LC-MS/MS法测定小鼠脑组织中色氨酸及其3种代谢物

目的:建立检测小鼠脑组织中色氨酸、5-羟基色氨酸、5-羟色胺和5-羟基吲哚乙酸含量的LC-MS/MS分析方法。方法:采用TSK Gel amide 80（2.0 mm×15 cm,3μm）色谱柱,柱温35℃,乙腈:甲酸铵水溶液（15 mmol·L-1,p H5.5）（40∶60,v/v）为流动相,流速0.4 m L·min-1,采用正离子多反应监测（MRM）模式进行扫描。结果:4种待测物均在5 min内完成测定,色氨酸、5-羟基色氨酸、5-羟色胺和5-羟基吲哚乙酸最低定量限分别为0.2、0.1、0.2、0.2 ng·m L-1,最低检测限分别为0.05、0.02、0.05、0.05 ng·m L-1,在1⁵00 ng·m L-1浓度范围内线性关系均良好,方法的精密度和加样回收率均符合生物样品的分析要求。将该方法应用于口服萱草花总黄酮的小鼠脑提取物检测后发现:脑内四种待测物浓度明显发生改变,且变化规律与阳性药物帕罗西汀相同。结论:本方法简便、准确、灵敏度高,专属性强,重复性好,适用于脑组织中色氨酸-五羟色胺代谢过程中的4种成分的测定,可应用于神经精神类药物的药理作用机制研究。      

随机质心映射优化法(RCO)提取皮亚曼石榴皮中黄酮类化合物

利用随机质心映射优化法(RCO),以乙醇浓度、超声时间、提取温度和料液比为影响因子,研究新疆皮亚曼石榴皮中黄酮类化合物的超声波提取工艺。结果表明:经过RCO两轮循环后得出超声波法提取石榴皮中黄酮类物质最佳工艺:乙醇浓度为87%、超声时间为37 min、提取温度为59℃、料液比为1∶24(g/m L)。优化后皮亚曼石榴皮中总黄酮的得率为25.56%。经过相关性分析得知,提取温度和乙醇浓度对总黄酮的得率影响较大,且呈负相关,表明皮亚曼石榴皮中黄酮类化合物的极性较大。当石榴皮黄酮浓度为12 mg/m L时,对DPPH自由基的清除率可达91.6%。      

乳酸菌氧化锆珠破壁方法的优化及适用性研究

本实验旨在优化氧化锆珠破壁方法,以期筛选出较佳的破壁条件,提高蛋白得率。实验在菌体重量、研磨buffer和研磨时间这3方面对该破壁方法进行了优化,并通过SDS-PAGE来分析其破壁效果。在优化后的条件下,同时对6株乳酸菌进行破壁处理并通过SDS-PAGE来分析其破壁效果。结果表明:在菌体重量、研磨buffer、锆珠三者的加入比例（W/V/W）为0.013 g∶300μL∶1 g的条件下,研磨15 min,提取的蛋白图谱条带清晰,丰度高;RIPA、PBS、PENP、GUS作为研磨buffer时,提取的蛋白图谱条带清晰且丰度高,而8 mol/L尿素作为研磨buffer时,图谱条带模糊且丰度低;6株乳酸菌经该方法破壁处理后,蛋白图谱条带均具有较高的丰度和清晰度。因此,对于乳酸菌的破壁,氧化锆珠破壁法具有快速、高效的优点。      

Progress in Laser Ablation and Biological Synthesis Processes: “Top-Down” and “Bottom-Up” Approaches for the Green Synthesis of Au/Ag Nanoparticles

Because of their small size and large specific surface area, nanoparticles (NPs) have special properties that are different from bulk materials. In particular, Au/Ag NPs have been intensively studied for a long time, especially for biomedical applications. Thereafter, they played a significant role in the fields of biology, medical testing, optical imaging, energy and catalysis, MRI contrast agents, tumor diagnosis and treatment, environmental protection, and so on. When synthesizing Au/Ag NPs, the laser ablation and biosynthesis methods are very promising green processes. Therefore, this review focuses on the progress in the laser ablation and biological synthesis processes for Au/Ag NP generation, especially in their fabrication fundamentals and potential applications. First, the fundamentals of the laser ablation method are critically reviewed, including the laser ablation mechanism for Au/Ag NPs and the controlling of their size and shape during fabrication using laser ablation. Second, the fundamentals of the biological method are comprehensively discussed, involving the synthesis principle and the process of controlling the size and shape and preparing Au/Ag NPs using biological methods. Third, the applications in biology, tumor diagnosis and treatment, and other fields are reviewed to demonstrate the potential value of Au/Ag NPs. Finally, a discussion surrounding three aspects (similarity, individuality, and complementarity) of the two green synthesis processes is presented, and the necessary outlook, including the current limitations and challenges, is suggested, which provides a reference for the low-cost and sustainable production of Au/Ag NPs in the future.     

