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1.
J Am Med Inform Assoc ; 27(7): 1121-1125, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32333753

RESUMO

OBJECTIVE: The study sought to create an online resource that informs the public of coronavirus disease 2019 (COVID-19) outbreaks in their area. MATERIALS AND METHODS: This R Shiny application aggregates data from multiple resources that track COVID-19 and visualizes them through an interactive, online dashboard. RESULTS: The Web resource, called the COVID-19 Watcher, can be accessed online (https://covid19watcher.research.cchmc.org/). It displays COVID-19 data from every county and 188 metropolitan areas in the United States. Features include rankings of the worst-affected areas and auto-generating plots that depict temporal changes in testing capacity, cases, and deaths. DISCUSSION: The Centers for Disease Control and Prevention does not publish COVID-19 data for local municipalities, so it is critical that academic resources fill this void so the public can stay informed. The data used have limitations and likely underestimate the scale of the outbreak. CONCLUSIONS: The COVID-19 Watcher can provide the public with real-time updates of outbreaks in their area.


Assuntos
Betacoronavirus , Informática Aplicada à Saúde dos Consumidores , Infecções por Coronavirus/epidemiologia , Surtos de Doenças/estatística & dados numéricos , Pneumonia Viral/epidemiologia , Interface Usuário-Computador , COVID-19 , Centers for Disease Control and Prevention, U.S. , Cidades , Infecções por Coronavirus/mortalidade , Humanos , Pandemias , Pneumonia Viral/mortalidade , SARS-CoV-2 , Software , Estados Unidos/epidemiologia
2.
Genet Med ; 22(2): 371-380, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31481752

RESUMO

PURPOSE: Clinicians and researchers must contextualize a patient's genetic variants against population-based references with detailed phenotyping. We sought to establish globally scalable technology, policy, and procedures for sharing biosamples and associated genomic and phenotypic data on broadly consented cohorts, across sites of care. METHODS: Three of the nation's leading children's hospitals launched the Genomic Research and Innovation Network (GRIN), with federated information technology infrastructure, harmonized biobanking protocols, and material transfer agreements. Pilot studies in epilepsy and short stature were completed to design and test the collaboration model. RESULTS: Harmonized, broadly consented institutional review board (IRB) protocols were approved and used for biobank enrollment, creating ever-expanding, compatible biobanks. An open source federated query infrastructure was established over genotype-phenotype databases at the three hospitals. Investigators securely access the GRIN platform for prep to research queries, receiving aggregate counts of patients with particular phenotypes or genotypes in each biobank. With proper approvals, de-identified data is exported to a shared analytic workspace. Investigators at all sites enthusiastically collaborated on the pilot studies, resulting in multiple publications. Investigators have also begun to successfully utilize the infrastructure for grant applications. CONCLUSIONS: The GRIN collaboration establishes the technology, policy, and procedures for a scalable genomic research network.


Assuntos
Gerenciamento de Dados/métodos , Processamento Eletrônico de Dados/métodos , Armazenamento e Recuperação da Informação/métodos , Bancos de Espécimes Biológicos/normas , Pesquisa Biomédica/métodos , Bases de Dados Factuais , Bases de Dados Genéticas , Comitês de Ética em Pesquisa , Genômica/métodos , Humanos , Disseminação de Informação , Pesquisadores
5.
Ecol Appl ; 28(8): 2197-2205, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30312519

RESUMO

Ongoing urban development has significant effects on ecosystems, including changes to land cover, environmental conditions, and species' distributions. These various impacts may have opposing or interacting effects on plant communities, making it difficult to predict how plant biodiversity will respond to urban development. A frequently cited conceptual framework predicts how urban development influences plant taxonomic, functional, and phylogenetic diversity by simplifying multiple coincident effects of urbanization into four primary filters of biodiversity: habitat transformation, fragmentation, the urban environment, and human preferences. Each filter prevents some plant species from persisting in urban areas while promoting others, but species introductions according to human preferences are expected to cause a net increase in biodiversity while the other filters limit diversity. In this study, we used structural equation modeling to test these predictions and examine the relative importance of each filter on the taxonomic, functional, and phylogenetic diversity of riparian forest plant species sampled along an urban-to-rural gradient in the Research Triangle area of North Carolina. Most diversity measures declined with urbanization, but some (e.g., functional Rao's Q) increased with urbanization. We found support for some of the predicted relationships between urbanization filters and biodiversity, as well as some unexpected relationships, including positive effects of urban environments. Overall, urban environments and human preferences were stronger predictors than habitat transformation and fragmentation. Our approach could be used to test a general framework predicting the effects of urbanization on plant diversity across multiple cities and contribute to a more synthetic understanding of urban biodiversity.


