bluuebunny/crossref_metadata_2025_split huggingface dataset:
Does morphology stick? Tailored particle morphologies by swelling polymerization process
Authors: Kirsch S. , Kutschera M. , Choi N.‐Y. , Frechen T. 
Published: May 2006

AbstractStructured dispersion particles suitable for pressure sensitive adhesives (PSA) were synthesized via swelling polymerization technique (EP 359562). Particles consisting of poly(n‐butyl acrylate) copolymerized with different types of carboxylic acids were used as seeds. The final particles were synthesized by swelling polymerization process, using 6 wt % styrene or 6 wt % methyl methacylate. The resulting particle morphology was analyzed by atomic force microscopy (AFM) and transmission electron microscopy (TEM). From previous works (Coll Surf A 2001, 183–185, 725–737; J Appl Polym Sci 2004, 91, 2610–2623) where two‐step emulsion polymerization was used on similar particles, it is expected that the particle morphology is affected by the polarity of the monomer used for swelling polymerization because of the phase compatibility (thermodynamic parameter). In this work, the seed particles used were always of a glass transition temperature (Tg) below polymerization temperature. The diffusion of the growing polymer chains from the swelling polymerization is therefore mainly affected by their own Tg and the influence of the carboxy groups on the chain length of the entering radicals (kinetic parameter). The different morphologies of the single particles are discussed qualitatively. The effects of reaction parameters are compared with the results given in the previous work. The structure of the corresponding dispersion films was characterized using AFM. Correlations to macroscopic properties such as the cohesive strength and peel adhesion to different substrates are discussed. The results are also compared with the application properties of the corresponding unmodified particles, statistical copolymers, and to blends with small sized PMMA or PS particles. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1444–1455, 2006
Preparation of bimodal polypropylene in two‐step polymerization
Authors: Abedi S. , Hassanpour N. 
Published: May 2006

AbstractPolymerization of propylene was carried out by using MgCl2.EtOH.TiCl4.DIBP.TEA.cHMDMS catalyst system in n‐heptane, where MgCl2, EtOH, TiCl4, DIBP (diisobutyl phthalate), TEA (triethyl aluminum), and cHMDMS (cyclohexyl methyl dimethoxy silane) were support, ethanol for alcoholation, catalyst, external donor, cocatalyst (activator), and internal donor, respectively. The catalyst activity and polymer isotacticity were studied by measuring the produced polymer and its solubility in boiling n‐heptane, respectively. The molecular weight and molecular weight distribution of the polymers were evaluated by gel permeation chromatography. Hydrogen was used for controlling the molecular weight. For producing the bimodal polypropylene, the polymerization was carried out in two steps (i.e., in the presence and absence of hydrogen). It was found that the catalyst showed high activity and stereoselectivity, on the other hand, bimodal polymer could simply be produced in two‐step polymerization by using MgCl2.EtOH.TiCl4.DIBP.TEA.cHMDMS catalyst system. Meanwhile, the effect of the step of the hydrogen adding on propylene polymerization was investigated. It was shown that the addition of hydrogen in the second step was more suitable. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1456–1462, 2006
Physical properties of polyamide 6/metallocene isotactic polypropylene conjugated filaments
Authors: Hsiao Kai‐Jen , Jue Zhi‐Feng , Kong Dan‐Cheng , Chen Frank L 
Published: May 2006

AbstractPolyamide 6 (PA 6) and metallocene isotactic polypropylene (m‐iPP) polymers were extruded (in proportions of 75/25, 50/50, and 25/75) from two melt twin‐screw extruders to prepare three PA 6/m‐iPP conjugated filaments. This study investigated the physical properties of PA 6/m‐iPP conjugated filaments with gel permeation chromatography, differential scanning calorimetry, thermogravimetric analysis, potentiometry, rheometry, density‐gradient measurements, wide‐angle X‐ray diffraction, extension stress–strain measurements, and scanning electron microscopy. The flow behavior of PA 6/m‐iPP polyblended polymers exhibited negative‐deviation blends, and a 50/50 PA 6/m‐iPP blend showed the minimum value of the melt viscosity. The experimental results from differential scanning calorimetry indicated that PA 6 and m‐iPP molecules formed an immiscible system. The tenacity of the PA 6/m‐iPP conjugated filaments decreased initially and then increased as the m‐iPP content increased. The crystallinities and densities of the PA 6/m‐iPP conjugated filaments had a linear relationship with the blend ratio. Morphological observations revealed that the blends had a dispersed‐phase structure. A pore/fiber morphology of a larger size (from 0.5 to 3 μm in diameter) was observed after a formic acid (PA 6 was moved)/xylene (m‐iPP was moved) treatment on the cross section of a PA 6/m‐iPP conjugated filament. PA 6 and m‐iPP polymers were proved to be an incompatible system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1471–1476, 2006
BSA treatment to enhance enzymatic hydrolysis of cellulose in lignin containing substrates
Authors: Yang Bin , Wyman Charles E. 
Published: May 2006

