Quantification and semiquantification of multiple representative components for the holistic quality control of Allii Macrostemonis Bulbus by ultra high performance liquid chromatography with quadrupole time‐of‐flight tandem mass spectrometry

Allii Macrostemonis Bulbus (named Xiebai in China) is a folk medicine with medicinal values for the treatment of thoracic obstruction and cardialgia, and a food additive as well. However, there is even no quantitative standard for Allii Macrostemonis Bulbus recorded in the current edition of the Chinese Pharmacopeia. Hence, simultaneous assay of multiple components is urgent. In this study, chemometric methods were firstly applied to discover the components with significant fluctuation among multiple Allii Macrostemonis Bulbus samples based on optimized fingerprints. Meanwhile, the major components and main absorbed components in rats were all selected as its representative components. Subsequently, a sensitive method was established for the simultaneous determination of 54 components (15 components for quantification and 39 components for semiquantification) by ultra high performance liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry. Moreover, the validated method was successfully applied to evaluate the quality of multiple samples on the market. It became known that multiple Allii Macrostemonis Bulbus samples varied significantly and showed poor consistency. This work illustrated that the proposed approach could improve the quality of Allii Macrostemonis Bulbus, and it also provided a feasible method for quality evaluation of other traditional Chinese medicines.     

Improved quality evaluation of Radix Salvia miltiorrhiza through simultaneous quantification of seven major active components by high-performance liquid chromatography and principal component analysis

A novel method, using high-performance liquid chromatography combined with principal component analysis, was developed for the quality evaluation of danshen through simultaneous determination of seven components, namely danshensu, protocatechuic acid, protocatechuic aldehyde, salvianolic acid B, tanshinone I, cryptotanshinone and tanshinone IIA. These seven components were simultaneously separated on a Zorbax SB-C(18) column. The mobile phase consisted of 0.05% phosphoric acid water and methanol:acetonitrile (1:1) with a gradient elution, and the detection wavelength was set at 280 nm. Thirty samples of danshen and its substitutes from different sources were investigated by the established method. The results showed that the content of each analyte varied considerably in different danshen samples. Among the seven components tested, salvianolic acid B, tanshinone IIA, cryptotanshinone, tanshinone I, danshensu and protocatechuic aldehyde were proved suitable and representative as chemical markers for the quality control of danshen except for protocatechuic acid. Moreover, principal component analysis was used for the similarity evaluation of different samples, and it could be straightforward and reliable to differentiate danshen samples of different origins. In conclusion, simultaneous quantification of multiple components by high-performance liquid chromatography combined with principal component analysis would be a better strategy for the quality evaluation of danshen.     

Phytochemical Analysis,Pharmacological and Safety Evaluations of Halophytic Plant,Salsola cyclophylla

Salsola cyclophylla, an edible halophyte, is traditionally used for inflammation and pain. To confirm the claimed anti-inflammatory and analgesic properties, a detailed study on respective pharmacological actions was undertaken. The activities are contemplated to arise from its phytoconstituents. The LC-MS analysis of S. cyclophylla 95% aqueous-ethanolic extract revealed the presence of 52 compounds belonging to phenols, flavonoids, coumarins, and aliphatics class. A high concentration of Mn, Fe, and Zn was detected by atomic absorption spectroscopic analysis. The ethyl acetate extract showed the highest flavonoid contents (5.94 ± 0.04 mg/g, Quercetin Equivalents) and Fe2⁺-chelation (52%) potential with DPPH radicals-quenching IC₅₀ at 1.35 ± 0.16 mg/mL, while the aqueous ethanolic extract exhibited maximum phenolics contents (136.08 ± 0.12 mg/g, gallic acid equivalents) with DPPH scavenging potential at IC₅₀ 0.615 ± 0.06 mg/mL. Aqueous ethanolic extract and standard quercetin DPPH radicals scavenging’s were equal potent at 10 mg/mL concentrations. The aqueous ethanolic extract showed highest analgesic effect with pain reduction rates 89.86% (p = 0.03), 87.50% (p < 0.01), and 99.66% (p = 0.0004) after 60, 90, and 120 min, respectively. Additionally, aqueous ethanolic extract exhibited the highest anti-inflammation capacity at 41.07% (p < 0.0001), 34.51% (p < 0.0001), and 24.82% (p < 0.0001) after 2, 3, and 6 h of extract’s administration, respectively. The phytochemical constituents, significant anti-oxidant potential, remarkable analgesic, and anti-inflammatory bioactivities of extracts supported the traditionally claimed anti-inflammatory and analgesic plant activities.     

