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941.
Carbon dioxide can be used as a reactant for the hydroformylation of alkenes. The ruthenium complexes derived from H4Ru4(CO)12 and LiCl effectively catalyze the hydroformylation of cyclohexene with CO2 to give hydroxymethylcyclohexane with a yield of 88%. 相似文献
942.
Ikushima S Tateishi Y Kanai K Shimada E Tanaka M Ishiguro T Mizutani S Kobayashi O 《Journal of Bioscience and Bioengineering》2012,113(4):496-501
Yeast plays a capital role in brewing fermentation and has a direct impact on flavor and aroma. For the evaluation of competent brewing strains during quality control or development of novel strains it is standard practice to perform fermentation tests, which are costly and time-consuming. Here, we have categorized DNA markers which enable to distinguish and to screen brewing strains more efficiently than ever before. Sequence analysis at 289 loci in the genomes of six bottom fermenting Saccharomyces pastorianus strains revealed that 30 loci contained single nucleotide polymorphisms (SNPs). By determining the nucleotide sequences at the SNP-loci in 26 other S. pastorianus strains and 20 strains of the top fermenting yeast Saccharomyces cerevisiae, almost all these strains could be discriminated solely on the basis of the SNPs. By comparing the fermentative phenotypes of these strains we found that some DNA markers showed a strong association with brewing characteristics, such as the production of ethyl acetate and hydrogen sulphide (H2S). Therefore, the DNA markers we identified will facilitate quality control and the efficient development of brewing yeast strains. 相似文献
943.
Specific response of osteoblast-like cells on hydroxyapatite layer containing serum protein 总被引:3,自引:0,他引:3
Kizuki T Ohgaki M Ichinose S Nakamura S Hashimoto K Toda Y Yokogawa Y Yamashita K 《Journal of materials science. Materials in medicine》2006,17(9):859-867
Accelerations of bone-like apatite deposition and cell growth on an electrically polarized ceramic hydroxyapatite have been
reported. A relationship between these phenomena was investigated in a previous report, and then it was suggested that osteoblast-like
cell’s (MC3T3-E1) growth had relevance to the mineral growth. The effect of the formed apatite layer especially appeared to
be on the cell adhesion. The acceleration of cell proliferation on the polarized HAp has been shown using fibroblastic cell
(L929) and nerve cell (SK-N-SH) lines, therefore the effect of the layer on L929 and SK-N-SH was investigated to support the
mechanism of acceleration of cell proliferation by polarization of HAp. In this study, the effect of the bone-like apatite
layer was not confirmed on L929 cell’s growth. On the other hand, the acceleration of nerve cell’s proliferation was confirmed
on the formed apatite layer. However, the remarkable improvement of the cell adhesion of SK-N-SH was not confirmed on the
apatite layer. Consequently, it was considered that the bone-like apatite containing serum protein obtained by the coprecipitation
of bone-like apatite and serum protein has a pronounced role only in the activity of osteoblast-like cells. 相似文献
944.
Aaron M. Koga Yoshiyuki Shibayama Keiya Shirahama 《Journal of Low Temperature Physics》2012,166(5-6):257-267
The growth of solid 4He on graphite from the superfluid phase is known to occur at pressures well below the bulk solidification point. The number of adsorbed layers increases with pressure and the solid growth undergoes non-continuous layer-by-layer growth at low temperature. We have studied this growth using the torsional oscillator method for isotherms down to 0.1?K. In contrast with simple layer-by-layer growth scenarios, our evidence suggests that the growth of adsorbed solid 4He is more complex and less solid is present on the graphite substrate at low temperature. 相似文献
945.
Shinya Yamanaka Nobuhiro Ito Koichiro Akiyama Atsuko Shimosaka Yoshiyuki Shirakawa Jusuke Hidaka 《Advanced Powder Technology》2012,23(2):268-272
Heterogeneous nucleation and nucleation period of calcium carbonate on the mica and the highly oriented pyrolytic graphite (HOPG) substrate have been investigated. Calcium carbonate was prepared by the reaction of calcium nitrate solution with sodium carbonate solution. In the reaction crystallization of calcium carbonate, calcite and vaterite were nucleated on the both substrates. We counted the number of crystalline calcium carbonate on the substrates obtained from various initial supersaturations of calcium carbonate. The number of crystals on the mica surface was much higher than on the HOPG surface. Additionally, the number of crystals on the mica was greatly affected by changing of initial supersaturation. In order to explain the difference between the mica and the HOPG surface, a possible model for the nucleation period of calcium carbonate has been discussed. The surface crystallization on the mica and the HOPG could be described by considering the supersaturation in the bulk solution and in the vicinity of substrate, separately. 相似文献
946.
Kazuhisa Terao Junpei Miyake Junji Watanabe Yoshiyuki Ikeda 《Materials science & engineering. C, Materials for biological applications》2012,32(4):988-993
Poly(trimethylene carbonate) (PTMC), poly(l-lactic acid) (PLA), and their copolymer are of great interest for various biomedical materials. These surface properties have the potential to be used as drug delivery carrier and interface on the biomaterials. PTMC surfaces including functional molecules of cholesterol, lithocholic acid (LA), and poly(ethylene glycol) monomethyl ether (mPEG), were transformed by changing external condition. PTMC including mPEG segment indicated inhibition of protein adsorption due to the surface enrichment of the mPEG. By blending of PTMC including LA unit and mPEG segment, it indicated much more suppression of protein immobilization than that of PTMC including only LA unit. Moreover, by increasing PLA composition in the PTMC–PLA copolymer, surface enrichment of the terminal molecule was inhibited by forming crystal structure by PLA in the membrane. It is considered that the property could be achieved by regulation of protein immobilization and adsorption. As a PTMC derivative, poly(5-methyl-5-carboxyl-1,3-dioxan-2-one) (PMBC) was prepared and total amount of protein immobilization was nicely enhanced. Therefore, more proteins were retained on PMBC surface. This study indicated protein immobilization or adsorption on controlled surface by selecting polymer. 相似文献
947.
