Showing papers on "Vanadate published in 2013"

The future of/for vanadium

Abstract: Vanadium compounds are stored or employed by several groups of bacterial and eukaryotic organisms. Two types of vanadium-dependent enzymes have so far been characterised: vanadate-dependent haloperoxidases from fungi, lichens, marine macroalgae and Streptomyces bacteria, and vanadium nitrogenases in proteo- and cyanobacteria. Several bacterial strains can employ vanadate(V) as an external electron acceptor in respiration, reducing vanadate to VO2+ and thus contributing to the mineralisation of vanadium and to the detoxification of vanadate-contaminated water. Amanita mushrooms and many sea squirts accumulate vanadium, without the importance of this practise being well understood. Further, the analogy between vanadate and phosphate implicates an interference of vanadate with metabolic processes involving phosphate, suggesting a regulatory role for vanadate in most if not all organisms, including humans, but also hinting at toxic effects at unphysiologically high vanadate concentrations. The antidiabetic effect of vanadium compounds is probably related to the phosphate–vanadate antagonism, as is the potentiality of vanadate in the amelioration of cardiovascular affliction. The anti-cancer action of vanadium compounds and their in vitro activity towards the protozoa causing amoebiasis, leishmaniasis and Chagas’ disease again may be rooted in the intervention of vanadate with the activity of phosphatases and kinases. In addition, most likely the ability of vanadate(V) and oxidovanadium(IV) to regulate the cellular production of reactive oxygen species comes in, thus influencing cellular signalling. Future developments of vanadium chemistry are likely to emphasize topics related to biological, environmental and medicinal aspects. Condensation of monovanadate results in the formation of oligovanadates, polyvanadates and finally colloidal and solid vanadium oxides that, in part, convey bio-mimetic functions comparable to those of simple vanadate, including its catalytic potential as an active centre in haloperoxidases and the lethal action against viruses, bacteria and protozoan parasites. Decavanadate has been shown to be stabilised by docking to proteins, and by integration into nanoscopic water pools of intracellular compartments, modelled by reverse micelles. The well established and approved use of vanadium oxides in, amongst other applications, catalysis has been recently impacted by the elucidation of the active surface species – VOx – of catalysts based on mixed vanadium oxides, and vanadium oxides on supports. Finally, materials based on vanadium oxides and vanadates play an increasingly important role as cathode materials in high density lithium batteries. An example is Ag2VO2PO4, which, in the discharge process, is reduced to Li3.2VO2PO4 and Ag. Oncoming developments in vanadium chemistry thus include oxide-based materials.

Vanadium. Its Role for Humans

Abstract: Vanadium is the 21st most abundant element in the Earth’s crust and the 2nd-to-most abundant transition metal in sea water. The element is ubiquitous also in freshwater and nutrients. The average body load of a human individual amounts to 1 mg. The omnipresence of vanadium hampers checks directed towards its essentiality. However, since vanadate can be considered a close blueprint of phosphate with respect to its built-up, vanadate likely takes over a regulatory function in metabolic processes depending on phosphate. At common concentrations, vanadium is non-toxic. The main source for potentially toxic effects caused by vanadium is exposure to high loads of vanadium oxides in the breathing air of vanadium processing industrial enterprises. Vanadium can enter the body via the lungs or, more commonly, the stomach. Most of the dietary vanadium is excreted. The amount of vanadium resorbed in the gastrointestinal tract is a function of its oxidation state (VV or VIV) and the coordination environment. Vanadium compounds that enter the blood stream are subjected to speciation. The predominant vanadium species in blood are vanadate and vanadyl bound to transferrin. From the blood stream, vanadium becomes distributed to the body tissues and bones. Bones act as storage pool for vanadate. The aqueous chemistry of vanadium(V) at concentration <10 μM is dominated by vanadate. At higher concentrations, oligovanadates come in, decavanadate in particular, which is thermodynamically stable in the pH range 2.3–6.3, and can further be stabilized at higher pH by interaction with proteins.

