Articoli di riviste sul tema "Hydrates transfer Cell"

The solid-state structures of the Na+, Li+, and NH4 + salts of the 4,5-dihydroxybenzene-1,3-disulfonate (tiron) dianion are reported, namely disodium 4,5-dihydroxybenzene-1,3-disulfonate, 2Na+·C6H4O8S2 2−, μ-4,5-dihydroxybenzene-1,3-disulfonato-bis[aqualithium(I)] hemihydrate, [Li2(C6H4O8S2)(H2O)2]·0.5H2O, and diammonium 4,5-dihydroxybenzene-1,3-disulfonate monohydrate, 2NH4 +·C6H4O8S2 2−·H2O. Intermolecular interactions vary with the size of the cation, and the asymmetric unit cell, and the macromolecular features are also affected. The sodium in Na2(tiron) is coordinated in a distorted octahedral environment through the sulfonate oxygen and hydroxyl oxygen donors on tiron, as well as an interstitial water molecule. Lithium, with its smaller ionic radius, is coordinated in a distorted tetrahedral environment by sulfonic and phenolic O atoms, as well as water in Li2(tiron). The surrounding tiron anions coordinating to sodium or lithium in Na2(tiron) and Li2(tiron), respectively, result in a three-dimensional network held together by the coordinate bonds to the alkali metal cations. The formation of such a three-dimensional network for tiron salts is relatively rare and has not been observed with monovalent cations. Finally, (NH4)2(tiron) exhibits extensive hydrogen-bonding arrays between NH4 + and the surrounding tiron anions and interstitial water molecules. This series of structures may be valuable for understanding charge transfer in a putative solid-state fuel cell utilizing tiron.

AbstractThe crystal structures of the 1:1 proton-transfer compounds of (4-aminophenyl)arsonic acid (p-arsanilic acid) with the strong organic acids, 2,4,6-trinitrophenol (picric acid), 3,5-dinitrosalicylic acid, (3-carboxy-4-hydroxy)benzenesulfonic acid (5-sulfosalicylic acid) and toluene-4-sulfonic acid have been determined at 200 K and their hydrogen–bonding patterns examined. The compounds are, respectively, anhydrous 4-arsonoanilinium 2,4,6-trinitrophenolate (1), the hydrate 4-arsonoanilinium 2-carboxy-4,6-dinitrophenolate monohydrate (2), the hydrate 4-arsonoanilinium (3-carboxy-4-hydroxy)benzenesulfonate monohydrate (3) and the partial solvate 4-arsonoanilinium toluene-4-sulfonate 0.8 hydrate (4). The asymmetric unit of2, a phenolate, comprises two independent but conformationally similar cation-anion pairs and two water molecules of solvation, and in all compounds, extensive inter-species hydrogen–bonding interactions involving arsono O–H···O and anilinium N–H···O hydrogen–bonds generate three-dimensional supramolecular structures. In the cases of1and2, the acceptors include phenolate and nitro O-atom acceptors, with3and4, additionally, sulfonate O-atom acceptors, and with the hydrates2–4, the water molecules of solvation. A feature of the hydrogen–bonding in3is the presence of primary chains extending along (010) through centrosymmetric cyclicR22(8) motifs together with conjoined cyclicR34(12) motifs, which include the water molecule of solvation. The primary hydrogen–bonding in the substructure of4involves homomolecular cation–cation arsono O–H···O interactions forming columns down the crystallographic four-fold axis of the unit cell.

A molecular dynamic model based on Lennard-Jones Potential, the interaction force between two particles, molecular diffusion, and radial distribution function (RDF) is presented. The diffusion of the hydrated ion, triggered by both Grotthuss and vehicle mechanisms, is used to study the proton transfer in Nafion 117. The hydrated ion transfer mechanisms and the effects of the temperature, the water content in the membrane, and the electric field on the diffusion of the hydrated ion are analyzed. The molecular dynamic simulation results are in good agreement with those reported in the literature. The modeling results show that when the water content in Nafion 117 is low, H3O+is the main transfer ion among the different hydrated ions. However, at higher water content, the hydrated ion in the form of H+(H2O)2is the main transfer ion. It is also found that the negatively charged sulfonic acid group as the fortified point facilitates the proton transfer in Nafion 117 better than the free water molecule. The diffusion of the hydrated ion can be improved by increasing the cell temperature, the water content in Nafion, and the electric field intensity.

Summary Hydrate formation and the relevant mass and heat transfers were numerically analyzed in a microscopic computational domain in which spherical glass beads, water, and methane gas were distributed separately. A hydrate-formation experiment was also carried out by use of a cylindrical pressure cell. The temperature in the cell was controlled by Peltier devices, which were attached to the outer walls of the cell to imitate the adiabatic boundary condition present in the numerical simulation. By history matching between the experiment and calculation, we first obtained a hydrate-formation rate constant per unit volume of water, assuming homogeneous nucleation. Then, after converting the rate by use of a surface-area model of water in porous media, we noted that the area-based rate constant and activation energy of the hydrate formation were estimated to be 6.33 × 1034 mol·m–2 Pa–1 s–1 and 238 × 103 J/mol, respectively, for temperatures of 1.5 to 3.4°C.

Polymeric models of the core prepared with a Raise3D Pro2 3D printer were employed for methane hydrate formation. Polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), carbon fiber reinforced (UltraX), thermoplastic polyurethane (PolyFlex), and polycarbonate (ePC) were used for printing. Each plastic core was rescanned using X-ray tomography to identify the effective porosity volumes. It was revealed that the polymer type matters in enhancing methane hydrate formation. All polymer cores except PolyFlex promoted the hydrate growth (up to complete water-to-hydrate conversion with PLA core). At the same time, changing the filling degree of the porous volume with water from partial to complete decreased the efficiency of hydrate growth by two times. Nevertheless, the polymer type variation allowed three main features: (1) managing the hydrate growth direction via water or gas preferential transfer through the effective porosity; (2) the blowing of hydrate crystals into the volume of water; and (3) the growth of hydrate arrays from the steel walls of the cell towards the polymer core due to defects in the hydrate crust, providing an additional contact between water and gas. These features are probably controlled by the hydrophobicity of the pore surface. The proper filament selection allows the hydrate formation mode to be set for specific process requirements.

Recently, it was reported that chitin and chitosan exhibited high-proton conductivity and function as an electrolyte in fuel cells. In particular, it is noteworthy that proton conductivity in the hydrated chitin becomes 30 times higher than that in the hydrated chitosan. Since higher proton conductivity is necessary for the fuel cell electrolyte, it is significantly important to clarify the key factor for the realization of higher proton conduction from a microscopic viewpoint for the future development of fuel cells. Therefore, we have measured proton dynamics in the hydrated chitin using quasi-elastic neutron scattering (QENS) from the microscopic viewpoint and compared the proton conduction mechanism between hydrated chitin and chitosan. QENS results exhibited that a part of hydrogen atoms and hydration water in chitin are mobile even at 238 K, and the mobile hydrogen atoms and their diffusion increase with increasing temperature. It was found that the diffusion constant of mobile protons is two times larger and that the residence time is two times faster in chitin than that in chitosan. In addition, it is revealed from the experimental results that the transition process of dissociable hydrogen atoms between chitin and chitosan is different. To realize proton conduction in the hydrated chitosan, the hydrogen atoms of the hydronium ions (H3O+) should be transferred to another hydration water. By contrast, in hydrated chitin, the hydrogen atoms can transfer directly to the proton acceptors of neighboring chitin. It is deduced that higher proton conductivity in the hydrated chitin compared with that in the hydrated chitosan is yielded by the difference of diffusion constant and the residence time by hydrogen-atom dynamics and the location and number of proton acceptors.

Upon entry into the state of anhydrobiosis, trehalose-based energy metabolism is arrested in Artemia embryos (cysts). We have compared changes in the levels of trehalose, glycogen, some glycolytic intermediates and adenylate nucleotides in hydrated embryos observed under conditions of aerobic development with those occurring after transfer to 50moll−1 NaCl. This treatment is known to reduce cellassociated water into a range previously referred to as the ametabolic domain. The trehalose utilization and glycogen synthesis that occur during development of fully hydrated cysts are both blocked during desiccation. Upon return to 0.25 moll−1 NaCl both processes are resumed. Analysis of glycolytic intermediates suggests that the inhibition is localized at the trehalase, hexokinase and phosphofructokinase reactions. ATP level remains constant during the 6-h period of dehydration, as does the adenylate energy charge. An additional dehydration experiment was performed in 5.0moll−1 NaCl containing 50mmoll−1 ammonium chloride (pH9-0). The resulting level of gaseous ammonia in the medium has been shown to maintain an alkaline intracellular pH (pHi) in the embryos. The metabolic response to dehydration under these conditions was very similar to the previous dehydration series. Thus, these results are taken as strong evidence that the metabolic suppression observed during dehydration does not require cellular acidification, in contrast to the pronounced inhibitory role of low pHi during entry of hydrated embryos into the quiescent state of anaerobic dormancy. The arrest of carbohydrate metabolism seen during anhydrobiosis indeed appears to be a strict function of embryo water content.

Advanced metal coating methods have greatly improved the localization of secondary electrons (SEI) from biological specimens staged in an in-lens field emission SEM. Using these metal coatings, molecular level structural information from cell membranes and isolated bio-molecules have been more accurately recorded from frozen-hydrated samples due to the presence of bound water rather than from chemically fixed and dried samples. Although in-lens cryo-SEM systems have provided images with equivalent resolution to TEM-replicas, several conditions are encountered which require optimizing techniques and hardware.A drop of hydrated Bakers yeast on a gold Balzers carrier was plunge-frozen in ethane at its melting point. Thermal properties of ethane, such as the large difference between melting and boiling points, and its low viscosity increase the heat transfer coefficient during plunging thereby leading to faster cooling of the sample than with other cryogens. Carriers were transferred to the cryo-workstation of the Oxford CT 3500 system.

The capacity to make measurements of elemental concentrations at the level of single cells by energy dispersive X-ray microanalysis of cryo-fixed, inherently-hydrated plant parts (CEDX) is changing or extending our understanding of many plant functions. We include in this review a wide-ranging catalogue of studies that have used CEDX which provides access to the literature on elements measured, plants and tissues studied, techniques used, level of quantitation and the significant findings. These findings include new perspectives on the following areas: salt tolerance; xylem maturation and solute content, root pressure and embolism refilling; the contents of intercellular spaces; sequestration of toxic elements; biomineralisation with silicon; movement of tracer homologues of native cations; indirect localisation of molecules with a distinctive element component; transfer of nutrients from vesicular-arbuscular (VA) mycorrhizas; the role of mucilages in protection and in generating mechanical force. In an Appendix we discuss the procedures involved in CEDX: cryo-fixation, specimen planing, etching, elemental quantitation and mapping. Limitations on sample numbers, elements measurable, spatial resolution, sensitivity and threshold concentrations quantifiable are outlined. A brief discussion of the potential of emerging technologies for cell-specific analysis of cryo-fixed, hydrated specimens is included. In the Accessory Publication we list our standard protocol for CEDX.

A nanocomposite of multi-walled carbon nanotubes (MWCNTs) decorated with molybdenum dioxide (MoO2) nanoparticles is fabricated through the reduction of phosphomolybdic acid hydrate on functionalized MWCNTs in a hydrogen–argon (10%) atmosphere in a tube furnace. The MoO2/MWCNTs composite is proposed as an anodic modification material for microbial fuel cells (MFCs). MWCNTs have outstanding physical and chemical peculiarities, with functionalized MWCNTs having substantially large electroactive areas. In addition, combined with the exceptional properties of MoO2 nanoparticles, the synergistic advantages of functionalized MWCNTs and MoO2 nanoparticles give a MoO2/MWCNTs anode a large electroactive area, excellent electronic conductivity, enhanced extracellular electron transfer capacity, and improved nutrient transfer capability. Finally, the power harvesting of an MFC with the MoO2/MWCNTs anode is improved, with the MFC showing long-term repeatability of voltage and current density outputs. This exploratory research advances the fundamental application of anodic modification to MFCs, simultaneously providing valuable guidance for the use of carbon-based transition metal oxide nanomaterials in high-performance MFCs.

