311 research outputs found

    Tetramethyl pyrazine exerts anti-apoptotic and antioxidant effects in a mouse model of MPTP-induced Parkinson's disease via regulation of the expressions of Bax, Bcl-2, Nrf2 and GCLC

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    Purpose: To investigate the effect of tetramethyl pyrazine (TMP) on MPTP)-mediated neuronal apoptosis and oxidative imbalance in mice, and the mechanism of action involved. Methods: Forty-five mice were assigned evenly to blank control, MPTP and TMP groups. The protein concentrations of Bax, Bcl-2, cytochrome C (Cyt c), Nrf2, GCLC and cleaved caspase-3; and levels of glutathione (GSH) and thiobarbituric acid reactive products (TBARS) were evaluated and compared amongst the groups. Results: Cyt c, Bax, and cleaved caspase-3 protein levels in TMP group were significantly lower than those in MPTP group, while Bcl-2 protein expression was higher in TMP group than in MPTP mice (p < 0.05). Furthermore, TBARS was lower in TMP group than in MPTP group, while GSH level increased, relative to MPTP mice. The levels of Nrf2 and GCLC were significantly higher in TMP group than in MPTP group (p < 0.05). Conclusion: Tetramethyl pyrazine exerts anti-apoptotic and antioxidant effects on MPTP-mediated Parkinsonism via regulation of the expressions of Bax, Bcl-2, Nrf2 and glutamate-cysteine ligase catalytic subunit. Thus, TMP has potential for use in the treatment Parkinson’s disease

    Capacitive Properties and Structure of RuOâ‚‚-HfOâ‚‚ Films Prepared by Thermal Decomposition Method

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    Binary RuO2-HfO2 films on Ti substrates were prepared by a thermal decomposition method. cyclic voltammetric and charge/discharge properties of the RuO2-HfO2 electrodes were characterized. It was determined that the incorporation of HfO2 into RuO 2 greatly improved the capacitive properties of the material. The RuO2-HfO2 electrodes showed excellent cyclic stability, with no decay in charge capability during 1000 CV cycles in acidic solution. A nominal content of 50 mol% RuO2 and 50 mol% HfO2 gave the highest specific capacitance of 789.3 F/g (RuO2). The excellent capacitive properties and stability were related to the hydrous amorphous mixed-oxides formed in the film. This work proves that high capacitive performance of RuO2-based electrode materials can be obtained by thermal decomposition, even with the retained chloride in the film

    Capacitive Properties and Structure of RuOâ‚‚-HfOâ‚‚ Films Prepared by Thermal Decomposition Method

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    Binary RuO2-HfO2 films on Ti substrates were prepared by a thermal decomposition method. cyclic voltammetric and charge/discharge properties of the RuO2-HfO2 electrodes were characterized. It was determined that the incorporation of HfO2 into RuO 2 greatly improved the capacitive properties of the material. The RuO2-HfO2 electrodes showed excellent cyclic stability, with no decay in charge capability during 1000 CV cycles in acidic solution. A nominal content of 50 mol% RuO2 and 50 mol% HfO2 gave the highest specific capacitance of 789.3 F/g (RuO2). The excellent capacitive properties and stability were related to the hydrous amorphous mixed-oxides formed in the film. This work proves that high capacitive performance of RuO2-based electrode materials can be obtained by thermal decomposition, even with the retained chloride in the film

    Vertically-aligned Mn(OH)2 nanosheet films for flexible all-solid-state electrochemical supercapacitors

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    The arrangement of the electrode materials is a significant contributor for constructing high performance supercapacitor. Here, vertically-aligned Mn(OH)2 nanosheet thin films were synthesized by cathodic electrodeposition technique on flexible Au coated polyethylene terephthalate substrates. Morphologies, microstructures, chemical compositions and valence state of the nanosheet films were characterized systematically. It shows that the nanosheets arranged vertically to the substrate, forming a porous nanowall structures and creating large open framework, which greatly facilitate the adsorption or diffusion of electrolyte ions for faradaic redox reaction. Electrochemical tests of the films show the specific capacitance as high as 240.2 F g−1 at 1.0 A g−1. The films were employed to assemble symmetric all-solid-state supercapacitors with LiCl/PVA gel severed as solid electrolyte. The solid devices exhibit high volumetric capacitance of 39.3 mF cm−3 at the current density 0.3 mA cm−3 with robust cycling stability. The superior performance is attributed to the vertically-aligned configuration

    Doped Titanium Dioxide Films Prepared by Pulsed Laser Deposition Method

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    TiO2 was intensively researched especially for photocatalystic applications. The nitrogen-doped TiO2 films prepared by pulsed laser deposition (PLD) method were reviewed, and some recent new experimental results were also presented in this paper. A new optical transmission method for evaluating the photocatalystic activity was presented. The main results are (1) PLD method is versatile for preparing oxide material or complex component films with excellent controllability and high reproducibility. (2) Anatase nitrogen-doped TiO2 films were prepared at room temperature, 200°C, and 400°C by PLD method using novel ceramic target of mixture of TiN and TiO2. UV/Vis spectra, AFM, Raman spectra, and photocatalystic activity for decomposition of methyl orange (MO) tests showed that visible light response was improved at higher temperature. (3) The automatic, continuous optical transmission autorecorder method is suitable for detecting the photodecomposition dynamic process of organic compound

