Self-organizing neural networks for modeling robust 3D and 4D QSAR: application to dihydrofolate reductase inhibitors

We have used SOM and grid 3D and 4D QSAR schemes for modeling the activity of a series of dihydrofolate reductase inhibitors. Careful analysis of the performance and external predictivities proves that this method can provide an efficient inhibition model.     

Unified scaling law for earthquakes

We show that the distribution of waiting times between earthquakes occurring in California obeys a simple unified scaling law valid from tens of seconds to tens of years. The short time clustering, commonly referred to as aftershocks, is nothing but the short time limit of the general hierarchical properties of earthquakes. There is no unique operational way of distinguishing between main shocks and aftershocks. In the unified law, the Gutenberg-Richter b value, the exponent -1 of the Omori law for aftershocks, and the fractal dimension d(f) of earthquakes appear as critical indices.     

Dislocation dynamics simulations with climb: kinetics of dislocation loop coarsening controlled by bulk diffusion

Dislocation climb mobilities, assuming vacancy bulk diffusion, are derived and implemented in dislocation dynamics simulations to study the coarsening of vacancy prismatic loops in fcc metals. When loops cannot glide, comparison of the simulations with a coarsening model based on the line tension approximation shows good agreement. Dislocation dynamics simulations with both glide and climb are then performed. Allowing for glide of the loops along their prismatic cylinders leads to faster coarsening kinetics, as direct coalescence of the loops is now possible.     

Information and preference reversals in lotteries

Several approaches have been proposed for evaluating information in expected utility theory. Among the most popular approaches are the expected utility increase, the selling price and the buying price. While the expected utility increase and the selling price always agree in ranking information alternatives, Hazen and Sounderpandian [11] have demonstrated that the buying price may not always agree with the other two. That is, in some cases, where the expected utility increase would value information A more highly than information B, the buying price may reverse these preferences. In this paper, we discuss the conditions under which all these approaches agree in a generic decision environment where the decision maker may choose to acquire arbitrary information bundles.     

Molecular Cloning, Expression, and Enzymatic Analysis of Cathepsin X from Starfish (Asterina pectinifera)

Cathepsin X, also known as cathepsin Z, is referred to as a “lysosomal proteolytic enzyme” and a member of the peptidase C1 family, which is involved in various biological processes such as immune response, cell adhesion, and proliferation. In the present study, the cDNA of starfish (Asterina pectinifera), which is known to cause serious damage to commercial shellfish mariculture, cathepsin X (ApCtX) was isolated through the combination of homology molecular cloning and rapid amplification of cDNA ends (RACE) methods for the application to find a way to reduce/control starfish densities. The full-length of ApCtX gene was determined to consist of the 2,240 bp nucleotide sequence, which encoded for a preproprotein of 296 amino acids with a molecular mass of about 32.7 kDa. The tissue type expression of ApCtX was determined in various tissues of A. pectinifera and was shown most abundantly in the liver. The cDNA encoding pro-mature enzyme of ApCtX was expressed in Escherichia coli BL21 (DE3) using the pGEX-4T-1 expression vector. Its activity was quantified by cleaving the synthetic peptide Z-Phe-Arg-AMC. The optimal pH for the protease activity was 6.5. The enzymatic activity of proApCtX was reduced by antipain, NEM, EDTA, EGTA, and 1,10-phenanthroline, and the proApCtX enzyme was significantly inhibited by CuSO₄, HgCl₂, CoCl₂, and SDS whereas Triton X-100 and Brij 35 might have potentially acted as an activator. Here, we demonstrated for the first time that the structural features and enzymatic characteristics of Echinoderms cathepsin X are similar to those of the other mammalian and piscine cathepsin X except its pH optimum, and the results of tissue-specific expression might explain their importance in food digestion by hepatic cecain starfish.     

Laser welding of polymers using unsymmetrical squaraine dyes

Transmission laser welding of plastic is typically achieved by incorporating a laser absorbing dye into one of the two pieces of plastic one wishes to weld together and mediating the welding process using a laser emitting light at a suitable wavelength. Desirable properties of laser absorbing dyes include: (1) the dye is colorless in the visible region but absorbs strongly in the region at the wavelength where the laser emits, (2) the dye has a good conversion of the energy from the laser to heat, (3) the dye is stable enough to be incorporated into the molten plastic, (4) the dye is soluble in the plastic of choice to give an even distribution in the plastic, and (5) the dye is nontoxic. Here, we explore an alternative approach to achieve laser welding of colorless plastics using a laser dye that is colored, but that can be bleached after the welding process. Nonsymmetrical squaraine dyes were prepared by condensation of squaric acid and two equivalents of various 3,5-dimethoxy-N,N-dialkylanilines. After the incorporation into polyethylene and laser welding, the plastic was bleached either by heat treatment or by irradiation with a high pressure Xe-lamp giving colorless polyethylene. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 2245–2254     

Efficient syntheses of the versatile phthalide building blocks, 5,6-diaminoisobenzofuran-1(3H)-one and 5H,7H-furo[3,4-f][2,1,3]benzothiadiazol-5-one

A new and efficient synthesis of 5,6-diaminophthalide and a novel thiadiazolophthalide has been accomplished. Both molecules are useful starting compounds for the construction of more complex heterocyclic systems and for the preparation of bioisosteres of methylenedioxyphenyl derivatives.