Sample records for diphenylamine

  1. Determination of Diphenylamine in Agricultural Products by HPLC-FL.

    Aoyagi, Mitsutoshi; Chiba, Masahiro; Kakimoto, Youichiro; Nemoto, Satoru


    A method for the determination of diphenylamine in agricultural products was developed. Diphenylamine was extracted with acetonitrile from a sample under an acidic condition, passed through a C18 cartridge column, re-extracted with n-hexane, cleaned up on a PSA cartridge column, determined by HPLC with fluorescence detector and confirmed by liquid chromatography with tandem mass spectrometry. Average recoveries (n=5) from brown rice, corn, soybeans, potato, cabbage, eggplant, spinach, orange, apple and green tea were in the range from 76.7 to 94.9%, and the relative standard deviations were from 0.6 to 5.8% at concentrations equal to the maximum residue limits (MRLs). The quantification limits were 0.01 mg/kg, which is the uniform limit in the positive list system for agricultural chemical residues in food in Japan.

  2. Esterification and Transesterification of greases to fatty acid methyl esters with highly active diphenylamine salts

    Diphenylamine sulfate (DPAS) and diphenylamine hydrochloride (DPACl) salts were found to be highly active catalysts for esterification and transesterification of inexpensive greases to fatty acid methyl esters (FAME). In the presence of catalytic amounts of DPAS or DPACl and excess methanol, the fr...

  3. Voltammetric Determination of Dinonyl Diphenylamine and Butylated Hydroxytoluene in Mineral and Synthetic Oil.

    Xiang, Yaling; Qian, Xuzheng; Hua, Meng; Cheng, Bingxue; Chen, Wu; Li, Jian


    A method is reported for the determination of diphenylamine and butylated hydroxytoluene in mineral and synthetic oil. The procedure used differential pulse voltammetry with a glassy carbon electrode. This method was then used for determining these antioxidants in supporting electrolyte consisting of dilute sulfuric acid and sodium dodecyl sulfonate in ethanol. Anodic peaks were obtained for both analytes. Oxidation peaks at 250 mV were observed from a mixture of butylated hydroxytoluene and dinonyl diphenylamine, allowing their simultaneous determination. This approach was successfully used for the determination of dinonyl diphenylamine and butylated hydroxytoluene in fortified mineral and synthetic oils with good accuracy and precision.

  4. Diphenylamine-induced renal lesions in the chicken.

    Sorrentino, F; Fella, A; Pota, A


    Chronic intoxication with diphenylamine (DPA), which causes a cystic kidney disease in the rat and the guinea-pig, caused degeneration of the renal tubular epithelium in the chicken. This was similar to but much more serious than that preceding the formation of cysts in the rodents, but did not actually result in cyst formation, probably because of the high mortality rate observed in the birds even at this early stage. In the chicken until now it had been possible to obtain a pattern of renal cysts only with polychlorinated biphenyls (PCB) which also induce the "chick oedema" syndrome. The renal lesions due to DPA in the chicken were similar to those produced by PCB, but were not accompanied by oedema, which suggests that "chick oedema" caused by PCB is not due to renal insufficiency. The differences in the renal lesions noted in the various animal species give credit to the hypothesis that DPA may have two effects on the tubular epitelium, one stimulating cell proliferation and one leading to degeneration. Cysts may be formed only in those species in which there is cell proliferation.

  5. Design of molecularly imprinted polymers for diphenylamine sensing.

    Granado, V L V; Rudnitskaya, A; Oliveira, J A B P; Gomes, M T S R


    A series of the polymers imprinted with diphenylamine (DPA) and respective non imprinted polymers were synthesized using precipitation polymerization. Synthesized polymers were characterized by Fourier Transform Infra-Red spectroscopy with Total Attenuated Reflectance (FTIR-ATR), Scanning Electron Microscopy (SEM) and equilibrium batch re-binding experiments. Influence of the synthesis conditions, namely monomer/template ratio and reaction duration, on the polymer binding capacity and selectivity towards aromatic compounds was investigated. Binding behavior of MIP was described using Freundlich isotherm. Significance of the effects of the synthesis conditions on the polymer properties was evaluated using ANOVA. MIPs synthesized at different conditions, which displayed different properties (binding capacity and selectivity), and respective non-imprinted polymers were employed for the fabrication of the potentiometric sensors. While sensors prepared using imprinted polymers had higher sensitivity and selectivity compared to the ones containing non-imprinted polymer, no difference was observed between sensors containing different imprinted polymers. No correspondence between polymers' characteristics obtained in the equilibrium re-binding studies and potentiometric behavior of the sensors based on the same polymers was observed. Therefore, equilibrium re-binding studies cannot be used for predicting sensor behavior.

  6. Alternative products to carbazoles in the oxidation of diphenylamines with palladium (II) acetate

    Raposo, M. Manuela M.; Campos, Ana M. F. Oliveira; Shannon, Patrick V. R.


    Although simple diphenylamines are conveniently oxidised with Palladium (II) acetate to give carbazoles, for more complex examples, carbazoles are minor products amongst many. CRUP (Portugal). British Council - Treaty of Windsor Programme. Junta Nacional de Investigação Científica e Tecnológica.

  7. Polarographic study on the evolution of the diphenylamine as stabiliser of the solid propellants.

    de Diego Martínez, A Pérez; Tascón, M L; Vázquez, M D; Sánchez Batanero, P


    Differential pulse polarography (DPP) and square wave voltammetry (SWV) were investigated, in order to know the stability of solid propellants which contain diphenylamine. The simultaneous determination of N-nitrousdiphenylamine (NnDPA), 2-nitrodiphenylamine (2nDPA), 4-nitrodiphenylamine (4nDPA) and 2,4-dinitrodiphenylamine (2,4dnDPA) by DPP and SWV was proposed due to these nitro-derivatives appear during the stabilisation process from degradation of diphenylamine (DPA) used as stabiliser in propellant compositions. The proposed methods were successfully applied to the simple base solid propellant (with nitrocellulose as the only active component), with its stabiliser DPA. In all cases and with both the techniques, detection limits propellants accurately, faster and cheaper than LC methods.

  8. Modification of the diphenylamine assay for cell quantification in three-dimensional biodegradable polymeric scaffolds.

    Pham, Edward A; Ho, Won Jin; Kamei, Daniel T; Wu, Benjamin M


    As three-dimensional (3D) cell culture systems gain popularity in biomedical research, reliable assays for cell proliferation within 3D matrices become more important. Although many cell quantification techniques have been established for cells cultured on nondegradable plastic culture dishes and cells suspended in media, it is becoming increasingly clear that cell quantification after prolonged culture in 3D polymeric scaffolds imposes unique challenges because the added presence of polymeric materials may contribute to background signal via various mechanisms including autofluorescence, diffusion gradients, and sequestering effects. Thus, additional steps are required to ensure complete isolation of cells from the 3D scaffold. The diphenylamine assay isolates cellular DNA, degrades the polymeric matrix materials, and reacts with the DNA to yield a colorimetric response. Thus, we report here a practical modification of the diphenylamine assay and show that the assay quantifies cells in 3D polyester scaffolds reliably and reproducibly as long as the necessary amount of the acidic working reagent is present. Our study also demonstrates that the sensitivity of the assay can be optimized by controlling the dimensions of the sampling volume. Overall, the DPA assay offers an attractive solution for challenges associated with 3D cell quantification.

  9. Microwave assisted transformation of N,N-diphenylamine as precursors of organic light emitting diodes (OLED)

    Jefri,; Wahyuningrum, Deana, E-mail: [Organic Chemistry Research Division, Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132 (Indonesia)


    In this research, study on the transformation of N,N-diphenylamine (DPA) using iodine (I2) utilizing solid state Microwave Assisted Organic Synthesis (MAOS) method has been carried out. The reaction was performed by variations of three parameters namely the mole of reagents, the amount and type of solid support (alumina/Al2O3), and the reaction conditions. Experimental results showed that neutral-alumina was a better solid support than basic-alumina. The optimum temperature for the reaction was approximately at 125-133 °C with reaction time of 15 minutes and microwave reactor power at 500-600 W. The separation of the yellowish green product solution with preparative Thin Layer Chromatography (TLC) method using n-hexane:ethyl acetate = 4:1 (v/v) as eluent yielded two fractions (I and II) and both fractions can undergo fluorescence under 365 nm UV light. Based on the LC chromatogram with methanol:water = 95:5 (v/v) as eluent and its corresponding mass spectra (ESI+), fraction I contained three compounds, which were tetracarbazole A, triphenylamine, and impurities in the form of plasticizer such as bis(2-ethylhexyl) phthalate. Fraction II also contained three compounds, which were tetracarbazole C, tetraphenylhydrazine, and plasticizer such as bis(2-ethylhexyl) phthalate. Both FT-IR (KBr disks) and NMR (500 MHz, CDCl{sub 3}) spectra of fraction I and II confirmed the aromatic amine groups in those compounds. The observed fluorescence colors of fraction I and II were violet and violet-blue, respectively. Based on their structures and fluorescence characters, the compounds in fraction I and II have the potential to be used as Organic Light Emitting Diode (OLED) compound precursors.

  10. Microwave assisted transformation of N,N-diphenylamine as precursors of organic light emitting diodes (OLED)

    Jefri, Wahyuningrum, Deana


    In this research, study on the transformation of N,N-diphenylamine (DPA) using iodine (I2) utilizing solid state Microwave Assisted Organic Synthesis (MAOS) method has been carried out. The reaction was performed by variations of three parameters namely the mole of reagents, the amount and type of solid support (alumina/Al2O3), and the reaction conditions. Experimental results showed that neutral-alumina was a better solid support than basic-alumina. The optimum temperature for the reaction was approximately at 125-133 °C with reaction time of 15 minutes and microwave reactor power at 500-600 W. The separation of the yellowish green product solution with preparative Thin Layer Chromatography (TLC) method using n-hexane:ethyl acetate = 4:1 (v/v) as eluent yielded two fractions (I and II) and both fractions can undergo fluorescence under 365 nm UV light. Based on the LC chromatogram with methanol:water = 95:5 (v/v) as eluent and its corresponding mass spectra (ESI+), fraction I contained three compounds, which were tetracarbazole A, triphenylamine, and impurities in the form of plasticizer such as bis(2-ethylhexyl) phthalate. Fraction II also contained three compounds, which were tetracarbazole C, tetraphenylhydrazine, and plasticizer such as bis(2-ethylhexyl) phthalate. Both FT-IR (KBr disks) and NMR (500 MHz, CDCl3) spectra of fraction I and II confirmed the aromatic amine groups in those compounds. The observed fluorescence colors of fraction I and II were violet and violet-blue, respectively. Based on their structures and fluorescence characters, the compounds in fraction I and II have the potential to be used as Organic Light Emitting Diode (OLED) compound precursors.

  11. Determination of o-phenylphenol, diphenylamine, and propargite pesticide residues in selected fruits and vegetables by gas chromatography/mass spectrometry.

    Yu, L; Schoen, R; Dunkin, A; Firman, M; Cushman, H; Fontanilla, A


    A simple and rapid method was developed to detect o-phenylphenol, diphenylamine, and propargite in selected fruits and vegetables. Gas chromatography/mass spectrometry in the selective-ion monitoring mode was used to identify and quantitate the 3 residues. Residues were extracted with acetonitrile and transferred to acetone. Limits of detection were 10, 8, and 15 ppb for o-phenylphenol, diphenylamine, and propargite, respectively. Recovery data were obtained by fortifying 4 matrixes (apples, oranges, canned peaches, and spinach) at 0.025-0.888 ppm. The method provides very good linearity data with low coefficients of variation.

  12. In situ UV-visible spectroelectrochemical studies on the copolymerization of diphenylamine with ortho-methoxy aniline

    Santhosh, P.; Gopalan, A.; Vasudevan, T.


    UV-visible spectroelectrochemical studies on copolymerization of diphenylamine (DPA) with ortho-methoxy aniline (OMA) were carried out for different feed ratios of DPA and OMA using indium tin oxide (ITO)-coated glass as working electrode. The UV-visible spectra show clear dependencies on the molar feed composition of DPA or OMA used in electropolymerization. Derivative cyclic voltabsorptogram (DCVA) was deduced at the wavelengths corresponding to the absorption by the intermediate species and used to confirm the intermediates generated during the electropolymerization. The composition of DPA and OMA in the copolymer for the copolymers synthesized with different molar feed ratios of DPA and OMA was determined by UV-visible spectroscopy. Reactivity ratios of DPA and OMA were deduced by using Fineman-Ross and Kelen-Tudos methods and correlated with spectroelectrochemical results.

  13. Triple-transforming gel prepared by β-cyclodextrin,diphenylamine and lithium chloride in N,N-dimethylacetamide

    Yuan Yuan Li; Wen Jing Zhao; Hua Cheng Zhang; Tao Sun; Wei An; Fei Fei Xin; Ai You Hao


    This paper describes a triple-transforming gel system(gel-sol-gel')for the first time,which is a thermo-responsive and multicomponent organogel prepared by β-cyclodextrin(β-CD),diphenylamine(DPA)and lithium chloride(LiCl)in N,N-dimethylacetamide(DMAC)in a suitable proportion based on the supramolecular interactions.In the triple-transforming gel system,a gel(gel A)could be formed by β-CD,DPA and LiCl in DMAC at room temperature based on stirring,then the gel could transform into a clear solution based on heating,and then the other gel(gel B)can be formed at a relatively high temperature(Tgel,the gelation temperature by heating).The two gel states in the triple-transforming gel system have different microstructures.This gel system was characterized by OM,SEM,IR and rheology.

  14. A tale of switched functions: from cyclooxygenase inhibition to M-channel modulation in new diphenylamine derivatives.

    Asher Peretz

    Full Text Available Cyclooxygenase (COX enzymes are molecular targets of nonsteroidal anti-inflammatory drugs (NSAIDs, the most used medication worldwide. However, the COX enzymes are not the sole molecular targets of NSAIDs. Recently, we showed that two NSAIDs, diclofenac and meclofenamate, also act as openers of Kv7.2/3 K(+ channels underlying the neuronal M-current. Here we designed new derivatives of diphenylamine carboxylate to dissociate the M-channel opener property from COX inhibition. The carboxylate moiety was derivatized into amides or esters and linked to various alkyl and ether chains. Powerful M-channel openers were generated, provided that the diphenylamine moiety and a terminal hydroxyl group are preserved. In transfected CHO cells, they activated recombinant Kv7.2/3 K(+ channels, causing a hyperpolarizing shift of current activation as measured by whole-cell patch-clamp recording. In sensory dorsal root ganglion and hippocampal neurons, the openers hyperpolarized the membrane potential and robustly depressed evoked spike discharges. They also decreased hippocampal glutamate and GABA release by reducing the frequency of spontaneous excitatory and inhibitory post-synaptic currents. In vivo, the openers exhibited anti-convulsant activity, as measured in mice by the maximal electroshock seizure model. Conversion of the carboxylate function into amide abolished COX inhibition but preserved M-channel modulation. Remarkably, the very same template let us generating potent M-channel blockers. Our results reveal a new and crucial determinant of NSAID-mediated COX inhibition. They also provide a structural framework for designing novel M-channel modulators, including openers and blockers.

  15. Semiquantitative determination of some nitrogen compounds by the formation of charge-transfer complexes of diphenylamine with p-dimethylaminobenzaldehyde by capillary solid-state spot-tests

    Ishaat; M.Khan


    The interactions of p-dimethylaminobenzaldehyde (p-DAB) and potassium hydrogen sulphate (PHS) in equimolar ratio with various concentration of diphenylamine (solid test material) have been investigated by capillary spot-tests technique in order to investigate the effect of temperature and volume of material in test-tube. The formation of the colored boundary in the capillary is taken for the detection of organic compounds by spot-tests at different temperature and volume of solid test material.

  16. Design, synthesis and 3D-QSAR studies of new diphenylamine containing 1,2,4-triazoles as potential antitubercular agents.

    Mohan Krishna, K; Inturi, Bharathkumar; Pujar, Gurubasavaraj V; Purohit, Madhusudan N; Vijaykumar, G S


    A new series of new diphenylamine containing 1,2,4-triazoles were synthesized from 4-arylideneamino-5-[2-(2,6-dichlorophenylamino) benzyl]-2H-1,2,4-triazole-3(4H)-thiones 3a-f. The synthesized compounds were screened for in-vitro antimycobacterial and antibacterial activities. The synthesized compounds 4a, 4e and 4d have shown potential activity against Mycobacterium tuberculosis H37Rv strain with MIC of 0.2, 1.6 and 3.125 μM respectively. To investigate the SAR of diphenylamine containing 1,2,4-triazole derivatives in more details, CoMFA (q(2)-0.432, r(2)-0.902) and CoMSIA (q(2)-0.511, r(2)-0.953) models on M. tuberculosis H37Rv were established. The generated 3D-QSAR models are externally validated and have shown significant statistical results, and these models can be used for further rational design of novel diphenylamine containing 1,2,4-triazoles as potent antitubercular agents.

  17. Isolation of a diphenylamine-degrading bacterium and characterization of its metabolic capacities, bioremediation and bioaugmentation potential.

    Perruchon, Chiara; Batianis, Christos; Zouborlis, Stelios; Papadopoulou, Evangelia S; Ntougias, Spyridon; Vasileiadis, Sotirios; Karpouzas, Dimitrios G


    The antioxidant diphenylamine (DPA) is used in fruit-packaging plants for the control of the physiological disorder apple scald. Its use results in the production of DPA-contaminated wastewater which should be treated before finally discharged. Biological treatment systems using tailored-made microbial inocula with specific catabolic activities comprise an appealing and sustainable solution. This study aimed to isolate DPA-degrading bacteria, identify the metabolic pathway of DPA and evaluate their potential for future implementation in bioremediation and biodepuration applications. A Pseudomonas putida strain named DPA1 able to rapidly degrade and utilize DPA as the sole C and N source was enriched from a DPA-contaminated soil. The isolated strain degraded spillage-level concentrations of DPA in liquid culture (2000 mg L(-1)) and in contaminated soil (1000 mg kg(-1)) and metabolized DPA via the transient formation of aniline and catechol. Further evidence for the bioremediation and biodepuration potential of the P. putida strain DPA1 was provided by its capacity to degrade the post-harvest fungicide ortho-phenylphenol (OPP), concurrently used by the fruit-packaging plants, although at slower rates and DPA in a wide range of pH (4.5-9) and temperatures (15-37 °C). These findings revealed the high potential of the P. putida strain DPA1 for use in future soil bioremediation strategies and/or as start-up inocula in wastewater biodepuration systems.

  18. Formation and cytotoxicity of a new disinfection by-product (DBP) phenazine by chloramination of water containing diphenylamine

    Wenjun Zhou; Linjie Lou; Lifang Zhu; Zhimin Li; Lizhong Zhu


    Disinfection by-products (DBPs) in drinking water have caused worldwide concern due to their potential earcinogenic effects.The formation of phenazine from diphenylamine (DPhA) chloramination was studied and its cytotoxicities for two human cancer cells were also investigated.Phenazine was detected synchronously with the consumption of DPhA by chloramination,which further confirmed that the new DBP phenazine can be produced along with N-nitrosodiphenylamine (NDPhA) from DPhA chloramination.The formation of phenazine had a maximum molar yield with solution pH increasing from 5.0 to 9.0,with phernazine as the main product for DPhA chloramination at lower pH,but higher pH favored the formation of NDPhA.Thus,solution pH is the key factor in controlling the formation of phenazine and NDPhA.Both the initial DPhA and chloramine concentrations did not show a significant effect on the molar yields of phenazine,although increasing the chloramine concentration could speed up the reacdon rate of DPhA with chloramines.The cytotoxicity assays showed that phenazine had significant cell-specific toxicity towards T24 (bladder cancer cell lines) and HepG2 (hepatic tumor cell lines) cells with IC50 values of 0.50 and 2.04 mmol/L,respectively,and T24 ceils being more sensitive to phenazine than HepG2 ceils.The IC50 values of phenazine,DPhA,and NDPhA for T24 cells were of the same order of magnitude and the cytotoxicity of phenazine for T24 cells was slightly lower than that of NDPhA (IC50,0.16 mmol/L),suggesting that phenazine in drinking water may have an adverse effect on human health.

  19. 二苯胺磺酸钠光度法测定Fe(Ⅲ)%Determination of iron (Ⅲ) by diphenylamine sulfonate spectrophotometry

    陈晓红; 徐玲


    The article has researched the reaction of mixing iron (Ⅲ) and diphenylamine sulfonate up. It has been found that absorbance of the production is in line with Beris law when the concentration of diphenylamine sulfonate varies from 0 ~ 7 μg· mL-1. The minimum concentration detected is 0. 21 μg· mL-1. To determine the quantity of iron (Ⅲ) of the sample of water with this method, the recoverie is 109.0% -101.0% and the relative meansquare is less than 5%. The result is satisfying.%研究了Fe(Ⅲ)与二苯胺磺酸钠的显色反应,建立了测定Fe(Ⅲ)的光度分析方法.该法测定线性范围为0~7 μg· mL-1,检出限为0.2μg·mL-1.用于水样中Fe(Ⅲ)的测定,回收率在109.0%~101.0%,相对标准偏差小于5%,结果较满意.

  20. A method for the determination of bacterial spore DNA content based on isotopic labelling, spore germination and diphenylamine assay; ploidy of spores of several Bacillus species.

    Hauser, P M; Karamata, D


    A reliable method for measuring the spore DNA content, based on radioactive DNA labelling, spore germination in absence of DNA replication and diphenylamine assay, was developed. The accuracy of the method, within 10-15%, is adequate for determining the number of chromosomes per spore, provided that the genome size is known. B subtilis spores were shown to be invariably monogenomic, while those of larger bacilli Bacillus megaterium, Bacillus cereus and Bacillus thuringiensis, often, if not invariably, contain two genomes. Attempts to modify the spore DNA content of B subtilis by altering the richness of the sporulation medium, the sporulation conditions (liquid or solid medium), or by mutation, were apparently unsuccessful. An increase of spore size with medium richness, not accompanied by an increase in DNA content, was observed. The implication of the apparently species-specific spore ploidy and the influence of the sporulation conditions on spore size and shape are discussed.

  1. Investigation of ionic conductivity and long-term stability of a LiI and KI coupled diphenylamine quasi-solid-state dye-sensitized solar cell.

    Agarwala, S; Peh, C K N; Ho, G W


    In this work, enhancement of ionic conductivity and long-term stability through the addition of diphenylamine (DPA) in poly(ethylene oxide) (PEO) is demonstrated. Potassium iodide (KI) is adopted as the crystal growth inhibitor, and DPA is used as a charge transport enhancer in the electrolyte. The modified electrolyte is used with titanium dioxide (TiO2) nanoparticles, which is systematically tuned to obtain high surface area. The dye-sensitized solar cell (DSSC) showed a photocurrent of 14 mAcm2 with a total conversion efficiency of 5.8% under one sun irradiation. DPA enhances the interaction of the TiO2 nanoparticle film and the I-/I3- electrolyte leading to high ionic conductivity (3.5 × 10-3 Scm-1), without compromising on the electrochemical and mechanical stability. Electrochemical impedance spectroscopy (EIS) studies show that electron transport and electron lifetime are enhanced in the DPA added electrolyte due to reduced sublimation of iodine. The most promising feature of the electrolyte is increased device stability with 89% of the overall efficiency preserved even after 40 days.

  2. Synthesis of diphenylamine from aniline- phenol by liquid phase condensation%苯胺—苯酚液相催化合成二苯胺

    王新平; 罗财红; 贺民; 蔡天锡


    The synthesis of diphenylamine from aniline-phenol by liquid phase condensation in the presence of Pd/C catalyst was studied. The effects of organic promoter, catalyst amount, reaction temperature and time on the synthesis were investigated. In the conditions of cyclohexylamine: aniline: phenol was 0.2:1:1 (mole ratio), catalyst amount was 0.2% of total reactants(mass) ,at 523 K for 2 h ,the conversion of aniline and the selectivity of catalyst was 81% and 80% ,respectively.%研究了在Pd/C催化剂存在下,通过液/固催化缩合反应由苯胺和苯酚合成二苯胺的方法。考察了有机助剂、催化剂用量、反应温度、反应时间等因素对反应的影响。在n(环己胺):n(苯胺):n(苯酚)=0.2:1:1、催化剂用量为0.2%(ω)、反应温度523 K及反应时间为2 h的条件下,苯胺的转化率和苯胺生成二苯胺的选择性分别为81%和80%。

  3. 阻抑动力学光度法测定纺织品中痕量二苯胺%Determination of trace diphenylamine in textiles by inhibitory kinetic spectrophotometry

    刘斌; 段红娟; 郁翠华; 陈立成


    Alkali dyes (methyl green) can be decolorized via oxidation by potassium periodate in acetic acid medium. This reaction can be inhibited greatly by diphenylamine and the inhibition degree is correlated with concentration of diphenylamine. A new method of determination of diphenylamine by inhibitory kinetic spectrophotometry is established according to the above principle. Effects of testing conditions on sensitivity are discussed and optimum conditions are determined as follows: acetic acid 1.0 mL, potassium periodate0.9 mL, methyl green 1.1 mL, reacting at 95 °C for 8 min. This method can be used for determination of diphenylamine in textiles with linear range 0.08 ~0.64 mg/L and detection limit 2.8 x 1-6 g/L.%在乙酸介质中,高碘酸钾能氧化碱性染料,使甲基绿褪色,而二苯胺能明显地阻抑这一反应,其阻抑程度与二苯胺的浓度相关.据此,建立了阻抑动力学分光光度法测定痕量二苯胺的新方法(以甲基绿为指示剂,高碘酸钾为氧化剂).通过考察各种试验条件对灵敏度的影响,得到优化的试验条件:乙酸1.0mL,高碘酸钾0.9mL,甲基绿1.1mL,反应温度95℃,反应时间8 min.此方法的线性范围0.08~0.64 mg/L,检出限为2.8×10-6 g/L,可应用于纺织品中二苯胺的测定.

