bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thickness uniformity of HDPE blown film: Relation to rheological properties and density
Authors: Higuchi Hiroyuki , Fujikawa Shinjiro , Sato Mikio , Koyama Kiyohito 
Published: June 2004

AbstractPrevious work has elucidated that the wall slip velocity and viscosity of polymer melts influence the thickness uniformity of blown film. The present study investigates the effects of the stress dependence of wall slip, the shear thinning and the density on the uniformity. We have prepared high‐density polyethylenes with a variety of molecular weight distributions, which have different rheological properties. Examination of the thickness uniformity of their blown film has shown that the uniformity is correlated with wall slip velocity, the stress dependence of the velocity, melt viscosity, shear thinning and density; the coefficient of the correlation is determined to be 0.990. The reason why the stress dependence of wall slip and the shear thinning affect the uniformity is explained in terms of polymer melt flow behavior in a die, while the effect of density is interpreted considering bubble fluctuation in the blow‐up process. Polym. Eng. Sci. 44:965–972, 2004. © 2004 Society of Plastics Engineers.
Proteomic characterization of herbicide safener‐induced proteins in the coleoptile of Triticum tauschii seedlings
Authors: Zhang Qin , Riechers Dean E. 
Published: June 2004

AbstractProteomic methods such as two‐dimensional gel electrophoresis and liquid chromatography tandem mass spectrometry, as well as immunoblotting, were used to identify herbicide safener‐induced proteins in the coleoptile of Triticum tauschii, a diploid wheat containing the D genome also found in the cultivated, hexaploid wheat Triticum aestivum. The herbicide safener fluxofenim dramatically increased protein abundance in the molecular weight (Mr) range of 24 to 30 kDa, as well as a few higher Mr proteins, in the coleoptile of T. tauschii seedlings. In total, twenty proteins were identified in this study. Eleven proteins were highly safener induced and only weakly expressed in the control; seven proteins were new safener induced proteins that were not detected in the control. Two other proteins were constitutively expressed in both the control and safener‐treated coleoptiles. Among the eighteen inducible proteins, fifteen were glutathione S‐transferase (GST) subunits that fall into three subclasses: eight proteins were from the tau subclass, six proteins were from the phi subclass, and one protein was from the lambda class. Another three safener inducible proteins showed homology to the aldo/keto reductase family and with proteins that have roles in glycolysis and the Krebs cycle. Two constitutively expressed proteins were identified, one having highest homology to the dehydroascorbate reductase subclass of GSTs and one with an ascorbate peroxidase. Immunoblot analyses, using two different antisera raised against the same GST protein but differing in their specificity, were used to further characterize the GST proteins expressed in response to safener treatment. Results from immunoblotting, combined with mass spectral analysis, showed that post‐translational modification of GST proteins in control and safener‐treated coleoptiles may occur.
Proteomic analysis of a ferric uptake regulator mutant of Helicobacter pylori: Regulation of Helicobacter pylori gene expression by ferric uptake regulator and iron
Authors: Lee Hyang Woo , Choe Yon Ho , Kim Dae Kyong , Jung Sung Yun , Lee Na Gyong 
Published: June 2004

AbstractThe ferric uptake regulator (Fur) protein is a Fe2+‐dependent transcriptional repressor that binds to the Fur‐box of bacterial promoters and down‐regulates gene expression. In this study, to investigate global gene regulation by Fur in response to iron in Helicobacter pylori, a causative agent of human gastric diseases, we compared the proteome profiles of the H. pylori strain 26695 and its isogenic fur mutant grown under iron‐rich and iron‐depleted conditions. In total, 93 protein spots were found to be up‐ or down‐regulated by more than 2‐fold by either a fur mutation or iron‐depletion. From these, 39 spots were identified by matrix‐assisted laser desorption/ionization time of flight analysis to be 29 different proteins of diverse functions, including energy metabolism, transcription and translation, detoxification, biosynthesis of amino acids and nucleotides and production of the cell envelope. Expression of six proteins was found to be higher in the fur mutant than in the wild‐type bacteria, indicating Fur‐mediated repression. Eleven proteins were activated by Fur; five responded to iron and the others were not iron‐responsive. The remaining 12 proteins were not under Fur‐regulation but responded to iron in a positive or negative manner. Seven different types of gene regulation via Fur and iron were identified. These findings demonstrate that the H. pylori Fur protein functions as a classical transcriptional repressor but can also function as an activator, providing evidence for the presence of Fur‐mediated positive regulation in H. pylori.
Toughness enhancements in poly(methyl methacrylate) by addition of oriented multiwall carbon nanotubes
Authors: Gorga Russell E. , Cohen Robert E. 
Published: June 2004

