Evidence of a Nodal Line in the Superconducting Gap Symmetry of Noncentrosymmetric ThCoC_{2}.

The newly discovered noncentrosymmetric superconductor ThCoC_{2} exhibits numerous types of unconventional behavior in the field dependent heat capacity data. Here we present the first measurement of the gap symmetry of ThCoC_{2} by muon spin rotation and relaxation (µSR) measurements. The temperature dependence of the magnetic penetration depth measured using the transverse field µSR experiment reveals the evidence of a nodal pairing symmetry. To understand this finding, we carry out calculations of the superconducting pairing eigenvalue and eigenfunction (pairing symmetry) due to the spin-fluctuation mechanism by directly implementing the ab initio band structures. We find that the system possesses a single Fermi surface with considerable three dimensionality and a strong nesting along the k_{z} direction. Such nesting promotes a superconducting state with a cosk_{z}-like pairing symmetry with a prominent nodal line on the k_{z}=±π/2 plane. The result agrees well with the experimental data.

Semiquinone anion radicals formed by the reaction of quinones with glutathione or amino acids.

Using ESR spectroscopy, we show that benzoquinone, 1,4-naphthoquinone and 5-hydroxy-1,4-naphthoquinone react readily with thiol containing compounds, such as glutathione, to form their respective semiquinone anion radicals. These quinones react similarly, but less readily, with the amino group of amino acids. The therapeutic or toxicological significance of the formation of semiquinone anion radicals from the reaction of quinones with nucleophiles, such as thiols and amines, remains to be assessed.

The use of a travelling ophthalmic technologist in a remote, sparsely populated region.

An attempt has been made to meet the ophthalmological needs of the population of the 500,000 square mile Mackenzie Zone of the Canadian Northwest Territories by the use of a well trained ophtalmic technologist who travels to each of the small, widely separated communities. He carries out the necessary refractions and screens patients selected by the local nurses for ocular disease and/or motility problems for referral to the ophtalmologist in charge. Patients requiring treatment or further investigation are referred to the supervising ophtalmologist who will provide instructions by phone or radio, will see them on a subsequent visit, or if indicated, will have them evacuated to the well equipped treatment centre in Yellowknife. Some of the advantages of this programme are as follows: 1. Communities are visited on a regular schedule with reasonable frequency by the same personnel. 2. The skills and training of the ophthalmologist are more effectively used by enabling him to spend most of his time at the centre where adequate medical and surgical facilities are available. 3. Standardized, centralized records are kept which are identical to those in patient's home community. It is suggested that the use of well-trained paramedical personnel may be of significant value in the provision of adequate medical care to widely dispersed population groups in the far north.