  4. Synergistic extraction of palladium (II) with 2-hydroxyl-4-sec-octyl-diphenylamine and trioctylphousphine oxide%2-羟基-4-仲辛基-二苯甲酮肟与三辛基氧化膦协同萃取钯



    Liquid extraction behavior of Pd(II)by the use 2-hydroxyl-4-sec-octyl- diphenylamine(abbreviated as H2L)in trichloromethane has been investigated at 298.2 K.Under some conditions,the synergistic extraction behavior with 2-hydroxyl4-sec-octyl- diphenylamine and trioctylphousphine oxide(TOPO)has also been studied.The slope analysis method shows that the composition of the extracted species are PdL and PdL(TOPO)2.Equilibrium extraction constants and thermodynamic pa rameters were calculated.The results showed that increasing temperature is favo rable to extraction of Pd(II)with 2-hydroxyl-4secoctyl-diphenylamine and more favourable to synergistic extraction with 2-hydroxyl-4sec-octyl-diphenylamine and TOPO.%研究了2-羟基-4-仲辛基-二苯甲酮肟在氯仿中萃取钯的行为及2-羟基-4-仲辛基-二苯甲酮肟与三辛基氧化膦协同萃取钯的行为.用斜率法确定了萃合物组成为PdL和PdL(TOPO)2.同时了计算平衡常数及热力学参数.实验结果表明,升高温度对2-羟基-4-仲辛基-二苯甲酮肟萃取钯及2-羟基-4-仲辛基-二苯甲酮肟与三辛基氧化膦协同萃取钯有利.

  5. 40 CFR 180.190 - Diphenylamine; tolerances for residues.


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  6. Study of the Pyrrol/Diphenylamine Copolymer by FT-IR spectroscopy and conductivity

    Carlos Alberto Perez


    Full Text Available The main goal of this study was to analyze the physical properties of the copolymer formed by the electrochemical deposition of the polydiphenylamine (PDPA on polypyrrole (Ppy and Ppy on PDPA, in different conditions, through the characterization of the materials formed by the resonant Raman, FT-IR and conductivity techniques. The interactions among the species which are present in the new copolymer structure and the changes in electronic conductivity, were verified. The copolymer was also synthesized electrochemically in the presence of iodide species and the material was characterized by FT-IR spectroscopy and conductivity. The role of the dopant was studied in the process of charge transfer between the copolymer-dopant, acting in the stabilization of the species in the polymer backbone and the increase of the electronic conductivity.

  7. HPLC测定单基火药中的二苯胺%HPLC Determination of Diphenylamine in Gunpowder

    徐同军; 李树兴; 王咸达; 栾志杰; 魏喜勤



  8. Synthesis, quantitative structure-activity relationship and biological evaluation of 1,3,4-oxadiazole derivatives possessing diphenylamine moiety as potential anticancer agents.

    Abdel Rahman, Doaa Ezzat


    Synthesis of 2,5-disubstituted-1,3,4-oxadiazole (2a-c), 3-substituted aminomethyl-5-substituted-1,3,4-oxadiazole-2(3H)-thione (4a-m) and 2-substituted thio-5-substituted-1,3,4-oxadiazole (5a, b) had been described. All the synthesized derivatives were screened for anticancer activity against HT29 and MCF7 cancer cell lines using Sulfo-Rodamine B (SRB) standard method. Most of the tested compounds exploited potent antiproliferative activity against HT29 cancer cell line rather than MCF7 cancer cell line. Compounds 2a-c, 4f and 5a exhibited potent cytotoxicity (IC(50) 1.3-2.0 µM) and selectivity against HT29 cancer cell line. Quantitative structure-activity relationship (QSAR) study was applied to find a correlation between the experimental antiproliferative activities of the newly synthesized oxadiazole derivatives with their physicochemical parameter and topological index.

  9. Studies of astaxanthin biosynthesis in Xanthophyllomyces dendrorhous (Phaffia rhodozyma). Effect of inhibitors and low temperature.

    Ducrey Sanpietro, L M; Kula, M R


    The effect of nicotine and diphenylamine on astaxanthin biosynthesis in Xanthophyllomyces dendrorhous was studied. The effects were analysed under standard and low temperature conditions. It was found that 10 mM-nicotine inhibits the cyclization of lycopene and de novo protein synthesis was not needed to reverse the inhibition. The oxidation of beta-carotene was irreversibly inhibited by 10 microM-diphenylamine while the dehydrogenation of phytoene was reversibly inhibited by 60 microM-diphenylamine. The simultaneous exposure to low temperature (4 degrees C) overcomes the inhibition of beta-carotene oxidation at low diphenylamine concentration.

  10. Simple & Safe Genomic DNA Isolation.

    Moss, Robert; Solomon, Sondra


    A procedure for purifying DNA using either bacteria or rat liver is presented. Directions for doing a qualitative DNA assay using diphenylamine and a quantitative DNA assay using spectroscopy are included. (KR)

  11. Polyvinyl Acetate Resin as a Binder Effecting Mechanical and CombustionProperties of Combustible Cartridge Case Formulations

    M.T. Shedge; C.H. Patel; S.K. Tadkod; G.D. Murthy


    Several combustible cartridge case (CCC) formulations containing nitrocellulose (NC) as anenergetic ingredient with diphenylamine (DPA) as stabiliser, cellulose fiber as reinforcing materialand polyvinyl acetate (PVAc) as a binder are processed to form combustible discs. A formulationcontaining  nitrocellulose (83 parts), cellulose (17 parts) , PVAc (20 parts) and  diphenylamine(1 part) by weight was observed with the improvement of  mechanical properties without anyadverse effect on combusti...

  12. Effect of new poly 2-acryloyl-N,N'-bis (4-nitrophenyl) propandiamide and poly 2-acryloyl-N,N'-bis (4-methylphenyl) propandiamide and their synergistic action on the stability of nitrocellulose.

    Shehata, A B; Hassan, M A; Nour, M A


    The stability of nitrocellulose can be significantly improved by incorporating two novel polymeric compounds as new stabilizers, each has two p-substituted phenyl rings in its repeating unit. The two prepared polymers were used independently and in three different blend ratios in comparison with the conventional propellant stabilizer, diphenylamine. The efficiency of the prepared stabilizers and their synergistic effect were evaluated using thermo gravimetric analysis (TGA), Bergmann-Junk test and differential scanning calorimetry (DSC). It was found that both polymers and their 50%:50% blend ratio are more efficient nitrocellulose stabilizers than diphenylamine.

  13. Polyvinyl Acetate Resin as a Binder Effecting Mechanical and CombustionProperties of Combustible Cartridge Case Formulations

    M.T. Shedge


    Full Text Available Several combustible cartridge case (CCC formulations containing nitrocellulose (NC as anenergetic ingredient with diphenylamine (DPA as stabiliser, cellulose fiber as reinforcing materialand polyvinyl acetate (PVAc as a binder are processed to form combustible discs. A formulationcontaining  nitrocellulose (83 parts, cellulose (17 parts , PVAc (20 parts and  diphenylamine(1 part by weight was observed with the improvement of  mechanical properties without anyadverse effect on combustion characteristics, safety parameters and compatibility with triplebase multi-tubular propellant. Dynamic firing performance was also satisfactory.

  14. Nitrogen-depleted Chlorella zofingiensis produces astaxanthin, ketolutein and their fatty acid esters: a carotenoid metabolism study

    Mulders, K.J.M.; Weesepoel, Y.J.A.; Bodenes, C.; Lamers, P.P.; Vincken, J.P.; Martens, D.E.; Gruppen, H.; Wijffels, R.H.


    Natural carotenoids such as astaxanthin, ß,ß-carotene and lutein are pigments with a high market value. We studied the effects of nitrogen depletion on the carotenoid metabolism of Chlorella zofingiensis (Chlorophyta) and the subsequent treatment with diphenylamine (DPA), an inhibitor of the biosynt

  15. Ethylene insensitivity alters ripening-associated metabolomic changes in apple peel

    Metabolomic changes were compared in untreated, diphenylamine treated, and 1-methylcyclopropene treated ‘Granny Smith’ apples stored for up to 6 months at 1 oC in air. Metabolomic evaluation, including 600+ metabolites, was employed to characterize ripening-related metabolism. Partial Least Square...

  16. X-ray Diffraction Study of Single-base Propellant Ageing


    Ageing of single-base propellants, extending over a storage period of more than 50 years, was investigated by X-ray diffraction analysis. X-ray degree of crystallinity and interplanar spacing were determined. Analysed was the effect of nitrogen content, degree of substitution (DOS) and diphenylamine (DPA) content on structural changes in propellants.

  17. Nitrogen-depleted Chlorella zofingiensis produces astaxanthin, ketolutein and their fatty acid esters: a carotenoid metabolism study

    Mulders, K.J.M.; Weesepoel, Y.J.A.; Bodenes, C.; Lamers, P.P.; Vincken, J.P.; Martens, D.E.; Gruppen, H.; Wijffels, R.H.


    Natural carotenoids such as astaxanthin, ß,ß-carotene and lutein are pigments with a high market value. We studied the effects of nitrogen depletion on the carotenoid metabolism of Chlorella zofingiensis (Chlorophyta) and the subsequent treatment with diphenylamine (DPA), an inhibitor of the

  18. Synthesis of highly substituted diphenylacetamides and diphenylsulfonamides by the goldberg coupling reaction

    Raposo, M. Manuela M.; Pereira, Alexandra M. B.; Campos, Ana M. F. Oliveira; Shannon, Patrick V. R.


    We report the synthesis and characterisation of multisubstituted diphenylacetamides, diphenylsulfonamides and diphenylamines (and some observations on cyclisation of the last). Fundação para a Ciência e a Tecnologia (FCT) ICCTI and CRUP (Portugal) and the British Council for financial support

  19. The classification of gunshot residue using laser electrospray mass spectrometry and offline multivariate statistical analysis

    Nonresonant laser vaporization combined with high-resolution electrospray time-of-flight mass spectrometry enables analysis of a casing after discharge of a firearm revealing organic signature molecules including methyl centralite (MC), diphenylamine (DPA), N-nitrosodiphenylamine (N-NO-DPA), 4-nitro...

  20. Secondary Metabolites from Halostachys caspica and Their Antimicrobial and Antioxidant Activities

    Jianglin Zhao


    Full Text Available Nine secondary metabolites have been isolated from the aerial parts of Halostachys caspica C. A. Mey. (Chenopodiaceae. By means of physicochemical and spectrometric analysis, they were identified as betaine (1, diphenylamine (2, benzyl-O-β-D-glucopyranoside (3, β-sitosterol (4, 4-hydroxy-3-methoxy benzoic acid (5, 4-hydroxy benzoic acid (6, 2-hydroxy benzoic acid (7, 4-hydroxy-3,5-dimethoxy benzoic acid (8, and 3,4-dihydroxy benzeneacrylic acid (9. All compounds were isolated from this plant species for the first time. They were screened to exhibit antimicrobial and antioxidant activities to some extent except for the compounds 1 and 3. The results indicated that the isolated phenol acids and diphenylamine (2 could be the main bioactive components in the crude ethanol extract of H. caspica.

  1. Mammalian Toxicological Evaluation of RDX


    glucose, sodium, potassium and calcium electrolytes, blood urea nitrogen (BUN), and alkaline phosphatase. Clinical chemistries parameters were...were stored in 1% KOH for two days then stained with alizarin red. 5 After differential decolorization, the skeletons were examined by experi- enced...feeding dams commercially aged diphenylamine containing DPA- derived impurities. 1 2 Histologic study of the thymus revealed subtle changes in two and a

  2. Mechanistic aspects of the oxidative and reductive fragmentation of n-nitrosoamines: a new method for generating nitrenium cations, amide anions, and aminyl radicals

    Piech, Krzysztof; Bally, Thomas; Sikora, Adam; Marcinek, Andrzej


    A new method for investigating the mechanisms of nitric oxide release from NO donors under oxidative and reductive conditions is presented. Based on the fragmentation of N-nitrosoamines, it allows generation and spectroscopic characterization of nitrenium cations, amide anions, and aminyl radicals. X-irradiation of N-nitroso-N,N-diphenylamine 1 in Ar matrices at 10 K is found to yield the corresponding radical ions, which apparently undergo spontaneous loss of NO° under the conditions of this...

  3. Antioxidant and antitranspirant protection of apple foliage against ozone injury

    Elfving, D.C.; Gilbert, M.D.; Edgerton, L.J.; Wilde, M.H.; Lisk, D.J.


    Visible injury to apple foliage from exposure to ozone includes brown stippling on lower leaf surfaces and a light yellow mosaic on upper surfaces. Histologically, chlorophyll is destroyed and palisade and spongy mesophyll cells collapse following disintegration of their protoplasm. Foliar spray applications of the antioxidant, diphenylamine (DPA) or the antitranspirant, Wilt Pruf offer protection against this visible and histological injury. Superior protection results from application of both agents in combination.

  4. Detailed and Simplified Chemical Kinetics of Aviation Fuels and Surrogates


    naphthalene, c) ethyl naphthalenes, d) C3-naphthalenes, e) diphenylamine, f) C4-naphthalenes, g) phenanthrene, h) anthracene, i) methyl anthracene [9...was assigned a rate from Oehlschlaeger et al. [80]. Approximately 34% of the benzyl radical reacts with the methyl radical and forms ethyl benzene... kerosene provide significant scope for large regional and source differences. The chemistry of high-performance fuels aimed at specific applications and

  5. Induction of DNA damage by the leaves and rhizomes of Curcuma amada Roxb in breast cancer cell lines

    Sivaprabha, J.; B Dharani; PR Padma; Sumathi, S.


    Objective: To evaluate DNA damage inducing effect of the methanolic extract of both the leaves and the rhizomes of Curcuma amada (C. amada) against breast cancer cell lines MCF-7 and MDA MB 231 and analyze the active components present in the methanolic extract of the leaves and the rhizomes. Methods: The DNA damage induced in yeast was assessed using diphenylamine method. The DNA damage induced by the extracts in cell lines was assessed using single cell gel electrophoresis (Comet assay)....

  6. Additive effects in halogen hot atom chemistry. I. Nuclear reaction (. gamma. ,n) in bromobenzene, fluorobenzene-amine systems

    Liu, Y.; Fu, K.; Li, W.; Wang, T.


    (1) For observing the chemical effects of the nuclear reaction /sup 79/Br(..gamma..,n)/sup 78/Br in liquid bromobenzene, the nitrogen-containing compounds, such as aniline, diphenylamine, phenylhydrazine and pyridine, were used as additives respectively during irradiation. Similarly, aniline, diphenylamine, phenylhydrazine, dimethylaniline and pyridine were added in liquid fluorobenzene when the reaction /sup 19/F(..gamma..,n)/sup 18/F proceeded. The curves indicating the dependence of recoil atom retention to the additive mole concentration were plotted, and each curve typically showed the general characteristics of dropping sharply in low mol % of additive and gradually in high mol %. (2) The relative effectiveness of additives in depressing organic retention was revealed in the following order: phenylhydrazine > aniline greater than or equal to dimethylaniline > diphenylamine greater than or equal to pyridine. In our opinion the reactivity of nitrogen lone-pair electrons, which is influenced and bounded by the Pi-bond delocalization of the aromatic amine molecule, substantially determines this effectiveness order. (3) Adding the inert additive benzene or toluene to the fluorobenzene system, a linear dependence of retention to additive concentration was obtained. The contribution of the reactive functional group NHNH/sub 2/ of phenylhydrazine in reducing the retention chemically could be evaluated by the comparison of the benzene line with the phenylhydrazine curve.

  7. In vivo modulation of the inflammatory response by nonsteroidal antiinflammatory drug-related compounds that trigger L-selectin shedding.

    Herrera-García, Ada; Domínguez-Luis, María; Arce-Franco, Mayte; López-Fernández, Judith; Feria, Manuel; Barreiro, Olga; Sánchez-Madrid, Francisco; Díaz-González, Federico


    Diphenylamine-based nonsteroidal antiinflammatory drugs (NSAIDs) are able to cause in vitro the shedding of L-selectin. The aim of this work was to determine the physio-logic relevance of L-selectin shedding in the antiinflammatory effect exerted by NSAIDs in vivo. Chemical compounds structurally related to NSAIDs - including diphenyl-amine, N-phenylanthranilic acid (N-Ph), diphenylacetic acid - as well as the traditional NSAID indomethacin were studied using the zymosan air-pouch mouse model. Animals intramuscularly pretreated with indomethacin or N-Ph, but not with diphenyl-amine or diphenylacetic acid, showed a significant dose-dependent reduction in the number of neutrophils compared with untreated animals (N-Ph, IC50 = 6.7 mg/kg). Except for indomethacin, none of these compounds caused any significant reduction in cyclooxygenase-1 activity in vivo. In flow chamber experiments, N-Ph reduced the capability of human neutrophils to pass across the endothelial barrier by interfering with leukocyte rolling step on HUVEC. N-Ph, but not diphenylacetic acid, induced activation-independent L-selectin shedding in mouse neutrophils. Interestingly, N-Ph exerted an antiinflammatory effect similar to that of the anti-L-selectin blocking antibody Mel-14, although no additive action was observed when both compounds were combined. These data suggest that the L-selectin shedding induced by NSAIDs may be involved in the antiinflammatory action exerted by these compounds in clinical settings.

  8. High Performance Liquid Chromatography of Propellants. Part 1. Analysis of M1, M6, and M10 Propellants


    High performance liquid chromatography permits the differentation among the stabilizers and their degradation products together with accurate quantitation. This progress report describes work carried out in the analysis of single base propellants containing diphenylamine (DPA) as the stabilizer. Several degradation products have been identified and the routine determination of these compounds is feasible. The degradation of DPA seems to follow a pattern that is unique for M1 and M6’s as compared to the pattern for M10’s. It is postulated

  9. Controlled Energy Transfer from a Ligand to an Eu(III) Ion: A Unique Strategy To Obtain Bright-White-Light Emission and Its Versatile Applications.

    Boddula, Rajamouli; Singh, Kasturi; Giri, Santanab; Vaidyanathan, Sivakumar


    A new diphenylamine-functionalized ancillary-ligand-coordinated europium(III) β-diketonate complex showed incomplete photoexcitation energy transfer from a ligand to a Eu(III) ion. A solvatochromism study led to a balancing of the primary colors to obtain single-molecule white-light emission. Thermal-sensing analysis of the europium complex was executed. The europium complex, conjugated with a near-UV-light-emitting diode (395 nm), showed appropriate white-light-emission CIE color coordinates (x = 0.34 and y = 0.33) with a 5152 K correlated color temperature.

  10. Phenazines and natural products; Novel synthesis of saphenic acid

    Petersen, Lars; Jensen, Knud Jørgen; Nielsen, John


    The natural product saphenic acid (6-(1-hydroxyethyl)1-phenazinecarboxylic acid) was synthesized from readily accessible starting materials. The desired product was obtained in an overall yield of 22% for four steps with the key steps being formation of a diphenylamine, followed by cyclization un...... under alkaline and reducing conditions. Assignments of H-1 NMR spectra were achieved by homo- and heteronuclear 1D and 2D correlations. Double pulsed field gradient spin-echo one-dimensional NOESY proved especially valuable for assignment of aromatic protons....

  11. Phenazines and natural products; novel synthesis of saphenic acid

    Petersen, Lars; Jensen, Knud J.; Nielsen, John


    The natural product saphenic acid (6-(1-hydroxyethyl)1- phenazinecarboxylic acid) was synthesized from readily accessible starting materials. The desired product was obtained in an overall yield of 22% for four steps with the key steps being formation of a diphenylamine, followed by cyclization u...... under alkaline and reducing conditions. Assignments of 1H NMR spectra were achieved by homo- and heteronuclear 1D and 2D correlations. Double pulsed field gradient spin-echo one-dimensional NOESY proved especially valuable for assignment of aromatic protons....

  12. Report on repetition analyses for pesticide residues: 1988-1995; Rapporto sulle revisioni di analisi per residui di antiparassitari-1995

    Di Muccio, A.; Attard Barbini, D.; De Merulis, G.; Vergori, L.; Girolimetti, S.; Sernicola, L.; Dommarco, R. [Ist. Superiore di Sanita`, Rome (Italy). Lab. di Tossicologia Applicata


    From 1988 to 1995, 1,254 analyses were carried out on samples of fruits (61%), vegetables (29%), cereals and derived products (3%). The analyses were for 80 different pesticides, of which 51% were fungicides, 31% insecticides, 8% diphenylamine and ethoxiquin (post-harvest antioxidans agents for protection of fruits), and 5% antigermogliants and herbicides. Regions that mostly contributed with samples were: Emilia-Romagna (35%), Piedmont (15%), Liguria (11%), Tuscany (10%). Global rate of confirmation between first analysis and repetition analysis was 64% for all the samples analysed.

  13. Detecting platform for phenolic compounds-characteristic of enzymatic electrode

    Cabaj, Joanna; Chyla, Antoni; Jędrychowska, Agnieszka; Olech, Kamila; Sołoducho, Jadwiga


    We report here on simple and universal method for the highly efficient, electrolytic immobilization of tyrosinase (from Agaricus bisporus), for amperometric biosensing purposes. Tyrosinase has been successfully deposited on the surface of thin, ordered films of copolymerized derivative of thiophene (3-methylthiophene/3-thiopheneacetic acid/bis(ethylenedioxythiophene)diphenylamine). The tyrosinase retains well its activity well within the fabricated copolymer matrix. Reduction peaks, observed in cyclic voltammetry at 0.125 to +0.07 V, were attributed to the reduction of enzymatically liberated quinone species. Considering the fact, that immobilization strategy showed high efficiency, obtained results suggest that the method for phenoloxidase immobilization has a great potential for fabrication of bioelectronics' devices.

  14. Synthetic utility of sydnones to couple pharmacologically important heterocycles for antitubercular activity

    Tasneem Taj


    Full Text Available In the present investigation we have utilized the 3-arylsydnones 1a–c to couple two biodynamic moieties in amide derivatives 7–10. The 3-arylsydnones were brominated to 4-bromo-3-arylsydnones 2a–c which further were reacted with benzotriazole/benzothiazolin-2-thione/morpholine/diphenylamine to the corresponding final compounds. The structures of the amide derivatives were confirmed by the spectral (IR, 1H NMR and Mass and analytical data. Further, these were subjected to the antitubercular activity against Mycobacterium tuberculae (H37Rv. The morpholine 7a–c and benzotriazole 8a–c derivatives have exhibited good inhibition.

  15. Quantitative Assessment of the Condensed Phase Heats of Reaction in a Double Base Propellant

    K. Kishore


    Full Text Available Heat of decomposition of the double base propellant has been calculated from the knowledge of the composition and decomposition enthalpy of the ingredients. This was compared with the experimentally observed value of the propellant decomposition which suggested that condensed phase contribution is very marginal (one twentieth of the total calorimetric value in double base propellants unlike composite solid propellants where condensed phase contribution is as high as one third. The condensed-phase in double base propellant was attributed to the nitration of the 2n-diphenylamine stabilizer in the propellant matrix.

  16. DAR Assisted Layer-by-Layer Assembly of Aromatic Compounds

    姜思光; 陈晓东; 张莉; 刘鸣华


    A facile DAR (diphenylamine-4-diazonium-formaldehyde resin)assisted layer-by-layer (LbL) assembly of uitrathin organic film of aromatic compounds has been investigated. The muitilayer of pyrene or anthracene was fabricated through simple dipping of the glass slide into the mixed solution of DAR with the target compounds. In this method, DAR acted as an assistant compound to help the assembling of the aromatic compounds. Such a convenient deposition method not only reserves the advantages of the traditional LbL technique but also simplifies the technique and extends the effectiveness of LbL technique to small molecules without any charge.

  17. Conversion of homothallic yeast to heterothallism through to gene disruption

    Van Zyl, WH


    Full Text Available ). DNA content. The cellular DNA of stationary-phase cells (5 x 109 cells per sample) was extracted with perchloric acid and the DNA content determined in duplicate according to the diphenylamine method described by Stewart (1975). Herring sperm DNA... few viable spores, it should be possible to enrich for such spores by ether treatment (Rockmill et al. 1991) prior to selection for G418 resis- tance. Acknowledgements. We thank Dr. James R. Broach at Princeton University, Princeton, N. J., USA...

  18. Synthesis of some 1H-indole-2, 3-dione Derivatives as Antibacterial, Analgesic and Antiinflammatory Agents

    Panda J 1,*


    Full Text Available The starting compound 1H-indole-2,3-dione on reaction with different substituted anilines formed the Schiff bases. The corresponding N-Mannich bases have been prepared by the reaction of the Schiff bases with diphenylamine in the presence of formaldehyde. The chemical structures of the title compounds have been confirmed and elucidated by means of their physical and spectral data respectively. The synthesized Mannich bases were screened for their antibacterial, analgesic and anti-inflammatory activities by the standard methods. Among the tested compounds, the compound containing chloro group showed the most favorable activity.

  19. Synthesis and characterization of processable multi-walled carbon nanotubes-sulfonated polydiphenylamine graft copolymers.

