bluuebunny/crossref_metadata_2025_split huggingface dataset:
SERS‐active sites on various copper substrates
Authors: Siemes C. , Bruckbauer A. , Goussev A. , Otto A. , Sinther M. , Pucci A. 
Published: January 2005

AbstractThe wavenumbers of the Raman bands of ethylene adsorbed on Cu in ultra‐high vacuum depend on the surface structure of the copper substrate. Thus it is possible to differentiate between ethylene adsorbed at Cu(110) sites, Cu(111) sites and surface defect sites of unknown configuration. These latter are the ‘SERS‐active sites.’ Only when these sites are annealed does the distance dependence of SERS follow the expectations from the electromagnetic model of SERS. In the presence of the SERS‐active sites, also the signal of ethylene at (111) sites shows a ‘first layer effect.’ Ethylene adsorbed on cold‐deposited copper films shows strong infrared absorption at the same wavenumber as the ethylene at SERS‐active sites in Raman scattering, irrespective of the Raman–infrared exclusion rule for the free centrosymmetric ethylene molecule. This raises the possibility that SERS‐active sites are also infrared‐active sites. The SERS‐active sites at stepped Cu surfaces decorated by 3 nm of cold‐deposited copper anneal below 200 K, whereas they prevail beyond 400 K on Cu island films. Copyright © 2001 John Wiley & Sons, Ltd.
Intensities of the vibrational spectra of siliceous zeolites by molecular dynamics calculations. II—Raman spectra
Authors: Bornhauser P. , Bougeard D. 
Published: January 2005

AbstractThree models based on electro‐optical parameters were tested for the calculation of the Raman intensities of the vibrational modes deduced from (molecular dynamics) calculations on four siliceous zeolites: sodalite, faujasite, zeolite A and silicalite. The best results were obtained from the electro‐optical model containing three parameters: the derivatives of the longitudinal and transversal polarizabilities of the SiO bond with respect to the SiO bond length and the anisotropy of the polarizability tensor of the SiO bond. These parameters permit the reproduction of the relative intensities over the whole wavenumber range. The bond stretching range over 700 cm−1 is driven by the first two parameters, whereas the equilibrium anisotropy participates significantly in the very low wavenumber region. Copyright © 2001 John Wiley & Sons, Ltd.
Vibrational spectra of KNbW2O9 hexagonal tungsten bronze
Authors: Maczka M. , Hanuza J. , Kojima S. , Majchrowski A. , van der Maas J. H. 
Published: January 2005

AbstractRaman and IR studies were performed for the first time for a single crystal of KNbW2O9 belonging to the novel class of valence‐balanced compounds crystallizing in the structure of hexagonal tungsten bronze and exhibiting ferroelectric properties. The observed vibrational modes were assigned to the respective motions of atoms in the unit cell. The observation of weak bands above 900 cm−1 was explained as a result of partial vacancy of W atoms in the hexagonal framework leading to the formation of terminal —WO bonds. Copyright © 2001 John Wiley & Sons, Ltd.
Experimental and theoretical vibrational spectroscopic study on symmetric and asymmetric halo‐bridged complexes of palladium(II) and platinum(II)
Authors: Kessenich E. , Schulz A. , Severin K. 
Published: January 2005

AbstractThe symmetric chloro‐bridged complexes [(Et3P)2PtCl(µ‐Cl)]2, [(Et3P)2Pt(µ‐Cl)]22+ and [(C3H5)Pd(µ‐Cl)]2 and the asymmetric complexes [(C3H5)Pd(µ‐Cl)2Pt(PEt3)2]+ and [(C3H5)Pd(µ‐Cl)2Pt(PEt3)Cl] were studied by means of vibrational spectroscopy (infrared, Raman) and computational chemistry. Assignments of all normal modes associated with skeletal stretching are suggested and their displacement vectors are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Resonance Raman spectra of deuterated cis‐stilbene
Authors: Baranović Goran 
Published: January 2005

