bluuebunny/crossref_metadata_2025_split huggingface dataset:
High and compact formation of baculoviral polyhedrin‐induced inclusion body by co‐expression of baculoviral FP25 in Escherichia coli
Authors: Li Lin , Kim Young Soo , Hwang Dong Soo , Seo Jeong Hyun , Jung Hee Jung , Du Juan , Cha Hyung Joon 
Published: September 2006

AbstractPreviously, we found that baculoviral polyhedrin (Polh) can successfully be used in Escherichia coli as a fusion partner for the expression of special foreign proteins as inclusion bodies, and the resulting, easily isolatable Polh‐induced fusion inclusion bodies had almost the same characteristics as the native Polh. Here, we investigated the effects of co‐expression of baculoviral FP25 protein on Polh‐induced inclusion‐body production in an E. coli expression system, as FP25 is known to be involved specifically in polyhedra formation. Using several analytical tools, including SDS–PAGE, pronase proteolysis, solubilization under alkaline conditions, and electron microscopy, we found that co‐expressed FP25 was associated with Polh‐induced inclusion bodies and that its co‐expression led to formation of compact inclusion bodies as well as high production levels. We confirmed that FP25 co‐expression induced higher production levels of other heterologous protein, antimicrobial peptide Hal18, fused with aggregation‐prone Polh. Therefore, co‐expression of baculoviral FP25 can be promisingly used to increase the levels of baculoviral Polh‐fused foreign proteins, especially harmful proteins, expressed as inclusion bodies in an E. coli expression system. Biotechnol. Bioeng. 2007;96:1183–1190. © 2006 Wiley Periodicals, Inc.
Sulfidogenic fluidized‐bed treatment of metal‐containing wastewater at low and high temperatures
Authors: Sahinkaya Erkan , Özkaya Bestamin , Kaksonen Anna H. , Puhakka Jaakko A. 
Published: September 2006

AbstractThe applicability of a fluidized‐bed reactor (FBR)‐based sulfate reducing bioprocess was investigated for the treatment of iron‐containing (40–90 mg/L) acidic wastewater at low (8°C) and high (65°C) temperatures. The FBRs operated at low and high temperatures were inoculated with cultures of sulfate‐reducing bacteria (SRB) originally enriched from arctic and hot mining environments, respectively. Ethanol was supplemented as carbon and electron source for SRB. At 8°C, ethanol oxidation and sulfate reduction rates increased steadily and reached 320 and 265 mg/L·day, respectively, after 1 month of operation. After this point, the rates did not change significantly during 130 days of operation. Despite the complete ethanol oxidation and iron precipitation, the average sulfate reduction efficiency was 35 ± 4% between days 30 and 130 due to the accumulation of acetate. At 65°C, a rapid startup was observed as 99.9, 46, and 29% ethanol, sulfate, acetate removals, in respective order, were observed after 6 days. The feed pH was decreased gradually from its initial value of 6 to around 3.7 during 100 days of operation. The wastewater pH of 4.3–4.4 was neutralized by the alkalinity produced in acetate oxidation and the average effluent pH was 7.8 ± 0.8. As in the low temperature FBR, acetate accumulated. Hence, the oxidation of acetate is the rate‐limiting step in the sulfidogenic ethanol oxidation by thermophilic and psychrotrophic SRB. The sulfate reduction rate is three times and acetate oxidation rate is four times higher at 65°C than at 8°C. Biotechnol. Bioeng. 2007;96:1064–1072. © 2006 Wiley Periodicals, Inc.
Modeling and rendering of realistic waterfall scenes with dynamic texture sprites
Authors: Guan Yu , Chen Wei , Zou Lincan , Zhang Long , Peng Qunsheng 
Published: September 2006

