Direct detection of dithiocarbamate fungicides by SALDI/MS using porous TiC ceramic powder as a substrate.

Dithiocarbamate fungicides (DTCs) have been widely used all over the world. Some of them show toxicities, such as growth toxicity and teratogenicity. Therefore, the analysis of DTCs in environments or crops is very significant. However, their direct and individual analysis was difficult, because most of them are metal complex compounds and have macromolecular properties and a low solubility in water or organic solvents. In the conventional analytical methods for DTCs, the total amount of DTCs was obtained by the quantification of the derivatives of the ligand or by measuring the carbon disulfide formed by the decomposition of the fungicides. Surface assisted laser desorption (SALDI)/MS can detect various compounds, such as metal complexes and macromolecules, present in a nanostructured substrate. The porous titanium carbide (TiC) ceramic powder shows adsorptive properties to various substances and can be used as a substrate for SALDI/MS. In this study, a method for the individual and direct detection of dithiocarbamate pesticides by SALDI/MS using porous TiC ceramics as a substrate has been developed. The dithiocarbamate fungicide was mixed with the porous TiC powder in a mortar, and the mixture was analyzed by SALDI/MS. The deprotonated ion of the ethylene-bis-dithiocarbamate complex, mancozeb or zineb, was detected in the negative ion mode. For the dimethyldithiocarbamate complexes, ferbam and ziram, the ion of the eliminated dithiocarbamate ligand was detected in the positive ion mode. Calibration curves by the present method for Manzeb showed good linearity by using an internal standard material. Based on these results, we concluded that this method is useful for the analysis of DTCs.

Anterior inferior cerebellar artery aneurysm with proximal parent artery stenosis: A case report.

Hemodynamic factors are associated with the progression of cerebral aneurysms. We report a 78-year-old woman with an anterior inferior cerebellar artery aneurysm and proximal stenosis of the anterior inferior cerebellar and basilar arteries. The aneurysm exhibited growth on annual follow-up imaging. Aneurysmal rupture occurred 4 years after diagnosis. Coil embolization resulted in aneurysm occlusion with parent artery preservation. Aneurysms adjacent to a more proximal region of severe stenosis in the parent vessel should be considered at high risk for growth or rupture. Such aneurysms require careful monitoring. Particular attention should be paid to posterior circulation aneurysms that occur at anatomically vulnerable sites.

Photoreduction of Cr(VI) by TiO2 adsorbed gold nanoparticles and perylene as a novel organic-inorganic hybrid photocatalyst.

The photoreduction of hexavalent chromium (Cr(VI)) using TiO2 adsorbed gold nanoparticles and perylene (Au/Pe/TiO2) as a novel organic-inorganic hybrid photocatalyst has been studied. The irradiation by a Xe lamp of a Cr (VI) aqueous solution (0.1 mM) with the Au/Pe/TiO2 powder resulted in the reduction of the Cr(VI). The rate of Cr(VI) reduction reached 98.3% by the irradiation for 60 min. The reaction rate constant using Au/Pe/TiO2 (0.0545 min-1) was higher than that of TiO2 (0.0218 min-1), Pe/TiO2 (0.0303 min-1), or Au/TiO2 (0.0393 min-1). Gold nanoparticles and perylene synergistically accelerated the TiO2 photocatalytic reaction. This result is due to the Z-scheme electron transfer between Pe and TiO2 and the suppression of charge recombination by the gold nanoparticles. The irradiation of sunlight also led to the photocatalytic reduction of the Cr(VI) by Au/Pe/TiO2. In addition, successive reduction of the Cr(VI) was achieved by using a column packed with the Au/Pe/TiO2 powder immobilized by calcium alginate gel.

"Plasma-Structural Coloring" of Penciling on a Paper.

The penciling part on a paper is colored by the formation of structural color, and the coloring of a paper without ink has been achieved. In a previous study, our group reported that structural color is formed by plasma irradiation (40-120 s) of the surface of a pencil lead or paper painted with a pencil. The formation of structural color due to the thin-layer interference of components of the pencil lead was observed. The clay exposed by removal of the surface graphite through plasma etching plays the role of a "thin layer". The pencil lead can be colored blue, red, and green by the method. In the case of the paper painted with a pencil (6B), the paper turned blue but could not form the other colors by the method. The reason is that the graphite layer on the paper is not thick enough to form thin-layer interference to show colors other than blue. We now present the method that forms structural colors by plasma irradiation of the paper painted by a graphite-rich pencil lead (9B and 12B). The formation of various structural colors, such as blue, yellow, red-purple, and green, on the paper was achieved. The colored site can be effaced by an eraser. This method is a novel coloring method without using colored inks. This environmentallly friendly coloring method can be applied to various activities, such as studies and art, and can contribute to the achievement of a sustainable society.

