ABSTRACT Eleutherococcus senticosus essential oil (ESEO) has the function of clearing heat and detoxifying, delaying aging. The ESEO yield obtained by traditional extraction methods is low because essential oils are encased in plant cell structures and are difficult to extract. In this work, we adopted the method of glucose oxidase promoting cellulase‐assisted hydrodistillation, and utilized the interaction of glucose oxidase and cellulase to promote the full destruction of cellulose in plant cells, resulting in a large amount of internal essential oil flowing out and improving the yield of ESEO. By optimizing the main factors of enzymatic hydrolysis, the optimal extraction conditions for ESEO were determined through Box–Behnken design experiments. The ratio of glucose oxidase to cellulase is 1:20, the concentration of the enzyme is 1.02%, the temperature of enzymatic hydrolysis is 40.0°C, and the pH value of enzymatic hydrolysis is 3.44. The optimal yield was 0.140%. The yield of essential oil extracted from E. senticosus was increased by 49.9% compared to a single cellulase‐assisted extraction method. The extraction process used in this work is milder, more environmentally friendly, and more efficient, which has important reference value for the industrial extraction and utilization of medicinal plants.

The treatment of polluted water is a serious environmental problem in the world. Biomass is easily modified and can be prepared into adsorbent materials, which is expected to solve the problem of heavy metal ion adsorption in sewage. In this paper, esterified tobacco straw based hydrogels (ETS-PAA) were synthesized from waste tobacco straw biomass. The structure and thermal stability of these hydrogels were characterized by FTIR, SEM, EDS, XPS and TG. The adsorption of metal ions by the hydrogel was measured by ICP-MS. The effects of initial ion concentration, adsorption time, pH, and temperature on the heavy metal adsorption were investigated. The results showed that ETS-PAA possessed more pores, which led to a better adsorption capacity. The maximum adsorption amounts of Pb 2+ , Cu 2+ and Cd 2+ were 2.41 mmol·g −1 , 1.93 mmol·g −1 and 1.77 mmol·g −1 , respectively. Finally, the adsorption mechanism and kinetics were analyzed. The adsorption was mainly accomplished by ion exchange of -COOK on the monomer chain with heavy metal ions, coordination of -OH and -CONH with heavy metal ions and interaction of ester bond, -COOH with heavy metal ions. The adsorption process was in accordance with the pseudo-second-order kinetic model and Freundlich model. The adsorption process belonged to multilayer chemisorption. This work shows that ETS-PAA was a promising material for the removal of heavy metal pollutants from aqueous solution.

In this work, a porous tobacco straw-based polyacrylic acid hydrogel STS-PAA with high adsorption performance was prepared by polymerizing pretreated waste tobacco straw (TS) with acrylic acid/potassium acrylate by UV radiation initiation. The adsorption performance of metal ions was investigated. The effects of different temperatures (25°C, 35°C, and 45°C), adsorption times (1–420 min), pH values (2.0–6.0) and initial concentrations (0.25–4.0 mmol L−1) of metal ions on the adsorption amount of heavy metal ions were investigated. The results showed that the hydrogel had a high removal rate of Pb2+, Cd2+ and Hg2+ in aqueous solution. The adsorption of Pb2+ was particularly effective. When C0 = 4.0 mmol L−1, pH = 6, the equilibrium adsorption amount of Pb2+, Cd2+ and Hg2+ reached 1.49 mmol g−1, 1.02 mmol L−1 and 0.94 mmol g−1, respectively. The chemical structure and morphology of the hydrogels were characterized by FT-IR, EDS, SEM and XPS. The Langmuir model fits well with the adsorption system. The kinetic data suggest the adsorption of Pb2+, Cd2+ and Hg2+ follow the pseudo-first-order model. This indicates that STS-PAA adsorption of three heavy metal ions is monolayer physical adsorption. Thermodynamic analysis shows that the adsorption of Pb2+, Cd2+ and Hg2+ by STS-PAA is an endothermic (ΔH>0) entropy increase (ΔS>0) non-spontaneous reaction.

Mitochondria-targetable fluorescent chemosensors, Rhodamine-B and rhodamine 6G bearing syringaldehyde based receptors were designed and synthesized for efficient chemosensing of Zinc(II) ions. The probes showed the very selective naked eye color change to pink from colorless upon addition of Zinc(II) ions, further these probes showing turn-on fluorescence enhancement with Zn(II) ions by opening of rhodamine spirolactam. The probes are very sensitive towards Zn(II) ions among other ions. These probes RBS and R6S will be applicable to detect zinc ions upto the low level concentration 0.18 and 0.19 nano molar respectively. The affinity of these sensors RBS and R6S for Zinc (II) ions was found to be in the range of 1.12 x 10(4) M-1 and 7.28 x 10(4) M-1 respectively. 1H-nmr titrations of the probes with Zn(II) ions clearly indicating the spiroring opening of the spirolactam. DFT calculations supporting that the perceived photophysical changes of the probes on appendage of the zinc ions. Probes RBS and R6S are useable for selective staining mitochondria. Both of the probes are applicable to reveal labile Zn(II) in live Hela and MCF-7 cells via fluorescence imaging. RBS and R6S are also finding application on quantification of Zinc(II) ions inside mitochondria via fluorescence imaging.

Herein, the NIR triggered difunctional phototherapy agent based on a single, versatile ionized copper phthalocyanine, Cu-1, was strategically synthesized to simultaneously integrate photothermal and photodynamic effects.

