Achirality in the low temperature structure and lattice modes of tris(acetylacetonate)iron(iii)

Tris(acetylacteonate) iron(III) is a relatively ubiquitous mononuclear inorganic coordination complex. The bidentate nature of the three acetylacteonate ligands coordinating around a single centre inevitably leads to structural isomeric forms, however whether or not this relates to chirality in the solid state has been questioned in the literature. Variable temperature neutron diffraction data down to T = 3 K, highlights the dynamic nature of the ligand environment, including the motions of the hydrogen atoms. The Fourier transform of the molecular dynamics simulation based on the experimentally determined structure was shown to closely reproduce the low temperature vibrational density of states obtained using inelastic neutron scattering

Orally administered oxygen nanobubbles enhance tumor response to sonodynamic therapy

Suspensions of oxygen-filled bubbles are under active investigation as potential means of relieving tissue hypoxia. Intravenous administration of large quantities of bubbles is, however, undesirable. Previous work by the authors has demonstrated that tumor oxygen levels can be increased following oral administration of phospholipid stabilized oxygen nanobubbles. The aim of this study was to determine whether this would enhance the efficacy of sonodynamic therapy (SDT), which is known to be inhibited in hypoxic tissue. Experiments were conducted in a murine model of pancreatic cancer. Animals were treated with SDT (intratumoural injection of 1 mM Rose Bengal followed by exposure to 1 MHz ultrasound, 0.1 kHz pulse repetition frequency, 30% duty cycle, 3.5 W cm−2 for 3.5 minutes) either with or without a prior gavage of oxygen bubbles. A statistically significant reduction in the rate of tumor growth was observed in the groups receiving oxygen nanobubbles either 5 or 20 minutes before SDT. Separate measurements of tumor oxygen using a fiber optic probe and expression of hypoxia inducible factor (HIF)1α following tumor excision, confirmed the change in tumor oxygen levels. These findings offer a potentially promising new approach to relieving tissue hypoxia in order to facilitate cancer therapy

Honouring heroes by branding in bronze: theorizing the UK's football statuary

As of 1 August 2012, there were 60 figurative subject-specific statues of association football players, managers, chairmen, owners or founding fathers sited at stadia or city centres within the UK, with all but three of these erected in the last 20 years. Clubs, their supporters and local authorities are investing substantial financial and logistical resources in adding to the cultural landscape. Their motivations are posited as a multifaceted marketing strategy that includes branding through success, the evocation of nostalgia and the creation of identity through heritage objects; a statement of cultural change, ownership and environmental improvement; and sympathy, as part of a developing mourning culture within football. Statues have been facilitated by the increasing availability of funding, and by spare capacity in fan organizations. Statue projects may be beneficial in bringing supporters together, but as a conduit for engaging the wider public in social history they are limited by subject choices driven by memory or sympathy. © 2013 © 2013 Taylor & Francis

Magnetically Responsive Microbubbles as Delivery Vehicles for Targeted Sonodynamic and Antimetabolite Therapy of Pancreatic Cancer

Magnetically responsive microbubbles (MagMBs), consisting of an oxygen gas core and a phospholipid coating functionalised with Rose Bengal (RB) and/or 5-fluorouracil (5-FU), were assessed as a delivery vehicle for the targeted treatment of pancreatic cancer using combined antimetabolite and sonodynamic therapy (SDT). MagMBs delivering the combined 5-FU/SDT treatment produced a reduction in cell viability of over 50% when tested against a panel of four pancreatic cancer cell lines in vitro. Intravenous administration of the MagMBs to mice bearing orthotopic human xenograft BxPC-3 tumours yielded a 48.3% reduction in tumour volume relative to an untreated control group (p<0.05) when the tumour was exposed to both external magnetic and ultrasound fields during administration of the MagMBs. In contrast, application of an external ultrasound field alone resulted in a 27% reduction in tumour volume. In addition, activated caspase and BAX protein levels were both observed to be significantly elevated in tumours harvested from animals treated with the MagMBs in the presence of magnetic and ultrasonic fields when compared to expression of those proteins in tumours from either the control or ultrasound field only groups (p<0.05). These results suggest MagMBs have considerable potential as a platform to enable the targeted delivery of combined sonodynamic / antimetabolite therapy in pancreatic cancer

Intermolecular Fermi resonance

The exceptionally broad feature at similar to3025 cm(-1) observed in the Raman spectrum of chloroform dissolved in liquid sulfur dioxide is shown to be due to the triple combination mode, nu(1)+nu(2)+nu(3), of sulfur dioxide gaining intensity by mixing with the fundamental C-H stretching mode of chloroform. Investigation of a number of similar systems shows that this broadening is unique to this system and is certainly not heterogeneous broadening due to C-H hydrogen bonding to SO2. This therefore is probably the first observation of the phenomenon of intermolecular Fermi resonance, between molecularly distinct species. (C) 2003 American Institute of Physics

Molecular dynamics of the self-organising strong hydrogen bonded 3,5-dimethylpyrazole

The family of pyrazoles containing only H and CH3 substituents displays a wide variation in physical properties which can be directly related to the manner in which the molecules self-organise in the solid state. Hydrogen-bonded multimeric motifs of the substituted pyrazoles are a recurring feature of this family. We have previously reported the use of quasielastic neutron scattering (QENS) to study 3,5-dimethylpyrazole which showed that the hydrogen-bonded amide protons within individual trimer units undergo a short range hopping motion between two equivalent sites straddling the direct N center dot center dot center dot H hydrogen-bond axis. This work was the first report of such a novel dynamic process in this family of materials. The current work extends the earlier study with additional QENS measurements of other isotopic variants, providing information on the methyl group dynamics, which lead us to the conclusion that the short-range amide motions are decoupled from the methyl torsions. Whilst the methyl groups were found to undergo 3-fold diffusive hopping motions on the QENS timescale (similar to 10(11) - 12(12) s(-1)), an appreciable non-mobile fraction of methyl groups was also detected at all temperatures studied

Phase transformations in CdSe quantum dots induced by reaction time

This paper reports the synthesis of high-quality TOP/TOPO capped CdSe nanocrystals using a simple colloidal method. The effects of varying the reaction time on the size and crystallinity of the synthesized CdSe quantum dots were studied in detail. Powder X-ray diffraction (PXRD) analysis showed a dependence of the crystallite phases as a function of reaction time, from cubic zinc-blende to hexagonal wurtzite and back again to the cubic phase. PXRD data was found to be consistent with high resolution transmission electron microscopy (HRTEM) images of the particles, whilst optical spectroscopy demonstrated the quantum dot nature of the particles. The reaction time-dependent phase behavior is best accounted for by rapid growth along the {111} crystallite facets, after which the facial facets then 'catch-up', resulting once again in cubic symmetry.3 page(s

Adsorption and desorption characteristics of 3-dimensional networks of fused graphene

Here we explore the exceptional structural characteristics of a set of graphene-related materials prepared by a wet chemical approach. We present a comprehensive study of the effects of morphology, sonication, temperature, probe species, and stacking behaviour on the measurement of graphene surface area. Nitrogen gas was used in the solid state gas adsorption measurements and methylene blue dye for adsorption measurements on aqueous dispersions of graphene. The surface area values obtained are among the highest reported for synthetic graphenes: 1700 m²g⁻¹ in aqueous dispersions and 612 m²g⁻¹ in the solid state. Microscopy revealed the graphene used in the study was present in large part as free sheets and electron diffraction confirmed the successful synthesis of high quality graphene with a regular C-C bond length of 1.41 ± 0.02 Å.6 page(s