Abstract  Abstract: Separation of Cs⁺ from acidic solution was investigated using ammonium molybdo- phosphate (AMP) based sorbents. Four sorbents including two AMP powders and two composites prepared by coating of AMP powder on polymethylmethacrylate (PMMA) beads were used in this study. Equilibrium sorption isotherms for Cs⁺ on AMP sorbents were determined. The effect of H⁺ concentration on Cs⁺ uptake by AMP–PMMA beads was examined. Two column runs were carried out to establish the Cs⁺ separation performance of AMP–PMMA beads from 1.0 M nitric acid having Cs⁺ concentration equivalent to 10 Ci of ¹³⁷Cs per litre. Recovery of Cs⁺ from loaded AMP–PMMA column was carried out by dissolution of AMP using NaOH solution. The feasibility of ion exchange purification of the recovered Cs⁺ solution was examined using resorcinol formaldehyde polycondensate resin (RFPR). The Cs⁺ sorption isotherm on RFPR from Cs-bearing dissolved AMP solution was determined. Purification of Cs⁺ from dissolved AMP solution was studied in two column runs using RFPR in loading-elution cycles. The results of these studies are useful in formulating a scheme for the recovery of purified ¹³⁷Cs product from high level waste for large-scale utilization as a radiation source in industrial irradiators. [Copyright 2008 Elsevier] Copyright of Desalination is the property of Elsevier Science Publishers B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts)

Abstract  The abundant lignocellulosic agricultural waste, coir pith is used to develop ZnCl(2) activated carbon and applied to the removal of toxic anions, heavy metals, organic compounds and dyes from water. Sorption of inorganic anions such as nitrate, thiocyanate, selenite, chromium(VI), vanadium(V), sulfate, molybdate, phosphate and heavy metals such as nickel(II) and mercury(II) has been studied. Removal of organics such as resorcinol, 4-nitrophenol, catechol, bisphenol A, 2-aminophenol, quinol, O-cresol, phenol and 2-chlorophenol has also been investigated. Uptake of acidic dyes such as acid brilliant blue, acid violet, basic dyes such as methylene blue, rhodamine B, direct dyes such as direct red 12B, congo red and reactive dyes such as procion red, procion orange were also examined to assess the possible use of the adsorbent for the treatment of contaminated ground water. Favorable conditions for maximum removal of all adsorbates at the adsorbate concentration of 20 mg/L were used. Results show that ZnCl(2) activated coir pith carbon is effective for the removal of toxic pollutants from water.

Abstract  We have investigated the influence of peroxides on DNA adduct formation in HL-60 cells treated with polyphenolic metabolites of benzene. Treatment of HL-60 cells with 50 mu M hydroquinone (HQ), 500 mu M catechol (CAT) or 200 mu M 1,2,4-benzenetriol (BT) resulted in adduct levels of 0.27, 0.21 and 0.21 x 10(-7), respectively. Addition of 50-250 mu M H2O2 or 250 mu M cumene hydroperoxide to HL-60 cells increased DNA adduct formation 2.7-10-fold following treatment with HQ or CAT but had no effect on adduct formation by BT. Treatment of HL-60 cells with the combinations of HQ plus either BT or phorbol myristate acetate (PMA) potentiated DNA adduct formation by 2.5-4-fold. Significant elevations of cellular H2O2 levels occurred after treatment of HL-60 cells with either PMA, CAT or BT. These results indicate that cellular levels of H2O2 regulate the peroxidase dependent activation of benzene metabolites to form DNA adducts. (C) 1996 Academic Press. Inc.

Abstract  An enrichment-separation procedure basedn the coprecipitationf gold(III), palladium(II) and lead(II)ons with nickel(II)-5-methyl-4-(2-thiazolylazo) resorcinol complex has beeneveloped. The analytical parametersncluding pH, amountsf 5-methyl-4-(2-thiazolylazo) resorcinol, sample volume, etc. wasnvestigated for quantitative recoveriesf Au(III), Pd(II) and Pb(II). Interferenceue to various cations and anions has also beennvestigated. Theetection limits for analyteons by 3sigma were 2.6 microg L(-1) for lead, 1.5 microg L(-1) for gold, 2.1 microg L(-1) for palladium. The accuracyf the method was evaluated by the analysisf certified reference materials (NIST SRM 2711 Montana soil, GBW 07309 Stream sediment). The proposed procedure was successfully applied to environmental samples for theeterminationsf analytes.

