bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Highly Stable, Water‐Dispersible Copper Nanoparticles as Catalysts for Nitrobenzene Reduction
Authors: Kaur Ravneet , Giordano Cristina , Gradzielski Michael , Mehta Surinder K. 
Published: October 2013

AbstractWe report an aqueous‐phase synthetic route to copper nanoparticles (CuNPs) using a copper–surfactant complex and tests of their catalytic efficiency for a simple nitrophenol reduction reaction under atmospheric conditions. Highly stable, water‐dispersed CuNPs were obtained with the aid of polyacrylic acid (PAA), but not with other dispersants like surfactants or polymethacrylic acid (PMAA). The diameter of the CuNPs could be controlled in the range of approximately 30–85 nm by modifying the ratio of the metal precursor to PAA. The catalytic reduction of p‐nitrophenol to p‐aminophenol takes place at the surface of CuNPs at room temperature and was accurately monitored by UV/Vis spectroscopy. The catalytic efficiency was found to be remarkably high for these PAA‐capped CuNPs, given the fact that at the same time PAA is efficiently preventing their oxidation as well. The activity was found to increase as the size of the CuNPs decreased. It can therefore be concluded that the synthesized CuNPs are catalytically highly efficient in spite of the presence of a protective PAA coating, which provides them with a long shelf life and thereby enhances the application potential of these CuNPs.
Fe(OTf)3‐Catalyzed α‐Benzylation of Aryl Methyl Ketones with Electrophilic Secondary and Aryl Alcohols
Authors: Pan Xiaojuan , Li Minghao , Gu Yanlong 
Published: October 2013

AbstractAcid‐catalyzed Friedel–Crafts alkylation of 1,3‐dicarbonyl compounds with electrophilic alcohols, is known to be an effective CC bond forming reaction. However, until now, this reaction has not been amenable for α‐alkylation of aryl methyl ketones because of the notoriously low nucleophilicities of these compounds. Therefore, α‐alkylation of aryl methyl ketone relies on precious metal catalysts and also, the use of primary alcohols is mandatory. In this study, we found that a system composed of a Fe(OTf)3 catalyst and chlorobenzene solvent is sufficient to promote the title Friedel–Crafts reaction by using benzhydrols as electrophiles. 3,4‐Dihydro‐9‐(2‐hydroxy‐4,4‐dimethyl‐6‐oxo‐1‐cyclohexen‐1‐yl)‐3,3‐dimethyl‐xanthen‐1(2 H)‐one was also applicable as an electrophile in this type of benzylation reaction. On the basis of this result, a three‐component reaction of salicylaldehyde, dimedone, and aryl methyl ketone was also developed, and this provided an efficient way for the synthesis of densely substituted 4H‐chromene derivatives.
An Improved Anti‐Windup Bumpless Transfer Structures Design for Controllers Switching
Authors: Qin Guozheng , Duan Zhisheng , Wen Guanghui , Yan Yingxin , Jiang Zhichao 
Published: October 2013

ABSTRACTIn this paper, an anti‐windup bumpless transfer (AWBT) control structure combined with linear interpolation method is proposed for smooth switching control. By choosing an appropriate scheduling signal, different controllers can be switched smoothly under a unified framework. Meanwhile, some robust specifications including H2/H∞ performance, pole placement constraint, and passivity of the closed‐loop system can be preserved through controller switching. Furthermore, for the linear system subject to input saturation, the stability and L2 gain of the closed‐loop system can be guaranteed. Finally, a cart‐spring pendulum system is simulated to demonstrate the effectiveness of the proposed scheme.
Best Tracking Performance of Networked Control Systems Based on Communication Constraints
Authors: Zhan Xi‐Sheng , Guan Zhi‐Hong , Zhang Xian‐He , Yuan Fu‐Shun 
Published: October 2013

ABSTRACTThe best tracking problem for a single‐input‐single‐output (SISO) networked control system with communication constraints is studied in this paper. The tracking performance is measured by the energy of the error signal between the output of the plant and the reference signal. The communication constraints under consideration are finite bandwidth and networked induced‐delay. Explicit expressions of the minimal tracking error have been obtained for networked control systems with or without communication constraints. It is shown that the best tracking performance dependents on the nonminimum phase zeros, and unstable poles of the given plant, as well as the bandwidth and networked induced‐delay. It is also shown that, if the constraints of the communication channel do not exist, the best tracking performance reduces to the existing tracking performance of the control system without communication constraints. The result shows how the bandwidth and networked induced‐delay of a communication channel may fundamentally constrain a control system's tracking capability. Some typical examples are given to illustrate the theoretical results.
Controllability of Multi‐Agent Dynamical Systems with a Broadcasting Control Signal
Authors: Yoon Myung‐Gon , Rowlinson Peter , Cvetković Dragoš , Stanić Zoran 
Published: October 2013

