Prodigiosin of Serratia marcescens ZPG19 Alters the Gut Microbiota Composition of Kunming Mice

Prodigiosin is a red pigment produced by Serratia marcescens with anticancer, antimalarial, and antibacterial effects. In this study, we extracted and identified a red pigment from a culture of S. marcescens strain ZPG19 and investigated its effect on the growth performance and intestinal microbiota of Kunming mice. High-performance liquid chromatography/mass spectrometry revealed that the pigment had a mass-to-charge ratio (m/z) of 324.2160, and thus it was identified as prodigiosin. To investigate the effect of prodigiosin on the intestinal microbiota, mice (n = 5) were administered 150 μg/kg/d prodigiosin (crude extract, 95% purity) via the drinking water for 18 days. Administration of prodigiosin did not cause toxicity in mice. High-throughput sequencing analysis revealed that prodigiosin altered the cecum microbiota abundance and diversity; the relative abundance of Desulfovibrio significantly decreased, whereas Lactobacillus reuteri significantly increased. This finding indicates that oral administration of prodigiosin has a beneficial effect on the intestinal microbiota of mice. As prodigiosin is non-toxic to mouse internal organs and improves the mouse intestinal microbiota, we suggest that it is a promising candidate drug to treat intestinal inflammation.     

Pure Ion Chromatograms Combined with Advanced Machine Learning Methods Improve Accuracy of Discriminant Models in LC–MS-Based Untargeted Metabolomics

Untargeted metabolomics based on liquid chromatography coupled with mass spectrometry (LC–MS) can detect thousands of features in samples and produce highly complex datasets. The accurate extraction of meaningful features and the building of discriminant models are two crucial steps in the data analysis pipeline of untargeted metabolomics. In this study, pure ion chromatograms were extracted from a liquor dataset and left-sided colon cancer (LCC) dataset by K-means-clustering-based Pure Ion Chromatogram extraction method version 2.0 (KPIC2). Then, the nonlinear low-dimensional embedding by uniform manifold approximation and projection (UMAP) showed the separation of samples from different groups in reduced dimensions. The discriminant models were established by extreme gradient boosting (XGBoost) based on the features extracted by KPIC2. Results showed that features extracted by KPIC2 achieved 100% classification accuracy on the test sets of the liquor dataset and the LCC dataset, which demonstrated the rationality of the XGBoost model based on KPIC2 compared with the results of XCMS (92% and 96% for liquor and LCC datasets respectively). Finally, XGBoost can achieve better performance than the linear method and traditional nonlinear modeling methods on these datasets. UMAP and XGBoost are integrated into KPIC2 package to extend its performance in complex situations, which are not only able to effectively process nonlinear dataset but also can greatly improve the accuracy of data analysis in non-target metabolomics.     

Synthesis and characterization of folic acid‐modified carboxymethyl chitosan‐ursolic acid targeted nano‐drug carrier for the delivery of ursolic acid and 10‐hydroxycamptothecin

Carboxymethyl chitosan (CMCS), as a water‐soluble, biocompatible, and biodegradable polymer, is an excellent carrier for a sustained drug delivery system. In this study, a amphiphilic carboxymethyl chitosan‐ursolic acid nano‐drug carrier modified by folic acid (FPCU) were prepared, and then the nano‐drug carrier wrapped another anticancer drug 10‐hydroxycamptothecin were self‐assembled into nanoparticles (FPCU/HCPT NPs). The FPCU/HCPT NPs had a suitable size, high drug loading efficiency of ursolic acid (6.4%) and 10‐hydroxycamptothecin (14.1%). The drug release study in vitro indicated that the nanoparticles have obviously sustained effect and pH sensitive behaviors, the drug release amount was higher at pH 5.5 than at pH 7.4. in vitro and in vivo study showed that the nanoparticles displayed a high antitumor efficiency to tumor cells compared with free drug. The nano delivery system as a carrier for ursolic acid (UA) and 10‐hydroxycamptothecin (HCPT) has good application prospects in cancer treatment.     

Coumarin Sulfonamides and Amides Derivatives: Design,Synthesis, and Antitumor Activity In Vitro

Coumarins possesses immeasurable antitumor potential with minimum side effects depending on the substitutions on the basic nucleus, which exhibits great prospects for antitumor drug development. In an attempt to develop novel antitumor candidates, a series of coumarin sulfonamides and amides derivatives were designed and synthetized. The majority of these derivatives showed good cytotoxic activity against MDA-MB-231 and KB cell lines, among which compound 9c was the most potent against MDA-MB-231 cells, with IC₅₀ value of 9.33 μM, comparable to 5-fluorouracil. Further investigation revealed that compound 9c had versatile properties against tumors, including inhibition of cell migration and invasion as well as inducing apoptosis. Reactive oxygen species (ROS) assay and western blotting analysis suggested that compound 9c promoted cancer cell apoptosis by increasing ROS levels and upregulating the expression of caspase-3 in MDA-MB-231 cells. These results indicated that compound 9c could be promising lead compound for further antitumor drug research.     

