婴幼儿奶嘴中12种N-亚硝胺类物质迁移量的检测

建立了婴幼儿奶嘴中12种N-亚硝胺类物质迁移量的测定方法。样品经人工唾液盐浸提后,以二氯甲烷为溶剂萃取N-亚硝胺,去水浓缩后,用气相色谱-质谱联用仪进行测定,外标法定量。结果表明,方法的检出限为0.027~0.031mg·L^-1,回收率为87%~120%,相对标准偏差为4.25%~8.31%,满足定量分析的要求。     

气质联用测定橡胶中的的11种N-亚硝胺物质的释放量

根据GB28482-2002对橡胶制品的亚硝胺和亚硝胺盐的释放量进行测试,为了快速,高效的检测橡胶制品中的N-亚硝胺物质的释放量,对样品前处理和GCMS的条件进行优化,建立了气相色谱-质谱联用测定橡胶制品的N-亚硝胺物质的释放量,方法线性范围0.05~2.00 mg/L,线性相关系数大于0.999,检出限达到0.05 mg/L,重复性实验得到相对标准偏差小于5%,加标回收率为85%~115%.满足GB28482-2002对橡胶制品的N-亚硝胺物质的释放量测试要求     

婴幼儿安抚奶嘴中N-亚硝胺和N-亚硝基物质释放量的测定不确定度评估

依据GB 28482-2012《婴幼儿安抚奶嘴安全要求》中对N-亚硝胺和N-亚硝基物质释放量的检测要求,用人工唾液模拟物对安抚奶嘴进行处理,以二氯甲烷作为溶剂,运用气相色谱-热能分析仪测定婴幼儿安抚奶嘴中N-亚硝胺和N-亚硝基物质释放量,并对该方法进行不确定度评估,依据《测量不确定度评定与表示指南》建立数学模型,进行不确定度的计算并合成不确定度。结果表明检测不确定度主要来源于标准曲线、样品重复性和标样纯度,11种标准物质的不确定度介于(0.116±0.023)mg/kg与(0.305±0.033)mg/kg之间,评定程序和方法符合规范要求,适用于同类型实验的不确定度评定。     

气相色谱-质谱联用测定水果和蔬菜中哒螨灵残留量

建立气相色谱-质谱联用测定水果和蔬菜中哒螨灵农药残留量的检测方法.样品经过提取、净化、浓缩后,用气质联用进行检测.方法的检出限0.05 mg/L,样品中哒螨灵的平均添加回收率在79.7%～89.5%之间,变异系数在3.21%～4.78%之间.     

气相色谱-质谱法同时检测枸杞子中的克百威、氧环唑、莎稗磷

建立了气相色谱-质谱法同时测定枸杞子中克百威、氧环唑和莎稗磷残留量的方法.样品用水溶解后,用乙腈提取,经水洗脱糖,后经C18、石墨化炭黑/N-丙基乙二胺(Carb/PSA)净化后,采用气相色谱-质谱联用,在选择离子监测模式下进行检测.用外标法定量.在0.05～5.0 mg/L范围内,克百威、氧环唑、莎稗磷的峰面积与其质量浓度呈良好的线性关系,最低检出限均可达到0.01 mg/kg,回收率为89.23%～97.36%,相对标准偏差为2.11%～5.92%.     

气相色谱-质谱联用法测定电子电气产品聚合物中的二甲苯麝香

建立了自动索氏浸提-气相色谱-质谱联用法测定电子电气产品聚合物中二甲苯麝香的方法。样品采用冷冻研磨仪粉碎后,用环己烷作为萃取剂,在自动索氏浸提装置中萃取,真空旋转蒸发仪浓缩后采用气相色谱-质谱联用仪选择离子监测进行定量分析。二甲苯麝香的检出限为0.06 mg/kg,定量限为0.2 mg/kg,在0.5、1.0、5.0 mg/kg三个添加水平范围内的平均回收率(每个添加浓度平行测定6次)为86.0%~98.5%,相对标准偏差(RSD)值均小于5%。该方法适用于对电子电气产品聚合物中二甲苯麝香的检测工作。     

固相萃取-气相色谱串联质谱测定饮用水中N-亚硝胺类消毒副产物

近年来,N-亚硝胺因其致癌性在水处理中引起了广泛关注,其为氯消毒或臭氧消毒产生的副产物。本试验建立了固相萃取-气相色谱串联质谱(SPE-GC-MS/MS)方法检测饮用水中9种亚硝胺类物质。结果表明,在最佳萃取条件、最优仪器参数下,9种N-亚硝胺含量在1.0～20 ng/L,采用内标法的线性相关系数R~2为0.992～0.999,最低检出限为0.3 ng/L。该检测方法灵敏度高、最低检出限低,适用于饮用水中的N-亚硝胺的检测。     