Glowing gold nanoparticle coating: restoring the lost property from bulk gold.

The unique electronic, optical, and catalytic properties of AuNPs caused by localized surface plasmon resonance (LSPR) have attracted many scientists, but the LSPR diminishes the captivating luster of bulk gold. An exciting challenge is the fabrication of golden-colored AuNPs, but a decisive factor for controlling the absorption/reflection of AuNPs remains elusive. We now propose a simple and versatile method for the fabrication of glowing AuNPs to restore the "lost golden color" of AuNPs in combination with the deposition of AuNPs on a cellulose filter or a PET/cotton fabric by the successive ionic layer adsorption and reaction (SILAR) method and simple pencil drawing. The obtained materials exhibited the glowing golden-color on the pencil-drawn surface and common red and blue colors on the other parts. Surprisingly, the golden-colored AuNPs still maintain a catalytic activity different from that of bulk gold and could be used as a catalyst for the reduction of p-nitrophenol, pendimethalin or 2,4-dinitrophenol in the presence of NaBH4. We believe that the re-endowment of such a property characteristic of bulk gold into gold nanomaterials would lead to further advancement in the arts and culture as well as electronics, optics, and catalysis.

Two-step extraction method for lead isotope fractionation to reveal anthropogenic lead pollution.

This study developed the 2-step extraction method which eluted the Pb adsorbing on the surface of sediments in the first solution by aqua regia and extracted the Pb absorbed inside particles into the second solution by mixed acid of nitric acid, hydrofluoric acid and hydrogen peroxide solution. We applied the method to sediments in the enclosed water area and found out that the isotope ratios of Pb in the second solution represented those of natural origin. This advantage of the method makes it possible to distinguish the Pb between natural origin and anthropogenic source on the basis of the isotope ratios. The results showed that the method was useful to discuss the Pb sources and that anthropogenic Pb in the sediment samples analysed was mainly derived from China because of transboundary air pollution.

Removal of polycyclic aromatic hydrocarbons from soil using a composite material containing iron and activated carbon in the freeze-dried calcium alginate matrix: Novel soil cleanup technique.

A novel clean-up technology to remove polycyclic aromatic hydrocarbons (PAHs) from solid samples by magnetic separation using a composite containing iron powder as a magnetic material and activated carbon as an adsorbent in the freeze-dried calcium alginate matrix (Fe-AC-alg) has been developed. The Fe-AC-alg powder (50 mg), mixed with 1.0 g of glass beads having 12 kinds of adsorbed PAHs, was shaken without adding solvents at 300 rpm. After shaking, the Fe-AC-alg powder was separated using a permanent magnet. The quantity of the PAHs extracted from the glass beads treated by this method was determined. The removal (%) of the PAHs was over 96%. A roadside soil sample (10 g) was mixed with the Fe-AC-alg (1.0 g) for 2 weeks. The removal (%) of benzo[a]pyrene from the sample by the presented technique was 78%. The toxic equivalent concentration (Σ BaPeq) for the sample decreased from 0.27 to 0.10 mg kg-1 by this method. The presented method is very simple, economical, and environment-friendly.

Evaluation of the Interaction between Pesticides and a Cell Membrane Model by Surface Plasmon Resonance Spectroscopy Analysis.

A surface plasmon resonance (SPR) spectroscopy analysis was used for the characterization of the interaction between pesticides and a cell membrane model. A liposome was immobilized onto the surface of the SPR sensor chip (L1), and the lipid bilayer membrane formed on the sensor chip was regarded as the cell membrane model. The solution containing a pesticide was flowed onto the sensor chip, and an SPR sensorgram, which reflected the interaction between the pesticide and the lipid bilayer membrane, was obtained. As the results, the pattern and strength of the interaction of the pesticides with the cell membrane model were visualized and quantified. Triflumizole, hexythiazox, and pentachlorophenol showed a strong interaction with the lipid bilayer. It is well-known that triflumizole and pentachlorophenol interact with the membrane and reveal toxicities for cell membranes. In addition, there was a tendency for higher residual ratios to be observed when the no observable adverse effect level (NOAEL) values for chronic toxicity (1 year toxicity study in dogs) were lower. We suggest that a novel parameter for the evaluation or presumption of the behaviors and chronic toxicities of pesticides is obtained by the presented method.

Electrochemical extraction of gold from wastes as nanoparticles stabilized by phospholipids.