Vanadium bioavailability and toxicity to soil microorganisms and plants

Abstract: Vanadium, V, is a redox-sensitive metal that in solution, under aerobic conditions, prevails as the oxyanion vanadate(V). There is little known regarding vanadium toxicity to soil biota, and the present study was set up to determine the toxicity of added vanadate to soil organisms and to investigate the relationship between toxicity and vanadium sorption in soils. Five soils with contrasting properties were spiked with 7 different doses (3.2-3200 mg V kg(-1)) of dissolved vanadate, and toxicity was measured with 2 microbial and 3 plant assays. The median effective concentration (EC50) thresholds of the microbial assays ranged from 28 mg added V kg(-1) to 690 mg added V kg(-1), and the EC50s in the plant assays ranged from 18 mg added V kg(-1) to 510 mg added V kg(-1). The lower thresholds were in the concentration range of the background vanadium in the untreated control soils (15-58 mg V kg(-1)). The vanadium toxicity to plants decreased with a stronger soil vanadium sorption strength. The EC50 values for plants expressed on a soil solution basis ranged from 0.8 mg V L(-1) to 15 mg V L(-1) and were less variable among soils than corresponding values based on total vanadium in soil. It is concluded that sorption decreases the toxicity of added vanadate and that soil solution vanadium is a more robust measure to determine critical vanadium concentrations across soils.

Ion pumps as biological targets for decavanadate

Abstract: The putative applications of poly-, oligo- and mono-oxometalates in biochemistry, biology, pharmacology and medicine are rapidly attracting interest. In particular, these compounds may act as potent ion pump inhibitors and have the potential to play a role in the treatment of e.g. ulcers, cancer and ischemic heart disease. However, the mechanism of action is not completely understood in most cases, and even remains largely unknown in other cases. In the present review we discuss the most recent insights into the interaction between mono- and polyoxometalate ions with ion pumps, with particular focus on the interaction of decavanadate with Ca2+-ATPase. We also compare the proposed mode of action with those of established ion pump inhibitors which are currently in therapeutic use. Of the 18 classes of compounds which are known to act as ion pump inhibitors, the complete mechanism of inhibition is only known for a handful. It has, however, been established that most ion pump inhibitors bind mainly to the E2 ion pump conformation within the membrane domain from the extracellular side and block the cation release. Polyoxometalates such as decavanadate, in contrast, interact with Ca2+-ATPase near the nucleotide binding site domain or at a pocket involving several cytoplasmic domains, and therefore need to cross through the membrane bilayer. In contrast to monomeric vanadate, which only binds to the E2 conformation, decavanadate binds to all protein conformations, i.e. E1, E1P, E2 and E2P. Moreover, the specific interaction of decavanadate with sarcoplasmic reticulum Ca2+-ATPase has been shown to be non-competitive with respect to ATP and induces protein cysteine oxidation with concomitant vanadium reduction which might explain the high inhibitory capacity of V10 (IC50 = 15 μM) which is quite similar to the majority of the established therapeutic drugs.

Oxidation-driven self-assembly gives access to high-nuclearity molecular copper vanadium oxide clusters

Abstract: We report a general fragmentation-and-re-assembly route which gives access to high-nuclearity, mixed-metal polyoxometalate clusters. Reduced vanadium(IV) precursors are oxidatively dis-assembled into reactive fragments which subsequently re-aggregate under template control in a one-pot reaction. It is shown that the oxidative dis-assembly is required, as the use of vanadium(V)-based precursors results in the formation of smaller clusters. The principle is exemplified by the synthesis of a ca. 1.8 × 1.7 × 1.0 nm3, 36-nuclear copper vanadium oxide cluster, (nBu4N)4[Cu6V30O82(NO3)2(CH3CN)6]. The cluster is characterized in the solid-state and in solution by single-crystal XRD, ESI-MS and other spectroscopic and electrochemical measurements. Several lines of evidence show that the compound is indeed formed exclusively by fully oxidized vanadium(V) centres. In addition, primary fragmentation products of the type [VO(dmso)5]2+ were isolated. The cuprovanadate cluster features pentagonal secondary building units of the type {(V)M5} (M = Cu, V) which show similar structural function as the well-known {(Mo)Mo5} pentagons observed in giant molybdate clusters. The observation suggests that more complex vanadate clusters might be accessible based on these pentagonal units.

