Chemically Recyclable, High Molar Mass Polyoxazolidinones via Ring-Opening Metathesis Polymerization.

The development of robust methods for the synthesis of chemically recyclable polymers with tunable properties is necessary for the design of next-generation materials. Polyoxazolidinones (POxa), polymers with five-membered urethanes in their backbones, are an attractive target because they are strongly polar and have high thermal stability, but existing step-growth syntheses limit molar masses and methods to chemically recycle POxa to monomer are rare. Herein, we report the synthesis of high molar mass POxa via ring-opening metathesis polymerization of oxazolidinone-fused cyclooctenes.

Early Auditory Event Related Potentials Distinguish Higher-Order From First-Order Aversive Conditioning.

Stimuli in reality rarely co-occur with primary reward or punishment to allow direct associative learning of value. Instead, value is thought to be inferred through complex higher-order associations. Rodent research has demonstrated that the formation and maintenance of first-order and higher-order associations are supported by distinct neural substrates.

Concentration-Dependent Solvation Structure and Dynamics of Aqueous Sulfuric Acid Using Multinuclear NMR and DFT.

Sulfuric acid is a ubiquitous compound for industrial processes, and aqueous sulfate solutions also play a critical role as electrolytes for many prominent battery chemistries. While the thermodynamic literature on it is quite well-developed, comprehensive studies of the solvation structure, particularly molecular-scale dynamical and transport properties, are less available. This study applies a multinuclear nuclear magnetic resonance (NMR) approach to the elucidation of the solvation structure and dynamics over wide temperature (-10 to 50 °C) and concentration (0-18 M) ranges, combining the O shift, line width, and relaxation measurements, S shift and line width measurements, and H pulsed-field gradient NMR measurements of proton self-diffusivity.

Intracellular pathways for lignin catabolism in white-rot fungi.

Lignin is a biopolymer found in plant cell walls that accounts for 30% of the organic carbon in the biosphere. White-rot fungi (WRF) are considered the most efficient organisms at degrading lignin in nature. While lignin depolymerization by WRF has been extensively studied, the possibility that WRF are able to utilize lignin as a carbon source is still a matter of controversy.

The Effects of Common Over-the-Counter Moisturizers on Skin Barrier Function: A Randomized, Observer-Blind, Within-Patient, Controlled Study.

Background: Moisturizers possibly improve atopic dermatitis (AD) by restoration of skin barrier, although some have detrimental effects.

Objective: The aim of the study was to estimate the effects of several routine moisturizers on barrier functions.

Methods: This is a randomized, forearm-controlled, observer-blind study.

Test performance evaluation of SARS-CoV-2 serological assays.

Background: Serological tests are crucial tools for assessments of SARS-CoV-2 exposure, infection and potential immunity. Their appropriate use and interpretation require accurate assay performance data.

Method: We conducted an evaluation of 10 lateral flow assays (LFAs) and two ELISAs to detect anti-SARS-CoV-2 antibodies.

Uncovering the Diversity and Activity of Methylotrophic Methanogens in Freshwater Wetland Soils.

Wetland soils are one of the largest natural contributors to the emission of methane, a potent greenhouse gas. Currently, microbial contributions to methane emissions from these systems emphasize the roles of acetoclastic and hydrogenotrophic methanogens, while less frequently considering methyl-group substrates (e.g.

Chemically reprogramming the phospho-transfer reaction to crosslink protein kinases to their substrates.

The proteomic mapping of enzyme-substrate interactions is challenged by their transient nature. A method to capture interacting protein kinases in complexes with a single substrate of interest would provide a new tool for mapping kinase signaling networks. Here, we describe a nucleotide-based substrate analog capable of reprogramming the wild-type phosphoryl-transfer reaction to produce a kinase-acrylamide-based thioether crosslink to mutant substrates with a cysteine nucleophile substituted at the native phosphorylation site.

Site-specific incorporation of phosphotyrosine using an expanded genetic code.