Proton exchange membrane fuel cells are currently being commercialized for numerous applications ranging from electric vehicles to stationary applications to miniature type of fuel applications. For the miniature fuel cells, it is desirable to operate at very high current densities in order to maximize the power density. Because at high current densities, the waste heat generation and removal becomes a substantial practical problem, gas diffusion layers (GDL) made out of perforated metals have recently become of interest. Here, a chemical etching process is applied to create uniform holes of equal size(around 80 microns) in a metal sheet. While this type of GDL has superior heat transfer properties and has been found to keep the fuel cell at an almost constant temperature, the uniformly sized holes must be kept from flooding. On the other hand, it is known that the fuel cell membrane must be kept hydrated in order to have a satisfactory proton conductivity. The purpose of this work is to investigate the possibility of maintaining a relative humidity of 100 % across the entire length of the flow channel. This is to keep the membrane perfectly hydrated while at the same time preventing flooding. The height and width of the flow channels in these fuel cells are in the range of 200 microns, causing a high pressure drop, and as the pressure decreases along the flow channel, the relative humidity would decrease. However, the relative humidity can then be maintained by adding water as a result of the electro-chemical chemical reaction in the fuel cell. Thereby, conditions for which the relative humidity stays constant at 100% over the entire channel length can be calculated, assuming the current density is uniform and that for simplicity all the product water exits the cell at the cathode side. In this work, a model will be constructed and solved in the Engineering Equation Solver (EES). The output of the model will be the required stoichiometric flow rate to maintain a constant relative humidity for different channel geometries, pressure gradients and temperatures.

We describe simple, sensitive and robust methods to monitor lipoprotein remodeling and cholesterol and apolipoprotein exchange, using fluorescent Lissamine Rhodamine B head-group tagged phosphatidylethanolamine (*PE) as a lipoprotein reference marker. Fluorescent Bodipy cholesterol (*Chol) and *PE directly incorporated into whole plasma lipoproteins in proportion to lipoprotein cholesterol and phospholipid mass, respectively. *Chol, but not *PE, passively exchanged between isolated plasma lipoproteins. Fluorescent apoA-I (*apoA-I) specifically bound to high-density lipoprotein (HDL) and remodeled *PE- and *Chol-labeled synthetic lipoprotein-X multilamellar vesicles (MLV) into a pre-β HDL-like particle containing *PE, *Chol, and *apoA-I. Fluorescent MLV-derived *PE specifically incorporated into plasma HDL, whereas MLV-derived *Chol incorporation into plasma lipoproteins was similar to direct *Chol incorporation, consistent with apoA-I-mediated remodeling of fluorescent MLV to HDL with concomitant exchange of *Chol between lipoproteins. Based on these findings, we developed a model system to study lipid transfer by depositing fluorescent *PE and *Chol-labeled on calcium silicate hydrate crystals, forming dense lipid-coated donor particles that are readily separated from acceptor lipoprotein particles by low-speed centrifugation. Transfer of *PE from donor particles to mouse plasma lipoproteins was shown to be HDL-specific and apoA-I-dependent. Transfer of donor particle *PE and *Chol to HDL in whole human plasma was highly correlated. Taken together, these studies suggest that cell-free *PE efflux monitors apoA-I functionality.

In this work, adsorption of the carcinogenic mycotoxin aflatoxin B1 (AFB1) by two sequestrants—a yeast cell wall-based adsorbent (YCW) and a hydrated sodium calcium aluminosilicate (HSCAS)—was studied across four laboratory models: (1) an in vitro model from a reference method was employed to quantify the sorption capabilities of both sequestrants under buffer conditions at two pH values using liquid chromatography with fluorescence detection (LC-FLD); (2) in a second in vitro model, the influence of the upper gastrointestinal environment on the mycotoxin sorption capacity of the same two sequestrants was studied using a chronic AFB1 level commonly encountered in the field (10 µg/L and in the presence of feed); (3) the third model used a novel ex vivo approach to measure the absorption of 3H-labelled AFB1 in the intestinal tissue and the ability of the sequestrants to offset this process; and (4) a second previously developed ex vivo model readapted to AFB1 was used to measure the transfer of 3H-labelled AFB1 through live intestinal tissue, and the influence of sequestrants on its bioavailability by means of an Ussing chamber system. Despite some sorption effects caused by the feed itself studied in the second model, both in vitro models established that the adsorption capacity of both YCW and HSCAS is promoted at a low acidic pH. Ex vivo Models 3 and 4 showed that the same tested material formed a protective barrier on the epithelial mucosa and that they significantly reduced the transfer of AFB1 through live intestinal tissue. The results indicate that, by reducing the transmembrane transfer rate and reducing over 60% of the concentration of free AFB1, both products are able to significantly limit the bioavailability of AFB1. Moreover, there were limited differences between YCW and HSCAS in their sorption capacities. The inclusion of YCW in the dietary ration could have a positive influence in reducing AFB1′s physiological bioavailability.

The present work is devoted to the study of crystalline polyantimonic acid (CPA) structural properties in conditions of ion exchange and heat treatment of its substituted Ag+, H+-forms. According to the obtained data of X-ray diffraction qualitative phase analysis, the compounds analyzed crystallize within the framework of the pyrochlore type structure (space group Fd-3m). For phases being isomorphic to this structural type, it was shown that with an increase in the degree of substitution α, a relative intensity redistribution of the group of reflections with even and odd indices and decrease of unit cell parameter a were observed.. The data of thermogravimetric analysis allows to conclude that the thermolysis of CPA’s ion-substituted forms proceeds in a wide temperature range from 297 to 973 K being accompanied by a decrease of samples weight. Applying the Rietveld method, the structural characteristics of CPA and its derivatives were refined, and a model of populating the corresponding metal ions by crystallographic positions within a pyrochlore-type structure was proposed. Using a complex of physicochemical methods (thermogravimetric and X-ray diffraction analyses), the effect of hydration of CPA compounds with a pyrochlore type structure on transport properties was determined. It is shown that with an increase of substitution degree α in samples of CPA’s Ag+, H+-forms in conditions of alternating current the value of the specific conductivity decreases monotonically. An increase of silver ions content in the phases of Ag+, H+-forms leads to the change of proton-binding energy with the crystal lattice. In the condition of elevated temperature in hydrated CPA compounds, charge transfer is performed by silver ions. It was found that the electrical conductivity in the samples analyzed can also rise with a silver ions amount decrease (16d-positions are partially filled with Sb3+).

With the aim to develop essential oil (EO) multi-antioxidant systems, combinatorial interactions of selected phenol and terpene-rich EOs (from Pimento Berry, Ceylon Cinnamon, Clove, Sage, White thyme; Oregano) enriched with individual polyphenols, crude plant extracts, and mixtures of their major polyphenols were investigated using single electron transfer (SET)-based DPPH and hydrogen atom transfer (HAT)-based ORAC assays. Polyphenols that enriched Eos the most favorably were rosmarinic acid (IC50 of 0.0891–0.1448 mg enriched EO/mg DPPH; 5772–17,879 µmol TE/g enriched EO) and quercetin (IC50 of 0.0682–0.1060 mg enriched EO/mg DPPH; Trolox Equivalents (TE) of 9776–14,567µmol /g enriched EO), whereas p-coumaric acid (IC50 of 0.1865–1.1424 mg enriched EO/mg DPPH; 7451.00–11,588 µmol TE/g enriched EO) and rutin hydrate (IC50 of 0.1140–0.3112 mg enriched EO/mg DPPH; 2298–6227 µmol TE/g enriched EO) were the least favorable. Enrichments with polyphenol mixes and crude extracts exhibited synergistic and additive effects in the SET-based DPPH assay. In the HAT-based ORAC assay, EO enrichments with crude extracts exhibited more additive effects, as well as less antagonistic effects, than enrichments with their major polyphenol mixes, revealing the significant contributions of minor compounds. EOs enriched with crude green tea and apple extracts exhibited synergistic or additive effects, whereas EOs enriched with grape seed and rosemary extracts exhibited equal antagonistic effects. Predictive models were developed to explain the variability between the observed and predicted antioxidant activities of enriched EOs.

ABSTRACTWhile the growth of pits in passive metals exposed to chloride solutions is well understood, the processes associated with the initiation and propagation of stable pits, versus pits that form and apparently re-passivate, are still a matter of conjecture. A major challenge in studying pit initiation using electron microscopy has been alteration of the structure and chemistry of the hydrated corrosion films upon transfer to the vacuum environment of the microscope. A recently developed technique uses a microfluidic liquid cell to maintain the aqueous environment in contact with the sample. This work uses such cells to directly observe pits initiating, and growing before reaching stability, in aluminum thin films under potentiostatic polarization in situ in the electron microscope. Polarization curves developed in the cell show good agreement with those observed under conventional electrochemical experimental conditions. We observed current transients representative of metastable pitting and were able to relate crystalline features found in situ with topographic features using atomic force microscopy (AFM). An accumulation of aluminum surrounding an initiated pit, combined with depth profiling using Auger electron spectroscopy suggests that aluminum metal is deposited during the pit initiation process, and may serve to reduce lateral dissolution of the aluminum film. Work is currently underway to determine if this observation is unique to the geometry of the microfluidics cell or if is a general result that occurs at the very beginning of pit initiation.

This study presented deposition of tin sulphide (SnS) thin film using a two-electrode electrochemical cell arrangement. The bath electrolyte comprised tin sulphate (SnSO4 ), hydrated sodium thiosulphate (Na2S2O3∙5H2O) and sulphuric acid (H2SO4 ). The acid was used to adjust the pH of the bath. The deposited film was characterised using Surface Profilometer, X-Ray Diffractometer (XRD), Uv-Visible Spectrophotometer and four point probe technique. Surface profiling revealed that the film is continuous with thickness of about 60 nm. The XRD result showed that the film has orthorhombic crystal structure. Film's crystallite size was estimated as 0.61 nm and interplanar spacing as 0.29 nm. The Uv-visible Spectrophotometer result reveals that, the film has good absorbance but poor reflectance and transmittance in the visible light region. The film has direct allowed transition with energy band gap of 1.69 eV. Values of surface resistivity and conductivity were deduced from data obtained from Four-point probe studies as 5.12 x 10-4Ω-cm and 1.96 x 103Ω-1cm-1 respectively. The I-V characteristics curve of ITO/SnS/Ag structure is linear indicating an Ohmic contact between the substrate electrode and the deposited layer. It can therefore be suggested that the film can allow pathway for photoabsorption and also aid charge transfer in photovoltaic process. Keywords: tin sulphide, orthorhombic, electrochemical deposition, characterization, photovoltaic and surface resistivity.

Experiments showing that water is decomposed by the action of high-energy radiations date back to the first days of the discovery of radioactivity, a century ago. On the occasion of this anniversary, we have attempted to give a comprehensive account of the radiation chemistry of water and its solutions since its origin, with special emphasis on the various physical and chemical stages that led to the present state of this science. To this aim, we describe the effect of different intervening factors on the molecular and radical yields, including dissolved solute concentration, pH, radiation intensity (or dose rate), type and energy of the radiation, presence of oxygen, temperature, phase, and pressure. We also discuss briefly the chemical behavior of the free radicals produced in radiolyzed aqueous solutions. A good, albeit incomplete, description of the phenomena is obtained that leads to various perspectives concerning, on the one hand, the development of this science and, on the other hand, its potential for applications.Key words : radical chemistry, dilution curve, water, hydrated electron, hydroxyl and superoxide radicals, free radicals, radiolysis, chain reactions, molecular and radical yields, cell survival, linear energy transfer.

Abstract Increasing attempts at using gas which leads to hydrate formation as a preservative tool in fresh-cut fruits and vegetables have been reported. In this study, changes in some physical and biochemical properties of fresh-cut green peppers under compressed noble gas treatments were examined. Mixed argonkrypton and argon treatments were performed before cold storage at 5°C for 15 days. Mass loss and cell membrane permeability were found to be the lowest in mixed argon-krypton samples. Besides, a lower CO2 concentration and vitamin C loss were detected in gastreated samples compared to untreated samples (control). While the total phenol degradation was moderately reduced, the effect of the treatment on polyphenoloxidase activity was better at the beginning of the storage period. The minimum changes in quality observed in cut peppers resulted from both mixed and gas treatment alone.