Crystal growth, structure, polarization, and magnetic properties of cesium vanadate, Cs2V3O8: a structure-property study.

Abstract: Cesium vanadate, Cs2V3O8, a member of the fresnoite-type structure, was synthesized via a hydrothermal route and structurally characterized by single-crystal X-ray diffraction. Cs2V3O8 crystallizes in a noncentrosymmetric polar space group, P4bm, with crystal data of a = 8.9448(4) A, c = 6.0032(3) A, V = 480.31(4) A3, and Z = 2. The material exhibits a two-dimensional layered crystal structure consisting of corner-shared V5+O4 and V4+O5 polyhedra. The layers are separated by the cesium cations. The alignment of the individual polyhedra results in a macroscopic polarity for Cs2V3O8. Frequency-dependent polarization measurements indicate that the material is not ferroelectric. A pyroelectric coefficient of −2.0 μC m–2 K–1 was obtained from pyroelectric measurements taken as a function of the temperature. The magnetic susceptibility data were measured as a function of the temperature and yielded an effective magnetic moment of 1.78 μB for the V4+ cation. Short-range magnetic ordering was observed around 7 K....

Intense red-emitting multi-rare-earth doped nanoparticles of YVO4 for spectrum conversion towards improved energy harvesting by solar cells

Abstract: Yttrium vanadate nano-particles doped with single and multi ions (Sm3+, Eu3+, Bi3+) have been successfully synthesized at room temperature by optimized co-precipitation method. Doped orthovanadate forms monophasic nanocrystals in the 10–50 nm size range. Photoluminescence (PL) excitation shows broad band in the range 250–350 nm due to vanadate absorption and sharp peaks in the range of 390–470 nm due to f–f transitions of Sm3+/Eu3+ and emission in intense red/orange (614, 645, 699 nm). The nanoparticles can efficiently convert UV and blue photons (250–470 nm) to intense red and orange light that can be harnessed by both Si and dye sensitized solar cells for photovoltaic conversion. PL and time-resolved decay suggest that excitation and charge transfer between host, dopant and co-dopants play a profound role in the photophysical processes of multi-ion doped yttrium vanadate nanophosphor. Thin films of such nanophosphor exhibit 80–90% transparency in the visible range. Nanophosphor films convert UV to visible leading to better photon harvesting by solar cells.

Structural and luminescence properties of Sr2VO4Cl and Sr5(VO4)3Cl: self-activated luminescence and unusual Eu3+ emission

Abstract: Novel self-activated vanadate phosphors, blue-emitting Sr2VO4Cl and green-emitting Sr5(VO4)3Cl, were synthesized via the solid-state reaction route, and the relationship between the structure and luminescence properties was comparatively investigated. Self-activated luminescence originating from the VO43− charge transfer (VCT) transition in relation to different V–O distances was verified in two vanadate phases with different crystal structures. Sr2VO4Cl showed a blue emission band from 375 to 600 nm with a peak at 424 nm, while Sr5(VO4)3Cl exhibited a green emission band from 375 to 700 nm with a peak at 517 nm. With the introduction of Eu3+ to Sr2VO4Cl, both the VCT and Eu3+ emissions were found; however, the VCT emission was quenched in Sr5(VO4)3Cl after Eu3+ doping. Sr5(VO4)3Cl:Eu3+ only shows the characteristic red emission lines originating from Eu3+, while Sr5(VO4)3Cl:Eu3+,Na+ shows typical emissions coming from the VCT transition and the Eu3+ ions. As a comparison, the emission intensity of Sr2VO4Cl:Eu3+,Na+ decreased compared to that of Sr2VO4Cl:Eu3+. The intrinsic luminescence mechanism is discussed based on the differences in the crystal structures and the measured lifetimes.

