bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polydisperse Aggregates of ZnO Nanocrystallites: A Method for Energy‐Conversion‐Efficiency Enhancement in Dye‐Sensitized Solar Cells
Authors: Zhang Qifeng , Chou Tammy P. , Russo Bryan , Jenekhe Samson A. , Cao Guozhong 
Published: May 2008

AbstractZnO films consisting of either polydisperse or monodisperse aggregates of nanocrystallites were fabricated and studied as dye‐sensitized solar‐cell electrodes. The results revealed that the overall energy‐conversion efficiency of the cells could be significantly affected by either the average size or the size distribution of the ZnO aggregates. The highest overall energy‐conversion efficiency of ∼4.4% was achieved with the film formed by polydisperse ZnO aggregates with a broad size distribution from 120 to 360 nm in diameter. Light scattering by the submicrometer‐sized ZnO aggregates was employed to explain the improved solar‐cell performance through extending the distance travelled by light so as to increase the light‐harvesting efficiency of photoelectrode film. The broad distribution of aggregate size provides the ZnO films with both better packing and an enhanced ability to scatter the incident light, and thus promotes the solar‐cell performance.
Embedding Ag Nanoparticles into MgF2 Nanorod Arrays
Authors: He Yuping , Zhang Zhongyue , Hoffmann Chris , Zhao Yiping 
Published: May 2008

AbstractUsing a unique glancing angle co‐deposition technique, face‐centered cubic Ag nanoparticles have been embedded into aligned polycrystalline MgF2 nanorods with different topological shapes, such as tilted, zigzag, vertical, and helical nanorods. The optical properties of the artificial nanocomposite materials, such as surface plasmon resonance and polarization absorbance, are determined by the size of the Ag nanoparticles as well as the alignment and shape of the MgF2 nanorod arrays. The combination of co‐deposition and glancing angle deposition provides a unique way to design novel nanocomposite materials and doped nanorod arrays.
Advanced structural foam molding using a continuous polymer/gas melt flow stream
Authors: Xu Xiang , Park Chul B. , Lee John W. S. , Zhu Xindong 
Published: May 2008

AbstractThis article introduces a patented advanced structural foam molding technology. By the implementation of a means of continuing the polymer matrix melt flow stream, the processing conditions are made consistent, and the injected gas is thus uniformly dispersed throughout the polymer matrix. Compared with its predecessors targeted at similar applications, this new technology generates single‐phase polymer/blowing agent solutions and is therefore capable of producing parts with smaller cell sizes, more uniform cell size distributions, higher void fractions, and similar geometric accuracy. Fine‐celled parts (>106 cells/cm3) with high void fractions (>30%) were successfully produced in this research with an advanced structural foam molding machine that was built in house. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Phase equilibrium characteristics of supercritical CO2/poly(ethylene terephthalate) binary system
Authors: Li Zhi‐Yi , Meng Ting‐Yu , Liu Xue‐Wu , Xia Yuan‐Jing , Hu Da‐Peng 
Published: May 2008

AbstractThe solubility of carbon dioxide in poly (ethylene terephthalate) (PET) at high pressure and elevated temperature conditions was investigated for a better understanding of the phase equilibrium characteristics of supercritical CO2/PET binary system and useful data for the process development of the supercritical fluid dyeing. Based on the principle of pressure decaying, a novel experimental apparatus suitable to high pressure and high temperature measurement was established. The solubilities of CO2 in PET were measured with the apparatus at temperatures of 110, 120, and 130°C and pressures up to 30.0 MPa. The results show that the solubility of CO2 in PET increases with the increase of pressure and CO2 density, respectively, at a constant temperature, whereas it decreases with the increase of temperature at a constant pressure. The Sanchez‐Lacombe equation of state (S‐L EOS) was used to correlate the experimental data. The calculated results are in good agreement with the experimental ones. The average absolute relative derivation (AARD) is less than 3.91%. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation of Zn2+‐chelated poly(HEMA‐MAH) cryogel for affinity purification of chicken egg lysozyme
Authors: Derazshamshir Ali , Ergün Bahar , Peşint Gözde , Odabaşı Mehmet 
Published: May 2008

