bluuebunny/crossref_metadata_2025_split huggingface dataset:
Homocysteine inhibits extra‐embryonic vascular development in the avian embryo
Authors: Latacha Kimberly S. , Rosenquist Thomas H. 
Published: August 2005

AbstractA strong association exists between pregnancy loss and maternal elevations of the sulfur‐containing amino acid, homocysteine. Because extra‐embryonic vascular growth is critical to maintaining a normal pregnancy, we examined the effects of homocysteine on vessel development by exposing avian embryos to exogenous homocysteine during critical periods of vascular growth. These experiments demonstrated that homocysteine significantly reduced survival and decreased angiogenesis in the extra‐embryonic vasculature. Homocysteine was also found to reduce mRNA and protein expression of vascular endothelial growth factor (VEGF), a key molecule for vascular development. Moreover, in cultured human umbilical vein endothelial cells, homocysteine increased the synthesis of nitric oxide, an important regulatory molecule for VEGF. Inhibiting the homocysteine‐induced up‐regulation of nitric oxide restored normal VEGF expression and vascular development. These results suggest that homocysteine may impair the development of the extra‐embryonic vasculature by reducing the expression of VEGF. Developmental Dynamics 234:323–331, 2005. © 2005 Wiley‐Liss, Inc.
Motor‐related cortical dynamics to intact movements in tetraplegics as revealed by high‐resolution EEG
Authors: Mattia Donatella , Cincotti Febo , Mattiocco Marco , Scivoletto Giorgio , Marciani Maria Grazia , Babiloni Fabio 
Published: August 2005

AbstractWe explored the cortical dynamics during movements of an unaffected body part in tetraplegic subjects with chronic spinal cord injury (SCI). The aims were to find out whether the intact movements were associated with a physiological time‐varying pattern of activity in the motor‐related cortical areas and whether the primary motor area (MI) activation followed a somatotopic distribution. Event‐related potentials to self‐initiated lip movements were analyzed by means of cortical source imaging of EEG recorded from seven tetraplegic subjects and seven control subjects. Regions of interest (ROIs) were selected on individual MRI and the time‐varying electrophysiologic activity (cortical current density, CCD) was estimated on these ROIs and subjected to across‐subject analysis. A significant, bilateral movement‐related pattern of MI activation was detected during motor task execution in SCI patients as well as in controls. The site of local maxima activation displayed a symmetrical discrete distribution within MI, consistently with a putative somatotopic lip representation, in all the subjects. The supplementary motor area proper (SMAp) was always coactivated with MI and coactivation was characterized by a time course with typical premotion and motion phases over both motor areas. A clear‐cut temporal delay between the SMAp and MI activation did not occur either in SCI patients or in controls. These findings obtained with noninvasive neuroelectrical source imaging document that in chronic SCI subjects “executive” motor areas are engaged with a preserved temporal and spatial pattern during preparation and execution of intact movements. Hum Brain Mapp, 2005. © 2005 Wiley‐Liss, Inc.
Sensorimotor organization in double cortex syndrome
Authors: Jirsch Jeffrey D. , Bernasconi Neda , Villani Flavio , Vitali Paolo , Avanzini Giuliano , Bernasconi Andrea 
Published: August 2005

AbstractSubcortical band heterotopia is a diffuse malformation of cortical development related to pharmacologically intractable epilepsy. On magnetic resonance imaging (MRI), patients with “double cortex” syndrome (DCS) present with a band of heterotopic gray matter separated from the overlying cortex by a layer of white matter. The function and connectivity of the subcortical heterotopic band in humans is only partially understood. We studied six DCS patients with bilateral subcortical band heterotopias and six healthy controls using functional MRI (fMRI). In controls, simple motor task elicited contralateral activation of the primary motor cortex (M1) and ipsilateral activation of the cerebellum and left supplementary motor area (SMA). All DCS patients showed task‐related contralateral activation of both M1 and the underlying heterotopic band. Ipsilateral motor activation was seen in 4/6 DCS patients. Furthermore, there were additional activations of nonprimary normotopic cortical areas. The sensory stimulus resulted in activation of the contralateral primary sensory cortex (SI) and the thalamus in all healthy subjects. The left sensory task also induced a contralateral activation of the insular cortex. Sensory activation of the contralateral SI was seen in all DCS patients and secondary somatosensory areas in 5/6. The heterotopic band beneath SI became activated in 3/6 DCS patients. Activations were also seen in subcortical structures for both paradigms. In DCS, motor and sensory tasks induce an activation of the subcortical heterotopic band. The recruitment of bilateral primary areas and higher‐order association normotopic cortices indicates the need for a widespread network to perform simple tasks. Hum Brain Mapp, 2005. © 2005 Wiley‐Liss, Inc.
Influence of surface self‐modification in Ringer's solution on the passive behavior of titanium
Authors: Alkhateeb E. , Virtanen S. 
Published: August 2005

