ENZYMATIC MACERATION OF APPLE PARENCHYMA TISSUE. II. EFFECT OF THE DEGREE OF RIPENESS ON THE KINETIC BEHAVIOUR

Apples of four degrees of ripeness were selected to investigate the effect of ripening on maceration of apple tissue by polyglacturonase (PG) using the model proposed to describe the kinetics of maceration [1]. This model permitted to describe the kinetics for all four samples but the precision of the adjustment showed a slight diminution with the degree of ripeness. The proportion of apple tissue macerated by the fast (process 1) and slow (process 2) processes was the only parameter of the model which changed with the degree of ripeness. Analysis of the maceration products (pulp and juice) revealed that these two fractions were gradually degraded during the maceration time.     

Chaotic multi-verse optimizer-based feature selection

Neural Computing and Applications - The multi-verse optimizer (MVO) is a new evolutionary algorithm inspired by the concepts of multi-verse theory namely, the white/black holes, which represents...     

Multi-objective orthogonal opposition-based crow search algorithm for large-scale multi-objective optimization

Neural Computing and Applications - Many engineering optimization problems are typically multi-objective in their natures and multidisciplinary with a large number of decision variables....     

Insights into Phase Evolution and Mechanical Behavior of the Eutectoid Ti–6.4(wt%)Ni Alloy Modified with Fe and Cr

Titanium alloys gain increasing importance in industry due to the expansion of advanced manufacturing technologies such as additive manufacturing. Conventional titanium alloys processed by such technologies suffer from formation of large primary grains and anisotropy of mechanical properties. Therefore, novel alloys are required. Herein, the effect of ternary alloying elements Fe and Cr on the Ti–6.4(wt%)Ni eutectoid system is investigated. Both elements act as eutectoid formers. Fe and Cr show sluggish transformation behavior, whereas Ni is an active eutectoid-forming element. Thereby, sluggish refers to slow and active to fast transformation kinetics. The focus of this work is on the combined addition of such elements studied under different heat-treatment conditions. It is shown in the results that largely varying microstructures can be generated resulting in hardness values ranging from 239 to 556 HV_0.1. Moreover, the formation of a substructure within the α phase of direct aged alloys is observed. The formation mechanism of this substructure is investigated in detail. The mechanical properties are discussed based on the microstructural characteristics. The presence of intermetallic Ti₂Ni phase increases the Young's modulus, whereas the presence of ω phase results in embrittlement. The results shed light upon the complex phase formation and decomposition behavior of titanium alloys based on Ti–6.4Ni.     

Tryptophan Synthase: Biocatalyst Extraordinaire

Tryptophan synthase (TrpS) has emerged as a paragon of noncanonical amino acid (ncAA) synthesis and is an ideal biocatalyst for synthetic and biological applications. TrpS catalyzes an irreversible, C−C bond-forming reaction between indole and serine to make l -tryptophan; native TrpS complexes possess fairly broad specificity for indole analogues, but are difficult to engineer to extend substrate scope or to confer other useful properties due to allosteric constraints and their heterodimeric structure. Directed evolution freed the catalytically relevant TrpS β-subunit (TrpB) from allosteric regulation by its TrpA partner and has enabled dramatic expansion of the enzyme's substrate scope. This review examines the long and storied career of TrpS from the perspective of its application in ncAA synthesis and biocatalytic cascades.     

Synthesis, structural analysis and pharmacological effects of N2-substituted 3,4-dihydrobenzo[h]quinolin-2-amines

The introduction outlines possibilities for the design of potentially pharmacologically interesting new modifications of phenylethylamine (1) and reviews already known and nearly prepared derivatives of 1 with bridged side chains. The N2-substituted 3,4-dihydrobenzo[h]quinolin-2-amines 11a-e represent bridged beta-azanaphthylethenamines or naphthyl-formamidines. Their synthesis started from 3-chloro-N-(1-naphthyl)propionamide (14) and led via dihydrobenzoquinolinone 15, thione 19 and methylthiobenzoquinoline hydroiodide 20. HI as intermediates first to the hydroiodides of 11a-e. Treatment of 11c, d. HI with sodium hydroxide yielded the free amines 11c, d. Structure, tautomerism, (Z, E)-isomerism and conformation of the prepared benzoquinolines were studied and elucidated by one and two dimensional NMR. A synopsis of the manyfold pharmacological effects, which were found in the course of the testing of 11a-e. HI, completes the paper.     

Activations of mitogen-activated protein kinases and phospholipase D in A7r5 vascular smooth muscle cells

Activation of mitogen-activated protein kinases (MAPKs) was examined in the A7r5 rat vascular smooth muscle cell line. Treatment of A7r5 cells with vasopressin, phorbol ester (PMA), or serum resulted in activation of two MAPKs, Erk-1 and Erk-2. Phosphatidylinositol-specific phospholipase C was activated in response to vasopressin but not to PMA. Vasopressin and PMA both caused maximal activation of PLD within 5 minutes. Application of bacterial phospholipase D (PLD) to A7r5 cells increased phosphatidic acid to levels similar to those seen with vasopressin or PMA. Acute exposure of the cells to vasopressin, PMA, or PLD increased phosphorylation of many of the same cytosolic and membrane proteins. However, bacterial PLD did not promote significant activation of Erk-1 and Erk-2. Phosphatidic acid and lysophosphatidic acid (LPA) likewise did not stimulate MAPK activity in A7r5 cells. Serum and vasopressin stimulated DNA synthesis when present for more than 30 min, while PLD, PMA, phosphatidic acid, and LPA were not mitogenic. These data suggest that activations of MAPKs and PLD are concurrent but independent responses to vasopressin in A7r5 cells. Acute activation of these enzymes is not sufficient to simulate DNA synthesis.     

电力系统发电侧和负荷侧共同碳责任分摊方法

在低碳电力的背景下,电力系统碳责任在各利益主体之间的分摊研究具有重要的理论和现实意义。发电机组和负荷作为电力系统的重要组成部分,两者都应该承担起电力系统节能减排的责任。文中提出将电力系统碳责任在发电侧和负荷侧进行共同分摊,将该问题建模成一个基于合作博弈的成本分摊问题,并采用Aumann-Shapley法进行具体地分摊求解,将双侧碳责任分摊机制与仅在发电侧碳责任分摊和仅在负荷侧碳责任分摊机制进行比较。算例结果显示在双侧碳责任分摊机制中,发电机组和负荷都承担了电力系统节能减排的责任,能激励发电机组和负荷的节能降耗行为,降低系统碳排放。