性别对刷牙习惯和釉质脱矿影响的临床研究

目的了解不同性别医学新生的刷牙状况和对釉质脱矿的影响,为宣传正确有效的刷牙知识提供依据。方法采用随机整群抽样的方法,对347名医学新生(男生194名,女生153名)进行刷牙问卷调查并进行釉质脱矿检查和脱矿指数的计算。结果女生在刷牙次数方面好于男生,差异显著(P0.01);每次刷牙时间超过3 min以上的新生只占少数,男生问题尤为突出;大多数人能采用横竖结合的正确方法刷牙,但很少人能清洁所有刷牙部位,能做到餐后刷牙的更是寥寥无几。两组人群釉质脱矿指数有显著的统计学差异(P0.05),女性明显好于男性。结论医学新生刷牙状况不佳,日常刷牙行为亟待改善。不同性别医学新生的刷牙认知和行为存在差异,导致两组人群脱矿程度不同,女性人群的釉质脱矿程度较轻。     

大同市居民对室内空气质量认知程度的调查

为了解大同市居民对室内空气质量的认知情况,并分析认知程度与教育的关系,于2016年3月至5月,在大同市城区的9个社区随机对居民进行问卷调查。问卷内容包括居民对室内空气质量安全知识的了解,检测室内空气质量的意愿和治理意愿3个方面。将居民所处地域、居民的年龄与学历对室内空气质量安全认知程度的影响分别进行统计学分析。结果表明,大同市居民室内空气质量安全认知程度总体得分15.8,得分率为52.7%;新城区的居民对室内空气质量安全认知水平高于老城区居民（p<0.05）;学历越高且越年轻的居民对室内空气质量安全的认知水平越高,寻求有关机构进行室内空气检测和治理的意愿更强烈,且对检测和治理的费用承受度较高。大同市居民对室内空气质量安全认知程度总体不高,还应加强对市民的室内空气质量安全方面的教育。     

耦合反应扩散体系中分布式延迟对图灵斑图的影响

在许多信息传递系统中都存在延迟现象,相关研究表明,耦合振子系统中的延迟作用能导致振死、多节律混沌、空间斑图和波等现象,其中多数现象已经得到的实验验证．图灵斑图与生物成型素具有潜在的联系,使其在理论和实验方面得到了多方面的研究．Barrio等发现图灵体系间的耦合作用可以得到与生物界相似的复杂斑图．Yang等也在耦合体系中发现了一系列新型图灵斑图．     

不同极性的临界介质对孔道中甲醇的脱附和萃取作用

针对临界溶剂对多孔介质中甲醇的脱附和萃取作用,利用Monte Carlo (MC)方法考察了溶剂的分子结构与外在因素（孔道尺寸）对甲醇合成过程的影响。研究表明,极性溶剂丙酮能够促进甲醇脱附,而非极性溶剂正庚烷对孔道中甲醇有更强的萃取能力。在一定范围内,随孔道尺寸的增加,溶剂对甲醇的脱附能力增加,但对孔道中甲醇的萃取能力却减弱。     

不同碳链临界正烷烃对孔道中甲醇作用的Monte Carlo模拟

利用Monte Carlo(MC)方法考察了烷烃的分子尺寸与介质孔道尺寸对孔道中甲醇脱附和萃取的影响.研究表明,随孔道尺寸的增加,不同碳链的正烷烃(C5~C8)对甲醇脱附作用受孔尺寸的影响在逐渐减小;孔道尺寸不同对正烷烃萃取能力的影响程度也不相同.     

