Molecular Simulations and Drug Discovery of Adenosine Receptors

G protein-coupled receptors (GPCRs) represent the largest family of human membrane proteins. Four subtypes of adenosine receptors (ARs), the A₁AR, A_2AAR, A_2BAR and A₃AR, each with a unique pharmacological profile and distribution within the tissues in the human body, mediate many physiological functions and serve as critical drug targets for treating numerous human diseases including cancer, neuropathic pain, cardiac ischemia, stroke and diabetes. The A₁AR and A₃AR preferentially couple to the G_i/o proteins, while the A_2AAR and A_2BAR prefer coupling to the G_s proteins. Adenosine receptors were the first subclass of GPCRs that had experimental structures determined in complex with distinct G proteins. Here, we will review recent studies in molecular simulations and computer-aided drug discovery of the adenosine receptors and also highlight their future research opportunities.     

Construction of Chiroptical Switch on Silica Nanoparticle Surface via Chiral Self-assembly of Side-chain Azobenzene-containing Polymer

In this contribution, we utilized surface-initiated atom transfer radical polymerization(SI-ATRP) to prepare organic-inorganic hybrid core/shell silica nanoparticles(NPs), where silica particles acted as cores and polymeric shells(PAzo MA*) were attached to silica particles via covalent bond. Subsequently, chiroptical switch was successfully constructed on silica NPs surface taking advantage of supramolecular chiral selfassembly of the grafted side-chain Azo-containing polymer(PAzo MA*). We foun...     

基于4-(2，4-二羧基苯氧基)邻苯二甲酸配体的锌配位聚合物的合成、结构及其荧光传感性能

基于H₄dpa和bpy (H₄dpa=4-(2,4-二羧基苯氧基)邻苯二甲酸,bpy=4,4''-联吡啶)为配体,在水热条件下设计、合成了金属锌配位聚合物(Zn-CP)[Zn(H₂dpa)(bpy)_1.5]_n (1),并用元素分析、红外光谱、X射线单晶衍射等对其进行了结构表征。在1中相邻Zn²⁺与H₂dpa^2-离子和bpy配位形成一维双链结构,相邻的一维双链通过氢键作用扩展形成三维超分子网结构。荧光研究表明：1是一种灵敏度高、选择性好、多响应的荧光传感器,可用于农药和硝基爆炸物的检测。有趣的是,2,4,6-三硝基苯(TNP)和嘧霉胺(Pth)对1的荧光发射显示出明显的猝灭效果,而抑霉唑(Ima)对1有荧光增强效果。此外,通过紫外可见吸收光谱、荧光寿命以及X射线光电子能谱探究了1的荧光传感机理。     

八种黄酮类天然产物对高危型HPV16/18 E6蛋白的分子对接研究

宫颈癌以其高发病率和高死亡率严重危害女性健康,传统治疗手段有效率低且治疗过程给患者带来极大痛苦。近年来,许多天然植物来源化合物已被确定为治疗和预防宫颈癌的有希望的药物来源,但天然产物治疗癌症的具体作用机制尚未明确。因此,本文选取了8种黄酮类天然小分子抑制剂,分别与高危型HPV16/18 E6蛋白重要位点LxxLL疏水口袋进行分子对接研究,以期探索天然产物抗宫颈癌的作用机制。对接分析显示,这些天然产物均与HPV18E6蛋白LxxLL疏水口袋产生较强相互作用,与HPV16 E6蛋白对接时,木犀草素则比其他7种黄酮类化合物结合得更为深入,这些相互作用可能有助于p53功能的恢复。对接分析有助于理解蛋白质-配体相互作用的分子机制,为设计治疗HPV感染的新药提供依据。     

Bola型表面活性剂合成及其应用

介绍了Bola型表面活性剂独特的结构特征与性质,概述了由Bola型两亲分子在气液界面自组装形成的单分子膜及囊泡的特征。重点综述了Bola型表面活性剂的合研究进展,并对其在纳米材料、药物缓释、生物矿化、光化学修饰及抑止金属腐蚀等方面的应用作了介绍。最后对其研究前景作了展望。     

Marker-Independent Food Identification Enabled by Combing Machine Learning Algorithms with Comprehensive GC × GC/TOF-MS

Reliable methods are always greatly desired for the practice of food inspection. Currently, most food inspection techniques are mainly dependent on the identification of special components, which neglect the combination effects of different components and often lead to biased results. By using Chinese liquors as an example, we developed a new food identification method based on the combination of machine learning with GC × GC/TOF-MS. The sample preparation methods SPME and LLE were compared and optimized for producing repeatable and high-quality data. Then, two machine learning algorithms were tried, and the support vector machine (SVM) algorithm was finally chosen for its better performance. It is shown that the method performs well in identifying both the geographical origins and flavor types of Chinese liquors, with high accuracies of 91.86% and 97.67%, respectively. It is also reasonable to propose that combining machine learning with advanced chromatography could be used for other foods with complex components.     

