Determination of phase transition temperatures of liquid crystals by a light scattering method

A simple analytical system using light scattering (LS) method has been developed to determine phase transition temperatures of liquid crystals (LCs). Intensity changes of the transmission light through a sample were measured as a function of temperature. All LCs and non-LCs showed appreciable changes in the transmission intensity at the phase transition temperature. The transition temperatures determined by the LS method were identical to those by differential scanning calorimetry (DSC).     

Observation of the structural consequences of a reversible S = 3/2 and S = 1/2 spin crossover in the single crystal

Highly saddle shaped iron(III) porphyrin complex 1 showing a novel spin crossover process between the S = 3/2 and S = 1/2 has been crystallographically analyzed at 298, 180, and 80 K. As the temperature is lowered, the lattice contraction has occurred specifically along the b-axis. Correspondingly, the iron-pyridine bonds, which tilt slightly from the b-axis, have decreased by 7.3%. In contrast, the lattice contractions along the a- and c-axes are much smaller and the iron-porphyrin bonds, which almost coincide with the a- and c-axes, have shown much smaller contraction, ca. 2.2%. The large contraction of the specific bonds caused by packing force raises the energy level of the d(z)2 orbital and induces the spin transition. The detailed structural and lattice changes in the single crystal, which may be regarded as a superstructure parallel to a protein matrix, have been clarified.     

First in vitro norlignan formation with Asparagus officinalis enzyme preparation

We report for the first time that an enzyme preparation from fungal-elicited Asparagus officinalis cultured cells catalyses the formation of a norlignan, (Z)-hinokiresinol, from two non-identical phenylpropanoid monomers, 4-coumaryl alcohol and 4-coumaroyl CoA, and from a dimer, 4-coumaryl 4-coumarate, without any additional cofactors.     

Growth of Na-doped Ca(2)CuO(2)Cl(2) single crystals under high pressures of several GPa

Single crystals of Na-doped Ca(2)CuO(2)Cl(2) have been grown for the first time by a flux method under high pressures of up to 5.5 GPa. By changing the Na-solubility limit through the applied pressure, the Na content x was successfully controlled without introducing appreciable compositional inhomogeneity within the millimeter-sized crystals. Structural and chemical characterization indicated that the crystals span the phase diagram continuously from the parent antiferromagnetic insulator to an underdoped high-temperature superconductor. Because of the well-defined cleavage plane and resulting high surface quality, these oxychloride single crystals will provide a unique opportunity to explore the electronic evolution of the high-temperature superconductors, using spectroscopic techniques such as scanning tunneling microscopy/spectroscopy and angle-resolved photoemission spectroscopy.     

NIRS的ECR离子源现状

Four ECR ion sources have been operated in National Institute of Radiological Sciences(NIRS). Two ECR ion sources supply various ion species for the Heavy Ion Medical Accelerator in Chiba(HIMAC). The 10GHz NIRS-ECR ion source mainly produces C~(2 ) ions for the heavy-ion therapy.Ions of Si,Ar,Fe,Kr and Xe are usually produced by the 18GHz NIRS-HEC ion source for physical and biological experiments.The other two compact ECR ion sources with all permanent magnet configuration have been developed for the new generation carbon therapy facility.One of these,the Kei-source,is a prototype which has been installed to the NIRS-930 cyclotron for axial injection.The other source,Kei2-source,is a demonstration source and utilized for the new generation Linac.In addition,both Kei sources have been used to study fundamental properties. In this paper,present status of the ion sources and recent developments are reported.     

Study of N=20 shell gap with 1H(28Ne,27,28Ne) reactions

This paper reports on the ¹H(²⁸Ne,²⁸Ne) and ¹H(²⁸Ne,²⁷Ne) reactions studied at intermediate energy using a liquid hydrogen target. From the cross section populating the first 2⁺ excited state of ²⁸Ne, and using the previously determined B(E2) value, the neutron quadrupole transition matrix element has been calculated to be M_n=13.8 ±3.7 fm². In the neutron knock-out reaction, two low-lying excited states were populated in ²⁷Ne. Only one of them can be interpreted by the sd shell model while the additional state may intrude from the fp shell. These experimental observations are consistent with the presence of fp shell configurations at low excitation energy in ^27,28Ne nuclei caused by a vanishing N=20 shell gap at Z=10.     

Regulation of macrophage-specific gene expression by degenerated lipoproteins

The effect of aggregated low-density lipoprotein (agLDL) on cell viability and macrophage-specific gene expression using human peripheral blood monocytes in culture was investigated. AgLDL suppressed activation-induced cell death of phorbol ester-treated macrophages. The inhibition of apoptosis was accompanied by downregulation of apoptosis-promoting proteases, including interleukin-1beta-converting enzyme (ICE) and CPP32 and upregulation of anti-apoptotic cytokine (interleukin-1beta (IL-1beta)). In contrast, macrophage-colony stimulating factor (M-CSF) enhanced cell death of lipid-bearing macrophages, suggesting that the anti-atherogenic action of M-CSF is at least in part mediated through apoptotic elimination of macrophages. Then, we attempted to isolate the genes specifically induced by agLDL in macrophages using a subtraction-based cloning strategy. One of the genes isolated, termed LIG (LDL-inducible gene), encodes a human homolog of E2 ubiquitin-conjugating enzyme. Ubiquitination of multiple intracellular proteins was observed in agLDL-treated macrophages, which coincided with upregulation of LIG. These results suggest that LIG acts as a direct mediator of foam cell formation through polyubiquitination and subsequent degradation of cellular proteins with apoptosis-inducing properties. The regulation of apoptosis by macrophage-specific gene expression may contribute to foam cell formation and atherosclerosis.