bluuebunny/crossref_metadata_2025_split huggingface dataset:
Capillary Force Lithography: A Versatile Tool for Structured Biomaterials Interface Towards Cell and Tissue Engineering
Authors: Suh Kahp‐Yang , Park Min Cheol , Kim Pilnam 
Published: July 2009

AbstractThis Feature Article aims to provide an in‐depth overview of the recently developed molding technologies termed capillary force lithography (CFL) that can be used to control the cellular microenvironment towards cell and tissue engineering. Patterned polymer films provide a fertile ground for controlling various aspects of the cellular microenvironment such as cell–substrate and cell–cell interactions at the micro‐ and nanoscale. Patterning thin polymer films by molding typically involves several physical forces such as capillary, hydrostatic, and dispersion forces. If these forces are precisely controlled, the polymer films can be molded into the features of a polymeric mold with high pattern fidelity and physical integrity. The patterns can be made either with the substrate surface clearly exposed or unexposed depending on the pattern size and material properties used in the patterning. The former (exposed substrate) can be used to adhere proteins or cells on pre‐defined locations of a substrate or within a microfluidic channel using an adhesion‐repelling polymer such as poly(ethylene glycol) (PEG)‐based polymer and hyaluronic acid (HA). Also, the patterns can be used to co‐culture different cells types with molding‐assisted layer‐by‐layer deposition. In comparison, the latter (unexposed substrate) can be used to control the biophysical surrounding of a cell with tailored mechanical properties of the material. The surface micropatterns can be used to engineer cellular and multi‐cellular architecture, resulting in changes of the cell shape and the cytoskeletal structures. Also, the nanoscale patterns can be used to affect various aspects of the cellular behavior, such as adhesion, proliferation, migration, and differentiation.
Mechanical Gradient Cues for Guided Cell Motility and Control of Cell Behavior on Uniform Substrates
Authors: Cortese Barbara , Gigli Giuseppe , Riehle Mathis 
Published: July 2009

AbstractA novel method for the fabrication and the use of simple uniform poly(dimethylsiloxane) PDMS substrates for controlling cell motility by a mechanical gradient is reported. The substrate is fabricated in PDMS using soft lithography and consists of a soft membrane suspended on top of a patterned PDMS substrate. The difference in the gradient stiffness is related to the underlying pattern. It is shown experimentally that these uniform substrates can modulate the response of cell motility, thus enabling patterning on the surfaces with precise cell motility. Because of the uniformity of the substrate, cells can spread equally and a directional movement to stiffer regions is clearly observed. Varying the geometry underlying the membrane, cell patterning and movement can be quantitatively characterized. This procedure is capable of controlling cell motility with high fidelity over large substrate areas. The most significant advance embodied in this method is that it offers the use of mechanical features to control cell adhesion and not topographical or chemical variations, which has not been reported so far. This modulation of the response of cell motility will be useful for the design and fabrication of advanced planar and 3D biological assemblies suitable for applications in the field of biotechnology and for tissue‐engineering purposes.
Precipitation dynamics of zinc sulfide multiscale agglomerates
Authors: Frédéric Gruy , Mohamed Kamal Mekki‐Berrada , Cournil Michel 
Published: July 2009

AbstractHomogeneous precipitation of zinc sulfide from thioacetamide decomposition in presence of zinc sulfate in acid solution results in the formation of four‐scale agglomerates. We present here experimental results relative to the monitoring of several physicochemical (pH, electrical conductivity, concentration in sulfide ions, turbidity) and morphological (agglomerate shape and size) parameters throughout the precipitation process. From these parameters essential characteristics of the precipitation process can be determined, especially the supersaturation level and the precipitated product mass. From this information and with the help of microphotographs of samples withdrawn at different stages of the precipitation, it is possible to formulate a new mechanism of zinc sulfide precipitation. In particular, the nature of the different agglomeration scales is elucidated as well their succession in time. © 2009 American Institute of Chemical Engineers AIChE J, 2009
General partial properties
Authors: Iglesias‐Silva Gustavo A. , Hall Kenneth R. 
Published: July 2009