AbstractWe propose an efficient approach for authoring dynamic and realistic waterfall scenes based on an acquired video sequence. Traditional video based techniques generate new images by synthesizing 2D samples, i.e., texture sprites chosen from a video sequence. However, they are limited to one fixed viewpoint and cannot provide arbitrary walkthrough into 3D scenes. Our approach extends this scheme by synthesizing dynamic 2D texture sprites and projecting them into 3D space. We first generate a set of basis texture sprites, which capture the representative appearance and motions of waterfall scenes contained in the video sequence. To model the shape and motion of a new waterfall scene, we interactively construct a set of flow lines taking account of physical principles. Along each flow line, the basis texture sprites are manipulated and animated dynamically, yielding a sequence of dynamic texture sprites in 3D space. These texture sprites are displayed using the point splatting technique, which can be accelerated efficiently by graphics hardware. By choosing varied basis texture sprites, waterfall scenes with different appearance and shapes can be conveniently simulated. The experimental results demonstrate that our approach achieves realistic effects and real‐time frame rates on consumer PC platforms. Copyright © 2006 John Wiley & Sons, Ltd.
Regulation of Transcription by Synthetic DNA‐Bending Agents
Authors: Bednarski David , Firestine Steven M. 
Published: September 2006

AbstractGene expression is regulated by a complex interplay between binding and the three‐dimensional arrangement of transcription factors with RNA polymerase and DNA. Previous studies have supported a direct role for DNA bending and conformation in gene expression, which suggests that agents that induce bends in DNA might be able to control gene expression. To test this hypothesis, we examined the effect of triple‐helix‐forming oligonucleotide (TFO) bending agents on the transcription of luciferase in an in vitro transcriptional/translational system. We find that transcription is regulated only by a TFO that induces a bend in the DNA. Related TFOs that do not induce bends in DNA have no effect on transcription. Reporter expression can be increased by as much as 80 % or decreased by as much as 50 % depending on the phasing of the upstream bend relative to the promoter. We interpret the results as follows: when the bend is positioned such that the upstream DNA is curved toward the RNA polymerase on the same DNA face, transcription is enhanced. When the upstream DNA is curved away, transcription is attenuated. These results support the hypothesis that DNA‐bending agents might have the capability to regulate gene expression, thereby opening up a previously undervalued avenue in research on the artificial control of gene expression.
Imaging by Sensitized Oxygenations of Photochromic Anthracene Films: Examination of Effects That Improve Performance and Reversibility
Authors: Fudickar Werner , Linker Torsten 
Published: September 2006

AbstractThe aliphatic anthracene compound 1 and the oligomeric anthracene 2 were synthesized. Thin films of 1 and 2 mixed with the sensitizers tetraphenylporphyrin (TPP) and methylene blue (MB) were irradiated with visible light in air. Upon formation of singlet oxygen, the anthracene units were converted quantitatively to the corresponding endoperoxides. Heating of the irradiated samples afforded the parent anthracenes with high yields. Here, we demonstrate that the kinetics and reversibility of this reaction strongly depend on the microenvironment of the anthracene groups in the two compounds. The photooxidation of thin films of 1 is accompanied by interesting changes in the morphology of the film and allows the first application of 1 as a nondestructive negative‐tone photoresist for lithography and as an oxidizing ink. The morphology of 2 remained unchanged after photooxidation as a result of the stabilizing oligomer backbone. This stabilizing effect significantly improves the photochromic performance of 2. The reversibility of the photooxidation is very high (>90 %) for oligomeric films of 2 after several cycles of irradiation and heating. Decomposition of the anthracene and a loss of the activity of the sensitizer diminish slightly the performance of the monomeric species.
Studies on Pd0‐Catalyzed Cyclization of N‐3,4‐Alkadienyl Toluenesulfonamides with Organic Halides: Selective Synthesis of 2,3‐Dihydropyrroles, 1,2,3,6‐Tetrahydropyrridines, and Azetidines
Authors: Ma Shengming , Yu Fei , Li Jing , Gao Wenzhong 
Published: September 2006

AbstractThe palladium‐catalyzed coupling–cyclization of β‐amino allenes with organic halides ranging from aryl halide to 1‐alkenyl halide was studied. 2,3‐Dihydro‐1H‐pyrroles were obtained by reaction of 3‐substituted‐5‐unsubstituted‐3,4‐allenyl amides under conditions A, while the reaction of 5‐substituted‐3,4‐allenyl amides afforded 1,2,5,6‐tetrahydropyridines and/or azetidines with high de under conditions B or C. The skeleton and relative configuration of the six‐membered products were established by the X‐ray diffraction studies of 10 ka. Allenyl amide 4 q reacted with 1,4‐diiodobenzene 6 r to afford double cyclization product 15. The structure of its major stereoisomer was also determined by the X‐ray diffraction study.
Supported Ionic‐Liquid Films (SILF) as Two‐Dimensional Nanoreactors for Enantioselective Reactions: Surface‐Mediated Selectivity Modulation (SMSM)
Authors: Castillo María R. , Fousse Leslie , Fraile José M. , García José I. , Mayoral José A. 
Published: September 2006

