Water-soluble Mn Research Articles

Manganese status in upland and lowland rubber-growing soils in Songkhla province, southern Thailand

Rubber trees, the most economic crop in southern Thailand, are generally cultivated in acid upland soils and currently have been extended into lowland areas which induce higher solubility of manganese (Mn) which may result in Mn toxicity to rubber. This study investigated soil Mn and leaf Mn levels in rubber trees grown in upland and lowland soils. Ninety soil samples from upland and lowland rubber plantations in Songkhla province were collected and analyzed for water soluble Mn, NH4OAc Mn, diethylenetriaminepentaacetic acid test (DTPA) Mn, reducible Mn and total Mn forms. Leaf Mn analysis was also undertaken on samples of each plantation. The results revealed that the Mn concentrations of all soil Mn forms and leaf Mn in the lowland soils were higher than those of the upland samples. Comparing the optimum level reported by the Rubber Research Institute, both DTPA Mn and leaf Mn in the upland and lowland samples were high. Correlation analysis showed high and significant positive correlations of DTPA Mn and water Mn (r = 0.715), NH4OAc Mn (r = 0.975), reducible Mn (r = 0.953) and total Mn (r = 0.809) in the lowland samples. Medium to high positive correlations among Mn forms were also found in the upland samples. The correlation of soil properties (pH, electrical conductivity, organic matter, available K, exchangeable Ca, Mg and Na and cation exchange capacity) and soil Mn were clearly defined. These results indicated that soil properties affect the release of Mn. However, a correlation between soil Mn and leaf Mn was not observed.

Manganese doped-iron oxide nanoparticle clusters and their potential as agents for magnetic resonance imaging and hyperthermia.

A simple, one pot method to synthesize water-dispersible Mn doped iron oxide colloidal clusters constructed of nanoparticles arranged into secondary flower-like structures was developed. This method allows the successful incorporation and homogeneous distribution of Mn within the nanoparticle iron oxide clusters. The formed clusters retain the desired morphological and structural features observed for pure iron oxide clusters, but possess intrinsic magnetic properties that arise from Mn doping. They show distinct performance as imaging contrast agents and excellent characteristics as heating mediators in magnetic fluid hyperthermia. It is expected that the outcomes of this study will open up new avenues for the exploitation of doped magnetic nanoparticle assemblies in biomedicine.

Highly sensitive and selective detection of phosphate using novel highly photoluminescent water-soluble Mn-doped ZnTe/ZnSe quantum dots

Herein, the facile method with high selectivity for phosphate ion (Pi) sensing using novel Type-II core/shell Mn: ZnTe/ZnSe quantum dots (QDs) was reported. This was the first time that Mn: ZnTe/ZnSe QDs with highlighted optical properties were used for sensing. The water-soluble Mn: ZnTe/ZnSe QDs with a high quantum yield of 7% were synthesized by aqueous synthetic method. Compared with traditional ZnSe QDs or Mn: ZnSe QDs, the smaller effective band gap, longer wavelength and lower ionization potential (high valence band edge) for effective hole localization made Type-II core/shell Mn: ZnTe/ZnSe QDs to be stable and had high photoluminescence (PL). Only Mg2+ was found to be able to enhance Mn: ZnTe/ZnSe QDs PL selectively. The mechanism of fluorescence enhancement was attributed to the passivated surface nonradiative relaxation centers of Mn: ZnTe/ZnSe QDs. In the presence of Pi anion, the PL intensity got quenched due to the aggregation species of QDs via electrostatic attraction between Pi and Mg2+ on the surface of Mn: ZnTe/ZnSe QDs. Therefore, the quenching effect can be used to detect Pi selectively. The PL was observed to be linearly proportional to the Pi analyte concentration in the range from 0.67 to 50.0μmol/L, with a detection limit of 0.2μmol/L (S/N=3). The novel “on–off” fluorescence nanosensor for Pi detection was sensitive and convenient in the real analysis application. The reported analytical method of Mn: ZnTe/ZnSe QDs is highly sensitive and selective, which can corroborate the extension of its usages in chemo/ biosensing and bioimaging.