AbstractThe mechanical properties of multiwall carbon nanotube (MWNT)/poly(methyl methacrylate) (PMMA) nanocomposites were studied as a function of nanotube orientation, length, concentration, and type. Orientation and dispersion were assessed by electron microscopy. A processing parameter study revealed the robust nature of fabricating nanotube/PMMA nanocomposites. An optimal set of extrusion conditions was found for minimizing the aggregate size in single‐wall carbon nanotube (SWNT)/PMMA nanocomposites; this set was also used for the fabrication of the MWNT/PMMA composites. Good dispersion was achieved for MWNTs in PMMA at 0.1–10 wt % loading levels (with the best dispersions at the lower loading levels). The orientation of MWNTs in PMMA proved to be the only way to substantially toughen the nanocomposite. A level of 1 wt % MWNTs in PMMA (oriented nanocomposite) exhibited the largest increase in tensile toughness with a 170% improvement over oriented PMMA. Increases in the modulus and yield strength were not nearly as pronounced (and occurred only at the highest loading of MWNTs, which was 10 wt %) with increases of 38 and 25%, respectively. A failure mechanism was proposed in which orientation of the MWNTs (normal to the direction of craze propagation and crack development) enabled them to toughen the brittle PMMA by bridging cracks that developed (via craze precursors) during the tensile test. None of the nanotube/PMMA composites showed mechanical properties close to the values expected from simple rule of mixture and orientation considerations. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2690–2702, 2004
P704P, P712P, and P775P: A genomic cluster of prostate‐specific genes
Authors: Stolk John A. , Jiang Yuqiu , Day Craig H. , Klee Jennifer I. , Zhang Xinqun , Dillon Davin C. , Houghton Raymond L. , Harlan Dianne , Reed Steven G. , Xu Jiangchun 
Published: May 2004

AbstractBACKGROUNDDiscovery of prostate cancer‐ and tissue‐specific genes will lead to an increased understanding of the molecular events associated with the malignant transformation and tumorigenesis of prostate cells. Such understanding will likely result in the development of promising new markers for screening, diagnosis, and prognosis, as well as potential therapeutic approaches for combating this disease.METHODSA PCR‐based subtraction method was combined with a high‐throughput microarray screening approach to identify prostate tissue‐ and/or cancer‐specific genes. Northern blot and quantitative real‐time PCR were used to confirm prostate specificity. Bioinformatics analysis was performed to determine gene localization and to identify the open reading frame of novel genes.RESULTSThree novel cDNA clones, P704P, P712P, and P775P, were identified and characterized to be specific for normal and malignant prostate tissues. Furthermore, P712P mRNA expression was found to be androgen responsive in LNCaP cells. Sequences for all three cDNAs were localized to an 80 kb genomic region on chromosome 22. Attempts to identify full‐length transcripts did not reveal any apparent open reading frames, indicating that P704P, P712P, and P775P may belong to a novel class of transcripts with specific patterns of gene expression that do not code for translated proteins.CONCLUSIONSA genomic cluster of prostate‐specific genes with no apparent open reading frame has been discovered using a high‐throughput approach combining subtraction with microarray. This may represent an important genomic region having possible connections to prostate biology with potential applications in prostate diagnostics and therapy. © 2004 Wiley‐Liss, Inc.
RETRACTED: Interleukin‐6 protects LNCaP cells from apoptosis induced by androgen deprivation through the Stat3 pathway
Authors: Lee Soo Ok , Lou Wei , Johnson Candace S. , Trump Donald L. , Gao Allen C. 
Published: May 2004

