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1.
J Hazard Mater ; 470: 134198, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38608582

ABSTRACT

A novel Ag3PO4/ZnWO4-modified graphite felt electrode (AZW@GF) was prepared by drop coating method and applied to photoelectrocatalytic removal of harmful algae. Results showed that approximately 99.21% of chlorophyll a and 91.57% of Microcystin-LR (MCLR) were degraded by the AZW@GF-Pt photoelectrocatalytic system under the optimal operating conditions with a rate constant of 0.02617 min-1 and 0.01416 min-1, respectively. The calculated synergistic coefficient of photoelectrocatalytic algal removal and MC-LR degradation by the AZW@GF-Pt system was both larger than 1.9. In addition, the experiments of quenching experiments and electron spin resonance (ESR) revealed that the photoelectrocatalytic reaction mainly generated •OH and •O2- for algal removal and MC-LR degradation. Furthermore, the potential pathway for photoelectrocatalytic degradation of MC-LR was proposed. Finally, the photoelectrocatalytic cycle algae removal experiments were carried out on AZW@GF electrode, which was found to maintain the algae removal efficiency at about 91% after three cycles of use, indicating that the photoelectrocatalysis of AZW@GF electrode is an effective emergency algae removal technology.


Subject(s)
Electrodes , Graphite , Marine Toxins , Microcystins , Silver Compounds , Graphite/chemistry , Graphite/radiation effects , Microcystins/chemistry , Microcystins/isolation & purification , Catalysis , Silver Compounds/chemistry , Phosphates/chemistry , Oxides/chemistry , Electrochemical Techniques , Tungsten/chemistry , Chlorophyll A/chemistry , Zinc/chemistry , Water Purification/methods , Chlorophyll/chemistry , Photochemical Processes , Harmful Algal Bloom
2.
J Inorg Biochem ; 255: 112543, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38554579

ABSTRACT

Acetylene hydratase is currently the only known mononuclear tungstoenzyme that does not catalyze a net redox reaction. The conversion of acetylene to acetaldehyde is proposed to occur at a W(IV) active site through first-sphere coordination of the acetylene substrate. To date, a handful of tungsten complexes have been shown to bind acetylene, but many lack the bis(dithiolene) motif of the native enzyme. The model compound, [W(O)(mnt)2]2-, where mnt2- is 1,2-dicyano-1,2-dithiolate, was previously reported to bind an electrophilic acetylene substrate, dimethyl acetylenedicarboxylate, and characterized by FT-IR, UV-vis, potentiometry, and mass spectrometry (Yadav, J; Das, S. K.; Sarkar, S., J. Am. Chem. Soc., 1997, 119, 4316-4317). By slightly changing the electrophilic acetylene substrate, an acetylenic-bis(dithiolene)­tungsten(IV) complex has been isolated and characterized by FT-IR, UV-vis, NMR, X-ray diffraction, and X-ray absorption spectroscopy. Activation parameters for complex formation were also determined and suggest coordination-sphere reorganization is a limiting factor in the model complex reactivity.


Subject(s)
Acetylene , Tungsten , Acetylene/chemistry , Tungsten/chemistry , Spectroscopy, Fourier Transform Infrared , Hydro-Lyases/chemistry
3.
Food Chem ; 448: 138994, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-38522301

ABSTRACT

Integrating a pre-enrichment step into electrochemical detection methodologies has traditionally been employed to enhance the performance of heavy metal detection. However, this augmentation also introduces a degree of intricacy into the sensing process and increases energy consumption. In this work, Mo-doped WO3 is grown in situ on carbon cloth by one-step electrodeposition. The electrode detect multiple heavy metal ions simultaneously in the range of 0.1-100.0 µM with LODs ranging from 11.2 to 17.1 nM. The electrode successfully detected heavy metal ions in diverse food samples. This pioneering detection strategy realized the direct and simultaneous detection of multiple heavy metal ions by utilizing the valence property of WO3 and oxygen vacancies generated by molybdenum doping. The Mo-WO3/CC pre-enrichment-free detection electrode boasts straightforward preparation, a streamlined detection procedure, swift response kinetics, and superior performance relative to previously reported electrodes, which makes it possible to develop a portable heavy metal ion detection device.