AbstractSupported ionic‐liquid films (SILF) of nanometric thickness containing bis(oxazoline)–copper complexes can be used as recoverable catalysts for enantioselective cyclopropanation reactions. When a thin film of ionic liquid is supported on a clay, the system behaves as a nearly two‐dimensional nanoreactor in which the restrictions in rotational mobility and the close proximity to the surface support produce variations in the stereo‐ and enantioselectivities, leading to a complete reversal of the overall selectivity of the reaction. As an example, the cyclopropanation of styrene changes from a preference for the (1S,2S)‐trans isomer in bulk solution to the (1R,2S)‐cis isomer in the SILF. This variation is strongly dependent on both the thickness of the film and the nature of the support. Only layered solids with negative charges in the layers (clays) give rise to this type of behaviour, showing that the formation of ion pairs may be a decisive factor. This unexpected effect also shows the existence of differences between bulk and supported ionic liquids.
Water‐Soluble Carbosilane Dendrimers: Synthesis Biocompatibility and Complexation with Oligonucleotides; Evaluation for Medical Applications
Authors: Bermejo Jesus F. , Ortega Paula , Chonco Louis , Eritja Ramon , Samaniego Rafael , Müllner Matthias , de Jesus Ernesto , de la Mata F. Javier , Flores Juan Carlos , Gomez Rafael , Muñoz‐Fernandez Angeles 
Published: September 2006

AbstractNovel amine‐ or ammonium‐terminated carbosilane dendrimers of type nG‐[Si{OCH2(C6H3)‐3,5‐(OCH2CH2NMe2)2}]x, nG‐[Si{O(CH2)2N(Me)(CH2)2NMe2}]x and nG‐[Si{(CH2)3NH2}]x or nG‐[Si{OCH2(C6H3)‐3,5‐(OCH2CH2NMe3+I−)2}]x, nG‐[Si{O(CH2)2N(Me)(CH2)2NMe3+I−}]x, and nG‐[Si{(CH2)3NH3+Cl−}]x have been synthesized and characterized up to the third generation by two strategies: 1) alcoholysis of SiCl bonds with amino alcohols and subsequent quaternization with MeI, and 2) hydrosilylation of allylamine with SiH bonds of the dendritic systems and subsequent quaternization with HCl. Quaternized carbosilane dendrimers are soluble in water, although degradation is apparent due to hydrolysis of SiO bonds. However, dendrimers containing SiC bonds are water‐stable. The biocompatibility of the second‐generation dendrimers in primary cell cultures of peripheral blood mononuclear cells (PBMCs) and erythrocytes have been analyzed, and they show good toxicity profiles over extended periods. In addition, we describe a study on the interactions between the different carbosilane dendrimers and DNA oligodeoxynucleotides (ODNs) and plasmids along with a comparative analysis of their toxicity. They can form complexes with DNA ODNs and plasmids at biocompatible doses via electrostatic interaction. Also a preliminary transfection assay has been accomplished. These results demonstrate that the new ammonium‐terminated carbosilane dendrimers are good base molecules to be considered for biomedical applications.
Temperature Effects on Ion Association and Hydration in MgSO4 by Dielectric Spectroscopy
Authors: Akilan Chandrika , Rohman Nashiour , Hefter Glenn , Buchner Richard 
Published: September 2006

AbstractA detailed investigation of aqueous solutions of magnesium sulfate has been made by dielectric relaxation spectroscopy (DRS) over a wide range of frequencies (0.2≤ν/GHz≤89), concentrations (0.02≤m/mol kg−1≤2.3) and temperatures (5≤ϑ/°C≤65). Consistent with literature data from other techniques, the spectra show clear evidence at all temperatures for the simultaneous existence of double solvent‐separated (2SIP), solvent‐shared (SIP) and contact (CIP) ion pairs and a triple ion (TI), Mg2SO42+(aq). Increased formation of CIPs and especially TIs occurs with increasing temperature. The overall standard ion‐association constant, KA°, corresponding to the equilibrium: Mg2+(aq)+SO42−(aq)⇌MgSO40(aq) is in good agreement with literature data at lower temperatures but is overestimated at higher temperatures due to processing difficulties. Despite the limited precision of the spectra, analysis of the individual steps in the ion‐association process is possible for the first time. The 2SIPs are formed with little disturbance to their hydration shells, the (partial) destruction of which appears to occur mostly during the formation of SIPs. Effective hydration numbers derived from the DRS spectra indicate that both Mg2+ and SO42− influence solvent water molecules beyond their first hydration spheres but that MgSO4(aq) is less strongly hydrated than the previously studied CuSO4(aq).
Seismic response of critical interdependent networks
Authors: Dueñas‐Osorio Leonardo , Craig James I. , Goodno Barry J. 
Published: September 2006

