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The present paper sets out to investigate the role of voltage pulse length on the properties of Nb:TiO2 films deposited by High Power Impulse Magnetron Sputtering (HiPIMS). Several characteristics of the films were investigated, namely, resistivity, transmittance, crystallinity and band gap values of Nb:TiO2 films. Reactive depositions were carried out in Ar/O2 plasma with 40 µs, 50 µs, 60 µs, and 70 µs pulses. Increasing the pulse length changes the deposition from compound to metal mode. As it gets closer to metal mode, the deposition rate increases by up to one order of magnitude, while the resistivity of the resulting Nb:TiO2 film becomes as low as 10-4 Ω.cm, without any significant loss in optical transmittance, which remains close to 90% for a wavelength around 450 nm, but reduction in 25% of heat transmission (above 800 nm) were observed. Results indicate the anatase phase for all deposition conditions, and Ti3+ states increase with the pulse length, which can be explained by the generation of a second band gap. Both the niobium doping and the Ti3+ states can contribute to increase the conductivity of the Nb:TiO2 films in the as-deposited condition.

This work reports on the properties of GaN films grown by reactive magnetron sputtering onto glass substrate kept at relatively low temperature (400°C), using different RF power applied to the Ga target. Their structural, morphological, vibrational and optical properties were characterized by X-ray diffraction, atomic force and scanning electron microscopies, Raman spectroscopy and UV-vis spectrophotometry. The films have wurtzite phase with strong preferential orientation in the c-axis direction. Moreover, two clear contributions to the (0002) diffraction peak could be found, indicating the presence of two different morphologies, which were discussed in terms of the formation of an intermediate layer between the substrate and a dominating columnar-like microstructured film.

In this work, thin films based on the Ti-Zr system were studied, deposited on a silicon substrate by the magnetron sputtering technique using simultaneously a combination of High-Power Impulse Magnetron Sputtering (HiPIMS) and Direct Current Magnetron Sputtering (DCMS) sources. The objective of this work is analyzing the effect of varying HiPIMS frequency (300 Hz, 400 Hz, 500 Hz, and 600 Hz) on the characteristics and properties of the thin films. The thickness increased between 300 Hz and 500 Hz, where the thickness measured 563 nm and 732 nm, respectively; then it decreased to 709 nm at 600 Hz. Hardness and elastic moduli also tended to decrease with increasing frequency, and the results for the first property were between 7 GPa and 10.3 Gpa, while the elastic moduli were from 114 Gpa to 157 Gpa, in which lower values were reached at higher frequencies. In the wettability test, lower contact angles were observed for samples with lower frequencies due to their high surface energy, providing better hydrophilic properties.

Abstract Colorectal cancer (CRC) is a global health concern, and the incidence of early onset (EO) CRC, has an upward trend. This study delves into the genomic landscape of EO-CRC, specifically focusing on pediatric (PED) and young adult (YA) patients, comparing them with adult (AD) CRC. In this retrospective monocentric investigation, we performed targeted next-generation sequencing to compare the mutational profile of 38 EO-CRCs patients (eight PED and 30 YA) to those of a ‘control group’ consisting of 56 AD-CRCs. Our findings reveal distinct molecular profiles in EO-CRC, notably in the WNT and PI3K-AKT pathways. In pediatrics, we observed a significantly higher frequency of RNF43 mutations, whereas APC mutations were more prevalent in adult cases. These observations suggest age-related differences in the activation of the WNT pathway. Pathway and copy number variation analysis reveal that AD-CRC and YA-CRC have more similarities than the pediatric patients. PED shows a peculiar profile with CDK6 amplification and the enrichment of lysine degradation pathway. These findings may open doors for personalized therapies, such as PI3K-AKT pathway inhibitors or CDK6 inhibitors for pediatric patients. Additionally, the distinct molecular signatures of EO-CRC underscore the need for age-specific treatment strategies and precision medicine. This study emphasizes the importance of comprehensive molecular investigations in EO-CRCs, which can potentially improve diagnostic accuracy, prognosis, and therapeutic decisions for these patients. Collaboration between the pediatric and adult oncology community is fundamental to improve oncological outcomes for this rare and challenging pediatric tumor.

