bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination by Raman scattering of the nature of pigments in cultured freshwater pearls from the mollusk Hyriopsis cumingi
Authors: Karampelas S. , Fritsch E. , Mevellec J.‐Y. , Gauthier J.‐P. , Sklavounos S. , Soldatos T. 
Published: November 2006

AbstractThe nature of pigments in naturally colored pearls is still under discussion. For this study, Raman scattering measurements were obtained for 30 untreated freshwater cultured pearls from the mollusk Hyriopsis cumingi covering their typical range of colors. The originality of this work is that seven different excitation wavelengths (1064 nm, 676.44 nm, 647.14 nm, 514.53 nm, 487.98 nm, 457.94 nm, 363.80 nm) are used for the same samples at the highest possible resolution. All colored pearls show the two major Raman features of polyenic compounds assigned to double carbon–carbon (CC) – at about 1500 cm−1 – and single carbon–carbon (CC) – at about 1130 cm−1 – bond stretching mode, regardless of their specific hue. These peaks are not detected in the corresponding white pearls, and therefore seem directly related to the major cause of body color. Additionally, the exact position of CC stretching vibration shows that these compounds are not members of the carotenoid family. Moreover, some changes are observed in intensities, shape and positions of the two main characteristic polyenic peaks from one sample to the next. Similar changes are observed also using several excitation wavelengths for the same point of the same pearl. The exact position of CC stretching vibration of polyenic molecules depends strongly on the number of double bonds (N) contained in their polyenic chain. Hence, using a constrained decomposition of this band for different excitation wavelengths, up to nine different pigments may be detected in the same pearl. Their general chemical formula is R‐(CHCH)N‐R′ with N = 6–14. All our colored samples contained at least four pigments (N = 8–11). Different colors are explained by different mixtures, not by a simple change of pigment. The chemical nature of the chain ends is still unknown, because it cannot be detected with Raman scattering. However, it is possible that these polyenes are complexed with carbonate molecules of the nacre. Similar coloration mechanisms are found in products from other living organisms (e.g. parrots feathers). Moreover, it seems that a similar series of pigments is found in other pearls also, as well as in some marine animals living in similar environments (e.g. corals). Copyright © 2006 John Wiley & Sons, Ltd.
The evaluation of oil and fatty acid composition in seed of cotton accessions from various countries
Authors: Lukonge Everina , Labuschagne Maryke T , Hugo Arno 
Published: November 2006

AbstractCottonseed oil has a 2:1 ratio of polyunsaturated to saturated fatty acid. Linoleic acid is an essential fatty acid, but in large amounts it contributes to a short shelf‐life due to rancidity. The aim of this study was to screen germplasm from various countries for oil and fatty acid content, to identify parents that can be used in hybridisation to increase stearic and oleic acids and reduce palmitic fatty acids. Oil content varied from 13.6% to 24.7%. Linoleic acid ranged from 51.5% to 63%, palmitic from 19.2% to 25.6%, oleic from 14.2% to 18.5% and stearic from 2.1% to 2.8%. Stearic and palmitic acids were positively correlated, and stearic and linoleic acids were negatively correlated; therefore breeding for increased stearic acid and reduced palmitic acid as well as breeding for increased stearic and linoleic acids at the same time might be difficult through conventional breeding. CIM70 and Cyto 12/74 had high values for stearic and oleic acids and Stoneville had high values of stearic and oleic acids and low palmitic acid. These can be used as parents to improve these two fractions. Copyright © 2006 Society of Chemical Industry
Travel stimulated by international students in Australia
Authors: Min‐En Aaron Tham 
Published: November 2006

AbstractThe international student (IS) market in Australia has been a growing export economy. Because of the traditional definition of tourism being that of ‘a leisure activity outside a usual work scope area for a period of less than a year’, tourism research on IS has been minimal. This research investigates the tourism demand stimulated by IS in Australia. Besides tourism statistics, the research involved 23 IS in focus groups who provided responses of their tourism activities while in Australia. The research illustrates that such IS are significant contributors to tourism by visiting places of interest, purchasing souvenirs, casual work in hospitality and visits by friends and relatives. Copyright © 2006 John Wiley & Sons, Ltd.
The relative efficiency of four representative cropland conversions in reducing water erosion: evidence from long‐term plots in the Loess hilly area, China
Authors: Huang Z. L. , Chen L. D. , Fu B. J. , Lu Y. H. , Huang Y. L. , Gong J. 
Published: November 2006

