倍硫磷表面印迹聚合物的制备及表征

为了制备高吸附性和特异性的倍硫磷分子印迹聚合物,采用表面印迹技术,以硅胶为载体,倍硫磷为模板分子,合成的N,O-双异丁烯酰丝氨醇为功能单体,制备倍硫磷分子印迹聚合物;并通过傅里叶红外光谱、场发射扫描电镜和吸附试验对其性能进行研究。结果表明,在硅胶载体表面成功地接枝了倍硫磷印迹聚合物,印迹聚合物存在2类不同的结合位点,平衡离解常数(Kd)和最大表观结合量(Qmax)分别为K_(d1)=0.282μg·mL~(-1)、Q_(max1)=1.071μg·mg~(-1)、K_(d2)=0.669μg·m L~(-1)、Q_(max2)=0.483μg·mg~(-1),对倍硫磷的吸附在60~80 min内达到平衡。该印迹聚合物对倍硫磷具有选择性识别性能,可用于固相萃取介质,这为食品中倍硫磷的残留检测奠定了研究基础。     

柚皮苷分子印迹聚合物微球的制备及表征

[目的]制备柚皮苷分子印迹聚合物微球（MIPMs）,并测定其吸咐能力。[方法]采用单步溶胀聚合法制备柚皮苷分子印迹聚合物微球,通过紫外光谱和平衡结合方法对分子印迹聚合物的分子识别行为进行研究。[结果]MIPMs对模板分子具有较强的特异吸附能力,以柚皮素为竞争底物,其分离因子达1.85。[结论]MIPMs具有较高的选择性和良好的吸咐能力,可用于中草药成分柚皮苷的分离提纯。     

铅离子印迹膜滤除沼液中Pb(‖)的工艺优化研究

本文应用铅离子印迹膜和设计的滤除装置,对沼液Pb(‖)进行滤除实验。研究了渗析时间（t）、跨膜压差（ΔP）、搅拌速率（?）三因素对铅离子通量和去除率的影响,并应用L9(33)正交试验设计,对滤除工艺参数进行优化,并与吸附剂吸附法进行比较。结果表明,三因素对沼液中Pb(‖)去除率的影响顺序为：搅拌速率>跨膜压差>渗析时间。该装置的最佳滤除工艺参数为：搅拌速率=70 r/min、ΔP=0.20 MPa、t=50 min,此时沼液中Pb(‖)去除率达99%,处理后沼液中Pb(‖)为0.007 mg/L。耦合化学清洗 超声清洗污染后的铅离子印迹膜,铅离子通量基本恢复到新膜的通量（平均恢复率达98%）,提升了铅离子印迹膜再生利用水平。该滤除工艺克服了吸附剂吸附法的不足,为沼液安全肥用提供一种新工艺和新技术。     

母源性印记基因在牛早期胚胎中的表达

为研究母源性印记基因Magel2、Sgce、SNRPN在牛早期胚胎中的表达规律,初步判定其印记发生的阶段。利用Real-time PCR技术,检测了这3个基因在牛孤雌激活 (Parthenogenetic Activation,PA) 胚胎和体外受精(In vitro Fertilization,IVF)胚胎中的表达水平。结果表明：在牛IVF和PA 2种胚胎间,3个母源性印记基因的印记表达模式明显不同,Magel2在牛IVF胚胎各阶段都有表达,而在PA胚胎中没有检测到表达信号;Sgce在牛IVF胚胎各阶段都有表达,而只在PA胚胎的2~4细胞阶段检测到表达,在其他发育阶段均没有表达;SNRPN在牛IVF胚胎各阶段都有表达,而只在PA胚胎的2细胞和囊胚阶段检测到很微弱的表达。实验结果表明,母源性印记基因Magel2、Sgce、SNRPN的正常表达对牛早期胚胎发育具有重要作用。     

分子印迹技术在食品安全检测中的应用

介绍了分子印迹技术的相关知识,综述了分子印迹聚合物作为固相萃取材料用于食品安全检测的研究进展,并对该技术的应用前景进行了展望。     

父源性印记基因在牛早期胚胎中的表达

【目的】研究父源印记基因在牛早期胚胎中的表达模式。【方法】利用Real-time PCR技术,检测Gnas、Grb10和Xist这3个父源性印记基因在牛体外受精（In vitro Fertilization,IVF）和孤雌激活（Parthenogenetic Activation,PA）胚胎各发育阶段的表达情况。【结果】对于IVF和PA两种来源的牛胚胎,Gnas在胚胎各发育阶段的表达没有明显差异;Grb10在2细胞阶段的PA胚胎中的表达量明显高于在IVF胚胎的,但从4细胞阶段到囊胚阶段,Grb10在两种来源的牛胚胎中表达没有明显差异;从2细胞阶段到8细胞阶段,Xist在两种来源的牛胚胎中表达没有明显差异,但从16细胞期开始,Xist在PA胚胎中的表达明显高于IVF胚胎的表达量。【结论】对于牛IVF胚胎和PA胚胎,Gnas、Grb10和Xist从2细胞期到囊胚期都可以检测到表达,但表达模式不同。这3个父源性印记基因在牛胚胎发育过程中可能发挥着重要的作用。     

