bluuebunny/crossref_metadata_2025_split huggingface dataset:
Raman and Fourier transform infrared study of phytol effects on saturated and unsaturated lipid multibilayers
Authors: Picquart M. , Lefèvre T. 
Published: January 2003

AbstractThe effects of phytol on DPPC and OPPC multilayers were investigated using FT‐IR and Raman spectroscopy. The results were compared with those obtained with α‐tocopherol (α‐T) and α‐tocopherol acetate (α‐TA). The chain packing was analyzed using Raman intensity ratios measured in the CH2 stretching region, whereas the number of gauche bonds introduced by phytol was estimated by the measure of the FT‐IR absorbance of the CH2 wagging progression modes. It is shown that the chain packing is reduced and that gauche rotamer formation is promoted by phytol in the gel phase. Phytol has a very similar effect on the acyl chains of DPPC to α‐T but does not have the same impact on the CO stretching vibrations of this lipid. The results indicate that phytol perturbs the interfacial region of DPPC causing dehydration or a conformational modification of the ester groups. Furthermore, the modification of the OPPC chain order induced by phytol is slightly different with respect to α‐T. It is concluded that (1) a hydrogen bond between the hydroxyl group of α‐T and the phospholipid carbonyl groups may not necessarily be associated with the stabilization of the membrane, (2) the studied phytyl compounds may be located more or less close to the membrane interface, (3) the presence of the chromanol ring may strongly influence the location of vitamin E within the membrane and, consequently, its capacity to catch free radicals and (4) the hydroxyl group, chroman moiety and phytyl chain all play a crucial role that determines the effects of α‐T on lipid acyl chains and its location within membranes, which in turn can affect its biological function. Copyright © 2002 John Wiley & Sons, Ltd.
Surface‐enhanced Raman scattering (SERS) of 4‐mercaptobenzoic acid on silver and gold substrates
Authors: Michota A. , Bukowska J. 
Published: January 2003

AbstractSurface‐enhanced Raman scattering (SERS) spectra were recorded for p‐mercaptobenzoic acid (PMBA) monolayers on Ag and Au surfaces. As evidenced by the relative intensities of the bands corresponding to the symmetric stretching COO− vibration and to the out‐of‐plane vibration of the phenyl ring, the molecules are at least tilted with respect to the surface and simultaneously bonded through the sulfur atom and COO− groups. This situation takes place when modification is carried out from aqueous solutions at natural or alkaline pH and at low concentrations of monomer. At higher concentration of the monomer (>10−3) and/or at acidic pH, carboxylic groups are protonated and PMBA molecules adopt a more vertical configuration. It was also found that rough Ag and Au surfaces that are applied in SERS experiments promote partial decarboxylation of PMBA. Copyright © 2002 John Wiley & Sons, Ltd.
A new version of AgFON substrates for high‐throughput analytical SERS applications
Authors: Stropp J. , Trachta G. , Brehm G. , Schneider S. 
Published: January 2003

AbstractThe drop coating technique was applied to generate thin films of various polymer nanospheres as a basis for the preparation of AgFON (Ag films over nanospheres). In contrast to the well known spin coating technique, the chosen procedure also allows the use of multiwell (microtiter) plates as substrate, thereby opening up the possibility of a high‐throughput analysis technique based on SERS. Employing commercially available spheres of polystyrene (diameter 533 nm) or silica (diameter 470 nm) and an Ag top layer 200 nm thick, SERS spectra of several food dyes were recorded; for Brillant Green (E 142), the detection limit was about 500 pg per well. Copyright © 2002 John Wiley & Sons, Ltd.
Vibrational spectroscopic studies of L‐argininium dinitrate
Authors: Ramaswamy S. , Rajaram R. K. , Ramakrishnan V. 
Published: January 2003

