Comparison of droplet digital PCR to real-time PCR for quantification of hepatitis B virus DNA

Quantitative real-time PCR (qPCR) has been widely implemented for clinical hepatitis B viral load testing, but a lack of standardization and relatively poor precision hinder its usefulness. Droplet digital PCR (ddPCR) is a promising tool that offers high precision and direct quantification. In this study, we compared the ddPCR QX100 platform by Bio-Rad with the CFX384 Touch Real-Time PCR Detection System (Bio-Rad, USA) to detect serial plasmid DNA dilutions of known concentrations as well as HBV DNA extracted from patient serum samples. Both methods showed a high degree of linearity and quantitative correlation. However, ddPCR assays generated more reproducible results and detected lower copy numbers than qPCR assays. Patient sample quantifications by ddPCR and qPCR were highly agreeable based on the Bland–Altman analysis. Collectively, our findings demonstrate that ddPCR offers improved analytical sensitivity and specificity for HBV measurements and is suitable for clinical HBV detection.     

Simulation of 3D tumor cell growth using nonlinear finite element method

We propose a novel parallel computing framework for a nonlinear finite element method (FEM)-based cell model and apply it to simulate avascular tumor growth. We derive computation formulas to simplify the simulation and design the basic algorithms. With the increment of the proliferation generations of tumor cells, the FEM elements may become larger and more distorted. Then, we describe a remesh and refinement processing of the distorted or over large finite elements and the parallel implementation based on Message Passing Interface to improve the accuracy and efficiency of the simulation. We demonstrate the feasibility and effectiveness of the FEM model and the parallelization methods in simulations of early tumor growth.     

走马胎的组织培养与快速繁殖

以走马胎(Ardisia gigantifolia)幼嫩茎段为外植体, 通过腋芽增殖的方式进行组织培养和快速繁殖研究。结果表明, 培养基MS+1.0 mg·L ^-1 6-BA+0.2 mg·L ^-1NAA和MS+0.5 mg·L ^-1 ZT均可用于腋芽的诱导和前期继代培养, 诱导率分别为89.3%和85.7%; 芽增殖最佳培养基为MS+0.5 mg·L ^-16-BA+0.1 mg·L ^-1ZT+0.1 mg·L ^-1NAA, 增殖系数为4.3倍; 根诱导最佳培养基为1/2MS+1.5 mg·L ^-1 IAA+1.0 mg·L ^-1 NAA, 生根率达92.3%, 且根系发达, 植株健壮; 生根苗在混合基质园土:泥炭:珍珠岩=3:1:1 (v/v/v )中移栽成活率为82%。该研究建立了走马胎种苗的组织培养快速繁殖技术体系, 且可应用于规模化生产。     

广西红壤土壤微生物溶磷基因的克隆与表达

本研究对广西红壤土壤微生物溶磷基因进行克隆,并在大肠杆菌中诱导表达。从广西红壤中提取宏基因组DNA,克隆了GabY基因,构建大肠杆菌原核表达载体p ETDuet-1,转化大肠杆菌DH5α得到重组工程菌。通过酶切验证重组体。重组体在诱导条件下24 h对难溶矿物质磷Ca_3(PO_4)_2的溶磷量为(40.73±1.32)μg/mL,而对照组仅为(5.11±0.08)μg/mL。重组体和对照随着诱导时间的增加,培养基pH值均有下降趋势,但重组体培养基pH值变化显著大于对照组,产酸能力显著优于对照组。证明成功克隆得到土壤微生物溶磷基因,并在大肠杆菌中得到表达。     

微波法和超声波法提取绿穗苋多糖响应面优化研究

绿穗苋是一种药食兼用作物,其中多糖成份具有很高的药食价值。本研究以绿穗苋地上部分为材料,以微波和超声波两种方法对绿穗苋多糖进行提取,并通过响应面分析法对提取进行优化,确定最佳工艺,通过水提醇沉的方法得到绿穗苋粗多糖。综合比较两种提取工艺,提取效果最佳工艺为微波提取法。其条件为:提取时间41.42 min,提取功率211.65 W,料液比1:33.338 (g/mL),实际得率为13.25%。该研究结果促进绿穗苋资源的有效利用,为绿穗苋多糖的提取工艺及产品的开发利用提供理论依据。