells (ESC-MSCs) in alleviating osteoarthritis (OA). Methods Exosomes were harvested from conditioned culture media of ESC-MSCs by a sequential centrifugation process. Primary mouse chondrocytes treated with interleukin 1 beta (IL-1β) were used as an in vitro model to evaluate the effects of the conditioned medium with or without exosomes and titrated doses of isolated exosomes for 48 hours, prior to immunocytochemistry or western blot analysis. Destabilization of the medial meniscus (DMM) surgery was performed on the knee joints of C57BL/6 J mice as an OA model. This was followed by intra-articular injection of either ESC-MSCs or their exosomes. Cartilage destruction and matrix degradation were evaluated with histological staining and OARSI scores at the post-surgery 8 weeks. Results We found that intra-articular injection of ESC-MSCs alleviated cartilage destruction and matrix degradation in the DMM model. Further in vitro studies illustrated that this effect was exerted through ESC-MSC-derived exosomes. These exosomes maintained the chondrocyte phenotype by increasing collagen type II synthesis and decreasing ADAMTS5 expression in the presence of IL-1β. Immunocytochemistry revealed colocalization of the exosomes and collagen type II-positive chondrocytes. Subsequent intra-articular injection of exosomes derived from ESC-MSCs successfully impeded cartilage destruction in the DMM model. Conclusions The exosomes from ESC-MSCs exert a beneficial therapeutic effect on OA by balancing the synthesis and degradation of chondrocyte extracellular matrix (ECM), which in turn provides a new target for OA drug and drug-delivery system development

    The effects of potato mud on the dough and the quality of bread

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    In order to increase the utilization rate of potato and enrich the type of staple bread, five different varieties of potato samples were selected and steamed into potato mud, which was added to bread flour in 30% proportions to make bread. The influences of the potato mud paste on the rheology and fermentation properties of mixed dough were investigated by a Brabender Farinograph, Extensograph and Chopin F4 Rheofermentometer. The effects of adding potato mud paste on the quality of bread were explored by sensory evaluation and instrumental analysis. The results showed that, in comparison with control samples, the addition of potato mud weakened the dough gluten and decreased processing performance slightly, whereas the dough remained the good gas holding capacity and gas production capacity. The fermentation performances of dough kept same level. After adding potato mud, the bread volume became larger. The instrumental analysis shows that the brightness of the bread slices increased and the volume of coarse stomata were improved after the additions of potato variety No.3, No.4 and No.5,. Furthermore,, potato variety No.5 showed superior processing quality and obtained higher sensory evaluation scores which is considered to be suitable for making potato-mixed bread
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