bluuebunny/crossref_metadata_2025_split huggingface dataset:
A competitive evaluation of urban energy systems from viewpoints of energy conservation and mitigating environmental impact
Authors: Sugihara Hideharu , Tomioka Hajime , Tsuji Kiichiro 
Published: April 2008

AbstractAlthough various energy system alternatives for business, commercial, and residential customers have recently been developed in order to reduce energy consumption and CO2 emission, it is important to evaluate competitive characteristics among such new energy system alternatives quantitatively, in consideration of tradeoff relations among economic cost, energy consumption, and CO2 emission. In this paper, using multiobjective optimization model for urban energy system planning, two competitive evaluations are performed. One is the break‐even cost analysis for introducing more efficient, but more expensive energy equipment, such as photovoltaic system and fuel cell system. The other is that we evaluate the competitiveness of a certain energy system from the viewpoint of a whole urban area because there are multiple alternatives for attaining the same target of reducing CO2 emission of energy consumption. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 164(2): 71–79, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20421
Interconnected power systems with superconducting magnetic energy storage
Authors: Nomura Shinichi , Hagita Takushi , Tsutsui Hiroaki , Sato Yoshihisa , Shimada Ryuichi 
Published: April 2008

AbstractThe objective of this work is to discuss the concept of back‐to‐back interconnection systems with energy storage, especially with a Superconducting Magnetic Energy Storage (SMES) incorporated into a back‐to‐back DC link. In this case, each converter of the back‐to‐back system is used as a power conditioning system for the SMES coils. Since the AC–DC converter can be designed independently of the frequency of the power system, a two‐way switch is connected to the AC side of each converter. This two‐way switch can select the interconnected power systems. By using the two‐way switches, this system can provide the stored energy in the SMES system to each interconnected power system through two AC–DC converters. For instance, lower‐cost power of each power network can be stored through two converters during the off‐peak hours and made available for dispatch to each power network during periods of demand peak. Then this system increases the reliability of electric power networks and enables the economical operations depending on the power demand. This paper describes the unique operations of the back‐to‐back interconnection with SMES and discuses the optimal SMES configuration for a 300‐MW‐class back‐to‐back interconnection. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 164(2): 37–43, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20482
Synthesis of Millimeter‐Range Orthorhombic V2O5 Nanowires and Impact of Thermodynamic and Kinetic Properties of the Oxidant on the Synthetic Process
Authors: Zhou Fu , Zhao Xuemei , Liu Yunqi , Yuan Cunguang , Li Li 
Published: April 2008

AbstractLarge‐scale orthorhombic V2O5 single‐crystalline nanowires with diameters of 60–80 nm and lengths into the millimeter range were synthesized through a facile template‐free, mild, and direct hydrothermal reaction between VOSO4·xH2O and KMnO4. The nanowires are nearly visible to the naked eye and are by far the longest 1D nanostructures of vanadium oxide ever fabricated. The impacts of the thermodynamic and kinetic properties of the oxidant were studied by parallel experiments by using different kinds of oxidants, and both were found to be crucial for the successful synthesis of the ultralong V2O5 nanowires.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A Novel Addition Mechanism for the Reaction of “Frustrated Lewis Pairs” with Olefins
Authors: Guo Yong , Li Shuhua 
Published: April 2008

AbstractDensity functional theory calculations have been carried out to investigate the addition mechanism for the reactions of “frustrated Lewis pairs” with olefins. Several reactions are studied in this work, which include a three‐component reaction between a sterically demanding phosphane [P(tBu)3], borane [B(C6F5)3], and ethylene, and a two‐component reaction between an olefin derivative of phosphane [CH2=CH–(CH2)3P(tBu)2] and B(C6F5)3. For the two‐component reaction, we find a concerted addition mechanism, in which the formation of the B–C and P–C bonds takes place simultaneously. For the three‐component reaction, our calculations show that the reaction may be initiated by the weak association of B(C6F5)3 with ethylene (to form a transient species) and then proceeds in a concerted transition state similar to that in the two‐component reaction under study. The natural population analyses for the corresponding transition states indicate that the CH2=CH group (in the two‐component reaction) and C2H4 (in the three‐component reaction) seem to act as a bridge for electron transfer from the Lewis base center P to the Lewis acid center B. We also investigate the reaction between P(tBu)3, propylene, and B(C6F5)3. The results account well for the experimentally observed regioselectivity. In addition, our calculations also indicate that the presence of fluorine atoms in the borane is essential for stabilizing the addition product.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Study of the hydrophilic‐enhanced ultrafiltration membrane
Authors: Gullinkala Tilak , Escobar Isabel 
Published: April 2008

