Combination of crystal growth with optical floating zone and evaluation of Nd3+:LaAlO3 crystals with the dynamic nuclear polarization of 139La and 27Al.

Producing a polarized lanthanum (La) target with high polarization and long relaxation time is crucial for realizing time-reversal violation experiments using polarized neutron beams. We use a LaAlO3 crystal doped with a small amount of Nd3+ ions for the polarized lanthanum target. Optimizing the amount of Nd3+ ions is considerably important because the achievable polarization and relaxation time strongly depend on this amount. We established a fundamental method to grow single crystals of Nd3+:LaAlO3 using an optical floating zone method that employs halogen lamps and evaluated the crystals with the dynamic nuclear polarization (DNP) method for polarizing nuclear spins. Two crystal samples were grown by ourselves and evaluated with the DNP at 1.3 K and 2.3 T for the first time, except for the target materials of protons. The enhancement of nuclear magnetic resonance signals for 139La and 27Al was successfully observed, and the enhancement factors were eventually 3.5 ± 0.3 and 13 ± 3 for the samples with Nd3+ ions of 0.05 and 0.01 mol. %, respectively. These enhancement factors correspond to absolute vector polarizations of 0.27% ± 0.02% (Nd3+ 0.05 mol. %) and 1.4% ± 0.3% (Nd3+ 0.01 mol. %). Although the obtained polarizations are still low, they are acceptable as a first step. The combination scheme of the crystal growth and the evaluation of the crystals is found to be effectively applicable for optimizing the amount of Nd3+ ions for improving the performance of the polarized target.

Discovery of flometoquin, a novel quinoline insecticide.

Flometoquin, 2-ethyl-3,7-dimethyl-6-[4-(trifluoromethoxy)phenoxy]quinolin-4-yl methyl carbonate, is a novel insecticide with a structurally unique phenoxy-quinoline. It was discovered in 2004 by the collaborative research of Nippon Kayaku and Meiji Seika Kaisha, Ltd. (currently, Mitsui Chemicals Crop & Life Solutions, Inc.). The compound demonstrates strong and quick insecticidal action against a variety of thrips species at the nymphal and adult stages through contact and feeding activity, which could minimize crop damage and economic loss by insect pest species. In addition, flometoquin is safe for tested non-target arthropods, which makes it suitable for controlling the insect pests mentioned above under Integrated Pest Management (IPM) programs. Here, we describe a structure-activity relationship study from lead generation to the discovery of flometoquin and its insecticidal properties, including knockdown activity and effects against non-targeted arthropods.

Redox reactions between ABTS•+ and dihydroxybenzenes as studied by cyclic voltammetry.

Redox reactions between several types of polyphenols and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS•+) used in a trolox equivalent antioxidant capacity (TEAC) assay were monitored by continuous cyclic voltammetry. The TEAC assay is one of the effective methods for clarifying the radical scavenging reaction mechanism of antioxidants. We obtained information on whether the reaction was a simple electron transfer, an electron transfer involving a subsequent chemical reaction of the antioxidant itself, or an electron transfer involving a coupling reaction between ABTS•+ and the antioxidant.

DFT Study of α-Keggin-type Iso-polyoxotungstate Anions [HnW12O40](8-n)- (n =1-4): Can [H4W12O40]4- Exist?

The Keggin-type iso-polyoxotungstate (iso-POT) anions [HnW12O40](8-n)- 's, in which their central vacancies are occupied by protons, are attractive materials. It is of importance to reveal if the vacancies can be fully occupied by four protons. For further understanding the speciation of these iso-POT anions, relative stabilities and proton transfer reactions between H1[Hn-1W12O40](8-n)- and [HnW12O40](8-n)- were examined in detail by using the first-principles calculations (the nudged elastic band method, the synchronous transit-guided quasi-Newton method, the intrinsic reaction coordinate method, and frequency analysis calculations). Thermochemistry analysis of the proton transfer was also performed. [HnW12O40](8-n)- was energetically more stable than H1[Hn-1W12O40](8-n)-. This held for n = 4. According to the results of thermochemistry analysis, the rate constant and the Wigner correction were respectively 3.1 × 101 s-1 and 2.2 at T = 298.15 K for the proton transfer from H1[H3W12O40]4- to [H4W12O40]4-, indicating that [H4W12O40]4- can exist when H1[H3W12O40]4- is formed by protonating [H3W12O40]5-.

How Viscous Is the Solidlike Structure at the Interface of Ionic Liquids? A Study Using Total Internal Reflection Fluorescence Spectroscopy with a Fluorescent Molecular Probe Sensitive to High Viscosity.

