仿刺参冷风干制工艺优化及不同干制方式的比较

以盐渍仿刺参为研究对象,以感官评分和脱水速率加权后的综合评分作为评价指标,采用单因素试验及响应面法对冷风干制(cold-air drying,CAD)工艺条件进行优化,并对CAD、真空冷冻干制(vacuum freeze drying,VFD)、热风干制(hot-air drying,HAD)和真空微波干制(vacuum microwave drying,VMD)工艺处理的仿刺参进行品质比较分析。结果表明:CAD最佳干制工艺条件为真空脱盐时间4.2 h、冷风温度19℃、冷风风速1.70 m/s,仿刺参的综合评分为0.77。在营养保持方面,VFD和CAD比HAD和VMD效果更好;在热收缩率方面,HADVMDCADVFD,其中CAD和VFD差异不大;在复水倍数方面,CADVFDHADVMD;在质构特性上,CAD和VFD质构指标明显优于HAD和VMD。对比结果说明CAD在工业生产中具有更高的实用性。     

Glucose-conjugated chitosan nanoparticles for targeted drug delivery and their specific interaction with tumor cells

A novel targeted drug delivery system, glucose-conjugated chitosan nanoparticles （GCNPs）, was developed for specific recognition and interaction with glucose transporters （Gluts） over-expressed by tumor cells. GC was synthesized by using succinic acid as a linker between glucosamine and chitosan （CS）, and successful synthesis was confirmed by NMR and elemental analysis. GCNPs were prepared by ionic crosslinking method, and characterized in terms of morphology, size, and zeta potential. The optimally prepared nanoparticles showed spherical shapes with an average particle size of （187.9 ± 3.8） nm and a zeta potential of （-15.43 ± 0.31） mV. The GCNPs showed negligible cytotoxicity to mouse embryo fibroblast and 4T1 cells. Doxorubicin （DOX） could be efficiently entrapped into GCNPs, with a loading capacity and encapsulation efficiency of 20.11% and 64.81%, respectively. DOX-Ioaded nanoparticles exhibited sustained-release behavior in phosphate buffered saline （pH 7.4）. In vitro cellular uptake studies showed that the GCNPs had better endocytosis ability than CSNPs, and the antitumor activity of DOX/GCNPs was 4-5 times effectiveness in 4T1 cell killing than that of DOX/CSNPs. All the results demonstrate that nanoparticles decorated with glucose have specific interactions with cancer cells via the recognition between glucose and Gluts. Therefore, Gluts-targeted GCNPs may be promising delivery agents in cancer therapies.     

Effect of nanocrystallization on giant magnetoimpedance effect of Fe-based microwires

We studied giant magnetoimpedance (GMI) effect and magnetic properties of Fe_70.8Cu₁Nb_3.1Si_14.5B_10.6 and Fe_71.8Cu₁Nb_3.1Si₁₅B_9.1 Finemet microwires. We observed that GMI effect and magnetic softness of glass-coated microwires produced by the Taylor–Ulitovski technique can be tailored either controlling magnetoelastic anisotropy of as-cast FeCuNbSiB microwires, and/or controlling their structure by heat treatment or by changing the fabrication conditions. High GMI effect has been observed in as-prepared Fe-rich and heat treated microwires with nanocrystalline structure.     

渔业养殖环境中抗生素残留检测与控制技术研究进展

养殖环境是渔业发展的重要基础,但由于养殖模式的改变和养殖环境的恶化,水生动物疾病频发。抗生素被应用于水产养殖的各个环节,可促进生物体的生长和预防、治疗疾病。水产养殖是水环境中抗生素的污染源之一,环境中抗生素污染受到广泛关注。养殖环境中的抗生素检测及控制技术对水产品的质量安全以及渔业生态建设意义重大。本文主要从水产养殖过程中抗生素使用状况和残留水平、水环境中抗生素的检测技术及消除技术3个方面进行阐述。2013年我国抗生素使用总量达16.2万吨,水产养殖中用得最多、最广的抗生素包括大环内酯类、β-酰胺类、磺胺类、四环素类以及喹诺酮类5大类。近年地表水中抗生素的检出率较高,而水产养殖业被认为是重要来源之一。结合固相萃取法(solid phase extraction,SPE)的色谱和质谱分析技术广泛应用于水环境中抗生素的检测,这些方法对水中同一类多种抗生素和不同类多种抗生素的检测均十分有效。水环境中抗生素的消除技术主要包括物理消除法、光降解法、化学消除法、生物消除法等。本文旨在为渔业养殖水环境的中抗生素监测与治理提供参考。     

