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Background: Hemp-derived delta-9 tetrahydrocannabinol (∆9 THC) products are freely available for sale across much of the USA, but the federal legislation allowing their sale places only minimal requirements on companies. Products must contain no more than 0.3% ∆9 THC by dry weight, but no limit is placed on overall dosage and there is no requirement that products are tested. However, some states—such as Colorado—specifically prohibit products created by "chemically modifying" a natural hemp component. Methods: Fifty-three ∆9 THC products were ordered and submitted to InfiniteCAL laboratory for analysis. The lab analysis considered potency, the presence of impurities, and whether the ∆9 THC present was natural or converted from CBD. The presence of age verification, company-conducted testing, and warning labels was also considered. Results: While 96.2% of products were under the legal ∆9 THC limit, 66.0% differed from their stated dosage by more than 10%, and although 84.9% provided a lab report to customers, 71.1% of these did not check for impurities. Additionally, 49% of products converted CBD to THC to achieve their levels, and only 15.1% performed age verification at checkout. Conclusions: Despite some positive findings, the results show that hemp ∆9 THC companies offer inaccurately labeled products that contain more THC than would be allowed in adult-use states. This raises serious issues around consumer safety, and consent when consuming intoxicating products. Steps to boost accountability for companies must be considered by either the industry or lawmakers if intoxicating hemp products are to remain on the market safely. [ABSTRACT FROM AUTHOR] more...

A correction is presented to the article titled "Potency and safety analysis of hemp delta‑9 products: the hemp vs. cannabis demarcation problem" which appeared in the August 5, 2023 issue.

Two novel ruthenium complexes, [Ru(2,2′-bipyridine-6,6′-diphosphonato)(pic)2] ( 2) (pic=4-picoline) and [Ru(6,6′-diisopropyl-2,2′-bipyridine-6,6′-diphosphonato)(pic)>2] ( 3) bearing phosphonate groups have been synthesized and characterized by NMR spectroscopy, elemental analyses, X-ray crystallography, cyclic voltammetry, and UV/Vis spectroscopy. Both complexes show catalytic water oxidation activity by electrochemistry. At pH 7, the RuII/III redox couple of 2 is observed at a lower potential than that of 3, yet significantly, 3 oxidizes water at a lower onset potential. At pH 1 however, 2 and 3 have comparable catalytic reactivity using sacrificial oxidant CeIV. We propose that water oxidation activities of 2 and 3 are influenced by overall charges. For example, in oxidizing from RuII to RuIII at pH 7, 2 acquires a −1 overall charge whereas 3 acquires a +1 charge. Charge-dictated electrostatic effects may govern binding of a water molecule to the metal site. [ABSTRACT FROM AUTHOR] more...

Pincer protic N-heterocyclic carbene (PNHC) complexes were synthesized by direct metalation, the formation of a metal carbon bond from an unfunctionalized C-H bond in a single synthetic step. Significantly, direct metalation succeeded even for a first-row metal, nickel. The chloride complexes were isolated and then converted to the acetate, triflate, or in the platinum case, a hydride analogue. Crystal structures and ¹H, 13C, and 15N NMR data, as well as IR spectra, document the effects of intramolecular hydrogen bonding and the planar but flexible pincer framework. Anti-Markovnikov addition of O¢H bonds to alkynes, including catalyzed alkyne hydration, were demonstrated on the Pt triflate analog. [ABSTRACT FROM AUTHOR] more...

Water-oxidation catalysts (WOCs) can potentially be improved by installing pendant electron-donor groups that may also be proton donors or acceptors. We have modified one of the most well-studied WOCs with alkoxy or hydroxy substituents on the bidentate bipyridine ligand (N,N), thereby forming [(terpy)RuII(N,N)X] (X = Cl, H2O; terpy = 2,2′;6′,2"-terpyridine). A combination of NMR spectroscopy (particularly 15N chemical-shift data), UV/Vis spectroscopy, X-ray diffraction, and oxygen evolution data point to interesting and beneficial effects of an oxygenated group proximal to X. A methoxy group on the 2,2′-bipyridyl (bipy) ring cis to X = Cl is shown to facilitate ionization of the chloride ligand in aqueous acetone, perhaps by acceptance of a hydrogen bond from the aquo ligand. Hydrogen-bond donation of a proximal hydroxy group to a bound aquo ligand is shown by X-ray diffraction. Distinct differences in p Ka values for the 4,4′- and 6,6′-dihydroxy bipy complexes are seen. In water oxidation driven by ceric ammonium nitrate, the 6,6′-dimethoxy species is somewhat faster and longer-lived than the analogue that lacks the oxygenated groups [a turnover number (TON) of 215 instead of 138 in 10 h, and a turnover frequency (TOF) of 0.36 min-1 instead of 0.23 over the same time period]. Taken together, oxygenated groups near the WOC active site are promising electron or proton donors and/or hydrogen-bond acceptors, and are the subject of further scrutiny. [ABSTRACT FROM AUTHOR] more...

