物理化学在线课程教学设计与实践——以热力学第二定律与卡诺热机为例*

提出在线课程应立足于对线下课堂教学内容的疏导、梳理、凝练和升华,并以“热力学第二定律与卡诺热机”在线课程为例进行介绍。采用问题链形式引导学生从卡诺热机推导热力学第二定律数学表达式,阐明了卡诺热机在热力学第二定律形成过程中的重要作用和地位,强调了卡诺对于热力学的重要贡献,培养了学生探究精神和学科素养。为在线课程提供了教学案例和设计思路。     

新型荧光分子印迹膜特异性识别和检测目标蛋白质

制备了一种新型荧光分子印迹膜(L-半胱氨酸修饰的量子点嵌入的分子印迹膜(QDs@MIM)),并将其作为荧光人工受体用于目标蛋白质(溶菌酶)的特异性识别和检测。QDs@MIM以溶菌酶为模板分子、丙烯酰胺为功能单体、L-半胱氨酸修饰的量子点为辅助单体、N,N′-亚甲基双丙烯酰胺为交联剂,在预硅烷化的玻璃板上制备而成。在最佳条件下,QDs@MIM对溶菌酶检测的线性范围为0.1~1.0μmol/L,吸附平衡时间为4 min,选择性因子为6.2。该方法操作简单、吸附平衡时间短、选择性高,具备作为生物传感器快速分析样品中目标蛋白质的潜力。     

Selective biocompatibility and responsive imaging property of cationic conjugated polyelectrolyte to cancer cells

Herein, we bring novel insights into a water-soluble conjugated polyelectlyte by deeply studying its properties in cells and observe fl uorescence enhancement of blue emission and turn-on of long-wavelength emission of PFP in HepG2 cells.     

Research on mechanical and dielectric properties of XLPE cable under accelerated electrical‐thermal aging

Research into the electrical‐thermal aging properties of cross‐linked polyethylene (XLPE) cable has great significance, because of its wide application. This study conducted accelerated electrical‐thermal aging tests on 10‐kV XLPE cable in order to assess the cable's mechanical and dielectric properties. After being aged by applying 34.8‐kV AC voltage at the four temperatures of 90, 103, 114, and 135°C, the cable samples were taken out in five stages according to the aging time and cut into slices. The slices were conducted experiments to test the breaking elongation, tensile strength, gel content, breakdown voltage, and frequency spectrums of the dielectric constant and dielectric loss. The results demonstrate that the mechanical strength and gel content of XLPE vary greatly under different aging temperatures, a finding that is associated with the crystallization characteristics of the material. The breakdown voltage shows a slight decreasing trend with aging time. The dielectric constant decreases with aging time in high‐frequency areas (10³–10⁶ Hz), while the dielectric loss factor increases with aging time at low frequencies (10^?2–0 Hz). These two parameters can be used to characterize the degree of aging in cable. Copyright © 2016 John Wiley & Sons, Ltd.     

Ag@AgCl embedded on cellulose film: a stable,highly efficient and easily recyclable photocatalyst

In this work, cellulose–Ag@AgCl composite films have been fabricated directly through a one-step coagulation of a cellulose/1-butyl-3-methylimidazolium chloride (BmimCl) solution with AgNO₃ and PVP. The AgCl was formed upon the addition of AgNO₃ to a cellulose/BmimCl solution, and underwent further reaction with excess Cl^?, leading to the complete dissolution of AgCl. The AgCl crystals were regenerated on the cellulose matrix during the coagulation process. The AgCl was partial decomposed to Ag⁰ and formed Ag@AgCl under visible light irradiation. The morphology of Ag@AgCl in the cellulose matrix was controlled by varying the concentration of PVP. The addition of PVP enabled the formation of stable cellulose films embedded with Ag@AgCl. The composite film demonstrated efficient photodegradation of methyl orange, which was retained upon recycling. This work thus provides a simple pathway for the preparation of Ag@AgCl embedded on a polymer support via one-step coagulation.     

