bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chiral Fluorescent Receptors Based on (R)‐1,1′‐Binaphthylene‐2,2′‐bisthiourea: Synthesis and Chiral Recognition
Authors: Lan‐Hua Wei , Yong‐Bing He , Kuo‐Xi Xu , Shun‐Ying Liu , Ling‐Zhi Meng 
Published: July 2005

AbstractTwo chiral fluorescent receptors 1 and 2 based on (R)‐1,1′‐binaphthylene‐2,2′‐bisthiourea were synthesized, and their chiral recognition properties for enantiomeric mandelate anions were studied by fluorescence spectra and molecular modeling. Addition of the L‐ and D‐mandelate anions caused considerable fluorescent increases in the fluorescent intensity of the host solution. The L‐enantiomer can enhance the fluorescence intensity of 1 much more than the D‐enantiomer can do, and 1 shows a better enantioselective recognition ability than 2.
A Short Synthesis of Natural Isocoumarin Glucoside Delphoside
Authors: Aamer Saeed 
Published: July 2005

AbstractA simple synthesis of delphoside, 3‐methyl‐6‐hydroxy‐8‐O‐β‐D‐glucopyranosyloxy isocoumarin (1), isolated from Delphinium spp. is described. 3,5‐Dimethoxyhomophthalic anhydride (2) on treatment with acetyl chloride in the presence of 1,1,3,3‐tetramethylguanidine (TMG) and triethyl amine afforded the 6,8‐dimethoxy‐3‐methylisocoumarin (3). Regioselective demethylation of the latter furnished 8‐hydroxy‐6‐methoxy‐3‐methylisocoumarin (4). Glycosylation with O‐(2,3,4,6‐tetra‐O‐acetyl‐D‐glucopyranosyl)trichloroacetimidate in presence of catalytic amount of boron trifluoride etherate followed by deacetylation using 5% potassium carbonate afforded 3‐methyl‐6‐methoxy‐8‐O‐β‐D‐glucopyranosyloxyisocoumarin (6) that was finally demethylated to yield delphoside 1.
Syntheses, Structures, and Optical Properties of β‐Ferrocenylacrylate Metal Polymers
Authors: Li Lin Ke , Song Ying Lin , Hou Hong Wei , Fan Yao Ting , Zhu Yu 
Published: July 2005

AbstractThe zero‐dimensional polymer [Pb6(μ2OOCCH=CHFc)2(μ3‐OOCCH=CHFc)2(μ2‐η2‐OOCCH=CHFc)2(η2‐OOCCH=CHFc)2(μ4‐O)2] (1), the one‐dimensional chain polymers [Pb(η1‐μ2‐OOCCH=CHFc)2(phen)]n (phen = phenanthroline; (2), {[Cd(μ2‐η2‐OOCCH=CHFc)(η2‐OOCCH=CHFc)(H2O)2](H2O)4}n (3), and the two‐dimensional hybrid polymer {[Cd(η2‐OOCCH=CHFc)(bbbm)1.5Cl]·1.5H2O}n [bbbm = 1,1'‐(1,4‐butanediyl)bis‐1H‐benzimidazole; 4] have been prepared by the reaction of sodium β‐ferrocenylacrylate [FcCH=CHCOONa, Fc = (η5‐C5H5)Fe(η5‐C5H4)] with the appropriate metal salts. Solution‐state differential pulse voltammetry for 1–4 indicated that the half‐wave potentials of the ferrocenyl moieties in these polymers are all shifted to positive potential compared with that of sodium β‐ferrocenylacrylate. The four polymers’ third‐order nonlinear optical (NLO) properties were determined by the Z‐scan technique in DMF solutions. The results show that these polymers possess good nonlinear optical refraction effects. Their hyperpolarizability (γ) values are calculated to be 4.80 × 10–30, 5.19 × 10–30, 1.57 × 10–29, and 2.04 × 10–29 esu for 1–4, respectively. The γ values of the CdII polymers (3 and 4) are slightly larger than those of the PbII polymers (1 and 2), which indicates that the metal ions play an important role in the NLO properties of these polymers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis of the Dimethyl Ester of 2'‐Cyano‐8'‐formyl‐N'‐methyl‐1',1a',5a',6'‐tetrahydroacrido[4,5,5a,6‐bcd]‐Annulated 2,3‐Dihydromesoporphyrin – A Novel System with Outstanding Properties as Basis for Photodynamic Therapy in the Far‐Red Region of the Visible Spectrum
Authors: van der Haas Richard N S. , Tang Siu‐Ha , Arenas Hernández Beatriz , de Jong Robertus L. P. , Erkelens Cornelis , Liu Yan , Gast Peter , Smijs Threes G. M. , Schuitmaker Hans J. , Lugtenburg Johan 
Published: July 2005

