bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrical properties of porous oxides with adsorbed water
Authors: Korolev Feodor A. , Kytin Vladimir G. , Nosova Ludmila , Kozlov Sergei N. 
Published: March 2005

AbstractThe impedance of porous alumina (por‐Al2O3) and titanium oxide (por‐TiO2) with adsorbed water has been investigated in a wide frequency range and at temperatures near the water–ice phase transition. The equivalent circuit of the investigated structures has been determined. It has been shown that water adsorption in the pores of a solid‐state matrix has a great influence on its electrical properties. The characteristics of the electrical properties of experimental structures related to the water–ice phase transition have been revealed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photodielectric effect in lead molybdate monocrystals
Authors: Volnianskiy M. D. , Kudzin A. Yu. , Plyaka S. N. , Balasmeh Z. H. 
Published: March 2005

AbstractIllumination by light with photon energy near the band gap increases the dielectric permittivity of lead molybdate (PbMoO4) crystals. This photodielectric effect (PDE) is observed at low measured frequencies (less than 10 kHz). A plot of dielectric permittivity against temperature has a wide maximum in the 470–500 K interval. The PDE essentially increases after exposure to sunlight or ultraviolet light. The PDE may be explained by the increase of polarizability of complex lattice defects by photoexcited electrons. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Clinical toxicology study of an herbal medicinal extract of Paullinia cupana, Trichilia catigua, Ptychopetalum olacoides and Zingiber officinale (Catuama®) in healthy volunteers
Authors: Oliveira Celso H. , Moraes Maria Elizabete A. , Moraes Manoel O. , Bezerra Fernando A. F. , Abib Eduardo , Nucci Gilberto De 
Published: March 2005

AbstractIn Brazil, a herbal medicinal extract named Catuama® containing a mixture of Paullinia cupana (guarana; Sapindaceae), Trichilia catigua (catuaba; Meliaceae), Ptychopetalum olacoides (muirapuama; Olacaceae) and Zingiber officinale (ginger; Zingiberaceae) is used as a body stimulant, energetic, tonic and aphrodisiac. The present study investigated the chronic administration of 25 mL Catuama® twice a day during 28 days for any toxic effect on healthy human volunteers of both sexes. No severe adverse reactions or haematological and biochemical changes were reported. Copyright © 2005 John Wiley & Sons, Ltd.
Protective value of Aloe vera against some toxic effects of arsenic in rats
Authors: Gupta Richa , Flora Swaran J. S. 
Published: March 2005

AbstractConcomitant oral supplementation of Aloe vera, (1, 2 or 5% w[sol ]v in drinking water) during arsenic exposure (0.2 mg[sol ]kg, intraperitoneally, once daily for 3 weeks) was investigated in rats for its protective value. Animals exposed to arsenic (III) showed a significant inhibition of δ‐aminolevulinic acid dehydratase (ALAD) activity, a marginal decrease in glutathione (GSH) and an increase in zinc protoporphyrin (ZPP) level in blood. White blood corpuscles (WBC) level decreased while most of the other clinical blood parameters like red blood cells count, haemoglobin, MCV, MCH, MCHC ratio and platelet number, etc. remained unaltered on arsenic exposure. Hepatic reduced GSH, oxidized glutathione (GSSG) level remained unaltered, thiobarbituric acid reactive substance (TBARS) level increased significantly while the activity of alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and catalase decreased on arsenic exposure. Renal GSH contents decreased while superoxide dismutase (SOD) activity decreased significantly on arsenic exposure. Concomitant administration of Aloe vera had remarkable protective action on inhibited blood ALAD activity and restored blood GSH level while most of the other blood biochemical parameters remained unchanged on Aloe vera supplementation. Interestingly, most of hepatic biochemical variables indicative of oxidative stress showed protection; no effect of Aloe vera on blood and liver arsenic concentration was noted. Also, no effect of Aloe vera on most of the altered renal biochemical parameters were noticed. The results thus lead us to conclude that simultaneous supplementation of Aloe vera protects against arsenic induced oxidative stress but does not influence the arsenic concentration in these organs. Copyright © 2005 John Wiley & Sons, Ltd.
Evaluation of chemopreventive action and antimutagenic effect of the standardized Panax ginseng extract, EFLA400, in Swiss albino mice
Authors: Panwar Meenakshi , Kumar Madhu , Samarth Ravindra , Kumar Ashok 
Published: March 2005

