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Lead ions (Pb 2+ ) are heavy metal environmental pollutants that can significantly impact biological health. In this study, the synthesis of a ternary nanocomposite, ErVO 4 /P@g-C 3 N 4 /SnS 2 , was achieved using a combination of hydrothermal synthesis and mechanical grinding. The as-fabricated photoelectrochemical (PEC) sensor was found to be an ideal substrate for Pb 2+ detection with high sensitivity and reliability. The ErVO 4 /P@g-C 3 N 4 /SnS 2 /FTO was selected as the substrate because of its remarkable and reliable photocurrent response. The Pb 2+ sensor exhibited a low detection limit of 0.1 pM and a broad linear range of 0.002-0.2 nM. Moreover, the sensor exhibited outstanding stability, selectivity, and reproducibility. In real-time applications, it exhibited stable recovery and a low relative standard deviation, ensuring reliable and accurate measurements. The as-prepared PEC sensor was highly stable for the detection of Pb 2+ in different water samples. This promising characteristic highlights its significant potential for use in the detection of environmental pollutants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background and Purpose: Metal-based therapeutic agents are limited by the required concentration of metal-based agents. Hereby, we determined if combination with 17β-oestradiol (E2) could reduce such levels and the therapy still be effective in type 2 diabetes mellitus (T2DM)., Experimental Approach: The metal-based agent (vanadyl acetylacetonate [VAC])- 17β-oestradiol (E2) combination is administered using the membrane-permeable graphene quantum dots (GQD), the vehicle, to form the active GQD-E2-VAC complexes, which was characterized by fluorescence spectra, infrared spectra and X-ray photoelectron spectroscopy. In db/db type 2 diabetic mice, the anti-diabetic effects of GQD-E2-VAC complexes were evaluated using blood glucose levels, oral glucose tolerance test (OGTT), serum insulin levels, homeostasis model assessment (homeostasis model assessment of insulin resistance [HOMA-IR] and homeostasis model assessment of β-cell function [HOMA-β]), histochemical assays and western blot., Key Results: In diabetic mice, GQD-E2-VAC complex had comprehensive anti-diabetic effects, including control of hyperglycaemia, improved insulin sensitivity, correction of hyperinsulinaemia and prevention of β-cell loss. Co-regulation of thioredoxin interacting protein (TXNIP) activation by the combination of metal complex and 17β-oestradiol contributed to the enhanced anti-diabetic effects. Furthermore, a potent mitochondrial protective antioxidant, coniferaldehyde, significantly potentiates the protective effects of GQD-E2-VAC complexes., Conclusion and Implications: A metal complex-E2 combinatorial approach achieved simultaneously the protection of β cells and insulin enhancement at an unprecedented low dose, similar to the daily intake of dietary metals in vitamin supplements. This study demonstrates the positive effects of combination and multi-modal therapies towards type 2 diabetes treatment., (© 2024 British Pharmacological Society.)

Sensitive and accurate analysis of pyrophosphate (PPi) is of great importance for preventing health hazard in environment. Nevertheless, most of sensors focus on sensitivity and selectivity, but practicality is also a significant quota. How to reconciling sensitivity, selectivity and practicability in one single sensor is desirable but remains challenging. Here, we created a novel metal-carbon nanozyme V 2 O 5 @C with two-dimensional (2D) morphology and high yet exclusive peroxidase (POD)-like activity via a glucose and NH 4 NO 4 -co-directed avenue, and further showed its application in constructing a portable and disposable paper-based analytical chip (PA-chip) for rapid, visual and onsite analysis of PPi. PPi etched V 2 O 5 to prevent the decomposition of H 2 O 2 into ·OH, resulting in weakened POD-like activity. In comparison with PPi deficiency, colorless TMB couldn't be oxidized into oxidized TMB with a dropped absorption at 652 nm. Therefore, obviously shallowed blue color on PA-chip surface was recorded, and demonstrated a negative relationship with PPi dosage, enabling rapid and visual detection of PPi with a limit of detection of 2.6 nM. This study demonstrated the burgeoning applications of nanozymes with POD-like activity in construction of PA-chips for PPi and will quicken the advancement of practical sensors, guaranteeing environmental safety., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Investigating the speciation of vanadium complexes in the presence of potential biomolecular targets under physiological conditions remains challenging, and further experimental techniques are needed to better understand the mechanism of action of potential metallodrugs. The interaction of two model peptides (angiotensin I and angiotensin II) with three well-known oxidovanadium(IV) compounds with antidiabetic and/or anticancer activity, [V IV O(pic) 2 (H 2 O)], [V IV O(ma) 2 ], and [V IV O(dhp) 2 ] (where pic, ma, and dhp are picolinate, maltolate, and 1,2-dimethyl-3-hydroxy-4(1H)-pyridinonate anions, respectively), was investigated by ESI-MS/MS (electrospray ionization tandem mass spectrometry) and complemented by EPR (electron paramagnetic resonance) spectroscopy measurements and theoretical calculations at the DFT (density functional theory) level. The results demonstrated that vanadium-peptide bonds are preserved after HCD (higher energy collisional dissociation) fragmentation, allowing for the identification of binding sites through a detailed analysis of the fragmentation spectra. Angiotensin I (AT1) and angiotensin II (AT2) exhibited different coordination behaviors. AT1, with two His residues (His6, His9), prefers to form [AT1 + VOL] adducts with both histidine residues coordinated to the metal ion, while AT2, which has only His6, can bind the metal in a monodentate fashion, forming also [AT2 + VOL 2 ] adducts. Insights from this study pave the way to ESI-MS/MS investigations of more complex systems, including target proteins and further development of vanadium-based drugs.

Characterization and evaluation of hazardous spent V 2 O 5 -WO 3 /TiO 2 catalysts are critical to determining their treatment or final disposal. This study employs a thermal approach to simulate the preparation of spent catalysts derived from commercial V 2 O 5 -WO 3 /TiO 2 catalysts and investigate the structure-activity relationship of the carrier changes during the deactivation process. The results indicate that the catalyst carrier undergoes two processes: an increase in grain size and a transformation in crystal structure. Both structural and catalytic investigations demonstrate that the grain size for catalyst deactivation is 24.62 nm, and the formation of CaWO 4 occurs before the crystalline transformation. The specific surface area is susceptible to an increase in grain size. The reactions of selective catalytic reduction involve the participation of both Brønsted acid and Lewis acid sites. The deactivation process of the carrier initially affects Brønsted acid sites, followed by a reduction in Lewis acid sites, resulting in a decline in NH 3 adsorption capacity and oxidation. Correlation analysis reveals that changes in the physicochemical properties of the catalyst reduce the NO conversion, with the order being The grain size > Total acid amount > The surface area. It is recommended to recycle the spent catalyst if the carrier grain size is less than 25 nm. The findings of this investigation contribute to expanding the database for evaluating and understanding the physicochemical properties of spent catalysts for disposal., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

