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Improving photocatalytic efficiency of MnFe2O4 ferrites via doping with Zn2+/La3+ ions: photocatalytic dye degradation for water remediation.

The interference of industrial effluents such as dyes, surfactants, metals, polycyclic aromatic hydrocarbons, and pharmaceutical waste has become a severe global problem for human health due to their carcinogenic, mutagenic, and toxic properties. Ferrites were considered promising photocatalysts for the degradation of organic and inorganic dyes. This study mainly focused on improving the photocatalytic performance of MnFe2O4 nanoferrites via doping of Zn2+ and La3+ ions. The zinc and lanthanum substituted Mn1-xZnxLayFe2-yO4 nanoferrites were prepared by the sol-gel auto-combustion technique fo…

A visualized ratiometric fluorescence sensing system for copper ions based on gold nanoclusters/perovskite quantum dot@SiO2 nanocomposites.

Excessive copper ions (Cu2+) cause serious environmental pollution and even endanger the health of organisms. Fluorescence chemosensing materials are widely used in the detection of metal ions due to their simple operation and high sensitivity. In this study, SiO2-encapsulated single perovskite quantum dot (PQD@SiO2) core-shell nanostructures which show strong, stable, and green fluorescence are synthesized and composited with gold nanoclusters (AuNCs) which show Cu2+-sensitive and red light-emitting fluorescence to obtain a visualized ratiometric fluorescence sensor (AuNCs/PQD@SiO2) for the d…

Silver enriched silver phosphate microcubes as an efficient recyclable SERS substrate for the detection of heavy metal ions.

A rapid, cost-effective and accurate detection of heavy metal ions is crucial for human health monitoring and environmental protection. Surface-enhanced Raman spectroscopy (SERS) has become a reliable method due to its outstanding performance for the identification of contaminants. In this paper, silver phosphate microcubes (Ag3PO4) were fabricated using two different precipitation methods for ultrasensitive SERS detection of heavy metal ions. The use of an organic linker (BPy) with Ag3PO4 enabled the immobilization of Hg2+ and Pb2+ ions. The formation of Ag3PO4 was confirmed by XRD, UV-DRS, F…

Recyclable Functionalized Material for Sensitive Detection and Exceptional Sorption of Hexavalent Chromium and Permanganate Ions with Biosensing Applications.

Environmental remediation with a single platform for selective sensing and removal of toxic analytes with recyclability of the material has always been a desirable system for sustainability. However, materials comprising all the abovementioned advantages are rarely known for oxoanions. We herein developed a fluorogenic napthalimide-based functionalized mesoporous silica material (SiO2@NBDBIA) as a signaling and remediation system for oxoanions (CrO42-, Cr2O72-, and MnO4-) from a pool of several anions. The fluorescence quenching of the SiO2@NBDBIA material in the presence of CrO42-, Cr2O72-, a…

Characterization of Global Gene Expression, Regulation of Metal Ions, and Infection Outcomes in Immune-Competent 129S6 Mouse Macrophages.

Nutritional immunity involves cellular and physiological responses to invading pathogens, such as limiting iron, increasing exposure to bactericidal copper, and altering zinc to restrict the growth of pathogens. Here, we examine infection of bone marrow-derived macrophages from 129S6/SvEvTac mice by Salmonella enterica serovar Typhimurium. The 129S6/SvEvTac mice possess a functional Slc11a1 (Nramp-1), a phagosomal transporter of divalent cations that plays an important role in modulating metal availability to the pathogen. We carried out global RNA sequencing upon treatment with live or heat-k…

Construction of a High-Nuclearity Elliptical Yb(III) Nanoring: NIR Luminescent Response to Metal Ions and Nitro Explosives.

One 14-metal Yb(III) nanoring [Yb14(HL)2L20(DMF)8(H2O)8] (1) with a size of about 1.1 × 2.5 × 2.7 nm was synthesized from a tridentate ligand. Under the excitation of ligand absorption bands, 1 exhibits the NIR luminescence of Yb(III) and displays high luminescence sensitivity and selectivity to Co(II), Cu(II), and 2,4,6-trinitrophenol (PA) at the parts per million level. The KSV values of 1 to Co(II), Cu(II), and PA are 6.0 × 104 M-1, 3.8 × 104 M-1, and 6.9 × 104 M-1, respectively. 1 exhibits high luminescent sensitivity to PA even in the presence of other explosives.

Differential effects of Cu2+ and Fe3+ ions on in vitro amyloid formation of biologically-relevant α-synuclein variants.