AbstractThe Fourier transform IR and Raman spectra of (C6H16N4O22+·2NO3−) crystal were studied and the observed IR and Raman lines were assigned. There is extensive intermolecular hydrogen bonding in the crystal and this is responsible for the changes in the position and intensity of several bands. The vibrational spectra show that the carboxyl group forms a strong hydrogen bond whereas the nitrogen atoms of the amino and guanidyl groups of the cation form normal hydrogen bonds with the oxygen atoms of the anions. Copyright © 2002 John Wiley & Sons, Ltd.
Analyse vibrationnelle et structurale en série aliphatique saturée. XI—Spectres de vibration de l'acide 3‐méthylglutarique et de ses sels alcalins
Authors: Roger J. , Delarbre J. L. , Maury et L. 
Published: January 2003

AbstractRaman and infrared spectra of 3‐methylglutaric acid and its sodium salts in aqueous solution (H2O and D2O) were recorded from 4000 to 200 cm−1. The analysis of the polarization of the Raman lines indicated that 3‐methylglutaric acid and its disodium salts belong to the Cs group whereas the acid salt belongs to the C1 group. On the basis of the intermolecular hydrogen bond present in the crystalline state of the acid salts, sodium 3‐methylglutarate can be classified as a type B structure whereas two polymorphic forms (A and B) of the potassium salt were identified. Copyright © 2002 John Wiley & Sons, Ltd.
Vibrational spectra of racemic and enantiomeric malic acids
Authors: Barańska H. , Kuduk‐Jaworska J. , Szostak R. , Romaniewska A. 
Published: January 2003

AbstractThe IR and Raman spectra of racemic (DL‐) and both enantiomeric (L‐ and D‐) forms of malic acids and also their silver salts and deuterated analogues were measured in the polycrystalline state in the range 4000–100 cm−1. Significant differences in the spectra of the racemic and enantiomeric forms of malic acid were described for the first time and are discussed in relation to the structural features, including crystal symmetry, geometric parameter distinctions and hydrogen bonding. The most significant spectral differences were noted in the ranges 3000–2800 and 1740–1630 cm−1. In the ν(CH) stretching region distinctions were strongly pronounced in the Raman spectra and the observed pattern was ascribed to crystal symmetry differences. In the second region differences were visible in both the IR and Raman spectra and they were explained as a result of distinctions in the geometric properties of carboxyl‐dimer rings of the L‐ and DL‐forms, namely two non‐equivalent types of H‐bonded carboxyl‐dimer rings are present in the crystal of DL‐form, which results in a doublet in the ν(CO) stretching region. In the case of the enantiomeric form, all H‐bonded carboxyl‐dimer rings are equivalent, so a single ν(CO) band is observed in their spectra. Other differences in the spectra of these species were observed in the region below 1500 cm−1 but their explanation is less straightforward. Copyright © 2002 John Wiley & Sons, Ltd.
Molecular‐level pursuit of yeast mitosis by time‐ and space‐resolved Raman spectroscopy
Authors: Huang Yu‐San , Karashima Takeshi , Yamamoto Masayuki , Hamaguchi Hiro‐o 
Published: January 2003

AbstractThe process of eukaryotic cell division has been studied at the molecular level by Raman spectroscopy. Time‐ and space‐resolved Raman spectra of a living fission yeast cell were successfully recorded with a 100 s time resolution and a 250 nm spatial resolution by using a confocal multi‐channel Raman microspectrometer. Raman spectra characteristic of the nucleus, mitochondrion and septum were identified and time‐dependent changes of major molecular components during the cell cycle were elucidated. Copyright © 2002 John Wiley & Sons, Ltd.
Comparative essential oil composition of various parts of the turpentine tree (Pistacia terebinthus L) growing wild in Turkey
Authors: Couladis M , Özcan M , Tzakou O , Akgül A 
Published: January 2003

AbstractThe essential oil contents (dry weight basis) of young shoots, flowers, unripe and ripe fruits of the turpentine tree (Pistacia terebinthus L) were determined as 0.74, 0.70, 0.54 and 0.73% respectively. The main components identified by GC/MS analysis (the identified components represents 90.7, 96.1, 98.0 and 99.0% of the respective oils) were limonene (3.0, 9.4, 34.2 and 32.8%), α‐pinene (5.3, 12.4, 15.6 and 5.3%), β‐pinene (1.4, 8.0, 11.5 and 22.5%) and germacrene D (trace, 19.9, 3.5 and 4.6%). Minor qualitative and major quantitative variations in some compounds of the analysed oils were determined with respect to the different parts of the turpentine tree.© 2002 Society of Chemical Industry
Effect of acetylation on the functional properties of lentil (Lens culinaris) globulin
Authors: Bora Pushkar Singh 
Published: January 2003