AbstractTo reduce hydrophobic interactions between natural organic matter (NOM) and the membrane surface, and thereby fouling due to NOM, hydrophilic poly(ethylene glycol) (PEG) monomer chains were attached to a commercially available membrane via in situ graft polymerization. Modification of the membrane was carried out using an oxidizing agent as initiator, PEG monomer, and a chain transfer agent (CTA) as terminating agent. Graft polymerization was carried out by two different methods, bulk (i.e. immersing the membranes in the reactant solutions) and drop (i.e. adding reactants dropwise to the membrane surface). Two different feed solutions were used to characterize the modification. Dextran solution was used to compare the efficiency of each modification method. Synthetic seawater was then used to determine the influence of graft polymerization on flux decline, organic carbon rejection and cake accumulation during filtration. The drop method of modification was found to be the optimal procedure resulting in higher flux and rejection along with improved fouling resistance. Graft polymerization led to an increase in permeability when filtering synthetic seawater containing NOM. FTIR spectra demonstrated the occurrence of modification by showing carbonyl attachment and OH stretching. AFM images indicated lower cake accumulation patterns after modification. © 2008 American Institute of Chemical Engineers Environ Prog, 2008
Testing for Granger (non‐)causality in a time‐varying coefficient VAR model
Authors: Christopoulos Dimitris K. , León‐Ledesma Miguel A. 
Published: April 2008

AbstractIn this paper we propose Granger (non‐)causality tests based on a VAR model allowing for time‐varying coefficients. The functional form of the time‐varying coefficients is a logistic smooth transition autoregressive (LSTAR) model using time as the transition variable. The model allows for testing Granger non‐causality when the VAR is subject to a smooth break in the coefficients of the Granger causal variables. The proposed test then is applied to the money–output relationship using quarterly US data for the period 1952:2–2002:4. We find that causality from money to output becomes stronger after 1978:4 and the model is shown to have a good out‐of‐sample forecasting performance for output relative to a linear VAR model. Copyright © 2008 John Wiley & Sons, Ltd.
Hydrodynamic modelling for water‐saving strategies in irrigation canals
Authors: Khan Muhammad Zubair , Ghumman Abdul Razzaq 
Published: April 2008

AbstractIn this paper a hydrodynamic model was applied for evaluation of water‐saving strategies in systems where there is wastage of water due to oversupply in periods of low demand. The one‐dimensional hydrodynamic model CanalMan was used to assess water saving in a secondary canal. Different operational scenarios were evaluated in comparison with the existing operational strategy. This included the operation of the canal at different discharges combined with night closure, in periods of low demand. Time–discharge hydrographs were prepared using the numerical model for operation of canals having daily opening and closing with full supply, 80 and 70% of design discharge. These hydrographs were used to estimate possible time duration of canal operation for these discharges in the case of night closure. Water saving by night closure was compared with that from operation having weekly rotations.Study of the existing operational practices indicated extremely high oversupply to the canal compared with crop water requirements, especially in the months of August, November and December. Significant water saving was found by night closure and operating the canal at reduced discharges. Copyright © 2008 John Wiley & Sons, Ltd.
Fabrication and characterization of novel nano‐ and micro‐HA/PCL composite scaffolds using a modified rapid prototyping process
Authors: Heo Su‐Jin , Kim Seung‐Eon , Wei Jie , Hyun Yong‐Taek , Yun Hui‐Suk , Kim Dong‐Hwa , Shin Ji Won , Shin Jung‐Woog 
Published: April 2008

