The Effect of Solvents on the Adduct Formation of Uranyl Thenoyltrifluoroacetonate with Tributyl Phosphate

Addition compound formation between uranyl bis-thenoyltrifluoroacetonate (UO_2A_2) and tributyl phosphate (S) was studied by partition method, using uranium-237 as the tracer. The formula of the adduct complex was shown to be UO_2A_2S. The solvent effect on the adduct formation constant was taken into account in connection with the activity ; the activity coefficients of each species in various solutions were calculated from the molar volume and the solubility parameter. The formation constants based on the molar fraction, K_x, in a number of solvents were preestimated, employing log K_x=7.08 in carbon tetrachloride as a reference. They are in agreement with the observed values. The formation constant in terms of activity was found to be constant log K°_s=5.77±0.30. A correlation between the formation constant of the two adducts, UO_2A_2S and ZnA_2S, was demonstrated

A New Species of Lithostrotion (Siphonodendron)(Rugosa) from the Hina Limestone, Okayama Prefecture, Southwest Japan

A new rugose coral species, Lithostrotion (Siphonodendron) hinensis is described in this paper. It was collected from the Carboniferous Hina limestone in Okayama Prefecture, Southwest Japan. Judging from the paleontological data, the age indicates probably Late Viaean, Early Carboniferous

Calcitonin-like substance in plasma of the hagfish, Eptatretus burgeri (Cyclostomata).

金沢大学環日本海域環境研究センター生物多様性研究部門Cyclostomes have been regarded as having no ultimobranchial gland. However, cells producing immunoreactive calcitonin (CT) were recently found in cyclostome brains. In the present study, we examined using biochemical and biological methods whether there is a CT-like substance in the plasma of the hagfish, Eptatretus burgeri. Hagfish plasma was first subjected to reverse-phase high-performance liquid chromatography (RP-HPLC) and then separated into twenty fractions. The presence of immunoreactive CT in each fraction was then investigated by Western blotting with salmon CT antiserum. Two fractions (36-39% CH3CN; 39-42% CH3CN) showed positive immunoreactivity. Hypocalcemic and hypophosphatemic activities were detected by a rat bioassay only in the former fraction (36-39% CH3CN). The molecular weight (MW) of the CT-like substance in this fraction was 3.5 kDa, which is equal to that of genuine CT. Furthermore, when hagfish plasma was examined by enzyme-linked immunosorbent assay using anti-salmon CT, the dilution curve of the plasma paralleled the standard curve of salmon CT. The CT-like substance detected here was present at a high concentration (14 ng/ml) in the plasma. From the results of the present study, the CT-like substance present in hagfish plasma appears to be very similar to salmon CT

Absence of a classical long-range order in S=1/2S=1/2 Heisenberg antiferromagnet on triangular lattice

We study the quantum phase transition of an $S=1/2$ anisotropic $\alpha$ $(\equiv J_z/J_{xy})$ Heisenberg antiferromagnet on a triangular lattice. We calculate the sublattice magnetization and the long-range helical order-parameter and their Binder ratios on finite systems with $N \leq 36$ sites. The $N$ dependence of the Binder ratios reveals that the classical 120$^{\circ}$ N\'{e}el state occurs for $\alpha \lesssim 0.55$, whereas a critical collinear state occurs for $1/\alpha \lesssim 0.6$. This result is at odds with a widely-held belief that the ground state of a Heisenberg antiferromagnet is the 120$^{\circ}$ N\'{e}el state, but it also provides a possible mechanism explaining experimentally observed spin liquids.Comment: 4 pages, 7 figure

Protective Effects of Antioxidants on Testicular Functions of Varicocelized Rats

Left varicocele detrimentally affects spermatogenesis and the epididymal sperm maturation process bilaterally. We analyzed the effect of antioxidants on sperm production and quality in rats which were varicocelized. Non-varicocelized rats served as controls (group A). Left varicocele was done in 5 groups (B, C, D, E and F) of rats of the same age. Antioxidants taurine, catalase or superoxide dismutase were administered intraabdominally twice a week in groups C, D or E, respectively. Group F received taurine, catalase and superoxide dismutase. Groups A and B received a vehicle dose of saline equally. Eight weeks after varicocele induction bilateral epididymal caudal sperm content, motility and fertilizing ability were analyzed. All the parameters were significantly lower in group B than in groups A, C, D, E and F, although the values in group A were higher than in the other groups. Bilateral testicular weight and testosterone responses to human chorionic gonadotropin stimulation were significantly higher in groups A, C, D, E and F than in the group B. There were no significant differences in serum testosterone basal profiles among groups A, B, C, D, E and F. These results indicated the effectiveness of antioxidants for the preservation of testicular function and the epididymal sperm maturation process in varicocelized subjects

Quantum Monte Carlo study of the formation of molecular polarizations and the antiferroelectric ordering in squaric acid crystals

Effects of geometrical frustration and quantum fluctuation are theoretically investigated for the proton ordering in a quasi-two-dimensional hydrogen-bonded system, squaric acid crystal. We elucidate the phase diagram for an effective model, the transverse-field Ising model on a frustrated checkerboard lattice, by using quantum Monte Carlo simulation. A crossover to liquidlike paraelectric state with well-developed molecular polarizations is identified, distinguishably from long-range ordering. Emergence of long-range order from the liquidlike state exhibits peculiar aspects originating from the lifting of quasi-macroscopic degeneracy, such as colossal enhancement of the transition temperature and a vanishingly small anomaly in the specific heat.Comment: 6 pages, 4 figures, accepted for publication in Physical Review