bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of diatomite/polyethylene glycol binary processing aids on the rheology of a metallocene linear low‐density polyethylene
Authors: Liu Xiaolong , Li Huilin 
Published: May 2004

AbstractFlow performance of metallocene linear low‐density polyethylene (mLLDPE) containing small amounts of polyethylene glycol (PEG) diatomite and diatomite/PEG binary processing aids respectively was investigated. The mLLDPE melt viscosity is increased by the addition of diatomite, but is decreased by addition of PEG or the diatomite/PEG binary processing aids. It was also found that the viscosity reduction of mLLDPE with the addition of diatomite/PEG binary processing aid was significantly greater than that obtained with the addition of only PEG. The flow curves of mLLDPE containing diatomite/PEG binary processing aid show extremely lower value and stronger dependence on shear rate than the others. It is suggested that the rheological improvement of mLLDPE with diatomite/PEG binary processing aids resulted not entirely from the wall slip promoted by PEG; the intrinsic structure may have changed under the application of shear flow. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1546–1552, 2004
Matrix Reactivity of Al and Ga Atoms (M) in the Presence of Silane: Generation and Characterization of the η2‐Coordinated Complex M⋅SiH4, the Insertion Product HMSiH3, and the MISpecies MSiH3in a Solid Argon Matrix
Authors: Gaertner Benjamin , Himmel Hans‐Jörg , Macrae Victoria A. , Downs Anthony J. , Greene Tim M. 
Published: May 2004

AbstractMatrix isolation experiments give evidence for the formation of the loosely bonded metal–silane complex M⋅SiH4by the spontaneous reaction of Al or Ga atoms (M) with silane in a solid Ar matrix at 12 K; however, Ga2appears to insert spontaneously into an SiH bond to form HGaGaSiH3, probably with the structure HGa(μ‐SiH3)Ga. In M⋅SiH4the metal atom is η2‐coordinated by the silane, resulting in a species withC2vsymmetry. The complex has a distinctive photochemistry: it can be converted on photolysis atλ≈410 or ≈254 nm to its tautomer, HMSiH3, which also has a doublet ground electronic state and from which it can be regenerated withλ≈580 nm radiation. Broadband UV‐visible photolysis (λ=200–800 nm) results in decomposition of HMSiH3, the univalent species MSiH3being the only detectable product. The experimental data collected for several silane isotopomers (SiH4, SiD4, and SiD3H) and different reagent concentrations, together with the results of sophisticated quantum chemical calculations, are used to explore in detail the properties of the detected species and the reaction pathways compassing their formation.
Tetrahedral Chalcogenide Clusters and Open Frameworks
Authors: Bu Xianhui , Zheng Nanfeng , Feng Pingyun 
Published: May 2004

AbstractBy integrating porosity with electrical or optical properties, microporous chalcogenides may have unique applications. Here we review recent advances and discuss concepts in the synthesis and crystal structure of tetrahedral clusters and their frameworks. These chalcogenides can be viewed as trivalent metal chalcogenides doped with tetra‐, di‐, or monovalent metal cations. Low‐valent cations help to increase the cluster size, while high‐valent cations have the opposite effect.
Self‐Assembly, Optical Behavior, and Permeability of a Novel Capsule Based on an Azo Dye and Polyelectrolytes
Authors: Tao Xia , Li Junbai , Möhwald Helmuth 
Published: May 2004

AbstractA novel capsule composed of an azo dye, Congo red (CR), and different polymers, including poly(styrenesulfonate, sodium salt) (PSS), poly(allylamine hydrochloride) (PAH), and poly(diallyldimethylammonium chloride) (PDDA), have been successfully fabricated by the layer‐by‐layer self‐assembly technique. The stepwise linear deposition process was monitored by means of UV‐visible absorption measurements. The formation of hollow capsules was verified by confocal laser scanning microscopy (CLSM) and scanning force microscopy (SFM). The resulting hollow PSS/PAH/CR/PDDA capsules displayed a sensitive response to visible light. Optical changes of the hollow capsules prior to and after the photoreaction were investigated in detail by means of UV‐visible spectroscopy, CLSM, and SFM. It was found that the photochemical reaction of the assembled hollow capsules depends strongly on the matrix. Qualitative results on the permeability of the hollow capsule walls with CR as one component indicate that the permeability of the walls can be easily photo‐controlled at varying irradiation time intervals without addition of external chemicals.
Notch1 expression on T cells is not required for CD4+ T helper differentiation
Authors: Tacchini‐Cottier Fabienne , Allenbach Cindy , Otten Luc A. , Radtke Freddy 
Published: May 2004

