开心果壳基活性炭的制备及其吸附性能研究

本文以开心果壳为原料,采用化学活化法制备开心果壳基活性炭。将开心果壳450 ℃在管式炉炭化4 h,按照活化剂KOH和活性炭质量比1:1混合研磨,在800 ℃活化2 h制备活性炭。采用傅里叶变换红外光谱仪表征活性炭表面官能团,并探究了pH、起始浓度、温度及吸附时间对开心果壳基活性炭吸附亚甲基蓝的影响。结果表明,开心果壳基活性炭对亚甲基蓝的吸附效果良好, Langmuir等温吸附模型和准二级吸附动力学方程能较好拟合吸附过程,开心果壳基活性炭对亚甲基蓝的吸附反应为吸热反应,自发进行。     

水足迹分析中国耕地水资源短缺时空格局及驱动机制

为全面评估区域农业水资源供需关系,基于水足迹理论构建了耕地水资源短缺指数(arablelandwaterscarcity index,AWSI)。在分析1999-2014年中国AWSI时空分布格局的基础上,借助偏最小二乘法揭示了AWSI的主控因子。结果显示:中国AWSI的年均值约为0.413,总体上处于高度水资源压力状态,且有随时间加剧的趋势;各年份AWSI以华北平原为中心向外递减式扩散;面临极高水资源压力(AWSI0.800)的省区均分布在北方地区,长江以南省区均面临中度水资源压力(0.100AWSI0.400);降水量与日照时数是与耕地水短缺最为密切的气象因子,农业机械总动力、粮食面积比重以及人均GDP是影响AWSI的主要社会经济条件。农业生产水平较高的粮食主产区应以水足迹调控为重要内容进行农业水管理策略的制定。     

Pinus taeda L. response to differential inoculum density of Leptographium terebrantis colonized toothpicks

Bark beetle‐vectored ophiostomatoid fungi, Leptographium terebrantis, is inoculated on the roots and lower stems of stressed Pinus species during the feeding activity of bark beetle. To determine the exact host response following inoculation, it is critical to challenge the host with a realistic amount of fungal inoculum. Thus, we designed a series of stepwise experiments using L. terebrantis colonized toothpicks which focused on the inoculum transfer from the toothpicks to excised Pinus taeda stem segments and living saplings, respectively, at different inoculum densities. The toothpicks served as a substrate for fungal growth and sporulation and the inoculation showed their utility in eliciting host's response to the pathogen. The inoculated fungus caused blue‐stain and sapwood occlusions in P. taeda stems and saplings, respectively. The volume of occluded, visually damaged sapwood increased by 1.96 cm³ per radial inoculation point on average. Fungal colonized toothpicks can be used as a suitable alternative to agar discs for studying bark beetles vectored fungi and their host interactions.     

蓝狐多巴胺受体D2基因部分序列的克隆测序

对蓝狐多巴胺受体D2(dopamine receptor,DRD2)基因进行克隆测序,为进一步探讨蓝狐DRD2基因与自咬行为的相关分析及染色体定位提供理论基础。本试验参考狗的DRD2基因序列(GenBank登录号:AF293962.1)设计特异引物,对蓝狐的基因组进行PCR扩增、克隆和测序,并进行序列的同源性分析。试验获得蓝狐DRD2基因序列819 bp,其序列与家犬的同源性最高,达97%,而在水貂和人及小鼠这些哺乳动物的同源性为85%~91%。本研究成功克隆了蓝狐DRD2基因的部分序列,表明其在物种间具有较高的保守性。     

PDE3与亮甲酚蓝在绵羊卵母细胞体外培养中的应用研究(英文)

[目的]探讨磷酸二酯酶3(PDE3)特异性抑制剂Milrinone与亮甲酚蓝染色液(BCB)相结合在绵羊卵母细胞体外培养中的应用。[方法]比较了BCB对绵羊卵母细胞的筛选与传统的形态分级之间的差异,以及对胚胎后期发育的影响;研究了Milrinone对绵羊卵母细胞的最佳抑制时间,并用于BCB-卵母细胞体外培养。[结果]A、B级卵母细胞中BCB+卵母细胞的比例为64.42%,极显著高于C级卵母细胞的17.00%; BCB+卵母细胞的成熟率(86.16%)、卵裂率(85.29%)、囊胚率(34.40%)分别极显著高于BCB-卵母细胞(50.94%、36.19%和6.73%);6 h是Milrinone对绵羊卵母细胞的最佳抑制时间,该试验组体外培养效率显著高于其他组;Milrinone对BCB-卵母细胞抑制培养6 h,极显著提高了体外胚胎发育率。[结论]为提高绵羊卵母细胞体外培养效率提供了依据。     

