Lipase-Catalyzed Esterification of Triterpene Alcohols and Phytosterols with Oleic Acid

Oleic acid esters of phytosterols (PSs) and triterpene alcohols (TAs), derived from rice bran, were synthesized using lipases under mild conditions. Some lipases, especially from Candida rugosa, type VII, showed very high substrate specificity towards both PSs and TAs, when a mixture of PS and TA (PS/TA mixture) was used as the substrate source. The maximum yield of PS esters was ca. 80 % in each case; however, the maximum yield of TA esters was much lower when the reaction was continued for 7 days. Due to the difficulty in purifying the esters obtained when the PS/TA mixture was used as source of substrate, free PSs and TAs were separated from the PS/TA mixture by silica-gel and reverse-phase chromatography prior to esterification. The pure PSs or TAs were esterified with oleic acid to obtain the corresponding esters with high purity. Differential scanning calorimetric analysis of the resulting esters revealed that their melting points ranged from 7.0 to 42 °C. These values were at least 100 °C lower than those of the free PSs and TAs.     

The preparation of TiO2 nanometer photocatalyst film by a hydrothermal method and its sterilization performance for Giardia lamblia

The photocatalytic property of TiO(2) is utilized to sterilize the Giardia lamblia in an aqueous solution in this study. The TiO(2) colloidal solution used for the film was prepared by the modified hydrothermal method and it was directly coated on a UV-lamp, which was set up using a photoreactor manufactured in our laboratory. The TiO(2) film was very stably attached to the UV-lamp, and it was transparent until 5-time coating. The size of the TiO(2) particle in the film was distributed around 20-30 nm and the film thickness was about 200 nm per 1-time coating.The G. lamblia cell was just partially damaged under UV-irradiation without a TiO(2) photocatalyst, but the dead cell became very small and the dead body finally disappeared with an increase in the intensity of UV-irradiation after 2 h. In addition, under the TiO(2)/UV-irradiation system, the sterilized (dead) rate of G. lamblia was very fast. The sterilizing power increased at lower pH in the initial step, but it rather increased at a higher pH in the final step. And the sterilization of G. lamblia was very sensitive to the temperature, and resulted in an increase in the sterilized rate at higher temperatures. On the basis of these experimental observations, it can be concluded that TiO(2) photocatalyst under UV-irradiation could be adopted as one of the sterilization modalities for the G. lamblia.     

固溶处理对添加Si的Cu-10Ni-8Sn合金胞状沉淀的影响

利用定量金相的方法,研究了固溶-退火条件(温度和时间)对添加0.2%Si的Cu-10Ni-8Sn合金450℃时效时晶界处胞状物的形核与长大的影响.在450℃时效过程中,基体的硬度几乎不受固溶-退火条件的影响.然而,时效过程中固溶-退火条件对胞状物的形核与长大的影响却非常显著.当固溶-退火温度或时间增加时,Si对于胞状沉淀的抑制作用下降.随固溶-退火温度或者时间的增加,淬火态样品中存在于基体晶粒和晶界上的Ni31Si12相颗粒被粗化.因此,可以认为,经较高温度或较长时间固溶-退火的样品时效时,Ni31Si12相颗粒占据胞状物在晶界上的形核位置并抑制胞状物前沿界面迁移的作用降低了.     

Charge transporting block copolymer for morphological control in light emitting device based on polymer blends

Bipolar charge transporting block copolymer composing of carbazole and oxadiazole monomers as hole and electron transporting units, respectively, was synthesized by nitroxide mediated radical polymerization. It is found that the current efficiency significantly increased with the addition of the block copolymer in the device based on polymer blend system. AFM measurement revealed that a phase-separated structure in the polymer blend layer changed to suitable morphology in the presence of block copolymer.     

Demonstration of infectious bovine rhinotracheitis virus antigen by immunoperoxidase method in tissues of aborted bovine fetuses preserved for 25 years in paraffin blocks

Infectious bovine rhinotracheitis (IBR) virus antigen was demonstrated by the immunoperoxidase method in tissues of two aborted bovine fetuses, which had been stored for 25 years after fixing in formalin and embedding in paraffin. Necrotic foci were detected in the liver, kidney, adrenal gland, and thymus of the fetuses. Coincidenting with the distribution of the necrotic foci, IBR virus antigen was demonstrated by immunostaining. The present study proved the immunoperoxidase method in one of useful techniques to demonstrate IBR virus antigen in tissue sections from preserved paraffin blocks.     