AbstractThe influence of the spontaneous surface modification of titanium by exposure to Ringer's solution at open‐circuit conditions on the passive behavior was studied. The electrochemical behavior of Ti was compared in a simple NaCl and in Ringer's physiological solution. Potentiodynamic polarization curves show significantly higher passive current densities in Ringer's solution as compared with the simple saline solution. Furthermore, impedance spectra measured at the open‐circuit potential as a function of time indicate that in saline solution a long‐term exposure over some days leads to a strong increase of the protectiveness of the passive film. This improvement of the passive behavior cannot be observed in Ringer's solution, but a strong modification of the passive film/electrolyte interface can be seen in the impedance spectra. The changes in the impedance spectra can be correlated with the results observed by surface characterization regarding the morphology (scanning electron microscopy) and chemical composition of the surface (X‐ray photoelectron spectroscopy). In agreement with previous work by others, a spontaneous modification of the surface of Ti by Ca and P species was observed. The composition of the Ca/P precipitates changes as a function of time, indicating a slow formation of a hydroxyapatite‐like deposit layer on the surface. The results of the present work indicate that the formation of the outer Ca‐P deposit layer on the passive Ti surface (which is beneficial for the biological performance) hinders the normal aging of the passive TiO2. Even though the protectiveness of the passive film can be considered as high also in Ringer's solution, significantly higher passive dissolution rates (i.e., higher metal‐ion release) for Ti exposed to Ringer's solution can be expected as compared with a simple saline solution. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Occipito‐vertebral fusion in ocean sunfishes (Teleostei: Tetraodontiformes: Molidae) and its phylogenetic implications
Authors: Britz Ralf , Johnson G. David 
Published: August 2005

AbstractWe describe the ontogeny of the occipital skull and anterior vertebrae of the molidsRanzania laevisandMasturus lanceolatusand compare it with that of the ostraciidLactophryssp. The first vertebra fuses to the basioccipital in early ontogeny in the two molids and previous authors thus confused that vertebra with the back of the basioccipital, so that all previous counts of their vertebral numbers are incorrect by one vertebra. As evidenced byLactophryssp., ostraciids are the only other tetraodontiforms with similar occipito‐vertebral fusion. In contrast to the molids, additional anterior vertebrae fuse with this complex in ostraciids. We conclude that the shared occipito‐vertebral fusion in molids and ostraciids and its otherwise extremely rare occurrence among teleosts provide support for a sister‐group relationship of the two families. J. Morphol. © 2005 Wiley‐Liss, Inc.
Polyphenol oxidase/caffeic acid may reduce the allergenic properties of peanut allergens
Authors: Chung Si‐Yin , Kato Yoji , Champagne Elaine T 
Published: August 2005

AbstractPolyphenol oxidase (PPO) catalyzes the oxidation of tyrosine residues of proteins and, therefore, their cross‐linking. Previously we demonstrated that cross‐links produced by peroxidase (POD), which also catalyzes tyrosine oxidation, led to a reduction in the allergenic properties of peanut allergens.11 We postulated in this study that PPO can also reduce the allergenic properties by cross‐linking the allergens. Because caffeic acid, a phenolic compound, can cross‐link proteins, its effect on peanut allergens was also examined. In the experiments, peanut extracts were treated with and without PPO, PPO/caffeic (pH 8, 37 °C for 1 h) and caffeic acid (pH 10.5, overnight), respectively. The samples were then analyzed for cross‐links and IgE binding by SDS‐PAGE, Western blots, and competitive inhibition ELISA. Results showed that, in all cases, cross‐links and a decrease of the levels of two peanut major allergens, Ara h 1 and Ara h 2, were observed. Of the three treatments, PPO/caffeic was the most effective in reducing IgE binding or the allergenic properties of peanut allergens. The availability of tyrosine residues was also demonstrated in a POD‐treated system, using a monoclonal antibody against dityrosine. We concluded that PPO/caffeic acid reduced the allergenic properties of Ara h 1 and Ara h 2 by cross‐linking and decreasing the levels of allergens. Copyright © 2005 Society of Chemical Industry
In vitro accessibility of β‐carotene from cooked Sri Lankan green leafy vegetables and their estimated contribution to vitamin A requirement
Authors: Chandrika U Gamage , Svanberg Ulf , Jansz Errol R 
Published: August 2005

