Effects of chemical oxidation on sorption and desorption of PAHs in typical Chinese soils

In situ chemical oxidation is a commonly applied soil and groundwater remediation technology, but can have significant effects on soil properties, which in turn might affect fate and transport of organic contaminants. In this study, it was found that oxidation treatment resulted mainly in breakdown of soil organic matter (SOM) components. Sorption of naphthalene and phenanthrene to the original soils and the KMnO(4)-treated soils was linear, indicating that hydrophobic partitioning to SOM was the predominant mechanism for sorption. Desorption from the original and treated soils was highly resistant, and was well modeled with a biphasic desorption model. Desorption of residual naphthalene after treating naphthalene-contaminated soils with different doses of KMnO(4) also followed the biphasic desorption model very well. It appears that neither changes of soil properties caused by chemical oxidation nor direct chemical oxidation of contaminated soils had a noticeable effect on the nature of PAH-SOM interactions.

Effectiveness of different oxidizing agents for removing sodium dodecylbenzenesulphonate in aqueous systems

The present study investigates the efficacy of various oxidizing treatments (ClO(-), ClO(2), KMnO(4), O(3), O(3)/H(2)O(2), O(3)/activated carbon) to remove from waters sodium dodecylbenzenesulphonate (SDBS), considered as model surfactant. Results obtained show that the use of ClO(-) and ClO(2) does not cause appreciable SDBS degradation. Additionally, in the case of ClO(-), trihalomethanes are generated, increasing system toxicity. Because the reaction kinetics between SDBS and KMnO(4) is very slow, a decrease in contaminant concentration is not observed, even at very acid pH values. SDBS reactivity with ozone is very low, with a kinetic constant (k(O)(3)) of 3.68 M(-1)s(-1), but its reactivity with HO() radicals is very high (k(OH)=1.16 x 10(10)M(-1)s(-1)), therefore O(3)/H(2)O(2) and O(3)/activated carbon, which can also generate HO(), appear as promising advanced oxidation processes to remove this contaminant from waters. The method based on ozone and activated carbon was the only process studied that produced both an increase in SDBS removal rate (due to the generation of HO() radicals in the O(3)-PAC or O(3)-GAC interaction) and a considerable reduction in the concentration of dissolved organic carbon in the system due to the PAC adsorbent properties.

Assays for transcription factor activity

Transcription factors interact at promoters to modulate the transcription of genes. This chapter describes three in vitro methods that can be used to monitor their activity: transcript assays, abortive initiation assays, and potassium permanganate footprinting. These techniques have been developed using bacterial systems, and can be used to study the kinetics of transcription initiation, and hence to unravel regulatory mechanisms.

Flow-injection chemiluminescence determination of chrysin and baicalein assisted by theoretical prediction of chemiluminescence behavior of chrysin and baicalein

In this paper, the molecular connectivity indices were applied to theoretically predict the direct chemiluminescence (CL) behavior of chrysin and baicalein with our recently proposed discriminant function. Then, combined with flow-injection analysis, a new CL system for determination of chrysin and baicalein was proposed. The method was based on the oxidation of chrysin and baicalein by acidic KMnO(4) in the presence of formaldehyde to produce strong CL emission. The present paper suggested a new model to discover new CL analytical system: first, to theoretical predict the CL behavior, and the second, to suggest analytical system.

Chemical cleavage of mismatch (CCM) to locate base mismatches in heteroduplex DNA

This protocol describes the use of the chemical cleavage of mismatch (CCM) method to assess whether a region of DNA contains mutations and to localize them. Compared with other mutation-detection techniques (such as single strand-conformation polymorphism (SSCP) analysis, denaturing high-performance liquid chromatography (DHPLC) and denaturing gradient gel electrophoresis (DGGE)) that detect mutations in short DNA fragments and require highly specific melting temperatures, CCM has a higher diagnostic sensitivity suited to the detection of mutations in tumor genes, and can analyze amplicons < or = 2 kb in length. To detect mutations, PCR heteroduplexes are incubated with two mismatch-specific reagents. Hydroxylamine modifies unpaired cytosine and potassium permanganate modifies unpaired thymine. The samples are then incubated with piperidine, which cleaves the DNA backbone at the site of the modified mismatched base. Cleavage products are separated by electrophoresis, revealing the identity and location of the mutation. The CCM method can efficiently detect point mutations as well as insertions and deletions. This protocol can be completed in 10 h.

