Click-ready iridium(iii) complexes as versatile bioimaging probes for bioorthogonal metabolic labeling.

Herein, we report the synthesis, photophysical characterization and validation of iridium(iii)-polypyridine complexes functionalized for click chemistry and bioorthogonal chemistry, as well as their versatile applications as probes in bioimaging studies exploiting metabolic labeling. The designed dyes are conjugated to chemical reporters in a specific manner within cells by CuAAC ligation and display attractive photophysical properties in the UV-visible range. They are indeed highly photostable and emit in the far-red to near-IR region with long lifetimes and large Stokes shifts.

Archaerhodopsin 3 is an ideal template for the engineering of highly fluorescent optogenetic reporters.

Archaerhodopsin-3 (AR-3) variants stand out among other rhodopsins in that they display a weak, but voltage-sensitive, near-infrared fluorescence emission. This has led to their application in optogenetics both in cell cultures and small animals. However, in the context of improving the fluorescence characteristics of the next generation of AR-3 reporters, an understanding of their ultrafast light-response in light-adapted conditions, is mandatory.

Selective CO Reduction Electrocatalysis Using AgCu Nanoalloys Prepared by a "Host-Guest" Method.

Multimetallic nanoalloy catalysts have attracted considerable interest for enhancing the efficiency and selectivity of many electrochemically driven chemical processes. However, the preparation of homogeneous bimetallic alloy nanoparticles remains a challenge. Here, we present a room-temperature and scalable, host-guest approach for synthesis of dilute Cu in Ag alloy nanoparticles.

Determination of concentration of basic sites on oxides by IR spectroscopy.

As it is commonly known, CO reacts simultaneously with basic O and basic OH sites on oxides forming carbonates and bicarbonates, which can be followed by infrared spectroscopy (IR). However, here, we succeeded to elaborate experimental conditions under which CO reacted solely with O forming CO for ZrO and CeO, and calculated the extinction coefficients of diagnostic bands of carbonate and bicarbonate species. For the first time, the developed IR method enabled the concentrations of O and basic OH for ZrO, CeO, AlO and CuO to be measured separately.

Blind instrument response function identification from fluorescence decays.

Time-resolved fluorescence spectroscopy plays a crucial role when studying dynamic properties of complex photochemical systems. Nevertheless, the analysis of measured time decays and the extraction of exponential lifetimes often requires either the experimental assessment or the modeling of the instrument response function (IRF). However, the intrinsic nature of the IRF in the measurement process, which may vary across measurements due to chemical and instrumental factors, jeopardizes the results obtained by reconvolution approaches.

The fundamental motor skill proficiency among Polish primary school-aged children: A nationally representative surveillance study.

Objectives: With the premise that physical education classes should promote physical activity by teaching and learning fundamental motor skills, this study aimed to evaluate the fundamental motor skill proficiency of primary school students and determine the level of achievement of established learning outcomes for fundamental motor skills, as specified in the Polish National Physical Education Curriculum.

Design And Methods: A cross-sectional design was used for this study. The sample consisted of 2605 children and adolescents enrolled in grades 1-3 (ages 7-9, n = 1165), 4-6 (ages 10-12, n = 837), and 7-8 (ages 13-14, n = 603), including 1353 boys and 1252 girls.

The fus test: a promising tool for evaluating fundamental motor skills in children and adolescents.

Fundamental motor skills (FMS) are essential for enjoyable, confident and skillful participation in physical activity across the lifespan. Due to the alarming low level of FMS proficiency in children and adolescents worldwide, the development of motor competency is an urgent issue for physical education. The promotion and implementation of a systematic process of teaching and learning FMS should be a physical education priority.

Ethoxy Groups on ZrO, CuO, CuO/ZrO AlO, GaO, SiO and NiO: Formation and Reactivity.

The reaction of ethanol with surface OH groups on ZrO, CuO/ZrO, CuO, AlO, GaO, NiO, and SiO was studied by IR spectroscopy. The basicity of oxides was followed by CO adsorption, and their ability to oxidize was investigated by H-TPR. It has been found that ethanol reacts with surface OH groups forming ethoxy groups and water.

Dynamics of the energy transfer involved in a diarylethene-perylenebisimide dyad: comparison between the molecule and the nanoparticle level.