A computational study based on derivatives of the anticancer VCp 2 Cl 2 compound and their interaction with representative models of deoxyribonucleic acid (DNA) is presented. The derivatives were obtained by substituting the cyclopentadienes of VCp 2 Cl 2 with H 2 O, NH 3 , OH - , Cl - , O 2- and C 2 O 4 2- ligands. The oxidation states IV and V of vanadium were considered, so a total of 20 derivative complexes are included. The complexes interactions with DNA were studied using two different models, the first model considers the interactions of the complexes with the pair Guanine-Cytosine (G-C) and the second involves the interaction of the complexes with adjacent pairs, that is, d(GG). This study compares methodologies based on density functional theory with coupled cluster like calculations (DLPNO-CCSD(T)), the gold standard of electronic structure methods. Furthermore, the change in the electron density of the hydrogen bonds that keep bonded the G-C pair and d(GG) pairs, due to the presence of vanadium (IV) and (V) complexes is rationalize. To this aim, quantities obtained from the topology of the electron densities are inspected, particularly the value of the electron density at the hydrogen bond critical points. The approach allowed to identify vanadium complexes that lead to significant changes in the hydrogen bonds indicated above, a key aspect in the understanding, development, and proposal of mechanisms of action between metal complexes and DNA., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Oxalic acid (OA) is a predominant constituent in kidney stones, contributing to 70-80% of all cases. Rapid detection of OA is vital for the early diagnosis and treatment of kidney stone conditions. This work introduces a novel electrochemical sensing approach for OA, leveraging vanadium disulfide (VS 2 ) nanoflowers synthesized via hydrothermal synthesis. These VS 2 nanoflowers, known for their excellent electrocatalytic properties and large surface area, are used to modify glassy carbon electrodes for enhanced OA sensing. The proposed OA sensor exhibits high sensitivity and selectivity across a wide linear detection range of 0.2-20 μM, with an impressively low detection limit of 0.188 μM. The practicality of this sensor was validated through interference studies, offering a promising tool for the early diagnosis and monitoring of kidney stone diseases.

In this study, a simple green synthesis of vanadium pentoxide nanoparticles (VNPs) was prepared by the extract of Kaffir lime fruit (Citrus hystrix) as a green reducing and stabilizing agent, along with the investigation of calcination temperature was carried out at 450 and 550 °C. It was affirmed that, at higher temperature (550 °C), the VNPs possessed a high degree crystalline following the construction of (001) lattice diffraction within an increase in crystalline size from 47.12 to 53.51 nm, although the band gap of the materials at 450 °C was lower than that of the VNPs-550 (2.53 versus 2.66 eV, respectively). Besides, the materials were assessed for the potential bioactivities toward antibacterial, antifungal, DNA cleavage, anti-inflammatory, and hemolytic performances. As a result, the antibacterial activity, with minimal inhalation concentration (MIC) < 6.25 μg/mL for both strains, and fungicidal one of the materials depicted the dose-dependent effects. Once, both VNPs exhibited the noticeable efficacy of the DNA microbial damage, meanwhile, the outstanding anti-inflammatory agent was involved with the IC 50 of 123.636 and 227.706 μg/mL, accounting for VNPs-450 and VNPs-550, respectively. Furthermore, this study also demonstrated the hemolytic potential of the VNPs materials. These consequences declare the prospects of the VNPs as the smart and alternative material from the green procedure in biomedicine., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Studies have shown that the inhibition of phosphatase and tensin homolog deleted on chromosome 10 (PTEN)was neuroprotective against ischemia/reperfusion(I/R) injury. Bisperoxovanadium (bpV), a derivative of vanadate, is a well-established inhibitor of PTEN. However, its function islimited due to its general inadequacy in penetrating cell membranes. Mxene(Ti 3 C 2 T x ) is a novel two-dimensional lamellar nanomaterial with an excellent ability to penetrate the cell membrane. Yet, the effects of this nanomaterial on nervous system diseases have yet to be scrutinized. Here, Mxene(Ti 3 C 2 T x ) was used for the first time to carry bpV(HOpic), creating a new nanocomposite Mxene-bpV that was probed in a cerebral I/R injury model. The findings showed that this synthetic Mxene-bpV was adequately stable and can cross the cell membraneeasily. We observed that Mxene-bpV treatment significantly increased the survival rate of oxygen glucose deprivation/reperfusion(OGD/R)--insulted neurons, reduced infarct sizes and promoted the recovery of brain function after mice cerebral I/R injury. Crucially, Mxene-bpV treatment was more therapeutically efficient than bpV(HOpic) treatment alone over the same period. Mechanistically, Mxene-bpV inhibited the enzyme activity of PTEN in vitro and in vivo. It also promoted the expression of phospho-Akt (Ser 473 ) by repressing PTEN and then activated the Akt pathway to boost cell survival. Additionally, in PTEN transgenic mice, Mxene-bpV suppressed I/R-induced inflammatory response by promoting M2 microglial polarization through PTEN inhibition. Collectively, the nanosynthetic Mxene-bpV inhibited PTEN' enzymatic activity by activating Akt pathway and promoting M2 microglial polarization, and finally exerted neuroprotection against cerebral I/R injury., (© 2024. The Author(s).)

The present work focuses on the synthesis of a vanadium nitride (VN)/carbon nanocomposite material via the thermal decomposition of vanadyl phthalocyanine (VOPC). The morphology and chemical structure of the synthesized compounds were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), Fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoemission spectroscopy (XPS). The successful syntheses of the VOPC and non-metalated phthalocyanine (H 2 PC) precursors were confirmed using FTIR and XRD. The VN particles present a needle-like morphology in the VN synthesized by the sol-gel method. The morphology of the VN/C composite material exhibited small clusters of VN particles. The XRD analysis of the thermally decomposed VOPC indicated a mixture of amorphous carbon and VN nanoparticles (VN(TD)) with a cubic structure in the space group FM-3M consistent with that of VN. The XPS results confirmed the presence of V(III)-N bonds in the resultant material, indicating the formation of a VN/C nanocomposite. The VN/C nanocomposite synthesized through thermal decomposition exhibited a high carbon content and a cluster-like distribution of VN particles. The VN/C nanocomposite was used as an anode material in LIBs, which delivered a specific capacity of 307 mAh g -1 after 100 cycles and an excellent Coulombic efficiency of 99.8 at the 100th cycle.

Despite the high medicinal value of tiopronin, there are substantial adverse effects such as yellow skin, yellow eyes, muscle aches, etc. Therefore, there is a huge necessity to identify tiopronin using advanced sensors in provided samples. Recently, the preference for graphene quantum dots (GQDs) and inorganic nanomaterial-based fluorescent sensors for the detection of pharmaceuticals has been extensively documented due to their plentiful advantages. Therefore, in this work, the cobalt-doped GQDs decorated vanadium pentoxide nanosheet-based fluorescence switch 'Off-On' sensor (Co-GQDs@V 2 O 5 -NS) was designed for highly sensitive and selective detection of tiopronin. Briefly, the green synthesis of highly fluorescent Co-GQDs was carried out using a hydrothermal method. Meanwhile, the synthesis of V 2 O 5 -NS was synthesized using the liquid exfoliation method. The synthesis of Co-GQDs@V 2 O 5 -NS was accomplished wherein Co-GQDs adsorbed on the surface of V 2 O 5 -NS that offered the quenching of fluorescence of Co-GQDs. Afterward, the addition of tiopronin into the quenched probe disclosed the proportional recovery of fluorescence of Co-GQDs. Here, the addition of tiopronin provides the decomposition of V 2 O 5 -NS and conversion into the V 4+ that aids in releasing the quenched fluorescence of Co-GQDs. The limit of detection and linearity range for tiopronin was found to be 1.43 ng/mL and 10-700 ng/mL, respectively. Moreover, it demonstrated high selectivity, good stability at experimental conditions, and practicality in analyzing tiopronin in spiked sample analysis. Hence, the designed Co-GQDs@V 2 O 5 -NS nanosized sensor enables high sensitivity, selectivity, simplicity, label-free, and eco-friendly tiopronin recognition. In the future, the utility of Co-GQDs@V 2 O 5 -NS can open a new door for sensing tiopronin in provided samples., (© 2024. The Author(s), under exclusive licence to The Japan Society for Analytical Chemistry.)