AbstractPartial molar properties are useful thermodynamic properties because their molar average equals the property itself. In this article, we present a description of partial properties in general, and we show that for many partial properties, partial molar properties being a subset, the property is a molar average of the partial properties. Although partial molar properties remain the most useful, several of the other partial properties could have practical applications. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Health‐related quality of life measures in genetic disorders: An outcome variable for consideration in clinical trials
Authors: Stevenson David A. , Carey John C. 
Published: July 2009

AbstractThe field of medical genetics is rapidly advancing, and therapeutic options to treat genetic syndromes are becoming increasingly available. An understanding of the pathophysiology of various genetic disorders has provided researchers the opportunity to propose and test pharmacologic agents in preclinical murine models with hopes of translation to human trials. The development of clinical trials can be costly and time consuming, particularly for rare conditions. Pilot feasibility studies should be performed when designing clinical trials for genetic disorders. The development and selection of appropriate outcome measures are particularly paramount in the implementation of clinical trials. The selection of inappropriate outcome measures can lead to non‐measurable differences or clinically insignificant findings. In addition, just as age appropriate measures are needed, some instruments may not apply to populations with specific genetic disorders that have significant cognitive and physical impairment, as the measures may not be sensitive enough to identify clinically significant changes. In the last decade, health‐related quality of life measures (HRQOL) have been increasingly included as an outcome measure in clinical trials. While traditional clinical outcomes are important, these newly developed instruments should be considered along with clinical indicators as measures of effect in clinical trials of interventions in genetic disorders. © 2009 Wiley‐Liss, Inc.
Synthesis of 2,4,6‐trisubstituted naphthalenes via novel copper‐promoted tandem coupling and intramolecular cyclization
Authors: Wang Yuguang , Zhu Bingchun , Zhu Qin 
Published: July 2009

AbstractAn unprecedented copper‐promoted tandem coupling and intramolecular cyclization reaction is disclosed. This strategy offers a simple and promising method for accessing 2,4,6‐trisubstituted naphthalenes. A reaction mechanism involving initial formation of diynes followed by a 6‐exo‐dig cyclization and subsequent rearrangement is proposed. Copyright © 2009 John Wiley & Sons, Ltd.
Local‐field effect on the fluorescence relaxation of Tm3+:LaF3 nanocrystals immersed in liquid medium
Authors: He Enjie , Zheng Hairong , Zhang Xisheng , Qu Shixian 
Published: July 2009

AbstractTm3+:LaF3 nanocrystals were synthesized with hydrothermal technique. Local‐field effect on the radiative relaxation rate was studied in the system of Tm3+:LaF3 nanocrystals immersed in several liquid media. The fluorescence lifetime was measured. It was found that the fluorescence decay presented the characteristics of second‐order exponential decay, for which the contribution from the ions inside the nanocrystal and ions at the interface of the nanocrystal were distinguished. Investigating the experimental results with proposed models, we found that the surface effect had to be eliminated. For rare earth doped LaF3 nanocrystals, real‐cavity model well explains the influence of surrounding medium on the fluorescence relaxation rate. Copyright © 2009 John Wiley & Sons, Ltd.
Determination of thiram in natural waters using flow‐injection with cerium(IV)–quinine chemiluminescence system
Authors: Waseem Amir , Yaqoob Mohammad , Nabi Abdul 
Published: July 2009

AbstractA simple and rapid flow‐injection chemiluminescence method has been developed for the determination of dithiocarbamate fungicide thiram based on the chemiluminescence reaction of thiram with ceric sulfate and quinine in aqueous sulfuric acid. The present method allowed the determination of thiram in the concentration range of 7.5–2500 ng/mL and the detection limit (signal‐to‐noise ratio = 3) was 7.5 ng/mL with sample throughput of 120/h. The relative standard deviation was 2.5% for 10 replicate analyses of 500 ng/mL thiram. The effects of foreign species including various anions and cations present in water at environmentally relevant concentrations and some pesticides were also investigated. The proposed method was applied to determine thiram in spiked natural waters using octadecyl bonded phase silica (C18) cartridges for solid‐phase extraction. The recoveries were in the range 99 ± 1 to 104 ± 1%. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and luminescent properties of Eu(TTA)3·3H2O nanocrystallines
Authors: Liu Qing , Wang Dong‐Mei , Li Yuan‐Yuan , Yan Mei , Wei Qin , Du Bin 
Published: July 2009