AbstractCellulase and bovine serum albumin (BSA) were added to Avicel cellulose and solids containing 56% cellulose and 28% lignin from dilute sulfuric acid pretreatment of corn stover. Little BSA was adsorbed on Avicel cellulose, while pretreated corn stover solids adsorbed considerable amounts of this protein. On the other hand, cellulase was highly adsorbed on both substrates. Adding a 1% concentration of BSA to dilute acid pretreated corn stover prior to enzyme addition at 15 FPU/g cellulose enhanced filter paper activity in solution by about a factor of 2 and beta‐glucosidase activity in solution by about a factor of 14. Overall, these results suggested that BSA treatment reduced adsorption of cellulase and particularly beta‐glucosidase on lignin. Of particular note, BSA treatment of pretreated corn stover solids prior to enzymatic hydrolysis increased 72 h glucose yields from about 82% to about 92% at a cellulase loading of 15 FPU/g cellulose or achieved about the same yield at a loading of 7.5 FPU/g cellulose. Similar improvements were also observed for enzymatic hydrolysis of ammonia fiber explosion (AFEX) pretreated corn stover and Douglas fir treated by SO2 steam explosion and for simultaneous saccharification and fermentation (SSF) of BSA pretreated corn stover. In addition, BSA treatment prior to hydrolysis reduced the need for beta‐glucosidase supplementation of SSF. The results are consistent with non‐specific competitive, irreversible adsorption of BSA on lignin and identify promising strategies to reduce enzyme requirements for cellulose hydrolysis. © 2006 Wiley Periodicals, Inc.
Mapping Electrochemiluminescence as Generated at Double‐Band Microelectrodes by Confocal Microscopy under Steady State
Authors: Amatore Christian , Pebay Cécile , Servant Laurent , Sojic Néso , Szunerits Sabine , Thouin Laurent 
Published: May 2006

AbstractA confocal microspectrometer was used to collect spatially resolved electrochemiluminescence (ECL) spectra from the annihilation reaction between Ru(bpy)3+ and Ru(bpy)33+, each species being generated at a platinum band microelectrode and separated by a micrometric insulating gap. The use of a confocal microspectrometer allows in situ photon detection of the ECL reaction with micrometric spatial resolution and observes the concentration distribution of the photon source in the vicinity of the interelectrode gap.
Phosphorylation and glycosylation interplay: Protein modifications at hydroxy amino acids and prediction of signaling functions of the human β3 integrin family
Authors: Ahmad Ishtiaq , Hoessli Daniel C. , Walker‐Nasir Evelyne , Choudhary M. Iqbal , Rafik Saleem M. , Shakoori Abdul Rauf , Nasir‐ud‐Din  
Published: May 2006

AbstractProtein functions are determined by their three‐dimensional structures and the folded 3‐D structure is in turn governed by the primary structure and post‐translational modifications the protein undergoes during synthesis and transport. Defining protein functions in vivo in the cellular and extracellular environments is made very difficult in the presence of other molecules. However, the modifications taking place during and after protein folding are determined by the modification potential of amino acids and not by the primary structure or sequence. These post‐translational modifications, like phosphorylation and O‐linked N‐acetylglucosamine (O‐GlcNAc) modifications, are dynamic and result in temporary conformational changes that regulate many functions of the protein. Computer‐assisted studies can help determining protein functions by assessing the modification potentials of a given protein. Integrins are important membrane receptors involved in bi‐directional (outside‐in and inside‐out) signaling events. The β3 integrin family, including, αIIbβ3 and αvβ3, has been studied for its role in platelet aggregation during clot formation and clot retraction based on hydroxyl group modification by phosphate and GlcNAc on Ser, Thr, or Tyr and their interplay on Ser and Thr in the cytoplasmic domain of the β3 subunit. An antagonistic role of phosphate and GlcNAc interplay at Thr758 for controlling both inside‐out and outside‐in signaling events is proposed. Additionally, interplay of GlcNAc and phosphate at Ser752 has been proposed to control activation and inactivation of integrin‐associated Src kinases. This study describes the multifunctional behavior of integrins based on their modification potential at hydroxyl groups of amino acids as a source of interplay. J. Cell. Biochem. 99: 706–718, 2006. © 2006 Wiley‐Liss, Inc.
Transcription factor RFX2 is abundant in rat testis and enriched in nuclei of primary spermatocytes where it appears to be required for transcription of the testis‐specific histone H1t gene
Authors: Wolfe Steven A. , van Wert Jane , Grimes Sidney R. 
Published: May 2006