The sensing modified electrode was prepared using glucose oxidase immobilized onto vanadium pentoxide xerogel with glass/FTO as support electrode to evaluate the possibility to construct a V 2 O 5 /GOx Extended Gate Field Effect Transistor biosensor. Previously, our studies exhibited a sensitivity of V 2 O 5 of 58.1 mV/pH. The use of Nafion® onto V 2 O 5 /GOx caused a decrease of mass loss after several cycles compared to the modified electrode without Nafion® during the EQCM and cyclic voltammetrics studies. Electrical characterization of V 2 O 5 /GOx demonstrated a tendency to stability after 200 s as a function of applied current. In presence of glucose and in different pH, the current decreased when the glucose concentration increased due to the lower active sites of enzyme. After ten voltammetric cycles, the total charge tends to structural stability. In pH = 5.0, the modified electrode based on V 2 O 5 /GOx Extended Gate Field Effect Transistor presented more tendency to sensitivity in different concentration of glucose., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The development of high-performance biosensors is a key focus in the nanozyme field, but the current limitations in biocompatibility and recyclability hinder their broader applications. Herein, we address these challenges by constructing core-shell nanohybrids with biocompatible poly(ethylene glycol) (PEG) modification using a galvanic replacement reaction between orthovanadate ions and liquid metal (LM) (VO x @EGaIn-PEG). By leveraging the excellent charge transfer properties and the low band gap of the LM surface oxide, the VO x @EGaIn-PEG heterojunction can effectively convert hydrogen peroxide into hydroxyl radicals, demonstrating excellent peroxidase-like activity and stability ( K m = 490 μM, v max = 1.206 μM/s). The unique self-healing characteristics of LM further enable the recovery and regeneration of VO x @EGaIn-PEG nanozymes, thereby significantly reducing the cost of biological detection. Building upon this, we developed a nanozyme colorimetric sensor suitable for biological systems and integrated it with a smartphone to create an efficient quantitative detection platform. This platform allows for the convenient and sensitive detection of glucose in serum samples, exhibiting a good linear relationship in the range of 10-500 μM and a detection limit of 2.35 μM. The remarkable catalytic potential of LM, combined with its biocompatibility and regenerative properties, offers valuable insights for applications in catalysis and biomedical fields.

F-doped V 2 O 5 -WO 3 /TiO 2 catalyst has been confirmed to have excellent denitration activity at low temperatures. Since the V 2 O 5 -WO 3 /TiO 2 catalyst is a structure-sensitive catalyst, the loading order of V 2 O 5 and WO 3 may affect its denitration performance. In this paper, a series of F-doped V 2 O 5 -WO 3 /TiO 2 catalysts with different V 2 O 5 and WO 3 loading orders were synthesized to investigate the effect of denitration performance at low temperatures. It was found that the loading orders led to significant gaps in denitration performance in the range of 120-240 °C. The results indicated loading WO 3 first better utilized the oxygen vacancies on the TiF carrier promoting the generation of reduced vanadium species. In addition, loading WO 3 first facilitated the dispersion of V 2 O 5 thus enhanced the NH 3 adsorption capacity of VWTiF. In situ DRIFT verified the rapid reaction between NO 2 , nitrate, and nitrite species and adsorbed NH 3 over the VWTiF, confirming that the NH 3 selective catalytic reduction (NH 3 -SCR) reaction over VWTiF at 240 °C proceeded by the Langmuir-Hinshelwood (L-H) mechanism. This research established the constitutive relationship between the loading order of V 2 O 5 and WO 3 and the denitration performance of the F-doped VWTi catalyst providing insights into the catalyst design process., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

NH 3 -SCR (SCR: Selective catalytic reduction) is an effective technology for the de-NO x process from both mobile and stationary pollution sources, and the most commonly used catalysts are the vanadia-based catalysts. An innovative V 2 O 5 -CeO 2 /TaTiO x catalyst for NO x removal was prepared in this study. The influences of Ce and Ta in the V 2 O 5 -CeO 2 /TaTiO x catalyst on the SCR performance and physicochemical properties were investigated. The V 2 O 5 -CeO 2 /TaTiO x catalyst not only exhibited excellent SCR activity in a wide temperature window, but also presented strong resistance to H 2 O and SO 2 at 275 ℃. A series of characterization methods was used to study the catalysts, including H 2 -temperature programmed reduction, X-ray photoelectron spectroscopy, NH 3 -temperature programmed desorption, etc. It was discovered that a synergistic effect existed between Ce and Ta species. The introduction of Ce and Ta enlarged the specific surface area, increased the amount of acid sites and the ratio of Ce 3+ , (V 3+ +V 4+ ) and O α , and strengthened the redox capability which were related to synergistic effect between Ce and Ta species, significantly improving the NH 3 -SCR activity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Over the last four decades, vanadium compounds have been extensively studied as potential antidiabetic drugs. With the present review, we aim at presenting a general overview of the most promising compounds and the main results obtained with in vivo studies, reported from 1899-2023. The chemistry of vanadium is explored, discussing the importance of the structure and biochemistry of vanadate and the impact of its similarity with phosphate on the antidiabetic effect. The spectroscopic characterization of vanadium compounds is discussed, particularly magnetic resonance methodologies, emphasizing its relevance for understanding species activity, speciation, and interaction with biological membranes. Finally, the most relevant studies regarding the use of vanadium compounds to treat diabetes are summarized, considering both animal models and human clinical trials. An overview of the main hypotheses explaining the biological activity of these compounds is presented, particularly the most accepted pathway involving vanadium interaction with phosphatase and kinase enzymes involved in the insulin signaling cascade. From our point of view, the major discoveries regarding the pharmacological action of this family of compounds are not yet fully understood. Thus, we still believe that vanadium presents the potential to help in metabolic control and the clinical management of diabetes, either as an insulin-like drug or as an insulin adjuvant. We look forward to the next forty years of research in this field, aiming to discover a vanadium compound with the desired therapeutic properties.

A series of oxovanadium(V) compounds 1-4 were prepared and explored as stereodynamic chiroptical probes to detect a simulant of sarin known as diethyl chlorophosphate (DCP) without any interference from the competing analytes. Simultaneous CD cum UV/vis based bimodal instant recognition of DCP using optically active probes is unprecedented. Upon fabricating the vanadium compound with a polymer has yielded a chiroptical membrane, which showed a change in its dichroic as well as colorimetric signals on interaction with DCP vapour at 1 ppm. EPR and UV/vis studies revealed an irreversible change of the CD-active V(V) to the CD-silent ternary V(V) species in presence of DCP via a transient V(IV) species. Nucleophilic attack of the alkoxo oxygen of 1-4 to the electrophilic P atom of DCP resulted in the formation of ternary V(V) compounds as confirmed by 51 V/ 31 P NMR.

We have previously synthesized and characterized the chrysin coordination complex with the oxidovanadium(IV) cation (V IV O(chrys) 2 ) and characterized in ethanolic solution and in solid state. Because suitable single crystals for X-ray diffraction determinations could not be obtained, in the present work, we elucidate the geometrical parameters of this complex by computational methodologies. The optimization and vibrational investigation were carried out both in ethanolic solution and in gas phase. The computational results support the experimentally proposed geometries of the V IV O(chrys) 2 complex, thus leading to the conclusion that the complex exists as conformers with trans-octahedral geometry in ethanolic solution and as conformers with cis-octahedral geometry in the solid state. The complex also exists as conformers with trans-octahedral geometry in aqueous media. The active species formed after dissolution in DMSO showed anticancer and antimetastatic behavior in human lung cell line A549 with moderate binding (K a ca. 10 5 M -1 ) to bovine serum albumin (BSA). The interaction through hydrogen bonding and van der Waals forces resulted in a spontaneous process. Site marker competitive experiments showed binding sites for chrysin mainly located in site II (subdomain IIIA) and in site I (subdomain IIIA) for the complex. FT-IR spectral measurements showed evidences of the alterations of protein secondary structure in the presence of chrysin and V IV O(chrys) 2 ., (Copyright © 2021 Elsevier B.V. All rights reserved.)