Subject(s)
Electrochemical Techniques , Electrodes , Food Contamination , Metals, Heavy , Molybdenum , Tungsten , Metals, Heavy/analysis , Food Contamination/analysis , Electrochemical Techniques/instrumentation , Electrochemical Techniques/methods , Tungsten/chemistry , Molybdenum/chemistry , Oxides/chemistry , Limit of Detection , Food Analysis/instrumentation , Food Analysis/methods
4.
J Hazard Mater ; 470: 134118, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38547752

ABSTRACT

Urine is the major source of nitrogen pollutants in domestic sewage and is a neglected source of H2. Although ClO• is used to overcome the poor selectivity and slow kinetics of urea decomposition, the generation of ClO• suffers from the inefficient formation reaction of HO• and reactive chlorine species (RCS). In this study, a synergistic catalytic method based on TiO2/WO3 photoanode and Sb-SnO2 electrode efficiently producing ClO• is proposed for urine treatment. The critical design is that TiO2/WO3 photoanode and Sb-SnO2 electrode that generate HO• and RCS, respectively, are assembled in a confined space through face-to-face (TiO2/WO3//Sb-SnO2), which effectively strengthens the direct reaction of HO• and RCS. Furthermore, a Si solar panel as rear photovoltaic cell (Si PVC) is placed behind TiO2/WO3//Sb-SnO2 to fully use sunlight and provide the driving force of charge separation. The composite photoanode (TiO2/WO3//Sb-SnO2 @Si PVC) has a ClO• generation rate of 260% compared with the back-to-bake assembly way. In addition, the electrons transfer to the NiFe LDH@Cu NWs/CF cathode for rapid H2 production by the constructed photoelectric catalytic (PEC) cell without applied external biasing potential, in which the H2 production yield reaches 84.55 µmol h-1 with 25% improvement of the urine denitrification rate. The superior performance and long-term stability of PEC cell provide an effective and promising method for denitrification and H2 generation.


Subject(s)
Antimony , Electrodes , Oxides , Tin Compounds , Titanium , Tungsten , Titanium/chemistry , Tungsten/chemistry , Tin Compounds/chemistry , Catalysis , Antimony/chemistry , Oxides/chemistry , Urine/chemistry , Chlorine/chemistry , Hydroxyl Radical/chemistry
5.
Environ Res ; 250: 118519, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38382660

ABSTRACT

The present study explores visible light-assisted photodegradation of ciprofloxacin hydrochloride (CIP) antibiotic as a promising solution to water pollution. The focus is on transforming the optical and electronic properties of BiOCl through the generation of oxygen vacancies (OVs) and the exposure of (110) facets, forming a robust S-scheme heterojunction with WS2. The resultant OVs mediated composite with an optimal ratio of WS2 and BiOCl-OV (4-WS2/BiOCl-OV) demonstrated remarkable efficiency (94.3%) in the visible light-assisted photodegradation of CIP antibiotic within 1.5 h. The CIP degradation using 4-WS2/BiOCl-OV followed pseudo-first-order kinetics with the rate constant of 0.023 min-1, outperforming bare WS2, BiOCl, and BiOCl-OV by 8, 6, and 4 times, respectively. Density functional theory (DFT) analysis aligned well with experimental results, providing insights into the structural arrangement and bandgap analysis of the photocatalysts. Liquid chromatography-mass spectrometry (LC-MS) analysis utilized for identifying potentially degraded products while scavenging experiments and electron paramagnetic resonance (EPR) spin trapping analysis elucidated the S-scheme charge transfer mechanism. This research contributes to advancing the design of oxygen vacancy-mediated S-scheme systems in the realm of photocatalysis, with potential implications for addressing water pollution concerns.