Aiming at the evaluation of the viscosity of the interfacial solidlike structure of ionic liquids (ILs), we performed total internal reflection fluorescence (TIRF) spectroscopy for N,N-diethyl-N'-phenyl-rhodamine (Ph-DER), a fluorescent probe that is sensitive to viscosity in a high-viscosity range. TIRF spectra at the glass interface of trioctylmethylammonium bis(nonafluorobutanesulfonyl)amide (TOMAC4C4N), a hydrophobic IL, showed that the fluorescence intensity of Ph-DER increases with the decrease of the evanescence penetration depth, suggesting that there exists a high-viscosity region at the interface. In contrast, glycerol, which is a molecular liquid with a bulk viscosity similar to that of TOMAC4C4N, did not show such a fluorescence increase, supporting that the formation of a highly viscous solidlike structure at the interface is intrinsic to ILs. A model analysis suggested that the high viscous region at the glass interface of TOMAC4C4N is at least twice thicker than the ionic multilayers at the air interface, implying that the solid substrate enhances the ordering of the interfacial structure of ILs. The viscosity at the glass interface of TOMAC4C4N was found to be at least 40 times higher than that of the liquid bulk.

Capillary zone electrophoresis determination of fluoride in seawater using transient isotachophoresis.

We developed capillary zone electrophoresis (CZE) with indirect UV detection for the determination of fluoride (F-) in seawater using transient isotachophoresis (tITP) as an on-line concentration procedure. A method of correcting sample salinity effects was also proposed so that F- concentrations were obtained using a calibration graph. The proposed method is simple: it requires no sample pretreatment aside from dilution. The following optimum conditions were established: background electrolyte (BGE), 5 mM 2,6-pyridinedicarboxylic acid (PDC) adjusted to pH 3.5 containing 0.03% m/v hydroxypropyl methylcellulose (HPMC); detection wavelength, 200 nm; vacuum (50 kPa) injection period of sample, 5 s (254 nL); and applied voltage, 23 kV with the sample inlet side as the cathode. The limit of detection (LOD, S/N = 3) and limit of quantification (LOQ, S/N = 10) for F- reached 0.024 and 0.070 mg/L, respectively. The respective values of the relative standard deviation (RSD) of the peak area, peak height, and migration time for F- were 2.5, 3.4, and 0.30%. The proposed method was applied for the determination of F- in seawater samples collected from coastal waters of western Japan during August 26-28, 2014. Both results obtained using standard addition method and a calibration graph agreed with those obtained using a conventional spectrophotometric method.

Development of Tetrahydrofuran/Water Optical Waveguide and Its Application to the Observation of Extraction Behavior of 1-Anilino-8-naphtalene Sulfonate at the Tetrahydrofuran/Water Interface.

A stable two-phase sheath flow using tetrahydrofuran (THF) for an inner flow and water for an outer flow was formed in a glass capillary, and worked as a stable liquid-core/liquid-cladding optical waveguide (THF/water LLW). Although THF and water were miscible with any ratio, the length of the stable THF/water LLW at 0.9 - 2.1 cm s-1 reached at least 150 mm. The THF/water LLW was applied to the observation of extraction behavior of solvatochromic fluorescence dye, 1-anilino-8-naphtalene sulfonate (ANS), through the THF/water interface. ANS was added to the water phase (clad solution) and its fluorescence, which was excited with the guided light (355 nm) through the LLW, was observed by changing the position of the detector. While the ANS stayed in the region of 70% THF to the end of the LLW without the addition of cationic surfactant, hexadecyltrimethylammonium ion (CTA+) at pH 3 and 11, the ion-pair of ANS and CTA+ was extracted into the higher concentration region of THF with the addition of CTA+ at pH 11.

Direct Detection of Aqueous CO2 by Infrared Waveguide Spectroscopy with an Amorphous Fluoropolymer Coating Rod.

Infrared waveguide spectroscopy using a sapphire rod coated with an amorphous fluoropolymer (Cytop, Asahi Glass Co., ltd, Japan) has been developed in order to directly observe CO2 in aqueous solutions. Since the amorphous fluoropolymer has a relatively high gas-permeability and hydrophobic feature, the aqueous CO2 transmits into the amorphous fluoropolymer coating film, but water cannot penetrate into the film. Good linearity of calibration curves for CO2 in the gas and the aqueous solution were obtained.

A novel method for determination of inorganic oxyanions by electrospray ionization mass spectrometry using dehydration reactions.

