A new behaviour of ac losses in superconducting Bi(2)Sr(2)CaCu(2)O(8) single crystals.

A new ac loss behaviour is observed in the superconducting state of Bi(2)Sr(2)CaCu(2)O(8) single crystals using a novel technique of measuring dissipation at radio frequencies. It is found that the ac loss in the superconducting state is larger than that in the normal state. This counter-intuitive result is explained in terms of the cumulative effect of repetitive decoupling of intrinsic Josephson junctions in the crystals and analysed in the framework of Ambegaokar-Baratoff theory. The ac losses are studied as a function of temperature, rf amplitude and magnetic field applied at different orientations. A peak in ac losses is observed in the superconducting state along the temperature scale. The amplitude of the peak decreases and shifts towards lower temperature with increasing field and also when the field orientation with respect to the c axis of the crystal changes from the perpendicular to parallel direction. The origin of the peak and its behaviour are discussed in the context of coupling energy of Josephson junctions present in the sample. In the presence of a magnetic field another peak in ac losses arises at temperatures close to T(c), which is associated with the Lorentz-force-driven motion of vortices.

Itinerant electron magnetism in CaRu(1-x)Mn(x)O(3) (0 ≤ x ≤ 0.5).

The effect of Mn substitution in paramagnetic metal CaRuO(3) was studied by magnetization and neutron diffraction measurements. Development of ferromagnetic order is observed for x≥0.2 in CaRu(1-x)Mn(x)O(3). For the sample with x = 0.4, the Curie temperature of ∼160 K is obtained from the Arrott plot and the ratio of effective moment and saturation moment P(eff)/M(0) is estimated to be ∼4.8. We further found that the magnetization is significantly suppressed with decreasing temperature T below ∼90 K. In the neutron diffraction experiment at T = 15 K, we observed the evolution of a magnetic Bragg peak originating from the G-type antiferromagnetic order as well as the ferromagnetic one. This strongly suggests that both ferromagnetic and antiferromagnetic states are coexistent with each other at low temperatures. In the M(T)(0)(2) against T(2) plot (here, M(T)(0) is a spontaneous magnetization estimated from the Arrott plot), M(T)(0)(2) linearly increases with decreasing T(2) in the ferromagnetic region between ∼90 and 160 K. The ferromagnetic properties of the CaRu(1-x)Mn(x)O(3) system (x≤0.5) are well explained in terms of spin fluctuation theory based on the itinerant electron model rather than the localized spin model.

Gastric mucin phenotype defines tumour progression and prognosis of intrahepatic cholangiocarcinoma: gastric foveolar type is associated with aggressive tumour behaviour.

AIMS: To identify the role of mucus core protein (MUC) in intrahepatic cholangiocarcinoma (ICC). METHODS AND RESULTS: We examined the expression profile of MUC2, MUC5AC and MUC6 by immunohistochemical staining in 100 ICCs and compared the clinicopathological factors and the immunohistochemical results. The expression frequency was: MUC2, 9%; MUC5AC, 40%; and MUC6, 21%. According to the gastric mucin expression profile, ICCs were classified into the following groups: null type (n = 43), gastric foveolar type (n = 36), pyloric gland type (n = 11) and gastric combined type (n = 10). Half of the gastric foveolar type and the gastric combined type were located in the hilar region, but the other types were predominant at the periphery (P = 0.0004). Well-differentiated components were more often detected in the gastric combined type and the pyloric gland type (P = 0.0281). The gastric foveolar type was associated with a higher incidence of lymph node metastasis (P < 0.0001). The pyloric gland type was associated with better survival and the gastric foveolar type was associated with worse survival. The gastric mucin phenotype was an independent prognostic factor by multivariate survival analysis. CONCLUSION: The gastric foveolar type of ICC was more often associated with aggressive tumour development, whereas the pyloric gland type exhibited less aggressive behaviour.

Ta 5d band symmetry of 1T-TaS1.2Se0.8 in the commensurate charge-density-wave phase.

We present a detailed angle-resolved photoemission study on the layered transition-metal dichalcogenide 1T-TaS1.2Se0.8 in the commensurate charge-density-wave (CDW) phase. A drastic reduction in the spectral weight along the high symmetry line GammaM, particularly around the point M, is observed when s-polarized light was used. This implies that the initial state must be symmetric with respect to a mirror plane perpendicular to the line GammaK, which is consistent with conventional band calculations in the absence of the CDW. We conclude that there is only a limited amount of modification of the electronic structure of 1T-TaS1.2Se0.8 in the commensurate CDW phase due to the CDW-related potential.

New anti-influenza agents, FR198248 and its derivatives. II. Characterization of FR198248, its related compounds and some derivatives.

