bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resolving the TCA cycle and pentose‐phosphate pathway of Clostridium acetobutylicum ATCC 824: Isotopomer analysis, in vitro activities and expression analysis
Authors: Crown Scott B. , Indurthi Dinesh C. , Ahn Woo Suk , Choi Jungik , Papoutsakis Eleftherios T. , Antoniewicz Maciek R. 
Published: November 2010

AbstractSolventogenic clostridia are an important class of microorganisms that can produce various biofuels. One of the bottlenecks in engineering clostridia stems from the fact that central metabolic pathways remain poorly understood. Here, we utilized the power of 13C‐based isotopomer analysis to re‐examine central metabolic pathways of Clostridium acetobutylicum ATCC 824. We demonstrate using [1,2‐13C]glucose, MS analysis of intracellular metabolites, and enzymatic assays that C. acetobutylicum has a split TCA cycle where only Re‐citrate synthase (CS) contributes to the production of α‐ketoglutarate via citrate. Furthermore, we show that there is no carbon exchange between α‐ketoglutarate and fumarate and that the oxidative pentose‐phosphate pathway (oxPPP) is inactive. Dynamic gene expression analysis of the putative Re‐CS gene (CAC0970), its operon, and all glycolysis, pentose‐phosphate pathway, and TCA cycle genes identify genes and their degree of involvement in these core pathways that support the powerful primary metabolism of this industrial organism.
Clinical outcomes following predilation with a novel 1.25‐mm diameter angioplasty catheter
Authors: Kandzari David E. , Zankar Ahmad A. , Teirstein Paul S. , Brilakis Emmanouil S. , Banerjee Subhash , Price Matthew J. , Stinis Curtiss T. , Hudson Paul A. , Dahle Thom G.A. , Eng Marvin , Brown Ryan , Ferguson Andrew , Addo Tayo A. , Popma Jeffrey J. 
Published: November 2010

AbstractObjective: An unmet need is represented in angioplasty catheters that permit the predilation stage of treating complex coronary anatomy oftentimes not amenable to conventional device therapies. Background: Lesion preparation with balloon angioplasty prior to stent placement remains the most common method of percutaneous coronary revascularization. Methods: Clinical and angiographic outcomes were evaluated following a treatment strategy of coronary artery disease that included predilation with a low‐profile, 1.25‐mm angioplasty catheter prior to stent placement. The study primary end point of procedural success was defined as successful device delivery and lesion treatment, including the absence of clinically significant perforation, arrhythmia, flow‐limiting dissection, or reduction in baseline Thrombolysis In Myocardial Infarction (TIMI) grade with final achievement of TIMI 3 flow. Results: Among 51 patients (54 lesions), predilation using a 1.25 mm angioplasty catheter was associated with procedural and device‐related success rates of 100%. In‐hospital target lesion failure occurred in one patient (2.0%) related to postprocedural myocardial infarction. Patient and angiographic characteristics included diabetes, 43.1%; lesion length ≥20 mm, 20.4%; bifurcation lesion, 31.5%; lesion classification B2/C, 74.1%; and baseline TIMI 0/1 flow, 13.0%. No subsequent in‐hospital adverse events occurred. Conclusions: Percutaneous coronary revascularization involving a predilation strategy with a low profile, 1.25‐mm angioplasty catheter is associated with favorable procedural safety and efficacy and may represent an effective initial treatment for complex coronary anatomy. © 2010 Wiley‐Liss, Inc.
Cation–Cation Complexes of Pentavalent Uranyl: From Disproportionation Intermediates to Stable Clusters
Authors: Mougel Victor , Horeglad Pawel , Nocton Grégory , Pécaut Jacques , Mazzanti Marinella 
Published: November 2010