Adsorption of fluoride in aqueous solutions using KMnO4-modified activated carbon derived from steam pyrolysis of rice straw

Fluoride in drinking water above permissible levels is responsible for human and skeletal fluorosis. In this study, activated carbons (AC) prepared by one-step steam pyrolysis of rice straw at 550, 650, 750 degrees C, respectively, were modified by liquid-phase oxidation using HNO3, H2O2 and KMnO4. Characterization of these 12 carbons was made by their surface area, porosity, acidity, basicity, pH(pzc), pH and ability to remove fluoride anion. Based on the data of the latter factor, the RS2/KMnO4 carbon was selected. Along with batch adsorption studies, which involve effect of pH, adsorbate concentration, adsorbent dosage, contact time, temperature, and Co-ions (SO4(2-), Cl-, Br-). The effects of natural organic matter (NOM) were also made to remove the fluoride from natural water. On the basis of kinetic studies, specific rate constants involved in the adsorption process using RS2/KMnO4 carbon was calculated and second-order adsorption kinetics was observed. Equation isotherms such as Langmuir (L), Freundlich (F), Langmuir-Freundlich (LF) and Dubinin-Radushkevich (DR) were successfully used to model the experimental data. From the DR isotherm parameters, it was considered that the uptake of F- by RS2/KMnO4 carbon proceeds by an ion-exchange mechanism (E=10.46 kJ mol(-1)). The thermodynamic parameters of fluoride sorption were calculated and the sorption process was chemical in nature. The ability of RS2/KMnO4 to remove F- from Egyptian crude phosphoric acid (P(2)O(5)=48.42%) was tested and the adsorption capacity of F- in H(3)PO(4) was greater than that in distilled water. This is may be due to fluoride adsorption enhanced at lower pH of crude acid.

Determination of tsumacide residues in vegetable samples using a flow-injection chemiluminescence method

A sensitive, simple and rapid flow-injection chemiluminescence (FI-CL) method is described to determine tsumacide pesticide residue based on the CL reaction of the alkaline degradation product of tsumacide with acidic KMnO(4) when rhodamine 6G was present. Under the optimum conditions, the relative CL intensity is linear with the concentration of tsumacide in the range of 2.0 x 10(-3)-0.20 mg/L. The detection limit is 6.6 x 10(-4) mg/L (3sigma) and the relative standard deviation for 2.0 x 10(-2) mg/L tsumacide solution was 2.28% (intra-day) and 4.85% (inter-day). The proposed method has been applied to determine the residue of tsumacide in vegetable samples and the recovery test is very satisfactory.

Expression and secretion of RANTES (CCL5) in granulomatous calcified tissue before and after lipopolysaccharide treatment in vivo

RANTES (regulated on activation, normal T cell-expressed and secreted) is a CC chemokine appearing to be involved in the recruitment of leukocytes at inflammation sites. RANTES is produced by CD8(+) T cells, epithelial cells, fibroblasts, and platelets. It acts in vitro in leukocyte activation and human immunodeficiency virus suppression, but its role in vivo is still uncertain. In our study, we established the involvement of RANTES in an in vivo model of chronic inflammation induced by potassium permanganate, leading to calcified granulomas. In our rat model, RANTES expression (mRNA and protein) was significantly upregulated in granulomatous tissue; RANTES expression was further increased upon i.p. injection of lipopolysaccharide (LPS), while it was kept at basal levels by dexamethasone (Dex) given 18 hours before sacrifice. LPS and Dex increased and decreased, respectively, the recruitment of mononuclear cells in granulomatous tissue compared with control granulomas from phosphate-buffered saline (PBS)-treated animals. In granuloma tissue, levels of RANTES were higher in LPS-treated rats and lower in the Dex group compared to controls. RANTES was also found in the conditioned medium of granuloma tissue from treated (LPS or Dex) and untreated (PBS) rats. When LPS was added in vitro for 18 hours, RANTES was further increased, except in the Dex group (P > 0.05). On serum analysis, RANTES levels were higher in the LPS group and lower in the Dex group compared to controls. This study shows for the first time that RANTES is produced in vivo in chronic, experimental inflammatory states, an effect increased by LPS and inhibited by Dex.