Prime Editing: An All-Rounder for Genome Editing

Prime editing (PE), as a “search-and-replace” genome editing technology, has shown the attractive potential of versatile genome editing ability, which is, in principle, currently superior to other well-established genome-editing technologies in the all-in-one operation scope. However, essential technological solutions of PE technology, such as the improvement of genome editing efficiency, the inhibition of potential off-targets and intended edits accounting for unexpected side-effects, and the development of effective delivery systems, are necessary to broaden its application. Since the advent of PE, many optimizations have been performed on PE systems to improve their performance, resulting in bright prospects for application in many fields. This review briefly discusses the development of PE technology, including its functional principle, noteworthy barriers restraining its application, current efforts in technical optimization, and its application directions and potential risks. This review may provide a concise and informative insight into the burgeoning field of PE, highlight the exciting prospects for this powerful tool, and provide clues for questions that may propel the field forward.     

基于系统化的老旧小区海绵化改造工程精细化设计案例

在青岛市湖畔雅居和石沟社区老旧小区海绵化改造工程中,对当地集中短历时强降雨的气象条件,丘陵地形起伏大、局部易积水的地形以及地下水位低、土壤渗透性好的地质等特点进行了精细化分析,对径流控制、污染物负荷削减、管网排放能力、山洪控制、雨水利用、内涝防治等进行了精细化计算与设计,同时引入"微分区"概念精细化校核各LID及所在的微分区的蓄水能力与实际蓄水量,实行串联转输流量、相邻分区消纳,以避免出现低效率甚至无效率的海绵设施,系统地将保障水安全、改善水环境、修复水生态、涵养水资源、提升水景观结合为一个整体,并强化设计"渗、蓄、排"的透水混凝土路面、雨水调蓄池、旱溪、砾石沟等海绵措施,配置了耐旱、耐湿、耐阴、耐污染而且科学、生态、富有观赏性的植物。基于精细化设计,该工程实际运行效果良好。     

长壁开采切顶短壁梁理论及其110工法——第三次矿业科学技术变革

为了深入了解近距离煤层群切顶留巷上覆岩层应力及变形演化规律,以白皎煤矿B₄煤层、B₃煤层、B₂煤层切顶成巷巷道2442、2443及2444运输平巷为研究对象,开展了3层煤回采巷道开挖物理试验研究,结果表明：①上煤层巷道切顶后,顶板卸压; 煤层开挖后,采空区顶板垮落并支撑巷道顶板,顶板增压; 煤层继续开挖,覆岩断裂,顶板卸压; 巷道顶板应力依次经历卸压、增压及卸压过程,其中,高位顶板应力增加较大,应力较高。②中部巷道切顶及煤层开挖后,上覆岩层压力同时向上煤层巷道围岩及本巷道采动破碎压实围岩转移,并在两巷道之间的上覆岩层中形成应力增高区。③下煤层巷道切顶及煤层开挖后,巷道围岩破坏严重,无集中应力,受前两次开挖卸压影响较大。④上覆岩层沿层理面出现错动变形,同时出现垂直拉伸剪切裂纹,采动影响越大,裂纹扩展程度越大。

     

基于BIM+5G环境的智慧工地集成化应用技术

“BIM+5G数字化管理”是指通过建立BIM的项目数字管控平台和5G数据抓取AI分析平台,并充分利用5G大带宽、低时延、广连接、移动性等特性,以BIM技术和AI人工智能技术为核心,结合物联网、云计算、大数据等新一代信息技术,改变传统施工现场管理的交互方式、工作方式和管理模式,完善智慧工地、突破固定模式,将人工智能引入项目管理,实现对“人机料法环测”的全方位可视化智能管理。本文以深圳悦彩城（北地块）项目为载体,详细介绍了BIM+5G数字化管理体系及其应用,为同类项目BIM+5G智慧工地建设提供方向。     

高淬透性硼微合金化特厚板钢成分优化设计

海洋工程用特厚板钢通常要求具有良好的淬透性,合理设计此类钢化学成分是改善其淬透性的主要方法之一.传统钢成分设计大多以实验为主,耗费巨大.本文以热力学计算软件Thermo-Calc和材料性能计算软件JMat Pro为工具,采用计算、预测与实验相结合的研究模式,对含B微合金化特厚板钢进行成分优化,以期获得高淬透性能.使用Thermo-Calc计算了B微合金化钢的热力学平衡析出相.通过对析出相的析出温度、析出量及相间关系分析,阐述了此类钢的成分设计原则,给出了可获得高淬透性的B微合金化钢的设计成分.采用JMat Pro对设计钢淬透性进行预测,预测结果很好地说明了设计钢成分的合理性.经过淬透性实验和化学相分析,进一步肯定了优化设计结果.理论计算与实验结果表明高铝含量有利于改善硼微合金化钢淬透性.