AbstractSupermacroporous poly(2‐hydroxyethyl methacrylate) [poly(HEMA)]‐based monolithic cryogel column was prepared by radical cryocopolymerization of HEMA with N‐methacryloyl‐L‐histidine methyl ester (MAH) as functional comonomer and N,N′‐methylene‐bisacrylamide (MBAAm) as crosslinker directly in a plastic syringe for affinity purification of lysozyme from chicken egg white. The monolithic cryogel containing a continuous polymeric matrix having interconnected pores of 10–50 μm size was loaded with Zn2+ ions to form the metal chelate with poly(HEMA‐MAH) cryogel. Poly(HEMA‐MAH) cryogel was characterized by swelling studies, FTIR, scanning electron microscopy, and elemental analysis. The equilibrium swelling degree of the poly(HEMA‐MAH) monolithic cryogel was 5.62 g H2O/g cryogel. Poly(HEMA‐MAH) cryogel containing 45.8 μmol MAH/g was used in the adsorption/desorption of lysozyme from aqueous solutions. The nonspecific adsorption of lysozyme was very low (7.5 mg/g). The maximum amount of lysozyme adsorption from aqueous solution in phosphate buffer was 209 mg/g at pH 7.0. It was observed that lysozyme could be repeatedly adsorbed and desorbed with the poly(HEMA‐MAH) cyogel without significant loss of adsorption capacity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Dendritic polychelatogens: Synthesis, characterization, and metal ion binding properties
Authors: Tülü Metin , Şenel Mehmet 
Published: May 2008

AbstractIn this article we demonstrate the synthesis of the dendritic polymers and their metal ion complexation. The concept of chemoremediation in liquid homogeneous phases using polymer reagents as a green technology is presented and outlined. First, as a hydrophilic ligand, AB3 type of dendron and its corresponding dendrimer using Poly(ethyleneoxide)‐Diacid (PEO‐DA) have been synthesized; second, surface of the three branched Poly(propyleneoxide)‐Triamine (PPO‐TA) was modified with methylacrylate and subsequently deprotected to a carboxylic acid. The dendrimers with pendant carboxylic groups were shown to be hydrolitically and termally stable. The metal complexing properties of the dendrimers were studied for Cr(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Pb(II) and Ag(I) ions in aqueous solution using the Liquid‐Phase Polymer‐Based Retention (LPR) method. In addition, the complexing capacity of synthesized PEO and PPO based dendrimers towards to Cu(II) were determined by inductively‐coupled plasma spectrometry (ICP) to be 260 and 142 mgg−1, respectively. According to the retention profiles determined as a function of filtration factor using LPR in conjunction with ICP, two and trivalent metal ions showed a strong interaction with these dendrimers © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis of an amphiphilic glucose‐carrying graft copolymer and its use for membrane surface modification
Authors: Wang Jianyu , Xu Youyi , Xu Hong , Zhang Fan , Qian Yanling , Zhu Baoku 
Published: May 2008

AbstractA graft copolymer of poly(vinylidene fluoride) (PVDF) with a glucose‐carrying methacrylate, 3‐O‐methacryloyl‐1,2:5,6‐di‐O‐isopropylidene‐D‐glucofuranose, was synthesized via the atom transfer radical polymerization technique with commercial PVDF as the macroinitiator. After a treatment with 88% formic acid, the isopropylidenyl groups of the precursor graft copolymer [poly(vinylidene fluoride)‐g‐poly(3‐O‐methacryloyl‐1,2:5,6‐di‐O‐isopropylidene‐ D‐glucofuranose)] were converted into hydroxyl groups, and this produced an amphiphilic graft copolymer (PVDF‐g‐PMAG) [poly(vinylidene fluoride)‐g‐poly(3‐O‐methacryloyl‐α,β‐D‐glucopyranose)] with glycopolymer side chains and a narrow molecular weight distribution (weight‐average molecular weight/number‐average molecular weight < 1.29). This glucose‐carrying graft copolymer was characterized with Fourier transform infrared, proton nuclear magnetic resonance, gel permeation chromatography, and thermogravimetric analysis. A novel porous membrane prepared from blends of PVDF with PVDF‐g‐PMAG via an immersion–precipitation technique exhibited significantly enhanced hydrophilicity and an anti‐protein‐adsorption property. The surface chemical composition and morphology of the membrane were studied with X‐ray photoelectron spectroscopy and scanning electron microscopy, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation and characterization of regenerated Bombyx mori silk fibroin fiber containing recombinant cell‐adhesive proteins; Nonwoven fiber and monofilament
Authors: Zhu Zhenghua , Ohgo Kosuke , Watanabe Reiko , Takezawa Toshiaki , Asakura Tetsuo 
Published: May 2008

