427 research outputs found

    Bis(2-phenyl-4,6-di-2-pyridyl-1,3,5-triazine-κ3 N 4,N 5,N 6)ruthenium(II) bis(hexa­fluoridophosphate)

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    The asymmetric unit of the title compound, [Ru(C19H13N5)2](PF6)2, consists of an RuII complex cation and two hexa­fluoridophosphate anions. The RuII atom is coordinated by three N atoms from the two outer pyridine and the central triazine rings of each of two tridentate ligands in a distorted octa­hedral environment. The ligands are approximately orthogonal to one another, with a dihedral angle of 88.34 (2)° between planes through the three six-membered rings of the two ligands. The pendant phenyl substituents are almost coplanar with the triazine rings to which they are bound, with dihedral angles of 5.41 (9) and 14.90 (10)°. This is reflected in the previously reported photophysical results with an increased lifetime of the triplet metal to ligand charge transfer (3MLCT) excited state [Fang, Taylor, Hanan, Loiseau, Passalacqua, Campagna, Nierengarten & Van Dorsselaer (2002). J. Am. Chem. Soc. 124, 7912–7913]

    (4′-Ferrocenyl-2,2′:6′,2′′-terpyridine-κ3 N 1,N 1′,N 1′′)(1,10-phenanthroline-κ2 N,N′)zinc(II) bis­(perchlorate) acetonitrile monosolvate

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    In the title complex, [FeZn(C5H5)(C20H14N3)(C12H8N2)](ClO4)2·CH3CN, the ZnII atom is five-coordinated by a tridentate chelating 4′-ferrocenyl-2,2′:6′,2′′-terpyridine (fctpy) ligand and a bidentate chelating 1,10-phenanthroline (phen) ligand in a distorted square-pyramidal environment with a phen N atom located at the apical position [Zn—N = 2.259 (4) Å]. The terpyridyl motif in each fctpy ligand is coplanar, but the cyclo­penta­dienyl ring is twisted by 9.5 (2)° out of coplanarity with each central pyridine. The two cyclo­penta­dienyl rings of the ferrocenyl group are almost eclipsed with a deviation of 4.5 (1)°. In addition, inter­molecular π–π inter­actions [centroid–centroid distance 3.753 (2) Å] are present between the cyclo­penta­dienyl and outer pyridyl rings of the fctpy ligands. One of the perchlorate anions is equally disordered over two positions

    Spectroscopic and Redox Properties of Novel d-Complexes Engineered from All Z-Ethenylthiophene-bipyridine Ligands

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    A series of quasilinear dinuclear complexes incorporating ruthenium(II)- and osmium(II)-tris(2,2′-bipyridine) units has been prepared in which the individual metal-containing moieties are separated by 3,4-dibutyl-2,5- diethenylthiophene spacers and end-capped by 3,4-dibutyl-2-ethenylthiophene subunits; related ruthenium(II) and osmium(II) mononuclear complexes have also been prepared where one bpy unit is likewise end-capped by 3,4- dibutyl-2-ethenylthiophene subunits [bpy ) 2,2′-bipyridine]. Overall, mononuclear species, labeled here Ru and Os, and dinuclear species, RuRu, OsOs, and RuOs, have been prepared and investigated. Their electrochemical behavior has been studied in CH3CN solvent and reveals ethenylthiophene-centered oxidations (irreversible steps at > +1.37 V vs SCE), metal-centered oxidations (reversible steps at +1.30 V vs SCE for Ru(II/III) and +0.82 V vs SCE for Os(II/III)), and successive reduction steps localized at the substituted bpy subunits. The spectroscopic studies performed for the complexes in CH3CN solvent provided optical absorption spectra associated with transitions of ligand-centered nature (LC, from the bpy and ethenylthiophene subunits) and metal-to-ligand charge-transfer nature (MLCT), with the former dominating in the visible region (400−600 nm). While the constituent ethenylthiophene- bpy ligands are strong fluorophores (fluorescence efficiency in CH2Cl2 solvent, φem ) 0.49 and 0.39, for the monomer and the dimer, respectively), only weak luminescence is observed for each complex in acetonitrile at room temperature. In particular, (i) the complexes Ru and RuRu do not emit appreciably, and (ii) the complexes Os, OsOs, and RuOs exhibit triplet emission of 3Os f L CT character, with φem in the range from 10-3 to 10-4. These features are rationalized on the basis of the role of nonemissive triplet energy levels, 3Th, centered on the ethenylthiophene spacer. These levels appear to lie lower in energy than the 3Ru f L CT triplet levels, and in turn higher in energy than the 3Os f L CT triplet levels, along the sequence 3Ru f L CT > 3Th > 3Os f L CT