Abstract How can an intentional movement be distinguished from the same movement done nonintentionally? How can this distinction be drawn without asking the subject, or in patients who are unable to communicate? Here we address these questions, by focusing on blinking. This is one of the most frequent spontaneous actions in our daily life, but it can also be done intentionally. Furthermore, blinking is often spared in patients with severe brain injuries, and for some, it is the only way to report complex meanings. Using kinematic and EEG-based measures, we found that intentional and spontaneous blinking are preceded by different brain activities, even when they are indistinguishable. Unlike spontaneous ones, intentional blinks are characterized by a slow negative EEG drift, resembling the classic readiness potential. We investigated the theoretical implication of this finding in stochastic decision models as well as the practical significance of using brain-based signals to improve the discrimination between intentional and nonintentional actions. As proof of principle, we considered three brain-injured patients with rare neurological syndromes characterized by motor and communicative impairments. Although further research is needed, our results indicate that brain-based signals can offer a feasible way to infer intentionality even in absence of overt communication.

Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation and Autonomic Dysregulation (ROHHAD) is a rare, life-threatening, pediatric disorder of unknown etiology, whose diagnosis is made difficult by poor knowledge of clinical manifestation, and lack of any confirmatory tests. Children with ROHHAD usually present with rapid onset weight gain which may be followed, over months or years, by hypothalamic dysfunction, hypoventilation, autonomic dysfunction, including impaired bowel motility, and tumors of neural crest origin. Despite the lack of evidence of inheritance in ROHHAD, several studies have been conducted in recent years that have explored possible genetic origins, with unsuccessful results. In order to broaden the search for possible genetic risk factors, an attempt was made to analyse the non-coding variants in two trios (proband with parents), recruited in the Gaslini Children’s Hospital in Genoa (Italy). Both patients were females, with a typical history of ROHHAD. Gene variants (single nucleotide variants, short insertions/deletions, splice variants or in tandem expansion of homopolymeric tracts) or altered genomic regions (copy number variations or structural variants) shared between the two probands were searched. Currently, we have not found any potentially pathogenic changes, consistent with the ROHHAD clinical phenotype, and involving genes, regions or pathways shared between the two trios. To definitively rule out the genetic etiology, third-generation sequencing technologies (e.g., long-reads sequencing, optical mapping) should be applied, as well as other pathways, including those associated with immunological and autoimmune disorders, should be explored, making use not only of genomics but also of different -omic datasets.

Background: Cortico-cortical evoked potentials (CCEPs) recorded by stereo-electroencephalography (SEEG) are a valuable tool to investigate brain reactivity and effective connectivity. However, invasive recordings are spatially sparse since they depend on clinical needs. This sparsity hampers systematic comparisons across-subjects, the detection of the whole-brain effects of intracortical stimulation, as well as their relationships to the EEG responses evoked by non-invasive stimuli. Objective: To demonstrate that CCEPs recorded by high-density electroencephalography (hd-EEG) provide additional information with respect SEEG alone and to provide an open, curated dataset to allow for further exploration of their potential. Methods: The dataset encompasses SEEG and hd-EEG recordings simultaneously acquired during Single Pulse Electrical Stimulation (SPES) in drug-resistant epileptic patients (N = 36) in whom stimulations were delivered with different physical, geometrical, and topological parameters. Differences in CCEPs were assessed by amplitude, latency, and spectral measures. Results: While invasively and non-invasively recorded CCEPs were generally correlated, differences in pulse duration, angle and stimulated cortical area were better captured by hd-EEG. Further, intracranial stimulation evoked site-specific hd-EEG responses that reproduced the spectral features of EEG responses to transcranial magnetic stimulation (TMS). Notably, SPES, albeit unperceived by subjects, elicited scalp responses that were up to one order of magnitude larger than the responses typically evoked by sensory stimulation in awake humans. Conclusions: CCEPs can be simultaneously recorded with SEEG and hd-EEG and the latter provides a reliable descriptor of the effects of SPES as well as a common reference to compare the whole-brain effects of intracortical stimulation to those of non-invasive transcranial or sensory stimulations in humans.

