Generalized Kerr–NUT–de Sitter metrics in all dimensions

We classify all spacetimes with a closed rank-2 conformal Killing–Yano tensor. They give a generalization of Kerr–NUT–de Sitter spacetimes. The Einstein condition is explicitly solved and written as an indefinite integral. It is characterized by a polynomial in the integrand. We briefly discuss the smoothness conditions of the Einstein metrics over compact Riemannian manifolds.     

Fabrication, microstructure and critical current density of screen-printed Ag-(Bi, Pb)2Sr2Ca2Cu3Ox superconducting tapes

The influence of the sintering conditions on the microstructure and critical current density J_c has been studied on screen-printed Ag-(Bi, Pb)₂Sr₂Ca₂Cu₃O_x tapes with a ceramics mono-layer core. Three kinds of fabrication processes, which consist of a combination of cold working (rolling and/or pressing) and sintering, are applied. Four times repetition of pressing and sintering after the pre-sintering produces the highest c-axis alignment and achieves J_c= 1.5 × 10⁴ A/cm² (77 K, 0 T). The J_c versus θ data with an angle θ between B and the c-axis elucidate the relation between the anisotropy ratio γ=J_c(Bc)/J_c(B|c and the half-height angular width Δθ of a peak for Bc. This is related to both grain alignment and the J_c value. An increase in J_c, which comes from an improvement for grain alignment, enhances γ and narrows Δθ. The J_c versus θ data are fitted to the expression J_c(B, θ)=J _c(B, 90°)/[(γ−1)|cos θ|ⁿ+1] by regarding both γ and n as adjustable parameters. Fabrication of screen-printed tapes with multilayers (1≤N≤5) is presented, where the critical current increases from 8.0 A to 30.2 A at 77 K and 0 T as N increases.     

Specific Induced Circular Dichroism and Enhanced B to Z Transitions of Duplexes Stabilized by Chromophore‐Linked Alkynylnucleoside Residues

We have developed an induced circular dichroism (ICD) probe with a chromophore‐linked alkynyldeoxyribose skeleton for analyzing higher‐order structures of DNA duplexes in the visible‐light region. When CG‐repeated oligonucleotides (ODNs) with the probe at their 5′ ends adopted Z‐form duplexes at a high NaCl concentration, strong ICD signals were observed at the absorptive region of the chromophore. On the other hand, their B‐form duplexes, formed at a low NaCl concentration, produced a faint ICD signal. The specific ICD for the Z‐form duplexes was found to appear only when the chromophores were attached at the 5′ ends of each of the ODNs. Furthermore, the chromophoric alkynylnucleoside residues effectively promoted the B to Z transition of the ODN.     

Effects of iron on the degradation of triphenyltin by pyoverdins isolated from Pseudomonas chlororaphis

The yellow compound pyoverdin was isolated from the bacteria Pseudomonas chlororaphis, isolated from mud in Japan. A study of the effects of iron, phosphorus, manganese and zinc on degradation of triphenyltin (TPT) by pyoverdin (20 mg) was carried out in distilled water (30 ml) containing 6 µg l^?1 concentration of TPT at 20 °C for 48 or 96 h. The organotins in water were analyzed by gas chromatograph–mass spectrometry in the selected ion mode. The degradation of TPT by pyoverdin decreased with increase of phosphorus at 0–35 mg l^?1 and Fe‐EDTA at 0–2 mg l^?1 concentrations. Also, degradation of diphenyltin by pyoverdin decreased with increase of Mn‐EDTA at 0–1 mg l^?1 and Zn‐EDTA at 0–1 mg l^?1. On the other hand, degradation of TPT by pyoverdin was found to be unaffected by manganese and zinc in water. Copyright © 2002 John Wiley & Sons, Ltd.     

Spectrofluorimetric assays for rat liver phenol sulphotransferases I/II and III/IV based on a common substrate

A spectrofluorimetric method for the separate assay of two subgroups of rat liver phenol sulphotransferases (PSTs I and II and PSTs III and IV) has been established. The method is based on the enzyme reaction using two different concentrations of p-hydroxybenzaldehyde (10 μM for PSTs III/IV and 3 mM for PSTs I/II) as the substrate and the spectrofluorimetric determination of the product p-formylphenyl sulphate by means of its reaction with 1,4-dimethyl-3-carbamoylpyridinium chloride, a selective reagent for aromatic aldehydes without free phenolic hydroxy groups. The detection limit of the sulphate is 50–70 pmol in the enzyme reaction mixutre. The K_m values for p-hydroxybenzaldehyde with PSTs I/II and III/IV were 1.1 mM and 2.1 μM, respectively. The effects of growth and of dexamethasone treatment of rats on the liver PST activities were also studied.