Synthesis and characterization of manganese vanadate nanorods as glassy carbon electrode modified materials for the determination of L-cysteine

Abstract: Manganese vanadate nanorods with a single crystalline triclinic Mn2V2O7 phase have been synthesized through a hydrothermal process using sodium lauryl sulfonate (SDS) as the surfactant. The manganese vanadate nanorods have a typical length in the range of 5 to 20 μm and a diameter of about 50 to 300 nm. The morphology of the manganese vanadate products is influenced by SDS concentration, hydrothermal temperature and duration time. SDS promotes the phase transformation of the products from irregular particles with an orthorhombic MnV2O5 phase to nanorods with a triclinic Mn2V2O7 phase. The growth process has been proposed as a nucleation and SDS adsorption growth process based on the analysis of the influence of growth conditions on the morphology of the manganese vanadate products. The manganese vanadate nanorods are used as glassy carbon electrode modified materials to analyze the electrochemical responses of L-cysteine. The manganese vanadate nanorod modified glassy carbon electrode exhibits a good analytical performance for the electrochemical determination of L-cysteine with a detection limit of 0.026 μM and linear range of 0.00005–2 mM.

Bis(acetylacetonato)-oxovanadium(IV), bis(maltolato)-oxovanadium(IV) and sodium metavanadate induce antilipolytic effects by regulating hormone-sensitive lipase and perilipin via activation of Akt

Abstract: The increased plasma free fatty acid levels due to the deregulated lipolysis in adipocytes are considered as one of the major risk factors for developing type II diabetes. Vanadium compounds are well-known for their antidiabetic effects both on glucose and lipid metabolism, but the mechanisms are still not completely understood. The present study suggests a mechanism for how vanadium compounds exert antilipolytic effects. It demonstrates that all the three vanadium compounds, bis(acetylacetonato)-oxovanadium(IV) (VO(acac)2), bis(maltolato)-oxovanadium(IV) (VO(ma)2) and sodium metavanadate (NaVO3), attenuated basal lipolysis in 3T3L1 adipocytes in a dose- (from 100 to 400 μM for VO(acac)2 and VO(ma)2, 1.0 to 4.0 mM for vanadate) and time-dependent (from 0.5 to 4 h) manner using the glycerol release as a marker of lipolysis. In addition, the three compounds inhibited lipolysis to a different extent. Among them, VO(acac)2 (from 100 to 400 μM) exerted the most potent effect and reduced the lipolysis to ∼60–20% of control after 4 h treatment. The antilipolytic effects of vanadium compounds were further evidenced by a decrease of the levels of phosphorylated HSL at Ser660 and phosphorylated perilipin, which were counteracted by inhibitors of PI3K or Akt but not by an MEK inhibitor. This indicates that though both Akt and ERK pathways are activated by the vanadium compounds, only Akt activation contributes to the antilipolytic effect of the vanadium compounds, without the involvement of ERK activation. We previously demonstrated that VO(acac)2 can block cell cycle progression at the G1/S phase via a highly activated ERK signal in human hepatoma HepG2 cells. Together with this study, we show that similar activated pathways may lead to differential biological consequences for cancer cells and adipocytes, indicating that vanadium compounds may be used in the prevention and treatment of both diabetes and cancer.

Effect of Ligand Coordination on the Structures and Visible-Light Photocatalytic Activity of Manganese Vanadate Hybrids

Abstract: A new manganese–vanadate hybrid structure, Mn(H2O)(bpy)V2O6 (I; bpy = 2,2′-bipyridine), has been synthesized via hydrothermal methods and characterized by single crystal X-ray diffraction [P21/n, Z = 4, a = 6.8557(4) A, b = 10.4900(6) A, c = 19.7921(13) A, β = 96.419(4)°], infrared spectroscopy, thermogravimetric analysis, magnetic susceptibility measurements, and UV–vis diffuse reflectance. The structure is comprised of manganese vanadate layers with 2,2’-bipyridine ligands coordinated to the Mn(II) cations. The water molecules coordinated to the manganese sites can be reversibly desorbed at ∼190 °C with the formation of a new hybrid structure before then further decomposing to MnV2O6 upon heating to 300 °C. Notably, I undergoes a reversible structural transformation to Mn(bpy)V4O11(bpy) (II) under hydrothermal conditions. This structural transformation results from additional bpy-ligand coordination to 1/4 of the vanadium sites. Magnetic data indicate Mn(II) cations in both I and II are high spin (S = 5...

