bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solution of fink & straight conjecture on path‐perfect complete bipartite graphs
Authors: Cao Weiting , Hamburger Peter 
Published: January 2007

AbstractWe consider various edge disjoint partitions of complete bipartite graphs. One case is where we decompose the edge set into edge disjoint paths of increasing lengths. A graph G is path‐perfect if there is a positive integer n such that the edge set E(G) of the graph G can be partitioned into paths of length 1,2,3,…,n. The main result of the paper is the proof of the conjecture of Fink and Straight [4]: A complete bipartite graph Ks,t on t + s vertices (t ≤ s) is path‐perfect if and only if there is a positive integer n such that the following two conditions are satisfied;

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Our proof gives a linear time algorithm to find an edge disjoint partition of a complete bipartite graph into paths of lengths 1,2,3,…,n. © 2007 Wiley Periodicals, Inc. J Graph Theory 55:91–111, 2007
Edge proximity conditions for extendability in cubic bipartite graphs
Authors: Aldred R. E. L. , Jackson Bill 
Published: January 2007

AbstractWe show that a set M of m edges in a cyclically (3m − 2)‐edge‐connected cubic bipartite graph is contained in a 1‐factor whenever the edges in M are pairwise distance at least f(m) apart, where

© 2007 Wiley Periodicals, Inc. J Graph Theory 55: 112–120, 2007
A lower bound on the order of regular graphs with given girth pair
Authors: Balbuena C. , Jiang T. , Lin Y. , Marcote X. , Miller M. 
Published: January 2007

AbstractThe girth pair of a graph gives the length of a shortest odd and a shortest even cycle. The existence of regular graphs with given degree and girth pair was proved by Harary and Kovács [Regular graphs with given girth pair, J Graph Theory 7 (1983), 209–218]. A (δ, g)‐cage is a smallest δ‐regular graph with girth g. For all δ ≥ 3 and odd girth g ≥ 5, Harary and Kovács conjectured the existence of a (δ,g)‐cage that contains a cycle of length g + 1. In the main theorem of this article we present a lower bound on the order of a δ‐regular graph with odd girth g ≥ 5 and even girth h ≥ g + 3. We use this bound to show that every (δ,g)‐cage with δ ≥ 3 and g ∈ {5,7} contains a cycle of length g + 1, a result that can be seen as an extension of the aforementioned conjecture by Harary and Kovács for these values of δ, g. Moreover, for every odd g ≥ 5, we prove that the even girth of all (δ,g)‐cages with δ large enough is at most (3g − 3)/2. © 2007 Wiley Periodicals, Inc. J Graph Theory 55: 153–163, 2007
Prediction of fibre components in oat hulls by near infrared reflectance spectroscopy
Authors: Redaelli Rita , Berardo Nicola 
Published: January 2007

AbstractThe fibre fractions of oat (Avena sativa L.) hulls, i.e. neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL), were evaluated, using a specifically developed near infrared reflectance spectroscopy (NIRS) equation model, in a set of cultivars grown in various locations across Italy. The results indicated that the NIRS technique can accurately predict the fibre composition of oat hulls. Statistical analysis of variance underlined the strong impact of cultivar on the accumulation of fibre components, whereas location generally played a minor role. The largest variability among cultivars was observed in ADL content, whereas the range of variation in NDF and ADF contents appeared to be reduced. The description of the chemical characteristics of oat hulls could be helpful in determining the most suitable end‐use for specific cultivars. Copyright © 2007 Society of Chemical Industry
Bioactivity of extracts from gonadal tissue of the edible Australian purple sea urchin Heliocidaris erythrogramma
Authors: Sheean Paul D , Hodges Lynn D , Kalafatis Nicolette , Wright Paul FA , Wynne Paul M , Whitehouse Michael W , Macrides Theodore A 
Published: January 2007