Assuntos
Biodiversidade , Florestas , Urbanização , Magnoliopsida/classificação , North Carolina , Filogenia , Árvores/classificação
6.
Genet Med ; 20(3): 329-336, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29389922

RESUMO

PurposeThe objective of this study was to assess the ability of our laboratory's exome-sequencing test to detect known and novel sequence variants and identify the critical factors influencing the interpretation of a clinical exome test.MethodsWe developed a two-tiered validation strategy: (i) a method-based approach that assessed the ability of our exome test to detect known variants using a reference HapMap sample, and (ii) an interpretation-based approach that assessed our relative ability to identify and interpret disease-causing variants, by analyzing and comparing the results of 19 randomly selected patients previously tested by external laboratories.ResultsWe demonstrate that this approach is reproducible with >99% analytical sensitivity and specificity for single-nucleotide variants and indels <10 bp. Our findings were concordant with the reference laboratories in 84% of cases. A new molecular diagnosis was applied to three cases, including discovery of two novel candidate genes.ConclusionWe provide an assessment of critical areas that influence interpretation of an exome test, including comprehensive phenotype capture, assessment of clinical overlap, availability of parental data, and the addressing of limitations in database updates. These results can be used to inform improvements in phenotype-driven interpretation of medical exomes in clinical and research settings.


Assuntos
Confiabilidade dos Dados , Exoma , Testes Genéticos , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Sequência de DNA , Biologia Computacional/métodos , Estudos de Associação Genética , Predisposição Genética para Doença , Testes Genéticos/métodos , Testes Genéticos/normas , Genômica/métodos , Genômica/normas , Humanos , Mutação INDEL , Polimorfismo de Nucleotídeo Único , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
8.
J Genet Couns ; 27(2): 392-405, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29274073

RESUMO

The paper-based pedigree is the current standard for family health history (FHH) documentation in genetic counseling. Several tools for electronic capture of family health data have been developed to improve re-use and accessibility, data quality and standardization, ease of updating, and integration with electronic medical records. One such tool, the tablet-based Proband application, provides a flexible approach to data capture in dynamic and diverse clinical settings. This study compared Proband FHH collection to paper-based methods and investigated the usability of Proband in a clinical setting. After one use by 23 genetic counselors and students, Proband had 91% accuracy with a FHH audio scenario, which was significantly less (p < 0.001) than paper's 96% accuracy. These differences were attributed to incorrect or missing ages of grandparents (p < 0.001) and great-aunts/uncles (p = 0.012) and missing documentation of consanguinity (p < 0.001). Possible explanations for these differences include greater experience with paper FHH documentation and pre-populated prompts for consanguinity on the paper template used. Proband's perceived usability increased with use, with individual System Usability Scores increasing between first and last use (p = 0.033). We conclude that tools for dynamic, provider-driven FHH documentation such as Proband show promise for improving risk assessment accuracy and quality patient care.


Assuntos
Aconselhamento Genético/métodos , Anamnese/métodos , Consanguinidade , Registros Eletrônicos de Saúde , Humanos , Percepção , Medição de Risco
9.
Inorg Chem ; 56(18): 11141-11150, 2017 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-28872310

RESUMO

A protocol for identifying ligand binding modes in a series of iridium pincer complexes bearing hemilabile aza-crown ether ligands has been developed using readily accessible NMR methods. The approach was tested on a collection of 13 structurally diverse pincer-crown ether complexes that include several newly characterized species. New synthetic routes enable facile interconversion of coordination modes and supporting ligands. Detailed structural assignments of five complexes reveal that the difference in chemical shift (Δδ) between geminal protons in the crown ether is influenced by diamagnetic anisotropy arising from halides and other ligands in the primary coordination sphere. The average difference in chemical shift between diastereotopic geminal protons in the crown ether macrocycle (Δδavg), as determined through a single 1H-13C HSQC experiment, provides information on the pincer ligand binding mode by establishing whether the macrocycle is in close proximity to the metal center. The Δδavg values for binding modes that involve chelating ether(s) bound to iridium are roughly 2-fold larger than those for tridentate complexes with no Ir-O bonds.