A NASICON-based Na 3 V 2 (PO 4 ) 2 F 3 (NVPF) cathode material is reported herein as a potential symmetric cell electrode material. The symmetric cell was active from 0 to 3.5 V and showed a capacity of 85 mAh/g at 0.1 C. With cycling, the NVPF symmetric cell showed a very long and stable cycle life, having a capacity retention of 61% after 1000 cycles at 1 C. The diffusion coefficient calculated from cyclic voltammetry (CV) and the galvanostatic intermittent titration technique (GITT) was found to be ~10 -9 -10 -11 , suggesting a smooth diffusion of Na + in the NVPF symmetric cell. The electrochemical impedance spectroscopy (EIS) carried out during cycling showed increases in bulk resistance, solid electrolyte interphase (SEI) resistance, and charge transfer resistance with the number of cycles, explaining the origin of capacity fade in the NVPF symmetric cell. Finally, the postmortem analysis of the symmetric cell after 1000 cycles at a 1 C rate indicated that the intercalation/de-intercalation of sodium into/from the host structure occurred without any major structural destabilization in both the cathode and anode. However, there was slight distortion in the cathode structure observed, which resulted in capacity loss of the symmetric cell. The promising electrochemical performance of NVPF in the symmetric cell makes it attractive for developing long-life and cost-effective batteries.

Background: Every year, we encounter more projects indicating the promising anticancer activity of vanadium molecules against different types of cancer cells. The new generation of metal-based drugs, targets the energy supplies of the cell through ROS generation leading them to cell arrest and apoptosis. The relatively low toxicity of vanadium metal, the different oxidation states that it can occur and in general, the lipophilicity of transition metals, gave attention to vanadium after the exhausting research in platinum-based drugs. Herein, the latest advances in the apoptotic activity of vanadium complex molecules have been reviewed and revealed the structure to action relationship. Future perspectives of vanadium anticancer drugs are also discussed., Methods: Data were collected from Web of Science, Scopus, Pubmed, through searching of these keywords: "apoptosis", "anticancer drugs", "vanadium complexes", "synthesis" and "cell arrest"., Results: A good amount of vanadium complexes gave promising results over the past few years, showing that a more careful approach of a ligand design could give rise to the next generation of vanadium drugs., Conclusion: The low toxicity of vanadium ion in combination with its V(IV) species selectivity gives the vanadium a head starts against other transition metal complexes., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Five new anionic aqueous dioxidovanadium(V) complexes, [{VO 2 L 1,2 }A(H 2 O) n ] α ( 1 - 5 ), with the aroylhydrazone ligands pyridine-4-carboxylic acid (3-ethoxy-2-hydroxybenzylidene)hydrazide (H 2 L 1 ) and furan-2-carboxylic acid (3-ethoxy-2-hydroxybenzylidene)hydrazide (H 2 L 2 ) incorporating different alkali metals (A = Na + , K + , Cs + ) as countercation were synthesized and characterized by various physicochemical techniques. The solution-phase stabilities of 1 - 5 were determined by time-dependent NMR and UV-vis, and also the octanol/water partition coefficients were obtained by spectroscopic techniques. X-ray crystallography of 2 - 4 confirmed the presence of vanadium(V) centers coordinated by two cis -oxido-O atoms and the O, N, and O atoms of a dianionic tridentate ligand. To evaluate the biological behavior, all complexes were screened for their DNA/protein binding propensity through spectroscopic experiments. Finally, a cytotoxicity study of 1 - 5 was performed against colon (HT-29), breast (MCF-7), and cervical (HeLa) cancer cell lines and a noncancerous NIH-3T3 cell line. The cytotoxicity was cell-selective, being more active against HT-29 than against other cells. In addition, the role of hydrophobicity in the cytotoxicity was explained in that an optimal hydrophobicity is essential for high cytotoxicity. Moreover, the results of wound-healing assays indicated antimigration in case of HT-29 cells. Remarkably, 1 with an IC 50 value of 5.42 ± 0.15 μM showed greater activity in comparison to cisplatin against the HT-29 cell line.

Vanadium pentoxide (V 2 O 5 ) was used as support material to immobilize the urease enzyme. V 2 O 5 was prepared from a sol-gel process, and the immobilization of urease was done onto the surface of the PET/ITO/V 2 O 5 film. Different concentrations of urea were tested to study the sensitivity of the biosensor. Tests with pH variation were carried out, and it was noticed that the total charge in the cyclic voltammograms decreases due to the increase in pH that influences the catalytic activity of the enzyme. From cyclic voltammograms, with a different scan rate, for linear correlation testing, it was observed that the anodic currents varied as a function of the scan rate. Based on the variation in the urea concentration, the current increased with the increase in the urea concentration, indicating the sensitivity of the material. The use of V 2 O 5 /urease showed favorable electrochemical responses for application in biosensors as well as being sensitive to the variation in the urea concentration and easy to obtain and prepare., (© 2020 International Union of Biochemistry and Molecular Biology, Inc.)

Wastewaters is generally polluted with various inorganic and organic contaminants which require effective multipurpose purification technology. In this respect, a novel V 2 O 5 @Ch/Cu-TMA nanobiosorbent was constructed via encapsulation of nanoscale metal organic frameworks (Cu-TMA) into vanadium pentoxide-imbedded-chitosan matrix to comprehensively investigate its efficiency in removal of levofloxacin drug (LEVO) (e.g., organic pollutant) and chromium (VI) (e.g., inorganic pollutant) from water. Both LEVO drug and Cr(VI) adsorptions were correlated to pseudo-second order (R 2  = 1) and Langmuir isotherm (R 2  = 0.9924 for LEVO and R 2  = 0.9815 for Cr(VI)). Adsorption of Cr(VI) was confirmed to be spontaneous and endothermic reactions, while LEVO was found to proceed via spontaneous and exothermic reactions based on the thermodynamic parameters. The emerged V 2 O 5 @Ch/Cu-TMA is regarded as an excellent nanobiosorbent for removal of inorganic contaminant as Cr(VI) from all natural water samples (tap, sea and wastewater) with percentages range 92.43%-96.95% and organic contaminant as LEVO drug from tap and wastewater (91.99%-97.20%)., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Vanadium has a good therapeutic potential, as several biological effects, but few side effects, have been demonstrated. Evidence suggests that vanadium compounds could represent a new class of non-platinum, metal antitumor agents. In the present study, we aimed to characterize the antiproliferative activities of fluorescent vanadyl complexes with acetylacetonate derivates bearing asymmetric substitutions on the β-dicarbonyl moiety on different cell lines. The effects of fluorescent vanadyl complexes on proliferation and cell cycle modulation in different cell lines were detected by ATP content using the CellTiter-Glo Luminescent Assay and flow cytometry, respectively. Western blotting was performed to assess the modulation of mitogen-activated protein kinases (MAPKs) and relevant proteins. Confocal microscopy revealed that complexes were mainly localized in the cytoplasm, with a diffuse distribution, as in podocyte or a more aggregate conformation, as in the other cell lines. The effects of complexes on cell cycle were studied by cytofluorimetry and Western blot analysis, suggesting that the inhibition of proliferation could be correlated with a block in the G2/M phase of cell cycle and an increase in cdc2 phosphorylation. Complexes modulated mitogen-activated protein kinases (MAPKs) activation in a cell-dependent manner, but MAPK modulation can only partly explain the antiproliferative activity of these complexes. All together our results demonstrate that antiproliferative effects mediated by these compounds are cell type-dependent and involve the cdc2 and MAPKs pathway.