AbstractNotch1 proteins are involved in binary cell fate decisions. To determine the role of Notch1 in the differentiation of CD4+ Th1 versus Th2 cells, we have compared T helper polarization in vitro in naive CD4+ T cells isolated from mice in which the N1 gene is specifically inactivated in all mature T cells. Following activation, Notch1‐deficient CD4+ T cells transcribed and secreted IFN‐γ under Th1 conditions and IL‐4 under Th2 conditions at levels similar to that of control CD4+ T cells. These results show that Notch1 is dispensable for the development of Th1 and Th2 phenotypes in vitro. The requirement for Notch1 in Th1 differentiation in vivo was analyzed following inoculation of Leishmania major in mice with a T cell‐specific inactivation of the Notch1 gene. Following infection, these mice controlled parasite growth at the site of infection and healed their lesions. The mice developed a protective Th1 immune response characterized by high levels of IFN‐γ mRNA and protein and low levels of IL‐4 mRNA with no IL‐4 protein in their lymph node cells. Taken together, these results indicate that Notch1 is not critically involved in CD4+ T helper 1 differentiation and in resolution of lesions following infection with L. major.
Impaired migration of NOD mouse thymocytes: a fibronectin receptor‐related defect
Authors: Cotta‐de‐Almeida Vinícius , Villa‐Verde Déa Maria Serra , Lepault Françoise , Pléau Jean‐Marie , Dardenne Mireille , Savino Wilson 
Published: May 2004

AbstractWe previously showed intrathymic alterations in non‐obese diabetic (NOD) mice, including the appearance of giant perivascular spaces, filled with mature thymocytes, intermingled with an extracellular matrix network. This raised the hypothesis of a defect in thymocyte migration with partial arrest of exiting thymocytes in the perivascular spaces. Herein, we investigated the expression of receptors for fibronectin [very late antigen (VLA)‐4 and VLA‐5] and laminin (VLA‐6), known to play a role in thymocyte migration. When compared with two normal and one other autoimmune mouse strains, a decrease of VLA‐5 expression in NOD thymocytes was noticed, being firstly observed in late CD4/CD8 double‐negative cells, and more pronounced in mature CD4+ and CD8+ thymocytes. Functionally, thymocyte exit from the lymphoepithelial complexes, the thymic nurse cells, was reduced. Moreover, NOD thymocyte adhesion to thymic epithelial cells as well as to fibronectin was diminished, and so was the migration of NOD thymocytes through fibronectin‐containing transwell chambers. In situ, intra‐perivascular space thymocytes were VLA‐5‐negative, suggesting a correlation between the thymocyte arrest within these structures and loss of VLA‐5 expression. Overall, our data reveal impairment in NOD thymocyte migration, and correspond to the first demonstration of a functional fibronectin receptor defect in the immune system.
Small interference RNA modulation of IL‐10 in human monocyte‐derived dendritic cells enhances the Th1 response
Authors: Liu Gentao , Ng Hiushan , Akasaki Yasuharu , Yuan Xiangpeng , Ehtesham Moneeb , Yin Dong , Black Keith L. , Yu John S. 
Published: May 2004

AbstractRNA interference technology has been used to modulate dendritic cell (DC) function by targeting the expression of genes such as IL‐12 and NF‐kB. In this paper, we demonstrate that transfectionof DC with IL‐10‐specific double strands of small interference RNA (siRNA) resulted in potent suppression of IL‐10 gene expression without inducing DC apoptosis or blocking DC maturation. Inhibition of IL‐10 by siRNA was accompanied by increased CD40 expression and IL‐12 production after maturation, which endowed DC with the ability to significantly enhance allogeneic T cell proliferation. IL‐10 siRNA transfection did not affect MHC class II, CD86, CD83, or CD54 expression in mature DC. To further test the ability of IL‐10 siRNA‐treated DC to induce a T cell response, naive CD4 T cells were stimulated by autologous DC pulsed with KLH. The results indicated that IL‐10 siRNA‐transfected DC enhanced Th1 responses by increasing IFN‐γ and decreasing IL‐4 production. These findings suggest the potential for a novel immunotherapeutic strategy of using IL‐10 siRNA‐transfected antigen‐presenting cells as vaccine delivery agents to boost the Th1 response against pathogens and tumors that are controlled by Th1 immunity.
Chemical Methods for Ether‐Bond Cleavage by Electron‐Transfer Reagents
Authors: Grobelny Zbigniew 
Published: May 2004

