In the framework of bio-circular economy, miscanthus biomass was valorized through a single-stage, low severity hydrothermal carbonization process. The produced hydrochars were characterized using elemental and spectroscopic methodologies. It was determined that as the temperature increased so did the C content (47.
View Article and Find Full Text PDFA self-assembled monolayer (SAM) on gold was prepared from a diaminoterephthalate (DAT) derivative as functional molecule and 1-decanthiol as a backfiller. The DAT derivative is -protected by a -butyloxycarbonyl (Boc) group and is anchored to the gold surface via a liponic acid as a stable anchor group. The terminal DAT moiety exhibits interesting effector properties such as fluorescence and electrochemical activity.
View Article and Find Full Text PDFMultinuclear transition metal complexes bridged by ligands with extended π-electronic systems show a variety of complex electronic transitions and electron transfer reactions. While a systematic understanding of the photochemistry and electrochemistry has been attained for binuclear complexes, much less is known about trinuclear complexes such as hexaphenyl-5,6,11,12,17,18-hexaazatrinaphthylene-tristitanocene [(Cp Ti) HATN(Ph) ]. The voltammogram of [(Cp Ti) HATN(Ph) ] shows six oxidation and three reduction waves.
View Article and Find Full Text PDFHerein we demonstrate a synthetic protocol for the regioselective thiocyanation of corroles. To the best of our knowledge, thiocyanato appended corrole has never been reported earlier. The resulting thiocyanato appended corrole turned out to be a good corrole based precursor for the facile synthesis of thiol protected gold nanoparticles (Au NPs).
View Article and Find Full Text PDFThis work investigates the fabrication of magnetic biochar (pncm) and FeO-loaded oxidized biochar (pncom) obtained from pine needles for uranium removal. Adsorbent properties were characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) techniques. Using batch-type experiments the effect of the uranium concentration, solution pH, contact time, temperature and ionic strength on the uranium adsorption was investigated.
View Article and Find Full Text PDFThe adsorption of Cu(II) ions by biochar fibres prior and after modification with 2-thiouracil on real and artificial samples has been studied by batch-type adsorption experiments, FTIR and XPS spectroscopy and competition reactions using U(VI) ions as competitor cations. The experimental data of the artificial samples clearly show that the modified material presents extraordinary higher affinity for Cu(II) ions even in the acidic pH range, the spectroscopic data indicate the formation of inner-sphere complexes and the competition reactions significantly higher selectivity of the 2-thiouracil modified biochar fibres for Cu(II). The 2-thiouracil-modified biochar fibres have been successfully applied to acid mine drainage (AMD) samples regarding the selective separation of Cu(II) ions from "real" samples.
View Article and Find Full Text PDFWe investigated the formation of Pt nanocubes (NCs) and their electrocatalytic oxygen reduction reaction (ORR) properties and structural stability using two different capping agents, namely, polyvinylpyrrolidone (PVP) and oleylamine (OAm). The mono-dispersity of the obtained Pt NCs and their interactions with PVP and OAm were analyzed by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), Fourier-transformed infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The TEM data show a high mono-dispersity (82 %) and a large mean particle size (9-10 nm) for the Pt NCs obtained by the oleylamine-assisted method compared to those prepared via the PVP-assisted procedure (68 %, 6-7 nm).
View Article and Find Full Text PDFA total of 35 intermetallic aluminum compounds have been synthesized from the elements via arc melting and characterized by powder X-ray diffraction. A total of 15 of them have been previously reported; however, detailed property investigations were missing. Compounds of the RETMAl (rare earth metal RE = Sc, Y, La-Nd, Sm, Gd-Tm, Lu) series with transition metal TM = Ni, Pd, and Pt crystallize isostructurally in the orthorhombic MgCuAl type structure ( Cmcm, oC16, fc).
View Article and Find Full Text PDFA new preparation route is developed for the synthesis of needle-like crystals of [Au(S CNH ) ]SCN, which avoids disproportionation of the Au salt used as a starting material. In the crystal structure, the two crystallographically independent Au centers are in a square-planar environment of two S CNH ligands. The Hirshfeld surface analysis reveals the presence of noncovalent intermolecular S⋅⋅⋅S interactions, which are essential for the spatial arrangement of the molecules.
