农田水样中微囊藻毒素-LR拉曼检测方法的研究

本研究建立了基于表面增强拉曼散射技术(Surface-enhanced Raman scattering,SERS)的农田水样中微囊藻毒素-LR(Microcystin-LR,MC-LR)的检测方法。采用柠檬酸钠还原法制备金种(Au nanoparticles,Au NPs),通过媒介增长法制备了刺状金纳米颗粒(Spiny gold nanoparticles,SGNPs),使用紫外-可见吸收光谱(Ultraviolet visible,UV-vis)、透射电镜(Transmission electron microscopy,TEM)和探针分子(对巯基苯甲酸,4-mercaptobenzoic acid,4-MBA)对SGNPs进行了表征及鉴定。研究以三角状金纳米颗粒作为基底,选择MC-LR在1 007 cm~(-1)和1 309 cm~(-1)处的特征峰作为定量峰,激光器激发波长为785 nm,积分时间20 s,建立检测方法。本研究建立的检测方法在1.0～100 000μg·L~(-1)的浓度范围内具有良好的线性关系,检测限(LOD)和回收率分别为1.0μg·L~(-1)和80%～102%,使用本方法对镇江市内运粮河及古运河的灌溉水样进行检测,MC-LR的检出率为40%,含量最高达1.81μg·L~(-1),检测结果与LC-MS/MS比对,相关系数为0.84。本研究建立的方法快速准确,前处理简单,能满足农田水样中MC-LR的现场快速检测的要求。     

磷钨酸银纳米粒子光散射法测定多巴胺

在醋酸-醋酸钠缓冲溶液pH=5.0的条件下,多酸纳米粒子Ag3PW12O40可以与多巴胺相互作用.以光散射信号为表征手段,可以得出在多巴胺浓度为3.0×10 8～1.2×10-5 mol/L的范围内光散射信号随着多巴胺浓度的增加呈线性增强,检出限(3σ)为1.4×10-8 mol/L.这种多巴胺的光散射测定方法被成功应用于盐酸多巴胺注射液的测定.     

以壳聚糖分子为稳定剂的银纳米颗粒的水热法合成研究

[目的]研究一种以壳聚糖作为还原剂及稳定剂、通过一步水热合成法制备纳米银颗粒的新方法.[方法]用水热法合成以壳聚糖为稳定剂的银纳米颗粒,利用水热法产生的较高温度和较高压力的条件来制备稳定的银纳米颗粒,并考察颗粒的稳定性.[结果]制备的纳米银溶胶具有较好的稳定性,可在室温下长期保存.通过改变反应初始pH值,可调控其大小和形貌.在酸性条件下,测得纳米银颗粒带正电,这非常有利于将其应用在抗菌研究中.[结论]该方法具有环保、简便、产量高等特点,有望应用到以壳聚糖分子为稳定剂的其他金属纳米材料的合成研究中.     

环糊精修饰的氟苯尼考PLGA纳米粒的制备及其体外释放评价

制备了环糊精修饰的氟苯尼考PLGA纳米粒(FF-2-HP-β-CD-PLGA NPs),筛选出其最优处方并进行评价。采用乳化溶剂挥发法制备FF-2-HP-β-CD-PLGA NPs,通过单因素考察,以乳化剂浓度、药脂比、药物浓度和2-HP-β-CD浓度为考察因素,包封率为考察指标,正交试验筛选最优处方,并对其进行体外释放试验。结果表明,制备FF-2-HP-β-CD-PLGA NPs的最佳工艺为PVA浓度2%,药物与PLGA用量比1∶15,药物浓度2.0 mg·mL^-1,2-HP-β-CD浓度为1.5%。测得平均包封率为(82.02±0.82)%,处方的重现性较好且工艺稳定可行。在体外药物释放试验中,FF-2-HP-β-CD-PLGA NPs释放速率明显较FF慢且平稳(P<0.05),后期可持续平稳释放至72 h,累积释放率为(82.08±1.71)%。结论表明,制备的FF-2-HP-β-CD-PLGA NPs具有较高的包封率,体外释药具有缓释行为。     

Effect of Temperature on the Induction of Bud Dormancy in Ecotypes of Betula pubescens and Betula pendula