AbstractResonance Raman intensities of perdeuterated cis‐stilbene were measured using excitation at 266 nm. For the six analysed bands at 1612, 1564, 1537, 1372, 1325 and 958 cm−1, no large changes in intensity distribution relative to the parent compound were found in accordance with the scrambling coefficients showing that the corresponding modes ν7, ν8, ν9, ν10, ν11 and ν15 of d12‐cis‐stilbene have all of the Raman activity. The S1 equilibrium geometry and vibrational force field for cis‐stilbene were calculated at the CIS/6–31G(d) level and the vibrational assignment for the parent compound and some of its symmetrically substituted isotopomers is considered. The obtained excited‐state geometry distortions are large, preventing the use of a simple displacement equation for relative Raman intensities. Therefore, in their determination the gradients of the S1 state, potential energy surfaces calculated at the ground‐state geometry were also used. Even in its simplest form this approach reproduces the experiment fairly reasonably. Copyright © 2001 John Wiley & Sons, Ltd.
Sb‐induced size effects in ZnO nanocrystallites
Authors: Zuo Jian , Xu Cunyi , Zhang Lihua , Xu Baokun , Wu Ruo 
Published: January 2005

AbstractSb‐doped ZnO nanocrystallites of average grain size about 10 nm were made by using the citrate method. Raman spectra of the Sb‐doped ZnO nanocrystallites at room temperature are reported. Shifts and broadening of the Raman peak with Sb increasing content were observed and it was found that the intensity of a new Raman peak increased at the same time. These effects are similar to finite size effects in ZnO nanocrystallites. It was found for the first time that the size effects are induced by the presence of Sb in the matrix. Copyright © 2001 John Wiley & Sons, Ltd.
Presence of furosine in honeys
Authors: Villamiel Mar , del Castillo M Dolores , Corzo Nieves , Olano Agustín 
Published: January 2005

AbstractNineteen commercial samples (with a shelf‐life of 2 years) and two artisanal samples (freshly collected and stored for 1 year respectively) of Spanish honeys were analysed for pH, protein content and furosine content. Most of the samples had pH values and protein contents within the limits reported in the literature. The presence of furosine was confirmed by comparison of its retention time with that of a furosine standard and by HPLC–MS. The level of furosine in the samples studied ranged from 4.32 to 13.62 g kg−1 protein. The lowest furosine value was observed in the freshly collected artisanal sample. Heat treatment under severe conditions (90 °C for up to 135 min) increased the furosine content from 4.43 to 14.38 g kg−1 protein. The results show that furosine seems to be a promising indicator to detect overheating during honey manufacture.© 2001 Society of Chemical Industry
Antioxidative and antimutagenic activities and polyphenol content of pesticide‐free and organically cultivated green vegetables using water‐soluble chitosan as a soil modifier and leaf surface spray
Authors: Ren Huifeng , Endo Hideaki , Hayashi Tetsuhito 
Published: January 2005

AbstractFive green vegetables (qing‐gen‐cai, Chinese Cabbage, spinach, Welsh onion and green pepper) commonly used in our daily diet were analysed to determine their antioxidative and antimutagenic activities and chemical content of polyphenols. We obtained pesticide‐free and organically cultivated (O) vegetables using water‐soluble chitosan as a soil modifier and leaf surface spray (as an alternative natural insecticide) in order to investigate biofunctions induced or enhanced by such specialised cultivation practices. In addition, we purchased the same varieties of vegetables cultivated on an adjacent farm in the conventional manner (C) using pesticides and chemical fertilisers in order to examine the differences in biological activities and distribution of constituents responsible for such activities. The antioxidative activity shown by O vegetables was 120% times higher than that shown by C vegetables in the case of spinach and 20–50% higher in the case of Welsh onion, Chinese cabbage and qing‐gen‐cai. In comparison with C vegetables, the antimutagenic activity shown by O vegetables was higher against 4‐nitroquinoline oxide (4NQO) in qing‐gen‐cai, Chinese cabbage and Welsh onion, against benzo[a]pyrene (BaP) in all five vegetables, against 2‐amino‐3‐methylimidazo[4,5‐f]quinoline (IQ) in qing‐gen‐cai, Chinese cabbage and green pepper and against 3‐amino‐1‐methyl‐5H‐pyrido[4,3‐b]indole acetate (Trp‐P‐2) in spinach only. Among all green vegetable juices tested for flavonoid composition, quercitrin, caffeic acid and baicalein in O vegetables were detected in concentrations 1.3–10.4 times higher than those found in C vegetables, suggesting the influence of different cultivation practices.© 2001 Society of Chemical Industry
Contribution of polyphenols to the oxidative stability of virgin olive oil
Authors: Gutiérrez F , Arnaud T , Garrido A 
Published: January 2005

