bluuebunny/crossref_metadata_2025 huggingface dataset:
Starter sequence for steady‐state free precession imaging
Authors: Foxall D. L.
Published: March 2005

The dynamic equilibrium exploited by balanced steady‐state free precession imaging develops slowly because its formation is dependent on both spin–spin and spin–lattice relaxation times. Attempting to image before steady state is established results in artifacts due to transient signal oscillations. Using a starter sequence to precondition the spin system can significantly reduce the delay before imaging. An improved design for a steady‐state starter sequence is presented. The new sequence has the advantage of uniformly exciting the steady‐state response for all resonance offsets and can be phase cycled to suppress banding artifacts. Magn Reson Med 53:919–929, 2005. © 2005 Wiley‐Liss, Inc.
Input parameter sensitivity analysis and comparison of quantification models for continuous arterial spin labeling
Authors: Steger Theodore R. , White R. Allen , Jackson Edward F.
Published: March 2005

The regional cerebral blood flow (rCBF) values determined using continuous arterial spin labeling (CASL) are subject to several sources of variability, including natural physiologic variations, sensitivity to the input parameters, and the use of different quantification models. To date, a thorough analysis of the impact of input parameters and the choice of quantification model has not been performed. These sources of variability were investigated through computer simulations using bootstrap techniques on actual CASL data. Coefficients of variation for representative single voxels were 6.7% for gray matter and 29% for white matter, and for eight‐voxel regions of interest they were 4.5% for gray matter and 23% for white matter. Comparison of nine CASL quantification models showed differences in gray matter rCBF values of up to 42%. An analysis of the sensitivity of the rCBF to input parameters for each of the nine quantification models demonstrated that accurate quantification of the inversion efficiency, tissue and arterial blood longitudinal relaxation times, and transit times were critical in calculating precise rCBF values. The large potential variations in rCBF and the effect of the choice of quantification model suggest that interpreting absolute rCBF values in CASL studies can be challenging and requires great care. Magn Reson Med 53:895–903, 2005. © 2005 Wiley‐Liss, Inc.
Jochimsen TH, et al. Quantifying the Intra‐ and Extravascular Contributions to Spin‐Echo fMRI at 3 T, Magn Reson Med 2004;52:724‐732.
Authors: Jochimsen Thies H.
Published: March 2005

The original article to which this Erratum refers was published in Magnetic Resonance in Medicine (2004) 52(4) 724–732.
Stabilized Crouzeix‐Raviart element for the Darcy‐Stokes problem
Authors: Burman Erik , Hansbo Peter
Published: March 2005

We stabilize the nonconforming Crouzeix‐Raviart element for the Darcy‐Stokes problem with terms motivated by a discontinuous Galerkin approach. Convergence of the method is shown, also in the limit of vanishing viscosity. Finally, some numerical examples verifying the theoretical predictions are presented. © 2005 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 21, 2005.
Risk factors for and prevention of tobacco use
Authors: Sussman Steve
Published: March 2005

This study describes the risk factors for and prevention of tobacco use among young people. Risk factors show differential importance along the course of tobacco use development. The contents of an effective prevention effort vary as a function of the age of target group. However, the mediation of the effects of effective programs is not well known. Various modalities of implementation of prevention programming may be important, though a majority of program evaluation has occurred in the school context. The majority of well‐evaluated tobacco use prevention programs that employ a comprehensive social influences model show effects over an average of 6 years post‐programming. Pediatr Blood Cancer 2005;44:614–619. © 2005 Wiley‐Liss, Inc.
High cumulative rate of secondary leukemia after continuous etoposide treatment for solid tumors in children and young adults
Authors: Le Deley Marie‐Cécile , Vassal Gilles , Taïbi Ahmed , Shamsaldin Akthar , Leblanc Thierry , Hartmann Olivier
Published: March 2005

Background

In a national pediatric case‐control study, we observed a very high relative risk of leukemia in patients who had received continuous etoposide (CE) over 6 months or more, but we could not estimate the absolute risk. The purpose of the present study was to estimate this absolute risk after CE.

Procedures

We report a study of 18 patients with refractory or recurrent tumors who received CE over 6 months or more between 1995 and 1997. It was administered either 3 days a week for 3/4 weeks (“3 × 3”, 14 patients) or 7 days a week for 3/4 weeks (“7 × 3”, four patients).

Results

Five patients developed secondary leukemia 10–25 months after the initiation of CE. All the others died of their first tumor. The cumulative incidence of leukemia at 30 months was 28% (95% CI, 10%–53%). A chromosome 11q23 rearrangement was found in 3/5 cases. All four patients who received the “7 × 3” CE schedule developed leukemia compared to 1/14 treated with the “3 × 3” CE schedule (P = 0.002).