Novel methods for the determination of inorganic oxyanions by electrospray (ES) ionization mass spectrometry have been developed using dehydration reactions between oxyanions and carboxylic acids at the ES interface. Twelve oxyanions (VO3 (-) , CrO4 (2-) , MoO4 (2-) , WO4 (2-) , BO3 (3-) , SiO3 (2-) , SiO4 (4-) , AsO4 (4-) , AsO2 (-) , SeO4 (2-) , SeO3 (2-) and NO2 (-) ), out of 16 tested, reacted with at least one of four aminopolycarboxylic acids, i.e. iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid and triethylenetetramine-N,N,N',N″,N'″,N'″-hexaacetic acid, at the ES interface to produce the dehydration products that gave intense mass ion responses, sufficient for trace analysis. As examples, trace determinations of Cr(VI) and silica in water samples were achieved after online ion exchange chromatography, where the dehydration product of CrO4 (2-) and NTA (m/z 290) and that of SiO4 (4-) and IDA (m/z 192) were measured. The limits of detection of the respective methods were 17 nM (0.83 ng Cr/ml) for Cr(VI) and 0.17 µM (4.8 ng Si/mL) for SiO4 (4-) .

[Prognostic factors and efficacy of molecular targeted therapy for metastatic clear cell renal cell carcinoma].

We retrospectively reviewed the medical records of patients with metastatic clear cell renal cell carcinoma who received molecular targeted therapy between 2005 and 2011. Cancer-specific survival was analyzed using the Kaplan-Meier method. Predictors of cancer-specific survival were analyzed using the Cox regression hazards model. A total of 89 patients, consisting of 50 first line patients and 39 patients receiving prior cytokine were included in the analysis. The two-year cancer-specific survival rate of the firstlinegroup was 60.2% and that of theprior cytokinethe rapy group was 62.1%. In univariateanalysis, Karnofsky performance status (KPS)＜80%, time from diagnosis to treatment less than one year, bone metastasis and C-reactive protein (CRP)＞1.3 mg/dl in were statistically significant prognostic factors (p＜0.05). In multivariate analysis, time from diagnosis to treatment less than one year (HR 2.46, 95%CI 1.11-5.82, p＝0.025) and CRP (HR 4.92, 95%CI 2.23-11.3, p＜0.001) were independent prognostic factors. Time from diagnosis to treatment less than one year and CRP were independent prognostic factors in patients who received molecular targeted therapy.

Electrospray ionization mass spectrometry for the quantification of inorganic cations and anions.

Recent studies from our laboratory on electrospray ionization mass spectrometry (ESI-MS) for the quantification of inorganic cations and anions are reviewed. Metal ions were determined by ESI-MS in negative-ion mode as monovalent negative ions of their aminopolycarboxylate (APC) complexes, where excess amounts of the APC agents were added to sample solutions. Among the APCs studied, we found trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (CyDTA, the chemical forms in a complex were expressed as H(n)cydta(n-4)) as the best chelating agent. A size exclusion column was used for on-line separation of the metal-APC complexes from matrix salts in samples. Total amounts of Al, Ni, Cu, Zn, and Pb in the biological certified reference materials (CRM), Olive Leaves (BCR-062) and Plankton (BCR-414), and in a soil CRM (JSAC-0401) were successfully determined by the proposed method. Halide ions (X(-) = F(-), Cl(-), Br(-) and I(-)) and cyanide (CN(-)) were determined by ESI-MS based on the formation of ternary complexes of metals, chelating agents and the analyte anions. Negative ions of the ternary complexes of group 13 elements, nitrilotriacetic acid (NTA, H(n)nta(n-3)), and halides, i.e., [AlF(nta)](-) for F(-), and [InX(nta)](-) for other halides, were measured; the limits of detection (LODs) were 10 nmol dm(-3) for F(-), 0.31 µmol dm(-3) for Cl(-), 3.8 nmol dm(-3) for Br(-), and 1.6 nmol dm(-3) for I(-), respectively. In the case of CN(-), an LOD of 20 nmol dm(-3) was obtained based on measurements of the ternary complex of Cu(II), CN(-) and 4-(2-pyridylazo)resorcinol (PAR, Hnpar(n-2)), i.e., [(63)Cu(II)(CN)(par)](-) (m/z 302). Moreover, quantitative methods for Cr(VI) and Cr(III) by ESI-MS were developed, where HCrO4(-) (m/z 117) for Cr(VI) and [Cr(III)(cydta)](-) for Cr(III) were used for measurements.

