Combining magnetic nanoparticle with biotinylated nanobodies for rapid and sensitive detection of influenza H3N2

Our objective is to develop a rapid and sensitive assay based on magnetic beads to detect the concentration of influenza H3N2. The possibility of using variable domain heavy-chain antibodies (nanobody) as diagnostic tools for influenza H3N2 was investigated. A healthy camel was immunized with inactivated influenza H3N2. A nanobody library of 8 × 10⁸ clones was constructed and phage displayed. After three successive biopanning steps, H3N2-specific nanobodies were successfully isolated, expressed in Escherichia coli, and purified. Sequence analysis of the nanobodies revealed that we possessed four classes of nanobodies against H3N2. Two nanobodies were further used to prepare our rapid diagnostic kit. Biotinylated nanobody was effectively immobilized onto the surface of streptavidin magnetic beads. The modified magnetic beads with nanobody capture specifically influenza H3N2 and can still be recognized by nanobodies conjugated to horseradish peroxidase (HRP) conjugates. Under optimized conditions, the present immunoassay exhibited a relatively high sensitive detection with a limit of 50 ng/mL. In conclusion, by combining magnetic beads with specific nanobodies, this assay provides a promising influenza detection assay to develop a potential rapid, sensitive, and low-cost diagnostic tool to screen for influenza infections.     

影响盐酸苯海拉明水溶液澄明度的原因剖析

利用高效液相色谱、红外光谱等分析测试手段,对盐酸苯海拉明中存在的各种杂质进行了全面剖析,并对各杂质含量进行了定量测定,阐述了影响产品水溶液澄明度的原因。这一剖析结果对产品的生产工艺及质量控制均有重要的指导意义。     

Hepatoprotection by palm tocotrienol‐rich fraction

Tocotrienols, a group of important phytonutrients of palm oil, have been shown to possess antioxidant, anticancer, neuroprotectory, and anti‐inflammatory activities. In this study, our objective was to examine the protective effects of tocotrienol‐rich fraction (TRF) from palm oil on chronic carbon tetrachloride (CCl₄)‐induced hepatotoxicity in rats. Animals were subjected to vehicle only (control), CCl₄ only, CCl₄ + 100 mg/kg silymarin (silymarin), CCl₄ + 25 mg/kg TRF (TRF‐25) and CCl₄ + 50 mg/kg TRF (TRF‐50) treatments for a period of 8 wks. Results showed that daily oral administration of TRF‐25, TRF‐50, and silymarin prevented the elevation of serum glutamate oxalate transaminase (sGOT) and glutamate pyruvate transaminase (sGPT), liver thiobarbituric acid reactive substances (TBARS), triglycerides and total cholesterol levels, as well as enhancing the liver catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) levels in rats with hepatotoxicity. At 50 mg/kg, the hepatoprotection of TRF was as good as or better than silymarin (100 mg/kg) in normalization of oxidative stress parameters in liver injury rats. These results suggest that TRF exerts effective protection against chronic CCl₄‐induced hepatic injury in rats, and its mechanism of action could be related to reducing oxidative stress in the liver tissue.     

程控式真空规校准装置

程控式真空规校准装置主要用于日常对工作用真空规的校准。它采用动态直接比对法、静态膨胀法和静态直接比对法等三种方法可以对１×１０５～５×１０－４Ｐａ范围内的真空规进行校准。采用可编程控制器对校准全过程实行自动控制，并具有保护、报警、语音提示等功能，提高了工作效率和安全可靠性，避免了由于误操作或真空系统故障造成的经济损失。     

Antibacterial ability and biocompatibility of fluorinated titanium by plasma-based surface modification

Biomaterial surfaces with satisfied antibacterial activity and appropriate cytocompatibility are a pressing clinical need for orthopedic and dental implants.Fluorinecontaining biomaterials have been demonstrated to obtain antibacterial activity and osteogenic property,while the effect of fluorine chemical compositions on antibacterial property and cytocompatibility is rarely studied.To this end,the coatings with different fluorine chemical compositions on titanium surface were prepared by plasma treatment to verify the antibacterial ability and cytocompatibility of fluorinated surfaces.Their antibacterial ability was evaluated by using Staphylococcus aureus,and the cell compatibility was investigated with MC3T3-E1 cells in vitro.The results show that both fluorocarbon coating and metal fluorides coating exhibited a hydrophilic and nano-scaled roughness.Rather than the fluorocarbon coating,the coating composed of metal fluorides presented satisfied bactericide effect and excellent cytocompatibility.The antibacterial mechanism is associated with the metal fluorides and released fluoride ion.This work would provide novel sight in optimizing the surface modification method of fluorinated biomaterials for biomedical applications.     

Microstructural Evolution in Multiphase NiAl-2.5Ta-7.5Cr Alloy during Annealing at Different Temperatures

研究了NiAl-2.5Ta-7.5Cr合金在不同的退火温度下的组织演变过程,结果表明该合金的铸态组织是由NiAl基底中包含Ta(CrNiAl)2的大晶粒Laves相和一些富含Cr的尺寸在400-500nm的小颗粒组成,其中大晶粒Laves相晶界处存在C14结构相。NiAl中Ta和Cr的浓度分别在~0.6at%和~2.5at%之间。将合金置于1000°C度下退火,有细小的棒状C15结构的Laves相在NiAl中开始弥散析出。而合金经过1200°C度退火2h后,这种颗粒的体积分数增加,同时NiAl基底中Ta的浓度减少到~0.2at%。当退火温度增加到1400°C,NiAl基底中的Laves析出相完全消失。因此,1000-1300°C温度范围内这种Laves相在NiAl基底中的析出,可归因于Ti元素在NiAl固溶后的过度饱和后发生扩散的缘故。     

富水砂性地层盾构渣土改良试验与喷涌防治技术

为解决土压平衡盾构穿越富水砂性地层螺旋输送机喷涌、排渣不畅等难题,基于渣土改良剂的地层适应性规律研发新型化学改良剂并开展相关室内试验.试验结果表明:非离子聚合型泡沫剂可兼备发泡倍数与稳定性能,适当提高泡沫剂浓度Cf能够增大发泡倍率FER和半衰期HT.当cf＞5％时,由于达到临界胶束浓度,FER和HT趋于最大值.透射电镜...     

Application of Taguchi method for the optimization of Fe2+ removal from contaminated synthetic groundwater using a rotating packed bed contactor

Malaysia contains elevated levels of iron in shallow groundwater in the range of 3–7 mg Fe/L compared to the USEPA safe limit of 0.3 mg Fe/L. Air Kelantan Sdn Bhd in Malaysia uses the ‘River Bank Filtration’ (RBF) technology to harvest hyporheic water. The RBF treatment removes the turbidity of the river water through the river bed acting as a filter, but is unable to remove the Fe from the harvested water. This work proposes a technology to reduce Fe concentration in the extracted water using granular activated carbon in a laboratory‐scale rotating packed bed contactor (RPBC). The Taguchi method was used for optimizing the operating conditions for the adsorption of Fe onto activated carbon in the RPBC system. Taguchi optimization results showed that a removal efficiency of 87% Fe from a 50 mg Fe/L concentration could be achieved by a RPBC at an initial pH of 6.5, a feed rate of 40 L/h, a rotating speed of 1600 rpm and a packing density of 357 kg/m³.