Autophagy is an evolutionarily conserved intracellular degradation process. During autophagy, a set of autophagy-related (ATG) proteins orchestrate the formation of double-bound membrane vesicles ...called autophagosomes to engulf cytoplasmic material and deliver it to the vacuole for breakdown. Among ATG proteins, the ATG8 is the only one decorating mature autophagosomes and therefore is regarded as a bona fide autophagic marker; colocalization assays with ATG8 are wildly used as a reliable method to identify the components of autophagy machinery or autophagic substrates. Here, we describe a colocalization assay with fluorescent-tagged ATG8 using a tobacco (
)-based transient expression system.
Two kinds of graphene coatings are obtained by the graphene drop-coating drying method (DCDM) and the coating graphene conductive adhesive (CGCA). The effects of these two kinds of graphene coatings ...on the friction, wear, and voltage signals of the electrical contact interface are explored. The test results show that the presence of the graphene coating can effectively reduce the friction coefficient and friction force, and the graphene coating prepared by the DCDM possesses the best ability in reducing the friction coefficient. Although the presence of the graphene coating will lead to the increase in interface contact voltage at the initial stage, the voltage signal gradually becomes stable with the progress of friction and wear, suggesting that the graphene coating will not affect the stability of sliding electrical contact. Wear analysis results show that the graphene coating prepared by the DCDM has a good anti-wear effect, and the graphene particles in the abrasion area play the role of solid lubrication. Finite element analysis results show that the graphene coating will generate thermal expansion when electric current is applied, accordingly avoid the direct contact between the metal substrate, and, thus, reduce the interface friction and alleviate the wear degree of interface. However, the normal force fluctuation of the interface may increase.
Lithium bis(oxalate)borate (LiBOB) has many unique properties, such as thermal stability and the formation of a stable passivation layer on the surface of carbonaceous anode. In this work, the ...electrochemical behaviors of sulfolane (SL) with LiBOB were studied by employment of dimethyl sulfite (DMS) and diethyl sulfite (DES) as mixed solvents, respectively. When used in Li/MCMB (mesophase carbon microbeads) cells at 60°C, only LiBOB-SL/DMS electrolyte exhibits not only excellent film-forming characteristics, but also good thermal stability of the interface film on the surface of MCMB. Besides, when used in LiFePO4/Li cells at 60°C, only LiBOB-SL/DMS electrolyte simultaneously exerts several advantages, such as good thermal stability of the interface film on the surface of LiFePO4, stable cycling performance, high mean voltage, and excellent discharge rate performance. It suggests that LiBOB-SL/DMS electrolyte is an excellent candidate electrolyte for high-temperature lithium ion batteries.
Regulator and substrate Li, Faqiang; Vierstra, Richard D.
Autophagy,
06/2012, Letnik:
8, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Like other organisms, plants rely on autophagy to recycle intracellular components needed for development, new growth and survival during nutrient stress. This 'self eating' is a catabolic process by ...which unwanted cytoplasmic materials and dysfunctional organelles are sequestered into vesicles and subsequently delivered to the vacuole for breakdown. The process is tightly regulated by the autophagy-related 1(ATG1)-ATG13 kinase complex which is controlled by multiple nutrient-responsive upstream regulators that integrate nutrient demand with availability. To further appreciate how autophagy is controlled in plants, we recently examined the functions of the ATG1-ATG13 complex in Arabidopsis thaliana. Our data revealed a dual role for the ATG1-ATG13 complex, first as a regulator of plant autophagy, and second as a substrate of this recycling process.
Sulfur and copper codoped TiO
2
nanoparticles were prepared by sol-hydrothermal process. And the samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Raman ...spectra analysis, scanning electron microscopy, Brunauer Emmett Teller analysis, UV–vis diffuse reflectance spectroscopy, X-ray photoelectron spectra and X-ray fluorescence analysis. It was found that the S, Cu-codoped TiO
2
became amorphous with the increase of Cu content, and copper on the surface of TiO
2
existed in the oxidation state of Cu(II) while S in the form of S
6+
species. And the codoped particles had higher surface area, smaller particle size, stronger spectral response in visible region compared with pure TiO
2
. The effects of doping amount in a wide range, catalyst dosage, and recycle on the photocatalytic activity of the codoped catalysts were investigated with Acid Orange 7 as the model compound under visible light illumination (λ > 447 nm). The results showed that S (2.0 %), Cu (5.0 %) codoped TiO
2
had the highest visible light photocatalytic activity and good reusability performance. The kinetic study showed that this photocatalytic process coincided with the Langmuir–Hinshelwood pseudo first order reaction model.