AbstractThis paper is concerned with the controllability of a multi‐agent dynamical system in which all identical first‐order dynamical agents receive a common exogenous control signal in addition to their inter‐agent communications. Existing graph theoretic results are used to determine conditions for controllability, and to study the dependency of controllability on the size of network and the number of connections. The fragility of controllability in the presence of hidden or broken connections is also investigated.
Toll pricing framework under logit‐based stochastic user equilibrium constraints
Authors: Liu Zhiyuan , Wang Shuaian , Meng Qiang 
Published: October 2013

SUMMARYThis paper addresses the toll pricing framework for the first‐best pricing with logit‐based stochastic user equilibrium (SUE) constraints. The first‐best pricing is usually known as marginal‐cost toll, which can be obtained by solving a traffic assignment problem based on the marginal cost functions. The marginal‐cost toll, however, has rarely been implemented in practice, because it requires every specific link on the network to be charged. Thus, it is necessary to search for a substitute of the marginal cost pricing scheme, which can reduce the toll locations but still minimize the total travel time. The toll pricing framework is the set of all the substitute toll patterns of the marginal cost pricing. Assuming the users' route choice behavior following the logit‐based SUE principle, this paper has first derived a mathematical expression for the toll pricing framework. Then, by proposing an origin‐based variational inequality model for the logit‐based SUE problem, another toll pricing framework is built, which avoids path enumeration/storage. Finally, the numerical test shows that many alternative pricing patterns can inherently reduce the charging locations and total toll collected, while achieving the same equilibrium link flow pattern. Copyright © 2013 John Wiley & Sons, Ltd.
Immunoassays of fungal laccases for screening of natural enzymes and control of recombinant enzyme production
Authors: Loginov Dmitry S. , Vavilova Ekaterina A. , Savinova Оlga S. , Abyanova Alfia R. , Chulkin Andrey M. , Vasina Daria V. , Zherdev Anatoly V. , Koroleva Olga V. 
Published: October 2013

AbstractBecause of the wide application of laccases in different biotechnological processes and intense studies of the enzymes from different sources, the development of efficient techniques for monitoring laccase level is a task of significant importance. Enzyme‐linked immunosorbent assay (ELISA) andWestern blotting techniques were developed to control total content and isoform composition of laccases, including their recombinant preparations. Because glycosylated and nonglycosylated forms have different structures and sets of epitopes, two kinds of polyclonal antibodies were obtained and applied. The first antibody recognized the native (glycosylated) laccase purified fromTrametes hirsutaand the second one reacted with recombinant (nonglycosylated) laccase expressed inEscherichia coli. Titers of the antibodies were analyzed by indirectELISAwith laccases isolated from several strains of basidiomycetes. The obtained cross‐reactivity data for both antibodies demonstrated a correspondence with sequence homology of the laccases. The antibodies raised against recombinant (nonglycosylated) laccase had higher titers and thus were preferable for screening of recombinant laccase in cultural media. Thus, optimal antibody preparations were selected for screening of laccase‐producing strains, and the control of recombinant enzymes and the efficiency of their use in immunochemical control of laccase levels were confirmed.
A comparison of commercial ethanol production systems from Brazilian sugarcane and US corn
Authors: Chum Helena L. , Warner Ethan , Seabra Joaquim E.A. , Macedo Isaias C. 
Published: October 2013