计算机模拟在分子印迹聚合物制备中的应用

基于分子印迹技术的痕量分离方法正成为分析测试领域的研究热点,其关键技术是获得高亲和性和高选择性的分子印迹聚合物.目前,计算机模拟技术在分子印迹物制备过程中发挥着越来越大的作用.本文就计算机模拟在分子印迹聚合物制备中的应用现状和发展前景进行分析阐述,以期为食品、环境中有害物质的分子印迹聚合物的制备以及分子印迹技术领域的研究提供参考.     

Optimal utilization of non-additive quantitative trait locus in animal breeding programs

Optimal selection on a single identified quantitative trait locus (QTL) with four modes of inheritance: normal autosomal, sex-limited, imprinting and X-linked, was evaluated in four breeding structures: single line selection (SLS), two-way crossing (2WC), three-way crossing (3WC) and reciprocal crossing (RC) by comparing extra benefit from mate selection over index selection to demonstrate effectiveness of mate selection in exploiting non-additive QTL. The results showed that the superiority varied at different QTL inheritance modes, initial favourable allele frequencies and breeding structures. The superiority tended to decrease with the increase of the favourable allele frequency except for over-dominant QTL and imprinted QTL in all breeding structures. Less superiority (below 9%) was observed for a recessive and a fully dominant QTL than for an over-dominant QTL (up to 27.11%). Normal autosomal and sex-linked QTL led to a similar trend of superiority from mate selection but the magnitude of the superiority with the latter was slightly higher than with the former for most combinations of the parameters. A high superiority (6.41-41.54%) was observed from mate selection over index selection for an imprinted QTL. A maternally imprinted QTL tended to lead to higher superiority from mate selection than a paternally imprinted QTL. X-linked QTL led to less superiority from mate selection than the other modes of QTL. A larger superiority from mate selection was observed for a recessive and a fully dominant QTL in structures 3WC and 2WC than structures RC and SLS. The superiority from autosomal QTL and X-linked QTL was lower in the structure RC than in other structures examined.     

Normal DNA methylation status in sperm from a somatic cell cloned bull and their fertilized embryos

Epigenetic reprogramming confers totipotency even during somatic cell nuclear transfer (SCNT), which has been used to clone various animal species. However, as even apparently healthy cloned animals sometimes have aberrant epigenetic status, the harmful effects of these defects could be passed onto their offspring. This is one of the biggest obstacles for the application of cloned animals for livestock production. Here, we investigated the DNA methylation status of four developmentally regulated genes (PEG3, XIST, OCT4, and NANOG) in sperms from a cloned and a non‐cloned bull, and blastocysts obtained by in vitro fertilization using those sperms and SCNT. We found no differences in the methylation status of the above genes between cloned and non‐cloned bull sperms. Moreover, the methylation status was also similar in blastocysts obtained with cloned and non‐cloned bull sperms. In contrast, the methylation status was compromised in the SCNT blastocysts. These results indicate that sperm from cloned bulls would be adequately reprogrammed during spermatogenesis and, thus, could be used to produce epigenetically normal embryos. This study highlights the normality of cloned bull offspring and supports the application of cloned cattle for calf production.     

分子印迹膜修饰丝网印刷电极快速测定饲料中的沙丁胺醇

以裸丝网印刷电极(SPE)为载体原位合成分子印迹膜(MIM),制得分子印迹膜修饰丝网印刷电极(MIM-SPE),从而建立MIM-SPE检测沙丁胺醇(SAL)的方法。首先通过SPE获得标准液中SAL的电化学行为图像,并计算得到标准曲线:I=2.9818+0.14302c,R=0.998,检测限为0.9mg/L,检测的线性范围为1.0~6.0mg/L;再用修饰电极测定SAL,得到标准方程:I=8.9433+0.79294c,R=0.996,检测的线性范围为0.50~8.0mg/L,检测限为0.2mg/L。该方法平均回收率可达86.7%,准确率为100%,存在相似干扰物的情况下,检出量为94.8%以上,结果比较理想。另外,此方法检测单个样品用时仅为150s,因此MIM-SPE可以方便快速检测SAL,检测成本较低,适用于现场的大批样品快速筛选工作。