Kinetic spectrophotometric determination of vanadium in steels based on the catalytic oxidation of thionine by potassium bromate

A sensitive and selective kinetic spectrophotometric method for the determination of V（V） was developed based on the catalytic oxidation of thionine by KBIO3 in 0.6 mol·L^-1 HaPO4 medium. The linear calibration range and detection limit at 25℃ were 0-0.5 μg·mL^-1 and 0.01 μg·mL^-1, respectively. In the presence of NaF and urea, most of the common ions did not interfere with the determination of V（V）. The proposed method was applied for the determination of vanadium in steels and satisfactory results were obtained.

A Novel Amperometric Nitric Oxide Sensor Based on Polythionine/Nation Modified Glassy Carbon Electrode

A novel amperometric sensor for the determination of nitric oxide was developed by coating polythionine / nation on a glassy carbon electrode. This sensor exhibited a great enhancement to the oxidation of nitric oxide. The oxidation peak currents were linear to the concentration of nitric oxide over the wide range from 3.6×10^-7 to 6.8×10^-5 mol·L^-1, and the detection limit was 7.2×10^-8 mol·L^-1. Experimental results showed that this nitric oxide sensor possessed excellent selectivity and longer stability. NO releasing from rat kidney was monitored by this sensor.

The Electrochemical Properties of Thionine Adsorbed Monolayer on Gold Electrode

A gold electrode modified with adsorbed thionine monolayer was investigated with ac impedance and cyclic voltammetry method. It was found there were some different redox properties for the adsorbed thionine depended on the different potential scanning rate. At the slower potential scanning rate (10 mV? s?1), the dimer of thionine appeared and possessed the catalytic activity for the oxidation of ascorbic acid. The underpotential deposition (UPD) and the bulk deposition of Cu2+ were also employed to investigate the monolayer of adsorbed thionine.

Photocatalytic Degradation of Methyl Thionine Chloride in Aqueous Solution over Nanometer (CdS/TiO_2)/MCM-41

（ CdS/ TiO2 ）/ MCM-41 loaded nanometer photocatalyst was prepared by the sol-gel method and dipping process, the photocatalytic degradation of methyl thionine chloride in water was investigated by using the photocatalyst. The experimental results show that the optimum concentration of CdS over TiO2 was 3% （ molar ratio ）, the photocatalytic activity was enhanced when making TiO2 the anatase ptase with a rise of the roasting temperature, and the carrier, mesoporous molecular sieve MCM-41, was beneficial to improving the photocatalytic activity of TiO2 for photocatalytic degradation of methyl thionine chloride. The morphology and the crystalline phase of the photocatalyst were discussed by means of XRD and SEM techniques, and the reaction mechanism of catalytic properties was also discussed.

A New Thionine Modified Electrode by Anchorage to Bi-(2-aminoethyl)-aminodithiocarboxyl Acid Self-assembled Monolayers through Coordination with Cu^(2+#)

A new method for preparing chemically modified gold electrode by anchoring thionine to self-assembled bi - (2 -aminoethyl) -aminodithiocarboxyl acid(BANTC) monolayers through coordination with Cu2+ is described. This thionine modified electrode exhibits two-new redox couples.Two protons were involved in the electrochemical process undergone by the couple I in the pH range of 5.0-10.0. The apparent surface electron transfer rate constant is about 0.050s-1.

Drug-DNA Interaction: A Theoretical Study of the Stability of CP-DNA Binding with Thionine

The recent study on binding of small molecules to double stranded DNA suggested that the intercalation of a tricyclic heteroaromatic molecule, thionine, with natural DNA provided thermal stabilization to the complex. In the present study, we reported theoretical analysis of thionine binding with Clostridium perfringenes DNA duplex (CP-DNA) by using an amended Zimm and Bragg theory, to explain the melting behaviour and heat capacity of CP-DNA with and without thionine binding. The experimental models of Paul et al. (2010) have been used for the study. The sharpness of transition has been examined in terms of half width and sensitivity parameter (?H/σ). The results of theoretical approach suggested that the various parameters such as transition profile, sharpness of the transition, heat capacity curve and half widths are in good agreement with the experimental measurements for binding of thionine. Therefore, the proposed theoretical analysis may be useful in order to understand interaction of small molecules to DNA that may be applied in the process of drug development and for designing more potential DNA binding therapeutic molecules.

