124 research outputs found

    Impact on the Population of the Triplet Excited State

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    Publisher Copyright: © 2022 American Chemical Society. All rights reserved.Two series of dinuclear gold(I) complexes that contain two Au-chromophore units (chromophore = dibenzofurane or dimethylfluorene) connected through a diphosphane bridge that differs in the flexibility and length (diphosphane = dppb for 1,4-bis(diphenylphosphino)butane, DPEphos for bis[(2-diphenylphosphino)phenyl]ether, xanthphos for 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene, and BiPheP for 2,2′-bis(diphenylphosphino)-1,1′-biphenyl) have been synthesized and structurally characterized. Their photophysical properties have been carefully investigated, paying attention to the role of the presence, or absence, of aurophilic contacts and their nature (intra- or intermolecular character). This analysis was permitted due to the X-ray crystallographic determination of all of the structures of the compounds discussed herein. The quantum yields of the triplet population, φT, have been calculated by nanosecond-laser flash photolysis measurements, and we could determine the main role of the character of the aurophilic contacts in the resulting φT, being especially favored in the presence of intermolecular contacts. Time-dependent density functional theory (TD-DFT) calculations support the absorption and emission assignments and the shorter distance between S1and the closest triplet excited state energy in the case of the compounds with a higher triplet-state population.publishersversionpublishe

    A coumarin based gold(I)-alkynyl complex: a new Q1 class of supramolecular hydrogelators

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    A phosphine-gold(I)-alkynyl-coumarin complex, [Au{7-(prop-2-ine-1-yloxy)-1-benzopyran-2-one}-(DAPTA)] (1), was synthesized and the formation of long luminescent fibers in solution was characterized via fluorescence microscopy and dynamic light scattering. The fibers presented strong blue and green luminescence, suggesting that the gold(I) in the complex increased intersystem crossing due to the heavy atom effect, resulting in a significant increase in triplet emission. The X-ray structure of the fibers indicates that both aurophilic, π-π interactions and hydrogen bonding contribute to their formation in aqueous solvents

    Gold(I)-doped films: new routes for efficient room temperature phosphorescent materials

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    The synthesis of four novel gold(I)-phosphane complexes coordinated to 9-phenanthrene chromophore has been carried out through the reaction of 9-phenanthreneboronic acid and the corresponding AuClPR3 (PR3 = PPh3 for triphenylphosphane (1a); 1,4-bis(diphenylphosphanyl)butane or dppb (2b); bis(diphenylphosphanyl)acetylene or dppa (2c); (AuCl)2(diphos) (diphos = bis(diphenylphosphanyl)methane or dppm (3)) sources. The X-ray crystal structures of compounds 1a and 2b show the existence of MOF-like intermolecular assemblies that contain empty inner cavities in the absence of aurophilic contacts. In contrast, the formation of a tetranuclear complex with intramolecular aurophilic interactions was evidenced for 3. Photophysical characterization indicates dual emission in all gold(I) complexes when oxygen is removed from the sample, while only fluorescence emission is recorded for the uncoordinated ligand. The introduction of the compounds within PMMA and Zeonex was assayed, and luminescent films containing gold(I) complexes where phosphorescence is the sole pathway for emission are obtained, instead of the dual emission (with significant fluorescence contribution) recorded in solution

    Room-Temperature Phosphorescence and Efficient Singlet Oxygen Production by Cyclometalated Pt(II) Complexes with Aromatic Alkynyl Ligands

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    The synthesis of five novel cyclometalated platinum(II) compounds containing five different alkynyl-chromophores was achieved by the reaction of the previously synthesized Pt-Cl cyclometalated compound (1) with the corresponding RC (math)CH by a Sonogashira reaction. It was observed that the spectral and photophysical characteristics of the cyclometalated platinum(II) complexes (Pt-Ar) are essentially associated with the platinum-cyclometalated unit. Room-temperature emission of the Pt-Ar complexes was attributed to phosphorescence in agreement with DFT calculations. Broad nanosecond (ns)-transient absorption spectra were observed with decays approximately identical to those obtained from the emission of the triplet state. From the femtosecond-transient absorption (fs-TA) data, two main excited- state decay components were identified: one in the order of a few picoseconds was assigned to fast intersystem crossing to populate the triplet excited-state and the second (hundreds of ns) was associated with the decay of the transient triplet state. In general, efficient singlet oxygen photosensitization quantum yields were observed from the triplet state of these complexes