Subject(s)
Ciprofloxacin , Oxygen , Photolysis , Wastewater , Water Pollutants, Chemical , Ciprofloxacin/chemistry , Water Pollutants, Chemical/chemistry , Wastewater/chemistry , Oxygen/chemistry , Bismuth/chemistry , Anti-Bacterial Agents/chemistry , Tungsten/chemistry , Catalysis , Light , Density Functional Theory
6.
Microb Pathog ; 189: 106571, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38341107

ABSTRACT

Nanomaterials containing tungsten (TNMs), characterized by diverse nanostructures had been extensively used in biomedical sector. Despite numerous reports focusing on TNM applications in specific biomedical areas, there is a noticeable absence of comprehensive studies that focused on detailed characterization of nanomaterials along with their biological applications. The present work described the structural, morphological, and antimicrobial properties of tungsten oxide (WO3) nanoparticles coated by antibiotics (nanobiotics), and their application on single and mixed bacterial culture. The nanobiotics included in this study were WO3 coated with ampicillin (W+A), WO3 coated with penicillin (P+W), and WO3 coated with ciprofloxacin (C+W). Techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray spectroscopy (EDX), Fourier transforms infrared spectroscopy (FTIR), Rrman spectroscopy, and UV-visible spectroscopy were used to characterize synthesized nanoparticles. The minimum inhibitory concentration of C+W nanobiotic against S. aureus, E. coli, and mixed culture (S. aureus +E. coli) was lower than that of P+W and A+W. The impact of incubation period showed significant differences for each of nanobiotic against S. aureus, E. coli, and mixed culture. However, there were also non-significant differences among incubation periods for antibacterial activity of nanobiotics. It was pertinent to note that percentage variation in susceptibility of S. aureus with respect to mixed culture remained higher as compared to E. coli, indicating it stronger candidate imposing resistance. This paper thus suggested the strategy of coating of antibiotics with with WO3 nanoparticles as an ideal combination for resistance modulation against single and mixed culture bacteria.


Subject(s)
Bacterial Infections , Metal Nanoparticles , Oxides , Humans , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Tungsten/pharmacology , Tungsten/chemistry , Escherichia coli , Staphylococcus aureus , Ciprofloxacin/pharmacology , Bacteria , Spectroscopy, Fourier Transform Infrared , Microbial Sensitivity Tests , Metal Nanoparticles/chemistry , X-Ray Diffraction
7.
Colloids Surf B Biointerfaces ; 234: 113742, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38271855

ABSTRACT

Because of the excellent performance in photochemistry, WO3 is increasingly applied in the field of biology and medicine. However, little is known about the mechanism of WO3 cytotoxicity. In this work, WO3 nanosheets with oxygen vacancy are synthesized by solvothermal method, then characterized and added to culture medium of human umbilical vein endothelial cells (HUVECs) with different concentrations. We characterized and analyzed the morphology of nano-WO3 by transmission electron microscopy and calculated the specific data of oxygen vacancy by XPS. It is the first time the effect of WO3-x on cells that WO3-x can cause oxidative stress in HUVEC cells, resulting in DNA damage and thus promoting apoptosis. Transcriptome sequencing is performed on cells treated with low and high concentrations of WO3-x, and a series of key signals affecting cell proliferation and apoptosis are detected in differentially expressed genes, which indicates the research direction of nanotoxicity. The expression levels of key genes are also verified by quantitative PCR after cell treatment with different concentrations of WO3-x. This work fills the gap between the biocompatibility of nano WO3-x materials and molecular cytology and paves the way for investigating the mechanism and risks of oxygen vacancy in cancer therapy.


