3,890 research outputs found

    A novel DR/NIR T-shaped aiegen: Synthesis and x-ray crystal structure study

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    We developed a new benzodifuran derivative as the condensation product between 2,6-diamino-4-(4-nitrophenyl)benzo[1,2-b:4,5-b’]difuran-3,7-dicarboxylate and 3-hydroxy-2-naphthaldehyde. The intramolecular hydrogen-bond interactions in the terminal half-salen moieties produce a sterically encumbered highly conjugated main plane and a D-A-D (donor-acceptor-donor) T-shaped structure. The novel AIEgen (aggregation-induced enhanced emission generator) fulfils the requirement of RIR (restriction of intramolecular rotation) molecules. DR/NIR (deep red/near infrared) emission was recorded in solution and in the solid state, with a noteworthy photoluminescence quantum yield recorded on the neat crystals which undergo some mechanochromism. The crystal structure study of the probe from data collected at a synchrotron X-ray source shows a main aromatic plane π-stacked in a columnar arrangement

    A novel l-shaped fluorescent probe for aie sensing of zinc (Ii) ion by a dr/nir response

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    In the field of optical sensors, small molecules responsive to metal cations are of current interest. Probes displaying aggregation-induced emission (AIE) can solve the problems due to the aggregation-caused quenching (ACQ) molecules, scarcely emissive as aggregates in aqueous media and in tissues. The addition of a metal cation to an AIE ligand dissolved in solution can cause a “turn-on” of the fluorescence emission. Half-cruciform-shaped molecules can be a winning strategy to build specific AIE probes. Herein, we report the synthesis and characterization of a novel L-shaped fluorophore containing a benzofuran core condensed with 3-hydroxy-2-naphthaldehyde crossed with a nitrobenzene moiety. The novel AIE probe produces a fast colorimetric and fluorescence response toward zinc (II) in both in neutral and basic conditions. Acting as a tridentate ligand, it produces a complex with enhanced and red-shifted emission in the DR/NIR spectral range. The AIE nature of both compounds was examined on the basis of X-ray crystallography and DFT analysis

    Thermo-Induced Fluorochromism in Two AIE Zinc Complexes: A Deep Insight into the Structure-Property Relationship

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    Solid-state emitters exhibiting mechano-fluorochromic or thermo-fluorochromic responses represent the foundation of smart tools for novel technological applications. Among fluo-rochromic (FC) materials, solid-state emissive coordination complexes offer a variety of fluorescence responses related to the dynamic of noncovalent metal-ligand coordination bonds. Relevant FC behaviour can result from the targeted choice of metal cation and ligands. Herein, we report the synthesis and characterization of two different colour emitters consisting of zinc complexes obtained from N,O bidentate ligands with different electron-withdrawing substituents. The two complexes are blue and orange solid-state fluorophores, respectively, highly responsive to thermal and me-chanical stress. These emitters show a very different photoluminescent (PL) pattern as recorded before and after the annealing treatment. Through X-ray structural analysis combined with thermal analysis, infrared (IR) spectroscopy, PL, and DFT simulation we provide a comprehensive analysis of the structural feature involved in the fluorochromic response. Notably, we were able to correlate the on-off thermo-fluorochromism of the complexes with the structural rearrangement at the zinc coordination core

    Epidemiological study on vocal disorders in paediatric age

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    Few studies analyzed the diffusion of vocal alterations especially in childhood. Aim of our study was to quantify the numbers of subjects, in paediatric age, in which dysphonia was diagnosed in our department of Phoniatrics, during a period of 5 years, (January 2002-December 2006), and also to evaluate the influence of some potential risk factors. In the considered period it emerged that the diagnosis of dysphonia was made in 312 children (17.2% of the patients affected from dysphonia), aged between 2 and 16 years old, with a major prevalence amongst males (57%) than females (43%). On the contrary in the adult population the prevalence was: 23% in males and 77% in females. In paediatric population, the most affected range of age is the one between 8 and 14, in both male and female gender (59.6%). In 82.4% of the cases there were vocal fold lesions. The 90.3% of children with vocal fold alterations presented lesions secondary to vocal abuse and misuse and classifiable as functional dysphonia. The proportion of functional dysphonia in our sample was 92%. The 65% of children belonged to large families with more than two children, and the 30% had a family history of dysphonia (brothers, parents). The study of the behavioural characteristics has shown aggressive and hyperactive attitudes in 83% of the cases. Since in the ethiopathogenesis of the childhood dysphonia the tendency to vocal abuse has a predominant role, it would be useful to encourage the diffusion of programmes of information to show the risks linked to this abuse in children, in order to prevent the development of dysphonia in paediatric age

    Benzodifuran-based fluorescent brighteners: A novel platform for plant cell wall imaging

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    Herein we designed three novel fluorescent brightening agents based on a benzodifuran skeleton. The compounds are colorless fluorophores emitting in the blue region with an improved water solubility and ability to interact with living cells. A complete understanding of the emission mechanisms was achieved by Density Functional Theory study based on X-ray crystallographic analysis. The fluorescence quantum yields were measured in different solvents and at different pH values. The ability of the different fluorophores to stain cell compartments of plant root samples was tested in water- and glycerol-based solutions. Through fluorescence microscopy technique two probes with a different functionalized branching chain proved to be efficient stains for plant root cell wall. The cationic probe has no harmful effect on plant tissues and is suitable for in vivo fluorescent visualization of plant root cell boundaries. This study sheds light on the potential use of brighteners containing a central benzodifuran core as tools for imaging of fixed and alive plant tissues

    p53-Mediated downregulation of H ferritin promoter transcriptional efficiency via NF-Y