AbstractVitamin A deficiency is an important issue for public health in Sri Lanka, where pro‐vitamin A carotenoids from green leafy vegetables provide most of the dietary vitamin A. The objective of this study was to analyse the β‐carotene content of seven types of green leafy vegetables and calculate the contribution of one traditionally cooked portion to the recommended daily allowance (RDA) of retinol. The total amount and in vitro accessibility of β‐carotene were determined using HPLC. The in vitro method simulates the conditions in the human intestinal tract. The all‐trans‐β‐carotene content in the fresh blanched vegetables ranged from 149 µg g−1 dry weight (DW) in leaves of Alternanthera sessilis (mukunuwanna) to 565 µg g−1 DW in Amaranthus caudatus (thampala). One portion (100 g) of green leaves cooked without fat (coconut) only contributed from 140 to 180 µg mg−1 of the recommended daily allowance. A. sessilis, Centella asiatica (gotukola), Spinacea oleracea (nivithi) and A. caudatus, cooked with coconut fat contributed 140–680 µg mg−1. However, stir‐fried or ‘malluma’ preparations (with coconut products) of Sesbania grandiflora (kathurumurunga) and Manihot esculenta (manioc) may provide more than 1.59–4.37 times the RDA of retinol. These results show that not only the choice of green leaves used but also the addition of fat while cooking is of great importance. Copyright © 2005 Society of Chemical Industry
Seasonal patterns of sucrose concentration in relation to other quality parameters of sugar beet (Beta vulgaris L.)
Authors: Kenter Christine , Hoffmann Christa M 
Published: August 2005

AbstractThe chemical composition of sugar beet is the most important parameter affecting its processing. Sugar factories require beet with high concentrations of sucrose and low concentrations of melassigenic substances to maximise the amount of extractable sugar. In order to plan the processing campaign, forecasts of root and sugar yield by prediction models are possible but there are no means to predict the technical quality of the beet. In the present study, the seasonal development and physiological relationships of different parameters of sugar beet quality were analysed. In order to estimate possibilities for quality forecasts, the concentrations of beet quality variables in October were correlated with corresponding quality measurements in late summer and to weather variables during the growing season by linear regressions. In 2000 and 2001, 27 field trials were conducted on commercial farm fields in all sugar beet growing areas in Germany. From June to October, sequential samples were taken every 4 weeks and the concentrations of sucrose, potassium, sodium, total soluble nitrogen, α‐amino nitrogen, nitrate, betaine, reducing sugars and marc in the beet were determined. The sucrose concentration increased progressively until the final harvest date in autumn, whereas the concentrations of the melassigenic substances decreased markedly until late summer and remained fairly constant as the season progressed. Marc concentration was the most stable of the parameters analysed. The sucrose concentration was positively correlated with the concentrations of dry matter, betaine and marc, but negatively with nitrate concentration and leaf yield throughout the season. The correlation between the concentrations of sucrose and nitrogenous compounds measured in summer and their final concentrations in autumn was rather weak. However, it was close for potassium, sodium and marc and a satisfactory prediction of their final concentrations was possible by the end of August. Based on weather data, beet quality was not predictable. Therefore, it seems to be difficult to integrate beet quality parameters into prediction models. Copyright © 2005 Society of Chemical Industry
Effect of postharvest handling on valerenic acids content of fresh valerian (Valeriana officinalis) root
Authors: Shohet Deborah , Wills Ron BH 
Published: August 2005

