Direct detection of single nucleotide polymorphism (SNP) with genomic DNA by the ferrocenylnaphthalene diimide-based electrochemical hybridization assay (FND-EHA).

A ferrocenylnaphthalene diimide-based electrochemical hybridization assay (FND-EHA) was applied to the direct detection of a C-to-G transition in a codon (TCA) for Ser-447 of the human lipoprotein lipase (LPL) gene, which resulted in the termination of the LPL protein there. Either one of two 13-meric oligonucleotide probes, S447 WT and S447X MT, representing sequences complementary to those of the wild type (WT) and mutated (MT) forms, was immobilized on a gold electrode, followed by hybridization with chromosomal DNA extracted from human leukocytes under the condition in which both WT- and MT-type sequences can form a duplex. These two electrodes were soaked in an electrolyte containing FND under a condition [0.1 M HOAc/KOAc (pH 5.6) containing 0.1 KCl and 0.05 mM FND at 40 degrees C], in which only the MT duplex could undergo dissociation. FND was concentrated in proportion to the amount of the duplex formed on the electrode to give rise to a current signal. The electrochemical signal ratios obtained for WT/WT, WT/MT and MT/MT were close to the theoretical 2:1:0 with the S447 WT-modified electrode, and was again close to 0:1:2 with the S447X MT-modified one.     

Dipyrrolyldiketone PtII Complexes: Ion-Pairing π-Electronic Systems with Various Anion-Binding Modes

A variety of π-electronic ion-pairing assemblies can be constructed by combining anion complexes of π-electronic systems and countercations. In this study, a series of anion-responsive π-electronic molecules, dipyrrolyldiketone Pt^II complexes containing a phenylpyridine ligand, were synthesized. The resulting Pt^II complexes exhibited phosphorescence emission, with higher emission quantum yields (0.30–0.42) and microsecond-order lifetimes, and solution-state anion binding, as revealed by our spectroscopic analyses. These Pt^II complexes displayed solid-state ion-pairing assemblies, exhibiting various anion-binding modes, which derived from pyrrole-inverted and pyrrole-non-inverted conformations, and packing structures, with the contribution of charge-by-charge assemblies, which were dependent on the substituents in the Pt^II complexes and the geometries and electronic states of their countercations.     

Pulsed NMR study of network formation in the course of bulk polymerization of methyl acrylate.

The proton spin-spin relaxation time (T2) during the bulk polymerization of methyl acrylate was measured as a function of the reaction time at various temperatures. Three kinds of T2 (T2L (long), T2S (short) and T2M (intermediate)) were obtained as the polymerization proceeded. The fraction of T2S (FS) increased sigmoidally at a certain reaction time, while that of T2L (FL) decreased reciprocally. The former corresponded to the amount of a polymer whose molecular weight was sufficiently high enough to cause a tight entanglement that produced a transient network structure; the latter reflected a decrease in the mixture of the monomer and the low molecular weight of the polymer. T2M is considered to arise from a relatively mobile region of the entanglement. The relationship between the fractions of T2S + T2M and the polymer yield was found to be linear, which led us to monitor the polymer yield in real time during the polymerization in a non-distractive manner. 13C DD (dipolar decoupling)/MAS (magic angle spinning) NMR spectra were also measured to monitor the polymerization process in terms of the molecular motions between the main chain and the side chain in the formation of a network structure. The 13C DD/MAS NMR spectra show that the side chain motion became restricted as well as the main chain when the "Trommosdorff effect" (gel effect) was observed, and a part of the monomers were trapped in the network structure.     

Rapid Evaluation of the Bioremediation of Fuel Oil in Soil by Gas Chromatography–Laser Ionization Time-of-Flight Mass Spectrometry

Gas chromatography–laser ionization time-of-flight mass spectrometry (GC-LI-TOFMS) was applied to the analysis of fuel oil in soil and soil treated by bioremediation. To demonstrate rapid and selective measurement, only filtered samples after extraction of fuel oil from soil were prepared. The required time for preparing three sample solutions from an oil-contaminated soil sample was only ca. 30?min. The degree of the decrease in the fuel oil in a soil sample by vaporization was confirmed by GC-LI-TOFMS, and after 7 days, the five peak areas arising from the constituents in fuel oil were decreased to between 39 and 79% of their original values. Next, the effect of bioremediation was confirmed by the addition of microbes (Rhodococcus sp. and Acinetobacter sp.). As a result, after 7 days, the five peak areas were decreased to between 61 and 81% of the values of the first decreases, after allowing for the effect of vaporization. This method showed sufficient selectivity, robustness, and rapidity for the measurement of oil-contaminated soil treated by bioremediation, which is essential for the evaluation of real environmental remediation.     

Convenient synthesis of antisepsis agent TAK-242 by novel optical resolution through diastereomeric N-acylated sulfonamide derivative

A convenient synthesis method of antisepsis agent TAK-242 ((R)-1) through diastereomeric resolution was developed. By condensation of racemate rac-1 with chiral acid (S)-O-acetylmanderic acid (6a), the desired diastereomer 5a was isolated with 98% de in 39% yield by simple crystallization. Deacylation of 5a with aq NaOH followed by recrystallization provided (R)-1 with 99% ee in 20% yield from rac-1.     