The Kuiper quadrangle (H06) is located at the equatorial zone of Mercury and encompasses the area between 288°E – 360°E and 22.5°N – 22.5°S. Using the NASA MESSENGER data, we compiled a geological map of the quadrangle at a 1:3,000,000 scale. The mapping was mainly based on photo-interpretation of an MDIS (Mercury Dual Imaging System) monochrome 166 m/pixel basemap. Additional datasets were also considered: stereo-DTM of the region, mosaics with high-incidence illumination, and the MDIS global color mosaic. The map shows that the quadrangle is characterized by the prevalence of crater materials which are distinguished into three classes based on their degradation degree. Different plain units were also identified and classified on the basis of their density of cratering. Several structures, mainly represented by contractional faults, were mapped in all quadrangle areas. The map represents the first complete geologic survey of H06 at this scale and provides a highly detailed analysis of the Kuiper quadrangle’s surface geology.

The pharmacological activation of G-protein coupled receptor-119 (GPR119) modulates glucose, energy, and hepatic lipid homeostasis in type-2 diabetes (T2D). We developed synthetic small-molecule GPR119 agonists targeting gastrointestinal receptors. This study investigates the chronic metabolic effects of lead candidates, ps297 and ps318, individually and in combination with sitagliptin, a dipeptidyl peptidase-IV (DPP-IV) inhibitor, in high-fat diet (HFD)-induced obese (DIO) mice. In a 10-week dose-escalation protocol, DIO mice were orally treated with the investigational agents alone (10-90 mg/kg/day) and in combination with sitagliptin (20 mg/kg/day). Weekly body weight, food intake, and random blood glucose levels were monitored during the treatment phase. Post-treatment, an intraperitoneal glucose tolerance test (ipGTT), estimation of plasma biomarkers and haematological assessment were conducted. The treatment's effect on hepatic steatosis was studied by estimating liver biomarkers and histological examinations. Ten-week sitagliptin combination therapy with the investigational entities restored incretins, insulin, and other metabolic hormonal secretions, accompanied by improved glucose homeostasis and retarded weight gain. Interestingly, monotherapy with investigational agents improved liver health by reducing liver weight, liver enzymes, and inflammation. Hepatic effects were further enhanced by co-administration of sitagliptin, evident by amelioration in hepatic steatosis endpoints such as liver weight, plasma liver enzyme concentrations, hepatic triglycerides (TG), total cholesterol (CHO), hydroxyproline content, and cytokine levels. Histopathological investigations confirmed regression in hepatic steatosis in the combination groups. These findings demonstrate the therapeutic potential of novel gut-oriented GPR119 agonists in combination with a DPP-IV inhibitor to ameliorate metabolic dysfunction-associated steatohepatitis (MASH), warranting further mechanistic investigations., Competing Interests: Declaration of Competing Interest MF and MM are inventors (MF is an owner) of a patent related to oleoyl-LPI mimetics. Curtin University received funding from Little Green Pharma Pty Ltd. to support MF to conduct the submitted work. LW was a paid employee of Little Green Pharma Pty Ltd. No other relationships or activities could appear to have influenced the submitted work., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Neurobiological research relies heavily on imaging techniques, such as fluorescence microscopy, to understand neurological function and disease processes. However, the number and variety of fluorescent probes available for ex vivo tissue section imaging limits the advance of research in the field. In this review, we outline the current range of fluorescent probes that are available to researchers for ex vivo brain section imaging, including their physical and chemical characteristics, staining targets, and examples of discoveries for which they have been used. This review is organised into sections based on the biological target of the probe, including subcellular organelles, chemical species ( e.g. , labile metal ions), and pathological phenomenon ( e.g. , degenerating cells, aggregated proteins). We hope to inspire further development in this field, given the considerable benefits to be gained by the greater availability of suitably sensitive probes that have specificity for important brain tissue targets.

The reaction of Re(CO) 5 Br with deprotonated 1H-(5-(2,2':6',2''-terpyridine)pyrid-2-yl)tetrazole yields a triangular assembly formed by tricarbonyl Re(I) vertices. Photophysical measurements reveal blue-green emission with a maximum at 520 nm, 32 % quantum yield, and 2430 ns long-lived excited state decay lifetime in deaerated dichloromethane solution. Coordination of lanthanoid ions to the terpyridine units red-shifts the emission to 570 nm and also reveals efficient (90 %) and fast sensitisation of both Eu(III) and Yb(III) at room temperature, with a similar rate constant k ET on the order of 10 7  s -1 . Efficient sensitisation of Eu(III) from Re(I) is unprecedented, especially when considering the close proximity in energy between the donor and acceptor excited states. On the other hand, comparative measurements at 77 K reveal that energy transfer to Yb(III) is two orders of magnitude slower than that to Eu(III). A two-step mechanism of sensitisation is therefore proposed, whereby the rate-determining step is a thermally activated energy transfer step between the Re(I) centre and the terpyridine functionality, followed by rapid energy transfer to the respective Ln(III) excited states. At 77 K, the direct Re(I) to Eu(III) energy transfer seems to proceed via a ligand-mediated superexchange Dexter-type mechanism., (© 2024 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

