Determination of organic acids evolution during apple cider fermentation using an improved HPLC analysis method

An efficient method for analyzing ten organic acids in food, namely citric, pyruvic, malic, lactic, succinic, formic, acetic, adipic, propionic and butyric acids, using HPLC was developed. Boric acid was added into the mobile phase to separate lactic and succinic acids, and a post-column buffer solution [5 mmol/L p-toluensulfonic acid (p-TSA) + 20 mmol/L bis (2-hydroxyethyl) iminotris (hydroxymethyl) methane (bis¿tris) + 100 ¿mol/L sodium ethylenediaminetetraacetic (EDTA-2Na)] was used to improve the sensitivity of detection. The average spiked recoveries for the ten organic acids ranged from 82.9 to 127.9% with relative standard deviations of 1.44¿4.71%. The linear ranges of determination were from 15 to 1,000 mg/L with correlation coefficients of 0.9995¿0.9999. The metabolism of organic acids in cider, and the effect of nutrients including diammonium phosphate (DAP), thiamine, biotin, niacinamide and pantothenic acid on their metabolism, were studied using this method of analysis. We found that before cider brewing, additions of 200 mg/L DAP and 0.3 mg/L thiamine to apple juice concentrate results in a high quality cider

Minimum Entangling Power is Close to Its Maximum

Given a quantum gate $U$ acting on a bipartite quantum system, its maximum (average, minimum) entangling power is the maximum (average, minimum) entanglement generation with respect to certain entanglement measure when the inputs are restricted to be product states. In this paper, we mainly focus on the 'weakest' one, i.e., the minimum entangling power, among all these entangling powers. We show that, by choosing von Neumann entropy of reduced density operator or Schmidt rank as entanglement measure, even the 'weakest' entangling power is generically very close to its maximal possible entanglement generation. In other words, maximum, average and minimum entangling powers are generically close. We then study minimum entangling power with respect to other Lipschitiz-continuous entanglement measures and generalize our results to multipartite quantum systems. As a straightforward application, a random quantum gate will almost surely be an intrinsically fault-tolerant entangling device that will always transform every low-entangled state to near-maximally entangled state.Comment: 26 pages, subsection III.A.2 revised, authors list updated, comments are welcom

Development of a high strength Al-Mg2Si-Mg-Zn based alloy for high pressure die casting

A high strength Al-Mg2Si-Mg-Zn based alloy has been developed for the application in high pressure die casting to provide improved mechanical properties. The effect of various alloying elements on the microstructure and mechanical properties including yield strength, ultimate tensile strength and elongation of the alloy was investigated under the as-cast and heat-treated conditions. The typical composition of the high strength alloy has been optimised to be Al-8.0wt%Mg2Si-6.0wt%Mg-3.5wt%Zn-0.6wt%Mn (Al-11.0wt%Mg-2.9wt%Si-3.5wt%Zn-0.6wt%Mn) with unavoidable trace impurities. The mechanical properties of the alloy were enhanced by a quick solution treatment followed by ageing treatment. The improved tensile properties were at a level of yield strength over 300MPa, the ultimate tensile strength over 420MPa and the elongation over 3% assessed using international standard tensile samples made by high pressure die casting. The microstructure of the die-cast alloy consisted of the primary α-Al phase, Al-Mg2Si eutectics, AlMgZn intermetallics and α-AlFeMnSi intermetallics under the as-cast condition. The AlMgZn intermetallic compound was dissolved into the Al-matrix during solution treatment and subsequently precipitated during ageing treatment for providing the effective improvement of the mechanical properties.The financial support is gratefully acknowledged for the Engineering and Physical Sciences Research Council (EPSRC) (Project number: EP/I038616/1), Technology Strategy Board (TSB) (Project number: 101172) and Jaguar Land Rover (JLR), United Kingdom

CO (J = 1–0) Observations toward Filamentary Molecular Clouds in the Galactic Region with l = [169.°75, 174.°75], b = [−0.°75, 0.°5]

We present observations of the CO isotopologues (12CO, 13CO, and C18O) toward the Galactic region with 169fdg75 ≤ l ≤ 174fdg75 and −0fdg75 ≤ b ≤ 0fdg5 using the Purple Mountain Observatory 13.7 m millimeter-wavelength telescope. Based on the 13CO (J = 1 − 0) data, we find five molecular clouds within the velocity range between −25 and 8 km s−1 that are all characterized by conspicuous filamentary structures. We have identified eight filaments with a length of 6.38–28.45 pc, a mean H2 column density of 0.70 × 1021–6.53 × 1021 cm−2, and a line mass of 20.24–161.91 M ☉ pc−1, assuming a distance of ~1.7 kpc. Gaussian fittings to the inner parts of the radial density profiles lead to a mean FWHM width of 1.13 ± 0.01 pc. The velocity structures of most filaments present continuous distributions with slight velocity gradients. We find that turbulence is the dominant internal pressure to support the fragmentation of filaments instead of thermal pressure. Most filaments have virial parameters smaller than 2; thus, they are gravitationally bound. Four filaments have an LTE line mass close to the virial line mass. We further extract dense clumps using the 13CO data and find that 64% of the clumps are associated with the filaments. According to the complementary IR data, most filaments have associated Class II young stellar objects. Class I objects are mainly found to be located in the filaments with a virial parameter close to 1. Within two virialized filaments, 12CO outflows have been detected, indicating ongoing star-forming activity therein.National Key Research & Development of China [2017YFA0402702]; European Unions Horizon 2020 research and innovation program [639459]; NSFC [11473069, 11503086, 11629302]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Identification of the functional binding pocket for compounds targeting small-conductance Ca²⁺-activated potassium channels.

Small- and intermediate-conductance Ca(2+)-activated potassium channels, activated by Ca(2+)-bound calmodulin, have an important role in regulating membrane excitability. These channels are also linked to clinical abnormalities. A tremendous amount of effort has been devoted to developing small molecule compounds targeting these channels. However, these compounds often suffer from low potency and lack of selectivity, hindering their potential for clinical use. A key contributing factor is the lack of knowledge of the binding site(s) for these compounds. Here we demonstrate by X-ray crystallography that the binding pocket for the compounds of the 1-ethyl-2-benzimidazolinone (1-EBIO) class is located at the calmodulin-channel interface. We show that, based on structure data and molecular docking, mutations of the channel can effectively change the potency of these compounds. Our results provide insight into the molecular nature of the binding pocket and its contribution to the potency and selectivity of the compounds of the 1-EBIO class