AbstractThree new cation–cation complexes of pentavalent uranyl, stable with respect to the disproportionation reaction, have been prepared from the reaction of the precursor [(UO2py5)(KI2py2)]n (1) with the Schiff base ligands salen2−, acacen2−, and salophen2− (H2salen=N,N′‐ethylene‐bis(salicylideneimine), H2acacen=N,N′‐ethylenebis(acetylacetoneimine), H2salophen=N,N′‐phenylene‐bis(salicylideneimine)). The preparation of stable complexes requires a careful choice of counter ions and reaction conditions. Notably the reaction of 1 with salophen2− in pyridine leads to immediate disproportionation, but in the presence of [18]crown‐6 ([18]C‐6) a stable complex forms. The solid‐state structure of the four tetranuclear complexes, {[UO2(acacen)]4[μ8‐]2[K([18]C‐6)(py)]2} (3) and {[UO2(acacen)]4[μ8‐]}⋅2 [K([222])(py)] (4), {[UO2(salophen)]4[μ8‐K]2[μ5‐KI]2[(K([18]C‐6)]}⋅2 [K([18]C‐6)(thf)2]⋅2 I (5), and {[UO2(salen)4][μ8‐Rb]2[Rb([18]C‐6)]2} (9) ([222]=[222]cryptand, py=pyridine), presenting a T‐shaped cation–cation interaction has been determined by X‐ray crystallographic studies. NMR spectroscopic and UV/Vis studies show that the tetranuclear structure is maintained in pyridine solution for the salen and acacen complexes. Stable mononuclear complexes of pentavalent uranyl are also obtained by reduction of the hexavalent uranyl Schiff base complexes with cobaltocene in pyridine in the absence of coordinating cations. The reactivity of the complex [UVO2(salen)(py)][Cp*2Co] with different alkali ions demonstrates the crucial effect of coordinating cations on the stability of cation–cation complexes. The nature of the cation plays a key role in the preparation of stable cation–cation complexes. Stable tetranuclear complexes form in the presence of K+ and Rb+, whereas Li+ leads to disproportionation. A new uranyl–oxo cluster was isolated from this reaction. The reaction of [UVO2(salen)(py)][Cp*2Co] (Cp*=pentamethylcyclopentadienyl) with its UVI analogue yields the oxo‐functionalized dimer [UO2(salen)(py)]2[Cp*2Co] (8). The reaction of the {[UO2(salen)4][μ8‐K]2[K([18]C‐6)]2} tetramer with protons leads to disproportionation to UIV and UVI species and H2O confirming the crucial role of the proton in the UV disproportionation.
Grid and P2P middleware for wide‐area parallel processing
Authors: Xhafa Fatos , Pllana Sabri , Barolli Leonard , Spaho Evjola 
Published: November 2010

AbstractGrid computing emerged as a paradigm for high‐performance computing and massive parallel processing. Currently, Grid systems have become an important paradigm for efficiently solving large‐scale complex problems from many fields. On the other hand, P2P paradigm originated from file‐sharing, but each time more is being used for the development of large‐scale distributed platforms. Grid and P2P systems have thus followed different trajectories pushed by different motivations, needs and research communities. In fact, both paradigms are evolving in a way that each time they are sharing more common characteristics and are mutually benefiting from their best features. Among these characteristics, we could distinguish the cooperative model for solving complex problems by exploiting their large computing capacity. As such, Grid and P2P systems have achieved notable success, in particular, for e‐Science applications, a family of complex applications arising in science and engineering that need considerable computation power. Despite important advances in the design and use of Grid and P2P systems, they remain still difficult to implement and apply to real‐life problems. The main difficulties reside in the lack of easy‐to‐use middleware for Grid and P2P, in the complexities of setting up and in the tedious task of deploying real‐world Grid/P2P platforms as well as in experimental studies which are often complex and not easy to repeat. In this paper we survey and analyze the advances in communication libraries and middleware for both Grid and P2P systems as well as their limitations when used in real Grid and P2P infrastructures. We also bring examples of real‐life applications of massive data processing that can be efficiently handled through Grid and P2P approaches. Copyright © 2010 John Wiley & Sons, Ltd.
A single‐stage LED lamp driver with low DC bus voltage for general lighting applications
Authors: Chiu Huang‐Jen , Lo Yu‐Kang , Cheng Shih‐Jen , Yan Yeong‐Chang , Lee Hung‐Chi , Wu Kuan‐Hung , Lin Chung‐Yi , Ho Shao‐Shih , Tseng Ming‐Hsiang , Huang Fu‐Hsien 
Published: November 2010

