Creation of polarized ultracold neutrons and observation of Ramsey resonance for electric dipole moment measurement

Polarized UCNs have been created by selecting only one spin state passing through a magnetized Fe foil. Typical degree of polarization was about 90 %. The polarization relaxation time in the prototype Ramsey cell was $T_1 =1100^{+800}_{-400}(Nd,Pr)-(Tb,Dy,Gd)-(Fe,Co,Al,Cu)-B magnets were heat treated in two different ways and investigated in the temperature range 4.2 to 400 K. After optimal heat treatment intrinsic coercive field _i H _c?= 1640 and 5040 kA/m for room temperature and 10 K was obtained and the temperature coefficient of remanence α?=??0.01 for temperature range 80 to 375 K was found. On basis of magnetic measurements and ⁵⁷Fe Mössbauer spectroscopy, the possible reasons for the increase of _i H _c during multi-step heat treatment are discussed.     

Manipulation of the heme electronic structure by external stimuli and ligand field

This review describes the switching behaviors of the electronic structure, which were observed in iron(III) porphyrinoids, by the addition of external stimuli. The combined analysis by various methods, such as EPR, M?ssbauer, SQUID, single crystal X-ray structure analysis, revealed a wide variety of electronic structures of the heme related complexes. This paper focuses in particular on the spin-crossover phenomenon in the solid state. An overview of spin-crossover phenomena found in iron(III) porphyrinoids between (i) S?= 5/2 and S?= 1/2, (ii) S?= 3/2 and S?= 1/2, (iii) S?= 5/2 and S?= 3/2, will be described.     

High-performance liquid chromatographic analysis of a new beta-lactam antibiotic, 6059-S (moxalactam)

Reversed-phase high-performance liquid chromatography was applied to the quantitative determination of a new beta-lactam antibiotic, 6059-S, ant its R- and S-epimers were resolved. The procedure was also applied to pharmaceuticals and human urine samples. Chromatographic separation was effected on a bonded hydrophobic stationary phase with two mobile phases: methanol-phosphate butter for the resolution of the epimers and methanol-tetra-n-butylammonium phosphate for the quantitation of 6059-S. For the determination of 6059-S in human urine, the latter mobile phase was used successfully without interference by the other urine components. An in vivo experiment was conducted by administering intravenously 1 g of 6059-S to seven volunteers and analysing their urine by chromatographic and microbiological assays, and a comparison of the results gave a correlation coefficient of 0.9954. One-compartment model analysis of the time-course data revealed that 6059-S was excreted in urine intact with a rate constant of 0.433h-1.     

Structural Study of Methyl Acrylate in a Nematic Liquid Crystal by 1H NMR with 13C Satellites

The molecular structure and conformation of methyl acrylate have been determined by analyzing the ¹H NMR spectrum with ¹³C satellites of the molecules dissolved in the liquid crystal ZLI 1132. In the structural analysis, direct coupling constants have been corrected for molecular vibrations and converted to those in the r structure. The correlation between reorientational motion and internal rotation has been taken into account by using the mean external potential described in terms of bond interaction tensors. The potential for the internal rotation about the bond has been represented as V() = (V ₁/2) (1 – cos ) + (V ₂/2)(1 – cos 2), where is zero for the s-cis configuration, and the determined values of V ₁ and V ₂ are 2.7(1) and 8.4(13) kJ mol^–1, respectively. The relative abundance of the s-cis conformer, 76(1)%, agrees with a gas-phase value, 67(11)%, determined by electron diffraction within experimental errors.     

