Tomographic reconstruction of velocity anomalies

An approximate inversion formula is proposed for the reconstruction of slowness anomalies in a known depth varying background field. The data are observed travel-time perturbations for reflections from a known planar reflector. The limitations of the formula are discussed and numerical examples are given

A stereodivergent asymmetric approach to difluorinated aldonic acids

A (bromodifluoromethyl)alkyne has been deployed in a stereoselective route to difluorinated aldonic acid analogues, in which a Sharpless asymmetric dihydroxylation reaction and diastereoisomer separation set the stage for phenyl group oxidation

Towards conformationally-locked difluorosugar analogues : an unexpected sense of dihydroxylation

Difluorinated cyclooctenones, synthesised using RCM, can be used as templates for stereoselective oxidative transformations to products that undergo transannular reactions to afford conformationally-locked analogues of 2-deoxy-2,2-difluorosugars with different stereochemical relationships between the C-2 and C-3 hydroxyl groups

Highly-functionalised difluorinated cyclohexane polyols via the Diels–Alder reaction : regiochemical control via the phenylsulfonyl group

A difluorinated dienophile underwent cycloaddition reactions with a range of furans to afford cycloadducts whichcould be processed regio- and stereoselectively via episulfonium ions, generated by the reaction between their alkenyl groups and phenylsulfenyl chloride. The oxabicyclic products were oxidised to the phenylsulfonyl level and ring opened via E1CB or reductive desulfonative pathways to afford, ultimately, difluorinated cyclohexene or cyclohexane polyols

GaN resistive hydrogen gas sensors

GaN epilayers grown by organometallic vapor phase epitaxy have been used to fabricate resistivegas sensors with a pair of planar ohmic contacts. Detectible sensitivity to H2 gas for a wide range of gas mixtures in an Ar ambient has been realized; the lowest concentration tested is ∼0.1% H2 (in Ar), well below the lower combustion limit in air. No saturation of the signal is observed up to 100% H2 flow. Real-time response to H2 shows a clear and sharp response with no memory effects during the ramping cycles of H2 concentration. The change in current at a fixed voltage to hydrogen was found to change with sensor geometry. This appears to be consistent with a surface-adsorption-induced change of conductivity; a detailed picture of the gas sensing mechanism requires further systematic studies

Managing Corn Residue with Different Tillage Systems and N Applications Field Days

Iowa State University Extension and Outreach will host two tours of residue management plots in July

Novel Trial Design: CHIEF-HF

BACKGROUND: The expense of clinical trials mandates new strategies to efficiently generate evidence and test novel therapies. In this context, we designed a decentralized, patient-centered randomized clinical trial leveraging mobile technologies, rather than in-person site visits, to test the efficacy of 12 weeks of canagliflozin for the treatment of heart failure, regardless of ejection fraction or diabetes status, on the reduction of heart failure symptoms. METHODS: One thousand nine hundred patients will be enrolled with a medical record-confirmed diagnosis of heart failure, stratified by reduced (≤40%) or preserved (\u3e40%) ejection fraction and randomized 1:1 to 100 mg daily of canagliflozin or matching placebo. The primary outcome will be the 12-week change in the total symptom score of the Kansas City Cardiomyopathy Questionnaire. Secondary outcomes will be daily step count and other scales of the Kansas City Cardiomyopathy Questionnaire. RESULTS: The trial is currently enrolling, even in the era of the coronavirus disease 2019 (COVID-19) pandemic. CONCLUSIONS: CHIEF-HF (Canagliflozin: Impact on Health Status, Quality of Life and Functional Status in Heart Failure) is deploying a novel model of conducting a decentralized, patient-centered, randomized clinical trial for a new indication for canagliflozin to improve the symptoms of patients with heart failure. It can model a new method for more cost-effectively testing the efficacy of treatments using mobile technologies with patient-reported outcomes as the primary clinical end point of the trial