Subject(s)
Oxides , Oxygen , Humans , Human Umbilical Vein Endothelial Cells , Oxides/chemistry , Tungsten/toxicity , Tungsten/chemistry
8.
Chemosphere ; 351: 141128, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38185424

ABSTRACT

Photocatalytic water purification has been extensively explored for its economic, eco-friendly, and sustainable aspects. In this study, tungsten (W) incorporated BaSn1-xWxO3 (x = 0 to 0.05) nanoparticles synthesized by facile hydrogen peroxide precipitation route has been demonstrated for photocatalytic degradation of methylene blue (MB) dye and ciprofloxacin (CIP) antibiotic. The structural analysis indicates the presence of hybrid composite-like nanostructures with reduced crystallinity. Optical studies reveal blueshift in bandgap and decrease in oxygen vacancy defects upon W-incorporation. Pure BaSnO3 shows overall enhanced photocatalytic activity towards MB (90.22%) and CIP (78.12%) after 240 min of white LED light and sunlight irradiation respectively. The 2 % W-incorporated BaSnO3 shows superior photocatalytic degradation of MB (26.89%) and CIP (45.14%) within first 30 min of irradiation confirming the presence of W to be beneficial in the process. The free radical study revealed the dominant role of reactive hole (h+) and oxygen radical (O2•-) species during photodegradation and their intermediates are investigated to elucidate the degradation mechanism of MB within 30 min of irradiation. This study is promising towards developing defect mediated and time-efficient photocatalysts for environmental remediation.


Subject(s)
Calcium Compounds , Ciprofloxacin , Nanoparticles , Oxides , Titanium , Ciprofloxacin/chemistry , Methylene Blue/chemistry , Tungsten/chemistry , Nanoparticles/chemistry
9.
J Environ Sci (China) ; 139: 569-588, 2024 May.
Article in English | MEDLINE | ID: mdl-38105077

ABSTRACT

Environmental pollution, such as water contamination, is a critical issue that must be absolutely addressed. Here, three different morphologies of tungsten-based photocatalysts (WO3 nanorods, WO3/WS2 nanobricks, WO3/WS2 nanorods) are made using a simple hydrothermal method by changing the solvents (H2O, DMF, aqueous HCl solution). The as-prepared nanocatalysts have excellent thermal stability, large porosity, and high hydrophilicity. The results show all materials have good photocatalytic activity in aqueous media, with WO3/WS2 nanorods (NRs) having the best activity in the photodegradation of bisphenol A (BPA) under visible-light irradiation. This may originate from increased migration of charge carriers and effective prevention of electron‒hole recombination in WO3/WS2 NRs, whereby this photocatalyst is able to generate more reactive •OH and •O2- species, leading to greater photocatalytic activity. About 99.6% of BPA is photodegraded within 60 min when using 1.5 g/L WO3/WS2 NRs and 5.0 mg/L BPA at pH 7.0. Additionally, the optimal conditions (pH, catalyst dosage, initial BPA concentration) for WO3/WS2 NRs are also elaborately investigated. These rod-like heterostructures are expressed as potential catalysts with excellent photostability, efficient reusability, and highly active effectivity in different types of water. In particular, the removal efficiency of BPA by WO3/WS2 NRs reduces by only 1.5% after five recycling runs and even reaches 89.1% in contaminated lake water. This study provides promising insights for the nearly complete removal of BPA from wastewater or different water resources, which is advantageous to various applications in environmental remediation.


Subject(s)
Light , Tungsten , Tungsten/chemistry , Benzhydryl Compounds/chemistry , Water , Catalysis
10.
Int J Mol Sci ; 24(19)2023 Sep 22.
Article in English | MEDLINE | ID: mdl-37833860

ABSTRACT

A comparative study of anticorrosive inhibited polymer films on the tungsten surface formed from an aqueous solution of inhibited formulations (INFOR) containing organosilane and corrosion inhibitors was carried out by means of the prolonged exposure of a tungsten product in a modifying solution and by the method of cataphoretic deposition (CPD). Depending on the method of forming films on tungsten, the molecular organization of the near-surface layers was studied (ATR-FTIR), and the subprimary structure of the films was explored (TEM). The optimal modes of cataphoresis deposition (CPD duration and current density applied to the sample) for the formation of a protective inhibited polymer film on the tungsten surface were established by means of SEM. The energy and thermochemical characteristics (sessile drop and DSC methods), as well as operational (adhesive behavior) and protective filming ability (EIS and corrosion behavior), according to the method of formation of inhibited polymer film, were determined. Based on the combined characteristics of the films obtained by the two methods and the deposition modes, the CPD method showed better performance than the electroless dipping method.