AbstractLarge areas of traditional slope cropland were recently converted to other land‐use types in the semiarid Loess Plateau of China. In this study, we selected four representative conversion options of slope croplands, i.e., pastureland rotated with cropland (cultivated with Medicago sativa L. and rotated with Triticum aestivum L.), shrubland and woodland (afforested with Hippophae rhamnoides L. and Pinus tabulaeformis), and grassland (native herbage Stipa breviflora) to study the effect of land‐use conversion by comparing with traditional cropland. Compared with slope cropland, the relative effects of different conversion options on surface runoff and soil erosion were assessed over a 14‐year measurement period. Observations showed that distinct features and consequences of vegetation succession were found among the conversion options. Plots of shrubland had the highest vegetation coverage with dense undergrowth; natural herbaceous and subshrub species gradually spread into plots of grassland resulting in higher vegetation cover. Neither bushes nor herbs colonized the plots of Pinus tabulaeformis, which resulted in a higher percentage of bare soil. Significant differences in runoff generation, sediment yield and conservation efficiencies among the selected conversion options were detected through an analyses of variance (ANOVA). Compared with cropland, total runoff and sediment decreased by 65 per cent and 95 per cent in shrubland, 41 per cent and 92·5 per cent in grassland, 18 per cent and 77 per cent in woodland, and 12 per cent and 58 per cent in pastureland, respectively. The ranking of soil and water conservation efficiencies was shrubland > grassland > woodland > pastureland > cropland. Based on the effectiveness of soil and water conservation, shrubland and grassland are highly recommended as promising options for cropland conversion projects. However, pastureland and woodland are not suggested as potential options for slope‐cropland conversion because of low soil and water conservation in the long term. Copyright © 2006 John Wiley & Sons, Ltd.
Ex vivo histological characterization of a novel ablative fractional resurfacing device
Authors: Hantash Basil M. , Bedi Vikramaditya P. , Chan Kin Foong , Zachary Christopher B. 
Published: November 2006

AbstractBackground and ObjectivesWe introduce a novel CO2 laser device that utilizes ablative fractional resurfacing for deep dermal tissue removal and characterize the resultant thermal effects in skin.Study Design/Materials and MethodsA prototype 30 W, 10.6 µm CO2 laser was focused to a 1/e2 spot size of 120 µm and pulse duration up to 0.7 milliseconds to achieve a microarray pattern in ex vivo human skin. Lesion depth and width were assessed histologically using either hematoxylin & eosin (H&E) or lactate dehyrdogenase (LDH) stain. Pulse energies were varied to determine their effect on lesion dimensions.ResultsMicroarrays of ablative and thermal injury were created in fresh ex vivo human skin irradiated with the prototype CO2 laser device. Zones of tissue ablation were surrounded by areas of tissue coagulation spanning the epidermis and part of the dermis. A thin condensed lining on the interior wall of the lesion cavity was observed consistent with eschar formation. At 23.3 mJ, the lesion width was approximately 350 µm and depth 1 mm. In this configuration, the cavities were spaced approximately 500 µm apart and interlesional epidermis and dermis demonstrated viable tissue by LDH staining.ConclusionA novel prototype ablative CO2 laser device operating in a fractional mode was developed and its resultant thermal effects in human abdominal tissue were characterized. We discovered that controlled microarray patterns could be deposited in skin with variable depths of dermal tissue ablation depending on the treatment pulse energy. This is the first report to characterize the successful use of ablative fractional resurfacing as a potential approach to dermatological treatment. Lasers Surg. Med. 39:87–95, 2007. © 2007 Wiley‐Liss, Inc.
Thermoplastic Starch Plasticized by Glycerol as Solid Polymer Electrolytes
Authors: Ma Xiaofei , Yu Jiugao , He Kang 
Published: November 2006

