A rapid,simple, and sensitive immunoagglutination assay with silica nanoparticles for serotype identification of Pseudomonas aeruginosa

An agglutination test based on colored silica nanoparticles (colored SiNps) was established to detect serotypes of Pseudomonas aeruginosa. Monodisperse colored SiNps were used as agglutination test carriers. The colored SiNps were prepared through reverse microemulsion with reactive dyes, sensitized with 11 kinds of mono-specific antibodies against P. aeruginosa, and denoted as IgG-colored SiNps. Eleven kinds of IgG-colored SiNps were individually mixed with P. aeruginosa on a glass slide. Different serotypes of P. aeruginosa could be identified by agglutination test with evident agglutination. The P. aeruginosa could be detected in a range from 3.6 × 10⁵ to 3.6 × 10¹² cfu mL^?1. This new agglutination test was confirmed to be a specific, sensitive, fast, easy-to-perform, and cost-efficient tool for the routine diagnosis of P. aeruginosa.     

电感耦合等离子发射光谱法测定水质中的金元素

应用电感耦合等离子体发射光谱法测定了废水中的金元素,探讨了金测定的谱线选择、离子干扰等问题,实验结果表明:在最佳仪器条件和测定条件下,该方法的检出限为0.008 mg/L,方法精密度的方法标准偏差(RSD)在4.28%~1.44%之间,回收率为96%~104%。该方法操作简便,快捷。     

保持金边虎尾兰金边不消失的繁殖方法

金边虎尾兰的金边属于嵌合体彩斑，叶插繁殖易使其金边消失。根据相关文献和实践经验，介绍了保持金边虎尾兰金边不消失的4种繁殖方法，其中根状茎扦插是一种新的繁殖方法。     

美洲大蠊提取物CⅡ-3纳米粒对免疫力低下小鼠的免疫调节作用

研究美洲大蠊(俗称蟑螂)提取物CⅡ-3纳米粒对免疫力低下小鼠免疫功能的改善作用。制备美洲大蠊提取物CⅡ-3纳米粒,并建立免疫功能低下小鼠模型,将小鼠随机分为正常对照组和模型组(灌胃生理盐水,0.2mL/10g),辅料组(灌胃空白纳米粒,40mg/kg,0.2mL/10g),阳性对照组(灌胃左旋咪唑,40mg/kg,0.2mL/10g),CⅡ-3组(灌胃美洲大蠊提取物CⅡ-3,40mg/kg,0.2mL/10g),CⅡ-3纳米粒5个剂量组(灌胃美洲大蠊提取物CⅡ-3纳米粒10、20、40、80、160mg/kg,0.2mL/10g),各组连续给药15d后,检测小鼠外周血白细胞、红细胞、血小板;脏器指数;巨噬细胞吞噬功能;血清中免疫球蛋白IgG、IgM的含量。研究结果显示,CⅡ-3纳米粒各剂量组均可以显著提高免疫低下小鼠的白细胞数量(P<0.05);能显著提高免疫力低下小鼠的肝脏、脾脏和胸腺指数(P<0.01);可显著提高其巨噬细胞吞噬能力(P<0.05)和免疫力低下小鼠血清中IgG、IgM的含量(P<0.01),说明CⅡ-3纳米粒有改善免疫力低下小鼠免疫功能的作用。     

The effect of copper nanoparticles and copper (II) salt on redox reactions and epigenetic changes in a rat model

The aim of the study was to evaluate the effects of a diet containing different levels of Cu in two different chemical forms (carbonate and nanoparticles) on redox reactions and epigenetic changes in a rat model. For 4 weeks, five experimental groups (eight rats in each) were fed diets with two dosages of added Cu (standard—6.5 mg/kg or half of the standard dosage—3.25 mg/kg, and as a negative control no additional Cu in the mineral mixture) in two forms (standard—CuCO₃ and copper nanoparticles). Addition of Cu nanoparticles resulted in higher Cp (ceruloplasmin) activity and LOOH (lipid peroxides) and MDA (malondialdehyde) content, as well as decrease the CAT (catalase) activity and level of PC (protein carbonyl), 3‐NT (3‐nitrotyrosine), 8‐OHdG (8‐hydroxydeoxyguanosine), GSH + GSSG (total glutathione) and DNA methylation. Reducing the dose of copper resulted in a decrease in the level of LOOH and GSH + GSSG as well as CAT activity, but increased the level of PC and methylated DNA. Based on these evidence, we concluded that addition of copper nanoparticles in the diet reduces protein oxidation and nitration as well as DNA oxidation and methylation. Lowering the level of Cu in the diet increases the oxidation of proteins and DNA methylation.     