AbstractStability, polyphenol, orthodiphenol, tocopherol, oleic/linoleic ratio, chlorophyll, carotenoid, peroxide and acidity values, K232, K270 and overall sensory score of virgin olive oils from Hojiblanca and Picual cultivars were determined during two consecutive seasons. Changes due to cultivar and season were evaluated, correlations between the changes were studied and their contribution to stability was investigated by multiple regression techniques. Removal of polyphenols from the original samples without altering other antioxidant components has permitted estimating, for the first time, the contribution of these compounds to virgin olive oil. Approximately 50% of the stability is contributed by polyphenols.© 2001 Society of Chemical Industry
Acetyldiaminobutanoic acid, a potential lathyrogenic amino acid in leaves of Acacia angustissima
Authors: Reed Jess D , Gebre‐Mariam Girma , Robinson Christopher J , Hanson Jean , Odenyo Agnes , Treichel Paul M 
Published: January 2005

AbstractAcacia angustissima has potential in agroforestry systems for forage production in tropical environments. However, feeding trials indicate that the leaves are potentially toxic. Signs of toxicity in sheep are similar to those presented by sheep fed flatpea (Lathyrus sylvestris) hay which contains a high concentration of the non‐protein amino acid 2,4‐diaminobutanoic acid (DABA). Cation exchange chromatography, high‐performance liquid chromatography (HPLC) and NMR were used to isolate and identify the non‐protein amino acid in A angustissima leaves. A quantitative HPLC method was used to determine the content of the non‐protein amino acid in leaves from 20 accessions. The non‐protein amino acid was identified as 4‐N‐acetyl‐2,4‐diaminobutanoic acid (ADAB), previously reported to occur in seeds. The average and range in ADAB content were 16.8 and 10.6–25.4 mg g−1 respectively. This content of ADAB is higher than the levels of DABA in flatpea hay that are toxic to sheep.© 2001 Society of Chemical Industry
Performance and carcass characteristics of growing pigs and broilers fed diets containing micronised barley, ground barley, wheat and maize
Authors: Yin Yu‐Long , Baidoo Samuel K , Boychuk J L L , Simmins Howard H 
Published: January 2005

AbstractTwo swine starter/grower/finisher trials utilising 216 24‐day‐old pigs and one 40‐day broiler growth trial utilising 1920 1‐day‐old chicks were conducted to determine the influence of dietary micronised dehulled barley (MDB) as a replacement for hulled barley (HB), wheat (W) and maize (M) on live performance, carcass and meat measurements, organ weights (swine), plasma urea nitrogen (PUN) level (swine) and intestinal digesta viscosity (broilers). Dehulling and micronising the barley reduced crude protein by 20%, neutral detergent fibre by 17% and amino acids by varying amounts. Replacing M or W with MDB in swine diets had no effect (P > 0.05) on any measured parameter, with the exception of decreased PUN (P  = 0.03) when MDB replaced 100% of W. Broilers fed W, M or HB generally had similar live performance, carcass traits and digesta viscosity, with the exception of reduced (P < 0.05) average daily gain and average daily feed intake for HB during the first 20 days of the trial. However, broilers fed MDB had slightly reduced (P  = 0.05) live performance during each phase of the trial and greatly increased (P  = 0.01) digesta viscosity. Addition of a commercial enzyme product to the diets reversed the reduced performance and increased the digesta viscosity of the MDB diet, but generally had no influence in the W, M and HB diets. These results suggest that MDB can be utilised in swine diets without affecting performance, but that reduced performance may result from its use in broiler diets.© 2001 Society of Chemical Industry
Nutritional assessment of protein from beans (Phaseolus vulgaris L) processed at different pH values, in growing rats
Authors: Nestares Teresa , Barrionuevo Mercedes , Urbano Gloria , López‐Frías Magdalena 
Published: January 2005

AbstractThe effect of the commonly used processing techniques of soaking (at different pH values) and cooking on the digestive and metabolic utilisation of protein from common beans (Phaseolus vulgaris L) in growing rats was studied. Before the cooking step, beans were soaked in solutions of pH 2.6, 5.3 or 8.4. Analyses of beans soaked at moderately acid pH (5.3) showed a significant increase in essential amino acids, especially cysteine. Food intake and growth indices were also dependent on pH. All indices were better in animals fed with beans soaked in a basic pH solution than when an acid soaking solution was used. In contrast with the findings expected on the basis of the chemical analysis of protein composition of the food, the worst results for food intake and growth were found in rats fed with beans soaked at pH 5.3. There were no significant differences in apparent digestibility coefficient between different groups of animals. The highest metabolic utilisation of protein (balance) was found in animals fed with beans soaked in a basic solution; however, the values were insufficient to account for the faster rate of growth in this group. The better growth rate was probably due to the improved utilisation of carbohydrates in beans soaked in the basic pH (8.4) solution.© 2001 Society of Chemical Industry
The response of proline metabolism to nitrogen deficiency in pods and seeds of French bean (Phaseolus vulgaris L cv Strike) plants
Authors: Sánchez Esteban , Ruiz Juan Manuel , Romero Luis 
Published: January 2005