AbstractEthers can easily be cleaved with various electron‐transfer reagents. New data concerning the chemical methods of the regioselective opening of the ether bond with alkali metals (M0), alkali metal aromatic radical anions (Ar·−, M+), alkalides (M−, M+C; C denotes a ligand) and low‐valent transition‐metal compounds are presented. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Enhancement of pool boiling heat transfer in water and ethanol/water mixtures (effect of surface‐active agent)
Authors: Inoue Toshiaki , Teruya Yoshio , Ishii Masaru , Monde Masanori 
Published: May 2004

AbstractThe surface tension of alcohol/water mixtures has been measured over the whole fraction range and then it has been measured when a surface‐active agent was added into the mixtures. The effect of the concentration of alcohol and the surface‐ active agent on surface tension was experimentally clarified, in order to gain base data related to enhancement of the heat transfer coefficient in the mixtures and water. The experiment was also carried out to enhance the boiling heat transfer coefficients of water and alcohol/water mixtures on a horizontal heated fine wire at a pressure of 0.1 MPa by adding a surface‐active agent into the tested liquid. The results show, the coefficients were enhanced in lower alcohol concentration (C ≦ 0.5) and low heat flux range which occur just after the onset of boiling. It was also found that the enhancement effect by the surfactant disappears in concentrations over 1000 ppm. Finally, we demonstrated that the surface tension remarkably affects the heat transfer coefficients in nucleate pool boiling. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(4): 229–244, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20010
Research on convective condensation heat transfer for a gas mixture in a vertical tube
Authors: Jia Li , Peng Xiaofeng 
Published: May 2004

AbstractThis paper discusses the convective condensation of a gas mixture in a vertical tube. A mathematical model was derived by combining a modified film model and Nusselt's condensation theory. The effect of wall temperature on film thickness and interfacial temperature was predicted and film thickness was calculated. When compared with the gas phase resistance method, the film model is better. The phenomenon of SO2 absorption into condensate is illustrated and discussed. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(4): 219–228, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20011
Heat transfer enhancement by crossflow‐induced vibration
Authors: Tian Mao‐cheng , Cheng Lin , Lin Yi‐qing , Zhang Guan‐min 
Published: May 2004

AbstractA new method of heat transfer enhancement by water crossflow‐induced vibration is presented. A heat transfer element which involves elastic tube bundles has been designed. This system has excellent response characteristics of vibration to the crossflow. A triangular pole device for producing pulsating flow was adopted. This device can induce vibration in a fixed range of frequencies and has a profound influence on heat transfer augmentation. For the constant heat flux boundary condition, experiments are carried out on the heat transfer characteristics of elastic tube bundles augmented by flow‐induced vibration in a water crossflow. Compared with static tube bundles, the out‐tube average convective heat transfer coefficients of the elastic tube bundles are increased by 100–150% under the condition of crossflow‐induced vibration. Dimensionless equations describing the outside heat transfer coefficient for the elastic tube bundles were acquired. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(4): 211–218, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20012
A low‐temperature biomimetic calcium phosphate surface enhances early implant fixation in a rat model
Authors: Kuroda S. , Virdi A. S. , Li P. , Healy K. E. , Sumner D. R. 
Published: May 2004

AbstractThe present study demonstrates increased early mechanical fixation of titanium implants coated with a new biomimetic apatite surface in a rat model. Male Sprague‐Dawley rats received unilateral femoral medullary implants for periods of 1–4 weeks. The strength of fixation of the implant to the host bone increased more rapidly in the group receiving apatite‐treated implants compared with the control group as evidenced by the apatite group's 21‐fold greater fixation strength at 1 week (p = 0.009), 4‐fold greater fixation strength at 2 weeks (p = 0.041), and 2‐fold greater fixation strength at 4 weeks (p = 0.093) compared with the control. Fixation strength was correlated with bone–implant contact as determined from micro computed tomography assessment of the specimens (r2 = 0.338, p = 0.011 in the control group and r2 = 0.543, p < 0.001 in the apatite group). Furthermore, for a given amount of bone–implant contact, the fixation strength was higher in the apatite group than in the control group (p = 0.011), suggesting that the bone formed a stronger bond to the apatite coating than to the titanium. This difference in bonding strength accounted for the difference in mechanical behavior. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 66–73, 2004
Endothelial cell barrier regulation by sphingosine 1‐phosphate
Authors: McVerry Bryan J. , Garcia Joe G.N. 
Published: May 2004