AbstractNanocrystallines of rare earth complex, Eu(TTA)3·3H2O, were synthesized by the chemical precipitation method and were characterized by elemental analysis, ultraviolet visible absorption spectroscopy (UV–vis), infrared spectroscopy (IR), differential thermal analysis–thermogravimetry (TG‐DTA), X‐ray diffraction (XRD) and transmission electron microscopy (TEM). The size of the nanocrystallines was tunable by selecting the proper buffer system, which was used to control the pH of the solution. A small polydispersity in particle size ranging from 70 to 250 nm was obtained when ammonia was used. The nanocrystallines showed the characteristic fluorescence of europium ions and energy transfer from the organic ligand to central ions was observed by fluorescence excitation and emission spectroscopy. These nanoparticles of rare earth complexes have potential application in luminescent materials due to their excellent fluorescence properties. Copyright © 2009 John Wiley & Sons, Ltd.
Comparison of chemiluminescence from luminol solution and luminol–TiO2 suspension after illumination of a 355 nm pulse laser
Authors: Min Lingyue , Chen Xueming , Wu Xing‐Zheng 
Published: July 2009

AbstractChemiluminescence (CL) from luminol solution and luminol–TiO2 suspension after illumination of a 355 nm pulse laser is compared. Both the CL systems showed the CL spectra with maximum wavelength of 430 nm, suggesting that the emission was from the excite state of 3‐aminophthalate ion. The TiO2 photocatalytically induced luminol CL could be separately detected either when the pulse laser power was smaller than 0.15 mJ/pulse or a slit was placed beyond −2–2 mm in the vertical direction of the laser beam. The TiO2 photocatalytically induced luminol CL intensity was linear to the laser power, while that of the 355 nm pulse laser‐induced was nonlinear. A log–log plot between the 355 nm pulse laser‐induced luminol CL intensity and laser power showed a near‐linear regression fit with a slope of 2.11, suggesting that a two‐photon absorption process of luminol was present in the 355 nm pulse laser‐induced luminol CL. Adsorbed oxygen on the surface of TiO2 seemed to greatly contribute to the photocatalytically induced CL. Copyright © 2010 John Wiley & Sons, Ltd.
Optimization of medium composition for the production of antimicrobial activity by Bacillus subtilis B38
Authors: Tabbene Olfa , Slimene Imen Ben , Djebali Kais , Mangoni Maria‐Luisa , Urdaci Maria‐Camino , Limam Ferid 
Published: July 2009

AbstractAn antimicrobial activity produced by Bacillus subtilis B38 was found to be effective against several bacteria, including pathogenic and spoilage microorganisms such as, Listeria monocytogenes, Salmonella enteridis, and clinical isolates of methicillin‐resistant Staphylococcus species. Nutrients such as carbon, nitrogen sources, and inorganic salts enhanced the production level of the antibacterial activity by B. subtilis B38. A first screening step showed that lactose, ammonium succinate, and manganese most influenced both cell growth and antibacterial activity production. These three factors varied at two levels in eight experiments using full factorial design. Results indicated that maximum cell growth (OD = 10.2) and maximum production of antibacterial activity (360 AU/mL) were obtained in a modified medium containing 1.5% (w/v) lactose, 0.15% (w/v) ammonium succinate, and 0.3 mg/L manganese. Depending on the indicator strain used, the antibacterial activity was 2‐ to 4‐fold higher in the modified culture medium than in TSB medium under the same conditions. Thin layer chromatography‐bioautography assay showed the presence of three active spots with Rf values of 0.47, 0.7, and 0.82 in TSB medium. However, the inhibition zone of two spots (Rf values of 0.7 and 0.82) was slightly larger in the modified medium. Moreover, a large zone of inhibition with an Rf value of 0.3, was observed in this modified medium, instead of the spot having an Rf value of 0.47. These results suggest that the nutrients act as environmental factors, quantitatively and qualitatively affecting the production of antibacterial compounds by B. subtilis B38. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Influence of peptide ligand surface density and ethylene oxide spacer arm on the capture of porcine parvovirus
Authors: Heldt Caryn L. , Gurgel Patrick V. , Jaykus Lee‐Ann , Carbonell Ruben G. 
Published: July 2009