AbstractPrevious work in our laboratory revealed upregulated transcription of the testis‐specific linker histone H1t gene in pachytene primary spermatocytes during spermatogenesis. Using the H1t X‐box as an affinity chromatography probe, we identified Regulatory Factor X2 (RFX2), a member of the RFX family of transcription factors, as a nuclear protein that binds the probe. We also showed that RFX2 activated the H1t promoter in transient expression assays. However, other RFX family members have the same DNA‐binding domain and they also may regulate H1t gene expression. Therefore, in this study we examined the distribution of RFX2 and other RFX family members in rat testis germinal cells and in several tissues. Among tissues examined, RFX2 is most abundant in testis. Testis RFX2 is most abundant in spermatocytes where transcription of the H1t gene is upregulated and the steady‐state H1t mRNA level is high. RFX2 levels decrease but RFX1 levels increase in early spermatids where H1t gene transcription is downregulated. Antibodies against RFX2 generate a shifted band in electrophoretic mobility shift assays (EMSA) using H1t or testisin X‐box DNA probes with nuclear proteins from spermatocytes. These data support the hypothesis that RFX2 expression is upregulated in spermatocytes where it participates in activating transcription of the H1t gene and other testis genes. These data also support the possibility that other RFX family members may bind to the H1t promoter in other testis germinal cell types and in nongerminal cells to downregulate H1t gene transcription. J. Cell. Biochem. 99: 735–746, 2006. © 2006 Wiley‐Liss, Inc.
Effects of sequential exposure to lipopolysaccharide and heat stress on dental pulp cells
Authors: Kitamura Chiaki , Nishihara Tatsuji , Ueno Yoshiko , Chen Ker‐Kong , Morotomi Takahiko , Yano Junya , Nagayoshi Masato , Terashita Masamichi 
Published: May 2006

AbstractIn the present study, we examined the effects of sequential exposure to bacterial lipopolysaccharide (LPS) and heat stress on dental pulp cells. LPS induced the proliferation of pulp cells through the activation of p38 MAPK. HSP27 was expressed in cells with or without LPS during the entire period of heat stress, while transiently phosphorylated by short‐term heat stress. In LPS‐treated cells, short‐term heat stress also induced the phosphorylation of HSF1. The immediate phosphorylation of HSF1 and HSP27 in LPS‐treated cells by short‐term heat stress occurred dependent on the activation of p38 MAPK. However, with long‐term heat stress, the activation of HSF1 and induction of HSP27 occurred independent of p38 MAPK. Further, full activation of Akt in LPS‐treated cells was immediately induced by short‐term heat stress and lasted during the entire period of heat stress. IκBα was induced and phosphorylated throughout sequential exposure to LPS and heat stress. These results suggest that LPS has the unique effects on the cytoprotection and the cell death of pulp cells during heat stress through the modification and the activation of heat stress responsive molecules, HSF1 and HSP27, and cell survival molecules, Akt and NF‐κB/IκBα. J. Cell. Biochem. 99: 797–806, 2006. © 2006 Wiley‐Liss, Inc.
Proteolytic processing of a sea urchin, ECM‐localized protein into lower mol mass species possessing collagen‐cleavage activity
Authors: Robinson John J. 
Published: May 2006

AbstractThe hyaline layer is an apically located extraembryonic matrix, which blankets the sea urchin embryo. Using gelatin substrate gel zymography, we have identified a number of gelatin‐cleaving activities within the hyaline layer and defined a precursor–product processing pathway which leads to the appearance of 40‐ and 38‐kDa activities coincident with the loss of a 50‐kDa species. Proteolytic processing of the precursor required the presence of both CaCl2 and NaCl at concentrations similar to those found in sea water. The cleavage activities utilized both sea urchin and rat tail tendon gelatins as substrates but demonstrated a species‐specific cleavage activity towards sea urchin collagen. The gelatin‐cleaving activities were refractory to inhibition by 1, 10‐phenanthroline but were inhibited by benzamidine. This latter result defines the serine protease nature of the cleavage activities. Both the 40‐ and 38‐kDa activities were found to comigrate with gelatin‐cleaving activities present in the sea urchin embryo. J. Cell. Biochem. 99: 816–823, 2006. © 2006 Wiley‐Liss, Inc.
A new hepatocytic isoform of PLZF lacking the BTB domain interacts with ATP7B, the Wilson disease protein, and positively regulates ERK signal transduction
Authors: Ko Jung Ho , Son Wonseok , Bae Gab Yong , Kang Joo Hyun , Oh Wonjun , Yoo Ook Joon 
Published: May 2006