    A Novel Partitivirus that Confers Hypovirulence on Plant Pathogenic Fungi

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    Members of the family Partitiviridae have bisegmented double-stranded RNA (dsRNA) genomes and are not generally known to cause obvious symptoms in their natural hosts. An unusual partitivirus, Sclerotinia sclerotiorum partitivirus 1 (SsPV1/WF-1), conferred hypovirulence on its natural plant-pathogenic fungal host, Sclerotinia sclerotiorum strain WF-1. Cellular organelles, including mitochondria, were severely damaged. Hypovirulence and associated traits of strain WF-1 and SsPV1/WF-1 were readily cotransmitted horizontally via hyphal contact to different vegetative compatibility groups of S. sclerotiorum and interspecifically to Sclerotinia nivalis and Sclerotinia minor. S. sclerotiorum strain 1980 transfected with purified SsPV1/WF-1 virions also exhibited hypovirulence and associated traits similar to those of strain WF-1. Moreover, introduction of purified SsPV1/WF-1 virions into strain KY-1 of Botrytis cinerea also resulted in reductions in virulence and mycelial growth and, unexpectedly, enhanced conidial production. However, virus infection suppressed hyphal growth of most germinating conidia of B. cinerea and was eventually lethal to infected hyphae, since very few new colonies could develop following germ tube formation. Taken together, our results support the conclusion that SsPV1/WF-1 causes hypovirulence in Sclerotinia spp. and B. cinerea. Cryo-EM (cryo-electron microscopy) reconstruction of the SsPV1 particle shows that it has a distinct structure with similarity to the closely related partitiviruses Fusarium poae virus 1 and Penicillium stoloniferum virus F. These findings provide new insights into partitivirus biological activities and clues about molecular interactions between partitiviruses and their hosts. IMPORTANCE: Members of the Partitiviridae are believed to occur commonly in their phytopathogenic fungal and plant hosts. However, most partitiviruses examined so far appear to be associated with latent infections. Here we report a partitivirus, SsPV1/WF-1, that was isolated from a hypovirulent strain of Sclerotinia sclerotiorum and describe its biological and molecular features. We have demonstrated that SsPV1 confers hypovirulence. Furthermore, SsPV1 can infect and cause hypovirulence in Botrytis cinerea. Our study also suggests that SsPV1 has a vigorous ability to proliferate and spread via hyphal contact. SsPV1 can overcome vegetative incompatibility barriers and can be transmitted horizontally among different vegetative compatibility groups of S. sclerotiorum, even interspecifically. Cryo-EM reconstruction of SsPV1 shows that it has a distinct structure with similarity to closely related partitiviruses. Our studies exploit a novel system, SsPV1 and its hosts, which can provide the means to explore the mechanisms by which partitiviruses interact with their hosts

    Effects of rotation angle and metal foam on natural convection of nanofluids in a cavity under an adjustable magnetic field

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    © 2019 Elsevier Ltd To investigate the natural convection heat transfer of Fe3O4-water nanofluids in a rectangular cavity under an adjustable magnetic field, two experimental systems are established. Meanwhile, several factors, such as nanoparticle mass fractions (ω = 0%, 0.1%, 0.3%, 0.5%), magnetic field directions (horizontal and vertical), magnetic field intensities (B = 0.0 T, 0.01 T, 0.02 T), rotation angles of the cavity (α = 0°, 45°, 90°, 135°), and PPI of Cu metal foam (PPI = 0, 5, 15) are taken into consideration to research the natural convection of Fe3O4-water nanofluids in a rectangular cavity. With the increasing nanoparticle mass fraction, Nusselt number firstly rises but then falls, and the maximum value of which appears at a nanoparticle mass fraction ω = 0.3%. Horizontal magnetic field is not significant to the thermal performance enhancement, but vertical magnetic field shows an opposite trend and makes a positive contribution to the thermal performance. The cavity with a rotation angle α = 90° shows the highest thermal performance. Nusselt number of the cavity filled with metal foam can be improved obviously compared with that without metal foam. But the increasing PPI of metal foam is disadvantageous to heat transfer performance

    Evaluation of in-shoe plantar pressure and shear during walking for diabetic foot ulcer prevention.

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    To investigate reliability and changes of in-shoe plantar pressure and shear during walking at three cadences with two insole designs. This was a precursor to the investigation of plantar loading in people with diabetes for potential foot ulcer prevention. A sensorised insole system, capable of measuring plantar pressure and shear at the heel, fifth metatarsal head (5MH), first metatarsal head (1MH) and hallux, was tested with ten healthy participants during level walking. Reliability was evaluated, using intra-class correlation coefficient (ICC), while varying the cadences and insole types. Percentage changes in pressure and shear relative to values obtained at self-selected cadence with a flat insole design were investigated. Mean±standard deviation of maximum pressure, medial-lateral and anterior-posterior shear of up to 380±24kPa, 46±2kPa and -71±4kPa, respectively, were measured. The ICC in ranges of 0.762-0.973, 0.758-0.987 and 0.800-0.980 were obtained for pressure, anterior-posterior and medial-lateral shear, respectively. Opposite anterior-posterior shear directions between 5MH and 1MH (stretching), and between 1MH and hallux (pinching) were observed for some participants. Increasing cadence increased pressure and anterior-posterior shear (by up to +77%) but reduced medial-lateral shear at the heel and hallux (by up to -34%). Slower cadence increased anterior-posterior shear (+114%) but decreased medial-lateral shear (-46%) at the hallux. The use of a flexible contoured insole resulted in pressure reduction at the heel and 5MH but an increase in anterior-posterior shear at the heel (+69%) and hallux (+75%). The insole system demonstrated good reliability and is comparable to reported pressure-only systems. Pressure measurements were sensitive to changes in cadence and insole designs in ways that were consistent with the literature. However, our plantar shear showed localised shear changes with cadences and insoles for the first time, as well as stretching and pinching effects on plantar tissue. This opens new possibilities to investigate plantar tissue viability, loading characteristics and orthotic designs aimed towards foot ulcer prevention
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