Europe's biodiversity faces increasing pressure from climate change, pollution, and habitat loss, while governments struggle to sustain the monitoring efforts required to respond effectively to these challenges. Addressing this gap calls for a coordinated and inclusive approach that brings together all relevant biodiversity stakeholders to co-design a robust European biodiversity monitoring system. To support this, the Europa Biodiversity Observation Network (EuropaBON) has established one of the most comprehensive biodiversity stakeholder networks in Europe.
View Article and Find Full Text PDFAs more satellite imagery has become openly available, efforts in mapping the Earth's surface have accelerated. Yet the accuracy of these maps is still limited by the lack of data needed to train machine learning algorithms. Citizen science has proven to be a valuable approach for collecting data through applications like Geo-Wiki and Picture Pile, but better approaches for optimizing volunteer time are still required.
View Article and Find Full Text PDF2-Carbamido-1,3-indanedione (CAID) is a fluorescent compound, existing in two tautomeric forms: A and B. Spectroscopic features of CAID suggest that the tautomeric equilibrium is possible both in ground and excited state. To further elucidate this, measurements of UV-Vis absorption and fluorescence spectra were recorded in various solvents.
View Article and Find Full Text PDFThe reactivity of nitrogen oxide, NO, as a ligand in complexes with [Fe2-S2] and [Co2-S2] non-planar rhombic cores is examined by density functional theory (DFT). The cobalt-containing nitrosyl complexes are less stable than the iron complexes because the Co-S bonds in the [Co2-S2] core are weakened upon NO coordination. Various positions of NO were examined, including its binding to sulfur centers.
View Article and Find Full Text PDFThe photophysical properties of two isostructural heteroligand lanthanide complexes of general formula Ln(pdtc)(phen) ( = pyrrolidinedithiocarbamate anion, = 1,10-phenanthroline), Ln = Sm (), Eu ()) were studied in solid state and dichloromethane (DCM) solution. The two lanthanide complexes were investigated by experimental techniques for structural (single-crystal X-ray diffraction analysis of , powder XRD, TG-DTA) and spectroscopic [electron paramagnetic resonance (EPR), infrared (IR), ultraviolet-visible (UV-vis), photoluminescence (PL)] characterization. DFT/TDDFT/ωB97xD and multireference SA-CASSCF/NEVPT2 calculations with perturbative spin-orbit coupling corrections were applied to construct the Jablonski energy diagrams and to discuss the excited state energy transfer mechanism with competing excited state processes and possible sensitized mechanism of metal-centered emission.
View Article and Find Full Text PDFMaterials (Basel)
December 2023
The tetracarbonyl complexes of transition metal chalcogenides MX(CO), where M = Fe, Co, Ni, Cu and X = S, Se, are examined by density functional theory (DFT). The MX core is cyclic with either planar or non-planar geometry. As a sulfide, it is present in natural enzymes and has a selective redox capacity.
View Article and Find Full Text PDFTackling antimicrobial resistance is of increasing concern in a post-pandemic world where overuse of antibiotics has increased the threat of another pandemic caused by antimicrobial-resistant pathogens. Derivatives of coumarins, a naturally occurring bioactive compound, and its metal complexes have proven therapeutic potential as antimicrobial agents and in this study a series of copper(II) and zinc(II) complexes of coumarin oxyacetate ligands were synthesised and characterised by spectroscopic techniques (IR, H, C NMR, UV-Vis) and by X-ray crystallography for two of the zinc complexes. The experimental spectroscopic data were then interpreted on the basis of molecular structure modelling and subsequent spectra simulation using the density functional theory method to identify the coordination mode in solution for the metal ions in the complexes.
View Article and Find Full Text PDFDuring December 2020, a crowdsourcing campaign to understand what has been driving tropical forest loss during the past decade was undertaken. For 2 weeks, 58 participants from several countries reviewed almost 115 K unique locations in the tropics, identifying drivers of forest loss (derived from the Global Forest Watch map) between 2008 and 2019. Previous studies have produced global maps of drivers of forest loss, but the current campaign increased the resolution and the sample size across the tropics to provide a more accurate mapping of crucial factors leading to forest loss.