AbstractIn previous work, we identified two trimeric peptide ligands (designated WRW and KYY), which bound specifically to porcine parvovirus (PPV) and demonstrated their ability to capture and remove the virus from solutions containing 7.5% human blood plasma. This article examines the influences of peptide density and the presence of an ethylene oxide spacer arm on the efficiency of virus capture using these two ligands. The WRW peptide bound the most virus from plasma solutions at the lowest peptide density tested (0.008 mmol/g dry resin), and binding was enhanced by the presence of the spacer arm. On the other hand, the KYY peptide bound the most viruses at the same low peptide density, but it performed better in the absence of the spacer arm. Of the two, the binding efficiency of the WRW peptide was more sensitive to peptide density and spacer arm presence. These results indicate that low peptide densities enhance binding selectivity, facilitating specific peptide‐virus binding even in the presence of plasma proteins which can theoretically bind nonspecifically. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Evaluation of the virtual network laboratory exercises using a method based on the rough set theory
Authors: Dobrilovic Dalibor , Brtka Vladimir , Berkovic Ivana , Odadzic Borislav 
Published: July 2009

AbstractThe development of computer network technologies increased the importance of network professional's education and resulted in extensive research in the field of computer science education. Virtual networking laboratories have been very popular in the past few years, especially for training and education of network professionals. These laboratories are emulated computer network environments, based on virtualization technology, and have a number of advantages comparing to classical laboratories. Even with a large number of developed laboratory platforms, there are a small number of attempts to evaluate these systems and to find out how effective they are. This paper presents an approach to the evaluation of the virtual networking laboratory, primarily by the evaluation of its exercises used for a computer‐networking course at the university. We are going to employ an approach based on the relation of indiscernibility and the rough set theory in order to produce a model based on if–then rules, starting from low‐level data. This model helps to identify the most important parts and eventual mistakes in the evaluated exercises, creating the possibility for their improvement and overall student's achievement as well. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 20: 29–37, 2012
Halodecarboxylation Reaction of 4‐Alkylidene‐β‐lactams
Authors: Galletti Paola , Quintavalla Arianna , Ventrici Caterina , Giacomini Daria 
Published: July 2009

AbstractThe synthesis of halo‐ and dihalovinyl‐β‐lactams by a halodecarboxylation reaction has been developed. Optimized procedures gave good yields of dibromo‐, iodo‐ and diiodovinyl derivatives. The unprecedented synthesis of dihalo compounds by a Hunsdieker reaction was investigated in detail by 1H NMR analysis, which allowed the formulation of a reaction mechanism and revealed the role of triethylamine as a deiodinating agent. The dibromo‐ and diiodoalkylidene‐β‐lactams obtained were tested in a cross‐coupling reaction with dimethylzinc. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Trend detection in hydrological series: when series are negatively correlated
Authors: Rivard Christine , Vigneault Harold 
Published: July 2009

AbstractThe objective of this paper is to verify the applicability of the trend‐free pre‐whitening (TFPW) approach, developed by Yue et al. (2002) for positively correlated series, to negatively correlated series using similar Monte Carlo simulations. This study was initiated when a project on trend detection for streamflow and baseflow series across Canada revealed that a significant number of series had negative correlation coefficients. The TFPW procedure confirmed to be also well suited for negatively correlated series. This study also showed that the estimated values for slopes (trends) and correlation coefficients of the pre‐whitened series are affected by the sample size, especially for negatively correlated series. Copyright © 2009 Her Majesty the Queen in right of Canada. Published by John Wiley & Sons. Ltd.
Chronic cigarette smoke extract treatment selects for apoptotic dysfunction and mitochondrial mutations in minimally transformed oral keratinocytes
Authors: Chang Steven S. , Jiang Wei Wen , Smith Ian , Glazer Chad , Sun Wen‐Yue , Mithani Suhail , Califano Joseph A. 
Published: July 2009