链霉素胶体金快速检测试纸条的研制

本研究建立了一种基于免疫胶体金技术的链霉素快速检测方法。该方法检测灵敏度10ng·ml-(101ppb),蜂蜜样本检出限是40ng·ml-(40ppb),单个样本检测时间为5～10min。所研制试纸条产品检测变异系数小,批1间、批内检测结果重复性良好,可以应用于蜂蜜样本中链霉素的快速检测和现场筛查,具有较高的市场应用前景。     

Using Chlorella vulgaris and iron oxide nanoparticles in a designed bioreactor for aquaculture effluents purification

Aquaculture operations produce high volumes of wastewater containing suspended solids and nutrients such as phosphorus and nitrogen. Treatment of water effluent from fish production ponds is essential for sustain environment. So, the present study was conducted to evaluate simultaneous use of microalgae and iron oxide nanoparticles (NPs) to purify aquaculture effluents within a designed bioreactor. For designing experiment, effluent samples were collected from fish farms in Sari, Iran. Iron oxide nanoparticles were prepared from Iranian Nano Pishgaman Company. Chlorella vulgaris was captured from the environment, then purified and cultured in the laboratory. After that, NP and microalgae were transferred to the reactor space. TSS (total suspended solid), TDS (total dissolved solid), BOD (biological oxygen demand), pH (power of hydrogen), EC (electrical conductivity), NO₃ (nitrates), NO₂ (nitrite), NH₄, (ammonium) and PO₄ (phosphates) were measured during the experiment period which NH₄ (93.67 %), NO₃ (92.23 %), NO₂ (89.3 %), and PO₄ (89.25 %) showed the highest reduction percentage, respectively. Also, significant differences among the calculated parameters (except for pH) were observed during the experiment (P < 0.05). Based on the obtained results, it is concluded that the simultaneous use of microalgae and nanoparticles is desirable for purification of aquaculture wastewaters.     

原位合成纳米金/石墨烯修饰玻碳电极检测水和土壤中痕量铅

为提高痕量铅的检测精度,提出了一种简单、可控的一步还原法在裸玻碳电极表面原位合成纳米金/石墨烯材料的方法,并通过循环伏安法(cyclic voltammetry,CV)对修饰电极进行电化学表征。利用修饰后的电极对醋酸-醋酸钠缓冲溶液中的铅离子(Pb(Ⅱ))标准样品进行检测,并对检测条件进行了优化。优化条件下的试验结果表明,在pH值为4.5的醋酸-醋酸钠缓冲溶液中,Pb(Ⅱ)的溶出峰为-0.08 V,在1～90μg/L范围内Pb(Ⅱ)的溶出峰电流与Pb(Ⅱ)浓度之间呈现良好的线性关系(R~2=0.985),最小检测下限为0.27μg/L。在优化后的条件下采用该电极测定了实际水样与土壤中的Pb(Ⅱ)含量,加标回收率区间分别为93.75%～109.20%和93.82%～109.9%,相对标准偏差均小于7%,可以用于对实际水样与土壤样本的检测。     

基于核酸适配体的阳离子聚合物聚集纳米金比色法检测水中睾酮

利用核酸适配体对睾酮特异性识别功能以及阳离子聚合物PDDA(poly dimethyl diallyl ammonium chloride,PDDA)聚集纳米金特性,建立了一种高灵敏度、高特异性测定睾酮的定量方法。在最优实验条件[10 mmol/L PB缓冲溶液(pH 7.4),孵育温度25℃,6nmol/L PDDA,6nmol/L睾酮核酸适配体]下,体系吸光度比值A_(650)/A_(520)与睾酮浓度C呈良好的线性关系,决定系数R2为0.995。该方法可检测睾酮浓度范围为2.27nmol/L~1.8μmol/L,最低检测限为2.27nmol/L,将本方法应用于检测自来水睾酮含量,加标回收率为99.81%~105.04%。本方法具有检测范围广、成本低、操作简便、检测灵敏等优点,具有良好实际应用前景。     

肉桂精油壳聚糖纳米粒在冷却肉保藏中的应用

【目的】制备肉桂精油壳聚糖纳米粒,以扩大肉桂精油(CEO)在冷却肉保鲜中的应用范围,克服其易挥发的缺陷。【方法】采用离子凝胶法制备肉桂精油壳聚糖纳米粒。通过透射电镜(TEM)、扫描电镜(SEM)对肉桂精油壳聚糖纳米粒的形态进行表征,测定其包封率。分别配制质量分数为3%和6%的肉桂精油壳聚糖纳米粒保鲜剂(CEO质量分数分别为0.2%和1.0%),用其处理冷却猪肉,检测其对肉样色泽(L值、a*值、b*值)、TBARS值、pH和菌落总数的影响。【结果】制备的肉桂精油壳聚糖纳米粒颗粒大小均匀、形态饱满、呈规则球形,冻干后形态仍较为均匀,包封率为(37.5±2.1)%。通过对冷却肉色泽、TBARS值、pH及菌落总数的分析得知,包埋质量分数1.0%肉桂精油的肉桂精油壳聚糖纳米粒试验组的冷却肉在(4±0.5)℃时储藏期可达到6d。【结论】制备的肉桂精油壳聚糖纳米粒表征良好,可在一定程度上延长冷却肉的贮藏期。