Sodium orthovanadate (vanadate), a potent mitigator of radiation-induced damage to the hematopoietic system in mice.

Abstract: Previous in vitro and in vivo studies have shown that sodium orthovanadate (vanadate), an inorganic vanadium compound, could effectively suppress radiation-induced p53-mediated apoptosis via both transcription-dependent and transcription-independent pathways. As a potent radiation protector administered at a dose of 20 mg/kg body weight (20 mg/kg) prior to total body irradiation (TBI) by intra-peritoneal (ip) injection, it completely protected mice from hematopoietic syndrome and partially from gastrointestinal syndrome. In the present study, radiation mitigation effects from vanadate were investigated by ip injection of vanadate after TBI in mice. Results showed that a single administration of vanadate at a dose of 20 mg/kg markedly improved the 30-day survival rate and the peripheral blood hemogram, relieved bone marrow aplasia and decreased occurrence of the bone marrow micronucleated erythrocytes in the surviving animals. The dose reduction factor was 1.2 when a single dose of 20 mg/kg was administered 15 min after TBI in mice using the 30-day survival test as the endpoint. Results also showed that either doubling the vanadate dose (40 mg/kg) in a single administration or continuing the vanadate treatment (after a single administration at 20 mg/kg) from the following day at a dose of 5 mg/kg per day for 4 consecutive days further significantly improved the efficacy for rescuing bone marrow failure in the 30-day survival test. Taken together, these findings indicate that vanadate would be a potent mitigator suppressing the acute lethality (hematopoietic syndrome) and minimizing the detrimental effects (anhematopoiesis and delayed genotoxic effects) induced by TBI in mice.

Raft localization of Type I Fcε receptor and degranulation of RBL-2H3 cells exposed to decavanadate, a structural model for V2O5

Abstract: Vanadium oxides (VOs) have been identified as low molecular weight sensitizing agents associated with occupational asthma and compromised pulmonary immunocompetence. Symptoms of adult onset asthma result, in part, from increased signal transduction by Type I Fce receptors (FceRI) leading to release of vasoactive compounds including histamine from mast cells. Exposure to (VOs) typically occurs in the form of particles which are insoluble. Upon contact with water or biological fluids, (VOs) form a series of soluble oxoanions, one of which is decavanadate, V10O286− abbreviated V10, which is structurally related to a common vanadium oxide, that is vanadium pentoxide, V2O5. Here we investigate whether V10 may be initiating plasma membrane events associated with activation of FceRI signal transduction. We show that exposure of RBL-2H3 cells to V10 causes a concentration-dependent increase in degranulation of RBL-2H3 and, in addition, an increase in plasma membrane lipid packing as measured by the fluorescent probe, di-4-ANEPPDHQ. V10 also increases FceRI accumulation in low-density membrane fragments, i.e., lipid rafts, which may facilitate FceRI signaling. To determine whether V10 effects on plasma membrane lipid packing were similarly observed in Langmuir monolayers formed from dipalmitoylphosphatidylcholine (DPPC), the extent of lipid packing in the presence and absence of V10 and vanadate was compared. V10 increased the surface area of DPPC Langmuir monolayers by 6% and vanadate decreased the surface area by 4%. These results are consistent with V10 interacting with this class of membrane lipids and altering DPPC packing.