A simple one-step method for the extraction of gold from wastes as nanoparticles stabilized by phospholipids is demonstrated. This is achieved by applying an AC voltage for 5s to the gold-containing wastes, which act as the electrodes in a buffer solution containing a dispersed phospholipid (1,2-dioleoyl-sn-glycero-3-phosphocholine, DOPC). This is an environmentally friendly and rapid method for recovering gold from wastes. The extracted gold nanoparticles have significant potential as a catalyst or biomedical material.

Application of Freeze-Dried Powders of Genetically Engineered Microbial Strains as Adsorbents for Rare Earth Metal Ions.

The adsorption behaviors of the rare earth metal ions onto freeze-dried powders of genetically engineered microbial strains were compared. Cell powders obtained from four kinds of strains, Bacillus subtilis 168 wild type (WT), lipoteichoic acid-defective (ΔLTA), wall teichoic acid-defective (ΔWTA), and cell wall hydrolases-defective (EFKYOJLp) strains, were used as an adsorbent of the rare earth metal ions at pH 3. The adsorption ability of the rare earth metal ions was in the order of EFKYOJLp > WT > ΔLTA > ΔWTA. The order was the same as the order of the phosphorus quantity of the strains. This result indicates that the main adsorption sites for the ions are the phosphate groups and the teichoic acids, LTA and WTA, that contribute to the adsorption of the rare earth metal ions onto the cell walls. The contribution of WTA was clearly greater than that of LTA. Each microbial powder was added to a solution containing 16 kinds of rare earth metal ions, and the removals (%) of each rare earth metal ion were obtained. The scandium ion showed the highest removal (%), while that of the lanthanum ion was the lowest for all the microbial powders. Differences in the distribution coefficients between the kinds of lanthanide ions by the EFKYOJLp and ΔWTA powders were greater than those of the other strains. Therefore, the EFKYOJLp and ΔWTA powders could be applicable for the selective extraction of the lanthanide ions. The ΔLTA powder coagulated by mixing with a rare earth metal ion, although no sedimentation of the WT or ΔWTA powder with a rare earth metal ion was observed under the same conditions. The EFKYOJLp powder was also coagulated, but its flocculating activity was lower than that of ΔLTA. The ΔLTA and EFKYOJLp powders have a long shape compared to those of the WT or ΔWTA strain. The shapes of the cells will play an important role in the sedimentation of the microbial powders with rare earth metal ions. As the results, three kinds of the genetically engineered microbial powders revealed unique adsorption behaviors of the rare earth metal ions.

Electrospray ionization mass spectrometric detection of low polar compounds by adding NaAuCl4.

Liquid chromatography electrospray ionization mass spectrometry (LC/ESI/MS) has been widely used for various analyses. However, it is difficult to use LC/ESI/MS for the analysis of low polar compounds, such as polycyclic aromatic hydrocarbons. It is well known that AuCl4- ion decomposes to AuCl3 by heating, and AuCl3 is a strong π-electrophilic Lewis acid. Low polar compounds (pyrene, benzo[a]pyrene, perylene, benzo[ghi]perylene, dibenzothiophene and p-dimethoxybenzene) were detected by ESI/MS in the positive ion mode by adding NaAuCl4 . The low polar compound interacts with AuCl3 formed at the ESI interface, and undergoes electron transfer to AuCl3 . The radical cation of the low polar compound was then detected by MS. In addition, the LC/ESI/MS determination of polycyclic aromatic hydrocarbons by the post-column addition of NaAuCl4 was studied. © 2016 The Authors Journal of Mass Spectrometry Published by John Wiley & Sons Ltd.

Motor recovery and microstructural change in rubro-spinal tract in subcortical stroke.

The mechanism of motor recovery after stroke may involve reorganization of the surviving networks. However, details of adaptive changes in structural connectivity are not well understood. Here, we show long-term changes in white matter microstructure that relate to motor recovery in stroke patients. We studied ten subcortical ischemic stroke patients who showed motor hemiparesis at the initial clinical examination and an infarcted lesion centered in the posterior limb of internal capsule of the unilateral hemisphere at the initial diffusion-weighted magnetic resonance imaging scan. The participants underwent serial diffusion tensor imaging and motor function assessments at three consecutive time points; within 2 weeks, and at 1 and 3 months after the onset. Fractional anisotropy (FA) was analyzed for regional differences between hemispheres and time points, as well as for correlation with motor recovery using a tract-based spatial statistics analysis. The results showed significantly increased FA in the red nucleus and dorsal pons in the ipsi-lesional side at 3 months, and significantly decreased FA in the ipsi-lesional internal capsule at all time points, and in the cerebral peduncle, corona radiata, and corpus callosum at 3 months. In the correlation analysis, FA values of clusters in the red nucleus, dorsal pons, midbody of corpus callosum, and cingulum were positively correlated with recovery of motor function. Our study suggests that changes in white matter microstructure in alternative descending motor tracts including the rubro-spinal pathway, and interhemispheric callosal connections may play a key role in compensating for motor impairment after subcortical stroke.

