bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monochromatic Hamiltonian 3‐tight Berge cycles in 2‐colored 4‐uniform hypergraphs
Authors: Gyárfás András , Sárközy Gábor N. , Szemerédi Endre 
Published: May 2009

AbstractHere improving on our earlier results, we prove that there exists an n0 such that for n⩾n0 in every 2‐coloring of the edges of K there is a monochromatic Hamiltonian 3‐tight Berge cycle. This proves the c=2, t=3, r=4 special case of a conjecture from (P. Dorbec, S. Gravier, and G. N. Sárközy, J Graph Theory 59 (2008), 34–44). © 2009 Wiley Periodicals, Inc. J Graph Theory 63: 288–299, 2010
Multi‐coloring the Mycielskian of graphs
Authors: Lin Wensong , Liu Daphne Der‐Fen , Zhu Xuding 
Published: May 2009

AbstractA k‐fold coloring of a graph is a function that assigns to each vertex a set of k colors, so that the color sets assigned to adjacent vertices are disjoint. The kth chromatic number of a graph G, denoted by χk(G), is the minimum total number of colors used in a k‐fold coloring of G. Let µ(G) denote the Mycielskian of G. For any positive integer k, it holds that χk(G) + 1≤χk(µ(G))≤χk(G) + k (W. Lin, Disc. Math., 308 (2008), 3565–3573). Although both bounds are attainable, it was proved in (Z. Pan, X. Zhu, Multiple coloring of cone graphs, manuscript, 2006) that if k≥2 and χk(G)≤3k−2, then the upper bound can be reduced by 1, i.e., χk(µ(G))≤χk(G) + k−1. We conjecture that for any n≥3k−1, there is a graph G with χk(G)=n and χk(µ(G))=n+ k. This is equivalent to conjecturing that the equality χk(µ(K(n, k)))=n+k holds for Kneser graphs K(n, k) with n≥3k−1. We confirm this conjecture for k=2, 3, or when n is a multiple of k or n≥3k2/ln k. Moreover, we determine the values of χk(µ(C2q+1)) for 1≤k≤q. © 2009 Wiley Periodicals, Inc. J Graph Theory 63: 311–323, 2010
Deformation of nasal septal cartilage during mastication
Authors: Al Dayeh Ayman A. , Rafferty Katherine L. , Egbert Mark , Herring Susan W. 
Published: May 2009

AbstractThe cartilaginous nasal septum plays a major role in structural integrity and growth of the face, but its internal location has made physiologic study difficult. By surgically implanting transducers in 10 miniature pigs (Sus scrofa), we recorded in vivo strains generated in the nasal septum during mastication and masseter stimulation. The goals were (1) to determine whether the cartilage should be considered as a vertical strut supporting the nasal cavity and preventing its collapse, or as a damper of stresses generated during mastication and (2) to shed light on the overall pattern of snout deformation during mastication. Strains were recorded simultaneously at the septo‐ethmoid junction and nasofrontal suture during mastication. A third location in the anterior part of the cartilage was added during masseter stimulation and manipulation. Contraction of jaw closing muscles during mastication was accompanied by anteroposterior compressive strains (around −1,000 με) in the septo‐ethmoid junction. Both the orientation and the magnitude of the strain suggest that the septum does not act as a vertical strut but may act in absorbing loads generated during mastication. The results from masseter stimulation and manipulation further suggest that the masticatory strain pattern arises from a combination of dorsal bending and/or shearing and anteroposterior compression of the snout. J. Morphol., 2009. © 2009 Wiley‐Liss, Inc.
Morphology of skin incubation in Pipa carvalhoi (Anura: Pipidae)
Authors: Greven Hartmut , Richter Susanne 
Published: May 2009

