The extent of dimerization in radical trap-assisted atom transfer radical coupling (RTA-ATRC) was studied as a function of solvent composition, with accelerated rates of coupling observed in solvent mixtures consisting of THF and hydrocarbons compared to either pure solvent. Aggregation of the nitroso radical trap was speculated to be responsible for the trend in coupling rates of RTA-ATRC reactions, with less polar solvents such as hydrocarbons favoring the active, monomeric form. The mixed solvent system of THF and cyclohexane was found to be transferrable to the synthesis of macrocyclic PS by intramolecular RTA-ATRC, with 50/50 (v/v) THF:cyclohexane reaction medium giving higher yields of cyclic product compared to reactions performed in the pure solvents.

The formation of ABA‐type triblock copolymers is studied as a function of chain end structure of the second block (benzylic alkyl bromides compared to α‐bromo esters) and the inclusion of the radical trap 2‐methyl‐2‐nitrosopropane (MNP) in the coupling reaction. In the case of coupling poly(methyl methacrylate)‐block‐polystyrene (PMMA‐b‐PSBr), both traditional atom transfer radical coupling (ATRC) reactions and analogous radical trap‐assisted ATRC (RTA‐ATRC) reactions lead to ABA‐type triblock copolymers. Contrastively, coupling of polystyrene‐block‐poly(methyl acrylate) precursors is unsuccessful in ATRC reactions lacking the nitroso radical trap, yet forming high amounts of triblock in analogous RTA‐ATRC reactions, consistent with lower KATRP values of the chain end α‐bromo ester. Synthesis of the triblocks is also attempted using coupling reactions of dibrominated PS and monobrominated poly(methyl acrylate), relying on selective coupling to be successful. In the presence of the radical trap MNP, substantial coupling is observed with gel permeation chromatography data indicating the formation of the triblock. Traditional ATRC reactions performed in an analogous manner do not produce the triblock to an appreciable extent, with lowered extents of coupling overall.

Background: Gastric cancer (GC) is a leading cause of cancer morbidity and mortality. Developing information systems which integrate clinical and genomic data may accelerate discoveries to improve cancer prevention, detection, and treatment. To support translational research in GC, we developed the GC Registry (GCR), a North American repository of clinical and cancer genomics data. Methods: Participants self-enrolled online. Entry criteria into the GCR included the following: (1) diagnosis of GC, (2) history of GC in a first- or second-degree relative, or (3) known germline mutation in the gene CDH1. Participants provided demographic and clinical information through a detailed survey. Some participants provided specimens of saliva and tumor samples. Tumor samples underwent exome sequencing, whole genome sequencing and transcriptome sequencing. Results: From 2011-2021, 567 individuals registered and returned the clinical questionnaire. For this cohort 65% had a personal history of GC, 36% reported a family history of GC and 14% had a germline CDH1 mutation. 89 GC patients provided tumor samples. For the initial study, 41 tumors were sequenced using next generation sequencing. The data was analyzed for cancer mutations, copy number variations, gene expression, microbiome, neoantigens, immune infiltrates, and other features. We developed a searchable, web-based interface (the GCR Genome Explorer) to enable researchers access to these datasets. Conclusions: The GCR is a unique, North American GC registry which integrates clinical and genomic annotation. Impact: Available for researchers through an open access, web-based explorer, the GCR Genome Explorer will accelerate collaborative GC research across the United States and world.

Background: Gastric cancer (GC) is a leading cause of global cancer morbidity and mortality. Developing information systems which integrate clinical and genomic data may accelerate discoveries to improve cancer prevention, detection, and treatment. To support translational research in GC, we developed the GC Registry (GCR), a North American repository of clinical and cancer genomics data. Methods: GCR is a national registry with online self-enrollment. Entry criteria into the GCR included the following: (1) diagnosis of GC, (2) history of GC in a first- or second-degree family member or (3) known pathogenic or likely pathogenic germline mutation in the gene CDH1. Participants provided demographic and clinical information through a detailed (412-item) online survey. A subset of participants provided specimens of saliva and tumor samples. These tumor samples underwent exome sequencing, whole genome sequencing and transcriptome sequencing. Results: From 2011-2021, 567 individuals registered for the GCR and returned the clinical questionnaire. For this cohort 65% had a personal history of GC, 36% reported a family history of GC and 14% had a germline CDH1 mutation. Eighty-nine GC patients provided tumor tissue samples. For the initial pilot study, 41 tumors were sequenced using next generation sequencing. The data was analyzed for cancer mutations, copy number variations, gene expression, microbiome presence, neoantigens, immune infiltrates, and other features. We developed a searchable, web-based interface (the GCR Genome Explorer) to enable researchers access to these datasets. Conclusions: The GCR is a unique, North American GC registry which integrates both clinical and genomic annotation. Impact: Available for researchers through an open access, web-based explorer, we hope the GCR Genome Explorer accelerates collaborative GC research across the United States.

No abstract