Enantiopure double ortho-oligophenylethynylene-based helical structures with circularly polarized luminescence activity

In this paper, we describe the optical and chiroptical properties of an enantiopure multipodal ortho-oligophenylethynylene (S,S,S,S)-1 presenting four chiral sulfoxide groups at the extremes. The presence of these groups together with alkynes allows the coordination with carbophilic Ag(I), and/or oxophilic Zn(II) cations, yielding double helical structures in an enantiopure way. In this sense, different behaviors in absorption, fluorescence, ECD and CPL spectra have been found depending on the stoichiometry and nature of the metal. We have observed that Zn(II) coordination favors an intensity increase of the electronic circular dichroism (ECD) spectra of compound (S,S,S,S)-1 yielding an M-helicity in the ortho-oligophenylene ethynylene (o-OPE) backbone. On the other hand, ECD spectra of final Ag(I) complex shows two different bands with an opposite sign to the free ligand, thus giving the P-helical isomer. In addition, circularly polarized luminescence (CPL) exhibit an enhanced intensity and negative sign in both complexes. Computational studies were also carried out, supporting the experimental result

2D self-assembly of o-OPE foldamers for chiroptical barcoding

We report on the preparation and characterization of two dimensional (2D) films of (S,S,P)-1 and (R,R,M)-1ortho-oligophenylene ethylene (o-OPE) enantiomers presenting high values of circularly polarized luminescence (CPL). The amphiphilic character of these two molecules allows a precise 2D self-assembly at the air/water interface and an efficient transfer onto a glass solid support. The morphological and chiroptical characterization of the solid supports after the transfer of 1, 8, 16 and 32 Langmuir films of (S,S,P)-1 and (R,R,M)-1 has been carried out. The strong chiroptical values of these monomers allow reliable ECD measurements to be obtained after a single transfer, with ECD values increasing as the number of transferred films increases. The semi-liquid behavior of the monomers on the solid substrate allows CPL measurements free of photoselection artifacts that show values similar to those obtained in solution and independent of monomer concentration. All these properties have allowed us to develop the first simple organic molecule (SOM)-based chiroptical barcoding presenting positive and negative regions as a proof of concept

Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

Contains fulltext : 172380.pdf (publisher's version ) (Open Access

Conglomerate, Racemate, and Achiral Crystals of Polymetallic Europium(III) Compounds of Bis- or Tris-β-diketonate Ligands and Circularly Polarized Luminescence Study

This work reports (a) conglomerate and racemic crystal structures of [(Δ,Δ,Δ,Δ,Δ,Δ)- or/and (Λ,Λ,Λ,Λ,Λ,Λ)-EuIII6(TTP)8(OH2)6Na4]n coordination polymers, (b) racemic crystal structures of (Δ,Δ,Δ,Δ)-/(Λ,Λ,Λ,Λ)-EuIII4(TTP)4(bipy)4(MEK)2(OH2)2 tetrahedral clusters, and (c) the achiral crystal structure of the [EuIII2(BTP)4(OH2)2Na2]n coordination polymer (where BTP = dianionic bis-β-diketonate, TTP = trianionic tris-β-diketonate, and bipy = 2,2′-bipyridine). The screw coordination arrangement of the TTP ligand has led to the formation of homoconfigurational racemic EuIII products. The conglomerate crystallization of [EuIII6(TTP)8(OH2)6Na4]n appears to be caused by the presence of the sodium, Na+ counterions, and interactions between oxygen atoms and the trifluoromethyl unit of the TTP ligand and Na+ ions. All the EuIII compounds exhibit characteristic red luminescence (5D0 → 7FJ, J = 0–4) in solution or in the solid crystalline state. Circularly polarized luminescence (CPL) was observed in the chiral EuIII6(TTP)8(OH2)6Na4]n species, displaying a |glum| value in the range of 0.15 to 0.68 at the 5D0 → 7F1 emission band. Subtle changes of the [EuIII6(TTP)8(OH2)6Na4]n structure which may be due to selection of twinned crystals or crystals that do not correspond to a perfect spontaneous resolution, are considered to be responsible for the variation in the observed CPL values

Implications of early respiratory support strategies on disease progression in critical COVID-19: a matched subanalysis of the prospective RISC-19-ICU cohort

Background: Uncertainty about the optimal respiratory support strategies in critically ill COVID-19 patients is wide‑ spread. While the risks and benefts of noninvasive techniques versus early invasive mechanical ventilation (IMV) are intensely debated, actual evidence is lacking. We sought to assess the risks and benefts of diferent respiratory sup‑ port strategies, employed in intensive care units during the frst months of the COVID-19 pandemic on intubation and intensive care unit (ICU) mortality rates. Methods: Subanalysis of a prospective, multinational registry of critically ill COVID-19 patients. Patients were subclas‑ sifed into standard oxygen therapy ≥10 L/min (SOT), high-fow oxygen therapy (HFNC), noninvasive positive-pressureBackground: Uncertainty about the optimal respiratory support strategies in critically ill COVID-19 patients is widespread. While the risks and benefits of noninvasive techniques versus early invasive mechanical ventilation (IMV) are intensely debated, actual evidence is lacking. We sought to assess the risks and benefits of different respiratory support strategies, employed in intensive care units during the first months of the COVID-19 pandemic on intubation and intensive care unit (ICU) mortality rates. Methods: Subanalysis of a prospective, multinational registry of critically ill COVID-19 patients. Patients were subclassified into standard oxygen therapy ≥10 L/min (SOT), high-flow oxygen therapy (HFNC), noninvasive positive-pressure ventilation (NIV), and early IMV, according to the respiratory support strategy employed at the day of admission to ICU. Propensity score matching was performed to ensure comparability between groups. Results: Initially, 1421 patients were assessed for possible study inclusion. Of these, 351 patients (85 SOT, 87 HFNC, 87 NIV, and 92 IMV) remained eligible for full analysis after propensity score matching. 55% of patients initially receiving noninvasive respiratory support required IMV. The intubation rate was lower in patients initially ventilated with HFNC and NIV compared to those who received SOT (SOT: 64%, HFNC: 52%, NIV: 49%, p = 0.025). Compared to the other respiratory support strategies, NIV was associated with a higher overall ICU mortality (SOT: 18%, HFNC: 20%, NIV: 37%, IMV: 25%, p = 0.016). Conclusion: In this cohort of critically ill patients with COVID-19, a trial of HFNC appeared to be the most balanced initial respiratory support strategy, given the reduced intubation rate and comparable ICU mortality rate. Nonetheless, considering the uncertainty and stress associated with the COVID-19 pandemic, SOT and early IMV represented safe initial respiratory support strategies. The presented findings, in agreement with classic ARDS literature, suggest that NIV should be avoided whenever possible due to the elevated ICU mortality risk