Here we present our preliminary studies into the inorganic pigments Han blue (BaCuSi 4 O 10 ) and Han purple (BaCuSi 2 O 6 ) as near-infrared luminescent fingerprint dusting powders. These pigments were developed in ancient China around 800 BCE and both show luminescence in the NIR region. There remains, however, ambiguity in the literature concerning their photophysical properties. Samples of Han blue and Han purple artist's pigments were characterized by optical microscopy, infrared, ultraviolet-visible absorbance and luminescence spectroscopy. Their performance as fingerprint dusting powders, without any further treatment, on non-porous surfaces were compared to exfoliated lipophilic coated Egyptian blue and commercial fluorescent powders in a pilot study. These results demonstrate for the first time that both ancient pigments show promise as alternative dusting powders for latent fingermarks., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Imaging with multiple modalities can maximise the information gained from the analysis of a single sample. probes for optical fluorescence and X-ray fluorescence microscopy based on brominated 4-amino-1,8-naphthalimide and BODIPY scaffolds have been successfully designed and synthesised. Herein we show that these prototype probes, based on each of these scaffolds, can be imaged in two different cancer cell lines, and that the respective optical fluorescence and X-ray fluorescence signals are well correlated in these images.

The escalating global prevalence of type-2 diabetes (T2D) and obesity necessitates the development of novel oral medications. Agonism at G-protein coupled receptor-119 (GPR119) has been recognized for modulation of metabolic homeostasis in T2D, obesity, and fatty liver disease. However, off-target effects have impeded the advancement of synthetic GPR119 agonist drug candidates. Non-systemic, gut-restricted GPR119 agonism is suggested as an alternative strategy that may locally stimulate intestinal enteroendocrine cells (EEC) for incretin secretion, without the need for systemic drug availability, consequently alleviating conventional class-related side effects. Herein, we report the preclinical acute safety, efficacy, and pharmacokinetics (PK) of novel GPR119 agonist compounds ps297 and ps318 that potentially target gut EEC for incretin secretion. In a proof-of-efficacy study, both compounds demonstrated glucagon-like peptide-1 (GLP-1) secretion capability during glucose and mixed-meal tolerance tests in healthy mice. Furthermore, co-administration of sitagliptin with investigational compounds in diabetic db/db mice resulted in synergism, with GLP-1 concentrations rising by three-fold. Both ps297 and ps318 exhibited low gut permeability assessed in the in-vitro Caco-2 cell model. A single oral dose PK study conducted on healthy mice demonstrated poor systemic bioavailability of both agents. PK measures (mean ± SD) for compound ps297 (C max 23 ± 19 ng/mL, T max range 0.5 - 1 h, AUC 0-24 h 19.6 ± 21 h*ng/mL) and ps318 (C max 75 ± 22 ng/mL, T max range 0.25 - 0.5 h, AUC 0-24 h 35 ± 23 h*ng/mL) suggest poor oral absorption. Additionally, examinations of drug excretion patterns in mice revealed that around 25 % (ps297) and 4 % (ps318) of the drugs were excreted through faeces as an unchanged form, while negligible drug concentrations (<0.005 %) were excreted in the urine. These acute PK/PD assessments suggest the gut is a primary site of action for both agents. Toxicity assessments conducted in the zebrafish and healthy mice models confirmed the safety and tolerability of both compounds. Future chronic in-vivo studies in relevant disease models will be essential to confirm the long-term safety and efficacy of these novel compounds., Competing Interests: Declaration of Competing Interest MF and MM are inventors (MF is owner) of a patent related to oleoyl-LPI mimetics. Curtin University received funding from Little Green Pharma Pty Ltd. to support MF to conduct the submitted work. LW was a paid employee of Little Green Pharma Pty Ltd. No other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