烟用香精香料中甲醇、仲丁醇的GC-MS分析

通过对色谱柱、色谱条件和前处理条件的选择优化,建立了毛细管气相色谱-质谱联用法准确、快速测定香精香料中甲醇和仲丁醇的分析方法。样品经过超声萃取过滤后,再注入气相色谱-质谱联用仪进行分析,采用选择离子和保留时间定性,内标法定量。香精香料中甲醇的回收率为95.56%~100.32%,相对标准偏差(RSD)2.0%(n=6),检出限为0.13 mg/L,定量限为0.44 mg/L;仲丁醇回收率为94.39%~103.32%,RSD5.0%(n=6),检出限为0.03 mg/L,定量限为0.10 mg/L。该方法与企业标准YQ/T 38-2013相比,测量结果具有良好的一致性,且该方法前处理简单、快速,准确度和灵敏度高,适合大批量样品的测定。     

气相色谱-串联质谱法测定塑料菜板中的多环芳烃

建立了气相色谱-串联质谱快速检测塑料菜板中多环芳烃的方法。样品经液氮冷冻研磨,甲苯超声提取、离心、旋转蒸发后,用气相色谱-质谱仪进行测定,外标法定量。采用DB-5MS柱进行分离,进样口温度280℃,氦气流速1.0 ml/min。检测结果表明:16种多环芳烃在0.1～10.0 mg/L浓度范围内呈良好的线性关系,方法的检出限(S/N=3)为0.03 mg/L,定量限(S/N=10)为0.1 mg/L,平均回收率为79.0%～97.0%,相对标准偏差(n=6)为5.2%～9.9%。该方法具有优异的灵敏度和稳定性,满足塑料菜板中多环芳烃的分析检测和准确定量。     

基于标准加入法的改进计算公式测定苹果中毒死蜱、戊唑醇残留量

采用标准加入法的改进计算公式定量,建立了苹果中毒死蜱、戊唑醇的气相色谱-串联质谱(GC-MS/MS)检测方法。前处理用乙腈提取,分散固相萃取净化,复溶后经气相色谱-串联质谱测定。在0.02～0.1 mg/L范围内,毒死蜱、戊唑醇线性关系良好,相关系数大于0.999,方法定量限为0.001～0.003 mg/kg。3个添加水平下的苹果样品的平均回收率为96.3%～106.0%,相对标准偏差为3.3%～4.9%。与传统计算公式相比,改进计算公式测定样品中毒死蜱、戊唑醇残留量z值更小,准确性更强,适合于样品含量的准确定量。     

Synergistic Interactions of Cannabidiol with Chemotherapeutic Drugs in MCF7 Cells: Mode of Interaction and Proteomics Analysis of Mechanisms

Cannabidiol (CBD), a nonpsychoactive phytocannabinoid, has recently emerged as a potential cytotoxic agent in addition to its ameliorative activity in chemotherapy-associated side effects. In this work, the potential interactions of CBD with docetaxel (DOC), doxorubicin (DOX), paclitaxel (PTX), vinorelbine (VIN), and 7-ethyl-10-hydroxycamptothecin (SN−38) were explored in MCF7 breast adenocarcinoma cells using different synergy quantification models. The apoptotic profiles of MCF7 cells after the treatments were assessed via flow cytometry. The molecular mechanisms of CBD and the most promising combinations were investigated via label-free quantification proteomics. A strong synergy was observed across all synergy models at different molar ratios of CBD in combination with SN−38 and VIN. Intriguingly, synergy was observed for CBD with all chemotherapeutic drugs at a molar ratio of 636:1 in almost all synergy models. However, discording synergy trends warranted the validation of the selected combinations against different models. Enhanced apoptosis was observed for all synergistic CBD combinations compared to monotherapies or negative controls. A shotgun proteomics study highlighted 121 dysregulated proteins in CBD-treated MCF7 cells compared to the negative controls. We reported the inhibition of topoisomerase II β and α, cullin 1, V-type proton ATPase, and CDK-6 in CBD-treated MCF7 cells for the first time as additional cytotoxic mechanisms of CBD, alongside sabotaged energy production and reduced mitochondrial translation. We observed 91 significantly dysregulated proteins in MCF7 cells treated with the synergistic combination of CBD with SN−38 (CSN−38), compared to the monotherapies. Regulation of telomerase, cell cycle, topoisomerase I, EGFR1, protein metabolism, TP53 regulation of DNA repair, death receptor signalling, and RHO GTPase signalling pathways contributed to the proteome-wide synergistic molecular mechanisms of CSN−38. In conclusion, we identified significant synergistic interactions between CBD and the five important chemotherapeutic drugs and the key molecular pathways of CBD and its synergistic combination with SN−38 in MCF7 cells. Further in vivo and clinical studies are warranted to evaluate the implementation of CBD-based synergistic adjuvant therapies for breast cancer.     