AbstractTo improve the cell‐adhesive character of Bombyx mori silk fibroin fiber, the regenerated B. mori silk fibroin fibers with recombinant cell‐adhesive proteins were prepared. The recombinant proteins were originally designed in our laboratory and expressed in Eschericchia coli; one is the protein with the primary structure of (TGRGDSPAS)8 which was designed based on the cell adhesive sequence in fibronectin and the other is (GERGDLGPQGIAGQRGVVGERGERGERGAS)8GPPGPCC GGG originated from the cell adhesive sequences in collagen. The nonwoven silk fibroin nano‐fibers including these recombinant proteins were prepared by electrospinning method from the hexafluoroisopropanol (HFIP) solutions of mixture of B. mori silk fibroin and the recombinant proteins. The cell‐adhesive characters of such nonwoven silk fibers were much improved compared with that of the nonwoven silk fibroin fibers without the recombinant proteins. In addition, the degradation rates of the nonwoven fibers were accelerated by mixing of the recombinant proteins into silk fibroin. Here, we also prepared the regenerated silk fibroin monofilaments including the recombinant proteins by wet spinning from the HFIP dope solution. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
A simplified approach to teaching medical students ocular movements and the rationale in testing the oculomotor, trochlear, and abducent nerves
Authors: Bernd Paulette , Jakway Jacqueline 
Published: May 2008

AbstractThe actions of the individual extraocular muscles are best explained to medical students in a lecture format by showing the relationship of each muscle to the axes of the globe and the walls of the bony orbit. The lateral and medial rectus muscles cross only the vertical axis, and consequently, cause only abduction and adduction, respectively. These muscles can be tested simply by asking the patient to abduct or adduct. Inability to do so indicates that the muscles and/or their innervation have been compromised. In contrast, the superior and inferior oblique and rectus muscles cross all three axes (vertical, horizontal, and anteroposterior) of the globe. Therefore, concentric contraction of each of these muscles results in three movements; abduction or adduction, elevation or depression, and intorsion or extorsion. These muscles must be tested with a sequence of two movements. Gaze can be either elevated or depressed by both an oblique and a rectus muscle. If abduction or adduction occurs first, one muscle of the pair becomes incapable of causing elevation or depression of the pupil. The rationale for abducting or adducting first is that either the oblique or rectus muscle of the pair will no longer cross the horizontal axis and will then be unable to effect the desired movement. Inability to elevate or depress gaze from the abducted or adducted position shows which muscle, the oblique or rectus, and/or its innervation has been compromised. Anat Sci Ed 1:126–129, 2008. © 2008 American Association of Anatomists.
Main‐Chain Length Control of Conformation, Membrane Activity, and Antibiotic Properties of Lipo­peptaibol Sequential Analogues
Authors: Oancea Simona , Hilma Geta , Peggion Cristina , Formaggio Fernando , Toniolo Claudio 
Published: May 2008