Photochromic materials are widely used to achieve fluorescence photoswitching. Understanding the energy transfer processes occurring in these systems would be an advantage for their use and better optimization of their properties. In this scope, we studied a diarylethene-perylenebisimide (DAE-PBI) dyad that presents a bright red emission and a large ON-OFF contrast, both in solution and in an aqueous suspension of nanoparticles (NPs).

Cloning and structural basis of fluorescent protein color variants from identical species of sea anemone, Diadumene lineata.

Diadumene lineata is a colorful sea anemone with orange stripe tissue of the body column and plain tentacles with red lines. We subjected Diadumene lineata to expression cloning and obtained genes encoding orange (OFP: DiLiFP561) and red fluorescent proteins (RFPs: DiLiFP570 and DiLiFP571). These proteins formed obligatory tetramers.

IR Studies of Ethoxy Groups on CeO.

The reaction of ethanol with a surface of CeO was studied using IR spectroscopy. In some experiments, CeO was pretreated in a vacuum at 820 K which caused a partial reduction. In other experiments, CeO was reduced with hydrogen at 770 K.

Is orange carotenoid protein photoactivation a single-photon process?

In all published photoactivation mechanisms of orange carotenoid protein (OCP), absorption of a single photon by the orange dark state starts a cascade of red-shifted OCP ground-state intermediates that subsequently decay within hundreds of milliseconds, resulting in the formation of the final red form OCP, which is the biologically active form that plays a key role in cyanobacteria photoprotection. A major challenge in deducing the photoactivation mechanism is to create a uniform description explaining both single-pulse excitation experiments, involving single-photon absorption, and continuous light irradiation experiments, where the red-shifted OCP intermediate species may undergo re-excitation. We thus investigated photoactivation of OCP using stationary irradiation light with a biologically relevant photon flux density coupled with nanosecond laser pulse excitation.

Rational Control of Off-State Heterogeneity in a Photoswitchable Fluorescent Protein Provides Switching Contrast Enhancement.

Reversibly photoswitchable fluorescent proteins are essential markers for advanced biological imaging, and optimization of their photophysical properties underlies improved performance and novel applications. Here we establish a link between photoswitching contrast, one of the key parameters that dictate the achievable resolution in nanoscopy applications, and chromophore conformation in the non-fluorescent state of rsEGFP2, a widely employed label in REversible Saturable OpticaL Fluorescence Transitions (RESOLFT) microscopy. Upon illumination, the cis chromophore of rsEGFP2 isomerizes to two distinct off-state conformations, trans1 and trans2, located on either side of the V151 side chain.

Ethoxy Groups on ZrO, CuO, and CuO/ZrO Studied by IR Spectroscopy.

The formation, properties, decomposition and reactions of ethoxy groups on ZrO, CuO, and CuO/ZrO were followed by IR spectroscopy. The reaction of ethanol with terminal Zr-OH groups leads to the formation of monodendate ethoxy groups (type I), whereas the reaction of ethanol with tribridged Zr-OH grups results in the formation of bidendate ethoxyls (type II). In both cases, water is produced.

Oligomerization processes limit photoactivation and recovery of the orange carotenoid protein.

The orange carotenoid protein (OCP) is a photoactive protein involved in cyanobacterial photoprotection by quenching of the excess of light-harvested energy. The photoactivation mechanism remains elusive, in part due to absence of data pertaining to the timescales over which protein structural changes take place. It also remains unclear whether or not oligomerization of the dark-adapted and light-adapted OCP could play a role in the regulation of its energy-quenching activity.

Structure-function-dynamics relationships in the peculiar Planktothrix PCC7805 OCP1: Impact of his-tagging and carotenoid type.

The orange carotenoid protein (OCP) is a photoactive protein involved in cyanobacterial photoprotection. Here, we report on the functional, spectral and structural characteristics of the peculiar Planktothrix PCC7805 OCP (Plankto-OCP). We show that this OCP variant is characterized by higher photoactivation and recovery rates, and a stronger energy-quenching activity, compared to other OCP studied thus far.

Unifying Perspective of the Ultrafast Photodynamics of Orange Carotenoid Proteins from : Peril of High-Power Excitation, Existence of Different S* States, and Influence of Tagging.

A substantial number of Orange Carotenoid Protein (OCP) studies have aimed to describe the evolution of singlet excited states leading to the formation of a photoactivated form, OCP. The most recent one suggests that 3 ps-lived excited states are formed after the sub-100 fs decay of the initial S state. The S* state, which has the longest reported lifetime of a few to tens of picoseconds, is considered to be the precursor of the first red photoproduct P.

