Incessant myopericarditis after mRNA vaccination requiring IL-1 receptor antagonist therapy and pericardiectomy: case report.

Background: During the COVID-19 pandemic, there has been global administration of novel mRNA vaccines that are effective in reducing the burden of COVID-19. In tandem with this administration, mRNA vaccine-associated complications have been identified. One such complication is mRNA vaccine-associated pericarditis. Case summary: This is a case of a 40-year old male who developed clinical pericarditis 3 days after his first dose of the Pfizer-BioNtech mRNA COVID-19 vaccination. The diagnosis of mRNA vaccine-induced pericarditis was confirmed on cardiac magnetic imaging and was resistant to numerous lines of medical therapy. These included substantial simple and opioid-based analgaesia, colchicine, prednisolone, interleukin-1 receptor antagonist therapy (anakinra), and a ketamine infusion that were all titrated over the course of eight hospital admissions. Ultimately, surgical pericardiectomy was performed that resulted in a favourable outcome. Discussion: This case depicts an example of incessant mRNA vaccine-associated pericarditis, a known complication of the Pfizer-BioNtech mRNA COVID-19 vaccination. There is limited evidence guiding the therapy of mRNA-induced pericarditis especially when recurrent and resistant to simple analgaesia, colchicine, and steroids. Thus, this case represents a potential framework to help future cases of incessant mRNA vaccine-induced pericarditis.

X-ray absorption spectroscopy of aqueous aluminum-organic complexes.

Aqueous-phase X-ray absorption near-edge structure (XANES) spectra were collected on dissolved Al complexes with organic ligands, including desferrioxamine B, EDTA, acetohydroxamate, malate, oxalate, and salicylate. Spectral interpretations were made using the density functional theory-based modeling package StoBe. The goals of this work were to study the geometric and electronic structural characteristics of these complexes relative to Al(H(2)O)(6)(3+) and to examine the utility of the aqueous Al XANES technique as a tool for probing Al speciation and structure. In the case of EDTA, aqueous Fourier-transform infrared spectroscopy was also used to corroborate the structures of the Al(EDTA)(-) and AlOH(EDTA)(2-) complexes. Synthetic XANES spectra calculated with StoBe reproduced the observed spectral differences between Al(H(2)O)(6)(3+), Al(dfoB)(+), and Al(EDTA)(-). The narrower XANES feature observed for Al(dfoB)(+) relative to Al(H(2)O)(6)(3+) can be attributed to a weaker splitting of the Al 3p-O 2p interactions in the former, while Al(EDTA)(-) exhibits split Al 3p-ligand interactions that likely result from the mixed O/N coordination. In complexes with mixed aqua/organic-oxygen ligation (Al-acetohydroxamate, Al-malate, Al-oxalate, and Al-salicylate), spectra exhibit linear, systematic changes in peak width as a function of H(2)O to organic ligand ratio in the Al coordination sphere. These results highlight the sensitivity of the aqueous Al K-edge XANES spectrum to coordination environment and demonstrate its utility as an experimental probe for future studies of Al speciation in complex solutions.

Influence of hydroxylamine conformation on stereocontrol in Pd-catalyzed isoxazolidine-forming reactions.

Palladium-catalyzed carboamination reactions between N-Boc-O-(but-3-enyl)hydroxylamine derivatives and aryl or alkenyl bromides afford cis-3,5- and trans-4,5-disubstituted isoxazolidines in good yield with up to >20:1 dr. The diastereoselectivity observed in the formation of cis-3,5-disubstituted isoxazolidines is superior to selectivities typically obtained in other transformations, such as 1,3-dipolar cycloaddition reactions, that provide these products. In addition, the stereocontrol in the C-N bond-forming Pd-catalyzed carboamination reactions of N-Boc-O-(but-3-enyl)hydroxylamines is significantly higher than that of related C-O bond-forming carboetherification reactions of N-benzyl-N-(but-3-enyl)hydroxylamine derivatives. This is likely due to a stereoelectronic preference for cyclization via transition states in which the Boc group is placed in a perpendicular orientation relative to the plane of the developing ring, which derives from the conformational equilibria of substituted hydroxylamines.