关于科研开发效率的思考

作者从认识论和方法论的角度出发，对提高科研开发效率提出如下看法：１．当代的经济竞争，实质是科技产业化能力的竞争。２．研究开发应是从投入到产出的完整系统。３．产业部门的研究开发要面向市场。４．只有充分利用专利保护，才能在国际竞争中赢得主动。５．要保持竞争优势，须把信息工作提到新水平。     

Interphases in the Adhesive Bonding of Fluoropolymers

Strong and durable adhesive bonds may be made between polytetrafluoroethylene (PTFE) and either cyanoacrylate (CA) or epoxy adhesives, if the PTFE surface is modified by the use of a “primer” such as triphenylphosphine (TPP) or diaminodiphenylmethane (DDM). The primer mixes with the PTFE surface, and the modified surface is then capable of forming an interphase, tens to hundreds of nanometers thick, where interpenetration of the adhesive and adherend occurs. Using CA adhesives, PTFE/CA/PTFE block compression shear bond strength (ASTM D4501-85) of over 10 MPa can be achieved, with failure occurring cohesively. Initial work with epoxy adhesives indicates that the use of DDM primer gives adhesive bonds comparable in strength with those produced by modification of the fluoropolymer surface by sodium naphthalenide.     

玉米肽-麦芽糊精糖基化产物与α-生育酚共组装纳米粒子的制备及其性质

通过美拉德反应制备玉米肽-麦芽糊精糖基化产物,再通过反溶剂法制备糖基化产物与α-生育酚共组装纳米粒子,系统地研究了制备参数对于复合粒子的影响。结果表明,糖基化产物浓度、玉米肽与α-生育酚质量比、pH对于复合粒子的粒度与ζ电位有重要的影响。采用动态光散射、ζ电位观察发现,通过调节制备参数,荷载α-生育酚的玉米肽-麦芽糊精糖基化产物可以形成平均粒度为80～100 nm的纳米粒子,其表面电荷分布在-23～-32 mV之间。与玉米肽、玉米肽/麦芽糊精混合物相比,玉米肽-麦芽糊精糖基化产物对于α-生育酚具有更高的荷载效率以及更好的pH稳定性。     

Participation of Amyloid and Tau Protein in Post-Ischemic Neurodegeneration of the Hippocampus of a Nature Identical to Alzheimer’s Disease

Recent evidence suggests that amyloid and tau protein are of vital importance in post-ischemic death of CA1 pyramidal neurons of the hippocampus. In this review, we summarize protein alterations associated with Alzheimer’s disease and their gene expression (amyloid protein precursor and tau protein) after cerebral ischemia, as well as their roles in post-ischemic hippocampus neurodegeneration. In recent years, multiple studies aimed to elucidate the post-ischemic processes in the development of hippocampus neurodegeneration. Their findings have revealed the dysregulation of genes for amyloid protein precursor, β-secretase, presenilin 1 and 2, tau protein, autophagy, mitophagy, and apoptosis identical in nature to Alzheimer’s disease. Herein, we present the latest data showing that amyloid and tau protein associated with Alzheimer’s disease and their genes play a key role in post-ischemic neurodegeneration of the hippocampus with subsequent development of dementia. Therefore, understanding the underlying process for the development of post-ischemic CA1 area neurodegeneration in the hippocampus in conjunction with Alzheimer’s disease-related proteins and genes will provide the most important therapeutic development goals to date.     

表面张力对自由落体液滴形变的影响

液滴运动过程中的形状变化对液滴的蒸发、燃烧等过程有重要影响,表面张力是影响其形状变化的因素之一。为研究表面张力对液滴形变的影响规律,采用低浓度的表面活性剂(十二烷基苯磺酸钠SDBS)配制表面张力为30~72mN·m^-1的水溶液。利用不同外径的针管得到3~5mm粒径的液滴。高速摄像机(PhantomV211,1000pps,800×600pixel)对这些液滴在自由落体过程中的形变规律进行了可视化实验研究,得到了关于Eötvös数(Eo)的半经验关系式。实验结果表明,液滴在自由落体过程中会形成周期性振动形变,振动周期和振幅随表面张力增大而减小。进一步研究发现,初始时液滴形成并断裂所引起的瞬态冲量使液滴内部动量传递进而表现出周期性振动形变。     

