Electronic Communication in the Mixed-valence States of Cyclobutadienecobalt Complexes having Two Ferrocenes and Two Anthraquinones

Two geometric isomers, Z and E forms of (η⁴-cyclobutadiene)(η⁵-cyclopentadienyl) cobalt simultaneously containing two ferrocene moieties and two anthraquinone moieties, 1 and 2, respectively, were synthesized, and their crystal structures were determined. These molecules formed double mixed-valence states caused by ferrocene–ferrocenium and anthraquinone–anthrasemiquinone electronic communications. In both 1 and 2, the thermodynamic stability of the mixed-valence state for the ferrocene moieties was higher than that of the anthraquinone moieties because of the orbital coupling of the CB–Co bridging unit. The comproportionation constant, K _c, for the ferrocene moieties was similar between 1 and 2, whereas the mixing coefficient, α, and the off-diagonal matrix-coupling element in the Marcus-Hush two-state model, H _AB, evaluated from analysis of the intervalence charge transfer (IVCT) band were larger for 1 than for 2. These results suggest the existence of higher electrostatic repulsion between two ferrocenium cations in 1 than in 2 and the occurrence of through-bond electronic communication. K _c for the anthraquinone moieties in the E form is smaller than that of the Z form, probably due to the through-space electronic interaction.     

Radionuclide release to stagnant water in the Fukushima-1 nuclear power plant1

After the severe accident at the Fukushima-1 nuclear power plant, large amounts of contaminated stagnant water have accumulated in turbine buildings and their surroundings. This rapid communication reports calculation of the radionuclide inventory in the core, collection of measured inventory in the stagnant water, and estimation of radionuclide release ratios from the core to the stagnant water. This evaluation is based on data obtained before 3 June 2011. The release ratios of tritium, iodine, and cesium were several tens of percent, whereas those of strontium and barium were smaller by one or two orders of magnitude. The release ratios in the Fukushima accident were equivalent to those in the accident of the Three Mile Island, Unit 2 (TMI-2).     

Cross-Sectional TEM Analysis of an ITO Surface Coated with Photosystem I and Molecular Wires

Photosystem I (PSI) from Thermosynechococcus elongatus was immobilized on ITO by using vitamin K₁ exchange with artificial molecular wires in PSI. A PSI-modified surface was prepared for observation of lateral TEM images to provide an understanding of its interfacial structure. This paper describes the use of an ultramicrotome to prepare ultra-thin (< 20 nm) sections of PSI on ITO substrates. Cross-sectional TEM and energy-dispersive X-ray spectrometry supported that monolayer PSI was attached to the ITO electrode.     

Synthesis, Crystal Structure and Magnetic Properties of a Nickel(II) Coordination Polymer Based the V-Shaped Ligands

Abstract  

A new nickel(II) coordination polymer, Ni₂(DBA)₂(BIDPE)₂(H₂O) (1) (H₂DBA = 4,4′-methylenedibenzoic acid and BIDPE = 4,4′-bis(imidazole-l-yl)diphenyl ether), has been prepared by hydrothermal synthesis and structurally characterized by IR, elemental analysis, TGA and single crystal X-ray diffraction. Complex 1 features a one-dimensional chain structure based on triply bridged binuclear units, which is further interlinked into a higher-dimensional supramolecular framework by intermolecular weak interactions. Variable-temperature magnetic data shows weak antiferromagnetic behavior in 1.     

Enhancement of tensile ductility and stretch formability of magnesium by addition of 0.2 wt%(0.035 at%)Ce

Mg–0.2 wt%(0.035 at.%)Ce alloy was hot-rolled and its mechanical properties were investigated by conducting tensile and Erichsen tests at room temperature and 433 K. The rolled Mg–Ce alloy exhibited greater elongation to failure and higher stretch formability than the rolled pure Mg. This was attributed to a reduction in basal texture intensity and the splitting of the basal plane by the addition of a small amount of Ce (0.2 wt%). Also, the small amount of Ce strongly affected the recrystallization behavior during hot rolling. Microstructural observation revealed that the prismatic slip was activated in the Mg–Ce alloy. The enhancement of the non-basal slip by the addition of Ce was not attributed to a reduction in the c/a ratio. An increase in stacking fault energy due to the addition of Ce is suggested to play a vital role in the activation of the non-basal slip.     