AbstractDisruption of vascular barrier integrity markedly increases permeability to fluid and solute and is the central pathophysiologic mechanism of many inflammatory disease processes, including sepsis and acute lung injury (ALI). Dynamic control of the endothelial barrier involves complex signaling to the endothelial cytoskeleton and to adhesion complexes between neighboring cells and between cells and the underlying matrix. Sphingosine 1‐phosphate (S1P), a biologically active lipid generated by hydrolysis of membrane lipids in activated platelets, organizes actin into a strong cortical ring and strengthens both intercellular and cell–matrix adherence. The mechanisms by which S1P increases endothelial barrier integrity remain the focus of intense basic research. The downstream structural changes induced by S1P interact to decrease vascular permeability to fluid and solute, which translates into a reduction lung edema formation in animal models of ALI, thus suggesting a potentially life‐saving therapeutic role for vascular barrier modulation in critically ill patients. © 2004 Wiley‐Liss, Inc.
Endoplasmic reticulum stress triggers an acute proteasome‐dependent degradation of ATF6
Authors: Hong Min , Li Mingqing , Mao Changhui , Lee Amy S. 
Published: May 2004

AbstractATF6, a 670 amino acid endoplasmic reticulum (ER) transmembrane glycoprotein with the electrophoretic mobility of a 90 kDa protein, is a key transcriptional activator of the unfolded protein response (UPR) that allows mammalian cells to maintain cellular homeostasis when the cells are subjected to a variety of environmental and physiological stress. Previous studies have established that ATF6 is a short‐lived protein, the activation of which involves relocation from the ER to the Golgi where it is cleaved by the S1P/S2P protease system to generate a nuclear form that acts as a transcriptional activator for ER‐stress inducible target genes such as Grp78/BiP. We report here that in addition to this process, ER‐stress mediated by thapsigargin triggers an acute proteasomal degradation of the pre‐existing pool of p90ATF6 independent of S1P/S2P cleavage. We showed that ATF6 is a direct target of proteasome‐ubiquitin pathway, and this process can be suppressed by proteasome inhibitors, ALLN and MG115. We further observed that in non‐stressed cells, p90ATF6 can be stabilized by MG115 but not ALLN and that treatment of cells with MG115 results in Grp78 induction in the absence of ER stress. These studies suggest that ER‐stress induced acute, transit degradation of p90ATF6 could represent a novel cellular defense mechanism to prevent premature cell death resulting from p90ATF6 activation. Further, inhibition of proteasome activity can result in chaperone protein gene induction through stabilization of p90ATF6 as well as accumulation of malfolded proteins. © 2004 Wiley‐Liss, Inc.
Gene expression profile of human bone marrow stromal cells determined by restriction fragment differential display analysis
Authors: Monticone Massimiliano , Liu Yi , Tonachini Laura , Mastrogiacomo Maddalena , Parodi Stefano , Quarto Rodolfo , Cancedda Ranieri , Castagnola Patrizio 
Published: May 2004

AbstractUsing an in vitro osteogenic culture system, we carried out a restriction fragment differential display (RFDD‐PCR) to identify genes expressed by these cells in their undifferentiated stage and not expressed, or expressed at a lower level, in a closely related but distinct cell type: bone marrow stromal cells (BMSC)‐derived osteoblasts (BDO). Forty‐seven candidate regulated genes, selected by RFDD, were analyzed by RT‐PCR analysis in three cell clones and in primary cultures from seven different donors. A subset of three genes were confirmed as upregulated in BMSC relative to BDO in every primary culture and cloned population examined: βIG‐h3, IGFbp3, and LOXL2. Their differential expression was confirmed by Northern analysis and the corresponding proteins were detected by immunolocalization in BMSC. © 2004 Wiley‐Liss, Inc.
Molecular circuits of apoptosis regulation and cell division control: The survivin paradigm
Authors: Altieri Dario C. 
Published: May 2004

AbstractThe coupling of cell proliferation to cell death is thought to function as a pivotal crossroad, essential to preserve normal homeostasis and to eliminate dangerous cells before they divide. Survivin is a prototype molecule at this crossroad, intercalated in protection against mitochondrial cell death and orchestrating various aspects of cell division. Dramatically exploited in cancer and an unfavorable gene signature for disease outcome, the survivin pathway has now provided tangible opportunities for targeted, rational cancer therapy. © 2004 Wiley‐Liss, Inc.
Accuracy of free energies of hydration using CM1 and CM3 atomic charges
Authors: Udier–Blagović Marina , Morales De Tirado Patricia , Pearlman Shoshannah A. , Jorgensen William L. 
Published: May 2004