A two-step method to synthesize water-dispersible Mn:ZnSe/ZnO core/shell quantum dots with pure dopant emission

Water-soluble Mn:ZnSe/ZnO core/shell quantum dots with pure dopant emission were prepared via a two-step method.

밭 토양에서 바닥재와 축분퇴비의 혼합시용이 토양의 중금속 함량 및 효소활성에 미치는 영향

Abstract BACKGROUND: Coal combustion bottom ash(BA) has high carbon and calcium content, and alkaline pH, which might improve nutrient cycling in soil related to microbial enzyme activities as it is used as soil amendment. However, it contains heavy metals such as copper(Cu), manganese (Mn), and zinc(Zn), which could cause heavy metals accumulation in soil. Compost might play a role that stabilize BA. The objective of this study was to evaluate effect of combined application of BA and compost as soil amendment on heavy metals concentration, enzyme activities, chemical properties, and crop yield in upland soil.METHODS AND RESULTS: BA was applied at the rate of 0, 20, 40, and 80 Mg/ha under different rate of compost application (0 and 30 Mg/ha) in radish (Raphanus sativus var) field. Combined application of BA and compost more improved chemical properties such as pH, EC, OM, total nitrogen, available phosphate, and exchangeable cations of soil than single application of BA. Water soluble Mn and Zn concentration in soil significantly decreased with increasing application rate of BA. Decrease in those metals concentration was accelerated with combined application of BA and compost. Urease and dehydrogenase activities significantly increased with increasing application rate of BA. Phosphotase activities were not affected with single application of BA but increased with combined application of BA and compost. Radish yield was not affected by application rate of BA.CONCLUSION: From the above results, combined application of BA and compost could be used as soil amendment to improve chemical properties and enzyme activities of soil without increase in heavy metal concentration and decrease in crop yield in upland soil.Research Article Open Access

Efficient single-strand cleavage of DNA mediated by a MnIIIMnIV-based artificial nuclease

A water-soluble Mn(IV) 1,4,7-triazacyclononane complex, [Mn(IV)2L2(μ-O)2](ClO4)2·2H2O (1), was prepared to serve as a nuclease mimic (L = 1,4,7-triazacyclononane-N-acetate). Complex 1 was readily synthesized from the highly water soluble ligand (L), with Mn(III) salt, [Mn3O(MeCO2)7]·3H2O in basic condition, and characterized by X-ray, IR, electronic spectroscopy, cyclic voltammetry and magnetic susceptibility as well as ESI-MS. The bond valence sum (BVS) analysis and magnetic data suggest that 1 is a Mn(IV)-μ-O2-Mn(IV) species. The electrospray mass spectrum and electronic spectrum of 1 in aqueous solution indicates that dinuclear Mn complex [Mn(III)Mn(IV)L2(μ-O)2](+) (2) is the active species. A predominantly hydrolytic cleavage mechanism was confirmed through experiments performed in the presence of various radical scavengers, T4 ligase and under anaerobic conditions. The kinetic aspects of DNA cleavage under pseudo- or true-Michaelis-Menten conditions were also detailed, kinetic parameters (kcat, KM, Vmax) were calculated to be 6.27 h(-1), 7.35 × 10(-5) M, 4.6 × 10(-4) M h(-1); 0.683 h(-1), 1.93 × 10(-5) M, 1.32 × 10(-5) M h(-1) for 2, respectively.

