Effect of solvents on the electrochemistry of olefins and aromatic molecules

Cyclic voltammetry and electrolysis studies were carried out in dimethyl sulfoxide, diglyme and liquid ammonia. The depolarizers were diethyl fumarate, ethyl cinnamate, stilbene and anthracene. The reduction reactions were carried out in the presence of organic halides, phenol, acids and water. The rates of the reactions were measured. The main solvent effect was noticed with water which reacts 100 times faster in diglyme than in liquid ammonia or DMSO. The results of electrolytic experiments with two reactants simultaneously were compared with those predicted from the kinetic data.     

Evaluation of process conditions and characterization of particle size and stability of oil-in-water nanoemulsions

This article reports on the oil in water (o/w) nanoemulsions, which were prepared using a mixture of solvents (decane, toluene and cyclohexane) as oils and the mixtures of ethoxylated lauryl alcohols with various concentrations as surfactants with HLB values ranged from 10 to 12. The Ultra-Turrax (rotor-stator type) stirring and/or ultrasound processing were applied for varied processing times. The data show that the particle sizes in nanoemulsions prepared with ultrasound were smaller than those produced by stirring. The stability of these emulsions was, however, enhanced, when the mixtures were preliminary processed with the shearing agitator. The most stable nanoemulsions were obtained in 10 wt % surfactant mixture of the alcohols with HLB 11 in the shearing agitator.     

Reaction of Lithium Cellulosate with Episulfides

The reactions of propylene, ethylene, and styrene sulfide with cotton fabrics in the form of their lithium cellulosate derivative, obtained by metallation with lithium methoxide, were studied. Both graft and homo-polymerization took place and in the reaction with propylene and ethylene sulfide, cotton fabrics with high polysulfide content were obtained. With propylene sulfide 50% of the monomer polymerized was grafted. The effects of monomer concentration, cellulosate degree of substitution, reaction time, and solvent on the polymerization were investigated. In contrast with propylene and ethylene sulfide, only small conversions were obtained in the reaction with styrene sulfide. The results were attributed to steric effects.     

Application of capillary electrochromatography using macroporous polyacrylamide columns for the analysis of lignans from seeds of Schisandra chinensis

Capillary electrochromatography (CEC) using polymer-based monolithic stationary phase has been developed as a promising method for the determination of lignans of Schisandra chinensis. The columns were prepared by in situ copolymerisation of acrylamide, N,N'-methylenebisacrylamide, vinylsulfonic acid and lauryl acrylate in presence of poly(ethylene glycol) as a porogenic agent. The columns [33 cm (24.5 cm effective length) x 75 microm I.D.] were successfully used to analyse and quantify the major lignans in extract of the seeds of Schisandra chinensis. Good separations were achieved in less than 35 min. The calibration graphs were linear in the range 0.025-1.0 mg/ml of given lignan with correlation coefficients between 0.9951 and 0.9996. The inter-day reproducibility of the peak area were below 3.9% and the inter-day reproducibility of the migration time were below 4.2%. The results of quantitative CEC analyses were compared with those obtained by reversed-phase HPLC, the levels of schizandrin, gomisin A, gomisin N and wuweizisu C determined by CEC were in a good agreement with those determined by HPLC.     

Synthesis of Isomeric Aminomethyl Derivatives of Furylmethanephosphonates

By chloromethylation of diethyl 2- and 3-furylmethanephosphonates 5-chloromethylfur-2(3)-ylmethanephosphonates were synthesized. The other four isomers of chloromethyl derivatives of furylmethanephosphonates were prepared by substitution of hydroxy groups in the corresponding phosphorylated furylmethanols via the reaction with thionyl chloride in the presence of pyridine. Thermal stability of these chlorides was sufficiently high, and they were involved in nucleophilic substitution of chlorine with azido group by treating with sodium azide in boiling acetonitrile in the presence of potassium iodide. No decomposition of substrates was observed. The azides obtained were reduced to amines with triphenylphosphine in ethanol.     