AbstractIn this paper, we study the feasibility of a single‐stage lighting LED lamp driver with low DC bus voltage. The operating principles and design considerations for the LED lamp driver in this study are analyzed and discussed in detail. A laboratory prototype has been built and tested. Using the prototype, high efficiency, high‐power factor and LED current control were achieved using a wide AC input voltage range from 90 to 270 V. Copyright © 2010 John Wiley & Sons, Ltd.
Qualitative analysis of an interrupted electric circuit with spike noise
Authors: Asahara Hiroyuki , Kousaka Takuji 
Published: November 2010

AbstractSwitching non‐ideality and its effects have been reported in DC‐DC converters. In this paper, we examine the qualitative property of an interrupted electric circuit with spike noise. First, we show the circuit model that have the switch interrupted by its own state and a periodic interval. Here, we artificially add spike noise via every switching action. Then, we explain its dynamics and derive the Poincaré map for the rigorous analysis in a circuit with ideal switching and a circuit with spike noise, respectively. Finally, we discuss the dynamical effects of spike noise from experimental and analytical viewpoints based on the Poincaré map and bifurcation diagrams. As a result, some dynamical effects of spike noise are clarified in terms of the invariant set, bifurcations, and existence regions of coexisting attractor. Copyright © 2010 John Wiley & Sons, Ltd.
Analysis and design of an active‐clamping zero‐voltage‐switching isolated inverse‐SEPIC converter
Authors: Lo Yu‐Kang , Liu Yu‐Chen , Lin Jing‐Yuan , Lin Chung‐Yi , Cheng Shih‐Jen 
Published: November 2010

SUMMARYThis paper presents an active‐clamping zero‐voltage‐switching (ZVS) isolated inverse‐SEPIC converter. The high voltage spikes when turning off the switches are eliminated. The energies stored in the parasitic elements can be recycled to achieve the ZVS of switches. Therefore, the conversion efficiency increases substantially, yet with a reduced circuit cost. Detailed analysis and design of the proposed topology are described. Experimental results are recorded for a prototype converter with a DC input voltage ranging from 130 to 180 V, an output voltage of 12 V and a rated output power of 120 W, operating at a switching frequency of 65 kHz. The average active‐mode efficiency is above 88%. Copyright © 2010 John Wiley & Sons, Ltd.
On constructing complex grid multi‐wing hyperchaotic system: Theoretical design and circuit implementation
Authors: Zhang Chaoxia , Yu Simin 
Published: November 2010

SUMMARYThis paper further investigates some novel methods for generating complex grid multi‐wing hyperchaotic attractors from four‐dimensional (4D) quadratic hyperchaotic systems, based on our previous works. First, a modified double‐wing hyperchaotic Lü system by using non‐uniform variable scaling transformation is obtained, and n‐wing hyperchaotic system equipped with a duality‐symmetric multi‐segment quadratic function is also constructed. Then, by switching control in the z direction, mirror symmetry conversion and rotation transformation, three classes of n × m‐wing hyperchaotic systems are respectively realized. Finally, two types of improved module‐based circuits are designed for generating various grid multi‐wing hyperchaotic attractors. One characteristic of the proposed approaches lies in their generality, which is also suitable for constructing 4D grid multi‐wing hyperchaotic Lorenz and Chen systems. Both numerical simulation and circuit implementation have demonstrated the feasibility and effectiveness of the proposed approaches. Copyright © 2010 John Wiley & Sons, Ltd.
OMAC: A new access control architecture for overlay multicast communications
Authors: Mohamed Emad Eldin , Barka Ezedin 
Published: November 2010

