Dissolution of oxidation-cured poly(carbosilane) fiber into polar organic solvents

The solubility of oxidation-cured polycarbosilane (PCS) fiber into benzene, tetrahydrofuran (THF), acetone, and ethanol was investigated. The solubility of the fiber in benzene and THF decreases as the curing temperature increases. The fiber cured at 433–463 K, however, shows higher solubility in acetone and ethanol than the original fiber and the fiber cured at 473 K. The remaining gels in benzene and THF keep their fibrous shape, while in acetone and ethanol often appear as swollen gels. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:261–265, 1997     

Imidazolate-bridged dinuclear copper(II) complex with new macrocyclic ligand bearing two 1H-imidazol-4-yl-pendants

A new imidazolate-bridged dicopper complex [Cu₂(L)(Im)](ClO₄)₃·H₂O has been synthesized by reaction of new macrocyclic ligand 6, 20-bis(1H-imidazol-4-ylmethyl)-3, 6, 9, 17, 20, 23-hexaazatricyclo[24.3.1.1^11,15]hentriaconta-1(29), 11, 13, 15(31), 26(30), 27-hexaene (L) with Cu(ClO₄)_2?6H₂O and imidazole, and structurally characterized as a model compound of Cu₂Zn₂-SOD. There is antiferromagnetic interaction with g = 2.08, ? 2 J = 66.5 cm^? 1 between the two imidazolate-bridged Cu(II) atoms. The complex displays moderate SOD activity with IC₅₀ of 1.42 μM.     

Catalytic hydrogenation of linoleic acid on nickel,copper, and palladium

The catalytic activity and selectivity for hydrogenation of linoleic acid were studied on Ni, Cu, and Pd catalysts. A detailed analysis of the reaction product was performed by a gas-liquid chromatograph, equipped with a capillary column, and Fourier transform-infrared spectroscopy. Geometrical and positional isomerization of linoleic acid occurred during hydrogenation, and many kinds of linoleic acid isomers (trans-9,trans-12; trans-8,cis-12 orcis-9,trans-13; cis-9,trans-12; trans-9,cis-12 andcis-9,cis-12 18∶2) were contained in the reaction products. The monoenoic acids in the partial hydrogenation products contained eight kinds of isomers and showed different isomer distributions on Ni, Cu, and Pd catalysts, respectively. The positional isomers of monoenoic acid were produced by double-bond migration during hydrogenation. On Ni and Pd catalysts, the yield ofcis-12 andtrans-12 monoenoic acids was larger than that ofcis-9 andtrans-9 monoenoic acids. On the contrary, the yield ofcis-9 andtrans-9 monoenoic acids was larger than that ofcis-12 andtrans-12 monoenoic acids on Cu catalyst. From these results, it is concluded that the double bond closer to the methyl group (Δ12) and that to the carboxyl group (Δ9) show different reactivity for hydrogenation on Ni, Cu, and Pd catalysts. Monoenoic acid formation was more selective on Cu catalyst than on Ni and Pd catalysts.     

Persistence of the socialist collective housing areas (KTTs): the evolution and contemporary transformation of mass housing in Hanoi,Vietnam

This study examined the spatial patterns and transformation of the socialist collective housing areas (KTTs). The areas experienced physical and functional changes with Hanoi’s urbanization after the country’s reforms. The KTTs were originally built on the outskirt of Hanoi during the 1960s–1980s. The development was influenced by the state-led mass housing model originated from the micro-district concept of the former Soviet Union. With the urban expansion of Hanoi, the KTTs have become situated in the city’s central area. The study attempted to analyze the location of Hanoi’s KTTs based on the distance from the inner-city area. The outcome of physical transformation, the use of spaces, housing prices, and conditions of the surrounding areas of the KTTs were investigated based on a resident survey of 240 households and field studies in six KTTs sites. Changes in the use of spaces on the ground-level, addition of self-extended structure from existing housing units, and wholesale redevelopment were observed from the field studies. The degree and pattern of changes were different by locational types. The KTTs located near the inner-city area with good accessibility was the most actively transformed. The study showed that the living conditions of the KTTs were influenced by the location as well as social and economic factors such as transitional living culture and an increase in the residents’ income. Furthermore, the study found that Hanoi’s KTTs play an essential role as adequate urban housing due to their locational advantages, the presence of an intimate community, and affordable housing prices.