Access to phosphoproteins with stoichiometric and site-specific phosphorylation status is key to understanding the role of protein phosphorylation. Here we report an efficient method to generate pure, active phosphotyrosine-containing proteins by genetically encoding a stable phosphotyrosine analog that is convertible to native phosphotyrosine. We demonstrate its general compatibility with proteins of various sizes, phosphotyrosine sites and functions, and reveal a possible role of tyrosine phosphorylation in negative regulation of ubiquitination.

Determination of ubiquitin fitness landscapes under different chemical stresses in a classroom setting.

Ubiquitin is essential for eukaryotic life and varies in only 3 amino acid positions between yeast and humans. However, recent deep sequencing studies indicate that ubiquitin is highly tolerant to single mutations. We hypothesized that this tolerance would be reduced by chemically induced physiologic perturbations.

Pasteurella multocida toxin (PMT) upregulates CTGF which leads to mTORC1 activation in Swiss 3T3 cells.

Pasteurella multocida toxin (PMT) is a mitogenic protein that hijacks cellular signal transduction pathways via deamidation of heterotrimeric G proteins. We previously showed that rPMT activates mTOR signaling via a Gαq/11/PLCβ/PKC mediated pathway, leading in part to cell proliferation and migration. Herein, we show that mTOR and MAPK, but not membrane-associated tyrosine kinases, are activated in serum-starved 3T3 cells by an autocrine/paracrine substance(s) secreted into the conditioned medium following rPMT treatment.

Mammalian target of rapamycin complex 1 (mTORC1) plays a role in Pasteurella multocida toxin (PMT)-induced protein synthesis and proliferation in Swiss 3T3 cells.

Pasteurella multocida toxin (PMT) is a potent mitogen known to activate several signaling pathways via deamidation of a conserved glutamine residue in the α subunit of heterotrimeric G-proteins. However, the detailed mechanism behind mitogenic properties of PMT is unknown. Herein, we show that PMT induces protein synthesis, cell migration, and proliferation in serum-starved Swiss 3T3 cells.

Percutaneous patent foramen ovale closure: outcomes with the Premere and Amplatzer devices.

Background: Transcatheter closure of patent foramen ovale (PFO) has rapidly evolved as the preferred management strategy for the prevention of recurrent cerebrovascular events in patients with cryptogenic stroke and presumed paradoxical embolus. There is limited outcome data in patients treated with this therapy particularly for the newer devices.

Methods: Data from medical records, catheter, and echocardiography databases on 70 PFO procedures performed was collected prospectively.

Reactions of aromatic N-heterocycles with a lutetium benzyl complex supported by a ferrocene-diamide ligand.

A comparison between the reactivity behavior of two lutetium benzyl complexes supported by different ferrocene-diamide ligands towards aromatic N-heterocycles, such as 1-methylimidazole, isoquinoline, and pyridines, is presented. The two ferrocene-diamide ancillary ligands differ in their nitrogen-donor substituent: adamantyl for one and t-butyldimethylsilyl for the other. The synthesis and characterization of the adamantyl-derived complex 1(Ad)-DME are reported.

Aluminum content of parenteral nutrition in neonates: measured versus calculated levels.

Background And Objective: Aluminum (Al) is associated with significant central nervous system toxicity and bone and liver damage. Because Al is a contaminant of parenteral nutrition (PN) components including calcium and phosphate additives, premature infants are at potentially high risk for toxicity. The US Food and Drug Administration (FDA) has mandated PN component product labeling and recommended maximum Al daily exposure limits.

Laboratory evaluation of inflammatory bowel disease.

Purpose Of Review: Recognizing inflammatory bowel disease (IBD) is straightforward when alarm symptoms are present, such as bloody diarrhea and weight loss. When the presentation is subtle or atypical, physicians must determine which patients warrant evaluation for IBD. Appropriate use of noninvasive tests can help identify which patients should undergo further investigation.

Transscaphoid transcapitate transtriquetral perilunate fracture-dislocation: a case report.

We present a rare stage III greater arc fracture-dislocation of the carpus including transscaphoid, transcapitate, and transtriquetral dorsal perilunate fracture-dislocation.