AbstractMulticast communications concern the transfer of data among multiple users. Multicast communications can be provided at the network layer—an example is IP multicast—or at the application layer, also called overlay multicast. An important issue in multicast communications is to control how different users—senders, receivers, and delivery nodes—access the transmitted data as well as the network resources. Many researchers have proposed solutions addressing access control in IP multicast. However, little attention has been paid to overlay multicast. In this paper, we investigate the access control issues in overlay multicast and present OMAC: a new solution to address these issues. OMAC provides access control for senders, receivers, and delivery nodes in overlay multicast. The proposed architecture, which is based on symmetric key cryptosystem, centralizes the authentication process in one server whereas it distributes the authorization process among the delivery nodes. Moreover, delivery nodes are utilized as a buffer zone between end systems and the authentication server, making it less exposed to malicious end systems. To evaluate our work, we have used simulation to compare the performance of OMAC against previous solutions. Results of the simulation show that OMAC outperforms previous multicast access control schemes. Copyright © 2010 John Wiley & Sons, Ltd.
3D video communications: Challenges and opportunities
Authors: Su Guan‐Ming , Lai Yu‐Chi , Kwasinski Andres , Wang Haohong 
Published: November 2010

AbstractThis paper surveys major techniques in 3D communications area, which covers the whole pipeline of the 3D video communication framework, including 3D content creation, data representation, compression, delivery, decompression, post‐processing, and 3D scene rendering stages. Both the current state‐of‐the‐art, stereo 3D, and future trend, free‐viewpoint 3D, are demonstrated in details. On the other hand, the paper highlights a few features in the emerging 4G wireless systems that are critical for 3D communications system design. At the end, the topics with potential but challenges, for example 3D over 4G networks, distributed 3D video coding, 3D multi‐user communication, scalability and universal 3D access, are discussed and pointed out to audiences for further investigation. Copyright © 2010 John Wiley & Sons, Ltd.
Low‐jitter slot assignment algorithm for deadline‐aware packet transmission in wireless video surveillance sensor networks
Authors: Tao Li Qiang , Yu Feng Qi 
Published: November 2010

AbstractThis work presents a distributed time‐slot assignment algorithm which adopts TDMA as Medium Access Control, specially suited to support applications with strict delay, jitter, and throughput requirements characterized by convergecast traffic pattern in sensor networks. (e.g. wireless video surveillance sensor networks). The proposed algorithm has three characteristics: (1) every node is guaranteed a path to the base station for its data delivery. In the path, sufficient resource is reserved and weighted fairness can be achieved. (2) It uses cascading time‐slot assignment and jitter minimization algorithm in each node to minimize jitter and end‐to‐end delay. (3) Nodes are only active during their scheduled slots and sleep otherwise. This offers energy saving by reducing idle listening and avoiding overhearing. The performance of the proposed algorithm is evaluated over simulations and analyzed theoretically in comparison with existing slot assignment algorithm. The results show that our algorithm provides lower end‐to‐end delay, jitter, and higher throughput. Copyright © 2010 John Wiley & Sons, Ltd.
Direct Detection of DNA and DNA‐Ligand Interaction by Impedance Spectroscopy
Authors: Witte C. , Lisdat F. 
Published: November 2010

