A combined effective fragment potential-fragment molecular orbital method. II. Analytic gradient and application to the geometry optimization of solvated tetraglycine and chignolin

The gradient for the fragment molecular orbital (FMO) method interfaced with effective fragment potentials (EFP), denoted by FMO∕EFP, was developed and applied to polypeptides solvated in water. The structures of neutral and zwitterionic tetraglycine immersed in water layers of 2.0, 2.5, 3.0, 3.5, 4.0, and 4.5 A? are investigated by performing FMO∕EFP geometry optimizations at the RHF∕cc-pVDZ level of theory for the solutes. The geometries optimized with FMO-RHF∕EFP are compared to those from the conventional RHF∕EFP and are found to be in very close agreement. Using the optimized geometries, the stability of the hydrated zwitterionic and neutral structures is discussed structurally and in terms of energetics at the second-order M?ller-Plesset theory (MP2)∕cc-pVDZ level. To demonstrate the potential of the method for proteins, the geometry of hydrated chignolin (protein data bank ID: 1UAO) was optimized, and the importance of the inclusion of water was examined by comparing the solvated and gas phase structures of chignolin with the experimental NMR structure.     

Molecular-shape selectivity by molecular gel-forming compounds: bioactive and shape-constrained isomers through the integration and orientation of weak interaction sites

A molecular gel system was assembled on carrier particles and the integrated effect of weak interaction sites enabled highly efficient separation of the bioactive and shape-constrained isomers of tocopherols, β-carotene, and polycyclic aromatic hydrocarbons (PAHs) by multiple interaction mechanisms.     

Preparation of magnetic nanoparticles by the use of self-assembled fluorinated oligomeric aggregates—A new approach to the dispersion of magnetic particles on poly(methyl methacrylate) film surface

Fluoroalkyl end-capped acrylic acid oligomer-encapsulated magnetic nanoparticles were prepared by the coprecipitation of aqueous ferric and ferrous ions in the presence of the corresponding oligomers under alkaline conditions. The dynamic light scattering measurements showed that these fluorinated oligomer magnetic nanoparticles were encapsulated in the self-assemblies of fluoroalkyl end-capped oligomers. Fluoroalkyl end-capped oligomer-encapsulated magnetic nanoparticles thus obtained were applied to the dispersion of magnetic particles on the poly(methyl methacrylate) film surface to exhibit not only the surface active property imparted by fluorine but also magnetic behavior toward a permanent magnet.     

Extractability of metals in municipal solid wastes fly ash using supercritical CO(2) containing Cyanex 302.

The extraction of lead from fly ash produced during the thermal treatment of municipal solid wastes was studied using supercritical carbon dioxide (SC-CO(2)) and Cyanex 302 (bis(2,4,4-trimethylpentyl)monophosphinic acid). The extraction of lead from the fly ash was carried out in a 5 cm(3) internal volume reaction vessel under static extraction conditions at 323 K, and 24 MPa for 1 h. The extraction efficiencies of lead ranged from 4% to the total extraction under the conditions of 0.05 g fly ash with 2 cm(3) Cyanex 302. There was a linear relationship between the extraction efficiencies of lead using the SC-CO(2) + Cyanex 302 and using a water-based method described by JLT13.     

Mathematics as Connection Making in Japanese Elementary Schools

Connection making is one of the major standards proposed by the National Council of Teachers of Mathematics, however, unlike problem solving, it has no long history of being designated as a goal of mathematics teaching. An examination of classroom observations of mathematics lessons taught in Japan reveal that connection making appears to be an implicit if not explicit standard for Japanese mathematics education. As a perspective from which to re-examine and re-assess our own practice, this paper describes several episodes of connection making as they occurred in Japanese elementary school classrooms. By reflecting upon the methods used in these classrooms, other approaches to connection making are suggested and explored.     

Synthetic studies on carbapenem antibiotics from penicillins.II. regio- and stereoselective aldol reaction of a chiral azetidinone: a synthesis of optically active 6-epicarpetimycins

Aldol and alkylation reactions of the chiral 4-allylazetidinone 1 gave 3,4-trans-azetidinones as major products, in which 10 was converted in several steps to the optically active 6-epicarpetimycins 2.