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    The tumor suppressor protein p53 triggers many of the cellular responses to DNA damage by regulating the transcription of a series of downstream target genes. p53 acts on the promoter of the target genes by interacting with the trimeric transcription factor NF-Y. H ferritin promoter activity is tightly dependent on a multiprotein complex called Bbf; on this complex NF-Y plays a major role. The aim of this work was to study the modulation of H ferritin expression levels by p53. CAT reporter assays indicate that: (i) p53 overexpression strongly downregulates the transcriptional efficiency driven by an H ferritin promoter construct containing only the NF-Y recognition sequence and that the phenomenon is reverted by p53 siRNA; (ii) the p53 C-terminal region is sufficient to elicitate this regulation and that a correct C-terminal acetylation is also required. The H ferritin promoter displays no p53-binding sites; chromatin immunoprecipitation assays indicate that p53 is recruited on this promoter by NF-Y. The p53–NF-Y interaction does not alter the NF-Y DNA-binding ability as indicated by electrophoretic mobility shift assay (EMSA) analysis. These results demonstrate that the gene coding for the H ferritin protein belongs to the family of p53-regulated genes, therefore adding a new level of complexity to the regulation of the H ferritin transcription and delineate a role for this protein in a series of cellular events triggered by p53 activation

    Evaluation of polygenic determinants of non-alcoholic fatty liver disease (NAFLD) by a candidate genes resequencing strategy

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    NAFLD is a polygenic condition but the individual and cumulative contribution of identified genes remains to be established. To get additional insight into the genetic architecture of NAFLD, GWAS-identified GCKR, PPP1R3B, NCAN, LYPLAL1 and TM6SF2 genes were resequenced by next generation sequencing in a cohort of 218 NAFLD subjects and 227 controls, where PNPLA3 rs738409 and MBOAT7 rs641738 genotypes were also obtained. A total of 168 sequence variants were detected and 47 were annotated as functional. When all functional variants within each gene were considered, only those in TM6SF2 accumulate in NAFLD subjects compared to controls (P = 0.04). Among individual variants, rs1260326 in GCKR and rs641738 in MBOAT7 (recessive), rs58542926 in TM6SF2 and rs738409 in PNPLA3 (dominant) emerged as associated to NAFLD, with PNPLA3 rs738409 being the strongest predictor (OR 3.12, 95% CI, 1.8-5.5, P 0.28 was associated with a 3-fold increased risk of NAFLD. Interestingly, rs61756425 in PPP1R3B and rs641738 in MBOAT7 genes were predictors of NAFLD severity. Overall, TM6SF2, GCKR, PNPLA3 and MBOAT7 were confirmed to be associated with NAFLD and a score based on these genes was highly predictive of this condition. In addition, PPP1R3B and MBOAT7 might influence NAFLD severity

    Ultra-processed food consumption and its correlates among Italian children, adolescents and adults from the Italian Nutrition & Health Survey (INHES) cohort study

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    Objective: To assess ultra-processed food (UPF) consumption and its socio-demographic, psychosocial and behavioural correlates in a general population of Italian children, adolescents and adults. Design: Cross-sectional telephone-based survey Setting: Italy, 2010-2013. Participants: In total, 9078 participants (5-97 years) from the Italian Nutrition & Health Survey. Dietary intakes were collected by a 1-d 24-h dietary recall. UPF was defined by the NOVA classification and expressed as percentage of total energies. Results: Average energy intake from UPF (95 % CI) was 17·3 % (17·1 %, 17·6 %) among adults and 25·9 % (24·8 %, 27·0 %) in children/adolescents. Top sources of UPF were processed meats (32·5 %) and bread substitutes (16·7 %). Among adults, age (β = -3·10; 95 % CI (-4·40, -1·80) for >65 years v. 20-40 years; βs are dimensionless) and residing in Southern Italy (β = -0·73; 95 % CI (-1·32, -0·14) v. Northern) inversely associated with UPF. Screen view during meals was directly linked to UPF, as well as poor self-rated health (β = 5·32; 95 % CI (2·66, 7·99)), adverse life events (β = 2·33; 95 % CI (1·48, 3·18)) and low sleep quality (β = 2·34; 95 % CI (1·45, 3·23)). Boys consumed two-point percent more UPF of the total energy than girls (β = 2·01; 95 % CI (0·20, 3·82)). For all ages, a Mediterranean diet was inversely associated with UPF (β = -4·86; 95 % CI (-5·53, -4·20) for good v. poor adherence in adults and (β = -5·08; 95 % CI (-8·38, -1·77) for kids). Conclusions: UPF contributes a modest proportion of energy to the diets of Italian adults while being one-quarter of the total energies in children/adolescents. UPF was associated with several psychosocial factors and eating behaviours. Increased adherence to Mediterranean diet would possibly result in lower UPF consumption
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