Syntheses, structures, and properties of intercalation compounds of silver(I) complex with [2.2]paracyclophane

Reaction of [2.2]paracyclophane (pcp) with silver(I) trifluoroacetate (AgCF(3)CO(2)) and silver(I) pentafluoroproprionate (AgC(2)F(5)CO(2)) has led to isolation of three novel intercalation polymers: [Ag(4)(pcp)(CF(3)CO(2))(4)](C(6)H(6)) (1), [Ag(4)(pcp)(CF(3)CO(2))(4)](C(6)H(3)Me(3)) (2), and [Ag(4)(pcp)(C(2)F(5)CO(2))(4)](pcp) (3). Structure studies using single crystal X-ray diffraction have shown that all compounds contain two-dimensional layered frameworks based on cation-pi interactions, in which pcp exhibits an unprecedented micro-tetra-eta(2) coordination mode. Guest molecules which weakly interact with the host pcp via C-H.pi interactions are intercalated between layers. The guest-eliminated complexes (1a and 2a) and guest-reincorporated ones (1b or 1c and 2b or 2c), accompanied by small structural changes, were confirmed by (1)H NMR, thermogravimetric analysis, mass spectra, and X-ray powder diffraction patterns. The structural changes from 1 --> 1a --> 1c (=1) can take place reversibly in the process of exposure of 1a to benzene vapor. The original framework of complex 2 is also completely recovered by immersing 2a in mesitylene as well as exposing it to mesitylene vapor.     

Photodynamic Therapy with a Diode Laser for Implanted Fibrosarcoma in Mice Employing Mono-L-Aspartyl Chlorin E6

Abstract— The authors performed photodynamic therapy (PDT), avoiding any hyperthermic effects, using a newly developed diode laser and photosensitizer, mono-L-aspar-tyl chlorin e₆ (NPe6), of Meth-A fibrosarcoma implanted in mice and achieved tumor therapeutic benefit. The photodynamic light treatment was performed 5 h following the photosensitizer administration. With 5.0 mg/kg NPe6 and light doses of 50, 100, 150 and 200 J/cm², the tumor cure rates were 20, 50, 70 and 90%, respectively. With 100 J/cm² laser exposure and NPe6 doses of 1.25, 2.5, 5.0, 7.5 and 10.0 mg/kg, the tumor cure rates were 0, 20, 50, 70 and 90%, respectively. A charge-coupled device (CCD) camera system was employed to measure the NPe6 fluorescence intensity correlating with the residual amount of the photosensitizer at deferent depth from the tumor surface. The ratios of the NPe6 fluorescence intensity at 3 mm from the tumor surface following 50, 100, 150 and 200 J/cm² laser exposure to no laser exposure were 0.73, 0.36, 0.22 and 0.16, respectively. With samples sectioned at 1 mm depth, after 50 J/cm² and the same photosensitizer dose (5 mg/kg) this ratio was 0.19. These results suggest that a certain increase in the tumor tissue level of NPe6 and a certain increase of laser light dose reaching deeper layers of tumor caused an increase in percent cure. In addition, the effectiveness of PDT depends on the total laser dose reaching deeper layers of tumors. Furthermore, the effectiveness of PDT tends to correlate with the amount of NPe6 photobleaching by PDT.     

Small-angle electron scattering by formaldehyde and ketene: Effects of electron correlation and chemical binding

The total (elastic plus inelastic) intensities of 51 keV electrons scattered by H₂CO and H₂CCO have been measured over a range of K = (4π/λ) sin(θ/2) = 1–9.5 Å^?1 and compared with the theoretical intensities calculated with SCF and CI wave functions. Significant discrepancies are found between the experimental intensities and the theoretical ones based on the SCF wave functions. Most of the chemical binding and electron correlation effects observed in the total scattered intensities are reproduced by the theoretical intensities based on the CI wave functions calculated with the basis set including polarization functions on all atoms. © 1992 John Wiley & Sons, Inc.     

Tetrahedral tellurate

A tetraethylammonium (TEA) salt of TeO 4 (2-) was synthesized by reacting Te(OH) 6 with tetraethylammonium hydroxide. X-ray structural analysis of (TEA) 2TeO 4.2H 2O confirmed that this new compound consists of discrete TeO 4 (2-) anions of distorted tetrahedral structure together with TEA cations and water molecules of crystallization [ a = 8.0820(9) A, b = 13.7730(12) A, c = 20.1590(18) A, V = 2244.0(4) A (3), Z = 4, and space group Pccb]. The (125)Te NMR spectrum indicated that water reacts with the TeO 4 (2-) anion to regenerate octahedral tellurate species in solution.