The development of catalysts with high activity for the ORR is essential to proton exchange membrane fuel cells (PEMFCs), since the majority of activation losses occur at the cathode and it turns into an interesting research area. In the present study, it is investigated the hydrothermal platinum functionalization of the CVD grown three-dimensional graphene foam (3D-GrFoam) using three concentrations of dihydrogen hexachloroplatinate (IV) hydrate [1]. The platinum functionalized graphene foam determined from XPS was 0.2at %, 0.3 at % and 0.4 at %, respectively.The catalytic activity towards ORR was analyzed from linear sweep voltammetry (LSV) plots recorded with a scan rate of 5 mV s-1 in oxygen saturated 0.5 M H2SO4. From the LSV curves and the Koutecky-Levich (K-L) plots for 0.4PtGrFoam as current density (mA-1 cm2 geo) vs. w-1/2 (rad s-1)-1/2), for various rotation speeds (among 250–1500 rpm) and different potentials (0.1 V-0.8 V). From the fitted K-L plots it is noticed a fair linear relationship at all potentials, that confirms the electroreduction of platinum. The number of transferred electrons is between 3.22 to 3.59 indicating the preponderance of the four-electron transfer mechanism in the ORR corresponding to the directly reduction of O2 to H2O. 1. Ion-Ebrasu, R.D. Andrei, S. Enache, S. Caprarescu, C. C. Negrila, C. Jianu, A. Enache, I. Boerasu, E. Carcadea, M. Varlam, B. S. Vasile, J. Ren, Materials 2021, 14, 4952.

The protein tyrosine phosphatases comprise a class of enzymes that are crucial for the regulation of a number of cellular processes. Because of this, they are attracting increasing attention, not only as legitimate therapeutic targets, but also because of their relationship to many fundamental cellular processes. Certain sulfotyrosine peptides derived from casein are known to be good inhibitors of the protein tyrosine phosphatase, PTP1B. In this study, NMR transfer nuclear Overhauser effect studies have been used to ascertain the bound-state conformation adopted by the 12-amino acid residue casein-derived peptide, CAS200 (NANEEE(sY)SIGSA) and N-terminal truncated forms of this peptide, CAS203 and CAS205. Each of the peptides were found to bind in an extended beta-strand conformation. Extensive molecular modelling and molecular dynamics simulations of the PTP1B/peptide complexes, in a fully hydrated model, allowed a detailed description of the potential sources of the binding interactions to be developed. In agreement with the NMR studies, the modelling provided a picture of binding of CAS200 in which only the central (E203- I208) residues contributed significantly to the binding while the 3 N-terminal and 3 C-terminal residues were quite fluxional. Critical cationic surface residues, lying near to, but outside the active site pocket were the source of strong stabilizing forces that complemented the stabilizing interactions of the active site pocket. Electrostatic, hydrophobic, and hydrogen bonding interactions, in a residue specific manner, were all found to make significant contributions to the binding of these inhibitors.Key words: protein tyrosine phosphatase, PTP1B, casein peptide, inhibitor, NMR structure, molecular modelling, molecular dynamics.

The current research was conducted to investigate the chemical profile, antiproliferative, and antioxidant activities of methanol extracts obtained by two different methods including maceration and Soxhlet from Berberis hispanica Boiss. & Reut. Antiproliferative activities were evaluated by the MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay in four human cancer cell lines including prostate (LnCap and 22 RV1) and breast cancer (MDA-MB-231 and MCF7). The antioxidant power was evaluated by DPPH ((2,2-diphenyl-1-picryl-hydrazyl-hydrate), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and FRAPS (Ferric reducing antioxidant power) tests. The chemical composition was conducted by gas chromatography-mass spectrometry (GC-MS) after methylation. Total phenolic and flavonoid contents were assessed using the Folin–Ciocalteu method. The phytochemical analysis showed that the tested extracts possessed inserting potentially active compounds. The MTT test revealed that both extracts (maceration and Soxhlet) reduced cell viability in all cell lines tested. In breast cancer cell lines MDA-MB-231 and MCF-7, the IC50 values obtained by maceration were 16.55 ± 0.58 and 17.95 ± 0.58 µg/mL, respectively. These values were slightly lower than those obtained with the Soxhlet extract toward MDA-MB-231 (19.93 ± 0.74 µg/mL) and MCF-7 (20.22 ± 0.89 µg/mL). Regarding prostate cancer cells 22 RV and LnCap, the IC50 values obtained by maceration extract (22 RV: 11.75 ± 0.35 µg/mL; LnCap: 11.91 ± 0.54 µg/mL) were also slightly lower than those obtained with Soxhlet (22 RV: 13.47 ± 0.52 µg/mL; LnCap: 19.64 ± 1.05 µg/mL). The antioxidant activity showed that the studied extracts had considerable antioxidant activity (DPPH, FRAP, and ABTS) with particular attention to the extract obtained with maceration. The Berberis hispanica Bois. and Reut. can serve society as it provides potentially bioactive compounds that may find application in the medical sector to control such diseases.

Voltage-dependent, anion-selective channels (VDAC) are formed in the mitochondrial outer membrane (mitOM) by a 30-kDa polypeptide. These channels form ordered 2D arrays when mitOMs from Neurospora crassa are treated with soluble phospholipase A2. We obtain low-dose electron microscopic images of unstained specimens of VDAC crystals preserved in vitreous ice, using a Philips EM420 equipped with a Gatan cryo-transfer stage. We then use correlation analysis to compute average projections of the channel crystals. The procedure involves Fourier-filtration of a region within a crystal field to obtain a preliminary average that is subsequently cross-correlated with the entire crystal. Subregions are windowed from the crystal image at coordinates of peaks in the cross-correlation function (CCF, see Figures 1 and 2) and summed to form averages (Figure 3).The VDAC channel forms several different types of crystalline arrays in mitOMs. The polymorph first observed during phospholipase treatment is a parallelogram array (a=13 run, b=11.5 run, θ==109°) containing 6 water-filled pores per unit cell. Figure 1 shows the CCF of a sub-field of such an “oblique” array used to compute the correlation average of Figure 3A. With increased phospholipase treatment, other polymorphs are observed, often co-existing within the same crystal. For example, two distinct (but closely related) types of lattices occur in the field corresponding to the CCF of Figure 2: a “contracted” version of the parallelogram lattice (a=13 run, b=10 run, θ=99°), and a near-rectangular lattice (a=8.5 run, b=5 nm). The pattern of maxima in this CCF suggests that a third, near-hexagonal lattice (a=4.5 nm) may also be present. The correlation averages of Figures 3B-D were computed from polycrystalline fields, using peak coordinates in regions of CCFs corresponding to each of the three lattice types.

Mineral trioxide aggregate (MTA) is well known as an effective root canal filling material for endodontics therapy. Within MTA, bismuth oxide (Bi2O3) serving as the radiopacifier still has biocompatibility concerns due to its mild cytotoxicity. In the present study, we tried to modify the Bi2O3 radiopacifier by doping hafnium ions via the sol-gel process and investigated the effects of different doping ratios (Bi2-xHfxO3+x/2, x = 0–0.3) and calcination temperatures (400–800 °C). We mixed various precursor mixtures of bismuth nitrate (Bi(NO3)3·5H2O) and hafnium sulfate (Hf(SO4)2) and controlled the calcination temperatures. The as-prepared Hf-doped Bi2O3 radiopacifier powders were investigated by thermogravimetric analysis (TGA), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). Portland cement/radiopacifier/calcium sulfate (75/20/5) were mixed and set by deionized water (powder to water ratio = 3:1). Changes in radiopacity, diametral tensile strength (DTS), and in vitro cell viability of the hydrated MTA-like cement were carried out. The experimental results showed that the group containing radiopacifier from sol-gelled Bi/Hf (90/10) exhibited significantly higher radiopacity (6.36 ± 0.34 mmAl), DTS (2.54 ± 0.29 MPa), and cell viability (84.0±8.1%) (p < 0.05) when compared to that of Bi/Hf (100/0) powders. It is suggested that the formation of β-Bi7.78Hf0.22O12.11 phase with hafnium addition and calcining at 700 °C can prepare novel bismuth/hafnium composite powder that can be used as an alternative radiopacifier for root canal filling materials.

Triclocarban and triclosan, two potent antibacterial molecules present in many consumer products, have been subject to growing debate on a number of issues, particularly in relation to their possible role in causing microbial resistance. In this computational study, we present molecular-level insights into the interaction between these antimicrobial agents and hydrated phospholipid bilayers (taken as a simple model for the cell membrane). Simulations are conducted by a novel ‘dual-resolution’ molecular dynamics approach which combines accuracy with efficiency: the antimicrobials, modelled atomistically, are mixed with simplified (coarse-grain) models of lipids and water. A first set of calculations is run to study the antimicrobials' transfer free energies and orientations as a function of depth inside the membrane. Both molecules are predicted to preferentially accumulate in the lipid headgroup–glycerol region; this finding, which reproduces corresponding experimental data, is also discussed in terms of a general relation between solute partitioning and the intramembrane distribution of pressure. A second set of runs involves membranes incorporated with different molar concentrations of antimicrobial molecules (up to one antimicrobial per two lipids). We study the effects induced on fundamental membrane properties, such as the electron density, lateral pressure and electrical potential profiles. In particular, the analysis of the spontaneous curvature indicates that increasing antimicrobial concentrations promote a ‘destabilizing’ tendency towards non-bilayer phases, as observed experimentally. The antimicrobials' influence on the self-assembly process is also investigated. The significance of our results in the context of current theories of antimicrobial action is discussed.

Within the field of battery applications, deep eutectic solvents (DESs) have emerged as innovative electrolytes for rechargeable Zinc-ion batteries (ZIBs) . ZIBs traditionally employ neutral or weakly acidic aqueous electrolytes, which are susceptible to the standard anode drawback such as dendrite formation and passivation. DES-based electrolytes can facilitate the reversible plating and stripping of Zn, mitigating also dendrite growth . One notable benefit of DES solvents over their aqueous counterparts is that the concentration of electroactive species controls the shape evolution of electrodes during electroplating. For this reason, the coordination chemistry and metal complex formed between the Lewis acid of the metal and the Lewis base of the DES play a central role. Moreover, water can be added to the eutectic mixtures to increase the diffusion coefficient of the electroactive species and lower the electrolyte viscosity without destroying the eutectic nature if the concentration is kept under 40%. Regarding metal plating/stripping processes, DESs offer a notable advantage due to their high capacity to dissolve metal salts, oxides, and hydroxides, inhibiting the formation of insoluble oxides and hydroxides . Moreover, the unique coordination properties of Zn2+ in DESs lead to an atypical voltammetric behavior, characterized by a cathodic peak in the cathodic branch of the anodic-going scan. The mechanistic studies of Zn electrodeposition onto glassy carbon (GC) from DESs have concluded that the metal is formed by the reduction of an intermediate Zn-containing species. Finally, the reactivity of choline chloride and ethylene glycol can impact coordination in that these species can be dehydrogenated at negative potential forming RO¯, which can replace one or more chloride ligands in [ZnCl4]2− . The correlation between the chemistry of Zn2+ solutions and DESs is elucidated, and the peculiarities of Zn electrochemistry can be rationalized in terms of the DES–electrode interface structure. Although few studies on hydrated DESs have been conducted, the literature remains scant. Shi et al. conducted a study on DES composed of ZnCl2 and acetamide with different concentration of water. The authors employed various spectroscopic techniques, including FT-IR, Raman, and 17O NMR, to investigate the effect of water on the coordination geometry of Zn2+ and its consequent impact on Zn plating. Interestingly, the authors observed that the addition of small amounts of water, below the threshold for direct water-water interaction, resulted in significant alterations of the Zn2+ coordination geometry. In fact, based on the accepted view that Zn electrodeposition is a process that involves desolvation and charge-transfer steps, [ZnCl(acetamide)2(H2O)]+ was shown to undergo successive deamidation and dehydration, yielding [ZnCl(acetamide)]+ from which the metal center is finally reduced. Although [ZnCl(acetamide)3]+ is the most stable species, the energy barrier for dehydration is significantly lower than that for deamidation. Therefore, [ZnCl(acetamide)2(H2O)]+ with lower dissociation energy is the actual electroactive species . The solvation of Zn also affects the nucleation overpotential, as Zn2+ in hydrated DES exhibits faster desolvation kinetics, resulting in a lower nucleation overpotential. In addition, Zhao et al. investigated the properties of a “water-in-DES” electrolyte (~30 mol.% H2O) based on the urea/LiTFSI/Zn(TFSI)2 mixture and discovered that the preferential interaction between water and metal cations promotes interfacial charge transfer. Notwithstanding the important contribution of these papers, the mechanism of Zn electrodeposition in DES has not been conclusively assessed. To address this knowledge gap, our research aims to investigate Zn electrodeposition from two distinct, hydrated DESs: ChU and ChEG with approximately 30% H2O content. To gain control of the impact of the cathode material, we carried out our electrochemical tests by employing GC, Zn, Pt and Au electrodes. Furthermore, to evaluate the performance of these electrolytes under realistic device conditions, electrochemical cycling tests were conducted on symmetric CR2023 coin cells. In this study, we have demonstrated the beneficial effect of water addition on reducing the electrolyte viscosity, which consequently resulted in lower anodic and cathodic overpotentials and improved charge/discharge cyclability. Specifically, the electrolytes ChEG and ChU failed due to passivation and short circuits, respectively. The ChU electrolyte showed regular chronopotentiometric transients until cell failure, and this was supported by multiple cyclic voltammetry (CV) measurements, which showed reversible Zn plating/stripping in this system. Notably, our cell cycling tests were performed at higher current densities and exhibited longer lifetimes compared to previous literature reports. The unusual CV patterns observed with gold and glassy carbon (GC) electrodes, featuring cathodic peaks on both forward and backward scans, were elucidated using complementary electrochemical and in situ Raman spectroscopy measurements. Figure 1