AbstractBACKGROUNDElevated expression of interleukin‐6 (IL‐6) is implicated in the progression of hormone refractory prostate cancer. Previous studies demonstrated that IL‐6 promotes androgen‐independent growth of prostate cancer cells. In this study, the effect of IL‐6 on apoptosis induced by androgen deprivation was investigated.METHODSThe effect of IL‐6 on apoptosis induced by androgen deprivation in LNCaP cells was examined by cell death ELISA and Western blot using cleaved poly (ADP‐ribose) polymerase (PARP) and caspase‐9, as well as Bcl‐xL and phosphorylated Bad. The Stat3 in IL‐6‐mediated anti‐apoptosis in prostate cancer cells was examined using either dominant‐negative or constitutively activated Stat3 mutants.RESULTSOverexpression of IL‐6 renders androgen sensitive LNCaP human prostate cancer cells more resistant to apoptosis induced by androgen deprivation. LNCaP cells undergo apoptosis after 72 hr of androgen deprivation, an outcome is largely absent in clones overexpressing IL‐6 as measured by cell death ELISA and chromatin degradation assays. IL‐6 over‐expressing cells resulted in a significant decrease in the expression of cleaved PARP and cleaved caspase‐9 as well as an increase in the expression of Bcl‐xL and phosphorylated Bad. Addition of IL‐6 antibody completely abolished the anti‐apoptotic activity of IL‐6. This protective effect of IL‐6 was reversed by the expression of a dominant‐negative Stat3 mutant, Stat3F. Furthermore, ectopic expression of a constitutively active Stat3 antagonized androgen deprivation‐induced cell death of LNCaP cells.CONCLUSIONThese results indicate that IL‐6 protects androgen sensitive LNCaP cells from apoptosis induced by androgen deprivation, and Stat3 activation play an important role in IL‐6‐mediated anti‐apoptosis in prostate cancer cells. © 2004 Wiley‐Liss, Inc.
The Combinatorial Synthesis of Purine, Pyrimidine and Triazine‐based Libraries
Authors: Bork Jacqueline T. , Lee Jae Wook , Chang Young‐Tae 
Published: June 2004

AbstractWith the advent of combinatorial chemistry, heterocyclic scaffolds can be efficiently used for the generation of large member libraries. Due to the pressing need for such compound libraries, unique synthesis reactions and techniques have been developed to expedite and further improve the process. Present review article summarizes synthetic strategies for the construction of purine, pyrimidine and triazine libraries in both solution and solid phase syntheses. Typical strategy includes the nucleophilc aromatic substitution, such as amination. Also, metal‐mediated synthesis has been used as a driving tool in expanding the diversity of the libraries. Demonstrated biological properties of these libraries, as a rich source of bioactivities, are also highlighted.
2D‐ and 3D‐QSAR Models of Interaction between Flavor Compounds and beta‐Lactoglobulin Using Catalyst and Cerius2
Authors: Tromelin Anne , Guichard Elisabeth 
Published: June 2004

AbstractThe present paper describes an application of Catalyst to three aroma sets (35, 24 and 21 compounds respectively) to generate activities‐based alignments, using the best significant generated hypotheses. The obtained Catalyst models confirmed the existence of at least two binding sites on the BLG.
High‐performance liquid chromatography/inductively coupled plasma mass spectrometry and tandem mass spectrometry for the detection of carbon‐containing compounds
Authors: Smith Christopher , Jensen Berit Packert , Wilson Ian D. , Abou‐Shakra Fadi , Crowther David 
Published: June 2004

AbstractHigh‐performance liquid chromatography (HPLC) combined with inductively coupled plasma mass spectrometry (ICPMS) has been studied as a means for the detection of carbon to provide a ‘universal’ method for detecting organic compounds in chromatographic eluents. Carbon is particularly difficult to ionise and the amount of carbon present in normal chromatographic systems leads to high backgrounds, making detection a challenge. Novel separation approaches were therefore employed, using either entirely aqueous eluents (at temperatures of 60 and 160°C, dependent on the column used) to eliminate the organic modifier completely, or isotopically enriched solvents. For the aqueous eluents, detection limits for sulphanilamide were found to be 2.26 μg, corresponding to 1.13 μmol (0.47 μmol of carbon), injected on a conventional 4.6 mm i.d. column. The use of a narrow bore column with highly isotopically enriched 12C‐methanol (99.95 atom%) as organic modifier for the mobile phase enabled the detection of 86 μmol for 13C‐triple‐labelled caffeine and 79 μmol for 13C‐double‐labelled phenacetin. The sensitive detection of 12C‐compounds with 13C‐enriched methanol as organic modifier proved impractical due to a lower level of isotopic enrichment (99 atom%) of this solvent, with the residual 12C‐methanol resulting in significant interference. Copyright © 2004 John Wiley & Sons, Ltd.
High‐performance liquid chromatography with electrospray ionisation mass spectrometry and diode array detection in the identification and quantification of the degradation products of calix[4]arene crown‐6 under radiolysis
Authors: Lamouroux C. , Aychet N. , Lelièvre A. , Jankowski C. K. , Moulin C. 
Published: June 2004

