环氧化植物油的制备

天然油脂在无溶剂加压（约０．１５ＭＰａ）条件下，经甲酸（８５％）、双氧水（５０％）环氧化，一步合成增塑剂兼稳定剂环氧化油脂，得微黄色油状透明液体；环氧大豆油和环氧葵子油的环氧值均在６．２％～６．６％，环氧玉米油的环氧值６．０％～６．４％；碘值小于３ｍｇ／ｇ；精油转化率１０４％～１０８％。     

Rapid analysis and characterization of multiple constituents of corn silk aqueous extract using ultra‐high‐performance liquid chromatography combined with quadrupole time‐of‐flight mass spectrometry

Corn silk is a well‐known traditional Chinese medicine that has been widely used for its antidiabetic, antioxidant, antihyperlipidemic, and other effects in China for thousands of years. Numerous studies have revealed that corn silk contains multiple bioactive constituents that are beneficial for human health. However, the constituents of corn silk in vivo remain ambiguous. In this study, high‐throughput ultra‐high‐performance liquid chromatography combined with quadrupole time‐of‐flight mass spectrometry technology using multivariate statistical analysis was established to systematically investigate the constituents migrating into blood from corn silk aqueous extract. As a result, 76 compounds were identified, including caffeic acid and ten of its derivatives, (E)‐p‐coumaric acid and two of its derivatives, ferulic acid and four of its derivatives, and five flavones. Among the identified constituents, 21 constituents, including nine prototype components and 12 metabolites derived from eight components, were characterized in sequence. Based on the significance of the results, the applied approach was powerful for the accurate determination and rapid screening of bioactive components from corn silk aqueous extract. The obtained results are valuable for the in‐depth understanding and further pharmacological study of corn silk aqueous extract.     

尿囊素对玉米幼苗的生物效应

用盆栽试验方法,通过对玉米幼苗期生物学性状及核酸含量的测定,研究玉米经不同浓度尿囊素溶液浸种处理后的生长发育情况．结果表明,尿囊素处理的玉米发芽率、株高、根长、地上和地下部生物学产量及核酸含量等均比对照有不同程度的提高,其中１０(－６)ｍｏｌ／Ｌ尿囊素处理尤为明显．     

QuEChERS-液相色谱-串联质谱法测定甜玉米及毛豆中32种磺酰脲类除草剂残留

建立了基于QuEChERS方法的液相色谱-串联质谱同时测定甜玉米及毛豆中32种磺酰脲类除草剂残留的方法。以提取液净化前后蒸发残渣质量及回收率为考察指标,评估了C18、氧化锆包覆硅胶(Z-Sep)/C18混合物、C18键合锆胶(Z-Sep+) 3种分散吸附剂对甜玉米的净化效果,结果Z-Sep/C18吸附剂的净化效果最佳。样品采用乙腈提取、无水硫酸镁及氯化钠盐析、Z-Sep/C18分散固相萃取净化;液相色谱以CSH C18色谱柱梯度洗脱分离,质谱分析采用电喷雾负离子电离、按时间表的多反应监测模式(Scheduled MRM),以基质匹配校准曲线外标法进行定量。32种农药在甜玉米及毛豆中3个添加水平(10、20、100 μg/kg)的回收率为80.0%~108.2%,相对标准偏差为1.2%~13.0%, 32种农药的定量限(S/N≥10)为0.2~5.0 μg/kg。方法简便、灵敏、环保,适用于甜玉米及毛豆中32种磺酰类除草剂残留的定性定量分析。     

An economic and environmental comparison of a biochemical and a thermochemical lignocellulosic ethanol conversion processes

With the world’s focus on rapidly deploying second generation biofuels technologies, there exists today a good deal of interest in how yields, economics, and environmental impacts of the various conversion processes of lignocellulosic biomass to transportation fuels compare. Although there is a good deal of information regarding these conversion processes, this information is typically very difficult to use on a comparison basis because different underlying assumptions, such as feedstock costs, plant size, co-product credits or assumed state of technology, have been utilized. In this study, a rigorous comparison of different biomass to transportation fuels conversion processes was performed with standard underlying economic and environmental assumptions so that exact comparisons can be made. This study looked at promising second-generation conversion processes utilizing biochemical and thermochemical gasification technologies on both a current and an achievable state of technology in 2012. The fundamental finding of this study is that although the biochemical and thermochemical processes to ethanol analyzed have their individual strengths and weaknesses, the two processes have very comparable yields, economics, and environmental impacts. Hence, this study concludes that based on this analysis there is not a distinct economic or environmental impact difference between biochemical and thermochemical gasification processes for second generation ethanol production.     

