利用产黄青霉培养液的上清液生物合成纳米银影响因素的研究

[目的]对利用产黄青霉培养液的上清液生物合成纳米银的影响因素进行研究。[方法]利用紫外-可见光谱和投射电镜研究硝酸银起始浓度、pH值、光照和微波辐照等条件对合成反应速率及合成纳米银粒径的影响。[结果]硝酸银的最佳起始浓度为2 mmol/L;随着反应体系pH值的升高,反应速率随之加快,合成纳米银粒子的粒径变小;光照和微波辐照均能有效促进纳米银的合成。[结论]该研究为实现纳米银的可控合成提供了试验基础。     

长丰鲢生长性状相关微卫星标记的初步筛选

为了筛选出与长丰鲢生长性状相关的分子标记,以指导其种质鉴定和选择育种工作,实验利用15个多态微卫星标记,对6、17和36月龄长丰鲢进行了遗传多样性和生长性状关联分析.结果 显示,各月龄长丰鲢的观测杂合度(Ho)和期望杂合度(Hc)均高于0.5,PIC均值分别为0.555、0.445和0.490,表明各月龄长丰鲢群体均具...     

Long-term dynamics of leaf and root decomposition and nitrogen release in a grey alder (Alnus incana (L.) Moench) and silver birch (Betula pendula Roth.) stands

The decomposition of the leaf litter, fine roots (d?<?2?mm) and coarser roots (2?≤?d?<?5?mm) of grey alder and silver birch, as well as of α-cellulose sheets using the litterbag method was studied in two experimental stands on Podzoluvisol soils in Southern Estonia. For both tree species, the coarser roots decomposed faster than the fine roots, (p?<?.05), tree species did not affect the decomposition rate of the roots (p?>?.5). The nitrogen (N) input to soil from aboveground litter was multiple times higher than the N flux from roots. The remaining relative ash-free mass of the leaves of grey alder and silver birch after three and a half years was similar. After 11 years the remaining relative ash-free mass of the fine and coarser roots of grey alder still accounted for around 10% of the initial value. For silver birch the remaining value was around 20% after 9 years. The litterbag method to underestimates in fertile soils the decomposition of organic matter and thus did not reflect the actual dynamics of decomposition.     

固体脂质纳米增强抗菌药物对胞内金黄色葡萄球菌活性的研究进展

金黄色葡萄球菌导致的乳房炎是危害奶牛养殖业最严重的疾病之一。抗菌药在胞内极易排出或失活,导致奶牛金黄色葡萄球菌乳房炎治疗效果差且容易复发。纳米粒子具有在巨噬细胞和上皮细胞等多种细胞中积累的能力,可提高药物在胞内的浓度和胞内停留时间,这使得它们可用于治疗细胞内感染。本文对固体脂质纳米抗金黄色葡萄球菌感染的研究进展进行综述,以指导和推动固体脂质纳米在治疗金黄色葡萄球菌乳腺炎方面的应用。     

SiO2纳米颗粒对猪粪好氧堆肥过程中重金属形态分布和细菌群落的影响

以猪粪和秸秆为原料, SiO₂纳米颗粒（SiO₂NPs）为添加剂,研究添加4 个浓度梯度下（0、0.5、1.0和2.0 g/kg）SiO₂NPs对好氧堆肥过程中腐熟度指标、重金属总量和形态分布规律以及细菌群落的影响,并探讨影响重金属生物利用度的因素。结果表明,添加SiO₂NPs提高堆体温度并延长堆肥高温期。与堆肥前相比,堆肥后的pH显著升高,而电导率和C/N显著降低。种子发芽指数由堆肥前的50%升高到堆肥后的163%~182%。添加SiO₂NPs有利于重金属组分由生物可利用形态（可交换态和可还原态）向稳定形态（可氧化态和残渣态）转化,Cu和Zn的钝化效率可分别达到65.10%~83.89%和6.62%~27.93%,极显著高于CK处理（分别为52.09%和1.83%,P<0.01）。添加SiO₂NPs增加嗜热菌科的丰度,提高总细菌的多样性和丰富度。与Cu相关的优势细菌门为厚壁菌门（Firmicutes）,与Zn相关的被鉴定为变形菌门（Proteobacteria）和放线菌门（Actinobacteria）。偏最小二乘路径模型分析表明Cu的生物利用度受环境因素（C/N和电导率）和细菌的交互作用,而Zn的生物利用度受细菌和温度的直接影响。     

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.     

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.