荧光和羟基修饰聚天冬氨酸的制备与阻垢性能——推荐一个综合化学实验

设计了荧光和羟基修饰聚天冬氨酸的制备、表征和阻垢性能的综合实验。首先合成了水溶性荧光物质和聚琥珀酰亚胺(PSI),然后用该荧光物质和乙醇胺修饰PSI并碱性水解,获得目标阻垢剂。用1H NMR、凝胶渗透色谱和荧光分光光度计表征该阻垢剂,并通过静态阻垢试验测试该阻垢剂的阻垢性能。本实验融合了高分子化学、有机化学和分析化学内容,体现了“合成–表征–分析”的科学研究过程,强调了“物质–结构–性能”的科研思维模式,可以培养学生的实验素养和科研能力。

思政元素与高分子化学课程的有机融合

将思政元素与教学内容有机融合是实现“立德树人”的有效举措。本文分别从高分子化学理论和实验教学入手,以学生为中心、产出为导向,构建思政目标,设计思政环节,对典型教学思政案例进行剖析,采用调查问卷和产出效果评价课程思政建设情况。结果表明,通过将思政元素有机融入在教学中,不仅加深了学生对专业知识的理解,而且提高了学生的思想政治素养。

沥滤法制备低蛋白天然橡胶的性能表征

低蛋白天然橡胶主要通过去除水溶性蛋白质来制备,且酶处理天然胶乳加离心法是脱除天然橡胶中水溶性蛋白质的主要方法。文章先采用碱性蛋白酶处理天然胶乳,然后用多次沥滤配合绉片去除水溶性蛋白质的方法制备低蛋白天然橡胶,并对沥滤法得到的低蛋白天然橡胶(L-LPNR)与离心法低蛋白天然橡胶(C-LPNR)进行性能对比,探究不同制备方法对低蛋白天然橡胶结构和性能的影响。由于沥滤法减小了离心力的作用,保留了天然橡胶分子链中的部分蛋白质水解产物。而蛋白质水解产物具备加速硫化和促进交联的作用,能使L-LPNR的硫化速度较快、交联密度较高;较高的交联密度限制了橡胶分子链间的滑移,相同的测试条件下L-LPNR的内生热比C-LPNR的大约低9℃。

Targeting cAMP in D1-MSNs in the nucleus accumbens, a new rapid antidepressant strategy

Studies have suggested that the nucleus accumbens(NAc)is implicated in the pathophysiology of major depression;however,the regulatory strategy that targets the NAc to achieve an exclusive and outstanding anti-depression benefit has not been elucidated.Here,we identified a specific reduction of cyclic adenosine monophosphate(cAMP)in the subset of dopamine D1 receptor medium spiny neurons(D1-MSNs)in the NAc that promoted stress susceptibility,while the stimulation of cAMP production in NAc D1-MSNs efficiently rescued depression-like behaviors.Ketamine treatment enhanced cAMP both in D1-MSNs and dopamine D2 receptor medium spiny neurons(D2-MSNs)of depressed mice,however,the rapid antidepressant effect of ketamine solely depended on elevating cAMP in NAc D1-MSNs.We discovered that a higher dose of crocin markedly increased cAMP in the NAc and consistently relieved depression 24 h after oral administration,but not a lower dose.The fast onset property of crocin was verified through multicenter studies.Moreover,crocin specifically targeted at D1-MSN cAMP signaling in the NAc to relieve depression and had no effect on D2-MSN.These findings characterize a new strategy to achieve an exclusive and outstanding anti-depression benefit by elevating cAMP in D1-MSNs in the NAc,and provide a potential rapid antidepressant drug candidate,crocin.

Prefrontal cortical circuits in anxiety and fear:an overview

Pathological anxiety is among the most difficult neuropsychiatric diseases to treat pharmacologically,and it represents a major societal problem.Studies have implicated structural changes within the prefrontal cortex(PFC)and functional changes in the communication of the PFC with distal brain structures in anxiety disorders.Treatments that affect the activity of the PFC,including cognitive therapies and transcranial magnetic stimulation,reverse anxiety-and fear-associated circuit abnormalities through mechanisms that remain largely unclear.While the subjective experience of a rodent cannot be precisely determined,rodent models hold great promise in dissecting well-conserved circuits.Newly developed genetic and viral tools and optogenetic and chemogenetic techniques have revealed the intricacies of neural circuits underlying anxiety and fear by allowing direct examination of hypotheses drawn from existing psychological concepts.This review focuses on studies that have used these circuit-based approaches to gain a more detailed,more comprehensive,and more integrated view on how the PFC governs anxiety and fear and orchestrates adaptive defensive behaviors to hopefully provide a roadmap for the future development of therapies for pathological anxiety.