A series of experiments, investigating vortex induced scour formation, show that the scour hole geometry induced by a rotating fluid flow, can be explained within the concept that the granular bed is eroded as the imposed shear stress overcomes a certain critical value inherent in the liquid/bed pair. The situation is seemingly kindred to that observed in the pseudoplastic Bingham fluids and the first experiment, investigating cylindrical scour, is conducted using a high viscous Bingham fluid with a low yield stress. Two other experiments investigating the two and three dimensional scour formation for the stationary flow regime are also conducted using a fluid and grain substrate pair. A simple model for vortex induced scour is derived for an infinitely long axisymmetric vortex with circular streamlines surrounded by a deformable boundary. The Navier–Stokes equations are solved by using a polynomial approximation of the tangential velocity. The model is then extended to two and three dimensional stationary flow situations by considering the torque balance between the fluid motion and the critical bed shear stress. The quantified results agree well with experimental results obtained in both the one dimensional Bingham fluid experiment and the two and three dimensional fluid/grain experiments. [ABSTRACT FROM AUTHOR] more...

Binding energy calculations for complexes of mutant and wild-type human dihydrofolate reductases with 2,4-diaminopteridine and 2,4-diaminoquinazoline inhibitors are reported. Quantitative insight into binding energetics of these molecules is obtained from calculations based on force field energy evaluation and thermal sampling by molecular dynamics simulations. The calculated affinity of methotrexate for wild-type and mutant enzymes is reasonably well reproduced. Truncation of the methotrexate glutamate tail results in a loss of affinity by several orders of magnitude. No major difference in binding strength is predicted between the pteridines and the quinazolines, while the N-methyl group present in methotrexate appears to confer significantly stronger binding. The recent improvement, which is used here, of our linear interaction energy method for binding affinity prediction, as well as problems with treating charged and flexible ligands are discussed. This approach should be suitable in a drug discovery context for prediction of binding energies of new inhibitors prior to their synthesis, when some information about the binding mode is available. [ABSTRACT FROM AUTHOR] more...

A recent method for estimating ligand binding affinities is extended. This method employs averages of interaction potential energy terms from molecular dynamics simulations or other thermal conformational sampling techniques. Incorporation of systematic deviations from electrostatic linear response, derived from free energy perturbation studies, into the absolute binding free energy expression significantly enhances the accuracy of the approach. This type of method may be useful for computational prediction of ligand binding strengths, e.g., in drug design applications. [ABSTRACT FROM AUTHOR] more...

Examines the physics of the flow past a submerged vane at high angles of attack. Process of determining the optical angle of attack; Longitudinal cross section view of velocity vectors at optical angle of attack; Schematic of photograph identifying location of stagnated line. more...

Muon spin rotation (μSR) data on a single crystalline sample of Dy have been obtained as function of temperature and applied hydrostatic pressure. The discontinuity observed in our new data at the phase transition at 85 K strongly suggests that the muons occupy tetrahedral interstitial sites, with a contact field BC=-2.5 T at the lowest temperatures. Measurements with applied pressures up to 0.8 GPa show that the magnitude of the local fields increases with pressure at 0.3 GPa, and that the muon signal in the antiferromagnetic phase has essentially disappeared at 0.8 GPa. [ABSTRACT FROM AUTHOR] more...

An electron-electron coincidence method for precise measurements of internal conversion probabilities is described. By using K-Auger electrons the atom itself provides a unity standard in the same nuclear decay. The method is applied to the decay ofIn in which the K-conversion probability of the 245 keV transition is determined to be 0.0494±0.0011. Relative internal conversion intensities and transition energies are determined using a double focussing spectrometer. These data make it possible to calculate conversion coefficients for all electron shells. [ABSTRACT FROM AUTHOR] more...