We isolated FR198248 from the cultured broth of Aspergillus terreus No. 13830 as a new anti-influenza agents. The structure of FR198248 was elucidated by several spectroscopic experiments as a novel tetrahydroxybenzaldehyde compound. Furthermore, we described the characteristics of FR198248, its related compounds and some derivatives.

FR198248, a new anti-influenza agent isolated from Apsergillus terreus No 13830. I. Taxomony, fermentation, isolation, physico-chemical properties and biological activities.

A novel anti-influenza agent, FR198248, was isolated from the cultured broth of a fungal strain No.13830. The strain was identified as Aspergillus terreus from morphological characteristics. FR198248, a new type of hydroxyl benzaldehyde compound, showed antiinfluenza virus activity in Madin-Darby canine kidney (MDCK) cells in vitro. The mode of action of FR198248 against influenza virus A could be ascribed to an inhibitory effect on the stage of virus adsorption. Furthermore, FR198248 possessed potent in vivo anti-influenza activity in a murine model of respiratory tract infection.

A novel and simple type of liposome carrier for recombinant interleukin-2.

The strong interaction between recombinant interleukin-2 (IL-2) and liposome was characterized and its possible application to drug-delivery control considered. The liposomes were prepared with egg phosphatidylcholine, distearoyl-phosphatidylglycerol (DSPG), dipalmitoyl-phosphatidylcholine, dipalmitoyl-phosphatidylglycerol or distearoyl-phosphatidylcholine (DSPC). Small and hydrophobic liposomes were selected, which were composed of saturated and long-fatty-acid-chain phospholipids. When the composition and the mixture ratio of IL-2 and the liposomewere optimized, morethan 95% ofthe lyophilized IL-2 (Imunace, 350000 JRU) was adsorbed consistently onto the DSPC-DSPG liposome (molar ratio, 10:1; 25 micromol mL(-1); 30 nm in size). Merely mixing IL-2 lyophilized with liposome suspension is convenient pharmaceutically. After intravenous administration to mice, liposomal IL-2 was eliminated half as slowly from the systemic circulation as free IL-2, with more than 13 and 18 times more IL-2 being delivered to the liver and spleen, respectively. After subcutaneous administration of liposomal IL-2 to mice, the mean residence time of IL-2 in the systemic circulation was 8 times that of free IL-2. These results show that IL-2 consistently adsorbs onto the surface of liposomes after optimization of its composition and mixing ratio. Intravenous and subcutaneous administration to mice demonstrates the gradual release of IL-2. Further trials are warranted using these liposomes.

Non-Sonogashira-type palladium-catalyzed coupling reactions of terminal alkynes assisted by silver(I) oxide or tetrabutylammonium fluoride.

Palladium-catalyzed reaction of aryl and alkenyl halides with terminal alkynes in the presence of silver(I) oxide as an activator furnishes various arylated or alkenylated alkynes in good to excellent yields. The similar coupling reaction is also found to proceed using tetrabutylammonium fluoride (TBAF) or tetrabutylammonium hydroxide (TBAOH) as an activator.

Palladium-catalyzed cross-coupling of silanols, silanediols, and silanetriols promoted by silver(I) oxide

Palladium-catalyzed cross-coupling of aryl- or alkenylsilanols, silanediols, and silanetriols with a variety of iodoarenes by the catalysis of palladium(0) and in the presence of silver(I) oxide furnished the coupling products in good to excellent yields. The reactions of silanediols or silanetriols under similar conditions proceeded much faster than those of silanols to afford the corresponding coupling products in excellent yields within shorter reaction periods (5-12 h). The measurement of the X-ray diffraction (XRD) pattern of the silver residue after the reaction revealed that silver(I) oxide was converted to silver(I) iodide.

Coupling Reactions of Alkynylsilanes Mediated by a Cu(I) Salt: Novel Syntheses of Conjugate Diynes and Disubstituted Ethynes.

Reaction of 1-trimethylsilylalkyne with copper(I) chloride in a polar solvent, DMF, at 60 degrees C under an aerobic conditions smoothly undergoes homo-coupling to give the corresponding symmetrical 1,3-butadiynes in 70-99% yields. In addition, (arylethynyl)trimethylsilanes are found to couple with aryl triflates and chlorides in the presence of Cu(I)/Pd(0) (10 mol %/5 or 10 mol %) cocatalyst system to give the corresponding diarylethynes in 49-99% yields. The cross-coupling reaction is applied to a one-pot synthesis of the corresponding unsymmetrical diarylethynes from (trimethylsilyl)ethyne via sequential Sonogashira-Hagihara and the present cross-coupling reactions using two different aryl triflates. The reactions of (arylethynyl)trimethylsilanes with aryl(chloro)ethynes in the presence of 10 mol % of CuCl also yield the corresponding unsymmetrical 1,3-butadiynes in 43-97% yields.