AbstractDuring the last decade, critical infrastructure systems such as electric power, water distribution, transportation and telecommunications have been stressed by significant natural hazards and human errors leading to malfunction. Earthquakes, blackouts and satellite failures have evidenced the vulnerability of these growing networked systems threatening the continuity of the United States' economy. The potential for malicious perturbations to these systems is also an important current concern. However, the underlying susceptibility of these networks to disruptive events is in large part due to the increasingly complex pattern of interdependencies that tie these civil infrastructures together. This paper mainly investigates the effect of seismic disruptions on the performance of real interdependent networks. Maintenance‐induced malfunctions and coordinated attacks are also studied for completeness. Several degrees of interconnectedness are explored. Interdependent network fragility curves are introduced to display the effect of these different strengths of coupling. Characterization of the performance displayed by the networks is utilized to propose mitigation actions and study propagation of their effects. It is shown that minimal strategic interventions propagated through the network can generate a more resilient interdependent entity. Copyright © 2006 John Wiley & Sons, Ltd.
Experimental study of dynamic damage of an arch dam
Authors: Wang Haibo , Li Deyu 
Published: September 2006

AbstractSeismic responses of a 292‐m high arch dam were studied by experiment on a shaking table. The model system included the arch dam with contraction joints, a part of a reservoir, and a partial foundation with a topographic feature near the dam. Potential rock wedges on the abutments and the mechanical properties including uplift on the kinematic planes were carefully simulated. A damping boundary consisting of a viscous liquid was introduced to simulate the effect of dynamic energy emission to far field, which made the dynamic interaction between the dam and the foundation be adequately represented in the model test of an arch dam system. Dynamic responses of the arch dam system under a sequence of seismic loadings in increasing strength were examined. Eleven cracks or overstresses on the model dam due to the earthquake excitations were observed, and consequently, its natural frequency dropped by about 14%, but the model dam was stable under the hydrostatic load of the impounded water after the test. Copyright © 2006 John Wiley & Sons, Ltd.
Energy dissipation in rocking bridge piers under free vibration tests
Authors: Cheng Chin‐Tung 
Published: September 2006

AbstractThis research aims to investigate the dynamic characteristic of rocking bridge columns subjected to quick release loads. Precast columns anchored by unbonded steel bars at the centre of each column can rock on the foundation surface without inducing any residual deformation after earthquakes. The restoring force of columns relies on gravity load from the superstructure and tensile strength in anchor bars. Radiation damping is evaluated through each impact of column rocking. To validate the theoretical damping proposed by previous researchers, four columns were constructed. Research parameters included steel or plastic materials used as rocking interfaces, area of anchor bars, aspect ratio and size effect of columns. Test results revealed that stocky columns slid apparently in the first impact then rocked, but taller columns rocked with minor slips in the entire motion. And freestanding columns slid significantly in the first impact that led to a higher damping. Radiation damping due to impact in the entire motion for all tests was within 5%. Copyright © 2006 John Wiley & Sons, Ltd.
Shaking‐table tests on reinforced concrete frames with different isolation systems
Authors: Dolce Mauro , Cardone Donatello , Ponzo Felice C. 
Published: September 2006