Several reports have revealed the superior biological activity of metal ion-flavonoid complexes when compared with the parent flavonoid. Among the different metal ions explored, vanadium and its compounds are in the forefront because of their anticancer and antidiabetic properties. However, the toxicity of vanadium-based ions and their inorganic derivatives limits their therapeutic applications. Complexation of vanadium with flavonoids not only reduces its adverse effects but also augments its biological activity. This Review discusses the nature of coordination in vanadium-flavonoid complexes, their structure-activity correlations, with special emphasis on their therapeutic activities. Several investigations suggest that the superior biological activity of vanadium complexes arise because of their ability to regulate metabolic pathways distinct from those acted upon by vanadium alone. These studies serve to decipher the underlying molecular mechanism of vanadium-flavonoid complexes that can be explored further for generating a series of novel compounds with improved pharmacological and therapeutic performance.

The development and optimization of sonosensitizers for elevating intratumoral reactive oxygen species (ROS) are definitely appealing in current sonodynamic therapy (SDT). Given this, branched vanadium tetrasulfide (VS 4 ) nanodendrites with a narrower bandgap (compared with the most extensively explored sonosensitizers) are presented as a new source of sonosensitizer, which allows a more effortless separation of sono-triggered electron-hole pairs for ROS generation. Specifically, platinum (Pt) nanoparticles and endogenous high levels of glutathione (GSH) are rationally engineered to further optimize its sono-sensitized performance. As cocatalyst, Pt is conducive to trapping electrons, whereas GSH, as a natural hole-scavenger, tends to capture holes. Compared with the pristine VS 4 sonosensitizer, the GSH-Pt-VS 4 nanocomposite can greatly prolong the lifetime of the charge and confer a highly efficacious ROS production activity. Furthermore, such nanoplatforms are capable of reshaping tumor microenvironments to realize ROS overproduction, contributed by overcoming tumor hypoxia to improve SDT-triggered singlet oxygen production, catalyzing endogenic hydrogen peroxide into destructive hydroxyl radicals for chemodynamic therapy, and depleting GSH to amplify intratumoral oxidative stress. All these combined effects result in a significantly efficient tumor suppression outcome. This study enriches sonosensitizer research and proves that sonosensitizers can be rationally optimized by charge separation engineering strategy., (© 2021 Wiley-VCH GmbH.)

To circumvent the von Neumann bottleneck, substantial progress has been made towards in-memory computing with synaptic devices. However, compact nanodevices implementing non-linear activation functions are required for efficient full-hardware implementation of deep neural networks. Here, we present an energy-efficient and compact Mott activation neuron based on vanadium dioxide and its successful integration with a conductive bridge random access memory (CBRAM) crossbar array in hardware. The Mott activation neuron implements the rectified linear unit function in the analogue domain. The neuron devices consume substantially less energy and occupy two orders of magnitude smaller area than those of analogue complementary metal-oxide semiconductor implementations. The LeNet-5 network with Mott activation neurons achieves 98.38% accuracy on the MNIST dataset, close to the ideal software accuracy. We perform large-scale image edge detection using the Mott activation neurons integrated with a CBRAM crossbar array. Our findings provide a solution towards large-scale, highly parallel and energy-efficient in-memory computing systems for neural networks.

Existing fluorescent labels used in life sciences are based on organic compounds with limited lifetime or on quantum dots which are either expensive or toxic and have low kinetic stability in biological environments. To address these challenges, luminescent nanomaterials have been conceived as hierarchical, core-shell structures with spherical morphology and highly controlled dimensions. These tailor-made nanophosphors incorporate Ln:YVO 4 nanoparticles (Ln = Eu(III) and Er(III)) as 50 nm cores and display intense and narrow emission maxima centered at ∼565 nm. These cores can be encapsulated in silica shells with highly controlled dimensions as well as functionalized with chitosan or PEG5000 to reduce nonspecific interactions with biomolecules in living cells. Confocal fluorescence microscopy in living prostate cancer cells confirmed the potential of these platforms to overcome the disadvantages of commercial fluorophores and their feasibility as labels for multiplexing, biosensing, and imaging in life science assays., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Cardiovascular complications are among the leading causes of morbidity and mortality in diabetes mellitus (DM). Despite the anti-hyperglycemic effects of various anti-diabetic therapeutic agents like insulin, some of these drugs are implicated in precipitating cardiovascular dysfunction. There is therefore an imperative need to seek alternative drugs that may ameliorate these complications. Accordingly, the aim of the study was to investigate the effects of a dioxidovanadium (V) complex, cis-[VO 2 (obz)py]) on selected cardiovascular function markers in STZ-induced diabetic rats. The vanadium complex (40 mg kg) was administered orally twice every 3rd day 5 weeks, non-diabetic and diabetic control groups received distilled water whereas the insulin group received subcutaneous insulin injections twice daily for 5 weeks. Blood glucose concentrations, mean arterial pressure (MAP), heart rate, triglycerides (TG) and total cholesterol concentrations were monitored weekly for 5 weeks. Rats were then euthanised and blood and hearts were collected for biochemical analysis. There was a significant decrease in blood glucose, triglycerides, cholesterol concentrations as well as blood pressure of vanadium treated rats compared to the untreated diabetic animals. Vanadium treatment also attenuated cardiac oxidative stress and decreased the expression of transforming growth factor β1 (TGFβ1) and Smad7. Lastly, the administration of the vanadium complex significantly decreased C reactive protein (CRP) and cardiotropin 1(CT-1) concentrations in the plasma and heart tissues. The administration of the dioxidovanadium(V) complex to diabetic rats culminated into cardio-protective effects. Taken together, these observations suggest that this metal complex exhibit a significant potential as an alternative therapeutic drug for DM management.

Herein, we report the syntheses of two lithium-vanadium oxide-fluoride compounds crystallized from the same reaction mixture through a time variation experiment. A low temperature hydrothermal route employing a viscous paste of V 2 O 5 , oxalic acid, LiF, and HF allowed the crystallization of one metastable phase initially, Li 2 VO 0.55 (H 2 O) 0.45 F 5 ⋅2H 2 O ( I ), which on prolonged heating transforms to a chemically similar yet structurally different phase, Li 3 VOF 5 ( II ). Compound I crystallizes in centrosymmetric space group, I 2/ a with a = 6.052(3), b = 7.928(4), c = 12.461(6) Å, and β = 103.99(2)°, while compound II crystallizes in a non-centrosymmetric (NCS) space group, Pna 2 1 with a = 5.1173(2), b = 8.612(3), c = 9.346(3) Å. Synthesis of NCS crystals are highly sought after in solid-state chemistry for their second-harmonic-generation (SHG) response and compound II exhibits SHG activity albeit non-phase-matchable. In this article, we also describe their magnetic properties which helped in unambiguous assignment of mixed valency of V (+4/+5) for Li 2 VO 0.55 (H 2 O) 0.45 F 5 ⋅2H 2 O ( I ) and +4 valency of V for Li 3 VOF 5 ( II ).

Representative pathogenic bacteria such as Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ) are widespread in nature and pose a threat to human health. To control the propagation of these pathogens from the source, the key is to design broad-spectrum antibacterial materials to reduce the serious damage of pathogenic bacteria. At present, more and more nanoparticles are widely researched and applied due to their multi-pathway antibacterial properties, such as regulating physiology, biochemistry and physical chemistry. In this work, we synthesized a uniformly dispersed and stable spherical nanoparticle (TiO 2 @V 2 O 5 ) synthesized by self-assembly of tianium dioxide and vanadium pentoxide. Based on its excellent photosensitive properties, TiO 2 @V 2 O 5 nanoparticles have showed excellent antibacterial properties under the light irradiation due to the production of hydroxyl radicals in antibacterial and mechanism tests. In addtion, related cell and plant experiments have showed that TiO 2 @V 2 O 5 nanoparticles are excellent biocompatible materials, it could be widely used in environmental pollution control, limiting the serious damage caused by pathogens.

