Delta chirality ruthenium ‘light-switch’ complexes can bind in the minor groove of DNA with five different binding modes

[Ru(phen)2(dppz)]2+ has been studied since the 1990s due to its “light-switch” properties. It can be used as a luminescent DNA probe, with emission switched on through DNA binding. The luminescence observed is dependent on the solvent accessibility of the pyrazine nitrogen atoms, and therefore is sensitive to changes in both binding site of the cation and chromophore orientation. The compound is also chiral, and there are distinct differences between the enantiomers in terms of the emission behaviour when bound to a variety of DNA sequences. Whilst a number of binary DNA-complex X-ray crystal structures is available, most include the Λ enantiomer, and there is very little structural information about binding of the Δ enantiomer. Here we present the first X-ray crystal structure of a Δ enantiomer bound to well-matched DNA, in the absence of the other, Λ, enantiomer. We show how the binding site observed here can be related to a more general pattern of motifs in the crystallographic literature and propose that the Δ enantiomer can bind with five different binding modes, offering a new hypothesis for the interpretation of solution data

Nocardia macrotermitis sp. nov. and Nocardia aurantia sp. nov., isolated from the gut of the fungus-growing termite Macrotermes natalensis

The taxonomic positions of two novel aerobic, Gram-stain-positive Actinobacteria, designated RB20$^{T}$ and RB56$^{T}$, were determined using a polyphasic approach. Both were isolated from the fungus-farming termite Macrotermes natalensis. Results of 16S rRNA gene sequence analysis revealed that both strains are members of the genus Nocardia with the closest phylogenetic neighbours Nocardia miyunensis JCM12860$^{T}$ (98.9 %) and Nocardia nova DSM44481$^{T}$ (98.5 %) for RB20$^{T}$ and Nocardia takedensis DSM 44801$^{T}$ (98.3 %), Nocardia pseudobrasiliensis DSM 44290$^{T}$ (98.3 %) and Nocardia rayongensis JCM 19832$^{T}$ (98.2 %) for RB56$^{T}$. Digital DNA–DNA hybridization (DDH) between RB20$^{T}$ and N. miyunensis JCM12860$^{T}$ and N. nova DSM 44481$^{T}$ resulted in similarity values of 33.9 and 22.0 %, respectively. DDH between RB56$^{T}$ and N. takedensis DSM44801$^{T}$ and N. pseudobrasiliensis DSM44290$^{T}$ showed similarity values of 20.7 and 22.3 %, respectively. In addition, wet-lab DDH between RB56$^{T}$ and N. rayongensis JCM19832$^{T}$ resulted in 10.2 % (14.5 %) similarity. Both strains showed morphological and chemotaxonomic features typical for the genus Nocardia , such as the presence of meso-diaminopimelic acid (A$_{2}$pm) within the cell wall, arabinose and galactose as major sugar components within whole cell-wall hydrolysates, the presence of mycolic acids and major phospholipids (diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol), and the predominant menaquinone MK-8 (H4, ω-cyclo). The main fatty acids for both strains were hexadecanoic acid (C$_{16 : 0}$), 10-methyloctadecanoic acid (10-methyl C$_{18 : 0}$) and cis-9-octadecenoic acid (C$_{18 : 1}$ ω9c). We propose two novel species within the genus Nocardia : Nocardia macrotermitis sp. nov. with the type strain RB20$^{T}$ (=VKM Ac-2841$^{T}$=NRRL B65541$^{T}$) and Nocardia aurantia sp. nov. with the type strain RB56$^{T}$ (=VKM Ac-2842$^{T}$=NRRL B65542$^{T}$)

Serum Amyloid A Facilitates Early Lesion Development in \u3cem\u3eLdlr\u3csup\u3e-/-\u3c/sup\u3e\u3c/em\u3e Mice

BACKGROUND: Atherosclerosis is a chronic inflammatory disorder, and several studies have demonstrated a positive association between plasma serum amyloid A (SAA) levels and cardiovascular disease risk. The aim of the study was to examine whether SAA has a role in atherogenesis, the underlying basis of most cardiovascular disease. METHODS AND RESULTS: Mice globally deficient in acute-phase isoforms Saa1 and Saa2 (Saa-/-) were crossed to Ldlr-/- mice (Saa-/-Ldlr-/-). Saa-/-Ldlr-/- mice demonstrated a 31% reduction in lesional area in the ascending aorta but not in the aortic root or innominate artery after consuming a high-fat, high-cholesterol Western-type diet for 6 weeks. The lesions were predominantly macrophage foam cells. The phenotype was lost in more mature lesions in mice fed a Western-type diet for 12 weeks, suggesting that SAA is involved in early lesion development. The decreased atherosclerosis in the Saa-/-Ldlr-/- mice occurred despite increased levels of blood monocytes and was independent of plasma lipid levels. SAA is produced predominantly by hepatocytes and macrophages. To determine which source of SAA may have a dominant role in lesion development, bone marrow transplantation was performed. Ldlr-/- mice that received bone marrow from Saa-/-Ldlr-/- mice had slightly reduced ascending aorta atherosclerosis compared with Saa-/-Ldlr-/- mice receiving bone marrow from Ldlr-/- mice, indicating that the expression of SAA by macrophages may have an important influence on atherogenesis. CONCLUSIONS: The results indicate that SAA produced by macrophages promotes early lesion formation in the ascending aorta