Subject(s)
Polymers , Tungsten , Polymers/chemistry , Tungsten/chemistry , Drug Compounding , Motion Pictures
11.
Chem Biodivers ; 20(11): e202301018, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37695826

ABSTRACT

Bacterial infections that cause chronic wounds provide a challenge to healthcare worldwide because they frequently impede healing and cause a variety of problems. In this study, loaded with tungsten oxide (WO3 ), Magnesium oxide (MgO), and graphene oxide (GO) on chitosan (CS) membrane, an inexpensive polymer casting method was successfully prepared for wound healing applications. All fabricated composites were characterized by X-ray powder diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). A scanning electron microscope (SEM) was used to study the synthesized film samples' morphology as well as their microstructure. The formed WO3/MgO@CS shows a great enhancement in the UV/VIS analysis with a highly intense peak at 401 nm and a narrow band gap (3.69 eV) compared to pure CS. The enhanced electron-hole pair separation rate is responsible for the WO3/MgO/GO@CS scaffold's antibacterial activity. Additionally, human lung cells were used to determine the average cell viability of nanocomposite scaffolds and reached 121 % of WO3 /MgO/GO@CS nanocomposite, and the IC50 value was found to be 1654 µg/mL. The ability of the scaffold to inhibit the bacteria has been tested against both E. coli and S. aureus. The 4th sample showed an inhibition zone of 11.5±0.5 mm and 13.5±0.5 mm, respectively. These findings demonstrate the enormous potential for WO3 /MgO/GO@CS membrane as wound dressings in the clinical management of bacterially infected wounds.


Subject(s)
Chitosan , Graphite , Humans , Chitosan/chemistry , Tungsten/chemistry , Graphite/chemistry , Magnesium Oxide , Magnesium , Staphylococcus aureus , Spectroscopy, Fourier Transform Infrared , Escherichia coli , Oxides/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry
12.
ACS Nano ; 17(16): 15763-15775, 2023 08 22.
Article in English | MEDLINE | ID: mdl-37556610

ABSTRACT

Highly porous sensitive materials with well-defined structures and morphologies are extremely desirable for developing high-performance chemiresistive gas sensors. Herein, inspired by the classical alkaloid precipitant reaction, a robust and reliable active mesoporous nitrogen polymer sphere-directed synthesis method was demonstrated for the controllable construction of heteroatom-doped mesoporous tungsten oxide spheres. In the typical synthesis, P-doped mesoporous WO3 monodisperse spheres with radially oriented channels (P-mWO3-R) were obtained with a diameter of ∼180 nm, high specific surface area, and crystalline skeleton. The in situ-introduced P atoms could effectively adjust the coordination environment of W atoms (Wδ+-Ov), giving rise to dramatically enhanced active surface-adsorbed oxygen species and unusual metastable ε-WO3 crystallites. The P-mWO3-R spheres were applied for the sensing of 3-hydroxy-2-butanone (3H2B), a biomarker of foodborne pathogenic bacteria Listeria monocytogenes (LM). The sensor exhibited high sensitivity (Ra/Rg = 29 to 3 ppm), fast response dynamics (26/7 s), outstanding selectivity, and good long-term stability. Furthermore, the device was integrated into a wireless sensing module to realize remote real-time and precise detection of LM in practical applications, making it possible to evaluate food quality using gas sensors conveniently.


