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151.
郭明  周伟  周珊  敬娇  杨萍 《分析化学》2013,41(2):193-198
采用1-(3-二甲氨基丙基)-3-乙基碳二亚胺方法合成氨基甲酸乙酯(Ethyl carbamate,EC)新型人工抗原.将衰减全反射红外光谱法(ATR-FTIR)应用于人工合成抗原的表征分析,并结合荧光光谱分析EC人工抗原的偶联效果以及载体蛋白质分子的二级结构变化;通过质谱结合紫外光谱、电泳方法进行人工抗原的系统表征,计算新型人工抗原中半抗原分子与载体蛋白质分子的偶联比.结果表明:合成路线合理,成功获得了氨基甲酸乙酯新型人工抗原.人工抗原分子的α-螺旋、β-折叠和β-转角结构与载体蛋白质分子相比含量发生变化,人工抗原的荧光相图满足线性型态变迁关系,符合“二态模型”.氨基甲酸乙酯人工抗原分析表征的红外衰减全反射方法、基质辅助激光解析飞行时间质谱法获得的检测结果与其它光谱方法、电泳方法表征结果一致,获得人工抗原的偶联比为15∶1~19∶1,EC新型人工抗原免疫小鼠抗血清的效价为1∶25600.  相似文献   
152.
A highly efficient oil-degrading bacteria JZX-01 was isolated from the oil-contaminated soil of the seacoast near the Boxi Offshore Oil Field of China. Morphological, physiological, and 16S rDNA gene sequence analyses indicated that JZX-01 was assigned to the genus Rhodococcus sp. This strain decomposed 65.27?±?5.63 % of the crude oil in 9 days. Gas chromatography–mass spectrometry analysis showed that even the long-chain hydrocarbons (C31–C38) and branched alkanes (pristine and phytane), which were regarded as the stubborn ones, could be degraded. Further study showed that the bacteria still has good oil degradation ability at low temperatures as well as under high salt conditions. Moreover, JZX-01 was found to have a biosurfactant-producing capacity, which significantly favors the surface tension reduction and crude oil degradation. The promising isolated strain Rhodococcus sp. JZX-01 could be further used for the bioremediation of oil-polluted soil or seawater in a wide range of temperatures and high salt conditions.  相似文献   
153.
154.
An efficient procedure for the oxidation of primary and secondary alcohols to aldehydes and ketones, respectively, with molecular oxygen under ambient conditions has been achieved. By applying catalytic amounts of Pd(OAc)2 in the presence of tertiary phosphine oxides (O?PR3) as ligands, a variety of substrates are selectively oxidized without formation of ester byproducts. Spectroscopic investigations and DFT calculations suggest stabilization of the active palladium(II) catalyst by phosphine oxide ligands.  相似文献   
155.
A novel N-halamine precursor with tertiary amino group (5,5-dimethylhydantoinyl-3-ylethyl)-dimethylamine (DEADH), was synthesized and then covalently bonded onto cotton fabrics modified by 3-chloropropyltrimethoxysilane to form quaternarized N-halamine precursor grafted cotton fabrics which could be transferred to N-halamine structure upon exposure to dilute sodium hypochlorite solution. The grafted cotton fabrics were characterized by FT-IR, X-ray photoelectron spectroscopy, and field emission scanning electron microscope. The antimicrobial test showed that the cotton fabrics grafted with the quaternarized N-halamine were capable of 7-log inactivation of Staphylococcus aureus and Escherichia coli O157:H7 within 1 min of contact time. Very interestingly, it was found that the grafting process and following chlorination had almost no adverse effect on the tensile strength of cotton fabrics. Furthermore, the antimicrobial cotton fabrics exhibited good washing durability and stability.  相似文献   
156.