AbstractThe sterically hindered [5‐(2'‐cyanovinyl)mesoporphyrin dimethyl ester]nickel complex 1 has been treated with N‐methylformanilide under Vilsmeier conditions. Besides the expected meso‐formylporphyrin derivatives, 22 % of a novel green compound was isolated. After removal of Ni2+ by treatment with concentrated sulfuric acid, the structure of the novel compound was elucidated by mass spectrometry and 1H and 13C NMR spectroscopy, which led to the unambiguous establishment of the unprecedented racemic dimethyl ester of 2'‐cyano‐8'‐formyl‐N'‐methyl‐1,1a,5a,6‐tetrahydroacrido[4,5,5a,6‐bcd]‐annulated 2,3‐dihydromesoporphyrin structure 5. This racemic form was efficiently separated into its two pure enantiomeric forms each of which shows the same electronic spectrum as the racemate mixture. The two optical isomers show the exact opposite circular dichroism spectra. The structure of this novel product is clearly formed after the initial attack of the carbenium ion formed from N‐methylformanilide and POCl3 at the α‐carbon atom of the appending meso‐acrylonitrile function. This processis thus far an unprecedented cyclization process underVilsmeier conditions. It is clear that in this case the aromatic system of the Vilsmeier reagent is intimately involved in this reaction. In order to further explore the reactivity of the starting material, we treated it with the Vilsmeier reagent prepared from dimethylformamide and POCl3. In this case we obtained, besides the expected formylation products, a mixture of two peri‐annulated quinoporphyrins. From the structures of the products and the starting material it could be established that in this case the attack of the Vilsmeier reagent is on the nitrogen atom of the appending acrylonitrile function. For the initial tests of 5 as the basis of a photodynamic therapy we found that in the presence of air and light it is an efficient singlet oxygen generator that is stable during the irradiation time. It shows no toxicity towards lung carcinoma cells in the dark while in the presence of air and light the compound leads to a rapid killing of the cancer cells at concentrations that are an order of magnitude lower than in the case of the quinoporphyrin systems. These are all promising properties for continued studies and further development towards a photodynamic cancer therapy. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
New Method for the General Synthesis of [1,2,4]Triazolo[1,5‐a]pyridines
Authors: Huntsman Elliott , Balsells Jaume 
Published: July 2005

Abstract[1,2,4]Triazolo[1,5‐a]pyridines without substituents on the 2‐position have been prepared from 2‐aminopyridines by cyclization of N‐(pyrid‐2‐yl)formamidoximes with trifluoroacetic anhydride. Triazoles substituted at any position on the pyridine ring may be prepared in good yields and under mild reaction conditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Nanoindentation of injection molded PLA and self‐reinforced composite PLA after in vitro conditioning for three months
Authors: Wright‐Charlesworth Debra D. , Miller Darinda M. , Miskioglu Ibrahim , King Julia A. 
Published: July 2005

AbstractPoly(lactic acid) (PLA) is used for medical devices such as sutures or orthopedic screws. A standard way to determine the loss of mechanical properties of a degradable polymer would be to soak the polymer in phosphate buffered saline (PBS) and test the desired property as a function of immersion time. This method is not sensitive enough to discern changes in mechanical properties through the cross‐section of the polymer and neglects the degradation that is occurring at the molecular level. This article presents results of a nanoindentation study carried out with PLA. The modulus and hardness of PLA is characterized as a function of processing method, immersion time in PBS, and location of the indent. Measuring local properties with the nanoindenter allowed detection of differences in material properties as a function of all three of these variables. The mechanical properties on the edge were lower than the interior of the sample after in vitro degradation, and changes were seen earlier for nanoindentation than for traditional flexural or tensile tests. The nanoindenter is a valuable tool for quantifying changes in material properties and may have applicability for accelerated tests to screen biomaterials. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
The electrochemical evaluation of a Zr‐based bulk metallic glass in a phosphate‐buffered saline electrolyte
Authors: Morrison M. L. , Buchanan R. A. , Leon R. V. , Liu C. T. , Green B. A. , Liaw P. K. , Horton J. A. 
Published: July 2005