盐酸胍诱导的变性卵清溶菌酶分子重折叠过程及其各稳定构象态的分布和过渡

采用变性和非变性电泳、 高效凝胶排阻色谱、 内源荧光发射光谱和荧光相图以及生物活性测定等方法, 研究了盐酸胍诱导的变性卵清溶菌酶分子的重折叠过程及此过程中卵清溶菌酶分子各稳定构象态的分布和过渡. 结果表明, 当复性液中盐酸胍浓度分别约为5.0和2.4 mol/L时, 变性卵清溶菌酶分子的重折叠过程各存在1个稳定折叠中间态, 重折叠过程符合"四态模型". 在卵清溶菌酶分子四态重折叠过程基础上, 结合盐酸胍与卵清溶菌酶分子之间的缔合-解离平衡, 给出了一个定量描述变性剂诱导的蛋白质分子复性过程中蛋白质分子复性率随溶液中变性剂浓度变化的方程. 该方程包含2个特征折叠参数, 一个是蛋白质分子从一个稳定构象态过渡到另一个稳定构象态的热力学过渡平衡常数k; 另一个是在此过程中平均每个蛋白质分子所结合的变性剂分子数目m. 通过这2个特征折叠参数能够定量描述盐酸胍诱导的变性卵清溶菌酶完全去折叠态、 折叠中间态和天然态分子随复性液中盐酸胍浓度变化的分布和过渡情况.     

用蛋白电泳和高效凝胶排阻色谱法分析还原脲变性蛋白溶菌酶稀释复性过程的集聚体

本文利用蛋白电泳和高效凝胶排阻层析法分析了还原脲变性蛋白溶菌酶稀释复性过程中的集聚体。当用复性液稀释复性还原脲变性蛋白溶菌酶时,会迅速产生可观量的沉淀。沉淀和上清液的不连续十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)和高效凝胶排阻层析分析结果表明,还原脲变性蛋白溶菌酶在稀释复性过程中除了能够复性成天然态蛋白溶菌酶分子外,还会形成可溶的蛋白溶菌酶分子二聚体和三聚体,二聚体和三聚体主要是靠分子间二硫键的错配连接而成的;可溶的蛋白溶菌酶分子二聚体之间通过非共价键相互作用而形成集聚体沉淀,而可溶的三聚体溶菌酶分子则仍处于复性液上清液中。     

Probing the Structure,Dynamics, and Bonding of Coinage Metal Complexes of White Phosphorus

A series of cationic white phosphorus complexes of the coinage metals Au and Cu have been synthesised and characterised both in the solid state and in solution. All complexes feature a P₄ unit coordinated through an edge P?P vector (η²‐like), although the degree of activation (as measured by the coordinated P?P bond length) is greater in the gold species. All of the cations are fluxional on the NMR timescale at room temperature, but in the case of the gold systems fluxionality is frozen out at ?90 °C. Electronic structure calculations suggest that this fluxionality proceeds via an η¹‐coordinated M?P₄ intermediate.     

Light-Struck Taste in White Wine: Protective Role of Glutathione,Sulfur Dioxide and Hydrolysable Tannins

Light exposure of white wine can cause a light-struck taste (LST), a fault induced by riboflavin (RF) and methionine (Met) leading to the formation of volatile sulfur compounds (VSCs), including methanethiol (MeSH) and dimethyl disulfide (DMDS). The study aimed to investigate the impact of different antioxidants, i.e., sulfur dioxide (SO₂), glutathione (GSH) and chestnut tannins (CT), on preventing LST in model wine (MW) and white wine (WW), both containing RF and Met. Both MW and WW samples were added with the antioxidants, either individually or in different combinations, prior to 2-h light exposure and they were stored in the dark for 24 months. As expected, the light induced the degradation of RF in all the conditions assayed. Met also decreased depending on the antioxidants added. The presence of antioxidants limited the formation of LST as lower concentrations of VSCs were found in both MW and WW samples. In the latter matrix, neither MeSH nor DMDS were detected in the presence of CT, while only DMDS was found in WW+GSH, WW+SO₂+GSH and WW+CT+SO₂ samples at a concentration lower than the perception thresholds. Considering the antioxidants individually, the order of their effectiveness was CT ≥ GSH > SO₂ in WW under the adopted experimental conditions. The results indicate tannins as an effective enological tool for preventing LST in white wine and their use will be further investigated in different white wines under industrial scale.     