Characterization of liquid-core/liquid-cladding optical waveguides of a sodium chloride solution/water system by computational fluid dynamics.

A stable liquid/liquid optical waveguide (LLW) was formed using a sheath flow, where a 15% sodium chloride (NaCl) solution functioned as the core solution and water functioned as the cladding solution (15% NaCl/water LLW). The LLW was at least 200 mm in length. The concentration distributions of the liquid core and liquid cladding solutions in the LLW system were predicted by computational fluid dynamics (CFD) to validate the characteristics of the waveguide. The broadening of the region of the fluorescence of Rhodamine B excited by the guided light and the increase in the critical angle of the guided light with the increase in the contact time of the core and the cladding solutions were well explained by CFD calculations. However, no substantial leakage of the guided light was observed despite the considerably large change in the refractive index profile of the LLW; thus, a narrower and longer waveguide was realized.

Determination of chromium(III), chromium(VI) and total chromium in chromate and trivalent chromium conversion coatings by electrospray ionization mass spectrometry.

Developed were the determination methods of Cr(VI) and Cr(III) by electrospray ionization mass spectrometry, where HCrO(4)(-) (m/z 117) and [Cr(III)(cydta)](-) (m/z 394) were measured, respectively. Moreover, total Cr was also determined by measuring [Cr(III)(cydta)](-) after reduction of Cr(VI) with ascorbic acid. Here, cydta denotes trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid. The detection limits were ca. 13 nmol/dm(3) for Cr(VI) and 56 nmol/dm(3) for Cr(III) and total Cr. The proposed methods were applied to analyze chromate and trivalent chromium conversion coatings and gave consistent results with those obtained by a diphenylcarbazide spectrophotometric method for Cr(VI) and ICP-AES for total Cr.

New determination methods of halides and cyanide ions by electrospray ionization mass spectrometry based on ternary complex formation.

Determination methods of halide ions (X(-) = F(-), Cl(-), Br(-) and I(-)) by electrospray ionization mass spectrometry (ESIMS) were developed, where negative ions of the ternary complexes of group-13 elements, nitrilotriacetic acid (NTA), and halides were measured. In particular, these halides were simultaneously determined by measuring [InX(nta)](-), and the limits of detection (LODs) were 1.1 µmol dm(-3) for F(-), 0.32 µmol dm(-3) for Cl(-), 3.8 nmol dm(-3) for Br(-), and 1.6 nmol dm(-3) for I(-), respectively. This approach was extended to the determination of CN(-), where the ternary complex of Cu(II), CN(-) and 4-(2-pyridylazo)resorcinol (PAR), i.e., [(63)Cu(II)(CN)(par)](-) (m/z 302) was measured. The LOD for CN(-) was 20 nmol dm(-3).

Quantification of trace elements in natural samples by electrospray ionization mass spectrometry with a size-exclusion column based on the formation of metal-aminopolycarboxylate complexes.

Metal ions were determined by ESI-MS in the negative ion mode as monovalent negative ions of their aminopolycarboxylic acid (APC) complexes, e.g., [Al(cydta)](-), [Pb(Hcydta)](-), where excess amounts of the APC agents were added to sample solutions. Among several APCs studied, we chose trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (CyDTA) as the best chelating agent because of higher stabilities and higher sensitivities of the complexes. The ionization efficiency of these metal complexes was strongly affected by the presence of matrix salts, e.g., NaCl, KNO(3), and etc. Thus, a size exclusion column (Sephadex G-10) was used for the online separation of the metal-APC complexes from other matrix salts. This method was successfully applied to the quantitative analyses for total amounts of Al, Ni, Cu, Zn, and Pb in the biological certified reference materials, olive leaves (BCR-062) and plankton (BCR-414). The detection limits of the present methods for these elements were several to several ten nanomolar levels. Moreover, this approach was extended to determine ultratraces of fluoride based on the formation of the ternary complex of aluminum, fluoride and nitrilotriacetic acid (NTA), i.e., [AlF(nta)](-). Its detection limit was 10 nM and was 2 orders of magnitude better than that of a fluoride ion selective electrode method. This method was applied to determine fluoride in tap water, river water, and green tea samples.

Identification of aluminum species in an aluminum-accumulating plant, hydrangea (Hydrangea macrophylla), by electrospray ionization mass spectrometry.