AbstractThe effectiveness of seismic isolation in protecting structural and non‐structural elements from damage has been assessed in an extensive programme of shaking‐table tests, carried out on four identical 1/3.3‐scale, two‐dimensional, reinforced concrete (R/C) frames. Four different isolation systems were considered, namely: (i) rubber‐based, (ii) steel‐based, (iii) shape memory alloy (SMA)‐based and (iv) hybrid, i.e. based on both SMA and steel components, isolation systems.This paper presents a comprehensive overview of the main results of the experimental tests on base‐isolated models, whose structural response is described through: (i) maximum base displacements; (ii) maximum interstorey drifts; (iii) maximum storey accelerations and (iv) maximum storey shear forces. The evolution of the fundamental frequency of vibration of the R/C frame during the tests is also described.The beneficial effects of using base isolation resulted in no or slight damage, under strong earthquakes, to both structural and non‐structural members, as well as to the internal content of the building. The comparison with the experimental results obtained in shaking‐table tests on similar fixed‐base models emphasizes these positive aspects. Finally, advantages and drawbacks related to the use of each isolation system are discussed in the paper. Copyright © 2006 John Wiley & Sons, Ltd.
A non‐diffusive, divergence‐free, finite volume‐based double projection method on non‐staggered grids
Authors: Aprovitola A. , Denaro F. M. 
Published: September 2006

AbstractSecond‐order accurate projection methods for simulating time‐dependent incompressible flows on cell‐centred grids substantially belong to the class either of exact or approximate projections. In the exact method, the continuity constraint can be satisfied to machine‐accuracy but the divergence and Laplacian operators show a four‐dimension nullspace therefore spurious oscillating solutions can be introduced. In the approximate method, the continuity constraint is relaxed, the continuity equation being satisfied up to the magnitude of the local truncation error, but the compact Laplacian operator has only the constant mode. An original formulation for allowing the discrete continuity equation to be satisfied to machine‐accuracy, while using a finite volume based projection method, is illustrated. The procedure exploits the Helmholtz–Hodge decomposition theorem for deriving an additional velocity field that enforces the discrete continuity without altering the vorticity field. This is accomplished by solving a second elliptic field for a scalar field obtained by prescribing that its additional discrete gradients ensure discrete continuity based on the previously adopted linear interpolation of the velocity. The resulting numerical scheme is applied to several flow problems and is proved to be accurate, stable and efficient.This paper has to be considered as the companion of: 'F. M. Denaro, A 3D second‐order accurate projection‐based finite volume code on non‐staggered, non‐uniform structured grids with continuity preserving properties: application to buoyancy‐driven flows. IJNMF 2006; 52(4):393–432. Now, we illustrate the details and the rigorous theoretical framework. Copyright © 2006 John Wiley & Sons, Ltd.
Edge‐based data structures for a symmetric stabilized finite element method for the incompressible Navier–Stokes equations with heat transfer
Authors: Kraft R. A. , Coutinho A. L. G. A. , de Sampaio P. A. B. 
Published: September 2006

AbstractThis work presents a new implementation of the De Sampaio–Coutinho formulation (Int. J. Numer. Meth. Fluids 1999; 29:289–309), a segregated Petrov–Galerkin/generalized least‐squares method, for the solution of the incompressible Navier–Stokes equations with heat transfer. Such a formulation produces symmetric, positive‐definite matrices, allowing the use of a preconditioned conjugate gradient solver for each unknown. The formulation also intrinsically introduces streamline upwinding by the choice of adequate time steps, providing a suitable description of convective dominated flows. The code was primarily written using element‐based data structures, making use of parallel/vector techniques and mesh adaptivity. However, schemes based on edge‐based data structures have been introduced with the aim of reducing flop count, memory demands and indirect addressing. In this work, the De Sampaio–Coutinho formulation has been re‐written considering an edge‐based arrangement. The effectiveness of the new scheme was observed solving some standard test cases, as shown in this paper, with a comparatively high gain in computational efficiency. Copyright © 2006 John Wiley & Sons, Ltd.
Compatibility between finite volumes and finite elements using solutions of shallow water equations for substance transport
Authors: Postma Leo , Hervouet Jean‐Michel 
Published: September 2006

AbstractThis paper formulates a finite volume analogue of a finite element schematization of three‐dimensional shallow water equations. The resulting finite volume schematization, when applied to the continuity equation, exactly reproduces the set of matrix equations that is obtained by the application of the corresponding finite element schematization to the continuity equation. The procedure allows the consistent and mass conserving coupling of the finite element Telemac model for three‐dimensional flow with the finite volume Delft3D‐WAQ model for water quality. The work has been carried out as part of a joint development by LNHE and WL∣Delft Hydraulics to explore the mutual interaction of their software. Copyright © 2006 John Wiley & Sons, Ltd.