Ion channels are ubiquitous throughout all forms of life. Potassium channels are even found in viruses. Every cell must communicate with its surroundings, so all cells have them, and excitable cells, in particular, especially nerve cells, depend on the behavior of these channels. Every channel must be open at the appropriate time, and only then, so that each channel opens in response to the stimulus that tells that channel to open. One set of channels, including those in nerve cells, responds to voltage. There is a standard model for the gating of these channels that has a section of the protein moving in response to the voltage. However, there is evidence that protons are moving, rather than protein. Water is critical as part of the gating process, although it is hard to see how this works in the standard model. Here, we review the extensive evidence of the importance of the role of water and protons in gating these channels. Our principal example, but by no means the only example, will be the Kv1.2 channel. Evidence comes from the effects of D2O, from mutations in the voltage sensing domain, as well as in the linker between that domain and the gate, and at the gate itself. There is additional evidence from computations, especially quantum calculations. Structural evidence comes from X-ray studies. The hydration of ions is critical in the transfer of ions in constricted spaces, such as the gate region and the pore of a channel; we will see how the structure of the hydrated ion fits with the structure of the channel. In addition, there is macroscopic evidence from osmotic experiments and streaming current measurements. The combined evidence is discussed in the context of a model that emphasizes the role of protons and water in gating these channels.

The human population is growing and needs more energy for optimal life. Since fossil fuel consumption is no longer accepted, new green energy sources are sought after, found, and further developed. One such energy carrier is hydrogen, which is used as fuel in various low-temperature proton exchange membrane (PEMFCs) and anion exchange membrane fuel cells (AEMFCs).1 Unfortunately, these technologies are expensive due to the application of electrochemically active platinum-based catalysts. Thus, to make fuel cell technology more affordable: cheaper, more active, and more stable, non-Pt catalysts are researched and developed. For example, Ag has shown comparable and competitive results to Pt-based catalysts in an alkaline environment when used in AEMFCs.2 In addition, Ag is nearly 50 times cheaper than Pt. In this work, Ag nanoparticles were deposited, using two different reducing agents – NaBH4 and hydrazine hydrate, onto two novel mesoporous engineered carbon support (ECS) materials with a well-defined and uniform mesoporous structure with pore sizes of 8 and 35 nm for ECS004601, and 7 and 25 nm for ECS004201 (Pajarito Powder, LLC). For comparison, conventional Vulcan carbon XC-72R was used as a support to see whether the ECS supports promote better dispersion of Ag particles. SEM micrographs confirm that the synthesized Ag particles covered the mesoporous carbon support homogeneously. According to the XRD analysis, the average size of Ag crystallites remained between 19 and 28 nm. According to the thermogravimetric analysis, electrochemical Ag stripping, and SEM-EDX analysis, the amount of Ag in the catalysts after synthesis remained close to the nominal 40 wt%. Figure 1a shows that half-wave potentials (E 1/2) remained in the range from -0.29 V to -0.37 V vs SCE, where catalyst Ag/4201_HH had the most positive E 1/2, and bulk Ag electrode had the most negative. The electron transfer number n was close to four for all the Ag-based catalysts. Catalysts Ag/4201_HH and Ag/4601_BH4 had the biggest mass activities and showed good stability during 1000 potential cycles, where E 1/2 shifted only by 30 mV for Ag/4601_BH4 and 36 mV for Ag/4201_HH. Thus, these materials were tested in H2/O2 AEMFC where Aemion+ anion exchange membrane was employed and Figure 1b shows that the peak power density for Ag/4201_HH was 243 mW cm-2 and for Ag/4601_BH4 310 mW cm-2. Therefore, these materials are promising cathode catalysts for the AEMFC application.3 References A. Sarapuu, E. Kibena-Poldsepp, M. Borghei, K. Tammeveski, Electrocatalysis of oxygen reduction on heteroatom-doped nanocarbons and transition metal-nitrogen-carbon catalysts for alkaline membrane fuel cells, Journal of Materials Chemistry A 6(3) (2018) 776-804. H. Erikson, A. Sarapuu, K. Tammeveski, Oxygen Reduction Reaction on Silver Catalysts in Alkaline Media: a Minireview, Chemelectrochem 6(1) (2019) 73-86. J. M. Linge, H. Erikson, M. Mooste, H-M Piirsoo, T. Kaljuvee, A. Kikas, J Aruväli, V. Kisand, A. Tamm, A. M. Kannan, K Tammeveski, Ag nanoparticles on mesoporous carbon support as cathode catalyst for anion exchange membrane fuel cell, International Journal of Hydrogen Energy (2023). Figure 1

Resumos escolhidos para publicação. Nessa edição, os títulos foram: Extramitochondrial Fumarate Inhibits Multiple 2-OG Oxygenases in Fumarate Hydratase Deficient Cells; What is the Best Treatment for Renal Lesions in VHL?; Characterization of the VHL-ECM Pathway; Induction of Extreme Metabolic Depression by the Nucleolus; Mutation of SDHB and Inherited RCC Susceptibility; Metabolic Links to Renal Cancer; Radiosurgery for Cerebellar Hemangioblastomas; Neoplastic Diagnosis Timing Profile in von Hippel-Lindau´s Patients in a Personal Series; Regulation of the VHL Tumor Suppressor; Destructive Targeting via VHL Beyond HIF; Folliculin Functional Studies and Mouse Models of Birt-Hogg-Dube’ Syndrome; A Zebrafish Model for VHL; Relief of Intractable Nausea after Resection of Brainstem Hemangioblastoma in Patients with von Hippel-Lindau Disease: a Clinical Series; Somatic Alteration of the VHL Gene in Sporadic Renal-Cell Carcinomas as a Potential Biomarker; VHL Tumor Suppressor Protein Regulates Oncogenic Macroautophagy in Renal Clear Cell Carcinoma (RCC); Identification of Germline Mutations in the VHL Gene of Families with the von Hippel-Lindau Disease; Expression Profile in von Hippel-Lindau Disease Associated and Sporadic Clear-Cell Renal Cell Carcinomas; Proposed Changes to the VHL Handbook; Evaluation of the Somatic Alterations of the VHL Gene in Renal Cell Carcinoma Associated with von Hippel-Lindau Disease (VHL); Copy Number Variation Analysis of a Pancreatic Neuroendocrine Tumor (NET) from a Patient with von Hippel-Lindau (VHL); Molecular Dynamics Study of the Mutant pVHL Phe76del and its Interactions with Components of the pVHL Complex; Genomic Copy Number Variation Analysis in VHL-Associated Renal Cell Carcinomas Suggests Clonality; Management of Brainstem and Spinal cord Hemangioblastomas in Patients with von Hippel-Lindau Disease; The Benefits of Ultrasound in Resection of CNS Hemangioblastomas; Management of Central Nervous System Hemangioblastomas in von Hippel-Lindau Disease; Neuronal Differentiation of Stem cells by Transfer of a VHL Peptide and Regenerative Therapy; Endolymphatic Sac Tumors (ELST) in VHL Patients - Evaluation of Screening Methods in a National Study; Delineating Genotype-Phenotype Correlations Among Brazilian Families with von Hippel-Lindau Disease; Endothelial Fenestrations Associated with VHL Gene Alteration is a Potent Target of Anti-VEGF Therap; Role of Pregnancy on Hemangioblastomas in von Hippel-Lindau Disease: a Retrospective French Study; An Evaluation of the Danish National Clinical Guidelines for Von Hippel-Lindau (VHL); Vitreoretinal Surgery for Severe Retinal Capillary Hemangiomas; Oncololytic Targeting of Renal Cell Carcinoma via Encephalomyocarditis Virus; Emerging Therapeutic Options for VHL Patients: a Tale of three Studies; Altering the Stability of Mutant VHL: Potential Therapeutic Consequences; Tale of the Tail: Clinical and Functional Properties of Novel VHL Mutation (X214L) Consistent with Type 2A Phenotype and Low Risk of Renal Cell Carcinoma; Knife for Intracranial Hemangioblastomas in von Hippel-Lindau Patients. When and How?; VHL in Brazil: Genetics, Biobanking and VHL Family Care; Understanding VHL Disease: Molecular Characterization of a Spanish Series; Case Report: Radiosurgery for Endolymphatic Sac Tumor in a Patient with von Hippel-Lindau Disease; Primary Cilium: a Tumor Suppressor Organelle.

Hydrated encysted embryos of the brine shrimp Artemia franciscana have the ability to withstand years in anaerobic sea water using metabolic strategies that enable them to inactivate all cell metabolic activities and then to resume development when placed in aerobic sea water. However, this unique characteristic of Artemia franciscana embryos is lost during a very short period, at the embryonic&shy;larval transition period of development, coincident with the appearance of prenauplius larvae. Thus, while encysted embryos show complete inhibition of proteolysis over at least 4 years under anoxia, control of this activity, together with resistance to anoxia, is lost in newly hatched nauplius larvae after only a few days in anaerobic sea water. In contrast to encysted embryos, young larvae in anaerobic sea water produce large amounts of lactic acid, which reaches a concentration of nearly 50 mmol l-1 within 12 h of incubation. The accumulated lactic acid is believed to reduce the intracellular pH (pHi) to considerably less than 6.3, the value found in encysted embryos after 5 months in anaerobic sea water. We find that larvae, in contrast to embryos, lose cytoplasmic proteins at the rate of 4&shy;5 ng h-1 larva-1 upon transfer to anaerobic sea water, while yolk proteins are not degraded in either embryos or larvae under anoxic conditions. The decline in cytoplasmic protein levels in anaerobic larvae may be due to activation of an endogenous cysteine protease (CP) as the pHi becomes acidic. Contributing to the apparent uncontrolled CP activity is a decrease in the level of cysteine protease inhibitor (CPI) activity during the embryonic&shy;larval transition period, resulting in an increase in the CP/CPI ratio, from approximately 0.5 in embryos to greater than 1.0 in newly hatched larvae. Finally, data are presented to suggest that loss of the 26 kDa stress protein from embryos during the embryonic&shy;larval transition may also contribute to the loss in resistance of young nauplius larvae of A. franciscana to anaerobic conditions.

The core subject of the present paper represents the interrelated spillover (effusion) phenomena both of the primary oxide and the H-adatoms, their theory and practice, causes, appearances and consequences, and evidences of existence, their specific properties, and their alterpolar equilibria and kinetic behavior, structural, and resulting catalytic, and double layer charging features. The aim is to introduce electron conductive and d-d interactive individual and composite (mixed valence) hypo-d-oxide compounds, of increased altervalent capacity, or their suboxides (Magnéli phases), as the interactive catalytic supports and therefrom provide (i) the strong metal-support interaction (SMSI) catalytic effect and (ii) dynamic spillover interactive transfer of primary oxides (M-OH) and free effusional H-adatoms for further electrode reactions and thereby advance the overall electrocatalytic activity. Since hypo-d-oxides feature the exchange membrane properties, the higher the altervalent capacity, the higher the spillover effect. In fact, altervalent hypo-d-oxides impose spontaneous dissociative adsorption of water molecules and then spontaneously pronounced membrane spillover transferring properties instantaneously resulting with corresponding bronze type (Pt/HxWO3) under cathodic and/or its hydrated state (Pt/W(OH)6), responsible for Pt-OH effusion, under anodic polarization, this way establishing instantaneous reversibly revertible alterpolar bronze features (Pt/H0.35WO3 Pt/W(OH)6) and substantially advanced electrocatalytic properties of these composite interactive electrocatalysts. Such nanostructured-type electrocatalysts, even of mixed-valence hypo-d-oxide structures (Pt/H0.35WO3/TiO2/C, Pt/HxNbO3/TiO2/C), have for the first time been synthesized by the sol-gel methods and shown rather high stability, electron conductivity, and nonexchanged initial pure monobronze spillover and catalytic properties. Such a unique electrocatalytic system, as the striking target issue of the present paper, has been shown to be the superior for substantiation of the revertible cell assembly for spontaneous reversible alterpolar interchanges between PEMFC and WE. The main target of the present thorough review study has been to throw some specific insight light on the overall spillover phenomena and their effects in electrocatalysis of oxygen and hydrogen electrode reactions from diverse angles of view and broad contemporary experimental methods and approaches (XPS, FTIR, DRIFT, XRD, potentiodynamic spectra, UHRTEM).