AbstractIn this work we present an impedimetric detection system for DNA‐ligand interactions. The sensor system consists of thiol‐modified single‐stranded DNA chemisorbed to gold. Impedance measurements in the presence of the redox system ferri‐/ferrocyanide show an increase in charge transfer resistance (Rct) after hybridisation of a complementary target. Different amounts of capture strands, used for gold electrode modification, result in surface coverages between 3 and 15 pmol/cm2ssDNA. The relative change inRctupon hybridisation increases with increasing amount of capture probe on the electrode from 1.5‐ to 4.5‐fold. Impedimetric detection of binding events of a metal‐intercalator ([Ru(phen)3]2+) and a groove binder (spermine) to double‐stranded DNA is demonstrated. Binding of [Ru(phen)3]2+and spermine exhibits a decrease in charge transfer resistance. Here, the ligand’s interaction leads to electrostatic shielding of the negatively charged DNA backbone. The impedance changes have been evaluated in dependence on the concentration of both DNA binders. Furthermore, the association of a single‐stranded binding protein (SSBP) is found to cause an increase in charge transfer resistance only when incubated with single‐stranded DNA. The specific binding of an anti‐dsDNA antibody to the dsDNA‐modified electrode surface decreases in contrast the interfacial impedance.
A Nonenzymatic Amperometric Method for Fructosyl‐Valine Sensing Using Ferroceneboronic Acid
Authors: Chien Hui‐Ching , Chou Tse‐Chuan 
Published: November 2010

AbstractFructosyl valine (Fru‐Val) is a glycosylated component of hemoglobin (HbA1c) that can serve as a diagnostic target for type 2 diabetes. While average blood glucose levels fluctuate significantly, the more stable levels of HbA1c can serve as a better long‐term diagnostic marker. Here a diagnostic system, incorporating an amperometric method, for detecting Fru‐Val (at +0.1 V vs. Ag/AgCl), using ferrocene boronic acid (FcBA) is presented. FcBA can complex diols, and has easily detectable redox properties. The boronic acid group in FcBA mediates complexation, while the Fe(II)/Fe(III) couple serves as a transducer. The diagnostic system, based on a miniaturized bare glassy carbon paste electrode (GCPE), has a fast response time.
Voltammetric Behavior of Methotrexate Using Mercury Meniscus Modified Silver Solid Amalgam Electrode
Authors: Šelešovská Renáta , Bandžuchová Lenka , Navrátil Tomáš 
Published: November 2010

AbstractVoltammetric behavior of methotrexate (MTX), an important chemotherapeutic drug, has been investigated using electrochemical methods: cyclic voltammetry, direct current voltammetry and differential pulse voltammetry on a mercury meniscus modified silver solid amalgam electrode (m‐AgSAE). The obtained results have been compared with those obtained using a hanging mercury drop electrode (HMDE). The optimal conditions for its determination have been found in a Britton‐Robinson buffer of pH 5 with the limit of detection equal to 1.8 nM. RSD at this concentration level amounted to less than 4 %. The proposed procedure of determination was verified on a real drug containing MTX.
Simultaneous Determination of Acetaminophen (Paracetamol) and Ascorbic Acid in Pharmaceutical Formulations by LC Coupled to a Screen Printed Carbon Based Amperometric Detector
Authors: Sarakbi Ahmad , Aydogmus Zeynep , Sidali Tarik , Gokce Gültekin , Kauffmann Jean‐Michel 
Published: November 2010

AbstractThe assay of acetaminophen (APAP) and ascorbic acid (AA) was performed by liquid chromatography (LC) with amperometric detection at a screen printed carbon based electrode poised at +0.6 V versus Ag pseudoreference electrode. A microparticle based conventional RP‐C18 and a monolithic RP‐C18 column were studied comparatively for the analytes separation using a mobile phase based on 0. 1 M phosphate buffer‐methanol 91 : 9 (v/v) at pH 6.5. The linear calibration range for both compounds was comprised within 2×10−7–1×10−4 M. Limit of detection (LOD) for APAP and AA was 2×10−7 and 5×10−7 M, respectively and the limit of quantification (LOQ) was 5. 10−7and 1×10−6 M, respectively. Square wave voltammetry at a Nafion modified glassy carbon electrode was developed and applied to the determination of APAP in order to validate the results obtained by the monolithic LC method for drug formulations.
Electrochemical Studies of Chemically Modified Nanometer‐Sized Electrodes
Authors: Guo Jing , Ho Chu‐Ngi , Sun Peng 
Published: November 2010