Determination of carcinoembryonic antigen using a novel amperometric enzyme-electrode based on layer-by-layer assembly of gold nanoparticles and thionine

Electrochemical sensing of carcinoembryonic antigen(CEA)on a gold electrode modified by the se- quential incorporation of the mediator,thionine(Thi),and gold nanoparticles(nano-Au),through co- valent linkage and electrostatic interactions onto a self-assembled monolayer configuration is de- scribed in this paper.The enzyme,horseradish peroxidase(HRP),was employed to block the possible remaining active sites of the nano-Au monolayer,avoid the non-specific adsorption,instead of bovine serum albumin(BSA),and amplify the response of the antigen-antibody reaction.Electrochemical ex- periments indicated highly efficient electron transfer by the imbedded Thi mediator and adsorbed nano-Au.The HRP kept its activity after immobilization,and the studied electrode showed sensitive response to CEA and high stability during a long period of storage.The working range for the system was 2.5 to 80.0 ng/mL with a detection limit of 0.90 ng/mL.The model membrane system in this work is a potential biosensor for mimicking the other immunosensor and enzyme sensor.

Direct Electrochemical Detection of Oligonucleotide Hybridization on Poly（thionine） Film

In this work, the application of a conducting polymer, poly（thionine）, modified electrode as matrix to DNA immobilization as well as transducer to label-free DNA hybridization detection was introduced. The electropolymerization of thionine onto electrode surface was carried out by a simple two-step method, which involved a preanodization of glassy carbon electrode at a constant positive potential in thionine solution following cyclic voltammetry scans in the solution. Electrochemical detection was performed by differential pulse voltammetry in the electroactivity potential domain of poly（thionine）. The resulting poly（thionine） modified electrode showed a good stability and electroactivity in aqueous media during a near neutral pH range. Additionally, the pendant amino groups on the poly（thionine） chains enabled poly（thionine） modified electrode to immobilize phosphate group terminated DNA probe via covalent linkage. Hybridization process induced a clear decrease in poly（thionine） redox current, which was corresponding to the decrease in poly（thionine） electroactivity after double stranded DNA was formed on the polymer film. The detection limit of this electrochemical DNA hybridization sensor was 1.0 × 10^-10mol/L. Compared with complementary sequence, the hybridization signal values of 1-base mismatched and 3-base mismatched samples were 63.9% and 9.2%, respectively.

Kinetics of Reduction of Thionine with Ribose and the Structural Properties of the Dye at Different pH Using DFT Method

The reaction between the thionine （Th） and the ribose was observed spectrophotometrically and changes in absorbance of Th were recorded at variable concentration of dye, reductant and pH. A pseudo first order rate of reaction was found to establish the reduction kinetics of the dye, studied at a pH range of 0.34 to 12.8. Absorption spectrum of Th at different pH, with ribose showed a pH （12.8） dependent introversion. The reduction most probably took place with enediol intermediate of the sugar at high pH. A full geometry optimization of predominant species of Th namely, mono-deprotonated, di-deprotonated Th, and LTh （leuco thionine） respectively, at low and high pH, was performed at B3LYP level of theory. The data obtained from the energy minimization were in excellent agreement with other experimental and theoretical observations. The calculated enthalpies of formation for both reduction reactions （mono-deprotonated Th＋H＋→leucothionine and di-deprotonated Th＋2H＋→leucothionine） provided evidences for maximum reduction of the dye at high pH.

Thionine sensitized areobic photooxidation of thiourea in acidic medium

An investigation of the thionine sensitized aerobic photooxidation of thiourea was observed spectrophotometrically at a wavelength of 598 nm.Articles reported two types of reactions which generally occur in the presence of oxygen:1)Singlet oxygen,produced by dye sensitization due to the hydrolysis that reacts with thiourea to form oxidative products like urea and other sulfur-containing fragments and 2)bleaching of dye,which leads to the reduction.The rate of reaction in all studied parameters followed first order kinetics with respect to maximum absorption of the dye in the visible band region.Reaction kinetics was significantly dependent upon the medium and the reaction accelerated more rapidly at low pH.A direct relation was exhibited between the thiourea concentration and dye sensitizer,which was not pragmatic with the concentration of dye.The reaction was effected by the temperature,and the values of energy parameters suggested that the energy of activation was low while the entropy of activation increases with the rise in temperature,which indicated a highly solvated state of intermediate complex.Lower value of ΔH* and ΔG*at elevated temperature showed that free energy is the driving force for the completion of reaction.A mechanism based on the above findings has been suggested.