In vitro determination of the release kinetics of peptides and free amino acids during the digestion of food proteins

The kinetics of peptide release during in vitro digestion of 4 protein sources (casein, cod protein, soy protein, and gluten) were investigated. Samples were sequentially hydrolyzed with pepsin (30 min) and pancreatin (2, 4, or 6 h) in a dialysis cell with continuous removal of digestion products. Nondialyzed digests were fractionated by ion-exchange chromatography and ultrafiltration. Animal proteins were digested at a greater rate than plant proteins. Target amino acids of specific enzymes appeared more rapidly in the dialyzed fractions when compared to other amino acids. Throughout the hydrolysis, nondialyzed digests contained a higher proportion of peptide mixtures with basic-neutral properties. Except for gluten, peptide fractions with molecular weights that exceeded 10 kDa (basic-neutral, BN > 10) were rapidly hydrolyzed during the first 2 h of pancreatin digestion. The kinetics of release and the composition of peptide fractions were different when the protein sources were compared. The analysis of amino acids revealed that threonine and proline proportions were relatively high in BN > 10 and in peptide fractions with molecular weight between 10-1 kDa (BN 10-1), while tyrosine, phenylalanine, lysine, and arginine predominated in the low molecular weight (<1 kDa) fractions. More resistant peptides were generally rich in proline and glutamic acid. The role of in vitro digestion assays in dietary protein quality evaluation is discussed.     

LC/MS/MS for identification of in vivo and in vitro metabolites of jatrorrhizine

The in vivo and in vitro metabolism of jatrorrhizine has been investigated using a specific and sensitive LC/MS/MS method. In vivo samples including rat feces, urine and plasma collected separately after dosing healthy rats with jatrorrhizine (34 mg/kg) orally, along with in vitro samples prepared by incubating jatrorrhizine with rat intestinal flora and liver microsome, respectively, were purified using a C(18) solid-phase extraction cartridge. The purified samples were then separated with a reversed-phase C(18) column with methanol-formic acid aqueous solution (70:30, v/v, pH3.5) as mobile phase and detected by on-line MS/MS. The structural elucidation of the metabolites was performed by comparing their molecular weights and product ions with those of the parent drug. As a result, seven new metabolites were found in rat urine, 13 metabolites were detected in rat feces, 11 metabolites were detected in rat plasma, 17 metabolites were identified in intestinal flora incubation solution and nine metabolites were detected in liver microsome incubation solution. The main biotransformation reactions of jatrorrhizine were the hydroxylation reaction, the methylation reaction, the demethylation reaction and the dehydrogenation reaction of parent drug and its relative metabolites. All the results were reported for the first time, except for some of the metabolites in rat urine.     

Effects of surface processing of lactose carrier particles on dry powder inhalation properties of salbutamol sulfate

The effects of the surface processing of lactose carrier particles on the dry powder inhalation properties of salbutamol sulfate were investigated. Lactose carrier particles were processed using a high-speed elliptical-rotor-type powder mixer (Theta-Composer). In the present study, drug/carrier powder mixtures were prepared, consisting of micronized salbutamol sulfate and coarse lactose carriers with various particle surface conditions prepared by surface processing. These powder mixtures were aerosolized by a Jethaler, and the in vitro inhalation properties of salbutamol sulfate were evaluated with a twin impinger. Compared with those of the powder mixed with unprocessed lactose carriers, the in vitro inhalation properties of the powder mixture prepared using the surface processed lactose carriers were significantly different, showing that the in vitro inhalation properties of salbutamol sulfate were improved. The in vitro inhalation properties increased with the rotor rotation rate. Using this surface processing system would thus be valuable for increasing the inhalation properties of dry powder inhalation with lactose carrier particles.     

内热针治疗肩周炎的疗效观察

目的分析内热针治疗肩周炎的疗效。方法抽取清远市阳山县中医院自2016年3月—2017年2月期间收治的80例肩周炎患者,依据治疗方法差异性均分两组,每组患者比例各40例。予以温针治疗+常规康复训练的患者作为对照组,予以内热针+常规康复训练治疗的患者作为治疗组,最后对两组患者的治疗效果进行统计分析。结果两组患者经不同方法治疗后,治疗组患者治疗总有效率同参照组比对明显较高,组间数据结果由统计工具进行检验呈现出统计学意义。结论肩周炎予以内热针治疗,效果理想,在临床上应用有重要意义。     

Development of extraction methods for speciation analysis of selenium in aqueous extracts of medicinal plants

Advanced extraction methods have been developed for direct speciation of dissolved inorganic and organic selenium (Se) species in aqueous extracts of medicinal plants (MPs). The inorganic species of Se (SeIV and SeVI) were separated from organic forms by adsorbing inorganic Se on alumina, while the organic Se was not retained. The retained inorganic Se species was eluted with 10 mL 0.2 M HCl. The total inorganic Se species was determined after prereduction of SeVI into SeIV with concentrated HCl. The SeIV in the eluent and total inorganic Se species were then complexed with diethyldithiocarbamate. The resultant complexes were entrapped in the nonionic surfactant Triton X-114. The total Se, organic Se, total inorganic Se, and SeIV species were determined by electrothermal atomic absorption spectrometry with a modifier. The SeVI concentration was obtained by subtracting SeIV from total inorganic Se contents. The main factors affecting the methodologies were investigated in detail. Under the optimized experimental conditions, the LOD for SeIV was 50 microg/L. Among dissolved inorganic and organic Se species in aqueous extracts of MPs, organic Se species were present in the range of 74-84%, SeIV 3.62-7.47%, and SeVI 12.4-18.57% of total Se contents.     