Alterations in metal ion homeostasis appear coupled to neurodegenerative disorders but mechanisms are unknown. Amyloid formation of the protein α-synuclein in brain cells is a hallmark of Parkinson's disease. α-Synuclein can bind several metal ions in vitro and such interactions may affect the assembly process. Here we used biophysical methods to study the effects of micromolar concentrations of Cu2+ and Fe3+ ions on amyloid formation of selected α-synuclein variants (wild-type and A53T α-synuclein, in normal and N-terminally acetylated forms). As shown previously, Cu2+ speeds up aggregation o…

Impacts of industrial atmospheric emissions on watershed export of dissolved ions in coastal streams: a Bayesian modeling approach.

Anthropogenic atmospheric emission and subsequent deposition of sulfur (S) has been linked to disrupted watershed biogeochemical processes through soil and surface water acidification. We investigated watershed-scale impacts of acidic deposition on tributary concentrations and watershed exports of major nutrients and ions for the Kitimat River Watershed, British Columbia. Since the 1950s, the Kitimat watershed had an aluminum smelting facility with substantial emissions at the river estuary. Emissions load the airshed overlying the watershed and potentially impact western tributaries leaving e…

MOF-derived porous ZnO-Co3O4 nanocages as peroxidase mimics for colorimetric detection of copper(ii) ions in serum.

Sensitive detection of copper ions (Cu2+) in biological samples is extremely important since an abnormal level of Cu2+ is linked with many diseases. Herein, we demonstrated a novel turn-on colorimetric sensor for selective detection of Cu2+ both in buffered solution and serum samples based on porous bimetallic transition metal oxide nanocages (ZnO-Co3O4 NCs) as peroxidase mimics. The ZnO-Co3O4 NCs were prepared by using ZnCo-zeolitic-imidazolate-framework (ZnCo-ZIF) as precursors via direct calcination. With the high peroxidase-like activity, the obtained ZnO-Co3O4 NCs can catalyze the oxidati…

Effect of calcium ions on the adsorption and lubrication behavior of salivary proteins on human tooth enamel surface.

The aim of this study is to investigate the effect of calcium ions on the adsorption and lubrication behavior of salivary proteins on human tooth enamel. Human whole saliva was collected from healthy donors. Three testing groups were calcium ion-enhanced saliva samples with an increased ion concentration of 1 mmol/L, 5 mmol/L, and 10 mmol/L, respectively. Normal saliva was used as a control. The adsorption behavior was tested using quartz crystal microbalance with dissipation (QCM-D), while the mechanical properties and lubricating behavior of salivary pellicle were examined by nano-indentatio…

What is the Mechanism of Nitric Oxide Conversion into Nitrosonium Ions Ensuring S-Nitrosating Processes in Living Organisms.

Here, I present the data testifying that the conversion of free radical NO molecules to nitrosonium ions (NO+), which are necessary for the realization of one of NO biological effects (S-nitrosation), may occur in living organisms after binding NO molecules to loosely bound iron (Fe2+ ions) with the subsequent mutual one-electron oxidation-reduction of NO molecules (their disproportionation). Inclusion of thiol-containing substances as iron ligands into this process prevents hydrolysis of NO+ ions bound to iron thus providing the formation of stable dinitrosyl iron complexes (DNIC) with thiol …

Progress in rapid optical assays for heavy metal ions based on the use of nanoparticles and receptor molecules.

This review (with 230 refs.) covers recent progress in rapid optical assays for heavy metals (primarily lead and mercury as the most relevant) based on the use of nanoparticles and receptor molecules. An introduction surveys the importance, regulatory demands (such as maximum permissible concentrations) and potential and limitations of various existing methods. This is followed by a general discussion on the use of nanoparticles in optical assays of heavy metals (including properties, basic mechanisms of signal generation). The next sections cover methods for the functionalization of nanoparti…

Кальциум Ионы непосредственно взаимодействуют с эболой-вирусным фузидом для содействия структурно-функциональному изменению, которое усиливает инфекцию.

Болезнь, вызванная вирусом Эболы, является серьезной проблемой для здоровья людей во всем мире, учитывая ее периодические случаи, высокую летальность и отсутствие утвержденных терапевтических средств. Некоторые лекарственные средства, которые изменяют внутриклеточный кальций, особенно эндолисосомы, как оказалось, препятствуют инфицированию вирусом Эбола; однако основополагающий механизм неизвестен. Здесь мы представляем доказательства того, что заирская эболавирусная инфекция поощряется в присутствии кальция в результате прямого взаимодействия кальция с синтезовым пептидом (ПФ) ИСОВ. Мы иденти

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Ebola virus disease is a serious global health concern given its periodic occurrence, high lethality, and the lack of approved therapeutics. … to EBOV's interaction with calcium. We show using spectroscopic and biophysical assays that interactions of the fusion peptide with Ca2+ ions lead to lipid ordering in the host membrane during membrane fusion, and these changes are promoted at low pH and can be correlated with infectivity. We further demonstrate using circular dichroism spectroscopy th …

Bioinspired Copolymers Based Nose/Tongue-Mimic Chemosensor for Label-Free Fluorescent Pattern Discrimination of Metal Ions in Biofluids.