    Lee, Kwang-Pill; Gopalan, Anantha Iyengar; Kim, Kyu Soo; Santhosh, Padmanabhan


    Water soluble and processable nanocomposites composed of multi-walled carbon nanotubes (MWNTs) and poly(diphenylamine sulfonic acid) (PDPASA) are synthesized and characterized. Two types of methodologies are adopted. MWNTs are covalently functionalized with 2,5-diaminobenzene sulfonic acid (DABSA) and further in situ polymerized with diphenylamine-4-sulfonic acid (DPASA). This results in the formation of nanocomposites, MWNT(DABSA)-g-PDPASA, in which PDPASA is presented as the graft chains onto MWNTs. In another approach, DPASA is in situ polymerized in presence of unfunctionalized MWNTs, results in a nanocomposite in which MWNTs are present as entrapped mass in PDPASA matrix. Both nanocomposites are found to be water soluble and can form free standing films. The conductivity of MWNT(DABSA)-g-PDPASA and MWNT/PDPASA is found to be 1.25 mS x cm(-1) and 0.65 mS x cm(-1), respectively, which is higher than that of pristine PDPASA (0.25 x 10(-5) S x cm(-1)). The nanocomposites are characterized for their structure, morphology, optical and thermal properties.

  20. Carbendazim and metalaxyl residues in post-harvest treated apples.

    Su, Yirong; Mitchell, S H; Mac AntSaoir, S


    Bramley apples were treated with Ridomil mbc 60 WP, containing carbendazim and metalaxyl, at half and full rate application at 10 and 20 degrees C, and with diphenylamine to control disease during storage. Carbendazim and metalaxyl residues were determined by HPLC and GC/MS, respectively, in apple core, flesh and peel at the initial time, 3 and 6 months after storage under controlled atmosphere conditions of 4.5 degrees C, 5% CO(2) and 1% O(2). The concentration of carbendazim residues in apple flesh was metalaxyl residues in apple flesh was metalaxyl in apple was 1.0 mg kg(-1). The temperature of the fungicide solution had little effect on the carbendazim residues but did have some effect on metalaxyl residues. Carbendazim residue content per apple was decreased when diphenylamine was included. A change in the ratio of carbendazim to metalaxyl was noted in the flesh, core and peel of the stored apple. The ratio of carbendazim to metalaxyl was 5:1 in the fungicide mix as applied. The ratio remained fairly constant in the core during storage. However, the ratio changed significantly in the peel and, to a lesser extent, and in a different direction, in the flesh. In the peel, the ratio was around 15:1 at 3 months of storage and 12:1 after 6 months of storage, whereas for flesh the ratios were 2:1 and 4:1, respectively.

  1. Free radical reaction characteristics of coal low-temperature oxidation and its inhibition method.

    Li, Zenghua; Kong, Biao; Wei, Aizhu; Yang, Yongliang; Zhou, Yinbo; Zhang, Lanzhun


    Study on the mechanism of coal spontaneous combustion is significant for controlling fire disasters due to coal spontaneous combustion. The free radical reactions can explain the chemical process of coal at low-temperature oxidation. Electron spin resonance (ESR) spectroscopy was used to measure the change rules of the different sorts and different granularity of coal directly; ESR spectroscopy chart of free radicals following the changes of temperatures was compared by the coal samples applying air and blowing nitrogen, original coal samples, dry coal samples, and demineralized coal samples. The fragmentation process was the key factor of producing and initiating free radical reactions. Oxygen, moisture, and mineral accelerated the free radical reactions. Combination of the free radical reaction mechanism, the mechanical fragmentation leaded to the elevated CO concentration, fracturing of coal pillar was more prone to spontaneous combustion, and spontaneous combustion in goaf accounted for a large proportion of the fire in the mine were explained. The method of added diphenylamine can inhibit the self-oxidation of coal effectively, the action mechanism of diphenylamine was analyzed by free radical chain reaction, and this research can offer new method for the development of new flame retardant.

  2. The protein scaffold of the lipocalin odorant-binding protein is suitable for the design of new biosensors for the detection of explosive components

    Ramoni, Roberto [Dipartimento di Produzioni Animali, Universita degli Studi di Parma (Italy); Bellucci, Stefano [INFN-Laboratori Nazionali di Frascati, Frascati (Italy); Grycznyski, Ignacy [University of North Texas, Forth Worth, TX (United States); Grycznyski, Zigmunt [University of North Texas, Forth Worth, TX (United States); Grolli, Stefano [Dipartimento di Produzioni Animali, Universita degli Studi di Parma (Italy); Staiano, Maria [Istituto di Biochimica della Proteine, CNR, Naples (Italy); Bellis, Giovanni De [INFN-Laboratori Nazionali di Frascati, Frascati (Italy); Micciulla, Federico [INFN-Laboratori Nazionali di Frascati, Frascati (Italy); Pastore, Roberto [INFN-Laboratori Nazionali di Frascati, Frascati (Italy); Tiberia, Alessandra [INFN-Laboratori Nazionali di Frascati, Frascati (Italy); Conti, Virna [Dipartimento di Produzioni Animali, Universita degli Studi di Parma (Italy); Merli, Elisa [Dipartimento di Produzioni Animali, Universita degli Studi di Parma (Italy); Varriale, Antonio [Istituto di Biochimica della Proteine, CNR, Naples (Italy); Rossi, Mose' [Istituto di Biochimica della Proteine, CNR, Naples (Italy); D' Auria, Sabato [Istituto di Biochimica della Proteine, CNR, Naples (Italy)


    The detection of hazard exposure is a current priority, including the detection of traces of explosive molecules in different environments like luggage storage rooms and public places, and is becoming a major requirement for homeland security. In the present study we carried out a preliminary investigation on the binding capacities of four forms of the lipocalin odorant-binding protein (OBP) for the detection of explosive components such as diphenylamine, dimethyl-phthalate, resorcinol and dinitrotoluene. The experimental results, showing that OBP binds these compounds with affinity constants ranging between 80 nM and 10.6 mM, indicate that this protein can be used as a probe for the realization of a biosensor to sense explosive compounds.


    Mao-feng Zhang; Qiao-hong Yao; Chun-hui Huang; Wei-xiao Cao


    A kind of azo-containing resin (Azo-R) was synthesized by a simple way through the coupling reaction of 2-nitroN-methyldiphenylamine-4-diazoresin (NDR) with phenol, and a new covalentely attached multilayer film from Azo-R as H-donor and photosensitive diazoresin, diphenylamine-4-diazoresin (DR) as H-acceptor via H-bonding attraction by selfassembly technique has been fabricated. Following the decomposition of diazonium group of DR under exposure to UV light, the H-bonds between the layers of the film convert to covalent bonds and the film becomes very stable toward polar solvents or electrolyte aqueous solutions. Thus the UV-irradiated azo-containing films can be used to measure photocurrent in a conventional three-electrode photoelectrochemical cell using KCl as supporting electrolyte. It was confirmed that the azo-containing multilayer film is responsible for the photocurrent generation.

  4. [Occupational hazards and bladder cancer].

    Nizamova, R S


    Occupational exposure to health hazards was studied in 258 industrial workers who had developed cancer of the bladder against 454 matched controls. All the test subjects and controls were residents of the Tambov Province centers of chemical industry. Statistical significance (relative risk-4.7) was established for exposure to aromatic amines. For those contacting with aniline dyes the relative risk (RR) made up 2.4. The risk to develop bladder cancer in powder shops (RR-3.2) was attributed to the hazards of dyes and diphenylamine. In leather-shoe and textile industry the exposure to dyes was not safe (RR-6.1), neither was it to chemicals, oil products, pesticides, overheating (RR-3.2, 1.6, 3.2 and 2.9, respectively). It is stated that in line with a significant risk to develop bladder cancer at exposure to aromatic amines there exist a number of occupational factors contributing to this risk.

  5. Sonophotocatalytic Degradation of Amines in Water

    Verman, Mayank; Pankaj

    Hazardous effects of various amines, produced in the environment from the partial degradation of azo dyes and amino acids, adversely affect the quality of human life through water, soil and air pollution and therefore needed to be degraded. A number of such studies are already available in the literature, with or without the use of ultrasound, which have been summarized briefly. The sonochemical degradation of amines and in the combination with a photocatalyst, TiO2 has also been discussed. Similar such degradation studies for ethylamine (EA), aniline (A), diphenylamine (DPA) and naphthylamine (NA) in the presence of ultrasound, TiO2 and rare earths (REs); La, Pr, Nd, Sm and Gd, in aqueous solutions at 20 kHz and 250 W power have been carried out and reported, to examine the combinatorial efficacy of ultrasound in the presence of a photocatalyst and rare earth ions with reactive f-electrons.

  6. Kinetic Study of the Oxidation of Catechols in the Presence of N-Methylaniline

    Lida Khalafi


    Full Text Available The reactions of electrochemically generated o-quinones from oxidation of catechol and 4-methylcatechol as Michael acceptors with N-methylaniline as nucleophile have been studied using cyclic voltammetry. Voltammetric responses show that oxidation of catechols is followed by Michael addition of N-methylaniline. The reaction products are believed to be diphenylamine derivatives of catechols that undergo electron transfer at more negative potentials than the catechols. The observed homogeneous rate constants for Michael addition were estimated by digital simulation and show that the reactivity of 4-methyluinone is considerably less than o-quinone. The oxidation potentials of the desired products drastically depend on the solution pH and their structures.

  7. Distribution of colored carotenoids between light-harvesting complexes in the process of recovering carotenoid biosynthesis in Ectothiorhodospira haloalkaliphila cells.

    Ashikhmin, Aleksandr; Makhneva, Zoya; Bolshakov, Maksim; Moskalenko, Andrey


    The processes of recovering colored-carotenoid (Car) biosynthesis in Car-less cells of the purple sulfur bacterium Ectothiorhodospira haloalkaliphila grown with diphenylamine (DPA-cells) have been studied. It has been found that (1) the rate of recovering colored-Car biosynthesis in the lag-phase is far ahead of the growth rate of the cells themselves; (2) several Cars (ζ-carotene, neurosporene etc.) act as intermediates in Car biosynthesis; (3) because filling the "empty" Car pockets in the LH1-RC complexes is faster than in LH2, available spirilloxanthin is preferentially incorporated into the nascent LH1-RC core particles; (4) as a consequence of the resulting lack of spirilloxanthin availability, the biosynthetic intermediates (anhydrorhodovibrin, rhodopin and lycopene) fill the empty nascent LH2 Car pockets. In the present report, we further discuss the process of colored Car incorporation into LH complexes during the recovery of Car biosynthesis in the DPA-cells of Ect.haloalkaliphila.

  8. Synthesis Characterization and Biological Activity Study of New Schiff and Mannich Bases and Some Metal Complexes Derived from Isatin and Dithiooxamide

    Ahlam J. Abdulghani


    Full Text Available Two new Schiff and Mannich bases, namely, 1-Morpholinomethyl-3(1′ -N-dithiooxamideiminoisatin (LIH and 1-diphenylaminomethyl-3-1′-N-dithiooxamideiminoisatin (LIIH, were prepared from condensation reaction of new Schiff base 3-(1′-N-dithiooxamideiminoisatin (SBH with morpholine or diphenylamine respectively in presence of formaldehyde . The structures were characterized by IR, 1HNMR, mass spectrometry, and CHN analyses. Metal complexes of the two ligands were synthesized, and their structures were characterized by elemental analyses, atomic absorption, IR and UV-visible spectra, molar conductivity, and magnetic moment determination. All complexes showed octahedral geometries except palladium complexes which were square planar. The biological activity of the prepared compounds and some selected metal complexes was tested against three types of bacteria and against cell line of human epidermoid larynx carcinoma (Hep-2.

  9. Chemical kinetics of Estane aging in PBX

    Pack, R.T.; Hanson, D.E.; Redondo, A. [Los Alamos National Lab., NM (United States). Theoretical Div.


    The Plastic-Bonded Explosive PBX 9501 is about 95% HMX, 2.5% Estane 5703, 2.5% nitroplasticizer (NP), and 0.1% stabilizer by weight. The NP, BDNPA/F, is a eutectic mixture of bis(2,2-dinitropropyl) acetal and bis(2,2-dinitropropyl)formal. The stabilizer is diphenylamine (DPA) or Irganox 1010. The Estane, a polyester-polyurethane, slowly degrades with time. Knowledge of the effect of the Estane aging on the mechanical properties of the PBX 9501 is required to predict with confidence the useful lifetime of the explosive with respect to safety and reliability. A detailed master equation model of the chemical mechanisms and kinetics of the aging of Estane 5703 in PBX 9501 is being developed. Its output will be used as input into other models being developed to calculate the changes in the mechanical properties of the PBX.

  10. Analysis of Pyrolysates for Polysulphoneamide Fiber by Py-GC/MS

    QIAN He-sheng; LIN Dan-li


    Pyrolysis of polysulphoneamide fiber has been investigated using pyrolysis gas chromatography-mass spectroscopy at the different temperatures from 420℃ to 750℃. Its compositions of pyrolysates have been analyzed. At 420 ℃,pyrolysis of molecular chain could not completely take place, 12 compounds of pyrolysis have only been identified.When the temperature increases, the compositions of pyrolysate increase sharply. Several compounds, especially sulfur dioxide, benzene, aniline, benzoic acid, 1,4-benzene dicaronitrile, N-phenyl-acetamide, diphenylamine, benzo[g]isoquinoline, N-phenyl-benzamide, N-( 4-cyanophenyl )benzamide, could be formed. The degradation mechanisms which are determined by structure and amount of the thermal decomposition products are described. During pyrolysis, for polysulphoneamide, polymeric chain scissions take place as a successive removal of the monomer units from the polymeric chain. The chain scissions are followed by secondary reactions, which lead to a variety of compounds.Additional reactions can also take place during pyrolysis.

  11. Synthesis and pharmacological evaluation of novel N-alkyl/aryl substituted thiazolidinone arecoline analogues as muscarinic receptor 1 agonist in Alzheimer's dementia models.

    Sadashiva, C T; Chandra, J N Narendra Sharath; Kavitha, C V; Thimmegowda, A; Subhash, M N; Rangappa, Kanchugarakoppal S


    Earlier we have reported the effect of arecoline thiazolidinone and morpholino arecoline analogues as muscarinic receptor 1 agonist in Alzheimer's dementia models. To elucidate further our SAR study on the chemistry and muscarinic receptor binding efficacy, a series of novel N-alkyl/aryl substituted thiazolidinone arecoline analogues 6(a-m) were designed and synthesized from 3-pyridine carboxaldehyde by reacting with different amines in the presence of gamma-ferrite as catalyst and subjected to in vitro muscarinic receptor binding studies using male Wistar rat brain membrane homogenate and extended to in vivo pharmacological evaluation of memory and learning in male Wistar rats. Derivative 6j having diphenylamine moiety attached to nitrogen of thiazolidinone showed significant affinity for the M1 receptor binding.

  12. Preparation, structural characterization of a novel egg-shell palladium sulfide catalyst and its application in selective reductive alkylation reaction

    Qun Feng Zhang; Xiao Nian Li; Jia Chun Wu; Chang Su; Feng Feng; Qiao Ling Ding; Zhao Lian Yuan; Hong Wang; Lei Ma; Chun Shan Lu


    A novel egg-shell Pd-S catalyst with palladium metal as the core and a membrane of palladium sulfide as the surface has been prepared by sulphidizing Pd/C with H2S.This catalyst is effective for the reductive alkylation of p-amino diphenylamine (PADPA)and methylisobutyl ketone (MIBK) to afford N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenedianine (DBPPD) with conversion up to 99.42% and selectivity to 97.46%.Comparing with the other common palladium sulfide catalysts,the membrane of palladium sulfide on the surface and the core of palladium metal cause the Pd on the surface of the new catalyst in a lower sulfur coordination,which improves its activity.Our result indicates that this new egg-shell Pd-S/C is an efficient hydrogenation catalyst.

  13. Identification and measurement of pesticide contaminants in food products by electron impact GC/MS

    Tusa, Florina; Moldovan, Zaharie [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Vlassa, Mircea, E-mail: zaharie.moldovan@itim-cj.r [Faculty of Chemistry and Chemical Engineering, Babes Bolyai University, 11 Arany Janos, 400028 Cluj-Napoca (Romania)


    The paper concern is determination of eight pesticides in food products samples. The target compounds are: Lindane, Heptachlor, Aldrin, o,p-DDE, Dieldrin, Endrin, p,p'-DDT, and Methoxychlor. The compounds quantities were performed from chromatographic area obtained in full scan GC/MS mode after baseline separation and by comparation with surrogate internal standard area (Diphenylamine). The samples were concentrated by extraction with organic solvents (acetone) by Solid-Liquid Extraction (SLE) procedures the recovery factors being better than 80% except for Heptachlors. The coefficient of correlation of detector response function was better than 0.913 and LOQ under 0.015 {mu}g/g. The method enables to determine pesticides at low {mu}g/g in food supplements.

  14. A molecularly imprinted polymer as the sorptive phase immobilized in a rotating disk extraction device for the determination of diclofenac and mefenamic acid in wastewater

    Manzo, Valentina; Ulisse, Karla [Department of Inorganic and Analytical Chemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, P.O. Box 653, Santiago (Chile); Rodríguez, Inés [Department of Analytical and Inorganic Chemistry, Faculty of Chemical Sciences, University of Concepción (Chile); Pereira, Eduardo, E-mail: [Department of Analytical and Inorganic Chemistry, Faculty of Chemical Sciences, University of Concepción (Chile); Richter, Pablo, E-mail: [Department of Inorganic and Analytical Chemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, P.O. Box 653, Santiago (Chile)


    The microextraction of diclofenac and mefenamic acid from water samples was performed by using rotating disk sorptive extraction (RDSE) with molecularly imprinted polymer (MIP) as the sorptive phase. The MIP was synthesized from the monomer 1-vinylimidazol (VI) together with the cross-linker divinylbenzene (DVB) using diphenylamine as the template molecule. Scanning electron microscopy (SEM) analyses of the MIP revealed clusters of spherical particles having a narrow size distribution, with diameters of approximately 1 μm. The optimized extraction conditions involved a disk rotation velocity of 3000 rpm, an extraction time of 120 min, a sample volume of 50 mL, and a sample pH of 2 as well as 25 mg of MIP immobilized in the disk. Desorption of the extracted analytes was performed with 5 mL of methanol for 10 min. Analysis by gas chromatography-mass spectrometry (GC–MS) was carried out after derivatization of the analytes with N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA). Nonmolecularly imprinted polymer (NIP) was also synthesized for comparison. It was observed that under the same conditions, MIP extracted significantly more NSAIDs containing diphenylamine (or part of this molecule) in their structure than NIP. Higher significant differences between MIP and NIP were observed for diclofenac, mefenamic acid and paracetamol, clearly indicating the effect of the template on the extraction. Recoveries of the method were between 100 and 112%, with relative standard deviations of 5–6%. The limits of detection were between 60 and 223 ng L{sup −1}. Water samples from a wastewater treatment plant (WWTP) of Santiago de Chile, were found to contain concentrations of these acidic drugs between 1.6 and 4.3 μg L{sup −1} and between 1.4 and 3.3 μg L{sup −1} in the influent and effluent, respectively. - Highlights: • A MIP immobilized in a rotating disk sucessfully extracts NSAIDs from wastewater. • MIP had remarkably superior binding

  15. Improvement of barrier function and stimulation of colonic epithelial anion secretion by Menoease Pills

    Jin-Xia Zhu; Ning Yang; Gui-Hong Zhang; Lai-Ling Tsang; Yu-Lin Gou; Hau-Yan Connie Wong; Yiu-Wa Chung; Hsiao-Chang Chan


    AIM: Menoease Pills (MP), a Chinese medicine-based new formula for postmenopausal women, has been shown to modulate the endocrine and immune systems[1]. The present study investigated the effects of MP and one of its active ingredients, ligustrazine, on epithelial barrier and ion transport function in a human colonic cell line, T84.METHODS: Colonic transepithelial electrophysiological characteristics and colonic anion secretion were studied using the short circuit current (ISC) technique. RT-PCR was used to examine the expression of cytoplasmic proteins associated with the tight junctions, ZO-1(zonula occludens-1) and ZO-2 (zonula occludens-2).RESULTS: Pretreatment of T84 cells with MP (15 μg/mL) for 72 h significantly increased basal potential difference,transepithelial resistance and basal ISC. RT-PCR results showed that the expressions of ZO-1 and ZO-2 were significantly increased after MP treatment, consistent with improved epithelial barrier function. Results of acute stimulation showed that apical addition of MP produced a concentrationdependent (10-5 000 μg/mL, EC50 = 293.9 μg/mL) increase in ISC. MP-induced ISC was inhibited by basolateral treatment with bumetanide (100 μmol/L), an inhibitor of the Na+-K+-2Cl- cotransporter, apical addition of Cl-channel blockers, diphenylamine-2, 2'-dicarboxylic acid (1 mmol/L) or glibenclamide (1 mmol/L), but not 4, 4'-diisothiocyanostilbene2, 2'-disulfonic acid or epithelial Na+ channel blocker,amiloride. The effect of MP on ZO-1 and ZO-2 was mimicked by Ligustrazine and the ligustrazine-induced ISC was also blocked by basolateral application of bumetanide and apical addition of diphenylamine-2, 2'-dicarboxylic acid or glibenclamide, and reduced by a removal of extracellular Cl-.CONCLUSION: The results of the present study suggest that MP and lligustrazine may improve epithelial barrier function and exert a stimulatory effect on colonic anion secretion, indicating the potential use of MP and its active ingredients


    Walter J. Cuadro

    Full Text Available In this research we have designed electron donors D-π-A type containing two different π fragments to obtain naphthopyrrole (D-NPR-A and naphthotiophene (D-NTP-A derivatives, proposed for the use in organic bulk hetero-junction (BHJ solar cells (OSCs. These derivatives were characterized by DFT and TD-DFT calculations. For all the electron donors the anchorage fragment was 2-methylenemalononitrile, while the chromophore fragment was spanned between diphenylamine, triphenylamine, thiophene. Properties affecting open-circuit photovoltage (VOC and short-circuit photocurrent (JSC from D-π-A type derivatives, such as geometric structure, frontier-molecular orbital energies, exciton driving force energy, natural bond orbital analysis, absorption spectra and light harvesting efficiency. Energy from HOMO and LUMO orbitals was discussed. Theoretical calculations from TD-DFT within Coulumb attenuation method CAM-B3LYP were able to predict excited state properties. The electron donors D-π-A type exhibit photoelectric conversion efficiency above 10%, being the naphthopyrrole derivatives (D-NPR-A along with the [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM the complexes with higher photoelectric properties, these complexes are proposed as photoactive materials in the construction of organic bulk hetero-junction solar cells.


    Guo-xin Jiang; Chun-lei Bian; Jun-qiao Ding; Li-xiang Wang


    Novel blue light-emitting poly(aryl ether)s comprising of bipolar oligofluorene pendants as chromophores have been designed and synthesized,in which pyrimidine and arylamine moieties are utilized as the electron acceptor and electron donor,respectively.Through varying π bridge length from monofluorene to bifluorene and end-cappers from hydrogen to carbazole and diphenylamine,the emission color of the resulting polymers covers from deep blue to greenish blue,and their HOMO and LUMO levels can be modulated to facilitate charge injection to improve the device performance.Polymer lightemitting diodes (PLEDs) are fabricated with the device structure of ITO/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS) (50 nm)/polymer (80 nm)/Ca (10 nm)/A1 (200 nm).Among these polymers,P2Cz5F-Py with bifluorene bridge and carbazole end-capper shows excellent trade-off between the efficiency and emission wavelength,having a peak luminous efficiency as high as 1.26 cd/A and Commission Internationale de L'Eclairage (CIE) coordinates of (0.17,0.17).

  18. Pesticide residues in some herbs growing in agricultural areas in Poland.

    Malinowska, Elżbieta; Jankowski, Kazimierz


    The aim of this paper was to assess residue content of plant protection products in selected herbs: Achillea millefolium L., Cichorium intybus L., Equisetum arvense L., Polygonum persicaria L., Plantago lanceolata L., and Plantago major L. The study comprises herbs growing in their natural habitat, 1 and 10 m away from crop fields. The herbs, 30 plants of each species, were sampled during the flowering stage between 1 and 20 July 2014. Pesticide residue content was measured with the QuECHERS method in the dry matter of leaves, stalks, and inflorescence, all mixed together. Out of six herb species growing close to wheat and maize fields, pesticide residues were found in three species: A. millefolium L., E. arvense L., and P. lanceolata L. Most plants containing the residues grew 1 m away from the wheat field. Two active substances of fungicides were found: diphenylamine and tebuconazole, and one active substance of insecticides: chlorpyrifos-ethyl. Those substances are illegal to use on herbal plants. Samples of E. arvense L. and P. lanceolata L. contained two active substances each, which constituted 10% of all samples, while A. millefolium L. contained one substance, which is 6.6% of all samples.

  19. Inhibition of Pro-oxidant induced DNA Damage in isolated human peripheral lymphocytes by methanolic extract of Guduchi (Tinospora cordifolia leaves.

