The application of proton nuclear magnetic resonance imaging for the in vivo characterisation of chemically induced renal lesions in rats over a prolonged time study

Renal cortical and medullary spin-lattice (T₁) relaxation times were measured at various time points over a period of 56 days following the administration of a single i.p. injection of 100 mg/kg 2-bromoethanamine hydrobromide (BEA), 200 mg/kg hexachloro-1,3-butadiene (HCBD) or 100 mg/kg puromycin aminonucleoside (PAN) to male Wistar rats. Administration of a single injection of HCBD caused a dramatic, immediate rise in the cortical T₁ values above control values, and these levels remained elevated until, by Day 28 postinjection the levels were back to control values. Administration of BEA also caused an elevation in cortical T₁ values, but in this case these values remained above control values for the rest of the study. The administration of PAN did not produce any significant increases in cortical T₁ values until 14 days postinjection. The elevated T₁ values remained above control values for the rest of the study. These increases observed in cortical T₁ values appeared to be mirrored by decreases in medullary T₁ values. Increases in cortical T₁ values were accompanied by visual changes in the NMR images and enlargement of the kidneys. The histological findings were consistent with the NMR data, confirming that morphologically the tissues did show a full recovery by Day 28 in the HCBD-treated animals. This was not the case following injection of both BEA and PAN, where necrosis was not reversible and there was no recovery of the tissues.     

The reactive chemisorption of alkyl iodides at Cu(110) and Ag(111) surfaces: a combined STM and XPS study

The chemisorption of methyl and phenyl iodide has been studied at Cu(110) and Ag(111) surfaces at 290 K with STM and XPS. At both surfaces dissociative adsorption of both molecules leads to chemisorbed iodine, with the STM showing c(2 x 2) and (square root 3 x square root 3)R30 structures at the Cu(110) and Ag(111) surfaces, respectively. At the Cu(110) surface a comparison of coexisting c(2 x 2) I(a) and p(2 x 1) O(a) domains shows the iodine adatoms to be chemisorbed in hollow sites with evidence at low coverage for diffusion in the (110) direction. In the case of methyl iodide no carbon adsorption is observed at either the silver or the copper surfaces, but chemisorbed phenyl groups are imaged at the Cu(110) surface after exposure to phenyl iodide. The STM images show the phenyl groups as bright features approximately 0.7 nm in diameter and 0.11 nm above the iodine adlayer, reaching a maximum surface concentration after approximately 6 Langmuir exposure. However, the phenyl coverage decreases with subsequent exposures to PhI and is negligible by approximately 1000 L exposure, consistent with the formation and desorption of biphenyl. The adsorbed phenyls are located above hollow sites in the substrate, they are stabilized at the top and bottom of step edges and in paired chains (1.1 nm apart) on the terraces with a regular interphenyl spacing within the chains of 1.0 nm in the (110) direction. The interphenyl ring spacing and diffusion of individual phenyls from within the chains shows that the chains do not consist of biphenyl species but may be a precursor to their formation. Although the XPS data shows carbon present at the Ag(111) surface after exposure to PhI, no features attributable to phenyl groups were observed by STM.     

Total synthesis of nigellicine and nigeglanine hydrobromide

[reaction: see text] The first syntheses of the pyridazinoindazolium alkaloids nigellicine and nigeglanine hydrobromide via a common intermediate are described. Ortho-lithiation/acylation and the direct amination of an isatin ring system are the key steps in the synthesis.     

Working group report: Heavy-ion physics and quark-gluon plasma

This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09 which was part of Working Group-4. Discussion and work on some aspects of quark-gluon plasma believed to have created in heavy-ion collisions and in early Universe are reported.     

The use of capillary electrophoresis with entangled polymer matrix to analyse plasmid DNA and a cationic lipid/cholesterol liposome: DNA complex

Summary A liposome based gene therapeutic product is being developed for the treatment of cystic fibrosis. The product comprises a complex of plasmid DNA and a cationic lipid/cholesterol liposome. Using CE with an entangled polymer matrix, routine separations of linear, supercoiled and open-circle conformers of DNA in plasmid DNA and the liposome complex have been performed. The CE method has been used to support novel quality control and process validation for the manufacture of plasmid DNA and to monitor the degradation of DNA in the liposome complex. Significant features of the method are simple sample preparation and the use of direct UV detection, avoiding the use of potentially mutagenic reagents.     

A survey of low velocity and coaxial jet noise with application to prediction

A review of recent published data on low velocity jet noise is given together with previously unpublished results taken from the Rolls-Royce Noise Research Programme on model rigs and full-scale engines. Noise correlations are given which show that at low jet velocities, the low frequency exhaust noise which is commonly referred to as jet noise, emitted from the fan stream of a turbofan engine is considerably lower in level than that from the (hot) centre stream. From this result, a new prediction procedure for coaxial jet noise of turbofan engines is then developed. Comparisons are given which show that this method gives good correlation with measured results from a number of full-scale turbofan engines. The importance of accurate estimation of the “ground reflection effect” is clearly demonstrated. A critical review of published jet noise data from model coaxial jets is given and the need for further extensive testing emphasized.     

Effect of terminal amino acids on the stability and specificity of PNA-DNA hybridisation

The effect of various charged or hydrophobic amino acids on the hybridisation of fully complementary and mismatch PNA-DNA duplexes was investigated via UV melting curve analysis. The results described here show that the thermal stability and binding specificity of PNA probes can be modified by conjugation to amino acids and these effects should be considered in experimental design when conjugating PNA sequences to solubility enhancing groups or cell transport peptides. Where stabilisation of a duplex is important, without there being a corresponding need for specific binding to fully complementary targets, the conjugation of multiple lysine residues to the C-terminus of PNA may be the best probe design. If, however, the key is to obtain maximum discrimination between fully complementary and mismatch targets, a replacement of glutamic acid for lysine as the routine solubility enhancing group is recommended.     

The Effect of Polydispersity in Primary Particle Size on Measurement of the Fractal Dimension of Aggregates

The use of the mass fractal dimension has become a popular method of characterising the structure of aggregates of fine particles. This parameter is often inferred from scattering experiments that exhibit a power law correlation between scattered intensity and the scattering vector. In this paper we demonstrate deviations from this behaviour that occur when the particles making up the aggregate are not monodisperse, even though the aggregate maintains the same fractal structure as observed in the monodisperse case. We have performed light scattering experiments with aggregating colloidal haematite and performed DLCA computer simulations to explain the observed behaviour. The behaviour can influence the determination of the mass fractal dimension, as can other factors such as scattering effects from primary particles.