Halogenated cladosporols produced by the sodium halide-supplemented fermentation of the plant-associated fungus Cladosporium sp. TMPU1621

A new cladosporol derivative, 2-chloro-cladosporol D (6), was isolated together with known cladosporol (1), cladosporols B–D (2–4), and cladosporol F (5) from the culture broth of plant-associated Cladosporium sp. TMPU1621. The structure of 6 was elucidated from spectroscopic analyses including NMR and MS data. The productivity of 6 increased in 3% NaCl-supplemented medium; therefore, fermentation of the producing fungus TMPU1621 with 3% NaBr was investigated, leading to the induced production of a new halogenated cladosporol, 2-bromo-cladosporol D (7). Compound 2 showed the lowest MIC values of 3.13 and 12.5?μg/mL against two MRSA strains, ATCC43300 and ATCC700698, respectively.     

An indirect spectrophotometric method for the determination of silicon in serum, whole blood and erythrocytes.

An indirect method for the determination of silicon in blood samples has been developed. The proposed method overcame interference from a large amount of salts and phosphate in blood samples, and enabled us to determine the silicon contents in serum and whole blood by the same operation. After blood samples were digested by microwave heating, silicon, present as silicate in the sample solution, was reacted with molybdate to form a silicomolybdate complex. The complex was then separated from unreacted molybdate by a cation-exchange resin column. The molybdate liberated from the complex was spectrophotometrically determined in place of silicon. Since the method is not affected the composition of matrices between serum and whole blood, it could achieve good precision and accuracy, and could also estimate the silicon contents in erythrocytes from those in serum and whole blood. The sensitivity of the method was almost equal to that of the conventional silicomolybdenum blue method, and the calibration curve was linear up to 50 micromol l(-1) of silicon with a detection limit of 1.1 micromol l(-1) in whole blood. The mean concentrations of silicon in five healthy subjects were 11 micromol l(-1) for serum, 28 micromol l(-1) for whole blood and 50 micromol l(-1) for erythrocytes. Thus, the obtained distribution ratio between serum and erythrocytes was in the range of 0.15-0.39, and was found to be included in a narrow range.     

Conversion of arsenobetaine by intestinal bacteria of a mollusc Liolophura japonica chitons

The intestinal micro-organisms of Liolophura japonica chitons converted arsenobetaine [(CH₃)₃As⁺CH₂COO^?] to trimethylarsine oxide [(CH₃)₃AsO] and dimethylarsinic acid [(CH₃)₂AsOOH] in the arsenobetaine-containing 1/5 ZoBell 2216E medium under aerobic conditions, no conversion being observed in an inorganic salt medium. This conversion pattern of arsenobetaine → trimethylarsine oxide ← dimethylarsinic acid was comparable with that shown by the microorganisms associated with marine macroalgae. On the other hand, no conversion was observed in either medium under anaerobic conditions.     

A Bohr-Mottelson model of nuclei at finite temperature

Starting from Boltzmann-Langevin equation and performing a fluid dynamical reduction, a system of coupled Langevin equations is derived for a multipolar velocity field. This system is then applied to monopole andβ-,γ-quadrupole resonances, making a link between microscopic approaches and phenomenological macroscopic ones.     

Fluorescence study of polyelectrolyte complex formation III: Mobility of probes in microdomains

The mobility of fluorescent probe molecules in the microdomains formed by polyelectrolyte complexes (PEC) in aqueous solution was investigated by the fluorescence polarization method. The degree of fluorescence polarization (p) for the anthracene (Anth) chromophores attached to anionic polyelectrolytes increased with complexation, indicating the restricted mobility of probe molecules in the PEC microdomains. These p values depended on the properties of added polycations, which were not in parallel with the fluorescence intensities of the Anth chromophores.     

Microwave optical double resonance and fluorescence spectrum of NO2 excited by the 4579 Å line of the argon-ion laser

A microwave-optical double resonance (MODR) involving the $\text{J =}\text{21}\text{2}\text{←}\text{19}\text{2}$ and $\text{J =}\text{21}\text{2}\text{←}\text{17}\text{2}$ components of the 10_{0, 10} ← 9_{1, 9} rotational transition of the ground vibronic state of ¹⁴N¹⁶O₂ has been observed using the 4579 Å Ar⁺ laser line for excitation. By means of high resolution study of the laser excited fluorescence, the optical transition has been assigned to the $\text{J =}\text{19}\text{2}\text{←}\text{21}\text{2}$ spin component of the 9_{0, 9} ← 10_{0, 10} transition from the ground vibronic state to an unknown vibrational state of A₁ symmetry of the ²B₂ electronic state.     

Pressure-induced ferroelectricity in {N(CH3)4}2FeCl4

The hydrostatic pressure effect on the stability of phases I, II, III and IV in {N(CH₃)₄}₂FeCl₄ was studied by dielectric and DTA measurements in the temperature and pressure region of -40-30°C and 0–2 kbar. The pressure-induced new phase V found at applied pressures between 0.3 and 1.0 kbar was confirmed to be ferroelectric by the observation of D-E hysteresis loop. These results are compared with those of {N(CH₃)₄}₂XCl₄ (X: Co, Zn and Mn) in this paper.