Subject(s)
Alkaloids , Listeria monocytogenes , Oxides/chemistry , Tungsten/chemistry , Biomarkers , Nitrogen
13.
Int J Mol Sci ; 24(12)2023 Jun 11.
Article in English | MEDLINE | ID: mdl-37373156

ABSTRACT

Due to their high abundance, polymeric character, and chemical tunability, polysaccharides are perfect candidates for the stabilization of photoactive nanoscale objects, which are of great interest in modern science but can be unstable in aqueous media. In this work, we have demonstrated the relevance of oxidized dextran polysaccharide, obtained via a simple reaction with H2O2, towards the stabilization of photoactive octahedral molybdenum and tungsten iodide cluster complexes [M6I8}(DMSO)6](NO3)4 in aqueous and culture media. The cluster-containing materials were obtained by co-precipitation of the starting reagents in DMSO solution. According to the data obtained, the amount and ratio of functional carbonyl and carboxylic groups as well as the molecular weight of oxidized dextran strongly affect the extent of stabilization, i.e., high loading of aldehyde groups and high molecular weight increase the stability, while acidic groups have some negative impact on the stability. The most stable material based on the tungsten cluster complex exhibited low dark and moderate photoinduced cytotoxicity, which together with high cellular uptake makes these polymers promising for the fields of bioimaging and PDT.


Subject(s)
Molybdenum , Tungsten , Molybdenum/chemistry , Tungsten/chemistry , Dextrans , Iodides , Dimethyl Sulfoxide , Hydrogen Peroxide
14.
Int J Biol Macromol ; 242(Pt 2): 124815, 2023 Jul 01.
Article in English | MEDLINE | ID: mdl-37182632

ABSTRACT

In this research, hydrothermally synthesized tungsten trioxide (WO3) nanocomposites doped polyvinylpyrrolidone (PVP) and chitosan (CS) were studied. Various concentrations (3, 6, and 9 wt%) of PVP were doped into a fixed amount of binary system (CS-WO3) nanocomposites. PVP/CS polymers showed attractive attention because of their different structure, functionality, and architecture control as dopant to WO3. The PVP/CS encapsulates the WO3 (ternary composite), which controls crystallite size (band gap reduction), rapidly overcomes the recombination electron-hole pairs issues, and generates the active sites, resulting in improved catalytic and antimicrobial activity. The synthesized nanocomposites revealed significant catalytic efficiency and methylene blue (MB) dye depletion of 99.9 % in the presence of reducing agent (NaBH4) in neutral and acidic media. Antimicrobial effectiveness of produced nanostructures towards Escherichia coli (E. coli) pathogen at low and high concentrations were investigated by Vernier caliper in mm. Furthermore, to their microbicidal action, docking experiments of CS-doped WO3 and PVP/CS-doped WO3 nanostructures for DHFR and FabI of Escherichia coli suggested blockage of aforesaid enzymes as the plausible pathway.


Subject(s)
Anti-Infective Agents , Chitosan , Nanocomposites , Povidone , Escherichia coli , Tungsten/chemistry
15.
Environ Sci Pollut Res Int ; 30(31): 77032-77043, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37253911

ABSTRACT

The WO3 nanostructures were synthesized by a simple hydrothermal route in the presence of C14TAB and gemini-based twin-tail surfactant. The impact of using these special shape and size directing agents for the synthesis of nanostructures was observed in the form of different shapes and sizes. The WO3 web of chains type nanostructure was obtained using C14TAB in comparison to the cube-shaped nanoparticles through twin-tail surfactant. On contrary, the twin-tail surfactant provides sustainable and controlled growth of cube shape nanoparticles of size ~ 15 nm nearly half of the size ~ 35 nm obtained using conventional surfactant C14TAB, respectively. For the detailed structural features, the Williamson-Hall analysis method was implemented to find out the crystalline size and lattice strain of the prepared nanostructures. Owing to the strong quantum confinement effect, the WO3 cube-shaped nanoparticles with an optical band gap of 2.69 eV of the prepared nanoparticles showed excellent photocatalytic efficacy toward organic pollutant (fast green FCF) compared to the web of chain nanostructures with an optical band gap of 2.66 eV. The ability of the prepared systems to decompose the organic pollutant (fast green FCF) in water was tested under visible light irradiations. The percentage degradation was found to be 94% and 86% for WO3 cube-shaped nanoparticles and WO3 web of chains, respectively. The simplicity of the fabrication method and the high photocatalytic performance of the systems can be promising in environmental applications to treat water pollution.