AbstractTo investigate the effect of backbone length and amphiphilicity on the 3D structure, membrane permeability, and antibacterial properties of trichogins, a subclass of lipopeptaibols, we prepared, by the segment condensation approach in solution and chemically characterized, a set of Nα‐1‐octanoylated ‐X‐(GLUG)n‐I‐L‐ ( X=G or U where U=Aib; n=1–4) sequential peptide esters. In parallel, the 12‐mer (UGGL)3 aneurism peptide, an analogue of the 11‐mer sequential peptide (n=2) with an amino acid insertion was also synthesized and studied. By FT‐IR absorption technique, we clearly showed that, in CDCl3 solution, all peptides essentially populate intramolecularly H‐bonded, helical conformations. Moreover, CD spectroscopy indicates that all peptides, with the single exception of the shortest oligomer (the heptamer), adopt mixed 310‐/α‐helical structures, to an extent approximately correlating with main‐chain length, in MeOH solution and sodium dodecylsulfate (SDS) micelles. Significant membrane permeability properties were found only for the three longest GLUG‐based peptides, with the 15‐mer oligomer (n=4) resulting the most active. The lack of activity exhibited by the aneurism peptide in this experiment strongly suggests a relevant role for the sequence amphiphilicity. In addition, antibacterial activity and selectivity were highlighted and demonstrated to be dependent on peptide main‐chain length and amphiphilicity, in the sense that the two shortest GLUG‐based homologues are active against Gram‐positive strains, whereas the two longest homologues are able to penetrate the membranes of the Gram‐negative strains, and the UGGL‐based aneurism peptide is inactive.
Quinolizidinyl‐benzimidazoles as Platelet‐Antiaggregating Agents
Authors: Vazzana Iana , Terranova Emanuela , Tasso Bruno , Tonelli Michele , Piana Antonietta , Gastaldi Stefanella , Sparatore Fabio 
Published: May 2008

AbstractTwo series of (±)‐2‐phenyl‐1‐(quinolizidin‐1α‐yl)benzimidazoles, 12A–26A, and (±)‐2‐phenyl‐1‐(quinolizidin‐1β‐yl)benzimidazoles, 12B–26B, were prepared and tested for the inhibition of human platelets aggregation induced by ADP, collagen, and adrenaline. All epimers A, i.e., 12A–26A, were devoid of any activity against the three agonists, while the epimers B, i.e., 12B–26B, exhibited different degrees of activity, though practically confined against the ADP‐induced aggregation. The best compounds were 19B, 24B, and 26B, which inhibited for 69–67% at 260 μM and for 40–29% at 65 μM concentration the ADP (2 μM)‐induced aggregation. The observed agonist and spatial structure selectivity warrant further investigations of this kind of benzimidazole derivatives.
New Pentacyclic Triterpenes from Gypsophila oldhamiana and Their Biological Evaluation as Glycogen Phosphorylase Inhibitors
Authors: Luo Jian‐Guang , Liu Jun , Kong Ling‐Yi 
Published: May 2008

AbstractThe three new pentacyclic triterpenes 1–3 were isolated and elucidated from the roots of Gypsophila oldhamiana, together with seven known triterpenes (4–10). These triterpenes were evaluated for their glycogen phosphorylase inhibitory activity and preliminary structure–activity trends are suggested.
Synthesis and Biological Evaluation of Novel 4‐Substituted 1‐{[4‐(10,15,20‐Triphenylporphyrin‐5‐yl)phenyl]methylidene}thiosemicarbazides as New Class of Potential Antiprotozoal Agents
Authors: Bhat Abdul R. , Athar Fareeda , Van Zyl Robyn L. , Chen Chien‐Teng , Azam Amir 
Published: May 2008