    Comparison between two cancer registry quality check systems: functional features and differences in an Italian network of cancer registries dataset

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    PurposeThe aim of this study was to compare the functional characteristics of two computer-based systems for quality control of cancer registry data through analysis of their output differences. MethodsThe study used cancer incidence data from 22 of the 49 registries of the Italian Network of Cancer Registries registered between 1986 and 2017. Two different data checking systems developed by the WHO International Agency for Research on Cancer (IARC) and the Joint Research Center (JRC) with the European Network of Cancer Registries (ENCR) and routinely used by registrars were used to check the quality of the data. The outputs generated by the two systems on the same dataset of each registry were analyzed and compared. ResultsThe study included a total of 1,305,689 cancer cases. The overall quality of the dataset was high, with 86% (81.7-94.1) microscopically verified cases and only 1.3% (0.03-3.06) cases with a diagnosis by death certificate only. The two check systems identified a low percentage of errors (JRC-ENCR 0.17% and IARC 0.003%) and about the same proportion of warnings (JRC-ENCR 2.79% and IARC 2.42%) in the dataset. Forty-two cases (2% of errors) and 7067 cases (11.5% of warnings) were identified by both systems in equivalent categories. 11.7% of warnings related to TNM staging were identified by the JRC-ENCR system only. The IARC system identified mainly incorrect combination of tumor grade and morphology (72.5% of warnings). ConclusionBoth systems apply checks on a common set of variables, but some variables are checked by only one of the systems (for example, checks on patient follow-up and tumor stage at diagnosis are included by the JRC-ENCR system only). Most errors and warnings were categorized differently by the two systems, but usually described the same issues, with warnings related to "morphology" (JRC-ENCR) and "histology" (IARC) being the most frequent. It is important to find the right balance between the need to maintain high standards of data quality and the workability of such systems in the daily routine of the cancer registry

    Safety of occasional ingestion of gluten in patients with celiac disease: a real-life study

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    Background Gluten-free diet (GFD) decreases the quality of life of celiac disease (CD) patients, who frequently ask to occasionally ingest gluten-containing food. We evaluated CD patients reporting voluntary and occasional transgressions to their GFD. Methods From October 2017 to September 2018, the patients reporting occasional and voluntary gluten ingestion (GFD-noncompliant) were prospectively enrolled. These patients underwent clinical examination, blood tests, duodenal biopsy, capsule enteroscopy (CE), and a validated food-frequency questionnaire (FFQ) assessing the frequency and quantity of gluten intake. Mortality was calculated and compared to the general population. A group of patients on strict GFD (GFD-adherent) acted as controls. Results One thousand three hundred seventy-eight CD patients were evaluated during the study period. One hundred nine (8%) reported occasional (weekly or monthly) voluntary ingestion of gluten. The mean gluten intake was 185.2 +/- 336.9 g/year, and the duration of their incorrect GFD was 8.6 +/- 6.9 years. Among the noncompliant patients, 57% did not present any histological alteration; furthermore, the Marsh score profile was not different between compliant and noncompliant patients. Seventy percent did not present any alteration at CE. Seventy-five percent of patients reported no gastrointestinal symptoms after gluten ingestion. Twenty-three percent of patients in the GFD-noncompliant group presented positive tTG-IgA. No association was found between gluten intake, clinical symptoms, and biomarkers. Mortality was not different between the groups and the general population. Conclusions Our results are that in a real-life scenario, a group of CD patients on long-term gluten intake showed no significant clinical symptoms or small bowel damage, thus suggesting that a degree of tolerance towards gluten consumption can be reached

    Molecular subtypes, metastatic pattern and patient age in breast cancer: An analysis of italian network of cancer registries (airtum) data