AbstractThe functional properties of native and acetylated (62.5, 84.1, 90.1 and 93.0%) globulins were evaluated. Acetylation caused a shift in isoelectric pH from 4.5 to 3.5. The solubility of acetylated globulins improved considerably above pH 4.0 but deteriorated below this pH. Increasing acetylation enhanced water absorption (from 1.08 to 1.67, 1.96, 2.29 and 2.33 ml g−1) but reduced oil absorption capacity (from 2.61 to 2.17, 2.15, 2.05 and 1.76 ml g−1). In comparison with native globulin the relative viscosity of acetylated globulins also increased, but with an increase in acetylation level there was a decrease in relative viscosity (2.13, 1.81, 1.65 and 1.62). The emulsifying activity of 62.5% acetylated globulin increased from 54.2% for native globulin to 56.0%, but above this level of acetylation the activity decreased. Emulsion stability followed a similar behaviour. The foaming capacity of native globulin was improved by 62.5% acetylation but reduced at higher acetylation levels. Maximum foam stability was observed for 90.1% acetylated globulin.© 2002 Society of Chemical Industry
Adaptive QoS parameters approach to modeling Internet performance
Authors: Yang Shin‐Jer , Chou Hung‐Cheng 
Published: January 2003

AbstractDue to the recent advances in Internet technologies and applications, the issue of Quality of Service (QoS) is more essential to Internet performance. In this paper, we address and discuss the influence factors and also finalize the QoS parameters for Internet performance. Then we present the simulation procedure for monitoring the performance evaluation and propose the algorithm for tuning the performance value. Based on simulation results and performance analysis, we can tune and adjust possible parameters' values and then refine the influence level of each QoS parameter. Finally, Internet performance can be enhanced and maintained through using the proposed approach over several sub‐networks. Hence, it increases the adaptability for implementing the QoS Internet. Copyright © 2002 John Wiley & Sons, Ltd.
The structure of self‐reported problem behaviors in Chinese children
Authors: Xin Tao , Zhou Zheng , Bray Melissa A. , Kehle Thomas J. 
Published: January 2003

AbstractThis study examined the structure of self‐reported problem behaviors in Mainland Chinese children. Third grade (n = 3011) and fifth grade (n = 3708) students completed a 20‐item Problem Behavior Frequency Checklist (PBFC). Findings suggested that among the four factors studied (physical aggression, substance use, delinquency, and self‐centered behaviors), self‐centered behaviors and physical aggression were reported most frequently by the Chinese elementary school children. Furthermore, boys had higher prevalence rates of problem behaviors than girls. Developmental differences were also present. Confirmatory factor analyses supported a model that included specific factors related to substance use, physical aggression, delinquency, and self‐centered behaviors. Therefore, the single factor conceptualization in which different types of problem behaviors are hypothesized to reflect a single underlying common factor may not hold for this population. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 19–33, 2003.
Chinese children's self‐concepts in the domains of learning and social relations
Authors: Wang Qi , Li Jin 
Published: January 2003

AbstractIn both academia and pop psychology, the Chinese self is often characterized as collectivist, putting group interest above self‐interest. This account of self misconstrues the complex nature of human psychosocial functioning in cultural contexts. This account further overlooks the dynamic process in which the self is formed and sustained. In this article, we propose, from a domain‐specific perspective, to reexamine the construct of self and its development in Chinese children. By presenting others' and our own research, we analyze Chinese children's self‐concept in two distinct domains—the domain of learning and the domain of social relations. We demonstrate that Chinese children's self‐concept has a strong autonomous component in the context of learning and achievement while displaying a social orientation in the context of relationships and family. We show how these tendencies of Chinese self relate to Confucian ethics and how they are shaped by early socialization. We then discuss implications of these findings for theories of the self. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 85–101, 2003.
Scientific Time and Temporal Experience: Pragmatism's Contribution to the Search for a Synthesis
Authors: Rosenthal Sandra 
Published: January 2003