Conclusions

Given its efficacy, CE may still have a place as a palliative treatment. However, the risk of leukemia must be borne in mind when considering its use in patients with a better prognosis. Pediatr Blood Cancer 2005; 45:25–31. © 2005 Wiley‐Liss, Inc.
Pilomyxoid astrocytoma in a patient with neurofibromatosis
Authors: Khanani Muhammad Faisal , Hawkins Cynthia , Shroff Manohar , Dirks Peter , Capra Michael , Burger P.C. , Bouffet Eric
Published: March 2005

Pilomyxoid astrocytoma (PMA), a recently described variant of low‐grade astrocytoma is associated with a high rate of recurrence and a propensity for CSF seeding. While cases of PMA have been reported in infants and young children, there has been no report of PMA in patients with neurofibromatosis. The first reportable case of PMA occurring in a child with neurofibromatosis type 1 (NF1) is described. Following presentation with obstructive hydrocephalus, the patient underwent a partial resection of a third ventricular tumor. Histology confirmed the typical features of PMA. The patient demonstrated a partial response to chemotherapy. The authors review the literature on PMA and discuss the specific issues associated with this diagnosis in the context of a child with neurofibromatosis. © 2005 Wiley‐Liss, Inc.
Less toxic acetylacetonates as initiators of trimethylene carbonate and 2,2‐dimethyltrimethylene carbonate ring opening polymerization
Authors: Dobrzynski Piotr , Pastusiak Malgorzata , Bero Maciej
Published: March 2005

This article presents the results of TMC and DMC polymerization with the use of acetylacetonates of low‐toxic metals: iron, zinc, and zirconium. Zinc (II) acetylacetonate proves to be a very good initiator of homopolymerization. The reaction carried out with the use of this initiator at 110 °C is very rapid and of high yield. Using both zinc and iron (III) acetylacetonates, as well as the zirconium (IV) one, in high temperatures it is possible to obtain PTMC possessing high molecular mass, thus ensuring optimization of the relation between the duration of the polymerization and its yield. A strong influence of thermal degradation on the course of the reaction has been observed, particularly at 160 °C, with the use of Fe(acac)3 as the initiator. DMC polymerization proceeds much more slowly when initiated by iron and zinc acetylacetonates. A high conversion of the monomer is obtained in this case as well. The relation between the molecular mass of the obtained PDMC and the conversion of the monomer is directly proportional; however, those masses, determined on the basis of polystyrene standards, are much lower than those estimated theoretically. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1913–1922, 2005
Kinetic study of the radical polymerization behavior of N‐(1‐phenylethylaminocarbonyl)methacrylamide
Authors: Seno Makiko , Yamada Takahiro , Wang Hongwei , Hirano Tomohiro , Sato Tsuneyuki
Published: March 2005

Polymerization of N‐(1‐phenylethylaminocarbonyl)methacrylamide (PEACMA) with dimethyl 2,2′‐azobisisobutyrate (MAIB) was kinetically studied in dimethyl sulfoxide (DMSO). The overall activation energy of the polymerization was estimated to be 84 kJ/mol. The initial polymerization rate (Rp) is given by Rp = k[MAIB]0.6[PEACMA]0.9 at 60 °C, being similar to that of the conventional radical polymerization. The polymerization system involved electron spin resonance (ESR) spectroscopically observable propagating poly(PEACMA) radical under the actual polymerization conditions. ESR‐determined rate constants of propagation and termination were 140 L/mol s and 3.4 × 104 L/mol s at 60 °C, respectively. The addition of LiCl accelerated the polymerization in N,N‐dimethylformamide but did not in DMSO. The copolymerization of PEACMA(M1) and styrene(M2) with MAIB in DMSO at 60 °C gave the following copolymerization parameters; r1 = 0.20, r2 = 0.51, Q1 = 0.59, and e1 = +0.70. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2013–2020, 2005
Influence of the catalyst on monomer insertion in the syndiospecific copolymerization of styrene and para‐methylstyrene
Authors: Schellenberg Jürgen
Published: March 2005