A pentamidine-treated acquired immunodeficiency syndrome patient associated with sudden onset diabetes mellitus and high tumor necrosis factor alpha level

Orbital implant infection is a rare cause of anophthalmic socket pain. Because of the potential danger of infection spreading to nearby structures, it is of paramount importance to diagnose the condition as soon as possible. Scintigraphy is a method for diagnosis of graft infections by radioisotopic imaging of inflammatory sites. We report on a patient with socket pain 3 months after implantation of an acrylic implant. The socket appearance was normal and there were no signs of infection other than culture-positive socket exudation. Three consecutive computed tomography scans revealed no abnormalities. 99mTc leukocyte scintigraphy revealed white blood cell accumulation at the implantation site. The implant was removed and cultured. This produced Staphylococcus epidermidis and R. equii. A parenteral antibiotic treatment was instituted with subsequent improvement of symptoms. Four months later, after negative scintigraphy, a hydroxyapatite implant was inserted, demonstrating full vascularization on a bone scan after 2 months. Two months later, the patient developed the previous symptoms, with all of the former findings, including positive scintigraphy. The implant was removed, revealing a microabscess on the anterior aspect, producing S. epidermidis on culture. We conclude that scintigraphy using 99mTc-labeled leukocytes is a useful technique in diagnosing low-grade orbital infection.     

高压下N_2、Ar、CH_4、CO_2和N_2O气体在丝光沸石上的吸附平衡及关联

本文用定容型吸附量测定装置,在压力为3.04×10~3至1.43×10~7Pa范围内,温度为—196、0、25、50和75°C下测定了N_2、Ar、CH_4、CO_2和N_2O等气体在氢型丝光沸石上的吸附平衡数据.实验结果表明:N_2、Ar和CH_4的吸附量随压力增加而增加,直到在6.08×10~6Pa附近达到饱和;CO_2和N_2O的吸附等温线出现了极大值,且不同温度同一吸附质的吸附等温线出现了相互交叉的现象.用扩展了的吸附势理论进行关联,取得了满意的结果.     

Direct isopropanol production from cellobiose by engineered Escherichia coli using a synthetic pathway and a cell surface display system

Efficient bio-production from lignocellulosic biomass is required for the purpose of developing an inexpensive, practical bio-refinery process. As one approach to address this problem, we genetically engineered Escherichia coli to produce isopropanol directly from cellobiose via the cellobiose degradation by Beta-Glucosidase (BGL) on the cell surface. First, we investigated the cellobiose consumption of two E.?coli strains with the BGL protein from Thermobifida fusca YX (Tfu0937) fused to the anchor protein Blc (Tfu0937/Blc) using different fusion sites. Next, we introduced the synthetic pathway for isopropanol production into those strains and compared their isopropanol production in the presence of glucose. Based on the results of these assays, TA212/pTA411, which was introduced Tfu-Blc fused protein expression system and the synthetic pathway for isopropanol production, was selected for the directly isopropanol production from cellobiose. TA212/pTA411 produced 69.0±11.6mM isopropanol at 21h of fermentation, whereas TA212/pTA147, which did not introduced the BGL/anchor fused protein but was introduced the synthetic pathway for isopropanol production, showed no cellobiose consumption and no isopropanol production during fermentation. To our knowledge, this is the first report of the production of a bio-product from cellobiose using E.?coli.     

Graphene etching controlled by atomic structures on the substrate surface

We etched graphene on a sapphire (1 ?1 0 2) surface using the reaction between graphene and hydrogen catalyzed by metal nanoparticles. To investigate effects of the atomic structure of the sapphire substrate on graphene etching, we used sapphire substrate with as-polished, air-annealed, and step-ordered surfaces. We investigated the relationship between the atomic arrangement of sapphire and graphene etching and found that graphene is selectively etched in the [1 ?1 0 ?1] direction of sapphire. This indicates that atomic structure of the sapphire surface can be used as a template to control graphene etching. By combining the transfer method for graphene sheets grown on metal substrates with the present etching technique, graphene nanoribbons can be fabricated at a wafer level.