The leaching behaviour and geochemical fractionation of trace elements in hydraulically disposed weathered coal fly ash

A five-step sequential extraction (SE) procedure was used to investigate the leaching behaviour and geochemical partitioning of the trace elements As, Zn, Pb, Ni, Mo, Cr and Cu in a 20-year-old fly ash (FA) dump. The weathered FA, which was hydraulically co-disposed with salt laden brine in slurry form (FA: brine ratio of 1:5), was analyzed and compared with fresh FA. The weathered FA samples were collected from three cores, drilled at a coal-fired power station in the Republic of South Africa while the fresh FA sample was collected from the hoppers in the ash collection system at the power station. The FA samples were sequentially leached using: ultrapure water; ammonium acetate buffer solution (pH 7); ammonium acetate buffer solution (pH 5); hydroxylamine hydrochloride in nitric acid (pH 2) and finally the residues were digested using a combination of HClO4: HF: HNO3 acids. Digestion of as received (unleached) FA samples was also done using a combination of HClO4: HF: HNO3 acids in order to determine the total metal content. The trace element analysis was done using ICP-OES (Varian 710-ES). The SE procedure revealed that the trace elements present in the fresh FA and the weathered FA samples obtained from the three cores could leach upon exposure to different environmental conditions. The trace elements showed continuous partitioning between five geochemical phases i.e., water soluble fraction, exchangeable fraction, carbonate fraction, Fe and Mn fraction and residual fraction. Although the highest concentration of the trace elements (ranging 65.51%–86.34%) was contained in the residual fraction, a considerable amount of each trace element (ranging 4.42%–27.43%) was released from the labile phases (water soluble, exchangeable and carbonate fractions), indicating that the trace species readily leach from the dumped FA under environmental conditions thus pose a danger to the receiving environment and to groundwater.

One-pot synthesis of stable water soluble Mn:ZnSe/ZnS core/shell quantum dots

In this paper, Mn:ZnSe/ZnS core/shell-doped quantum dots (d-dots) with 3-mercaptopropionic acid as the stabilizer are successfully synthesized through a simple one-pot synthesis procedure in aqueous solution. The average diameter of Mn:ZnSe/ZnS core/shell d-dots is about 2.9 nm, which is lager than that of Mn:ZnSe cores (about 1.9 nm). The optical features and structure of the obtained Mn:ZnSe/ZnS core/shell quantum dots have been characterized by UV–Vis and fluorescence spectroscopy, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The photostability against UV irradiation and chemical stability against H2O2 etching have been studied, and the results showed that the prepared Mn:ZnSe/ZnS core/shell d-dots are more stable than CdTe quantum dots prepared in aqueous solution. Finally, the resulting core/shell quantum dots are used as fluorescent label in human osteoblast-like HepG2 cell imaging.

A water soluble Mn(ii) polymer with aqua metal bridges

The first water soluble and crystallographically determined polynuclear Mn(II) complex, with water molecules bridging every two Mn centers, is reported. This is an unusual feature in 1D oligomer Mn(II) compounds with a nuclearity higher than 2. The polymer structure is largely preserved in water.

Chemiluminescence of Mn-Doped ZnS Nanocrystals Induced by Direct Chemical Oxidation and Ionic Liquid-Sensitized Effect as an Efficient and Green Catalyst

A novel chemiluminescence (CL) method was proposed for doping water-soluble Mn in ZnS quantum dots (QDs) as CL emitter. Water-soluble Mn-doped ZnS QDs were synthesized by using L-cysteine as stabilizer in aqueous solution. These nanoparticles were structurally and optically characterized by X-ray powder diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption spectroscopy, and photoluminescence (PL) emission spectroscopy. The CL of ZnS QDs was induced directly by chemical oxidation and its ionic liquid-sensitized effect in aqueous solution was then investigated. It was found that oxidants, especially hydrogen peroxide, could directly oxidize ZnS QDs to produce weak CL emission in basic solutions. In the presence of 1,3-dipropylimidazolium bromide/copper, a drastic light emission enhancement was observed which is related to a strong interaction between Cu2+and the imidazolium ring. In these conditions, an efficient CL light was produced at low pH which is suggested to be beneficial to the biological analysis. The CL properties of QDs not only will be helpful to study physical chemistry properties of semiconductor nanocrystals but also they are expected to find use in many fields such as luminescence devices, bioanalysis, and multicolor labeling probes.