    Storying an interconnected web of relationships in Indigenous language reclamation work and scholarship

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    Indigenous language work is manifested in a diversity of community-led responses of resilience and persistence. Indigenous persons who are reclaiming their languages have entered academia with goals of contributing to community language reclamation efforts and broader resurgence movements. Adapting Archibald’s (2008) concept of storywork—experiential narratives that privilege a cultural lens—we take a dialogic approach for scholar-educators to story their Indigenous language work within a web of interrelated relationships. From our positionalities as Chikashsha, Hopisino, Kanaka Hawaiʻi, myaamia, and Brazilian scholars, we ask and reflect on the following questions: Who are we storying with and for? What does language work look like in our community contexts and academic collaborations? How do we define cultural praxis in our work? What principles inform and emerge from our collective work? How do we co-construct knowledge that will sustain our language work and relationships? This reflective and reflexive process engages and maintains a continual balance of the cumulative past and present toward the future. Foremost, we aspire to act and work consistently in ways that are good for our peoples and communities, which includes a view of the research we undertake as purposeful journeying (Hill & Wilkinson, 2014) within our academic contexts and scholarship.Ye

    A longitudinal follow-up of autoimmune polyendocrine syndrome type 1

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    Source:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4971337/Context: Autoimmune polyendocrine syndrome type 1 (APS1) is a childhood-onset monogenic disease defined by the presence of two of the three major components: hypoparathyroidism, primary adrenocortical insuffi- ciency, and chronic mucocutaneous candidiasis (CMC). Information on longitudinal follow-up of APS1 is sparse. Objective: To describe the phenotypes of APS1 and correlate the clinical features with autoantibody profiles and autoimmune regulator ( AIRE) mutations during extended follow-up (1996–2016). Patients: All known Norwegian patients with APS1. Results: Fifty-two patients from 34 families were identified. The majority presented with one of the major disease components during childhood. Enamel hypoplasia, hypoparathyroidism, and CMC were the most frequent compo- nents.Withage,mostpatientspresentedthreetofivediseasemanifestations,althoughsomehadmilderphenotypes diagnosed in adulthood. Fifteen of the patients died during follow-up (median age at death, 34 years) or were deceasedsiblingswithahighprobabilityofundisclosedAPS1.Allexceptthreehadinterferon- )autoantibodies,and allhadorgan-specificautoantibodies.Themostcommon AIRE mutationwasc.967_979del13,foundinhomozygosity in 15 patients. A mild phenotype was associated with the splice mutation c.879 1G A. Primary adrenocortical insufficiency and type 1 diabetes were associated with protective human leucocyte antigen genotypes. Conclusions: Multiple presumable autoimmune manifestations, in particular hypoparathyroidism, CMC, and enamel hypoplasia, should prompt further diagnostic workup using autoantibody analyses (eg, interferon- ) and AIRE sequencing to reveal APS1, even in adults. Treatment is complicated, and mortality is high. Structured follow-up should be performed in a specialized center

    The equigenic effect of greenness on the association between education with life expectancy and mortality in 28 large Latin American cities.

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    BACKGROUND: Recent studies highlight the equigenic potential of greenspaces by showing narrower socioeconomic health inequalities in greener areas. However, results to date have been inconsistent and derived from high-income countries. We examined whether urban greenness modifies the associations between area-level education, as a proxy for socioeconomic status, and life expectancy and cause-specific mortality in Latin American cities. METHODS: We included 28 large cities, >137 million inhabitants, in nine Latin American countries, comprising 671 sub-city units, for 2012-2016. Socioeconomic status was assessed through a composite index of sub-city level education, and greenness was calculated using the normalized difference vegetation index. We fitted multilevel models with sub-city units nested in cities, with life expectancy or log(mortality) as the outcome. FINDINGS: We observed a social gradient, with higher levels of education associated with higher life expectancy and lower cause-specific mortality. There was weak evidence supporting the equigenesis hypothesis as greenness differentially modified the association between education and mortality outcomes. We observed an equigenic effect, with doubling magnitudes in the violence-related mortality reduction by education in areas with low greenness compared to medium-high greenness areas among men (16% [95% CI 12%-20%] vs 8% [95% CI 4%-11%] per 1 SD increase in area-level education). However, in contradiction to the equigenesis hypothesis, the magnitude in cardiovascular diseases (CVD) mortality reduction by education was stronger in areas with medium-high greenness compared to areas with low greenness (6% [95% CI 4%-7%] vs 1% [95% CI -1%-3%] and 5% [95% CI 3%-7%] vs 1% [95% CI -1%-3%] per 1 SD increase in area-level education, in women and men, respectively). Similarly, each 1-SD increase in greenness widened the educational inequality in life expectancy by 0.15 years and 0.20 years, in women and men, respectively. The equigenic effect was not observed in violence-related mortality among women and in mortality due to communicable diseases, maternal, neonatal and nutritional conditions (CMNN). INTERPRETATION: Our results confirm socioeconomic health inequalities in Latin American cities and show that the equigenic properties of greenspace vary by health outcome. Although mixed, our findings suggest that future greening policies should account for local social and economic conditions to ensure that greenspaces provide health benefits for all, and do not further exacerbate existing health inequalities in the region. FUNDING: Wellcome Trust (Grant, 205177/Z/16/Z)