8种海藻和3类海带的色素抗氧化活性的研究

实验选取褐藻、绿藻、红藻及微藻中的8种代表性海藻,采取酶辅助有机溶剂法提取色素,测其含量及抗氧化活性,筛选出一种高抗氧化活性的海藻,研究其不同加工方式对色素的抗氧化活性产生的影响,并对色素含量与抗氧化活性进行了相关性分析。结果表明,8种海藻色素粗提物都具有一定的体外抗氧化活性,海带、裙带菜、石莼的色素粗提物体外抗氧化活性较好,尤以海带为佳。在海带色素粗提液终浓度0.8 mg/mL下,DPPH自由基的清除率为52.58%,羟自由基清除率为68.14%,超氧阴离子自由基清除率为60.79%。3种海带色素的含量和抗氧化活性的大小均为:新鲜海带 > 盐渍海带 > 晒干海带。相关性和线性回归分析表明,三种自由基清除率与叶绿素含量和类胡萝卜素含量的相关性都达到了0.75以上,且显著性都呈极显著,叶绿素含量与类胡萝卜素含量对三种自由基的清除率的影响是具有共同作用的,但类胡萝卜素含量与三种自由基的清除率的相关性更高。     

Adsorption of tropomyosin from pink shrimp (Pandalus eous) on stainless steel surface

Cross contamination of allergen to other food products is a serious problem in the food plant where many products shared the same equipment or processing lines. In order to decide a suitable cleaning method, understanding on adsorption of allergen onto the food-contact surface is required. In this study, the adsorption behavior of tropomyosin, a major allergen in shrimp, on stainless steel surface was investigated using shrimp extract as a sample food material. It was found that tropomyosin was adsorbed favorably on stainless steel surface than other proteins in the shrimp extract. Furthermore, the adsorption of proteins in the shrimp extract, including tropomyosin, was hardly removed by water.     

Rapid measurement of suspended C,N, and P from Precambrian Shield Lakes using Near-infrared Reflectance Spectroscopy

Rapid (<2 min), simultaneous, non-chemical, non-destructive, cost-efficient measurement of the C, N, and P concentrations in suspended, particulate matter in water from lakes of varying trophic status, pH, and extent of metal contamination was attempted by the use of near-infrared reflectance spectroscopy (NIRS). This technique, widely used in the agricultural, food, pharmaceutical, petrochemical, and textile industries, is being explored for its applications to aquatic and environmental sciences. Suspended matter from lake water (10–100 ml) was collected on 2.5 cm dia. G/FC glass fibre filters so that filters bore 10.5–109.2 μg C, 0.8–18.9 μg N, and 0.09-2.67 μg P per filter. Filters were oven-dried and scanned with an NIRSystems 6500 near-infrared spectrophotometer. The spectral data were treated by multiple linear regression analysis to develop mathematical relationships (calibrations) between absorbance at particular wavelengths and amounts of C, N, and P determined by conventional chemical analytical methods. These calibrations were used to predict C, N, and P from an independent set of spectra. Agreement between these NIRS-predicted values and their chemical values was generally greater than 0.9 for C, N, and P (r² from 0.88 to 0.97).     

Integration of power devices in advanced mixed signal analog BiCMOS technology

This paper outlines lateral power devices in Power BiCMOS (PBC) technologies where increasing application circuit complexity is driving the need to maintain compatibility with advanced CMOS technology and integration by parts remains a challenge. Different device strategies and process roadmaps are required to maintain competitive products. The need for compatibility with these leading edge CMOS technologies complicates the push for reduced complexity. Product application drivers, device styles combined with process integration challenges and methods, and the future problems with shrinking geometry are discussed.