Thermal, spectroscopic and laser characterization of monoclinic vanadate Nd:LaVO_4 crystal

Abstract: The monoclinic vanadate Nd:LaVO4 crystal was characterized, including the first investigation of thermal properties and anisotropic laser performance to our knowledge. The thermal properties behave anisotropically with the highest thermal conductivity of 3.27 W/m/K along the c* direction. With a laser diode as the pump source, the efficient continuous-wave (cw) and passively Q-switched monoclinic Nd:LaVO4 crystal lasers were realized, which resulted in the nearly isotropic maximum output power and laser wavelength. The maximum cw output power is 3.56 W with a slope efficiency of 41.4%, and the passively Q-switched pulse width is 10.9 ns with pulse energy of 38.3 μJ. Based on the laser results, the thermal shock parameter anisotropy is calculated to be 1:1.28. The results show that, in contrast to other vanadate crystals, Nd:LaVO4 is a novel laser material with low symmetry.

A 3-D chiral organic–inorganic hybrid zinc vanadate assembled from helical units

Abstract: A novel 3-D chiral organic–inorganic hybrid zinc vanadate, [Zn2(μ-en)V2O7]n (1, en = ethylenediamine), which is assembled from rare 1-D [(ZnO3)(μ-en)(ZnO4)]n helical chains and dimeric [V2O7] units, has been hydrothermally synthesized. The theoretical band structure and optical properties have also been studied.

V2O5 nanostructure arrays: controllable synthesis and performance as cathodes for lithium ion batteries

Abstract: V2O5 nano-arrays with different structural units (i.e. rods, plates, and belts) were prepared by tailoring the protonation and dehydration of vanadate using different acids (HCl, H3PO4, HAc, and H2C2O4). The nanobelt-arrays showed a specific capacity as high as 255 mA h g−1, while the nanoplate-arrays showed the best rate capability.

Comparable Structural and Luminescent Characterization of the La1-xEuxVO4 Solid Solutions Synthesized by Solid State and Co-Precipitation Methods

Abstract: Luminescence properties of the two series of the La1-xEuxVO4 (x ranges from to 0.3) solid solutions synthesized by the solid state and co-precipitation methods were investigated.. Luminescence spectra of the investigated samples consist of narrow spectral lines caused by inner f - f electron transitions in the impurity Eu3+ ions. Excitation spectra consist of three main bands those correspond to different types of transitions in the investigated matrices. There are O - Eu3+ charge transfer transitions, band-to-band transitions in the matrix of the vanadate compounds and electron transitions in the VO43- vanadate anion. Dependences of the structure and luminescence properties on rate compositions and method of synthesis were studied. Origins of the observed differences between luminescence characteristics of the samples obtained by two different methods are discussed.

An Initial Exploration of Corrosion Inhibition of AA6061 and AA7075 by Aqueous Vanadates

Abstract: Aqueous tetrahedrally coordinated vanadate species have been recognized as corrosion inhibitors of AA2024-T3. Inhibition is primarily attributed to the suppression of the oxygen reduction reaction on Cu-containing intermetallics. This work focuses on whether aqueous vanadates provide similar inhibition to other wrought precipitation age-hardened aluminum alloys like AA6061-T6 and AA7075-T6, which contain less Cu than AA2024-T3. A combination of open circuit potential measurements, potentiodynamic polarization experiments, and exposure tests in dilute vanadate and vanadate-free NaCl solutions indicate that vanadates provide the strongest inhibition on AA2024-T3 and AA7075-T6 with relatively less inhibition observed on AA6061-T6.

Alternative Nitrogenases in Anabaena variabilis: The Role of Molybdate and Vanadate in Nitrogenase Gene