The effect of the kind of transition‐metal catalyst on the extent of comonomer insertion in the syndiospecific complex‐coordinative copolymerization of styrene and para‐methylstyrene has been investigated. The results for the influence of the polymerization conditions have shown that there is no real difference between solution copolymerization in toluene and solvent‐free styrene copolymerization in bulk, with respect to the reactivity ratio for para‐methylstyrene (r2), under comparable conditions in the presence of methylaluminoxane and triisobutylaluminum and at low polymerization conversions. All the investigated catalysts lead to a preferred incorporation of para‐methylstyrene into the polymer chain in comparison with styrene and over the whole range of monomer compositions. The increasing capability of the different catalysts to provide copolymers with enhanced para‐methylstyrene concentrations can be summarized by the increasing r2 values for the copolymerization in bulk as follows: η5‐pentamethylcyclopentadienyl titanium trichloride < η5‐octahydrofluorenyl titanium trimethoxide < η5‐octahydrofluorenyl titanium tristrifluoroacetate < η5‐cyclopentadienyl titanium(N,N‐dicyclohexylamido)dichloride < η5‐cyclopentadienyl titanium trichloride. For a correlation between the catalyst structure and the comonomer insertion, the catalysts can be described by electronic effects (electrostatic charge of the transition‐metal atom) and steric effects (minimum structural cone angle). The results show that the steric properties of the transition‐metal complexes have the most important effect on the insertion of para‐methylstyrene into the copolymer. If the minimum structural cone angle of the ligand of the transition‐metal catalyst decreases, the incorporation of the comonomer para‐methylstyrene increases significantly. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2061–2067, 2005
Role of vacuum ultraviolet irradiation in plasma‐induced graft polymerization in the pore‐filling polymerization of porous materials
Authors: Kai Teruhiko , Ueno Wataru , Yamaguchi Takeo , Nakao Shin‐Ichi
Published: March 2005

The role of vacuum ultraviolet (VUV) rays contained in the plasma during plasma‐induced graft polymerization in the pores of a porous high‐density polyethylene (HDPE) substrate was investigated through the separation of the VUV rays from the plasma with LiF, CaF2, and quartz filters. Two characteristic phenomena, the effect of the solvent on the grafting rate and the graft polymerization in the pores of the porous substrate, were observed in the VUV‐induced graft polymerization process. These results provided clear evidence that VUV rays in the plasma played an important role in the formation of grafted layers in the pores of the HDPE substrate. The relationship between the penetration depth of the VUV rays and the distribution of the grafted layer inside the substrate was examined. The calculated penetration depth of the VUV rays (and hence the distribution of radicals) and the distribution of the grafted layer were not consistent. However, this inconsistency could be explained by the fact that the effective density of the radicals that could react with the monomer to grow the grafting polymer was very low because of the steric hindrance of the grafted chains. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2068–2074, 2005
Cover Picture: Plasma Process. Polym. 3/2005
Authors: Marotta Ester , Scorrano Gianfranco , Paradisi Cristina
Published: March 2005

Cover: The Figure on the cover shows the schematics of APCI‐MS and APCI‐TQ mass spectrometers which are used for the diagnostics of ions formed from chlorinated volatile organic compounds by corona discharges. In addition positive APCI mass spectra of CCl4 in synthetic air recorded at (a) 30 °C and ΔV = 1 V, (b) 30 °C and ΔV = 150 V and (c) 300 °C and ΔV = 150 V are presented. Further details can be found in the Full Paper by E. Marotta, G. Scorrano, and C. Paradisi* on page 209.
Interferon‐γ induces neuroendocrine‐like differentiation of human prostate basal‐epithelial cells
Authors: Untergasser Gerold , Plas Eugen , Pfister Gerald , Heinrich Elmar , Berger Peter
Published: March 2005

BACKGROUND

Prostatic neuroendocrine (NE) cells are intraglandular hybrid epithelial‐neural‐endocrine cells that express and secrete numerous hormones and neuropeptides, which presumably regulate growth, differentiation, and secretory activity of the prostatic epithelium. This specialized cell type appears to differentiate from a common basal/precursor/stem cell that also gives rise to the secretory epithelium. In order to elucidate mechanisms of NE‐differentiation the effects of type 1 (α, β) and type 2 (γ) interferons (IFNs) on human prostate basal cells (PrECs) were evaluated.

METHODS AND RESULTS

Application of α/β IFN increased the expression of the cell‐cycle inhibitor p21CIP1 and inhibited DNA synthesis, while only IFN‐γ led to increased apoptosis, cell‐cycle inhibitor p27KIP1 upregulation, and differentiation of PrECs into NE‐like cells. In vitro differentiated NE‐like cells expressed the glycolytic enzyme neuron‐specific enolase (NSE) and chromogranin A (CgA), known markers of NE‐cells in vivo in the prostate. These NE‐like cells also changed cytokeratin (CK) expression patterns by upregulating CK 8/18, predominantly found in terminally‐differentiated secretory luminal/NE epithelial cells.