We have experimentally studied the influence of pulsed laser deposition parameters on the morphological and electrophysical parameters of vanadium oxide films. It is shown that an increase in the number of laser pulses from 10,000 to 60,000 and an oxygen pressure from 3 × 10 -4 Torr to 3 × 10 -2 Torr makes it possible to form vanadium oxide films with a thickness from 22.3 ± 4.4 nm to 131.7 ± 14.4 nm, a surface roughness from 7.8 ± 1.1 nm to 37.1 ± 11.2 nm, electron concentration from (0.32 ± 0.07) × 10 17 cm -3 to (42.64 ± 4.46) × 10 17 cm -3 , electron mobility from 0.25 ± 0.03 cm 2 /(V·s) to 7.12 ± 1.32 cm 2 /(V·s), and resistivity from 6.32 ± 2.21 Ω·cm to 723.74 ± 89.21 Ω·cm. The regimes at which vanadium oxide films with a thickness of 22.3 ± 4.4 nm, a roughness of 7.8 ± 1.1 nm, and a resistivity of 6.32 ± 2.21 Ω·cm are obtained for their potential use in the fabrication of ReRAM neuromorphic systems. It is shown that a 22.3 ± 4.4 nm thick vanadium oxide film has the bipolar effect of resistive switching. The resistance in the high state was (89.42 ± 32.37) × 10 6 Ω, the resistance in the low state was equal to (6.34 ± 2.34) × 10 3 Ω, and the ratio R HRS /R LRS was about 14,104. The results can be used in the manufacture of a new generation of micro- and nanoelectronics elements to create ReRAM of neuromorphic systems based on vanadium oxide thin films.

In the past few decades, various vanadium compounds have displayed potential in cancer treatment. However, fast clearness in the body and possible toxicity of vanadium compounds has hindered their further development. Vanadium-based nanomaterials not only overcome these limitations, but take advantage of the internal properties of vanadium in photics and magnetics, which enable them as a multimodal platform for cancer diagnosis and treatment. In this paper, we first introduced the basic biological and pharmacological functions of vanadium compounds in treating cancer. Then, the synthesis routes of three vanadium-based nanomaterials were discussed, including vanadium oxides, 2D vanadium sulfides, carbides and nitrides: V m X n (X = S, C, N) and water-insoluble vanadium salts. Finally, we highlighted the applications of these vanadium-based nanomaterials as tumor therapeutic and diagnostic agents.

Wearable conducting polymer-based NH 3 sensors are highly desirable in real-time environmental monitoring and human health protection but still a challenge for their relatively long response/recovery time and moderate sensitivity at room temperature. Herein, we present an effective route to fulfill this challenge by constructing porous and neural network-like Au/polypyrrole (Au/PPy) electrospun nanofibrous film with hollow capsular units for NH 3 sensor. Taking the unique architecture and synergistic effect between Au and PPy, our sensor exhibits not only super-rapid response/recovery time (both ∼7 s), faster than all reported sensors, but also stable and ultrahigh sensitivity (response reaches ∼2.3 for 1 ppm NH 3 ) at room temperature even during repeated deformation. Furthermore, good selectivity has been also achieved. These outstanding properties make our sensor hold great potential in real-time NH 3 -related disease diagnosis and environmental monitoring at room temperature.

Sonodynamic therapy (SDT), a noninvasive and highly penetrating tumor therapy, which employs ultrasound and sonosensitizers, has attracted extensive attention because of its ability to treat deep tumors. However, many current sonosensitizers have drawbacks in phototoxicity and limited sonodynamic effect. Herein, as a novel kind of sonosensitizer, iron-doped vanadium disulfide nanosheets (Fe-VS 2 NSs) are constructed by a high-temperature organic-solution method and further modified with polyethylene glycol (PEG). With Fe doping, the sonodynamic effect of Fe-VS 2 NSs is greatly enhanced, owing to the prolonged electron-hole recombination time. Simultaneously, such Fe-VS 2 -PEG NSs as a good Fenton agent can be utilized for chemodynamic therapy (CDT) by using the endogenous H 2 O 2 in the tumor microenvironment (TME). Moreover, the multivalent Fe and V elements in the Fe-VS 2 NSs can consume glutathione to amplify the reactive oxygen species-induced oxidative stress by SDT and CDT. Utilizing the strong near-infrared optical absorbance and enhanced magnetic resonance (MR) contrast by Fe-VS 2 NSs, photoacoustic/MR biomodal imaging reveals a high accumulation of Fe-VS 2 -PEG NSs in the tumor. The great tumor suppression effect is then achieved by the in vivo combined CDT&SDT treatment. Importantly, most of the injected Fe-VS 2 -PEG NSs can be gradually decomposed and excreted from the mice, making them as safe sonosensitizers for cancer treatment. Our work highlights a new type of biodegradable sonosensitizer with the ability of regulating TME for applications in cancer theranostics.

Based on the signal amplification elements of planar VS 2 /AuNPs nanocomposites and CoFe 2 O 4 nanozyme, we herein developed an electrochemical biosensor for sensitive kanamycin (Kana) quantification. A ratiometric sensing platform was presented by incorporating VS 2 /AuNPs nanocomposites as a support material with excellent conductivity and high specific surface area, as well as hairpin DNA (hDNA) with complementary hybridization of biotinylated Kana-aptamer. In addition, streptavidin-functionalized CoFe 2 O 4 nanozyme with superior peroxidase-like catalytic activity were immobilized onto the aptasensor, hence the peroxidase-like catalytic reaction could yield amplified electrochemical signals. With the presence of Kana, the aptamer-biorecognition resulted in a quantitative decrease of nanozyme accumulation and an increase of methylene blue response. Under optimal conditions, the electrochemical signal ratio of the aptasensor revealed a linear relation along with the logarithmic concentration of Kana from 1 pM to 1 μM, with the limit of detection reaching to 0.5 pM. Moreover, this aptasensor exhibited excellent precision, as well as high repeatability, hence possessing potentials in real samples and for diverse targets detection by easy replacement of the matched aptamer.

Transition metal-based compounds have shown promising uses as therapeutic agents. Among their unique characteristics, these compounds are suitable for interaction with specific biological targets, making them important potential drugs to treat various diseases. Copper compounds, of which Casiopeinas ® are an excellent example, have shown promising results as alternatives to current cancer therapies, in part because of their intercalative properties with DNA. Vanadium compounds have been extensively studied for their pharmacological properties and application, mostly in diabetes, although recently, there is a growing interest in testing their activity as anti-cancer agents. In the present work, two compounds, [Cu(Metf)(bipy)Cl]Cl·2H 2 O and [Cu(Impy)(Gly)(H 2 O)]VO 3 , were obtained and characterized by visible and FTIR spectroscopies, single-crystal X-ray diffraction, and theoretical methods. The structural and electronic properties of the compounds were calculated through the density functional theory (DFT) using the Austin-Frisch-Petersson functional with dispersion APFD, and the 6-311 + G(2d,p) basis set. Non-covalent interactions were analyzed using Hirshfeld surface analysis (HSA) and atom in molecules analysis (AIM). Additionally, docking analysis to test DNA/RNA interactions with the Casiopeina-like complexes were carried out. The compounds provide metals that can interact with critical biological targets. In addition, they show interesting non-covalent interactions that are responsible for their supramolecular arrangements.