Flow-injection determination of carbaryl and carbofuran based on KMnO4–Na2SO3 chemiluminescence detection

A flow-injection method is described for the determination of carbaryl and carbofuran. It was found that a strong chemiluminescence (CL) signal was generated when these pesticides were mixed with Na(2)SO(3) and KMnO(4) in acidic medium. Under the optimum experimental conditions, the enhanced CL intensity was linear, with the concentrations in the range 0.1-2.0 microg/mL (r(2) = 0.9996 and 0.9993, n = 6) with relative standard deviation (n = 4) in the range 1.0-2.3%. The limits of detection (3sigma blank) were 10 and 50 ng/mL, respectively, with a sample throughput of 180/h. The proposed method was applied to determine carbaryl and carbofuran in freshwaters with satisfactory results. Most metal and non-metal ions and some pesticides, such as carbophenothion and aldicarb, do not interfere with the determination. Dinoseb, diazinon and malathion calibration graphs (in the range 0.2-2.0 microg/mL, r(2) = 0.9966-0.9988, n = 6) were also established with relative standard deviations (n = 4) in the range 1.2-2.0% with limits of detection (3sigma blank) in the range 100-300 ng/mL.

Flow-injection chemiluminescent determination of cefprozil using Tris (2,2'-bipyridyl) ruthenium (II)-permanganate system

A rapid and sensitive chemiluminescence (CL) method using flow-injection (FI) has been developed for the determination of a second generation cephalosporin, cefprozil. The method is based on the CL reaction of cefprozil with acidic potassium permanganate and tris (2,2'-bipyridyl) ruthenium (II), Ru (bipy)3(2+). The CL intensity is greatly enhanced when quinine sulfate is used as a sensitizer. After optimization of the different experimental parameters, a calibration graph was obtained over a concentration range of 0.1-3.0 microg ml(-1) with minimum detectability of 0.005 microgml(-1) (S/N=3). The correlation coefficient was 0.9998 (n=6) with a relative standard deviation (%R.S.D.) of 1.63% for 2.0 microgml(-1). The proposed method was successfully applied to commercial tablets. The average percentage recovery (n=6) was 99.9+/-1.40.

The determination of psilocin and psilocybin in hallucinogenic mushrooms by HPLC utilizing a dual reagent acidic potassium permanganate and tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection system

This paper describes a procedure for the determination of psilocin and psilocybin in mushroom extracts using high-performance liquid chromatography with postcolumn chemiluminescence detection. A number of extraction methods for psilocin and psilocybin in hallucinogenic mushrooms were investigated, with a simple methanolic extraction being found to be most effective. Psilocin and psilocybin were extracted from a variety of hallucinogenic mushrooms using methanol. The analytes were separated on a C12 column using a (95:5% v/v) methanol:10 mM ammonium formate, pH 3.5 mobile phase with a run time of 5 min. Detection was realized through a dual reagent chemiluminescence detection system of acidic potassium permanganate and tris(2,2'-bipyridyl)ruthenium(II). The chemiluminescence detection system gave improved detectability when compared with UV absorption at 269 nm, with detection limits of 1.2 x 10(-8) and 3.5 x 10(-9) mol/L being obtained for psilocin and psilocybin, respectively. The procedure was applied to the determination of psilocin and psilocybin in three Australian species of hallucinogenic mushroom.

[Study on dynamics of tannin in different growth phase of Cynomorium songaricum]

Potassium permanganate titration and complexometry were used to determine the content of tannin in different growth phase of wild and cultivated Cynomorium songaricum Rupr. The result showed that the content appeared regularly changing and the content in coming-up phase was higher than other phases. The quality in this phase would be better if the tannin was regarded as one of the effective components. The result might provide science foundation for the quality control of Herb Cynomorii.