MOFs/水凝胶复合材料的制备及其应用研究

金属有机框架(MOFs)具有大量的孔隙结构和活性位点,在气体吸附、催化、医疗等领域均发挥了巨大的作用。MOFs是晶体粉末,具有脆性较大、在水中易分解和不易回收等缺点,从而限制了其应用。通过MOFs与柔性高分子的复合,特别是与水凝胶的复合,极大地改善了复合材料的柔顺性、可回收和可加工性等特性,进一步拓宽了MOFs的应用领域。本文详细阐述了基于水凝胶MOFs原位生成法、MOFs /水凝胶同时生成法和水凝胶包裹MOFs法等三种不同方法制备MOFs/水凝胶复合材料的研究进展,并对上述三种制备方法的特点及其产物特征进行了总结,进一步归纳了复合材料在生物医药、催化、废水处理和气体吸附等领域的应用。最后,对MOFs/水凝胶复合材料制备方法的改进和复合材料应用前景进行了深入讨论和展望。     

初中化学“溶液”的项目式教学*——白砂糖的梦想之路

以“白砂糖的梦想之路”为项目学习主题,呈现了初中化学“溶液”的项目教学案例。基于棒棒糖的制作过程开发了系列学习任务,有助于学生在真实的问题情境中发展核心素养和构建灵活的知识基础。     

强化基础引导创新——核磁共振实验教学体系建设*

面对不同年级本科生和研究生设计了由浅入深、梯度渐进的核磁共振实验教学体系,利用实验教学全面介绍了核磁共振这一重要的分析手段,结合线上教学、课堂互动等新颖的教学模式,加深对重要知识点的认识和了解,与理论教学有机结合,取得了良好的教学效果。     

“功能涂料”课程的教学改革:打造趣味性、互动性和挑战性的课堂*

本着培养涂料行业精英人才的宗旨,针对涂料行业对人才需求的特点,结合多年教学经验,从教材的选择、教学内容设置、教学方法改进以及考核方法改革等4个方面探索了“功能涂料”课程的教学方法改革与课程实践。通过自编教材,精心设置授课内容,将科研成果、前沿知识、生活场景、新闻事件与书本知识相结合,提高课堂的趣味性;通过讨论法和交换式互动上课来加强课堂的互动性;通过过程性评价提高课程的学业挑战度。通过教学改革,本课程的选课率和出勤率得到了大幅提高,学生对涂料的兴趣明显增加,毕业后选择进入涂料领域工作的学生也越来越多。     

超高效液相色谱-串联质谱法测定医用口罩中有机磷酸酯

该研究优化了医用口罩样本中16种有机磷酸酯（OPEs）的萃取和净化前处理过程,建立了超高效液相色谱－串联质谱（UPLC－MS/MS）测定方法。样本经甲醇超声萃取后,采用ENVI－18固相萃取小柱净化,最终使用Acquity UPLC BEH C18色谱柱以5 mmol/L乙酸铵缓冲溶液－甲醇为流动相进行分离,采用UPLC－MS/MS测定,内标法定量。结果表明,16种OPEs在0.1～50 μg/L质量浓度范围内呈良好的线性关系（r > 0.995）,方法检出限为0.004 60～1.03 ng/dm2,定量下限为0.015 2～3.43 ng/dm2,加标回收率为68.8%～140%,相对标准偏差为0.70%～18%。采用所建立的方法对42个医用口罩中16种OPEs进行测定,其总浓度为6.60～2 387 ng/dm2,其中12种OPEs的检出率高于50%,表明这些OPEs在医用口罩中普遍存在。磷酸三苯酯（TPHP）和磷酸三（1-氯-2-丙基）酯（TCIPP）为主要的OPEs,浓度分别为0.131～2 274 ng/dm2和0.370～79.8 ng/dm2。整体上OPEs的浓度均较低,推测口罩样本中的OPEs可能是生产和包装过程中受空气或塑料包装污染所致。     

人体毛发中氯胺酮及其代谢物的超高效液相色谱-串联质谱法检验及含量统计分析

建立了一种高动能研磨结合超高效液相色谱－串联质谱（UPLC－MS/MS）快速检验毛发中氯胺酮及其代谢物的方法,并考察了清洗程序和提取方法对氯胺酮及其代谢物检出效果的影响。确定最佳实验方法为：50 mg头发经0.1%十二烷基硫酸钠、超纯水和丙酮清洗2次后取20 mg置于专用研磨管内,加入1 mL甲醇,使用球磨仪以3 000 r/min研磨3 min,超声2 h,离心过膜进样。结果显示：毛发中氯胺酮、去甲氯胺酮和羟基去甲氯胺酮含量分别在0.01～5.0、0.01～5.0、0.05～5.0 ng/mg范围内线性关系良好,相关系数（r）均大于0.99,回收率为86.7%～106%,基质效应为88.1%～99.6%,日内及日间精密度分别为0.72%～4.1%和1.9%～6.3%。采用该方法检测了50份实际毛发样本,并对氯胺酮、去甲氯胺酮和羟基去甲氯胺酮在阳性毛发中的含量数据进行统计,分析了毛发中氯胺酮及其两种主要代谢物的含量分布情况及原药与代谢物的含量关系,50份真实毛发样本中氯胺酮的最低含量为0.30 ng/mg,羟基去甲氯胺酮与氯胺酮的含量相近且去甲氯胺酮与氯胺酮之间的含量比率为0.05～0.60。该研究结果可为禁毒人员处理涉毒案件提供理论支撑与方法参考。