Adsorption of Cationic Dyes on a Magnetic 3D Spongin Scaffold with Nano-Sized Fe3O4 Cores

The renewable, proteinaceous, marine biopolymer spongin is yet the focus of modern research. The preparation of a magnetic three-dimensional (3D) spongin scaffold with nano-sized Fe₃O₄ cores is reported here for the first time. The formation of this magnetic spongin–Fe₃O₄ composite was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA) (TGA-DTA), vibrating sample magnetometer (VSM), Fourier-transform infrared spectroscopy (FTIR), and zeta potential analyses. Field emission scanning electron microscopy (FE-SEM) confirmed the formation of well-dispersed spherical nanoparticles tightly bound to the spongin scaffold. The magnetic spongin–Fe₃O₄ composite showed significant removal efficiency for two cationic dyes (i.e., crystal violet (CV) and methylene blue (MB)). Adsorption experiments revealed that the prepared material is a fast, high-capacity (77 mg/g), yet selective adsorbent for MB. This behavior was attributed to the creation of strong electrostatic interactions between the spongin–Fe₃O₄ and MB or CV, which was reflected by adsorption mechanism evaluations. The adsorption of MB and CV was found to be a function of pH, with maximum removal performance being observed over a wide pH range (pH = 5.5–11). In this work, we combined Fe₃O₄ nanoparticles and spongin scaffold properties into one unique composite, named magnetic spongin scaffold, in our attempt to create a sustainable absorbent for organic wastewater treatment. The appropriative mechanism of adsorption of the cationic dyes on a magnetic 3D spongin scaffold is proposed. Removal of organic dyes and other contaminants is essential to ensure healthy water and prevent various diseases. On the other hand, in many cases, dyes are used as models to demonstrate the adsorption properties of nanostructures. Due to the good absorption properties of magnetic spongin, it can be proposed as a green and uncomplicated adsorbent for the removal of different organic contaminants and, furthermore, as a carrier in drug delivery applications.     

紫蓝粒小麦研究进展

紫蓝粒小麦是采用不同的育种手段培育出来的特用型优质小麦新品种,籽粒呈紫色、蓝色或黑紫色,营养丰富。在介绍紫蓝粒小麦起源的基础上,概述了紫蓝粒小麦粒色遗传规律和色素性状方面的研究进展,并提出了今后紫蓝粒小麦研究利用方向。     

液相色谱-安培法检测养殖水体中的几种染料类抗菌剂

利用液相色谱—安培法检测分析养殖水体中3种染料—孔雀石绿、结晶紫、亚甲基蓝及其代谢物,无需衍生,养殖水样品采用阳离子反相混合模式MCX小柱富集,色谱柱为Waters Xettra C18(250×4.6 mm,5μm)流动相采用70%甲醇[甲醇∶0.1 mol.L-1乙酸钠=7∶3(V/V),pH4.5],流速为1 mL.min-1。采用直流安培检测,氧化电位1.4 V,工作电极为玻碳电极。3种染料及其代谢物在0.05~100μg.mL-1范围内具有良好的线性关系,检测限在0.2~0.5μg.L-1范围内,回收率为66%~101%,方法的精密度在0.5%~4.8%。该方法具有灵敏度高、选择性好的优点。     

Functional and Biochemical Characterization of Proteins Remaining in Solution After Isoelectric Precipitation

ABSTRACT

The resulting supernatant from the isoelectric precipitation of “sawdust” from Cape hake portioning and blue whiting muscle was concentrated by ultrafiltration and the retentate spray-dried. Two main peaks corresponding to molecular weights of 15 kDa and 65 kDa were detected in the supernatant from both raw materials; in the retentate the main proteins had approximately 18 kDa and 73 kDa, and some proteins with 59 kDa were detected in the permeate. The protein content was 74.0% and 70.0% for hake by-products and blue whiting, respectively. Dried proteins had relatively low emulsifying and foaming capacity but high foaming stability and were whitish in color. Hydrophobicity and sulphydryl content were similar to those from other protein sources.     

An Improved Process for Retort Cooking Atlantic Blue Crab

Abstract

Non-uniform steam distribution and large temperature differences are frequently found within the retort during pressure steam cooking of blue crabs. A precook treatment involving evacuation of air from the retort prior to introduction of steam was found to decrease this unevenness in temperature distribution. The conventional and modified treatments were compared by (1) determination of temperature profiles within a retort during the conventional cooking process and the modified process; and (2) testing the resulting product from the two processing methods for differences in meat moisture and pH. The modified process improved the temperature distribution and reduced cook time by up to 50%. Meat moisture content increased in crabs processed using the vacuum process while pH testing of the cooked meat showed little difference in meat from the two processes. It was concluded that the improved temperature distribution would shorten cook time and increase throughput, product yield, product safety, and process efficiency.