Imaging active site chemistry and protonation states: NMR crystallography of the tryptophan synthase α-aminoacrylate intermediate.

NMR-assisted crystallography-the integrated application of solid-state NMR, X-ray crystallography, and first-principles computational chemistry-holds significant promise for mechanistic enzymology: by providing atomic-resolution characterization of stable intermediates in enzyme active sites, including hydrogen atom locations and tautomeric equilibria, NMR crystallography offers insight into both structure and chemical dynamics. Here, this integrated approach is used to characterize the tryptophan synthase α-aminoacrylate intermediate, a defining species for pyridoxal-5'-phosphate-dependent enzymes that catalyze β-elimination and replacement reactions. For this intermediate, NMR-assisted crystallography is able to identify the protonation states of the ionizable sites on the cofactor, substrate, and catalytic side chains as well as the location and orientation of crystallographic waters within the active site.

Analytical and clinical evaluation of a heat shock SARS-CoV-2 detection method without RNA extraction for N and E genes RT-qPCR.

Background: The COVID-19 pandemic has caused significant supply shortages worldwide for SARS-CoV-2 molecular diagnosis, like RNA extraction kits.

Objective: The aim of our study was to evaluate the clinical performance and analytical sensitivity of a simple SARS-CoV-2 diagnosis protocol based on heat shock without RNA extraction using both "CDC" (N gene) and "Charite" (E gene) RT-qPCR protocols.

Results: 1,036 nasopharyngeal samples, 543 of them SARS-CoV-2 positive, were analyzed.

Best practices for Electronically Activated Recorder (EAR) research: A practical guide to coding and processing EAR data.

Since its introduction in 2001, the Electronically Activated Recorder (EAR) method has become an established and broadly used tool for the naturalistic observation of daily social behavior in clinical, health, personality, and social science research. Previous treatments of the method have focused primarily on its measurement approach (relative to other ecological assessment methods), research design considerations (e.g.

Evaluation of the SO(2) and NH(3) gas adsorption properties of CuO/ZnO/Mn(3)O(4) and CuO/ZnO/NiO ternary impregnated activated carbon using combinatorial materials science methods.

Impregnated activated carbons (IAC) are widely used materials for the removal of toxic gases in personal respiratory protection applications. The combinatorial method has been employed to prepare IACs containing different types of metal oxides in various proportions and evaluate their adsorption performance for low molecular weight gases, such as SO(2) and NH(3), under dry conditions. Among the metal oxides used for the study, Mn(3)O(4) was found to have the highest capacity for retaining SO(2) gas under dry conditions.

SO2 and NH3 gas adsorption on a ternary ZnO/CuO/CuCl2 impregnated activated carbon evaluated using combinatorial methods.

Ternary libraries of 64 ZnO/CuO/CuCl(2) impregnated activated carbon samples were prepared on untreated or HNO(3)-treated carbon and evaluated for their SO(2) and NH(3) gas adsorption properties gravimetrically using a combinatorial method. CuCl(2) is shown to be a viable substitute for HNO(3) and some compositions of ternary ZnO/CuO/CuCl(2) impregnated carbon samples prepared on untreated carbon provided comparable SO(2) and NH(3) gas removal capacities to the materials prepared on HNO(3)-treated carbon. Through combinatorial methods, it was determined that the use of HNO(3) in this multigas adsorbent formulation can be avoided.

Gas adsorption properties of the ternary ZnO/CuO/CuCl(2) impregnated activated carbon system for multigas respirator applications assessed through combinatorial methods and dynamic adsorption studies.

A ternary library of 64 ZnO/CuO/CuCl(2) impregnated activated carbon samples was synthesized and screened automatically using a combinatorial (combi) method. The ability of the samples to adsorb toxic gases was screened gravimetrically. The stoichiometric ratio of reaction (SRR) between the moles of toxicant and the total moles of impregnant was obtained from the calculated mass increase of the samples after chemisorption, with a high SRR indicating high efficiency of toxicant removal.

Spontaneous intrahepatic hemorrhage: a case report.

Etiology of the acute abdomen can be difficult to determine in the acute care setting, as both medical and surgical emergencies can present with a similar clinical presentation. Prompt work-up is essential to reveal the diagnosis and allow for successful treatment. We present a rare case of spontaneous intrahepatic hemorrhage in a patient with multiple comorbidities, including multiple myeloma and lung cancer.

Wandering spleen: a rare cause of abdominal pain.

Torsion of a wandering spleen is a rare cause of abdominal pain in children. The most common presentation is acute abdominal pain, although signs and symptoms vary widely. Due to the risk of splenic infarction, rapid and accurate diagnosis is essential.

Production of swainsonine by fungal endophytes of locoweed.

Consumption of locoweeds, legumes endemic in arid western USA, has long been associated with locoism, a disease of ruminant animals. To explore the relationship between fungi associated with locoweed and locoweed toxicity, 11 locoweed populations from various sites in New Mexico were assessed for endophytic fungi. Endophytes were isolated from the leaves, stems, seeds, and flowers of eight populations of the toxic locoweeds Astragalus mollissimus, Oxytropis lambertii, and O.