AbstractSummary: Melt extrusion can be used to prepared GPTPS mixed with alkali metal chlorides (LiCl, NaCl and KCl) as a potential solid polymer electrolytes. SEM reveals that excess salt results in the congregation of salt crystals, which affects the mechanical properties and conductivities of GPTPS. FT‐IR spectroscopy shows that alkali metal ions can interact with starch, which restrains starch recrystallization, as proved by XRD. The introduction of salts improves the elongation at break, but reduces the tensile stress of GPTPS. Both salt content and water content have an effect on the conductance of GPTPS. The introduction of salts increases the conductance by a factor of 1–2, while the conductance increases about 5 orders of magnitude as the water content increases from 0.05 to 0.55 wt.‐%. The relationship of conductance versus water content can be well described by a second‐order polynomial, with R2 > 0.96. The type of salt has no obvious effect on the correlation between the conductance and water contents.SEM micrographs of native starch granules and fractured surfaces of GPTPS filled with different types and amounts of alkali metal chlorides per 100 g starch.magnified imageSEM micrographs of native starch granules and fractured surfaces of GPTPS filled with different types and amounts of alkali metal chlorides per 100 g starch.
Stereocomplex Formation from Enantiomeric Polyamides Derived from Tartaric Acid
Authors: Marín Romina , Alla Abdelilah , Muñoz‐Guerra Sebastián 
Published: November 2006

AbstractSummary: The formation of stereocomplexes from the pair of enantiomorphs of the chiral polyamide poly(hexamethylene di‐O‐methyl tartaramide) was investigated for a variety of experimental conditions. DSC and X‐ray diffraction data evidenced that efficiency in enantiomeric association is highly sensitive to the procedure used for preparing the complex. A comparative isothermal crystallization study revealed that the stereocomplex crystallized from the melt at a rate lower than the enantiomerically pure components. The radial growth of individual spherulites was also delayed in the crystallization of the complex. No evidence of stereocoupling was detected for other poly(alkylene di‐O‐methyl tartaramide)s with the alkylene unit length different from six. It was concluded that molecular interlocking of hydrogen bonds in the enantiomeric pair is highly selective in this family of polymers.Spherulitic growth at 200 °C from the melt.magnified imageSpherulitic growth at 200 °C from the melt.
Thermoreversible Gelation of Polybenzimidazole in Phosphoric Acid
Authors: Sannigrahi Arindam , Arunbabu Dhamodaran , Jana Tushar 
Published: November 2006

AbstractSummary: We report a study of thermoreversible gelation of polybenzimidazole (PBI) in phosphoric acid (PA). The PBI gel in PA exhibits fibrillar network morphology and reversible first order phase transition. The gelation rate is measured by the tube tilting method and found to depend both upon gelation concentration and gelation temperature. The UV‐vis study demonstrates that the gelation process is a two‐step process: conformational transformation and aggregation which produces crystallites for gel formation. The WAXS study supports the presence of crystallites in the gel. The PA doping level of the membrane increases significantly because of gelation.Thermoreversible gelation of polybenzimidazole in phosphoric acid and the membrane produced from the gel.magnified imageThermoreversible gelation of polybenzimidazole in phosphoric acid and the membrane produced from the gel.
Saturated Red‐Emitting Electrophosphorescent Polymers with Iridium Coordinating to β‐Diketonate Units in the Main Chain
Authors: Zhang Kai , Chen Zhao , Yang Chuluo , Gong Shaolong , Qin Jingui , Cao Yong 
Published: November 2006