AbstractNovel three‐dimensional scaffolds consisting of nano‐ and microsized hydroxyapatite (HA)/poly(ϵ‐caprolactone) (PCL) composite were fabricated using a modified rapid‐prototyping (RP) technique for bone tissue engineering applications. The size of the nano‐HA ranged from 20 to 90 nm, whereas that of the micro‐HA ranged from 20 to 80 μm. The scaffold macropores were well interconnected, with a porosity of 72–73% and a pore size of 500 μm. The compressive modulus of the nano‐HA/PCL and micro‐HA/PCL scaffolds was 3.187 ± 0.06 and 1.345 ± 0.05 MPa, respectively. The higher modulus of the nano‐HA/PCL composite (n‐HPC) was to be likely caused by a dispersion strengthening effect. The attachment and proliferation of MG‐63 cells on n‐HPC were better than that on the micro‐HA/PCL composite (m‐HPC) scaffold. The n‐HPC was more hydrophilic than the m‐HPC because of the greater surface area of HA exposed to the scaffold surface. This may give rise to better cell attachment and proliferation. Bioactive n‐HA/PCL composite scaffold prepared using a modified RP technique has a potential application in bone tissue engineering. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Polymer surfaces structured with random or aligned electrospun nanofibers to promote the adhesion of blood platelets
Authors: Wan Ling‐Shu , Xu Zhi‐Kang 
Published: April 2008

AbstractFibrous membranes (nonwoven meshes) prepared via electrospinning technique have great potential in tissue engineering. This work is the first study on the behaviors of blood platelets at the nanostructured surface generated by electrospinning. Poly[acrylonitrile‐co‐(N‐vinyl‐2‐pyrrolidone)] (PANCNVP) that shows excellent antiplatelet adhesion ability was directly electrospun onto its dense membrane surface. Polyacrylonitrile (PAN) samples were used as controls. The depth as well as the density of the nanofibers can be easily controlled. The results showed that the PANCNVP dense membrane certainly suppressed the activation and adhesion of platelets. However, whether the nanofibers and underlying membranes were composed of PAN or PANCNVP, the nanostructured surfaces promoted the activation, adhesion, and orientation of platelets. It was also found that, if the space between fibers was too large or the depth of fibers was too small, the nanostructured surface did not change the property of antiplatelet adhesion of PANCNVP. The promotion of activation and adhesion of platelets was obviously due to the presence of nanofibers, which induced the changes of surface topography and charge. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Quantitative in vivo cytokine analysis at synthetic biomaterial implant sites
Authors: Rodriguez Analiz , Meyerson Howard , Anderson James M. 
Published: April 2008

AbstractTo further elucidate the foreign body reaction, investigation of cytokines at biomaterial implant sites was carried out using a multiplex immunoassay and ELISA. Macrophage activation cytokines (IL‐1β, IL‐6, and TNFα), cytokines important for macrophage fusion (IL‐4 and IL‐13), antiinflammatory cytokines (IL‐10 and TGFβ), chemokines (GRO/KC, MCP‐1), and the T‐cell activation cytokine IL‐2 were quantified at biomaterial implant sites. Empty cages (controls) or cages containing synthetic biomedical polymer (Elasthane 80A (PEU), silicone rubber (SR), or polyethylene terephthalate (PET)) were implanted subcutaneously in Sprague‐Dawley rats for 4, 7, or 14 days, and cytokines in exudate supernatants and macrophage surface adhesion and fusion were quantified. The presence of a polymer implant did not affect the levels of IL‐1β, TGFβ, and MCP‐1 in comparison to the control group. IL‐2 was not virtually detected in any of the samples. Although the levels of IL‐4, IL‐13, IL‐10, and GRO/KC were affected by polymer implantation, but not dependent on a specific polymer, IL‐6 and TNFα were significantly greater in those animals implanted with PEU and SR, materials that do not promote fusion. The results indicate that differential material‐dependent cytokine profiles are produced by surface adherent macrophages and foreign body giant cells in vivo. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Bacterial adherence to SiO2‐based multifunctional bioceramics
Authors: Kinnari Teemu J. , Esteban Jaime , Gomez‐Barrena Enrique , Zamora Nieves , Fernandez‐Roblas Ricardo , Nieto Alejandra , Doadrio Juan C. , López‐Noriega Adolfo , Ruiz‐Hernández Eduardo , Arcos Daniel , Vallet‐Regí María 
Published: April 2008