    Chandrashekar S


    Full Text Available The present preliminary investigation reveals the anti-oxidant effects of Guduchi (Tinospora cordifolia leaves. Dried and powdered leaves of Tinospora cordifolia was subjected to methanol extraction, and total phenols, sugars and proteins were determined. DNA fragmentation was carried out using isolated human peripheral lymphocytes and Calf thymus DNA as a model system. The results showed that the methanol extract of Tinospora cordifolia is rich in total polyphenols (>3 mg/g in comparison to sugars (<2 mg/g and protein (<1 mg/g. DNA fragmentation was measured by diphenylamine method. The polyphenols rich fraction of Tinospora cordifolia leaves were found to offer 64% protection on Fe:As (10:100μmole induced DNA fragmentation, where as BHA offered protection by 88% and was found to have direct correlation between the total polyphenols and its protective against pro-oxidant induced DNA fragmentation. The in-vitro anti-oxidant activity of Tinospora cordifolia justifies the medicinal use of this plant.

  20. Application of Receiver Operating Characteristic (ROC Curves for Explosives Detection Using Different Sampling and Detection Techniques

    Mimy Young


    Full Text Available Reported for the first time are receiver operating characteristic (ROC curves constructed to describe the performance of a sorbent-coated disk, planar solid phase microextraction (PSPME unit for non-contact sampling of a variety of volatiles. The PSPME is coupled to ion mobility spectrometers (IMSs for the detection of volatile chemical markers associated with the presence of smokeless powders, model systems of explosives containing diphenylamine (DPA, 2,4-dinitrotoluene (2,4-DNT and nitroglycerin (NG as the target analytes. The performance of the PSPME-IMS was compared with the widely accepted solid-phase microextraction (SPME, coupled to a GC-MS. A set of optimized sampling conditions for different volume containers (1–45 L with various sample amounts of explosives, were studied in replicates (n = 30 to determine the true positive rates (TPR and false positive detection rates (FPR for the different scenarios. These studies were obtained in order to construct the ROC curves for two IMS instruments (a bench-top and field-portable system and a bench top GC-MS system in low and high clutter environments. Both static and dynamic PSPME sampling were studied in which 10–500 mg quantities of smokeless powders were detected within 10 min of static sampling and 1 min of dynamic sampling.

  1. Characterization of smokeless powders using multiplexed collision-induced dissociation mass spectrometry and chemometric procedures.

    Reese, Kristen L; Jones, A Daniel; Smith, Ruth Waddell


    This work demonstrates a non-targeted mass spectrometry approach for identification of organic compounds in smokeless powders. Unburned powders were removed from various commercial ammunitions of different brand, primer composition, caliber, and age. The unburned powders and corresponding fired residues were analyzed by liquid chromatography-atmospheric pressure chemical ionization-time-of-flight mass spectrometry (LC-APCI-TOFMS). Multiplexed collision-induced dissociation was performed at increasing collision potentials resulting in successive fragmentation that provided structural information for compound identification in a non-targeted manner. Nine compounds were identified in the powders, including akardite II, ethyl centralite, diphenylamine, N-nitrosodiphenylamine, and dibutyl phthalate. Multivariate statistical procedures were performed to first investigate association and discrimination of the unburned powders. Principal components analysis (PCA) of the chemical profiles suggested nine distinct groups of powders, according to the dominant organic compounds present. The clusters formed in hierarchical cluster analysis (HCA) were mostly in agreement with PCA groupings although HCA provided a metric to quantify the similarity. Finally, association of the fired residue to the corresponding unburned powder was possible although the success was highly dependent on the composition of the unburned powder and the extent of compound depletion as a result of firing.

  2. Glass transition dynamics and charge carrier mobility in conjugated polyfluorene thin films

    Qin, Hui; Liu, Dan; Wang, Tao

    Conjugated polymers are commonly used in organic optoelectronic devices, e.g. organic photovoltaics (OPVs), light-emitting diodes (LEDs) and field effect transistors (FETs). In these devices, the conjugated polymers are prepared as thin films with thicknesses in the range of tens to hundreds of nanometers, and are interfaced with different function layers made from organic or inorganic materials. We have studied the glass transition temperature (Tg) of poly(9, 9-dioctylfluorene)-co-N-(1, 4-butylphenyl)diphenylamine) (TFB) thin films supported on different substrates, as well as their SCLC charge carrier mobility in photodiodes. Both Monotonic and non-monotonic Tg deviations are observed in TFB thin films supported on Si/SiOx and PEDOT:PSS, respectively. With low to moderate thermal crosslinking, the thickness dependent Tg deviation still exists, which diminishes in TFB films with a high crosslinking degree. The vertical charge carrier mobility of TFB thin films extracted from the SCLC measurements is found increase with film thickness, a value increases from 1 to 50 x 10-6 cm2 V-1 s-1 in the thickness range from 15 to 180 nm. Crosslinking was found to reduce the carrier mobility in TFB thin films. The Tg deviations are also discussed using the classic layered models in the literature. Our results provide a precise guide for the fabrication and design of high performance optoelectronic devices.

  3. Retinoidal pyrimidinecarboxylic acids. Unexpected diaza-substituent effects in retinobenzoic acids.

    Ohta, K; Kawachi, E; Inoue, N; Fukasawa, H; Hashimoto, Y; Itai, A; Kagechika, H


    Several pyridine- and pyrimidine-carboxylic acids were synthesized as ligand candidates for retinoid nuclear receptors, retinoic acid receptors (RARs) and retinoic X receptors (RXRs). Although the pyridine derivatives, 6-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)carbamoyl]pyri dine-3-carboxylic acid (2b) and 6-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)carboxamido]py ridine-3-carboxylic acid (5b) are more potent than the corresponding benzoic acid-type retinoids, Am80 (2a) and Am580 (5a), the replacement of the benzene ring of Am580 (5a), Am555 (6a), or Am55 (7a) with a pyrimidine ring caused loss of the retinoidal activity both in HL-60 cell differentiation assay and in RAR transactivation assay using COS-1 cells. On the other hand, pyrimidine analogs (PA series, 10 and 11) of potent RXR agonists (retinoid synergists) with a diphenylamine skeleton (DA series, 8 and 9) exhibited potent retinoid synergistic activity in HL-60 cell differentiation assay and activated RXRs. Among the synthesized compounds, 2-[N-n-propyl-N-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)a mino]pyrimidine-5-carboxylic acid (PA013, 10e) is most active retinoid synergist in HL-60 assay.

  4. [Formation of 55-kDa Fragments under Impaired Coordination Bonds and Hydrophobic Interactions in Peripheral Light-Harvesting Complexes Isolated from Photosynthetic Purple Bacteria].

    Solov'ev, A A; Erokhin, Y E


    Size exclusion chromatography was used to assess the relative size of intact and diphenylamine-treated (DPA, with suppressed carotenoid synthesis) peripheral light-harvesting complexes (LH2 complexes) of the sulfurbacterium Allochromatium minutissimum. Both LH2 complexes were nonamers and had the same elution volume V(e), coinciding with that for the LH2 complex of Rhodoblastus acidophilus (strain 10050). Their molecular mass was 150 kDa. Bot pheophytinization of bacteriochlorophyll (BChl) at low pH and treatment with the detergent LDAO, affecting the hydrophobic interactions between the neighboring protomers, result in the fragmentation of the ring of the isolated LH2 complexes and formation of 55-kDa fragments with molecular masses corresponding to one-third of the initial value. Fragmentation caused by both pheophytinization and detergent treatment was much more rapid in DPA-treated LH2 complexes than in the intact ones. The 55-kDa fragments formed at low pH values contained monomeric bacteriopheophytin, while the fragments of a similar molecular mass formed at pH 8.0 in the presence of the detergent contained monomeric BChl. The observed fragmentation was hypothesized to reflect the inherent C3 symmetry of the LH2 complexes, with the preliminarily assembled trimers used as building blocks.

  5. Modulation of radiation-induced apoptosis and G{sub 2}/M block in murine T-lymphoma cells

    Palayoor, S.T.; Macklis, R.M.; Bump, E.A.; Coleman, C.N. [Harvard Medical School, Boston, MA (United States)


    Radiation-induced apoptosis in lymphocyte-derived cell lines is characterized by endonucleolytic cleavage of cellular DNA within hours after radiation exposure. We have studied this phenomenon qualitatively (DNA gel electrophoresis) and quantitatively (diphenylamine reagent assay) in murine EL4 T-lymphoma cells exposed to {sup 137}Cs {gamma} irradiation. Fragmentation was discernible within 18-24 h after exposure. It increased with time and dose and reached a plateau after 8 Gy of {gamma} radiation. We studied the effect of several pharmacological agents on the radiation-induced G{sub 2}/M block and DNA fragmentation. The agents which reduced the radiation-induced G{sub 2}/M-phase arrest (caffeine, theobromine, theophylline and 2-aminopurine) enhanced the degree of DNA fragmentation at 24 h. In contrast, the agents which sustained the radiation-induced G{sub 2}/M-phase arrest (TPA, DBcAMP, IBMX and 3-aminobenzamide) inhibited the DNA fragmentation at 24 h. These studies on EL4 lymphoma cells are consistent with the hypothesis that cells with radiation-induced genetic damage are eliminated by apoptosis subsequent to a G{sub 2}/M block. Furthermore, it may be possible to modulate the process of radiation-induced apoptosis in lymphoma cells with pharmacological agents that modify the radiation-induced G{sub 2}/M block, and to use this effect in the treatment of patients with malignant disease. 59 refs., 7 figs.

  6. Laser desorption-ion mobility spectrometry as a useful tool for imaging of thin layer chromatography surface.

    Ilbeigi, Vahideh; Sabo, Martin; Valadbeigi, Younes; Matejcik, Stefan; Tabrizchi, Mahmoud


    We present a novel method for coupling thin layer chromatography (TLC) with ion mobility spectrometry (IMS) using laser desorption technique (LD). After separation of the compounds by TLC, the TLC surface was sampled by the LD-IMS without any further manipulation or preparation. The position of the laser was fixed and the TLC plate was moved in desired directions by the motorized micro-positioning stage. The method was successfully applied to analyze the TLC plates containing explosives (tri nitro toluene, 1,3,5-trinitro- 1,3,5-triazacyclohexane, pentaerythritol tetranitrate, 2,4-dinitro toluene and 3,4-dinitro toluene), amino acids (alanine, proline and isoleucine), nicotine and diphenylamine mixtures and detection limits for these compounds were determined. Combination of TLC with LD-IMS technique offers additional separation dimension, allowing separation of overlapping TLC analytes. The time for TLC sampling by LD-IMS was less than 80s. The scan rate for LD is adjustable so that fast and effective analysis of the mixtures is possible with the proposed method. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Production of menaquinone (vitamin K2)-7 by Bacillus subtilis.

    Sato, T; Yamada, Y; Ohtani, Y; Mitsui, N; Murasawa, H; Araki, S


    Menaquinone-7 (MK-7) is a highly bioactive homologue of vitamin K. We obtained a diphenylamine-resistant mutant strain D200-41 from Bacillus subtilis strain MH-1 which was isolated from fermented soybeans, natto. The mutant strain exhibited decreased production of MK-6. Using strain D200-41, efficient production of MK-7 was achieved. We found that, compared with an agitated and aerated culture, production of MK-7 was increased by static culture. The sporulation of the cells progressed more slowly in a static culture than in an agitated culture. The maximum concentration of MK reached about 60 mg/l in a medium containing 10% soybean extract, 5% glycerol, 0.5% yeast extract and 0.05% K2HPO4 (pH 7.3) when D200-41 cells as well as MH-1 cells were statically cultured at 45 degrees C for 5 d after being cultured with shaking at 37 degrees C for 1 d.

  8. Particle size distributions of currently used pesticides in ambient air of an agricultural Mediterranean area

    Coscollà, Clara; Muñoz, Amalia; Borrás, Esther; Vera, Teresa; Ródenas, Milagros; Yusà, Vicent


    This work presents first data on the particle size distribution of 16 pesticides currently used in Mediterranean agriculture in the atmosphere. Particulate matter air samples were collected using a cascade impactor distributed into four size fractions in a rural site of Valencia Region, during July to September in 2012 and from May to July in 2013. A total of 16 pesticides were detected, including six fungicides, seven insecticides and three herbicides. The total concentrations in the particulate phase (TSP: Total Suspended Particulate) ranged from 3.5 to 383.1 pg m-3. Most of the pesticides (such as carbendazim, tebuconazole, chlorpyrifos-ethyl and chlorpyrifos-methyl) were accumulated in the ultrafine-fine (<1 μm) and coarse (2.5-10 μm) particle size fractions. Others like omethoate, dimethoate and malathion were presented only in the ultrafine-fine size fraction (<1 μm). Finally, diuron, diphenylamine and terbuthylazine-desethyl-2-OH also show a bimodal distribution but mainly in the coarse size fractions.

  9. The coating of conducting copolymer on coordination polymer nanorod: A visible light active p-n heterojunction photocatalyst for H2 production

    Jia, Yuan; Mei, Ming-liang; Xu, Xin-xin; Wang, Lin-shan


    A visible light active p-n heterojunction photocatalyst was synthesized successfully through in-situ chemical oxidation copolymerization of aniline (ANI) and diphenylamine-4-sulfonate (DPAS) with the existence of coordination polymer nanorod (CPNR) under initiation of ammonium persulfate (APS). Compared with neat coordination polymer nanorod, the resulted p-n heterojunction photocatalyst exhibits higher H2 generationrate under visible light irradiation. In this heterojunction photocatalyst, as a p-type semiconductor possessing suitable energy levels with coordination polymer nanorod, poly-(aniline-co-N-(4-sulfophenyl)-aniline) (PAPSA) forms p-n heterojunction with n-type coordination polymer nanorod, the inner electric field of p-n heterojunction accelerates the separation of electrons and holes, which enhances H2 production performance. Furthermore, the influence of concentration ratio between DPAS and ANI on photocatalytic property of the p-n heterojunction photocatalyst was discussed and a reasonable condition to fabricate photocatalyst with high H2 generationrate had been obtained. During photocatalytic water splitting H2 generation, the p-n heterojunction photocatalyst exhibited outstanding stability.

  10. Silver nanoparticle decorated poly(2-aminodiphenylamine) modified carbon paste electrode as a simple and efficient electrocatalyst for oxidation of formaldehyde

    Reza Ojani; Saeid Safshekan; Jahan-Bakhsh Raoof


    This work describes the promising activity of silver nanoparticles on the surface of a poly(2-amino diphenylamine) modified carbon paste electrode (CPE) towards formaldehyde oxidation. Electro-deposition of the conducting polymer film on the CPE was carried out using consecutive cyclic voltammetry in an aqueous solution of 2-aminodiphenylamine and HCl. Nitrogen groups in the polymer backbone had a Ag ion accumulating effect, allowing Ag nanoparticles to be electrochemi-cally deposited on the surface of the electrode. The electrochemical and morphological characteris-tics of the modified electrode were investigated. The electro-oxidation of formaldehyde on the sur-face of electrode was studied using cyclic voltammetry and chronoamperometry in aqueous solu-tion of 0.1 mol/L NaOH. The electro-oxidation onset potential was found to be around-0.4 V, which is unique in the literature. The effect of different concentrations of formaldehyde on the electrocat-alytic activity of the modified electrode was investigated. Finally, the diffusion coefficient of formal-dehyde in alkaline media was calculated to be 0.47 × 10-6 cm2/s using chronoamperometry.

  11. Mild conditions for deuteration of primary and secondary arylamines for the synthesis of deuterated optoelectronic organic molecules.

    Krause-Heuer, Anwen M; Yepuri, Nageshwar R; Darwish, Tamim A; Holden, Peter J


    Deuterated arylamines demonstrate great potential for use in optoelectronic devices, but their widespread utility requires a method for large-scale synthesis. The incorporation of these deuterated materials into optoelectronic devices also provides the opportunity for studies of the functioning device using neutron reflectometry based on the difference in the scattering length density between protonated and deuterated compounds. Here we report mild deuteration conditions utilising standard laboratory glassware for the deuteration of: diphenylamine, N-phenylnaphthylamine, N-phenyl-o-phenylenediamine and 1-naphthylamine (via H/D exchange in D2O at 80 °C, catalysed by Pt/C and Pd/C). These conditions were not successful in the deuteration of triphenylamine or N,N-dimethylaniline, suggesting that these mild conditions are not suitable for the deuteration of tertiary arylamines, but are likely to be applicable for the deuteration of other primary and secondary arylamines. The deuterated arylamines can then be used for synthesis of larger organic molecules or polymers with optoelectronic applications.

  12. Study of the pore filling fraction of carbazole-based hole-transporting materials in solid-state dye-sensitized solar cells

    Marwa Ben Manaa


    Full Text Available Carbazole-based molecular glasses have emerged as a promising alternative to the widely used hole-transporting materials (HTM spiro-OMeTAD in solid-state dye-sensitized solar cells (DSSCs. The pore filling fraction (PFF of the mesoporous TiO2 layer by the HTM appears as a key parameter determining the final efficiency of a DSSC. In this work, the pore-filling properties of a family of carbazole-based HTMs are investigated for the first time and the photovoltaic behavior of DSSC devices (fabricated using the D102 dye is discussed in light of the present findings. It is found that N-aryl substituted 3,6-bis(diphenylaminyl-carbazole derivatives exhibit relatively low PFF of ca. 60%. Methoxy groups on the diphenylamine moieties have little influence on the PFF, indicating that the strong enhancement in power conversion efficiency (PCE is not related to an improved filling of the pores by the HTM. N-alkylated HTMs lead to higher PFF, increasing with the alkyl chain length, up to 78%.

  13. The evaluation of solid phase micro-extraction fibre types for the analysis of organic components in unburned propellant powders.

    Dalby, Oliver; Birkett, Jason W


    This work describes the evaluation of various solid phase micro-extraction (SPME) fibre types for the detection of compounds originating from particles of unburned propellant powders. These compounds may also be found in association with organic gunshot residues (OGSR). Seven SPME fibres were assessed based on their ability to extract the compounds of interest (diphenylamine (DPA), 4-nitrodiphenylamine (4-NDPA), ethyl centralite (EC), nitroglycerin (NG) and dibutyl phthalate (DBP)) from four ammunition types across three calibres (9 mm, 5.56 mm and 7.62 mm). Extracts were analysed by gas chromatography/mass spectrometry (GC/MS). Results indicated that the 65 μm polydimethylsiloxane/divinylbenzene (PDMS/DVB) was the most suitable fibre type for the extraction of these compounds across the ammunition types tested. Optimal extraction time parameters were also assessed with a 35-min period determined to be suitable. A number of previously unreported considerations for extracting propellant powders and potentially OGSR related materials are discussed.

  14. Noninvasive detection of concealed explosives: depth profiling through opaque plastics by time-resolved Raman spectroscopy.

    Petterson, Ingeborg E Iping; López-López, María; García-Ruiz, Carmen; Gooijer, Cees; Buijs, Joost B; Ariese, Freek


    The detection of explosives concealed behind opaque, diffusely scattering materials is a challenge that requires noninvasive analytical techniques for identification without having to manipulate the package. In this context, this study focuses on the application of time-resolved Raman spectroscopy (TRRS) with a picosecond pulsed laser and an intensified charge-coupled device (ICCD) detector for the noninvasive identification of explosive materials through several millimeters of opaque polymers or plastic packaging materials. By means of a short (250 ps) gate which can be delayed several hundred picoseconds after the laser pulse, the ICCD detector allows for the temporal discrimination between photons from the surface of a sample and those from deeper layers. TRRS was applied for the detection of the two main isomers of dinitrotoluene, 2,4-dinitrotoluene, and 2,6-dinitrotoluene as well as for various other components of explosive mixtures, including akardite II, diphenylamine, and ethyl centralite. Spectra were obtained through different diffuse scattering white polymer materials: polytetrafluoroethylene (PTFE), polyoxymethylene (POM), and polyethylene (PE). Common packaging materials of various thicknesses were also selected, including polystyrene (PS) and polyvinyl chloride (PVC). With the demonstration of the ability to detect concealed, explosives-related compounds through an opaque first layer, this study may have important applications in the security and forensic fields.

  15. Putrescine, DNA, RNA and protein contents in human uterine, breast and rectal cancer.

    Bandopadhyay M


    Full Text Available AIMS: To find out the status of DNA, RNA and protein in human uterine, ovarian, breast and rectal carcinoma. MATERIAL AND METHODS: In this prospective study, patients of age group between late thirties and late fifties suffering from uterine, ovarian, breast and rectal cancer were taken as subjects of the present study. The total number of cases studied for each cases was ten. Pieces of human carcinomatous tissues of above mentioned cases were taken along with surrounding normal tissues. From the tissue samples, putrescine is separated by the method of Herbst et al, DNA analysed by Diphenylamine method, RNA by Orcinol method and protein by Biuret method. RESULTS: Tissue content of putrescine rises simultaneously with that of DNA, RNA and protein in carcinomatous growths as above in comparison to their respective adjacent normal tissue, the differences being statistically highly significant. CONCLUSIONS: Increase in DNA, RNA and protein concentration may be a pre-requisite for increased synthesis of putrescine in carcinomatous tissue and thereby the concentration of other di- and poly-amines.

  16. Residues of plant protection products in grey partridge eggs in French cereal ecosystems.

    Bro, Elisabeth; Devillers, James; Millot, Florian; Decors, Anouk


    The contamination of the eggs of farmland birds by currently used plant protection products (PPPs) is poorly documented despite a potential to adversely impact their breeding performance. In this context, 139 eggs of 52 grey partridge Perdix perdix clutches, collected on 12 intensively cultivated farmlands in France in 2010-2011, were analysed. Given the great diversity of PPPs applied on agricultural fields, we used exploratory GC/MS-MS and LC/MS-MS screenings measuring ca. 500 compounds. The limit of quantification was 0.01 mg/kg, a statutory reference. A total of 15 different compounds were detected in 24 clutches. Nine of them have been used by farmers to protect crops against fungi (difenoconazole, tebuconazole, cyproconazole, fenpropidin and prochloraz), insects (lambda-cyhalothrin and thiamethoxam/clothianidin) and weeds (bromoxynil and diflufenican). Some old PPPs were also detected (fipronil(+sulfone), HCH(α,β,δ isomers), diphenylamine, heptachlor(+epoxyde), DDT(Σisomers)), as well as PCBs(153, 180). Concentrations ranged between literature.

  17. Effect of Cl- on photosynthetic bicarbonate uptake in two cyanobacteria Microcystis aeruginosa and Synechocystis PCC6803

    CHEN Zhen; CHENG HuiMin; CHEN XiongWen


    Photosynthetic inorganic carbon utilization was investigated in two cyanobacteria Microcystis aeruginosa and Synechocystis PCC6803 grown in standing culture. Photosynthetic rates for the two algae reached about 10 times the theoretical CO2 supply rate at low dissolved inorganic carbon (DIC) of 100 μmol/L, and the rates were unaffected by the addition of 20 mmol/L Na+, indicating that the two algae possessed Na+-independent HCO3- utilization for photosynthesis under low DIC. Their photo-synthetic rates at low DIC were inhibited by higher Cl-and the degrees of inhibition were increased with the rise of Cl- concentration, and in the presence of Diphenylamine-2-carboxylate (DPC), a reported Cl-channel inhibitor, the rates decreased by 74%-82%, implying that putative DPC-sensitive Cl- channels participate In Na+-indepandent HCO3- uptake for photosynthesis. The experiment of intracellular 14C-DIC accumulation for photosynthesis showed that internal DIC pools decreased by about 80% with 200 pmol/L DPC and by 64%-70% with 100 mmol/L Cl-. The experiment of chlorophyll a fluorescence quenching showed that initial rates and extents of fluorescence quenching obviously decreased with 200 μmol/L DPC or 100 mmol/L Cl-. The two experiments gave further evidence that putative DPC-sen-sitive Cl- channels participate in Na+-independent HCO3- uptake for photosynthesis in the two algae grown in standing culture.

  18. Mild Conditions for Deuteration of Primary and Secondary Arylamines for the Synthesis of Deuterated Optoelectronic Organic Molecules

    Anwen M. Krause-Heuer


    Full Text Available Deuterated arylamines demonstrate great potential for use in optoelectronic devices, but their widespread utility requires a method for large-scale synthesis. The incorporation of these deuterated materials into optoelectronic devices also provides the opportunity for studies of the functioning device using neutron reflectometry based on the difference in the scattering length density between protonated and deuterated compounds. Here we report mild deuteration conditions utilising standard laboratory glassware for the deuteration of: diphenylamine, N-phenylnaphthylamine, N-phenyl-o-phenylenediamine and 1-naphthylamine (via H/D exchange in D2O at 80 °C, catalysed by Pt/C and Pd/C. These conditions were not successful in the deuteration of triphenylamine or N,N-dimethylaniline, suggesting that these mild conditions are not suitable for the deuteration of tertiary arylamines, but are likely to be applicable for the deuteration of other primary and secondary arylamines. The deuterated arylamines can then be used for synthesis of larger organic molecules or polymers with optoelectronic applications.

  19. Cell wall, cell membrane, and volatile metabolism are altered by antioxidant treatment, temperature shifts, and peel necrosis during apple fruit storage.

    Leisso, Rachel; Buchanan, David; Lee, Jinwook; Mattheis, James; Rudell, David


    The transition from cold storage to ambient temperature alters apple quality through accelerated softening, flavor and color changes, and development of physiological peel disorders, such as superficial scald, in susceptible cultivars. To reveal global metabolism associated with this transition, the 'Granny Smith' peel metabolome was evaluated during storage of 6 months and shelf life periods. Treatment with the antioxidant diphenylamine (DPA) reduced scald, creating a metabolic contrast with untreated fruit, which developed superficial scald. Superficial scald symptoms developed on control fruit after 120 days of storage, and symptoms progressed following transition to ambient-temperature shelf life. The metabolic profile of control and DPA-treated fruit was divergent after 30 days of cold storage due to differing levels of α-farnesene oxidation products, methyl esters, phytosterols, and other compounds potentially associated with chloroplast integrity and oxidative stress response. Hierarchical cluster analysis revealed coregulation within the volatile synthesis pathway including control of the availability of methyl, propyl, ethyl, acetyl, and butyl alcohol and/or acid moieties for ester biosynthesis. Overall, the application of metabolomics techniques lends new insight into physiological processes leading to cell death and ripening processes that affect fruit flavor, appearance, and overall quality.

