Didcot Community Hospital

IntroductionRegadenoson is a highly selective adenosine A2 receptor blocker. It induces profound coronary vasodilation, without significant atrioventricular block or bronchoconstriction, enabling sustained uptake of radioisotopes for up to 30 minutes to enable myocardial perfusion imaging (MPI). However, its effect on the QTc interval remains uncertain with previous literature reporting mixed results.MethodsDuring the covid-19 pandemic, as the use of aerosol-generating procedures including exercise stress tests was restricted, an increase in MPI use was seen in our centre, and we thus undertook a prospective evaluation of the effect of Regadenoson on QTc. Consecutive patients were enrolled (n=34) between October 2021 and February 2022. Patients with QTc >460ms at baseline or a paced rhythm were excluded from the study. QTc was measured from a 12-lead ECG at baseline, immediately after Regadenoson and radioisotope were administered intravenously via a brachial vein (t=40secs), and then at 2-minute intervals from the start of Regadenoson administration until any QTc prolongation (if present) had resolved.ResultsMedian baseline QTc was 425 ms (range: 389 ms – 460 ms, figure 1). Median QTc at peak prolongation (observed at 40 secs in 32 patients and 4 mins in 2 patients) was 477 ms (range 434 ms - 545 ms) including, of note, 4 (11%) patients with QTc prolongation >500ms. The median time for QTc to return to ≤460ms was 4 mins (2 mins - 32 mins). No significant side effects or dysrhythmias were reported. 8 Figure 1Peak QTc prolongation at baseline vs post-regadenoson administrationConclusionRegadenoson administration was well tolerated by patients. As a result of the QTc prolongation of >500ms seen in some patients, albeit with the absence of dysrhythmia, regadenoson administration should be undertaken by experienced staff in an appropriate clinical setting. However, more research is needed to ascertain with greater accuracy the average QTc prolongation of Regadenoson, as it shows promise as a potential agent where exercise is either not possible or not permitted due to restrictions.

Glyceline, a deep eutectic solvent comprising glycerol and choline chloride, is a green nonaqueous solvent with potential industrial applications. Molecular mechanisms of surfactant self-assembly in deep eutectic solvents are expected to differ from those in their constituent polar components and are not well understood. Here we report the observation of self-assembled SDS fractal dendrites with dimensions up to ∼mm in glyceline at SDS concentrations as low as cSDS ∼ 0.1 wt%. The prevalence of these dendritic fractal aggregates led to the formation of a gel phase at SDS concentrations above ≥1.9 wt% (the critical gelation concentration cCGC). The gel microscopic structure was visualised using polarised light microscopy (PLM); rheology measurements confirmed the formation of a colloidal gel, where the first normal stress difference was negative and the elastic modulus was dominant. Detailed nano-structural characterisation by small-angle neutron scattering (SANS) further confirmed the presence of fractal aggregates. Such SDS aggregation or gelation has not been observed in water at such low surfactant concentrations, whereas SDS has been reported to form lamellar aggregates in glycerol (a component of glyceline). We attribute the formation of the SDS fractal dendrites to the condensation of counterions (i.e. the choline ions) around the SDS aggregates - a diffusion-controlled process, leading to the aggregate morphology observed. These unprecedented results shed light on the molecular mechanisms of surfactant self-assembly in deep eutectic solvents, important to their application in industrial formulation.

The main viral protease (Mpro) of SARS-CoV-2 is a nucleophilic cysteine hydrolase and a current target for anti-viral chemotherapy. We describe a high-throughput solid phase extraction coupled to mass spectrometry Mpro assay. The results reveal some β-lactams, including penicillin esters, are active site reacting Mpro inhibitors, thus highlighting the potential of acylating agents for Mpro inhibition.

In this study, we investigate the effect of thermal treatment/calcination on the stability and activity of a Na-Mn-W/SiO2 catalyst for the oxidative coupling of methane. The catalyst performance and characterisation measurements suggest that the W species are directly involved in the catalyst active site responsible for CH4 conversion. Under operating conditions, the active components, present in the form of a Na-W-O-Mn molten state, are highly mobile and volatile. By varying the parameters of the calcination protocol, it was shown that these molten components can be partially stabilised, resulting in a catalyst with lower activity (due to loss of surface area) but higher stability even for long duration OCM reaction experiments.

Cs2HfCl6 (CHC) and Cs2ZrCl6 (CZC) single crystals were grown by a vertical Bridgman method.

Paramagnetic suppression in TTTA at pressure is caused by a steady decrease in the separation between moieties containing the radical electron along π-stacking chains with no phase transition.

Changes in the structural dynamics of double stranded (ds)DNA upon ligand binding have been linked to the mechanism of allostery without conformational change, but direct experimental evidence remains elusive. To address this, a combination of steady state infrared (IR) absorption spectroscopy and ultrafast temperature jump IR absorption measurements has been used to quantify the extent of fast (∼100 ns) fluctuations in (ds)DNA·Hoechst 33258 complexes at a range of temperatures. Exploiting the direct link between vibrational band intensities and base stacking shows that the absolute magnitude of the change in absorbance caused by fast structural fluctuations following the temperature jump is only weakly dependent on the starting temperature of the sample. The observed fast dynamics are some two orders of magnitude faster than strand separation and associated with all points along the 10-base pair duplex d(GCATATATCC). Binding the Hoechst 33258 ligand causes a small but consistent reduction in the extent of these fast fluctuations of base pairs located outside of the ligand binding region. These observations point to a ligand-induced reduction in the flexibility of the dsDNA near the binding site, consistent with an estimated allosteric propagation length of 15 Å, about 5 base pairs, which agrees well with both molecular simulation and coarse-grained statistical mechanics models of allostery leading to cooperative ligand binding.

Sunscreen lotions and creams are arguably the most popular products used to protect the skin against harmful UV radiation. Several studies have been conducted to untangle the internal microstructure of creams and lotions. However, the effect of UV filters and other materials such as preservatives, on the internal microstructure and the aesthetics of these products is not yet fully understood. Using small-angle neutron scattering (SANS), we were able to investigate the effect of adding the commonly used organic UV filters (avobenzone (AVB), ethylhexyl methoxycinnamate (EMC), ethylhexyl triazone (EHT) and bemotrizinol (BMT)) and the water soluble preservatives (1,5-pentanediol (1,5-PD) and 1,2-hexanediol (1,2-HD)), on the internal architecture and microstructure of an oil-in-water (o/w) based sunscreen lotion. Our findings highlight the complexities of these formulations, and how the introduction of different additives could influence their structure and possibly their performance.

The structural and dielectric properties of barium/strontium substituted Bi0.5Na0.5TiO3 were examined in compositions of general formula (Ba0.4Sr0.6TiO3)x(Bi0.5Na0.5TiO3)1−x.