AbstractThe promyelocytic leukemia zinc finger (PLZF) protein has been described as a transcriptional repressor of the BTB‐domain/zinc‐finger family, and shown to regulate the expression of Hox genes during embryogenesis and the expression of cyclin A in the cell cycle progression. Here, a 45‐kDa isoform of PLZF without a BTB domain was identified via yeast two‐hybrid screening using the C‐terminal region of ATP7B as bait in our determination of the biological roles of the Wilson disease protein outside of its copper‐binding domain. Our immunoprecipitation experiments showed that the hepatocytic isoform of PLZF could specifically interact with the C‐terminal region of ATP7B. The immunostaining of HepG2 cells revealed that the ATP7B and PLZF proteins were apparently colocalized into the trans‐Golgi complexes. It was also determined that disruption of PLZF expression in the HepG2 cells affected an attenuation of ERK activity in a dose‐dependent manner. The hepatocytic activities of ERK kinase were found to be enhanced as the result of PLZF or ATP7B expression, but this enhancement was abrogated by the deletion of the C‐terminal region of ATP7B. Furthermore, a transgenic Drosophila strain that ectopically expressed the hepatocytic ΔBTB‐PLZF exhibited phenotypic changes in eye and wing development, and these alterations were fully recovered as the result of ATP7B expression, indicating the obvious in vivo interaction between the two proteins. Those PLZF‐induced abnormalities were attributed to the enhancement of ERK signaling, as was shown by phenotypic reversions with loss‐of‐function mutations in ERK signal transduction in Drosophila. These data suggest the existence of a mechanism that regulates ERK signaling via the C‐terminus of ATP7B and the ATP7B‐interacting hepatocytic PLZF. J. Cell. Biochem. 99: 719–734, 2006. © 2006 Wiley‐Liss, Inc.
Orthogonal designs via computational algebra
Authors: Kotsireas Ilias S. , Koukouvinos Christos 
Published: May 2006

AbstractWe detail the Williamson array construction based on quaternions, following the description by Baumert and Hall. By analogy, we extend the construction to larger arrays using matrix representations of the algebras of octonions and sedenions. In the case of octonions, we obtain the full orthogonal design OD(8;1,1,1,1,1,1,1,1) or order 8 with 8 variables. In the case of sedenions we obtain the full orthogonal design OD(16;1,1,7,7) of order 16 with 4 variables and the full orthogonal design OD(16;1,1,2,2,2,2,2,2,2) of order 16 with 9 variables. We use OD(16;1,1,2,2,2,2,2,2,2) to search for inequivalent Hadamard matrices of orders 112, 144, 176 and we establish constructively three new lower bounds for the numbers of inequivalent Hadamard matrices of these three orders. © 2006 Wiley Periodicals, Inc. J Combin Designs 14: 351–362, 2006
Cubic s‐regular graphs of order 2p3
Authors: Feng Yan‐Quan , Kwak Jin Ho , Xu Ming‐Yao 
Published: May 2006

AbstractA graph is s‐regular if its automorphism group acts regularly on the set of its s‐arcs. Malnič et al. (Discrete Math 274 (2004), 187–198) classified the connected cubic edge‐transitive, but not vertex‐transitive graphs of order 2p3 for each prime p. In this article, we determine the s‐regularity of all connected cubic symmetric graphs of order 2p3 for each prime p and each s. © 2006 Wiley Periodicals, Inc. J Graph Theory
Finding a monochromatic subgraph or a rainbow path
Authors: Gyárfás András , Lehel Jenő , Schelp Richard H. 
Published: May 2006

AbstractFor simple graphs G and H, let f(G,H) denote the least integer N such that every coloring of the edges of KN contains either a monochromatic copy of G or a rainbow copy of H. Here we investigate f(G,H) when H = Pk. We show that even if the number of colors is unrestricted when defining f(G,H), the function f(G,Pk), for k = 4 and 5, equals the (k − 2)‐ coloring diagonal Ramsey number of G. © 2006 Wiley Periodicals, Inc. J Graph Theory
Heterozygous P0 deficiency protects mice from vincristine‐induced polyneuropathy
Authors: Üçeyler Nurcan , Kobsar Igor , Biko Lydia , Ulzheimer Jochen , Levinson S. Rock , Martini Rudolf , Sommer Claudia 
Published: May 2006