AbstractThe bacterial adherence onto different multifunctional silica‐based bioceramics has been evaluated. Staphylococcus aureus and Staphylococcus epidermidis were chosen, as they cause the majority of the implant‐related infections in this field. Two SiO2 mesoporous materials (MCM‐41, SBA‐15), an ordered SiO2‐CaO‐P2O5 mesoporous glass (OMG), and a biphasic magnetic bioceramic (BMB), were incubated with S. aureus and S. epidermidis for 90 min, and subsequently sonicated to quantify the number of adhered bacteria on each material. It was found that S. aureus and S. epidermidis (108 CFU/mL) adhered significantly less to BMB samples when compared to MCM‐41, SBA‐15, or OMG. However, when the material pores accessible for bacteria in each material were taken into account, the lowest bacterial adherence was found in MCM‐41, and the highest in SBA‐15. The results show that bacterial adherence is higher on mesoporous bioceramics, although this higher microbial attachment is mainly due to the intergranular porosity and grain size morphology rather than to the mesoporous structure. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Effect of dynamic 3‐D culture on proliferation, distribution, and osteogenic differentiation of human mesenchymal stem cells
Authors: Stiehler Maik , Bünger Cody , Baatrup Anette , Lind Martin , Kassem Moustapha , Mygind Tina 
Published: April 2008

AbstractEx vivo engineering of autologous bone tissue as an alternative to bone grafting is a major clinical need. In the present study, we evaluated the effect of 3‐D dynamic spinner flask culture on the proliferation, distribution, and differentiation of human mesenchymal stem cells (MSCs). Immortalized human MSCs were cultured on porous 75:25 PLGA scaffolds for up to 3 weeks. Dynamically cultured cell/scaffold constructs demonstrated a 20% increase in DNA content (21 days), enhanced ALP specific activity (7 days and 21 days), a more than tenfold higher Ca2+ content (21 days), and significantly increased transcript levels of early osteogenesis markers (e.g., COL1A1, BMP2, RUNX‐2) as compared with static culture. Despite the formation of a dense superficial cell layer, markedly increased cell ingrowth was observed by fluorescence microscopy on day 21. Furthermore, increased extracellular matrix deposition was visualized by scanning electron microscopy after 1 and 3 weeks of dynamic culture. The observed increased ingrowth and osteogenic differentiation of 3‐D dynamically cultured human MSCs can be explained by generation of fluid shear stress and enhanced mass transport to the interior of the scaffold mimicking the native microenvironment of bone cells. This study provides evidence for the effectiveness of dynamic culture of human MSCs during the initial phase of ex vivo osteogenesis. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Interactions of coronary artery smooth muscle cells with 3D porous polyurethane scaffolds
Authors: Grenier Stéphanie , Sandig Martin , Holdsworth David W. , Mequanint Kibret 
Published: April 2008

AbstractOne strategy in vascular tissue engineering is the design of hybrid vascular substitutes where vascular cells infiltrate biostable porous scaffolds that provides favorable environment for guided cell repopulation and acts as a mechanically supporting layer after the tissue regeneration process. The aim of the present work was to study the interaction of human coronary artery smooth muscle cells (HCASMC) with 3D porous polyurethane scaffolds. We therefore fabricated porous and highly interconnected 3D polyurethane scaffolds that can promote HCASMC attachment, proliferation, and migration. SEM and microCT studies of the fabricated scaffolds showed that the current scaffolds had highly open and interconnected pore structures, with an average porosity of 84%. HCASMC interaction on polyurethane films revealed that cells adhere and express specific marker proteins (vinculin and h‐caldesmon). This expression was further enhanced by coating the polyurethane with Matrigel. On uncoated 3D scaffolds, dense spherical aggregates of cells were often encountered with little adhesion of individual cells alongside the struts of the scaffold, independent of the porogens used. In contrast, when cultured on Matrigel‐coated scaffolds, cell numbers quickly increased after 14 days and spread along the entire scaffold. At the upper scaffold surface, elongated cells were seen adhering to one another and also to the scaffold surface. These cells were elongated, aligned in parallel and contained abundant F‐actin bundles suggesting a differentiated contractile phenotype. Deep into the scaffold, cells were encountered that formed actin‐rich lamellipodial extensions spreading along the strut and lacked stress fibers, suggesting active cell migration along the substrate. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Resorbable polymeric scaffolds for bone tissue engineering: The influence of their microstructure on the growth of human osteoblast‐like MG 63 cells
Authors: Pamula Elzbieta , Filová Elena , Bačáková Lucie , Lisá Věra , Adamczyk Daniel 
Published: April 2008