AbstractDichloromethane (DCM), methanol (MeOH) and aqueous extracts of male gonadal tissue from Heliocidaris erythrogramma were screened for bioactivity. None of the extracts were antibacterial against Gram‐positive Staphylococcus aureus and Gram‐negative Escherichia coli. The aqueous extract scavenged the reactive oxygen species (ROS), hydrogen peroxide (H2O2), but did not react with the hydroxyl radical (OH·) or with the stable free radical 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH·). No antioxidant potential was evident for the DCM and MeOH extracts. The extracts displayed various levels of anti‐inflammatory action in connection with inhibition of cyclooxygenase (ovine COX‐1 and COX‐2), but were insignificant inhibitors of lipoxygenase (soybean 15‐LO) pure enzyme. Anti‐inflammatory action related to reduction of leukotriene production by stimulated porcine neutrophils was affected only by the aqueous extract. The DCM and aqueous extracts, but not the MeOH extract, showed anti‐inflammatory activity in rats developing adjuvant‐induced polyarthritis. Overall, the DCM extract was 75% inhibitory of arthritis symptoms, and the aqueous extract was 55% inhibitory. Suppression of growth of the mouse leukaemic lymphoblastic (P388) cell line was evident for the DCM extract only. This extract was also able to exert a cytotoxic effect on the tumour cell line. For all extracts, no general cytotoxicity against isolated rat hepatocytes was observed. Copyright © 2007 Society of Chemical Industry
Fatty acid composition of herring (Clupea harengus L.): influence of time and place of catch on n‐3 PUFA content
Authors: Jensen Kristina Nedenskov , Jacobsen Charlotte , Nielsen Henrik Hauch 
Published: January 2007

AbstractThe fatty acid composition (FAC) was determined in muscle samples from 963 herring (Clupea harengus L.) caught during 2001–2003 in waters around Denmark. The overall variation in FAC was mainly related to seasonal (summer or winter) and annual (2001, 2002 or 2003) variation. No clear variation due to place of catch (Baltic Sea, Skagerrak, Kattegat or the northern, western or eastern part of the North Sea) was found. Of the nutritionally important n‐3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), EPA seemed to show a seasonal variation, with the highest amount during summer, whereas no periodic variation was observed for DHA. Herring from one catch, however, were found to have an extraordinarily high amount of EPA (11%) compared with all other catches (amounts of EPA ranging from 4 to 8%). This high EPA content found only in herring caught in May 2003 in the northern North Sea (NSN) was in large contrast to the herring caught in the same place 3 months earlier, which had the lowest EPA content overall. The abrupt increase in EPA level from February to May was not correlated with biological parameters such as spawning type, maturity status, age, sex and size, but it might be related to variation in the FAC of the calanoid copepods on which the herring feed. Considering the nutritional aspects, the high‐EPA herring from the NSN catch in May 2003 had a relatively low lipid content (7%), making them highly suitable for human consumption. Copyright © 2007 Society of Chemical Industry
Insight into the host–parasite interplay by proteomic study of host proteins copurified with the human parasite, Schistosoma japonicum
Authors: Liu Feng , Hu Wei , Cui Shu‐Jian , Chi Ming , Fang Cai‐Yun , Wang Zhi‐Qin , Yang Peng‐Yuan , Han Ze‐Guang 
Published: January 2007

AbstractThe tegument proteins of schistosome have attracted the most attention in studies of host–parasite interplay, while the host proteins acting at the host–parasite interface remained largely elusive. Here, we undertook a high‐throughput proteomic approach to characterize the schistosome‐adsorbed host proteins. Fifty five distinct host proteins were confidently identified in S. japonicum samples, including cercaria, schistosomula, adults, eggs, and miracidia, together with tegument and eggshell preparations, of which 23 and 38 host proteins were identified in adult worms and eggs, respectively. Among the schistosome‐adsorbed host proteins, host neutrophil elastases were found in the granuloma initiated by schistosome egg deposition, implying that the host innate immune molecules could participate in the granuloma formation for fighting against schistosome invasion, except for the adaptive immune system. In addition, some host proteins, such as proteinase inhibitor and superoxide dismutase, might be utilized by schistosome to counteract or attenuate the host attacks. These parasite‐adsorbed host proteins will provide new insights into the host immune responses against schistosome infection, the evasive behavior of the adult worms, and the granuloma formation, which could render an in‐depth understanding for the host–parasite interplay.
Influence of Ki‐ras‐driven oncogenic transformation on the protein network of murine fibroblasts
Authors: Recktenwald Christian V. , Mendler Simone , Lichtenfels Rudolf , Kellner Roland , Seliger Barbara 
Published: January 2007

