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31.
Interaction between light signaling and stress response has been recently reported in plants. Here, we investigated the role of CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), a key regulator of light signaling, in endoplasmic reticulum (ER) stress response in Arabidopsis. The cop1-4 mutant Arabidopsis plants were highly sensitive to ER stress induced by treatment with tunicarmycin (Tm). Interestingly, the abundance of nuclear-localized COP1 increased under ER stress conditions. Complementation of cop1-4 mutant plants with the wild-type or variant types of COP1 revealed that the nuclear localization and dimerization of COP1 are essential for its function in plant ER stress response. Moreover, the protein amount of ELONGATED HYPOCOTYL 5 (HY5), which inhibits bZIP28 to activate the unfolded protein response (UPR), decreased under ER stress conditions in a COP1-dependent manner. Accordingly, the binding of bZIP28 to the BIP3 promoter was reduced in cop1-4 plants and increased in hy5 plants compared with the wild type. Furthermore, introduction of the hy5 mutant locus into the cop1-4 mutant background rescued its ER stress-sensitive phenotype. Altogether, our results suggest that COP1, a negative regulator of light signaling, positively controls ER stress response by partially degrading HY5 in the nucleus.  相似文献   
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Yeonhwa Wi 《Polymer》2008,49(26):5626-5635
A well-defined poly(methacrylic acid) (PMAA) macro-RAFT agent has been synthesized by the bulk polymerization using 4-toluic acid dithiobenzoate as a RAFT agent and successfully employed as a reactive emulsifier in the soap-free emulsion polymerization of styrene, leading to a formation of stable latex. The amphiphilic block copolymer, prepared from the in situ micelle formation, contains a hydrophilic PMAA block and a hydrophobic PS block, via styrene monomer transfer reaction to the dithioester function in PMAA macro-RAFT agent during the nucleation step. The chemical structure of the synthesized PS with the PMAA macro-RAFT agent was confirmed using FTIR and NMR. In addition, it was confirmed that the macro-RAFT agent is present on the particle surface via the ESCA measurement. The reaction mechanism was proposed that the stable spherical particles enlarged by the aggregation of small particles, which were also produced by the chemical or physical bonding between the tiny small particles. The results indicate that the PMAA macro-RAFT agent is used as emulsifier for the formation of PS particles and block copolymer [P(S-b-MAA)] in situ.  相似文献   
34.
Zinc oxide (ZnO) and cerium oxide (CeO2) nanoparticles were deposited on the surface of preformed silica spheres with diameters ranging from 60 to 750 nm. Ultrasonic irradiation was employed to promote the deposition of the metal oxide nanoparticles on the surface of silica. Silica-supported zinc oxide or cerium oxide was used as a catalyst in the glycolysis of polyethylene terephthalate, one of the key processes in the depolymerization of polyethylene terephthalate. The effect of the support size on the catalytic activity was studied in terms of monomer yield, and the monomer concentration was analyzed via high-performance liquid chromatography (HPLC). The morphologies and surface properties of the catalysts were characterized using a scanning electron microscope, a transmission electron microscope, and a BET surface area analyzer, while the monomer was characterized via HPLC and nuclear-magnetic-resonance spectroscopy. Both the zinc oxide and cerium oxide deposited on a smaller support showed better distribution and less aggregation. The high specific surface area of the smaller support catalysts provided a large number of active sites. The highest monomer yield was obtained with a catalyst of 60-nm silica support.  相似文献   
35.
Latent heat thermal energy storage using phase change materials (PCMs) is considered to be the method with the most potential to solve the energy shortage problem. In this study, paraffin-based mixed shape-stabilized PCM (SSPCM) (PBMS) was made by vacuum impregnation method. The prepared PBMS was added to gypsum powder as a fine aggregate. In the experiment, the n-hexadecane and n-octadecane was used as the PCM and the materials have latent heat capacities of 254.7 and 247.6 J/g, and melting points of 20.84 and 30.4 °C, respectively. The PBMS was prepared by an impregnation method in a vacuum, following the manufacturing process. The physical and thermal properties of the PBMS gypsum board were analyzed by Fourier transform infrared spectrometry (FTIS), differential scanning calorimetry, enthalpy analysis, and thermogravimetric analysis. From the Fourier transform infrared analysis, PBMS could be maintained in the structure of the gypsum board due to its physical rather than chemical bonding. From the specific heat and enthalpy analysis, the PBMS has high enthalpy and thermal inertia property. In addition, the gypsum board with PBMS has high latent heat capacity and high thermal efficiency.  相似文献   
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37.
米根霉直接发酵玉米粉生产L-(+)乳酸的新工艺   总被引:1,自引:0,他引:1  
利用米根霉(Rhizopus oryzae)NRRL395HS99为菌种,玉米粉为基质,研究了一种新的L-(+)-乳酸发酵工艺。该工艺克服了淀粉浓度过高时基质变为凝胶而不能发酵的困难,不需要液化程序。当基质浓度为150g/l,接种量5×106个孢子/100ml时,于33℃下摇瓶培养(180r/min)64h,可产L-(+)-乳酸88.75g/l,L-(+)-乳酸对葡萄糖的转化率为72.2%。本法工艺简单,具有较高的工业应用价值。  相似文献   
38.
Sintered ceramics, represented by ceramic tiles or clinker bricks, are widely used in the building materials industry due to their technological properties and visual qualities. The topic of color changing of ceramic materials from cream-firing clays with the use of mineral additives has not been addressed to date. The aim of the paper was to investigate the effect of granulation of dolomite additives to ceramic masses based on cream-firing Borkowice clay on the color and properties of fired ceramic materials. The paper proposes that grain size of mineral additive affects the color of sintered ceramics. In order to confirm this hypothesis, a number of experiments were performed, consisting of determination of the color and technological properties of ceramic materials. The conducted tests showed that the color and technological properties of sintered ceramics are influenced by the grain size of the additives used.  相似文献   
39.
Iontronic graphene tactile sensors (i‐GTS) composed of a top floating graphene electrode and an ionic liquid droplet pinned on a bottom graphene grid, which can dramatically enhance the performance of capacitive‐type tactile sensors, are presented. When mechanical stress is applied to the top floating electrode, the i‐GTS operates in one of the following three regimes: air–air, air–electric double layer (EDL) transition, or EDL–EDL. Once the top electrode contacts the ionic liquid in the i‐GTS, the spreading behavior of the ionic liquid causes a capacitance transition (from a few pF to over hundreds of pF). This is because EDLs are formed at the interfaces between the electrodes and the ionic liquid. In this case, the pressure sensitivity increases to ≈31.1 kPa?1 with a gentle touch. Under prolonged application of pressure, the capacitance increases gradually, mainly due to the contact line expansion of the ionic liquid bridge pinned on the graphene grid. The sensors exhibit outstanding properties (response and relaxation times below 80 ms, and stability over 300 cycles) while demonstrating ultimate signal‐to‐noise ratios in the array tests. The contact‐induced spreading behavior of the ionic liquid is the key for boosting the sensor performance.  相似文献   
40.
In urine of 25 patients with bladder carcinoma the antigen of tissue type plasminogen activator (t-PA) was assessed. The level of t-PA was much higher in patients with bladder carcinoma in comparison with a control group. We also analyzed the level of t-PA between patients with superficial and invasive bladder carcinoma the level of t-PA was higher. In conclusion, there is t-PA in urine of patients with bladder carcinoma and its level is correlated with staging of neoplasm.  相似文献   
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