AbstractThe objective of the present work was to determine the impact of nitrogen deficiency on proline metabolism in order to use this amino acid as a bioindicator of the N status of the pods and seeds of French bean (Phaseolus vulgaris L cv Strike) plants. We also identify the pathway of proline synthesis which is favoured under our experimental conditions. N was applied to the nutrient solution in the form of NH4NO3 at 1.45 mM (N1), 2.90 mM (N2) and 5.80 mM (N3, optimal level). Our results indicate that N deficiency is characterised by a decline in proline accumulation in both the pod and the seed, fundamentally because proline degradation is encouraged by stimulation of the enzyme proline dehydrogenase under these conditions. However, although the enzymes in charge of proline biosynthesis (ornithine‐δ‐aminotransferase and Δ1‐pyrroline‐5‐carboxylate synthetase) vary in behaviour depending on the N status, this amino acid appeared to be synthesised mainly by the enzyme ornithine‐δ‐aminotransferase, suggesting predominance of the ornithine pathway over the glutamine pathway. Finally, under our experimental conditions, proline can be regarded as a good indicator of N deficiency, particularly in the seeds of French bean plants.© 2001 Society of Chemical Industry
Protective effects of chlorophyll a and pheophytin a derived from green tea (Camellia sinensis) on p‐nonylphenol‐induced cell growth inhibition and oxygen radical generation in yeast (Saccharomyces cerevisiae)
Authors: Okai Yasuji , Higashi‐Okai Kiyoka 
Published: January 2005

AbstractWe recently reported that the endocrine disruptor p‐nonylphenol (NP) caused suppressive effects on cell growth and cellular respiration in the yeast Saccharomyces cerevisiae and that these effects were associated with NP‐induced oxygen radical generation (Okai Y et al, FEMS Microbiol Lett 185:65–70 (2000)). In the present study we found preventive effects of photosynthetic pigments chlorophyll a and pheophytin a from green tea (Camellia sinensis) on NP‐induced inhibition of cell growth and cellular respiration in yeast. Their preventive activities were much higher than those of a synthetic sodium–copper salt form of chlorophyll, chlorophyllin. These pigments also prevented NP‐induced oxygen radical generation in yeast cells, showing suppressive activities proportional to their preventive activities against inhibition of cell growth and cellular respiration. The significance of this finding is discussed from the viewpoint of protective activity of photosynthetic pigments against endocrine disruptor‐induced harmful effects.© 2001 Society of Chemical Industry
Enzymic peeling of Indian grapefruit (Citrus paradisi)
Authors: Prakash S , Singhal R S , Kulkarni P R 
Published: January 2005

AbstractThe tough nature of grapefruit (Citrus paradisi) peel and its close adherence to the inner fruit sections limit the industrial processing of grapefruit. Two commercial peeling enzymes coded as ‘Brand A’ and ‘Brand B’ were studied for enzymic peeling of Indian grapefruit by vacuum infusion. The peeling process was optimised with respect to process parameters such as scalding time, enzyme concentration, vacuum infusion time and incubation time.© 2001 Society of Chemical Industry
Influence of heating conditions and starch on the storage modulus of Russet Burbank and Yukon Gold potatoes
Authors: Bu‐Contreras Renan , Rao M A 
Published: January 2005

AbstractThe storage modulus of Russet Burbank (RB) and Yukon Gold (YG) potato discs (13.3 mm × 4.5 mm) was measured continuously during heating in water at temperatures ranging from 40 to 80 °C for 120 min using a dynamic mechanical analyser with a heating stage. The starch content of YG potatoes was higher than that of RB potatoes, but the raw starch granule size distribution of both varieties was similar. RB samples had the highest storage modulus values (25% higher than raw tissue) when heated in 60 °C water for 35 min. Image analysis revealed that the perimeters of starch granules in the potato samples increased by about 50% during heating for 30 min at 60 °C. Heating temperature and time and starch content influenced the storage modulus.© 2001 Society of Chemical Industry
Sensory and chemical changes in Chilean Cabernet Sauvignon wines during storage in bottles at different temperatures
Authors: Sivertsen Hanne K , Figenschou Erik , Nicolaysen Frithjof , Risvik Einar 
Published: January 2005