10.
J Am Chem Soc ; 139(25): 8661-8666, 2017 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-28581747

RESUMO

An enantioselective [3 + 2] cycloaddition reaction between nitrile oxides and transiently generated enolates of α-keto esters has been developed. The catalyst system was found to be compatible with in situ nitrile oxide-generation conditions. A versatile array of nitrile oxides and α-keto esters could participate in the cycloaddition, providing novel 5-hydroxy-2-isoxazolines in high chemical yield with high levels of diastereo- and enantioselectivity. Notably, the optimal reaction conditions circumvented concurrent reactions via O-imidoylation and hetero-[3 + 2] pathways.


Assuntos
Ésteres/química , Cetonas/química , Nitrilas/química , Óxidos/química , Álcoois/química , Catálise , Reação de Cicloadição , Estrutura Molecular , Estereoisomerismo
11.
J Am Chem Soc ; 139(15): 5305-5308, 2017 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-28383261

RESUMO

The conversion of metal nitride complexes to ammonia may be essential to dinitrogen fixation. We report a new reduction pathway that utilizes ligating acids and metal-ligand cooperation to effect this conversion without external reductants. Weak acids such as 4-methoxybenzoic acid and 2-pyridone react with nitride complex [(H-PNP)RuN]+ (H-PNP = HN(CH2CH2PtBu2)2) to generate octahedral ammine complexes that are κ2-chelated by the conjugate base. Experimental and computational mechanistic studies reveal the important role of Lewis basic sites proximal to the acidic proton in facilitating protonation of the nitride. The subsequent reduction to ammonia is enabled by intramolecular 2H+/2e- proton-coupled electron transfer from the saturated pincer ligand backbone.

12.
Birth Defects Res ; 109(4): 271-295, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28398664

RESUMO

BACKGROUND: Previous studies using different cardiac phenotypes, technologies and designs suggest a burden of large, rare or de novo copy number variants (CNVs) in subjects with congenital heart defects. We sought to identify disease-related CNVs, candidate genes, and functional pathways in a large number of cases with conotruncal and related defects that carried no known genetic syndrome. METHODS: Cases and control samples were divided into two cohorts and genotyped to assess each subject's CNV content. Analyses were performed to ascertain differences in overall CNV prevalence and to identify enrichment of specific genes and functional pathways in conotruncal cases relative to healthy controls. RESULTS: Only findings present in both cohorts are presented. From 973 total conotruncal cases, a burden of rare CNVs was detected in both cohorts. Candidate genes from rare CNVs found in both cohorts were identified based on their association with cardiac development or disease, and/or their reported disruption in published studies. Functional and pathway analyses revealed significant enrichment of terms involved in either heart or early embryonic development. CONCLUSION: Our study tested one of the largest cohorts specifically with cardiac conotruncal and related defects. These results confirm and extend previous findings that CNVs contribute to disease risk for congenital heart defects in general and conotruncal defects in particular. As disease heterogeneity renders identification of single recurrent genes or loci difficult, functional pathway and gene regulation network analyses appear to be more informative. Birth Defects Research 109:271-295, 2017. © 2017 Wiley Periodicals, Inc.


Assuntos
Variações do Número de Cópias de DNA , Redes Reguladoras de Genes , Predisposição Genética para Doença , Cardiopatias Congênitas/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Perfilação da Expressão Gênica , Ontologia Genética , Heterogeneidade Genética , Genótipo , Cardiopatias Congênitas/diagnóstico , Cardiopatias Congênitas/patologia , Humanos , Masculino , Anotação de Sequência Molecular , Fenótipo
13.
Chem Sci ; 8(5): 4108-4122, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30155215

RESUMO

The iron half-sandwich [Cp'Fe(µ-I)]2 (Cp' = 1,2,4-(Me3C)3C5H2, 1) reacts with the pseudohalides NCO-, SCN-, SeCN- and N3- to give [Cp'Fe(µ-NCO)]2 (2), [Cp'Fe(µ-S)]2 (3), [Cp'Fe(µ-Se2)]2 (4) and [Cp'Fe(µ-N)]2 (5), respectively. Various spectroscopic techniques including X-ray diffraction, solid-state magnetic susceptibility studies and 57Fe Mössbauer spectroscopy were employed in the characterization of these species. Mössbauer spectroscopy shows a decreasing isomer shift with increasing formal oxidation state, ranging from Fe(ii) to Fe(iv), in complexes 1 to 5. The sulfido-bridged dimer 3 exhibits strong antiferromagnetic coupling between the Fe(iii) centers. This leads to temperature-independent paramagnetism (TIP) at low temperature, from which the energy gap between the ground and the excited state can be estimated to be 2J = ca. 700 cm-1. The iron(iv) nitrido complex [Cp'Fe(µ-N)]2 (5) shows no reactivity towards H2 (10 atm), but undergoes clean reactions with CO (5 bar) and XylNC (Xyl = 2,6-Me2C6H3) to form the diamagnetic isocyanate and carbodiimide complexes [Cp'Fe(CO)2(NCO)] (7) and [Cp'Fe(CNXyl)2(NCNXyl)] (8), respectively. All compounds were fully characterized, and density functional theory (DFT) computations provide useful insights into their formation and the electronic structures of complexes 3 and 5.