针对现有图像采集设备获取的烟草薄片难以从图像背景中分离,目标图像有效像元信息丢失,提出一种基于领域标签融合的烟草薄片视觉提取方法.首先对原始采集图像进行空域高斯算子平滑处理,消除噪声点并保留图像细节信息.为更便于将前景与背景进行分离,进行L ab坐标空间变换.在上述处理基础上,进行聚类分割操作,分析各聚类标签及其临近区域相关关系,合并相邻相似标签提取完整烟草薄片信息.通过与传统的Ostu、最大信息熵等方法对比显示,该文采用方法具备较好的图像细节保留能力.

为考查酯类单体香料在加热卷烟气溶胶中的转移行为,利用GC-MS分析方法,测定了质量分数分别为0.01％和0.05％的添加水平下,6种酯类单体香料在加热卷烟气溶胶中的逐口释放量和在烟丝中的含量,分析了6种酯类单体香料在加热卷烟气溶胶中的转移率.结果表明:随着抽吸口数的增加,6种酯类单体香料在加热卷烟气溶胶中逐口释放量呈现先增加后减小的趋势,且转移峰值出现在第3～5口.在2种添加水平下,6种酯类单体香料在加热卷烟气溶胶中的逐口转移率为0.70％～8.06％,总转移率为10.50％～52.98％,前N口的总转移率与抽吸口序之间具有良好的线性正相关关系.

采用固相反应法制备温度稳定型BaTiO3-Nb2 O5-Co3 O4-La2 O3体系陶瓷材料,研究了助烧剂ZnO-B2 O3和BaTiO3基料晶粒尺寸对瓷料性能的影响.实验结果表明,适当用量的助烧剂引入,瓷料可以在900～1000℃范围内实现烧结,并保持X7R、X8R特性所需的介电性能.同时,制得的陶瓷材料晶粒为亚微米级,粒度分布范围窄,有利于减薄MLCC的介质厚度.BaTiO3基料的晶粒尺寸对陶瓷材料的介电性能有明显影响.当基料为900℃预烧的小晶粒BaTiO3时,在助烧剂掺杂量为最优值时,样品烧结后致密度高,损耗小,介电常数处于峰值.此后,随着助烧剂含量增加,介电常数逐渐下降;当基料是1000℃预烧的大晶粒BaTiO3时,随着助烧剂的掺杂量增加,样品烧结后的直径收缩、介电常熟、介电损耗也一直增加,并不在某点出现峰值.

[目的]研究烟叶不同区位半挥发性有机酸含量的差异,探索烟叶分切加工的化学物质基础,为烤烟原料的分切加工提供参考.[方法]以河南浓香型初烤烟叶为材料,从叶尖到叶基分切成10段(HN-1～HN-10),利用单因素方差分析、相关回归分析研究叶片不同区位半挥发性有机酸含量的变化,并基于半挥发性有机酸含量对不同区位进行聚类分析.[结果]烟叶不同区位半挥发性有机酸总量平均为12.43 mg/g,变幅为9.01～20.56 mg/g,各组分平均含量表现为:亚麻酸(5.59 mg/g)＞棕榈酸(2.83 mg/g)＞亚油酸(2.04mg/g)＞油酸(1.02mg/g)＞硬脂酸(0.89mg/g)＞十五酸(0.06mg/g).棕榈酸、亚油酸以及半挥发性有机酸总量在不同区位间的差异达到极显著水平.棕榈酸、亚油酸、亚麻酸以及半挥发性有机酸总量与区位(HN-1→HN-10)呈极显著负相关关系.从叶尖到叶基,亚油酸和亚麻酸呈逐渐降低的抛物线型变化,棕榈酸和半挥发性有机酸总量呈先增加后降低的抛物线型变化.基于半挥发性有机酸含量的不同区位聚类结果表明,不同区位聚为3段,第1段叶尖部(HN-1～HN-5)半挥发性有机酸含量为12.83mg/g,第2段叶中部(HN-6～HN-8)半挥发性有机酸含量为12.30mg/g,第3段叶基部(HN-9～HN-10)半挥发性有机酸含量为11.61mg/g.[结论]不同区位的半挥发性有机酸含量存在较大差异,且从叶尖到叶基呈规律性变化;烟叶HN-2～HN-5区位工业可用性相对较高.

以间苯二酚和乙酰乙酸乙酯为原料,合成了4-甲基-7-羟基香豆素（Ⅰ）,再经酯化得到4-甲基-7-乙酰氧基香豆素（Ⅱ）;采用2,2’-偶氮二异丁基脒二盐酸盐（AAPH）、HO·、Cu 2+ /还原型谷胱甘肽（GSH）自由基氧化DNA的反应体系对化合物的抗氧化活性进行了测试;通过淬灭2,2’-偶氮-双-（3-乙基苯并噻唑啉-6-磺酸）二铵盐自由基（ABTS+·）、二苯苦味酰肼自由基（DPPH·）、2,6-二叔丁基-（3,5-二叔丁基-4-氧代-2,5-环己二烯）-对-甲苯氧（galvinoxyl）自由基体系探索了化合物还原自由基的能力,进而探究了羟基对香豆素抗氧化性能的影响。结果表明:在抑制AAPH引发的DNA氧化反应体系中,每个化合物Ⅰ能够捕获1.61个自由基,而化合物Ⅱ不能捕获自由基;在抑制HO·和GS·引发的DNA氧化反应体系中,化合物Ⅰ相对空白硫代巴比妥酸活性物质（TBARS）吸光度分别为76.5%和64.1%,化合物Ⅱ相对空白TBARS吸光度分别为87.1%和81.7%;化合物Ⅰ能够捕获ABTS+·、DPPH·、galvinoxyl自由基,而化合物Ⅱ仅能够捕获ABTS+·和DPPH·两种自由基;化合物Ⅰ抑制自由基引发的DNA氧化反应活性和捕获自由基能力均优于化合物Ⅱ,是一种潜在的抗氧化剂。