AbstractAbsolute free energies of hydration (ΔGhyd) have been computed for 25 diverse organic molecules using partial atomic charges derived from AM1 and PM3 wave functions via the CM1 and CM3 procedures of Cramer, Truhlar, and coworkers. Comparisons are made with results using charges fit to the electrostatic potential surface (EPS) from ab initio 6‐31G* wave functions and from the OPLS‐AA force field. OPLS Lennard–Jones parameters for the organic molecules were used together with the TIP4P water model in Monte Carlo simulations with free energy perturbation theory. Absolute free energies of hydration were computed for OPLS united‐atom and all‐atom methane by annihilating the solutes in water and in the gas phase, and absolute ΔGhyd values for all other molecules were computed via transformation to one of these references. Optimal charge scaling factors were determined by minimizing the unsigned average error between experimental and calculated hydration free energies. The PM3‐based charge models do not lead to lower average errors than obtained with the EPS charges for the subset of 13 molecules in the original study. However, improvement is obtained by scaling the CM1A partial charges by 1.14 and the CM3A charges by 1.15, which leads to average errors of 1.0 and 1.1 kcal/mol for the full set of 25 molecules. The scaled CM1A charges also yield the best results for the hydration of amides including the E/Z free‐energy difference for N‐methylacetamide in water. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1322–1332, 2004
Determining sequences and post‐translational modifications of novel conotoxins in Conus victoriae using cDNA sequencing and mass spectrometry
Authors: Jakubowski Jennifer A. , Keays David A. , Kelley Wayne P. , Sandall David W. , Bingham Jon‐Paul , Livett Bruce G. , Gayler Ken R. , Sweedler Jonathan V. 
Published: May 2004

AbstractA combination of cDNA cloning and detailed mass spectrometric analyses was employed to identify novel conotoxins from Conus victoriae. Eleven conotoxin sequences were determined using molecular methods: one belonging to the A superfamily (Vc1.1), six belonging to the O superfamily (Vc6.1–Vc6.6) and four members of the T superfamily (Vc5.1–Vc5.4). In order to verify the sequences and identify the post‐translational modifications (excluding the disulfide connectivity) of three Conus victoriae conotoxins, vc1a, vc5a and vc6a, deduced from sequences Vc1.1, Vc5.1, and Vc6.1, respectively, liquid chromatography/electrospray ionization ion trap mass spectrometry, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry and nanospray ionization ion trap mass spectrometry with collisionally induced dissociation were performed on reduced and alkylated venom fractions. We report that vc1a, the native form of α‐conotoxin Vc1.1 (an unmodified 16 amino acid residue peptide that has notable pain‐relieving capabilities), includes a hydroxyproline and a γ‐carboxyglutamate residue. Conotoxin vc5a is a 10‐residue peptide with two disulfide bonds and a hydroxyproline and vc6a is a 25 amino acid peptide with three disulfide bonds. Copyright © 2004 John Wiley & Sons, Ltd.
Optimising flax production in the South Atlantic region of the USA
Authors: Foulk Jonn A , Akin Danny E , Dodd Roy B , Frederick James R 
Published: May 2004

AbstractWorldwide the USA is the largest user of flax fibre, though very little is actually grown or produced in the USA. ‘Ariane’ flax was grown in 1990–1991, 1991–1992 and 1998–1999 in South Carolina, USA and evaluated for production characteristics. Plots (15 m long and 2 m wide) in the fall of 1990 and 1991 generated dry matter plant yields ranging from 4510 (early harvest at a seeding rate of 67 kg ha−1) to 7340 (late harvest at a seeding rate of 134 kg ha−1) kg ha−1. Based on these results, seed was sown on a private farm using a drill in 19 cm rows at a seeding rate of 101 kg ha−1 in 1998–1999. Early harvest, selected for optimal fibre quality, produced a dry matter plant yield that averaged 4076 kg ha−1. Late harvest, selected to optimise seed plus fibre, produced a dry matter plant yield that averaged 5076 kg ha−1. Stubble remaining in the field after mowing at about 6.0–7.6 cm above the soil surface resulted in a fibre loss of about 3% of total plant dry matter or 10% of potential total fibre yield. Dry matter and fibre yields suggested that flax could be produced in the southeastern USA using traditional farming methods for the area. Copyright © 2004 Society of Chemical Industry