290 research outputs found

    Novel solid-state emissive polymers and polymeric blends from a T-Shaped benzodifuran scaffold: A comparative study

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    Two novel polyimines were synthesized from a benzodifuran based diamino monomer and two dialdehydes bearing bulky groups and a flexible spacer. The polymers display tuned luminescence performance according to the presence of half-salen groups. The effect of the intramolecular bond on the emission properties were examined. Two model compounds, replicating the same emissive Schiff base cores, were synthetized. From the models, dye-doped blends in the fluorophore/matrix ratio, resembling the polymers, were produced. Amorphous thin films of the covalent polymers and the polymeric blends were obtained by spin-coating technique. The Photoluminescent (PL) response of the different macromolecular systems were qualitatively and quantitatively examined and compared

    A highly water-soluble fluorescent and colorimetric pH probe

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    A new 5-(4-((2-(benzothiazole-2-carbonyl)hydrazono)methyl)-3-hydroxyphenoxy)N,N,N-trimethylpentan-1-aminium bromide (BTABr) fluorescent and colorimetric pH probe was easily synthesized by the condensation reaction of benzothiazole-2-carbohydrazide with 5-(4-formyl-3-hydroxyphenoxy)-N,N,N-trimethylpentan-1-aminium bromide. The benzothiazole moiety provided the emissive part of the molecule and the charged trimethyl amino group guaranteed outstanding solubility in water, for an organic molecule. pH titration experiments indicated that the probe is useful for monitoring acidic and alkaline solutions, turning reversibly in color/fluorescence just at a neutral pH value. Naked-eye colorimetric response was observed both in solution and in the solid state. In addition, the probe showed high stability and selectivity and large Stokes shifts. Because of these features, BTABr can potentially work as an on-off real-time pH sensor for intracellular pH imaging. The crystal structure of BTABr examined by single-crystal analysis showed a planar geometry of the molecule and confirmed the presence of a molecular stacking between molecules joined in a complex tridimensional hydrogen bonding pattern

    High nonlinear optical response in 4-chlorothiazole-based azo dyes

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    Four azo dyes showing high nonlinear optical properties were prepared, based on a 4-chlorothiazole azo moiety functionalized with strong acceptor groups and/or further donor/acceptor groups along the conjugated backbone. The effects of the acceptors as well as the lateral donor/acceptor groups upon absorption properties, thermal stability and second order nonlinear optical activity were evaluated. © 2010 Elsevier Ltd. All rights reserved

    Naphthalenone polyketides produced by Neofusicoccum parvum , a fungus associated with grapevine Botriosphaeria dieback

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    A strain of Neofusicoccum parvum isolated from declining vines was pathogenic to grapevine cultivar Inzolia in Sicily. This strain produced some metabolites in liquid medium. Crude extract, through a bio-guided purification process, yielded four naphthalenone polyketides. They were identified by comparison with spectroscopic data and optical proprieties reported in literature as: (3S, 4S)-7-ethyl-3,4,8-trihydroxy-6-methoxy-3,4-dihydro-1-(2H)-naphthalenone, (3S*, 4S*)-3,4-dihydro-3,4,8-trihydroxy-7-(1-hydroxyethyl)-6-methoxy-1-(2H)-naphthalenone, (4S)-3,4-dihydro-4,8-dihydroxy-1-(2H)-naphthalenone, named botryosphaerones D and A, isosclerone, respectively, and (3S*,4S*)-3,4,5-trihydroxy-1-tetralone (1-4). Phytotoxic activity of the isolated compounds (1-4) was tested on grapevine leaves at using the leaf puncture assay. All tested compounds were phytotoxic, with botryosphaerone D showing the greatest activity. The phytotoxic effects decreased when treated leaves were exposed to light. All of the metabolites did not show in vitro antifungal activity against Diplodia seriata, Lasiodiplodia mediterranea, Neofusicoccum vitifusiforme, or Phytophthora citrophthora. This is the first report of in vitro production of botryosphaerones D and A, and 3,4,5-trihydroxy-1-tetralone by N. parvum