AbstractBulk metallic glasses (BMGs) represent an emerging class of materials with an amorphous structure and a unique combination of properties. The objectives of this investigation were to define the electrochemical behavior of a specific Zr‐based BMG alloy in a physiologically relevant environment and to compare these properties to standard, crystalline biomaterials as well as other Zr‐based BMG compositions. Cyclic‐anodic‐polarization studies were conducted with a Zr52.5Cu17.9Ni14.6Al10.0Ti5.0(at %) BMG in a phosphate‐buffered saline electrolyte with a physiologically relevant oxygen content at 37°C. The results were compared to three common, crystalline biomaterials: CoCrMo, 316L stainless steel, and Ti‐6Al‐4V. The BMG alloy was found to have a lower corrosion penetration rate (CPR), as compared to the 316L stainless steel, and an equivalent CPR, as compared to the CoCrMo and Ti‐6Al‐4V alloys. Furthermore, the BMG alloy demonstrated better localized corrosion resistance than the 316L stainless steel. However, the localized corrosion resistance of the BMG alloy was not as high as those of the CoCrMo and Ti‐6Al‐4V alloys in the tested environment. The excellent electrochemical properties demonstrated by the BMG alloy are combined with a low modulus and unparalleled strength. This unique combination of properties dramatically demonstrates the potential for amorphous alloys as a new generation of biomaterials. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
A fast, scalable method for the parallel evaluation of distance‐limited pairwise particle interactions
Authors: Shaw David E. 
Published: July 2005

AbstractClassical molecular dynamics simulations of biological macromolecules in explicitly modeled solvent typically require the evaluation of interactions between all pairs of atoms separated by no more than some distanceR, with more distant interactions handled using some less expensive method. Performing such simulations for periods on the order of a millisecond is likely to require the use of massive parallelism. The extent to which such simulations can be efficiently parallelized, however, has historically been limited by the time required for interprocessor communication. This article introduces a new method for the parallel evaluation of distance‐limited pairwise particle interactions that significantly reduces the amount of data transferred between processors by comparison with traditional methods. Specifically, the amount of data transferred into and out of a given processor scales asO(R3/2p−1/2), wherepis the number of processors, and with constant factors that should yield a substantial performance advantage in practice. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1318–1328, 2005
Inhibition of lipopolysaccharide‐induced microglial activation by preexposure to neurotrophin‐3
Authors: Tzeng Shun‐Fen , Huang Hsin‐Ying , Lee Tsung‐I , Jwo Jeng‐Kuan 
Published: July 2005

AbstractMicroglia activated by neural injuries produce proinflammatory mediators, but activated microglia also appear in developing neural tissue to phagocytose cell debris resulting from programmed cell death without inducing tissue damage. Thus, factors associated with the developing CNS may modulate microglial activities. Previously we reported that pretreatment with neurotrophin‐3 (NT‐3), a factor known to regulate neural development, inhibits the production of proinflammatory mediators, nitric oxide (NO), tumor necrosis factor‐α, and interleukin‐1β, in BV2 activated by inflammagen lipopolysaccaride (LPS). In this study, the inhibition of proinflammatory mediators by NT‐3 pretreatment (preNT‐3) in primary microglia with LPS stimulation was corroborated. Moreover, pretreatment of LPS‐activated microglia with NT‐3 induced a trend of reduction in phagocytotic ability. By using LPS‐activated BV2 cells, we further found that reduced expression of inducible NO synthetase by preNT‐3 was mediated by MAP kinase and PI3 kinase signaling pathways. Moreover, pretreatment of BV2 cells with NT‐3 led to reduced levels of the p65 subunit of nucleus factor‐κB (NFκB) and its DNA binding activity. Accordingly, our results indicate that preexposure of microglia to NT‐3 leads to a reduced production of proinflammatory mediators in activated microglia by the induction of MAP kinase and PI3 kinase signaling, which in turn may reduce NFκB DNA binding activity. This suggests that an NT‐enriched microenvironment may be favorable for preventing the inflammatory reaction of microglia. © 2005 Wiley‐Liss, Inc.
Core/Shell Particles Containing 3‐(Methacryloxypropyl)‐Trimethoxysilane in the Shell: Synthesis, Characterization, and Application
Authors: Cao Shunsheng , Liu Bailing , Deng Xiaobo , Li Songjun 
Published: July 2005