Subject(s)
Nanostructures , Nanostructures/chemistry , Oxides/chemistry , Tungsten/chemistry , Surface-Active Agents
16.
Molecules ; 28(10)2023 May 11.
Article in English | MEDLINE | ID: mdl-37241758

ABSTRACT

The development of tungsten biochemistry is sketched from the viewpoint of personal participation. Following its identification as a bio-element, a catalogue of genes, enzymes, and reactions was built up. EPR spectroscopic monitoring of redox states was, and remains, a prominent tool in attempts to understand tungstopterin-based catalysis. A paucity of pre-steady-state data remains a hindrance to overcome to this day. Tungstate transport systems have been characterized and found to be very specific for W over Mo. Additional selectivity is presented by the biosynthetic machinery for tungstopterin enzymes. Metallomics analysis of hyperthermophilic archaeon Pyrococcus furiosus indicates a comprehensive inventory of tungsten proteins.


Subject(s)
Aldehyde Oxidoreductases , Pyrococcus furiosus , Aldehyde Oxidoreductases/genetics , Tungsten/chemistry , Oxidation-Reduction , Pyrococcus furiosus/genetics , Pyrococcus furiosus/metabolism
17.
Chemosphere ; 334: 139014, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37224979

ABSTRACT

A co-precipitation technique has been used to prepare Bismuth tungstate nanoparticles (Bi2WO6) for electrochemical capacitors and electrochemical sensing of Ascorbic acid (AA). Using a scanning rate of 10 mV s -1, the electrode was performed as the pseudocapacitance behavior and the specific capacitance to be up to 677 Fg -1 at 1 A/g. Bi2WO6 versus Glassy carbon electrode (GCE) was also used to study the behavior of the Bi2WO6 modified electrodes in detecting ascorbic acid. This electrochemical sensor shows excellent electrocatalytic performance when ascorbic acid is present, as determined by differential pulse voltammetry. In solution, ascorbic acid diffuses to an electrode surface and controls its surface properties. Based on the results from the investigation, the sensor showed a detection sensitivity of 0.26 mM/mA, and a limit of detection (LOD) of 77.85 mM. It is clear from these results that Bi2WO6 may find application as an electrode material for supercapacitors and glucose sensors.


Subject(s)
Metal Nanoparticles , Tungsten , Tungsten/chemistry , Bismuth , Electrodes , Metal Nanoparticles/chemistry , Ascorbic Acid/chemistry , Electrochemical Techniques/methods
18.
Curr Protoc ; 3(4): e760, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37068198

ABSTRACT

In the brain, cell morphology often reflects function and thus provides a first glance into cell-specific changes in health and disease. Studying the morphology of individual cells, including neurons and glia, is essential to fully understand brain connectivity and changes in disease states. Many recent morphological studies of brain cells have relied on transgenic animals and viral vectors to label individual cells. However, transgenic animals are not always available, and in non-human primate (NHP) models, viral transduction poses several practical and financial challenges, limiting the number of researchers that can thoroughly investigate cell morphology in NHP or other non-transgenic animals. The diOlistic system for delivering fluorescent lipophilic dye-coated gold or tungsten particles into brain tissue has been used to label single cells, but the currently available systems are expensive, have limited applications, and are rare in laboratories. Investigations of cell morphology without transgenic or viral approaches rely on immunohistochemical markers that may not reveal structural detail, such as in astrocytes. To overcome these practical limitations to expand our understanding of cell morphology across species with an emphasis on astrocytes, we constructed a low-cost ballistic method to deliver dye-coated gold or tungsten particles into NHP and rodent brain slices. We have optimized the tissue processing parameters to achieve penetration of DiI-coated particles, allowing for the complete reconstruction of individual cells within a brain slice. While we report on astrocytes in rodent and NHP brain slices, this protocol can be adapted and implemented across species and tissue types to evaluate cell morphology. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Building the diOlistic device Basic Protocol 2: Preparation of dye "bullet" carriers Basic Protocol 3: Perfusion, brain sectioning, and diOlistic labeling Alternate Protocol: Immunohistochemical labeling of sections prior to diOlistic bombardment.