Study of a myo-inositol hexaphosphate-based cream to prevent dystrophic calcinosis cutis

BACKGROUND

Calcinosis cutis is a disorder caused by abnormal deposits of calcium phosphate in the skin and is observed in diverse disorders. Myo-inositol hexaphosphate (InsP(6)) is a diet-dependent molecule found in all mammalian fluids and tissues, which exhibits an extraordinary capacity as a crystallization inhibitor of calcium salts.

OBJECTIVES

To establish the effects of topically administered InsP(6) cream on artificially provoked dystrophic calcifications in soft tissues.

METHODS

Fourteen male Wistar rats were randomly assigned into two groups: control and treated groups. Rats were fed with an InsP(6)-free or phytate diet. Plaque formation was induced by subcutaneous injection of 0.1% KMnO(4) solution. From 4 days before plaque induction to the end of the experiment, control rats were treated topically with a standard cream, whereas treated rats were treated with the same cream with 2% InsP(6) or phytate (as sodium salt). Calcification of plaques was allowed to proceed for 10 days. InsP(6) in urine was determined. The plaques were excised and weighed.

RESULTS

It was found that when InsP(6) was administered topically through a moisturizing cream (2% InsP(6)-rich), the plaque size and weight were notably and significantly reduced compared with the control group (1.6 +/- 1.1 mg InsP(6)-treated, 26.7 +/- 3.0 mg control). The InsP(6) urinary levels for animals treated with the InsP(6)-enriched cream were considerably and significantly higher than those found in animals treated topically with the cream without InsP(6) (16.96 +/- 4.32 mg L(-1) InsP(6)-treated, 0.06 +/- 0.03 mg L(-1) control).

CONCLUSIONS

This demonstrates the important capacity of InsP(6) as a crystallization inhibitor and also demonstrates that it is possible to propose topical use as a new InsP(6) administration route.

TFIIH XPB mutants suggest a unified bacterial-like mechanism for promoter opening but not escape

DNA helicases open the duplex during DNA replication, repair and transcription. However, RNA polymerase II is the only member of its family with this requirement; RNA polymerases I and III and bacterial RNA polymerases open DNA without a helicase. In this report, characterization of XPB mutants indicates that its helicase activity is not used for RNA polymerase II promoter opening, which is instead driven by its ATPase activity. The mutants have parallels in sigma(54) bacterial transcription and this suggests a similar mode of opening DNA for both RNA polymerases, involving ATP-dependent enzyme conformational changes. Promoter escape is defective in these XPB mutants, suggesting that the XPB helicase acts as an ATP-driven motor to reorganize the tightly wrapped multiprotein eukaryotic preinitiation complex during the remodeling that precedes elongation and the coupling to RNA processing events.

Effects of chemically amended litter on broiler performances, atmospheric ammonia concentration, and phosphorus solubility in litter

The effects of 6 different litter amendments on broiler performance, level of atmospheric ammonia (NH3) concentration, and soluble reactive phosphorus (SRP) in litter was determined. Through 3 experiments conducted on 2 different commercial farms, one chemical amendment was added to the litter and then was compared with a control. Broiler performance was not affected by any of the amendments except the ferrous sulfate amendment for which mortality was 25.5%. Application of aluminum chloride (AlCl3 x 6H2O) to the litter lowered atmospheric ammonia concentrations at 42 d by 97.2%, whereas ferrous sulfate (FeSO4 x 7H2O) lowered it by 90.77%. Ammonia concentrations were reduced by 86.18, 78.66, 75.52, and 69.00% by aluminum sulfate [alum or Al2(SO4)3 x 14H2O)], alum + CaCO3, aluminum chloride + CaCO3, and potassium permanganate (KMnO4), respectively, when compared with each control at 42 d. Each amendment except KMnO4 significantly reduced SRP contents. Alum and aluminum chloride were the effective compounds evaluated on the commercial farms with respect to reducing ammonia contents, phosphorus solubility, and mortality.