Prevention of post-stroke disuse muscle atrophy with a free radical scavenger.

In spite of appropriate treatment in the acute phase of stroke, quite a few patients with hemiparetic stroke become disabled and stay in a wheelchair or bedridden state in the chronic phase. In stroke patients, gait dysfunction results mainly from severe hemiparesis due to ischemic damage to the motor neuron tract and partly from disuse muscle atrophy in paretic and nonparetic legs. Disuse muscle atrophy occurs even in healthy subjects as early as 4 days after bed rest immobilization and progresses further correlating with the duration of immobilization. Although detailed mechanisms of disuse muscle atrophy remain unclear, free radical scavengers are known to play an important role in the development of disuse muscle atrophy. One of the neuroprotective agents, edaravone, a free radical scavenger, succeeded in proving clinical usefulness in a phase III clinical trial in Japan. In this trial, stroke patients were administered edaravone for 14 days consecutively. The results of the edaravone trial are taken to indicate that long-term administration of a free radical scavenger may prevent disuse atrophy thereby improving functional outcome. We performed a randomized pilot study in hemiparetic stroke patients to test the validity of this view. Acute stroke patients were randomly allocated to two groups, one receiving edaravone for 3 days (short-term group) and the other for 10-14 days (long-term group). At 3 months after stroke, the grade of femoral muscle atrophy was significantly milder and the maximum walking speed was significantly faster in the long-term group than in the short-term group. The study suggests that long-term administration of a free radical scavenger may prevent the development of leg disuse atrophy thereby ameliorating locomotor function. Attention should be paid to myoprotective drug therapy in acute stroke, since it may be easier and clinically more effective than neuroprotective therapy from the viewpoint of functional prognosis.

Development of a novel evaluation method for air particles using surface plasmon resonance spectroscopy analysis.

The aim of this study was to develop a novel evaluation method for air particles using surface plasmon resonance spectroscopy (SPR) analysis. An L1 sensor chip modified with immobilized liposome was used as a model of the membrane of epithelial cells in organs of respiration. A test suspension of dispersed air particles was flowed onto the sensor chip. The interaction between the surface of the sensor chip and particulates in the sample solution was detected by SPR. It is deduced that the SPR measurement provides information about the adsorption/desorption behavior of the particles on the membrane. Environmentally certified reference materials, diesel particulate matter, vehicle exhaust particulates, urban particulate matter, coal fly ash, and rocks, were used as air particulate samples. Filtrates of suspensions of these samples were analyzed by SPR. Each sample revealed characteristic SPR sensor-gram patterns. For example, diesel particulate matter strongly interacted with the lipid bilayer, and was hardly dissociated. On the other hand, coal fly ash and rock particles interacted poorly with the membrane. The presented method could be used to evaluate or characterize air particles.

Removal of Pb(II) from water using keratin colloidal solution obtained from wool.

The aim of this study is to investigate the use of keratin colloidal solution, which was obtained from wool, for the removal of Pb(II) from water. The addition of keratin colloidal solution (15 g L(-1), 0.30 mL) to a Pb(II) solution (1.0 mM, 0.90 mL, pH 5.0) resulted in the formation and precipitation of a Pb-keratin aggregate. Measurement of the Pb(II) and protein concentrations in the supernatant solution revealed that 88 and 99 % of the Pb(II) and keratin protein were removed from the solution, respectively. The maximum Pb(II) uptake capacity of keratin in the colloidal solution was 43.3 mg g(-1). In addition, the Pb-keratin aggregate was easily decomposed via the addition of nitric acid, which enabled the recovery of Pb(II). However, aggregation did not occur in solutions with Pb(II) concentrations below 0.10 mM. Therefore, we used a keratin colloidal solution encapsulated in a dialysis cellulose tube to remove Pb(II) from 0.10 mM solutions, which enabled the removal of 95 % of the Pb(II). From these results, we conclude that keratin colloidal solution is useful for the treatment of water polluted with Pb(II).

Adsorption of rare earth ions onto the cell walls of wild-type and lipoteichoic acid-defective strains of Bacillus subtilis.