View Article and Find Full Text PDFIn this paper the concept of a compact high-resolution spectrometer based on the combination of dispersive and interferometric elements is presented. Dispersive elements are used to spectrally resolve the light in one direction with coarse resolution (Δλ < 0.5 nm), while perpendicular to that direction an etalon provides high spectral resolution (Δλ < 50 pm).
View Article and Find Full Text PDFScanning electrochemical microscopy with soft microelectrode array probes has recently been used to enable reactivity imaging of extended areas and to compensate sample corrugation perpendicular to the scanning direction. Here, the use of a new type of microelectrode arrays is described in which each individual microelectrode can independently compensate corrugations of the sample surface. It consists of conventional Pt microelectrodes enclosed in an insulating glass sheath.
View Article and Find Full Text PDFIn humans, the L-cysteine desulfurase NFS1 plays a crucial role in the mitochondrial iron-sulfur cluster biosynthesis and in the thiomodification of mitochondrial and cytosolic tRNAs. We have previously demonstrated that purified NFS1 is able to transfer sulfur to the C-terminal domain of MOCS3, a cytosolic protein involved in molybdenum cofactor biosynthesis and tRNA thiolation. However, no direct evidence existed so far for the interaction of NFS1 and MOCS3 in the cytosol of human cells.
View Article and Find Full Text PDFA series of new monocationic iridium(III) complexes [Ir(C^N)(2)(N^N)]PF(6) with "large-surface"α,α'-diimin ligands N^N (dap = 1,12-diazaperylene, dmedap = 2,11-dimethyl-1,12-diazaperylene, dipdap = 2,11-diisopropyl-1,12-diazaperylene) and different cyclometalating ligands C^N (piq = 1-phenylisoquinoline, bzq = benzo[h]quinoline, ppz = 1-phenylpyrazole, thpy = 2-(2-thienyl)pyridine, ppy = 2-phenylpyridine, meppy = 2-(4-methylphenyl)pyridine, dfppy = 2-(2,4-difluorophenyl)pyridine) were synthesized. The solid structures of the complexes [Ir(piq)(2)(dap)]PF(6), [Ir(bzq)(2)(dap)]PF(6), [Ir(ppy)(2)(dipdap)]PF(6), [Ir(piq)(2)(dmedap)]PF(6), [Ir(ppy)(2)(dap)]PF(6) and [Ir(ppz)(2)(dap)]PF(6) are reported. In [Ir(piq)(2)(dap)]PF(6), the dap ligand and one of the piq ligands of each cationic complex are involved in π-π stacking interactions forming supramolecular channels running along the crystallographic c axis.
View Article and Find Full Text PDFJ Colloid Interface Sci
July 2012
The well-known cationic surfactant hexadecyltrimethylammonium bromide (CTAB) was used as a model carrier to study drug-carrier interactions with fluorescence probes (5-hexadecanoylaminofluorescein (HAF) and 2,10-bis-(3-aminopropyloxy)dibenzo[a,j]perylene-8,16-dione (NIR 628) by applying ensemble as well as single molecule fluorescence techniques. The impact of the probes on the micelle parameters (critical micelle concentration, average aggregation number, hydrodynamic radius) was investigated under physiological conditions. In the presence of additional electrolytes, such as buffer, the critical micelle concentration decreased by a factor of about 10.
View Article and Find Full Text PDFWe studied two pathways that involve the transfer of persulfide sulfur in humans, molybdenum cofactor biosynthesis and tRNA thiolation. Investigations using human cells showed that the two-domain protein MOCS3 is shared between both pathways. MOCS3 has an N-terminal adenylation domain and a C-terminal rhodanese-like domain.
View Article and Find Full Text PDFThe intrinsic non-radiative decay (internal conversion) from the triplet excited state in phosphorescent dyes can be described by a multi-phonon emission process. Since non-radiative decay of triplet excitons can be a significant process in organic light-emitting diodes, a detailed understanding of this decay mechanism is important if the overall device efficiency is to be controlled. We compare a deuterated Pt(II)-containing phenylene ethynylene with its non-deuterated counterpart in order to investigate which phonon modes control to the non-radiative decay path.