Soil Mobilisation of Al, Fe and Mn Due to Vicinal Intensive Hog Farming Operation Located in East Mediterranean

Concentrated Animal Feeding Operation activities lead to soil degradation in vicinity with the livestock breeding facilities, mainly due to ammonia emissions from the various stages of the process. In this research, the soil degradation effects of an intensive hog farming operation (IHFO) located at a Mediterranean limestone soil coastal area, have been investigated. Soil samples of the upper mineral soil were taken in various distances (10–1,500 m) and directions from the IHFO boundaries. Thirteen experimental cycles were carried out in the duration of 1.5 years starting in March 2009 until October 2010. The soil samples were analysed on total, exchangeable and water-soluble Al, Fe and Mn. Significantly higher concentrations of the exchangeable and water-soluble Al, Fe and Mn were observed on soil samples at increasing proximity downwind from the farm (south). Southern soil average concentrations of exchangeable Al3+, Fe3+ and Mn2+ ranged between 3.56 and 7.45 mmol Al3+ kg−1 soil, 5.85 and 7.11 mmol Fe3+ kg−1 soil and 2.36 and 5.03 mmol Mn2+ kg−1 soil, respectively. Southern soil average concentrations of water-soluble Al, Fe and Mn forms ranged between 1.1 and 4.6 ppm Al, 0.5 and 0.8 ppm Fe and 0.4 and 1 ppm Mn, respectively.

Detailed mechanism of the autoxidation of N-hydroxyurea catalyzed by a superoxide dismutase mimic Mn(iii) porphyrin: formation of the nitrosylated Mn(ii) porphyrin as an intermediate

The in vitro autoxidation of N-hydroxyurea (HU) is catalyzed by Mn(III)TTEG-2-PyP(5+), a synthetic water soluble Mn(III) porphyrin which is also a potent mimic of the enzyme superoxide dismutase. The detailed mechanism of the reaction is deduced from kinetic studies under basic conditions mostly based on data measured at pH = 11.7 but also including some pH-dependent observations in the pH range 9-13. The major intermediates were identified by UV-vis spectroscopy and electrospray ionization mass spectrometry. The reaction starts with a fast axial coordination of HU to the metal center of Mn(III)TTEG-2-PyP(5+), which is followed by a ligand-to-metal electron transfer to get Mn(II)TTEG-2-PyP(4+) and the free radical derived from HU (HU˙). Nitric oxide (NO) and nitroxyl (HNO) are minor intermediates. The major pathway for the formation of the most significant intermediate, the {MnNO} complex of Mn(II)TTEG-2-PyP(4+), is the reaction of Mn(II)TTEG-2-PyP(4+) with NO. We have confirmed that the autoxidation of the intermediates opens alternative reaction channels, and the process finally yields NO(2)(-) and the initial Mn(III)TTEG-2-PyP(5+). The photochemical release of NO from the {MnNO} intermediate was also studied. Kinetic simulations were performed to validate the deduced rate constants. The investigated reaction has medical implications: the accelerated production of NO and HNO from HU may be utilized for therapeutic purposes.

A partially water-soluble cationic Mn(III)–salphen complex for catalytic epoxidation

Synthesis and application of new cationic Mn(III)–salphen complexes for catalytic epoxidation of olefins to epoxides in a homogeneous reaction media have been reported. The experimental data showed that the cationic salphen is more active than its neutral form. The acceleration of the reaction rate is attributed to the phase-transfer capability of the built-in phenazinium salt of the Mn(III)–salphen catalyst.

