类蚕丝丝素结晶区蛋白表达载体的构建与表达

为探讨蚕丝结构与性能的关系,设计了几种类似蚕丝丝素结晶区高度重复序列结构(GAGAGX)n的基因序列,并构建了大肠杆菌表达载体,在BL-21菌株中成功诱导表达了4种约由110个氨基酸组成的小分子蛋白。对表达产物进行W estern印迹分析和ELISA检测的结果显示,(GAGAGA)n、(GAGAGY)n、(GAGAGV)n3种蛋白都有小于14.4 kD的大小相同的条带,而(GAGAGS)n有一条稍大于20.1 kD的条带。以超声波破菌的缓冲液作空白对照,4种蛋白的ELISA的结果均比对照的BL-21(无质粒)高,显示为阳性。     

Nanostructured liquid crystalline particle assisted delivery of 2,4-dichlorophenoxyacetic acid to weeds,crops and model plants

Routine agricultural practices are heavily dependent on the use of surfactants, many of which are toxic to humans and detrimental to the environment. In proof of concept work we have previously shown the potential of nanostructured liquid crystalline particles (NLCP) to safely interact with plant leaf cuticular surfaces with minimal impact on epicuticular waxes. Here we demonstrate the use of NLCP to effectively deliver the auxin herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) to plant leaves in laboratory and field studies. In the laboratory, the physiological stress responses of lupin, Lupinus angustifolius (L.) (Fabaceae) towards NLCP spray applications were shown to be much reduced in comparison with application of two common surfactants. Phytotoxicity assays of 2,4-D loaded NLCP were used to validate the herbicidal effects on Arabidopsis thaliana (L.) Heynth. (Brassicaceae) and established a similarity with that of surfactant assisted 2,4-D delivery when tested at a concentration of 0.1%. Field trials were conducted to test the efficacy of NLCP-assisted delivery of 2,4-D in comparison with commercial surfactants for the control of the invasive weed wild radish, Raphanus raphanistrum (L.) (Brassicaceae), in wheat, Triticum aestivum (L.) (Poaceae) crop fields. Compared against Estercide 800, a commercially available 2,4-D formulation, NLCP assisted delivery of 2,4-D was effective at low concentrations of 0.03% and 0.06%. The crop yield remained similar for all the tested concentrations and formulations of 2,4-D loaded NLCP and Estercide 800. This is the first report to directly show that, as an alternative to conventional methods, NLCP can be used under both laboratory and field conditions to successfully delivery an agrochemical.     

Effects of Liquid Crystalline Epoxy Resin on the Properties of Bio-based Cardanol-furfural Resin北大核心CSCD

By using polarized optical microscopy, differential scanning calorimetry, scanning electron microscopy and impact strength measurements,the effects of liquid crystalline on the morphologies, thermal properties and mechanical properties of the composite resins were studied. It was found that the synthesized 4,4-diglycidyloxybiphenyl (BP) and sulfanilamide (SAA) were used to generate novel liquid crystalline (LC) epoxy resins notably. The results revealed that the curing of the cardanol-furfural resins was accelerated and the thermal properties were considerably improved by adding the LC epoxy resins.When the addition of BP-SAA was 50%, the glass transition temperature increased from 60.4 ℃ to 70.2 ℃, and the thermal decomposition temperature increased from 300.3 ℃ to 377.4 ℃, respectively. When the addition of BP-SAA was 30%, the impact strength of the modified resins was 15 kJ/m2 and about three-fold higher than that of the unmodified counterpart. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

细胞壁微纤丝角和结晶区对木材物理力学性能影响研究进展

木材是由不同种类的细胞组成的天然材料,其实体物质是组成其结构的各类型细胞的细胞壁。细胞壁的超微构造主要包括微纤丝和结晶区,微纤丝角能表征纤维素微纤丝的取向,纤维素大分子链排列的有序程度及排列形态决定其结晶程度和微晶形态等结晶区特征。基于前人的研究,系统概述了细胞壁微纤丝和结晶区对木材物理力学性能影响的研究进展,重点围绕微纤丝角和结晶度2个方面,分别归纳了二者对木材密度、尺寸稳定性、木材声学等物理性质以及弹性模量、强度等力学性质的影响作用,同时阐述了微纤丝角与木材硬度和刚度以及结晶度与冲击韧性等的相互关系,并概述了细胞壁微晶形态对木材润湿性和纤维强度影响方面的研究进展,最后对今后的研究方向进行了展望。     

虾蛄光感受器组织学特点研究

为进一步探讨甲壳类光感受器的结构和功能,采用石蜡切片技术对虾蛄复眼组织结构进行了研究.分析发现虾蛄复眼呈短棒状,由折光系统、感光系统和反光系统组成.折光系统包括角膜和晶锥.感光系统由6个远端小网膜细胞和7个近端小网膜细胞构成,彼此之间通过突起相连接.感杆束较短,为闭合型.反光系统由色素组成.近端小网膜细胞之间分布有一种合胞体细胞,可能也有感光功能.     