Determination of thermal degradation of vulcanized rubbers using diffracted SH ultrasonic waves

Thermal degradation of NBR and CR heated in air was determined by analysis of diffracted SH ultrasonic waves. Thermal degradation was evaluated by examining wave pattern characteristics of SH waves passing through the surface depth between transmitter and receiver. Thermal crosslinking of main chains in thermally degraded NBR and CR, accompanied by lowering of mechanical properties, can evaluate by decrease of launched time and appearance of 0.9 MHz side peak of the power spectrum. The thermal degradation also causes phase delay at high frequencies, showing regression of viscoelasticity associated with formation of dangling ends. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 497–503, 1999     

Film‐formation property of vinylidene chloride‐methyl methacrylate copolymer latex. I. Effect of emulsion‐polymerization process

Changes in minimum film‐formation temperature (MFFT) during storage of latexes prepared from 91:9 wt % vinylidene chloride (VDC)‐methyl methacrylate (MMA) monomer mixture by seeded batch and seeded semicontinuous emulsion polymerization were investigated, with attention centered on polymer‐crystallization behavior during storage in the dispersed state. MFFT of latex prepared by the seeded batch process rose to 47 °C, whereas that of latex prepared by seeded semicontinuous process remained below 14 °C with storage at 20 °C for 12 weeks. Infrared absorption of latexes in the dispersed state and wide‐angle X‐ray diffraction of powder polymers obtained by lyophilization of fresh and stored latexes both indicated a much greater increase in polymer crystallinity during storage with latex prepared by the seeded batch process than with that prepared by the seeded semicontinuous process. Analysis of the copolymer composition drift calculated from reactivity ratios and ¹H NMR analysis indicated a wider sequence distribution and longer VDC sequences in polymer prepared by the seeded batch process than in polymer prepared by the seeded semicontinuous process. This explained the higher rate of crystallization during storage with latex prepared by the seeded batch process than with that prepared by the seeded semicontinuous process. Rising crystallinity during storage in the dispersed state is believed to have caused the MFFT rise. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 939–947, 2002     

Simultaneous determination of histamine and prostaglandin D<Subscript>2</Subscript> using an LC-ESI-MS/MS method with positive/negative ion-switching ionization modes: application to the study of anti-allergic flavonoids on the degranulation of KU812 cells

A new method for simultaneous determination of histamine and prostaglandin D₂ (PGD₂) by liquid chromatography–electrospray ionization tandem mass spectrometry operated in positive and negative ionization switching modes was developed and validated without a previous derivatization step. This method was used to measure histamine and PGD₂ release following degranulation of KU812 human basophilic cells, using pyrazol and d₄-PGD₂ as internal standards. Analyses were performed on a liquid chromatography system employing a Cosmosil 5C₁₈ PAQ column and an isocratic elution with mixed solution of methanol–water (7:3, v/v) with 0.0015% trifluoroacetic acid at a flow rate of 0.2 mL/min. A triple-quadrupole mass spectrometer operating in selected reaction monitoring mode simultaneously monitored using the following transitions: positive m/z 112/95 for histamine and negative m/z 351/271 for PGD₂. The retention times of histamine and pyrazol were 4.2 and 5.0 min, respectively. PGD₂ and d₄-PGD₂ had retention times of 8.5 min. The limits of detection were 0.3 and 0.5 ng/mL for histamine and PGD₂, respectively. The relative standard deviations of the retention time and peak area for histamine were between 1.6% and 7.7%, and were 1.2% and 7.8% for PGD₂. This method was used to evaluate the anti-allergic effects of 26 flavonoids and sodium cromoglicate which are first-line anti-allergic drugs. Of these compounds, baicalein and morin were the most potent inhibitors.     

Study of Conformers of 6,6'-Dimethyl-2,2'-bipyridine in the Ground and Excited States

UV absorption, luminescence, and luminescence-excitation spectra of the trans and metal-free cis conformers of 6,6'-dimethyl-2,2'-bipyridine (6,6'-Me₂bpy) and its Zn²⁺ complex have been observed in 2-propanol and 2-propanol-water mixtures at 77 K. The stable conformation of 6,6'-Me₂bpy in the ground state depends on the composition of the mixture at 77 K and the conformation remains unchanged upon photoexcitation. The lowest excited sing let energy is sensitive to the coordination to Zn²⁺, while the fluorescence lifetime is sensitive to both the conformation change of 6,6'-Me₂bpy and to the coordination to Zn²⁺.     

Cluster glass-like behavior of the diluted antiferromagnet Fe x Mg1−x TiO3 (x=0.2,x=0.3)

A diluted antiferromagnet Fe _x Mg_1–x TiO₃ has been shown to behave as a spin glass (x=0.2) and a reentrant spin glass (x=0.3) near the Fe percolation concentrationx 0.25. In order to obtain microscopic information on these samples, we performed Mössbauer measurements. At considerably higher temperatures than the transition temperatures, magnetically broadened spectra appear superimposed upon the paramagnetic doublets. A remarkable feature is that the intensity of the magnetic spectra increases accompanying the decrease of their linewidth. This behavior can be ascribed to the gradual slow-down of fluctuations of the antiferromagnetic clusters formed at high temperatures. To investigate the temperature variations of the relaxation time of the clusters, we analyzed the Mössbauer spectra using the method formulated by Blume. It has been shown that becomes long with decreasing temperature and the rate of the slow-down of is hastened aroundT _SG andT _N.