AbstractGlobal biofuels production grew rapidly from 2007 to 2012, led by the United States and Brazil, the world's two largest fuel‐ethanol‐producing systems. In this paper we provide insights into the characteristics of mature Brazilian sugarcane and maturing US dry mill corn ethanol industries. Both systems continue to improve as measured by life cycle data such as total renewable energy produced per unit of fossil energy consumed [renewable energy ratio (RER)]. Sugarcane self‐benchmarking systems showed RER values of 7.0 in 2002 to 9.4 in 2009 as the industry started to switch to mechanized harvesting. The average US RER improved from 1.1 to 1.7 from 2000 to 2010. RERs of 4.4 to 5.5 are observed in corn ethanol plants employing natural gas or corn stover combined heat and power. Ethanol systems configured to produce ethanol and electricity had similar net energy balances (a ratio of net energy produced to energy contained in the fuel). One measure of greenhouse gas (GHG) emissions reductions (biomass use efficiency) compares the effectiveness of displacing carbon from combustion of fossil fuels with renewable carbon. Advanced corn ethanol systems reach higher GHG emission reduction levels compared to sugarcane ethanol by displacing coal‐based electricity. Sugarcane systems achieve double the GHG emissions reductions per unit of harvested land relative to corn ethanol because sugarcane and corn are grown as perennial and annual crops in tropical and temperate climatic zones, respectively. Carbon dioxide capture and storage systems could offer additional GHG emission reductions for both corn and sugarcane ethanol systems. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd
Understanding the evolution of environmental and energy performance of the US corn ethanol industry: evaluation of selected metrics
Authors: Chum Helena L. , Zhang Yimin , Hill Jason , Tiffany Douglas G. , Morey R. Vance , Goss Eng Alison , Haq Zia 
Published: October 2013

AbstractThroughout the past two decades, numerous studies characterized the greenhouse gas (GHG) emissions and net energy balance of corn ethanol production in the USA. A wide range of reported values resulted from differences in the vintage of the data used to evaluate the ethanol conversion technology and the agricultural practices of corn production, which evolved substantially during the rapid growth phase of the industry. Methodological differences in life cycle assessments also caused the reported values to vary widely. With corn dry mills growing from 30% of total installed ethanol production capacity in 1990 to 80–90% from 2006 to 2011, we document the evolution of this industry using vintage‐specific data to analyze selected energy and environmental metrics, including GHG emissions, fossil energy use, direct land use, and GHG emissions reduction per hectare of land harvested for ethanol production. Our estimates indicate that production and use of corn ethanol emitted 44% fewer GHG emissions, consumed 54% less fossil energy and required 44% less land in 2010 compared to 1990 (on a life cycle basis). Our review and analysis point to strategies for reducing the carbon footprint of the corn dry mill industry by building on the progress already achieved. Using biomass (e.g. residues from corn production) for process heat or combined heat and power is one such strategy. Additional environmental benefits are projected from the adoption of integrated gasification combined cycle technology (using corn residues), which leads to energy‐self‐sufficient mills or net electricity producers depending on the power system configuration. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd
Population‐based meta‐analysis of hydrochlorothiazide pharmacokinetics
Authors: Van Wart Scott A. , Shoaf Susan E. , Mallikaarjun Suresh , Mager Donald E. 
Published: October 2013

ABSTRACTHydrochlorothiazide (HCTZ) is a thiazide diuretic used for the treatment of hypertension and edema associated with fluid overload conditions such as congestive heart failure (CHF). A population‐based meta‐analysis approach in NONMEM® was used to develop a PK model to characterize the time‐course of HCTZ concentrations in plasma and excretion into the urine for healthy subjects and CHF patients. Data from healthy subjects receiving 100 mg of oral HCTZ were supplemented with additional plasma concentration and urinary excretion versus time data published in the literature following administration of oral HCTZ doses ranging from 10 to 500 mg to healthy subjects or patients with renal failure, CHF or hypertension. A two‐compartment model with first‐order oral absorption, using a Weibull function, and first‐order elimination best described HCTZ PK. Creatinine clearance (CLCR) was a statistically significant predictor of renal clearance (CLR). Non‐renal clearance was estimated to be 2.44 l/h, CLR was 18.3 l/h and T1/2,α was 1.6 h and T1/2,β was 14.8 h for a typical individual with normal renal function (CLCR = 120 ml/min). However, CLR was reduced to 10.5, 5.47 and 2.70 l/h in mild (CLCR = 80 ml/min), moderate (CLCR = 50 ml/min) and severe (CLCR = 30 ml/min) renal impairment, respectively. Model diagnostics helped to demonstrate that the population PK model reasonably predicts the rate of urinary HCTZ excretion over time using dosing history and estimated CLCR, allowing for the convenient assessment of PK–PD relationships for HCTZ when given alone or in combination with other agents used to treat fluid overload conditions. Copyright © 2013 John Wiley & Sons, Ltd.
Systems‐based understanding of pharmacological responses with combinations of multidisciplinary methodologies
Authors: Kariya Yoshiaki , Honma Masashi , Suzuki Hiroshi 
Published: October 2013

