34 research outputs found
NIR-emission from Yb(III)- and Nd(III)-based complexes in the solid state sensitized by a ligand system absorbing in a broad UV and visible spectral window
In this contribution, we present the synthesis, characterization and spectroscopic investigation of the heteroleptic (R,R)-YbL1(tta) and (R,R)-NdL1(tta) complexes (with tta = 2-thenoyltrifluoroacetonate and L1 = N,N'-bis(2-(8-hydroxyquinolinate)methylidene)-1,2-(R,R or S,S)-cyclohexanediamine) in the solid state. The f-f metal-centered NIR luminescence emission of Nd(III) and Yb(III) is efficiently sensitized by both chromophoric ligands in a very broad range of wavelengths [from 250 to 600 nm, in the case of Nd(III) and from 250 to 650 nm, for Yb(III)]. A possible energy transfer mechanism is proposed: for (R,R)-NdL1(tta) complex a classical Ligand-to-Metal Energy Transfer (LMET) mechanism (antenna effect) is suggested, whilst in the case of the (R,R)-YbL1(tta) complex, the presence of a ligand-to-metal charge transfer (LMCT) state determines the sensitization of Yb(III) luminescence. We propose that this level is populated by the singlet and triplet excited states belonging to pi -> pi* and n -> pi* transitions of both ligands and it can transfer the excitation energy to F-2(5/2)
Circularly Polarized Luminescence from New Heteroleptic Eu(III) and Tb(III) Complexes
The complexes [Eu(bpcd)(tta)], [Eu(bpcd)(Coum)], and [Tb(bpcd)(Coum)] [tta = 2-thenoyltrifluoroacetyl-acetonate, Coum = 3-acetyl-4-hydroxy-coumarin, and bpcd = N,N′-bis(2-pyridylmethyl)-trans-1,2-diaminocyclohexane-N,N′-diacetate] have been synthesized and characterized from photophysical and thermodynamic points of view. The optical and chiroptical properties of these complexes, such as the total luminescence, decay curves of the Ln(III) luminescence, electronic circular dichroism, and circularly polarized luminescence, have been investigated. Interestingly, the number of coordinated solvent (methanol) molecules is sensitive to the nature of the metal ion. This number, estimated by spectroscopy, is >1 for Eu(III)-based complexes and <1 for Tb(III)-based complexes. A possible explanation for this behavior is provided via the study of the minimum energy structure obtained by density functional theory (DFT) calculations on the model complexes of the diamagnetic Y(III) and La(III) counterparts [Y(bpcd)(tta)], [Y(bpcd)(Coum)], and [La(bpcd)(Coum)]. By time-dependent DFT calculations, estimation of donor-acceptor (D-A) distances and of the energy position of the S1and T1ligand excited states involved in the antenna effect was possible. These data are useful for rationalizing the different sensitization efficiencies (ηsens) of the antennae toward Eu(III) and Tb(III). The tta ligand is an optimal antenna for sensitizing Eu(III) luminescence, while the Coum ligand sensitizes better Tb(III) luminescence {φovl= 55%; ηsens≥ 55% for the [Tb(bpcd)(Coum)] complex}. Finally, for the [Eu(bpcd)(tta)] complex, a sizable value of glum(0.26) and a good quantum yield (26%) were measured
Determining minimal clinically important differences in the Hammersmith Functional Motor Scale Expanded for untreated spinal muscular atrophy patients: An international study
\ua9 2024 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.Background and purpose: Spinal muscular atrophy (SMA) is a rare and progressive neuromuscular disorder with varying severity levels. The aim of the study was to calculate minimal clinically important difference (MCID), minimal detectable change (MDC), and values for the Hammersmith Functional Motor Scale Expanded (HFMSE) in an untreated international SMA cohort. Methods: The study employed two distinct methods. MDC was calculated using distribution-based approaches to consider standard error of measurement and effect size change in a population of 321 patients (176 SMA II and 145 SMA III), allowing for stratification based on age and function. MCID was assessed using anchor-based methods (receiver operating characteristic [ROC] curve analysis and standard error) on 76 patients (52 SMA II and 24 SMA III) for whom the 12-month HFMSE could be anchored to a caregiver-reported clinical perception questionnaire. Results: With both approaches, SMA type II and type III patients had different profiles. The MCID, using ROC analysis, identified optimal cutoff points of −2 for type II and −4 for type III patients, whereas using the standard error we found the optimal cutoff points to be 1.5 for improvement and −3.2 for deterioration. Furthermore, distribution-based methods uncovered varying values across age and functional status subgroups within each SMA type. Conclusions: These results emphasize that the interpretation of a single MCID or MDC value obtained in large cohorts with different functional status needs to be made with caution, especially when these may be used to assess possible responses to new therapies
Different trajectories in upper limb and gross motor function in spinal muscular atrophy
INTRODUCTION:
The Hammersmith Functional Motor Scale Expanded (HFMSE) and the Revised Upper Limb Module (RULM) have been widely used in natural history studies and clinical trials. Our aim was to establish how the scales relate to each other at different age points in spinal muscular atrophy (SMA) type 2 and 3, and to describe their coherence over 12 mo.