AbstractKi‐ras gene mutations that specifically occur in codons 12, 13 and 61 are involved in the carcinogenesis of acute myeloid leukemia, melanoma and different carcinomas. In order to define potential mutation‐specific therapeutic targets, stable transfectants of NIH3T3 cells carrying different Ki‐ras4B gene mutations were generated. Wild type Ki‐ras transformants, mock transfectants and parental cells served as controls. These in vitro model systems were systematically analyzed for their protein expression pattern using two‐dimensional gel electrophoresis followed by mass spectrometry and/or protein sequencing. Using this approach, a number of target molecules that are differentially but coordinately expressed in the ras transfectants were identified next to other proteins that exhibit a distinct regulation pattern in the different cell lines analyzed. The differentially expressed proteins predominantly belong to the families of cytoskeletal proteins, heat shock proteins, annexins, metabolic enzymes and oxidoreductases. Their validation was assessed by real‐time quantitative RT‐PCR and/or Western blot analysis. Our results suggest that the Ki‐ras‐transformed cells represent a powerful tool to study Ki‐ras gene mutation‐driven protein expression profiles. In addition, this approach allows the discovery of ras‐associated cellular mechanisms, which might lead to the identification of physiological targets for pharmacological interventions of the treatment of Ki‐ras‐associated human tumors.
Predicting peptides bound to I‐Ag7 class II histocompatibility molecules using a novel expectation‐maximization alignment algorithm
Authors: Chang Kuan Y. , Suri Anish , Unanue Emil R. 
Published: January 2007

AbstractThe useful structural features of class II MHC molecules are rarely integrated into T‐cell epitope predictions. We propose an approach that applies a novel expectation‐maximization algorithm to align the naturally processed peptides selected by the class II MHC I‐Ag7 molecule – focusing on the five MHC‐specific anchor positions. Based on the alignment profile, log of odds (LOD) scores supplemented with the Laplace plus‐one pseudocounts method are applied to identify the potential T‐cell epitopes. In addition, an innovative computational concept of hindering residues using statistical and structural information is developed to refine the prediction. Performance analysis by receiver operating characteristics statistics and the experimental validation of the LOD scores demonstrate the accuracy of our predictive model. Furthermore, our model successfully predicts T‐cell epitopes of hen egg‐white lysozyme protein antigen. Our study provides a framework for predicting T‐cell epitopes in class II MHC molecules.
Facile synthesis of conjugated rod‐coil block copolymers
Authors: Wang Hengbin , Jost Robert , Wudl Fred 
Published: January 2007

AbstractA facile synthetic approach of conjugated rod‐coil block copolymers with poly(para‐phenylene) as the rod block and polystyrene or polyethylene glycol as the coil block was developed. The block copolymers were synthesized through a TEMPO‐mediated radical polymerization of 3,5‐cyclohexadiene‐1,2‐diol‐derived monomers (diacetate, dibenzonate, and dicarbonate), followed by thermal aromatization of the polymer precursor. The living character of the polymerization and the structure of the copolymers were studied by NMR, GPC, TGA, and UV–vis spectroscopy. The average conjugation lengths of the copolymers were calculated according to their maxima in UV–vis spectroscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 800–808, 2007
Photosensitive polybenzoxazole based on a poly(o‐hydroxy amide), a dissolution inhibitor, and a photoacid generator
Authors: Ogura Tomohito , Ueda Mitsuru 
Published: January 2007

AbstractA positive‐type photosensitive polybenzoxazole (PSPBO), based on a poly(o‐hydroxy amide) (PHA), the dissolution inhibitor (DI) 9,9‐bis(4‐tert‐butoxycarbonyloxyphenyl)fluorene (t‐Boc BHF), and the photoacid generator (5‐propylsulfonyloxyimino‐5H‐thiophene‐2‐ylidene)‐(2‐methylphenyl)acetonitrile (PTMA), was developed. Several new tert‐butoxycarbonylated compounds as DIs for PSPBOs were prepared from phenolic compounds having a cardolike structure with di‐tert‐butyl dicarbonate in the presence of 4‐dimethylaminopyridine. Among them, t‐Boc BHF and 5,5′,6,6′‐tetra(tert‐butoxycarbonyl)‐3,3,3′,3′‐tetramethyl‐1,1′‐spirobiindane acted as excellent DIs, giving a large dissolution contrast between the exposed and unexposed areas in a 2.38 wt % tetramethylammonium hydroxide solution (TMAHaq)/5 wt % iso‐propanol (i‐PrOH). The dissolution behavior of this PSPBO system was studied in relation to the PTMA and t‐Boc BHF loadings and postexposure baking temperature. A PSPBO consisting of PHA (77 wt %), t‐Boc BHF (20 wt %), and PTMA (3 wt %) exhibited a sensitivity of 34 mJ/cm2 and a contrast of 5.8 when exposed to 365‐nm light (i‐line) and developed with an aqueous alkaline developer, 2.38 wt % TMAHaq/5 wt % i‐PrOH. A clear, positive image with 6‐μm features and a 10‐μm‐thick pattern with high sensitivity and contrast was produced by contact printing and converted into polybenzoxazole patterns upon heating at 350 °C for 1 h. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 661–668, 2007
Preparation and characterization of heteroarm H‐shaped terpolymers by combination of reversible addition‐fragmentation transfer polymerization and ring‐opening polymerization
Authors: Han De‐Hui , Pan Cai‐Yuan 
Published: January 2007