Subject(s)
Rodentia , Tungsten , Animals , Rodentia/metabolism , Staining and Labeling , Tungsten/chemistry , Brain , Fluorescent Dyes/metabolism , Primates/metabolism , Animals, Genetically Modified , Gold
19.
Int J Mol Sci ; 24(4)2023 Feb 07.
Article in English | MEDLINE | ID: mdl-36834697

ABSTRACT

The threshold displacement energy (TDE) is an important measure of the extent of a material's radiation damage. In this study, we investigate the influence of hydrostatic strains on the TDE of pure tantalum (Ta) and Ta-tungsten (W) alloy with a W content ranging from 5% to 30% in 5% intervals. Ta-W alloy is commonly used in high-temperature nuclear applications. We found that the TDE decreased under tensile strain and increased under compressive strain. When Ta was alloyed with 20 at% W, the TDE increased by approximately 15 eV compared to pure Ta. The directional-strained TDE (Ed,i) appears to be more influenced by complex ⟨i j k⟩ directions rather than soft directions, and this effect is more prominent in the alloyed structure than in the pure one. Our results suggest that radiation defect formation is enhanced by tensile strain and suppressed by compressive strain, in addition to the effects of alloying.


Subject(s)
Tantalum , Tungsten , Tantalum/chemistry , Tungsten/chemistry , Alloys/chemistry
20.
Environ Sci Pollut Res Int ; 30(8): 20775-20789, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36258116

ABSTRACT

In this study, Ag-WO3/bentonite nanocomposites were synthesized through a sol-gel process, a microwave irradiation technique, and a sol-immobilization process to examine their impact on the photocatalytic activity in the degradation of humic acids. The optical and structural properties of the synthesized materials were characterized using X-ray diffraction (XRD), Fourier-transform-infrared spectra (FTIR), field emission scanning electron microscope (FE-SEM) with energy dispersive X-ray (EDX), UV-Vis diffused reflectance spectra (UV-Vis DRS), Brunauer-Emmett-Teller (BET) method, and transmission electron microscope (TEM). The presence of Ag and WO3 peaks in the XRD and EDX spectra confirmed the synthesis of Ag-WO3 nanoparticles in the composite. The monoclinic structure of the produced WO3 samples are shown by powder X-ray diffraction patterns. The WO3-based nanocomposites' photocatalytic activity was improved by the composition of Ag and bentonite, which reduced the optical bandgap energy of WO3. The binary (Ag-WO3) nanocomposite showed improved photocatalytic activity towards the degradation of humic acid (HA) from 58% (pristine WO3) to 82% (Ag-WO3) when compared with the pristine WO3 sample under the visible light irradiation. Notably, the ternary (Ag-WO3/bent) nanocomposite demonstrated an outstanding photocatalytic efficiency of HA degradation (91.0%) under normal conditions (pH = 7.0 and 25 °C). Humic acid degradation in Ag-WO3/bent was expressed by the pseudo-first-order kinetic. To summarize, integrating Ag, WO3, bentonite, and visible light radiation to activate HA efficiently can be offered as a successful and promising technique for wastewater treatment.


Subject(s)
Nanocomposites , Water , Water/chemistry , Humic Substances , Bentonite/chemistry , Tungsten/chemistry , Nanocomposites/chemistry , Catalysis
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