AbstractTwo Chilean wines made from the Cabernet Sauvignon grape were stored in bottles at four different temperatures for a period of 44 months. During storage they were evaluated by sensory descriptive and chemical analyses. Different sensory profiles were obtained for the wines stored at the different temperatures. Smaller differences were found in the profiles of the two wines stored at the same temperatures. Wines were stored at different temperatures to determine if it was possible to predict the shelf‐life of wines stored at optimal temperatures. This was not achieved in this study. Partial least squares regression was used to examine possible relationships between the chemical and sensory descriptive data.© 2001 Society of Chemical Industry
Chelation and reduction of iron by chicken muscle protein digests: the role of sulphhydryl groups
Authors: Vattem Dhiraj A , Seth Anahita , Mahoney Raymond R 
Published: January 2005

AbstractThe role of sulphhydryls in the chelation and reduction of iron by digests of chicken muscle was investigated. The salt‐soluble (DSSP) and myofibrillar (DSIP) proteins were extracted from chicken muscle and digested with pepsin/pancreatin, and the digests were then incubated with ferric iron. The DSIP digest bound twice as much iron as the DSSP digest; about half the bound iron was ferrous. Iron binding was accompanied by a 74% drop in free sulphhydryls in the DSSP digest and a 72% drop in the DSIP digest. Modification of sulphhydryls in the digests by either oxygen, N‐ethylmaleimide or p‐chloromercuribenzoate led to a loss of ∼90% in reactive sulphhydryl groups and was accompanied by losses in iron binding which averaged 79% for DSSP and 67% for DSIP. Losses in ferrous bound iron were proportional to the loss in total bound iron. It was concluded that for the muscle protein fractions, sulphhydryl residues are the principal component responsible for iron binding, but that other residues may play a minor role.© 2001 Society of Chemical Industry
Effect of fermentation time on texture and microstructure of pickled carrots
Authors: Llorca Empar , Puig Ana , Hernando Isabel , Salvador Ana , Fiszman Susana M , Lluch Ma Angeles 
Published: January 2005

AbstractA study was made of the effect of pickling on the texture of carrots. Five different devices and tests were applied: puncture with needle, penetration with sphere or cylinder, texture profile analysis (TPA) and Warner–Bratzler knife. Phloem and xylem areas of samples were tested separately when possible. The results indicated a considerable difference in texture between unprocessed and 1 day pickled carrots. Some of the tests were able to discriminate between phloem and xylem in the samples. None of the tests applied was able to detect differences in texture between samples taken after 1 day of pickling and samples taken at any other point in the pickling process. Scanning electron microscopy (SEM) observations showed structural differences between phloem and xylem which reflected corresponding differences in texture. Some penetration of salt could be seen after 1 day of the pickling process, and a massive penetration of salt at the end of it.© 2001 Society of Chemical Industry
In vitro inhibition of α‐chymotryptic activity by phenolic compounds
Authors: Rohn Sascha , Rawel Harshadrai M , Pietruschinski Nadine , Kroll Jürgen 
Published: January 2005

Abstractα‐Chymotrypsin was modified by covalent attachment of selected phenolic and related compounds (caffeic acid, chlorogenic acid, ferulic acid, gallic acid, quinic acid, m‐/o‐/p‐dihydroxybenzene and p‐benzoquinone) at pH 9. The derivatives formed were characterised in terms of their activity and selected physicochemical properties. In vitro experiments showed that the proteolytic digestion of food proteins with α‐chymotrypsin derivatives was adversely affected. This decrease depended on the reactivity of the phenolic and related substances tested as well as on the kind of substrate applied. The derivatisation was accompanied by a reduction in the amount of free lysine and tryptophan residues. Moreover, the solubility of the derivatives decreased over a broad pH range, with a parallel increase in the hydrophobicity. The isoelectric point was shifted to a lower pH value, and formation of high‐molecular‐weight fractions was documented by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE).© 2001 Society of Chemical Industry