化学学科核心素养导向的教学实践改革思考*——基于2019版AP化学课程标准的分析

《普通高中化学课程标准(2017年版)》的颁布,开启了我国化学学科核心素养导向的教学实践的新时代。美国高中阶段实施的2019版AP化学课程凸显科学实践的课程目标,以4个化学大概念为依据选择、组织课程内容,倡导教、学、评一体化的教学策略,开展以学生为中心的引导性探究实验,设计多样化的评价任务。对比我国现行化学教学实践中缺少大规模教、学、评一体化平台,科学解释和论证能力目标外显不足,教师难以建立化学知识与学科观念素养间联系的现状,提出聚焦课程目标建设过程性评价体系,深度挖掘教学内容背后的科学解释和科学论证能力要求,深入理解知识承载的认识功能和价值等思考。     

澳大利亚化学教育中科学阅读教学评一体化策略研究*—以维多利亚州为例

我国科学教育中科学阅读的现状并不乐观。比较澳大利亚的化学教育,以维多利亚州为例对其官方文件、化学教材、高考考题进行剖析,得出教学评一体化策略可以加强科学阅读,全面提升学生科学素养。借鉴这一策略,可以通过课内与课外、阅读与写作、教学与评价这3方面的相辅相成来促进科学阅读的开展,发展学生的核心素养。     

新工科背景下通识教育类课程的教学模式探索*——以材料导论课程为例

通识教育类课程是新工科背景下推进大类招生与专业分流的重要组成部分。针对高校通识教育类课程教学过程中存在的弊端,从课程定位、教学方式、资源配置和评价体系等4个方面进行统筹规划、整体推进,以最大程度地提升学生的学习效果和人才的培养质量,旨为通识教育类课程的教学改革提供一定的参考。     

基于GIS的高密度城市声景质量及其影响因素研究 ——以广州天河区为例*

密度城市空间背景下,声景质量对居住舒适度及居民身心健康的影响显著。已有声景研究中鲜有针对街区尺度的声景时空特征及其与居民交互关系的探究,不利于高质量宜居城市空间构建。本文基于地理学视角,通过声景漫步与问卷调查对广州市天河区的声源类型、声环境特征、心理声学感知进行调查研究,旨在阐述城市街区尺度声景质量的空间特征及其影响因素。研究认为：1）声压级低、主观响度低、柔和、舒适、安静、自然的声环境有利于提升声景总体满意度,同时声景感知结构的空间性在总体满意度上存在性别差异;2）城市声景特征的空间结构与道路功能和土地利用功能等要素密切相关,其中建筑密度、道路等级、城市综合密度的提升均不利于声景总体满意度的提升,城市生活活力的提升有助于声景总体满意度的提升。基于此,本文认为应通过城市声景空间规划优化高密度城市声环境质量并提升声景满意度,通过合理规划道路、用地功能、与建筑密度等手段,促进积极声景空间营造,促进并实现健康人居环境。     

Fitness of others' evaluation effect promotes cooperation in spatial public goods game