View Article and Find Full Text PDFSeveral global high-resolution built-up surface products have emerged over the last five years, taking full advantage of open sources of satellite data such as Landsat and Sentinel. However, these data sets require validation that is independent of the producers of these products. To fill this gap, we designed a validation sample set of 50 K locations using a stratified sampling approach independent of any existing global built-up surface products.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
October 2020
Excited state energy level diagrams of coumarin-3-carboxylic acid (HCCA) chromophore, Eu(CCA)Cl(HO) (1), Eu(CCA)Cl(HO) (2) Eu(CCA)(HO) (3), Tb(CCA)Cl(HO) (4) and Tb(CCA)(NO)(HO) (5) in gas phase and polar solution have been calculated by means of DFT/TDDFT/ωB97XD methods. Based on these results, the ability of CCA to sensitize Eu(III) and Tb(III) luminescence has been examined. The competitive excited state processes in the complexes - fluorescence, intersystem crossing (ISC) and phosphorescence, were analyzed depending on the environment, number of the ligands, Ln(III) ion type (Eu and Tb) and counteranion (Cl and NO).
View Article and Find Full Text PDFThe structures of non-ionic [Ag(Tu)(CN)] (1) and ionic [Ag(Dmtu)][Ag(CN)] (2) and [Ag(Imt)][Ag(CN)] (3) silver(I) complexes, where Tu = thiourea, Dmtu = N,N'-dimethylthiourea and Imt = imidazoline-2-thione), were modeled by periodic DFT/PAW-PBE calculations; results were in good agreement with experiments. The bonding ability of the thiourea ligands (Tu, Dmtu and Imt) and the rival Ag-C, Ag-S, Ag-N and Ag-Ag bonds were estimated by natural population analysis and natural bonding orbital calculations. The metal-ligand bond strengths were found to decrease in the following order Ag-C > Ag-S > Ag-N, and the main bonding contribution was covalent, donor-acceptor and electrostatic, respectively.
View Article and Find Full Text PDFBackground: Deep learning convolutional neural networks (CNN) may facilitate melanoma detection, but data comparing a CNN's diagnostic performance to larger groups of dermatologists are lacking.
Methods: Google's Inception v4 CNN architecture was trained and validated using dermoscopic images and corresponding diagnoses. In a comparative cross-sectional reader study a 100-image test-set was used (level-I: dermoscopy only; level-II: dermoscopy plus clinical information and images).
Semiclassical ab initio simulations of the absorption spectra of neutral and anionic p-hydroxybenzylidene-2,3-dimethylimidazolinone (p-HBDI), a model chromophore of green fluorescent protein (GFP) and of a positively charged neutral (N+)-HBDI chromophore model, were performed in gas phase with the resolution-of-identity algebraic diagrammatic construction through second-order (RI-ADC(2)) method. The calculated absorption spectra in gas phase are composed of one band centered at 3.51 eV (HBDI), 2.
View Article and Find Full Text PDFJ Inorg Biochem
October 2016
Novel silver(I) complexes of coumarin oxyacetate ligands and their phenanthroline adducts have been prepared and characterised by microanalytical data and spectroscopic techniques (IR, H, C NMR, UV-Vis). The crystal structure of one Ag(I) complex was determined by X-ray diffraction analysis. The experimental spectroscopic data have been interpreted on the basis of molecular structure modeling and subsequent spectra simulation with density functional theory method.
View Article and Find Full Text PDFJ Inorg Biochem
December 2015
The structural processes leading to dual fluorescence of 4-(dimethylamino)benzonitrile in the gas phase and in acetonitrile solvent were investigated using a combination of multireference configuration interaction (MRCI) and the second-order algebraic diagrammatic construction (ADC(2)) methods. Solvent effects were included on the basis of the conductor-like screening model. The MRCI method was used for computing the nonadiabatic interaction between the two lowest excited ππ* states (S2(La, CT) and S1(Lb, LE)) and the corresponding minimum on the crossing seam (MXS) whereas the ADC(2) calculations were dedicated to assessing the role of the πσ* state.
View Article and Find Full Text PDFEnviron Sci Technol
October 2014
Interaction between the goethite surface and 4-chloro-2-methylphenoxyacetic acid (MCPA) herbicide was studied using density functional theory (DFT) calculations combined with molecular dynamics (MD). The important step made here lies in the use of a periodic DFT method enabling the study of a mineral surface of different protonation states, in strong contrast with previous molecular modeling studies limited to single protonation state corresponding to the point of zero charge. Different surface OH groups and MCPA proton states were used to mimic the strong effects of pH on the outer- and inner-sphere surface complexes that are theoretically possible, together with their binding energies, and their bond lengths.