     

Promoting Effect of Basic Fibroblast Growth Factor in Synovial Mesenchymal Stem Cell-Based Cartilage Regeneration

Synovial mesenchymal stem cell (SMSC) is the promising cell source of cartilage regeneration but has several issues to overcome such as limited cell proliferation and heterogeneity of cartilage regeneration ability. Previous reports demonstrated that basic fibroblast growth factor (bFGF) can promote proliferation and cartilage differentiation potential of MSCs in vitro, although no reports show its beneficial effect in vivo. The purpose of this study is to investigate the promoting effect of bFGF on cartilage regeneration using human SMSC in vivo. SMSCs were cultured with or without bFGF in a growth medium, and 2 × 10⁵ cells were aggregated to form a synovial pellet. Synovial pellets were implanted into osteochondral defects induced in the femoral trochlea of severe combined immunodeficient mice, and histological evaluation was performed after eight weeks. The presence of implanted SMSCs was confirmed by the observation of human vimentin immunostaining-positive cells. Interestingly, broad lacunae structures and cartilage substrate stained by Safranin-O were observed only in the bFGF (+) group. The bFGF (+) group had significantly higher O’Driscoll scores in the cartilage repair than the bFGF (−) group. The addition of bFGF to SMSC growth culture may be a useful treatment option to promote cartilage regeneration in vivo.     

Potentially probiotic acetic acid bacteria isolation and identification from traditional dairies microbiota

Among probiotics, acetic acid bacteria (AAB) can be used as preservative agents because of their high fermentation and acidification activities. This study aimed to isolate, identify and biologically characterise Acetobacter strains from traditional Iranian dairy products. Acetobacter strains were identified by catalase assay, Gram staining, and combined repetitive sequence‐based PCR [(GTG)₅‐PCR fingerprints] and 16S rDNA gene sequencing. We identified eight strains belonging to four species, including Acetobacter aceti, Acetobacter indonesiensis, Acetobacter cibinongensis and Acetobacter syzygii. The molecular techniques could be used as an effective and rapid alternative tool to identify and characterise dairy‐associated AAB. Primary probiotic assessments, including low pH and high bile salt tolerance tests, antagonistic activity test against pathogens, and antibiotic susceptibility confirmed the probiotic properties of these AAB, particularly A. cibinongensis 34L strain, which was isolated from curd. Therefore, this strain can be introduced as novel candidate probiotics that could be used in the food industry.     

MicroRNA-214 and MicroRNA-126 Are Potential Biomarkers for Malignant Endothelial Proliferative Diseases

Malignant endothelial proliferative diseases including human angiosarcoma (AS) and canine hemangiosarcoma (HSA) are serious diseases with a grave prognosis. Establishing liquid biopsy-based biomarkers for screening has definite clinical utility; however, plasma miRNAs up- or down-regulated in these sarcomas have been unclear. For identifying possible diagnostic plasma miRNAs for these sarcomas, we investigated whether plasma miR-214 and miR-126, which miRNAs play important roles in angiogenesis and tumorigenesis, were elevated in malignant endothelial proliferative diseases. For this investigation, human angiosarcoma and canine hemangiosarcoma cell lines and clinical plasma samples of canine hemangiosarcoma were examined by performing miRNA qRT-PCR. We report here that human angiosarcoma and canine hemangiosarcoma cell lines over-secreted miR-214 and miR-126 via microvesicles; in addition, their levels in the plasma samples from canines with hemangiosarcoma were increased. Moreover, the surgical resection of primary tumors decreased the levels of plasma miR-214 and miR-126. Our findings suggest that these malignant endothelial proliferative diseases over-secreted miR-214 and miR-126, thus suggesting that these miRNAs have potential as diagnostic biomarkers for malignant endothelial proliferative diseases in canine and possible in human angiosarcoma.     

Use of Blended Precursors of Poly(vinylsilane) in Polycarbosilane for Silicon Carbide Fiber Synthesis with Radiation Curing

Blended organosilicon precursors containing 10 or 20% of poly(vinylsilane) (PVS) in polycarbosilane (PCS) were prepared and shaped into fiber form by melt-spinning. The influence of PVS addition on the spinning, radiation-curing, and pyrolysis processes was investigated. The addition of PVS increased the spinability of the precursor melt and increased the oxidation sensitivity of the precursor. By adjusting the precursor compositions and the radiation conditions, highly heat-resistant silicon carbide fibers were obtained.     

A field evaluation of in situ biodegradation of trichloroethylene through methane injection

A field study of biodegradation of trichloroethylene (TCE) through methane injection was conducted at the yard of a home in Japan. Methane was selected as the safest substrate for injection into groundwater. Methane, oxygen, nitrate, and phosphate were introduced into groundwater contaminated with 220 microg/L of TCE. After a week of biostimulation, methane concentrations gradually decreased below the detection limit. Methane oxidizing bacterial numbers increased from 10 to 10(4) cells/mL with methane consumptions. During methane injection. 10-20% of TCE removal was observed. The biotransformation yield was 3-13 mgTCE/gCH4 in this field test. After methane injections were stopped, TCE removal was not observed. These results indicated that bioremediation using methane was useful as a safe technology for a TCE-contaminated area near homes.