Polymerization from the surface of single-walled carbon nanotubes - preparation and characterization of nanocomposites

Single-walled carbon nanotubes were functionalized along their sidewalls with phenol groups using the 1,3-dipolar cycloaddition reaction. These phenols could be further derivatized with 2-bromoisobutyryl bromide, resulting in the attachment of atom transfer radical polymerization initiators to the sidewalls of the nanotubes. These initiators were found to be active in the polymerization of methyl methacrylate and tert-butyl acrylate from the surface of the nanotubes. However, the polymerizations were not controlled, leading to the production of high molecular weight polymers with relatively large polydispersities. The resulting polymerized nanotubes were analyzed by IR, Raman spectroscopy, DSC, TEM, and AFM. The nanotubes functionalized with poly(methyl methacrylate) were found to be insoluble, while those functionalized with poly(tert-butyl acrylate) were soluble in a variety of organic solvents. The tert-butyl groups of these appended polymers could also be removed to produce nanotubes functionalized with poly(acrylic acid), resulting in structures that are soluble in aqueous solutions.     

超声造影联合增强CT诊断不典型肝血管平滑肌脂肪瘤的临床价值

选取2011年6月~2017年6月于我院就诊的经病理学检查明确确诊为肝血管平滑肌脂肪瘤(HAML)的43例患者,通过对纳入患者的49个HAML病灶的超声造影(CEUS)及增强CT(CECT)的影像学表现及术前诊断结果进行分析,探讨CEUS联合CECT在诊断不典型HAML中的临床价值。结果显示,HAML在女性中的发病率显著高于男性(P<0.001),且HAML多为单发病灶(P<0.001)。术前经CECT准确诊断HAML者有34.69%,经CEUS准确诊断HAML者有57.14%,二者联合准确诊断HAML者有77.55%,联合诊断的准确性显著高于单独应用CECT或CEUS(P<0.05)。HAML在CECT和CEUS上的表现具有一定的特征性,二者联合应用可以提高HAML诊断正确率。     

光谱法比较喜树碱与溶菌酶、过氧化氢酶的相互作用

采用紫外可见吸收、红外、荧光等多种光谱学方法研究了抗癌药物喜树碱和溶菌酶及过氧化氢酶两种蛋白之间的相互作用,结果表明,喜树碱与之均形成基态复合物并引起蛋白内源荧光猝灭。通过计算确定了喜树碱和蛋白相互作用的结合常数、结合位点数、主要作用力类型以及与蛋白中色氨酸的结合距离。喜树碱对过氧化氢酶具有较高的结合能力,这主要是由于喜树碱不仅与过氧化氢酶中的色氨酸存在相互作用,也与酶中的酪氨酸及血红素产生相互作用。喜树碱的存在可引起蛋白构象发生变化,使α-螺旋二级结构减少。     

苦瓜成分的提取工艺探索

考察了溶剂用量(1-10mL)、浸泡时间(1～24h)、超声时间(0～20min)对0．2g苦瓜的籽、果实、叶子中成分提取的影响,利用均匀设计(3因素5水平)与固定单因素的方法相结合(9个实验)获取14个不同实验条件,通过多元线性回归得到相关系数大于0．95的4因素表达式。结果表明,超声波对同一个样品中不同的组分有效果相反的作用,即对有些组分降解破坏的同时却会提高另外一些组分的提取率。实验验证了MATLAB预测的最佳实验条件和实验结果,预测准确率大于97％。对于所研究的苦瓜籽、果实、叶子样品0．2g,最佳提取溶剂体积10mL,浸泡时间24h,超声时间0min(果实)或20min(籽、叶子)。     