小胶质细胞对阿尔兹海默病发生发展的影响作用

阿尔兹海默病(老年性痴呆,AD)是由β淀粉样蛋白(Aβ)和微管相关蛋白(Tau)聚集形成的具有毒性作用的寡聚物而引起的老年人主要以记忆力下降和脑部形成老年斑、神经纤维缠绕为特征的神经退行性疾病. 小胶质细胞作为中枢神经系统中的固有免疫细胞,是脑内免疫监视的关键成分,发挥内源性免疫防御作用. 正常生理状态的小胶质细胞能有效吞噬和清除毒性Aβ寡聚体,阻止AD发生. 在AD病理过程中,过度激活的小胶质细胞通过补体依赖途径过度吞噬突触,导致突触丧失,同时大量释放炎症因子,促进Tau相关病理变化,对神经元造成直接损伤,导致认知功能下降. 由此可见,小胶质细胞在AD发生发展过程中起着双刃剑的作用,探明小胶质细胞的极化状态及其在AD疾病机理中的作用将为攻克AD的药物研发提供突破性思路.     

Gender-Dependent Deregulation of Linear and Circular RNA Variants of HOMER1 in the Entorhinal Cortex of Alzheimer’s Disease

The HOMER1 gene is involved in synaptic plasticity, learning and memory. Recent studies show that circular RNA derived from HOMER1 (circHOMER1) expression is altered in some Alzheimer’s disease (AD) brain regions. In addition, HOMER1 messenger (mRNA) levels have been associated with β-Amyloid (Aβ) deposits in brain cortical regions. Our aim was to measure the expression levels of HOMER1 circRNAs and their linear forms in the human AD entorhinal cortex. First, we showed downregulation of HOMER1B/C and HOMER1A mRNA and hsa_circ_0006916 and hsa_circ_0073127 levels in AD female cases compared to controls by RT-qPCR. A positive correlation was observed between HOMER1B/C, HOMER1A mRNA, and hsa_circ_0073128 with HOMER1B/C protein only in females. Global average area of Aβ deposits in entorhinal cortex samples was negatively correlated with HOMER1B/C, HOMER1A mRNA, and hsa_circ_0073127 in both genders. Furthermore, no differences in DNA methylation were found in two regions of HOMER1 promoter between AD cases and controls. To sum up, we demonstrate that linear and circular RNA variants of HOMER1 are downregulated in the entorhinal cortex of female patients with AD. These results add to the notion that HOMER1 and its circular forms could be playing a female-specific role in the pathogenesis of AD.     

On the several molecules and nanostructures of water

This paper investigates the water molecule from a variety of viewpoints. Water can involve different isotopes of Hydrogen and Oxygen, it can form differently shaped isomer molecules, and, when frozen, it occupies space differently than most other substances do. The tool for conducting the investigation of all this is called 'Algebraic Chemistry'. This tool is a quantitative model for predicting the energy budget for all sorts of changes between different ionization states of atoms that are involved in chemical reactions and in changes of physical state. The model is based on consistent patterns seen in empirical data about ionization potentials, together with rational scaling laws that can interpolate and extrapolate for situations where no data are available. The results of the investigation of the water molecule include comments, both positive and negative, about technologies involving heavy water, poly water, Brown's gas, and cold fusion.     

辉光放电电解降解水体中阳离子桃红FG的机理

用辉光放电电解（GDE）技术对模拟染料废水阳离子桃红FG的降解过程进行了研究。通过发射光谱法测定了GDE产生的活性粒子,用紫外光谱和总有机碳（TOC）分析仪研究了不同放电时间下的脱色率和去除率,用电导率仪和酸度计测定了降解过程中溶液的电导率和pH的变化,同时用离子色谱对降解中间产物进行了分析。结合各种分析结果,探讨了GDE降解阳离子桃红FG的机理。结果表明,在最佳电压600 V时,溶液中产生HO·、O·、H·等高活性粒子;放电120 min时,200 ml 20 mg/L阳离子桃红FG的脱色率和TOC去除率分别可达99.0%和72.6%;降解液pH先减小后增大,电导率存在先增大后减小的趋势;离子色谱测试表明,降解过程中产生多种有机小分子酸。羟基自由基（HO·）对阳离子桃红FG的降解起关键作用,GDE降解阳离子桃红FG的机理为：HO·作用下助色基团键断裂,产生酚类等中间产物,然后继续被降解为醌和小分子有机酸,最终矿化为Cl^-、NO₃^-、CO₂和H₂O。