A protective protein matrix improves the discrimination of nitroxyl from nitric oxide by Mn III protoporphyrinate IX in aerobic media

The selectivity of Mn III/II porphyrinates toward nitroxyl or nitric oxide donors provides a convenient starting point for the development of new materials for the speciation of these nitrogen-containing redox relatives. In the present report, we describe the insertion of Mn III protoporphyrinate IX in apomyoglobin and its chemical behavior toward HNO or NO donors, either under anaerobic or aerobic conditions. For comparison and discussion, the Mn III porphyrinate, devoid of the protein matrix, was studied in parallel. The Mn III reconstituted globin successfully reacted with the nitroxyl donor trioxodinitrate, while it was unreactive toward NO or NO donors, in good agreement with previously reported data on water soluble Mn III porphyrinates. The estimated association rate constant for the reaction with the nitroxyl donor was of the same order of magnitude for the reconstituted globin and the free porphyrinate, suggesting that the protein environment is not involved in the reaction mechanism. In contrast, the reaction product exhibited enhanced stability in the presence of dioxygen only when the porphyrinate was included in the protein matrix; this feature is ascribed to the role of the distal residues on the metal centered reactivity. This behavior is required for spectroscopic detection under biologically relevant conditions.

Distribution and forms of manganese in vertisols of Serbia

Soil samples taken from the Ap horizont of arable land and meadows at ten different localities were analyzed for different forms of manganese, including total (HF), pseudo-total (HNO3), 0.1 M HClextractable and DTPA-extractable. A sequential fractional procedure was used for Mn portioning into fractions: water soluble and exchangeable Mn (I), specifically adsorbed Mn with carbonates (II), reductant releasable Mn in oxides (III), Mn bonded with organic matter (IV) and Mn structurally bonded in silicates (residual fraction) (V). Serbian vertisols have a normal Mn content, comparable with similar soils. The total (HF) and pseudo-total (HNO3) Mn contents were not correlated with soil properties, whereas the humus content positively influenced the 0.1 M HCl-extractable Mn in soil (r = 0.49

Mn Forms and Environmental Impact of Electrolytic Manganese Residue

Mn Forms and the effect on environment of electrolytic manganese residue (EMR) in Chongqing have been investigated through water extracting and sulpharic acid leaching. The ways of comprehensive utilization on EMR has been discussed in this research. The results show that the forms of Mn in EMR are chiefly water soluble Mn (II), the manganese carbonate and manganese dioxide. The groundwater pollution and the eco-environment damage will present if the EMR is randomly stacked and thrown. Having appropriate methods, the EMR may be used as recovery manganese (e.g. manganese sulfate and producing Fe-Mn bimetal oxide). The second residue from EMR can prepare water disposal agent.

生きている電流発生菌Ｓｈｅｗａｎｅｌｌａの電気化学―外膜チトクロームｃを経由する細胞外電子移動―

Genus Shewanella is a gram-negative microorganism which has a unique property of utilizing solid state metal-oxide as a terminal electron acceptor. The extracellular electron transfer (ET) occurs via cytochromes located in the outer membrane (outer membrane-cytochrome, OMC). Due to the unique property, Shewanella has attracted a lot of attentions from the view point of biogeochemical cycle and microbial fuel cell. In this review, our recent results on the extracellular ET will be introduced with Shewanella loihica PV-4. We used various electrochemical techniques as well as spectroscopic ones to investigate the ET between the microbes and the (solid) electrode. Based on the various experimental results, we show evidences of the existence of direct ET path from OMC to electrode. We also show that the addition of water soluble Mn Porphyrines, semiconducting iron oxide nano colloids, etc., greatly enhances the ET efficiency. The extracellular ET process can be applied to microbial fuel cell. The power output of thin fuel cell, so far we achieved, is ca. 2 W/l, which is almost equal to one of the most efficient bio-fuel cells using isolated protein catalysts.