The aim of this study is to investigate the potential of cell walls of wild-type and lipoteichoic acid-defective strains of Bacillus subtilis 168 to adsorb rare earth ions. Freeze-dried cell powders prepared from both strains were used for the evaluation of adsorption ability for the rare earth ions, namely, La(III), Eu(III), and Tm(III). The rare earth ions were efficiently adsorbed onto powders of both wild-type strain (WT powder) and lipoteichoic acid-defective strain (∆LTA powder) at pH 3. The maximum adsorption capacities for Tm(III) by WT and ∆LTA powders were 43 and 37 mg g(-1), respectively. Removal (in percent) of Tm(III), La(III), and Eu(III) from aqueous solution by WT powder was greater than by ∆LTA powder. These results indicate that rare earth ions are adsorbed to functional groups, such as phosphate and carboxyl groups, of lipoteichoic acid. We observed coagulated ∆LTA powder in the removal of rare earth ions (1-20 mg L(-1)) from aqueous solution. In contrast, sedimentation of WT powder did not occur under the same conditions. This unique feature of ∆LTA powder may be caused by the difference of the distribution between lipoteichoic acid and wall teichoic acid. It appears that ∆LTA powder is useful for removal of rare earth ions by adsorption, because aggregation allows for rapid separation of the adsorbent by filtration.

Interactions of microorganisms with rare earth ions and their utilization for separation and environmental technology.

In recent years, rare earth elements (REEs) have been widely used in various modern technological devices and the global demand for REE has been increasing. The increased demand for REEs has led to environmental exposure or water pollution from rare earth metal mines and various commercial products. Therefore, the development of a safe technology for the separation and adsorption of REEs is very important from the perspective of green chemistry and environmental pollution. In this review, the application and mechanisms of microorganisms for the removal and extraction of REEs from aqueous solutions are described. In addition, the advantages in using microorganisms for REE adsorption and future studies on this topic are discussed.

Estimation of stroke etiology from lesion patterns on diffusion-weighted magnetic resonance imaging in patients with carotid artery occlusive disease.

BACKGROUND: Various mechanisms can be considered in ischemic stroke with internal carotid artery (ICA) occlusive diseases. We clarified the etiologic mechanisms from lesion patterns on diffusion-weighted imaging (DWI). METHODS: One hundred and twenty consecutive ischemic stroke patients with ipsilateral ICA occlusive diseases were enrolled and classified into 3 groups according to the size of DWI lesions: group A, massive; group B, moderate-to-large; and group C, small. Group C was divided into 3 subgroups according to the number of lesions: C1, 1-3; C2, 4-9; and C3, 10 or more. The relationship between the DWI findings and stroke subtypes according to the TOAST classification was investigated. RESULTS: Cardioembolism was significantly more common in groups A and B than in group C, while large-artery atherosclerosis (LAA) was more frequent in group C than in groups A and B. In group A, cardioembolism accounted for 32%, while LAA was not observed. Statistical analyses showed trends toward a higher frequency of LAA in groups C2 and C3 than in group C1. CONCLUSIONS: Mechanisms of acute stroke in ICA diseases can be simply assessed from the lesion size and number, which may be useful in considering acute therapeutic strategies.

Rapid quantitative CBF and CMRO(2) measurements from a single PET scan with sequential administration of dual (15)O-labeled tracers.

Positron emission tomography (PET) with (15)O tracers provides essential information in patients with cerebral vascular disorders, such as cerebral blood flow (CBF), oxygen extraction fraction (OEF), and metabolic rate of oxygen (CMRO(2)). However, most of techniques require an additional C(15)O scan for compensating cerebral blood volume (CBV). We aimed to establish a technique to calculate all functional images only from a single dynamic PET scan, without losing accuracy or statistical certainties. The technique was an extension of previous dual-tracer autoradiography (DARG) approach, but based on the basis function method (DBFM), thus estimating all functional parametric images from a single session of dynamic scan acquired during the sequential administration of H(2)(15)O and (15)O(2). Validity was tested on six monkeys by comparing global OEF by PET with those by arteriovenous blood sampling, and tested feasibility on young healthy subjects. The mean DBFM-derived global OEF was 0.57±0.06 in monkeys, in an agreement with that by the arteriovenous method (0.54±0.06). Image quality was similar and no significant differences were seen from DARG; 3.57%±6.44% and 3.84%±3.42% for CBF, and -2.79%±11.2% and -6.68%±10.5% for CMRO(2). A simulation study demonstrated similar error propagation between DBFM and DARG. The DBFM method enables accurate assessment of CBF and CMRO(2) without additional CBV scan within significantly shortened examination period, in clinical settings.