AbstractSummary: In comparison to the corresponding single‐component counterparts, core/shell particles are widely used due to their better physical and chemical properties. The surface properties of core/shell particles evidently play an important role in the process of application. It is easy to deduce that surface properties mostly depend on the properties of the component in the shell. Therefore, desirable materials of shell are very significant for the study of composite materials, especially in core/shell field. It is well known that polysiloxane has excellent properties, such as the water repellency, high flexibility, low surface energy, and biocompatibility. Its application, however, is limited due to poor cohesiveness and poor film‐forming properties. Recently, much endeavor has been made to overcome such flaws. It is found that polyacrylate is commonly considered for its good cohesiveness and excellent film‐forming property. The combination of polysiloxane and polyacrylate has been shown to be important in the composite material field, especially as core/shell particles. Unfortunately, their hydrophobicity is considerably different and thus, the core/shell particles consisting of polyacrylate (PA)/polysiloxane (PSi) are hard to prepare by general seeded emulsion polymerization, and are also scarcely available in the literature. In this study, the new core/shell PA/PSi particles with poly(butyl methacrylate) (PA) as the core and poly(3‐(methacryloxypropyl)‐trimethoxysilane) (PSi) as the shell were prepared by dispersion polymerization under the kinetically controlled conditions. The characterization of the particles by TEM, DSC, particle size analyzer as well as static contact angle confirmed the formation of core/shell structure. The application of core/shell (PA/PSi) particles also has been considered and discussed here.TEM micrographs of core/shell (PA/PSi) particles.magnified imageTEM micrographs of core/shell (PA/PSi) particles.
Novel Poly(amido‐amine)‐Based Hydrogels as Scaffolds for Tissue Engineering
Authors: Ferruti Paolo , Bianchi Sabrina , Ranucci Elisabetta , Chiellini Federica , Caruso Vincenzina 
Published: July 2005

AbstractSummary: Biodegradable and biocompatible amphoteric poly(amido‐amine) (PAA)‐based hydrogels, containing carboxyl groups along with amino groups in their repeating unit, were considered as scaffolds for tissue engineering applications. These hydrogels were obtained by co‐polymerising 2,2‐bisacrylamidoacetic acid with 2‐methylpiperazine with or without the addition of different mono‐acrylamides as modifiers, and in the presence of primary bis‐amines as crosslinking agents. Hybrid PAA/albumin hydrogels were also prepared. The polymerisation reaction was a Michael‐type polyaddition carried out in aqueous media. The PAA hydrogels were soft and swellable materials. Cytotoxicity tests were carried out by the direct contact method with fibroblast cell lines on the hydrogels both in their native state (that is, as free bases) and as salts with acids of different strength, namely hydrochloric, sulfuric, acetic and lactic acid. This was done in order to ascertain whether counterion‐specific differences in cytotoxicity existed. It was found that all the amphoteric PAA hydrogels considered were cytobiocompatible both as free bases and salts. Selected hydrogels samples underwent degradation tests under controlled conditions simulating biological environments, i.e. Dulbecco medium at pH 7.4 and 37 °C. All samples degraded completely and dissolved within 10 d, with the exception of hybrid PAA/albumin hydrogels that did not dissolve even after eight months. The degradation products of all samples turned to be non‐cytotoxic. All these results led us to conclude that PAA‐based hydrogels have a definite potential as degradable matrices for biomedical applications.
magnified image
Epigenetic silencing of the PRSS3 putative tumor suppressor gene in non‐small cell lung cancer
Authors: Marsit Carmen J. , Okpukpara Chinedu , Danaee Hadi , Kelsey Karl T. 
Published: July 2005

AbstractThe serine protease family member PRSS3 (trypsinogen‐IV) has been implicated as a putative tumor suppressor gene due to its loss of expression, which is correlated with promoter hypermethylation, in esophageal squamous cell carcinoma and gastric adenocarcinoma. As epigenetic alteration is common in non‐small cell lung cancer (NSCLC), we sought to determine if promoter hypermethylation of PRSS3 occurred in this disease, and if it was associated with clinical features of NSCLC or tobacco‐related exposures in these patients. Using methylation‐specific PCR, we determined the promoter hypermethylation status of PRSS3 in a case series study of primary NSCLC, and found methylation of this gene to be common, occurring in 53% (86 of 166) of tumors examined. There was no association of this alteration with patient demographics, tumor features, or exposure histories of the patients. The lack of association is of interest, as it may suggest a lack of specific selection for inactivation of this gene. On the other hand, the high prevalence of this alteration makes PRSS3 methylation an attractive biomarker for use in diagnostic or screening applications in NSCLC. © 2005 Wiley‐Liss, Inc.
The Cauchy–Neumann problem for a multi‐dimensional isentropic hydrodynamic model for semiconductors
Authors: Li Yeping 
Published: July 2005