AbstractA novel series of 4‐substituted 1‐{[4‐(10,15,20‐triphenylporphyrin‐5‐yl)phenyl]methylidene}thiosemicarbazide, 4a–4n, was synthesized in 9–21% yield by the condensation of 4‐(10,15,20‐triphenylporphyrin‐5‐yl)benzaldehyde (3) with various substituted thiosemicarbazides in presence of catalytic amount of AcOH. These compounds were assayed for in vitro antiamoebic activity, and the results showed that out of 14 compounds 9 were found with IC50 values lower than metronidazole corresponding to 1.05‐ to 4.7‐fold increase in activity. MTT Assay showed that all the compounds are nontoxic to human kidney epithelial cell line. 4‐(m‐Toluidinyl)‐1‐{[4‐(10,15,20‐triphenylporphyrin‐5‐yl)phenyl]methylidene}thiosemicarbazide (4h) showed the highest antiamoebic activity with least cytotoxicity. Some of the compounds were screened for their antimalarial activities and ability to inhibit β‐haematin formation, but none of them showed an activity better than chloroquine and quinine. Only one compound out of six showed an activity comparable to standard drug.
Surprising Structural Lability of a Cysteine‐S‐Conjugate Precursor of 4‐Methyl‐4‐sulfanylpentan‐2‐one, a Varietal Aroma in Wine of Vitis vinifera L. cv. Sauvignon Blanc
Authors: Shinkaruk Svitlana , Thibon Cécile , Schmitter Jean‐Marie , Babin Pierre , Tominaga Takatoshi , Degueil Marie , Desbat Bernard , Jussier Christophe , Bennetau Bernard , Dubourdieu Denis , Bennetau‐Pelissero Catherine 
Published: May 2008

Abstract4‐Methyl‐4‐sulfanylpentan‐2‐one (1; 4MSP) provides a characteristic aroma compound of wines made from Vitis vinifera L. cv. Sauvignon blanc. 4MSP has a strong box‐tree odor with a very low perception threshold and is derived from the cysteinylated precursor S‐(1,1‐dimethyl‐3‐oxobutyl)cysteine (4; P‐4MSP). P‐4MSP is transformed into 4MSP during alcoholic fermentation and is an excellent marker of varietal aroma potential. An improved synthesis of P‐4MSP as well as of its deuterium‐labeled analogue [D6]‐P‐4MSP is described. Several analytical methods (NMR, IR, LSI‐MS, GC/MS, ESI‐MSn) were combined to elucidate spontaneous reversible structural changes of P‐4MSP at different pH values. At low pH, P‐4MSP has a linear keto form. The keto–enol tautomerism was observed at neutral pH. At pH 8, the formation of N‐substituted intramolecular hemiaminal was characterized by ESI‐MS and ESI‐MSn experiments. The hemiaminal loses H2O at high pH to produce a cycloimine, which is easily opened by acid hydrolysis. The keto–enol tautomerism explained the incorporation of only six D‐atoms during the preparation of the P‐4MSP deuterated standard even if [D10]mesityl oxide was used. Derivatization conditions for GC/MS analysis strongly affected the ratio of the monosilylated intramolecular cyclic form and the disilylated linear form of P‐4MSP. The structural changes of P‐4MSP may have a considerable impact on the development of methods of measuring varietal aroma potential.
Intraflagellar transport, cilia, and mammalian Hedgehog signaling: Analysis in mouse embryonic fibroblasts
Authors: Ocbina Polloneal Jymmiel R. , Anderson Kathryn V. 
Published: May 2008

AbstractGenetic studies in the mouse have shown that Intraflagellar Transport (IFT) is essential for mammalian Hedgehog (Hh) signal transduction. In this study, we take advantage of wild type and IFT mutant mouse embryonic fibroblasts (MEFs) to characterize additional aspects of the relationship between IFT and Hh signaling. Exposure to Sonic hedgehog (Shh) ligand or expression of an activated allele of Smo, SmoA1, activates an Hh reporter in wild‐type MEFs, but not in MEFs derived from embryos that lack IFT172 or the Dync2h1 subunit of the retrograde IFT motor. Similarly, decreased activity of either Sufu or PKA, two negative regulators of Hh signal transduction, activates the pathway in wild‐type, but not IFT mutant, MEFs. In contrast to wild‐type MEFs, Smo is constitutively present in the cilia of Dync2h1 mutant MEFs. This finding suggests that IFT‐dependent trafficking of Hh pathway components through the cilium is essential for their function. Developmental Dynamics 237:2030–2038, 2008. © 2008 Wiley‐Liss, Inc.
Influenza A virus abrogates IFN‐γ response in respiratory epithelial cells by disruption of the Jak/Stat pathway
Authors: Uetani Kohsaku , Hiroi Miki , Meguro Tadamichi , Ogawa Hiroshi , Kamisako Toshinori , Ohmori Yoshihiro , Erzurum Serpil C. 
Published: May 2008