AbstractThe extraction of 135Cs from high‐activity liquid waste, arising from reprocessing of spent nuclear fuel, can be achieved by using calix[4]arene crown‐6 compounds. The radiolytic degradation of di(n‐octyloxy)calix[4]arene crown‐6 (octMC6), in aliphatic or aromatic solvent in contact with 3 M nitric acid, was studied by high‐performance liquid chromatography directly coupled to electrospray ionisation mass spectrometry (LC/ESI‐MS). More than 50 distinct degradation products were observed, and about 30 of these were identified. These compounds can be assigned to three categories, namely, products of reactions involving radical cleavage or addition, of oxidation reactions, or of aromatic substitution reactions. The major product, corresponding to substitution by an NO2 group, was quantified by external standard calibration using a purified synthetic sample. Despite the observation of all these degradation compounds, octMC6 appears to be remarkably stable under these drastic conditions, combining hydrolysis (HNO3 3 M) and an extreme exposure to radiolysis (106 Gy). Less than 35% degradation of octMC6 was observed in aromatic solvent under these conditions. Copyright © 2004 John Wiley & Sons, Ltd.
Micropropulsion for small spacecraft: a new challenge for field effect electric propulsion and microstructured liquid metal ion sources
Authors: Mitterauer J. 
Published: June 2004

AbstractThe growing interest in the use of microspacecraft is driving a critical need for new micropropulsion systems. The constraints on mass, dimension and power with which microspacecraft have to contend pose severe challenges to the system design. This general definition allows the inclusion of a wide range of concepts, from scaled‐down versions of existing thrusters operating at reduced power levels to completely redesigned microelectromechanical‐fabricated thrusters with micron characteristic sizes. More than ten years ago, microelectromechanical‐based propulsion was first introduced in the form of a proposed microfabricated field effect electric propulsion (FEEP) liquid metal ion thruster concept. Now a review will be given on basic features of liquid metal field emission sources, on selection criteria for liquid metal propellants for FEEP thrusters, on the principles of microstructured liquid metal ion sources (MILMIS) and finally on the miniaturization of MILMIS. Copyright © 2004 John Wiley & Sons, Ltd.
Kinetic instabilities in the NO/H2 reaction on platinum
Authors: Chau Thoi‐Dai , Visart de Bocarmé Thierry , Kruse Norbert 
Published: June 2004

AbstractWe have studied the catalytic reduction of nitric oxide (NO) with hydrogen (H2) on platinum using both field ion microscopy (FIM) and pulsed field desorption mass spectrometry (PFDMS). Under certain conditions of temperature and gas pressure this reaction exhibits non‐linear behaviour, i.e. hysteresis effects and rate oscillations occur. Ensembles of kink sites of the <100> zones are found to act as pacemakers, which is in line with earlier studies demonstrating {012} planes to ignite in a quasi‐concerted manner.1,2 Experiments with tips of varying radius of curvature always lead to the same sequence of image patterns. Large variations in the H2 partial pressure has little influence on the frequency of the rate oscillations.Using PFDMS under the reaction conditions we show that NO+ rather than H2O+/H3O+ (the neutrals are formed during the reaction process) is the imaging species in FIM. Interestingly, $\hbox{PtO}_{{x}}^{n+} (x \leq 3)$ are seen in the mass spectra, indicating that the reaction is controlled by a vacant site mechanism with the inclusion of partial oxidation of the Pt surface. Copyright © 2004 John Wiley & Sons, Ltd.
Solute cluster formation in austenitic and ferritic alloys under ion irradiation: a three‐dimensional atom probe characterization
Authors: Krummeich R. , Pareige P. , Massoud J. P. , Jumel S. 
Published: June 2004