  20. Polydiphenylamine/carbon nanotube composites for applications in rechargeable lithium batteries

    Baibarac, Mihaela, E-mail: [National Institute of Materials Physics, Lab. of Optical Process in Nanostructured Materials, P.O. Box MG-7, R-77125 Bucharest (Romania); Baltog, Ioan [National Institute of Materials Physics, Lab. of Optical Process in Nanostructured Materials, P.O. Box MG-7, R-77125 Bucharest (Romania); Lefrant, Serge [Institut des Materiaux ' Jean Rouxel' , 2 rue de la Houssiniere, B.P. 32229, F-44322 Nantes (France); Gomez-Romero, Pedro [Centre d' Investigacio en Nanociencia i Nanotecnologia, CIN2 (CSIC-ICN), Campus de la UAB, 08193 Bellaterra (Spain)


    Polydiphenylamine/single walled carbon nanotube (PDPA/SWNT) composites were synthesized electrochemically aiming at their application as active electrode materials for rechargeable lithium batteries. The electrochemical polymerization of diphenylamine (DPA) on a SWNT film immersed in a 1 M HCl solution was studied by cyclic voltammetry. Comparing cyclic voltammograms recorded on a blank Pt electrode with those obtained for a SWNT film deposited on Pt electrode one observes in the latter case a decrease of the DPA reduction potential. To elucidate electrochemical polymerization mechanism, photoluminescence studies on DPA/SWNT and PDPA/SWNT systems were carried out. Additional information concerning the functionalization process of SWNT with PDPA was obtained by Raman and IR spectroscopy. Using the PDPA/SWNT composite as active material for the positive electrode of a rechargeable lithium cell (LiPF{sub 6} electrolyte), the charge-discharge tests show a specific discharge capacity of ca. 245 mA h g{sup -1}, much higher than the 35 mA h g{sup -1} for pure PDPA.

  1. Extracellular acidification elicits a chloride current that shares characteristics with ICl(swell).

    Nobles, Muriel; Higgins, Christopher F; Sardini, Alessandro


    A Cl- current activated by extracellular acidification, ICl(pHac), has been characterized in various mammalian cell types. Many of the properties of ICl(pHac) are similar to those of the cell swelling-activated Cl- current ICl(swell): ion selectivity (I- > Br- > Cl- > F-), pharmacology [ICl(pHac) is inhibited by 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), 1,9-dideoxyforskolin (DDFSK), diphenylamine-2-carboxylic acid (DPC), and niflumic acid], lack of dependence on intra- or extracellular Ca2+, and presence in all cell types tested. ICl(pHac) differs from ICl(swell) in three aspects: 1) its rate of activation and inactivation is very much more rapid, currents reaching a maximum in seconds rather than minutes; 2) it exhibits a slow voltage-dependent activation in contrast to the fast voltage-dependent activation and time- and voltage-dependent inactivation observed for ICl(swell); and 3) it shows a more pronounced outward rectification. Despite these differences, study of the transition between the two currents strongly suggests that ICl(swell) and ICl(pHac) are related and that extracellular acidification reflects a novel stimulus for activating ICl(swell) that, additionally, alters the biophysical properties of the channel.

  2. 一起罕见的汽轮机油变绿原因分析%Reason Analysis on One Rare Event of Steam Turbine Oil Changing Green

    万涛; 李臻; 周舟; 何铁祥; 冯兵; 龚尚昆


    In allusion to problems of steam turbine oil discoloring and its abnormality in practical production,this paper ana-lyzes various performance index of steam turbine oil and considers that colored substances could not affect usability of the oil while antioxidant may cause the oil discolor. Gas chromatography-mass spectrometer(GC-MS)and ultraviolet spectrum anal-ysis was conducted for extracted green substances and it was discovered reason for oil discoloring was partially using alkylated diphenylamines antioxidant. Meanwhile,it was pointed out that XDHX-1 typed high-effective adsorbent had good desorp-tion effect for colored substances.%针对生产实际中汽轮机油变色、不正常的问题,分析了汽轮机油各项性能指标,认为发色物质并未影响油品使用性能,可能为抗氧化剂造成变色。将萃取的绿色物质进行气质联用和紫外光谱分析,发现油品变色应为部分使用了烷基化二苯胺新型抗氧化剂所致,并指出 XDHX-1型高效吸附剂对发色物质具有良好的脱除效果。

  3. PBX 9501 Outgas Analysis by SPME/GC/MS

    Chambers, D.M.


    The authors used equilibrium headspace gas chromatography/mass spectrometry (GC/MS) to monitor volatile and semivolate species that are expected to migrate through PBX 9501 under environmentally relevant conditions. In this work they screened 11 samples taken from deployed parts. Although a number of chemical permeates were identified, the antioxidant signature provided the most information with regard to decomposition aging. Specifically, they were able to monitor butylated hydroxytoluene (BHT) and other antioxidants, which are apparently added to either the Estane adipate or MDI precursor by the manufacturer. They found that in those parts where diphenylamine (DPA) was used as a stabilizer, BHT response was significantly lower than in those formulations stabilized with Irganox 1010 (Irganox). These results imply that DPA is less efficient as a radical scavenger than Irganox. This lower efficiency might be related to the lack of oxygen in the weapon environment, which is initially < 0.1%. With regard to DPA, it has been reported that radical scavenging activity is proportional to the oxygen pressure. At this time they are uncertain whether the low DPA efficiency is mainly attributed to the oxygen level or if there is another rate limiting step that would lead to the preferential consumption of BHT.

  4. Migration of PBX 9501 constituents

    Spontarelli, T.


    The nominal composition of PBX is 94.9% HMX, 2.5% Estane 5703, 2.5% bis-2,2-dinitropropyl acetal/formal (nitroplasticizer, NP), and 0.1% stabilizer (diphenylamine, DPA or Irganox 1010). In addition to the stabilizer added to the PBX formulation, the NP eutectic liquid contains 0.1% of the stabilizer phenyl-beta-naphthylamine (PBNA). For PBX 9501 containing weapons, it is known that NP migrates from the charge into the shield polymer, and ethylene-vinyl acetate-vinyl alcohol terpolymer, becomes saturated over time with NP and that migration is then stopped. Experiments have been performed showing the saturation concentration of the shield material to be 8.8 weight percent. Prior to this work, analyses were performed on weapon components from a W76 unit that had been in the stockpile for 172 months. The HE, stress cushions, and shields were analyzed for NP and for possible products of NP decomposition. Although no evidence of NP decomposition was found, it was discovered that the PBX stabilizer and the HMX impurity, RDX, were also moving into the shields. This paper will summarize the analytical data obtained from a number of weapons of various ages. Quantitation of NP, DPA, Irganox, RDX, and PBNA has been performed on shields from six different W76 units.

  5. Preferential incorporation of coloured-carotenoids occurs in the LH2 complexes from non-sulphur purple bacteria under carotenoid-limiting conditions.

    Gall, Andrew; Henry, Sarah; Takaichi, Shinichi; Robert, Bruno; Cogdell, Richard J


    The effect of growing Rhodopseudomonas (Rps.) acidophila and Rps. palustris in the presence of different concentrations of the carotenoid (Car) biosynthetic inhibitor diphenylamine (DPA) has been investigated. Growth with sub-maximal concentrations of DPA induces Car limitation. The exact response to DPA is species dependent. However, both Rps. acidophila and Rps. palustris respond by preferentially incorporating the limiting amount of coloured Cars into their LH2 complexes at the expense of the RC-LH1 complexes. As inhibition by DPA becomes more severe there is an increase in the percentage of Cars with reduced numbers of conjugated C=C bonds. The effect of this changed Car composition on the structure and function of the antenna complexes has been investigated using absorption, fluorescence, CD and Raman spectroscopies. The results show that although the presence of Car molecules is important for the stability of the LH2 complexes that the overall native structure can be maintained by the presence of many different Cars.

  6. [Exposure pathways to pesticides in schoolchildren in the Province of Talca, Chile].

    Muñoz-Quezada, María Teresa; Lucero, Boris; Iglesias, Verónica; Muñoz, María Pía


    To describe pesticide concentrations in distinct environmental matrices at two time points (low and high seasons in local agricultural production) and to estimate the association between the presence of pesticide residues in matrices and the use of pesticides in the home with the sociodemographic variables of schoolchildren in the Province of Talca, Chile. A cross-sectional study was conducted in 190 schoolchildren. Families were surveyed about their children's vegetable consumption in school and at home, the use of pesticides in the home, and other sociodemographic variables. Additionally, we measured pesticide residues in vegetables and water consumed by the schoolchildren and in the soil of 14 schools. At both time points, the vegetable matrix had the highest pesticide concentration, both in urban and rural schoolchildren. The most common pesticide residues in vegetables were chlorpyrifos, diphenylamine, pyrimethanil, and thiabendazole. In the home, pyrethroid and organophosphate pesticides were mainly used in summer. Dangerous pesticide residues such as azinphos methyl and dimethoate were found in vegetables consumed by the children in schools and households, and organochlorines were found in the soil in some schools. Pesticide exposure should be limited and the health effects related to pesticide exposure should be assessed in the school population. Copyright © 2013 SESPAS. Published by Elsevier Espana. All rights reserved.

  7. Dissolution and transport of 2,4-DNT and 2,6-DNT from M1 propellant in soil.

    Dontsova, Katerina M; Pennington, Judith C; Hayes, Charolett; Simunek, Jiri; Williford, Clint W


    Live-fire training exercises can result in particulate propellant contamination on military training ranges and can potentially contaminate ground water. This study was conducted to evaluate dissolution of the 2,4-dinitrotoluene (2,4-DNT) and 2,6-dinitrotoluene (2,6-DNT) from the propellant formulation, M1 (87.6% nitrocellulose, 7.3% 2,4-DNT, 0.57% 2,6-DNT, 1.06% diphenylamine, 3.48% dibutyl phthalate) and their subsequent transport in soil. Batch dissolution studies were followed by saturated column transport experiments. Neat, dissolved 2,4-DNT, and M1 in solid and dissolved forms were used as influent to columns filled with Plymouth loamy sand (mesic, coated Typic Quartzipsamments) from Camp Edwards, MA. Dissolution rates and other fate and transport parameters were determined using the HYDRUS-1D code. M1 dissolution was limited by DNT diffusion from the interior of the pellet, resulting in an exponential decrease in dissolution rate with time. The HYDRUS-1D model accurately described release and transport of 2,4- and 2,6-DNT from M1 propellant. Dissolution rates for M1 in the stirred reactor and column studies were similar, indicating that batch dissolution rates are potentially useful to represent field conditions.

  8. Semimicro spectrophotometric determination of nitroglycerine in propellants by use of 2,4-xylenol.

    Norwitz, G; Keliher, P N


    A semimicro spectrophotometric method using 2,4-xylenol is proposed for the determination of nitroglycerine in propellants. The propellant is extracted with methylene chloride, the extract is diluted, and a 10-ml aliquot is evaporated just to dryness. Then 2,4-xylenol reagent and 63% v/v sulphuric acid are added to hydrolyse the nitroglycerine to nitrate and form 6-nitro-2,4-xylenol which is steam-distilled in a Parnas-Wagner Kjeldahl distillation apparatus into a water-ammonia-isopropyl alcohol mixture. The absorbance of the yellow solution of the anion of the 6-nitro-2,4-xylenol is measured. The calibration curve is prepared from potassium nitrate and an empirical factor (5.50) is used to convert from nitrogen content to nitroglycerine (the theoretical factor is 5.40). The 2,4-xylenol should be added before the sulphuric acid in order to prevent interference from diphenylamine and ethyl centralite. The method is designed for the usual nitrocellulose double-base propellants containing 8-50% of nitroglycerine.

  9. Synthesis, Crystal Structure and Electrochemical Properties of 2D Hydrogen-bonded network Complex[Ni(en)2(dpas)2]%氢键构筑的二维网状结构镍配合物[Ni(en)2(dpas)2]的合成、晶体结构及电化学性质

    王祥; 罗芳; 高文涛


    A new 2D Hydrogen-bonded network complex [Ni(en)2(dpas)2] (Nadpas=sodium diphenylamine sulphonic acid salt, en=ethanediamine) has been synthesized in aqueous solution, and characterized by elemental analysis, IR.The crystal structure was determined by single-crystal X-ray diffraction. The complex crystallizes in space group P21/c,with cell parameters a=0.605 6(5) nm, b=1.448 1(5) nm, c=1.711 9(5) nm,β=93.257(5), and V=1.498 9(14) nm3, De= 1.497 g·cm-3, Z=2, F(000)=708, R =0.027 7, wR =0.072 5. The crystal structure shows that the nickel atom is coordinated with four nitrogen atoms from the two en and two oxygen atoms from two dpas to form a mononuelear complex. Furthermore, the adjacent complex units are extended into a 2D supramolecular network through hydrogen bonds. CCDC: 674868

  10. A New Fungal Diterpene Induces VDAC1-dependent Apoptosis in Bax/Bak-deficient Cells.

    Huang, Li; Han, Junjie; Ben-Hail, Danya; He, Luwei; Li, Baowei; Chen, Ziheng; Wang, Yueying; Yang, Yanlei; Liu, Lei; Zhu, Yushan; Shoshan-Barmatz, Varda; Liu, Hongwei; Chen, Quan


    The pro-apoptotic Bax and Bak proteins are considered central to apoptosis, yet apoptosis occurs in their absence. Here, we asked whether the mitochondrial protein VDAC1 mediates apoptosis independently of Bax/Bak. Upon screening a fungal secondary metabolite library for compounds inducing apoptosis in Bax/Bak-deficient mouse embryonic fibroblasts, we identified cyathin-R, a new cyathane diterpenoid compound able to activate apoptosis in the absence of Bax/Bak via promotion of the VDAC1 oligomerization that mediates cytochrome c release. Diphenylamine-2-carboxilic acid, an inhibitor of VDAC1 conductance and oligomerization, inhibited cyathin-R-induced VDAC1 oligomerization and apoptosis. Similarly, Bcl-2 overexpression conferred resistance to cyathin-R-induced apoptosis and VDAC1 oligomerization. Silencing of VDAC1 expression prevented cyathin-R-induced apoptosis. Finally, cyathin-R effectively attenuated tumor growth and induced apoptosis in Bax/Bak-deficient cells implanted into a xenograft mouse model. Hence, this study identified a new compound promoting VDAC1-dependent apoptosis as a potential therapeutic option for cancerous cells lacking or presenting inactivated Bax/Bak.

  11. A New Fungal Diterpene Induces VDAC1-dependent Apoptosis in Bax/Bak-deficient Cells*

    Huang, Li; Han, Junjie; Ben-Hail, Danya; He, Luwei; Li, Baowei; Chen, Ziheng; Wang, Yueying; Yang, Yanlei; Liu, Lei; Zhu, Yushan; Shoshan-Barmatz, Varda; Liu, Hongwei; Chen, Quan


    The pro-apoptotic Bax and Bak proteins are considered central to apoptosis, yet apoptosis occurs in their absence. Here, we asked whether the mitochondrial protein VDAC1 mediates apoptosis independently of Bax/Bak. Upon screening a fungal secondary metabolite library for compounds inducing apoptosis in Bax/Bak-deficient mouse embryonic fibroblasts, we identified cyathin-R, a new cyathane diterpenoid compound able to activate apoptosis in the absence of Bax/Bak via promotion of the VDAC1 oligomerization that mediates cytochrome c release. Diphenylamine-2-carboxilic acid, an inhibitor of VDAC1 conductance and oligomerization, inhibited cyathin-R-induced VDAC1 oligomerization and apoptosis. Similarly, Bcl-2 overexpression conferred resistance to cyathin-R-induced apoptosis and VDAC1 oligomerization. Silencing of VDAC1 expression prevented cyathin-R-induced apoptosis. Finally, cyathin-R effectively attenuated tumor growth and induced apoptosis in Bax/Bak-deficient cells implanted into a xenograft mouse model. Hence, this study identified a new compound promoting VDAC1-dependent apoptosis as a potential therapeutic option for cancerous cells lacking or presenting inactivated Bax/Bak. PMID:26253170

  12. cAMP Stimulation of HCO3- Secretion Across Airway Epithelia

    Welsh MJ


    Full Text Available To test for the presence of HCO(3(- transport across airway epithelia, we measured short-circuit current in primary cultures of canine and human airway epithelia bathed in a Cl(--free, HCO(3(-/CO(2-buffered solution. cAMP agonists stimulated a secretory current that was likely carried by HCO(3(- because it was absent in HCO(3(--free solutions. In addition, the cAMP-stimulated current was inhibited by the carbonic anhydrase inhibitor, acetazolamide, and by the apical addition of a blocker of cystic fibrosis transmembrane conductance regulator (CFTR, diphenylamine-2-carboxylate. The current was dependent on Na(+ because it was inhibited by removing Na(+ from the submucosal solution and by inhibition of the Na(+-K(+-ATPase with ouabain. The cAMP-stimulated current was absent in cystic fibrosis (CF airway epithelia. These data suggest that cAMP agonists can stimulate HCO(3(- secretion across airway epithelia and that CFTR may provide a conductive pathway for HCO(3(- movement across the apical membrane.

  13. Synthesis and Photoelectrical Properties of Two Potential Solution-Processed Blue Fluorescent Emitters Based on Fluorene-Arylamine Derivatives End-Capped with Anthracene/Pyrene Molecules%基于蒽/芘分子封端的芴-芳胺衍生物的可溶液加工的蓝光材料的合成与光电性质

    欧阳密; 吴启超; 余振伟; 李洪飞; 张诚


    Two novel potential solution-processed blue fluorescent emitters composed of a core fluorene-diphenylamine unit capped with either anthracene (FAn) or pyrene (FPy) were synthesized and characterized. They were both soluble in common organic solvents and solutions gave smooth films after spin coating. Their optical properties in solution and in the film were investigated by UV-visible and photoluminescence (PL) spectroscopy. The PL emission maximum of FAn and FPy in the film state were found to be 449 and 465 nm, respectively. The electrochemical properties of the as-prepared samples were studied by cyclic voltammetry. The estimated highest occupied molecular orbital (HOMO) energy levels were-5.37 and-5.36 eV for FAn and FPy, respectively. These results indicate that the introduction of diphenylamine effectively prevents plane stacking of the molecules in the solid state, which suppresses the formation of long-wavelength aggregates, and the high HOMO levels enhance the hole-injection ability of the compounds. The results of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) indicate that the two materials have excellent thermal stability with the glass transition temperature of FAn reaching 207 °C and the thermal decomposition temperature as high as 439 ° C. The good performance of the fluorescent emitters makes them promising candidates as solution-processed blue organic light-emitting diodes.%合成了两类分别基于芘和蒽封端的芴-芳胺衍生物(FAn, FPy)的新型可溶液加工蓝色发光分子,两种材料均溶于常规的有机溶剂,并且可以旋涂成膜.通过紫外-可见光谱和荧光光谱对其在溶液中和固态薄膜下的光学性能进行了表征,发现这两类分子在固态下发射峰分别位于449和465 nm,属于蓝色发光材料.并通过循环伏安法表征了其电化学性能,计算得出FAn和FPy的最高占据分子轨道(HOMO)能级分别为-5.37和-5.36 eV.结果表明N-己基二苯胺

  14. Maximizing the reactivity of phenolic and aminic radical-trapping antioxidants: just add nitrogen!

    Valgimigli, Luca; Pratt, Derek A


    Hydrocarbon autoxidation, the archetype free radical chain reaction, challenges the longevity of both living organisms and petroleum-derived products. The most important strategy in slowing this process is via the intervention of radical-trapping antioxidants (RTAs), which are abundant in nature and included as additives to almost every petroleum-derived product as well as several other commercial products. Accordingly, a longstanding objective of many academic and industrial scientists has been the design and development of novel RTAs that can outperform natural and industrial standards, such as α-tocopherol, the most biologically active form of vitamin E, and dialkylated diphenylamines, respectively. Some time ago we recognized that attempts to maximize the reactivity of phenolic RTAs had largely failed because substitution of the phenolic ring with electron-donating groups to weaken the O-H bond and accelerate the rate of H atom transfer to radicals leads to compounds that are unstable in air. We surmised that incorporating nitrogen into the phenolic ring would render them more stable to one-electron oxidation, enabling their substitution with strong electron-donating groups. Guided by computational chemistry, we demonstrated that replacing the phenyl ring in very electron-rich phenols with either 3-pyridyl or 5-pyrimidyl rings leads to phenolic-like RTAs with good air stability and great reactivity. In fact, rate constants determined for the reactions of some compounds with peroxyl radicals were almost 2 orders of magnitude greater than those for α-tocopherol and implied that the reactions proceeded without an enthalpic barrier. Following extensive thermochemical and kinetic characterization, we took our studies of these compounds to more physiologically relevant media, such as lipid bilayers and human low density lipoproteins, where the heterocyclic analogues of vitamin E shone, displaying unparalleled abilities to inhibit lipid peroxidation and prompting

  15. Application of zirconium dioxide nanoparticle sorbent for the clean-up step in post-harvest pesticide residue analysis.

    Uclés, Ana; Herrera López, Sonia; Dolores Hernando, Maria; Rosal, Roberto; Ferrer, Carmen; Fernández-Alba, Amadeo R


    The use of yttria-stabilized zirconium dioxide nanoparticles as d-SPE clean-up sorbent for a rapid and sensitive liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the determination of post-harvest fungicides (carbaryl, carbendazim, chlorpropham, diphenylamine, ethoxyquin, flutriafol, imazalil, iprodione, methomyl, myclobutanil, pirimiphos-methyl, prochloraz, pyrimethanil, thiabendazole, thiophanate-methyl and tolclofos-methyl) in orange and pear samples has been evaluated and validated. The sample preparation was a modification of the QuEChERS extraction method using yttria-stabilized zirconium dioxide and multi-walled carbon nanotubes (MWCNTs) nanoparticles as the solid phase extraction (d-SPE) clean-up sorbents prior to injecting the ten-fold diluted extracts into the LC system. By using the yttria-stabilized zirconium dioxide extraction method, more recoveries in the 70-120% range were obtained - thus this method was used for the validation. Quantification was carried out using a matrix-matched calibration curve which was linear in the 1-500 µg kg(-1) range for almost all the pesticides studied. The validated limit of quantification was 10 µg kg(-1) for most of the studied compounds, except chlorpropham, ethoxyquin and thiophanate-methyl. Pesticide recoveries at the 10 and 100 µg kg(-1) concentration levels were satisfactory, with values between 77% and 120% and relative standard deviations (RSD) lower than 10% (n=5). The developed method was applied for the determination of selected fungicides in 20 real orange and pear samples. Four different pesticide residues were detected in 10 of these commodities; 20% of the samples contained pesticide residues at a quantifiable level (equal to or above the LOQs) for at least one pesticide residue. The most frequently-detected pesticide residues were: carbendazim, thiabendazole and imazalil-all were below the MRL. The highest concentration found was imazalil at 1175 µg kg

  16. Skin absorption of six performance amines used in metalworking fluids.

    Roux, Lauriane N; Brooks, James D; Yeatts, James L; Baynes, Ronald E


    Every year, 10 million workers are exposed to metalworking fluids (MWFs) that may be toxic. There are four types of MWFs: neat oils and three water-based MWFs (soluble oil, semisynthetic and synthetic), which are diluted with water and whose composition varies according to the mineral oils ratio. MWFs also contain various additives. To determine the absorption of six amines used as corrosion inhibitors and biocides in MWFs, porcine skin flow-through diffusion cell experiments were conducted with hydrophilic ethanolamines (mono-, di- and triethanolamine, MEA, DEA and TEA respectively) and a mixture of lipophilic amines (dibutylethanolamine, dicyclohexylamine and diphenylamine). The six amines were dosed in four vehicles (water and three generic water-based MWF formulations) and analyzed using a scintillation counter or gas chromatography/mass spectrometry. These 24 h studies showed that dermal absorption significantly (P < 0.05) increased from water for the six amines (e.g. 1.15 ± 0.29% dose; DEA in water) compared to other formulations (e.g. 0.13 ± 0.01% dose; DEA in semisynthetic MWF) and absorption was greatest for dibutylethanolamine in all the formulations. The soluble oil formulation tended to increase the dermal absorption of the hydrophilic amines. The permeability coefficient was significantly higher (P < 0.05) with TEA relative to the other hydrophilic amines (e.g. 4.22 × 10(-4) ± 0.53 × 10(-4) cm h(-1) [TEA in synthetic MWF] vs. 1.23 × 10(-4) ± 0.10 × 10(-4) cm h(-1) [MEA in synthetic MWF]), except for MEA in soluble oil formulation. Future research will confirm these findings in an in vivo pig model along with dermatotoxicity studies. These results should help MWF industries choose safer additives for their formulations to protect the health of metalworkers. Copyright © 2014 John Wiley & Sons, Ltd.