Abstract  Bambusae Caulis in Liquamen (BCL) is the distilled product of the condensation from the burning of Phyllostachys nigra var. henosis (Gramineae). The activity-guided isolation of BCL yielded four phenolic compounds: 2,6-dimethoxyphenol (1), 1,2-dihydroxybenzene (2), 1,3-dihydroxybenzene (3) and 1,2-dibenzenecarboxylic acid (4). We evaluated the anti-oxidative, anti-inflammatory and whitening effects of these compounds, via assays, of 1,1-diphenyl-2-picrylhydazyl (DPPH) radical scavenging activity and inhibition of nitric oxide (NO) production in lipopolysaccharide-stimulated RAW 264.7 macrophage cells as well as inhibition of tyrosinase activity and melanin production in B16F10 melanoma cells. The results showed that 2 and 3 exhibited significant DPPH radical scavenging activity as well as inhibitory effects on NO production, tyrosinase activity and melanin production. These results suggested that BCL and compounds 2 and 3 can be developed as anti-oxidative, anti-inflammatory and whitening ingredients.

Abstract  Groups of 6-week-old male Syrian golden hamsters were given 13 different phenolic compounds for 20 weeks. Of these compounds, 2(3)-tert-butyl-4-methoxyphenol (BHA), 2-tert-butyl-4-methylphenol (TBMP) and p-tert-butylphenol (PTBP) strongly induced hyperplasia and tumorous lesions in the forestomach. Catechol, p-methylphenol (PMYP), p-methoxyphenol (PMOP), caffeic acid, methylhydroquinone (MHQ) and pyrogallol were less active, and resorcinol, hydroquinone, propylparabene and tert-butylhydroquinone (TBHQ) were not active. The labelling index in the forestomach epithelium was significantly increased by addition to the diet of BHA, TBMP, catechol, PMOP, PTBP and MHQ. PMOP induced epithelial damage and regenerative hyperplasia of the pyloric region. Catechol, caffeic acid and PMYP induced similar though less marked lesions. The labelling index in the glandular stomach was significantly increased by oral catechol (P less than 0.05) or PMOP (P less than 0.05). No histopathological lesions were observed in the urinary bladder epithelium, but propylparabene (P less than 0.05), catechol, TBHQ and MHQ increased the labeling index. These findings indicate that PTBP and TBMP may be carcinogenic for hamster forestomach after long-term administration, and that both one hydroxy and tert-butyl substituents may be important for induction of hamster forestomach tumors.

Abstract  #Modifying effects of the environmental contaminant catechol, and its isomers resorcinol and hydroquinone, on methyl-N-amylnitrosamine (MNAN)-induced carcinogenesis were studied in male F344 rats. Groups of 15 rats were given three i.p. injections of 25 mg/kg of body weight of MNAN within the initial 2-wk period, and commencing 1 wk thereafter they were administered 0.8% catechol, 0.8% resorcinol, or 0.8% hydroquinone in powdered basal diet or were given basal diet alone for 49 wk. Additional groups of 10 to 15 rats were similarly treated without prior carcinogen exposure. Histological examination after sacrifice at wk 52 revealed that the incidences of tongue papillomas and esophageal squamous cell carcinomas in the groups given MNAN followed by catechol (57.1% and 64.3%) or resorcinol (50% and 58.8%) were significantly higher than those in the carcinogen only controls (9.1, and 0%, respectively). Hydroquinone also enhanced the development of esophageal squamous cell carcinomas but was less active than catechol or resorcinol. The incidence of alveolar hyperplasia in the lungs of the group given MNAN followed by catechol (0%) was, in contrast, significantly reduced as compared to the control value (54.5%). Hydroquinone and resorcinol showed a similar but nonsignificant tendency. These results indicated that the environmental contaminant, catechol and its isomers, may play a role in the development of human upper gastrointestinal cancer, in addition to exerting modifying effects in other organs.