A Simple Spectrophotometric Determination of Trace Level Mercury Using 1,5-Diphenylthiocarbazone Solubilized in Micelle

A very simple, ultra-sensitive and fairly selective non-extractive spectrophotmetric method is presented for the rapid determination of mercury(II) at ultra-trace level using 1,5-diphenylthiocarbazone (dithizone) as a new micellar spectrophotometric reagent (lambdamax = 490 nm) in a slightly acidic (0.07 - 0.17 M H2SO4) aqueous solution. The presence of a micellar system avoids the previous steps of solvent extraction and reduces the cost, toxicity while enhancing the sensitivity, selectivity and the molar absorptivity. The reaction is instantaneous and the absorbance remains stable for over 24 h. The average molar absorption coefficient and Sandell's sensitivity were found to be 5.02 x 10(4) L mol(-1) cm(-1) and 10 ng cm(-2) of Hg, respectively. Linear calibration graphs were obtained for 0.05 - 10 mg L(-1) of Hg; the stoichiometric composition of the chelate is 1:2 (Hg:dithizone). The method is characterized by a detection limit of 1 microg L(-1) of Hg. Large excesses of over 60 cations, anions and complexing agents (e.g. EDTA, tartrate, oxalate, citrate, phosphate, thiourea, azide, SCN-) do not interfere in the determination. The method was successfully applied to a number of environmental water samples (potable and polluted), biological samples (human blood and urine; milk and fish) and soils; solutions contained both mercury(I) and mercury(II) as well as complex synthetic mixtures. The method has high precision and accuracy (s = +/-0.01 for 0.1 mg L(-1)).

Determination of methyltestosterone using flow injection with chemiluminescence detection

Methyltestosterone (MT) enhanced the chemiluminescence of potassium permanganate-sodium thiosulphate system in sulphuric acid medium, and this was used as the basis of a novel flow-injection chemiluminescence method for the determination of methyltesterone. Under optimum conditions, the linear response of MT was in the range 3.0 x 10(-8)-8.0 x 10(-6) g/mL, and the detection limit for determination of MT was 1.0 x 10(-8) g/mL. The method was applied to the analysis of fish with recovery in the range 88.0-113.8% with an average RSD of 1.66% (n = 8).

Determination of methotrexate in pharmaceutical formulations by flow injection analysis exploiting the reaction with potassium permanganate

A highly sensitive, precise and accurate flow injection procedure for the determination of methotrexate (MTX) was described. The method was based on oxidation of MTX into highly fluorescence product (2,4-diaminopteridine-6-carboxylic acid) by acidic potassium permanganate. A three-line manifold was used with potassium permanganate as an oxidant (3 mmol l(-1)) and sulfuric acid (6 mmol l(-1)) as carrier streams. The oxidation process was conducted at 65 degrees C through a reaction coil of 3 m (0.5 mm, i.d.). It was essential to eliminate the excess of potassium permanganate before passing to the detector using 8 mmol l(-1) sodium sulfite as a decolorizing stream. The fluorescence intensity was measured at excitation and emission wavelengths of 369 and 465 nm, respectively. The calibration graph was linear over the range 40-400 ng ml(-1) MTX. The developed method was successfully applied to the determination of MTX in pharmaceutical formulations, at a sampling rate of 90 sample h(-1) and showed a % recovery ranging from 99.96 to 100.07 and SD% ranging from 0.51 to 0.65%.

lacP1 promoter with an extended -10 motif. Pleiotropic effects of cyclic AMP protein at different steps of transcription initiation

The cyclic AMP receptor protein (CRP), which activates transcription from the wild-type lacP1 promoter and most of its mutants, represses productive RNA synthesis from a lacP1 promoter variant that contains an extended -10 element, although CRP enhances RNA polymerase binding as well as open complex formation in both promoters. Moreover, abortive RNA synthesis, which is already higher in the extended -10 variant compared with the parent promoter, was further enhanced by CRP. These results, together with the observed decrease in productive RNA synthesis, indicate that CRP, while facilitating the earlier steps of initiation, inhibits transcription from the extended -10 lacP1 by hindering promoter clearance. We propose that CRP decreases energetic barriers to RNA polymerase binding, isomerization, and abortive RNA synthesis but stabilizes the abortive RNA initiating complex, which results in increasing the activation energy of the transition state before the elongation complex. The results demonstrate for the first time that a DNA-binding regulatory protein acts as an activator or a repressor in different steps of the transcription initiation pathway because of the energetic differences of the intermediate complex in the same promoter.