刺五加叶黄酮脂质体和滴丸的药动学差异比较

采用液质联用(LC-MS/MS)方法,分析刺五加叶黄酮脂质体、刺五加叶滴丸和刺五加叶黄酮提取物经大鼠灌胃给药后其主要成分金丝桃苷的药代动力学和生物利用度,考察刺五加叶黄酮的适宜剂型。用PKsolver软件进行药代动力学数据处理,大鼠灌胃刺五加叶黄酮提取物、刺五加叶滴丸和刺五加叶黄酮脂质体后测得金丝桃苷的最大血药浓度(C_(max))分别为(210.24±10.3)、(254.12±9.2)、(349.34±12.5)μg/L;0~t时间内药时曲线面积(AUC_(0-t))分别为(30.7±2.7)、(35.01±1.98)、(45.2±2.8)μg/(m L·min);平均驻留时间(MRT)分别为(334.42±75.36)、(394.56±90.26)和(640.35±84.26)min。结果表明,刺五加叶黄酮脂质体血药达峰浓度增加,清除速率降低,药时曲线下面积加大,生物利用度显著提高,脂质体有望成为刺五加叶黄酮的适宜剂型。     

Bayesian variable selection with sparse and correlation priors for high-dimensional data analysis

The main challenge in working with gene expression microarrays is that the sample size is small compared to the large number of variables (genes). In many studies, the main focus is on finding a small subset of the genes, which are the most important ones for differentiating between different types of cancer, for simpler and cheaper diagnostic arrays. In this paper, a sparse Bayesian variable selection method in probit model is proposed for gene selection and classification. We assign a sparse prior for regression parameters and perform variable selection by indexing the covariates of the model with a binary vector. The correlation prior for the binary vector assigned in this paper is able to distinguish models with the same size. The performance of the proposed method is demonstrated with one simulated data and two well known real data sets, and the results show that our method is comparable with other existing methods in variable selection and classification.     

Determination of Polycyclic Aromatic Hydrocarbons in Mosses by Ultrasonic-Assisted Extraction and Gas Chromatography–Tandem Mass Spectrometry

A facile method for the determination of polycyclic aromatic hydrocarbons in mosses is reported using ultrasonic-assisted extraction and gas chromatography–tandem mass spectrometry. The efficiency of ultrasonic-assisted extraction and the reagents was optimized. Tandem mass spectrometry with selective reaction monitoring was used to enhance the selectivity to reduce matrix interferences and simplify the purification protocol. The detection limits were from 0.1 to 2.0?ng/mL. The linear calibration range was two orders of magnitude and the coefficients of linear correlation exceeded 0.9992 for all analytes. The relative standard deviations within 1 day and 3 days were less than 9.0%. Recoveries from 56.8 to 109.0% were obtained in fortified mosses. The rapid, low solvent gas chromatography–tandem mass spectrometry method was used to determine polycyclic aromatic hydrocarbons in mosses.     

Solubility and Solution Thermodynamic Properties of 4-(4-Hydroxyphenyl)-2-butanone (Raspberry Ketone) in Different Pure Solvents

The solubility of 4-(4-hydroxyphenyl)-2-butanone (raspberry ketone) in six pure solvents was experimentally determined at temperatures ranging from 283.15 to 313.15 K under the pressure 0.10 MPa by employing a gravimetrical method. The experimental results indicate that the solubility of raspberry ketone in all studied solvents is temperature dependent, a rise in temperature brings about an increase in solubility. The experimental solubility data of raspberry ketone in six pure solvents (acetone, ethanol, ethyl acetate, n-propyl alcohol, n-butyl alcohol, and distilled water) was correlated by using several commonly used thermodynamic models, including the Apelblat, van’t Hoff and λh equations. The results of the error analysis indicate that the van’t Hoff equation was able to give more accurate and reliable predictions of solubility with root-mean-square deviation less than 0.56%. Furthermore, the changes of dissolution enthalpies (Δ_diss H°), dissolution entropies (Δ_diss S°) and dissolution Gibbs energies (Δ_diss G°) of raspberry ketone in the solvents studied were estimated by the van’t Hoff equation. The positive value of Δ_diss H°, Δ_diss S°, and Δ_diss G° indicated that these dissolution processes of raspberry ketone in the solvents studied were all endothermic and enthalpy-driven.