AbstractIn the present investigation the chemopreventive action and antimutagenic effects of a standardized Panax Ginseng extract (EFLA400, processed Panax ginseng extract containing a high titre of ginsenoside Rg3 (>3.0% w[sol ]w) known as Phoenix ginseng) in Swiss albino mice have been evaluated. The oral administration of EFLA400 at 1, 3 and 10 mg[sol ]kg body weight at pre, peri and post‐initiational phases, showed significant reductions in the number, size and weight of the papillomas. A significant reduction in tumour incidence (71.41 ± 6.73%, 72.19 ± 4.54% and 70.46 ± 0.38% at 1, 3 and 10 mg[sol ]kg body weight, respectively) was observed in animals in the EFLA400 treated group compared with 100% tumour incidence in the control group. The cumulative number of papillomas during an observation period of 16 weeks was significantly reduced in the EFLA400 treated group (24 ± 0.94, 16 ± 1.41 and 11 ± 1.41 at 1, 3 and 10 mg[sol ]kg body weight, respectively). However, the average latent period was significantly increased from 10.81 ± 0.1 weeks in the control group to 12.39 ± 0.28 weeks in the treated group (10 mg[sol ]kg body weight). The average tumour weight was recorded as 128.55 ± 8.48, 116.00 ± 8.48 and 57.5 ± 3.29 mg in 1, 3 and 10 mg[sol ]kg body weight EFLA400 treated groups respectively. Chromosomal aberrations and micronuclei induction was also evaluated in bone marrow cells. These genotoxicity end‐points were compared with papilloma occurrence at the same dose levels of carcinogen and ginseng. In the EFLA400 treated groups significantly reduced frequencies of chromosomal aberrations and micronuclei induced by DMBA and croton oil were observed. However, the maximum decrease in the frequencies of chromosomal aberrations and micronuclei were recorded in the 10 mg[sol ]kg body weight EFLA400 treated group than that of the 1 and 3 mg[sol ]kg body weight EFLA400 treated animals. The results from the present study suggest the dose dependent effectiveness of EFLA400 in chemoprevention and antimutagenicity in Swiss albino mice. Copyright © 2005 John Wiley & Sons, Ltd.
Guggulu (Commiphora mukul) potentially ameliorates hypothyroidism in female mice
Authors: Panda Sunanda , Kar Anand 
Published: March 2005

AbstractThe efficacy of guggulu, the gum resin of Commiphora mukul in regulating hypothyroidism was evaluated in female mice. In addition to estimating serum levels of thyroxine and triiodothyronine, hepatic 5′ monodeiodinase, hepatic glucose‐6‐phospatase and lipid‐peroxidation (LPO), the activities of the anti‐oxidative enzymes, superoxide dismutase (SOD) and catalase (CAT), were investigated. While 6‐n‐propyl‐2‐thiouracil (PTU, 10.00 mg[sol ]kg[sol ]d for 30 days) induced hypothyroidism in mice, as evidenced by a decrease in thyroid hormone concentration and in hepatic 5′D‐I activity, simultaneous administration of guggulu (200 mg[sol ]kg[sol ]d for 30 days) reversed this effect, indicating its potential to stimulate thyroid function. Although in PTU treated animals a marginal increase in hepatic LPO was observed, when simultaneously treated with guggulu, it was decreased. A parallel increase in the activity of endogenous antioxidants, SOD and CAT, in the latter group indicated the safe and antiperoxidative nature of the drug. These findings suggest the possible use of guggulu in the amelioration of hypothyroidism. Copyright © 2005 John Wiley & Sons, Ltd.
Evaluation of antioxidant potential of the cultured mycobiont of a lichen Usnea ghattensis
Authors: Behera B. C. , Verma Neeraj , Sonone Anjali , Makhija Urmila 
Published: March 2005