14.
J Am Chem Soc ; 138(40): 13344-13352, 2016 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-27631725

RESUMO

We report a functional synthetic model for studying the noncovalent networks (NCNs) required for complex protein functions. The model [2]-catenane is self-assembled from dipeptide building blocks and contains an extensive network of hydrogen bonds and aromatic interactions. Perturbations to the catenane cause compensating changes in the NCNs structure and dynamics, resulting in long-distance changes reminiscent of a protein. Key findings include the notion that NCNs require regions of negative cooperativity, or "frustrated" noncovalent interactions, as a source of potential energy for driving the response. We refer to this potential energy as latent free energy and describe a mechanistic and energetic model for responsive systems.


Assuntos
Antracenos/química , Materiais Biomiméticos/química , Proteínas/química , Glicina/química , Ligação de Hidrogênio , Modelos Moleculares , Conformação Molecular , Termodinâmica
15.
Hum Genomics ; 9: 15, 2015 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-26187847

RESUMO

BACKGROUND: Conditions associated with sudden cardiac arrest/death (SCA/D) in youth often have a genetic etiology. While SCA/D is uncommon, a pro-active family screening approach may identify these inherited structural and electrical abnormalities prior to symptomatic events and allow appropriate surveillance and treatment. This study investigated the diagnostic utility of exome sequencing (ES) by evaluating the capture and coverage of genes related to SCA/D. METHODS: Samples from 102 individuals (13 with known molecular etiologies for SCA/D, 30 individuals without known molecular etiologies for SCA/D and 59 with other conditions) were analyzed following exome capture and sequencing at an average read depth of 100X. Reads were mapped to human genome GRCh37 using Novoalign, and post-processing and analysis was done using Picard and GATK. A total of 103 genes (2,190 exons) related to SCA/D were used as a primary filter. An additional 100 random variants within the targeted genes associated with SCA/D were also selected and evaluated for depth of sequencing and coverage. Although the primary objective was to evaluate the adequacy of depth of sequencing and coverage of targeted SCA/D genes and not for primary diagnosis, all patients who had SCA/D (known or unknown molecular etiologies) were evaluated with the project's variant analysis pipeline to determine if the molecular etiologies could be successfully identified. RESULTS: The majority of exons (97.6 %) were captured and fully covered on average at minimum of 20x sequencing depth. The proportion of unique genomic positions reported within poorly covered exons remained small (4 %). Exonic regions with less coverage reflect the need to enrich these areas to improve coverage. Despite limitations in coverage, we identified 100 % of cases with a prior known molecular etiology for SCA/D, and analysis of an additional 30 individuals with SCA/D but no known molecular etiology revealed a diagnostic answer in 5/30 (17 %). We also demonstrated 95 % of 100 randomly selected reported variants within our targeted genes would have been picked up on ES based on our coverage analysis. CONCLUSIONS: ES is a helpful clinical diagnostic tool for SCA/D given its potential to successfully identify a molecular diagnosis, but clinicians should be aware of limitations of available platforms from technical and diagnostic perspectives.


Assuntos
Morte Súbita Cardíaca , Exoma/genética , Genômica , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Adolescente , Alelos , Criança , Genoma Humano , Humanos , Análise de Sequência de DNA , Adulto Jovem
16.
Circ Res ; 115(10): 884-896, 2014 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-25205790