AbstractThe problem of the relation between lived temporal experience and scientific time is an ongoing philosophical issue which has led to numerous and well entrenched radical solutions that in one way or another sever human temporal experience from the time of the universe. This presentation will offer a bird's eye view of the roots of the philosophical problem both historically and as it manifests itself today in major positions or movements that contour the contemporary philosophical landscape. It will then sketch the path to a possible solution from the perspective of classical American pragmatism, the philosophical movement encompassing the writings of Charles Peirce, William James, John Dewey, C.I. Lewis, and G.H. Mead. For pragmatism the roots of the problem are ultimately located in the understanding of time as discrete and confusions among the mathematical time of physical science, the time of the universe, and lived temporal experience.
Cloning of a muscle-specific calpain from the American lobsterHomarus americanus: expression associated with muscle atrophy and restoration during moulting
Authors: Yu Xiaoli , Mykles Donald L. 
Published: January 2003

SUMMARYA cDNA (1977 bp) encoding a crustacean calpain (Ha-CalpM; GenBank accession no. AY124009) was isolated from a lobster fast muscle cDNA library. The open reading frame specified a 575-amino acid (aa) polypeptide with an estimated mass of 66.3 kDa. Ha-CalpM shared high identity with other calpains in the cysteine proteinase domain (domain II; aa 111-396) and domain III (aa 397-575), but most of the N-terminal domain (domain I; aa 1-110) was highly divergent. Domain II contained the cysteine, histidine and asparagine triad essential for catalysis, as well as two conserved aspartate residues that bind Ca2+. In domain III an acidic loop in the C2-like region, which mediates Ca2+-dependent phospholipid binding, had an expanded stretch of 17 aspartate residues. Ha-CalpM was classified as a non-EF-hand calpain, as it lacked domain IV, a calmodulin-like region containing five EF-hand motifs. Northern blot analysis, relative reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR showed that Ha-CalpM was highly expressed in skeletal muscles, but at much lower levels in heart, digestive gland, intestine, integument, gill, nerve cord/thoracic ganglion and antennal gland. An antibody raised against a unique N-terminal sequence recognized a 62 kDa isoform in cutter claw and crusher claw closer muscles and a 68 kDa isoform in deep abdominal muscle. Ha-CalpM was distributed throughout the cytoplasm, as well as in some nuclei, of muscle fibers. Purification of Ha-CalpM showed that the 62 kDa and 68 kDa isoforms co-eluted from gel filtration and ion exchange columns at positions consistent with those of previously described Ca2+-dependent proteinase III(CDP III; 59 kDa). Ha-CalpM mRNA and protein did not change during the moulting cycle. The muscle-specific expression of Ha-CalpM and the ability of Ha-CalpM/CDP III to degrade myofibrillar proteins suggest that it is involved in restructuring and/or maintaining contractile structures in crustacean skeletal muscle.
Condition, prolonged swimming performance and muscle metabolic capacities of codGadus morhua
Authors: Martínez M. , Guderley H. , Dutil J.-D. , Winger P. D. , He P. , Walsh S. J. 
Published: January 2003

