One-pot synthesis of difluoromethyl ketones by a difluorination/fragmentation process

Difluoromethyl ketones are an under-studied class of ketones which have great potential as useful building blocks for materials and drug design. Here we report a simple and convenient synthesis of this class of compounds via a one-pot difluorination/fragmentation of 1-trifluoromethyl-1,3-diketones which should now allow the chemistry of difluoromethyl ketones to be fully developed

EXPERIMENTAL CHARACTERIZATION AND MODELING OF FLAME HEAT FEEDBACK AND OXIDATIVE PYROLYSIS FOR SIMULATION OF BENCH SCALE FIRE TESTS

Two important bench scale fire tests, the cone calorimeter test and UL-94V, werecharacterized experimentally to allow for predictions using a numerical pyrolysis solver, ThermaKin2Ds with pyrolysis parameter sets. Flame heat feedback was measured in cone calorimeter tests for several polymers to develop a generalized flame model. Flame heat flux was measured in the center and near one side and was found to be 11–23 kW m-2 and 32–49 kW m-2, respectively. Based on the difference in measured heat flux, a center zone and a side zone were defined and separate models developed. The final model was an area-weighted combination of the center and side zone simulations. Heat release rate data were predicted well by the final model. Ignition times for low irradiation were not predicted well initially but a correction was made to account for the effect of oxygen. The UL-94V test required characterization of the flame heat feedback but also of the burner flame (temperature, heat flux, and oxygen content). UL-94V tests were performed using polymers of different flammability ratings to evaluate the model; some samples had insulated sides to investigate edge effects. Additional UL-94V tests performed with an embedded heat flux gauge served to measure polymer flame heat feedback. All UL-94V tests were recorded on video using a 900-nm narrow-band filter to focus on emissions from soot for tracking flame length over time. Flame heat fluxes of insulated PMMA samples confirmed a previously developed wall flame submodel, while non-insulated PMMA samples had significantly greater heat fluxes; the wall flame submodel was scaled accordingly. Burner flame oxygen content was measured to be about 5 vol% and was found to enhance decomposition of two materials; oxidation submodels were then developed accordingly. Overall, the model predicted flame spread on insulated UL-94V samples reasonably well but significantly underpredicted the results on non-insulated samples. Discrepancies were attributed to burning and spread on the edges which were not modeled explicitly. Finally, given the importance of oxidation on predictions of ignition time, oxidative pyrolysis was studied both in mg-scale and gram-scale pyrolysis experiments. Kinetic parameters were first developed based on inverse analysis of TGA tests in atmospheres of varied oxygen content. Two models were developed: a surface reaction model and a volumetric model. Mass flux data from gram-scale gasification tests were used to evaluate the models. The anaerobic model gave the best predictions of mass flux for 15 kW m-2 gasification tests, but the oxidative models gave better predictions for the 25 kW m-2 gasification tests. The volumetric model gives better predictions unless mass transport of oxygen is considered in which case, the surface model gives better predictions

Improved Venting for Flammability Limit Testing Using ASTM E681 Apparatus

The literature on the determination of flammability limits was reviewed and experts on the ASTM E681 standard were interviewed to identify new means of improving the reproducibility of the ASTM E681 test. Venting was identified as a variable of flammability limits not yet addressed. Limitations of the current system for sealing and venting (a rubber stopper) were identified and addressed by the development of a custom burst disc. The burst disc was evaluated for its ability to hold and maintain a vacuum, its ability to vent at pressures of interest, and for its venting phenomena. The burst disc was deemed to be a satisfactory alternative to the rubber stopper and is recommended to be included in the ASTM E681 standard

High Power, Low Frequency Ultrasound: Meniscal Tissue Interaction and Ablation Characteristics