A new family of ionic Ir(III) cyclometalated complexes with general formula [Ir(CN) 2 (NN)][Br], was designed and prepared to be assessed as photocalysts for the visible light assisted ATRP polymerization of MMA. To this purpose, our design strategy involved both: i) the decoration of the cyclometalating (CN) and the ancillary (NN) ligands with various electron withdrawing and/or electron donor substituents and, ii) the use of Br - as the counter anion for these cationic Ir(III) species. After an extensive screening in which the [Ir(CN) 2 (NN)][Br]-type compounds were compared to the model neutral complex fac-[Ir(ppy) 3 ], the "fully" amino-substituted ion pairs abbreviated as [10][Br] and [11][Br], exhibited the best photocatalytic performances under irradiation with CFL lamps. It is worth noting that the outcomes of transient absorption spectroscopy (TAS) experiments combined with theoretical DFT calculations, enlightened the role played by the Ir(III) complexes in the mechanism of the photoATRP process, and suggested the rationalization of the different performances that were highlighted by our Ir(III) catalyst in the visible light assisted photopolymerization of MMA., (© 2024 Wiley-VCH GmbH.)

Rhenium(I) tricarbonyl complexes are widely studied for their cell imaging properties and anti-cancer and anti-microbial activities, but the complexes with S-donor ligands remain relatively unexplored. A series of six fac -[Re(NN)(CO) 3 (SR)] complexes, where (NN) is 2,2'-bipyridyl (bipy) or 1,10-phenanthroline (phen), and RSH is a series of thiocarboxylic acid methyl esters, have been synthesized and characterized. Cellular uptake and anti-proliferative activities of these complexes in human breast cancer cell lines (MDA-MB-231 and MCF-7) were generally lower than those of the previously described fac -[Re(NN)(CO) 3 (OH 2 )] + complexes; however, one of the complexes, fac -[Re(CO) 3 (phen)(SC(Ph)CH 2 C(O)OMe)] (3b), was active (IC 50 ∼ 10 μM at 72 h treatment) in thiol-depleted MDA-MB-231 cells. Moreover, unlike fac -[Re(CO) 3 (phen)(OH 2 )] + , this complex did not lose activity in the presence of extracellular glutathione. Taken together these properties show promise for further development of 3b and its analogues as potential anti-cancer drugs for co-treatment with thiol-depleting agents. Conversely, the stable and non-toxic complex, fac -[Re(bipy)(CO) 3 (SC(Me)C(O)OMe)] (1a), predominantly localized in the lysosomes of MDA-MB-231 cells, as shown by live cell confocal microscopy ( λ ex = 405 nm, λ em = 470-570 nm). It is strongly localized in a subset of lysosomes (25 μM Re, 4 h treatment), as shown by co-localization with a Lysotracker dye. Longer treatment times with 1a (25 μM Re for 48 h) resulted in partial migration of the probe into the mitochondria, as shown by co-localization with a Mitotracker dye. These properties make complex 1a an attractive target for further development as an organelle probe for multimodal imaging, including phosphorescence, carbonyl tag for vibrational spectroscopy, and Re tag for X-ray fluorescence microscopy.

Morpholine motifs have been used extensively as targeting moieties for lysosomes, primarily in fluorescence imaging agents. Traditionally these imaging agents are based on organic molecules which have several shortcomings including small Stokes shifts, short emission lifetimes, and susceptibility to photobleaching. To explore alternative lysosome targeting imaging agents we have used a rhenium based phosphorescent platform which has been previously demonstrated to have an improved Stokes shift, a long lifetime emission, and is highly photostable. Rhenium complexes containing morpholine substituted ligands were designed to accumulate in acidic compartments. Two of the three complexes prepared exhibited bright emission in cells, when incubated at low concentrations (20 μM) and were non-toxic at concentrations as high as 100 μM, making them suitable for live cell imaging. We show that the rhenium complexes are amenable to chemical modification and that the morpholine targeted derivatives can be used for live cell confocal fluorescence imaging of endosomes-lysosomes.