The purpose of this study was to determine the influence of temperature applied during short day-induced budset on induction of dormancy in six ecotypes of Betula pubescens Ehrh. and two ecotypes of Betula pendula Roth. Seedlings were grown in a phytotron at constant temperatures of 9–21°C under a 12 h photoperiod (SD) during dormancy induction. Induction of dormancy was monitored by following bud flushing and shoot growth after transfer to long photoperiod conditions (24 h) at 18°C. Chilling requirement was studied in seedlings exposed to 10 weeks of SD. In both species induction of bud dormancy developed most rapidly at 15–18°C, and both 9–12°C and 21°C delayed the induction of dormancy. Raising the temperature (from 9 to 21°C) applied during induction of dormancy significantly increased the chilling requirement. These responses were noted for all ecotypes tested, but in general the northern ecotypes entered dormancy more quickly than the southern ones. No such trend was recorded for chilling requirement, although a B. pubescens ecotype from Iceland and another from the coast of northern Norway appeared to require a longer chilling treatment than the other ecotypes. In conclusion, induction and depth of bud dormancy in birch are significantly affected by temperature conditions and these effects may explain some of the annual variation in dormancy and chilling requirement observed in nature.     

Epidemiological investigations of trichostrongylid infections in young cattle in different parts of Norway

The occurrence of trichostrongylid nematodes in young cattle was studied in relation to climate and geographical location, by examination of herbage and faecal samples from 8 farms in 7 different regions in Norway, during 3 consecutive summers. Species of Ostertagia and Cooperia were dominant. Infective larvae, especially those of Ostertagia, were able to survive the winter in the pasture to a great extent in all the areas studied. The spring larval counts varied considerably from place to place, and from year to year, but were often at fairly high levels. This confirms previous findings that the larvae which overwinter on the pasture may be a major cause of losses. Overt clinical disease, however, was only seen at 1 farm during this investigation.The large number of larvae often seen in the autumn seems to be of less significance as a cause of disease, due to the late appearance, but is of major importance as a source of the larvae which survive the winter in the pasture and infect young cattle the following spring.There was no obvious correlation between pasture larval counts and the climate, except that there seemed to be higher counts in the warmer parts of the country, where the grazing season is also longer. The only place were both faecal egg counts and larval counts in the herbage were consistently low, was in the very far north.     

SILVER IMPREGNATION IN SITU

In evaluating radiographs of the limb joints and head, students encounter difficulty where superimposition occurs. By replacing calcium with silver salts in the bone, enhanced radiopacity can be produced. In this study, silver impregnation was used to increase the radiopacity of individual carpal and tarsal bones, selected bones of the skull and the sinuses, and guttural pouch of the horse. This provides an interpretation aid for teaching radiographic anatomy of these regions.     

CdS纳米颗粒的合成、表面修饰及光学特性研究

用一步室温固相化学反应法合成CdS纳米颗粒，并以氨催化水解法对其表面进行了修饰，得到了具有CdS／SiO2核／壳结构的纳米微球，以透射电子显微镜和X-射线衍射仪对其结构和物相进行了表征，并研究了其光致发射光谱的性质，研究结果表明：固相反应完全，产物为纯相CdS，室温固相化学反应法避免了传统湿法存在的团聚现象的缺点，具有产率高、无污染、节能等优点；而且CdS纳米颗粒表面经SiO2修饰后，其带边发射显增强，缺陷发射减弱，且在一定范围内随着SiO2包覆层厚度的增加，荧光强度增加。     

银染mRNA差异显示方法在致突变实验中的初步应用

为建立在药物致突变研究中应用银染 m RNA差异显示的方法 ,试验提取未经过 /经过环磷酰胺处理的 Balb/c小鼠肝组织的总 RNA ,并以此为模板 ,采用 d T1 2 CG、d T1 2 AG、d T1 2 GG为锚定引物 ,通过反转录、差异显示 PCR反应 ,以 6 %变性聚丙烯酰胺凝胶电泳分离差异条带 ,回收后将其再扩增。结果表明 ,RNA投入量为 3μg、镁离子浓度为 1.5～ 2 .0 mm ol/L、退火温度为 4 0℃时 ,扩增的片段条带清晰、背景低 ,差异条带明显 ,再扩增条带单一。银染 m RNA差异显示技术可成功应用于药物致突变的研究。     

基于纳米材料的免疫层析试纸在兽药残留检测中的应用

兽药残留是食品安全的重要影响因素,开发兽药残留检测方法是保证食品安全的重要手段。免疫层析试纸是一种操作简单、生产成本低且具有良好灵敏度的检测方法,适用于现场检测、大规模食品筛选,在兽药残留检测中具有巨大的应用价值。纳米材料可提供特殊的检测信号,是影响免疫层析试纸检测灵敏度和定量分析的关键因素。文章主要对胶体金、磁性纳米材料、量子点以及时间分辨荧光微球这几种纳米标记材料进行介绍,指出各自的优缺点及应用情况,并对该技术在兽药残留检测中的应用趋势进行展望。