AbstractSouth American Pipidae show a unique reproductive mode, in which the fertilized eggs develop in temporarily formed brood chambers of the dorsal skin after eggs have been deposited on the back of the female. We studied the skin incubation of Pipa carvalhoi using light microscopy and scanning electron microscopy. The skin consists of a stratified epithelium with a one‐layered stratum corneum, and the dermis. The dermis of the dorsal skin of nonreproductive and reproductive females lacks a distinct stratum compactum, which is typical for most anuran skins. The entire dermis shows irregularly arranged collagen bundles like a stratum spongiosum. Before egg laying, the skin swells, primarily by thickening and further by loosening of the middle zone of the dermis. In the epidermis, large furrows develop that are the prospective sites of egg nidation. The epidermis, which forms a brood chamber around the developing egg becomes bi‐layered and very thin and lacks a stratum corneum. Further, the dermis loosens and becomes heavily vascularized. Egg carrying females do not have mature oocytes in their ovaries indicating a slow down or interruption of egg maturation during this period. Similarities with the brood pouch of marsupial frogs are discussed. J. Morphol., 2009. © 2009 Wiley‐Liss, Inc.
Identification of intact oxidation products of glycerophospholipids in vitro and in vivo using negative ion electrospray iontrap mass spectrometry
Authors: Yin Huiyong , Cox Brian E. , Liu Wei , Porter Ned A. , Morrow Jason D. , Milne Ginger L. 
Published: May 2009

AbstractFree radical‐induced oxidation products of polyunsaturated fatty acids esterified to phospholipids have been implicated in a number of human diseases including atherosclerosis and neurodegenerative diseases. Some of these phospholipid oxidation products have potent biological activities and likely contribute to human pathophysiological conditions. Oxidation products have also been used as markers of oxidative stress in vivo. Identification and quantification of phospholipid oxidation products are often performed by analyzing the oxidized free fatty acid moieties after hydrolysis from the phospholipids head groups by gas chromatography–mass spectrometry (GC–MS) or liquid chromatography–mass spectrometry (LC–MS). We now describe the definitive identification of intact oxidized products of glycerophospholipids including glycerophosphatidylcholine (GPC), glycerophosphatidylethanolamine (GPE), and glycerophosphatidylserine (GPS) in vitro and in vivo using iontrap MS. For these analyses, the negative ions of the oxidation products of phospholipids are fragmented to MSn and unequivocal structural characterization is obtained based on collision‐induced dissociation (CID) of the sn‐2 carboxylate ion. This technique overcomes the need to hydrolyze fatty acids from phospholipids in the analysis. The method has been used to identify a number of oxidation products of glycerophospholipids including hydroxyeicosatetraenoates (HETEs) and isoprostanes (IsoPs) esterified to different classes of glycerophospholipids in vitro and in vivo. These studies thus provide a new approach to identify the intact oxidation products of glycerolphospholipids. Copyright © 2009 John Wiley & Sons, Ltd.
Reactivity of Tyr–Leu and Leu–Tyr dipeptides: identification of oxidation products by liquid chromatography–tandem mass spectrometry
Authors: Fonseca Conceição , Domingues M. Rosário M. , Simões Cláudia , Amado Francisco , Domingues Pedro 
Published: May 2009

AbstractThe exposure of peptides and proteins to reactive hydroxyl radicals results in covalent modifications of amino acid side‐chains and protein backbone. In this study we have investigated the oxidation the isomeric peptides tyrosine–leucine (YL) and leucine–tyrosine (LY), by the hydroxyl radical formed under Fenton reaction (Fe2+/H2O2). Through mass spectrometry (MS), high‐performance liquid chromatography (HPLC‐MS) and electrospray tandem mass spectrometry (HPLC‐MSn) measurements, we have identified and characterized the oxidation products of these two dipeptides. This approach allowed observing and identifying a wide variety of oxidation products, including isomeric forms of the oxidized dipeptides. We detected oxidation products with 1, 2, 3 and 4 oxygen atoms for both peptides; however, oxidation products with 5 oxygen atoms were only present in LY. LY dipeptide oxidation leads to more isomers with 1 and 2 oxygen atoms than YL (3 vs 5 and 4 vs 5, respectively). Formation of the peroxy group occurred preferentially in the C‐terminal residue. We have also detected oxidation products with double bonds or keto groups, dimers (YL–YL and LY–LY) and other products as a result of cross‐linking. Both amino acids in the dipeptides were oxidized although the peptides showed different oxidation products. Also, amino acid residues have shown different oxidation products depending on the relative position on the dipeptide. Results suggest that amino acids in the C‐terminal position are more prone to oxidation. Copyright © 2009 John Wiley & Sons, Ltd.
Raman and infrared analysis of glues used for pottery conservation treatments
Authors: Asquier Magali , Colomban Philippe , Milande Véronique 
Published: May 2009