AbstractThe biologically active compounds, antioxidant activities and free radical scavenging effects of dry matter of cultural medium (DMCM), filtrate (DMF) and different solvent extracts of mycobiont from lichen species Usnea ghattensis in submerged culture (UGSC) were investigated. DMF showed the strongest inhibition of lipid peroxidation as a function of its concentration, and was comparable to the antioxidant activity of BHA at the same concentration of 0.2 mg[sol ]mL. The hexane extract of mycobiont had the weakest antioxidant ability, whereas other mycobiont extracts exhibited a modest to strong inhibition of lipid peroxidation and in free radical scavenging activity. The antioxidant activities of mycobiont extracts were correlated with the presence of total polyphenol content in the extract. It was found that antioxidant components in methanol, acetone, ethanol and hexane extracts must be derived from the secondary metabolites produced by the lichen mycobiont. The results presented herein indicate that extracts of cultured mycobiont of lichen Usnea ghattensis could possibly act as chemopreventing agent with respect to free radical‐related diseases. Copyright © 2005 John Wiley & Sons, Ltd.
In vitro antimycotic activity of some plant extracts towards yeast and yeast‐like strains
Authors: Turchetti B. , Pinelli P. , Buzzini P. , Romani A. , Heimler D. , Franconi F. , Martini A. 
Published: March 2005

AbstractAs part of screening aimed at the selection of novel antimycotic compounds of vegetable origin, leaf extracts of Camellia sinensis L., Cupressus sempervirens L. and Pistacia lentiscus L. and the seed extract of Glycine soja Sieb. et Zucc. were tested against yeast and yeast‐like species implicated in human mycoses. Of the extracts only those of C. sinensis (obtained from a commercial preparation of green tea) exhibited broad activity towards Candida glabrata, Clavispora lusitatiae, Cryptococcus laurentii, Filobasidiella neoformans, Issatchenkia orientalis, Saccharomyces cerevisiae and Prototheca wickerhamii strains. MICs ranging from 300 to 4800 µg extract[sol ]mL (corresponding to 130–2010 µg[sol ]mL total polyphenols) were observed. Concentrations of the C. sinensis extract over 25 000 µg[sol ]mL caused a rapid decrease of viable cells of Fil. neoformans and its activity was dose‐dependent. Tests carried out using the pure polyphenols present in C. sinensis extract composition, showed that only epicatechin‐3‐O‐gallate (ECG) and epigallocatechin‐3‐O‐gallate (EGCG) possess antimycotic activity. Copyright © 2005 John Wiley & Sons, Ltd.
Fucoidan inhibits the development of proteinuria in active Heymann nephritis
Authors: Zhang Quanbin , Li Ning , Zhao Tingting , Qi Huimin , Xu Zuhong , Li Zhien 
Published: March 2005

AbstractFucoidan, the sulphated polysaccharide extracted from brown seaweed, has various biological activities. The effect of fucoidan on the formation of proteinuria and renal functions in active Heymann nephritis was investigated in this study. Active Heymann nephritis was induced by administering brush border protein of rat proximal uriniferous tubules (FX1A). Fucoidan was administered by oral intubation to Heymann nephritis rats at three doses (50, 100 and 200 mg[sol ]kg) once daily for 4 weeks. The elevated urinary protein excretion and plasma creatinine due to the induction of Heymann nephritis were significantly reduced by fucoidan at doses of 100 and 200 mg[sol ]kg. The results indicated that fucoidan has a renoprotective effect on active Heymann nephritis and is a promising therapeutic agent for nephritis. Copyright © 2005 John Wiley & Sons, Ltd.
Vibrational spectroscopies: Description of general analytical TDHF schemes for their simulation
Authors: Quinet Olivier 
Published: March 2005

AbstractThe Raman and hyper‐Raman intensities have been determined by means of analytical procedures generalizing the CPHF and TDHF methodologies. The frequency dispersion effects for these quantities are important. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Effect of the environment on vibrational infrared and circular dichroism spectra of (s)‐proline
Authors: Cappelli Chiara , Monti Susanna , Rizzo Antonio 
Published: March 2005

AbstractThe infrared and vibrational circular dichroism of proline in water solution are investigated ab initio employing density functional theory and the integral equation formalism (IEF) version of the polarizable continuum model (PCM). Three solvent models are exploited to evaluate solvent effects in the 1000–2000 cm−1 frequency range: a pure implicit continuum approach, a pure explicit model (limited to three solvent molecules), and a combined specific/continuum approach. Effects on spectra arising from different protonation states (neutral, zwitterionic, cationic, and anionic) are analyzed. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Electronic structure analysis of two crystalline phases of Fe3O2BO3
Authors: Matos Maria , Souza Anivaldo X. 
Published: March 2005