AbstractHeteroarm H‐shaped terpolymers, [(poly(L‐lactide))(polystyrene)]poly(ethylene oxide)[(polystyrene)(poly(L‐lactide))], [(PLLA)(PS)]PEO[(PS)(PLLA)], in which PEO acts as a main chain and PS and PLLA as side arms, have been successfully prepared via combination of reversible addition–fragmentation transfer (RAFT) polymerization and ring‐opening polymerization (ROP). The first step is the synthesis of the PEO capped with one terminal dithiobenzoate group and one hydroxyl group at every chain end, [(HOCH2)(PhC(S)S)]PEO[(S(S)CPh)(CH2OH)] from the reaction of carboxylic acid with ethylene oxide. Then, the RAFT polymerization of styrene (St) was carried out using [(HOCH2)(PhC(S)S)]PEO[(S(S)CPh)(CH2OH)] as RAFT agent and AIBN as initiator, and the triblock copolymer, [(HOCH2)(PS)]PEO[(PS)(CH2OH)], was formed. Finally, the heteroarm H‐shaped terpolymers, [(PLLA)(PS)]PEO[(PS)(PLLA)], were produced by ROP of LLA, using triblock copolymer, [(HOCH2)(PS)]PEO[(PS)(CH2OH)], as macroinitiator and Sn(Oct)2 as catalyst. The target products and intermediates were characterized by 1H NMR spectroscopy and gel permeation chromatography. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 789–799, 2007
Sequence distribution and crystal structure of poly(ethylene/butylene terephthalate) copolyesters compared with poly(ethylene/trimethylene terephthalate) copolyesters
Authors: Shyr Tien‐Wei , Lo Chih‐Ming , Ye Sheng‐Rong , Bian Jie 
Published: January 2007

AbstractPoly(ethylene/butylene terephthalate) (EB) copolyesters were synthesized from ethylene glycol (EG), 1,4‐butanediol (BDO), and dimethyl terephthalate with different molar volume ratios. The constitutional units, characterized by 13C NMR, revealed a random distribution in the molecular chain. Nevertheless, crystallites formed across the full range of EG/BDO composition can be observed with the use of a differential scanning calorimeter and a wide angle X‐ray diffraction method. The reflection profile of the EB copolyesters was deconvoluted. Also, in the poly(ethylene/trimethylene terephthalate) (ET) copolyesters previously studied, the crystal structure was dominated by the sequence distribution of the copolyesters. The crystal structures of EB and ET copolyesters, in comparison with the different constitutional repeating units in the molecular chain, are discussed in this study. The glass transition temperature of EB and ET copolyesters were analyzed, considering the copolymer composition and the sequencing of the monomers, and their values were compared to the Johnston's equation. In addition, the analysis of the melting temperatures of both the EB and the ET copolyesters was carried out. The equilibrium melting temperatures of both copolyesters were calculated according to the Hoffman‐Weeks extrapolative method. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 405–419, 2007
Mechanical degradation of polypropylene solutions under large pressure drops
Authors: Martini Raquel E. , Brignole Esteban A. , Barbosa Silvia E. 
Published: January 2007

AbstractThe degradation of polypropylene (PP), dissolved in n‐alkanes at high temperatures and pressures, during the solution discharge to ambient conditions was experimentally studied. Molecular weight distributions (MWD) of the solubilized PP were measured by gel permeation chromatography. The MWD curves of PP obtained after discharge of the polymer solution shift to the low molecular weight side of the distribution and the polydispersity is reduced. In this work, a systematic study on the discharge products was performed to elucidate the degradation mechanism and the effects of temperature and concentration on this phenomenon. Initially, pure polymers, PP and polystyrene (PS) were studied varying the solution temperature. In a second stage, the effect of polymer concentration on chain scission was assessed using experiments on physical blends of PP/PS. In all cases, thermal and oxidative degradation were previously analyzed. Mechanical degradation was found to be the main chain scission mechanism. A negative linear functionality of the chain scission was found in both temperature and polymer concentration. To analyze the relationship between polymer degradation and molecular weight, the chain scission distribution function was calculated. On this basis, a critical molecular weight for the beginning of chain scission was obtained. This value is a function of temperature but remains constant with concentration. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 455–465, 2007
Modelling of the ABL and ARG proteins predicts two functionally critical regions that are natively unfolded
Authors: Buffa Pietro , Manzella Livia , Consoli Maria Letizia , Messina Angelo , Vigneri Paolo 
Published: January 2007

