Intermediate coupling model description of55Fe and57Fe

The properties of the negative parity states of⁵⁵Fe and⁵⁷Fe are investigated in the framework of the intermediate coupling model. In the model, a neutron or a quasineutron is coupled to anharmonic vibrations of the core. Anharmonicities of the vibrations are estimated through the observed properties of the core. Energy levels, spectroscopic factors and electromagnetic properties have been calculated. The results of the present calculations are also compared with available experimental results and other theoretical results. The model reasonably accounts for many of the properties of the low-lying states.     

ICT integration in mathematics initial teacher training and its impact on visualization: the case of GeoGebra

This case study investigates the impact of the integration of information and communications technology (ICT) in mathematics visualization skills and initial teacher education programmes. It reports on the influence GeoGebra dynamic software use has on promoting mathematical learning at secondary school and on its impact on teachers’ conceptions about teaching and learning mathematics. This paper describes how GeoGebra-based dynamic applets – designed and used in an exploratory manner – promote mathematical processes such as conjectures. It also refers to the changes prospective teachers experience regarding the relevance visual dynamic representations acquire in teaching mathematics. This study observes a shift in school routines when incorporating technology into the mathematics classroom. Visualization appears as a basic competence associated to key mathematical processes. Implications of an early integration of ICT in mathematics initial teacher training and its impact on developing technological pedagogical content knowledge (TPCK) are drawn.     

Effect of radiative cooling on collapsing charged grains

The effect of the radiative cooling of electrons on the gravitational collapse of cold dust grains with fluctuating electric charge is investigated. We find that the radiative cooling as well as the charge fluctuations, both, enhance the growth rate of the Jeans instability. However, the Jeans length, which is zero for cold grains and nonradiative plasma, becomes finite in the presence of radiative cooling of electrons and is further enhanced due to charge fluctuations of grains resulting in an increased threshold of the spatial scale for the Jeans instability.     

Automatic Structure Determination of Organic Molecules： Principle and Implementation of the LSD Program

The LSD (Logic for Structure Determination) program gener-ates organic molecular structures from 1D and 2D NMR data without resorting to chemical shift databases. Its use in the res-olution of natural product structure determination problems has been already reported in the literature. This paper describes how data and structures are internally represented and pro-cessed by LSD to build solution structures.     

Synthesis of a novel bicyclic scaffold inspired by the antifungal natural product sordarin

A simplified bicyclic scaffold inspired by the antifungal natural product sordarin was designed and synthesized which maintains the carboxylic acid/aldehyde (or nitrile) pharmacophore. Docking studies with the target for sordarin, the fungal protein eukaryotic elongation factor 2 (eEF2), suggested that the novel scaffolds may bind productively. A densely functionalized chiral cyclopentadiene was constructed in 8 steps and utilized in a Diels-Alder reaction with acrylonitrile. The resulting [2.2.1] cycloheptene was transformed into a scaffold possessing vicinal carboxylic acid and nitrile groups, with orientations predicted to provide high affinity for eEF2. The synthetic approach disclosed here sets the stage for a renewed medicinal chemistry campaign against eEF2.     

DFT-assisted design and evaluation of bifunctional copper(I) catalysts for the direct intermolecular addition of aldehydes and ketones to alkynes

Bifunctional catalysts containing discrete metal pi-acid and amine sites were designed and investigated for the direct intermolecular addition of aldehydes and ketones to unactivated alkynes. Copper(I)-based catalysts were prioritized based on intramolecular (Conia-ene type) reactions, and complexes were designed with tridentate ligands and potentially hemilabile heterocyclic spacers. The structures of the designed catalysts were computed using density functional theory (DFT), and the relative energies of putative catalytic intermediates were estimated and used to prioritize catalyst designs. Novel bifunctional precatalysts containing a thiazole spacer were synthesized via a 9-step sequence and combined with transition metals before screening for the direct addition of aldehydes and ketones to several internal and terminal alkynes. Despite the lack of desired intermolecular reactions, DFT calculations of putative catalyst intermediates appears to be a promising strategy for the design and prioritization of bifunctional catalysts for CC bond formation.