42 research outputs found

    Novel β-cyclodextrin–eosin conjugates

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    Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy and mass spectrometry. Preliminary spectroscopic investigations showed that the β-cyclodextrin–EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin–EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in aqueous medium, which precludes any response to light excitation

    The Science Case for Multi-Object Spectroscopy on the European ELT

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    This White Paper presents the scientific motivations for a multi-object spectrograph (MOS) on the European Extremely Large Telescope (E-ELT). The MOS case draws on all fields of contemporary astronomy, from extra-solar planets, to the study of the halo of the Milky Way and its satellites, and from resolved stellar populations in nearby galaxies out to observations of the earliest 'first-light' structures in the partially-reionised Universe. The material presented here results from thorough discussions within the community over the past four years, building on the past competitive studies to agree a common strategy toward realising a MOS capability on the E-ELT. The cases have been distilled to a set of common requirements which will be used to define the MOSAIC instrument, entailing two observational modes ('high multiplex' and 'high definition'). When combined with the unprecedented sensitivity of the E-ELT, MOSAIC will be the world's leading MOS facility. In analysing the requirements we also identify a high-multiplex MOS for the longer-term plans for the E-ELT, with an even greater multiplex (>1000 targets) to enable studies of large-scale structures in the high-redshift Universe. Following the green light for the construction of the E-ELT the MOS community, structured through the MOSAIC consortium, is eager to realise a MOS on the E-ELT as soon as possible. We argue that several of the most compelling cases for ELT science, in highly competitive areas of modern astronomy, demand such a capability. For example, MOS observations in the early stages of E-ELT operations will be essential for follow-up of sources identified by the James Webb Space Telescope (JWST). In particular, multi-object adaptive optics and accurate sky subtraction with fibres have both recently been demonstrated on sky, making fast-track development of MOSAIC feasible.Comment: Significantly expanded and updated version of previous ELT-MOS White Paper, so there is some textual overlap with arXiv:1303.002

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Structure simplification of the Securinine skeleton reveals the importance of BCD ring system for the cytotoxic activity on HCT116 and HL60 cell lines

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    International audienceFunction-oriented molecular editing of the polycyclic scaffold of securinine led to the preparation of a library of simplified analogs that have been evaluated for their cytotoxicity potential against HCT116 and HL60 human cell lines. Chemical diversity at the C14 position (securinine numbering) was generated through the site-selective γ-iodination followed by Pd-catalyzed Sonogashira and Suzuki-Miyaura reactions. To explain the selectivity in the iodination step, a reaction mechanism has been proposed. Surprisingly, the piperidine ring (ring A) of the securinine skeleton has been found to be irrelevant for the cytotoxic activity. Based on this finding, the pharmacophoric core of securinine could be simplified to the key BCD motif. The nature of the substituent at the nitrogen can vary from a methyl or an isobutyl group to a benzyl or a carbamate moiety. Interestingly, the N-benzyl substituted simplified analog exhibited the same cytotoxic activity as the parent compound securinine. This functional group tolerance paves the way for the installation of reactive handles for the synthesis of molecular probes for target identification

    Nouveaux lipides amphiphiles ramifiés

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    The present invention relates to novel branched amphiphilic lipids. In particular, the present invention relates to novel branched amphiphilic lipids of general formula (II). The present invention also provides a method for synthesis of said compounds of formula (II) from unsaturated amphiphilic compounds of general formula (I). The invention also relates to the use of compounds of general formula (II) and lipoplexes obtained by formulating the compounds of general formula (II) for applications, including transfection, in which improved melting properties are sought.The invention relates to novel branched amphiphilic lipids. The invention specifically relates to novel branched amphiphilic lipids of general formula (II). The invention also relates to a method of synthesis for said compounds of formula (II), from unsaturated amphiphilic compounds of general formula (I). The invention further relates to the use of the compounds of general formula (II) and lipoplexes obtained by formulation of the compounds of general formula (II) for applications, particularly transfection, in which improved fusion properties are desired

    Ultra-low-energy catalytic degradation of ozone by off-stoichiometric delafossite Cu–Cr–O for highly selective low-temperature solid-state O3 sensors

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    Off-stoichiometric copper-chromium delafossite featuring giant catalytic degradation of ozone is demonstrated for the very first time. This leads to the reversible low-temperature detection of ozone onto resistive thin-film devices to values as low as 50 ppb. The selectivity when compared with molecular oxygen is also evidenced. Near-Atmospheric Pressure X-Ray Photoelectron Spectroscopy led to the understanding of the ozone - Cu0·66Cr1·33O2 surface reaction. The partial oxidation of copper into Cu2+ dependence on the ozone concentration is for the first time revealed. The apparition of a new peak associated with chemisorbed oxygen proves that the specific sub-stochiometric copper sites of the delafossite phase are driving the efficient and selective catalytic decomposition of ozone into monoatomic oxygen at the neat surface of thin films. The sensing response in ambient air is not limited by ozone decomposition but by the number of available adsorption sites. This work discloses pioneering results for the sensing networks integration of competitive ozone sensors based on Cu0·66Cr1·33O2
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