麦秆超临界醇解液化产物的萃取分离及分析

[目的]探寻生物油中高附加值化合物,提高生物油的利用价值和综合竞争力。[方法]将麦秆在超临界甲醇中醇解液化所得生物油通过减压蒸馏得到轻质组分和重质组分,重质组分(重油)用不同极性及溶解性的溶剂萃取分离。[结果]生物油重质组分(重油)5个馏分中,正己烷馏分(Fz)主要含酚类化合物;苯馏分(FB)主要含酚和环戊烯醇酮;乙醚馏分(FYM)主要含吡喃糖苷和呋喃糖苷;而乙酸乙酯馏分(FY)和丙酮馏分(FBT)经GC/MS检测不到物质。[结论]麦秆超临界醇解液化得到的生物质重质油,含有大量的高附加值化合物。     

不同枫树叶片中酚酸类物质高效毛细管电泳检测方法的研究

采用正交试验的方法,研究了缓冲液pH、分离电压、运行温度等电泳参数对枫树叶片中酚酸类物质提取检测的影响,建立了4种槭树科枫叶中绿原酸、原儿茶酸、没食子酸和咖啡酸4种酚酸类化合物检测分离的高效毛细管电泳(HPCE)方法。得出了最佳分离条件为:紫外检测波长214 nm,缓冲液为20 mmol·L-1的磷酸-硼砂,pH 8.0,电压为22 kV,温度25℃。在此条件下,4种酚酸类化合物在9 min内完全分离,且各组分浓度与峰面积呈良好的线性关系,r2为0.974 8～0.996 5。迁移时间的RSD≤0.84%,峰面积的RSD≤5.29%,加标回收率为80.38%～96.88%。4种枫树叶片中均含有绿原酸,其中蚜虫宿主三角枫中绿原酸含量最低。     

酸樱桃中原花青素的分离与纯化

以NKA树脂为吸附剂,对酸樱桃(Prunus cerasus)中原花青素的分离纯化进行了研究。通过单因素试验分析确定了原花青素分离纯化的最佳工艺条件为,上样浓度7 mg/L,上样流速1.0 mL/min,用体积分数为95%的乙醇溶液作为洗脱剂,以1.0 mL/min流速进行洗脱。经树脂纯化后的原花青素通过HPLC/ESI-MS分析确定其主要含两种组分,分别为原花青素-3-葡萄糖苷和(-)-表儿茶素没食子酸酯。     

基因枪介导的玉米NPR1基因的遗传转化(英文)

[目的]探索出玉米基因枪转化的条件。[方法]以玉米自交系7239的幼胚胚性愈伤组织为受体材料,研究了轰击距离、气体压力、真空度和轰击次数对转化率的影响。[结果]转化时以金粉用量100μg/枪、发射点与靶细胞距离9cm、气体压力1350psi、真空度25In·Hg、轰击次数2次的组合最佳。经潮霉素(Hygromycin)筛选,获得了再生植株,PCR分析及Southern杂交结果表明NPR1基因已整合到玉米基因组中,平均转化率为1.76%。[结论]该研究为玉米优良抗病品种的培育奠定了基础。     

酪蛋白糖巨肽的生理功能特性及其应用

阐述了酪蛋白糖巨肽(CGMP)的化学结构、制备、分离纯化、检测方法和生物学性质,及研究现状与应用前景。     

Surveillance of verocytotoxigenic Escherichia coli in Irish bovine dairy herds

Verocytotoxigenic Escherichia coli (VTEC) are highly significant zoonotic threats to public health, and have been the causative agent implicated in numerous high-profile outbreaks affecting large numbers of people. Serovar O157 is most frequently linked with human illness; however, other serovars, such as O26, O103, O111 and O145, have also been implicated. This study aimed to characterize the prevalence and virulence determinants of these five serovars in Irish dairy farm herds, and their milk. Using real-time PCR (RTi-PCR), bovine rectal faecal swabs and raw milk samples, along with milk filters, were screened for the presence of vt genes. Positive samples were then screened for the five serovars using sero-specific PCR. Serovar-positive samples were subjected to immunomagnetic separation, to isolate viable VTEC strains. These isolates were subsequently screened for four virulence factors: vt1, vt2, eaeA and hlyA. Three hundred and eighty six of the 600 rectal faecal swabs, 85 of the 117 milk-filters and 43 of the 120 bulk-tank milk samples, were positive for vt genes. From these 514 total vt-positive samples, 58 O26, 162 O103, 1 O111, 324 O145 and 26 O157 positives were detected by sero-specific RTi-PCR. Immunomagnetic separation yielded 12 O26, 26 O103, 0 O111, 19 O145 and 10 O157 isolates. Ten of these isolates contained at least one of the four virulence determinants screened for (i.e. vt1, vt2, eaeA and hlyA). Of these 10 isolates, pulsed-field gel electrophoresis showed that two of the O26 isolates from different farms were indistinguishable. Two O157 isolates were also indistinguishable. This study found serovars O103 and O145 to be the most prevalent in samples tested. Apart from the occurrence of VTEC in dairy herds, this study shows a high occurrence of vt genes in the environment, creating the possibility of horizontal gene transfer and emergence of new VTEC strains.     