ABSTRACTThe importance of systems‐based pharmacological approaches to drug discovery and development has increasingly been recognized. This reviews summarizes recent advances in the development of systems pharmacology and introduces the methods used for analysis. To understand the cellular response at the molecular level, pathway maps must be prepared to show how the function of the constituent molecules within cells are linked and integrated to form molecular networks. First, the methods used to prepare these pathway maps, such as databases, knowledge bases and software platforms, are introduced. Then the mathematical theories used to analyse the behavior of molecular networks are summarized. To quantitatively predict cellular responses, simulations are performed that are based on the rate equations for each reaction within the pathway map. If the number of reactions described in the pathway map is small, and if the parameter values for the rate constants are available, it is possible accurately to simulate the behavior of the molecular networks. However, to analyse complex maps, mathematical abstraction is required. Such abstraction methods are important to integrate cellular responses and to understand tissue/organ and in vivo pharmacological/toxicological responses. The scope and limitations of the methods are also discussed. Copyright © 2013 John Wiley & Sons, Ltd.
Pharmacokinetics, bioavailability and tissue distribution of geniposide following intravenous and peroral administration to rats
Authors: Wang Fugang , Cao Juan , Hao Jifu , Liu Ke 
Published: October 2013

ABSTRACTIn order to characterize the pharmacokinetics, bioavailability and tissue distribution of geniposide following intravenous and peroral administration to rats, a reliable gradient HPLC‐based method has been developed and validated. After p.o. administration of geniposide, the peak concentration of geniposide in plasma occurred at 1 h and plasma geniposide was eliminated nearly completely within 12 h. The AUC0→∞ values of geniposide were 6.99 ± 1.27 h · µg/ml and 6.76 ± 1.23 h · µg/ml after i.v. administration of 10 mg/kg and p.o. administration of 100 mg/kg of geniposide, respectively. The absolute oral bioavailability (%F) of geniposide was calculated as 9.67%. After p.o. administration of geniposide, the AUC0→4h values in tissues were in the order of kidney > spleen > liver > heart > lung > brain. This study improved the understanding of the pharmacokinetics, bioavailability and tissue distribution of geniposide in rats and may provide a meaningful basis for clinical application of such a bioactive compound of herbal medicines. Copyright © 2013 John Wiley & Sons, Ltd.
Neurophysiological characterization of transpinal evoked potentials in human leg muscles
Authors: Knikou Maria 
Published: October 2013

AbstractThe objectives of this study were to characterize the neurophysiological properties of the compound muscle action potentials (CMAPs) evoked by transcutaneous electric stimulation of the spine (tsESS), and the effects of tsESS on the soleus H‐reflex in seated and standing healthy human subjects. In seated semi‐prone subjects with the trunk semi‐flexed, two re‐usable self‐adhering electrodes (cathode), connected to act as one electrode, were placed bilaterally on the iliac crests. A re‐usable pregelled electrode (anode) was placed on the thoracolumbar region at thoracic 10–lumbar 1 and held under constant pressure throughout the experiment. CMAPs were recorded bilaterally from ankle muscles with subjects seated semi‐prone at 1.0, 0.3, 0.2, 0.125, and 0.1 Hz following tsESS. The soleus H‐reflex, evoked by posterior tibial nerve stimulation via conventional methods, was measured following tsESS at inter‐stimulus intervals (ISIs) that ranged from −100 to 100 ms with the subjects seated semi‐prone and during standing. The tsESS‐induced CMAPs were not decreased at low stimulation frequencies, and the soleus H‐reflex excitability was profoundly decreased by tsESS at ISIs that ranged from −5 to 20 ms with the subjects seated semi‐prone and during standing. CMAPs induced by tsESS may be utilized to assess spinal‐to‐muscle conduction time while bypassing spinal motoneuron excitability and tsESS can be used as a modality to decrease spinal reflex hyper‐excitability in neurological disorders. Bioelectromagnetics 34:630–640, 2013. © 2013 Wiley Periodicals, Inc.
Resonance light scattering determination of trace bisphenol A with signal amplification by aptamer–nanogold catalysis
Authors: Yao Dongmei , Liang Aihui , Yin Wenqing , Jiang Zhiliang 
Published: October 2013