Geometric and electronic structure of the aqueous Al(H2O)6(3+) complex.

The bonding environment of the aqueous Al(H2O)6(3+) complex was studied using X-ray absorption near-edge structure (XANES) spectroscopy at the Al K-edge, with spectral interpretations based on density functional theory (DFT). Calculations for a highly symmetric complex (T(h) symmetry) indicate electron transitions into Al3 p-O 2s and Al3 p-O 2p antibonding orbitals, with a split O 2p contribution that appears to be due to a weak pi-interaction of the Al 3p orbitals with water ligands off-axis (equatorial) with respect to the Al 3p axis. Calculations were performed with several hypothetical structures to assess the effects of Al-O bond length, orientation of water ligands in the first coordination shell, and the presence of a second solvation shell on the XANES spectrum. Similar transitions were observed in all of these cases, but with further splitting on addition of 12 solvation waters, inward tilting and random twisting of the water ligands, and nonuniform Al-O bond lengths. Although it was previously hypothesized that the broadness of the XANES spectrum for this complex is due to an asymmetric geometry, these results illustrate how an Al(H 2O)6(3+) geometry that is octahedral (O(h)) with respect to the Al-O6 core could produce the broad spectrum observed. Because geometric distortions would affect relative Al-O bond strengths, an understanding of the equilibrium Al(H2O)6(3+) geometry is prerequisite to a quantitative description of reaction chemistry, including acidity and ligand exchange.

Quantitative determination of absolute organohalogen concentrations in environmental samples by X-ray absorption spectroscopy.

An in situ procedure for quantifying total organic and inorganic Cl concentrations in environmental samples based on X-ray absorption near-edge structure (XANES) spectroscopy has been developed. Cl 1s XANES spectra reflect contributions from all Cl species present in a sample, providing a definitive measure of total Cl concentration in chemically heterogeneous samples. Spectral features near the Cl K-absorption edge provide detailed information about the bonding state of Cl, whereas the absolute fluorescence intensity of the spectra is directly proportional to total Cl concentration, allowing for simultaneous determination of Cl speciation and concentration in plant, soil, and natural water samples. Absolute Cl concentrations are obtained from Cl 1s XANES spectra using a series of Cl standards in a matrix of uniform bulk density. With the high sensitivity of synchrotron-based X-ray absorption spectroscopy, Cl concentration can be reliably measured down to the 5-10 ppm range in solid and liquid samples. Referencing the characteristic near-edge features of Cl in various model compounds, we can distinguish between inorganic chloride (Cl(inorg)) and organochlorine (Cl(org)), as well as between aliphatic Cl(org) and aromatic Cl(org), with uncertainties in the range of approximately 6%. In addition, total organic and inorganic Br concentrations in sediment samples are quantified using a combination of Br 1s XANES and X-ray fluorescence (XRF) spectroscopy. Br concentration is detected down to approximately 1 ppm by XRF, and Br 1s XANES spectra allow quantification of the Br(inorg) and Br(org) fractions. These procedures provide nondestructive, element-specific techniques for quantification of Cl and Br concentrations that preclude extensive sample preparation.

Synthesis of polysubstituted tetrahydrofurans via Pd-catalyzed carboetherification reactions.

Pd-catalyzed carboetherifications of 1-, 2-, or 3-substituted γ-hydroxy internal alkenes afford tetrahydrofuran products bearing three stereocenters in good yield with moderate to good stereoselectivity.

Palladium-catalyzed synthesis of 2,1'-disubstituted tetrahydrofurans from gamma-hydroxy internal alkenes. Evidence for alkene insertion into a Pd-O bond and stereochemical scrambling via beta-hydride elimination.