FR191512, a novel anti-influenza agent isolated from a fungus strain No.17415. I. Taxonomy, fermentation, isolation, physico-chemical properties and structure elucidation.

In the course of our screening for anti-influenza agents of microbial origin, FR191512 was isolated from the cultured broth of fungus strain No. 17415 as colorless powder. The structure of FR191512 was determined by several spectroscopic experiments as a novel polyphenolic compound. This compound showed potent antiviral activity against influenza A virus.

FR191512, a novel anti-influenza agent isolated from a fungus strain No.17415. II. Biological properties.

FR191512, a novel polyphenolic compound, inhibited the infectivity of influenza A virus in Madin-Darby canine kidney (MDCK) cells in vitro. Furthermore, FR191512 showed good in vivo anti-influenza activity in a mouse model of intranasal infection with influenza A virus. The cytotoxic activity of FR191512 against MDCK cells was very weak.

Antioxidants from Lespedeza homoloba. (I).

The stems of Lespedeza homoloba yielded eight new and three known phenolic compounds. Their structures have been elucidated on the basis of their spectral data. These compounds had strong antioxidative activity against lipid peroxidation in the rat brain homogenate test. 3,9-Dihydroxypterocarp-6a-en and lespedezol A2 showed significant antiallergic activity in allergic (type I) mice.

Determination of the entrapped volume of liposomes: dilution method.

A novel method was developed for the determination of the entrapped volume of liposomes. The obtained values of the entrapped volume by our "dilution method" agreed very well with those of the conventional "quenching method." The dilution method also offered the great advantages of simple procedure and high reproducibility. The principle and validity of our method are discussed.

Compositional Homogeneity of Liposomal Membranes Investigated by Capillary Electrophoresis.

Capillary electrophoresis has been demonstrated to be a new powerful tool for investigating the compositional homogeneity of liposomal membranes composed of phospholipids and guest molecules. In the case of charged components distributed heterogeneously on membranes, electropherograms show several distinguishable peaks even with monodisperse size distributions of liposomes because each liposomal particle carries a different amount of charge. The heterogeneity of noncharged components, when the lipids and the guest components have significantly different molar absorptivities at two different wavelengths, can also be judged from the signal ratio observed at the two wavelengths using a photodiode array detector. This new method can be used for the quality control of liposomal products. Copyright 1998 Academic Press.

Alveolar bone loss in rats infected with a strain of Prevotella intermedia and Fusobacterium nucleatum isolated from a child with prepubertal periodontitis.

Prevotella intermedia and fusobacterium nucleatum are associated with various forms of periodontal disease. The purpose of the present study was to infect the clinical isolates of these periodontopathic bacteria and to induce a significant loss of alveolar bone in specific pathogen-free (SPF) rats in the absence of ligatures. P. intermedia YKD8 and F. nucleatum YKZ5 were isolated from a prepubertal periodontitis patient, while P. gingivalis MWB13 was from a patient with juvenile periodontitis. At first, SPF Sprague-Dawley rats (70 days of age, male) were infected with A. viscosus Ny1R and subsequently superinfected with P. gingivalis MWB13, P. intermedia YKD8, or F. nucleatum YKZ5, respectively. The control group was infected with A. viscosus Ny1R alone. All rats were killed and periodontal bone levels were assessed morphometrically 135 days after the first infection with A. viscosus. P. intermedia YKD8 was recovered frequently from rats, with serum antibody levels remaining highly elevated throughout the experiment. Significant loss of alveolar bone was found in rats infected with P. intermedia YKD8, the virulence of which was equivalent to that of P. gingivalis MWB13. F. nucleatum YKZ5 also induced alveolar bone loss, but not significantly when compared with rats infected with A. viscosus Ny1R alone.

Influence of ego strength on associations of alexithymia and depression.

This study examined the association of scores for ego strength with the scores on a measure of alexithymia and with depressive symptoms in two samples of 260 college students and 92 psychiatric outpatients. In both samples, scores on alexithymia were significantly correlated with those for depressive symptoms; however, correlations became nonsignificant when scores for ego strength were controlled for. The results suggest that the association between alexithymia scores and depressive symptoms is decreased by lower scores for ego strength.

An investigation of the psychometric properties of the 26 item Toronto Alexithymia Scale in a Japanese culture.

We investigated the psychometric properties of the Japanese version of the 26 item Toronto Alexithymia Scale in a Japanese culture, testing a sample of 1,008. The validity and reliability of this Japanese version were suggested by significant correlations with the Beth Israel Hospital Psychosomatic Questionnaire and estimates to test-retest and internal consistency. These results suggest that this version may be suitable for Japanese populations. Although alexithymia scores were correlated negatively with increasing age, the result, based on the large sample, seems to be of minimal significance.