Physical properties and phase separation structure of Antheraea pernyi/Bombyx mori silk fibroin blend films

The physical structure and compatibility of solution-cast Antheraea pernyi/Bombyx mori silk fibroin blend films were stuided by differential scanning calorimetry (DSC), thermomechanical (TMA) and thermogravimetric (TGA) analysis, dynamic viscoelastic measurement, infrared spectroscopy, and x-ray diffractometry. The DSC curves of the blend films showed independent endotherms at 280 and 358°C, corresponding to the thermal decomposition of B. mori and A. pernyi silk fibroins with random coil conformation. The intensity was roughly proportionate to the amount of each component in the blend. The thermal behavior corresponding to the conformational transitions induced by heating on A. pernyi and B. mori silk fibroins overlapped in the temperature range 190–230°C. Thermal expansion and contraction properties, as well as weight retention behavior of the blend films were intermediate between the pure components, as shown by the TMA and TGA curves. The onset temperature of the storage modulus curve decreased markedly, approaching that of B. mori silk fibroin film when the amount of this component in the blend increased. The loss modulus curve of the blend films showed two peaks at ca. 190 and 210°C, the former corresponding to B. mori, and the latter to A. pernyi silk fibroin. Infrared spectra of the blends exhibited absorption bands characteristic of the pure components overlapping in the spectral region 2000–400 cm^?1. The x-ray diffraction peaks at 23 and 21.5°, attributed to the crystalline spacings of A. pernyi and B. mori fibroins, respectively, overlapped in the diffraction curves of the blends, while the peak at 11.4°, of A. pernyi, increased as the content of this fibroin in the blend increased. The degree of crystallinity, calculated from the x-ray diffraction curves, diminished as the amount of B. mori silk fibroin decreased. A low degree of compatibility exists between the two fibroins when they are cast from aqueous solution in the experimental conditions adopted in this work. © 1994 John Wiley & Sons, Inc.     

Major-to-ultratrace elements in bone-marrow fluid as determined by ICP-AES and ICP-MS.

The major-to-ultratrace elements in human bone-marrow fluid were determined by ICP-AES (inductively coupled plasma atomic emission spectrometry), and ICP-MS (inductively coupled plasma mass spectrometry). The bone-marrow fluid sample was centrifuged prior to acid digestion to exclude the bone piece from bone marrow, and then digested with nitric acid. As a result, 20 elements could be determined over the concentration range from 1610 microg g(-1) for Na to 0.00043 microg g(-1) for W. It was found that Fe, Zn and Sb were enriched by ca. 264-, 7- and 15-fold, respectively, in bone-marrow fluid, compared to those in human blood serum. Alkali metals (K, Rb, Cs), except for Na, were also significantly enriched in bone-marrow fluid. Furthermore, the concentrations of various elements, such as Fe, P, Al, Zn, Cu, Se, Zr, Sn, Ag and W, were significantly higher than those in open seawater.     

Heavy element nuclear chemistry at JAERI

The present status of heavy element nuclear chemistry research at JAERI (Japan Atomic Energy Research Institute) is reviewed. Production of the transactinide nuclei ²⁶¹Rf and ²⁶²Db via the reactions of ²⁴⁸Cm(¹⁸O,5n) and ²⁴⁸Cm(¹⁹F, 5n), respectively, at the JAERI tandem accelerator is reported. Study of the aqueous chemistry of Rf is being carried out with a newly developed rapid ion-exchange separation apparatus. Anion-exchange behavior of Rf in acidic solution is briefly discussed. Recent experimental results on decay studies of neutron-deficient actinide nuclei using the gas-jet coupled JAERI-ISOL are given. We also discuss characteristics of nuclear deformation properties at scission in symmetric and asymmetric fission of actinides. Prospects for studies in the near future are briefly considered.     

Holomorphic Maps of Compact Generalized Hopf Manifolds

We investigate holomorphic maps between compact generalized Hopf manifolds (i.e., locally conformal Kähler manifolds with parallel Lee form). We show that they preserve the canonical foliations. Moreover, we study compact complex submanifolds of g.H. manifolds and holomorphic submersions from compact g.H. manifolds.     

Synthesis and antiallergy activity of [1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyrimidin-9(3H)-one derivatives. II. 6-Alkyl- and 6-cycloalkylalkyl derivatives.

A series of 6-alkyl- or 6-(cycloalkylalkyl)-[1,3,4]thiadiazolo[3,2- a]-1,2,3-triazolo[4,5-d]pyrimidin-9(3H)-ones 1b--o was synthesized from the corresponding 1,3,4-thiadiazol-5-amines 3b--o and the antiallergic activities of the products were evaluated. Among the compounds 6-(2-cyclohexylethyl)- [1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyrimidin-9(3H)-one 1h, whose X-ray crystallographic stereostructure is shown, was found to be a promising new antiallergic agent, which has low toxicity and dual activity as a leukotriene D4 receptor antagonist and as an orally active mast cell stabilizer.     

Initial mode of radical pair formation in n-hydrocarbons irradiated at 1.5 and 4.2 K

The ESR spectra of X-irradiated (at 1.5 and 4.2 K) single crystals of n-decane-d₂₂, n-decane-h₂₂ and their mixtures have been measured at 1.5 and 4.2 K. It is concluded that almost all alkyl radicals are inherently formed in pairs in a fairly random fashion and that the spacial distribution of the radicals depends on the irradiation temperatures. In the crystal of n-decane-d₂₂, a 1,3-carbon intrachain radical pair is identified together with a number of very close interchain pairs which are formed between almost all kinds of the first neighboring chains. The crystal of n-decane-h₂₂ gives considerably larger spacial distribution of radicals, indicating a remarkable mass effect on the radical pair formation.     

Synthesis of 21-nor-22-oxa-1α,25-dihydroxyvitamin D3 derivatives in quest of a drug with low calcemic activity

Two 21-nor-22-oxa-1α,25-dihydroxyvitamin D₃ derivatives have been synthesized in quest of a drug with lower calcemic activity than Maxacalcitol, 22-oxa-1α,25-dihydroxyvitamin D₃, being used as antihyperparathyroidism and antipsoriatic drug. Of two 21-nor products obtained, the product carrying one carbon elongated side chain with diethylcarbinol moiety has been found to exhibit comparable differentiation-inducing activity to Maxacalcitol with much lower exhibition of calcemic activity.     

Effect of surface covering of lactose carrier particles on dry powder inhalation properties of salbutamol sulfate

The effect of the surface covering of lactose carrier particles on the dry powder inhalation properties of salbutamol sulfate was investigated. Lactose carrier surfaces were covered with sucrose tristearate (J-1803F) by a high-speed elliptical-rotor-type powder mixer (Theta-Composer). In the present study, drug/carrier powder mixtures were prepared consisting of micronized salbutamol sulfate and lactose carriers with various particle surface conditions prepared by surface covering. These powder mixtures were aerosolized by a Jethaler), and the in vitro inhalation properties of salbutamol sulfate were evaluated by a twin impinger. Compared with the powder mixed with uncovered lactose carrier, the in vitro inhalation properties of the powder mixture prepared using the surface covering lactose carrier were significantly different, showing that the in vitro inhalation properties of salbutamol sulfate were improved. In vitro inhalation properties increased with the percentage of J-1803F added. Using this surface covering system would thus be valuable for increasing the inhalation properties of dry powder inhalation with lactose carrier particles.