New generation of electrochemical energy storage devices is needed to face the continuous increase in energy stored capacity demand at lower costs from human society. Moreover, due to the constant increase in number of batteries produced, the development of more sustainable devices without the consumption of limited resources at affordable costs is an actual research challenge. The conventional lithium batteries, the most widespread kind of electrochemical energy storage devices, made by an intercalation cathode (e.g., LiCoO2, LiFePO4) and a graphite anode suffer of limited capacity for high-performance application (such as in electric vehicles) and use limited mineral resources with adverse environmental consequences. Iron fluoride is a promising conversion cathode for positive electrodes in next-gen lithium batteries due to its low cost, great abundance, and ease of extraction1,2. The main problems of metal fluoride-based cathodes are the low conductivity and the structural changes during charge/discharge cycles that limit device capacity and lifespan. To effectively increase the storage capacity, several attempts to use metal lithium anodes have been made. However, this solution is now limited to primary batteries because of dendrites growth during metal plating that causes capacity fading and safety concerns. In the last decade, batteries based on fluoride-ion shuttling are drawing attention3,4 due to the possibility to use a high-capacity conversion cathode, exploiting a multi-electron transfer, and a metal anode without dendrites formation. This kind of devices, in the early stage of development, rely on electrochemical fluorination of an electropositive metal anode and the defluorination of a more “noble” metal fluoride without a metal plating-stripping process. Nowadays, electrolyte limitation is the main challenge for the development of a fluoride-ion battery that can compete with state-of-the-art lithium-ion batteries. In this work, a surfactant-assisted solvothermal route to obtain iron fluoride hydrate (FeF3 0.33 H2O) is presented. A hierarchical grape-like structure was obtained and it was tested as cathode active material in a 2025 coin-cell working in a metal-lithium battery configuration. In these tests it showed improved performance, compared to the same synthesis without surfactant. The synthetized material was also characterized by morphological and electrochemical point of view by means of Electrochemical Impedance Spectroscopy (EIS), galvanostatic charge discharge (GCD) and cyclic voltammetry (CV). The possibility to use the same cathodic material in a room-temperature fluoride-ion battery with a metal anode was assessed by using fluoride conducting liquid electrolytes5: encouraging results about the feasibility were achieved; however, further research in the field of liquid electrolytes resulted fundamental for bringing performances of this technology to the level of actual lithium batteries. References: [1] Bai, Y.; Zhou, X.; Zhan, C.; Ma, L.; Yuan, Y.; Wu, C.; Chen, M.; Chen, G.; Ni, Q.; Wu, F.; Shahbazian-Yassar, R.; Wu, T.; Lu, J.; Amine, K. Nano Energy 2017, 32, 10–18. [2] Wei, S.; Wang, X.; Jiang, M.; Zhang, R.; Shen, Y.; Hu, H. J. Alloys Compd. 2016, 689, 945–951. [3] Reddy, M. A.; Fichtner, M. Journal of Materials Chemistry 2011, 21 (43), 17059–17062. [4] Xiao, A. W.; Galatolo, G.; Pasta, M. Joule 2021, 5 (11), 2823–2844. [5] Davis, V. K.; Bates, C. M.; Omichi, K.; Savoie, B. M.; Momčilović, N.; Xu, Q.; Wolf, W. J.; Webb, M. A.; Billings, K. J.; Chou, N. H.; others. Science 2018, 362 (6419), 1144–1148.