AbstractSummary: A series of novel copolymers with fluorene‐alt‐carbazole segments and β‐diketonate moieties coordinating to iridium were synthesized by Suzuki polycondensation, and characterized by 1H NMR, 13C NMR, and GPC. In the absorption spectra of the copolymers, metal‐to‐ligand charge‐transfer transitions coming from iridium complex increased in intensity with increasing content of Ir complex in copolymers. The photoluminescence spectra of the copolymers were dominated by emission from the iridium complex with peak at ca. 620 nm even at the feed ratio of the complex as low as 0.5 mol‐%. The electrochemical investigation indicated that the incorporation of carbazole and iridium complex units reduce the barrier for both hole and electron injection compared with the polyfluorene. The light‐emitting diodes using the copolymers as emission layer under different device configurations were fabricated. The devices with 2‐(4‐biphenylyl)‐5‐(4‐tert‐butylphenyl)‐1,3,4‐oxadiazole (PBD) show significantly higher external quantum efficiencies than those without PBD. A saturated red‐emitting polymer light‐emitting diode with emission peak at 628 nm, the maximum external quantum efficiency of 0.6% at the current density (J) of 38.5 mA · cm−2, and the maximum luminance of 541 cd · m−2 at 15.8 V was achieved from the device ITO/PEDOT/PFCzIrpiq3 + PBD (40%)/Ba/Al.Novel copolymers with fluorene‐alt‐carbazole segments and iridium coordinating to β‐diketonate in the main chain.magnified imageNovel copolymers with fluorene‐alt‐carbazole segments and iridium coordinating to β‐diketonate in the main chain.
Preparation and SO2 Absorption/Desorption Properties of Crosslinked Poly(1,1,3,3‐Tetramethylguanidine Acrylate) Porous Particles
Authors: Wu Linbo , An Dong , Dong Jie , Zhang Zhengmin , Li Bo‐Geng , Zhu Shiping 
Published: November 2006

AbstractSummary: Novel crosslinked porous particles based on the ionic copolymer of 1,1,3,3‐tetramethylguanidine acrylate (TMGA) and N,N‐methylenebisacrylamide (MBA) were prepared via an inverse suspension polymerization using cyclohexane as continuous phase and Span 60 as the dispersant. The SO2 absorption–desorption properties of the P(TMGA‐co‐MBA) particles were studied for the first time. The particles showed excellent SO2 absorption properties: high capacity and rate. These absorption properties, as well as the particle volume, shape, and morphology, remained unchanged during the SO2 absorption–desorption cycles. The material appeared to be a good candidate as SO2 absorbent for fuel gas desulfurization (FGD) and purification of other SO2‐containing gases.Optical microscope image of the P(TMGA‐co‐MBA) porous particles.magnified imageOptical microscope image of the P(TMGA‐co‐MBA) porous particles.
Ions in space
Authors: Petrie Simon , Bohme Diethard Kurt 
Published: November 2006

AbstractWe review the detection history, observation, distribution, and reactivity of molecular ions in extraterrestrial space, with particular (though not exclusive) reference to interstellar monocations. The diversity of interstellar ion chemistry is highlighted with reaction examples, drawn from the authors' own laboratories and elsewhere, and attempt to provide an overview of this broad and increasingly divergent field. Emphasis is given to the role of ions in the synthesis of molecules, including their ability to catalyze the transformation of neutral molecules. © 2006 Wiley Periodicals, Inc., Mass Spec Rev 26:258–280, 2007
Valproate‐induced Parkinsonism in epilepsy patients
Authors: Jamora Dominic , Lim Shih‐Hui , Pan Andrew , Tan Louis , Tan Eng‐King 
Published: November 2006

AbstractWe systematically examined 226 epilepsy patients in a tertiary‐referral center and found 6 (5.04%) to have valproate‐induced Parkinsonism. There was a significantly higher prevalence of patients with Parkinsonism in the group of patients treated with valproate compared to those who were on other antiepileptic drugs (6 [5.04%] of 119 vs. 0 [0%] of 107; χ2 = 5.54; P = 0.025). These six patients had been on valproate for more than 3 years (mean, 75.67 ± 25.32 months) at an average dose of 750 ± 273.86 mg/day. The valproate doses were decreased or discontinued with supplementation from another antiepileptic medication. The mean UPDRS motor score significantly improved from 10.67 ± 5.1 to 4.75 ± 2.75 (P < 0.05). There was no relapse of seizures. Clinicians working in tertiary‐referral centers should have a high index of suspicion for valproate‐induced Parkinsonism. Early recognition and switching into another antiepileptic medication may help reduce unnecessary suffering in these patients. © 2006 Movement Disorder Society
Acute effects of immediate and controlled‐release levodopa on mood in Parkinson's disease: A double‐blind study
Authors: Kulisevsky Jaime , Pascual‐Sedano Berta , Barbanoj Manel , Gironell Alexandre , Pagonabarraga Javier , García‐Sánchez Carmen 
Published: November 2006