Abstract  It was found that the weak chemiluminescence produced from the reaction of polyhydroxy phenols with luminol in alkaline solution could be strongly enhanced by ferricyanide and ferrocyanide. Based on this found, a new flow injection chemiluminescence method is proposed for the determination of four polyhydroxy phenols: pyrogallol, phlorglucinol, quinol and resorcinol. The detection limits of the method are 0.03 mug ml(-1) pyrogallol, 0.03 mug ml(-1) phlorglucinol, 0.04 mug ml(-1) quinol, and 0.02 mug ml(-1) resorcinol. The possible mechanism of CL reactions is also discussed briefly.

Abstract  Nanoparticles of NaAlH(4) have been infiltrated in nanoporous carbon aerogel with TiCl(3) nanoparticles in order to explore possible synergetic effects between nanoconfinement and a functionalized catalytic scaffold. Resorcinol formaldehyde carbon aerogels with an average pore size of 17 nm and total pore volume of 1.26 mL/g were infiltrated with TiCl(3) to obtain an aerogel doped with 3.0 wt % TiCl(3) nanoparticles. NaAlH(4) was melt-infiltrated into the functionalized carbon aerogel at 189 °C and p(H(2)) ∼ 186-199 bar. Energy-dispersive spectrometry (EDS) combined with focused ion beam (FIB) techniques revealed the presence of Na, Al, Ti, and Cl inside the aerogel scaffold material. The infiltrated NaAlH(4) was X-ray amorphous, whereas (27)Al magic-angle spinning (MAS) NMR spectroscopy confirmed the presence of nanoconfined NaAlH(4). Temperature-programmed desorption mass spectroscopy (TPD-MS) and Sieverts' measurements demonstrated significantly improved hydrogen desorption kinetics for this new nanoconfined NaAlH(4)-TiCl(3) material as compared to nanoconfined NaAlH(4) without the catalysts TiCl(3) and to bulk ball-milled samples of NaAlH(4)-TiCl(3). We find that the onset temperature for hydrogen release was close to room temperature (T(onset) = 33 °C), and the hydrogen release rate reached a maximum value at 125 °C, which demonstrates favorable synergetic effects between nanoconfinement and catalyst addition.

Abstract  Carbon aerogels are a unique class of high-surface-area materials derived by sol-gel chemistry. Their high mass-specific surface area and electrical conductivity, environmental compatibility and chemical inertness make them very promising materials for many energy related applications, specifically in view of recent developments in controlling their morphology. In this perspective we will review the synthesis of monolithic resorcinol-formaldehyde based carbon aerogels with hierarchical porosities for energy applications, including carbon nanotube and graphene composite carbon aerogels, as well as their functionalization by surface engineering. Applications that we will discuss include hydrogen and electrical energy storage, desalination and catalysis.

Abstract  Acrolein, four methacrylates, two guanidine compounds and resorcinol were tested for embryotoxicity on three day chicken embryos. The most potent chemical was acrolein, with the ED50 0.05 mumol per egg for the total effect, including deaths and malformations. The substances next in potency were N,N'-di-o-tolyl-guanidine and N,N-diphenylguanidine, with ED50 values 0.17 and 0.20 mumol per egg, respectively. Resorcinol and the methacrylates had ED50 values ranging from 2.4 to 22.0 mumol per egg. Acrolein, diphenylguanidine, tetrahydrofururylmethacrylate and trimethylolpropanetrimethacrylate caused the largest amounts of malformed embryos.

