Near-infrared Fourier transform room-temperature photoluminescence of erbium complexes

A modified Fourier transform (FT) Raman bench spectrometer designed for the detection of weak light emission in the 800–1700 nm wavelength region has been used to demonstrate the advantages of FT spectroscopy for measuring near-infrared photoluminescence spectra of lanthanide complexes with a good resolution and very good sensitivity. This apparatus has been tested with an ultraviolet laser source (325 nm) on three standard erbium complexes. The 4I13/24I15/2 emission of tris-(acetylacetonato) (1,10 phenanthroline) erbium [Er(acac)3(phen)], tris-(4,4,4,-trifluoro-1-(2 thenoyl)-1,3-butenedione) (1,10 phenanthroline) erbium [Er(TTFA)3(phen)] and tris(8-hydroxyquinolinato) erbium [Erq3] has thus been recorded in solution and in the solid state and compared with literature. ©2003 American Institute of Physics

Dye-sensitized Er3+-doped CaF2 nanoparticles for enhanced near-infrared emission at 1.5 μm

Lanthanide (Ln)-doped nanoparticles have shown potential for applications in various fields. However, the weak and narrow absorption bands of the Ln ions (Ln3+), hamper efficient optical pumping and severely limit the emission intensity. Dye sensitization is a promising way to boost the near-infrared (NIR) emission of Er3+, hence promoting possible application in optical amplification at 1.5 μm, a region that is much sought after for telecommunication technology. Herein, we introduce the fluorescein isothiocyanate (FITC) organic dye with large absorption cross section as energy donor of small-sized (∼3.6 nm) Er3+-doped CaF2 nanoparticles. FITC molecules on the surface of CaF2 work as antennas to efficiently absorb light, and provide the indirect sensitization of Er3+ boosting its emission. In this paper, we employ photoluminescence and transient absorption spectroscopy, as well as density functional theory calculations, to provide an in-depth investigation of the FITC → Er3+ energy transfer process. We show that an energy transfer efficiency of over 89% is achieved in CaF2:Er3+@FITC nanoparticles resulting in a 28 times enhancement of the Er3+ NIR emission with respect to bare CaF2:Er3+. Through the multidisciplinary approach used in our work, we are able to show that the reason for such high sensitization efficiency stems from the suitable size and geometry of the FITC dye with a localized transition dipole moment at a short distance from the surface of the nanoparticle

The COVID-19 outbreak increases maternal stress during pregnancy, but not the incidence of postpartum depression

The COVID-19 pandemic affects society and may especially have an impact on mental health of vulnerable groups, such as perinatal women. This prospective cohort study compared perinatal symptoms of depression and stress during and before the pandemic. Pregnancy-specific stress increased significantly in women during the pandemic. We found no increase in depressive symptoms during pregnancy nor an increase in incidence of postnatal depression during the pandemic. Clinicians should be aware of increased stress in pregnant women and offer adequate care

Antitumor activity of organoruthenium complexes with chelate aromatic ligands, derived from 1,10-phenantroline: Synthesis and biological activity

The monocationic chloro complexes containing chelating N∩N ligands: [(η6-p-cymene)Ru(L1–4)Cl]+ (1–4), where L1 = 4-methyl-1,10-phenantroline, L2 = dipyrido[3,2-a:2′,3′-c]phenazine, L3 = 11-chloro-dipyrido[3,2-a:2′,3′-c]phenazine, L4 = 11-nitro-dipyrido[3,2-a:2′,3′-c]phenazine; p-cymene = 1-methyl-4-isopropylbenzene) have been prepared and characterized as the hexafluorophosphate salts. The biological activity of 1–4 has been investigated in selected 2D monolayer cell cultures (A549, PANC-1, MDA-MB-231, MRC-5). All investigated ruthenium complexes showed similar or even better cytotoxicity to cisplatin. However, there was no significant reduction in growth of PANC-1 cells in a 3D cell culture of multicellular tumor spheroids (MCTS) after treatment with 2–4, while the cisplatin treatment induced retardation in MCTS growth. Flow cytometry analysis of the cell cycle of PANC-1 cells shows that 3 caused changes of cell cycle phase distribution characterized by slight accumulation of cells in the G2-M phase. Absence of the Sub-G1 phase in the cell cycle of the treated cells indicated that there was no fragmentation of DNA for the analyzed time intervals (48 and 72 h treatment). Fluorescent microscopy, after acridine orange/ethidium bromide staining, revealed that the investigated ruthenium complexes induced some characteristics of apoptotic morphology (shrinking and condensation of chromatin) with notably preserved integrity of the plasma membrane. Investigation of cellular uptake and DNA - fraction accumulation performed by inductively coupled plasma mass spectrometry in PANC-1 cells with equimolar concentrations (5 μM) of 2–4 and cisplatin showed more efficient cellular uptake and DNA - fraction accumulation of complex 3 compared to complexes 2 and 4