ABSTRACTHAuCl4 was reduced by sodium citrate to prepare 10 nm gold nanoparticles (AuNPs) that were modified by the bisphenol A aptamer (Apt) to obtain an aptamer–nanogold probe (Apt‐AuNP) for bisphenol A (BPA). The probes were aggregated nonspecifically to form large clusters, which showed a strong resonance light scattering (RLS) peak at 520 nm, under preparation conditions (pH 7.6 Na2HPO4‐NaH2PO4 buffer and ultrasonication). Upon addition of BPA, the probe reacted specifically to form dispersed BPA‐Apt‐AuNP conjugates that exhibited strong catalysis of the two particle reactions of glucose‐Cu(II) and hydrazine hydrochloride‐Cu(II) with a strong RLS peak at 360 nm and 510 nm respectively. When the BPA concentration increased, the RLS intensity at 360 nm and 510 nm increased respectively. Accordingly, two new and highly‐sensitive RLS methods were established for the detection of BPA, using the Apt‐AuNP catalytic amplification. Copyright © 2013 John Wiley & Sons, Ltd.
A simple and sensitive resonance Rayleigh scattering method for determination of As(III) using aptamer‐modified nanogold as a probe
Authors: Tang Meiling , Wen Guiqing , Liang Aihui , Jiang Zhiliang 
Published: October 2013

ABSTRACTA simple and selective aptamer (ssDNA)‐modified nanogold probe (AussDNA) was prepared for the determination of trace As(III) in HEPES buffer solution (pH 8.2) containing 0.05 mol/L NaCl. The method coupled the aptamer reaction of AussDNA–As(III) and the resonance Rayleigh scattering (RRS) of nanogold aggregations at 278 nm. When the As(III) concentration increased, the RRS intensity at 278 nm increased to form more nanogold aggregation and a stable As(III)–ssDNA complex. Under selected conditions, the increased RRS intensity (ΔI) was linear to the concentration of As(III) in the range 3.8–230.4 ng/mL, with a detection limit of 1.9 ng/mL. This RRS method was applied to detect As(III) in water samples, with simplicity, sensitivity and selectivity. Copyright © 2013 John Wiley & Sons, Ltd.
A DAF‐16/FoxO3a‐dependent longevity signal is initiated by antioxidants
Authors: Kim Juewon , Ishihara Naoko , Lee Tae Ryong 
Published: October 2013

AbstractThe precise mechanisms of antioxidant‐mediated longevity are poorly understood. We show that an antioxidant treatment can extend the lifespan of Caenorhabditis elegans (C. elegans) through the nuclear translocation of the forkhead box O transcription factor (FoxO) homolog DAF‐16. This pathway was found to involve 3‐phosphoinositide‐dependent kinase‐1 (PDK‐1) and serum‐ and glucocorticoid‐regulated kinase‐1 (SGK‐1), distinct from the known oxidative stress‐mediated mechanism in which FoxO3a translocation is regulated by c‐Jun N‐terminal kinase (JNK) and mammalian sterile 20‐like kinase‐1 (MST‐1). The differences in the mechanisms of FoxO activation by antioxidants and oxidants result in differences in FoxO phosphorylation and target gene expression. Based on these results, we found that a combination of early antioxidant treatment and late oxidant treatment is most effective for lifespan extension in C. elegans. © 2013 BioFactors, 40(2):247–257, 2014
Thermal denaturation and aggregation of apoform of glycogen phosphorylase b. Effect of crowding agents and chaperones
Authors: Eronina Tatyana B. , Chebotareva Natalia A. , Roman Svetlana G. , Kleymenov Sergey Yu. , Makeeva Valentina F. , Poliansky Nikolay B. , Muranov Konstantin O. , Kurganov Boris I. 
Published: October 2013

ABSTRACTThe effect of protein and chemical chaperones and crowders on thermal stability and aggregation of apoform of rabbit muscle glycogen phosphorylase b (apoPhb) has been studied at 37°C. Proline suppressed heat‐induced loss in ability of apoPhb to reconstitution at 37°C, whereas α‐crystallin did not reveal a protective action. To compare the antiaggregation activity of intact and crosslinked α‐crystallins, an adsorption capacity (AC) of a protein chaperone with respect to a target protein was estimated. This parameter is a measure of the antiaggregation activity. Crosslinking of α‐crystallin results in 11‐fold decrease in the initial AC. The nonlinear character of the relative initial rate of apoPhb aggregation versus the [intact α‐crystallin]/[apoPhb] ratio plot is indicative of the decrease in the AC of α‐crystallin with increasing the [α‐crystallin]/[apoPhb] ratio and can be interpreted as an evidence for dynamic chaperone structure and polydispersity of α‐crystallin–target protein complexes. As for chemical chaperones, a semisaturation concentration of the latter was used as a characteristic of the antiaggregation activity. A decrease in the semisaturation concentration for proline was observed in the presence of the crowders (polyethylene glycol and Ficoll‐70). © 2013 Wiley Periodicals, Inc. Biopolymers 101: 504–516, 2014.