The use of electrospray ionization mass spectrometry (ESI-MS) in negative ion mode was investigated as a direct probe for identifying Al species in Al-accumulating hydrangea (Hydrangea macrophylla) samples. Cell sap solutions of hydrangea leaves were purified using Sephadex G-10 liquid chromatography and each fraction was analyzed using ESI-MS and ESI-MS/MS to identify Al species. In hydrangea leaves, a 1:1 Al-citrate complex was found as [AlH(-1)cit](-) (m/z 215), where H(3)cit denotes citric acid. This result is consistent with that of Ma et al. who used (27)Al-NMR.

Synthesis, structures, and properties of meso-phosphorylporphyrins: self-organization through P-oxo-zinc coordination.

The synthesis, structures, and optical and electrochemical properties of meso-phosphorylporphyrins are described. The copper-catalyzed carbon-phosphorus cross-coupling reaction of a meso-iodoporphyrin with di-n-butyl phosphite and diphenylphosphane oxide has proved to be an efficient and general method for the synthesis of meso-phosphorylporphyrins. Zinc phosphorylporphyrins thus obtained readily undergo self-organization through P-oxo-Zn coordination to form noncovalently linked, cofacial porphyrin dimers or linear oligomers, which have been characterized by spectroscopic methods and X-ray crystallographic analyses. In toluene, CH(2)Cl(2), and CHCl(3), the zinc phosphorylporphyrins exist mostly as dimers or monomers, depending on their concentrations, the temperature, and the presence of additives. The self-association constants for dimerization in toluene have been determined by UV/Vis absorption titration measurements. The meso-diphenylphosphorylporphyrin dimer displays excitonic coupling of the Soret band with a splitting energy of 940 cm(-1). Fluorescence lifetimes of the zinc phosphorylporphyrins have been found to be affected only slightly by the concentration of the solution, and by the addition of triphenylphosphane oxide, suggesting that the effect of dimerization on their photodynamics in the S(1) state is negligible. On the other hand, the effect of dimerization is clearly reflected in their electrochemical oxidation processes, as the initially produced radical cations are efficiently delocalized over the two porphyrin rings. These findings demonstrate the potential utility of meso-phosphorylporphyrins as new models for the special pair in photosynthesis and as new building blocks for porphyrin-based supramolecular materials.

Slab optical waveguide high-acidity sensor based on an absorbance change of protoporphyrin IX.

A sensitive and fast-responsive evanescent wave absorption sensor has been constructed for pH measurements in highly acidic ranges. This sensor is based on a pH-dependent color change of protoporphyrin IX (PPIX). For the sensitive detection, a visible attenuated total reflection spectrometer with a slab optical waveguide (SOWG) was laboratory-made, and the guiding layer surface was modified with a PPIX-immobilized acrylamide-based thin membrane. The sensing membrane with a thickness of approximately 1 mum was directly fabricated on the SOWG glass surface by copolymerization of acrylamide, N,N'-methylene bisacrylamide, and PPIX in the narrow space confined by a cover plate. PPIX possesses two double bonds in its structure, and so it can be covalently incorporated into the membrane. The response characteristics of the PPIX-immobilized optode membrane were explored using aqueous solutions with different concentrations of HNO(3) or HCl. The optode membrane provided characteristic Soret band absorption spectra depending on the hydrogen ion concentration; the absorbance at 410 nm increased with increasing the concentrations in the range of 0.15-2 M, corresponding to the range of pH -0.3 to 0.8. The absorption signal reached 90% of its final value within 10 s, while the absorption signal was quite readily returned to background level simply by passing 2 mL of distilled water through a flow cell with a volume of 16.5 muL placed on the SOWG. Due to the rapid response and reversibility, this sensor could be operated in a flow-through mode as well as in a conventional static mode, where deionized water was conveniently used as a carrier and conditioning solution. In terms of the stability and precision, this sensor showed no significant change in response even after 100 assays and after being stored in a dry condition for over 6 months. Relative standard deviations for 10 replicate measurements were less than 1.8% in the linear range, and the detection limit calculated from 3 times of the standard deviation was 0.02 pH unit.

Liquid core waveguide spectrophotometry for the sensitive determination of nitrite in river water samples.

A flow injection analysis system was built with a liquid core waveguide spectrophotometric detector using an 80 cm Teflon AF-1600 capillary tube (2,2-bistrifluoromethyl-4,5-difluoro-1,3-dioxole/tetrafluoroethylene). The system was applied to determine nitrite ion in river water samples. The lower limit of detection for nitrite was 2.1 nmol dm(-3) (0.1 ng dm(-3) as NO(2)(-)) and the relative standard deviation of measurements was typically 0.56% (n = 5) at 0.21 micromol dm(-3).