Abstract—This study evaluates high power low frequency ultrasound transmitted via a flat vibrating probe tip as an alternative technology for meniscal debridement in the bovine knee. An experimental force controlled testing rig was constructed using a 20 kHz ultrasonic probe suspended vertically from a load cell. Effect of variation in amplitude of distal tip displacement (242–494 mm peak-peak) settings and force (2.5–4.5 N) on tissue removal rate (TRR) and penetration rate (PR) for 52 bovine meniscus samples was analyzed. Temperature elevation in residual meniscus was measured by embedded thermocouples and histologic analysis. As amplitude or force increases, there is a linear increase in TRR (Mean: 0.9 to 11.2 mg/s) and PR (Mean: 0.08 to 0.73 mm/s). Maximum mean temperatures of 84.6C and 52.3C were recorded in residual tissue at 2 mm and 4 mm from the ultrasound probe-tissue interface. There is an inverse relationship between both amplitude and force, and temperature elevation, with higher settings resulting in less thermal damage.

Development of an evidence-based regimen of prednisolone to treat giant cell arteritis - the Norwich regimen

We have reviewed the literature to form a bespoke regimen for daily oral prednisolone (DP) in GCA. Initial DP in clinical trials is 40-60 mg daily, but relapse rates are 67-92%. Cumulative prednisolone (CP) of 3.2 and 3.9 g (at 6 months) resulted in a relapse rate of 83 and 67%, respectively; and 3 and 3.9 g (at 12 months) resulted in 92 and 82% relapse, respectively. CP was 6.2-7.1 g in the first year. Mean DP was 18.8 mg at 3 months and 6.6-7.4 mg at 12 months. The duration of treatment with prednisolone for GCA was 22-26 months. The CP to achieve discontinuation was 6.5-12.1 g. Using these data, the Norwich regimen starts DP at 1 mg/kg/day of lean body mass, discontinuing over 100 weeks. For the average UK woman, initial DP is 45 mg daily, reaching 21 mg daily by 12 weeks and 6 mg daily by 52 weeks. The CP for the average UK woman would be 6.5 g at 52 weeks and 7.4 g to discontinuation

Mapping ground instability in areas of geotechnical infrastructure using satellite InSAR and Small UAV Surveying: a case study in Northern Ireland

Satellite Interferometric Synthetic Aperture Radar (InSAR), geological data and Small Unmanned Aerial Vehicle (SUAV) surveying was used to enhance our understanding of ground movement at five areas of interest in Northern Ireland. In total 68 ERS-1/2 images 1992–2000 were processed with the Small Baseline Subset (SBAS) InSAR technique to derive the baseline ground instability scenario of key areas of interest for five stakeholders: TransportNI, Northern Ireland Railways, Department for the Economy, Arup, and Belfast City Council. These stakeholders require monitoring of ground deformation across either their geotechnical infrastructure (i.e., embankments, cuttings, engineered fills and earth retaining structures) or assessment of subsidence risk as a result of abandoned mine workings, using the most efficient, cost-effective methods, with a view to minimising and managing risk to their businesses. The InSAR results provided an overview of the extent and magnitude of ground deformation for a 3000 km2 region, including the key sites of the disused salt mines in Carrickfergus, the Belfast–Bangor railway line, Throne Bend and Ligoniel Park in Belfast, Straidkilly and Garron Point along the Antrim Coast Road, plus other urbanised areas in and around Belfast. Tailored SUAV campaigns with a X8 airframe and generation of very high resolution ortho-photographs and a 3D surface model via the Structure from Motion (SfM) approach at Maiden Mount salt mine collapse in Carrickfergus in 2016 and 2017 also demonstrate the benefits of very high resolution surveying technologies to detect localised deformation and indicators of ground instabilit

Three step synthesis of benzylacetone and 4-(4-methoxyphenyl)butan-2-one in flow using micropacked bed reactors