AbstractWe investigate a multi‐dimensional isentropic hydrodynamic (Euler–Poisson) model for semiconductors, where the energy equation is replaced by the pressure–density relation p(n) . We establish the global existence of smooth solutions for the Cauchy–Neumann problem with small perturbed initial data and homogeneous Neumann boundary conditions. We show that, as t→+∞, the solutions converge to the non‐constant stationary solutions of the corresponding drift–diffusion equations. Moreover, we also investigate the existence and uniqueness of the stationary solutions for the corresponding drift–diffusion equations. Copyright © 2005 John Wiley & Sons, Ltd.
Fully discrete approximation of a velocity and temperature tracking problem for the Boussinesq equations with piecewise distributed controls
Authors: Lee Hyung‐Chun , Shin Byeong Chun 
Published: July 2005

AbstractIn this article, we study the dynamics of a fully discrete piecewise optimal distributed control problem for the Boussinesq equations which models a velocity tracking over time coupled to thermal dynamics. We prove that the rates of velocity and‐ temperature tracking are exponential. We also give some computational results which reinforces the theoretical results derived. Copyright © 2005 John Wiley & Sons, Ltd.
Silicon surface modification with trialkoxysilyl‐functionalized star‐shaped polymers
Authors: Viswanathan Kalpana , Long Timothy E. , Ward Thomas C. 
Published: July 2005

AbstractThe synthesis of trimethoxysilane end‐capped linear polystyrene (PS) and star‐branched PS and subsequent silicon (Si) surface modification with linear and star polymers are described. Trimethoxysilane terminated PS was synthesized using sec‐butyl lithium initiated anionic polymerization of styrene and subsequent end‐capping of the living anions with p‐chloromethylphenyl trimethoxysilane (CMPTMS). 1H and 29Si NMR spectroscopy confirmed the successful end‐capping of polystyryllithium with the trimethoxysilane functional group. The effect of a molar excess of end‐capper on the efficiency of functionalization was also investigated, and the required excess increased for higher molar mass oligomers. Acid catalyzed hydrolysis and condensation of the trimethoxysilane end‐groups resulted in star‐branched PS, and NMR spectroscopy and SEC analysis were used to characterize the star polymers. This is the first report of core‐functionalized star‐shaped polymers as surface modifiers and the first comparative study showing differences in surface topography between star and linear polymer modified surfaces. Surface‐sensitive techniques such as ellipsometry, contact angle goniometry, and AFM were used to confirm the attachment of star PS, as well as to compare the characteristics of the star and linear PS modified Si surfaces. The polymer film properties were referenced to polymer dimensions in dilute solution, which revealed that linear PS chains were in the intermediate brush regime and the star‐branched PS produced a surface with covalently attached chains in the mushroom regime. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3655–3666, 2005
Mechanical properties of the novel organometallic polymer poly(ferrocenyldimethylsilane)
Authors: Smith Chris W. , Tan Kheng H. , Evans Ken E. , Resendes Rui , Bartole‐Scott Alexandra , Manners Ian 
Published: July 2005

AbstractA study of the mechanical properties of poly(ferrocenyldimethylsilane) [Fe(η‐C5H4)2SiMe2]n, 3, a novel organometallic polymer, has been performed on thin films of this material. The Young's modulus and Poisson's ratio of film samples (15 × 1 × 1 mm) of 3 were measured in quasi‐static tension using a video extensometer. For 3, the values of the Young's moduli (E) and Poisson's ratios (ν) were similar between axes in the plane and independent of the splicing direction used during sample preparation. The mean and standard deviation of the Young's modulus and Poisson's ratio were 0.78 ± 0.08 GPa and 0.37 ± 0.06 GPa, respectively. Thermomechanical analysis of 3 revealed a steady decrease of E from a room temperature value of approximately 0.70 GPa. Additionally, it was found that at 150 °C, 3 was unable to support even small stresses, consistent with the onset of a melt transition (ca. 135 °C). A mathematical model based on molecular geometry is developed to describe the results. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2280–2288, 2005
Quantitative risk evaluations of LNG equipment applying ASME risk‐based maintenance concepts
Authors: Ochiai Shigemi , Makita Takenori , Sanjo Takashi , Sato Kazu , Katagiri Masafumi 
Published: July 2005

AbstractFuture regulatory requirements in Japan will mandate that all high‐pressure gas production companies impose a maintenance system based on predictive data rather than on equipment inspections. This paper describes a risk‐based maintenance (RBM) system to achieve these new regulatory requirements. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005