AbstractThe conservation of ceramics and glass involves the repair or the restoration of broken and fragmented artefacts with polymer adhesives and gap fillers. In the past, many different adhesives had been used. Re‐restoration is often required and the fast identification of adhesive residues on objects would be very useful to define the best of way to remove them, in particular to avoid the use of noxious chemicals. Sixteen pottery artefacts restored during the 19th and 20th centuries at the Musée National de Céramique in Sèvres have been analysed by non‐destructive Raman microspectroscopy. For comparison purposes, the artefacts were also sampled in order to acquire infrared (IR) absorption spectra in KBr pellets. Modern adhesives (methyl metacrylate/acrylate, vinyl acetate, polychloroprene, methyl 2‐cyanoacrylate and diglycidylether biphenol) were also characterised with the same methods. IR and Raman spectra were obtained for all ancient glue residues, but among the 16 analysed items, only 7 adhesives have been identified unambiguously, and an assignment proposed for 4 others solely on the basis of the Raman signature. Copyright © 2009 John Wiley & Sons, Ltd.
A resonance Raman spectroscopic investigation into the effects of fixation and dehydration on heme environment of hemoglobin
Authors: Asghari‐Khiavi Mehdi , Mechler Adam , Bambery Keith R. , McNaughton Don , Wood Bayden R. 
Published: May 2009

AbstractThe effects of fixation and dehydration procedures on heme environment inside human erythrocytes were examined using resonance Raman spectroscopy. The resonance Raman spectroscopic data along with far‐infrared spectra show that hemoglobin in air‐dried red blood cells and those fixed in the precipitating fixatives, methanol and acetone, changes to hemichrome, a low‐spin component in which the sixth coordination site of the iron is occupied by the imidazole group of the distal histidine. The cross‐linking fixatives, formaldehyde and glutaraldehyde, maintain hemoglobin in its native conformational state (oxyhemoglobin) as evidenced by the appearance of the oxygen ligand marker bands along with the skeletal sensitive modes. However, polymerization with cross‐linking fixatives increases the auto‐oxidation kinetics of hemoglobin and gradually oxidizes it to the met state. Moreover, the dehydration of a red blood cell under N2 results in a change of oxyhemoglobin to a six coordinate low‐spin FeII derivative of hemoglobin, hemochrome. Copyright © 2009 John Wiley & Sons, Ltd.
Structural modifications in metal complexes of a plant metallothionein caused by reductive radical stress: a Raman study
Authors: Torreggiani Armida , Domènech Jordi , Tinti Anna 
Published: May 2009

AbstractThe effect of radical stress in the biological environment is a very active field of research connecting various disciplines of life science. Thus, a comprehensive vision of all possible reactive species is necessary for contributing to the solution of puzzling questions on free radicals. In this contest, damages to Zn(II) and Cd(II) complexes of a plant metallothionein (Quercus suber—QsMT), because of reductive radical stress, were investigated by Raman spectroscopy. QsMT is a low‐molecular‐weight cysteine‐rich protein obtained by in vivo synthesis to have a physiologically representative model. Gamma‐irradiation was used to simulate the endogenous formation of reductive species. By changing the appropriate conditions of irradiation, a selection of the reacting radical species (hydrogen atom and hydrated electron) was carried out. Specific damages occur at sensitive amino acid sites, selectively, rather than indiscriminately. In particular, Cys resulted to be among the most sensitive residues toward radical attack, suggesting that the thiolate clusters of both metal and QsMTs act as efficient interceptors of reducing species. Under reductive stress, Zn–QsMT undergoes a significant thiolate group oxidation and the participation of ligands other than the cysteine‐derived thiolate bonds (i.e. His) in zinc coordination becomes necessary for the protein stabilization. Regarding Met residues, they resulted to be more sensitive to the reductive radical attack when the protein binds Cd(II) ions, indicating that the protein structure can play a significant role in blocking the ready access of free radicals to the sulfur‐containing residues, so strongly affecting the radiosensitivity of the protein. In conclusion, the results obtained from γ‐irradiation experiments indicate that reductive stress causes changes in the primary QsMT structure and in the secondary and tertiary structures, and the radical‐induced effects are dependent on the metal bound. Copyright © 2009 John Wiley & Sons, Ltd.
Temperature‐depending Raman line‐shift of silicon carbide
Authors: Bauer Michael , Gigler Alexander M. , Huber Andreas J. , Hillenbrand Rainer , Stark Robert W. 
Published: May 2009