(111)晶面暴露的NiO纳米催化剂的制备及其CO催化氧化性能

采用溶剂热法,以Ni(NO_3)_3·6H_2O、均苯三甲酸以及N,N-二甲基甲酰胺(DMF)为原料快速合成金属有机骨架材料Ni_3(BTC)_2·12H_2O晶体。以Ni_3(BTC)_2·12H_2O为前体,通过焙烧得到具有(111)面的NiO颗粒用于CO催化氧化反应,并与由硝酸镍热解得到的NiO(R)催化剂进行对比。通过X射线衍射(XRD)、N_2物理吸附-脱附、透射电子显微镜(TEM)以及X射线光电子能谱(XPS)等方法对具有(111)面的NiO颗粒的组成、结构和形貌进行表征。CO催化氧化结果表明,具有(111)面的NiO颗粒的催化活性优于普通NiO催化剂的催化活性。     

缺氧和有毒微囊藻胁迫下三角帆蚌鳃和主要消化器官以及晶杆体的扫描电镜观察

为了阐明缺氧和有毒铜绿做囊藻对三角帆蚌鳃和主要消化器官的毒理效应和组织病理,实验利用扫描电镜研究了暴露于缺氧和有毒铜绿做囊藻下三角帆蚌的鳃、胃、肠以及晶杆体等器官组织病理学变化。结果显示,从第7天开始缺氧和有毒藻类复合胁迫组三角帆蚌的鳃丝及柱状细胞出现大量坏死和脱落,胃肠腔面纤毛脱落、上史细胞破裂坏死,晶杆体在第5天已经完全消失;第7天单独缺氧组和单独有毒藻类组的鳃和消化道出现少量的病变,单独缺氧组晶杆体在第7天完全消失,单独有毒藻类组晶杆体则一直存在。胁迫消失后,3个实验暴露组的晶杆体都未恢复正常对照组水平,因此缺氧和有毒铜绿做囊藻对三角帆蚌鳃和消化系统产生不可恢复性损伤,双重胁迫组影响最为严重,缺氧胁迫组相对有毒铜绿做囊藻胁迫组影响更为显著。本研究为三角帆蚌在缺氧和有毒藻类胁迫下的生理适应机制提供了组织病理学上的参考,并为其作为富营养化水体治理工具种的可行性提供了理论依据。     

一株降解结晶纤维素细菌的分离、筛选、鉴定及其产纤维素酶特性

从广西5个自然保护区内采集原始森林深层腐殖土壤等样品147份,采用平板活性筛选法分离得到3500多株能降解结晶纤维素的细菌,并从中筛选到一株能在pH5.0、28℃条件下可高效降解结晶纤维素的细菌菌株N9-1-1.N9-1-1产纤维素酶水解微晶纤维素和纸浆的最适pH、最适温度分别为:4.0、40 ℃和4.5、35 ℃,但对羧甲基纤维素无水解活性.该菌株所产纤维素酶比较符合纤维素同步糖化共发酵工艺生产乙醇的要求.以菌株N9-1-1的总DNA为模板,对其16S rRNA基因进行PCR扩增和序列分析,结果表明,菌株N9-1-1的16S rRNA基因序列和粘质沙雷氏菌(Serratia marcescens)的同源性最高,为99%.形态特征观察和生理生化检测结果表明,菌株N9-1-1具有粘质沙雷氏菌的鉴别性特征.因此,将N9-1-1鉴定为粘质沙雷氏菌(Serratia marcescens).     

三角帆蚌消化酶的分布特性和晶杆的形态结构

三角帆蚌(Hyriopsis cumineii)隶属瓣鳃纲、真瓣鳃目、蚌科,是我国的特有种[1],也是我国生产淡水珍珠的主要贝类[2],产出的珍珠以其品质高而享誉全球.     

Synthesis of liquid crystalline spiroxazine derivatives

Liquid crystalline spiroxazine derivatives have been synthesized. The spiroxazines obtained were characterized by¹H-NMR, IR spectroscopy, UV and GC-MS.