We report on studies that demonstrate how the chemical composition of the surface of copper nanoparticles (CuNPs) - in terms of percentage copper(I/II) oxides - can be varied by the presence of N-donor ligands during their formation via laser ablation. Changing the chemical composition thus allows systematic tuning of the surface plasmon resonance (SPR) transition. The trialed ligands include pyridines, tetrazoles, and alkylated tetrazoles. CuNPs formed in the presence of pyridines, and alkylated tetrazoles exhibit a SPR transition only slightly blue shifted with respect to CuNPs formed in the absence of any ligand. On the other hand, the presence of tetrazoles results in CuNPs characterized by a significant blue shift of the order of 50-70 nm. By comparing these data also with the SPR of CuNPs formed in the presence of carboxylic acids and hydrazine, this work demonstrates that the blue shift in the SPR is due to tetrazolate anions providing a reducing environment to the nascent CuNPs, thus preventing the formation of copper(II) oxides. This conclusion is further supported by the fact that both AFM and TEM data indicate only small variations in the size of the nanoparticles, which is not enough to justify a 50-70 nm blue-shift of the SPR transition. High-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) studies further confirm the absence of Cu(II)-containing CuNPs when prepared in the presence of tetrazolate anions.

Twelve Re(I) tricarbonyl diimine (2,2'-bipyridine and 1,10-phenanthroline) complexes with thiotetrazolato ligands have been synthesised and fully characterised. Structural characterisation revealed the capacity of the tetrazolato ligand to bind to the Re(I) centre through either the S atom or the N atom with crystallography revealing most complexes being bound to the N atom. However, an example where the Re(I) centre is linked via the S atom has been identified. In solution, the complexes exist as an equilibrating mixture of linkage isomers, as suggested by comparison of their NMR spectra at room temperature and 373 K, as well as 2D exchange spectroscopy. The complexes are photoluminescent in fluid solution at room temperature, with emission either at 625 or 640 nm from the metal-to-ligand charge transfer excited states of triplet multiplicity, which seems to be exclusively dependent on the nature of the diimine ligand. The oxygen-sensitive excited state lifetime decay ranges between 12.5 and 27.5 ns for the complexes bound to 2,2'-bipyrdine, or between 130.6 and 155.2 ns for those bound to 1.10-phenanthroline. Quantum yields were measured within 0.4 and 1.5%. The complexes were incubated with human lung (A549), brain (T98g), and breast (MDA-MB-231) cancer cells, as well as with normal human skin fibroblasts (HFF-1), revealing low to moderate cytotoxicity, which for some compounds exceeded that of a standard anti-cancer drug, cisplatin. Low cytotoxicity combined with significant cellular uptake and photoluminescence properties provides potential for their use as cellular imaging agents. Furthermore, the complexes were assessed in disc diffusion and broth microdilution assays against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), Escherichia coli ( E. coli ), and Pseudomonas aeruginosa ( P. aeruginosa ) bacterial strains, which revealed negligible antibacterial activity in the dark or after irradiation.

Photophysical and magnetic properties arising from both ground and excited states of lanthanoid ions are relevant for numerous applications. These properties can be substantially affected, both adversely and beneficially, by ligand-to-metal charge-transfer (LMCT) states. However, probing LMCT states remains a significant challenge in f-block chemistry, particularly in the solid state. Intriguingly, the europium compounds [Eu III (18- c -6)(X 4 Cat)(NO 3 )]·MeCN (18- c -6 = 18- crown -6; X = Cl (tetrachlorocatecholate, 1-Eu ) or Br (tetrabromocatecholate, 2-Eu ) are distinctly darkly-colored, in marked contrast to the analogues with other lanthanoid ions in the 1-Ln and 2-Ln series (Ln = La, Ce, Nd, Gd, Tb, and Dy). Herein, we report a multi-technique investigation of these compounds that has allowed elucidation of the LMCT character of the relevant absorption bands using magnetometry, absorption and emission spectroscopies, and solid-state electrochemistry. To support experimental observations, we present a semi-quantitative multireference ab initio model that (i) captures the anomalously low-lying LMCT excited state observed in the visible spectrum of 1-Eu (and its absence in the other 1-Ln analogues); (ii) elucidates the contribution of the LMCT excitation to the crystal field split 7 F J ground-state wave functions; and (iii) identifies the crucial role played by radial dynamical correlation of the Eu III 4f electrons in the description of the LMCT excited state, modeled by the inclusion of 4f → 5f excitations in the optimized wave function. By providing a set of experimental and theoretical tools, this work establishes a framework for the elucidation of LMCT excited states in lanthanoid compounds in the solid state.