Effects of a low severity prescribed fire on water-soluble elements in ash from a cork oak ( Quercus suber) forest located in the northeast of the Iberian Peninsula

Wildfire is the major disturbance in Mediterranean forests. Prescribed fire can be an alternative to reduce the amount of fuel and hence decrease the wildfire risk. However the effects of prescribed fire must be studied, especially on ash properties, because ash is an important nutrient source for ecosystem recovery. The aim of this study is to determine the effects of a low severity prescribed fire on water-soluble elements in ash including pH, electrical conductivity (EC), calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), aluminum (Al), manganese (Mn), iron (Fe), zinc (Zn), silica (SiO 2) and total sulphur (TS). A prescribed fire was conducted in a cork oak ( Quercus suber) (Q.S) forest located in the northeast part of the Iberian Peninsula. Samples were collected from a flat plot of 40×70 m mainly composed of Q.S and Quercus robur (Q.R) trees. In order to understand the effects of the prescribed fire on the soluble elements in ash, we conducted our data analysis on three data groups: all samples, only Q.S samples and only Q.R samples. All three sample groups exhibited a significant increase in pH, EC ( p<0.001), water-soluble Ca, Mg, Na, SiO 2 and TS and a decrease in water-soluble Mn, Fe and Zn. Differences were identified between oak species for water-soluble K, Al and Fe. In Q.S samples we registered a significant increase in the first two elements p<0.001 and p<0.01, respectively, and a non-significant impact in the third, at p<0.05. In Q.R data we identified a non-significant impact on water-soluble K and Al and a significant decrease in water-soluble Fe ( p<0.05). These differences are probably due to vegetation characteristics and burn severity. The fire induced a higher variability in the ash soluble elements, especially in Q.S samples, that at some points burned with higher severity. The increase of pH, EC, Ca, Mg, Na and K will improve soil fertility, mainly in the study area where soils are acidic. The application of this low severity prescribed fire will improve soil nutrient status without causing soil degradation and thus is considered to be a good management strategy.

Synthesis of highly luminescent Mn:ZnSe/ZnS nanocrystals in aqueous media

High-quality water-dispersibleMn2 + -doped ZnSe core/ZnS shell (Mn:ZnSe/ZnS) nanocrystals have been synthesized directly inaqueous media. Overcoating a high bandgap ZnS shell around the Mn:ZnSe cores canbring forward an efficient energy transfer from the ZnSe host nanocrystals to thedopant Mn. The quantum yields of the dopant Mn photoluminescence in theas-prepared water-soluble Mn:ZnSe/ZnS core/shell nanocrystals can be up to35 ± 5%. The optical features and structure of the obtained Mn:ZnSe/ZnS core/shell nanocrystals havebeen characterized by UV–vis, PL spectroscopy, TEM, XRD and ICP elementary analysis.The influences of various experimental variables, including the Mn concentration, theSe/Zn molar ratio as well as the kind and amount of capping ligand used in the core productionand shell deposition process, on the luminescent properties of the obtained Mn:ZnSe/ZnSnanocrystals have been systematically investigated.

Fluorescent Method for the Determination of Sulfide Anion with ZnS:Mn Quantum Dots

Water-soluble Mn(2+)-doped ZnS quantum dots (QDs) were prepared using mercaptoacetic acid as the stabilizer. The optical properties and structure features were characterized by X-Ray, absorption spectrum, IR spectrum and fluorescence spectrum. In pH 7.8 Tris-HCl buffer, the QDs emitted strong fluorescence peaked at 590 nm with excitation wavelength at 300 nm. The presence of sulfide anion resulted in the quenching of fluorescence and the intensity decrease was proportional to the S(2-) concentration. The linear range was from 2.5 x 10(-6) to 3.8 x 10(-5) mol L(-1) with detection limit as 1.5 x 10(-7) mol L(-1). Most anions such as F(-), Cl(-), Br(-), I(-), CH(3)CO(2) (-), ClO(4) (-), CO(3) (2-), NO(2) (-), NO(3) (-), S(2)O(3) (2-), SO(3) (2-) and SO(4) (2-) did not interfere with the determination. Thus a highly selective assay was proposed and applied to the determination of S(2-) in discharged water with the recovery of ca. 103%.