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The United States Environmental Protection Agency held an international two-day workshop in June 2018 to deliberate possible performance targets for non-regulatory fine particulate matter (PM2.5) and ozone (O3) air sensors. The need for a workshop arose from the lack of any market-wide manufacturer requirement for documented sensor performance evaluations, the lack of any independent third party or government-based sensor performance certification program, and uncertainty among all users as to the general usability of air sensor data. A multi-sector subject matter expert panel was assembled to facilitate an open discussion on these issues with multiple stakeholders. This summary provides an overview of the workshop purpose, key findings from the deliberations, and considerations for future actions specific to sensors. Important findings concerning PM2.5 and O3 sensors included the lack of consistent performance indicators and statistical metrics as well as highly variable data quality requirements depending on the intended use. While the workshop did not attempt to yield consensus on any topic, a key message was that a number of possible future actions would be beneficial to all stakeholders regarding sensor technologies. These included documentation of best practices, sharing quality assurance results along with sensor data, and the development of a common performance target lexicon, performance targets, and test protocols. Keywords: Low-cost air quality sensors, Performance targets, PM2.5, Ozone

X-ray crystal structures of three salts of protonated triethylenetetramine, (H4TETA)4+, with succinate, maleate, and fumarate anions are reported. Structures of the complexes (H4-triethylenetetramine)(hydrogenmaleate)4·2H2O [(H4TETA)(Hmal)4·2H2O] (1), (H4-triethylenetetramine)(hydrogenfumarate)4·3.3H2O [(H4TETA)(Hfum)4·3.3H2O] (2), and (H4-triethylenetetramine)(succinate)2 [(H4TETA)(suc)2] (3) all form assemblies of alternating two-dimensional layers of (H4TETA)4+ and the anionic species via hydrogen-bond networks. Both classical and nonclassical hydrogen bonds between the protonated amine groups, anions, and water molecules were observed. X-ray powder diffraction measurements, differential thermal analysis/thermogravimetry, density vapor sorption, and Karl Fischer titration measurements were performed to obtain confirmatory information about the water content in the structures 1 and 2 and to examine polymorphism within the salts. The nonhydrated salt 3 was determined to be the most favorable salt formula...

The thermal decomposition of chloroacetyl chloride, propanoyl chloride, 3-chloropropanoyl chloride, acryloyl chloride, E-2-butenoyl chloride, methacryloyl chloride, and cyclopropanecarbonyl chloride has been investigated using infrared laser-powered homogeneous pyrolysis, together with product analysis using IR spectroscopy, gas chromatography/mass spectrometry, matrix isolation spectroscopy and tuneable diode laser spectroscopy. Decomposition is usually initiated by 1,2-HCl elimination (where possible), followed by further decomposition of ketene products. Reaction pathways have been validated in many cases by the ab initio calculation of activation energies.

Heart disease is the major cause of death in diabetes, a disorder characterized by chronic hyperglycemia and cardiovascular complications. Although altered systemic regulation of transition metals in diabetes has been the subject of previous investigation, it is not known whether changed transition metal metabolism results in heart disease in common forms of diabetes and whether metal chelation can reverse the condition. We found that administration of the Cu-selective transition metal chelator trientine to rats with streptozotocin-induced diabetes caused increased urinary Cu excretion compared with matched controls. A CuII-trientine complex was demonstrated in the urine of treated rats. In diabetic animals with established heart failure, we show here for the first time that 7 weeks of oral trientine therapy significantly alleviated heart failure without lowering blood glucose, substantially improved cardiomyocyte structure, and reversed elevations in left ventricular collagen and β1 integrin. Oral trientine treatment also caused elevated Cu excretion in humans with type 2 diabetes, in whom 6 months of treatment caused elevated left ventricular mass to decline significantly toward normal. These data implicate accumulation of elevated loosely bound Cu in the mechanism of cardiac damage in diabetes and support the use of selective Cu chelation in the treatment of this condition.

SF6-photosensitiZed IR laser pyrolysis of W(CO)6 in the gas phase at moderate temperatures leads to unsaturated W(CO)n (n < 6) species; these prove to be effective abstractors of O atoms from a range of organic substrates, and afford a simple, clean and low-energy route from carbonyl compounds into gas phase carbene chemistry.

SF6-photosensitised IR laser pyrolysis of W(CO)6 in the gas phase at moderate temperatures leads to unsaturated W(CO)n species; these prove to be very effective and selective abstractors of Cl atoms from a wide range of organic substrates, and offer a low energy and clean route into gas phase organic radical chemistry.