采用密度泛函理论(DFT)方法研究了系列含绿色荧光蛋白发色团双自由基分子光学异构体的几何结构、极化率(αs)和第一超极化率(βtot).结果表明,引入电子给受体取代基使分子的极化率增大,而对第一超极化率有不同影响.对于光照前的反式结构,引入电子受体βtot值增加,且βtot值随取代基吸电子能力的增强而增大;引入电子给体βtot值降低,且βtot值随取代基给电子能力的增强而减小.当分子变成相应的顺式结构时,其βtot值变化趋势与反式结构的结果正好相反.光异构化前后分子的βtot值变化不同,引入电子受体使顺式结构的βtot值比反式结构的小,其中―NO2使顺式结构的βtot值减小为反式结构的1/6;引入电子给体使反式结构的βtot值比顺式结构的小,其中―NH2使反式结构的βtot值减小为顺式结构的1/6.从而,光异构化起到调节非线性光学(NLO)响应的作用.  相似文献   
157.
建立了定量肽段串联体蛋白质(concatamers of Q peptides, QconCATs)结合18O同位素标记-多反应监测质谱的蛋白质绝对定量新方法。首先对QconCAT重组蛋白质进行了纯度表征,十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)表征结果表明重组蛋白质的纯度在99%以上,相对分子质量约为63.4 kDa。对QconCAT重组蛋白质酶切后的肽段混合物进行质谱分析,并经pFind和pLabel软件处理,验证了目标肽段。还考察了QconCAT重组蛋白质的酶切效率和18O标记效率,并对QconCAT蛋白质结合18O标记-同位素稀释-多反应监测质谱方法进行了评价。实验结果表明,采用该方法对腾冲嗜热厌氧菌(Thermoanaerobacter tengcongensis, TTE)中选定蛋白质的肽段进行绝对含量测定时,相对标准偏差小于20%,准确度较高,说明该方法可用于复杂生物样本中蛋白质的绝对定量。更重要的是所建方法不仅解决了细胞培养氨基酸稳定同位素标记(SILAC)技术的重标试剂价格昂贵的问题,也为定量蛋白质组学提供了一种新的方法。  相似文献   
158.
提出了气相色谱法测定木材中五氯酚残留量的方法。样品用乙醇经加速溶剂萃取仪在100℃静态萃取10 min。采用DB-5毛细管柱分离,电子捕获检测器测定五氯酚含量。五氯酚的质量浓度在0.01~50 mg·L-1范围内与峰面积呈线性关系,方法的检出限(3S/N)为0.01 mg·kg-1。以木材样品为基体,进行加标回收试验,回收率在94.2%~98.2%之间,测定值的相对标准偏差(n=6)小于4%。  相似文献   
159.
A novel copper‐catalyzed aerobic oxidative C(CO) C(alkyl) bond cleavage reaction of aryl alkyl ketones for C N bond formation is described. A series of acetophenone derivatives as well as more challenging aryl ketones with long‐chain alkyl substituents could be selectively cleaved and converted into the corresponding amides, which are frequently found in biologically active compounds and pharmaceuticals.  相似文献   
160.
Environmental pollution caused by toxic metals (heavy metals, radioactive metals, etc.) is one of the major global issues, thus removal of toxic metals from contaminated water seems to be particularly important. On the other hand, the recovery and enrichment of metals, especially noble metals, from waste water is also crucial. To address these issues, nanotechnology plays an essential role in environmental monitoring and pollution control. To remove metals from contaminated water, or enrich metals from waste water, carbon nanotubes (CNTs) and their composites have attracted great attention due to their excellent adsorption performance. The removal efficiency for metal ions by CNTs was observed aroud 10–80 %, which could be improved to approach 100 % by selectively functionalizing CNTs with organic ligands. Herein, we review the applications of CNTs in treatment of toxic metal-containing wastewater for environmental monitoring and metals recovery. Due to their higher sensitivity and selectivity towards the enrichment of metals or detection of toxic metal pollution of the environment, and the latest research progress of using CNT composites for metal treatment is also discussed.  相似文献   
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