AbstractCigarette smoke demonstrates a carcinogenic effect through chronic exposure, not acute exposures. However, current cell line models study only the acute effects of cigarette smoke. Using a cell line model, we compared the effects of acute versus chronic cigarette smoke extract (CSE) on mitochondria in minimally transformed oral keratinocytes (OKF6). OKF6 cells were treated with varying concentrations of CSE for 6 months. Cells were analyzed monthly by flow cytometry for mitochondrial membrane potential (MMP), cytochrome c release, caspase 3 activation and viability after CSE exposure. At each time point, the same assays were performed after 24 hr of valinomycin (MMP‐depolarizing agent) treatment. The mitochondrial DNA of chronically CSE‐treated cells was sequenced. After 6 months of CSE treatment, the cells were increasingly resistant to CSE‐mediated and valinomycin‐induced cell death. In addition, chronic CSE treatment caused chronic depolarization of MMP, cytochrome c release and caspase activation. Cells grown in the presence of only CSE vapor also exhibited the same resistance and chronic baseline apoptotic activation. Mitochondrial DNA sequencing found that chronic CSE‐treated cells had more amino acid‐changing mitochondrial mutations than acutely treated cells. CSE treatment of normal cells select for apoptotic dysfunction as well as mitochondrial mutations. These findings suggest that chronic tobacco exposure induces carcinogenesis via selection of apoptosis resistance and mitochondrial mutation in addition to previously known genotoxic effects that were found by acute treatments. Chronic models of tobacco exposure on upper aerodigestive epithelia may be more insightful than models of acute exposure in studying head and neck carcinogenesis
Alkylcarboxylate grafting to polyethylenimine: a simple approach to producing a DNA nanocarrier with low toxicity
Authors: Oskuee Reza K. , Dehshahri Ali , Shier Wayne T. , Ramezani Mohammad 
Published: July 2009

AbstractBackgroundVarious strategies have been examined to improve both transfection efficiency and cytotoxicity of polyethylenimine (PEI), a widely used polycationic nonviral gene vector. In the present study, we sought to improve PEI transfection efficiency by combining the osmotic burst mechanism for lysing endocytotic vesicles with the lipid depletion mechanism, which was accomplished by maintaining buffering capacity at the same time as adding a lipid‐absorbing hydrophobic shell.MethodsPEI was altered via the substitution of various percentages of its primary amines with carboxylate‐terminated short, moderate and long alkyl chains, by reaction with bromoacetic, 6‐bromohexanoic, 10‐bromodecanoic and 16‐bromohexadecanoic acids. Modified polymers were complexed with plasmid and the particle size and zeta potential of the polyplexes were determined. Ethidium bromide dye exclusion was used to show the DNA‐binding ability of the polymers and their transfection activity and cytotoxicity was evaluated in Neuro2A mammalian cells.ResultsDecreased DNA‐binding ability resulted from increases in either the degree of substitution or hydrocarbon chain length. Particle size and zeta potential measurements demonstrated that modified PEI polymers were able to form nanoparticles in the size range 60–195 nm, and surface charge decreased with an increasing degree of substitution. Higher degrees of substitution resulted in decreased cytotoxicity of polymers. Alkylcarboxylate substitution of primary amines on PEI enhanced transfection efficiencies by up to approximately five‐fold relative to underivatized PEI, with the greatest increases occurring with 6‐bromohexanoic acid derivatives at degrees of substitution below 10%.ConclusionsThe results obtained suggest that an appropriate balance between cationic and hydrophobic regions of alkylated PEI yields the optimal nonviral vector with high transfection efficiency and low toxicity. Copyright © 2009 John Wiley & Sons, Ltd.