RESUMO

RATIONALE: Congenital heart disease (CHD) is among the most common birth defects. Most cases are of unknown pathogenesis. OBJECTIVE: To determine the contribution of de novo copy number variants (CNVs) in the pathogenesis of sporadic CHD. METHODS AND RESULTS: We studied 538 CHD trios using genome-wide dense single nucleotide polymorphism arrays and whole exome sequencing. Results were experimentally validated using digital droplet polymerase chain reaction. We compared validated CNVs in CHD cases with CNVs in 1301 healthy control trios. The 2 complementary high-resolution technologies identified 63 validated de novo CNVs in 51 CHD cases. A significant increase in CNV burden was observed when comparing CHD trios with healthy trios, using either single nucleotide polymorphism array (P=7×10(-5); odds ratio, 4.6) or whole exome sequencing data (P=6×10(-4); odds ratio, 3.5) and remained after removing 16% of de novo CNV loci previously reported as pathogenic (P=0.02; odds ratio, 2.7). We observed recurrent de novo CNVs on 15q11.2 encompassing CYFIP1, NIPA1, and NIPA2 and single de novo CNVs encompassing DUSP1, JUN, JUP, MED15, MED9, PTPRE SREBF1, TOP2A, and ZEB2, genes that interact with established CHD proteins NKX2-5 and GATA4. Integrating de novo variants in whole exome sequencing and CNV data suggests that ETS1 is the pathogenic gene altered by 11q24.2-q25 deletions in Jacobsen syndrome and that CTBP2 is the pathogenic gene in 10q subtelomeric deletions. CONCLUSIONS: We demonstrate a significantly increased frequency of rare de novo CNVs in CHD patients compared with healthy controls and suggest several novel genetic loci for CHD.


Assuntos
Variações do Número de Cópias de DNA/genética , Exoma/genética , Frequência do Gene/genética , Cardiopatias Congênitas/genética , Polimorfismo de Nucleotídeo Único/genética , Estudos de Casos e Controles , Estudos de Coortes , Redes Reguladoras de Genes/genética , Cardiopatias Congênitas/diagnóstico , Humanos , Dados de Sequência Molecular
17.
Birth Defects Res A Clin Mol Teratol ; 100(12): 951-64, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25066379

RESUMO

BACKGROUND: We sought to characterize the landscape of structural variation associated with the subset of congenital cardiac defects characterized by left-sided obstruction. METHODS: Cases with left-sided cardiac defects (LSCD) and pediatric controls were uniformly genotyped and assessed for copy number variant (CNV) calls. Significance testing was performed to ascertain differences in overall CNV incidence, and for CNV enrichment of specific genes and gene functions in LSCD cases relative to controls. RESULTS: A total of 257 cases of European descent and 962 ethnically matched, disease-free pediatric controls were included. Although there was no difference in CNV rate between cases and controls, a significant enrichment in rare LSCD CNVs was detected overall (p=7.30 × 10(-3) , case/control ratio=1.26) and when restricted either to deletions (p=7.58 × 10(-3) , case/control ratio=1.20) or duplications (3.02 × 10(-3) , case/control ratio=1.43). Neither gene-based, functional nor knowledge-based analyses identified genes, loci or pathways that were significantly enriched in cases as compared to controls when appropriate corrections for multiple tests were applied. However, several genes of interest were identified by virtue of their association with cardiac development, known human conditions, or reported disruption by CNVs in other patient cohorts. CONCLUSION: This study examines the largest cohort to date with LSCD for structural variation. These data suggest that CNVs play a role in disease risk and identify numerous genes disrupted by CNVs of potential disease relevance. These findings further highlight the genetic heterogeneity and complexity of these disorders.


Assuntos
Aberrações Cromossômicas , Cromossomos Humanos/genética , Variações do Número de Cópias de DNA/genética , Predisposição Genética para Doença , Cardiopatias Congênitas/genética , Polimorfismo de Nucleotídeo Único/genética , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Genótipo , Cardiopatias Congênitas/diagnóstico , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino
18.
BMC Bioinformatics ; 15: 248, 2014 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-25047600

RESUMO

BACKGROUND: Exome sequencing is a promising method for diagnosing patients with a complex phenotype. However, variant interpretation relative to patient phenotype can be challenging in some scenarios, particularly clinical assessment of rare complex phenotypes. Each patient's sequence reveals many possibly damaging variants that must be individually assessed to establish clear association with patient phenotype. To assist interpretation, we implemented an algorithm that ranks a given set of genes relative to patient phenotype. The algorithm orders genes by the semantic similarity computed between phenotypic descriptors associated with each gene and those describing the patient. Phenotypic descriptor terms are taken from the Human Phenotype Ontology (HPO) and semantic similarity is derived from each term's information content. RESULTS: Model validation was performed via simulation and with clinical data. We simulated 33 Mendelian diseases with 100 patients per disease. We modeled clinical conditions by adding noise and imprecision, i.e. phenotypic terms unrelated to the disease and terms less specific than the actual disease terms. We ranked the causative gene against all 2488 HPO annotated genes. The median causative gene rank was 1 for the optimal and noise cases, 12 for the imprecision case, and 60 for the imprecision with noise case. Additionally, we examined a clinical cohort of subjects with hearing impairment. The disease gene median rank was 22. However, when also considering the patient's exome data and filtering non-exomic and common variants, the median rank improved to 3. CONCLUSIONS: Semantic similarity can rank a causative gene highly within a gene list relative to patient phenotype characteristics, provided that imprecision is mitigated. The clinical case results suggest that phenotype rank combined with variant analysis provides significant improvement over the individual approaches. We expect that this combined prioritization approach may increase accuracy and decrease effort for clinical genetic diagnosis.