Identification of forensically important fly eggs using a potassium permanganate staining technique

Fly eggs found in corpses can be utilized as entomological evidence in forensic investigations of deaths if the species of fly and the developmental rate at a temperature similar to the death scene are known. The species identification of fly eggs is particularly important, and previously, scanning electron microscope has been used for this purpose. Herein, we report a simple technique, using light microscopy, to identify forensically important eggs of Chrysomya rufifacies (Macquart), Chrysomya megacephala (Fabricius), Chrysomya pacifica Kurahashi, Chrysomya nigripes Aubertin, Aldrichina grahami (Aldrich), Lucilia cuprina (Wiedemann), Musca domestica L. and Megaselia scalaris (Loew). A 1% potassium permanganate solution was used to stain egg surfaces for 1 min, followed by dehydration in 15, 70, and 95%, absolute alcohol (each solution for 1 min) and the eggs were permanently mounted. The characteristics are based on the width of plastron, morphology of plastron area surrounding the micropyle and chorionic sculpturing, with the length of egg being used as supplemental feature.

Cationic lipids and cationic ligands induce DNA helix denaturation: detection of single stranded regions by KMnO4probing

Cationic lipids and cationic polymers are widely used in gene delivery. Using 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) as a cationic lipid, we have investigated the stability of the DNA in DOTAP:DNA complexes by probing with potassium permanganate (KMnO4). Interestingly, thymidines followed by a purine showed higher susceptibility to cationic ligand-mediated melting. Similar studies performed with other water-soluble cationic ligands such as polylysine, protamine sulfate and polyethyleneimine also demonstrated melting of the DNA but with variations. Small cations such as spermine and spermidine and a cationic detergent, cetyl trimethylammonium bromide, also rendered the DNA susceptible to modification by KMnO4. The data presented here provide direct proof for melting of DNA upon interaction with cationic lipids. Structural changes subsequent to binding of cationic lipids/ligands to DNA may lead to instability and formation of DNA bubbles in double-stranded DNA.

Analysis of the open region and of DNA-protein contacts of archaeal RNA polymerase transcription complexes during transition from initiation to elongation

The archaeal transcriptional machinery is polymerase II (pol II)-like but does not require ATP or TFIIH for open complex formation. We have used enzymatic and chemical probes to follow the movement of Pyrococcus RNA polymerase (RNAP) along the glutamate dehydrogenase gene during transcription initiation and transition to elongation. RNAP was stalled between registers +5 and +20 using C-minus cassettes. The upstream edge of RNAP was in close contact with the archaeal transcription factors TATA box-binding protein/transcription factor B in complexes stalled at position +5. Movement of the downstream edge of the RNAP was not detected by exonuclease III footprinting until register +8. A first structural transition characterized by movement of the upstream edge of RNAP was observed at registers +6/+7. A major transition was observed at registers +10/+11. In complexes stalled at these positions also the downstream edge of RNA polymerase started translocation, and reclosure of the initially open complex occurred indicating promoter clearance. Between registers +11 and +20 both RNAP and transcription bubble moved synchronously with RNA synthesis. The distance of the catalytic center to the front edge of the exo III footprint was approximately 12 nucleotides in all registers. The size of the RNA-DNA hybrid in an early archaeal elongation complex was estimated between 9 and 12 nucleotides. For complexes stalled between positions +10 and +20 the size of the transcription bubble was around 17 nucleotides. This study shows characteristic mechanistic properties of the archaeal system and also similarities to prokaryotic RNAP and pol II.