A study of the family environment of some autistic children and approaches to teaching them basic skills

SIGLELD:D45504/83(2vols) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Unimolecular reaction rate measurements for molecules with excited overtone vibrations

Unimolecular reaction rate constant measurements on systems with well known total energy contents permit detailed comparison with the predictions of statistical theories. Vibrational overtone excitation is a preparation technique that adds a precise energy increment to the reacting molecules and, when applied to a sample cooled in a free jet expansion, produces an ensemble with a known total energy content. Combining this preparation scheme with time resolved product detection yields the unimolecular reaction rate constant for a large molecule, tetramethyldioxetane. These free jet data serve to fix the parameters in an RRKM calculation, which is then averaged over a thermal distribution of initial vibrational energy for comparison to extensive room temperature measurements on the vibrational overtone initiated reaction. Applying this excitation scheme to a small molecule, hydrogen peroxide, in a free jet expansion permits the spectroscopic inference of its fast unimolecular reaction rate. Observation of the width of individual features in the well resolved vibrational overtone excitation spectrum establishes an upper limit to the unimolecular reaction rate constant for these molecules in their few lowest angular momentum states

Unusual copper(II) coordination mode from a potential Schiff-base reaction

The Schiff-base ligands (1–3) formed from the reaction of 3-hydroxybenzaldehyde with three alkyl diamines have been synthesised and characterised. They are stable both in solution and in the solid state for several weeks, with no degradation to the starting amines and aldehyde observed. The reactions of the three Schiff-base ligands with various MX2 salts (M = Cu, Ni or Zn; X = chloride, perchlorate or acetate) resulted in the cleavage of the imine bond and formation of metal–amine complexes, as well as the entrapment of a two coordinate CuCl2 molecule within the lattice in one particular case

Calix[4]arene Schiff bases—potential ligands for fluorescent studies

A series of novel double-armed calix[4]arene derivatives incorporating imine substituents were synthesised from the Schiff-base reaction of 25,27-bis[2-[(1-formyl-2-phenyl)oxy]ethyl]-p-tert-butylcalix[4]arene (1) with the appropriate amine or hydrazone. All compounds were characterised by various spectroscopic and analytical techniques, and in three cases, by X-ray crystallographic studies. In the case of compound 2, inclusion compounds were synthesised with both m-xylene and dimethylformamide and their X-ray structures revealed these inclusion sites—between the pendant arms and in the upper cavity, respectively. In all cases, the pendant arms are bent away from each rather than adopting a face-to-face conformation

Guidelines of the International Headache Society for Controlled Clinical Trials in Cluster Headache

In 1995, a committee of the International Headache Society developed and published the first edition of the Guidelines for Controlled Trials of Drugs in Cluster Headache. These have not been revised. With the emergence of new medications, neuromodulation devices and trial designs, an updated version of the International Headache Society Guidelines for Controlled Clinical Trials in Cluster Headache is warranted. Given the scarcity of evidence-based data for cluster headache therapies, the update is largely consensus-based, but takes into account lessons learned from recent trials and demands by patients. It is intended to apply to both drug and neuromodulation treatments, with specific proposals for the latter when needed. The primary objective is to propose a template for designing high quality, state-of-the-art, controlled clinical trials of acute and preventive treatments in episodic and chronic cluster headache. The recommendations should not be regarded as dogma and alternative solutions to particular methodological problems should be explored in the future and scientifically validated.Paroxysmal Cerebral Disorder