玉米须提取液对尿液中草酸钙晶体形成的影响

本文采用X射线衍射(XRD)、红外光谱(FTIR)、扫描电子显微镜(SEM)等方法分析了玉米须提取液对正常人尿液中草酸钙晶体形成的影响,通过电导率法研究了草酸钙晶体生长的动力学过程,以及从生物矿化的角度对玉米须提取液影响尿液中草酸钙晶体的可能机理进行了探讨。由于玉米须提取液中有机酸或多糖的羟基、羰基等通过配位作用与Ca²⁺结合形成可溶性配位化合物,减少了Ca²⁺与Oxa^2-的结合能力,从而抑制了CaOxa的成核和生长。同时,可能由于玉米须提取液中有效成分与二水草酸钙(COD)的吸附点键合,增强了COD晶体在溶液中的热力学稳定性,进而抑制了COD晶体向热力学更稳定态的一水草酸钙(COM)晶体转变。结果显示,这种抑制作用随玉米须浓度增大而增大,且COD晶体尺寸随着玉米须浓度的增大而减小。玉米须抑制COD晶体向COM晶体转变的作用为开发预防和治疗尿结石的药物提供了启示。     

非离子型表面活性剂辅助酶水解玉米秸杆蒸爆渣

研究纤维素酶对蒸汽爆破预处理玉米秸杆的水解过程. 实验结果表明,玉米秸杆蒸爆渣中的木质素对纤维素酶存在非生产性吸附,降低了纤维素酶对玉米秸杆蒸爆渣的水解率;通过添加非离子型表面活性剂PEG 6000,减少纤维素酶的非生产性吸附,改善纤维素酶对玉米秸杆蒸爆渣的水解性能;在pH值为4.8,温度为50℃,PEG 6000浓度为3.5g/L的优化条件下,纤维素酶水解玉米秸杆蒸爆渣48h,还原糖水解率和葡萄糖水解率分别为83.61%和64.15%.     

玉米淀粉固态电解质质子\电子杂化突触晶体管

随绿色可持续发展观念的深入人心,研究人员致力于寻找天然有机材料应用于功能性电子器件.淀粉以其低廉的价格、丰富的来源和优异的机械性能进入了科研人员的视野.淀粉可由玉米、马铃薯、甘薯和葛根等含淀粉的物质中提取而得,一般不溶于水,在和水加热至一定温度时,则糊化成胶状溶液.本文通过旋涂法将玉米淀粉的胶状溶液旋涂至氧化铟锡玻璃表面,然后在30?C恒温环境中晾干制备成固态胶合状薄膜.以此薄膜作为固态电解质制备了氧化铟锌突触晶体管,并实现了生物神经突触的双脉冲易化、学习记忆能力、高通滤波等可塑性行为的仿真.本研究以玉米淀粉固态胶合薄膜作为电解质大大降低了氧化物薄膜晶体管固态电解质的成本,且该电解质无毒性、来源丰富,将为人工神经网络的开发提供一种可选择的元件.     

Nanoparticles Synthesis from Corn Cob (Xylan) and Their Potential Application as Colon-Specific Drug Carrier

Summary: Corn Cob based Xylan, a natural polysaccharide extracted from agro-waste may be used as a tool to deliver drugs especially to the colon because of their timely retention in the physiological environment of stomach and small intestine and can only be degraded in colon by vast anaerobic microflora like bifidobacterium. The objective of present research study is to incorporate the drug namely 5-aminosalicylic acid (5-ASA) into xylan macromolecular backbone, either by surface adsorption or by intermolecular covalent bond formation so that absorption of drugs is prevented in upper gastrointestinal tract (GIT). To achieve the above objective, xylan prodrug of 5-ASA was synthesized via activation of carboxylic acid with N,N-carbonyldiimidazole. The structure of obtained xylan prodrug was evaluated by means FT-IR spectroscopy. The ester carbonyl absorption band was observed at 1690 cm⁻¹ in addition to the bands originated from 5-ASA and xylan. The resulting prodrug and xylan itself assembled into spherical nanoparticles were analyzed by scanning electron microscopy. The prodrug of 5-ASA was synthesized which might be active against inflammatory bowel diseases, a novel thought towards advanced drug delivery from xylan based nanoparticles will be presented.     

AFB1–AP Conjugate for Enzyme Immunoassay of Aflatoxin B1 in Corn Samples

Abstract

This article describes the conjugation between aflatoxin B₁ (AFB₁), one of the major mycotoxins, and alkaline phosphatase (AP), one of the most used enzymes for immunoassays. In addition, an application of the ELISA method for aflatoxin B₁ determination in corn is presented. Three AFB₁–AP conjugates in different toxin–enzyme ratios were prepared and tested. The ELISA results, developed with the most effective conjugate obtained, showed a satisfactory working range between 2.4 and 4000 ng of toxin/g of corn. The detection limit was 2 ng/g in corn samples, and recoveries ranged from 105 to 120%.