Effect of the edge type and strain on the structural, electronic and magnetic properties of the BNRs
We present the effect of edge structures on the edge energy and stress of BN nanoribbons. Ab initio density functional calculations show that the armchair edge is lower in energy than the zigzag edge by 0.43 eV/angstrom. Both types of the edges are under the compressive stress. The zigzag edges are mechanically more stable than the armchair edges. Based on the calculated edge energies, the equilibrium shape of the BN flakes are found to be regular hexagonal, and dominated by the armchair edges. The zigzag ribbons are found to be half-metallic, whereas the armchair ribbons are semiconducting. 相似文献
948.
Da-Yong Zhou Lei Qin Bei-Wei Zhu Xiao-Dong Wang Hui Tan Jing-Feng Yang Dong-Mei Li Xiu-Ping Dong Hai-Tao Wu Li-Ming Sun Xiu-Ling Li Yoshiyuki Murata 《Food chemistry》2011
Purple sea urchin (Strongylocentrotus nudus) spines were dissolved in HCl–ethanol-aqueous solution. The polyhydroxylated 1,4-naphthoquinone (PHNQ) pigments were condensed and purified by using macroporous resin in static adsorption mode. PHNQ in the extract were characterised rapidly by using an ultra-performance liquid chromatography (UPLC) coupled to hybrid quadrupole orthogonal acceleration time-of-flight mass spectrometer (Q-TOFMS). Six known compounds including spinochrome E, 2,7-dihydroxynaphthazarin, spinochrome B, spinochrome C, spinochrome A and echinochrome A, and two new compounds with molecular formula of aminopentahydroxynaphthoquinone and acetylaminotrihydroxynaphthoquinone were identified tentatively. The pigment extract was evaluated for antioxidant activity by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging capacity assay, Fe2+ chelating assay, reducing power assay, lipid peroxidation inhibition assay and tertiary-butyl hydroperoxide (t-BOOH)-induced macrophages protection assay. In all testing methods, the extract showed excellent activity, indicating the PHNQ from S. nudus spines are potential sources of natural antioxidants. 相似文献
949.
Zhuo Luan Katsumi Higaki Prof. Matilde Aguilar‐Moncayo Haruaki Ninomiya Dr. Kousaku Ohno Prof. M. Isabel García‐Moreno Dr. Carmen Ortiz Mellet Prof. José M. García Fernández Prof. Yoshiyuki Suzuki Prof. 《Chembiochem : a European journal of chemical biology》2009,10(17):2780-2792
Gaucher disease (GD), the most prevalent lysosomal storage disorder, is caused by mutations of lysosomal β‐glucosidase (acid β‐Glu, β‐glucocerebrosidase); these mutations result in protein misfolding. Some inhibitors of this enzyme, such as the iminosugar glucomimetic N‐(n‐nonyl)‐1‐deoxynojirimycin (NN‐DNJ), are known to bind to the active site and stabilize the proper folding for the catalytic form, acting as “chemical chaperones” that facilitate transport and maturation of acid β‐Glu. Recently, bicyclic nojirimycin (NJ) analogues with structure of sp2 iminosugars were found to behave as very selective, competitive inhibitors of the lysosomal β‐Glu. We have now evaluated the glycosidase inhibitory profile of a series of six compounds within this family, namely 5‐N,6‐O‐(N′‐octyliminomethylidene‐NJ (NOI‐NJ), the 6‐thio and 6‐amino‐6‐deoxy derivatives (6S‐NOI‐NJ and 6N‐NOI‐NJ) and the corresponding galactonojirimycin (GNJ) counterparts (NOI‐GNJ, 6S‐NOI‐GNJ and 6N‐NOI‐GNJ), against commercial as well as lysosomal glycosidases. The chaperone effects of four selected candidates (NOI‐NJ, 6S‐NOI‐NJ, 6N‐NOI‐NJ, and 6S‐NOI‐GNJ) were further evaluated in GD fibroblasts with various acid β‐Glu mutations. The compounds showed enzyme enhancement on human fibroblasts with N188S, G202R, F213I or N370S mutations. The chaperone effects of the sp2 iminosugar were generally stronger than those observed for NN‐DNJ; this suggests that these compounds are promising candidates for clinical treatment of GD patients with a broad range of β‐Glu mutations, especially for neuronopathic forms of Gaucher disease. 相似文献
950.
The fabrication of thin film silicon devices based on solution processes rather than on conventional vacuum processes is of substantial interest since cost reductions may result. Using a solution process, we coated substrates with polydihydrosilane solution and studied the pyrolytic transformation of the material into hydrogenated amorphous silicon (a-Si:H). From thermal gravimetry and differential thermal analysis data a significant reduction in weight of the material and a construction of SiSi bonds are concluded for the pyrolysis temperature Tp = 270 to 360 °C. The appearance of amorphous silicon phonon bands in Raman spectra for films prepared at Tp ≥ 330 °C suggests the construction of a three-dimensional amorphous silicon network. Films prepared at Tp ≥ 360 °C exhibit a hydrogen content near 10 at.% and an optical gap near 1.6 eV similar to device-grade vacuum processed a-Si:H. However, the infrared microstructure factor, the spin density, and the photosensitivity require significant improvements. 相似文献