AbstractValerian (Valeriana officinalis) is a medicinal herb native to Europe and North Asia, the roots and rhizomes of which are used as a sedative for nervous tension, sleeplessness, anxiety and stress. The impact of washing and drying on the valerenic acids concentration in valerian roots was investigated. The valerenic acids content of roots that were washed, soaked or cut prior to drying was not significantly different from that of whole valerian roots that were dried without washing, but cutting markedly decreased the drying time. Increasing the drying temperature from 15 to 70 °C reduced drying time by 176 h, with a 23% loss of valerenic acids from 15 to 40 °C. A further 36% loss occurred from 40 to 50 °C but no further significant change was evident at higher temperatures. The use of a heat pump dryer reduced the drying time at 40 °C by 25% compared with a hot air drier operated at the same temperature with no significant difference in the level of valerenic acids. There was no significant change in the level of valerenic acids in fresh whole roots held at ambient conditions for 10 days but a considerable decrease in water content. Hence valerian growers can separate or soak roots prior to washing and can store fresh roots before drying without concern over loss of valerenic acids. However, drying at the lowest feasible temperature is recommended. Copyright © 2005 Society of Chemical Industry
Degradation of Poly(lactic acid) into Repolymerizable Oligomer using Montmorillonite K10 for Chemical Recycling
Authors: Okamoto Kohei , Toshima Kazunobu , Matsumura Shuichi 
Published: August 2005

AbstractSummary: The degradation of poly(L‐lactic acid) (PLLA) into a repolymerizable oligomer was carried out using a clay catalyst, montmorillonite K10 (MK10), with the objective of developing a chemical recycling process. PLLA having an $\overline M _{\rm w}$ of 120 000 was degraded by MK10 in toluene at 100 °C for 6 h to produce the corresponding linear‐type oligomers having a molecular weight of a few hundreds in a yield of greater than 90%. The oligomer was readily polymerized by a conventional chemical catalyst to give a high‐molecular‐weight PLLA. No isomerization of L‐lactic acid occurred during the degradation process using MK10. The MK10 could be repeatedly used at least five times without any significant decrease in its activity. The degradation of PLLA was accelerated by the addition of a small amount of ethanol in toluene using anhydrous MK10 to produce oligomers with ethyl ester end groups.Degradation of poly(L‐lactic acid) (PLLA) into a repolymerizable oligomer.magnified imageDegradation of poly(L‐lactic acid) (PLLA) into a repolymerizable oligomer.
High‐Content Pendant Photochromic Copolymer with Dithienylethene/Fluorene 2:1 Mole Ratio
Authors: Li Xiaochuan , Tian He 
Published: August 2005

AbstractSummary: Two photochromic dithienylethene units were incorporated into one fluorene unit as a monomer and the mole ratio of photochromic unit/repeat unit reached to 2:1 using this monomer. The content of dithienylethene component in the polymer could be improved effectively by polymerization of this monomer, which contains more than one dithienylethene units. All the starting materials concerned in the synthesis are commercially available and so the synthesis could be performed on a large scale. The polymer obtained by typical palladium‐catalyzed Suzuki coupling reaction is photochromic both in solution and in solid state and possesses good solubility. The photochromic and photomodulation luminescence properties of the polymer are also presented.Structure of the photochromic polymer based on dithienylethene.magnified imageStructure of the photochromic polymer based on dithienylethene.
Core complementarities of the corporation: organization of an innovating firm
Authors: Leiponen Aija 
Published: August 2005

AbstractDespite the proliferation of arrangements to outsource or cooperate in Research and Development, the benefits and costs of alternative organizational forms are not very well understood. This paper develops a supermodularity model to highlight the conditions under which internal or external modes of organizing innovation activities are likely to occur. The technological and institutional environment drives firms' decisions to organize innovation and invest in learning, which determine firm performance in terms of innovation and growth. Internal organization is beneficial when complementarities among activities are strong. However, independent governance of complementary activities may become optimal when depreciation of knowledge is rapid due to radical technical change. Copyright © 2005 John Wiley & Sons, Ltd.
Price‐matching policy with imperfect information
Authors: Mao Wen 
Published: August 2005