Abstract  We developed a method to analyze airborne lead concentrations in the field. It was a modification of the colorimetric method using the reaction between 4(2-pyridylazo)-resorcinol (PAR) and lead with cyanex302 in an acid medium to reduce interfering metals. The lead concentration was detected with a photometer made in Thailand. The developed method uses an impinger containing 1% nitric acid solution as an absorbing agent to collect airborne lead at a flow rate of less than or equal to one liter/minute. Cyanex302 solution in toluene was used to extract metals from the samples and 0.1M nitric acid was used to extract just lead. The lead solution was reacted in 0.5 ml of 0.03% PAR solution, with 1 ml ammonium chloride buffer; the absorption of this solution was measured by a photometer. The results show the limit of detection (LOD) was 0.01 mg/l. The limit of quantification (LOQ) was 0.03 mg/l. The percent recovery of the lead concentrations of 0.05 - 3.0 mg/l was 94.0 to 103.5%. The precision presented as %CV ranged from 0.65 to 10.27%. Lead concentration in a lead smelting factory detected by this method was not significantly different from that detected by the NIOSH method: 7,303 at a 95% confidence level.

Abstract  A novel fluorescent sensor 4((E)-(N-(rhodamine-6G)lactam-ethylenediamineimino)methyl)benzene-1,3-diol (1), which has a unique spirolactam ring formation, show a reversible, selective, and sensitive fluorescence enhancement response to Cu(II) at biological pH value for practical use. Also, the selectivity of this system for Cu(II) over other metal ions is remarkably high, and its sensitivity is below 2 ppb in methanol solutions. Furthermore, its high cell permeability grants the access to employ 1 as Cu(II) detector in living cells. (C) 2010 Elsevier B.V. All rights reserved.

Abstract  The title compound [systematic name: 5,11,17,23-tetramethyl-2,8,14,16-tetrakis(2-phenylethyl) pentacyclo[19.3.1.1(3,7).1(9,13).-1(15,19)] octacosa-1(25),3,5,7(28), 9,11,13 (27), 15,17,19(26), 21,23-dodecaene- 4,6,10,12,16,18,22,24-octol methanol pentasolvate 0.10-hydrate], C64H64O8 center dot 5CH(4)O center dot 0.103H(2)O, was synthesized as a new synthetic intermediate for resorcin[4] arene cavitand formation. The structure displays extensive O-H center dot center dot center dot O intra- and intermolecular hydrogen bonding.

Abstract  Trichosporon cutaneum R57 is known as effective biodegradant able to utilize and thus remove a number of toxic aromatic compounds from the environment. In the present study, the dynamics of the processes of degradation of monohydoxyl derivatives of phenol (resorcinol, catechol and hydroquinone) in concentrations up to 1.6 g/l were investigated and inhibitory constants (k(i)) of these compounds were determined 0.58, 0.55, and 0.6 g/l correspondingly. The biodegradation of significantly more toxic aromatic compounds 2,6- dinitrophenol (k(i) = 0. 13 g/l), alpha-methylstyrene (k(i) = 0.25 g/l) and acetophenone (k(i) = 0. 15 g/l) was also described. Based on summarized qualitative and quantitative data and the ""if-then"" rules developed, a fuzzy model was designed to describe the processes despite the degree of toxicity and concentration of the aromatic compounds. The output linguistic variables ""normal"", ""check"" and ""attention"" were defined, which determine further measures for improvement of process quality. The model suggested provides opportunity for early estimation of the biodegradation process quality. (C) 2007 Elsevier B.V. All rights reserved.

Abstract  Singularities of the rhodium trichloride reaction with calix[4]resorcinol functionalized with CH2N center dot (CH3)(2) groups in ethanol on the upper rim of the molecule, and also of calix[4]resorcinol with ethanol solution of rhodium trichloride saturated with nitrogen monoxide were studied. Neutral complex compounds separated in the solid form were characterized by IR spectroscopy, Raman spectroscopy, H-1 NMR, ESR, X-ray electron spectroscopy, electronic spectroscopy, and conductometry. Quantum-chemical calculations were performed on the basis of the density functional method in order to determine the geometric structure and energy characteristics of the complex compound and the zwitter-ion form of the ligand.