AbstractSilicon carbide (SiC) is often used for electronic devices operating at elevated temperatures. Spectroscopic temperature measurements are of high interest for device monitoring because confocal Raman microscopy provides a very high spatial resolution. To this end, calibration data are needed that relate Raman line‐shift and temperature. The shift of the phonon wavenumbers of single crystal SiC was investigated by Raman spectroscopy in the temperature range from 3 to 112°C. Spectra were obtained in undoped 6HSiC as well as in undoped and nitrogen‐doped 4HSiC. All spectra were acquired with the incident laser beam oriented parallel as well as perpendicular to the c‐axis to account for the anisotropy of the phonon dispersion. Nearly all individual peak centers were shifting linearly towards smaller wavenumbers with increasing temperature. Only the peak of the longitudinal optical phonon A1(LO) in nitrogen‐doped 4HSiC was shifting to larger wavenumbers. For all phonons, a linear dependence of the Raman peaks on both parameters, temperature and phonon frequency, was found in the given temperature range. The linearity of the temperature shift allows for precise spectroscopic temperature measurements. Temperature correction of Raman line‐shifts also provides the ability to separate thermal shifts from mechanically induced ones. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of cooking and reheating methods on the fatty acid profile of sea bream treated with rosemary extract
Authors: Ozogul Yesim , Ozyurt Gulsun , Kuley Boga Esmeray 
Published: May 2009

AbstractBACKGROUND:The effects of rosemary extract on the fatty acid profile of sea bream fillets cooked by different methods (oven baking, grilling and pan frying) as well as the effects of different reheating methods (microwave and conventional oven) on the fatty acid composition of fish after frozen storage for 4 months were investigated.RESULTS:The proportion of saturated fatty acids increased only slightly in fried samples but significantly in oven‐baked and grilled samples, while the proportion of polyunsaturated fatty acids (PUFAs) increased significantly in fried samples but only slightly in oven‐baked and grilled samples. The proportion of monounsaturated fatty acids remained relatively constant after cooking. Of the fatty acids analysed, the most significant increases (P< 0.05) were observed in C18:1n‐9 and C18:2n‐6 and the most significant decreases (P< 0.05) in C14:0, C16:1, C20:5n‐3 and C22:6n‐3. Although sea bream fillets fried in sunflower oil showed an increase in PUFAs, the lowest eicosapentaenoic and docosahexaenoic acid contents were found in fried samples.CONCLUSION:Sea bream fillets treated with rosemary extract showed slower oxidation than untreated fish. Neither conventional nor microwave reheating after frozen storage for 4 months had a detrimental effect on the fatty acid profile and its stability. Copyright © 2009 Society of Chemical Industry
Chemical characterisation of CTC black tea of northeast India: correlation of quality parameters with tea tasters' evaluation
Authors: Bhuyan Lakshi P , Hussain Assma , Tamuly Pradip , Gogoi Ramen C , Bordoloi Prasanna K , Hazarika Mridul 
Published: May 2009

AbstractBACKGROUND: Consumers have different regional perceptions of tea quality. Objective evaluation based on biochemical data for different regions has been needed for a long time. Biochemical factors regulating this variation would help to remove regional disparities. This study was undertaken on CTC (crust, tear and curl) black tea to generate the biochemical data responsible for quality along with tea tasters' evaluation of three geographical regions of northeast India and to determine the reason for the variation.RESULTS: Brahmaputra valley teas had highest theaflavin (TF), thearubigin (TR), brightness (BR) and total colour (TC) and low crude fibre content (CFC) and total polyphenol (TPP). Brahmaputra valley and Dooars region teas showed high total soluble solid (TSS). Barak valley teas had highest CFC and low TSS, caffeine (CA), TF, TR and TC. Dooars region teas had high CA and TPP and low BR. Dooars region and Barak valley teas contained higher levels of residual catechin than Brahmaputra valley teas.CONCLUSION: Overall quality as evaluated by tea tasters was found to be highest for Brahmaputra valley teas followed by Dooars region and Barak valley teas. This high evaluation can be attributed to higher levels of TF, TR, BR and TSS. Barak valley and Dooars region teas contained high residual catechin, indicating limitation in oxidation during processing. Copyright © 2009 Society of Chemical Industry
Time for a shift in crop production: embracing complexity through diversity at all levels
Authors: Østergård Hanne , Finckh Maria R , Fontaine Laurence , Goldringer Isabelle , Hoad Steve P , Kristensen Kristian , Lammerts van Bueren Edith T , Mascher Fabio , Munk Lisa , Wolfe Martin S 
Published: May 2009