AbstractA theoretical electronic structure analysis was performed on two crystalline phases of the homometallic Fe ludwigite, appearing in a structural transition recently found experimentally to occur at 283 K. The extended Hückel method was used to study different subunits of the compound, which is known to present low dimensionality in magnetic properties. Total energy calculations show an electronic stability of the low‐temperature (distorted) phase, in agreement with experiment. A longitudinal Fe2+‐Fe2+ interaction (perpendicular to the flat planes of the orthorhombic unit cell) appears to be mainly responsible for the stabilization. A contribution of another Fe2+ ion was seen to be related to an enhancement of Fe‐O interaction. A remarkable result is the reversal of these results when high spin FeO6 monomers are considered. In that case, it is the Fe‐O interaction in an Fe3+‐Fe2+‐Fe3+ triad which seems to drive the stabilization of the distorted phase. It is suggested that spin effects might be important to the structural transition in Fe3O2BO3. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Thermochemistry of molecules in the B/F/H/N system
Authors: Barreto Patrícia R. P. , Vilela Alessandra F. A. , Gargano Ricardo 
Published: March 2005

AbstractA self‐consistent set of thermochemical data for 88 chemical species in the B/F/H/N system is obtained from ab initio electronic structure calculation. Calculations were performed for both stable and radical species. The quantities calculated include the atomization energy (∑ D0), heat of formation (ΔHf) at 0 K and 298.15 K, and bond dissociation energies (BDE) for all species. Good agreement is found between the calculation data and experimental or theoretical reference data for the quantities analyzed in this work for several species containing B, F, H, and N atoms. We also present a compilation of experimental and theoretical atomization energies (16 experimental × 26 theoretical data), heat of formation at 0 K (25 experimental × 26 theoretical data), heat of formation at 298 K (29 experimental × 36 theoretical data), and bond dissociation energy for several species. Polynomial fits of the predicted thermodynamic data (heat capacity, entropy, and enthalpy) over the 200–6000 K temperature range are also included, for the 88 species. The species analyzed in this study are important in a kinetic mechanism for growth boron nitride films in a Chemical Vapour Deposition (CVD) reactor. It is generally difficult to optimize conditions in a CVD reactor because films properties depend on complex interactions involving heat and mass transport, chemical kinetics, and thermochemistry. Developing a reliable set of thermodynamic data is a necessary first step for system optimization, since it provides important constraints on the possible reaction mechanism. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Electrospray ionization mass spectrometry for identification and structural characterization of pregnane glycosides
Authors: Dal Piaz Fabrizio , De Leo Marinella , Braca Alessandra , De Simone Francesco , Morelli Ivano , De Tommasi Nunziatina 
Published: March 2005

AbstractPregnane glycosides are a class of naturally occurring substances characterized by some interesting biological activities and widely distributed in the plant kingdom and in some marine organisms. Their toxicity and use in herbal drugs and folk medicines has generated great interest in the chemical characterization of these molecules. In the study reported here the potential of electrospray ionization mass spectrometry (ESI‐MS) in the identification and structural characterization of pregnane glycosides was examined. ESI‐MS/MS and ESI‐MSn analyses were performed on 27 different compounds employing two mass spectrometers equipped with a triple‐quadrupole or an ion‐trap analyzer. The data illustrate the ability of the ESI techniques in the identification of pregnane glycosides, including the nature of the pregnane core, the kind of ester substituents, the types of sugar residues (hexose, deoxyhexose, dideoxyhexose, O‐methyldeoxyhexose and O‐methyldideoxyhexose), and the primary structure of the saccharide chain. From these data, a generalized fragmentation pathway was proposed by comparing the spectra acquired for all the compounds. Interestingly, similar results were obtained from the two instruments, thus demonstrating that detailed analyses of product ion spectra obtained using a triple‐quadrupole mass spectrometer led to structural information comparable to those obtainable in MSn experiments using an ion trap. Different and complementary information was deduced by fragmenting the [M+H]+ or the [M+Na]+ ions, or the protonated aglycone [Agl+H]+ generated by in‐source fragmentation. The present evidence clearly suggests that, in order to obtain a complete characterization of pregnane glycosides by MS, all three of these species should be accurately analyzed. Copyright © 2005 John Wiley & Sons, Ltd.
Identification of degradation products formed during performic oxidation of peptides and proteins by high‐performance liquid chromatography with matrix‐assisted laser desorption/ionization and tandem mass spectrometry
Authors: Dai Jingquan , Zhang Yangjun , Wang Jinglan , Li Xiaohai , Lu Zhuang , Cai Yun , Qian Xiaohong 
Published: March 2005

