105 research outputs found

    Sulfur Trioxide Micro-Thermal Explosion for Rice Straw Pretreatment

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    Wave Characteristics of Falling Film on Inclination Plate at Moderate Reynolds Number

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    Falling water film on an inclined plane is studied by shadowgraphy. The ranges of inclination angle and the film Reynolds number are, respectively, up to 21° and 60. Water is used as working fluid. The scenario of wave regime evolution is identified as three distinctive regimes, namely, initial quiescent smooth film flow, two-dimensional regular solitary wave pattern riding on film flow, and three-dimensional irregular wave pattern. Three characteristic parameters of two-dimensional solitary wave pattern, namely, inception length, primary pulse spacing, and propagation velocity, are examined, which are significant in engineering applications for estimation of heat and mass transfer on film flow. The present experimental data are well in agreement with the Koizumi correlations, the deviation from which is limited to 20% and 15%, respectively, for primary pulse spacing and propagation velocity. Through the scrutiny of the present experimental observation, it is concluded that wave evolution on film flow at the moderate Reynolds number is controlled by gravity and drag and the Rayleigh-Taylor instability that occurred on the steep front of primary pulse triggers the disintegration of continuous two-dimensional regular solitary wave pattern into three-dimensional irregular wave pattern

    A Thermostable β-Glucuronidase Obtained by Directed Evolution as a Reporter Gene in Transgenic Plants

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    A β-glucuronidase variant, GUS-TR3337, that was obtained by directed evolution exhibited higher thermostability than the wild-type enzyme, GUS-WT. In this study, the utility of GUS-TR337 as an improved reporter was evaluated. The corresponding gus-tr3337 and gus-wt genes were independently cloned in a plant expression vector and introduced into Arabidopsis thaliana. With 4-MUG as a substrate, plants containing the gus-wt gene showed no detectable β-glucuronidase activity after exposure to 60°C for 10 min, while those hosting the gus-tr3337 gene retained 70% or 50% activity after exposure to 80°C for 10 min or 30 min, respectively. Similarly, in vivo β-glucuronidase activity could be demonstrated by using X-GLUC as a substrate in transgenic Arabidopsis plants hosting the gus-tr3337 gene that were exposed to 80°C for up to 30 min. Thus, the thermostability of GUS-TR3337 can be exploited to distinguish between endogenous and transgenic β-glucuronidase activity, which is a welcome improvement in its use as a reporter

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

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    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

    First measurement of the Z→μ+μ− angular coefficients in the forward region of pp collisions at √s = 13 TeV

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    The first study of the angular distribution of μ + μ − pairs produced in the forward rapidity region via the Drell-Yan reaction p p → γ ∗ / Z + X → ℓ + ℓ − + X is presented, using data collected with the LHCb detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.1     fb − 1 . The coefficients of the five leading terms in the angular distribution are determined as a function of the dimuon transverse momentum and rapidity. The results are compared to various theoretical predictions of the Z -boson production mechanism and can also be used to probe transverse-momentum-dependent parton distributions within the proton

    Effect of Tween 80 on production of lactic acid by <i>Lactobacillus casei</i>

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    Batch fermentation was performed to investigate the effect of Tween 80 on the growth and the production of lactic acid of Lactobacillus casei. Both, amount and yield of lactic acid, increased by 8% when the fermentation medium was supplemented with 0.1% (w/v) Tween 80 in comparison with the control (without Tween 80 addition) at 48 h. Optimization of Tween 80 concentration in the range of 0.04-0.5% (w/v) showed that 0.07% (w/v) Tween 80 was the optimum for lacticacid production and cell growth. With addition of 0.07% (w/v) Tween 80, yeast extract concentration could be decreased from 1.0% to 0.7% (w/v) while still maintaining high lactic acid yield and sugar conversion

    Phosphine Catalyst-Controlled Cycloaddition or Dienylation Reactions of Trifluoromethyl Aryl Ketones with Bis-Substituted Allenoates

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    A chemoselective phosphine-catalyzed cycloaddition or dienylation reaction between trifluoromethyl-substituted ketones and bis-substituted allenoates was described. Under the catalysis of triarylphosphine, the reaction gave a range of trifluoromethylated tetrahydrofurans with broad substrate tolerance and good to excellent stereoselectivity, while the use of trialkylphosphine switched the reaction pathway to furnish CF<sub>3</sub>-substituted dienyl tertiary alcohols chemoselectively. Moreover, a preliminary study on the asymmetric version of the reaction was also performed, which represents the first example of a phosphine-catalyzed asymmetric reaction between allenoates and carbonyl compounds
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