The activity coefficients of oxygen in Ni-S and Co-S melts

Activity coefficients of oxygen,γ _o, in nickel-sulfur melts and cobalt-sulfur melts were determined at 1423 K utilizing a modified coulometric titration technique with the following electrochemical cell: O in Ni-S or Co-S melt/ZrO₂(+CaO)/air, Pt. Theγ _o values around N_NI=0.26 and N_CO=0.35 are much smaller than those in the hypothetically undercooled liquid nickel and cobalt, respectively, at 1423 K, which were evaluated by extrapolating the literature values at higher temperatures. Theγ _o values in the nickel-sulfur and cobalt-sulfur melts are rapidly increased with increasing the sulfur compositions. The shapes of the Inγ _o vs solvent composition curves are quite similar to those in Cu-S, Cu-Te, and Tl-Te melts. The present results are discussed in terms of several solution models. former name, SHINYA OTSUKA Formerly Graduate Students, Osaka University     

Radioimmunotherapy of orthotopically transplanted pancreatic cancer with 131I-labeled chimeric monoclonal antibody Nd2

Recent study demonstrated high susceptibility of plasma LDL to lipid peroxidative modification in patients with variant angina. Oxidized stress state, especially oxidized LDL, may induce coronary artery spasm by its impairing effect of endothelium-dependent arterial relaxation, but precise mechanisms remain unclear. Study subjects included 93 patients who underwent coronary angiographic examination: 12 patients with coronary artery spasm provoked by ergonovine without organic stenosis (group I), 11 patients who did not demonstrate coronary artery spasm or organic stenosis (group II) and 70 patients with organic coronary artery stenosis (group III). Levels of plasma HDL-cholesterol and apoA-I in group I were similar to those in III but were significantly lower than those in II, although the other plasma lipid parameters were not different among the three groups. The levels of TBARS in plasma and HDL were significantly higher in group I than in II or III (2.94+/-1.56 vs. 1.91+/-0.35 or 2.23+/-0.89 nmol MDA/ml and 1.23+/-1.00 vs. 0.54+/-0.37 or 0.70+/-0.63 nmol MDA/mg protein; P < 0.05), although the levels of TBARS in LDL were not significantly different. In the monitoring curve of diene production during copper-induced lipid peroxidation of HDL, its propagation slope was steeper and levels of maximum diene absorbance was higher in group I as compared with that in II or III, but not found in those of LDL. These results suggested that high susceptibility of HDL to lipid peroxidative modification in group I may contribute to the genesis of coronary artery spasm, and oxidized HDL rather than oxidized LDL is more likely to be related to coronary artery spasm.     

Structure and function of the extracellular matrix of anuran eggs

The extracellular matrix (ECM) surrounding the anuran egg is composed of jelly coat layers, an envelope, and the perivitelline space, which separates the envelope from the egg plasma membrane. Both the jelly coat layers and egg envelopes are required for fertilization in anurans. This paper reviews the current understanding of the structure-function relations of the ECM, with emphasis on the egg envelope. The fibrous egg envelope exists in four related forms. The envelope forms differ in their ultrastructures, macromolecular compositions, and cellular functions. After the oocyte is released from the ovary, conversion of one envelope form to another is brought about by factors secreted by the oviduct prior to fertilization and by factors released from the egg in the sperm-triggered cortical reaction. An additional extracellular matrix structure, located in the perivitelline space, has recently been identified in Xenopus laevis, as well as a previously undescribed reorganization of envelope fibers occurring at fertilization. The molecular changes in the ECM glycoproteins (limited proteolysis, lectin-ligand binding, and conformational changes) and the oviductal and egg macromolecules responsible for the conversion of envelope forms are discussed. New experimental evidence that supports the lectin-ligand hypothesis for the formation of the fertilization layer is presented. It is proposed that the molecular changes in the ECM are responsible for the ultrastructural alterations of the ECM and for modifications of the fertilization and developmental functions of the anuran egg ECM.     

Variations of trap states and dangling bonds in CVD Si3N4 layer on Si substrate by NH3/SiH4 ratio

This study is concerned with deep trap densities and energy levels in CVD Si₃N₄ layers deposited on Si substrates at 700°C with various gas flow ratio NH₃/SiH₄. As the ratio NH₃/SiH₄ increases from 10 to 1000, the trap density decreases from 8 × 10^l9 t0 2 x l0¹⁹cm⁻³, and energetical distribution of trap states becomes lower and/or electron emission probability from trap states less. The results are discussed in terms of chemical and optical properties of Si₃N₄ film revealed by infrared absorption, Auger electron spectroscopy, and ellipsometry. It is shown that (i) Si dangling bonds create deep trap states and (ii) 0 and H atoms act as terminators to decrease trap density. A part of this paper was presented at the 23rd Annual Electronic Materials Conference, University of California, Santa Barbara, 1981. On leave from Yasu Plant, IBM Japan Ltd., Yasu-cho Shiga 520-23, Japan.     

"CT angiogram sign" in obstructive pneumonitis and pneumonia

Malrotation is a rare aetiological factor of intestinal occlusion in adult. We report our experience of 16 cases collected from 1976 to 1991. The incidence is about 0.2-0.5% with two peaks, at 25 and 55 years respectively. Mean age is of 41 years. The symptoms were occlusion in more than 90%. A contrast enema was performed in acute as well as in chronic situations. The surgical treatment whatever it is, is the treatment of choice but has to be put in balance with age.