In this work, we propose a non-orthogonal multiple-relaxation-time (MRT) lattice Boltzmann method (LBM) for the two-dimensional (2D) incompressible Navier-Stokes equations in vorticity-stream ...function formulation. In this method, the vorticity and the streamfunction equations are calculated by two separate LB equations, which are constructed by using the non-orthogonal transformation matrix. Most importantly, to eliminate the residual term that may appear in the recovered vorticity equation, the convection term is handled as a source term in the LB equation rather than being directly recovered by the evolution equation. In addition, due to the convection term in our method is computed with a local scheme, it retains the parallel feature of the standard LBM. We then test the accuracy and the stability of the present LBM by considering various benchmark examples. The results show that the present method has a second-order convergence rate in space. Our numerical results indicate that the present LBM is a good candidate for solving streamfunction-vorticity formulation.
•A MRT LBM is proposed for vorticity-streamfunction formulation.•The present model is constructed with a simple non-orthogonal matrix.•The convection term in vorticity equation is treated as a source in the LBE.
Despite ongoing research on carotenoid biosynthesis in model organisms, there is a paucity of information on pathway regulation operating in the grasses (Poaceae), which include plants of world-wide ...agronomic importance. As a result, efforts to either breed for or metabolically engineer improvements in carotenoid content or composition in cereal crops have led to unexpected results. In comparison to maize (Zea mays), rice (Oryza sativa) accumulates no endosperm carotenoids, despite having a functional pathway in chloroplasts. To better understand why these two related grasses differ in endosperm carotenoid content, we began to characterize genes encoding phytoene synthase (PSY), since this nuclear-encoded enzyme appeared to catalyze a rate-controlling step in the plastid-localized biosynthetic pathway. The enzyme had been previously associated with the maize Y1 locus thought to be the only functional gene controlling PSY accumulation, though function of the Y1 gene product had never been demonstrated. We show that both maize and rice possess and express products from duplicate PSY genes, PSY1 (Y1) and PSY2; PSY1 transcript accumulation correlates with carotenoid-containing endosperm. Using a heterologous bacterial system, we demonstrate enzyme function of PSY1 and PSY2 that are largely conserved in sequence except for N- and C-terminal domains. By database mining and use of ortholog-specific universal PCR primers, we found that the PSY duplication is prevalent in at least eight subfamilies of the Poaceae, suggesting that this duplication event preceded evolution of the Poaceae. These findings will impact study of grass phylogeny and breeding of enhanced carotenoid content in an entire taxonomic group of plant crops critical for global food security.
Carotenoids are a complex class of isoprenoid pigments playing diverse roles in plants and providing nutritional value. Metabolic engineering of the biosynthetic pathway has been of interest to ...specifically address global vitamin A deficiency by breeding cereal crop staples in the Poaceae (Grass family) for elevated levels of provitamin A carotenoids. However, there remain open questions about the rate-controlling steps that limit predictability of metabolic engineering in plants, whether by transgenic or nontransgenic means. We decided to focus on the first committed biosynthetic step which is mediated by phytoene synthase. Our studies revealed that in the Grasses, PSY is encoded by three genes. Maize transcript profiling, together with carotenoid and ABA analysis, revealed that the three PSY copies have subfunctionalized and provide the Grasses with a fine tine control of carotenogenesis in response to various developmental and external cues. Promoter analysis supports subfunctionalization; cis-element analysis of maize PSY1 alleles and comparison with Grass orthologs suggests that man's selection of yellow maize endosperm has occurred at the expense of a change of gene regulation in photosynthetic tissue as compared to the progenitor white endosperm PSY1 allele.
Boron removal by ion exchange resin from refined brine which was used to produce low-boron lithium salts was studied. A new boron-specific resin, XSC-800 was used in the experiments for the ...separation of boron. The column-mode and batch-mode sorption studies were both performed so as to obtain the optimum conditions for boron removal from refined brine. Parameters such as flow rate of brine, boron concentration, temperature, pH, height/diameter (
H/
D) ratio of the column, anion concentration, stirring speed and diameter of the resin were investigated. The results showed that the removal effect of boron by XSC-800 improved with increasing temperature, pH,
H/
D ratio, and with decreasing the flow rate of brine, boron concentration, chloride anion concentration and diameter of the resin. While the stirring speed and the recycles of the resin had no significant effects on boron removal. As a result, boron can be removed from refined brine much completely by the resin at the optimum conditions. On the other hand, kinetics of the exchange process was studied by using the moving boundary model. In order to describe the kinetics more accurately, the model was modified by introducing a time correction factor. The results showed that the rate-determining step of this process under the conditions studied was controlled by particle diffusion. In addition, the apparent activation energy
E
a of the process was found to be 20.38
kJ/mol.
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