A Clean,Sensitive and Lasting New Spot Test for Paper and Thin-Layer Chromatograms of Perbromate Ion

Abstract

Benzidine in dilute acetic acid reacts with perbromate ion to give initially a blue colored spot which, on further heating, changes to a dark bluish-grey spot. The latter serves as a sensitive clean test for the detection of perbromate ion on paper and thin-layer chromatograms and electrophoregrams. The reagent can also be used to detect bromate, iodate and periodate ions as well as free halogens.     

Characterisation of Flavour Attributes in Egg White Protein Using HS-GC-IMS Combined with E-Nose and E-Tongue: Effect of High-Voltage Cold Plasma Treatment Time

Egg white protein (EWP) is susceptible to denaturation and coagulation when exposed to high temperatures, adversely affecting its flavour, thereby influencing consumers’ decisions. Here, we employ high-voltage cold plasma (HVCP) as a novel nonthermal technique to investigate its influence on the EWP’s flavour attributes using E-nose, E-tongue, and headspace gas-chromatography-ion-mobilisation spectrometry (HS-GC-IMS) due to their rapidness and high sensitivity in identifying flavour fingerprints in foods. The EWP was investigated at 0, 60, 120, 180, 240, and 300 s of HVCP treatment time. The results revealed that HVCP significantly influences the odour and taste attributes of the EWP across all treatments, with a more significant influence at 60 and 120 s of HVCP treatment. Principal component analyses of the E-nose and E-tongue clearly distinguish the odour and taste sensors’ responses. The HS-GC-IMS analysis identified 65 volatile compounds across the treatments. The volatile compounds’ concentrations increased as the HVCP treatment time was increased from 0 to 300 s. The significant compounds contributing to EWP characterisation include heptanal, ethylbenzene, ethanol, acetic acid, nonanal, heptacosane, 5-octadecanal, decanal, p-xylene, and octanal. Thus, this study shows that HVCP could be utilised to modify and improve the EWP flavour attributes.     

White analytical chemistry-driven stability-indicating concomitant chromatographic estimation of thiocolchicoside and aceclofenac using response surface analysis and red,green, and blue model

White analytical chemistry is a novel concept for the assessment of analytical methods on basis of its validation efficiency, greenness power, and economical efficiency. White analytical chemistry-driven stability indicating chromatographic method has been developed for the concomitant analysis of thiocolchicoside and aceclofenac. The proposed chromatographic method has been developed using a safe and environmental-friendly organic solvents for the concomitant stability study of thiocolchicoside and aceclofenac. The analytical risk assessment was carried out for the identification of high-risk analytical risk factors and analytical method performance attributes. The mixture design was applied for the design of experiments-based response surface modeling of high-risk analytical risk factors and analytical method performance attributes. The degradation products were isolated and characterized using infrared, nuclear magnetic resonance, and mass spectral data. The proposed method was compared for its validation efficiency, greenness power, and cost-efficiency with published chromatographic methods using the red, green, and blue models. The white score of the proposed and reported method was calculated by averaging the red, green, and blue scores of the methods. The proposed method was found to be robust, green, and economical for the concomitant stability study of thiocolchicoside and aceclofenac.     

高效液相色谱/二极管阵列法快速测定白酒、配制酒与葡萄酒中5种人工合成甜味剂

建立了一种快速检测白酒、配制酒和葡萄酒中安赛蜜、糖精钠、阿斯巴甜、阿力甜及纽甜5种人工合成甜味剂的高效液相色谱分析方法。采用C_(18)柱为分离柱,对流动相的组成和洗脱方式、检测波长等参数进行优化。结果表明,以乙腈和0.02 mol/L硫酸铵(p H 4.4)溶液为流动相,梯度洗脱,柱温40℃,可使5种人工合成甜味剂在15 min内实现基线分离。最佳检测波长下,5种甜味剂在4~200 mg/L浓度范围内呈良好的线性关系,相关系数均大于0.999。样品加标回收率为95.2%~103.2%,相对标准偏差(n=5)均不大于3.4%。该方法简便、快捷、准确、灵敏度较高,适用于白酒、配制酒和葡萄酒等各类酒中5种人工合成甜味剂的快速检测。     