Fluorescence microscopy is a key tool in the biological sciences, which finds use as a routine laboratory technique (e.g., epifluorescence microscope) or more advanced confocal, two-photon, and super-resolution applications. Through continued developments in microscopy, and other analytical methods, the importance of lipids as constituents of subcellular organelles, signalling or regulating molecules continues to emerge. The increasing recognition of the importance of lipids to fundamental cell biology (in health and disease) has prompted the development of protocols and techniques to image the distribution of lipids in cells and tissues. A diverse suite of spectroscopic and microscopy tools are continuously being developed and explored to add to the "toolbox" to study lipid biology. A relatively recent breakthrough in this field has been the development and subsequent application of metal-based luminescent complexes for imaging lipids in biological systems. These metal-based compounds appear to offer advantages with respect to their tunability of the photophysical properties, in addition to capabilities centred around selectively targeting specific lipid structures or classes of lipids. The presence of the metal centre also opens the path to alternative imaging modalities that might not be applicable to traditional organic fluorophores. This review examines the current progress and developments in metal-based luminescent complexes to study lipids, in addition to exploring potential new avenues and challenges for the field to take., (© 2022. The Author(s).)

Cholesterol is vital to control membrane integrity and fluidity, but is also a precursor to produce steroid hormones, bile acids, and vitamin D. Consequently, altered cholesterol biology has been linked to many diseases, including metabolic syndromes and cancer. Defining the intracellular pools of cholesterol and its trafficking within cells is essential to understand both normal cell physiology and mechanisms of pathogenesis. We have synthesized a new cholesterol mimic (ReTEGCholestanol), comprising a luminescent rhenium metal complex and a cholestanol targeting unit, linked using a tetraethylene glycol (TEG) spacer. ReTEGCholestanol demonstrated favourable imaging properties and improved water solubility when compared to a cholesterol derivative, and structurally related probes lacking the TEG linker. A non-malignant and three malignant prostate cell lines were used to characterize the uptake and intracellular distribution of ReTEGCholestanol. The ReTEGCholestanol complex was effectively internalized and mainly localized to late endosomes/lysosomes in non-malignant PNT1a cells, while in prostate cancer cells it also accumulated in early endosomes and multivesicular bodies, suggesting disturbed cholesterol biology in the malignant cells. The ReTEGCholestanol is a novel imaging agent for visualizing endosomal uptake and trafficking, which may be used to define cholesterol related biology including membrane integration and altered lipid trafficking/processing., (© The Author(s) 2022. Published by Oxford University Press.)

This paper describes the syntheses of several functionalized dihydropyrene (DHP) molecular switches with different substitution patterns. Regioselective nucleophilic alkylation of a 5-substituted dimethyl isophthalate allowed the development of a workable synthetic protocol for the preparation of 2,7-alkyne-functionalized DHPs. Synthesis of DHPs with surface-anchoring groups in the 2,7- and 4,9-positions is described. The molecular structures of several intermediates and DHPs were elucidated by X-ray single-crystal diffraction. Molecular properties and switching capabilities of both types of DHPs were assessed by light irradiation experiments, spectroelectrochemistry, and cyclic voltammetry. Spectroelectrochemistry, in combination with density functional theory (DFT) calculations, shows reversible electrochemical switching from the DHP forms to the cyclophanediene (CPD) forms. Charge-transport behavior was assessed in single-molecule scanning tunneling microscope (STM) break junctions, combined with density functional theory-based quantum transport calculations. All DHPs with surface-contacting groups form stable molecular junctions. Experiments show that the molecular conductance depends on the substitution pattern of the DHP motif. The conductance was found to decrease with increasing applied bias.

Photoredox catalysts are primarily selected based on ground and excited state properties, but their activity is also intrinsically tied to the nature of their reduced (or oxidized) intermediates. Catalyst reactivity often necessitates an inherent instability, thus these intermediates represent a mechanistic turning point that affords either product formation or side-reactions. In this work, we explore the scope of a previously demonstrated side-reaction that partially saturates one pyridine ring of the ancillary ligand in heteroleptic iridium(III) complexes. Using high-throughput synthesis and screening under photochemical conditions, we identified different chemical pathways, ultimately governed by ligand composition. The ancillary ligand was the key factor that determined photochemical stability. Following photoinitiated electron transfer from a sacrificial tertiary amine, the reduced intermediate of complexes containing 1,10-phenanthroline derivatives exhibited long-term stability. In contrast, complexes containing 2,2'-bipyridines were highly susceptible to hydrogen atom transfer and ancillary ligand modification. Detailed characterization of selected complexes before and after transformation showed differing effects on the ground and excited state reduction potentials dependent on the nature of the cyclometalating ligands and excited states. The implications of catalyst stability and reactivity in chemical synthesis was demonstrated in a model photoredox reaction.