AbstractPatients with hereditary neuropathies are more susceptible to vincristine (VIN)‐induced neuropathy than patients without this comorbidity. The heterozygous P0+/– mouse is an animal model of a distinct form of inherited neuropathies. These mice produce only 50% of the major myelin protein protein zero (P0) and display signs of demyelination in motor nerves at 4 months of age. Here we investigated the development of neuropathic signs in P0+/– and wild‐type (wt) mice after VIN treatment. Neuropathy was induced by daily intraperitoneal injections of VIN (0.5 mg/kg body weight) over 10 days. Behavioral and electrophysiological tests were performed at regular time points. Wt mice developed significant hypersensitivity to heat and mechanical stimuli between days 7 and 38 after the first VIN injection. Surprisingly, P0+/– mice did not show sensory or motor signs of neuropathy over the whole testing period. Immunohistochemical analysis showed an increase in macrophage numbers in sciatic nerve sections of wt mice after VIN, whereas P0+/– mice had higher baseline levels of macrophages without changes after VIN treatment. Semithin sections revealed a decrease in the number of small‐diameter myelinated fibers in the sciatic nerves of wt mice after VIN application, whereas P0+/– mice had higher baseline values of this fiber subtype that did not change under treatment. Dorsal root ganglion neurons of both genotypes showed an up‐regulation of voltage‐gated sodium channel immunoreactivity after VIN application without differences between the genotypes. Thus, the P0+/– phenotype seems to be protected against VIN‐induced neuropathy. The mechanism of this neuroprotection remains elusive. © 2006 Wiley‐Liss, Inc.
Micellar electrokinetic capillary chromatography determination of zinc bacitracin and nystatin in animal feed
Authors: Injac Rade , Kac Javor , Mlinaric Ales , Karljikovic‐Rajic Katarina 
Published: May 2006

AbstractAn MEKC procedure was developed for the separation of zinc bacitracin (Zn‐BC) and nystatin (NYS) in mixtures and in animal feedstuff. The running buffer was 15 mM borate/19 mM phosphate, pH 8.2, containing 20 mM SDS and 10% v/v methanol. Samples were run at 25°C, the applied voltage was 25 kV, and an additional pressure of 5 mbar was applied. Both analytes were detected by UV simultaneously at 215 nm, Zn‐BC alone at 192 and 254 nm, and NYS alone at 305 nm. The method was shown to be specific, accurate (recoveries were 100.0 ± 0.6% and 100.1 ± 0.6% for Zn‐BC and NYS, respectively), linear over the tested range (correlation coefficients 0.9991 and 0.9994), and precise (RSD below 1.3% for both analytes). The method was applied to determine Zn‐BC and NYS as additives in animal feed.
Rapid separation of four main taxoids in Taxus species by a combined LLP‐SPE‐HPLC (PAD) procedure
Authors: Zu Yuangang , Fu Yujie , Li Shuangming , Sun Rui , Li Qingyong , Schwarz Günter 
Published: May 2006

AbstractA method is described for the simultaneous determination of paclitaxel and three related taxoids, 10‐deacetylbaccatin III (10‐DAB III), baccatin III, and cephalomannine, in the extracts from the needles of three Chinese yew species, Taxus cuspidata, T. chinensis, and T. media. SPE was applied as the sample preparation technique and RP‐HPLC with a photodiode array detector (PAD) was used for the analysis of extract samples. The crude extracts were treated with an improved SPE cartridge packed with a combination of 1‐vinyl‐pyrrolidin‐2‐one and divinyl‐benzene. The eluent was 75% methanol. The following separation was achieved with a gradient program on an HIQ SIL C18W column in a system of ACN/water within 60 min. The samples were detected by PAD at wavelengths of 232.1 nm for 10‐DAB III, 229.8 nm for baccatin III and paclitaxel, and 223.9 nm for cephalomannine. The content of 10‐DAB III, baccatin III, cephalomannine, and paclitaxel varied from 0.0277 to 0.0875, 0.0254 to 0.0405, 0.0715 to 0.2486, and 0.0996 to 0.1301 mg/g in fresh needles of the above yew species, respectively. The assay achieved good resolution in the separation between the four compounds, and it can be used for quality control or purity determination for those in bulk and pharmceutical dosage forms.