A new fluorimetric and colorimetric dual-mode probe, 4-bromo-2-(hydrazonomethyl) phenol (BHP) has been synthesized and successfully utilized for the recognition of Cd2+/F‒ ions in DMSO/H2O (9:1, v/v) system. The probe displays dual channel of detection via fluorescence enhancement and colorimetric changes upon binding with F‒ and Cd2+ ions respectively. The Job’s plot analysis, ESI-MS studies, Density Functional Theoretical (DFT) calculations, 1H NMR and 19F NMR titration results were confirmed and highly supported the 1:1 binding stoichiometry of the probe was complexed with Cd2+/F‒ ions. Furthermore, intracellular detection of F‒ ions in HeLa cells and fluorescence imaging analysis in Zebrafish embryos results of the probe BHP might be used to reveal their potential applications in a biological living system. Introduction The quantification and detection of toxic metal ions in diverse fields have fascinated more attention in recent years due to their prominent and significant roles in clinical diagnosis and ecological system.1–6 Besides metal ions, anions also play an exclusive role in a variety of chemical and biological processes.7–12 In earlier, analytical methods for the detection of cations/anions has required highly sophisticated and expensive instruments such as atomic absorption spectrometry, inductively coupled plasma mass spectrometry, ion sensitive electrodes, and gas and ion chromatography. Amid, fluorescent techniques have more expedient in terms of rapidness, excellent sensitivity and selectivity, low cost, easy and feasible detection. In addition, optical detection mode analysis is a more appropriate method because of their potential features such as easy handling, real-time analysis and different signal output modes.13–16 Besides, colorimetric assays are more feasible and potent tool as they provide a simple visible authentication for analyte detection in the absence of instruments and tedious techniques. In this perspective, the recent research area has been mainly focused to design the novel multi-functional fluorometric and colorimetric sensors for the detection of ions in the different environments. Cadmium (Cd2+) is one of the important hazardous heavy transition metal ions17 in the environment due its carcinogenic nature. The higher accumulation of Cd2+ ion and inhalation of Cd-dust prompts more awful health issues in human like cancer, cardiovascular diseases, kidneys and liver damage.18 Furthermore, the Cd2+ ion has more advantages in several industries such as pigments in plastics, electroplating and batteries, etc. On the other hand, fluoride ions play an ample role in dental health and in the treatment of osteoporosis.19–22 The excess of fluoride ingestion prompted severe disease in human health like gastric and kidney problems.23 In some remote areas, the high level contamination of fluoride ions in drinking water triggered bone disease such as fluorosis.24–31 Thus, to develop and synthesize novel multifunctional probe for the detection and quantification of both cations and anions is a highly anticipated and imperative task. Scheme 1. Synthesis of probe BHP Herein, we have fabricated and synthesized a novel chromogenic and fluorogenic assay based on bromo substituted salicylhydrazone moiety for the colorimetric and fluorometric detection of F‒ ions and colorimetric detection of Cd2+ ions in DMSO/H2O (9:1, v/v) system. The UV-visible and fluorescence spectral analysis of BHP with Cd2+/F‒ ions exposed an outstanding ratiometric absorbance and colorimetric responses towards F‒ ions and also showed a visible colorimetric response towards Cd2+ ions. The fluorescence enhancement of BHP with F‒ ion was highly evaluated by DFT calculations. As well, the cell viability experimental results of BHP can be used for the detection of F‒ ions in both HeLa cells and Zebrafish embryos via high content analysis system. Experimental Methods 2.1 Materials All the chemicals used in the present study were in the analytical reagent grade and solvents used were of HPLC grade. Reagents were used as such received without any further purification. Metal ions such as K+, Na+, Ca2+, Mg2+, Fe2+, Fe3+, Ag+, Zn2+, Mn2+, Cu2+, Co2+, Ni2+, Cd2+, Al3+, Cr3+, Pb2+ and Hg2+ were purchased from Merck and S.D. Fine chemicals. The anions of Cl-, Br-, I-, SCN-, CN-, H2PO4-, HSO4-, NO3-, AcO- and F- were purchased as their tetrabutylammonium salts from Sigma–Aldrich Pvt. Ltd. Absorption measurements were performed on JASCO V-630 spectrophotometer in 1 cm path length quartz cuvette with a volume of 2 mL at room temperature. Fluorescence measurements were made on a JASCO and F- 4500 Hitachi Spectrofluorimeter with excitation slit set at 5.0 nm band pass and emission at 5.0 nm band pass in 1 cm ×1 cm quartz cell. 1H and 13C NMR spectra were obtained on a Bruker 300 MHz NMR instrument with TMS as internal reference using DMSO-d6 as solvent. Standard Bruker software was used throughout. 19F NMR spectra were recorded at 293K on BRUKER 400 MHz FT-NMR spectrometers using DMSO-d6 as solvent. ElectroSpray Ionisation Mass Spectrometry (ESI-MS) analysis was performed in the positive/negative ion mode on a liquid chromatography-ion trap mass spectrometer (LCQ Fleet, Thermo Fisher Instruments Limited, US). Fluorescence microscopic imaging measurements were determined using Operetta High Content Imaging System (PerkinElmer, US) 2.2. Synthesis of (E)-4-bromo-2-(hydrazonomethyl) phenol, BHP An absolute alcoholic solution (50 ml) of 5-bromosalicylaldehyde (0.5gm, 2.49 mmol) was refluxed under hydrazine hydrate (in excess) for 5 hr and the pale yellow color solid product was collected after recrystallized with ethanol and ethyl acetate mixture (yield, 95 %). 1H NMR (300 MHz, DMSO-d6) δ (ppm): 8.92 (s, 1H), 11.89 (s, 1H), 7.53 (d, J = 8.7 Hz, 1H), 6.94 (d, J = 5.8 Hz, 1H); 13C NMR (75 MHz, DMSO-d6) δ (ppm): 161.36, 158.51, 135.84, 131.82, 120.86, 119.69, 106.72. 2.3 Photophysical analysis of BHP The optical mode analysis of BHP towards various cations/anions in DMSO/H2O (9:1, v/v) system was carried out by using absorbance and fluorescence spectroscopy. UV-visible and fluorescence analysis of BHP with cations were gauged by using their corresponding acetate salts of metal ions. Tetrabutylammonium salts of competing anions were used for the anionic sensing analysis. 2.4 Computational Studies The optimized geometrical and ground state energy level calculations of BHP were obtained by Density functional theoretical (DFT) calculations were executed using Gaussian 09 program 32 with the 6-311G basis set. The optimized geometries and the fluorescence enhancement of probe BHP complexed with Cd2+/F- ions were attained by DFT-B3LYP level theory using 6-311G and LANL2DZ basis sets. 2.5 Cytotoxicity studies HeLa cell lines were procured from the National Center for Cell Science (NCCS), Pune, India. Cell lines are kept in the Dulbecco's Modified Eagle's medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 1% antimycotic and antibiotic solution was used in this study. The cells were kept in an incubator at 25 °C with humidified atmosphere comprising 5% of CO2 and 95% of air. HeLa cells were loaded over the wells of 96 well-culture plates with a density of 1 x 104 cells/well. After 48 h of incubation, previous DMEM medium was exchanged with new medium and BHP (dissolved in DMSO) was added in the range of 0-200 µM to all the wells and further incubated over 3h. Cytotoxicity of BHP was measured by using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. After incubation of HeLa cells with BHP, the medium was detached. Further, 100 μl of DMSO was added and the resulting formazan crystals were dissolved in DMSO. The cell viability was determined by measuring the absorbance of each well at 540-660 nm (formation of formazan) using a microplate reader. 2.6 In vivo fluorescence analysis in Zebrafish embryos The fluorescence imaging analysis was performed in four days old embryos. The embryos were seeded over F- ion alone for 2 h in the E3 medium. The E3 medium was prepared by dissolving 5.0 mM NaCl, 0.17mM KCl, 0.33mM CaCl2, 0.33mM MgSO4 ingredients in H2O (2L) and the pH 7.2 was adjusted by adding NaOH. The embryos were thoroughly washed with E3 medium. Successively, incubated embryos were sowed over 25 mM of BHP (in DMSO) solution for 3h. Further, embryos were washed again with E3 medium and fixed in 10% methyl cellulose solution for the good oriented images. The fluorescent images of BHP-F- were logged using high content screening microscopy. (Excitation wavelength of 482 nm and emission wavelength range of 500-700 nm). Results and discussion The probe, (E)-4-bromo-2-(hydrazonomethyl) phenol (BHP) has been synthesized by one step condensation between hydrazine and 5-bromosalicylaldehyde in ethanol (yield, 95 %) as shown in Scheme 1. The structure of the probe BHP was confirmed via 1H, 13C NMR analysis (Figure S1-S2, See ESI) 3.1. UV–vis spectral analysis of cations with BHP To investigate the cation sensing events of BHP towards different cations in DMSO/H2O (9:1, v/v) system by using UV-vis and fluorescence titration experiments. Initially, free probe BHP exhibited an absorption band at 367 nm and further addition of mono, di and trivalent cations such as Li+, K+, Ag+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Fe2+, Hg2+, Na+, Mg2+, Ca2+, Pb2+, Fe3+ and Cr3+ exhibited tiny changes in absorption spectr due to their weak interaction towards BHP except Cd2+ ion as shown in Figure 1. Interestingly, upon titrated with Cd2+ ion, a new absorption band appeared at 470 nm due to the highly resonance induced charge transfer ability of bromo substituted salicyl moiety while the solution turns into dark yellow color from pale yellow. Increasing addition of Cd2+ ion results gradual reduction of both higher and lower energy bands at 367 nm and 470 nm respectively as depicted in Figure 2. Figure 1. UV-vis spectra of BHP (10 µM) with different cations (5 × 10-3 M) in DMSO/H2O (9: 1, v/v) system. Figure 2. UV-vis spectra of BHP (10 µM) with Cd2+ (0 – 100 µM) in DMSO/H2O (9: 1, v/v) system Besides, fluorescence response of probe BHP towards various cations such as Li+, K+, Ag+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Fe2+, Hg2+, Na+, Mg2+, Ca2+, Pb2+, Fe3+ and Cr3+ including Cd2+ ion have been inspected in DMSO/H2O (9:1, v/v) system. Initially, the probe BHP displayed low intensed fluorescence band in free state. Addition of other commonly coexistent metal ions including Cd2+ ions exhibited trivial changes in fluorescence spectra. From these results, it is concluded that the probe BHP could serve as an excellent colorimetric assay for the detection of Cd2+ ions. 3.2. The sensing analysis of BHP towards anions Moreover, the anion binding attraction of BHP towards anions have been investigated in DMSO/H2O (9:1, v/v) system via both UV-visible and fluorescence spectral techniques. Initially the probe BHP showed the absorption band at 367 nm. Upon titrated with other anions such as Cl‒, Br‒, I‒, NO3‒, AcO‒, HSO4‒, H2PO4‒ and CN‒ were failed to alter the absorbance of the probe BHP except F‒ ions as shown in Figure 3a. Moreover, the incremental addition of F‒ ions (0-50 µM), the higher energy band at 367 nm was decreased along with the increment in new absorption band at 482 nm results an excellent ratiometric response. The new low energy band observed at 482 nm due to the deprotonation of–OH group present in salicyl moiety initiated by hydrogen bonding [Figure 3b]. At that affair, the solution turns into orange color from pale yellow and it was simply discerned by naked eye [Figure 4]. Besides, under identical condition, the fluorescence titration experiment of BHP was carried out in the presence of different anions. Interestingly, the probe BHP displayed low intensed fluorescence band at 601 nm and the other competing anions were failed to affect the fluorescence intensity except F‒ ions as shown in [Figure 5a]. Further, the incremental addition of F‒ ions triggers the enhancement in intensity results an excellent “turn on” fluorescence response due to the deprotonation and the inhibition of charge transfer state stimulated by resonance around the moiety [Figure 5b]. 3.3. Competitive experiments To gauge the selectivity and recognizing ability of BHP, competitive analysis was performed in the presence of varying concentration of F‒ ion (0-50 µM). Initially, the probe was treated with 5 × 10-3 M of different anions such as, CN-, I-, Br-, Cl-, NO2-, CH3COO-, H2PO4- and HSO4-. The other common competing anions were failed to bind with the probe BHP except F- ion [Figure 6 (a) and (b)]. From these observations, it is ensured that BHP could act as an excellent selective and sensitve chromogenic receptor for F- ions in real time monitoring and different biological applications. Figure 3 (a): UV-vis spectra of BHP with 5 × 10-3 M of other anions in DMSO/H2O (9: 1 v/v) system. (b) UV-visible spectra of BHP (5 µM) with F‒ (0-50 µM) in DMSO/H2O (9: 1 v/v) system. Figure 4. Naked eye detection of F‒ ions with BHP under visible light (top) and UV-lamp (bottom) and BHP with Cd2+ visible light only (bottom). Figure 5 (a): Fluorescence spectra of BHP (5µM) with 5 × 10-3 M of other anions in DMSO/H2O (9: 1, v/v) system. Excitation at 482 nm. Slit width is 5 nm. (b) Fluorescence spectra of BHP (5µM) with F‒ (0-50 µM) in DMSO/H2O (9: 1, v/v) system. Excitation at 482 nm. Slit width is 5 nm. Figure 6 (a): Selectivity analysis of F‒ ion with BHP in the presence of competing anions. Excitation at 480 nm, Slit width = 5 nm. (b) The blue bars represent the change of the fluorescence intensity of BHP with the consequent addition of other anions. The pink bars represent the addition of the competing anions to BHP. Excitation at 480 nm, Slit width = 5 nm. 3.4. Job’s plot analysis and calculation of binding constant of BHP for Cd2+/F‒ ions Furthermore, the Job’s plot [Figure 7(a) and (b)] analysis based on UV-visible and fluorescence titration experiments results confirmed the 1:1 binding stoichiometry of BHP with both Cd2+/F‒ ions respectively. To further support the binding stoichiometry of BHP with Cd2+/F‒ions, ESI-MS spectral analysis were performed. The ESI-MS spectral analysis of BHP-Cd2+/BHP-F‒ disclosed peaks at 327.45/258.28 corresponds to [BHP+Cd2++Na+]/[BHP+F‒+H++Na+] respectively (Figure S3-S4, See ESI). Furthermore, the 1:1 binding stoichiometry of BHP with F− ions was confirmed via 1H NMR titration profile (Figure 8) and 19F NMR. The deprotonation of ‒OH group present in the salicyl moiety was initiated by hydrogen bonding and the plausible binding mode of BHP with Cd2+ and F‒ ion is shown in Scheme 2. Further, the absorbance and fluorescence intensity changes of Cd2+ ions (A472 nm) and F‒ ions (A482 nm, I603 nm) were plotted against [Cd2+] and [F‒] respectively provided a good linear relationship between both BHP and Cd2+/F‒ ions (Figure S5, S6 and S7, See ESI). From absorbance and fluorescence titration profile, the binding constant values of BHP for Cd2+/F‒ ions were calculated using modified Benesi-Hildebrand method ions (Figure S8, S9 and S10, See ESI). The binding constant values of BHP with Cd2+ ions were found to be 4.26 ×10-4 M from UV-visible titration profile. Similarly, the binding constant values of BHP with F‒ ions were estimated to be 6.03 ×10-3 M / and 3.01 × 10-4 M from UV-visible and fluorescence titration profile respectively. The detection limits (LOD) of F‒ were calculated to be 0.05 nM respectively. Moreover, the LOD values of BHP signifies that the probe might be utilized for the quantitative determination of F‒ ions in environment and real system. Figure 7 (a) Job’s plot for BHP with F‒ ion. (b) Job’s plot for BHP with Cd2+ ion Scheme 2. Binding mode of BHP with Cd2+/F‒ ions 3.5. 1H NMR titrations of BHP with F- ions In addition, to confirm and highly supported the 1:1 binding stoichiometry of probe with F- ions, 1H NMR titrations was performed. Upon addition of F- ion (0.5 equiv), the proton signal corresponds to phenolic –OH group at 11.14 ppm was gradually decreased. Further, addition of 1 equiv. of F- ions to BHP showed the complete disappearance of –OH proton signal as depicted in Figure 8. Moreover, the binding stoichiometric ratio of F- ion with BHP was further supported by 19F NMR experiment. The (H2F)- signal appeared at -124.33 ppm (Figure S11-S12, See ESI) confirms the deprotonation process arose from phenolic –OH proton. Figure 8 1H NMR titration of BHP with F- (0-1equiv) in DMSO-d6 3.6. DFT calculations of BHP with Cd2+/F- ion To recognize the fluorescence enhancement of probe BHP after complexation with F-, DFT calculations were accomplished. The optimized structures of BHP, BHP-Cd2+ and BHP-F- were obtained using DFT/B3LYP-6-311G and B3LYP/LanL2DZ basis sets respectively. The frontier molecular orbital diagram obtained from optimized structure of BHP is presented in Figure 9. Upon binding with Cd2+ ion, the HOMO and LUMO are delocalized over the entire salicyl unit and their energy gap was reduced. It is noteworthy that inhibition of charge transfer in probe BHP renders the reduction of absorbance at 367 nm and 470 nm. Moreover, Complexation of F- ion to the probe BHP leads to lowering of HOMO-LUMO energy gap. In the presence of F-, HOMO and LUMO are distributed over the whole molecule of BHP. From these results, the F- ion was efficiently binded and complexed with BHP than Cd2+ ion. Figure 9. Frontier molecular orbital diagram of BHP, BHP-Cd2+and BHP-F‒ 3.7. Live cell Imaging analysis of BHP in HeLa cells / Zebrafish embryos The cell viability or cytotoxicity analysis of BHP (0–200 µM) against Human HeLa cells were performed using MTT assay. In 100 µM of BHP, cell viability was obtained as too high as 98%. (Figure S13, See ESI). Hence, the probe was sucessfully used for live cell imaging analysis of F- ions in Figure 10. Live cell fluorescence imaging analysis of BHP in HeLa cells. (a) Bright field images of HeLa cells incubated with BHP (25 µM) for 3h (b) Fluorescence merged images of HeLa cells incubated with BHP (25 µM) (c) Fluorescence image of HeLa cells incubated with BHP (25 µM) alone (d) Fluorescence image of HeLa cells incubated with BHP (25 µM) and 25 µM of F‒ ions for 1 h HeLa cells. Further, the HeLa cells were pre-treated with 25 µM of BHP alone for 3 h. Then HeLa cells were seaded with 25 µM of F- ions for 1h. In the absence of F- ions, the probe BHP exposed a weak yellow fluorescence. However, addition of F- ions to the probe BHP induced a bright orange fluorescence (Figure 10). These results endorsed that the probe BHP can be successfully utilized for the intracellular fluorescence imaging analysis of F- ions in HeLa cells. Besides, the exceptional cell viability output of BHP has been further explored in four days Zebrafish embryos. Zebrafish has positioned as a well-known vertebrate model in numerous biological applications. From this perspective, we have utilized also zebrafish embryos as a living animal model to expose the excellent imaging potential of BHP for the detection of F‒ ion in the biological environment (Figure 11) . Figure 11. Fluorescence imaging analysis of F‒ ion in 4 days old Zebrafish embryos developed with BHP and various concentrations of F‒ ion (a) bright field images of BHP (25 µM) alone, (b) fluorescence merged images of BHP and F- ion (25 µM) (c) fluorescence image of BHP (25 µM) alone (d) 25 µM of F‒ ion for 2 h continuously incubated with BHP (25 µM) for 3 h. 3.8. Evaluation of BHP with previous reports The probe BHP has valid and multi features such as single step synthesis, dual-mode recognition, turn-on fluorescence response and colorimetric change. The probe BHP displayed unique sensing property among other dual sensors. Table S1 compares the sensing performance of BHP with recently reported F‒ receptors. Amid, BHP exhibits too low limit of detection when compared with other previously reported chemoreceptors cited in table S1. Also, the limit of detection of BHP is within the range of recommended limits set by both EPA and WHO for F‒ Ions. Moreover, the fluorescence imaging experiments inferred that the probe BHP can be utilized as potential tool for mapping F‒ ion distribution in HeLa cells and Zebrafish embryos. Conclusions We have designed and synthesized a new chromogenic and fluorogenic probe based on salicylhydrazone derivative for the selective and sensitive detection of both Cd2+/F- ions by colorimetrically and fluorimetrically respectively. As per our knowledge, it is a novel simple hydrazone receptor for sensing carcinogenic heavy metal Cd2+ via colorimetric method and biologically significant F‒ ion by both colorimetric and fluorimetric methods. The binding constant value of Cd2+ ion was found to be 4.26×10-4 M by UV-visible method where as 6.03×10-3 and 3.01×10-4 M for F- ion by both UV-visible and fluorescence methods respectively. The limit of detection was found to be 0.05 nM for F- ion. The excellent biological potential of BHP has been successfully utilized for the detection of F- ions in Zebrafish embryos and human HeLa cells. Acknowledgments The authors acknowledge the financial support from the Council of Scientific and Industrial Research, Extramural Research, New Delhi, India (Grant No. 01(2901)17/EMR-II. The Department of Science and Technology, SERB, Extramural Major Research Project (Grant No. EMR/2015/000969), Department of Science and Technology, CERI, New Delhi, India (Grant No. DST/TM/CERI/C130(G) and we acknowledge the DST-FIST, DST-PURSE,DST-IRPHA, UPE programme and UGC-NRCBS, SBS, MKU for providing instrumentation facilities. References Jäkle, F. Chem. Rev. 2010, 110, 3985. Chen, X.; Zhou, Y.; Peng, X.; Yoon, J. Chem. Soc. 2010, 39, 2120. Kim, H. N.; Guo, Z.; Zhu, W.; Yoon J.; Tian, H. Chem. Soc. Rev. 2011, 40, 79. Zhang, J. F.; Zhou, Y.; Yoon, J.; Kim, J. S. Chem. Soc. Rev. 2011, 40, 3416. Zhou, Y.; Yoon, J. Chem. Soc. Rev. 2012, 41, 52. Chen, X.; Pradhan, T.; Wang, F.; Kim, J. S.; Yoon, J. Chem. Rev. 2012, 112, 1910. Wade, C. R.; Broomsgrove, A. E. J.; Aldridge, S.; Gabbaï, F. P. Chem. Rev. 2010, 110, Gale, P. A. Chem. Soc. Rev. 2010, 39, 3746. Wenzel, M.; Hiscock, J. R.; Gale P. A. Chem. Soc. Rev. 2012, 41, 480. Xu, Z.; Chen, X.; Kim, H. N.; Yoon, J. Chem. Soc. Rev. 2010, 39, 127. Galbraith, E.; James, T. D.; Chem. Soc. Rev. 2010, 39, 3831. Xu, Z.; Kim, S. K.; Yoon, J. Chem. Soc. Rev. 2010, 39, 1457. Zhou,Y.; Xu, Z.; Yoon, J.; Chem. Soc. Rev. 2011, 40, Quang, D. T.; Kim, J. S. Chem. Rev. 2010, 110, 6280. Zhou, Y.; Zhang, J. F.; Yoon, J.; Chem. Rev. 2014, 114, 5511. Martínez-Máñez, R.; Sancenón, F. Fluorogenic and chromogenic chemosensors and reagents for anions, 2003. Waisberg, M.; Joseph, P.; Hale, B.; Beyersmann, D. Toxicology. 2003, 192, 95. McFarland, C. N.; Bendell-Young, L. I.; Guglielmo, C.; Williams, T. D. J. Environ. Monit. 2002, 4, Nordberg, G. F.; Herber R. F. M.; Alessio, L. Cadmium in the Human Environment, Oxford University Press, Oxford, UK, 1992. Akula, M.; Thigulla, Y.; Nag, A.; Bhattacharya, RSC Adv. 2015, 5, 57231. Michael Kleerekoper. Clin. North Am. 2018, 65, 441. Erdal, S.; Buchanan, S. N.; Environ. Health Perspect. 2005, 113, Michigami, Y.; Kuroda, Y.; Ueda, K.; Yamamoto, Y.; Anal. Chim. 1993, 274, 299. Sivamani, J.; Siva, A. Sens. Actuators, B, 2017, 242, 423. Sarveswari, S.; Jesin Beneto, A.; Siva, A. Sens. Actuators, B, 2017, 245, 428. Sivamani, J.; Sadhasivam, V.; Siva, A.; Sens. Actuators, 2017, 246, 108. Jesin Beneto, A.; Siva, A.; Sens. Actuators, 2017, 247, 526. Krishnaveni, K.; Iniya, M.; Jeyanthi, D.; Siva, A.; Chellappa, D. Spectrochim. Acta A. 2018, 205, 557. Krishnaveni, K.; Murugesan, S.; Siva, A. New J. 2019, 4, 9021. Krishnaveni, K.; Iniya, M.; Siva, A.; Vidhyalakshmi, N.; Ramesh, U.; Sasikumar, S.; Murugesan, S.; J. Mol. 2020, 1217, 128446. Krishnaveni, K.; Harikrishnan, M.; Murugesan S.; Siva, A. Microchem. J. 2020, 159, 105543. Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, B. Mennucci, G. A. Petersson, H. Nakatsuji, M. Caricato, V.; Li, X.; Hratchian, H. P.; Izmaylov, A. F.; Bloino, J.; Zheng, G.; Sonnenberg, J. L.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Montgomery, J. A.; Peralta, J. E. Jr.; Ogliaro, F.; Bearpark, M.; Heyd, J. J.; Brothers, E.; Kudin, K. N.; Staroverov, V. N.; Kobayashi, R.; Normand, J.; Raghavachari, K.; Rendell, A.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.; Cossi, M.; Rega, N.; Millam, J. M.; Klene, M.; Knox, J. E.; Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Martin, R. L.; Morokuma, K.; Zakrzewski, V. G.; Voth, A.; Salvador, P.; Dannenberg, J. J.; Dapprich, S.; Daniels, A. D.; Farkas, O.; Foresman, J. B.; Ortiz, J. V.; Cioslowski J.; Fox, D. J. Gaussian 09, Revision A. 02, Gaussian, Inc., Wallingford C T, York, 1991.