Synergistic Treatment of Congo Red Dye with Heat Treated Low Rank Coal and Micro-Nano Bubbles

In this study, the adsorption method and micro-nano bubble (MNB) technology were combined to improve the efficiency of organic pollutant removal from dye wastewater. The adsorption properties of Congo red (CR) on raw coal and semi-coke (SC) with and without MNBs were studied. The mesoporosity of the coal strongly increased after the heat treatment, which was conducive to the adsorption of macromolecular organics, such as CR, and the specific surface area increased greatly from 2.787 m²/g to 80.512 m²/g. MNBs could improve the adsorption of both raw coal and SC under different pH levels, temperatures and dosages. With the use of MNBs, the adsorption capacity of SC reached 169.49 mg/g, which was much larger than that of the raw coal at 15.75 mg/g. The MNBs effectively reduced the adsorption time from 240 to 20 min. In addition, the MNBs could ensure the adsorbent maintained a good adsorption effect across a wide pH range. The removal rate was above 90% in an acidic environment and above 70% in an alkaline environment. MBs can effectively improve the rate of adsorption of pollutants by adsorbents. SC was obtained from low-rank coal through a rapid one-step heating treatment and was used as a kind of cheap adsorbent. The method is thus simple and easy to implement in the industrial context and has the potential for industrial promotion.     

Multi-Objective Optimization of the Basic and Regenerative ORC Integrated with Working Fluid Selection

A multi-objective optimization based on the non-dominated sorting genetic algorithm (NSGA-II) is carried out in the present work for the basic organic Rankine cycle (BORC) and regenerative ORC (RORC) systems. The selection of working fluids is integrated into multi-objective optimization by parameterizing the pure working fluids into a two-dimensional array. Two sets of decision indicators, exergy efficiency vs. thermal efficiency and exergy efficiency vs. levelized energy cost (LEC), are adopted and examined. Five decision variables including the turbine inlet temperature, vapor superheat degree, the evaporator and condenser pinch temperature differences, and the mass fraction of the mixture are optimized. It is found that the turbine inlet temperature is the most effective factor for both the BORC and RORC systems. Compared to the reverse variation of exergy efficiency and thermal efficiency, only a weak conflict exists between the exergy efficiency and LEC which tends to make the binary objective optimization be a single objective optimization. The RORC provides higher thermal efficiency than BORC at the same exergy efficiency while the LEC of RORC also becomes higher because the bare module cost of buying one more heat exchange is higher than the cost reduction due to the reduced heat transfer area. Under the heat source temperature of 423.15 K, the final obtained exergy and thermal efficiencies are 45.6% and 16.6% for BORC, and 38.6% and 20.7% for RORC, respectively.     

有机化学在线课堂教学实践探索

2020年春季学期受到新冠肺炎疫情的影响,全国各地高校的教学工作无法正常开展。我校积极响应教育部提出的"停课不停教、停课不停学"要求,利用"雨课堂"和"腾讯会议"等教学软件对学生进行在线课堂教学。本文以有机化学教学为例,介绍了在线课堂教学的实施过程和教学效果。针对在线课堂教学的特殊性,改变教学模式,确保教学工作正常有序进行。     

CdZnTe像素阵列探测器成像评价模型及实验

考虑载流子陷获效应建立了碲锌镉(CdZnTe)像素阵列探测器感应电荷分布模型,并从非平衡载流子连续方程出发,推导了晶体内部陷获载流子数密度分布,得到了CdZnTe探测器成像调制传递函数评价模型。数值计算结果表明：随入射光子能量的增加,探测器成像质量明显下降;当电子载流子与空穴载流子迁移寿命积范围分别为0.510-3 to 5.010-3 cm2/V,2.010-5 to 7.510-5 cm2/V时,电子载流子感应信号是探测器响应信号的主要来源,而空穴迁移寿命积变化对探测器成像性能的影响有限,所建立模型的载流子收集特性与实际探测器载流子收集特性相符。搭建了40 mm40 mm的CdZnTe成像探测系统,探测并获得了系统预采样调制传递函数。实验结果表明:模型理论值与实验数据相符合,实际CdZnTe晶体中存在的固有深能级缺陷、实验所采用的非单色性X射线源及较大的实际像素间隙是造成理论值与实验结果存在一定偏差的主要原因。