    Intense beam of metastable Muonium

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    Precision spectroscopy of the Muonium Lamb shift and fine structure requires a robust source of 2S Muonium. To date, the beam-foil technique is the only demonstrated method for creating such a beam in vacuum. Previous experiments using this technique were statistics limited, and new measurements would benefit tremendously from the efficient 2S production at a low energy muon (<20<20 keV) facility. Such a source of abundant low energy μ+\mathrm{\mu^+} has only become available in recent years, e.g. at the Low-Energy Muon beamline at the Paul Scherrer Institute. Using this source, we report on the successful creation of an intense, directed beam of metastable Muonium. We find that even though the theoretical Muonium fraction is maximal in the low energy range of 2−52-5 keV, scattering by the foil and transport characteristics of the beamline favor slightly higher μ+\mathrm{\mu^+} energies of 7−107-10 keV. We estimate that an event detection rate of a few events per second for a future Lamb shift measurement is feasible, enabling an increase in precision by two orders of magnitude over previous determinations

    High familial burden of cancer correlates with improved outcome from immunotherapy in patients with NSCLC independent of somatic DNA damage response gene status

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    Family history of cancer (FHC) is a hallmark of cancer risk and an independent predictor of outcome, albeit with uncertain biologic foundations. We previously showed that FHC-high patients experienced prolonged overall (OS) and progression-free survival (PFS) following PD-1/PD-L1 checkpoint inhibitors. To validate our findings in patients with NSCLC, we evaluated two multicenter cohorts of patients with metastatic NSCLC receiving either first-line pembrolizumab or chemotherapy. From each cohort, 607 patients were randomly case–control matched accounting for FHC, age, performance status, and disease burden. Compared to FHC-low/negative, FHC-high patients experienced longer OS (HR 0.67 [95% CI 0.46–0.95], p = 0.0281), PFS (HR 0.65 [95% CI 0.48–0.89]; p = 0.0074) and higher disease control rates (DCR, 86.4% vs 67.5%, p = 0.0096), within the pembrolizumab cohort. No significant associations were found between FHC and OS/PFS/DCR within the chemotherapy cohort. We explored the association between FHC and somatic DNA damage response (DDR) gene alterations as underlying mechanism to our findings in a parallel cohort of 118 NSCLC, 16.9% of whom were FHC-high. The prevalence of ≥ 1 somatic DDR gene mutation was 20% and 24.5% (p = 0.6684) in FHC-high vs. FHC-low/negative, with no differences in tumor mutational burden (6.0 vs. 7.6 Mut/Mb, p = 0.6018) and tumor cell PD-L1 expression. FHC-high status identifies NSCLC patients with improved outcomes from pembrolizumab but not chemotherapy, independent of somatic DDR gene status. Prospective studies evaluating FHC alongside germline genetic testing are warranted

    Effect of concomitant medications with immune-modulatory properties on the outcomes of patients with advanced cancer treated with immune checkpoint inhibitors: development and validation of a novel prognostic index

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    Background: Concomitant medications are known to impact on clinical outcomes of patients treated with immune checkpoint inhibitors (ICIs). We aimed weighing the role of different concomitant baseline medications to create a drug-based prognostic score. Methods: We evaluated concomitant baseline medications at immunotherapy initiation for their impact on objective response rate (ORR), progression-free survival (PFS) and overall survival (OS) in a single-institution cohort of patients with advanced cancer treated with ICIs (training cohort, N = 217), and a drug-based prognostic score with the drugs resulting significantly impacting the OS was computed. Secondly, we externally validated the score in a large multicenter external cohort (n = 1012). Results: In the training cohort (n = 217), the median age was 69 years (range: 32–89), and the primary tumours were non–small-cell lung cancer (70%), melanoma (14.7%), renal cell carcinoma (9.2%) and others (6%). Among baseline medications, corticosteroids (hazard ratio [HR] = 2.3; 95% confidence interval [CI]: 1.60–3.30), systemic antibiotics (HR = 2.07; 95% CI: 1.31–3.25) and proton-pump inhibitors (PPIs) (HR = 1.57; 95% CI: 1.13–2.18) were significantly associated with OS. The prognostic score was calculated using these three drug classes, defining good, intermediate and poor prognosis patients. Within the training cohort, OS (p &lt; 0.0001), PFS (p &lt; 0.0001) and ORR (p = 0.0297) were significantly distinguished by the score stratification. The prognostic value of the score was also demonstrated in terms of OS (p &lt; 0.0001), PFS (p &lt; 0.0001) and ORR (p = 0.0006) within the external cohort. Conclusion: Cumulative exposure to corticosteroids, antibiotics and PPIs (three likely microbiota-modulating drugs) leads to progressively worse outcomes after ICI therapy. We propose a simple score that can help stratifying patients in routine practice and clinical trials of ICIs
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