AbstractSelf‐assembled monolayers (SAMs) of 4‐aminothiophenol (4‐ATP) has been successfully deposited onto nanometer‐sized gold (Au) electrodes. The cyclic voltammograms obtained on a 4‐ATP SAMs modified electrode show peaks and the peak height is proportional to the scan rate, which is similar to that on an electroactive SAMs modified macro electrode. The electrochemical behavior and mechanism of outer‐sphere electron transfer reaction on the 4‐ATP SAMs modified nanometer‐sized electrode has also been studied. The 4‐ATP SAMs modified electrode is further modified with platinum (Pt) nanoparticles. Electrochemical behaviors show that there is electrical communication between Pt nanoparticles and Au metal on the Pt nanoparticles/4‐ATP SAMs/Au electrode. However, scanning electron microscopic image shows that the Pt nanoparticles are not evenly covered the electrode.
Experimental study on critical breakage stress of float glass with different thicknesses under conditions with temperatures of 25 and 200°C
Authors: Xie Qiyuan , Zhang Heping , Si Dongya 
Published: November 2010

AbstractThe objective of this study is to directly measure the critical breakage stress for glass through mechanical tensile experiments based on MTS 810 apparatus. Two series of experiments were, respectively, conducted under the condition with a room temperature (25°C) and a hot environment (200°C) for float glass. The results show that the critical breakage stresses of 6, 8, 10 and 12 mm float glass are, respectively, 74, 127, 158 and 198% larger than that of 4 mm float glass under the condition with a room temperature (25°C). Similarly, the critical breakage stresses of 6, 10 and 12 mm float glass are, respectively, 29, 72 and 93% larger than 4 mm glass in the hot environment (200°C). In addition, through the comparison between the two series of experiments, it suggests that the critical breakage stresses of 6, 8, 10 and 12 mm thick float glass in a hot environment are, respectively, 7, 48, 16 and 19% smaller than that in a room temperature. It is suggested that the measured critical breakage stress of float glass here is relatively smaller than those in the previous measurements. Copyright © 2010 John Wiley & Sons, Ltd.
Immunohistochemical study identifying prognostic biomolecular markers in nasopharyngeal carcinoma treated by radiotherapy
Authors: Kim Yeon‐Joo , Go Heounjeong , Wu Hong‐Gyun , Jeon Yoon Kyung , Park Suk Won , Lee Seung Hee 
Published: November 2010

AbstractBackgroundWe evaluated the predictive significance of 14 reported markers using immunohistochemical study in nasopharyngeal carcinoma.MethodsImmunohistochemical stainings were done in 38 patients for Met, cyclooxygenase‐2 (COX‐2), nm23‐H1, epidermal growth factor receptor (EGFR), p63, early growth response factor 1 (Egr1), chromosome segregation 1‐like (CSE1L), cathepsin‐D (aspartyl protease), C‐erbB2, p53, signal transducers and activators of transcription (STAT3/STAT5), CD138 (Syndecan‐1), and LIN28 with the usual methods.ResultsThe median follow‐up time was 30 months (11–83 months). High Met and CD138 expression were statistically significant negative prognostic factors on survival. The expression of Egr1 had a positive prognostic effect on survival. The combined score of these 3 markers, Met plus CD138 minus Egr1, was a strong prognostic factor. The median survival curve was distinctly separated in accord with this combined score. No prognostic value was revealed in COX‐2, nm23‐H1, EGFR, p63, CSE1L, cathepsin‐D, C‐erbB2, p53, STAT3, STAT5, and LIN28.ConclusionsThe combined score of these markers could be used to stratify biomolecular risk groups. © 2010 Wiley Periodicals, Inc. Head Neck, 2010