AbstractDegradable three‐dimensional porous scaffolds applicable as cell carriers for bone tissue engineering were developed by an innovative solvent casting/particulate leaching technique from poly(L‐lactide‐co‐glycolide) (PLG). Three types of PLG scaffolds were prepared, and these had the same high porosity (83%) but increasing diameter of the pores (180–200 μm, 250–320 μm, and 400–600 μm) and increasing pore interconnectivity. The colonization of the scaffolds with human osteoblast‐like MG 63 cells was then studied in vitro in a conventional static cell culture system. The number of cells growing on the scaffolds on days 1 and 7 after seeding was highest in the material with the largest pore diameter, but on day 15, the differences among the scaffolds disappeared. Confocal microscopy revealed that on day 1 after seeding, the cells penetrated to a depth of 490 ± 100 μm, 720 ± 170 μm, and 720 ± 120 μm into the scaffolds of small, medium, and large pore size, respectively. Incorporation of bromodeoxyuridine into newly synthesized DNA and the concentration of vinculin, β‐actin, osteopontin, and osteocalcin in cells on the scaffolds of all pore sizes were similar to the values obtained on standard tissue culture polystyrene, which indicated good biocompatibility of the scaffolds. These results suggest that all scaffolds could serve as good carriers for bone cells, although the quickest colonization with cells was found in the scaffolds with the largest pore diameter from 400 to 600 μm. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
In vitro and in vivo evaluation of acellular diaphragmatic matrices seeded with muscle precursors cells and coated with VEGF silica gels to repair muscle defect of the diaphragm
Authors: Conconi Maria T. , Bellini Silvia , Teoli Debora , de Coppi Paolo , Ribatti Domenico , Nico Beatrice , Simonato Enea , Gamba Pier G. , Nussdorfer Gastone G. , Morpurgo Margherita , Parnigotto Pier P. 
Published: April 2008

AbstractIn this work, a bioartificial system consisting of VEGF‐loaded porous silica gel and myoblasts cultured on acellular diaphragmatic matrix (ADM) has been implanted to repair a surgically created diaphragmatic defect in Lewis rats. ADMs exerted a strong angiogenic response on chorio‐allantoic membrane. Cytotoxicity, VEGF release and matrix erodibility in vitro tests demonstrated that the silica support was nontoxic and that the VEGF bioactivity was maintained after matrix entrapment and it was released within a timeframe that can be modulated by synthesis parameters. Different grafts composed by ADMs with and without autologous male myoblasts or/and VEGF‐loaded porous silica gel have been implanted to repair previously created diaphragmatic defects in female Lewis rats. Patches composed of ADMs and myoblasts appeared well preserved until 8 weeks, and contained multinucleated cells and cholinergic fibers. At 8 weeks, the implanted cells were still present inside the patches. The disappointing results obtained when VEGF was delivered by porous silica gel were probably due to an abnormal angiogenic response following an excess of local growth factor concentration. Taken together, these results confirmed that our matrices contained biologically active angiogenic factors which were per se sufficient to induce neo‐vessels formation, thus allowing the survival of implanted myoblasts. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
EP4 agonist accelerates osteoinduction and degradation of β‐tricalcium phosphate by stimulating osteoclastogenesis
Authors: Nasu Tomonori , Takemoto Mitsuru , Akiyama Norihiro , Fujibayashi Shunsuke , Neo Masashi , Nakamura Takashi 
Published: April 2008

AbstractPorous β‐tricalcium phosphate (TCP) has been known to have osteoinductive potential in ectopic site implantation in canine models without the use of osteoinductive substances or cell transplantation. Prostaglandin E2 receptors, particularly EP4, are known to play an important role in osteogenesis. EP4 agonists have been demonstrated to have positive effects on bone remodeling and bone morphogenic protein‐induced ectopic bone formation in rodent models. We examined the efficiency of porousβ‐TCP‐induced osteoinduction in beagles by the graded‐release EP4 agonist, which was injected at their buttocks intramuscularly. Newly formed bone was observed on and after 3 weeks in the EP4 agonist‐injected, while on and after 6 weeks in control groups, respectively. After that the bone resorption and the β‐TCP degradation was accelerated in EP4 agonist‐injected group. Tartarate‐resistant acid phosphatase‐positive cells appeared in each group before bone formation, and the number of these cells reduced gradually; however, more multinucleated and larger cells appeared, particularly in the injected group. Injection of an EP4 agonist was proved to accelerate the osteoinduction and degradation of β‐TCP in canine model. Histological analysis revealed that the EP4 agonist stimulated osteoclastogenesis before bone formation. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009