The proton transport in one-dimensional (1D) confined water chains has been extensively studied as a model for ion channels in cell membrane and fuel cell. However, the mechanistic understanding of the proton transfer (PT) process in 1D water chains remains incomplete. In this study, we demonstrate that the two limiting structures of the hydrated excess proton, H5O2+ (Zundel) and H3O+ (linear H7O3+), undergo a change in dominance as the water chain grows, causing two co-existing and opposing PT mechanisms. Specifically, H5O2+ is stable in the middle of the chain, whereas H3O+ serves as a transition state (TS). Except for this region, H3O+ is stabilized while H5O2+ serves as a TS. The interaction analysis shows that the electrostatic interaction plays a crucial role in the difference in PT mechanisms. Our work fills a knowledge gap between the various PT mechanisms reported in bulk water and long 1D water chains, contributing to a deeper understanding of biological ion channels at the atomic level.

AbstractOne candidate for the cytosolic labile iron pool is iron(II)glutathione. There is also a widely held opinion that an equivalent cytosolic labile heme pool exists and that this pool is important for the intracellular transfer of heme. Here we describe a study designed to characterise conjugates that form between heme and glutathione. In contrast to hydrated iron(II), heme reacts with glutathione, under aerobic conditions, to form the stable hematin–glutathione complex, which contains iron(III). Thus, glutathione is clearly not the cytosolic ligand for heme, indeed we demonstrate that the rate of heme degradation is enhanced in the presence of glutathione. We suggest that the concentration of heme in the cytosol is extremely low and that intracellular heme transfer occurs via intracellular membrane structures. Should any heme inadvertently escape into the cytosol, it would be rapidly conjugated to glutathione thereby protecting the cell from the toxic effects of heme.

AbstractHydrogels are highly hydrated materials that may absorb from 10% to 20% up to hundreds of times their dry weight in water and are composed of three-dimensional hydrophilic polymeric networks that are similar to those in natural tissue. The structural integrity of hydrogels depends on cross-links formed between the polymer chains. Hydrogels have been extensively explored as injectable cell delivery systems, owing to their high tissue-like water content, ability to mimic extracellular matrix, homogeneously encapsulated cells, efficient mass transfer, amenability to chemical and physical modifications, and minimally invasive delivery. A variety of naturally and synthetically derived materials have been used to form injectable hydrogels for tissue engineering applications. The current review article focuses on these biomaterials, on the design parameters of injectable scaffolds, and on the

Cryogenic electron tomography (cryo-ET) combined with sub-tomogram averaging, allows in-situ visualization and structure determination of macromolecular complexes at sub-nanometre resolution. Cryogenic focused ion beam (cryo-FIB) micromachining is used to prepare a thin lamella-shaped sample out of a frozen-hydrated cell for cryo-ET imaging, but standard cryo-FIB fabrication is blind to the precise location of the structure or proteins of interest. Fluorescence-guided focused ion beam (FIB) milling at target locations requires multiple sample transfers prone to contamination, and relocation and registration accuracy is often insufficient for 3D targeting. Here, we present in-situ fluorescence microscopy-guided FIB fabrication of a frozen-hydrated lamella to address this problem: we built a coincident 3-beam cryogenic correlative microscope by retrofitting a compact cryogenic microcooler, custom positioning stage, and an inverted widefield fluorescence microscope (FM) on an existing focused ion-beam scanning electron microscope (FIB-SEM). We show FM controlled targeting at every milling step in the lamella fabrication process, validated with transmission electron microscope (TEM) tomogram reconstructions of the target regions. The ability to check the lamella during and after the milling process results in a higher success rate in the fabrication process and will increase the throughput of fabrication for lamellae suitable for high-resolution imaging.

AbstractAqueous zinc‐based energy storage devices possess superior safety, cost‐effectiveness, and high energy density; however, dendritic growth and side reactions on the zinc electrode curtail their widespread applications. In this study, these issues are mitigated by introducing a polyimide (PI) nanofabric interfacial layer onto the zinc substrate. Simulations reveal that the PI nanofabric promotes a pre‐desolvation process, effectively desolvating hydrated zinc ions from Zn(H2O)62+ to Zn(H2O)42+ before approaching the zinc surface. The exposed zinc ion in Zn(H2O)42+ provides an accelerated charge transfer process and reduces the activation energy for zinc deposition from 40 to 21 kJ mol−1. The PI nanofabric also acts as a protective barrier, reducing side reactions at the electrode. As a result, the PI‐Zn symmetric cell exhibits remarkable cycling stability over 1200 h, maintaining a dendrite‐free morphology and minimal byproduct formation. Moreover, the cell exhibits high stability and low voltage hysteresis even under high current densities (20 mA cm−2, 10 mAh cm−2) thanks to the 3D porous structure of PI nanofabric. When integrated into full cells, the PI‐Zn||AC hybrid zinc‐ion capacitor and PI‐Zn||MnVOH@SWCNT zinc‐ion battery achieve impressive lifespans of 15000 and 600 cycles with outstanding capacitance retention. This approach paves a novel avenue for high‐performance zinc metal electrodes.

AbstractCryo-focused ion beam milling of frozen-hydrated cells and subsequent cryo-electron tomography (cryo-ET) has enabled the structural elucidation of macromolecular complexes directly inside cells. Application of the technique to multicellular organisms and tissues, however, is still limited by sample preparation. While high-pressure freezing enables the vitrification of thicker samples, it prolongs subsequent preparation due to increased thinning times and the need for extraction procedures. Additionally, thinning removes large portions of the specimen, restricting the imageable volume to the thickness of the final lamella, typically <300 nm. Here we introduce Serial Lift-Out, an enhanced lift-out technique that increases throughput and obtainable contextual information by preparing multiple sections from single transfers. We apply Serial Lift-Out to Caenorhabditis elegans L1 larvae, yielding a cryo-ET dataset sampling the worm’s anterior–posterior axis, and resolve its ribosome structure to 7 Å and a subregion of the 11-protofilament microtubule to 13 Å, illustrating how Serial Lift-Out enables the study of multicellular molecular anatomy.

BackgroundHereditary leiomyomatosis and renal cell cancer (HLRCC) is a rare autosomal dominant inheritable disease caused by Fumarate hydratase (FH) gene germline mutation. It is speculated that for HRLCC infertility women with multiple uterine leiomyomas, preimplantation genetic testing may help block transmission of mutated FH gene during pregnancy.Case presentationWe present the case of a 26-year-old nulligravida with a history of early-onset uterine leiomyomatosis had a heterozygous nonsense mutation [NM_000143.4 (FH): c.1027C &gt; T(p.Arg343Ter)] in the HRLLC gene. After ovulation induction and in vitro fertilization, preimplantation genetic testing for monogenic disorders (PGT-M) on embryos revealed the absence of the pathogenic allele in two blastomeres. Uterine fibroids were identified before embryo transfer, leading to a submucosal myomectomy and long period of pituitary suppression by Gonadotropin-releasing hormone analog (GnRHa). The patient achieved a healthy live birth after the second cycle of frozen–thawed embryo transfer.ConclusionThis case details the successful treatment of an infertile patient with an HRLLC family history, resulting in a healthy birth through myomectomy and PGT-M selected embryo transplantation. Our literature search indicates the first reported live birth after HRLLC-PGT-M.

Abstract This study has developed a two-dimensional, two-phase transport model to investigate the transport characteristics in direct methanol fuel cells (DMFCs) using platinum group metal (PGM)-free cathode catalysts. The model considered anisotropic properties of the gas diffusion layer (GDL) caused by current collector’s mechanical compression, the interfacial mass transfer of water and methanol between liquid and vapor, and unique properties of the cathode PGM-free catalyst layer. Results showed that the liquid methanol solution from the anode could provide sufficient water to hydrate the proton exchange membrane (PEM), and the relative humidity of the cathode air did not impact the membrane hydration. Fully hydrating the cathode air may deteriorate the fuel cell performance, especially when the operating temperature is close to 100 °C because the exponential increase of the saturated water pressure with temperature decreased the partial pressure of oxygen. The optimized operating temperature increased with the increase of air pressure and was about 80 °C at 1.5 atm cathode pressure. To achieve the US Department of Energy’s performance target of 300 mW/cm2 peak power density, catalytic activities of both the anode and cathode catalysts need to be improved by one order of magnitude compared with the state-of-the-art commercial catalysts.