The present article demonstrates the synthesis of the nanocomposite of reduced graphene oxide (rGO) with CdSe and CdSe/V 2 O 5 core/shell quantum dots by a two-step facile synthesis approach and subsequently studies their relative biocompatibility in different cells. Various characterization techniques have been applied including transmission electron microscopy (TEM), an x-ray diffractometer (XRD) and Raman spectroscopy to confirm the successful formation of CdSe-rGO and CdSe/V 2 O 5 -rGO nanocomposites. The average sizes of CdSe and CdSe/V 2 O 5 QDs have found to be ∼3 and 5.5 nm, respectively with a good dispersion over the surface of rGO nanosheets. A crystal phase change has occurred during the formation of the V 2 O 5 shell over the surface of CdSe QDs and confirmed through XRD. Raman spectroscopy has shown some useful insight of the surface state of CdSe and consequent changes in the surface with V 2 O 5 shell growth. Further, MTT and cell growth assays have been performed to analyze their biocompatibility in A549 and Hela cells with various concentrations of as-synthesized materials. Our results demonstrate the toxicity of CdSe-rGO nanocomposite to be substantially reduced by the growth of the V 2 O 5 shell. The in vivo studies in Drosophila show a remarkable decrease in the reactive oxygen species (ROS) and apoptosis levels for a CdSe/V 2 O 5 -rGO composite as compared to a CdSe-rGO nanocomposite, which paves a promising pathway for the CdSe/V 2 O 5 -rGO nanocomposite to be used as an efficient biocompatible material.

Glutamine gets transformed to 2-hydroxy-5-oxoproline with NH 4 VO 3 in a neutral solution as a product of 2,2'-bipyridine oxidovanadium(v) 2-hydroxy-5-oxoproline [V V 2 O 3 (hop) 2 (bpy) 2 ]·7H 2 O [1, H 2 hop = 2-hydroxy-5-oxoproline] with yields of 65.6%. Similarly, histidine and arginine are converted into the corresponding α-hydroxycarboxylates as 2,2'-bipyridine oxidovanadium(iv) 3-(1H-imidazolyl-5-yl)-2-hydroxyacrylate [V IV 2 O 2 (imha) 2 (bpy) 2 ]·bpy [2, H 2 imha = 3-(1H-imidazolyl-5-yl)-2-hydroxyacrylic acid] and guanidinium oxidovanadium(v) 1-(aminoiminomethyl)-2-hydroxyproline (CN 3 H 6 )[V V O 2 (Haimhp) 2 ]·2H 2 O [3, H 2 aimhp = 1-(aminoiminomethyl)-2-hydroxyproline] with V 2 O 5 in low yields respectively, where an aggregate of oxidovanadium(v) arginine (H 2 arg) n (V V O 3 ) n ·½nH 2 O (4, Harg = arginine) has been isolated preferentially in an initial experiment for 3. α-Hydroxycarboxylates chelate bidentately with vanadium viaα-alkoxy and α-carboxy groups in 1-3, as observed from structural analyses. Their racemizations have been observed after the conversions. There is no coordination in 4 based on solid-state 13 C NMR spectra, and only strong hydrogen bonds exist in the anion chains (V V O 3 ) - and protonated arginines. 1 and 4 were fully characterized by elemental analysis, UV-vis, IR and solid-state 13 C NMR spectroscopies, TG and X-ray structural analyses, and theoretical bond valence calculations (BVS). The conversions of glutamine, histidine and arginine occur spontaneously in a solution under ambient conditions.

The chemistry and short lifetimes of metal-based anti-cancer drugs can be turned into an advantage for direct injections into tumors, which then allow the use of highly cytotoxic drugs. The release of their less toxic decomposition products into the blood will lead to decreased toxicity and can even have beneficial effects. We present a ternary V V complex, 1 ([VOL 1 L 2 ], where L 1 is N-(salicylideneaminato)-N'-(2-hydroxyethyl)ethane-1,2-diamine and L 2 is 3,5-di-tert-butylcatechol), which enters cells intact to induce high cytotoxicity in a range of human cancer cells, including T98g (glioma multiforme), while its decomposition products in cell culture medium were ≈8-fold less toxic. 1 was 12-fold more toxic than cisplatin in T98g cells and 6-fold more toxic in T98g cells than in a non-cancer human cell line, HFF-1. Its high toxicity in T98g cells was retained in the presence of physiological concentrations of the two main metal-binding serum proteins, albumin and transferrin. These properties favor further development of 1 for brain cancer treatment by intratumoral injections., (© 2020 Wiley-VCH GmbH.)

In this study, Li 3 V 2 (PO 4 ) 3 (LVP) powders are prepared by a solution synthesis method. The effects of two reducing agents on crystal structure and morphology and electrochemical properties are investigated. Preliminary studies on reducing agents such as oxalic acid and citric acid, are used to reduce the vanadium (V) precursor. The oxalic acid-assisted synthesis induces smaller particles (30 nm) compared with the citric acid-assisted synthesis (70 nm). The LVP powders obtained by the oxalic acid exhibit a higher specific capacity (124 mAh g -1 at 1C) and better cycling performance (122 mAh g -1 following 50 cycles at 1C rate) than those for the citric acid. This is due to their higher electronic conductivity caused by carbon coating and downsizing the particles. The charge-discharge plateaus obtained from cyclic voltammetry are in good agreement with galvanostatic cycling profiles.

VS 2 spheres and VS 2 sheets with doped compositions (Mo, Ag and graphite) were successfully prepared by one-step hydrothermal method and characterized by different techniques including X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N 2 adsorption isotherms. Catalysts were applied for the depolymerization of alkali lignin. VS 2 spheres exhibited lower yield of degraded lignin and bio-oil than those with VS 2 sheets and VS 2 flowers heated to 250 °C and held for 1.5 h with 2.0 MPa H 2 . The catalytic depolymerization performance was markedly affected by the dopant in the VS 2 sheets, with the highest degraded lignin yield of 81.22%, achieved over 5 wt% Ag-VS 2 at 290 °C under 2.0 MPa H 2 for 1.5 h, yielding 61.23% bio-oil. The VS 2 -based catalysts show excellent selectivity in the interruption of the lignin structure and target production of bio-oil. The bio-oil showed that the relevant contents of a phenolic-type compound changes significantly according to the dopant in the VS 2 catalyst., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Porous V 2 O 5 /TiO 2 nanoheterostructure films with different atomic ratios of Ti/V (4:1, 2:1, 1:1, and 1:2) were synthesized by a sparking method for the first time. The sparking method, which is a simple and cost-effective process, can synthesize highly porous and composite films in one step. Field-emission scanning electron microscope (FE-SEM) images revealed the porosity morphology of all prepared samples. V 2 O 5 /TiO 2 nanoheterostructure films were confirmed by Raman spectroscopy, high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). The secondary particle size and band gap of the samples were highly correlated to the V 2 O 5 proportion, resulting in enhanced visible-light absorbance. V 2 O 5 /TiO 2 nanoheterostructure films at an atomic ratio of 1:1 showed the highest photocatalytic performance, which improved the degradation rate up to 24% compared to pure TiO 2 film. It is believed that the formed nanoheterostructure and greater portion of V 4+ ions are reflected by this ratio.