Abstract: Anabaena variabilis ATCC 29413 has two distinct nitrogenases that function in heterocysts, a conventional Mo-nitrogenase and an alternative V-nitrogenase. Synthesis of these two enzymes was repressed in cells growing with a source of fixed nitrogen, such as ammonium; however, the V-nitrogenase was also repressed by Mo. Expression of the V-nitrogenase which was not affected by V and expression of the Mo-nitrogenase was not affected by the presence or absence of either Mo or V. In the absence of both Mo and V in an environment lacking fixed nitrogen, cells became starved for both metals; however, low levels of nitrogen fixation and slow growth persisted. A mutant lacking the V-nitrogenase was still able to grow very slowly in Mo-and V-free medium; however, loss of the Mo-nitrogenase in a nifDK1 mutant abolished the residual growth, suggesting that only the Mo-nitrogenase functioned under these conditions to support slow growth. The addition of vanadate, molybdate, or tungstate, which is transported by the molybdate transporter, to cells starved for these metals resulted in an increase in nitrogenase activity within two hours after the addition of the metal and this increase required new protein synthesis. While tungstate functioned about as well as vanadate in supporting acetylene reduction, the cells were not able to grow any better with tungstate than with no added metal. A mutant lacking the V-nitrogenase showed no increase in nitrogenase activity upon addition of tungstate, suggesting that the V-nitrogenase was able to incorporate tungstate. Tungstate was able to substitute for molybdate in repressing transcription of a Mo-transport gene, but it did not repress transcription of the vnfH gene, which was repressed by Mo. The availability of Mo and V plays an important role in controlling whether the Mo-or the V-nitrogenase is used for nitrogen fixation.

Sodium vanadate combined with L-ascorbic acid delays disease progression, enhances motor performance, and ameliorates muscle atrophy and weakness in mice with spinal muscular atrophy.

Abstract: Proximal spinal muscular atrophy (SMA), a neurodegenerative disorder that causes infant mortality, has no effective treatment. Sodium vanadate has shown potential for the treatment of SMA; however, vanadate-induced toxicity in vivo remains an obstacle for its clinical application. We evaluated the therapeutic potential of sodium vanadate combined with a vanadium detoxification agent, L-ascorbic acid, in a SMA mouse model. Sodium vanadate (200 μM), L-ascorbic acid (400 μM), or sodium vanadate combined with L-ascorbic acid (combined treatment) were applied to motor neuron-like NSC34 cells and fibroblasts derived from a healthy donor and a type II SMA patient to evaluate the cellular viability and the efficacy of each treatment in vitro. For the in vivo studies, sodium vanadate (20 mg/kg once daily) and L-ascorbic acid (40 mg/kg once daily) alone or in combination were orally administered daily on postnatal days 1 to 30. Motor performance, pathological studies, and the effects of each treatment (vehicle, L-ascorbic acid, sodium vanadate, and combined treatment) were assessed and compared on postnatal days (PNDs) 30 and 90. The Kaplan-Meier method was used to evaluate the survival rate, with P < 0.05 indicating significance. For other studies, one-way analysis of variance (ANOVA) and Student's t test for paired variables were used to measure significant differences (P < 0.05) between values. Combined treatment protected cells against vanadate-induced cell death with decreasing B cell lymphoma 2-associated X protein (Bax) levels. A month of combined treatment in mice with late-onset SMA beginning on postnatal day 1 delayed disease progression, improved motor performance in adulthood, enhanced survival motor neuron (SMN) levels and motor neuron numbers, reduced muscle atrophy, and decreased Bax levels in the spinal cord. Most importantly, combined treatment preserved hepatic and renal function and substantially decreased vanadium accumulation in these organs. Combined treatment beginning at birth and continuing for 1 month conferred protection against neuromuscular damage in mice with milder types of SMA. Further, these mice exhibited enhanced motor performance in adulthood. Therefore, combined treatment could present a feasible treatment option for patients with late-onset SMA.

Selective catalytic reduction wall flow filter incorporating a vanadate

Abstract: A filter incorporates a catalyst for the Selective Catalytic Reduction (SCR) of NΟ x gases and removal of pa rticulate matter from the exhaust gas of a lean burn combustion engine, wherein the catalyst includes a vanadate component having an alkaline earth metal, a transition metal, a rare earth metal, or combinations thereof The vanadate component may be iron vanadate The filter includes a supported vanadate component disposed on a wall-flow filter The method of making the filter includes applying an aqueous mixture of the supported vanadate component as a washcoat on the wall-flow filter or extruding a composition containing the supported vanadate component The method of treating exhaust gases from an engine includes contacting the exhaust gas with the catalyst including the vanadate component