AbstractVessel and internal core steels of nuclear power reactors are subjected to energetic neutron irradiation. The production of point defects in the material results from elastic collisions in displacement cascades. On a microscopic scale, changes in the microstructure and local microchemistry are observed in both steels. On a global scale, a shift in the transient ductile to brittle temperature of vessel steels and an increase in the irradiation‐assisted stress‐corrosion‐cracking susceptibility of internal core stainless steels are observed. Also, on a nanometre scale, radiation‐induced phase transformation occurs in both steels. A systematic approach has proved its efficiency here to study the specific role of displacement cascades on cluster formation in two different materials: ferritic steels (bcc structure) and austenitic steels (fcc structure). In order to produce the primary knock atom, model ferritic steels containing a small amount of copper as well as a commercial austenitic steel (316) were irradiated using Fe and Ni ions, respectively. The different resulting microstructures are then studied on a nanoscale using tomographic atom probe three‐dimensional reconstruction. Copyright © 2004 John Wiley & Sons, Ltd.
Three‐dimensional atom probe study of irradiated, annealed and re‐irradiated VVER 440 weld metals
Authors: Pareige P. , Radiguet B. , Suvorov A. , Kozodaev M. , Krasikov E. , Zabusov O. , Massoud J. P. 
Published: June 2004

AbstractThe radiation embrittlement of the welds of old VVER 440 reactor pressure vessels promoted research on technical ways to ensure their safe operation during design service life. One of those is the recovery annealing of the reactor pressure vessel. Today, very few data are available concerning re‐irradiated materials. These data are essential in order to understand the mechanism of re‐embrittlement and to be able to predict the evolution of the microstructure and the mechanical properties of the steel during in‐service re‐irradiation. For that purpose a research programme was launched to carry out atom probe studies of the microstructure of weld metals in irradiated, irradiated–annealed and re‐irradiated conditions. This work demonstrates that neutron irradiation promotes the formation of ultra‐fine copper‐enriched clusters and solute segregation to crystal defects in these Cr–Mo–V steels. The study of the annealed materials allows us to explain how the mechanical properties of the irradiated materials can be recovered. Also, study of the re‐irradiated material points out the non‐detection of copper‐enriched clusters and the phosphorus behaviour during re‐irradiation. Copyright © 2004 John Wiley & Sons, Ltd.
Characterization of the precipitation in Al–Li–Cu–Mg–(Mn, Zr) alloys
Authors: Davin Laury , Cerezo Alfred , Gao Nong , Starink Marco 
Published: June 2004

AbstractThe three‐dimensional atom probe has been used to characterize the precipitates in two Li‐containing 2xxx series aluminium alloys: Al–6Li–Cu–Mg–0.2Mn (alloy A) and Al–6Li–Cu–Mg–0.03Zr (alloy B). The alloys have been heat treated at 150°C for times in the range 6–24 h. In alloy A, the particles identified can be classified into two categories: those rich in Cu and Mg (similar to GPB zones and S′ precipitates); and spherical particles rich in Li (δ′ precipitates). Clusters rich in Li are also observed. The same phases are observable in alloy B, although growth of the δ′ phase precipitates is accompanied by the formation of a Zr‐rich phase similar to β′. Copyright © 2004 John Wiley & Sons, Ltd.
Oxidation improvement of field electron emission from diamond nanomaterials
Authors: Karabutov A. V. , Gordeev S. K. , Ralchenko V. G. , Korchagina S. B. , Maslakov K. I. , Dementjev A. P. 
Published: June 2004

AbstractPorous diamond/sp2‐bonded carbon nanocomposites were studied to determine how their field electron emission properties and electrical conductivity depend on composition and post‐growth treatment. It was found that a treatment enriching the nanocomposites with oxygen could significantly improve the field emission from the diamond samples. The oxidized composites exhibited lower emission threshold fields (Eth = 1–2 V µm−1 compared with Eth = 4–6 V µm−1 for non‐oxidized samples) and improved emission uniformity (the number of emission sites per unit area). The composites with low sp2‐bonded carbon content, i.e. the more porous samples, typically show better results. The structure of the samples was studied using a C KVV Auger spectrometer, with x‐ray excitation of Auger emission. Possible reasons for the emission improvement by oxidation in this two‐phase carbon system are discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Study of modulation methods in field emission displays
Authors: Wei Lei , Zhang Xiaobing , Li Juntao , Wang Baoping , Yin Hanchun 
Published: June 2004

AbstractField emission displays have many characteristics that are similar to cathode ray tubes but the field emission display panel can be thin. With the development of field emission materials, field emission devices have shown promise for display devices in the near future. In this paper, an electron optical system is introduced into a field emission display device. The modulation voltage changes the divergence angle of the electron beam. Consequently, the current of the electron beam that bombards the phosphor screen can be modulated. From the simulation results it can be seen that the modulation voltage is smaller than that for a conventional triode. Copyright © 2004 John Wiley & Sons, Ltd.