蚯蚓纤溶酶的分离纯化及临床作用研究进展

蚯蚓纤溶酶是从蚯蚓中分离的一种丝氨酸蛋白水解酶,有抗凝溶血栓、抗癌抗肿瘤、抗炎、神经修复等作用,在临床上是预防和治疗血栓疾病的有效药物。本文对蚯蚓纤溶酶的分离纯化与药理作用加以概述,为临床蚯蚓溶栓药物的研究提供依据。     

Preparation and Antioxidant Activity of Chitosan Dimers with Different Sequences

As a popular marine saccharide, chitooligosaccharides (COS) has been proven to have good antioxidant activity. Its antioxidant effect is closely related to its degree of polymerization, degree of acetylation and sequence. However, the specific structure–activity relationship remains unclear. In this study, three chitosan dimers with different sequences were obtained by the separation and enzymatic method, and the antioxidant activity of all four chitosan dimers were studied. The effect of COS sequence on its antioxidant activity was revealed for the first time. The amino group at the reducing end plays a vital role in scavenging superoxide radicals and in the reducing power of the chitosan dimer. At the same time, we found that the fully deacetylated chitosan dimer DD showed the strongest DPPH scavenging activity. When the amino groups of the chitosan dimer were acetylated, it showed better activity in scavenging hydroxyl radicals. Research on COS sequences opens up a new path for the study of COS, and is more conducive to the investigation of its mechanism.     

云南半细毛羊毛囊干细胞生物学特性分析

为研究云南半细毛羊毛囊干细胞（hair follicle stem cells,HFSCs）的生物学特性,采用组织块法分离培养云南半细毛羊HFSCs,并对其细胞形态、生长动力学、冷冻与复苏、染色体核型等生物学特性进行分析.结果表明：HFSCs为贴壁生长,体积小,核质比高,呈典型的铺路石状,在显微镜下折光性强、胞体透亮.细胞生长曲线为“S”型.冻存前细胞活率98.2％,复苏后细胞活率96.4％.染色体中正常二倍体数目2n=54,其中,长染色体中有3对为中着丝点染色体,23对为端着丝点染色体,X染色体为最大的近端着丝点染色体,Y染色体为最小的亚中着丝点染色体.所得细胞呈现典型的HFSCs特征,细胞活性好,细胞系为稳定的二倍体细胞系.     

机采棉中残地膜静电吸附法分级去除

提出一种基于静电吸附方法分级去除机采棉中残地膜的方法,以新疆阿拉尔地区种植的新陆早26号机采棉为研究对象,根据机采棉中残地膜曲直形态与荷电极化程度存在一定的相关性,利用图像处理提取机采棉中各种残地膜杂质特征并进行聚类算法分级,将残地膜分成Ⅰ、Ⅱ、Ⅲ等级。搭建静电吸附分离平台,对掺有不同等级残地膜的机采棉进行不同荷电时间、飞入速度、极板电压下的试验,以除杂率为测定指标,找出对应级别残地膜的最佳参数组合,以期达到残地膜杂质与机采棉的分离最大化。试验表明,对除杂率影响显著的因素由大到小为:飞入速度、荷电时间、极板电压。掺有Ⅰ级残地膜的机采棉除杂最佳荷电时间为24 s,飞入速度为4. 7 m/s,极板电压为39 k V,分离率为96. 2%;Ⅱ级最佳荷电时间为29. 8 s,飞入速度为5. 8 m/s,极板电压为37. 6 k V,分离率为98. 1%;Ⅲ级最佳荷电时间为30. 1 s,飞入速度为3. 5 m/s,极板电压为46. 2 k V,分离率为97. 2%。研究结果表明:基于静电吸附分级去除残地膜的方法可行,能够满足实际生产需要。