  17. Tetramethylpyrazine stimulates cystic fibrosis transmembrane conductance regulator-mediated anion secretion in distal colon of rodents

    Qiong He; Jin-Xia Zhu; Ying Xing; Lai-Ling Tsang; Ning Yang; Dewi Kenneth Rowlands; Yiu-Wa Chung; Hsiao-Chang Chan


    AIM: To investigate the effect of tetramethylpyrazine (TMP), an active compound from Ligustiun Wollichii Franchat, on electrolyte transport across the distal colon of rodents and the mechanism involved.METHODS: The short-circuit current (ISC) technique in conjunction with pharmacological agents and specific inhibitors were used in analyzing the electrolyte transport across the distal colon of rodents. The underlying cellular signaling mechanism was investigated by radioimmunoassay analysis (RIA) and a special mouse model of cystic fibrosis.RESULTS: TMP stimulated a concentration-dependent rise in ISC, which was dependent on both Cl- and HCO3-, and inhibited by apical application of diphenylamine-2,2'-dicarboxylic acid (DPC) and glibenclamide, but resistant to 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt hydrate (DIDS). Removal of Na+ from basolateral solution almost completely abolished the ISC response to TMP, but it was insensitive to apical Na+ replacement or apical Na+channel blocker, amiloride. Pretreatment of colonic mucosa with BAPTA-AM, a membrane-permeable selective Ca2+chelator, did not significantly alter the TMP-induced ISC. No additive effect of forskolin and 3-isobutyl-1-methylxanthine (IBMX) was observed on the TMP-induced ISc, but it was significantly reduced by a protein kinase A inhibitor, H89.RIA results showed that TMP (1 mmol/L) elicited a significant increase in cellular cAMP production, which was similar to that elicited by the adenylate cyclase activator, forskolin (10 μmol/L). The TMP-elicited ISC as well as forskolin- or IBMX-induced ISC were abolished in mice with homozygous mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) presenting defective CFTR functions and secretions.CONCLUSION: TMP may stimulate cAMP-dependent and CFTR-mediated Cl- and HCO3- secretion. This may have implications in the future development of alternative treatment for constipation.

  18. Effect of DPA and 1-MCP on chemical compounds related to superficial scald of Granny Smith apples

    Moggia, C.; Moya-Leon, M. A.; Pereira, M.; Yuri, J. A.; Lobos, G. A.


    Research was carried out to study the mode of action of diphenylamine (DPA) and 1-methylcyclopropene (1-MCP), on control of superficial scald of Granny Smith apples (Malus domestica Borkh.), and its relation with chemical compounds. Fruit was harvested from a commercial orchard in Chile, 182 and 189 days after full bloom and received the following treatments: DPA (2,000 ppm); 1-MCP (1.2 ppm) and control (no treatment). All fruit was stored for 4 or 6 months at 0 degree centigrade. A completely randomized factorial design was used (2 harvest dates by 3 post harvest treatments). Monthly measurements were made on maturity indices, ethylene production rate (EPR), scald related compounds [a-farnesene (AF), conjugated trienes (CT), total anti-oxidants (AO)], and cell membrane stability. Following 4 and 6 months of storage, plus 7 days at 20 degree centigrade, scald was evaluated. After 6 months, DPA-treated fruit, from both harvests, showed similar firmness, EPR and AO, compared to the control. However, AF and CT were lower, and cell membrane stability higher. Conversely, 1-MCP-treated fruit showed a noticeable EPR suppression and AF inhibition, along with higher firmness, lower CT and AO, compared to the control and DPA. Furthermore, cell membrane stability was superior to that of the control and similar to that of the DPA. Treated fruit (DPA and 1-MCP) showed an important reduction in scald compared to the control. The effect of 1-MCP on the investigated compounds and the reduction in scald, confirms that ethylene plays a major role on its development. (Author) 50 refs.

  19. A new series of short axially symmetrically and asymmetrically 1,3,6,8-tetrasubstituted pyrenes with two types of substituents: Syntheses, structures, photophysical properties and electroluminescence

    Zhang, Ran; Zhang, Tengfei; Xu, Lu; Han, Fangfang; Zhao, Yun; Ni, Zhonghai


    A new series of short axially symmetrically (4a and 4b) and asymmetrically (4c and 4d) 1,3,6,8-tetrasubstituted pyrene-based compounds with two phenyl moieties and two diphenylamine units on the pyrene core were designed and synthesized based on stepwise synthetic strategy. These compounds were structurally characterized and their photoelectric properties were investigated by spectroscopy, electrochemical and theoretical studies. The structures of 4a and 4b were determined by single-crystal X-ray diffraction analysis, indicating that the compounds are twisted by the peripheral substituents and the intermolecular π-π interactions have been efficiently interrupted. The four compounds exhibit high absolute fluorescence quantum yields (VF) in dichloromethane (83.31-88.45%) and moderate VFs in film states (20.78-38.68%). In addition, compounds 4a and 4b display relatively higher absolute VFs than those of 4c and 4d in film states. All the compounds exhibit high thermal stability with decomposition temperatures above 358 °C and the values of 4c and 4d are higher than 4a and 4b. Compounds 4a and 4b can form morphologically stable amorphous thin films with Tg values of 146 °C and 149 °C, respectively. However, there are no obvious Tg observed in compounds 4c and 4d. Electroluminescent devices using 4a and 4b as doped emission layer show promising device performance with low turn-on voltage (3.0 V), maximum brightness around 15100 cd/m2 and 16100 cd/m2, maximum luminance efficiency of 12.4 cd/A and 13.6 cd/A and maximum external quantum efficiency of 5.34% and 5.63%, respectively.

  20. Potential for bioremediation of agro-industrial effluents with high loads of pesticides by selected fungi.

    Karas, Panagiotis A; Perruchon, Chiara; Exarhou, Katerina; Ehaliotis, Constantinos; Karpouzas, Dimitrios G


    Wastewaters from the fruit packaging industry contain a high pesticide load and require treatment before their environmental discharge. We provide first evidence for the potential bioremediation of these wastewaters. Three white rot fungi (WRF) (Phanerochaete chrysosporium, Trametes versicolor, Pleurotus ostreatus) and an Aspergillus niger strain were tested in straw extract medium (StEM) and soil extract medium (SEM) for degrading the pesticides thiabendazole (TBZ), imazalil (IMZ), thiophanate methyl (TM), ortho-phenylphenol (OPP), diphenylamine (DPA) and chlorpyrifos (CHL). Peroxidase (LiP, MnP) and laccase (Lac) activity was also determined to investigate their involvement in pesticide degradation. T. versicolor and P. ostreatus were the most efficient degraders and degraded all pesticides (10 mg l⁻¹) except TBZ, with maximum efficiency in StEM. The phenolic pesticides OPP and DPA were rapidly degraded by these two fungi with a concurrent increase in MnP and Lac activity. In contrast, these enzymes were not associated with the degradation of CHL, IMZ and TM implying the involvement of other enzymes. T. versicolor degraded spillage-level pesticide concentrations (50 mg l⁻¹) either fully (DPA, OPP) or partially (TBZ, IMZ). The fungus was also able to rapidly degrade a mixture of TM/DPA (50 mg l⁻¹), whereas it failed to degrade IMZ and TBZ when supplied in a mixture with OPP. Overall, T. versicolor and P. ostreatus showed great potential for the bioremediation of wastewaters from the fruit packaging industry. However, degradation of TBZ should be also achieved before further scaling up.

  1. Transepithelial electrical potential of nonsensory region of gerbil utricle in vitro.

    Marcus, D C


    Transepithelial electrical potential difference (VT) was measured across the vestibular labyrinth of the inner ear in vitro by puncturing the epithelial wall of the utricle with a glass microelectrode. A region of nonsensory cells of the utricle was isolated from the sensory regions by introducing columns of liquid Sylgard 184. Under control conditions, the VT of this region was +7.5 +/- 0.3 mV (means +/- SE), lumen positive. This potential difference was rapidly reduced by either 1 mM ouabain, 10-100 microM bumetanide, 0.5-5.0 mM Ba (in the bathing solution), or cooling, but not by the disulfonic stilbene, 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid. Changes in VT due to reductions of Cl or Na or to increases of K in the bathing solution in exchange for presumably impermeant ions were observed in this region and were compared with those in a preparation in which the insulating seals were absent. The K-induced voltage change was significantly higher in the unblocked preparation, a finding consistent with a high K permeability of the sensory cells. The voltage change due to reduction of Cl was not inhibited by Cl channel blockers (9-anthracenecarboxylate and diphenylamine-2-carboxylate) in the bathing solution. These results represent the first direct demonstration that the nonsensory cells of the utricle produce a lumen-positive active-transport potential and characterize some of the properties of the cell membranes in terms of their pharmacological sensitivities and net voltage responses to changes in the bathing medium ions Na, K, and Cl.

  2. Carcinogenesis switched on by DNA cross-link between complementary bases aroused by aflatoxin and N-nitroso compounds

    DAI Qianhuan; LU Ping; PENG Shaohua; ZHANG Qingrong


    The di-region theory put forward by Dai Qianhuan, a molecular mechanism of chemical carcinogenesis, concluded that the carcinogenesis induced by most of the environmental carcinogens is switched on by the cross-linking between DNA complementary bases aroused by the bifunctional alkylation of their metabolic intermediates. It was evidenced in this paper with DNA filter elution method that one carcinogenic mycotoxin, aflatoxin G1, four carcinogenic N-nitroso compounds, N-nitrosodiethyl-amine, N-nitrosodibutyl-amine, N-nitrosomorpholine and N-nitrosopyrrolidine, one carcinogenic diazo color, 4-dimethylaminodiazobenzene and one carcinogenic nitrogen-containing heterocyclic compound, quinoline, all induced DNA interstrands cross-linking with dosage correlation after metabolic activation. However, the non-carcinogens in corresponding series for control, aflatoxin B2, N-nitroso-diphenylamine, 4′-bromo-4-dimethylaminodiazobenzene and isoquinoline, cannot induce DNA interstrands cross-linking at all in the same condition. A method for the determination of cross-linking ratio between DNA complementary bases in total DNA interstrands cross-linking, which has no monitoring measure as yet, has been established for the first time based upon a 24 hour repairing experiment. The DNA complementary pair cross-linking ratio induced by a metabolized carcinogen is correlated with its carcinogenic potential. It may be concluded that the mutations including point and frameshift mutagenesis induced by aflatoxin and other carcinogens are switched on by their corresponding cross-linking base pair between complementary bases. Therefore, the di-region theory is a reasonable molecular mechanism for chemical, endogenous and physical carcinogenesis.

  3. Direct block of the cystic fibrosis transmembrane conductance regulator Cl(-) channel by niflumic acid.

    Scott-Ward, T S; Li, H; Schmidt, A; Cai, Z; Sheppard, D N


    Niflumic acid is widely used to inhibit Ca(2+) -activated Cl(-) channels. However, the chemical structure of niflumic acid resembles that of diphenylamine-2-carboxylate, a drug that inhibits the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel. To investigate how niflumic acid inhibits CFTR Cl(-) channel, we studied recombinant wild-type human CFTR in excised inside-out membrane patches. When added to the intracellular solution, niflumic acid caused a concentration- and voltage-dependent decrease of CFTR Cl(-) current with half-maximal inhibitory concentration (K(i)) of 253 microM and Hill co-efficient of approximately 1, at -50 mV. Niflumic acid inhibition of single CFTR Cl(-) channels was characterized by a very fast, flickery block that decreased dramatically current amplitude without altering open-probability. Consistent with these data, spectral analysis of CFTR Cl(-) currents suggested that channel block by niflumic acid was described by the closed open blocked kinetic scheme with blocker on rate (k(on)) = 13.9 x 10(6) M(-1)s(-1), off rate (k(off))=3348 s(-1) and dissociation constant (K(d)) = 241 microM, at -50 mV. Based on these data, we tested the effects of niflumic acid on transepithelial Cl(-) secretion and cyst growth using type I MDCK epithelial cells. Niflumic acid (200 microM) inhibited cAMP-stimulated, bumetanide-sensitive short-circuit current by 55%. Moreover, the drug potently retarded cyst growth. We conclude that niflumic acid is an open-channel blocker of CFTR that inhibits Cl(-) permeation by plugging the channel pore. It or related agents might be of value in the development of new therapies for autosomal dominant polycystic kidney disease.

  4. Land Spreading of Wastewaters from the Fruit-Packaging Industry and Potential Effects on Soil Microbes: Effects of the Antioxidant Ethoxyquin and Its Metabolites on Ammonia Oxidizers

    Papadopoulou, Evangelia S.; Tsachidou, Bella; Sułowicz, Sławomir; Menkissoglu-Spiroudi, Urania


    Thiabendazole (TBZ), imazalil (IMZ), ortho-phenylphenol (OPP), diphenylamine (DPA), and ethoxyquin (EQ) are used in fruit-packaging plants (FPP) with the stipulation that wastewaters produced by their application would be depurated on site. However, no such treatment systems are currently in place, leading FPP to dispose of their effluents in agricultural land. We investigated the dissipation of those pesticides and their impact on soil microbes known to have a key role on ecosystem functioning. OPP and DPA showed limited persistence (50% dissipation time [DT50], 0.6 and 1.3 days) compared to TBZ and IMZ (DT50, 47.0 and 150.8 days). EQ was rapidly transformed to the short-lived quinone imine (QI) (major metabolite) and the more persistent 2,4-dimethyl-6-ethoxyquinoline (EQNL) (minor metabolite). EQ and OPP exerted significant inhibition of potential nitrification, with the effect of the former being more persistent. This was not reflected in the abundance (determined by quantitative PCR [qPCR]) of the amoA gene of ammonia-oxidizing bacteria (AOB) and archaea (AOA). Considering the above discrepancy and the metabolic pattern of EQ, we further investigated the hypothesis that its metabolites and not only EQ were toxic to ammonia oxidizers. Potential nitrification, amoA gene abundance, and amoA gene transcripts of AOB and AOA showed that QI was probably responsible for the inhibition of nitrification. Our findings have serious ecological and practical implications for soil productivity and N conservation in agriculturally impacted ecosystems and stress the need to include metabolites and RNA-based methods when the soil microbial toxicity of pesticides is assessed. PMID:26590271

  5. Steam stripping of polycyclic aromatics from simulated high-level radioactive waste

    Lambert, D.P.; Shah, H.B.; Young, S.R.; Edwards, R.E.; Carter, J.T.


    The Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) will be the United States` first facility to process High Level radioactive Waste (HLW) into a borosilicate glass matrix. The removal of aromatic precipitates by hydrolysis, evaporation, liquid-liquid extraction and decantation will be a key step in the processing of the HLW. This step, titled the Precipitate Hydrolysis Process, has been demonstrated by the Savannah River Technology Center with the Precipitate Hydrolysis Experimental Facility (PHEF). The mission of the PHEF is to demonstrate processing of simulated high level radioactive waste which contains tetraphenylborate precipitates and nitrite. Aqueous washing or nitrite destruction is used to reduce nitrite. Formic acid with a copper catalyst is used to hydrolyze tetraphenylborate (TPB). The primary offgases are benzene, carbon dioxide, nitrous oxide, and nitric oxide. Hydrolysis of TPB in the presence of nitrite results in the production of polycyclic aromatics and aromatic amines (referred as high boiling organics) such as biphenyl, diphenylamine, terphenyls etc. The decanter separates the organic (benzene) and aqueous phase, but the high boiling organic separation is difficult. This paper focuses on the evaluation of the operating strategies, including steam stripping, to maximize the removal of the high boiling organics from the aqueous stream. Two areas were investigated, (1) a stream stripping comparison of the late wash flowsheet to the HAN flowsheet and (2) the extraction performance of the original decanter to the new decanter. The focus of both studies was to minimize the high boiling organic content of the Precipitate Hydrolysis Aqueous (PHA) product in order to minimize downstream impacts caused by organic deposition.

  6. Clay/Polyaniline Hybrid through Diazonium Chemistry: Conductive Nanofiller with Unusual Effects on Interfacial Properties of Epoxy Nanocomposites.

    Jlassi, Khouloud; Chandran, Sarath; Poothanari, Mohammed A; Benna-Zayani, Mémia; Thomas, Sabu; Chehimi, Mohamed M


    The concept of conductive network structure in thermoset matrix without sacrificing the inherent mechanical properties of thermoset polymer (e.g., epoxy) is investigated here using "hairy" bentonite fillers. The latter were prepared through the in situ polymerization of aniline in the presence of 4-diphenylamine diazonium (DPA)-modified bentonite (B-DPA) resulting in a highly exfoliated bentonite-DPA/polyaniline (B-DPA/PANI). The nanocomposite filler was mixed with diglycidyl ether of bisphenol A (DGEBA), and the curing agent (4,4'-diaminodiphenylsulfone) (DDS) at high temperature in order to obtain nanocomposites through the conventional melt mixing technique. The role of B-DPA in the modification of the interface between epoxy and B-DPA/polyaniline (B-DPA/PANI) is investigated and compared with the filler B/PANI prepared without any diazonium modification of the bentonite. Synergistic improvement in dielectric properties and mechanical properties points to the fact that the DPA aryl groups from the diazonium precursor significantly modify the interface by acting as an efficient stress transfer medium. In DPA-containing nanocomposites, unique fibril formation was observed on the fracture surface. Moreover, dramatic improvement (210-220%) in fracture toughness of epoxy composite was obtained with B-DPA/PANI filler as compared to the weak improvement of 20-30% noted in the case of the B/PANI filler. This work shows that the DPA diazonium salt has an important effect on the improvement of the interfacial properties and adhesion of DGEBA and clay/PANI nanofillers.

  7. Synthesis and characterization of disulfonated thionines. Redox mediators for electrochemical energy conversion systems

    Albery, W.J.; Bartlett, P.N.; Lithgow, A.M.; Riefkoehl, J.L.; Rodriguez, L.A.; Romero, L.; Souto, F.A.


    A general synthetic strategy for the preparation of disubstituted thionines is described. A new method based on the nucleophilic coupling of a p-phenylenediamine with the synthetic equivalent of an aniline has resulted in considerable improvement, regarding particularly the suppression of byproducts (15-20% yield). The relatively low yields obtained still with the new route are an indication that thionation and ring closure of diphenylamines are difficult when electron-withdrawing groups are present. The new route has enabled the unambiguous structural characterization of two isomeric DST's known as DST-1 and DST-2 to be 4,6- and 2,6-DST, respectively. The 470-MHz /sup 1/H NMR and the UV-vis spectra for thionine, 2,6-DST, and 4,6-DST are reported. The effect of the sulfonates in the visible region has been slightly hypsochromic, the lambda/sub max/ not deviating much from that of thionine. This shift has been accounted for in terms of Dewar's rules for substituent effects in the UV-vis spectrum of odd alternate aromatic hydrocarbons. The effect in diffusion and extinction coefficients has been negligible. Disulfonation has resulted in an increased solubility in 50 mM H/sub 2/SO/sub 4/ (about 10/sup -3/ M) and less tendency to form ground-state molecular aggregates, around 10/sup -4/ M, compared to thionine, 10/sup -4/ and 10/sup -6/ M, respectively. It is concluded that it is potentially possible to design dye derivatives with improved characteristics while maintaining the best existing basic features of thionine. Derivatization of thionine with anionic substituents has permitted its solubilization in positively functionalized surfactant assemblies. This is not possible with the parent cationic thionine and can provide much higher solubilities than those observed. 33 references, 1 figure, 2 tables.

  8. Reversible heat-set organogel based on supramolecular interactions of beta-cyclodextrin in N,N-dimethylformamide.

    Li, Yuanyuan; Liu, Jian; Du, Guangyan; Yan, Hui; Wang, Hongyao; Zhang, Huacheng; An, Wei; Zhao, Wenjing; Sun, Tao; Xin, Feiei; Kong, Li; Li, Yueming; Hao, Aiyou; Hao, Jingcheng


    This paper describes the first reversible, heat-set organogel based on the supramolecular interactions of beta-cyclodextrin (beta-CD). The gel was prepared by interaction of diphenylamine (DPA) with beta-CD and lithium chloride in N,N-dimethylformamide (DMF). In this gel system, DPA could be gelated in DMF as the temperature increased and then dissolved again as the temperature decreased. In the microscopic structure of gel, beta-CDs play a key role in the formation of nanorods and microfibers. Some important features of the gel were observed. (1) The system is a multicomponent solution, in which each of the four components is required for the organogelation property. (2) The system is a reversible, thermo-responsive organogel composed of small organic molecules. When the temperature is lower than T(gel), the gel transforms back into a solution. The reversible thermo-transition was confirmed by differential scanning calorimetry (DSC). The gel system is responsive to the concentration of LiCl. No gel was formed without LiCl. The stimuli responses of the system with other salts such as KCl and NaCl were weaker than with LiCl. (4) The system is responsive to the addition of guest molecules. The structures and sizes of the guest molecules could influence the gel formation. Generally, T(gel) decreased by adding guest molecules in the gel system, but some guest molecules, whose structures are exactly fitted to the cavity of CDs, could prevent gel formation. This work may provide new avenues in delivery of functional molecules as well as design of intelligent materials and biomaterials.

  9. Screening of agrochemicals in foodstuffs using low-temperature plasma (LTP) ambient ionization mass spectrometry.

    Wiley, Joshua S; García-Reyes, Juan F; Harper, Jason D; Charipar, Nicholas A; Ouyang, Zheng; Cooks, R Graham


    Low-temperature plasma (LTP) permits direct ambient ionization and mass analysis of samples in their native environment with minimal or no prior preparation. LTP utilizes dielectric barrier discharges (DBDs) to create a low power plasma which is guided by gas flow onto the sample from which analytes are desorbed and ionized. In this study, the potential of LTP-MS for the detection of pesticide residues in food is demonstrated. Thirteen multi-class agricultural chemicals were studied (ametryn, amitraz, atrazine, buprofezin, DEET, diphenylamine, ethoxyquin, imazalil, isofenphos-methyl, isoproturon, malathion, parathion-ethyl and terbuthylazine). To evaluate the potential of the proposed approach, LTP-MS experiments were performed directly on fruit peels as well as on fruit/vegetable extracts. Most of the agrochemicals examined displayed remarkable sensitivity in the positive ion mode, giving limits of detection (LOD) for the direct measurement in the low picogram range. Tandem mass spectrometry (MS/MS) was used to confirm identification of selected pesticides by using for these experiments spiked fruit/vegetable extracts (QuEChERS, a standard sample treatment protocol) at levels as low as 1 pg, absolute, for some of the analytes. Comparisons of the data obtained by direct LTP-MS were made with the slower but more accurate conventional LC-MS/MS procedure. Herbicides spiked in aqueous solutions were detectable at LODs as low as 0.5 microg L(-1) without the need for any sample preparation. The results demonstrate that ambient LTP-MS can be applied for the detection and confirmation of traces of agrochemicals in actual market-purchased produce and in natural water samples. Quantitative analysis was also performed in a few selected cases and displayed a relatively high degree of linearity over four orders of magnitude.

  10. New ultra deep blue emitters based on chrysene chromophores

    Shin, Hwangyu; Kang, Seokwoo; Jung, Hyocheol; Lee, Hayoon; Lee, Jaehyun; Kim, Beomjin; Park, Jongwook


    Chrysene, which has a wide band gap, was selected as an emission core to develop and study new materials that emit ultra-deep-blue light with high efficiency. Six compounds introducing various side groups were designed and synthesized: 6, 12-bis(30,50-diphenylphenyl)chrysene (TP-C-TP), 6-(30,50-diphenylphenyl)-12-(3,5-diphenylbiphenyl-400-yl)chrysene (TP-C-TPB) and 6,12-bis(300,500-diphenylbiphenyl-40-yl)chrysene (TPB-C-TPB), which contained bulky aromatic si de groups; and N,N,N0 ,N0-tetraphenyl-chrysene-6,12-diamine (DPA-C-DPA), [12-(4-diphenylamino-phenyl)-chrysene-6-yl]-diphenylamine(DPA-C-TPA) and 6,12-bis[4-(diphenylamino)phenyl]chrysene (TPA-C-TPA), which contained aromatic amine groups, were designed to afford improved hole injection properties. The synthesized materials showed maxi mum absorption wavelengths at 342-402 nm in the film state and exhibited deep-blue photoluminescence (PL) emission s at 417-464 nm. The use of TP-C-TPB in a non-doped organic light emitting diode (OLED) device resulted in ultra-deep-blue emission with an external quantum efficiency (EQE) of 4.02% and Commission Internationale de L'Eclairage coo rdinates (CIE x, y) of (0.154, 0.042) through effective control of the internal conjugation length and suppression of the p -p* stacking. The use of TPA-C-TPA, which includes an aromatic amine side group, afforded an excellent EQE of 4.83 % and excellent color coordinates CIE x, y of (0.147, 0.077).