View Article and Find Full Text PDFAm J Dermatopathol
August 2014
Seborrheic keratosis (SK) represents a frequent epidermal skin tumor. Although lacking a malignant potential, these tumors reveal multiple oncogenic mutations. A previous study identified activating mutations in 89% of SK, particularly in FGFR3 and PIK3CA genes.
View Article and Find Full Text PDFTheoretical and spectroscopic studies of a series of monomeric and dimeric complexes formed through the modification of a zirconium butoxide precursor with acetylacetone and subsequent hydrolysis and/or condensation have been performed by applying DFT/B3LYP/6-31++G(d) and highly accurate RI-ADC(2) methods as well as IR and UV-Vis transmittance and diffuse reflectance spectroscopies. Based on DFT model calculations and simulated and experimental UV-Vis and IR spectra of all the studied structures, the most probable building units of the Zr(IV)-AcAc gel were predicted: the dimeric double hydroxo-bridged complex Zr(2)(AcAc)(2)(OH)(4)(OH)(2br) 9 and the monooxo-bridged complex Zr(2)(AcAc)(2)(OH)(4)O(br)·2H(2)O 12. In both structures, the two AcAc ligands are coordinated to one Zr atom.
View Article and Find Full Text PDFSolvatochromic and ionochromic effects of the iron(II)bis(1,10-phenanthroline)dicyano (Fe(phen)(2)(CN)(2)) complex were investigated by means of combined DFT/TDDFT calculations using the PBE and B3LYP functionals. Extended solvation models of Fe(phen)(2)(CN)(2) in acetonitrile and aqueous solution, as well as including interaction with Mg(2+), were constructed. The calculated vertical excitation energies reproduce well the observed solvatochromism in acetonitrile and aqueous solutions, the ionochromism in acetonitrile in the presence of Mg(2+), and the absence of ionochromic effect in aqueous solution.
View Article and Find Full Text PDFThe adsorption of NO on Co(II)-exchanged chabazite (CHA), mordenite (MOR), and ferrierite (FER) has been investigated by periodic density functional theory calculations. The most stable configurations of Co(II) in alpha and beta sites of the zeolites with two framework Al/Si substitutions at short distances and Al-(Si)(n>1)-Al ordering are used for calculating the adsorption energy of NO molecules on Co(II) cations and at Al framework sites. The less stable configurations of alpha-Co(II)-MOR/FER show larger adsorption energies for one and two NO molecules.
View Article and Find Full Text PDFMolecular modeling of the La(III) complex of 3,3'-(benzylidene)bis(4-hydroxycoumarin) (PhDC) was performed using density functional theory (DFT) methods at B3LYP/6-31G(d) and BP86/TZP levels. Both Stuttgart-Dresden effective core potential and ZORA approximation were applied to the La(III) center. The electron density distribution and the nucleophilic centers of the deprotonated ligand PhDC(2-) in a solvent environment were estimated on the basis of Hirshfeld atomic charges, electrostatic potential values at the nuclei, and Nalewajski-Mrozek bond orders.
View Article and Find Full Text PDFThe interaction of lanthanide(III) cations (Ln(III) = Sm(III), Eu(III), and Tb(III)) with the deprotonated form of the coumarin-3-carboxylic acid (cca-) has been investigated by density functional theory (DFT/B3LYP) and confirmed by reference MP2 and CCSD(T) computations. Solvent effects on the geometries and stabilities of the Ln(III) complexes were computed using a combination of water clusters and a continuum solvation model. The following two series of systems were considered: (i) Ln(cca)2+, Ln(cca)2+, Ln(cca)3 and (ii) Ln(cca)(H2O)2Cl2, Ln(cca)2(H2O)2Cl, Ln(cca)3.
View Article and Find Full Text PDFTDDFT, RI-CC2, and CIS calculations have been performed for the nondissociative excited-state proton transfer (ESPT) in the S1 state of 7-hydroxy-4-methylcoumarin (7H4MC) along a H-bonded water wire of three water molecules bridging the proton donor (OH) and the proton acceptor (C[double bond]O) groups (7H4MC.(H2O)3). The observed structural reorganization in the water-wire cluster is interpreted as a proton-transfer (PT) reaction along the H2O solvent wire.
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