AbstractThe innate immunity to viral infections induces a potent antiviral response mediated by interferons (IFN). Although IFN‐γ is detected during the acute stages of illness in the upper respiratory tract secretions and in the serum of influenza A virus‐infected individuals, control of influenza A virus is not dependent upon IFN‐γ as evidenced by studies using anti‐IFN‐γ Ab and IFN‐γ–/– mice. Thus, we hypothesized that IFN‐γ is not critical in host survival because influenza A virus has mechanisms to evade the antiviral activity of IFN‐γ. To test this, A549 cells, an epithelial cell line derived from lung adenocarcinoma, were infected with influenza virus strain A/Aichi/2/68 (H3N2) (Aichi) and/or stimulated with IFN‐γ to detect IFN‐γ‐stimulated MHC class II expression. Influenza A virus infection inhibited IFN‐γ‐induced up‐regulation of HLA‐DRα mRNA and the IFN‐γ induction of class II transactivator (CIITA), an obligate mediator of MHC class II expression. Nuclear translocation of Stat1α upon IFN‐γ stimulation was significantly inhibited in influenza A virus‐infected cells and this was associated with a decrease in Tyr701 and Ser727 phosphorylation of Stat1α. Thus, influenza A virus subverts antiviral host defense mediated by IFN‐γ through effects on the intracellular signaling pathways.
Mesenchymal stem cells for graft‐versus‐host disease: Close encounters with T cells
Authors: Dazzi Francesco , Marelli‐Berg Federica M. 
Published: May 2008

AbstractMesenchymal stem cells (MSC) have recently received centre stage attention because of their potent immunosuppressive effect which has also been successfully exploited in the clinical setting to treat graft‐versus‐host disease (GVHD); however, the path to clinical efficacy is hindered by the limited understanding of how MSC work and how best to use their potential. In this issue of the European Journal of Immunology, it is shown, using an animal model, that MSC can treat GVHD only if administered in the presence of active disease and that this requirement is strictly related to the presence of IFN‐γ. Here we summarise the knowledge regarding MSC mediated tolerance and the evidence supporting the notion that MSC must be ‘licensed’ to exert their effects. We also propose the idea that the instrumental effect of IFN‐γ activity on MSC‐mediated immunomodulation relies upon IFN‐γ's ability to gather and retain suppressive and effector cells in the same anatomical compartment.See accompanying article: http://dx.doi.org/10.1002/eji.200738129
A Modular Approach Towards Nonsymmetrical Bis(metallosalen) Building Blocks
Authors: Curreli Simona , Escudero‐Adán Eduardo C. , Benet‐Buchholz Jordi , Kleij Arjan W. 
Published: May 2008

AbstractNew bis(metallosalen) building blocks are described that can be accessed through di‐ or tetraimine precursors derived from the 3,3′‐diaminobenzidine backbone. A selective procedure for the introduction of two imine groups in 3,3′‐diaminobenzidine was developed to furnish starting materials for nonsymmetrical metallosalen complexes. The procedure proved to be widely applicable and several diimine derivatives were isolated and fully characterized. The diimine compounds were used to prepare the first nonsymmetrical bis(salen) complexes (M = Zn, Ni) with different peripheral groups upon treatment with various salicylaldehydes in a one‐pot procedure. The identity of the bis(metallosalen)s was verified by a range of analytical techniques, and for two of these derivatives the X‐ray molecular structures are described. The crystallographic data revealed that the biphenylene linker between the two N2O2 donor sets can adopt conformations with different dihedral angles. The supramolecular potential of the bis[Zn(salen)] derivatives was investigated by combining two of these complexes with a ditopic ligand to yield supramolecular assemblies with nanoscale dimensions.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)