AbstractOxidation of proteins with performic acid is extensively used to cleave disulfide bonds. Due to its efficiency and many other advantages it deserves more attention especially in proteomics as a method for sample treatment. However, some unwanted degradations can occur during performic oxidation. In this work the degradation products during performic oxidation of two peptides and bovine serum albumin as model substrates were explored by coupling high‐performance liquid chromatography (HPLC) to matrix‐assisted laser desorption/ionization tandem mass spectrometry (MALDI‐TOF/TOFMS). In addition to well‐known modifications such as oxidation of tryptophan and oxidation and chlorination of tyrosine, novel degradation products including nonspecific cleavage after asparagine or tryptophan, formylation of lysine, and β‐elimination of cysteine, were observed. Although almost all of these modification/degradation products except oxidation products of tryptophan were formed at sub‐stoichiometric levels, they can cause confusion as a result of the sensitivity of mass spectrometry in analysis of the oxidized samples, especially in proteomics research. The results presented here will facilitate the interpretation of analytical data for performate‐oxidized samples, and help to select appropriate methods for each unique sample. Copyright © 2005 John Wiley & Sons, Ltd.
Determination of urinary S‐phenylmercapturic acid, a specific metabolite of benzene, by liquid chromatography/single quadrupole mass spectrometry
Authors: Maestri Luciano , Negri Sara , Ferrari Massimo , Ghittori Sergio , Imbriani Marcello 
Published: March 2005

AbstractA high‐performance liquid chromatography/single quadrupole mass spectrometry (LC/MS) method is described for the determination of urinary S‐phenylmercapturic acid (S‐PMA), a specific metabolite of benzene. Urine samples were spiked with [13C6]S‐PMA (used as the internal standard) and acidified; then they were purified by solid‐phase extraction (SPE) on C18 cartridges. Analyses were conducted on a reversed‐phase column by gradient runs with 1% aqueous acetic acid/methanol mixtures at different proportions as the mobile phase. The detector was used in electrospray negative ion mode (ESI–), the ions m/z 238 for S‐PMA and 244 for [13C6]S‐PMA being recorded simultaneously. The detection limit (for a signal‐to‐noise ratio = 3) was 0.2 μg/L, thus allowing for the measurement of background excretion of S‐PMA in the general population. The use of the internal standard allowed us to obtain good precision (CV% values <3%) and a linear calibration curve within the range of interest for monitoring occupational exposure to benzene (up to 500 μg/L). The method was applied to assay the metabolite concentration in a group of 299 workers (68 smokers and 231 non‐smokers) occupationally exposed to relatively low levels of benzene (environmental concentration = 0.4–220 μg/m3, mean 11.4 μg/m3) and 236 non‐exposed subjects (134 smokers and 102 non‐smokers). The results clearly showed that smoking must be taken into account for the correct interpretation of the results of S‐PMA measurements for the assessment of work‐related benzene exposure. When only non‐smokers were selected, the mean excretion of S‐PMA was significantly higher in workers exposed to benzene (1.2 ± 0.9 μg/g creatinine) than in the control group (0.7 ± 0.6 μg/g creatinine) (p < 0.001), thus confirming the role of S‐PMA as a biomarker of benzene on a group basis, even for relatively low exposure degrees. Copyright © 2005 John Wiley & Sons, Ltd.
Systemic action research for postgraduate education in agriculture and rural development
Authors: Packham Roger , Sriskandarajah Nadarajah 
Published: March 2005

AbstractThis paper discusses the theory of Systemic Action Research and its use in postgraduate research education, in the context of agriculture and rural development. The paper discusses what systems thinking is and introduces the concepts of Systemic Development. This is followed by an argument for a paradigm shift in how agriculture is viewed, and an associated shift in education from teaching to learning. The core ideas of action research are then described and illustrated by two case studies drawn from PhD research projects supervised by the authors. Introducing the ideas of technical, practical, and emancipatory action research, the paper further expands upon these concepts of action research, illuminated by two additional PhD projects. Overall the paper demonstrates the usefulness of Systemic Action Research as the basis for postgraduate research to deal with real contextual issues in their true complexity, and in a holistic way. In this process, genuine participation and the encouragement of diversity are seen as rights rather than as means to greater research efficiency, thus giving power to people to act through the generation of knowledge by critical reflection. Copyright © 2005 John Wiley & Sons, Ltd.