AbstractMood fluctuations related to levodopa (LD) dosing are well‐known psychiatric complications of Parkinson's disease (PD). No formal studies explored how affective response to LD relates to the type of motor response to oral LD (stable or wearing‐off) and to different pharmacokinetic profiles of oral LD. We used an intrasubject randomized double‐blind crossover design to study 14 patients (7 stable, 7 wearing‐off) who were monitored for motor status, mood, anxiety, and plasma LD levels 1 hour before and 6 hours after an oral dose of immediate‐release (IR) and controlled‐release LD formulations. Analysis of the dose–response curves showed a significant interaction between the type of motor response and the type of LD. Only the wearing‐off patients had a significant mood elevation, and this effect was only significant following challenge with IR LD. Motor status strongly correlated with LD plasma levels and anxiety but not with mood ratings. Mood changes in PD patients are related to the patient's type of motor response to oral LD and also to the kinetic profile of the LD formulation used for dopaminergic replacement. © 2006 Movement Disorder Society
Analysis of L–L transmission line metamaterials with coupled inductances
Authors: Alù Andrea , Bilotti Filiberto , Vegni Lucio 
Published: November 2006

AbstractHere we solve the transmission‐line equations for a metamaterial having shunt and series inductances electromagnetically coupled together. We derive and analyze the anomalous wave properties that such a metamaterial may have, envisioning its realization both as a transmission‐line metamaterial and as a bulk complex material whose electromagnetic relations may be read in terms of the present theory. The dependence of the wave impedances on the coupling factor between the inductive elements is derived in closed form, showing an anomalous distinct behavior between the incident and reflected waves. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 94–97, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22028
Design of a CPW‐fed ultrawideband fractal antenna
Authors: Ding Min , Jin Ronghong , Geng Junping , Wu Qi 
Published: November 2006

AbstractA new ultrawideband antenna is presented in this letter, and the fractal structure is used to obtain such a wideband feature. The parameters and the characteristics of the antenna are given. The simulated and the measured results show that a bandwidth larger than 6:1 is achieved. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 173–176, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22078
Modelling of non linear elements using an extended iterative method
Authors: Glaoui Mohamed , Hajlaoui El Amjed , Zairi Hassen , Trabelsi Hichem , Baudrand Henri 
Published: November 2006

AbstractThis paper presents an iterative method based on the wave concept for investigation of structures including Non‐linear components. The principle of the iterative method consists to establishing a relationship between incident and reflected waves in order to characterize the studied structure. A passage from frequency domain to time domain is used to describe the behavior of a non‐linear transmission line (NLTL) including eight Varactor diodes. It is demonstrated that the NLTL plays the role of a delay time line (DTL). The reflected and transmission coefficients are determined. The numerical results are compared with published data. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 143–147, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22079
Accurate equivalent circuit for etched resonator with effective negative permittivity
Authors: Wu Hung‐Wei , Weng Min‐Hang , Su Yan‐Kuin , Yang Ru‐Yuan , Hung Cheng‐Yuan 
Published: November 2006

AbstractThis latter demonstrates an accurate equivalent circuit for a negative permittivity resonator using single‐cell complementary split ring resonator underneath a microstrip line that introduces two attenuation poles in desired frequencies. The proposed equivalent circuit consists of lumped elements that can be accurately extracted from the measured S‐parameters. Good agreement with response of equivalent circuit, electromagnetic simulation, and measurement is demonstrated. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 231–234, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22090
A compact wide‐band bandpass filter integrating SCMRC and SIRW structures
Authors: Che Wenquan , Deng Kuan , Xu Lei , Wang Dapeng 
Published: November 2006

AbstractA wideband bandpass filter constructed into substrate integrated rectangular waveguide (SIRW) and incorporating spiral compact microstrip resonant cell (SCMRC) is proposed. Design considerations of these two dissimilar structures are introduced separately. A prototype was fabricated and measured. Good agreements are observed between the experimental results and the simulations. The results demonstrate a wide bandwidth of 70.7% (from 8.6 to 18 GHz), and the ripple in the entire passband is less than 2 dB. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 195–198, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22092