Determination of Total Tannin of White and Red Rind Pomegranate (Punica Granatum L.) by Colorimetry Method Using Reagent 1, 10 Phenantroline

Determination of the total tannin of white and red rind pomegranate (Punica granatum L.) has been carried out by colorimetry method using reagent 1,10 phenantroline. This method is based on reduction of iron (III) into iron (II) by tannin at temperature 80⁰C for 20 min. Then the formed of iron (II) was reacted with 1,10 phenantroline to form orange red colour complex that could be measured by spectrophotometer visible at maximum absorption wavelength of 508 nm. The limit of detection (LOD) and the limit of quantitation (LOQ) obtained were 0.34 μg/mL and 1.14 μg/mL, respectively. This result was found to be linier with R value of 0.9984; accuracy as percent recovery was 84.69 ± 0.85% and coefficient of variant (KV) was 1.003% for white rind pomegranate while red rind pomegranate percent recovery was 84.38 ± 0,45% and coefficient of variant (KV) was 0.53%. The total tannin of white rind pomegranate was 18.28 ± 0.072%b/b and red rind pomegranate was 17.33 ± 0.081%b/b     

Investigation of the New Inhibitors by Sulfadiazine and Modified Derivatives of α-D-glucopyranoside for White Spot Syndrome Virus Disease of Shrimp by In Silico: Quantum Calculations,Molecular Docking,ADMET and Molecular Dynamics Study

The α-D-glucopyranoside and its derivatives were as the cardinal investigation for developing an effective medication to treat the highest deadly white spot syndrome virus (WSSV) diseases in Shrimp. In our forthcoming work, both computational tools, such as molecular docking, quantum calculations, pharmaceutical kinetics, ADMET, and their molecular dynamics, as well as the experimental trial against WSSV, were executed to develop novel inhibitors. In the beginning, molecular docking was carried out to determine inhibitors of the four targeted proteins of WSSV (PDB ID: 2ED6, 2GJ2, 2GJI, and 2EDM), and to determine the binding energies and interactions of ligands and proteins after docking. The range of binding affinity was found to be between −5.40 and −7.00 kcal/mol for the protein 2DEM, from −5.10 to 6.90 kcal/mol for the protein 2GJ2, from −4.70 to −6.2 kcal/mol against 2GJI, and from −5.5 kcal/mol to −6.6 kcal/mol for the evolved protein 2ED6 whereas the L01 and L03 display the highest binding energy in the protein 2EDM. After that, the top-ranked compounds (L01, L02, L03, L04, and L05), based on their high binding energies, were tested for molecular dynamics (MD) simulations of 100 ns to verify the docking validation and stability of the docked complex by calculating the root mean square deviation (RMSD) and root mean square fluctuation (RMSF). The molecules with the highest binding energy were then picked and compared to the standard drugs that were been applied to fish experimentally to evaluate the treatment at various doses. Consequently, approximately 40–45% cure rate was obtained by applying the dose of oxytetracycline (OTC) 50% with vitamin C with the 10.0 g/kg feed for 10 days. These drugs (L09 to L12) have also been executed for molecular docking to compare with α-D-glucopyranoside and its derivatives (L01 to L08). Next, the evaluation of pharmacokinetic parameters, such as drug-likeness and Lipinski’s principles; absorption; distribution; metabolism; excretion; and toxicity (ADMET) factors, were employed gradually to further evaluate their suitability as inhibitors. It was discovered that all ligands (L01 to L12) were devoid of hepatotoxicity, and the AMES toxicity excluded L05. Additionally, all of the compounds convey a significant aqueous solubility and cannot permeate the blood-brain barrier. Moreover, quantum calculations based on density functional theory (DFT) provide the most solid evidence and testimony regarding their chemical stability, chemical reactivity, biological relevance, reactive nature and specific part of reactivity. The computational and virtual screenings for in silico study reveals that these chosen compounds (L01 to L08) have conducted the inhibitory effect to convey as a possible medication against the WSSV than existing drugs (L09, L10, L11 and L12) in the market. Next the drugs (L09, L10, L11 and L12) have been used in trials.