Assuntos
Ontologias Biológicas , Biologia Computacional/métodos , Mineração de Dados/métodos , Doença/genética , Fenótipo , Semântica , Algoritmos , Bases de Dados Genéticas , Exoma/genética , Humanos , Software
19.
J Am Chem Soc ; 136(10): 3981-94, 2014 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-24571611

RESUMO

The oxidation of [Ir(Cp*)(phpy)(NCAr(F))][B(Ar(F))4] (1; Cp* = η(5)-pentamethylcyclopentadienyl, phpy = 2-phenylene-κC(1')-pyridine-κN, NCAr(F) = 3,5-bis(trifluoromethyl)benzonitrile, B(Ar(F))4 = tetrakis[3,5-bis(trifluoromethyl)phenyl]borate) with the oxygen atom transfer (OAT) reagent 2-tert-butylsulfonyliodosobenzene (sPhIO) yielded a single, molecular product at -40 °C. New Ir(Cp*) complexes with bidentate ligands derived by oxidation of phpy were synthesized to model possible products resulting from oxygen atom insertion into the iridium-carbon and/or iridium-nitrogen bonds of phpy. These new ligands were either cleaved from iridium by water or formed unreactive, phenoxide-bridged iridium dimers. The reactivity of these molecules suggested possible decomposition pathways of Ir(Cp*)-based water oxidation catalysts with bidentate ligands that are susceptible to oxidation. Monitoring the [Ir(Cp*)(phpy)(NCAr(F))](+) oxidation reaction by low-temperature NMR techniques revealed that the reaction involved two separate OAT events. An intermediate was detected, synthesized independently with trapping ligands, and characterized. The first oxidation step involves direct attack of the sPhIO oxidant on the carbon of the coordinated nitrile ligand. Oxygen atom transfer to carbon, followed by insertion into the iridium-carbon bond of phpy, formed a coordinated organic amide. A second oxygen atom transfer generated an unidentified iridium species (the "oxidized complex"). In the presence of triphenylphosphine, the "oxidized complex" proved capable of transferring one oxygen atom to phosphine, generating phosphine oxide and forming an Ir-PPh3 adduct in 92% yield. The final Ir-PPh3 product was fully characterized.

20.
Congenit Heart Dis ; 9(1): 83-6, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23682798

RESUMO

SETTING: Left-sided cardiac lesions have a birth prevalence of approximately 1 in 1000 and have been shown to be heritable in pedigree studies. A large microdeletion at 16p12.1 is associated with childhood developmental delay, and initial studies describing this deletion identified left-sided lesions as an enriched phenotype compared with a control population. OBJECTIVE: The aim of this study is to determine whether patients with left-sided cardiac lesions have an increased frequency of 16p12.1 microdeletions as compared with control populations. DESIGN: A cohort of 262 probands with left-sided lesions, including 53 with isolated aortic stenosis/bicuspid aortic valve, 83 with coarctation of the aorta with or without aortic stenosis/bicuspid aortic valve, and 126 with hypoplastic left heart syndrome were assessed for copy number variation at 16p12.1. The control cohort included 595 patients with conotruncal defects as a cardiac control and 971 healthy children. RESULTS: We detected one patient in the left-sided lesion cohort with a large duplication partially overlapping the reported 16p12.1 microdeletion, along with one patient each in the conotruncal and control cohorts with a deletion in the same region. None of these patients had dysmorphic features, extracardiac malformations, or developmental delay. CONCLUSION: In our cohort, structural variation at 16p12.1 was not identified with increased frequency in patients with left-sided lesions as compared with controls.


Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 16 , Cardiopatias Congênitas/genética , Estudos de Casos e Controles , Variações do Número de Cópias de DNA , Predisposição Genética para Doença , Cardiopatias Congênitas/diagnóstico , Humanos , Fenótipo , Polimorfismo de Nucleotídeo Único , Fatores de Risco
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