There is a close correlation between body health and the level of biofluid-derived metal ions, which makes it an attractive model analyte for noninvasive health monitoring. The present work has developed a novel nose/tongue-mimic chemosensor array based on bioinspired polydopamine/polyethylenimine copolymers (PDA/PEI n) for label-free fluorescent determination of metal ions in biofluids. Three types of PDA/PEI n (PDA/PEI6, PDA/PEI18, and PDA/PEI48) were prepared by using different concentrations of PEI to construct the proposed sensor array, which would lead to unique fluorescence response pat…

Photophysical properties of a D-π-A Schiff base and its applications in the detection of metal ions.

A D-π-A Schiff-base compound, 2-amino-3({[4-(diethylamino)-2-hydroxylphenyl]methylene}amino)-but-2-enedinitrile (H2L), was prepared using di … ex turned into the CuL' complex as time prolonged. H2L acted as a dual channel chemosensor for Cu2+ ions in THF/HEPES (v/v: 2 : 8, pH = 8.0) and the CuL complex was stable in this medium. H2L is also a naked-eye probe for Mn2+ ions in CH3CN. The limits of detection are much lower than the allowable level of copper(ii) and manganese(ii) in drinking wate …

Grafted iron(iii) ions significantly enhance NO2 oxidation rate and selectivity of TiO2 for photocatalytic NO x abatement.

Semiconductor photocatalysis could be an effective means to combat nitrogen oxides (NO x ) based air pollution through mineralisation of NO x to nitrate. However, most of the typically TiO2-based catalysts employed show a much higher reactivity towards NO than NO2, leading to an accumulation of this unwanted and toxic intermediate. By grafting the photocatalyst with small amounts (≤0.1 at%) of isolated iron(iii) ions, the reactivity towards NO2 is increased by the factor of 9, bringing it up to par with the NO-reactivity and alleviating the problem with intermediate accumulation. Consequently,…

A reaction-based ratiometric fluorescent sensor for the detection of Hg(ii) ions in both cells and bacteria.

A novel reaction-based fluorescent probe (ATC-Hg) was designed and synthesized via the "covalent assembly" principle, which exhibited excellent selectivity and high sensitivity for Hg2+ and CH3Hg+. Moreover, it is the first Hg(ii) sensitive fluorescent probe that has been successfully applied in imaging in both cells and Escherichia coli.

Forensic utility of a nitrogen and oxygen isotope ratio time series of ammonium nitrate and its isolated ions.

Ammonium nitrate (AN) based fertilizers are inexpensive and easily obtained, characteristics that often lead to their use in homemade explosive devices. The stable nitrogen and oxygen isotope ratios (15N/14N and 18O/16O, expressed as δ15N and δ18O) of AN have the potential to aid in forensic investigations by providing supplemental properties for sample-to-sample comparison in materials which are otherwise chemically identical. The forensic utility of stable isotope analyses depends on demonstrated variation between different sources and minimal variation within a source. To test the variabili…

Fragmentation of pure and hydrated clusters of 5Br-uracil by low energy carbon ions: observation of hydrated fragments.

The fragmentation of the isolated 5-bromouracil (5BrU) molecule and pure and nano-hydrated 5BrU clusters induced by low energy 12C4+ ions has been studied. A comparison indicates that the environment, on the one hand, protects the system against the complete break-up into small fragments, but, on the other hand, triggers 'new' pathways for fragmentation, for example the loss of the OH group. The most striking result is the observation of several series of hydrated fragments in the hydrated cluster case, with water molecules bound to hydrophilic sites of 5BrU. This highlights the strong interac…

Electrostatic interactions between ions near Thomas-Fermi substrates and the surface energy of ionic crystals at imperfect metals.

The electrostatic interaction between two charged particles is strongly modified in the vicinity of a metal. This situation is usually accounted for by the celebrated image charges approach, which was further extended to account for the electronic screening properties of the metal at the level of the Thomas-Fermi description. In this paper we build upon a previous approach [M. A. Vorotyntsev and A. A. Kornyshev, Zh. Eksp. Teor. Fiz., 1980, 78(3), 1008-1019] and successive works to calculate the 1-body and 2-body electrostatic energy of ions near a metal in terms of the Thomas-Fermi screening l…