CONCLUSIONS

IFN‐γ produced locally in the prostate by basal cells and, under proinflammatory conditions, by infiltrating lymphocytes could support NE cell differentiation and play a role in NE differentiation processes of tumor cells in hormone‐refractory prostate cancer. © 2005 Wiley‐Liss, Inc.
Characterization of AlGaN layer with high Al content grown by mixed‐source HVPE
Authors: Ahn H. S. , Kim K. H. , Yang M. , Yi J. Y. , Lee H. J. , Chang J. H. , Kim H. S. , Kim S. W. , Lee S. C. , Honda Y , Yamaguchi M. , Sawaki N.
Published: March 2005

Using mixed‐source hydride vapor‐phase epitaxy (HVPE), an AlGaN layer with high Al content on GaN/Al2O3 substrate is obtained. The AlGaN layer grown by mixed‐source HVPE is characterized by X‐ray diffraction (XRD) measurements and cathodoluminescence (CL) spectra. In the mixed‐source HVPE technique, the AlGaN material is compounded from the chemical reaction between NH3 and an aluminum–gallium chloride formed using HCl that is flowed over metallic Ga mixed with Al. The XRD measurements indicate that single‐crystal hexagonal AlGaN with high Al content had been grown. The CL spectra at 4 K show that the distribution of the Al on the AlGaN surface for very high Al content (x = 0.8 in AlxGa1–xN) is not uniform. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical properties of porous oxides with adsorbed water
Authors: Korolev Feodor A. , Kytin Vladimir G. , Nosova Ludmila , Kozlov Sergei N.
Published: March 2005

The 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

Illumination 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

In 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

Concomitant 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

In 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

The 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

The 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

As 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

Fucoidan, 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

The 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

The 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

A 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

A 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

Pregnane 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

Oxidation 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

A 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

This 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.
Preparation and Physicochemical Properties of Dialdehyde Tapioca Starch
Authors: Wongsagon Rungtiwa , Shobsngob Sujin , Varavinit Saiyavit
Published: March 2005

Tapioca starch was oxidized by periodic acid (sodium metaperiodate plus hydrochloric acid) to form dialdehyde tapioca starch (DAS). The influence of periodate concentration (NaIO4, 0.05 N, 0.1 N, 0.2 N and 0.3 N) on the physicochemical properties of DAS such as aldehyde and carboxyl contents, relative crystallinity, thermal properties, pasting properties, swelling power, solubility and molecular weight distribution was investigated. The results indicated that aldehyde and carboxyl contents of DAS increased linearly with the increasing of periodate concentration. X‐ray diffraction patterns of DAS remained unchanged after periodate oxidation whereas the relative crystallinity decreased as periodate concentration increased. Furthermore, the gelatinization temperatures (To and Tp) of DAS were also increased, whereas the gelatinization enthalpy decreased. As determined in the Rapid Visco Analyser, the periodate oxidation increased the pasting temperature and peak viscosity as well as breakdown of the tapioca starch. The swelling power of DAS was higher than that of unmodified tapioca starch at 60°C and 70°C, but was lower at 80°C and 90°C. However, the solubility was higher than that of native tapioca starch at all incubation temperatures. Both amylose and amylopectin fractions were degraded during the oxidation reaction as measured by HPSEC. The thermal stability of DAS at boiling temperature was also investigated and depolymerization of the DAS could not be detected at any heating time as demonstrated for the thermal stability of the DAS.
Effects of Extraction Methods on Yam (Dioscorea alata) Starch Characteristics
Authors: Daiuto Érica , Cereda Marney , Sarmento Silene , Vilpoux Olivier
Published: March 2005

Starch extraction from roots and tubers uses grating with water and sieves to separate the starch slurry from residual mass. The starch is recovered by decantation or centrifugation. The yam starch extraction is difficult due to high viscosity of the slurry caused by non‐starch polysaccharides (NSP). The establishment of an efficient extraction process may turn yam into a competitive raw material. In this paper Dioscorea alata starch extracted by four methods was characterized in order to establish the impact of treatments. When the tubers were digested with an aqueous oxalic acid/ammonium oxalate (OA/AO) 1/1 solution, it was easier to separate the starch slurry from residual mass, because viscosity was reduced. For all the others methods tested, the viscosity remained almost the same. The nitrogen present in yam tubers was removed during the different extractions to a different extent. The largest nitrogen reduction was observed with OA/AO followed by the control (water). The spectrum of starch granules sizes obtained also varied according to the treatment. Results proved that NSP carries small starch granules over to the waste water. The smaller starch granules diameter varied from 1.9 µm (OA/AO extraction) to 13.5 µm (water and pectinase extractions). The larger diameter varied from 41.0 µm (NaOH treatment) to 67.7 µm (OA/AO). All starches extracted showed a RVA behavior in agreement with literature for yam starch, but with small differences due to the influence of methods. OA/AO extraction showed the best recovery (18 g of starch/100 g tuber yam) and granular variation but it interfered with the rheological behavior of starch.
Isolation, Physicochemical Characterization and Application of Yam (Dioscorea spp.) Starch as Thickening and Gelling Agent
Authors: Brunnschweiler Judith , Luethi Denise , Handschin Stephan , Farah Zakaria , Escher Felix , Conde‐Petit Béatrice
Published: March 2005