The synthesis of benzylacetone from benzyl alcohol and of 4-(4-methoxyphenyl)butan-2-one from 4-methoxybenzyl alcohol, which were previously performed in a batch cascade, were successfully performed in a telescoped flow system consisting of three micropacked bed reactors and a tube-in-tube membrane to remove oxygen. The system consisted of approximately 10 mg of 1 wt% AuPd/TiO2 catalyst for oxidation, 150-250 mg of anatase TiO2 for C-C coupling and 10 mg of 1 wt% Pt/TiO2 for reduction, operating at 115 °C, 130 °C and 120 °C respectively. Oxygen and hydrogen flowrates were 2 and 1.5 NmL/min and alcohol solution inlet flowrates were 10-80 µL/min, while the system operated at a back pressure of 5 barg. This system achieved significantly increased yields of benzylacetone compared to the batch cascade (56% compared to 8%) and slightly increased yields of 4-(4-methoxyphenyl)butan-2-one (48% compared to 41% when using the same catalyst supports). The major advantage of the telescoped flow system was the ability to separate the three reactions, so that each reaction could have its own catalyst and operating conditions, which led to significant process intensification

Examination of the comfort and pain experienced with blood flow restriction training during post-surgery rehabilitation of anterior cruciate ligament reconstruction patients: A UK National Health Service trial.

Examine the comfort and pain experienced with blow flow restriction resistance training (BFR-RT) compared to standard care heavy load resistance training (HL-RT) during anterior cruciate ligament reconstruction (ACLR) patient rehabilitation. Randomised controlled trial. United Kingdom National Health Service. Twenty eight patients undergoing unilateral ACLR surgery with hamstring autograft were recruited. Following surgery participants were block randomised to either HL-RT at 70% repetition maximum (1RM) (n = 14) or BFR-RT (n = 14) at 30% 1RM and completed 8 weeks of twice weekly unilateral leg press training on both limbs. Perceived knee pain, muscle pain and rating of perceived exertion (RPE) were assessed using Borg's (1998) RPE and pain scales during training. Knee pain was also assessed 24 h post-training. There were no adverse events. Knee pain was lower with BFR-RT during (p  0.05) for both BFR-RT and HL-RT. ACLR patients experienced less knee joint pain and reported similar ratings of perceived exertion during and following leg press exercise with BFR-RT compared to traditional HL-RT. BFR-RT may be more advantageous during the early phases of post-surgery ACLR rehabilitation. [Abstract copyright: Copyright © 2019. Published by Elsevier Ltd.

Association between community-based self-reported COVID-19 symptoms and social deprivation explored using symptom tracker apps: A repeated cross-sectional study in Northern Ireland

Objectives: The aim of the study was to investigate the spatial and temporal relationships between the prevalence of COVID-19 symptoms in the community-level and area-level social deprivation. Design: Spatial mapping, generalised linear models, using time as a factor and spatial-lag models were used to explore the relationship between self-reported COVID-19 symptom prevalence as recorded through two smartphone symptom tracker apps and a range of socioeconomic factors using a repeated cross-sectional study design. Setting: In the community in Northern Ireland, UK. The analysis period included the earliest stages of non-pharmaceutical interventions and societal restrictions or \u27lockdown\u27 in 2020. Participants: Users of two smartphone symptom tracker apps recording self-reported health information who recorded their location as Northern Ireland, UK. Primary outcome measures: Population standardised self-reported COVID-19 symptoms and correlation between population standardised self-reported COVID-19 symptoms and area-level characteristics from measures of multiple deprivation including employment levels and population housing density, derived as the mean number of residents per household for each census super output area. Results: Higher self-reported prevalence of COVID-19 symptoms was associated with the most deprived areas (p \u3c 0.001) and with those areas with the lowest employment levels (p \u3c 0.001). Higher rates of self-reported COVID-19 symptoms within the age groups, 18-24 and 25-34 years were found within the most deprived areas during the earliest stages of non-pharmaceutical interventions and societal restrictions (\u27lockdown\u27). Conclusions: Through spatial regression of self-reporting COVID-19 smartphone data in the community, this research shows how a lens of social deprivation can deepen our understanding of COVID-19 transmission and prevention. Our findings indicate that social inequality, as measured by area-level deprivation, is associated with disparities in potential COVID-19 infection, with higher prevalence of self-reported COVID-19 symptoms in urban areas associated with area-level social deprivation, housing density and age