Infections in Biological and Targeted Synthetic Drug Use in Rheumatoid Arthritis:Where do We Stand? A Scoping Review and Meta-analysis

Introduction: The advent of biological and targeted synthetic therapies has revolutionized rheumatoid arthritis (RA) treatment. However, this has come at the price of an increased risk of infections. The aim of this study was to present an integrated overview of both serious and non-serious infections, and to identify potential predictors of infection risk in RA patients using biological or targeted synthetic drugs. Methods: We systematically reviewed available literature from PubMed and Cochrane and performed multivariate meta-analysis with meta-regression on the reported infections. Randomized controlled trials and prospective and retrospective observational studies including patient registry studies were analyzed, combined as well as separately. We excluded studies focusing on viral infections only. Results: Infections were not reported in a standardized manner. Meta-analysis showed significant heterogeneity that persisted after forming subgroups by study design and follow-up duration. Overall, the pooled proportions of patients experiencing an infection during a study were 0.30 (95% CI, 0.28–0.33) and 0.03 (95% CI, 0.028–0.035) for any kind of infections or serious infections only, respectively. We found no potential predictors that were consistent across all study subgroups. Conclusions: The high heterogeneity and the inconsistency of potential predictors between studies show that we do not yet have a complete picture of infection risk in RA patients using biological or targeted synthetic drugs. Besides, we found non-serious infections outnumbered serious infections by a factor 10:1, but only a few studies have focused on their occurrence. Future studies should apply a uniform method of infectious adverse event reporting and also focus on non-serious infections and their impact on treatment decisions and quality of life.</p

Nonlinear optical spectroscopy and two-photon excited fluorescence spectroscopy reveal the excited states of fluorophores embedded in a beetle's elytra

This is the author accepted manuscript. The final version is available via the DOI in this record.Upon illumination by ultraviolet light, many animal species emit light through fluorescence processes arising from fluorophores embedded within their biological tissues. Fluorescence studies in living organisms are however relatively scarce and so far limited to the linear regime. Multiphoton excitation fluorescence analyses as well as nonlinear optical techniques offer unique possibilities to investigate the effects of the local environment on the excited states of fluorophores. Herein, these techniques are applied for the first time to study of the naturally controlled fluorescence in insects. The case of the male Hoplia coerulea beetle is investigated because the scales covering the beetle's elytra are known to possess an internal photonic structure with embedded fluorophores, which controls both the beetle's coloration and the fluorescence emission. An intense two-photon excitation fluorescence signal is observed, the intensity of which changes upon contact with water. A third-harmonic generation signal is also detected, the intensity of which depends on the light polarization state. The analysis of these nonlinear optical and fluorescent responses unveils the multi-excited states character of the fluorophore molecules embedded in the beetle's elytra. The role of form anisotropy in the photonic structure, which causes additional tailoring of the beetle's optical responses, is demonstrated by circularly polarized light and nonlinear optical measurements.Wallonia–Brussels InternationalBelgian National Fund for Scientific Research2018 Biomimetics Travel AwardFWO FlandersHercules FoundationAction de Recherche ConcerteNanoscale Quantum OpticsFRSFNRSMinistry of Science, Republic of Serbi