    Retrospective analysis of breast cancer prognosis among young and older women in a Brazilian cohort of 738 patients, 1985-2002

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    Invasive breast cancer (BC) is infrequent among women aged.5.40 years, however, the disease outlook in these younger patients is generally worse than among older women. The present study aimed to compare socio-demographic, clinical and pathological characteristics, and their association with long-term survival, between two random cohorts of young (<= 40 years) and older (50-69 years) Brazilian patients with BC. The cohort comprised of 738 randomly selected women who were diagnosed with BC at Barretos Cancer Hospital, Pio XII Foundation (Barretos, Brazil) between January 1985 and December 2002; the patients included young women (n=376) and older women (n=362). The current analysis suggested that BC in young women is associated with numerous pathological features of aggressiveness. Second cancer and bilateral BC were independent predictors of a poor outcome in the younger group. Furthermore, C-erB-2 was positively correlated with poor outcome in the older group, whereas estrogen receptor status and TNM stage were associated with disease prognosis in both groups. The overall survival rates of the two age groups were similar except when analyzed according the treatment period (1997-2002). Although patients aged <= 40 years harbored tumors with more aggressive clinicopathological characteristics, these characteristics were not independent predictors of overall survival. The present study indicates that medical advances associated with prevention of breast cancer may improve screening programs, which may therefore increase early diagnosis and subsequently lower mortality rates.The authors thank the Public Ministry of Labor (Research, Prevention and Education of Occupational Cancer) in Campinas, Brazil, and the Lions Club of Brazil for partial financial support of the present study and Dr. Vinicius de Lima Vazquez (Department of Skin cancer and Melanoma, Barretos Cancer Hospital, Pio XII Foundation, Barretos, Brazil) for assistance with the statistical analysis. The abstract was previously published in The Breast 23 (Suppl): S11, 2014.info:eu-repo/semantics/publishedVersio

    Exome Sequencing and Genetic Testing for MODY

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    Context: Genetic testing for monogenic diabetes is important for patient care. Given the extensive genetic and clinical heterogeneity of diabetes, exome sequencing might provide additional diagnostic potential when standard Sanger sequencing-based diagnostics is inconclusive. Objective: The aim of the study was to examine the performance of exome sequencing for a molecular diagnosis of MODY in patients who have undergone conventional diagnostic sequencing of candidate genes with negative results. Research Design and Methods: We performed exome enrichment followed by high-throughput sequencing in nine patients with suspected MODY. They were Sanger sequencing-negative for mutations in the HNF1A, HNF4A, GCK, HNF1B and INS genes. We excluded common, non-coding and synonymous gene variants, and performed in-depth analysis on filtered sequence variants in a pre-defined set of 111 genes implicated in glucose metabolism. Results: On average, we obtained 45 X median coverage of the entire targeted exome and found 199 rare coding variants per individual. We identified 0–4 rare non-synonymous and nonsense variants per individual in our a priori list of 111 candidate genes. Three of the variants were considered pathogenic (in ABCC8, HNF4A and PPARG, respectively), thus exome sequencing led to a genetic diagnosis in at least three of the nine patients. Approximately 91% of known heterozygous SNPs in the target exomes were detected, but we also found low coverage in some key diabetes genes using our current exome sequencing approach. Novel variants in the genes ARAP1, GLIS3, MADD, NOTCH2 and WFS1 need further investigation to reveal their possible role in diabetes. Conclusion: Our results demonstrate that exome sequencing can improve molecular diagnostics of MODY when used as a complement to Sanger sequencing. However, improvements will be needed, especially concerning coverage, before the full potential of exome sequencing can be realized
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