SUMMARYThis study evaluated the link between swimming endurance and condition of Atlantic cod Gadus morhua that had been fed or starved during the 16 weeks preceding the tests, and assessed whether muscle metabolic capacities explain such links. The condition factor [(somatic mass × fork length-3)×100] of starved cod was 0.54±0.1 whereas that of fed cod was 0.81±0.1. In white and red muscle, we measured four glycolytic enzymes: phosphofructokinase (PFK), pyruvate kinase (PK), creatine kinase (CK) and lactate dehydrogenase (LDH), two mitochondrial enzymes:cytochrome c oxidase (CCO) and citrate synthase (CS), a biosynthetic enzyme, nucleoside diphosphate kinase (NDPK), glycogen and protein levels and water content. Muscle samples were taken at three positions along the length of the fish; starvation affected the metabolic capacities of white muscle more than those of red muscle. The levels of glycolytic enzymes and glycogen changed more in white than red muscle during starvation. Both in fed and starved cod, muscle metabolic capacities varied with position along the fish;starvation reduced this longitudinal variation more in white than red muscle. In white muscle of fed cod, the glycolytic enzyme levels increased from head to tail, while in starved cod this longitudinal variation disappeared. In red muscle mitochondrial enzyme levels were highest in the caudal sample, but fewer differences were found for glycolytic enzymes. Swimming endurance was markedly affected by fish condition, with starved fish swimming only 30% of the time (and distance) of fed fish. This endurance was closely linked with the number of burst—coast movements during the test and the activity of CCO and LDH in white muscle. The number of burst—coast movements was significantly linked with condition factor and PFK activity in caudal red muscle and gill arch mass. Our data indicated that cod use both glycolytic and oxidative capacities to support endurance swimming. Furthermore, swimming endurance is linked with the metabolic capacities of red and white muscle.
On-line venous oxygen tensions in rainbow trout during graded exercise at two acclimation temperatures
Authors: Farrell A. P. , Clutterham S. M. 
Published: January 2003

SUMMARYFor most teleost fish, the majority of the myocardial oxygen supply is provided by the oxygen reserve remaining in venous blood after other tissues have extracted oxygen. We examined the effect of graded exercise and water temperature on this venous blood oxygen supply to the heart (termed the cardiac circulation) by performing novel on-line measurements of venous partial pressure of oxygen (PvO2) using a fibreoptic micro-optode implanted in the ductus Cuvier of rainbow trout(Oncorhynchus mykiss). As expected, PvO2 decreased progressively and significantly as swimming velocity approached the critical swimming speed(Ucrit). Unsteady swimming behaviours during the graded exercise, however, caused abrupt and generally short-lived decreases in PvO2. For the cold-acclimated (6-10°C)fish, PvO2 reached a minimum plateau value of 15.3±3.7 torr (1 torr=133.3 Pa) before Ucrit was reached, and so increased swimming effort near to Ucritdid not reduce PvO2 further. Warm-acclimated fish had a significantly higher PvO2(28.9±3.5 torr) at Ucrit. Despite this difference in the PvO2 at Ucrit, we estimated that there was little difference between warm- and cold-acclimated fish in terms of oxygen supply in the cardiac circulation because of a right-shift in the haemoglobin—oxygen dissociation curve at warm temperatures. Furthermore, although PvO2decreased significantly at Ucrit, our estimates suggest that the expected increase in cardiac output would easily maintain the oxygen supply in venous blood at a level similar to that found in resting fish. Although unsteady swimming behaviours decreased PvO2, unsteady swimming rarely decreased the minimum PvO2 value observed at Ucrit by more than 10%. The findings are discussed in terms of a threshold PvO2 required to maintain adequate rates of oxygen diffusion from the cardiac circulation to the myocardial tissues.
Magnet-induced disorientation in hatchling loggerhead sea turtles
Authors: Irwin William P. , Lohmann Kenneth J. 
Published: January 2003

SUMMARYLaboratory experiments have indicated that hatchling loggerhead sea turtles(Caretta caretta) are able to establish and maintain courses using information from the Earth's magnetic field. In previous experiments, turtles were tested in relatively uniform magnetic fields generated by large coil systems surrounding an orientation arena. In this study, we investigated the orientation behavior of hatchlings with either magnets or magnetically inert brass bars attached to their carapaces. Control turtles (with brass bars)oriented significantly towards the east whereas turtles bearing magnets were not significantly oriented as a group. The two distributions were statistically different. These results indicate that magnetic orientation behavior of hatchling sea turtles can be disrupted by attaching a small magnet to the carapace. This finding may prove useful both in field experiments and in efforts to localize magnetoreceptors.