Abstract  New carbon aerogels have been prepared from urea-branched phenol-resorcinol-formaldehyde resin. Such material, called ""blue glue"" and used as cold-set adhesive for wood, has been modified in order to obtain highly porous organic gels. The latter were prepared at different pH (5, 7 and 9), dried with supercritical methanol, and carbonised at two different heating rates (2.5 and 5 degrees C min(-1)). FTIR analysis confirmed the expected chemical structure of the gel, and GC-MS analysis of the solvent condensed after supercritical drying suggested a slight chemical degradation of the gels during the drying process. However, low-density (0.15-0.31 g cm(-3)), monolithic, carbon gels could be successfully derived from these materials, having high BET surface areas (900-1300 m(2) g(-1)) and high mesopore fractions (60-80%). These ranges of values originate from the conditions tested for preparing the materials. Such carbon aerogels are two times cheaper than their traditional resorcinol- formaldehyde-based counterparts and present similar, if not more developed, porous structures. (C) 2012 Elsevier Inc. All rights reserved.

Abstract  The title reactions proceed in high yields without high dilution techniques as long as substituents allow hydrogen bonds between the phenolic units and do not lead to steric hindrance. Isomerization rates for three epimeric cyclophanes, including a hitherto undiscovered one, are obtained by least-squares fit with integrated rate equations. The buildup sequences of oligomers, polymers, and macrocycles are analyzed by numerical stepwise integration with 50 rate constants, based on the fit of time-concentration curves of seven identified structures that were followed by proton NMR. Macrocyclization is favored by the following: (a) fast degradation of oligomers, (b) fast ring closure of tetramers, as well as (c) fast chain growth to these in comparison to ring opening. Homogeneous reaction conditions, here with methanol as solvent, are essential not only for the quantitative analyses, but also for the solubility of polymers in view of their degradation and for the observation of new stereoisomers. Molecular mechanics calculations with the CHARMm field and model considerations identify the factors responsible for the unique preference for cyclization over polymerization. Both hydrogen bonds between the phenolic units and 1.5 interactions between phenolic groups and the methyl substituent-stemming from the acetaldehyde-strongly favor folded conformers with small distances around d = 3.3-4.6 angstrom between the terminal reacting centers in comparison to stretched conformations with d = 12.2-18.3 angstrom.

Abstract  Based on the inhibition by hydroquinone, catechol and resorcinol of chemiluminescence from luminol-potassium hexacyanoferrate(III) system, a high performance liquid chromatographic procedure with chemiluminescent detection was developed for simultaneous determination of hydroquinone, catechol and resorcinol. The separation was carried out on RP-C-18 column at 37 degrees C by using a step gradient elution made by the mobile phases of methanol(A) and 0. 05% H3PO4 (B), The gradient elution condition was 95% B, 5 min; 95%B-50%B, 1 min; 50% B, 6 min, This method has the merits of high senstivity and good selectivity. The detection limits for hydroquinone, catechol and resorcinol are 2. 0 x 10(-9), 3. 2 x 10(-9) and 6. 8 x 10(-7) g/mL, respectively, The relative standard deviation(n = 5) is 1. 9% for 2. 5 x 10(-7) g/mL hydroquinone, 1. 0% for 7. 5 x 10(-7) g/mL catechol, 4. 0% for 5. 0 x 10(-5) g/mL resorcinol, respectively. The recovery is in the range of 94%-104%.

Abstract  A series of zeolite composites with hierarchically porous structures and tunable acidities were prepared. The structural, crystalline, and textural properties of the as-synthesized materials, as well as the reference Y and beta zeolite samples, were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM)/transmission electron microscopy (TEM) analyses, Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption/desorption techniques. The acidic properties of the surface were determined by in situ FTIR of adsorbed pyridine. The hierarchy factor is an appropriate tool to classify hierarchically structured materials, and the hierarchical pores of the as-synthesized zeolite composite samples were investigated during the catalytic cracking of isopropylbenzene. The results show that the catalytic activity of isopropylbenzene cracking over the catalysts has a linear dependence with their hierarchy factor (HF). The tunable acidities were tested by methanol dehydration to dimethyl ether (DME), and the dehydration activity of methanol over the catalysts shows a linear decrease with the increased Lewis/Bronsted ratio, while the selectivity of DME shows a linear increase with the enhanced Lewis/Bronsted ratio. (C) 2011 Elsevier B.V. All rights reserved.