112 research outputs found

    A Multicatalytic Approach to the Hydroaminomethylation of α-Olefins.

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    We report an approach to conducting the hydroaminomethylation of diverse α-olefins with a wide range of alkyl, aryl, and heteroarylamines at relatively low temperatures (70-80 °C) and pressures (1.0-3.4 bar) of synthesis gas. This approach is based on simultaneously using two distinct catalysts that are mutually compatible. The hydroformylation step is catalyzed by a rhodium diphosphine complex, and the reductive amination step, which is conducted as a transfer hydrogenation with aqueous, buffered sodium formate as the reducing agent, is catalyzed by a cyclometallated iridium complex. By adjusting the ratio of CO to H2 , we conducted the reaction at one atmosphere of gas with little change in yield. A diverse array of olefins and amines, including hetreroarylamines that do not react under more conventional conditions with a single catalyst, underwent hydroaminomethylation with this new system, and the pharmaceutical ibutilide was prepared in higher yield and under milder conditions than with a single catalyst

    Girls Are Good At STEM: Opening Minds And Providing Evidence Reduce Boys\u27 Stereotyping Of Girls\u27 STEM Ability

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    Girls and women face persistent negative stereotyping within STEM (science, technology, engineering, mathematics). This field intervention was designed to improve boys\u27 perceptions of girls\u27 STEM ability. Boys (N = 667; mostly White and East Asian) aged 9-15 years in Canadian STEM summer camps (2017-2019) had an intervention or control conversation with trained camp staff. The intervention was a multi-stage persuasive appeal: a values affirmation, an illustration of girls\u27 ability in STEM, a personalized anecdote, and reflection. Control participants discussed general camp experiences. Boys who received the intervention (vs. control) had more positive perceptions of girls\u27 STEM ability, d = 0.23, an effect stronger among younger boys. These findings highlight the importance of engaging elementary-school-aged boys to make STEM climates more inclusive

    Studies on the actin-binding protein HS1 in platelets

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    <p>Abstract</p> <p>Background</p> <p>The platelet cytoskeleton mediates the dramatic change in platelet morphology that takes place upon activation and stabilizes thrombus formation. The Arp2/3 complex plays a vital role in these processes, providing the protrusive force for lamellipodia formation. The Arp2/3 complex is highly regulated by a number of actin-binding proteins including the haematopoietic-specific protein HS1 and its homologue cortactin. The present study investigates the role of HS1 in platelets using HS1<sup>-/- </sup>mice.</p> <p>Results</p> <p>The present results demonstrate that HS1 is not required for platelet activation, shape change or aggregation. Platelets from HS1<sup>-/- </sup>mice spread normally on a variety of adhesion proteins and have normal F-actin and Arp2/3 complex distributions. Clot retraction, an actin-dependent process, is also normal in these mice. Platelet aggregation and secretion is indistinguishable between knock out and littermates and there is no increase in bleeding using the tail bleeding assay.</p> <p>Conclusion</p> <p>This study concludes that HS1 does not play a major role in platelet function. It is possible that a role for HS1 is masked by the presence of cortactin.</p

    Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

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    Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts

    Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas

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    Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN

    Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

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    This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin

    Spatial Organization and Molecular Correlation of Tumor-Infiltrating Lymphocytes Using Deep Learning on Pathology Images

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    Beyond sample curation and basic pathologic characterization, the digitized H&E-stained images of TCGA samples remain underutilized. To highlight this resource, we present mappings of tumorinfiltrating lymphocytes (TILs) based on H&E images from 13 TCGA tumor types. These TIL maps are derived through computational staining using a convolutional neural network trained to classify patches of images. Affinity propagation revealed local spatial structure in TIL patterns and correlation with overall survival. TIL map structural patterns were grouped using standard histopathological parameters. These patterns are enriched in particular T cell subpopulations derived from molecular measures. TIL densities and spatial structure were differentially enriched among tumor types, immune subtypes, and tumor molecular subtypes, implying that spatial infiltrate state could reflect particular tumor cell aberration states. Obtaining spatial lymphocytic patterns linked to the rich genomic characterization of TCGA samples demonstrates one use for the TCGA image archives with insights into the tumor-immune microenvironment

    Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans

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    Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in 25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16 regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP, while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium (LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region. Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the refined data for existing association signals, we estimate that these loci now explain ∌38.9% of the familial relative risk of PrCa, an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent signals within the same regio

    Gene-Educational attainment interactions in a Multi-Population Genome-Wide Meta-Analysis Identify Novel Lipid Loci

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