Modulation of ODH Propane Selectivity by Zeolite Support Desilication: Vanadium Species Anchored to Al-Rich Shell as Crucial Active Sites.

The commercially available zeolite HY and its desilicated analogue were subjected to a classical wet impregnation procedure with NHVO to produce catalysts differentiated in acidic and redox properties. Various spectroscopic techniques (in situ probe molecules adsorption and time-resolved propane transformation FT-IR studies, XAS, V MAS NMR, and 2D COS UV-vis) were employed to study speciation, local coordination, and reducibility of the vanadium species introduced into the hierarchical faujasite zeolite. The acid-based redox properties of V centres were linked to catalytic activity in the oxidative dehydrogenation of propane.

Selective population of triplet excited states in heavy-atom-free BODIPY-C based molecular assemblies.

Photophysical studies on a BODIPY-fullerene-distyryl BODIPY triad (BDP-C-DSBDP) and its reference dyads (BODIPY-fullerene; BDP-C and distyryl BODIPY-fullerene; DSBDP-C) are presented herein. In the triad, the association of the two chromophore units linked by a fullerene moiety leads to strong near UV-Visible light absorption from 300 to 700 nm. The triplet-excited state was observed upon visible excitation in all these assemblies, and shown to be localized on the C or BODIPY moieties.

Structural Information about the -to- Isomerization Mechanism of the Photoswitchable Fluorescent Protein rsEGFP2 Revealed by Multiscale Infrared Transient Absorption.

RsEGFP2 is a reversibly photoswitchable fluorescent protein used in super-resolved optical microscopies, which can be toggled between a fluorescent On state and a nonfluorescent Off state. Previous time-resolved ultraviolet-visible spectroscopic studies have shown that the Off-to-On photoactivation extends over the femto- to millisecond time scale and involves two picosecond lifetime excited states and four ground state intermediates, reflecting a to excited state isomerization, a millisecond deprotonation, and protein structural reorganizations. Femto- to millisecond time-resolved multiple-probe infrared spectroscopy (TRMPS-IR) can reveal structural aspects of intermediate species.

Multivariate Curve Resolution Slicing of Multiexponential Time-Resolved Spectroscopy Fluorescence Data.

Time-resolved fluorescence spectroscopy (TRFS), i.e., measurement of fluorescence decay curves for different excitation and/or emission wavelengths, provides specific and sensitive local information on molecules and on their environment.

The Properties of Cu Ions in Zeolites CuY Studied by IR Spectroscopy.

The properties of both Cu and Cu ions in zeolite CuY were followed with NO and CO as probe molecules. Cu was found to be located in S, S, and S sites, whereas Cu was found in S and S sites. The fine analysis of the spectra of Cu-NO and Cu-CO adducts suggests that both in S and in S sites two kinds of Cu cations exist.

Mechanism and dynamics of fatty acid photodecarboxylase.

Fatty acid photodecarboxylase (FAP) is a photoenzyme with potential green chemistry applications. By combining static, time-resolved, and cryotrapping spectroscopy and crystallography as well as computation, we characterized FAP reaction intermediates on time scales from subpicoseconds to milliseconds. High-resolution crystal structures from synchrotron and free electron laser x-ray sources highlighted an unusual bent shape of the oxidized flavin chromophore.

Photoactive Organic/Inorganic Hybrid Materials with Nanosegregated Donor-Acceptor Arrays.

The synthesis of the first mesogenic donor-acceptor polyoxometalate (POM)-based hybrid is herein described. The structural and electronic properties of the hybrid compound were evaluated through combination of small- and wide-angle X-ray scattering, optical microscopy, electrochemistry and photoluminescence. In the solid state, the compound behaves as a birefringent solid, displaying a lamellar organization in which double-layers of POMs and bis(thiophene)thienothiophene organic donors alternate regularly.

Control of the Photo-Isomerization Mechanism in 3-Naphthopyrans to Prevent Formation of Unwanted Long-Lived Photoproducts.

In the photochromic reactions of 3-naphthopyrans, two colored isomers TC (transoid-) and TT (transoid-) are formed. In terms of optimized photo-switchable materials, synthetic efforts are nowadays evolving toward developing 3-naphthopyran derivatives that would not be able to photoproduce the long-living transoid-, TT, photoproduct. The substitution with a methoxy group at position 10 results in significant reduction of the TT isomer formation yield.