Yam starch of the species Dioscorea alata and D. cayenensis‐rotundata was isolated, characterized by differential scanning calorimetry (DSC), X‐ray diffraction, iodine titration, hot‐stage microscopy and rheology, and compared to potato (Solanum tuberosum) and tapioca (Manihot esculenta) starch. The amylose content of yam starch was around 24% and tended to decrease during postharvest storage. Wide‐angle X‐ray diffraction showed a mixed A‐ and B‐type crystalline packing. Differences between yam starches from different species and varieties were revealed by DSC. However, the largest differences between the different yam starches were found in terms of their rheological behavior. Yam starch shows an intermediate viscosity increase upon initial heating, but a stable viscosity during further thermal treatment in the Viscograph. Hot‐stage microscopy showed a good preservation of the granular yam structure during heating, which is thought to be responsible for a rather high viscosity at low stress paired with a strong shear‐thinning effect. The mechanical properties of yam starch gels suggest that the preservation of the granular integrity upon swelling limits amylose leaching, but that the aging behavior is primarily determined by the short‐term changes of the amylose fraction. Yam starch has potential as thickening and gelling agent in food.
Amylose Determination of Native High‐Amylose Corn Starches by Differential Scanning Calorimetry
Authors: Polaske Nathan W. , Wood Amanda L. , Campbell Mark R. , Nagan Maria C. , Pollak Linda M.
Published: March 2005

Differential scanning calorimetry (DSC) was investigated as an alternative method to more conventional iodine‐binding methods for determining starch amylose in a maize breeding program, because it requires fewer steps. In addition, many current DSC instruments are now equipped with sampling robots for performing automated analysis. The iodine‐binding method and a recently described DSC method for amylose determination were compared using five commercial starch samples. In addition, two sets (Set 1 and Set 2) of germplasm samples obtained from a high‐amylose breeding program were examined using each method. Correlation coefficients (r2) between the two methods for the commercial starch samples, Set 1 and Set 2 were found to be 0.99, 0.89 and 0.82, respectively, suggesting a good correlation but with greater discrepancy between them with increasingly higher amylose values. The DSC method appeared to have an improved repeatability, because its associated CV value was lower (4.1%) compared to the iodine‐binding method (5.8%). It was concluded that the DSC method should be effective in discriminating high‐amylose genotypes in a breeding program specifically designed to identify maize starches with amylose values at or above 70%.
The Mast on the House
Authors: Landberg Lars
Published: March 2005

An often encountered problem when preparing the basic input data for a wind atlas study is the correction for the influence of the house or hut on which the mast—whose data form the basis of this wind atlas—is placed. The article will describe an experiment where this problem has been addressed. The knowledge gained will be used to give guidelines as to the use of the WAsP program to correct the observations. Should the house/hut simply be treated as an extension of the mast, should the house/hut be treated as a hill with speed‐up effects, or should the house/hill be ignored completely? The paper will show that the house/hut should indeed be treated as a hill with speed‐up effects. Placing meteorological masts on houses or huts is common practice in quite a few countries in the world. The problem is therefore one which most people involved in detailed wind resource assessment will face sooner or later. The article will show that the effect of the house/hut is such that it cannot be ignored. Copyright © 2001 John Wiley & Sons, Ltd.
More than just being there: Balancing the participation equation
Authors: Weiss Heather B. , Little Priscilla M.D. , Bouffard Suzanne M.
Published: March 2005

Understanding participation as a three‐part construct of enrollment, attendance, and engagement can help stakeholders maximize participation in and benefits from out‐of‐school‐time programs.
To participate or not to participate: That is the question
Authors: Borden Lynne M. , Perkins Daniel F. , Villarruel Francisco A. , Stone Margaret R.
Published: March 2005

Improving access to and interest in out‐of‐school‐time programs is an important goal. A recent study examined the reasons that youth participated or not in programs, with a focus on the experiences of ethnic minority youth.