AbstractThe model of price‐matching policy emphasizes on the importance of information imperfection. The demand is derived based on the assumptions that consumers have different reservation prices and different preferences over location. When a firm undercuts its competitor's price, it changes the demand structure of the market. The result shows that price‐matching policies are anticompetitive, but they do not facilitate monopoly price. Copyright © 2005 John Wiley & Sons, Ltd.
Technological and organizational changes as determinants of the skill bias: evidence from the Italian machinery industry
Authors: Piva Mariacristina , Santarelli Enrico , Vivarelli Marco 
Published: August 2005

AbstractRecent empirical literature has introduced the ‘Skill Biased Organizational Change’ (SBOC) hypothesis, according to which organizational change can be considered as one of the main causes of the skill bias (increase in the number of highly skilled workers) exhibited by manufacturing employment in developed countries. This paper focuses on the importance of the SBOC with respect to the more traditional ‘Skill Biased Technological Change’ in driving the skill composition of workers in the Italian machinery sector. A dynamic panel data analysis is proposed which uses a unique firm‐level dataset. The results show that both skilled and unskilled workers are negatively affected by technological change, while organizational change—which in turn may be linked to new technologies—is positively linked to skilled workers. Copyright © 2005 John Wiley & Sons, Ltd.
Evidence for further genetic locus heterogeneity and confirmation of RLS‐1 in restless legs syndrome
Authors: Winkelmann Juliane , Lichtner Peter , Pütz Benno , Trenkwalder Claudia , Hauk Stephanie , Meitinger Thomas , Strom Tim , Muller‐Myhsok Bertram 
Published: August 2005

AbstractRestless legs syndrome (RLS; MIM 102300) is a common neurological disorder characterized by dysesthesias and an urge to move the lower limbs. The symptoms predominantly occur at rest, in the evening, and improve with movement. There is a high familial aggregation but gene mutations have not yet been found. Three loci for RLS on chromosomes 12q, 14q, and 9p (RLS‐1, RLS‐2, and RLS‐3) have been reported with a recessive (RLS‐1) and autosomal dominant (RLS‐2, RLS‐3) mode of inheritance, respectively. The overall contribution of these loci to this disorder is not known. To evaluate the significance of these loci, we investigated 12 RLS families for possible linkage to these chromosomal regions. Genotyping was carried out in 70 affected family members using 26 polymorphic microsatellite markers (chromosome 12: 7; chromosome 14: 7, chromosome 9: 12). Linkage analysis was carried out using the published parameters applied in the original studies (chromosome 12: q = 0.25, f0 = 0.005, f1 = 0.005, f2 = 0.8; chromosome 14: q = 0.003, f0 = 0.005, f1 = f2 = 0.95; chromosome 9: q = 0.001, f0 = 0.005, f1 = f2 = 0.95; affected individuals only). In addition, transmission disequilibrium test (TDT) analyses were done. We found evidence for linkage on chromosome 12 using the TDT. Linkage to RLS‐2 and RLS‐3 was excluded in 1 of 12 families. This supports the existence of RLS‐1 and provides evidence for the likelihood of further genetic locus heterogeneity of RLS. Investigations in additional RLS families are required to confirm the known loci and further genome wide linkage analyses have the potential to identify additional RLS loci. © 2005 Movement Disorder Society
Syncoilin upregulation in muscle of patients with neuromuscular disease
Authors: Brown Susan C. , Torelli Silvia , Ugo Isabella , De Biasia Floriana , Howman Emily V. , Poon Ellen , Britton Joanna , Davies Kay E. , Muntoni Francesco 
Published: August 2005

AbstractSyncoilin may have a role in linking the desmin‐associated intermediate filament network of the muscle fiber with the dystrophin‐associated protein complex (DAPC). We have evaluated syncoilin in a range of neuromuscular disorders including Duchenne and Becker muscular dystrophy, central core disease, congenital muscular dystrophies, and neurogenic disorders. Our results show that syncoilin immunolabeling is not only altered in muscle fibers with alterations in the DAPC but also in response to a variety of genetic defects, including those associated with proteins of the extracellular matrix and the intracellular Ca2+‐release channel (ryanodine receptor). The pattern of syncoilin immunolabeling in these diseases appeared to reflect a rearrangement of the intermediate filament–associated cytoskeleton that characterizes both muscle fiber development and conditions in which the cytoskeletal organization of the muscle fiber is significantly affected. These observations raise the possibility that mutations in the gene encoding for syncoilin may underlie some forms of muscle disease. Muscle Nerve, 2005