Background. New surface treatments have been proposed to expand the clinical indications of zirconia prostheses. This study aimed to evaluate the effect of silica and fluorine nanofilms on zirconia ceramic on the resin cement bond strength. Methods. Zirconia blocks and discs underwent different surface treatments: untreated zirconia (CON), sandblasted, silica-coated alumina particles (30 µm) (SC), silica nanofilm (SN), and fluorine nanofilm (FN). Nanofilm deposition was performed through plasma enhanced chemical vapor deposition (PECVD). Zirconia surfaces were characterized on disks by morphology (atomic force microscopy, AFM), chemical analysis (x-ray photoelectron spectroscopy, XPS), and contact angle analysis. A silane coupling agent was applied on each treated surface, and a cylinder of resin cement was built up. Half of the specimens in each group were submitted to 6000 thermal cycles (TC). Bond strength was analyzed using the shear test, and the fractographic analysis was performed with stereomicroscopy and SEM/EDS. Statistical analysis was performed through one-way ANOVA and Tukey test in the non-aged and aged specimens. Results. Nanofilms modified the zirconia surface, which became more hydrophilic and chemically reactive. Chemical bonding between Si-O was found in SN, and FN promoted a fluorination process on the ceramic surface, converting zirconia into zirconium oxyfluoride. Specimens of the SN (TC) group failed on pre-testing. FN (TC) bond strength (3.8 MPa) was lower than SC (TC) and CON (TC) after shearing. Adhesive failure predominated in the experimental groups. Silica nanofilm failure occurred after aging. Conclusion. Silica and fluorine nanofilms deposited by PECVD did not promote effective bonding between zirconia and resin cement., (©2022 The Author(s).)

The management of radioactive waste is a worldwide activity based on the guidelines of the International Atomic Energy Agency (IAEA), and all stages of management require scientifically proven methods for possible deployment. The management of radioactive waste is a huge challenge due to the high risk in the collection, gathering, transport, handling, and storage. In this study, a thermal plasma treatment process was evaluated for its efficiency to process solid radioactive waste. Experiments were carried out with the application of stable isotopes of Lead, Iodine, Cobalt, and Cesium. After the thermal plasma treatments, the slag and the residual gas were analyzed to verify the influence of process time and discharge power on the efficiency of the process. The treatment for 25 min and 10 kW was sufficient to reduce the mass by 50% of the slag. When the applied power was increased to 15 kW, an expressive reduction in the treatment time (10 min) was able to promote the same mass reduction. The results indicated that the treatment of radioactive waste by thermal plasma is a promising method to manage and reduce the mass and volume for the final disposal., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Hexagonal boron-nitride nanoparticle coating was deposited on AISI 1045 steel surface. The deposition process included a transformation of B-containing thin organic film into nanocrystalline BN using two methods: thermal annealing at 450-850 °C and reactive ion etching in Ar/N 2 plasma. The film structure, phases, and film morphology of deposited nanoparticles of boron nitride on AISI 1045 steel were characterized by XPS, XRD, and EDS. Post-annealing at 450 °C does not lead to the formation of a BN phase in the layer. A non-stoichiometric BN phase with nitrogen deficiency appears at 650 °C. At 850 °C annealing, the formed BN phase is completely stoichiometric. The effects of deposited and incorporated BN on the friction and hardness properties of AISI 1045 steel were also studied. The post-annealing process improved the hardness from 5.35 to 11.4 GPa, showing a pronounced linear temperature dependence. An original approach was adopted to quantify the energy-dependent growth constants based on the indentation load-discharge curves measured on samples treated under different conditions. Those constants describe the rate of the reactions and the type of interdiffusion process characteristic for each material used. This approach can partially fulfill the role of the Rutherford backscattering spectrometry profile, which is an expensive and time-consuming process, mainly when light elements such as boron and nitrogen are used.