  11. In and out of the minor groove: interaction of an AT-rich DNA with the drug CD27

    Acosta-Reyes, Francisco J. [Universitat Politécnica de Catalunya, Diagonal 647, 08028 Barcelona (Spain); Dardonville, Christophe [Instituto de Química Médica, IQM–CSIC, Juan de la Cierva 3, 28006 Madrid (Spain); Koning, Harry P. de; Natto, Manal [University of Glasgow, 120 University Place, Glasgow G12 8TA, Scotland (United Kingdom); Subirana, Juan A.; Campos, J. Lourdes, E-mail: [Universitat Politécnica de Catalunya, Diagonal 647, 08028 Barcelona (Spain)


    New features of an antiprotozoal DNA minor-groove binding drug, which acts as a cross-linking agent, are presented. It also fills the minor groove of DNA completely and prevents the access of proteins. These features are also expected for other minor-groove binding drugs when associated with suitable DNA targets. The DNA of several pathogens is very rich in AT base pairs. Typical examples include the malaria parasite Plasmodium falciparum and the causative agents of trichomoniasis and trypanosomiases. This fact has prompted studies of drugs which interact with the minor groove of DNA, some of which are used in medical practice. Previous studies have been performed almost exclusively with the AATT sequence. New features should be uncovered through the study of different DNA sequences. In this paper, the crystal structure of the complex of the DNA duplex d(AAAATTTT){sub 2} with the dicationic drug 4, 4′-bis(imidazolinylamino)diphenylamine (CD27) is presented. The drug binds to the minor groove of DNA as expected, but it shows two new features that have not previously been described: (i) the drugs protrude from the DNA and interact with neighbouring molecules, so that they may act as cross-linking agents, and (ii) the drugs completely cover the whole minor groove of DNA and displace bound water. Thus, they may prevent the access to DNA of proteins such as AT-hook proteins. These features are also expected for other minor-groove binding drugs when associated with all-AT DNA. These findings allow a better understanding of this family of compounds and will help in the development of new, more effective drugs. New data on the biological interaction of CD27 with the causative agent of trichomoniasis, Trichomonas vaginalis, are also reported.

  12. Monitoring of selected priority and emerging contaminants in the Guadalquivir River and other related surface waters in the province of Jaén, South East Spain.

    Robles-Molina, José; Gilbert-López, Bienvenida; García-Reyes, Juan F; Molina-Díaz, Antonio


    The province of Jaén counts with four natural parks, numerous rivers, reservoirs and wetlands; moreover, it is probably the region with higher olive oil production in the world, which makes this zone a proper target to be studied based on the European Water Framework Directive 2000/60/CE. The aim of this survey is to monitor a total number of 373 compounds belonging to different families (pesticides, PAHs, nitrosamines, drugs of abuse, pharmaceuticals and life-style compounds) in surface waters located at different points of the province of Jaén. Among these compounds some priority organic substances (regulated by the EU Directive 2008/105/EC) and pollutants of emerging concern (not regulated yet) can be found. A liquid chromatography electrospray time-of-flight mass spectrometry (LC-TOFMS) method covering 340 compounds was developed and applied, together with a gas chromatography triple-quadrupole mass spectrometry (GC-MS/MS) method which enabled the analysis of 63 organic contaminants (30 of these compounds are analyzed by LC-TOFMS as well). From April 2009 to November 2010 a total of 83 surface water samples were collected (rivers, reservoirs and wetlands). In this period numerous organic contaminants were detected, most of them at the ng L(-1) level. The most frequently priority substances found were chlorpyrifos ethyl, diuron and hexachlorobenzene. Within the other groups, the most frequently detected compounds were: terbuthylazine, oxyfluorfen, desethyl terbuthylazine, diphenylamine (pesticide family); fluorene, phenanthrene, pyrene (PAHs group), codeine, paracetamol (pharmaceuticals compounds) and caffeine, nicotine (life-style compounds). As is could be expected, the total concentration of emerging contaminants is distinctly larger than that of priority pollutants, highlighting the importance of continuing with the study of their presence, fate and effects in aquatic environments. However, concentration levels (at the ng per liter level) are low in

  13. Effective indirect enrichment and determination of nitrite ion in water and biological samples using ionic liquid-dispersive liquid-liquid microextraction combined with high-performance liquid chromatography.

    He, Lijun; Zhang, Kaige; Wang, Caijuan; Luo, Xianli; Zhang, Shusheng


    An ionic liquid dispersive liquid-liquid microextraction high-performance liquid chromatography (IL-DLLME-HPLC) method for effective enrichment and determination of nitrite ion in water and biological samples was developed. The method was based on the reaction of nitrite ion with p-nitroaniline in the presence of diphenylamine in acid media and IL-DLLME of azo product. The optimization of reaction and extraction conditions, such as kind and concentration of acid, reaction time, volume of reaction solvent, temperature, kind of extraction and dispersive solvent, volume of extraction and dispersive solvent, addition of salt, extraction and centrifugal time were studied. Under the optimal conditions, 1-octyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide IL-DLLME procedure provided high enrichment factor of 430 and good extraction recovery of 91.7% for nitrite ion. The linearity was observed in the range of 0.4-500.0 μg L⁻¹ with good correlation coefficient (r²=0.9996). The relative standard deviations (RSDs) for five replicate measurements varied between 1.5% and 4.8%. The limit of detection of the method (S/N=3) was 0.05 μg L⁻¹. The interference effect of some anions and cations was also tested. The developed method allowed achieving an excellent enrichment factor, yielding a lower LOD in comparison with other methods. Moreover, the proposed method was able to analyze nitrite ion in water and biological samples with satisfactory recovery ranged from 96.5% to 107.3%.


    Cheng-long Zhang; Yi-xian Wu; Xiao-yan Meng; Qiang Huang; Guan-ying Wu; Ri-wei Xu


    The highly reactive polyisobutylenes (PIBs) with 6t-double bonds (87.5 mol%) or tert-chloro (tert-Cl) groups (95 mol%) could be prepared via the cationic polymerization of isobutylene (IB) coinitiated by BF3 or TiCl4 respectively. The Friedel-Crafts alkylation of diphenylamine (DPA) with the highly reactive PIB with α-double bonds was further conducted under different conditions, such as at different alkylation temperature, in the mixed solvents of CH2Cl2/n-hexane with different solvent polarity and at DPA concentration ([DPA]). The resultant PIBs with sec-arylamino terminal groups were characterized by GPC with RI/UV dual detectors and 1H-NMR spectrum. The experimental results indicated that alkylation efficiency increased with increases in reaction temperature, solvent polarity and [DPA]. The 77 mol% of sec-arylamino terminated PIBs could be obtained in 10/90 (V/V) mixture of nHex/CH2Cl2 with [DPA]/[PIB] of 3.0 at 60℃ for 45 h. Moreover, the alkylation of DPA with highly reactive PIBs with mainly tert-CI terminal groups was also carried out in 10/90 (V/V) mixture of CH2/Cl2/nHex with [DPA]/[PIB] = 3.0 at 60℃ for 45 h, and almost monoalkylation with 100 mol% sec-arylamino terminal groups could be achieved. These results will help further explorations of the molecular engineering via combination of cationic polymerization with alkylation.

  15. United purification effect of aquatic plants-electrolysis on azo dye wastewater%偶氮染料废水的水生植物-电解联合净化效应研究

    丁绍兰; 杨冰; 朱超; 樊文娟


    结合电解处理技术和植物修复技术理论,建立了植物-电解联合净化系统,并用于对混合偶氮染料溶液的处理实验。结果表明,偶氮染料废水经植物-电解联合净化后水质更加稳定,脱色率和COD去除率最高分别可达98.7%和85%;出水微生物抑制率和生物抗过氧化能力显著降低,出水苯二胺和芳香胺类物质残留最大削减量分别为81.25%和99.17%。%Combining electrolysis treatment technique with phytoremediation technique ,the plants-electrolysis united purification system has been set up and used for the treatment experiments of mixed azo dye solution. The re-sults show that after azo dye wastewater has been purified jointly by plant-electrolysis process ,the water quality be-comes more steady. Its maximum decolorization rate and COD removing rate can reach 98.7%and 85%,respective-ly. The effluent microorganism inhibiting rate and biological over-oxidation ability are decreased obviously. The ma-ximum reduction rates of effluent diphenylamine and aromatic amines substance residues are 81.25%and 99.17%, respectively.

  16. Astilbic Acid Induced COLO 205 cell Apoptosis by Regulating Bcl-2 and Bax Expression and Activating Caspase-3

    ZhengXiao-liang; SunHong-xiang; LiuXue-li; ChenYun-xiang; QianBo-chu


    To investigate the effect of astilbic acid (3β,6β-dihydroxyolean-12-en-27-oic acid, AA) on human colorectal carcinoma COLO 205 cell proliferation and apoptosis.Methods Proliferation of COLO 205 cells was measued by MTT assay. Content of DNA in COLO 205 cell was measued by modified diphenylamine assay. AA-induced morphological changes was observed with fluorescence microscope and transmission electron microscope.DNA fragmentation was visualized by agarose gel electrophoresis.Apoptosis rate and cell cycle distribution were deter-mined by flow cytometric analysis.Expressions of Bcl-2 and Bax proteins were visioned by immunohistochemical analysis.The change of relative mitochondral transmembrane potential (MTP) in COLO 205 cell was analyzed with FCM after rhodamine 123 staining. Results The IC50 (96h) of AA for inhibiting COLO 205 cell proliferation was 61.56±0.34 μmol/L.AA induced a marked concentration- and time-dependent inhibition of COLO 205 cell proliferation and reduced the DNA content in COLO 205 cell. Cells treated with AA 64 μmol/L showed typical morphological changes of apoptosis and DNA “ladder” pattern. The cell cycle was arrested in G0/G1 phase, and the apoptosis rate was 28.25% for COLO 205 cells treated with AA 64 μmol/L for 48h. Meanwhile the expression of Bcl-2 protein was decreased while that of Bax was increased and relative MTP was decreased as well. DEVD-CHO 1μmol/L could increase the viability of COLO 205 cells treated with AA for 48h.Conclusion AA showed potent inhibitory activity on COLO 205 cells proliferation,and could induce COLO 205 cells apoptosis through disturbing DNA replication, down-regulating Bcl-2 expression, and up-regulating Bax expression, lowering relative MTP, and activating caspase-3 pathway.

  17. Astilbic acid induced COLO 205 cell apoptosis by regulating Bcl-2 and Bax expression and activating caspase-3

    Xiao-liang ZHENG; Hong-xiang SUN; Xue-li LIU; Yun-xiang CHEN; Bo-chu QIAN


    AIM: To investigate the effect of astilbic acid (3β, 6β-dihydroxyolean-12-en-27-oic acid, AA) on human colorectal carcinoma COLO 205 cell proliferation and apoptosis. METHODS: Proliferation of COLO 205 cells was measued by MTT assay. Content of DNA in COLO 205 cell was measued by modified diphenylamine assay. AA-induced morphological changes was observed with fluorescence microscope and transmission electron microscope. DNA fragmentation was visualized by agarose gel electrophoresis. Apoptosis rate and cell cycle distribution were determined by flow cytometric analysis. Expressions of Bcl-2 and Bax proteins were visioned by immunohistochemical analysis. The change of relative mitochondral transmembrane potential (MTP) in COLO 205 cell was analyzed with FCM after rhodamine 123 staining. RESULTS: The ICs0 (96 h) of AA for inhibiting COLO 205 cell proliferation was 61.56±0.34 μmol/L. AA induced a marked concentration- and time-dependent inhibition of COLO 205 cell proliferation and reduced the DNA content in COLO 205 cell. Cells treated with AA 64 μmol/L showed typical morphological changes of apoptosis and DNA "ladder" pattern. The cell cycle was arrested in G0/G1 phase, and the apoptosis rate was 28.25 % for COLO 205 cells treated with AA 64 μmol/L for 48 h. Meanwhile the expression of Bcl-2 protein was decreased while that of Bax was increased and relative MTP was decreased as well. DEVD-CHO 1 μmol/L could increase the viability of COLO 205 cells treated with AA for 48 h. CONCLUSION: AA showed potent inhibitory activity on COLO 205 cells proliferation, and could induce COLO 205 cells apoptosis through disturbing DNA replication, down-regulatin Bcl-2 expression,and up-regulating Bax expression,lowering relative MTP, and activating caspase-3 pathway.

  18. Functional expression of cystic fibrosis transmembrane conductance regulator in rat oviduct epithelium

    Minhui Chen; Jianyang Du; Weijian Jiang; Wulin Zuo; Fang Wang; Manhui Li; Zhongluan Wu; Hsiaochang Chan; Wenliang Zhou


    The aim of this study was to investigate the functional expression of cystic fibrosis transmembrane conductance regulator (CFFR) with electrophysiological and molecular technique in rat oviduct epithelium. In whole-cell patch clamp,oviduct epithelial cells responded to 100 μM 8-bromo-adenosine 3',5'-cycfic monophosphate (8-Br-cAMP) with a rise in inward current in Gap-free mode, which was inhibited successively by 5 μM CFTR(inh)-172, a CFTR specific inhibitor, and 1 mM diphenylamine-2-carboxylate (DPC), the CI- channel blocker. The cAMP-activated current exhibited a linear current-voltage (I-V) relationship and time- and voltage-independent characteristics. The reversal potentials of the cAMP-activated currents in symmetrical CI- solutions were close to the CI- equilibrium, 0.5±0.2 mV (n=4). When CI- concentration in the bath solution was changed from 140mM to 70 mM and a pipette solution containing 140 mM CI-was used, the reversal potential shifted to a value close to the new equilibrium for Ci-, 20±0.6 mV (n=4), as compared with the theoretic value of 18.7 mV. In addition, mRNA expression of CFTR was also detected in rat oviduct epithelium. Western blot analysis showed that CFTR protein is found in the oviduct throughout the cycle with maximal expression at estrus, and immunofluorescence and immunohistochemistry analysis revealed that CFYR is located at the apical membrane of the epithelial cells. These results showed that the cAMP-activatod CI- current in the oviduct epithelium was characteristic of CFTR, which provided direct evidence for the functional expression of CFTR in the rat oviduct epithelium. CFTR may play a role in modulating fluid transport in the oviduct.

  19. Cellular mechanisms underlying the laxative effect of flavonol naringenin on rat constipation model.

    Zi-Huan Yang

    Full Text Available BACKGROUND & AIMS: Symptoms of constipation are extremely common, especially in the elderly. The present study aim to identify an efficacious treatment strategy for constipation by evaluating the secretion-promoting and laxative effect of a herbal compound, naringenin, on intestinal epithelial anion secretion and a rat constipation model, respectively. METHODS/PRINCIPAL FINDINGS: In isolated rat colonic crypts, mucosal addition of naringenin (100 microM elicited a concentration-dependent and sustained increase in the short-circuit current (I(SC, which could be inhibited in Cl- free solution or by bumetanide and DPC (diphenylamine-2-carboxylic acid, but not by DIDS (4, 4'- diisothiocyanatostilbene-2, 2'-disulfonic acid. Naringenin could increase intracellular cAMP content and PKA activity, consisted with that MDL-12330A (N-(Cis-2-phenyl-cyclopentyl azacyclotridecan-2-imine-hydrochloride pretreatment reduced the naringenin-induced I(SC. In addition, significant inhibition of the naringenin-induced I(SC by quinidine indicated that basolateral K+ channels were involved in maintaining this cAMP-dependent Cl- secretion. Naringenin-evoked whole cell current which exhibited a linear I-V relationship and time-and voltage- independent characteristics was inhibited by DPC, indicating that the cAMP activated Cl- conductance most likely CFTR (cystic fibrosis transmembrane conductance regulator was involved. In rat constipation model, administration of naringenin restored the level of fecal output, water content and mucus secretion compared to loperamide-administrated group. CONCLUSIONS: Taken together, our data suggest that naringenin could stimulate Cl- secretion in colonic epithelium via a signaling pathway involving cAMP and PKA, hence provide an osmotic force for subsequent colonic fluid secretion by which the laxative effect observed in the rat constipation model. Naringenin appears to be a novel alternative treatment strategy for constipation.

  20. Clinical significance of sialic acid in acute rheumatic fever with and without carditis

    Maher H. Gomaa


    Full Text Available Objective: In Egypt, acute rheumatic fever (ARF is the most common cause of acquired heart disease. ARF is a clinical syndrome without a specific diagnostic test or single pathognomonic feature, so the aim of this study is to investigate the utility of using serum total sialic acid (TSA in differentiation between children suffering from ARF with and without carditis. Methods: In the present study, 62 children were divided into three groups: first group, 16 healthy children; second group, 20 patients suffering from chronic rheumatic heart disease (RHD; and third group, 26 patients suffering from ARF, subdivided into three subgroups as (A 10 patients suffering from arthritis without carditis, (B 10 patients with carditis but without congestive heart failure (CHF, and (C 6 patients with carditis and CHF. Antistreptolysin O titre (ASOT by latex agglutination test, erythrocyte sedimentation rate (ESR by Westergren method, C-reactive protein (CRP by turbidimetric immunoassay method, lactate dehydrogenase (LDH activity by kinetic method, immunoglobulin levels by radial immunodifussion assay (RID, cardiac troponin I (cTnI by ELISA test kit and TSA by diphenylamine (DPA method were performed. Results: Significant elevated values of ESR, CRP, LDH, IgG and IgA were obtained in ARF as compared to both control and RHD groups; significant values of IgM were found between B and C as compared to control and RHD groups; cTnI showed insignificant difference between all groups; values of TSA showed highly significant difference between ARF as compared to both control and RHD groups as well as between RHD and control groups; significant difference was found between B and C groups as compared to group A. Conclusion: The results of the present study point out the possibility that the levels of TSA could be of help in differentiation between ARF patients with and without carditis. [J Exp Integr Med 2012; 2(4: 305-311

  1. Determination of antioxidants in new and used lubricant oils by headspace-programmed temperature vaporization-gas chromatography-mass spectrometry

    Nogal Sanchez, Miguel del; Perez Pavon, Jose Luis; Garcia Pinto, Carmelo; Moreno Cordero, Bernardo [Universidad de Salamanca, Departamento de Quimica Analitica, Nutricion y Bromatologia, Salamanca (Spain); Glanzer, Paul [University of Vienna, Department of Analytical Chemistry, Vienna (Austria)


    A sensitive method is presented to determine antioxidants (2-, 3-, and 4-tert-butylphenol, 2,6-di-tert-butylphenol, 3-tert-butyl-4-hydroxyanisol, 2,6-di-tert-butyl-4-methylphenol, 1-naphthol, and diphenylamine) in new and used lubricant oil samples. Research was carried out on a GC device equipped with a headspace sampler, a programmed temperature vaporizer, and an MS detector unit. The proposed method does not require sample treatment prior to analyses, hence eliminating possible errors occurring in this step. Sample preparation is reduced when placing the oil sample (2.0 g) in the vial and adding propyl acetate (20 {mu}L). Solvent vent injection mode permits a pre-concentration of the compounds of interest in the liner filled with Tenax-TA {sup registered}, while venting other species present in the headspace. Thereby, both the life of the liner and the capillary column is prolonged, and unnecessary contamination of the detector unit is avoided. Calibration was performed by adding different concentrations of analytes to a new oil which did not contain any of the studied compounds. Limits of detection as low as 0.57 {mu}g/L (2-tert-butylphenol) with a precision lower or equal to 5.3% were achieved. Prediction of the antioxidants in new oil samples of different viscosities (5W40, 10W40, and 15W40) was accomplished with the previous calibration, and the results were highly satisfactory. To determine antioxidants in used engine oils, standard addition method was used due to the matrix effect. (orig.)

  2. Study on the Synergistic Effects of the Antioxidants for Lubricant%润滑油抗氧剂协同作用研究

    姚俊兵; Gaston Aguilar; Steven G. Donnelly


    The basic oxidation mechanism of lubricant was reviewed briefly. The antioxidants were classified as three major species: radical scavenger (for examples, phenol and amine antioxidants), hydroperoxide decomposer (for examples, dithiocarbamate derivatives), and antioxidation synergist (for example, phosphorous and sulfur free molybdate ester). Pressurized Differential Scanning Calorimetry (PDSC) was employed to evaluate the antioxidation performances of different antioxidants and their synergism. The research indicated, as a hydroperoxide decomposer, modified ashless dithiocarbamate possesses better antioxidation performance than phenol and amine antioxidants, which reveals the great application potential of hydroperoxide decomposer as antioxidant. The investigation also showed that, the antioxidants with same action mechanism, for example, as both radical scavengers, phenol and amine antioxidants are synergistic (homosynergism); But the synergistic effects between two antioxidants with different action mechanism, such as radical scavenging phenol and amine antioxidants, and hydroperoxide decomposing ashless dithiocarbamate, are much stronger (heterosynergism), and the heterosynergism between dithiocarbamate and alkylated diphenylamine is outstanding, which can serve as high temperature ashless high performance antioxidant combination; The heterosynergism among three antioxidants with three different action mechanisms, for example, the tri-component combination of alkylated diphenylamine, zinc dithiocarbamate and organic molybdate ester, can achieve excellent antioxidation performance. The heterosynergism of antioxidants not only exhibits good antioxidation properties, but also brings extra extreme pressure (EP), antiwear and friction-reducing performances, for instant, the tri-component combination of alkylated diphenylamine, zinc dithiocarbamate and organic molybdate ester is also an outstanding friction-reducing and antiwear additives.%对润滑油的氧化机

  3. Exposure to mutagenic airborne particulate in a rubber manufacturing plant.

    Fracasso, M E; Franceschetti, P; Mossini, E; Tieghi, S; Perbellini, L; Romeo, L


    Epidemiological studies conducted in the 1980s revealed that people working in the rubber manufacturing industry had an increased risk of cancer. Even now, workers employed in rubber processing are still at risk despite the measures adopted to improve their working conditions. The aim of the study was to evaluate the presence of a genotoxic risk in a rubber industry and to verify whether or not it was possible to locate the most dangerous position among the different rubber-working processes. The mutagenic activity of airborne particulate was evaluated in samples collected in the mixing department of a rubber manufacturing plant. Ambient air samples were taken over 3-h period in two stable positions near the mixing (Banbury mixer) and calendering areas. Personal air samples were taken over 2-h period during a normal workday from five workers employed in different rubber processing operations (mixing, weighing, calendering, compounding and extruding). The mutagenic activity of the air samples was determined by plate incorporation assay using Salmonella typhimurium strains (TA 98, TA 98NR, TA 100, YG 1021) with and without metabolic activation. Polycyclic aromatic hydrocarbon (PAH) concentrations were determined by high-performance liquid chromatography (HPLC); the presence of other presumable contaminants were carried out by gas chromatography-mass spectrometry (GC-MS). The results showed substantial direct and indirect frameshift mutagenicity in both ambient and personal samples. No mutagenic activity was present in S. typhimurium TA 100, except in the personal sample from a worker employed on the Banbury mixer. HPLC analysis revealed very low concentrations of PAHs. GC-MS analysis showed the presence of compounds such as azulene derivative, 1,2-dihydro-2,2,4-trimethylquinoline, N-methyl N-phenylbenzenamine, diphenylamine, bis(2-ethylhexyl)phthalate and bis(methyl-propyl)phthalate. We conclude that the high levels of mutagenic activity in ambiental and personal

  4. Structure-based design of selective inhibitors of dihydrofolate reductase: synthesis and antiparasitic activity of 2, 4-diaminopteridine analogues with a bridged diarylamine side chain.

    Rosowsky, A; Cody, V; Galitsky, N; Fu, H; Papoulis, A T; Queener, S F


    As part of a larger search for potent as well as selective inhibitors of dihydrofolate reductase (DHFR) enzymes from opportunistic pathogens found in patients with AIDS and other immune disorders, N-[(2,4-diaminopteridin-6-yl)methyl]dibenz[b,f]azepine (4a) and the corresponding dihydrodibenz[b,f]azepine, dihydroacridine, phenoxazine, phenothiazine, carbazole, and diphenylamine analogues were synthesized from 2, 4-diamino-6-(bromomethyl)pteridine in 50-75% yield by reaction with the sodium salts of the amines in dry tetrahydrofuran at room temperature. The products were tested for the ability to inhibit DHFR from Pneumocystis carinii (pcDHFR), Toxoplasma gondii (tgDHFR), Mycobacterium avium (maDHFR), and rat liver (rlDHFR). The member of the series with the best combination of potency and species selectivity was 4a, with IC(50) values against the four enzymes of 0. 21, 0.043, 0.012, and 4.4 microM, respectively. The dihydroacridine, phenothiazine, and carbazole analogues were also potent, but nonselective. Of the compounds tested, 4a was the only one to successfully combine the potency of trimetrexate with the selectivity of trimethoprim. Molecular docking simulations using published 3D structural coordinates for the crystalline ternary complexes of pcDHFR and hDHFR suggested a possible structural interpretation for the binding selectivity of 4a and the lack of selectivity of the other compounds. According to this model, 4a is selective because of a unique propensity of the seven-membered ring in the dibenz[b,f]azepine moiety to adopt a puckered orientation that allows it to fit more comfortably into the active site of the P. carinii enzyme than into the active site of the human enzyme. Compound 4a was also evaluated for the ability to be taken up into, and retard the growth of, P. carinii and T. gondii in culture. The IC(50) of 4a against P. carinii trophozoites after 7 days of continuous drug treatment was 1.9 microM as compared with previously observed IC(50

  5. Polystyrene nanoparticles activate ion transport in human airway epithelial cells

    McCarthy J


    Full Text Available J McCarthy1, X Gong2, D Nahirney2, M Duszyk2, MW Radomski11School of Pharmacy and Pharmaceutical Sciences, Panoz Institute, Trinity College Dublin, Dublin, Ireland; 2Department of Physiology, University of Alberta, Edmonton, Alberta, CanadaBackground: Over the last decade, nanotechnology has provided researchers with new nanometer materials, such as nanoparticles, which have the potential to provide new therapies for many lung diseases. In this study, we investigated the acute effects of polystyrene nanoparticles on epithelial ion channel function.Methods: Human submucosal Calu-3 cells that express cystic fibrosis transmembrane conductance regulator (CFTR and baby hamster kidney cells engineered to express the wild-type CFTR gene were used to investigate the actions of negatively charged 20 nm polystyrene nanoparticles on short-circuit current in Calu-3 cells by Ussing chamber and single CFTR Cl- channels alone and in the presence of known CFTR channel activators by using baby hamster kidney cell patches.Results: Polystyrene nanoparticles caused sustained, repeatable, and concentration-dependent increases in short-circuit current. In turn, these short-circuit current responses were found to be biphasic in nature, ie, an initial peak followed by a plateau. EC50 values for peak and plateau short-circuit current responses were 1457 and 315.5 ng/mL, respectively. Short-circuit current was inhibited by diphenylamine-2-carboxylate, a CFTR Cl- channel blocker. Polystyrene nanoparticles activated basolateral K+ channels and affected Cl- and HCO3- secretion. The mechanism of short-circuit current activation by polystyrene nanoparticles was found to be largely dependent on calcium-dependent and cyclic nucleotide-dependent phosphorylation of CFTR Cl- channels. Recordings from isolated inside-out patches using baby hamster kidney cells confirmed the direct activation of CFTR Cl- channels by the nanoparticles.Conclusion: This is the first study to identify

  6. Variation in the toxicity of sediment-associated substituted phenylamine antioxidants to an epibenthic (Hyalella azteca) and endobenthic (Tubifex tubifex) invertebrate.