Palladium-catalyzed reactions of gamma-hydroxy internal acyclic alkenes with aryl bromides afford 2,1'-disubstituted tetrahydrofurans in good yields with diastereoselectivities of 3-5:1. The analogous transformations of substrates bearing internal cyclic alkenes afford fused bicyclic and spirocyclic tetrahydrofuran derivatives in good yields with excellent diastereoselectivities (>20:1). A series of deuterium labeling experiments indicate that the origin of the modest diastereoselectivity in reactions of acyclic internal alkene substrates likely derives from a series of reversible beta-hydride elimination and sigma-bond rotation processes that occur following a rare intramolecular alkene syn-insertion into an intermediate Pd(Ar)(OR) complex. In addition, these studies shed light on the chemoselectivity of insertion, suggesting that the alkene inserts into the Pd-O bond in preference to the Pd-C bond.

Palladium-catalyzed synthesis of tetrahydrofurans from gamma-hydroxy terminal alkenes: scope, limitations, and stereoselectivity.

A new, stereoselective synthesis of substituted tetrahydrofurans via Pd-catalyzed reactions of aryl and vinyl bromides with gamma-hydroxy terminal alkenes is described. This transformation affords trans-2,5- and trans-2,3-disubstituted tetrahydrofurans with up to >20:1 dr. This methodology also provides access to bicyclic and spirocyclic tetrahydrofuran derivatives in good yield with 10-20:1 dr. The scope and limitations of these transformations are discussed in detail, as are the effect of substrate sterics and electronics on yield and stereoselectivity. A proposed mechanism of these transformations is presented along with a model that rationalizes the stereochemical outcome of the reactions.

Synthesis of N-Aryl-2-allyl Pyrrolidines via Palladium-catalyzed Carboamination Reactions of γ-(N-Arylamino)alkenes with Vinyl Bromides.

A palladium-catalyzed carboamination reaction of γ-N-arylamino alkenes with vinyl bromides that affords N-aryl-2-allyl pyrrolidines is described. These reactions proceed with high diastereoselectivity for the formation of trans-2,3- and cis-2,5-disubstituted pyrrolidines. Conditions for a tandem N-arylation/carboamination sequence that leads to the formation of an N-aryl-2-allyl pyrrolidine or indoline via the coupling of a primary γ-amino alkene, an aryl bromide, and a vinyl bromide are also reported. The mechanism of the carboamination reactions and the origin of unexpected products that formally derive from rearrangement of the vinyl bromide are discussed.

Two-dimensional condensed phases from particles with tunable interactions.

We present a conceptually simple experimental model for condensed phases, consisting of an ensemble of identical magnetic dipoles on a vibrating bed. The model combines tunable and accurately known pair potentials, equilibration times of seconds, and lattice structure and dynamics visible to the naked eye. Fundamental ensemble properties--specifically phonon propagation, edge relaxation, and binary condensation--are directly observed and quantitatively linked to the underlying pair potential.

Evaluation of the film-coating properties of a hydroxyethyl cellulose/hydroxypropyl methylcellulose polymer system.

The effect of different grades of hydroxyethyl cellulose (HEC) and hydroxypropyl methllcellulose (HPMC) on the film-formation and taste-masking ability for ibuprofen granules was evaluated. Three batches of coated ibuprofen granules were prepared using a roto-granulator, each with a different coating composition. Two grades of HEC [MW300,000 (H) and MW90,000 (L)] were combined with three different grades of HPMC [MW 11,000 (L), MW 25,000 (M) and MW 35,000 (H)] to prepare the coating solutions. Mechanical strength and physical properties of the polymer films were evaluated. Films made from HPMC (L)/HEC (H), HPMC (M)/HEC (H), and HPMC (H)/HEC (H) were stronger and more flexible than the HPMC (L) HEC (L) films. The assay, dissolution, particle size distribution, and environmental scanning electron microscopy (ESEM) data of the three batches of the coated ibuprofen granules were similar.