Monte Carlo multi-track chemistry simulations were carried out to study, from a radiation chemistry perspective, the effect of “linear energy transfer” (LET) on the transient yields and concentrations of radiolytic oxygen consumption in the high dose-rate (~10⁷ Gy/s) radiolysis of both pure air-saturated (0.25 mM O₂) and oxygenated (30 µM O₂) cell water, in the interval ~1 ps–10 µs. Our simulation model consisted of randomly irradiating water with single pulses of 5-MeV (LET ~ 8 keV/µm), 1.5-MeV (LET ~ 19.5 keV/µm), and 0.7-MeV (LET ~ 33 keV/µm) protons at 25 °C. Similar to what is observed with low-LET irradiation (~300-MeV protons, LET ~ 0.3 keV/µm), our calculations showed that, in pure aerated water, the concentration of depleted oxygen, [–O₂], exhibits a pronounced maximum around ~0.1–0.2 μs for all three high-LET irradiating protons studied. This maximum increased markedly with increasing LET. As expected, the effect of adding competing scavengers of both hydrated electrons and •OH radicals on the radiolytic O₂ depletion in oxygenated cell water (a more bio-mimetic model of cells) irradiated by 5-MeV protons delivered at the same dose rate led to a marked decrease in the maximum of [–O₂] around 1 μs. However, contrary to what is observed for low-LET irradiation, we found that the transient O₂ consumption is quite substantial under high-LET irradiation conditions. This is explained by the fact that, even though their underlying mechanism of action differs, high-LET particles affect radiolysis yields in a similar way to high dose rates.

We developed a sensitive and robust in vitro method to monitor lipoprotein cholesterol and protein exchange and lipoprotein remodeling, using non-exchangeable fluorescent phosphatidylethanolamine (PE) as a lipoprotein marker. We applied this method to monitor the exchange of unesterified cholesterol (FC) and apoA-I among isolated human lipoproteins and synthetic lipoprotein-X (LpX). Fluorescent FC, but not PE, rapidly equilibrated between VLDL and HDL, and transferred almost entirely from VLDL or HDL to LDL. Fluorescent apoA-I bound specifically to HDL and remodeled fluorescent PE and FC-labeled LpX into a new lipoprotein particle that contained both fluorescent lipids and apoA-I. LpX-derived fluorescent PE incorporated into plasma HDL only. The incorporation of LpX-derived fluorescent FC into plasma lipoproteins was similar to fluorescent FC alone, consistent with remodeling of LpX to HDL with concomitant exchange of FC between lipoproteins. LPL remodeled fluorescent PE and FC-tagged VLDL into a new particle containing both fluorescent lipids and apoA-I. We also developed a model system to study lipid transfer in vitro and in vivo by depositing lipids on calcium silicate hydrate crystals to form dense lipid coated donor particles that are readily separated from acceptor membranes and can be used as a surrogate for cell-dependent cholesterol efflux. These methodologies can readily be applied to study the other members of the vast lipoprotein proteome and the wide variety of remodeling events involved in lipoprotein-mediated lipid homeostasis in health and disease.

AbstractWe present a microfluidic platform for studying structure-function relationships at the cellular level by connecting video rate live cell imaging with in situ microfluidic cryofixation and cryo-electron tomography of near natively preserved, unstained specimens. Correlative light and electron microscopy (CLEM) has been limited by the time required to transfer live cells from the light microscope to dedicated cryofixation instruments, such as a plunge freezer or high-pressure freezer. We recently demonstrated a microfluidic based approach that enables sample cryofixation directly in the light microscope with millisecond time resolution, a speed improvement of up to three orders of magnitude. Here we show that this cryofixation method can be combined with cryo-electron tomography (cryo-ET) by using Focused Ion Beam milling at cryogenic temperatures (cryo-FIB) to prepare frozen hydrated electron transparent sections. To make cryo-FIB sectioning of rapidly frozen microfluidic channels achievable, we developed a sacrificial layer technique to fabricate microfluidic devices with a PDMS bottom wall <5 µm thick. We demonstrate the complete workflow by rapidly cryo-freezing Caenorhabditis elegans roundworms L1 larvae during live imaging in the light microscope, followed by cryo-FIB milling and lift out to produce thin, electron transparent sections for cryo-ET imaging. Cryo-ET analysis of initial results show that the structural preservation of the cryofixed C. elegans was suitable for high resolution cryo-ET work. The combination of cryofixation during live imaging enabled by microfluidic cryofixation with the molecular resolution capabilities of cryo-ET offers an exciting avenue to further advance space-time correlative light and electron microscopy (st-CLEM) for investigation of biological processes at high resolution in four dimensions.

Abstract In planta, H2O2 is produced as a by-product of enzymatic reactions and during defense responses. Ascorbate peroxidase (APX) is a key enzyme involved in scavenging cytotoxic H2O2. Here, we report the crystal structure of cytosolic APX from sorghum (Sorghum bicolor) (Sobic.001G410200). While the overall structure of SbAPX was similar to that of other APXs, SbAPX uniquely displayed four bound ascorbates rather than one. In addition to the ɣ-heme pocket identified in other APXs, ascorbates were bound at the δ-meso and two solvent-exposed pockets. Consistent with the presence of multiple binding sites, our results indicated that the H2O2-dependent oxidation of ascorbate displayed positive cooperativity. Bound ascorbate at two surface sites established an intricate proton network with ascorbate at the ɣ-heme edge and δ-meso sites. Based on crystal structures, steady-state kinetics and site-directed mutagenesis results, both ascorbate molecules at the ɣ-heme edge and the one at the surface are expected to participate in the oxidation reaction. We provide evidence that the H2O2-dependent oxidation of ascorbate by APX produces a C2-hydrated bicyclic hemiketal form of dehydroascorbic acid at the ɣ-heme edge, indicating two successive electron transfers from a single bound ascorbate. In addition, the δ-meso site was shared with several organic compounds, including p-coumaric acid and other phenylpropanoids, for the potential radicalization reaction. Site-directed mutagenesis of the critical residue at the ɣ-heme edge (R172A) only partially reduced polymerization activity. Thus, APX removes stress-generated H2O2 with ascorbates, and also uses this same H2O2 to potentially fortify cell walls via oxidative polymerization of phenylpropanoids in response to stress.

Abstract Background LYRM4 is necessary to maintain the stability and activity of the human cysteine desulfurase complex NFS1-LYRM4-ACP. The existing experimental results indicate that cancer cells rely on the high expression of NFS1. However, the role of LYRM4 in liver hepatocellular carcinoma (LIHC) remains unclear. Methods In this study, we combined bioinformatics analysis and clinical specimens to evaluate the mRNA, protein expression, and gene regulatory network of LYRM4 in LIHC. Furthermore, we detected the activity of several classical iron-sulphur proteins in LIHC cell lines through UV-vis spectrophotometry. Results The mRNA and protein levels of LYRM4 were upregulated in LIHC. Subsequent analysis revealed that the LYRM4 mRNA expression was related to various clinical stratifications, prognosis, and survival of LIHC patients. In addition, the mRNA expression of LYRM4 was significantly associated with ALT, tumour thrombus, and encapsulation of HBV-related LIHC patients. IHC results confirmed that LYRM4 was highly expressed in LIHC tissues and showed that the expression of LYRM4 protein in LIHC was significantly correlated with age and serum low-density lipoprotein (LDL) and triglyceride (TG) content. In particular, the mRNA expression of key iron- sulphur proteins POLD1 and PRIM2 was significantly overexpressed and correlated with poor prognosis in LIHC patients. Compared with hepatocytes, the activities of mitochondrial complex I and aconitate hydratase (ACO2) in LIHC cell lines were significantly increased. These results indicated that the iron-sulphur cluster (ISC) biosynthesis was significantly elevated in LIHC, leading to ISC-dependent metabolic reprogramming. Changes in the activity of ISC-dependent proteins may also occur in paracancerous tissues. Further analysis of the biological interaction and gene regulation networks of LYRM4 suggested that these genes were mainly involved in the citric acid cycle and oxidative phosphorylation. Finally, LYRM4 expression in LIHC was significantly positively correlated with the infiltrating levels of six immune cell types, and both factors were strongly associated with prognosis. Conclusion LYRM4 could be a novel prognostic biomarker and molecular target for LIHC therapy. In particular, the potential regulatory networks of LYRM4 overexpression in LIHC provide a scientific basis for future research on the role of the ISC assembly mechanism and LYRM4-mediated sulphur transfer routes in carcinogenesis.

Radioactive waste management agencies all around the world are focusing their efforts to provide a reliable technical solution to the Deep Geological Disposal (DGD) concept, in order to store high level (HLW) and intermediate level long lived (IL-LLW) radioactive waste. The protection and isolation of radionucleides is guaranteed by a set of barriers. Bentonite/sand blocks -in proportion of 40/60 on dry mass of the mixture- constitute the main core of the sealing barrier in the French concept run by the French National Radioactive Waste Management Agency (Andra). Its high swelling potential (>2MPa) during hydration, its low hydraulic permeability (<10-11 m/s) and its gas entry pressure (<2MPa) make it ideal to seal the DGD galleries excavated inside the host rock used as geological barrier. Bentonite/sand blocks are placed at unsaturated state during construction. Afterwards, water migration –in both liquid and vapour states- from the saturated host rock to the blocks will induce the humidification of the blocks until hydraulic equilibrium is reached, hypothetically reaching the saturation state. As this natural process will take hundreds of years, a multitude of experimental devices have been reported at laboratory [3, 5] and real scale [4] to understand the evolution of water transfer in bentonite mixtures and support the predictions of numerical models [1]. In laboratory experiments, samples made of a compacted bentonite mixture are usually placed inside a rigid cell connected to a water source. The infiltration of water is not measured directly but deduced by relative humidity gradients measured along the specimen height. Numerical models and experimental results have not yet reached accurate predictions of how long it takes for bentonite mixtures to hydrate until complete saturation or how the unsaturated hydraulic permeability evolves. In this context, there is a motivation to study this phenomena by advanced techniques able to capture, image and quantify water transfer through porous media. Thus, an experimental campaign based on Magnetic Resonance Imaging (MRI) and 3D X-Ray micro computed tomography (µCT) is proposed to analyze water infiltration in bentonite/sand blocks. MRI is extensively used in health sciences to create images where the contrast is given by the water’s hydrogen proton content in the different tissues of the body. For geological media, where water content is much smaller than in biological tissues and relaxation times of the porewater are shorter -from 0.1 to 2 ms for compacted bentonite/sand [2]- the experimental requirements are different and less documented. On the other hand, µCT scanning provides high spatial resolution images based on the contrast between the X-Ray absorption properties of the constitutive phases observed. Its temporal variations, in a bentonite/sand mixture, might be the result of concurrent phenomena, namely, porosity and saturation changes together with heterogenous motions induced by hydromechanical couplings -the swelling of bentonite solids when they absorb water-. On going MRI and µCT experimental campaigns on a PEEK cell aim at proving the suitability of these techniques to track the evolution of water infiltration in compacted bentonite/sand mixtures, characterizing the water front and the water content along the specimen in function of time. At this stage, preliminary MRI tests have shown the potential of Single Point Imaging (SPI) sequence to quantify, with one-dimensional images, the water content along the bentonite/sand specimen based on a linear correlation with its signal intensity. Preliminary X-Ray radiography tests (Figure 1) run on a cylindric cell of PMMA filled with small blocks of 12 mm in diameter and 10 mm high, prove that X-Ray radiography image analysis gives access to observable and quantifiable increase of absorption associated to the measured decrease in grey level at different transversal sections of the sample. This evolution is linked to the increase of apparent density of the solids -that indeed are absorbing the water-, as described by the Beer-Lambert equation. Even though apparent density increase is goverened by the augmentation of water content, changes in porosity due to the hydromechanical coupling along the sample cannot be neglected. Thus, observing the liquid phase evolution (hydraulics) by MRI, as well as the evolution of the solid/liquid phase (hydromechanics) by 3D-µCT imaging, will potentially provide complementary insight into the mechanisms governing water infiltration in bentonite/sand mixtures.