    Prosser, R S; Bartlett, A J; Milani, D; Holman, E A M; Ikert, H; Schissler, D; Toito, J; Parrott, J L; Gillis, P L; Balakrishnan, V K


    Substituted phenylamine antioxidants (SPAs) are produced in relatively high volumes and used in a range of applications (e.g., rubber, polyurethane); however, little is known about their toxicity to aquatic biota. Therefore, current study examined the effects of chronic exposure (28 d) to four sediment-associated SPAs on epibenthic (Hyalella azteca) and endobenthic (Tubifex tubifex) organisms. In addition, acute (96-h), water-only exposures were conducted with H. azteca. Mortality, growth and biomass production were assessed in juvenile H. azteca exposed to diphenylamine (DPA), N-phenyl-1-napthylamine (PNA), N-(1,3-dimethylbutyl)-N'-phenyl-1,4-phenylenediamine (DPPDA), or 4,4'-methylene-bis[N-sec-butylaniline] (MBA). Mortality of adult T. tubifex and reproduction were assessed following exposure to the four SPAs. The 96-h LC50s for juvenile H. azteca were 1443, 109, 250, and >22 μg/L and 28-d LC50s were 22, 99, 135, and >403 μg/g dry weight (dw) for DPA, PNA, DPPDA, and MBA, respectively. Reproductive endpoints for T. tubifex (EC50s for production of juveniles > 500 μm: 15, 9, 4, 3.6 μg/g dw, for DPA, PNA, DPPDA, and MBA, respectively) were an order of magnitude more sensitive than endpoints for juvenile H. azteca and mortality of adult worms. The variation in toxicity across the four SPAs was likely related to the bioavailability of the sediment-associated chemicals, which was determined by the chemical properties of the SPAs (e.g., solubility in water, Koc). The variation in the sensitivity between the two species was likely due to differences in the magnitude of exposure, which is a function of the life histories of the epibenthic amphipod and the endobenthic worm. The data generated from this study will support effect characterization for ecological risk assessment. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  7. Mechanism Analysis on Viscosity Degradation of Poly α-Olefin Aviation Lubricating Base Oil%聚α-烯烃航空润滑油基础油黏度衰变机理分析

    费逸伟; 郭峰; 姚婷; 杨宏伟; 郭青鹏


    以聚α-烯烃(PAO)基础油、2,6-二叔丁基对甲酚(T501)和 p,p’-二异辛基二苯胺(Tz516)混合油样为研究对象,运用高温高压反应釜装置,模拟航空发动机工作环境,测定不同温度反应后的运动黏度,借助 GC/MS 现代检测手段,根据检测到的产物分布,从分子水平推测 PAO 基础油的黏度衰变机理。结果表明,高温环境中,基础油主要发生了热裂解和热氧化等反应,其中分子链的断裂是最主要的反应,产生链长较短的正构烷烃、异构烷烃和烯烃,使分子间作用力减弱,进而降低油样的运动黏度。抗氧剂 T501和 Tz516的加入能够极大地延缓了基础油的黏度降解。%Under stimulated aeroengine working condition in high temperature and high pressure reaction kettle, the kinematic viscosity of poly-α-olefin (PAO) aviation lubricating base oil with 2,6 ditbutyl-p-cresol (T501) and p,p'-diisooctyl diphenylamine (Tz516) after the reaction at different temperature was determined. Meanwhile, the composition and structure of reacted samples were detected by gas chromatography/mass spectrometry (GC/MS) to investigate the mechanism of viscosity degradation. The results show that, under high temperature, pyrolysis and thermal oxidation of the aviation lubricating base oil can happen, the breakage of molecular chain can produce n-alkanes, iso-paraffins and olefins, which will cause intermolecular force reduce to decrease the kinematic viscosity. In addition, adding T501 and Tz516 can prevent the thermal oxidation of PAO significantly.

  8. Determination of P-phenylenediamine in the Air of Workplace by Capillary Gas Chromatography%毛细管气相色谱测定工作场所空气中对苯二胺

    谢碧俊; 杨长晓


    Objective To establish a method to determine p-phenylenediamine in the air of workplace by capillary gas chromatography. Methods The p-phenylenediamine in the air of workplace was sampled with silica gel tubes and eluted with ethanol, separated by SE - 54 capillary column and determined by gas chromatography under the optimal instrument conditions. The experimental study was carried out according to the requirements of Methods for Determination of Chemical Substances in the Air of Workplace. Results p-Phenylenediamine showed good linearity at the range of 0 - 1 120 μg/ml (r = 0. 999 6 ) . The limit of detection was 0. 39 μg/ml (s/n -3; injection volume, 1 μl) and the detectable concentrition of sample was 0. 13 mg/ m (3L of air sample). Samples of high, middle and low concentrations were re-determined for 6 times and the RSD was 0. 0% -0. 45% with the desorption efficiency at the range of 95. 2% to 96. 4% . Benzene, methylbenzene, xy-lene, acetone, diphenylamine, phenylamine, o-phenylenediamine, m-phenylenediamine, diphenyl and trieth-ylamine, which may coexist with p-phenylenediamine in the air of workplace, had no interference on the determination. Conclusion The method has the advantages of simple operation, rapid performance, high sensitivity and low detection limit, and coexisting substances have no interfering influence on the determination, so it is suitable to determine the p-phenylenediamine in the air of workplace.%目的 建立工作场所空气中对苯二胺毛细管气相色谱测定方法.方法 硅胶管采样,乙醇解吸,SE - 54毛细管色谱柱分离,在最佳仪器条件下用气相色谱仪测定,按照《工作场所空气中化学物质的测定方法》的要求,进行实验室方法研究.结果 对苯二胺在0~1120 μg/ml之间有良好的线性关系,相关系数0.9996.方法的最低检出浓度为0.39 μg/ml(进样1μl解吸液,以3倍噪音计算),样品最低检出浓度为0.13 mg/m3(采样体积以3L

  9. Environmental and human risk hierarchy of pesticides: A prioritization method, based on monitoring, hazard assessment and environmental fate.

    Tsaboula, Aggeliki; Papadakis, Emmanouil-Nikolaos; Vryzas, Zisis; Kotopoulou, Athina; Kintzikoglou, Katerina; Papadopoulou-Mourkidou, Euphemia


    A pesticide prioritization approach was developed and implemented in the Pinios River Basin of Central Greece. It takes under consideration the Level of Environmental Risk containing information on the frequency of occurrence of pesticides above environmental thresholds, the intensity of this occurrence and the spatial distribution as well as information about the fate and behavior of pesticides in the environment and the potential to have adverse impact on humans' health. Original 3-year monitoring data from 102 Stationary Sampling Sites located on rivers and their tributaries, reservoirs, streams and irrigation/drainage canals giving rise to a collection of 2382 water samples resulting in 7088 data sets, were included in this integrated prioritization study. Among 302 monitored active ingredients, 119 were detected at least once and the concentrations found in the aquatic systems for 41% of compounds were higher than the respective lowest Predicted Non-Effect Concentration (PNEC) values. Sixteen and 5 pesticides were found with risk ratios (MECmax/PNEC) above 10 (high concern) and 100 (very high concern), respectively. However, pesticides with maximum Measured Environmental Concentration (MECmax) values exceeding by 1000 times the respective lowest PNEC values were also found which were considered of extremely high concern; in the latter group were included prometryn, chlorpyrifos, diazinon, λ-cyhalothrin, cypermethrin, α-cypermethrin deltamethrin, ethalfluralin and phosmet. The sensitivity of the analytical methods used in the monitoring study was considered inadequate to meet the toxicological endpoints for 32 pesticides. The widest distribution of occurrence in the Stationary Sampling Sites of the monitoring program was found for the pesticides, prometryn, fluometuron, terbuthylazine, S-metolachlor, chlorpyrifos, diphenylamine, acetochlor, alachlor, 2,4-D, etridiazole, imidacloprid and lindane (γ-ΗCH). Among the 27 priority pesticides included in the

  10. Tris(2,2'-azobispyridine) complexes of copper(II): X-ray structures, reactivities, and the radical nonradical bis(ligand) analogues.

    Maity, Suvendu; Kundu, Suman; Weyhermüller, Thomas; Ghosh, Prasanta


    Tris(abpy) complexes of types mer-[Cu(II)(abpy)3][PF6]2 (mer-1(2+)[PF6(–)]2) and ctc-[Cu(II)(abpy)2(bpy)][PF6]2 (ctc-2(2+)[PF6(–)]2) were successfully isolated and characterized by spectra and single-crystal X-ray structure determinations (abpy = 2,2′-azobispyridine; bpy = 2,2′-bipyridine). Reactions of mer-1(2+) and ctc-2(2+) ions with catechol, o-aminophenol, p-phenylenediamine, and diphenylamine (Ph–NH–Ph) in 2:1 molar ratio afford [CuI(abpy)2](+) (3(+)) and corresponding quinone derivatives. The similar reactions of [Cu(II)(bpy)3](2+) and [Cu(II)(phen)3](2+) with these substrates yielding [Cu(I)(bpy)2](+) and [Cu(I)(phen)2](+) imply that these complexes undergo reduction-induced ligand dissociation reactions (phen = 1,10-phenanthroline). The average −N═N– lengths in mer-1(2+)[PF6(–)]2 and ctc-2(2+)[PF6(–)]2 are 1.248(4), while that in 3(+)[PF6(–)]·2CH2Cl2 is relatively longer, 1.275(2) Å, due to dCu → πazo* back bonding. In cyclic voltammetry, mer-1(2+) exhibits one quasi-reversible wave at −0.42 V due to Cu(II)/Cu(I) and abpy/abpy(•–) couples and two reversible waves at −0.90 and −1.28 V due to abpy/abpy(•–) couple, while those of ctc-2(2+) ion appear at −0.44, −0.86, and −1.10 V versus Fc(+)/Fc couple. The anodic 3(2+)/3(+) and the cathodic 3(+)/3 redox waves at +0.33 and −0.40 V are reversible. The electron paramagnetic resonance spectra and density functional theory (DFT) calculations authenticated the existence of abpy anion radical (abpy(•–)) in 3, which is defined as a hybrid state of [Cu(I)(abpy(0.5•–))(abpy(0.5•–))] and [Cu(II)(abpy(•–))(abpy(•–))] states. 3(2+) ion is a neutral abpy complex of copper(II) of type [Cu(II)(abpy)2](2+). 3 exhibits a near-IR absorption band at 2400–3000 nm because of the intervalence ligand-to-ligand charge transfer, elucidated by time-dependent DFT calculations in CH2Cl2.

  11. Determination of designer doping agent--2-ethylamino-1-phenylbutane--in dietary supplements and excretion study following single oral supplement dose.

    Wójtowicz, Marzena; Jarek, Anna; Chajewska, Katarzyna; Turek-Lepa, Ewa; Kwiatkowska, Dorota


    The quantitative analysis of a new designer doping agent, 2-ethylamino-1-phenylbutane (EAPB) and its metabolite, 2-amino-1-phenylbutane (APB) in urine samples, and the determination of EAPB in dietary supplement samples, have been presented. The main purpose of the present study was to develop simple and reliable gas chromatography-mass spectrometry method (GC-MS) for excretion study following a single oral administration of dietary supplements containing EAPB. Three analytical methods for the determination of EAPB in urine and supplement samples, and APB in urine samples using the GC-MS system, have been validated. The method of the determination of EAPB in supplement samples was applied to analyze seventeen dietary supplements, CRAZE and DETONATE. Two other methods were used to determine the urinary excretion profile of EAPB and APB in the case of three healthy volunteers and, on further investigation, it was applied to the anti-doping control in sport. Quantification was obtained on the basis of the ions at m/z 86, 58 and 169, monitored for EAPB, APB and diphenylamine (used as an internal standard), respectively. The limits of detection and quantification were 2.4 and 7.3μg/g for EAPB in the case of supplement analysis, 2.9 and 8.8ng/mL for EAPB in the case of urine analysis, and 3.2 and 9.7ng/mL for APB. The other validation parameters as linearity, precision and trueness have been also investigated with the acceptable results. The extraction yield of all presented methods was above 69%. EAPB was detected in fourteen analyzed supplements (not included EAPB in their labels) and its content varied between 1.8 and 16.1mg/g. Following oral administration of three supplements with EAPB to one male and two female volunteers, the parent compound of EAPB and its metabolite were monitored and the excretion parameters as the maximum concentration of the analyte in urine (2.2-4.2μg/mL for EAPB; 1.1-5.1μg/mL for APB) and the time for the maximum height of the excretion

  12. Assessing two different peroxidases´ potential for application in recalcitrant organic compound bioremediation Evaluación del potencial de dos peróxidas para su aplicación en biorremedación de compuestos orgánicos recalcitrantes

    Torres Rodrigo


    Full Text Available This work shows the promising future presented by the following enzymes: Chloroperoxidase (CPO from Caldariomyces fumago and royal palm peroxidase (Roystonea regia, PPR. These peroxidases were obtained from different sources (microbial and vegetable and used as biocatalysts for applicating them in bioremediation of recalcitrant organic compounds. Each one of the enzymes' peroxidase catalytic activity was evaluated in organic phase systems, using different model compounds such as: PAHs (pyrene and anthracene, organic-nitrogenated compounds (diphenylamine, monoaromatic phenolic molecules (guayacol and dyes (methyl orange and ABTS. The reaction systems were composed of mono-phase water mixtures and organic miscible solvent (methanol, ethanol, isopropanol, acetonitrile, tetrahydrofuran, dimethyl sulfoxide and dimethyl formamide, on which both peroxidases' catalytic activity was evaluated. The two enzymes' catalytic activity was observed on the evaluated substrates in most of these assays. However, PPR did not show biocatalytic oxidation for methyl orange dye and some PAHs. This enzyme did show the best tolerance to the evaluated solvents. Its catalytic activity was appreciably enhanced when low hydrophobic solvents were used. The kcat was calculated from this experimental data (as kinetic parameter leading to each enzyme's biocatalytic performance on substrates being compared.El presente trabajo demuestra el promisorio futuro que presentan las enzimas cloroperoxidasa del hongo Caldariomyces fumago (CPO y la peroxidasa de palma real (Roystonea regia, PPR, dos peroxidasas de diferente fuente (microbiana y vegetal, usadas como biocatalizadores para aplicación en biorremediación de compuestos orgánicos recalcitrantes. Para este estudio, se evaluó la actividad catalítica tipo peroxidasa, en sistemas de fase orgánica, de cada una de las enzimas empleando diferentes compuestos modelos tales como: PAH's (pireno y antraceno, órgano nitrogenados

  13. Development of improving processing HNBR

    LI Jin-shan; HU Hai-hua


    viscosities.It is evident that HNBR-1 has almost the same properties in spite of lower polymer Mooney viscosities compared with HNBR-2.Table 1 Comparison of physicalproperties of HNBR-1 and HNBR-2**Compounding formulation(weight part):HNBR 100,ZnO 5.0,stearic acid 0.5,N770 carbon 50,polyester plasticizer 5.0,dicumyl peroxide 6.5,triallyl isocyanurate 1.75,styrenized diphenylamine 1.5,zinc salt of 2-mercaptobenzimidazole 0.5.

  14. Survivin反义寡核苷酸逆转顺铂诱导的人肺腺癌细胞凋亡耐受作用%Antisense oligodeoxynucleotides targeting survivin gene reverse apoptotic resistance induced by cisplatin in human lung adenocarcinoma cells

    张梅春; 胡成平; 赵子文; 曾军


    [Objective] To explore whether antisense oligodeoxynucleotides(ASODN) targeting survivin gene can reverse apoptotic resistance induced by cisplatin in human lung adenocarcinoma cells. [Methods] A549/CDDP cell lines were cultured routinely with RPMI-1640 medium. Survivin ASODN mediated by cytofectin was transfected into the A549/CDDP cells .The influence of ASODN transfection on apoptosis was determined by Diphenylamine assay (DPA) ,caspase-3 colorimetric assay and flow cytometry. 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was performed to detect the cell viability, half-maximum inhibitory concentration (IC50) and cisplatin resistant index(RI) were thereby calculated, respectively. [Results] In the A549/CDDP cells transfected by survivin ASODN for 48 hrs, the percentage of DNA fragmentation, apoptotic index and caspase-3 activity was enhanced to (43.55±6.07)%, (34.03±2.25)% and (1.1298±0.2502),respectively (P <0.05), it was obviously significant,compared to the controls. While combination with ASODN and 10 μmol/L cisplatin caused far more obvious apoptotic alterations in the cells, of which the percentage of DNA fragmentation, AI and caspase-3 activity was reached to (76.73±2.04)%, (65.85±5.47)% and (1.6805±0.2758)(P <0.05), respectively, and even compared to single ASODN group, it was still significant (P <0.05). Transfected with survivin ASODN single and with combination of cisplatin for 48 hrs, the rate of cell growth inhibition in the resistant cells was enhanced to 59.3% and 83.7%, respectively(P<0.05), while cell viability inversely had the lowest reduction. And the half-maximum inhibitory concentration of cisplatin was reduced from (225.03±10.59)μmol/L to(158.84±4.256) μmol/L, while the resistant index was conversely reduced from 11.9 to 8.39. Non-sense oligodeoxynucleotides(NSODN) and liposome had no effect on the cells(P>0.05). [Conclusion] Transfection of antisense oligodeoxynucleotides targeting

  15. Simultaneous Determination of Nicotine and Metabolite Cotinine in Urine, Hair and Saliva by Gas Chromatography- Mass Spectrometry%尿液和头发及唾液中尼古丁及其代谢物可替宁的气相色谱-质谱同时测定法

    何怡; 徐东群


    To establish a assay method for simultaneous determination of nicotine and its metabolite cotinine in urine, hair and saliva by gas chromatography-mass spectrometry. Methods The sample (urine, hair and saliva) was alkalized by NaOH, diphenylamine as an internal standard, and nicotine and cotinine were extracted simultaneously with chloroform, and then were determined by gas chromatography-mass spectrometry, the concentration of nicotine and cotinine in urine would be corrected by creatinine. Results The limits of detection of the method were 6.5 ng/ml and 14.5 ng/ml for nicotine and cotinine respectively.The limits of quantification were 22 ng/ml and 48 ng/ml respectively. The line ranges of the method were 0.022-4 μg/ml and 0.048-4 μg/ml for nicotine and cotinine respectively. The precisions of the method were 1.98%-2.69% and 4.70%-6.65% for nicotine and cotinine in urine, 0.87%-2.89% for nicotine in hair, 4.89%-4.54% for cotinine in saliva respectively. The recoveries of the spiked samples were 82.40%-106.48% and 81.80%-99.55% for nicotine and cotinine respectively in urine, 85.37%103.91% for nicotine in hair, 80.50%-93.00% for cotinine in saliva. Conclusion The method is simple, rapid and accurate, and it is satisfying to evaluate the human tobacco exposure.%目的 建立利用气相色谱-质谱(GC-MS)法同时测定人体尿液、头发、唾液中尼古丁及其代谢物可替宁的方法.方法 将样品(消解完全的头发、尿液、唾液)经NaOH碱化后用三氯甲烷萃取,气相色谱分离,质谱检测采用选择离子扫描,并以二苯胺作为内标物进行定量.尿液中尼古丁和可替宁的浓度用尿肌酐校正.结果 该方法的尼古丁和可替宁的检出限为分别为6.5、14.5 ng/ml,测定下限分别为22、48 ng/ml;尼古丁和可替宁的线性范围分别为0.022~4μg/ml、0.048~4μg/ml.尿液中尼古丁和可替宁的精密度分别为2.02%~2.62%、5.27%~7.24%;头发

  16. Determination of Nicotine and Cotinine in Urine and Hair by Capillary Gas Chromatography%尿液和头发中尼古丁和可替宁的毛细管气相色谱测定法

    朱琳; 杨丽君; 孙丽艳


    目的 建立尿液和头发中尼古丁和可替宁的气相色谱标准检测方法.方法 尿液或头发样品用NaOH溶液完全消解后用三氯甲烷萃取,经毛细管柱分离,NPD检测器检测,保留时问定性,以二苯胺作为内标物进行定量.结果 尿液中尼古丁和可替宁的检测范围分别为0.017~5μg/ml和0.024~5μg/ml,重复测定相对标准偏差(RSD)分别为1.7%~2.1%和1.5%~2.8%,加标回收率分别为102%~104%和90%~106%,回归方程分别为y=2.508x+0.072,r=0.999 2和y=1.797x+0.050 9,r=0.999 6;头发中尼古丁的检测范围为0.017~4μg/ml,重复测定相对标准偏差(RSD)为0.87%~2.5%,加标回收率92.5%~96.1%,回归方程为y=2.456x-0.054 6,r=0.999 8.本方法测定尼古丁和可替宁时,在进样1μl条件下,检出限分别为0.005μg/ml和0.007μg/ml,测定下限分别为0.017和0.024 μg/ml.结论 本方法适合测定主动吸烟和被动吸烟者体内的尼古丁和可替宁含量,评估暴露者的烟草暴露剂量和程度.%Objective To establish a gas chromatography standard method for the determination of nicotine and cotinine in urine and hair. Methods The urine and hair samples were digested with NaOH, extracted with trachloromethane,separated by capillary column and determined with NPD detector, diphenylamine as the internal standard substance. Results The samples of nicotine and cotinine were injected at 1 lμl respectively, and the limits of detection were 0.005 μg/ml and 0.007 μg/ml, and limits of quantification were 0.017 μg/ml and 0.024 μg/ml respectively. The linear ranges of nicotine and cotinine in urine were 0.017-5 μg/ml and 0.024-5 μg/ml, the relative standard deviations(RSD) of determination were 1.7%2.1% and 1.5%-2.8%, the rates of recovery of spiked samples were in the range of 102%-104% and 90%-106%, and the regression equations were y=2.508x+O.072, r=0.999 2 and y=l.797x+O.050 9, r=0.999 6. The linear range of nicotine in hair was 0.017-4

  17. Inhibitory effect of compound 6F isolated from Pteris semipinnata L. on the activity of protein kinase C in HL-60 cells%半边旗提取物6F抑制HL-60细胞蛋白激酶C活性

    何承伟; 梁念慈; 莫丽儿; 李金华; 张晓


    目的探讨半边旗提取物6F的细胞毒作用及诱导DNA片段化与蛋白激酶C(PKC)信号转导途径的关系,检测6F对PKC活性的影响.方法受试对象为HL-60细胞,超速离心法获得的胞液(可溶部分)及颗粒(不可溶部分,包括细胞膜系统及胞核)部分用作PKC活性测定.经0.4 g@L-1磷脂酰丝氨酸,0.04g@L-1甘油二油酸酯激动剂作用酶粗提物后,用液体闪烁计数仪计数[γ-32P]ATP参入外源底物的量以测定PKC活性.MTT法测定HL-60细胞的活力,二苯胺法测定6F诱导DNA片段化程度.结果在所测试的浓度范围内(0.5~312 μmol@L-1),化合物6F显著抑制胞液及颗粒部分PKC活性,最大抑制率达88.6%,呈浓度依赖关系(胞液部分r=0.781,P<0.05,颗粒部分r=0.931,P<0.01).6F诱导HL-60细胞DNA片段化及对细胞的毒性作用可被具有致癌作用的PKC激活剂肉豆蔻酸酯(PMA,浓度为65 nmol@L-1)拮抗,抑制率分别是30%和44%(P<0.01).PMA单独用使HL-60细胞线粒体将MTT还原为甲臜的能力增强14%(P<0.01),即增强细胞活力.结论化合物6F是PKC的抑制剂.6F对HL-60细胞DNA片段化的诱导作用及其细胞毒作用至少可部分归因于其对PKC活性的抑制作用.%AIM To investigate whether compotmd 6F isolated from Pteris semipinnata L inhibits the activity of protein kinase C (PKC) and whether the DNA fragment induction and cytotoxicity of 6F on HL-60 cells relate to PKC signaling pathway. METHODS HL-60 cells were used as in vitro model and its cytosol (soluble sample)and particle( insoluble sample including membrane system and nuclei) fractions obtained by ultracentrifugation were used as samples for PKC assay. PKC activity was measured by incorporation of [ γ-32p]ATP into exogenous substrate after stimulated by phosphatidylserine and diolein.Diphenylamine assay and MTT staining methods were applied for DNA fragmentation detection and cytotoxicity assay, respectively. RESUL TS PKC activities in cytosol and particle