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    Breast cancer stage at diagnosis, patient age and molecular tumor subtype influence disease progression. The aim of this study was to analyze the relationships between these factors and survival in breast cancer patients among the Italian population using data from the AIRTUM national database. We enrolled women with primary breast cancer from 17 population‐based cancer registries. Patients were subdivided into older (>69 years), middle (50–69 years) and younger age groups (<50 years) and their primary tumors categorized into four molecular subtypes based on hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status. There were 8831 patients diagnosed between 2010 and 2012 included. The most represented age group was 50– 69 years (41.7%). In 5735 cases the molecular subtype was identified: HER2–/HR+ was the most frequent (66.2%) and HER2+/HR− the least (6.2%). Of the 390 women with metastases at diagnosis, 38% had simultaneous involvement of multiple sites, independent of age and molecular profile. In women with a single metastatic site, bone (20% of cases), liver (11%), lung (7%) and brain (3%) were the most frequent. In the studied age groups with different receptor expression profiles, the tumor metastasized to target organs with differing frequencies, affecting survival. Five‐year survival was lowest in women with triple‐negative (HER2−/HR–) tumors and women with brain metastases at diagnosis

    Metal Ion Enhanced Charge Transfer in a Terpyridine-bis-Pyrene System

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    The synthesis, electrochemical and photophysical properties of a branched molecule 3,5-bis(pyrene-1-yl)-4′-phenyl-2,2′:6′,2″-terpyridine are reported. Spectroscopy in different solvents reveals that an optical electron transfer from the pyrene donor to the terpyridyl electron acceptor can occur in polar media, as the system displays both charge transfer (CT) absorption and CT emission. Furthermore, the study of the zinc complex as well as the bis-protonated form shows an enhancement of the electron transfer character of the system, by an increase of the acceptor strength. This is accompanied by a large increase of the non-radiative processes. With sub-nanosecond transient absorption spectroscopy, the CT state, consisting of the pyrene radical cation and the terpyridine radical anion, has been detected. At room temperature, the study of the nanosecond transient absorption spectra reveals the formation of a low-lying triplet excited state that we attribute to the pyrene moiety through which the CT state decays. At 77K, the absence of the terpyridine triplet emission also suggests the population of a low-lying triplet state of the pyrene unit

    Mesomorphism and Photophysics of Some Metallomesogens Based on Hexasubstituted 2,2':6', 2''-Terpyridines : 6', 2''-Terpyridines

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    The luminescent and mesomorphic properties of a series of metal complexes based on hexacatenar 2,2':6',2''-terpyridines are investigated using experimental methods and density functional theory (DFT). Two types of ligand are examined, namely 5,5''-di(3,4,5-trialkoxyphenyl)terpyridine with or without a fused cyclopentene ring on each pyridine and their complexes were prepared with the following transition metals: ZnII, CoIII, RhIII, IrIII, EuIII and DyIII. The exact geometry of some of these complexes was determined by single X-ray diffraction. All complexes with long alkyl chains were found to be liquid crystalline, which property was induced on complexation. The liquid-crystalline behaviour of the complexes was studied by polarising optical microscopy and small-angle X-ray diffraction. Some of the transition metal complexes (for example, those with ZnII and IrIII) are luminescent in solution, the solid state and the mesophase; their photophysical properties were studied both experimentally and using DFT methods (M06-2X and B3LYP)

    Spectral splitting photovoltaics using perovskite and wideband dye-sensitized solar cells

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    The extension of the light absorption of photovoltaics into the near-infrared region is important to increase the energy conversion efficiency. Although the progress of the lead halide perovskite solar cells is remarkable, and high conversion efficiency of >20% has been reached, their absorption limit on the long-wavelength side is similar to 800 nm. To further enhance the conversion efficiency of perovskite-based photovoltaics, a hybridized system with near-infrared photovoltaics is a useful approach. Here we report a panchromatic sensitizer, coded DX3, that exhibits a broad response into the near-infrared, up to similar to 1100 nm, and a photocurrent density exceeding 30 mA cm(-2) in simulated air mass 1.5 standard solar radiation. Using the DX3-based dye-sensitized solar cell in conjunction with a perovskite cell that harvests visible light, the hybridized mesoscopic photovoltaics achieved a conversion efficiency of 21.5% using a system of spectral splitting.open0
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