It remains a great challenge to integrate effective photothermal therapeutic materials with upconversion nanoparticles (UCNPs) into one structure with small size. Herein, a new and simple method was developed to combine the luminescent UCNPs with vanadium disulfide (VS2) heterogeneously growing on the UCNPs. VS2 was grown directly on the surface of UCNPs to obtain oil-soluble nanocomposites, UCNPs@VS2. Then polyethylene glycol (mPEG) was functionalized on the surface of the nanocomposites to improve the water solubility, resulting in the integrated nanostructure UCNPs@VS2-mPEG (with an approximate size of 25 nm) for bioimaging and photothermal therapy in vitro. Importantly, cytotoxicity test results show that the final nanostructure has good biocompatibility. Furthermore, due to the excellent photothermal effects of VS2 and the unique imaging function of UCNPs, the nanostructure shows effective photothermal therapy for HeLa cells and was successfully applied in magnetic resonance imaging and upconversion luminescence imaging in vitro. Therefore, this study demonstrates a simple yet powerful method of growing VS2 on the surface of UCNPs, which provides an effective method to establish one integrated nanostructure with a nanoscale advantage for dual-model bioimaging and treatment.

For a long time the biological role of vanadium was not known, while now the possibility of using its derivatives as potential therapeutic agents has given rise to investigations on their probable side effects. Vanadium compounds may inhibit different biochemical processes and lead to a variety of toxic effects and serious diseases. But, on the other hand, vanadium is an essential element for life. In recent years, increasing evidence has been acquired on the possible roles of vanadium in the higher forms of life. Despite several biochemical and physiological functions that have been suggested for vanadium and notwithstanding the amount of the knowledge so far accumulated, it still does not have a clearly defined role in the higher forms of life. What functions could vanadium or its very stable oxidovanadium(IV) derivatives have had in the prebiotic world and in the origins of life? In this review, we have briefly tried to highlight the most useful aspects that can be taken into consideration to give an answer to this still unresolved question and to show the high versatility of the oxidovanadium(IV) group to act as promoter of several oxidation reactions when coordinated with a variety of ligands, including diketones like acylpyrazolones.

Peroxidovanadium(V) and oxidovanadium(IV) compounds have been tested as peroxidase-similar compounds. Their catalytic performance was tested on phenol red and pyrogallol substrates. Bromination kinetic studies revealed Michaelis-Menten behavior with respect to phenol red for both complexes. Catalytic efficiency is ~ 10 4 M -1 min -1 . Both vanadium complexes showed the capacity to oxidize pyrogallol, but only the oxidovanadium (IV) complex follows Michaelis-Menten kinetics with respect to this substrate (K m = 1.05 × 10 -3 M). Peroxidovanadium(V) complex displayed a more complex mechanism, and further studies became necessary to elucidate it. The structure-activity relationship was also assessed.

Sensitive and accurate detection methods for infectious viruses are the pressing need for effective disease diagnosis and treatment. Herein, based on V 2 O 5 nanoparticles-encapsulated liposomes (VONP-LPs) we demonstrate a dual-modality sensing platform for ultrasensitive detection of the virus. The sensing performance relies on intrinsic peroxidase and electrochemical redox property of V 2 O 5 nanoparticles (V 2 O 5 NPs). The target-specific antibody-conjugated VONP-LPs and magnetic nanoparticles (MNPs) enrich the virus by magnetic separation and the separated VONP-LPs bound viruses are hydrolyzed to release the encapsulated V 2 O 5 NPs. These released nanoparticles from captured liposomes act as peroxidase mimics and electrochemical redox indicator resulting in noticeable colorimetric and robust electrochemical dual-signal. Utilizing the superiority of dual-modality sensor with two quantitative analysis forms, norovirus like particles (NoV-LPs) can be detected by electrochemical signals with a wide linear range and low detection limit. To verify the applicability in real samples, norovirus (NoV) collected from actual clinical samples are effectively-identified with excellent accuracy. This proposed detection method can be a promising next-generation bioassay platform for early-stage diagnosis of virus disease and surveillance for public health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A new six intraperitoneal injections insulin-mimetic vanadyl(IV) compounds [(VO)(FA)(AA n )] (where n = 1-6: AA 1 = isoleucine, AA 2 = threonine, AA 3 = proline, AA 4 = phenylalanine, AA 5 = lysine, and AA 6 = glutamine) were synthesized by the chemical reactions between folic acid (FA), VOSO 4 , and amino acids (AA n ) with equal molar ratio 1:1:1 in neutralized media. These complexes were characterized by elemental analysis and estimation of vanadyl(IV) metal ions. The thermal stability behavior of these complexes was studied by TG-DTG-DTA analyses. The structures of these complexes were elucidated by spectroscopic methods like infrared, electron spin resonance (ESR), and solid reflectance spectroscopes. The powder X-ray diffraction (XRD) study suggested the crystalline nature of the complexes. Magnetic moments and electronic spectra revealed the square-pyramid geometrical structure of the complexes. The conductivity results refereed that all synthesized vanadyl(IV) complexes were of a non-electrolyte behavior. The infrared spectra assignments of these complexes revealed that the FAH 2 and AA n chelates act as a bidentate ligation. The chelation towards vanadyl (IV) ions existed via deprotonation of one of the carboxylic groups of FAH 2 drug ligand, and so amino acids act as bidentate ligands via N-amino and O-carboxylate groups. Both scanning and transmission electron microscope (SEM and TEM) techniques were used to investigate the surface morphology. The main task of this research is the aim of designing a new insulin alternative antidiabetic drug agent. The antidiabetic efficiency of these complexes was evaluated in streptozotocin-induced diabetic male albino rats. Liver and kidney functions, insulin and blood glucose levels, lipid profile, and superoxide dismutase antioxidant (SOD) are verified identifiers for the efficiency of VO(IV)/FA/AA n system compounds as antidiabetic drug agents., Competing Interests: The authors declare no potential conflicts of interest with respect to the research, authorship, and publication of this article.

In the present study, radiation shielding properties of two glassy composite materials that are widely used in electronics, photovoltaic applications, and sensor technology, were investigated in the photon energy range from 15 keV to 15 MeV. The materials chosen were (ITO)/V 2 O 5 /B 2 O 3 and ZnO/V 2 O 5 /B 2 O 3 including various concentrations of B 2 O 3 . Radiation interaction was simulated and shielding parameters calculated by means of the MCNP and BXCOM codes. More specifically, buildup factors, effective electron density ([Formula: see text]) and effective atomic number ([Formula: see text]) were calculated with BXCOM, while mass attenuation coefficients ([Formula: see text]), half-value layer (HVL) and tenth-value layer (TVL) values were calculated with MCNP. The results were compared with those obtained with the WinXCOM code, for validation. Acceptable and preferable results were obtained for both composites as alternative to other glassy shielding materials. The composite including ITO showed better shielding properties than the composite including ZnO. In terms of radiation shielding, both composites turned out to be better than concrete and close to lead.

Vanadium compounds are promising anti-diabetic agents, and graphene quantum dots (GQDs) are emerging as potential drug delivery systems to improve drug solubility in water and membrane transport. Using highly dispersible and water-soluble GQDs, we herein prepared a novel GQD-VO (p-dmada) complex, in which vanadium coordination compounds [VO(p-dmada)] were packed closely on one side of the GQD sheets possibly via the π-π stacking mechanism. The in vitro tests showed that GQD-VO(p-dmada) exhibited membrane permeability (Papp) as good as that of GQDs with reduced cytotoxicity. In vivo tests on type 2 diabetic mice demonstrated that GQD-VO(p-dmada) exhibited a delayed glucose lowering profile but more profound effects on insulin enhancement and β-cell protection after three-week treatment compared to VO(p-dmada) alone. In addition, GQD alone was observed for the first time to effectively lower the blood lipid levels of the db/db mice. Overall, GQD-VO(p-dmada) showed improved pharmacokinetic performance and hypoglycemic effects, and using GQD as a nanoplatform for drug delivery may provide vast opportunities for the further design of metal-based pharmaceutical agents.