METHODS:
The study was performed by cross-sectional and longitudinal reanalysis of previously published natural history data. The longitudinal analysis of the 12-mo changes also included the analysis of concordance between scales with changes grouped as stable (±2 points), improved (>+2) or declined (>−2).
RESULTS:
Three hundred sixty-four patients were included in the cross-sectional analysis, showing different trends in score and point of slope change for the two scales. For type 2, the point of slope change was 4.1 y for the HFMSE and 5.8 for the RULM, while for type 3, it was 6 y for the HFMSE and 7.3 for the RULM. One-hundred-twenty-one patients had at least two assessments at 12 mo. Full concordance was found in 57.3% of the assessments, and in 40.4% one scale remained stable and the other changed. Each scale appeared to be more sensitive to specific age or functional subgroups.
DISCUSSION:
The two scales, when used in combination, may increase the sensitivity to detect clinically meaningful changes in motor function in patients with SMA types 2 and 3
NIR-emission from Yb(III)- and Nd(III)-based complexes in the solid state sensitized by a ligand system absorbing in a broad UV and visible spectral window
In this contribution, we present the synthesis, characterization and spectroscopic investigation of the heteroleptic (R,R)-YbL1(tta) and (R,R)-NdL1(tta) complexes (with tta = 2-thenoyltrifluoroacetonate and L1 = N,N′-bis(2-(8-hydroxyquinolinate)methylidene)-1,2-(R,R or S,S)-cyclohexanediamine) in the solid state. The f-f metal-centered NIR luminescence emission of Nd(III) and Yb(III) is efficiently sensitized by both chromophoric ligands in a very broad range of wavelengths [from 250 to 600 nm, in the case of Nd(III) and from 250 to 650 nm, for Yb(III)]. A possible energy transfer mechanism is proposed: for (R,R)-NdL1(tta) complex a classical Ligand-to-Metal Energy Transfer (LMET) mechanism (antenna effect) is suggested, whilst in the case of the (R,R)-YbL1(tta) complex, the presence of a ligand-to-metal charge transfer (LMCT) state determines the sensitization of Yb(III) luminescence. We propose that this level is populated by the singlet and triplet excited states belonging to π → π * and n → π * transitions of both ligands and it can transfer the excitation energy to 2F5/2
Near Infared Circularly Polarized Luminescence From Water Stable Organic Nanoparticles Containing a Chiral Yb(III) Complex
We report the first example of very efficient NIR Circularly Polarized Luminescence (CPL) (around 970 nm) in water, obtained thanks to the combined use of a chiral Yb complex and of poly lactic-co-glycolic acid (PLGA) nanoparticles. [YbL(tta)2]CH3COO (L=N, N’-bis(2-pyridylmethylidene)-1,2-(R,R+S,S) cyclohexanediamine and tta=2-thenoyltrifluoroacetonate) shows good CPL in organic solvents, because the tta ligands efficiently sensitize Yb NIR luminescence and the readily prepared chiral ligand L endows the complex with the necessary dissymmetry. PLGA nanoparticles incorporate the complex and protect the metal ion from the intrusion of solvent molecules, while ensuring biocompatibility, water solubility and stability to the complex. Hydrophilic NIR-CPL optical probes can find applications in the field of NIR-CPL bio-assays
MPXV DNA kinetics in bloodstream and other body fluids samples
Since spring 2022, the global epidemiology of the monkeypox virus (MPXV) has changed. The unprecedented increase of human clade II MPXV cases worldwide heightened concerns about this emerging zoonotic disease. We analysed the positivity rates, viral loads, infectiousness, and persistence of MPXV DNA for up to 4 months in several biological samples from 89 MPXV-confirmed cases. Our data showed that viral loads and positivity rates were higher during the first two weeks of symptoms for all sample types. Amongst no-skin-samples, respiratory specimens showed higher MPXV DNA levels and median time until viral clearance, suggesting their usefulness in supporting MPXV diagnosis, investigating asymptomatic patients, and monitoring viral shedding. Infectious virus was cultured from respiratory samples, semen, and stools, with high viral loads and collected within the first 10 days. Notably, only one saliva and one semen were found positive for viral DNA after 71 and 31 days from symptoms, respectively. The focus on bloodstream samples showed the best testing sensitivity in plasma, reporting the overall highest MPXV DNA detection rate and viral loads during the 3-week follow-up as compared to serum and whole-blood. The data here presented can be useful for MPXV diagnostics and a better understanding of the potential alternative routes of its onward transmission