创新型综合实验设计:6-氟-N-苯甲酰基四氢喹啉的合成

针对本科实验教学中缺乏安全有效的亲电氟代反应的相关内容,设计了含氟精细化学品中间体的合成与表征综合性化学实验。实验利用N-羟基邻苯二甲酰亚胺(NHPI)作为催化剂,1-氯甲基-4-氟-1,4-二氮杂双环[2.2.2]辛烷二(四氟硼酸)盐(Selectfluor)为亲电氟化试剂,在温和条件下实现了四氢喹啉芳环上的高选择性亲电氟代反应,并对合成产物进行了红外、核磁和高分辨质谱表征。实验从有机合成、分离纯化、结构表征等多方面对学生进行理论和实验技能的综合训练,具备综合性、设计性和应用性,贴合精细化工专业学科发展。通过实验教学使学生掌握了含氟精细化学品的制备方法,拓展了学生的专业视野,培养了科研创新理念以及独立思考、分析解决问题的能力。

Morphological evolution and flow conduction characteristics of fracture channels in fractured sandstone under cyclic loading and unloading

In coal mining,rock strata are fractured under cyclic loading and unloading to form fracture channels.Fracture channels are the main flow narrows for gas.Therefore,expounding the flow conductivity of fracture channels in rocks on fluids is significant for gas flow in rock strata.In this regard,graded incremental cyclic loading and unloading experiments were conducted on sandstones with different initial stress levels.Then,the three-dimensional models for fracture channels in sandstones were established.Finally,the fracture channel percentages were used to reflect the flow conductivity of fracture channels.The study revealed how the particle size distribution of fractured sandstone affects the formation and expansion of fracture channels.It was found that a smaller proportion of large blocks and a higher proportion of small blocks after sandstone fails contribute more to the formation of fracture channels.The proportion of fracture channels in fractured rock can indicate the flow conductivity of those channels.When the proportion of fracture channels varies gently,fluids flow evenly through those channels.However,if the proportion of fracture channels varies significantly,it can greatly affect the flow rate of fluids.The research results contribute to revealing the morphological evolution and flow conductivity of fracture channels in sandstone and then provide a theoretical basis for clarifying the gas flow pattern in the rock strata of coal mines.

Single-cell spatial transcriptomics in cardiovascular development,disease,and medicine

Cardiovascular diseases(CVDs)impose a significant burden worldwide.Despite the elucidation of the etiology and underlying molecular mechanisms of cvDs by numerous studies and recent discovery of effective drugs,their morbidity,disability,and mortality are still high.Therefore,precise risk stratification and effective targeted therapies for CvDs are warranted.Recent improvements in single-cell RNA sequencing and spatial transcriptomics have improved our understanding of the mechanisms and cells involved in cardiovascular phylogeny and CvDs.Single-cell RNA sequencing can facilitate the study of the human heart at remarkably high res-olution and cellular and molecular heterogeneity.However,this technique does not provide spatial information,which is essential for understanding homeostasis and disease.Spatial tran-scriptomics can elucidate intracellular interactions,transcription factor distribution,cell spatial localization,and molecular profiles of mRNA and identify cell populations causing the disease and their underlying mechanisms,including cell crosstalk.Herein,we introduce the main methods of RNA-seq and spatial transcriptomics analysis and highlight the latest ad-vances in cardiovascular research.We conclude that single-cell RNA sequencing interprets dis-ease progression in multiple dimensions,levels,perspectives,and dynamics by combining spatial and temporal characterization of the clinical phenome with multidisciplinary tech-niques such as spatial transcriptomics.This aligns with the dynamic evolution of CVDs(e.g.,"angina-myocardial infarction-heart failure"in coronary artery disease).The study of pathways for disease onset and mechanisms(e.g.,age,sex,comorbidities)in different patient subgroups should improve disease diagnosis and risk stratification.This can facilitate precise individualized treatment of CVDs.

抗生素和肠道细菌对小菜蛾适合度的影响

【目的】小菜蛾是危害十字花科蔬菜的世界性重要害虫。通过分析抗生素对小菜蛾的毒性效应,了解肠道细菌对小菜蛾适合度的影响,有助于更好地阐明小菜蛾肠道细菌的功能。【方法】利用抗生素处理含有高丰度肠道细菌的萝卜苗饲养品系(FZss)小菜蛾幼虫,同时利用抗生素处理饲料饲养的无肠道细菌(SLss)小菜蛾幼虫,分析抗生素及肠道细菌对小菜蛾适合度的影响。【结果】抗生素处理FZss品系小菜蛾导致了小菜蛾发育历期延长,虫重、蛹重、化蛹率、产卵量和成虫寿命降低。利用抗生素处理无肠道菌的SLss品系小菜蛾幼虫,小菜蛾化蛹率和单雌产卵量均显著降低,而对发育历期、虫重和蛹重则无影响。【结论】综合两个研究的结果发现抗生素处理后宿主适合度的降低一方面是由于抗生素的毒性效应导致,另一方面是由于小菜蛾肠道细菌的缺失引起。抗生素的毒性效应主要表现为对化蛹率和单雌产卵量的影响,而肠道细菌则对小菜蛾的发育历期、虫重、蛹重以及成虫寿命具有重要的促进作用。

Fast-response fluorescent probe with favorable water solubility for highly sensitive imaging of endogenous tyrosinase in living cells and zebrafish model

Tyrosinase(TYR) is an important polyphenolic oxidase enzyme and usually regards as a biomarker of melano ma cancer.Highly effective tracking TYR activity in vivo will help to study the mechanism of TYR in living organisms and forecasts related diseases.In this study,we present a novel TYR-activatable fluo rescent probe(CHMC-DOPA) for tracking TYR activity in vitro and in vivo.CHMC-DOPA is constructed by incorporating dopamine(DOPA) moiety into a fluorescent chloro-hydroxyl-merocyanine(CHMC)scaffold.Upon exposure to TYR,the dopamine unit in CHMC-DOPA is oxidized to a dopaquinone derivative,and an intramolecular photo-induced electron transfer(PET) process between CHMC fluorophore and o-dopaquinone will take place,the fluorescence of CHMC-DOPA is quenched rapidly.Therefore,the evaluation of TYR activity is established in terms of the relationship between fluorescence quenching efficiency and TYR activity.In our experiments,CHMC-DOPA shows various advantages,such as fast response(8 min),low concentration of TYR activation(0.5 U/mL),good water-solubility,as well as the lowest detection limit(0.003 U/mL) compared with previously reported works.Furthermore,CHMCDO PA also exhibits excellent cell membrane permeability and low cytotoxicity,which is successfully used to monitor endogenous TYR activity in living cancer cells and zebrafish models.CHMC-DOPA performs well,and we anticipate that this newly designed novel platform will provide an alternative for high effective monitoring TYR activity in biosystems.

Asymmetric Hydrosilylation of Aromatic Ketones Catalyzed by an Economical and Effective Copper-Diphosphine Catalytic System in Air

In the presence of the inexpensive and non-toxic polymethylhydrosiloxane, the combination of copper(II) acetateand a chiral diphosphine displayed high catalytic efficiency in the asymmetric hydrosilylation of a series ofaromatic ketones in air atmosphere and at room temperature. (R)-1-Arylethanols were obtained with up to 99%yield and 93% enantiomeric excess. Meanwhile, the electron effect and steric hindrance of substituents on the aromaticring had an interesting influence on both the yields and enantioselectivities. Furthermore, a possible mechanismwas presented to explain the influence of some key factors on the reaction.