Payoff-driven strategy updating rule has always been adopted as a classic mechanism, but up to now, there have been a great many of researches on considering other forms of strategy updating rules, among which pursuing high fitness is one of the most direct and conventional motivations in the decision-making using game theory. But there are few or no researches on fitness from the perspective of others' evaluation. In view of this, we propose a new model in which the evaluation effect with fitness-driven strategy updating rule is taken into consideration, and introduce an evaluation coefficient to present the degree of others' evaluation on individual's behavior. The cooperative individuals can get positive evaluation, otherwise defective individuals get negative evaluation, and the degree of evaluation is related to the number of neighbors who have the same strategy of individual. Through numerical simulation, we find that the evaluation effect of others can enhance the network reciprocity, thus promoting the cooperation. For a strong dilemma, the higher evaluation coefficient can greatly weaken the cooperation dilemma; for a weak one, the higher evaluation coefficient can make cooperator clusters spread faster, however, there is no significant difference in the level of cooperation in the final stable state among different evaluation coefficients. The cooperation becomes more flourish as the number of fitness-driven individuals increases, when all individuals adopt fitness-driven strategy updating rule, the cooperators can quickly occupy the whole population. Besides, we demonstrate the robustness of the results on the WS small-world network, ER random network, and BA scale-free network.     

Thermosonication effect on bioactive compounds,enzymes activity,particle size,microbial load,and sensory properties of almond (Prunus dulcis) milk

The object of this research was to appraise the physicochemical characteristics of almond milk and consumer acceptability after the thermosonication (TS) processing. The almond milk was subjected to TS processing (frequency: 40 kHz; power: 600 W; Temperature: 30, 45, and 60 °C; Time: 10, 20, 30, and 40 min) and pasteurization (for 60 s at 90 °C). After treatments, all samples were analyzed for bioactive compounds, antioxidant activities, microbial, enzymatic, and sensory attributes. The results showed a non-significant difference in total soluble solids and pH while TS processing at 45 and 60 °C significantly increased the cloudiness, viscosity, browning index, and color properties. TS processing increased the bioavailability of total phenolic, flavonols, flavonoids, condensed tannin contents, and antioxidant activity as compared to untreated and pasteurized samples. TS processing also significantly reduced the particle size distribution through acoustic cavitation. Microbial inactivation with TS at 60 °C resulted in ≥ 5 log reduction of total plate count and ≥ 4 log reduction of yeast & mold was achieved. The highest inhibition of lipoxygenase (LOX) and peroxidase (POD) were observed at 60 °C for 30 min. Moreover, the best sensorial properties were observed after TS processing at 60 °C. Thus; TS processing can increase the almond milk quality and safety as a viable substitute for thermal processing.     

超高效液相色谱-串联质谱法测定螺旋藻多糖的单糖组成

建立了同时测定螺旋藻多糖水解产物中鼠李糖、木糖、阿拉伯糖、果糖、甘露糖、葡萄糖、半乳糖、甘露醇、核糖、岩藻糖、葡萄糖醛酸、半乳糖醛酸12种糖类化合物的超高效液相色谱-串联质谱分析方法。螺旋藻样品经超声波辅助提取,用三氟乙酸水解,经Waters Acquity BEH Amide色谱柱(100 mm×2.1 mm,1.7μm)分离,以10mmol/L甲酸铵和10 mmol/L甲酸铵-乙腈为流动相,在电喷雾电离源负离子(ESI-)模式下,用多反应监测(MRM)模式检测。结果表明,12种糖类化合物的定量限为0.005~0.15 mg/kg,线性范围为0.05~5 mg/L。按照样品中每种糖本底含量的50%、100%、150%进行添加,回收率为80.21%~121.6%。应用该方法对螺旋藻样品进行分析,结果发现:大部分样品都能检测到岩藻糖、半乳糖、阿拉伯糖、鼠李糖、葡萄糖、果糖、木糖、核糖,含量在0.3~889.4 mg/g之间。此外,测定的15个样品中岩藻糖、半乳糖、阿拉伯糖、鼠李糖、葡萄糖、果糖、木糖、核糖是共有组分,含量差异较大,但在所有样品中均未检测到甘露醇和甘露糖。该方法的建立可为阐明螺旋藻多糖的结构组成及其活性提供技术支撑及基础数据。