Unilateral spontaneous rupture of a testicular implant thirteen years after bilateral insertion: a case report

<p>Abstract</p> <p>Introduction</p> <p>We describe a case of spontaneous, non traumatic rupture of a single artificial testis in a patient who had undergone bilateral, staged radical orchidectomy followed by prosthesis insertion. The consequences and radiological appearances of implant rupture are discussed. We believe it is the longest time interval recorded between prosthesis insertion and rupture.</p> <p>Case presentation</p> <p>A 50 year old Caucasian man presented to our outpatient department with an altered consistency in his right testicular prosthesis without any systemic symptoms or local inflammation. His left testicular prosthesis had retained its consistency since insertion.</p> <p>Conclusion</p> <p>The majority of cases reported to date have required exploration due to symptoms but we describe a case that was managed conservatively.</p

Adaptive Prediction Emerges Over Short Evolutionary Time Scales.

Adaptive prediction is a capability of diverse organisms, including microbes, to sense a cue and prepare in advance to deal with a future environmental challenge. Here, we investigated the timeframe over which adaptive prediction emerges when an organism encounters an environment with novel structure. We subjected yeast to laboratory evolution in a novel environment with repetitive, coupled exposures to a neutral chemical cue (caffeine), followed by a sublethal dose of a toxin (5-FOA), with an interspersed requirement for uracil prototrophy to counter-select mutants that gained constitutive 5-FOA resistance. We demonstrate the remarkable ability of yeast to internalize a novel environmental pattern within 50-150 generations by adaptively predicting 5-FOA stress upon sensing caffeine. We also demonstrate how novel environmental structure can be internalized by coupling two unrelated response networks, such as the response to caffeine and signaling-mediated conditional peroxisomal localization of proteins

An Investigation of the Effect of Graphite Degradation on the Irreversible Capacity in Lithium-ion Cells

The effect of surface structural damage on graphitic anodes, commonly observed in tested Li-ion cells, was investigated. Similar surface structural disorder was artificially induced in Mag-10 synthetic graphite anodes using argon-ion sputtering. Raman microscopy, scanning electron microscopy (SEM) and Brunauer Emmett Teller (BET) measurements confirmed that Ar-ion sputtered Mag-10 electrodes display similar degree of surface degradation as the anodes from tested Li-ion cells. Artificially modified Mag-10 anodes showed double the irreversible charge capacity during the first formation cycle, compared to fresh un-altered anodes. Impedance spectroscopy and Fourier transform infrared (FTIR) spectroscopy on surface modified graphite anodes indicated the formation of a thicker and slightly more resistive SEI layer. Gas chromatography/mass spectroscopy (GC/MS) analysis of solvent extracts from the electrodes detected the presence of new compounds with M{sub w} on the order of 1600 g mol{sup -1} for the surface modified electrode with no evidence of elevated M{sub w} species for the unmodified electrode. The structural disorder induced in the graphite during long-term cycling maybe responsible for the slow and continuous SEI layer reformation, and consequently, the loss of reversible capacity due to the shift of lithium inventory in cycled Li-ion cells

The initial measurement structure of the Home Drinking Assessment Scale (HDAS)

Aims: To evaluate the initial psychometric properties of a novel Home Drinking Assessment Scale (HDAS). Participants: Five-hundred and twenty-five (58% female) participants recruited from the internet address book of an English University. This also included a sub-sample (6%) recruited from Twitter and Facebook contacts. Design and methods: Internet-based survey analysed using a two-stage factor analysis protocol and internal consistency(IC) assessment. Findings: A power calculation was made on the basis of pilot data and this established that 317 interviewees were required to test the reliability of the HDAS. The items comprising the HDAS were found to offer the best fit to data when they comprised two-subscales: (1) emotional reasons for home drinking (5-items) and (2) practical reasons for home drinking (3-items). Subscale 1 was also found to have acceptable IC whereas subscale 2 exhibited sub-optimal IC characteristics. Conclusions: This initial study indicates that the HDAS has promise as a measure of the individuals' rationale for home drinking. Subscale 1, may usefully be used in future research whereas the IC characteristics of subscale 2 suggests that further development is required, including the evaluation of additional items