AbstractA radical shift in our approach to crop production is needed to ensure food security and to address the problems of soil degradation, loss of biodiversity, polluted and restricted water supplies, coupled with a future of fossil fuel limitations and increasingly variable climatic conditions. An interdisciplinary network of European scientists put forward visions for future crop production embracing the complexity of our socio‐ecological system by applying the principle of diversity at all levels from soil micro‐organisms to plant varieties and cropping systems. This approach, integrated with careful deployment of our finite global resources and implementation of appropriate sustainable technology, appears to be the only way to ensure the scale of system resilience needed to cope with many of our concerns. We discuss some of the most important tools such as (i) building soil fertility by recycling of nutrients and sustainable use of other natural and physical resources, (ii) enhancing biological diversity by breeding of crops resilient to climate change and (iii) reconnecting all stakeholders in crop production. Finally, we emphasise some of the changes in agricultural and environmental regulation and policy needed in order to implement the visions. Copyright © 2009 Society of Chemical Industry
Instrumental and sensory characterisation of industrially processed applesauces
Authors: Colin‐Henrion Muriel , Mehinagic Emira , Patron Corinne , Jourjon Frédérique 
Published: May 2009

AbstractBACKGROUND: In the context of fruit consumption promotion, applesauce is an interesting ready‐to‐eat product. However, little information has been gathered on its sensory properties. Yet, the processing involved easily triggers rheological and structural changes, possibly modifying these sensory properties. The aim of this study was thus to provide a global approach for applesauce characterisation by studying instrumental and sensory properties, with knowledge of the processing conditions applied. Four applesauce samples processed under controlled parameters were therefore compared with seven purchased applesauces.RESULTS: The four studied samples were characterised by their high creaminess and low graininess. These products were homogeneous and presented a small average particle size (332–354 µm). Their flow properties were best described with the Hershel–Bulkey model. The products were shear‐thinning with low yield stress. Interestingly, significant differences in textural and flow properties were also found among these four manufactured samples.CONCLUSION: Sensory characterisation revealed aromatic and textural diversity even though applesauce is considered as a common product. Differences found among the samples of interest might be related to postharvest maturity of fruits and consequent pectic degradation from cell walls. Finally, the candied odour and flavour that distinguished these products could be related to the extensive heating applied during processing. Copyright © 2009 Society of Chemical Industry
Optimization of hydrolysis of sardine (Sardina pilchardus) heads with Protamex: enhancement of lipid and phospholipid extraction
Authors: Dumay Justine , Allery Marion , Donnay‐Moreno Claire , Barnathan Gilles , Jaouen Pascal , Carbonneau Marie Elise , Bergé Jean Pascal 
Published: May 2009

AbstractBACKGROUND: Fish by‐products are not considered as valuable raw materials even if they usually contain valuable components such as lipids. Fish lipids are well known for their nutritional potential and health effects but their extraction remains problematic due to the use of organic solvents. Enzymatic hydrolysis such as the proteolysis of tissues can lead to lipid extraction.RESULTS: Hydrolysis of sardine heads by Protamex was studied (temperature, hydrolysis time and enzyme–substrate ratio) using response surface methodology in order to obtain the highest release of lipids and particularly phospholipids. No relation between the degree of hydrolysis and lipid recovery were depicted; however, optimum conditions for both the release of lipids and phospholipids were found to be similar (29 min, 31 °C with 2.6 g kg−1 enzyme). Under these hydrolysis conditions, rich lipid and phospholipid fractions (oily and aqueous fractions) can be recovered when time, temperature and enzyme consumption are minimized. Analytical data have revealed that they contain high‐quality lipids, especially ω3 fatty acid.CONCLUSION: This study demonstrated that proteolysis can be used for high lipid recovery from little‐exploited biomass like fish heads without requiring solvent or thermal treatment. Resulting phospholipids, fatty acids and peptides could be utilized for nutritional or feed purposes. Copyright © 2009 Society of Chemical Industry