Ce0.67Zr0.33O2对CH4燃烧催化剂Fe2O3/Al2O3的改性作用

固定n(Ce)/n(Zr)比为0.67/0.33,用共沉淀法制得一系列CeO2-ZrO2-Al2O3固溶体.采用这些固溶体作载体,以Fe2O3为活性组分,用浸渍法制备了一系列催化剂.BET结果显示,将适量Ce0.67Zr0.33O2引入到Al2O3载体中有助于催化剂保持较高的比表面积.TPR结果显示,载体中引入适量的Ce0.67Zr0.33O2可以改善催化剂的氧化还原性能.XRD结果表明,Fe2O3在CeO2-ZrO2-Al2O3载体上呈现出良好的分散状况,老化前后催化剂的晶相结构基本无明显变化.特别是当载体中m(Ce0.67Zr0.33O2)∶m(Al2O3)的值为1∶2时,Fe2O3/CeO2-ZrO2-Al2O3催化剂在甲烷催化燃烧中显示出最佳的催化性能和抗高温老化性能.     

非紧密堆积型光子晶体凝胶的胀缩行为

制备了Bragg衍射峰波长位置在700～800 nm之间的非紧密堆积型光子晶体凝胶(NCPPCGs). 通过自然干燥失水, 复水浸泡, 不同浓度的乙醇溶液浸泡和不同pH缓冲溶液浸泡等处理, 研究了NCPPCGs的溶胀、收缩(胀缩)行为和Bragg衍射峰迁移的关系; 在凝胶自然干燥失水过程中, Bragg衍射峰蓝移, 复水浸泡后, Bragg衍射峰快速红移至干燥前的位置; 凝胶经不同浓度的乙醇溶液浸泡后, 凝胶体积改变, 并且乙醇浓度升高时, Bragg衍射峰蓝移; 经水解处理的NCPPCGs具有pH 响应特性, 当其浸泡在pH为2.2～9.6的缓冲溶液中时, 随pH值的增大Bragg衍射峰红移, pH为9.6～10.6时, Bragg衍射峰蓝移. 外界因素导致NCPPCGs的Bragg衍射峰位置的迁移覆盖整个可见光区域.     

Thermochemical study of the influence of tetraalkylammonium cation sizes on the interaction of their salts with formamide and carbamide in aqueous solutions

Solutions of tetrahexylammonium salts in mixtures of water with additives of hydrophilic substances formamide and carbamide were studied by the thermochemical method at 298.15 K. The enthalpies of solution of tetrahexylammonium perchlorate were measured by the sedimentation method, and the enthalpies of solution of tetrahexylammonium bromide were calculated. The enthalpic coefficients of pair interaction electrolyte—amide in an aqueous solution were determined. The data obtained were compared with those for te tramethyl- tetraethyl- and tetrabutylammonium salts to study the influence of the tetraalkylammonium cation size on its solvation and interaction with amides in an aqueous solution.     

气相色谱-质谱联用结合化学计量学方法分析光照对鱼腥草挥发性成分的影响

采用色谱-质谱联用技术结合化学计量学方法对不同光照生长条件的鱼腥草挥发性成分进行分析。水蒸气蒸馏法提取鱼腥草挥发油,气相色谱-质谱进行分析。色谱指纹图谱结合主成分分析与相似度评价以探究不同光照挥发油成分的异同。直观推导式演进特征投影法(Heuristic evolving latent projections,HELP)分辨重叠色谱峰,NIST标准质谱库结合相关文献进行定性,峰面积归一化法定量,t-检验比较不同光照组成分含量间是否有显著性差异。3种光照下的鱼腥草挥发油指纹图谱存在一定的共性和差异,共鉴定出33种化合物,共有化合物26种。随着光照强度的减少,单萜类化合物含量减少,非萜类含量增多,倍半萜类变化不大。癸酰乙醛和甲基正壬酮在全光照组的含量明显低于遮光组的含量。研究结果表明,适度的遮光有利于鱼腥草挥发性有效成分含量的提高,鱼腥草药材挥发性成分种类及含量与生长条件密切相关。     

Polymerization of cyclic derivatives of uracil and thymine

Cyclic derivatives of uracil and thymine were synthesized from their corresponding 1-(2′-chloroethyl) derivatives by dehydrochlorination. These compounds were found to undergo a variety of reactions, giving many valuable derivatives of uracil and thymine. The cyclic derivatives, as monomers, were polymerized with a cationic initiator by a unique ring-opening process. The polymerization proceeded by ring opening with isomerization of the pyrimidine ring to give a polymer in which pyrimidine rings were connected with ethylene between N-1 and N-3 or O-4 in the pyrimidine ring. The structure of these polymers was determined by nuclear magnetic resonance (NMR), ultraviolet (UV), infrared (IR), and mass spectra. The structure was affected by polymerization temperature.