AbstractThe ABL and ARG tyrosine kinases regulate many pivotal cellular processes and are implicated in the pathogenesis of several forms of leukemia. We have modelled the previously uncharacterized core domain (SH3‐SH2‐tyrosine kinase) and C‐terminal actin‐binding domain of ARG. We have also investigated the structural arrangement of the ABL and ARG Cap region and of the long multifunctional region located downstream of the tyrosine kinase domain. We report that the ARG core domain is homologous to the corresponding ABL region, therefore suggesting that ARG catalytic activity is likely regulated by the same SH3–SH2 clamp described for ABL. We also report that the Cap of both ABL and ARG is natively unfolded. Hence, biological events determining the folding of the Cap are critical to allow its interaction with the tyrosine kinase C‐lobe. Furthermore, our results show that, with the exception of the C‐terminal actin‐binding domain, the entire region encoded by the ABL and ARG last exon is natively unfolded. Phosphorylation events or protein–protein interactions regulating the folding of this region will therefore modulate the activity of its numerous functional domains. Finally, our analyses show that the C‐terminal actin‐binding domain of ARG displays a four‐helix bundle structure similar to the one reported for the corresponding ABL region. Our findings imply that many biological activities attributed to ABL, ARG, and their oncogenic counterparts are regulated by natively unfolded regions. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Fabrication of SAG‐AlGaN/InGaN/AlGaN LEDs by mixed‐source HVPE with multi‐sliding boat system
Authors: Kim K. H. , Jang K. S. , Hwang S. L. , Jeon H. S. , Choi W. J. , Yang M. , Ahn H. S. , Kim S. W. , Honda Y. , Yamaguchi M. , Sawaki N. , Yoo J. , Lee S. M. , Koike M. 
Published: January 2007

AbstractThe selective area growth (SAG) of AlGaN/InGaN/AlGaN light‐emitting diodes (LEDs) is performed by mixed‐source hydride vapor phase epitaxy (HVPE). In order to obtain the SAG‐AlGaN/InGaN/AlGaN heterostructure, a special graphite fixture to use in HVPE is designed. First, an n‐type AlGaN layer is grown at 1090 °C on a GaN templated (0001) sapphire substrate with a patterned SAG‐structure of a silicon oxide (SiO2). On this selectively grown n‐type AlGaN layer, a nominally undoped‐InGaN layer is grown using an In‐Ga mixed metallic source at 990 °C. After the growth of InGaN layer, Mg‐doped AlGaN and Mg‐doped GaN layers are grown as a cladding and capping layers at 1090 °C and 1050 °C, respectively. All of the epitaxial layers of LED structure are grown consecutively with a multi‐sliding boat system. Room‐temperature electroluminescence (EL) characteristics show an emission peak wavelength of 415 nm with a full width at half‐maximum (FWHM) of approximately 0.37 eV. We find that the mixed‐source HVPE method with multi‐sliding boat system is possible to be one of the growth methods of III‐nitride LEDs. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of GaN decomposition in an atmospheric MOVPE vertical reactor
Authors: Fathallah W. , Boufaden T. , El Jani B. 
Published: January 2007

AbstractThe GaN decomposition versus the annealing ambient (H2, N2 + H2) have been investigated in atmospheric pressure metal organic vapor phase epitaxy (AP‐MOVPE) vertical reactor. A comparison between the low temperature GaN (LT‐GaN) decomposition in a vertical reactor and a horizontal one was discussed in order to explain the failure of high temperature GaN (HT‐GaN) growth on Al2O3 using 2D buffer layer under a mixture of H2 and N2 in our vertical reactor. Decomposition rates versus temperature and ambient gas were measured using real time laser reflectometry. The surfaces of these films were analyzed using a scanning electron microscopy (SEM). Hydrogen seems to considerably affect the LT‐GaN surface morphology by a mass transport, diffusion on the substrate surface and by a decomposition process even in the presence of ammonia and nitrogen. The high decomposition rates of the LT‐GaN measured in comparison to that determined for the HT‐GaN one is attributed to the amorphous‐like structure of the layer and the instability of Ga‐N bonds. This favors the appearance of a mirror‐like gallium surface in the beginning of this layer decomposition. The presence of liquid gallium catalyzes the decomposition process. HT‐GaN SEM analysis revealed that the surface of the “totally” decomposed GaN surface is dominated by gallium droplets. These were removed. The region around and under these droplets is capped by a porous like GaN film. The coalesced gallium droplets may cover some areas of partially decomposed GaN and preserve them from H2 attack and total decomposition. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)