肝性脑病脑组织病理形态观察

我们于九十年代初起不加选择收集肝硬变死亡者肝、脑组织,对照临床表现和血液检查,探讨肝性脑病(HE)的病理基础,共观察70例,现总结报道如下。 资料和方法 一、一般资料 70例患者的临床表现和实验室检查均符合肝硬变诊断,肝组织病理切片检查,均可见典型肝硬变的病理特点。男51例,女19例,年龄7岁～71岁,平均48.7岁。临床显示HE,死于肝衰者41例,

Photoelectrochemical Detection of Glucose by Using an Enzyme-Modified Photoelectrode

A new photoelectrochemical method for the determination of glucose based on the photoelectrochemical effect of poly（thionine） photoelectrode to hydrogen peroxide （H202） was reported. The H2Oz-sensitive photoelectrode was fabricated by electropolymerizing thionine on the surface of ITO electrode. And then glucose oxidase was immobilized on the photoelectrode via the aid of chitosan enwrapping, forming an enzyme-modified photoelectrode. The photoelectrode was employed as an electron acceptor; H2O2 from the catalytic reaction of enzyme was employed as an electron donor, developing an analytical method of glucose without hydrogen peroxidase. In the paper, the pho- toelectrochemical effects of photoelectrode to H202 and glucose were studied. The effects of the bias voltage and the electrolyte pH on the photocurrent were investigated. The linear response of glucose concentrations ranged from 0.05 to 2.00 mmol/L was obtained with a detection limit of 22.0 μmol/L and sensitivity of 73.2 nA/（mmol·L-1）. The applied feasibility of method was acknowledged through monitoring the glucose in practical samples.

受光抑制的大麦叶片特导Thionin的cDNA序列

Thionin(硫堇)是一类小分子量多肽.这种蛋白最早在小麦面粉中发现,随后在其它禾谷类作物和一些双子叶植物如十字花科的Crambe abyssinica的种子中也发现了类似的蛋白.1987年在大麦叶片、1993年在烟草花器中又发现了叶片和花特异的thionin.Thionin有以下几个特点:分子量小约500D,热稳定性高,带正电荷,巯基含量高.

Langmuir Aggregation of Thionin in Nucleic Acids and Its Application

The microsurface adsorption-spectral correction (MSASC) technique has been described. The formation of the double electrostatic films in nucleic acids causes the monolayer aggregation of stain molecules. The interaction of thionin (TN) with nucleic acids, ctD-NA, sDNA and yRNA, has been investigated at pH 7.8. Results show that the binding ratios of TN to ctDNA-P, sDNA-P and yR-NA-P are 1.27, 1.30 and 1.40, respectively, the binding constants of the aggregates are 2.8 · 104, 9.10 · 104 and 6.49 · 103 and their molar absorptivities are 1.04 · 104, 1.25 · 104 and · 104 L· mol?1, cm?1 at 630 nm. The aggregation may be applied to the spectrophotometric detection of nucleic acids samples.

Comparative physiological and transcriptomic analyses illuminate common mechanisms by which silicon alleviates cadmium and arsenic toxicity in rice seedlings

The inessential heavy metal/loids cadmium(Cd)and arsenic(As),which often co-occur in polluted paddy soils,are toxic to rice.Silicon(Si)treatment is known to reduce Cd and As toxicity in rice plants.To better understand the shared mechanisms by which Si alleviates Cd and As stress,rice seedlings were hydroponically exposed to Cd or As,then treated with Si.The addition of Si significantly ameliorated the inhibitory effects of Cd and As on rice seedling growth.Si supplementation decreased Cd and As translocation from roots to shoots,and significantly reduced Cd-and As-induced reactive oxygen species generation in rice seedlings.Transcriptomics analyses were conducted to elucidate molecular mechanisms underlying the Si-mediated response to Cd or As stress in rice.The expression patterns of the differentially expressed genes in Cd-or As-stressed rice roots with and without Si application were compared.The transcriptomes of the Cd-and As-stressed rice roots were similarly and profoundly reshaped by Si application,suggesting that Si may play a fundamental,active role in plant defense against heavy metal/loid stresses by modulating whole genome expression.We also identified two novel genes,0s01g0524500 and 0s06g0514800,encoding a myeloblastosis(MYB)transcription factor and a thionin,respectively,which may be candidate targets for Si to alleviate Cd and As stress in rice,as well as for the generation of Cd-and/or As-resistant plants.This study provides valuable resources for further clarification of the shared molecular mechanisms underlying the Si-mediated alleviation of Cd and As toxicity in rice.