View Article and Find Full Text PDFActive transport of NaCl across thick ascending limb (TAL) epithelium is accomplished by Na(+),K(+),2Cl(-) cotransporter (NKCC2). The activity of NKCC2 is determined by vasopressin (AVP) or intracellular chloride concentration and includes its amino-terminal phosphorylation. Co-expressed Tamm-Horsfall protein (THP) has been proposed to interact with NKCC2.
View Article and Find Full Text PDFThe intracellular ion homeostasis in cockroach salivary acinar cells during salivation is not satisfactorily understood. This is mainly due to technical problems regarding strong tissue autofluorescence and ineffective ion concentration quantification. For minimizing these problems, we describe the successful application of two-photon (2P) microscopy partly in combination with fluorescence lifetime imaging microscopy (FLIM) to record intracellular Na(+) and Cl(-) concentrations ([Na(+)](i), [Cl(-)](i)) in cockroach salivary acinar cells.
View Article and Find Full Text PDFIn response to stress small organic compounds termed osmolytes are ubiquitously accumulated in all cell types to regulate the intracellular solvent quality and to counteract the deleterious effect on the stability and function of cellular proteins. Given the evidence that destabilization of the native state of a protein either by mutation or by environmental changes triggers the aggregation in the neurodegenerative pathologies, the modulation of the intracellular solute composition with osmolytes is an attractive strategy to stabilize an aggregating protein. Here we report the effect of three natural osmolytes on the in vivo and in vitro aggregation landscape of huntingtin exon 1 implicated in the Huntington's disease.
View Article and Find Full Text PDFThe [6.6](9,10)anthracenophane 1 (Scheme 1) is a selective fluoroionophore for the detection of PdCl(2) with a large fluorescence enhancement factor (I/I(0) > 250).
View Article and Find Full Text PDFFluoroionophores of fluorophore-spacer-receptor format were prepared for detection of PdCl(2) by fluorescence enhancement. The fluorescent probes 1-13 consist of a fluorophore group, an alkyl spacer and a dithiomaleonitrile PdCl(2) receptor. First, varying the length of the alkylene spacer (compounds 1-3) revealed a dominant through-space pathway for oxidative photoinduced electron transfer (PET) in CH(2)-bridged dithiomaleonitrile fluoroionophores.
View Article and Find Full Text PDFA series of new ligands suitable for the formation of luminescent lanthanide complexes in water is described. The chelates are designed for analyte labeling and play the role of fluorescent donor in homogeneous time-resolved fluorescence assays using LEDs as a light source for excitation at 370 nm. Ligands are constructed from a coumarin nucleus, for lanthanide sensitization, and different aminomethylenecarboxy moieties are introduced in positions 7 and 5, 6, or 8 of the sensitizer.
View Article and Find Full Text PDFJ Colloid Interface Sci
October 2009
In our study we determined the diffusion coefficient of Tween 20 micelles at different surfactant concentrations (10(-4)-10(-2) M) via fluorescence correlation spectroscopy. The hydrophobic fluorescent dye 9,10-bis(phenylethynyl)anthracene, located in the micellar phase, was used as marker for the diffusion of Tween 20 micelles. The hydrodynamic radius of the micelles, R(h), was estimated from the diffusion coefficient and compared with literature values from previous studies.
View Article and Find Full Text PDFAlthough chloride plays an important role in many cellular processes, there is a lack of data about intracellular chloride concentrations [Cl(-)](i), particularly due to technical problems. To overcome that, in this study fluorescence lifetime imaging microscopy in the time-domain by using time-correlated single-photon counting was combined with two-photon excitation (2P-FLIM). This 2P-FLIM setup has been successfully used with the Cl(-)-sensitive fluorescent dye N-(ethoxycarbonylmethyl)-6-methoxy-quinolinium bromide (MQAE) in order to measure [Cl(-)](i) in cockroach salivary glands, a well-established model system for studying epithelial ion transport processes.
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